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1.	Lindgren, Per, et al. (författare) A Real-Time Semantics for the IEC 61499 standard 2015 Ingår i: Proceedings of 2015 IEEE 20th International Conference on Emerging Technologies & Factory Automation (ETFA 2015). - Piscataway, NJ : IEEE Communications Society. - 9781467379298 Konferensbidrag (refereegranskat)abstract The IEC 61499 standard provides an executable model for distributed control systems in terms of interacting function blocks. However, the current IEC 61499 standard lacks appropriate timing semantics for the speciﬁcation of timing requirements, reasoning on timing properties at the model level, and for the timing veriﬁcation of a speciﬁc deployment. In this paper we address this fundamental shortcoming by proposing Real-Time-4-FUN, a real-time semantics for IEC 61499. The key property is the preservation of non-determinism, allowing us to reason on (and verify) timing properties at the model level without assuming any speciﬁc scheduling policy or stipulating speciﬁc order of execution for the deployment. This provides for a clear separation of concerns, where the designer can focus on properties of the application prior to, and separately from, deployment veriﬁcation. The proposed timing semantics is backwards compatible to the current standard, thus allow for reuse of existing designs. The transitional property allows timing requirements to propagate to downstream sub-systems, and can be utilized for scheduling both at device and network level. Based on a translation to RTFM-tasks and resources, IEC 61499 the models can be analyzed, compiled and executed. As a proof of concept the timing semantics has been experimentally implemented in the RTFM-core language and the accompanying (thread based) RTFM-RT run-time system.
2.	Lindgren, Per, et al. (författare) Abstract Timers and their Implementation onto the ARM Cortex-M family of MCUs 2016 Ingår i: SIGBED Review. - : Association for Computing Machinery (ACM). - 1551-3688. ; 13:1 Tidskriftsartikel (refereegranskat)abstract Real-Time For the Masses (RTFM) is a set of languages andtools being developed to facilitate embedded software developmentand provide highly ecient implementations gearedto static verication. The RTFM-kernel is an architecturedesigned to provide highly ecient and predicable Stack ResourcePolicy based scheduling, targeting bare metal (singlecore)platforms.We contribute by introducing a platform independent timerabstraction that relies on existing RTFM-kernel primitives.We develop two alternative implementations for the ARMCortex-M family of MCUs: a generic implementation, usingthe ARM dened SysTick/DWT hardware; and a targetspecic implementation, using the match compare/free runningtimers. While sacricing generality, the latter is moreexible and may reduce overall overhead. Invariants for correctnessare presented, and methods to static and run-timeverication are discussed. Overhead is bound and characterized.In both cases the critical section from release timeto dispatch is less than 2us on a 100MHz MCU. Queue andtimer mechanisms are directly implemented in the RTFMcorelanguage (-core in the following) and can be includedin system-wide scheduling analysis.
3.	Lindgren, Per, et al. (författare) End-to-End Response Time of 61499 Distributed Applications over Switched Ethernet 2017 Ingår i: IEEE Transactions on Industrial Informatics. - : IEEE. - 1551-3203 .- 1941-0050. ; 13:1, s. 287-297 Tidskriftsartikel (refereegranskat)abstract The IEC 61499 standard provides means to specify distributed control systems in terms of function blocks. For the deployment, each device may hold one or many logical resources, each consisting of a function block network with service interface blocks at the edges. The execution model is event driven (asynchronous), where triggering events may be associated with data (and seen as messages). In this paper, we propose a low complexity implementation technique allowing to assess end-to-end response times of event chains spanning over a set of networked devices. Based on a translation of IEC 61499 to RTFM1-tasks and resources, the response time for each task in the system at device-level can be derived using established scheduling techniques. In this paper, we develop a holistic method to provide safe end-to-end response times taking both intra- and inter-device delivery delays into account. The novelty of our approach is the accuracy of the system scheduling overhead characterization. While the device-level (RTFM) scheduling overhead was discussed in previous works, the network-level scheduling overhead for switched Ethernets is discussed in this paper. The approach is generally applicable to a wide range of COTS Ethernet switches without a need for expensive custom solutions to provide hard real-time performance. A behavior characterization of the utilized switch determines the guaranteed response times. As a use case, we study the implementation onto (single-core) ARMcortex based devices communicating over a switched Ethernet network. For the analysis, we define a generic switch model and an experimental setup allowing us to study the impact of network topology as well as 802.1Q quality of service in a mixed critical setting. Our results indicate that safe sub millisecond end-to-end response times can be obtained using the proposed approach.
4.	Lindgren, Per, et al. (författare) Response Time for IEC 61499 over Ethernet 2015 Ingår i: IEEE International Conference on Industrial Informatics. - Piscataway, NJ : IEEE Communications Society. - 9781479966493 ; , s. 1206-1212 Konferensbidrag (refereegranskat)abstract The IEC 61499 standard provides means to specify distributed control systems in terms of function blocks. For the deployment, each device may hold one or many logical resources, each consisting of a function block network with service interface blocks at the edges. The execution model is event driven (asynchronous), where triggering events may be associated with data (and seen as a message). In this paper we propose a low complexity implementation technique allowing to asses end-to-end response time of event chains spanning a networked devices. Based on a translation of IEC 61499 to RTFM-tasks and resources, the response time for each task in the system can be derived using established scheduling techniques. In this paper we develop a method to provide safe end-to-end response time taking both intra- and inter-device delivery delays into account. As a use case we study the implementation onto (single-core) ARMcortex based devices communicating over a switched Ethernet network. For the analysis we deﬁne a generic switch model, and an experimental setup allowing us to study the impact of network topology as well as 802.1Q quality of service in a mixed critical setting. Our results indicate that safe sub milli-second end-to-end response times can be obtained using the proposed approach.
5.	Lindgren, Per, et al. (författare) RTFM-core : Language and Implementation 2015 Ingår i: 2015 IEEE 10th Conference on Industrial Electronics and Applications (ICIEA). - Piscataway, NJ : IEEE Communications Society. - 9781479983896 ; , s. 990-995 Konferensbidrag (refereegranskat)abstract Robustness, real-time properties and resource efﬁciency are key properties to embedded devices of the CPS/IoT era. In this paper we propose a language approach RTFMcore, and show its potential to facilitate the development process and provide highly efﬁcient and statically veriﬁable implementations. Our programming model is reactive, based on the familiar notions of concurrent tasks and (single-unit) resources. The language is kept minimalistic, capturing the static task, communication and resource structure of the system. Whereas C-source can be arbitrarily embedded in the model, and/or externally referenced, the instep to mainstream development is minimal, and a smooth transition of legacy code is possible. A prototype compiler implementation for RTFM-core is presented. The compiler generates C-code output that compiled together withtheRTFM-kernelprimitivesrunsonbaremetal.TheRTFMkernel guarantees deadlock-lock free execution and efﬁciently exploits the underlying interrupt hardware for static priority scheduling and resource management under the Stack Resource Policy. This allows a plethora of well-known methods to static veriﬁcation (response time analysis, stack memory analysis, etc.) to be readily applied. The proposed language and supporting tool-chain is demonstrated by showing the complete process from RTFM-core source code into bare metal executables for a lightweight ARM-Cortex M3 target.
6.	Lindgren, Per, et al. (författare) Well formed Control-flow for Critical Sections in RTFM-core 2015 Ingår i: IEEE International Conference on Industrial Informatics. - Piscataway, NJ : IEEE Communications Society. - 9781479966493 ; , s. 1438-1445 Konferensbidrag (refereegranskat)abstract The mainstream of embedded software development as of today is dominated by C programming. To aid the development, hardware abstractions, libraries, kernels and lightweight operating systems are commonplace. Such kernels and operating systems typically impose a thread based abstraction to concurrency. However, in general thread based programming is hard, plagued by hazards of race conditions and dead-locks. For this paper we take an alternative outset in terms of a language abstraction, RTFM-core, where the system is modelled directly in terms of tasks and resources. In compliance to the Stack Resource Policy (SRP) model, the language enforces (well formed) LIFO nesting of claimed resources, thus SRP based analysis and scheduling can be readily applied. For the execution onto bare-metal single core architectures, the rtfm-core compiler performs SRP analysis on the model, and render an executable that is deadlock free and (through RTFM-kernel primitives) exploits the underlying interrupt hardware for efﬁcient scheduling. The RTFM-core language embeds C-code and links to C-object ﬁles and libraries, and is thus applicable to the mainstream of embedded development. However, while the language enforces well formed resource management, control ﬂow in the embedded C-code may violate the LIFO nesting requirement, thus correctness is left with the programmer to ensure well formed nesting (through restricted control ﬂow). In this paper we address this issue by lifting a subset of C into the RTFM-core language allowing arbitrary control ﬂow at the model level. In this way well formed LIFO nesting can be enforced, and models ensured to be correct by construction. We demonstrate the feasibility trough a prototype implementation in the rtfm-core compiler. Additionally, we develop a set of running examples, and show in detail how control ﬂow is handled at compile time and during run-time execution.
