41. 
 Bhatt, Mehul, Professor, 1980, et al.
(författare)

Architecture, computing, and design assistance
 2013

Ingår i: Automation in Construction.  : Elsevier.  09265805 . 18727891. ; 32, s. 161164

Tidskriftsartikel (refereegranskat)abstract
 Design is one of the most complex of human endeavors requiring an enormous number of often conflicting criteria to be contemplated when identifying optimal solutions. Design is constrained by guidelines, codes, and standards applicable to the specific cultural and locational context that the design will be sited. Furthermore, a design has to be created within a collaborative team consisting of many professionals focused on specific subsystems and expert preferences that provide unique functionality to the overall design. The increasing use and capability of software tools involved in the creation and processing of such spatial information has also led to elevated levels of complexity that spurred a need to structure, query and reason about multiple spatial representations of buildings and their components in new ways.


42. 
 Broström, Robert, et al.
(författare)

Correlation between safety assessments in the drivercar interaction design process
 2011

Ingår i: Applied Ergonomics.  00036870 . 18729126. ; 42:4, s. 575582

Tidskriftsartikel (refereegranskat)abstract
 With the functional revolution in modern cars, evaluation methods to be used in all phases of drivercar interaction design have gained importance. It is crucial for car manufacturers to discover and solve safety issues early in the interaction design process. A current problem is thus to find a correlation between the formative methods that are used during development and the summative methods that are used when the product has reached the customer. This paper investigates the correlation between efficiency metrics from summative and formative evaluations, where the results of two studies on sound and navigation system tasks are compared. The first, an analysis of the J.D. Power and Associates APEAL survey, consists of answers given by about two thousand customers. The second, an expert evaluation study, was done by six evaluators who assessed the layouts by task completion time, TLX and Nielsen heuristics. The results show a high degree of correlation between the studies in terms of task efficiency, i.e. between customer ratings and task completion time, and customer ratings and TLX. However, no correlation was observed between Nielsen heuristics and customer ratings, task completion time or TLX. The results of the studies introduce a possibility to develop a usability evaluation framework that includes both formative and summative approaches, as the results show a high degree of consistency between the different methodologies. Hence, combining a quantitative approach with the expert evaluation method, such as task completion time, should be more useful for drivercar interaction design.


43. 
 Broström, Robert, et al.
(författare)

Perceived styling and usability in integrated centre panel layouts as a function of interaction style and age
 2007

Ingår i: Human Factors Issues in Complex System Performance.  Maastricht : Shaker Verlag.  9789042303256 ; , s. 193204

Konferensbidrag (refereegranskat)abstract
 In the past ten years information and entertainment functionality has become an increasingly important part of the car interior. Infotainment functions have been growing in number and diversity, concurrently with a trend towards utilization of fewer controls and graphical displays in integrated centre panel layouts. This evolution has solved many functional and styling issues. However, as a consequence, several usability and safety concerns have been raised. A number of these concerns are related to age, a factor that is especially important in the premium car segment where a majority of drivers are older than 50 years. This study investigated perceived styling and usability of premium car centre panel layouts among different age groups. The investigation was based on APEAL customer survey data from the North American market, associated with the sound system. Questions on the appearance (styling), understanding (usability) and ease of use while driving (usability/safety) of the stereo faceplate and controls were analysed. The results showed that all age groups perceived the appearance of integrated centre panel layouts similarly. However, with rising age, there is a decrease in perceived understanding and ease of use while driving in the case of a number of premium car models.


44. 
 Byass, Peter, et al.
(författare)

Comparing verbal autopsy cause of death findings as determined by physician coding and probabilistic modelling : a public health analysis of 54 000 deaths in Africa and Asia
 2015

Ingår i: Journal of Global Health.  20472978 . 20472986. ; 5:1, s. 6573

Tidskriftsartikel (refereegranskat)abstract
 BACKGROUND: Coverage of civil registration and vital statistics varies globally, with most deaths in Africa and Asia remaining either unregistered or registered without cause of death. One important constraint has been a lack of fitforpurpose tools for registering deaths and assigning causes in situations where no doctor is involved. Verbal autopsy (interviewing caregivers and witnesses to deaths and interpreting their information into causes of death) is the only available solution. Automated interpretation of verbal autopsy data into cause of death information is essential for rapid, consistent and affordable processing.METHODS: Verbal autopsy archives covering 54 182 deaths from five African and Asian countries were sourced on the basis of their geographical, epidemiological and methodological diversity, with existing physiciancoded causes of death attributed. These data were unified into the WHO 2012 verbal autopsy standard format, and processed using the InterVA4 model. Causespecific mortality fractions from InterVA4 and physician codes were calculated for each of 60 WHO 2012 cause categories, by age group, sex and source. Results from the two approaches were assessed for concordance and ratios of fractions by cause category. As an alternative metric, the Wilcoxon matchedpairs signed ranks test with two onesided tests for stochastic equivalence was used.FINDINGS: The overall concordance correlation coefficient between InterVA4 and physician codes was 0.83 (95% CI 0.75 to 0.91) and this increased to 0.97 (95% CI 0.96 to 0.99) when HIV/AIDS and pulmonary TB deaths were combined into a single category. Over half (53%) of the cause category ratios between InterVA4 and physician codes by source were not significantly different from unity at the 99% level, increasing to 62% by age group. Wilcoxon tests for stochastic equivalence also demonstrated equivalence.CONCLUSIONS: These findings show strong concordance between InterVA4 and physiciancoded findings over this large and diverse data set. Although these analyses cannot prove that either approach constitutes absolute truth, there was high public health equivalence between the findings. Given the urgent need for adequate cause of death data from settings where deaths currently pass unregistered, and since the WHO 2012 verbal autopsy standard and InterVA4 tools represent relatively simple, cheap and available methods for determining cause of death on a large scale, they should be used as current tools of choice to fill gaps in cause of death data.


