Compositional Set Invariance in Network Systems with Assume-Guarantee Contracts

This paper presents an assume-guarantee reasoning approach to the computation of robust invariant sets for network systems. Parameterized signal temporal logic (pSTL) is used to formally describe the behaviors of the subsystems, which we use as the template for the contract. We show that set invariance can be proved with a valid assume-guarantee contract by reasoning about individual subsystems. If a valid assume-guarantee contract with monotonic pSTL template is known, it can be further refined by value iteration. When such a contract is not known, an epigraph method is proposed to solve for a contract that is valid, ---an approach that has linear complexity for a sparse network. A microgrid example is used to demonstrate the proposed method. The simulation result shows that together with control barrier functions, the states of all the subsystems can be bounded inside the individual robust invariant sets.Comment: Submitted to 2019 American Control Conferenc

Injury Patterns of Drivers and Other Vehicle Occupants in the Banja Luka Region (Bosnia and Herzegovina)

Background: Traffic traumatism in Bosnia and Herzegovina has not been given adequate attention and there is a lack of serious research on this problem. Motor vehicle occupants represent a significant number of fatalities on local roads. The aim of this study was to identify particular risk groups of traffic participants and determine the differences in injuring due to the position of the vehicle.Methods: Study included 400 injured and fatally injured occupants among 2009-2013 in Banja Luka. We analyzed of demographic and injury characteristics, cause of death and alcohol intoxication of drivers. Data are presented numerically and in percentages, statistically analyzed.Results: Men account for nearly 3/4 of the total number of deaths and over 95% of dead drivers. Nearly two-thirds of victims were aged 15-44 years, and one third of injured were in the third decade of life. Drivers more often had AIS3+ injuries of head, chest, abdomen and AIS2+ injuries of thoracic spine and lower extremities. More often drivers and front passengers had AIS3+ chest injuries, while the back seat occupants had AIS3+ head injuries. There was a positive correlation between age and frequency of AIS3+ chest injuries and AIS2+ spinal injuries. The most common cause of death were head (41%) and chest injuries (33.3%). Nearly 3/4 of injured persons were died at the scene of accident or during transport to the nearest health care facility. Nearly 60% of killed drivers had legally prohibited BAC (> 0.3 g/kg).Conclusion: Men in motor vehicles more often die in traffic accidents, and a particularly vulnerable category is young male drivers. Seat belts using on domestic routes is dissatisfactory and additional efforts are required

Function and biotechnology of extremophilic enzymes in low water activity

Enzymes from extremophilic microorganisms usually catalyze chemical reactions in non-standard conditions. Such conditions promote aggregation, precipitation, and denaturation, reducing the activity of most non-extremophilic enzymes, frequently due to the absence of sufficient hydration. Some extremophilic enzymes maintain a tight hydration shell and remain active in solution even when liquid water is limiting, e.g. in the presence of high ionic concentrations, or at cold temperature when water is close to the freezing point. Extremophilic enzymes are able to compete for hydration via alterations especially to their surface through greater surface charges and increased molecular motion. These properties have enabled some extremophilic enzymes to function in the presence of non-aqueous organic solvents, with potential for design of useful catalysts. In this review, we summarize the current state of knowledge of extremophilic enzymes functioning in high salinity and cold temperatures, focusing on their strategy for function at low water activity. We discuss how the understanding of extremophilic enzyme function is leading to the design of a new generation of enzyme catalysts and their applications to biotechnology

Error Estimations, Error Computations, and Convergence Rates in FEM for BVPs

This paper presents derivation of a priori error estimates and convergence rates of finite element processes for boundary value problems (BVPs) described by self adjoint, non-self adjoint, and nonlinear differential operators. A posteriori error estimates are discussed in context with local approximations in higher order scalar product spaces. A posteriori error computational framework (without the knowledge of theoretical solution) is presented for all BVPs regardless of the method of approximation employed in constructing the integral form. This enables computations of local errors as well as the global errors in the computed finite element solutions. The two most significant and essential aspects of the research presented in this paper that enable all of the features described above are: 1) ensuring variational consistency of the integral form(s) resulting from the methods of approximation for self adjoint, non-self adjoint, and nonlinear differential operators and 2) choosing local approximations for the elements of a discretization in a subspace of a higher order scalar product space that is minimally conforming, hence ensuring desired global differentiability of the approximations over the discretizations. It is shown that when the theoretical solution of a BVP is analytic, the a priori error estimate (in the asymptotic range, discussed in a later section of the paper) is independent of the method of approximation or the nature of the differential operator provided the resulting integral form is variationally consistent. Thus, the finite element processes utilizing integral forms based on different methods of approximation but resulting in VC integral forms result in the same a priori error estimate and convergence rate. It is shown that a variationally consistent (VC) integral form has best approximation property in some norm, conversely an integral form with best approximation property in some norm is variationally consistent. That is best approximation property of the integral form and the VC of the integral form is equivalent, one cannot exist without the other, hence can be used interchangeably. Dimensional model problems consisting of diffusion equation, convection-diffusion equation, and Burgers equation described by self adjoint, non-self adjoint, and nonlinear differential operators are considered to present extensive numerical studies using Galerkin method with weak form (GM/WF) and least squares process (LSP) to determine computed convergence rates of various error norms and present comparisons with the theoretical convergence rates

On some batch code properties of the simplex code

The binary $k$-dimensional simplex code is known to be a $2^{k-1}$-batch code and is conjectured to be a $2^{k-1}$-functional batch code. Here, we offer a simple, constructive proof of a result that is "in between" these two properties. Our approach is to relate these properties to certain (old and new) additive problems in finite abelian groups. We also formulate a conjecture for finite abelian groups that generalizes the above-mentioned conjecture

The experiences, needs and outcomes for carers of people with dementia: Literature Review

This literature review was conducted as part of my role at the Association of Dementia Studies, University of Worcester.RSAS is developing new and innovative ways of supporting carers, people living with dementia and their families. The charity aims to enhance the health and well-being of carers through providing services that increase their knowledge and understanding of dementia, further enhances their caring skills and provides supportive and therapeutic services to them. This literature review provides an up-to-date review concerning the evidence in relation to the following questions: 1 What is the experience of caregiving for a person living with dementia, and in what context does caregiving take place? 2 What implications does caregiving have for the person/family member involved in caregiving and the person with dementia? 3 What is currently known about the factors that protect or increase the risk of poor outcomes in caregiving? 4 What evidence is there for interventions to support family caregiving and reduce the risk of poor outcomes and how is this delivered in relation to: a Information and Education b Multi-component, psycho-educational interventions c Psychological Interventions d Peer support and other social interventions e Assistive technology and new media 5 What form of service provision is required to support family caregivers? This will include consideration of such issues as: a How might a service be delivered? b What factors will influence delivery including location, design, accessibility and flexibility? 6 Who will the service be for and how can family caregivers be supported to engage with the service

Compositional Set Invariance in Network Systems with Assume-Guarantee Contracts

This paper presents an assume-guarantee reasoning approach to the computation of robust invariant sets for network systems. Parameterized signal temporal logic (pSTL) is used to formally describe the behaviors of the subsystems, which we use as the template for the contract. We show that set invariance can be proved with a valid assume-guarantee contract by reasoning about individual subsystems. If a valid assume-guarantee contract with monotonic pSTL template is known, it can be further refined by value iteration. When such a contract is not known, an epigraph method is proposed to solve for a contract that is valid, -an approach that has linear complexity for a sparse network. A microgrid example is used to demonstrate the proposed method. The simulation result shows that together with control barrier functions, the states of all the subsystems can be bounded inside the individual robust invariant sets