7.	Lindner, Andreas, et al. (författare) RTFM-RT: a threaded runtime for RTFM-core towards execution of IEC 61499 2015 Ingår i: Proceedings of 2015 IEEE 20th International Conference on Emerging Technologies & Factory Automation (ETFA 2015). - Piscataway, NJ : IEEE Communications Society. - 9781467379298 Konferensbidrag (refereegranskat)abstract The IEC 61449 standard provides an outset for designing and deploying distributed control systems. Recently, a mapping from IEC 61499 to the RTFM-kernel API has been presented. This allows predictable real-time execution of IEC 61499 applications on light-weight single-core platforms. However, integrating the RTFM-kernel (bare-metal runtime) into potential deployments requires developing device drivers, protocol stacks, and the like. For this presentation, we apply the mapping from IEC 61499 to the RTFM-MoC task and resource modelimplementedbytheRTFM-corelanguage.Thecompilation from RTFM-core can be targeted to both, RTFM-kernel and the introduced runtime system RTFM-RT. In this paper, we detail thegenericRTFM-RTruntimearchitecture,whichallowsRTFMcore programs to be executed on top of thread based environments. Furthermore, we discuss our implementation regarding scheduling speciﬁcs of Win32 threads (Windows) and Pthreads (Linux and Mac OS X). Using our RTFM-RT implementation for deployment,predictableIEC61499executiontogetherwithaccess to abovementioned operating system functions are achieved. For further developments, we discuss the needed scheduling options to achieve hard real-time and analysis required to eliminate deadlocks.
8.	Lindner, Marcus, et al. (författare) RTFM-core : course in compiler construction 2016 Ingår i: The SIGBED Review. - : Association for Computing Machinery (ACM). - 1551-3688. ; 14:1, s. 29-36 Tidskriftsartikel (refereegranskat)abstract The course in Compiler Construction is part of the Computer Science masters program at Luleå University of Technology (LTU). Since the fall of 2014, the course is given by the Embedded Systems group. This paper outlines the course syllabus and its relation to CPS/IoT and embedded systems in general. In particular, the course introduces domain specific language design with the outset from the imperative RTFM-core language. Students are exposed to design choices for the language, spanning from programming model, compiler design issues, back-end tools, and even runtime environments. The intention is to give a holistic perspective and motivate the use of compilation techniques towards robust, efficient, and verifiable (embedded) software. Of course, developing basic skills is not overlooked and as part of the laboratory assignments, students extend the min-imalistic Object Oriented language RTFM-cOOre and develop the compiler accordingly targeting the RTFM-core language as an intermediate representation. As the RTFM-core/-cOOre compilers are implemented using OCaml/Men-hir, the students are also exposed to functional languages and to their advantages in the context of compiler construction. However, for their own development they may choose alternative design tools and languages. This gives us the opportunity to review and correlate achievements and efficiency to the choice of tools and languages and it is an outset for future course development.
9.	Lindner, Marcus, et al. (författare) Safe tasks : run time verification of the RTFM-lang model of computation 2016 Ingår i: 2016 IEEE 21st International Conference on Emerging Technologies and Factory Automation (ETFA). - Piscataway, NJ : IEEE conference proceedings. - 9781509013142 - 9781509013135 Konferensbidrag (refereegranskat)abstract Embedded systems for critical applications are typicallyspecified with requirements on predictable timing andsafety. While ensuring predictable timing, the RTFM-lang (Real-Time For the Masses) model of computation (MoC) currentlylacks memory access protection among real-time tasks. In thispaper, we discuss how to safely verify task execution given aspecification using the RTFM-MoC. Furthermore, an extensionto the RTFM-core infrastructure is outlined and tested with usecases of embedded development. We propose a method for runtime verification exploiting memory protection hardware. Forthis purpose, we introduce memory resources to the declarativelanguage RTFM-core allowing compliance checks. As a proofof concept, compiler support for model analysis and automaticgeneration of run time verification code is implemented togetherwith an isolation layer for the RTFM-kernel. With this verificationfoundation, functional run time checks as well as furtheroverhead assessments are future research questions.
10.	Andersson, Tommy, et al. (författare) De första donationerna och transplantationerna utförda i svenskt njurbytesprogram 2019 Ingår i: Läkartidningen. - 0023-7205. Tidskriftsartikel (refereegranskat)
11.	Aparicio Rivera, Jorge, et al. (författare) Heapless : Dynamic Data Structures without Dynamic Heap Allocator for Rust 2018 Ingår i: 2018 IEEE 16TH INTERNATIONAL CONFERENCE ON INDUSTRIAL INFORMATICS (INDIN). - Piscataway, NJ : IEEE. - 9781538648292 ; , s. 87-94 Konferensbidrag (refereegranskat)abstract Dynamic memory management is typically implemented using a global memory allocator, which may negatively impact the performance, reliability, and predictability of a program; in effect standards around safety-critical applications often discourage or even disallow dynamic memory management. This paper presents heapless, a collection of dynamic data structures (for vectors, strings, and circular buffers) that can be either stack or statically allocated, thus free of global allocator dependencies. The proposed data structures for vectors and strings closely mimic the Rust standard library implementations while adding support to gracefully handling cases of capacity exceedance. Our circular buffers act as queues and allowing channel like usage (by splitting). The Rust memory model together with the ability of local reasoning on memory requirements (brought by heapless) facilitates establishing robustness/safety guarantees and minimize attack surfaces of (industrial) IoT systems. We show that the heapless data structures are highly efficient and have predictable performance, thus suitable for hard real-time applications. Moreover, in our implementation heapless data structures are non-relocatable allowing mapping to hardware, useful, e.g., to DMA transfers. The feasibility, performance, and advantages of heapless are demonstrated by implementing a JSON serialization and de-serialization library for an ARM Cortex-M based IoT platform.
12.	Ben-Shabat, Ilan, et al. (författare) Isolated hepatic perfusion as a treatment for liver metastases of uveal melanoma. 2015 Ingår i: Journal of visualized experiments : JoVE. - : MyJove Corporation. - 1940-087X. ; :95 Tidskriftsartikel (refereegranskat)abstract Isolated hepatic perfusion (IHP) is a procedure where the liver is surgically isolated and perfused with a high concentration of the chemotherapeutic agent melphalan. Briefly, the procedure starts with the setup of a percutaneous veno-venous bypass from the femoral vein to the external jugular vein. Via a laparotomy, catheters are then inserted into the proper hepatic artery and the caval vein. The portal vein and the caval vein, both supra- and infrahepatically, are then clamped. The arterial and venous catheters are connected to a heart lung machine and the liver is perfused with melphalan (1 mg/kg body weight) for 60 min. This way it is possible to locally perfuse the liver with a high dose of a chemotherapeutic agent, without leakage to the systemic circulation. In previous studies including patients with isolated liver metastases of uveal melanoma, an overall response rate of 33-100% and a median survival between 9 and 13 months, have been reported. The aim of this protocol is to give a clear description of how to perform the procedure and to discuss IHP as a treatment option for liver metastases of uveal melanoma.
13.	Ben-Shabat, Ilan, et al. (författare) Long-Term Follow-Up Evaluation of 68 Patients with Uveal Melanoma Liver Metastases Treated with Isolated Hepatic Perfusion. 2016 Ingår i: Annals of surgical oncology. - : Springer Science and Business Media LLC. - 1534-4681 .- 1068-9265. ; 23:4, s. 1327-34 Tidskriftsartikel (refereegranskat)abstract This report describes the outcomes and long-term follow-up data from all isolated hepatic perfusions (IHPs) performed at a single institution in Sweden between the years 1989 and 2013 for patients with isolated uveal melanoma metastases.
