| 1. |
- Al-Dhaqm, Arafat, et al.
(författare)
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Face validation of database forensic investigation metamodel
- 2021
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Ingår i: Infrastructures. - Basel : MDPI. - 2412-3811. ; 6:2, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- Using a face validity approach, this paper provides a validation of the Database Forensic Investigation Metamodel (DBFIM). The DBFIM was developed to solve interoperability, heterogeneity, complexity, and ambiguity in the database forensic investigation (DBFI) field, where several models were identified, collected, and reviewed to develop DBFIM. However, the developed DBFIM lacked the face validity-based approach that could ensure DBFIM’s applicability in the DBFI field. The completeness, usefulness, and logic of the developed DBFIM needed to be validated by experts. Therefore, the objective of this paper is to perform the validation of the developed DBFIM using the qualitative face validity approach. The face validity method is a common way of validating metamodels through subject expert inquiry on the domain application of the metamodel to assess whether the metamodel is reasonable and compatible based on the outcomes. For this purpose, six experts were nominated and selected to validate the developed DBFIM. From the expert review, the developed DBFIM was found to be complete, coherent, logical, scalable, interoperable, and useful for the DBFI field.
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| 2. |
- Große, Christine, Fil.Dr, 1974-, et al.
(författare)
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Resilience Endangered : The Role of Regional Airports in Remote Areas in Sweden
- 2021
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Ingår i: Infrastructures. - : MDPI AG. - 2412-3811. ; 6:12
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Tidskriftsartikel (refereegranskat)abstract
- This paper examines the role of regional airports in regional and municipal crisis preparedness based on evidence from a case study in Sweden. During the summer of 2018, Sweden experienced some of the most extensive wildfires in modern time. Aerial suppression, for which airports provided the essential preconditions, played an important role in extinguishing these fires. This study includes analyses of public policies that shape the Swedish airport system as well as evidence from interviews and a workshop with stakeholders. The results show that an efficiently operated network of regional airports is critical not only for crisis management but also to ensure important societal services such as health care in sparsely inhabited regions. Moreover, access toquick transportation by air is necessary for the Swedish Prison and Probation Service, tourism industry, public institutions and private businesses. Additionally intensified by effects of both the public debate on flight shame and the COVID-19 pandemic on air-based transportation, the insights arising from this study emphasise that the currently one-sided focus on the number of passengers is an insufficient foundation for the Swedish airport system to construct a resilient base for regional development, crisis management and civil defense.
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| 3. |
- Malm, Richard, 1980-, et al.
(författare)
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Lessons Learned Regarding Cracking of a Concrete Arch Dam Due to Seasonal Temperature Variations
- 2020
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Ingår i: Infrastructures. - : MDPI. - 2412-3811. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- Dams located in cold areas are subjected to large seasonal temperature variations and many concrete dams have cracked as a result. In the 14th International Commission on Large Dams (ICOLD) Benchmark Workshop, a case study was presented where contributors should predict the cracking and displacements due to seasonal variations. In this paper, the conclusions from this case study are presented. Overall, the results from the contributors are well in line with the observations that can be made on the dam and the measurements performed. This shows that using non-linear numerical models is a suitable tool to accurately predict cracking and estimate the displacements of cracked dams. This case study also highlighted important aspects that need special consideration in order to obtain realistic results that can be used to predict the crack pattern, these being: (1) the importance of performing transient thermal analyses based on robin boundary conditions; (2) the influence of contact formulation between the concrete dam and the foundation; and (3) the use of realistic non-linear material properties. The results and conclusions presented in this paper constitute one important step in achieving best practices to estimate dam safety and better understand the potential failure modes and ageing of concrete dams.
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| 4. |
- Woltjer, Rogier, et al.
(författare)
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Air Transport System Agility: The Agile Response Capability (ARC) Methodology for Crisis Preparedness
- 2022
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Ingår i: Infrastructures. - : MDPI AG. - 2412-3811 .- 2412-3811. ; 7:2, s. 11-11
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Tidskriftsartikel (refereegranskat)abstract
- Aviation is a highly inter-connected system. This means that a problem in one area maycause effects in other countries or parts of the Air Transport System (ATS). Examples range from localair traffic disruptions to the 2010 volcanic ash crisis. Agility, like resilience, refers to the ability to copewith dynamics and complexity in a flexible manner, by adjusting and adapting performance and theorganization of work to fit changing demands. The aim of this work is to help ATS organizationswith increasing their agility in the face of crises and challenges. To this end, this article presents theAgile Response Capability (ARC) guidance material. ARC was developed from a literature study anda number of case studies that combined past event analysis, interviews, focus groups, workshops,questionnaires, and exercise observation methodologies. ARC aims to help aviation organizations toset up, run, and evaluate exercises promoting agility to handle disturbances and crises, and to enablestructured pro-active and retrospective analysis of scenarios and actual events. The elements andsteps of the ARC approach are illustrated and exemplified with data from three case studies. TheARC methodology facilitates more agile and resilient ways of responding to the fundamental andnovel surprises that have become almost commonplace in the past decade, and are likely to continueto do so.