45. 
 Chen, Mo, et al.
(författare)

Molecular Dynamics Simulations of the Ionic Liquid 1nButyl3Methylimidazolium Chloride and Its Binary Mixtures with Ethanol
 2014

Ingår i: Journal of Chemical Theory and Computation.  : American Chemical Society (ACS).  15499618 . 15499626. ; 10:10, s. 44654479

Tidskriftsartikel (refereegranskat)abstract
 Room temperature ionic liquids (ILs) of the imidazolium family have attracted much attention during the past decade for their capability to dissolve biomass. Besides experimental work, numerous compuational studies have been concerned with the physical properties of both neat ILs and their interactions with different solutes, in particular, carbohydrates. Many classical force fields designed specifically for ILs have been found to yield viscosities that are too high for the liquid state, which has been attributed to the fact that the effective charge densities are too high due to the lack of electronic polarizability. One solution to this problem has been uniform scaling of the partial charges by a scale factor in the range 0.60.9, depending on model. This procedure has been shown to improve the viscosity of the models, and also to positively affect other properties, such as diffusion constants and ionic conductivity. However, less attention has been paid to how this affects the overall thermodynamics of the system, and the problems it might create when the IL models are combined with other force fields (e.g., for solutes). In the present work, we employ three widely used IL force fields to simulate 1nbuty13methylimidazolium chloride in both the crystal and the liquid state, as well as its binary mixture with ethanol. Two approaches are used: one in which the ionic charge is retained at its full integer value and one in which the partial charges are uniformly reduced to 85%. We investigate and calculate crystal and liquid structures, molar heat capacities, heats of fusion, selfdiffusion constants, ionic conductivity, and viscosity for the neat IL, and ethanol activity as a function of ethanol concentration for the binary mixture. We show that properties of the crystal are less affected by charge scaling compared to the liquid. In the liquid state, transport properties of the neat IL are generally improved by scaling, whereas values for the heat of fusion are unaffected, and results for the heat capacity are ambiguous. Neither full nor reduced charges could reproduce experimental ethanol activities for the whole range of compositions.


46. 
 Dahlin, Jakob, 1976
(författare)

Aerosols of Isocyanates, Amines and Anhydrides : Sampling and Analysis
 2007

Doktorsavhandling (övrigt vetenskapligt)abstract
 This thesis presents methods for air sampling and determination of isocyanates, amines, aminoisocyanates and anhydrides. These organic compounds are generated during thermal degradation of polymers such as polyurethane (PUR) or epoxy.Isocyanates, amines and anhydrides are airway irritants known to cause occupational asthma. Some of the compounds are listed as human carcinogens. Many workers are exposed.Isocyanates and anhydrides are reactive and needs to be immediately derivatized during sampling. Methods have been developed for determination of airborne isocyanates, aminoisocyanates and anhydrides using dinbutylamine (DBA) as reagent to form stabile urea derivatives or amide derivatives. Liquid chromatographytandem mass spectrometry (LCMS/MS) enabled detection limits as low as 10 attomoles. A nitrogenselective LCdetector enabled quantification of DBAderivatives in reference solutions. A novel sampler is presented. The sampler consists of a denuder in series with a threestage cascade impactor and an end filter. The sampler made it possible to reveal the distribution of isocyanates between gas and different particle size fractions. During thermal degradation of PUR, isocyanates were associated to particle size fractions (<1 µm) that may penetrate to the lower airways. The distribution during 8 minutes changes noticeably. Aromatic isocyanates become associated to small particles (<1 µm). As a reference method, airsampling was performed using an impinger filled with dinbutylamine (DBA) in toluene, connected in series with a glass fiber filter. There was a good agreement between the denuderimpactor sampler and the reference method.