14.	Carlbring, Per, et al. (författare) Behavioral Activation vs. Physical Exercise in the Treatment of Mild to Moderate Depression 2015 Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract Despite their potential as low-threshold, low-cost and high-flexibility treatments of depression, behavioral activation and physical exercise have not yet been directly compared. This study has examined the effects of these interventions, administered via the Internet. In this randomized controlled trial a total of 312 participants meeting the diagnostic criteria for mild to moderate major depression, recruited in multiple cycles and randomized to either a waiting list control group with delayed treatment, or one of the four active treatment groups: (1) physical exercise without a clear psychological treatment rationale; (2) physical exercise with a psychological treatment rationale; (3) behavioral activation a la Lewinsohn; or (4) behavioral activation a la Martel. A total of 72% were women and the average age of the participants were M=42.3 years (SD=13,5). More than half (53,9%) had a history of previous psychological treatment. Primary outcome measure was the 9-item Patient Health Questionnaire. Assessments were made on a weekly basis for the full duration of the acute treatment which was 12 weeks. The preliminary results are in line with previous online studies showing that all active treatment groups were superior to the waitlist (large effect sizes) and that only minor differences could be identified between the four active groups (large within effect sizes). At the time of the conference 6-month follow-up data will be available in addition to the already collected post-assessment data (analyzed according to the intention-to-treat principle).
15.	Carlbring, Per, et al. (författare) Behavioral activation vs physical exercise in the treatment of mild to moderate depression 2015 Konferensbidrag (övrigt vetenskapligt/konstnärligt)
16.	Carlbring, Per, et al. (författare) In session virtual reality use for public speaking anxiety : A randomized controlled trial 2017 Konferensbidrag (refereegranskat)abstract Fear of public speaking is common and for some individuals this interferes significantly with the person's life and causes marked distress. We wanted to test a newly developed virtual reality assisted 1-session in-person treatment (3 hours). The therapist guided session consisted of a series of behavioral experiments based on the expectancy violation principle. This was followed by a 4-week booster intervention delivered via the internet. Following a diagnostic interview a total of 50 individuals with a score of ≥ 60 on the Personal Report of Public Speaking Anxiety questionnaire were randomized to a treatment or a control condition. A total of 78% also met criteria for social anxiety disorder. Considering only having had one treatment session in-person the preliminary results were promising with a between group effect size on the primary outcome (Public Speaking Anxiety Scale) of Cohen’s d=1.32 before commencing the internet-based booster program. Four weeks later the between-group effect size was d=1.90. However, on the secondary outcome measures the effect sizes were more often moderate than large. At the time of the conference 6-month follow-up data will be available in addition to the already collected post-assessment data (analyzed according to the intention-to-treat principle).
17.	Carlbring, Per, et al. (författare) ITSY : A Gamified One-Session Virtual Reality App With 12-Month Follow-Up Data 2017 Ingår i: Program Book. ; , s. 396-396 Konferensbidrag (refereegranskat)abstract Introduction: This is the first large randomized-controlled trial to evaluate whether commercially available VR hardware and software can be used for exposure therapy. The aim of this study was to compare gold-standard One Session Therapy (OST) for reduction of spider phobia symptoms and avoidance behavior using in vivo spiders and a human therapist, to a newly developed single-session gamified Virtual Reality Exposure Therapy (VRET) application with modern, consumer-available VR hardware, virtual spiders, and a virtual therapist.Method: Subjects (N=100) with spider phobia, diagnosed, and meeting inclusion criteria were recruited from the general population and randomized to 2 treatment arms. In 1-week intervals, pre-measurement, 3-hr treatment and post-measurement were completed with an in-vivo behavioral approach test (BAT) serving as the primary outcome measure for both groups. This study was powered to detect a non-inferiority margin of a 2-point between-group difference on the BAT, with a standard deviation of 4 (at 80% power).Results: 98 patients commenced treatment and 97 patients completed post-measurement. Per protocol analysis indicated VR was not non-inferior to OST. Repeated-measures ANOVA identified a significant main effect of time (p < .001) and time x group effect (p < .05). Both OST and VR participants experienced large BAT within-group effect sizes (d=2.28 and d=1.45, respectively). By the time of the conference there will be 12-month follow-up data including prediction analysis and the effect of treatment credibility and working alliance (with the virtual therapist).Conclusion: OST is the superior treatment option for spider phobia. VRET is an effective alternative if OST cannot be provided, as pure self-help, as the initial intervention in a stepped-care model, or as a possible post-OST booster.
18.	Carlbring, Per, et al. (författare) The effects of a 12-week relapse prevention program following acute depression treatment : A randomised controlled trial 2019 Konferensbidrag (refereegranskat)abstract Context: Depression can be effectively treated using internet interventions. However, the relapse rate is non-ignorable. Methods: 286 participants were randomized to an additional relapse prevention program or a control group. Monthly telephone calls using the MINI diagnostic interview as well as online assessments were carried out for 24 months. Intervention: Standard cognitive behaviour therapy via the internet without guidance. Results: Relapse rates of 27.1% and 22.0% were reported in the relapse prevention program group and the control group respectively. A log-rank test of the Kaplan-Meier model did not show any significant difference between the prevention program group and the control group (χ2(1) = 0.87; p = .352) in terms of relapse rates. At the one-year follow-up, 79.2% in the prevention program group and 82.9% of the participants in the control group had PHQ-9 scores indicating them to be in remission. By the second-year follow-up the rate of remission was 75.8% in the relapse prevention program group and 81.2% in the control group. No significant differences could be seen neither at the one-year follow-up (χ2(1) = 0.36; p = .552) nor the two-year follow-up (χ2(1) = 0.53; p = .467). Conclusions: Don’t do it!
19.	Carlbring, Per, et al. (författare) The effects on depression of Internet-administered behavioral activation vs. physical exercise 2015 Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract Despite their potential as low-threshold, low-cost and high-flexibility treatments of depression, behavioral activation and physical exercise have not yet been directly compared. This study has examined the effects of these interventions, administered via the Internet. In this randomized controlled trial a total of 312 participants meeting the diagnostic criteria for mild to moderate major depression, recruited in multiple cycles and randomized to either a waiting list control group with delayed treatment, or one of the four active treatment groups: (1) physical exercise without a clear psychological treatment rationale; (2) physical exercise with a psychological treatment rationale; (3)behavioral activation a la Lewinsohn; or (4) behavioral activation a la Martel. A total of 72% were women and the average age of the participants were M=42.3 years (SD=13,5). More than half (53,9%) had a history of previous psychological treatment. Primary outcome measure was the 9-item Patient Health Questionnaire. Assessments were made on a weekly basis for the full duration of the acute treatment which was 12 weeks. The preliminary results are in line with previous online studies showing that all active treatment groups were superior to the waitlist (large effect sizes) and that only minor differences could be identified between the four active groups (large within effect sizes). At the time of the conference 6-month follow-up data will be available in addition to the already collected post-assessment data (analyzed according to the intention-to-treat principle).
20.	Carlbring, Per, et al. (författare) The efficacy of internet-based virtual reality exposure therapy for public speaking anxiety : A randomized controlled trial 2017 Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract Fear of public speaking is common and for some individuals this interferes significantly with the person's life and causes marked distress. We wanted to test a newly developed virtual reality assisted 1-session in-person treatment (3 hours). The therapist guided session consisted of a series of behavioral experiments based on the expectancy violation principle. This was followed by a 4-week booster intervention delivered via the internet. Following a diagnostic interview a total of 50 individuals with a score of ≥ 60 on the Personal Report of Public Speaking Anxiety questionnaire were randomized to a treatment or a control condition. A total of 78% also met criteria for social anxiety disorder. Considering only having had one treatment session in-person the preliminary results were promising with a between group effect size on the primary outcome (Public Speaking Anxiety Scale) of Cohen’s d=1.32 before commencing the internet-based booster program. Four weeks later the between-group effect size was d=1.90. However, on the secondary outcome measures the effect sizes were more often moderate than large. At the time of the conference 6-month follow-up data will be available in addition to the already collected post-assessment data (analyzed according to the intention-to-treat principle).