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| 5. |
- Agriesti, Serio Angelo Maria, et al.
(författare)
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Roadworks warning-closure of a lane, the Impact of C-ITS messages
- 2020
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Ingår i: Infrastructures. - : MDPI AG. - 2412-3811. ; 5:3
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Tidskriftsartikel (refereegranskat)abstract
- By now, it is widely acknowledged among stakeholders and academia that infrastructures will have to be composed both by a physical component and a digital one. The deployment of technologies exploiting dedicated short-range communications is viewed as the most cost-effective solution to face the foreseen growth of mobility. Still, little has been done to define the best implementation logic of DSRC. Aim of this paper is to frame the possible impacts arising by the implementation of a cooperative intelligent transport system (C-ITS)-use case: roadworks warning.closure of a lane, and, in order to achieve this result, microsimulations are exploited. The results are intended to support both road operators and car-makers in defining the best operational logics and the possible benefits achievable by presenting the cooperative message at a certain distance for certain market penetrations. Moreover, if the C-ITS message actually entails benefits or simply disrupts the upstream traffic should be assessed in advance, before implementing the system. The obtained results show that the risk of disruption and of reduction in traffic efficiency arises at lower market penetration levels. Nevertheless, a consistent trend in delay reduction is recorded upstream the roadworks, the highest reduction being equal to 8.66%. Moreover, the average speed at the roadworks entrance on the closing lane increases by a difference equal to around 10 km/h, while the average time in the queue at the highest market penetration reduces by 60 s on the open lane and 25 s on the closing one. These presented results reflect the way the traffic shifts from the slow to the fast lane thanks to the C-ITS system and effectively frames both the potentialities and the risks of the system.
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| 6. |
- Danielski, Itai, 1973-, et al.
(författare)
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In situ measurements of thermal properties of building fabrics using thermography under non-steady state heat flow conditions
- 2018
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Ingår i: Infrastructures. - : MDPI. - 2412-3811. ; 3:3
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Tidskriftsartikel (refereegranskat)abstract
- This study describes a quantitative method using thermography to measure the thermal properties of building fabrics that are subjected to non-steady state heat flow due to consistently changing meteorological conditions. The method includes two parts. First, the convection heat transfer coefficient is measured by thermography and heat flux meters on a small segment of the examined building fabric with uniform surface temperature. Then, thermal properties of large building fabrics are evaluated by thermography. The two parts are measured simultaneously. The method was tested on 140/160/190 mm thick massive laminated spruce timber walls of a test facility cabin located in Östersund, Sweden. The results varied by only a few percent in comparison to validation measurements performed with heat flux meters and in comparison, to values from the literature. Due to rapid changes in weather conditions the measured values had large disparity, but still a linear regression with low confidence interval was obtained. Obtaining an accurate value of convection heat transfer was important for achieving high measurement accuracy and, therefore, the value of this parameter should be measured. Other important factors to consider are solar radiation, reflected infrared (IR) radiation from nearby objects and the number of thermal images.
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| 7. |
- Degerman, Helene
(författare)
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Barriers towards Resilient Performance among Public Critical Infrastructure Organizations : The Refugee Influx Case of 2015 in Sweden
- 2021
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Ingår i: infrastructures. - : MDPI. - 2412-3811. ; 6:8
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Tidskriftsartikel (refereegranskat)abstract
- During the autumn of 2015, Europe experienced a sharp increase in refugee influx, and many refugees arrived in the European Øresund Region. Refugees travelled through Denmark and over the Øresund Bridge, arriving in the third largest city in Sweden, Malmö. Private, public and voluntary organizations in Malmö had to change the way they worked to meet the new entry demands. Flexible adaptations to changing circumstances can be described as resilient performance and are supported or hindered by societal and organizational drivers and barriers. Qualitative interview data from Swedish organizations managing the refugee reception in Malmö were analyzed through the theoretical lens of Resilience Engineering (RE). The analysis results showed that necessary adaptations were not supported by the managerial design of the responsible public organizations. The analysis also showed that preconditions created from societal steering hinders value responsiveness at the public management level, i.e., the public management level has barriers towards becoming familiar with the organization’s value structures. Familiarity with the system value and goal structure is essential for an efficient prioritizing of conflicting goals, which is why it is suggested that this aspect be explicitly included in RE principles.