47. 
 de Jong, Roelof S., et al.
(författare)

4MOST4metre MultiObject Spectroscopic Telescope
 2014

Ingår i: Groundbased and Airborne Instrumentation for Astronomy V.  : SPIE.  1996756X . 0277786X. ; 9147

Konferensbidrag (refereegranskat)abstract
 4MOST is a widefield, highmultiplex spectroscopic survey facility under development for the VISTA telescope of the European Southern Observatory (ESO). Its main science drivers are in the fields of galactic archeology, highenergy physics, galaxy evolution and cosmology. 4MOST will in particular provide the spectroscopic complements to the large area surveys coming from space missions like Gaia, eROSITA, Euclid, and PLATO and from groundbased facilities like VISTA, VST, DES, LSST and SKA. The 4MOST baseline concept features a 2.5 degree diameter fieldofview with similar to 2400 fibres in the focal surface that are configured by a fibre positioner based on the tilting spine principle. The fibres feed two types of spectrographs; similar to 1600 fibres go to two spectrographs with resolution R> 5000 (lambda similar to 390930 nm) and similar to 800 fibres to a spectrograph with R> 18,000 (lambda similar to 392437 nm & 515572 nm & 605675 nm). Both types of spectrographs are fixedconfiguration, threechannel spectrographs. 4MOST will have an unique operations concept in which 5 year public surveys from both the consortium and the ESO community will be combined and observed in parallel during each exposure, resulting in more than 25 million spectra of targets spread over a large fraction of the southern sky. The 4MOST Facility Simulator (4FS) was developed to demonstrate the feasibility of this observing concept. 4MOST has been accepted for implementation by ESO with operations expected to start by the end of 2020. This paper provides a toplevel overview of the 4MOST facility, while other papers in these proceedings provide more detailed descriptions of the instrument concept[1], the instrument requirements development[2], the systems engineering implementation[3], the instrument model[4], the fibre positioner concepts[5], the fibre feed[6], and the spectrographs[7].


48. 
 De Rezende, Susanna F., et al.
(författare)

Automating algebraic proof systems is NPhard
 2021

Ingår i: STOC 2021  Proceedings of the 53rd Annual ACM SIGACT Symposium on Theory of Computing.  : Association for Computing Machinery (ACM).  07378017.  9781450380539 ; , s. 209222

Konferensbidrag (refereegranskat)abstract
 We show that algebraic proofs are hard to find: Given an unsatisfiable CNF formula F, it is NPhard to find a refutation of F in the Nullstellensatz, Polynomial Calculus, or SheraliAdams proof systems in time polynomial in the size of the shortest such refutation. Our work extends, and gives a simplified proof of, the recent breakthrough of Atserias and Müller (JACM 2020) that established an analogous result for Resolution.


49. 
 De Rezende, Susanna F., et al.
(författare)

KRW composition theorems via lifting
 2020

Ingår i: Proceedings  2020 IEEE 61st Annual Symposium on Foundations of Computer Science, FOCS 2020.  : IEEE Computer Society.  02725428.  9781728196220  9781728196213 ; 2020November, s. 4349

Konferensbidrag (refereegranskat)abstract
 One of the major open problems in complexity theory is proving superlogarithmic lower bounds on the depth of circuits (i.e., mathrm{P} nsubseteq text{NC}{1}). Karchmer, Raz, and Wigderson [13] suggested to approach this problem by proving that depth complexity behaves'as expected' with respect to the composition of functions f diamond g. They showed that the validity of this conjecture would imply that mathrm{P} nsubseteq text{NC}{1}. Several works have made progress toward resolving this conjecture by proving special cases. In particular, these works proved the KRW conjecture for every outer function, but only for few inner functions. Thus, it is an important challenge to prove the KRW conjecture for a wider range of inner functions. In this work, we extend significantly the range of inner functions that can be handled. First, we consider the monotone version of the KRW conjecture. We prove it for every monotone inner function whose depth complexity can be lower bounded via a querytocommunication lifting theorem. This allows us to handle several new and wellstudied functions such as the stconnectivity, clique, and generation functions. In order to carry this progress back to the nonmonotone setting, we introduce a new notion of semimonotone composition, which combines the nonmonotone complexity of the outer function with the monotone complexity of the inner function. In this setting, we prove the KRW conjecture for a similar selection of inner functions, but only for a specific choice of the outer function f.


50. 
 de Rezende, Susanna F., 1989, et al.
(författare)

Lifting with Simple Gadgets and Applications to Circuit and Proof Complexity

Annan publikation (övrigt vetenskapligt)abstract
 We significantly strengthen and generalize the theorem lifting Nullstellensatz degree to monotone span program size by Pitassi and Robere (2018) so that it works for any gadget with high enough rank, in particular, for useful gadgets such as equality and greaterthan. We apply our generalized theorem to solve two open problems:We present the first result that demonstrates a separation in proof power for cutting planes with unbounded versus polynomially bounded coefficients. Specifically, we exhibit CNF formulas that can be refuted in quadratic length and constant line space in cutting planes with unbounded coefficients, but for which there are no refutations in subexponential length and subpolynomialline space if coefficients are restricted to be of polynomial magnitude.We give the first explicit separation between monotone Boolean formulas and monotone real formulas. Specifically, we give an explicit family of functions that can be computed with monotone real formulas of nearly linear size but require monotone Boolean formulas of exponential size. Previously only a nonexplicit separation was known.An important technical ingredient, which may be of independent interest, is that we show that the Nullstellensatz degree of refuting the pebbling formula over a DAG G over any field coincides exactly with the reversible pebbling price of G. In particular, this implies that the standard decision tree complexity and the parity decision tree complexity of the corresponding falsified clause search problem are equal.