21.	Carlbring, Per, et al. (författare) The relative effects of behavioral activation vs. physical exercise in the treatment of mild to moderate depression 2016 Konferensbidrag (refereegranskat)abstract Aim: Despite their potential as low-threshold, low-cost and high-flexibility treatments of depression, behavioral activation and physical exercise have not yet been directly compared. This study has examined the effects of these interventions, administered via the Internet.Method: In this randomized controlled trial a total of 312 participants meeting the diagnostic criteria for mild to moderate major depression, recruited in multiple cycles and randomized to either a waiting list control group with delayed treatment, or one of the four active treatment groups: (1) physical exercise without a clear psychological treatment rationale; (2) physical exercise with a psychological treatment rationale; (3) behavioral activation a la Lewinsohn; or (4) behavioral activation a la Martel.Results: A total of 72% were women and the average age of the participants were M=42.3 years (SD=13,5). More than half (53,9%) had a history of previous psychological treatment. Primary outcome measure was the 9-item Patient Health Questionnaire. Assessments were made on a weekly basis for the full duration of the acute treatment which was 12 weeks.Conclusion: The preliminary results are in line with previous online studies showing that all active treatment groups were superior to the waitlist (large effect sizes) and that only minor differences could be identified between the four active groups (large within effect sizes). At the time of the conference 6-month follow-up data will be available in addition to the already collected post- assessment data (analyzed according to the intention-to-treat principle).
22.	Carlbring, Per, et al. (författare) Therapist and Internet Administered One-Session Virtual Reality Exposure Therapy for Public Speaking Anxiety : A Randomized Controlled Trial 2018 Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract Fear of public speaking is common and for some individuals this interferes significantly with the person's life and causes marked distress. We wanted to test a newly developed virtual reality assisted 1-session in-person treatment (3 hours). The therapist guided session consisted of a series of behavioral experiments based on the expectancy violation principle. This was followed by a 4-week booster intervention delivered via the internet. Following a diagnostic interview a total of 50 individuals with a score of ≥ 60 on the Personal Report of Public Speaking Anxiety questionnaire were randomized to a treatment or a control condition. A total of 78% also met criteria for social anxiety disorder. Considering only having had one treatment session in-person the preliminary results were promising with a between group effect size on the primary outcome (Public Speaking Anxiety Scale) of Cohen’s d=1.32 before commencing the internet-based booster program. Four weeks later the between-group effect size was d=1.90. However, on the secondary outcome measures the effect sizes were more often moderate than large. At the time of the conference 6-month follow-up data will be available in addition to the already collected post-assessment data (analyzed according to the intention-to-treat principle).
23.	Carlbring, Per, et al. (författare) Unified protocol vs. diagnostic specific treatment of social anxiety : a randomized treatment study with a factorial design 2018 Ingår i: Scientific Programme. Konferensbidrag (refereegranskat)abstract Traditionally, Cognitive Behavior Therapy researchers have developed and tested diagnostic specific treatment manuals. Most of which are efficacious. However, since comorbidity between anxiety and mood disorders is common and as the choice of the best suited treatment manual for each patient can be hard when delivering the treatment via the internet, transdiagnostic interventions have been put forward.The purpose of this study was to compare the effect of unified protocol vs. diagnostic specific treatment in a group of 147 individuals with social anxiety. The score on Liebowitz Social Anxiety Scale at pre-treatment was M=52.7.The interventions were both delivered via the internet during 9 weeks. In addition, the relative effect of no guidance vs. guidance on demand was investigated in a factorial design with 25 % of the patients randomized into each of the four groups. The preliminary results at week 9 show large within group effects (average Cohen’s d = 1,03), but no significant between-group differences as measured with the self-report MINI-SPIN-R and OASIS/ODSIS.At the time of the conference 6-month follow-up data will be available in addition to the already collected post-assessment data (analyzed according to the intention-to-treat principle).
24.	Carlbring, Per, et al. (författare) Unified protocol vs. diagnostic specific treatment of social anxiety – a randomized treatment study with a factorial design 2018 Konferensbidrag (övrigt vetenskapligt/konstnärligt)
25.	De Angelis, A., et al. (författare) Science with e-ASTROGAM A space mission for MeV-GeV gamma-ray astrophysics 2018 Ingår i: Journal of High Energy Astrophysics. - : Elsevier. - 2214-4048 .- 2214-4056. ; 19, s. 1-106 Tidskriftsartikel (refereegranskat)abstract e-ASTROGAM ('enhanced ASTROGAM') is a breakthrough Observatory space mission, with a detector composed by a Silicon tracker, a calorimeter, and an anticoincidence system, dedicated to the study of the non-thermal Universe in the photon energy range from 0.3 MeV to 3 GeV - the lower energy limit can be pushed to energies as low as 150 keV for the tracker, and to 30 keV for calorimetric detection. The mission is based on an advanced space-proven detector technology, with unprecedented sensitivity, angular and energy resolution, combined with polarimetric capability. Thanks to its performance in the MeV-GeV domain, substantially improving its predecessors, e-ASTROGAM will open a new window on the non-thermal Universe, making pioneering observations of the most powerful Galactic and extragalactic sources, elucidating the nature of their relativistic outflows and their effects on the surroundings. With a line sensitivity in the MeV energy range one to two orders of magnitude better than previous generation instruments, e-ASTROGAM will determine the origin of key isotopes fundamental for the understanding of supernova explosion and the chemical evolution of our Galaxy. The mission will provide unique data of significant interest to a broad astronomical community, complementary to powerful observatories such as LIGO-Virgo-GEO600-KAGRA, SKA, ALMA, E-ELT, TMT, LSST, JWST, Athena, CTA, IceCube, KM3NeT, and LISA.
26.	Fagernäs, Simon, et al. (författare) Moderating effects of presence and adherence in internetbased CBT with virtual reality exposure therapy for public speaking anxiety 2017 Konferensbidrag (refereegranskat)abstract Introduction: Previous research has revealed that Virtual Reality Exposure Therapy (VRET) is an effective method for reducing symptoms of public speaking anxiety (PSA). Research about presence in the virtual environment indicates a moderating effect on physiological arousal, but more ambiguous effect on treatment effects where some research indicates a small effect while other indicate no effect. Furthermore, previous research has found adherence to home work assignments to moderate treatment outcome. In this treatment study which aimed for treating public speaking anxiety with VRET and a internetbased CBT-program, we investigated whether presence in the virtual environment and adherence to home work moderated treatment effects.Methods: N=25 adult participants from the general public with clinically significant PSA were recruited to a wait-list to another study. After five weeks on waitlist, they started the treatment with a self-guided in virtuo exposure session followed by a four week online maintenance promoting in-vivo exposure. Participants got a simple VR headset by post. The three-hour exposure session included psychoeducation in text, and the participants conducted speech exercises, framed as behavioral experiments targeting idiosyncratic catastrophic beliefs, in front of virtual audiences, and listening to audio recording afterwards. Primary outcome measure was self-reported PSA. To measure moderating effects of presence on the primary outcome measure a self-reported validated scale with subscales for presence (iGroup Presence Questionnaire, IPQ) were used, and for adherence a score were manually calculated based on the number of completed home-work assignments in both a linear model and a binary model dividing participants in two groups: one with at least one completed home work assignment and one with no completed home work assignment. The analysis on presence included both the effects of the VRET-session alone and in combination with the internetbased CBT-program. Data were analyzed using mixed effects modeling.Results: No significant results were found in moderating effects of presence with its subscales on the primary outcome measure for either the VRET-session (p = .375-.616) nor in combination with the internetbased CBT-program (p = .454 - .877). Moderating effects of adherence on primary outcome measure neither revealed no significant results in the linear model (p = .368) nor the binary model (p = .113).Conclusions: The findings of this study indicate, in line with some previous research, that presence in the virtual environment has no significant moderating effect on treatment outcome. Furthermore, in contrast to previous research, this study found no significant moderating effect on adherence to home work assignments on primary treatment outcome. Internal- and external validity and other potential explanations are discussed in detail in the poster.
27.	Hansson, Josefin, et al. (författare) The risk of graft loss 5 years after kidney transplantation is increased if cold ischemia time exceeds 14 hours 2018 Ingår i: Clinical Transplantation. - : Wiley. - 0902-0063. ; 32:9 Tidskriftsartikel (refereegranskat)abstract Background: The state of the evidence is unclear regarding the impact of cold ischemia time (CIT) on the outcome of kidney transplantation. The aim of this study was to investigate the effect of CIT on the short- and long-term function of kidneys transplanted at the Sahlgrenska University Hospital in 2007-2009 from donors after brain death (DBDs). Methods: This study was designed as a retrospective analysis of data from local and national transplantation registers. The study endpoints were as follows: delayed graft function (DGF), primary nonfunction (PNF), biopsy-proven acute rejection (BPAR), serum creatinine (S-creatinine) level at discharge, days of hospitalization after transplantation, and graft survival at 5 years post-transplantation. Adjusted regression analyses were used to determine causal relationships with CIT. A further aim was to estimate a threshold for CIT by analyzing event rates and coordinates of the receiver-operated characteristic (ROC) curve. Results: There was a causal relationship between CIT as a continuous variable and the following endpoints: graft survival at 5 years post-transplantation, though this was not significant (hazard ratio (HR) 1.07, P = 0.057), DGF (odds ratio (OR) 1.09, P = 0.03) and S-creatinine (P = 0.003). In our material, the risk for impaired outcome was higher with longer CIT. We were therefore able to estimate a threshold value for CIT, set to 14 hours for both graft survival at 5 years post-transplantation and DGF. This was proved with significance by analyzing both event rates and the coordinates of the ROC curve. The risk of graft loss increased, with HR 2.3 (P = 0.023), when comparing a CIT cutoff of >= 14 hours with CIT < 14 hours. Delayed graft function increased, with an OR of 2.6 (P = 0.001). Conclusion: Our study confirms that, in this patient material, longer CIT was associated with increased risk for both impaired graft survival and incidence of DGF. We estimated a threshold for CIT of 14 hours.