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| 8. |
- Große, Christine, Fil.Dr, 1974-
(författare)
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Multi-level planning for enhancing critical infrastructure resilience against power shortages—an analysis of the swedish system of styrel
- 2021
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Ingår i: Infrastructures. - : MDPI AG. - 2412-3811. ; 6:5
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Tidskriftsartikel (refereegranskat)abstract
- The protection of infrastructure that is critical to society’s functionality, survival and progression has gained significance because of its large-scale and interdependent nature. This complex system-of-system (SoS) imposes extensive requirements on governance efforts to foster critical infrastructure protection (CIP). This paper uses the kaleidoscope for integrative system analysis (KISA) to investigate a Swedish approach for CIP against power shortages, called STYREL. Based on multiple sources of evidence, such as documents with regard to the case, interviews and a survey with involved experts, the analysis focuses on the system of emergency planning and the usage of the resulting plan. The results deliver insights into the governance of the multi-level planning, including issues regarding policies, the management and operation of STYREL, and accelerating problems in the adaption, emergence and entropy of the SoS, during and between process iterations. Since this large-scale approach largely fails to involve the private sector to enhance the resilience of the society, this proceeding results in uncalculated consequences. In addition, the current design of the approach hampers transparency and evaluation, which poses obstacles to the cultivation of mutual trust, collective learning and a shared understanding as well as proper risk communication with the wider public.
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| 9. |
- Haghani Dogaheh, Reza, 1979, et al.
(författare)
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Fiber reinforced polymer culvert bridges—a feasibility study from structural and lcc points of view
- 2021
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Ingår i: Infrastructures. - : MDPI AG. - 2412-3811. ; 6:9
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Tidskriftsartikel (refereegranskat)abstract
- Soil–steel composite bridges (SSCB) have become increasingly popular for short-span bridges as an alternative to concrete slab bridges mainly due to their low initial cost, rapid manufac-ture, simplified construction, and geometrical adaptability. SSCBs have a variety of applications and can be used over waterways or roadways. While conventional bridges tend to lose their load-carrying capacity due to degradation, SSCBs gain strength because of backfill soil consolidation. However, the load carrying capacity and integrity of such structures highly depends on the condition and load-carrying capacity of the steel arch element. A major drawback of SSCBs, especially those located on waterways or with poor drainage, is corrosion and subsequent loss of cross-sectional capacity. Unfortunately, the inspection of such bridges is not straightforward and any damage/collapse will be very costly to repair/replace. Fiber reinforced polymer (FRP) composites offer an attractive alternative to replace the steel in these types of bridges. FRP composites have significantly improved durability characteristics compared to steel, which will reduce maintenance costs and improve life-cycle costs (LLCs). This paper presents a new concept to use glass FRP as a construction material to construct soil–FRP composite bridges (SFCB). Various aspects of design and manufacturing are presented along with results and conclusions from a case study involving alternative bridge designs in steel and FRP composites.
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| 10. |
- Hellgren, Rikard, et al.
(författare)
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Progressive Failure Analysis of a Concrete Dam Anchored with Passive Rock Bolts
- 2020
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Ingår i: Infrastructures. - Basel, Switzerland : MDPI. - 2412-3811 .- 2412-3811. ; 5:3
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Tidskriftsartikel (refereegranskat)abstract
- Passive rock bolts are commonly used to anchor concrete dams, and they may have a significant impact on stability-evaluations. However, these bolts are often omitted from dam safety analysis due to uncertainties regarding their condition and the size of displacements required in the dam-rock interface to mobilize significant bearing forces in the passive rock bolts. This paper address the latter question by studying the failure process of a small concrete dam anchored with rock bolts. Failure simulations were performed with the increased density method in a finite element model consisting of a dam, the corresponding part of the rock and rock bolts. Two types of approaches are used to simulate the anchorage of the rock bolts; a method where the anchorage to the rock is simulated using a fixed boundary condition; and a method where the anchoring of the bolts are modelled using springs. Depending on the method of analysis, the rock bolts contribute with 40–75% of the load-carrying capacity of the dam. The rock bolts increase the load-bearing capacity of the dam, partly through anchorage forces, but also by keeping the contact surface between rock and concrete together and thereby increase the shear capacity of the interface.
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