28.	Hellström, Vivan (författare) The clinical perspective on malignancies in renal transplanted patients 2016 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Post-transplant malignancies cause significant morbidity and mortality. In this thesis we investigated malignancies in renal transplanted patients from a clinical viewpoint. The use of regional tumour registries considerably improved identification of pre- and post-transplant malignancies, which are generally underreported in transplant registries.Despite previously adequate cancer treatments with favourable prognosis, patients with pre-transplant malignancies showed higher incidence of post-transplant cancer and reduced survival compared to a 1:3 ratio matched control group of patients without a previous cancer from the Collaborative Transplant Study in Europe. A careful oncological surveillance pre-transplant and post-transplant is recommended.A multidisciplinary team evaluated the immunosuppressive and oncological treatment in a clinical prospective observational study of 120 renal transplanted patients with post-transplant malignancies. In two-thirds of the patients immunosuppression was possible to change to mTOR inhibitors with anti-tumour effects. Oncological treatment was adjusted in 50% of patients with solid or haematological tumours. MDT assessments are essential for optimizing treatment of post-transplant malignancies.Number of previous cutaneous squamous cell carcinoma (SCC) posed the most significant risk variable in predicting subsequent SCCs during a two-years study of 73 transplanted patients with at least one SCC.Incidence of transplant-derived tumours is 5 times higher than anticipated. Three of eleven cancers in urinary tract and two of four cancers in the transplants were transplant-derived. Five of eleven cancers of the urinary tract were BK-virus positive. Allograft immune response against these tumours offer new options for cancer treatment such as immunomodulatory or anti-viral treatment in combination with modified immunosuppression.
29.	Ivanova, Ekaterina, et al. (författare) Experiences of responsible gambling tools among non-problem gamblers : A survey of active customers of an online gambling platform 2019 Ingår i: Addictive Behaviors Reports. - : Elsevier BV. - 2352-8532. ; 9 Tidskriftsartikel (refereegranskat)abstract Introduction: Responsible gambling (RG) tools, aiming at helping gamblers to avoid gambling-related harms, are common in online gambling platforms. Gambling industry, policy makers, and researchers have warned that RG tools can potentially disturb recreational gamblers, channeling them to less protective operators. No evidence exists to support these concerns, and they can hinder the development of effective RG tools. The current study aimed to investigate the recreational gamblers' experiences of RG tools.Methods: A total of 10,200 active customers of an online gambling service were invited to complete an online survey and rate their overall reactions, attitudes, disturbance and irritation towards RG tools, as well as their inclination to abandon a gambling service due to overexposure to RG tools. N = 1223 surveys were completed.Results: Non-problem gamblers had positive experiences of RG tools. Moderate-risk gamblers had more positive overall reaction and less irritation to previous experiences of RG tools compared to non-problem gamblers. Problem gamblers had least positive attitudes, most disturbance and most irritation towards RG pictures. Non-problem gamblers had lowest rates of having abandoned a service because of perceived overexposure to RG tools (5.2% compared to 25.9% of problem gamblers), with a significant between-group difference (OR [95%CI] = 7.17 [3.61–14.23], p < .001).Conclusions: Non-problem gamblers were not particularly disturbed by RG tools and were not at risk of abandoning online gambling services because of overexposure to RG tools. The study found no grounds for limiting the design and implementation of RG tools due to fears of disturbing recreational gamblers.
30.	Ivanova, Ekaterina, et al. (författare) Guided and unguided Acceptance and Commitment Therapy for social anxiety disorder and/or panic disorder provided via the Internet and a smartphone application : A randomized controlled trial 2016 Ingår i: Journal of Anxiety Disorders. - : Elsevier BV. - 0887-6185 .- 1873-7897. ; 44, s. 27-35 Tidskriftsartikel (refereegranskat)abstract Acceptance and Commitment Therapy (ACT) can be effective in treating anxiety disorders, yet there has been no study on Internet-delivered ACT for social anxiety disorder (SAD) and panic disorder (PD), nor any study investigating whether therapist guidance is superior to unguided self-help when supplemented with a smartphone application. In the current trial, n = 152 participants diagnosed with SAD and/or PD were randomized to therapist-guided or unguided treatment, or a waiting-list control group. Both treatment groups used an Internet-delivered ACT-based treatment program and a smartphone application. Outcome measures were self-rated general and social anxiety and panic symptoms. Treatment groups saw reduced general (d = 0.39) and social anxiety (d = 0.70), but not panic symptoms (d = 0.05) compared to the waiting-list group, yet no differences in outcomes were observed between guided and unguided interventions. We conclude that Internet-delivered ACT is appropriate for treating SAD and potentially PD. Smartphone applications may partially compensate for lack of therapist support.
31.	Ivanova, Ekaterina, et al. (författare) Guided and unguided CBT for social anxiety disorder and/or panic disorder via the Internet and a smartphone application 2015 Ingår i: Abstracts from the 7th Swedish Congress on internet interventions (SWEsrii). - Linköping : Linköping University Press. ; , s. 9-9 Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract Background: As Acceptance and Commitment Therapy (ACT) becomes a part of the clinical practice, the interest for alternative ways of providing it continue to grow. Internet-based CBT, both guided and unguided, has proved to be effective for the treatment of a wide range of psychiatric disorders, including anxiety disorders. Moreover, the tremendous accessibility of smartphones makes them a potentially powerful instrument for providing psychological treatment. The purpose of this study was to investigate the effects of an Internet-based ACT-program for social anxiety disorder and panic disorder using both computers and smartphones, and with and without therapist support. Method: The participants were recruited from the general public by filling out an online screening form, which consisted of LSAS, PDSS-SR, GAD-7, PHQ-9, QOLI (the scales later served as outcome measures) and demographic questions. The individuals who met the inclusion criteria were contacted for a diagnostic telephone interview. The 152 people chosen for participation were then randomized into two treatment groups (guided and unguided) and a waiting list control group. The participants in the treatment groups were given access to an Internet-provided ACT-based treatment program consisting of 8 modules, as well as a smartphone application with content that corresponded to the Internet treatment program. Additionally, the participants in the guided group received minimum therapist support (15 min/week) through the smartphone application from psychology students undergoing their clinical training. The participants worked with the program for 10 weeks. They were evaluated twice during treatment, once after completing treatment, and once again 12-months later as a follow-up measure. A mixed effect model was used to analyze the data. Results: Regardless of diagnosis, as a whole the treated groups showed significant decreases in anxiety, with a moderate within-group effect size. This improvement appeared to be maintained when the groups were evaluated again during the follow-up. The participants suffering primarily from social anxiety disorder showed significant improvements, with moderate within-group effect sizes in both the guided (Cohen's d = 0.79) and unguided group (Cohen's d = 0.71). This improvement also appeared to be maintained when these participants were evaluated during the follow-up. No significant changes were observed in the symptoms of the participants suffering primarily from panic disorder. Discussion: Internet-delivered ACT-based treatment provided via both computer and smartphone can be effective for reducing general anxiety symptoms, as well as social anxiety symptoms. The guided treatment was not clearly superior to the unguided treatment. Some of the study’s uncertainties are likely due to the presence of a large number of different components, which made it difficult to isolate the effects of each individual component.
32.	Ivanova, Ekaterina, et al. (författare) Guided and unguided transdiagnostic Acceptance and Commitment Therapy for anxiety disorders provided via a computer and a smartphone application : A randomized controlled trial 2016 Ingår i: EABCT 2016 Abstract Book. ; , s. 530-530 Konferensbidrag (refereegranskat)abstract Technology-assisted psychological treatments are becoming well-known in the scientific networks throughout the world and are being implemented into routine health care in a number of countries. The interest in evaluating the potential of different devices is growing. The main objective of the current study was to evaluate the effects of guided and unguided computerand smartphone-based Acceptance and Commitment Therapy (ACT) for social anxiety disorder (SAD) and panic disorder (PD).A total of 152 participants were randomized into a guided treatment group, an unguided treatment group and a waiting list control group. Both treatment groups got access to a computer-based ACT-treatment and a smartphone application (app) with corresponding content. The eight modules treatment program covered a number of topics such as the nature of anxiety, functional analyses, acceptance, mindfulness and valued actions. The purpose of the app was to make it easier for the participants to access the key points of the program and to do homework assignments in their everyday life. Automatic messages in the app aimed to give feedback to the participants on their work as well as to prompt them to continue with the program. In addition to that, the participants in the guided group got therapist support via the app. The therapists were encouraged to work with each of their patient 15 min/week during the 10 weeks treatment period and focus on motivating, validating and correcting mistakes. On the whole group level GAD-7 was used as the primary outcome measure. LSAS and PDSS-SR were used for subgroup analyses in SAD and PD participants respectively. The measurements were collected at pre-, mid- and post-treatment and at 12-months follow-up.There were no significant differences in adherence between the treatment groups except for significantly higher rates of smartphone usage in the guided group. No significant differences in treatment outcome were found between the treatment groups with moderate within-group effects (Cohen’s d = 0.75 for the guided and Cohen’s d = 0.66 for the unguided group). The treated participants improved significantly in comparison to the control group both on the whole group level (between group Cohen’s d = 0.39) and for the participants suffering primarily from SAD (between group Cohen’s d = 0.70). Within group effect sizes were large for the PD-participants (Cohen’s d = 1.00) but the study was very underpowered in this part.Discussion. The treatment program as it was used in the present study appeared to be effective in treating social anxiety disorder and decreasing general anxiety symptoms, but the effects are smaller than seen in previous studies. The guided treatment was not clearly superior to the unguided one. The study contributes to the growing body of evidence on technology-assisted ACT.Conclusion. Computer- and smartphone-based ACT can be made into an effective treatment for anxiety disorders. A smartphone application seems to have a clear potential to partly compensate for the absence of therapist support which needs to be studied further.
33.	Johansson, Junko, 1989, et al. (författare) Isolated Limb Perfusion With Melphalan Triggers Immune Activation in Melanoma Patients 2018 Ingår i: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 8 Tidskriftsartikel (refereegranskat)abstract Hyperthermic isolated limb perfusion with melphalan (M-ILP) is a treatment option for melanoma patients with metastases confined to the limbs. This study aimed at defining the role of cellular immunity for the clinical response to M-ILP in melanoma patients. It was observed that patients with enhanced cytotoxic CD8(+) T cell reactivity to common antigens (HCMV/EBV/influenza virus) prior to M-ILP were more likely to achieve a complete disappearance of macroscopic tumors (complete response). Following M-ILP treatment, the proportions of CD16(+) intermediate and non-classical monocytes in peripheral blood were significantly enhanced along with induction of HLA-DR on CD4(+) and CD8(+) T cells. For further studies of the mechanism behind melphalan-induced immune activation an in vitro model, aiming at mimicking the clinical M-ILP protocol, was established, where PBMCs were co-cultured with melanoma cells, which had been pre-exposed to melphalan under mild hyperthermia. Upon exposure to melphalan, melanoma cells showed increased expression of immune-related markers including MHC class I and Hsp70. Moreover, when the melphalan-treated melanoma cells were co-cultured with PBMCs, this triggered an increased proportion of CD33(+)CD14(+)CD16(++) non-classical monocytes among the PBMCs. Furthermore, the melphalan-treated melanoma cells stimulated the expansion of CD8(+) T cells in the co-cultured PBMCs. These cells produced enhanced levels of IFN-gamma and granzyme B and were capable of killing melanoma cells. To further verify an immunogenic role of melphalan, mice were vaccinated with melphalan-exposed murine melanoma cells. When challenged with live melanoma cells, vaccinated mice showed reduced tumor growth and enhanced infiltration of tumor-specific T cells into tumors. We conclude that melphalan-exposed melanoma cells trigger expansion of CD16(+) monocytes and activate cytotoxic T cells and that these events may contribute to the antitumoral efficacy of M-ILP.
34.	Lindgren, Per, et al. (författare) A Formal Perspective on IEC 61499 Execution Control Chart Semantics 2015 Ingår i: 2015 IEEE Trustcom/BigDataSE/ISPA. - Piscataway, NJ : IEEE Communications Society. - 9781467379519 ; , s. 293-300 Konferensbidrag (refereegranskat)abstract The IEC 61499 standard proposes an event driven execution model for distributed control applications for which an informal execution semantics is provided. Consequently, run-time implementations are not rigorously described and therefore their behavior relies on the interpretation made by the tool provider. In this paper, as a step towards a formal semantics, we focus on the Execution Control Chart semantics, which is fundamental to the dynamic behavior of Basic Function Block elements. In particular we develop a well-formedness criterion that ensures a ﬁnite number of Execution Control Chart transitions for each triggering event. We also describe the ﬁrst step towards the mechanization of the well-formedness checking algorithm in the Coq proof-assistant so that, ultimately, we are able to show, once andforall,thatthisalgorithmiseffectivelycorrectwithrespectto our proposed execution semantics. The algorithm is extractable from the mechanization in a correct-by-construction way, and can be directly incorporated in certiﬁed toolchain for analysis, compilation and execution of IEC 61499 models. As a proof of concept a prototype tool RTFM-4FUN has been developed. It performs well-formedness checks on Basic Function Blocks using the extracted algorithm’s code.
35.	Lindgren, Per, et al. (författare) Contract Based Verification of IEC 61499 2017 Ingår i: IEEE International Conference on Industrial Informatics (INDIN). - Piscataway, NJ : Institute of Electrical and Electronics Engineers (IEEE). - 9781509028702 ; , s. 132-141 Konferensbidrag (refereegranskat)abstract The IEC 61499 standard proposes an event drivenexecution model for component based (in terms of FunctionBlocks), distributed industrial automation applications. However,the standard provides only an informal execution semantics, thusin consequence behavior and correctness relies on the designdecisions made by the tool vendor. In this paper we presentthe formalization of a subset of the IEC 61499 standard inorder to provide an underpinning for the static verification ofFunction Block models by means of deductive reasoning. Specifically,we contribute by addressing verification at the component,algorithm, and ECC levels. From Function Block descriptions, enrichedwith formal contracts, we show that correctness of componentcompositions, as well as functional and transitional behaviorcan be ensured. Feasibility of the approach is demonstrated bymanually encoding a set of representative use-cases in WhyML,for which the verification conditions are automatically derived(through the Why3 platform) and discharged (using automaticSMT-based solvers). Furthermore, we discuss opportunities andchallenges towards deriving certified executables for IEC 61499models.
36.	Lindgren, Per, et al. (författare) Embedded Programming adopting Functional Constructs in Rust 2018 Konferensbidrag (refereegranskat)
37.	Lindgren, Per, et al. (författare) Introducing Certified Compilation in Education by a Functional Language Approach 2019 Ingår i: Proceedings Seventh International Workshop on Trends in Functional Programming in Education. - : Open Publishing Association. ; , s. 65-78 Konferensbidrag (refereegranskat)abstract Classes on compiler technology are commonly found in Computer Science curricula, covering aspects of parsing, semantic analysis, intermediate transformations and target code generation. This paper reports on introducing certified compilation techniques through a functional language approach in an introductory course on Compiler Construction. Targeting students with little or no experience in formal methods, the proof process is highly automated using the Why3 framework. Underlying logic, semantic modelling and proofs are introduced along with exercises and assignments leading up to a formally verified compiler for a simplistic imperative language.This paper covers the motivation, course design, tool selection, and teaching methods, together with evaluations and suggested improvements from the perspectives of both students and teachers.
38.	Lindgren, Per, et al. (författare) Towards Certified Compilation of RTFM-core Applications 2016 Ingår i: 2016 IEEE 21st International Conference on Emerging Technologies and Factory Automation (ETFA). - Piscataway, NJ : IEEE conference proceedings. - 9781509013142 - 9781509013135 Konferensbidrag (refereegranskat)abstract Concurrent programming is dominated by threadbased solutions with lock based critical sections. Careful attentionhas to be paid to avoid race and deadlock conditions. Real-Timefor The Masses (RTFM) takes an alternative language approach,introducing tasks and named critical sections (via resources)natively in the RTFM-core language. RTFM-core programs canbe compiled to native C-code, and efficiently executed ontosingle-core platforms under the Stack Resource Policy (SRP)by the RTFM-kernel. In this paper we formally define thewell-formedness criteria for SRP based resource management,and develop a certified (formally proven) implementation ofthe corresponding compilation from nested critical sections ofthe input RTFM-core program to a resulting flat sequence ofprimitive operations and scheduling primitives. Moreover weformalise the properties for resource ceilings under SRP anddevelop a certified algorithm for their computation.The feasibility of the described approach is shown throughthe adoption of the Why3 platform, which allows the necessaryverification conditions to be automatically generated and dischargedthrough a variety of automatic external SMT-solversand interactive theorem provers. Moreover, Why3 supports theextraction of certified Ocaml code for proven implementationsin WhyML. As a proof of concept the certified extracteddevelopment is demonstrated on an example system.
39.	Lindner, Marcus, et al. (författare) Concurrent Reactive Objects in Rust Secure by Construction 2019 Ingår i: Ada User Journal. - : Ada Language UK Ltd.. - 1381-6551. ; 40:1 Tidskriftsartikel (refereegranskat)abstract Embedded systems of the IoT era face the software developer with requirements on a mix of resource efficiency, real-time, safety, and security properties. As of today, C/C++ programming dominates the mainstream of embedded development, which leaves ensuring system wide properties mainly at the hands of the programmer. We adopt a programming model and accompanying framework implementation that leverages on the memory model, type system, and zero-cost abstractions of the Rust language. Based on the outset of reactivity, a software developer models a system in terms of Concurrent Reactive Objects (CROs) hierarchically grouped into Concurrent Reactive Components (CRCs) with communication captured in terms of time constrained synchronous and asynchronous messages. The developer declaratively defines the system, from which a static system instance can be derived and analyzed. A system designed in the proposed CRC framework has the outstanding properties of efficient, memory safe, race-, and deadlock-free preemptive (single-core) execution with predictable real-time properties. In this paper, we further explore the Rust memory model and the CRC framework towards systems being secure by construction. In particular, we show that permissions granted can be freely delegated without any risk of leakage outside the intended set of components. Moreover, the model guarantees permissions to be authentic, i.e., neither manipulated nor faked. Finally, the model guarantees permissions to be temporal, i.e., never to outlive the granted authority. We believe and argue that these properties offer the fundamental primitives for building secure by construction applications and demonstrate its feasibility on a small case study, a wireless autonomous system based on an ARM Cortex M3 target.
40.	Lindner, Marcus, et al. (författare) Hardware-in-the-loop based WCET analysis with KLEE 2018 Ingår i: 2018 IEEE 23RD INTERNATIONAL CONFERENCE ON EMERGING TECHNOLOGIES AND FACTORY AUTOMATION (ETFA). - Piscataway, NJ : IEEE. - 9781538671085 ; , s. 345-352 Konferensbidrag (refereegranskat)abstract C programming dominates the mainstream of embedded development as of today. To aid the development, hardware abstractions, libraries, kernels, and light-weight operating systems are commonplace. However, these typically offer little or no help to automatic worst-case execution time (WCET) estimation, and thus manual test and measurement based approaches remain the de facto standard. For this paper, we take the outset from the Real-Time For the Masses (RTFM) framework, which is developed to facilitate embedded software development for IoT devices and provides highly efficient implementations, suitable to the mainstream of embedded system design. Although the Rust language plays currently a minor part in embedded development, we believe its properties add significant improvements and thus implement our RTFM framework in Rust. We present an approach to worst-case execution time estimation in the context of RTFM tasks and critical sections, which renders sufficient information for further response time and schedulability analysis. We introduce our test bench, which utilizes the KLEE tool for automatic test vector generation and subsequently performs cycle accurate hardware-in-the-loop measurements of the generated tests. The approach is straightforward and fully automatic. Our solution bridges the gap in between measurement based and static analysis methods for WCET estimation. We demonstrate the feasibility of the approach on a running example throughout the paper and conclude with a discussion on its implications and limitations.
41.	Lindner, Marcus, et al. (författare) No Panic! Verification of Rust Programs by Symbolic Execution 2018 Konferensbidrag (refereegranskat)abstract The Rust language stands out with a type system and underlying memory model targeting memory safety. The accompanying rustc compiler is typically able to statically prove the safety conditions and accept or reject input programs accordingly. However, e.g., cases of raw array indexing are in general out of reach for static analysis and promoted to runtime verification rendering executables with partial correctness guarantees (aborting with a panic on safety violations). For safety-critical applications, this requires proper panic handling, which is by itself a hard problem. Moreover, runtime verification may be undesirable for performance reasons and hence calling for stronger methods to static program analysis. In this paper, we take the approach of symbolic execution and propose a generic contract based verification process for programs written in Rust. For the verified properties (assertions), the program is both safe and panic free. Besides correctness, this implies further performance improvements as code for runtime verification can be safely dropped. We demonstrate the feasibility of the approach by adopting the KLEE symbolic execution engine to analyze LLVM bitcode extracted from Rust programs and libraries under verification and discuss its implications and limitations.
42.	Lindner, Marcus (författare) !secure(system) <=?=> !safe(system) : On Security and Safety of Industrial Software Systems 2019 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract The focus of our research work is on readily accessible, embedded, real-time development with concurrency support. To this end, we develop the Real-Time For the Masses (RTFM) programming framework with a model of computation based on tasks and resources and that stipulates a timing semantics. Typically, hard real-time requirements are a characteristic of safety-critical applications. In contrast to runtime verification, such applications primarily require static assurances concerning safety and security attributes. This thesis discusses the building blocks for a statically analyzable programming paradigm for embedded real-time applications and its implementation. Svenska kraftnät funded the research presented in this thesis and set the scope to industrial automation. Consequently, we also investigate the applicability of our RTFM framework for scheduling and resource management for the runtime environments of industrial applications. We start by reviewing relevant and well-established industry standards to build background knowledge of the state-of-the-art safety and security requirements in software development. Special attention is placed on the IEC 61131 and IEC 61499 standards for industrial software development and their programming and execution model. We show the feasibility of using IEC 61499 as a holistic, distributed, and hierarchical model with mappings from the functional layer (IEC 61499 function block networks) and safety layer (PLCopen safety function blocks) to RTFM. We also demonstrate that our Rust-based RTFM implementation enables static verification for a myriad of safety and security attributes. Moreover, our investigations reveal a mutual dependency of safety and security in the context of software systems. For this reason, we believe and argue that safety and security cannot be considered independent during the design and implementation of safety-critical applications. Upon closer examination, we even conclude that safety and security are equivalent.
43.	Lindner, Marcus, et al. (författare) Verification of Safety Functions Implemented in Rust : a Symbolic Execution based approach 2019 Ingår i: 2019 IEEE 17th International Conference on Industrial Informatics (INDIN). - : IEEE. ; , s. 432-439 Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract Symbolic execution allows us to observe and assert properties of program code executing under (partially) unknown inputs and state. In this work we present a case study demonstrating that safety functions implemented in the Rust programming language can be verified by an assertion based approach. To this end, we leverage on previous developments adopting LLVM-KLEE for symbolic execution of Rust programs.In particular we show that reliability can be ensured by proven absence of undefined behavior and that safety properties (expressed as assertions) can be ensured for all reachable paths of the underlying implementation (under symbolic inputs). Moreover, the verification (besides stating assertions) is fully automatic and can be applied without any changes made to the implementation. While assertions have the advantage of being familiar to the mainstream programmer, they lack the expressiveness of dedicated logic developed for model checking. The paper also discusses complexity issues arising from path/state explosion inherent to symbolic execution. The feasibility of the approach is demonstrated on a representative use case implementing a safety function (equality) from the PLCopen library. We obtain complete path- (466) and state- (8) coverage in under 2 seconds for the given example on an i7-7700 laptop computer.
44.	Lindner, Philip, et al. (författare) Attitudes Toward and Familiarity With Virtual Reality Therapy Among Practicing Cognitive Behavior Therapists : A Cross-Sectional Survey Study in the Era of Consumer VR Platforms 2019 Ingår i: Frontiers in Psychology. - : Frontiers Media S.A.. - 1664-1078. ; 10 Tidskriftsartikel (refereegranskat)abstract Virtual reality exposure therapy (VRET) is an efficacious treatment for fear and anxiety and has the potential to solve both logistic issues for therapists and be used for scalable self-help interventions. However, VRET has yet to see large-scale implementation in clinical settings or as a consumer product, and past research suggests that while therapists may acknowledge the many advantages of VRET, they view the technology as technically inaccessible and expensive. We reasoned that after the 2016 release of several consumer virtual reality (VR) platforms and associated public acquaintance with VR, therapists' concerns about VRET may have evolved. The present study surveyed attitudes toward and familiarity with VR and VRET among practicing cognitive behavior therapists (n = 185) attending a conference. Results showed that therapists had an overall positive attitude toward VRET (pros rated higher than cons) and viewed VR as applicable to conditions other than anxiety. Unlike in earlier research, high financial costs and technical difficulties were no longer top-rated negative aspects. Average negative attitude was a larger negative predictor of self-rated likelihood of future use than positive attitude was a positive predictor and partially mediated the positive association between VRET knowledge and likelihood of future use, suggesting that promotional efforts should focus on addressing concerns. We conclude that therapist's attitudes toward VRET appear to have evolved in recent years, and no longer appear to constitute a major barrier to implementing the next generation of VR technology in regular clinical practice.
45.	Lindner, Philip, et al. (författare) Attitudes towards and familiarity with Virtual Reality therapy among practicing cognitive behavior therapists : A first survey study in the era of consumer VR platforms 2018 Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract Objectives: To survey attitudes towards, knowledge of and familiarity with Virtual Reality (VR) technology and VR exposure therapy among practicing cognitive behavior therapists, after the recent release of consumer VR platforms, with the aim of identifying potential human barriers to implementing this technology and therapeutic method in regular care. Participants: 185 practicing cognitive behavior therapists attending a conference.Measures: Self-rated likelihood of future use of VR in a clinical setting, applicability of VR to treating specific mental disorders, as well as ratings of different positive and negative aspects of VR exposure therapy – all assessed using a standardized survey.Results: Very few respondents reported having used VR clinically. Therapists had an overall positive attitude toward VRET (pros rated higher than cons) and viewed VR as applicable to conditions other than anxiety. Unlike in earlier research, a high financial cost was no longer a top-rated negative aspects. Average negative attitude was a larger negative predictor of self-rated likelihood of future use than positive attitude was a positive predictor.Conclusions: We conclude that therapist’s attitudes towards VRET appear to have evolved in recent years, coinciding with the release of consumer VR platforms, and no longer appear to constitute a major barrier to implementing the next generation of VR technology in regular clinical practice.
46.	Lindner, Philip, et al. (författare) Cognitive flexibility does not predict symptom reduction in Internet interventions 2015 Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract PURPOSE: Little is known about whether individual differences in executive functions predict outcomes after Internet-delivered psychological treatments. We hypothesized that learning and utilizing skills taught in treatment is reliant on cognitive flexibility, as measurable by perseverative errors (PE) on the 64-card Wisconsin Card Sorting Test (WCST). We tested this by correlating PE scores with symptom reduction following treatment for social anxiety disorder (n=116), depression (n=42) and tinnitus discomfort (n=28). METHOD: In all groups, the WCST was administered online prior to treatment and partial correlation (controlling for age) were calculated between PE and percentage symptom reduction on the respective primary outcome measure. RESULTS: Number of PE did not correlate with pre-treatment symptom scores in any group. There was no generic association between symptom reduction and PE, and, after outlier removal, no group-specific associations either. CONCLUSIONS: Lower cognitive flexibility does not appear to impede symptom reduction in Internet-delivered psychological treatments.
47.	Lindner, Philip, et al. (författare) Correction: Therapist-led and self-led one-session virtual reality exposure therapy for public speaking anxiety with consumer hardware and software: A randomized controlled trial (vol 61, pg 45, 2019) 2019 Ingår i: Journal of Anxiety Disorders. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0887-6185 .- 1873-7897. ; 64, s. 90-90 Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract n/a
48.	Lindner, Philip, et al. (författare) Creating state of the art, next-generation Virtual Reality exposure therapies for anxiety disorders using consumer hardware platforms : Design considerations and future directions 2017 Ingår i: Cognitive Behaviour Therapy. - : Informa UK Limited. - 1650-6073 .- 1651-2316. ; 46:5, s. 404-420 Forskningsöversikt (refereegranskat)abstract Decades of research and more than 20 randomized controlled trials show that Virtual Reality exposure therapy (VRET) is effective in reducing fear and anxiety. Unfortunately, few providers or patients have had access to the costly and technical equipment previously required. Recent technological advances in the form of consumer Virtual Reality (VR) systems (e.g. Oculus Rift and Samsung Gear), however, now make widespread use of VRET in clinical settings and as self-help applications possible. In this literature review, we detail the current state of VR technology and discuss important therapeutic considerations in designing self-help and clinician-led VRETs, such as platform choice, exposure progression design, inhibitory learning strategies, stimuli tailoring, gamification, virtual social learning and more. We illustrate how these therapeutic components can be incorporated and utilized in VRET applications, taking full advantage of the unique capabilities of virtual environments, and showcase some of these features by describing the development of a consumer-ready, gamified self-help VRET application for low-cost commercially available VR hardware. We also raise and discuss challenges in the planning, development, evaluation, and dissemination of VRET applications, including the need for more high-quality research. We conclude by discussing how new technology (e.g. eye-tracking) can be incorporated into future VRETs and how widespread use of VRET self-help applications will enable collection of naturalistic “Big Data” that promises to inform learning theory and behavioral therapy in general.
49.	Lindner, Philip, et al. (författare) Differential impact of performance and interaction related types of social anxiety symptoms on different quality of life domains 2016 Ingår i: EABCT 2016 Abstract Book. ; , s. 748-748 Konferensbidrag (refereegranskat)abstract Social anxiety disorder (SAD) is a common disorder associated with impaired quality of life (QoL), that indexes anxious distress and avoidance related to social situations. The DSM-5 features a specifier to delineate those with only performance-related social anxiety, yet little is known whether performance- and interaction-related anxieties have a differential impact on total QoL and on different QoL domains. To investigate this, we pooled screening data from eight intervention studies for SAD (n = 2017). Total sample mean age was 35.28 (SD = 12.26) and 69% were female. SAD symptoms were measured using the self-rated Liebowitz Social Anxiety Scale with items classified as measuring either performance or interaction anxiety. QoL, both total and across four domains, was measured using the Quality of Life Inventory. Data was analyzed using multiple regression models featuring the two anxiety scores as predictors, and by simulating the Performance-only specifier through 2˙2 median-split subgrouping and standard ANOVAs. Both interaction and performance anxieties were independently associated with lower QoL in general and across domains. Interaction anxiety had a larger negative impact on Personal Growth- and Achievement-related QoL than performance anxiety. The High-Performance/Low-Interaction-group rated higher Achievement-related QoL compared to the Low-Performance/High-Interaction-group (p = .012), yet groups were matched on total QoL and on other domains. Other group differences were in the expected direction.QoL impairments in SAD is primarily driven by number of feared social situations, and only secondarily by types of fear social situations, with interaction anxiety having a larger, negative impact on some QoL domains.
50.	Lindner, Philip, et al. (författare) Does cognitive flexibility predict treatment gains in Internet-delivered psychological treatment of social anxiety disorder, depression, or tinnitus? 2016 Ingår i: PeerJ. - : PeerJ. - 2167-8359. ; 4 Tidskriftsartikel (refereegranskat)abstract Little is known about the individual factors that predict outcomes in Internet-administered psychological treatments. We hypothesized that greater cognitive flexibility (i.e. the ability to simultaneously consider several concepts and tasks and switch effortlessly between them in response to changes in environmental contingencies) would provide a better foundation for learning and employing the cognitive restructuring techniques taught and exercised in therapy, leading to greater treatment gains. Participants in three trials featuring Internet-administered psychological treatments for depression (n = 36), social anxiety disorder (n = 115) and tinnitus (n = 53) completed the 64-card Wisconsin Card Sorting Test (WCST) prior to treatment. We found no significant associations between perseverative errors on the WCST and treatment gains in any group. We also found low accuracy in the classification of treatment responders. We conclude that lower cognitive flexibility, as captured by perseverative errors on the WCST, should not impede successful outcomes in Internet-delivered psychological treatments.

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