A review on simulation models applied to emergency medical service operations

Emergency medical services (EMS) are public safety systems responsible for the pre-hospital stabilization and transport of seriously injured patients. The goal of such systems is to respond adequately to population calls by providing first aid services and transferring patients, when needed, to the emergency department of the appropriate hospital. In order to achieve this goal, a variety of tools (e.g. simulation, mathematical programming and queuing theory models) have been used to improve the performance of EMS. This paper focuses specifically on computer simulation models used for the analysis and improvement of EMS. In particular, we give a critical overview of the existing international literature on simulation models for EMS by pinpointing the issues considered, the associated modeling assumptions as well as the results obtained. Such a contribution is lacking in the current literature.     

A dynamic logic of action

The paper presents a logical treatment of actions based on dynamic logic. This approach makes it possible to reflect clearly the differences between static and dynamic elements of the world, a distinction which seems crucial to us for a representation of actions.Starting from propositional dynamic logic a formal system (DLA) is developed, the programs of which are used to model action types. Some special features of this system are: Basic aspects of time are incorporated in DLA as far as they are needed for our purpose. Names for states and for instants are simulated by formulas. It is possible to express formally that a formula is satisfiable or valid. A special program is introduced to reflect developments which are not caused by an official agent but by external influences.Having presented our basic system DLA we give some examples to illustrate how a logical system of this kind could be used for analysing essential aspects of actions. We therefore touch on such topics asthe results of actions, abilities of the agent, parallel performances of actions. Possibilities of and problems with logical representations of these features are informally discussed. Afterwards first steps towards integrating them into our basic systems are proposed by formally presenting an extension of DLA for each of the topics mentioned. Statement of exclusive submission. This paper has not been submitted elsewhere in identical or similar form.     

Expressiveness of temporal query languages: on the modelling of intervals, interval relationships and states

Storing and retrieving time-related information are important, or even critical, tasks on many areas of computer science (CS) and in particular for artificial intelligence (AI). The expressive power of temporal databases/query languages has been studied from different perspectives, but the kind of temporal information they are able to store and retrieve is not always conveniently addressed. Here we assess a number of temporal query languages with respect to the modelling of time intervals, interval relationships and states, which can be thought of as the building blocks to represent and reason about a large and important class of historic information. To survey the facilities and issues which are particular to certain temporal query languages not only gives an idea about how useful they can be in particular contexts, but also gives an interesting insight in how these issues are, in many cases, ultimately inherent to the database paradigm. While in the area of AI declarative languages are usually the preferred choice, other areas of CS heavily rely on the extended relational paradigm. This paper, then, will be concerned with the representation of historic information in two well known temporal query languages: Templog in the context of temporal deductive databases, and TSQL2 in the context of temporal relational databases. We hope the results highlighted here will increase cross-fertilisation between different communities. This article can be related to recent publications drawing the attention towards the different approaches followed by the Databases and AI communities when using time-related concepts.     

Dynamic NC simulation of milling operations

To increase productivity in manufacturing, accurate cutting-simulation systems have increasingly been used to study the performance of machining processes. A new dynamic cutting-simulation system that can simulate the dynamic behaviour of the milling cutting force along the programmed NC toolpath is presented in the paper. The radial and axial depths of cut in the cutting process are extracted from a geometric cutting-simulation system on a workstation. Then, the radial and axial depths of cut and the other given cutting parameters are transmitted to a mechanistic model of the milling process from which the dynamic cutting force is obtained. There is good agreement between the simulated and measured cutting forces.     

基于因果关系的行动理论扩充

在因果条件逻辑的基础上进一步改进因果理论语义,并给出扩充的行动理论,统一表述动作执行和原因蕴涵,从而可以整体论述逻辑语言本身相互动作的独立与非独立性,使得处理并发动作和动作之间独立与非独立性关系变得更为自然形式化．     

基于微分动态逻辑的铁路道口控制分析

利用微分动态逻辑对铁路道口控制进行形式化分析与建模.在火车从发送接近信号到进入道口的运动过程中,根据火车到达道口时间上的要求,将火车速度控制问题抽象成一个混成系统的安全性性质,用微分动态逻辑来描述,并使用混成系统证明工具KeYmaera对系统的安全性进行验证,以实现对火车进入道口前速度的正确控制.     

行为时序逻辑中四级公平性下的活性推理规则

公平性是行为时序逻辑用于表达系统活性的形式,直接影响到系统描述的正确性与完整性,对其进行细化与完善能有效提高行为时序逻辑的系统描述能力。然而在对公平性进行细化的同时,却缺乏相应的、运用于性质验证的推理规则。针对这一问题,通过对公平性内涵的分析,给出了四级公平性体系下的活性推理规则,并分别进行了证明。作为示例,运用新的活性推理规则,对一个程序实例进行了推理验证。在建立起相应的活性推理规则后,四级公平性才能够被有效运用到实际的系统描述与验证中。     

Use of multi-attribute decision analysis for designing operations system framework in telecommunications management network

This paper is concerned with the design of an Operations System (OS) framework for implementing a proper telecommunications network in Korea Telecom. Since several types of OS frameworks are under consideration, the telecommunication network manager should now choose the best alternative for use later in establishing the infrastructure of operations systems. The decision making is done in this paper by means of a Multi-Attribute Decision-Making (MADM) analysis. A point to be noted in the present case is that the decision relevant information such as attribute weights and values of alternatives are not known exactly. Rather, these are to be taken in the form of rankings and/or bounds. To deal with such incomplete information, we employ a mathematical programming model-based MADM approach to the choice of an optimal OS framework design. This approach enables us to check dominance of alternatives and to obtain a set of non-dominated alternatives from evaluating five alternatives in reference to Telecommunications Management Network (TMN) standards.

Scope and purpose

Telecommunications Management Network (TMN) can be stated as a globalized and unified skeleton to meet the advanced operational environments of telecommunications networks and to handle heterogeneous and complex network elements. Although there are various subjects that should be addressed to accomplish TMN, we confine our attention to dealing with one important subject, design of an Operations System (OS) framework. This is necessary to manage telecommunications resources including networks in effective manner and for use as guidance in developing individual operations systems and in constructing a network management center.Several types of OS frameworks have been suggested by TMN standards. It is hence needed to evaluate each of these OS frameworks and then to choose an appropriate one in Korean TMN situation. Since this evaluation involves multiple criteria (or attributes), it is realized in this paper by a Multi-Attribute Decision-Making (MADM) analysis approach. The decision relevant information such as trade-off weights and individual criterion values are elicited from expert opinions which, however, is rather incomplete than exact numerical values. The decision making process with the incompletely identified information is presented in this paper.     

Temporal Coordination –On Time and Coordination of CollaborativeActivities at a Surgical Department

An activity is inseparably bound up with time, and interdependentcooperative activities thus need to be coordinated in time. The nature oftime is therefore an ever-present issue in the design of computer systemssupporting coordination. Based on Activity Theory this paper defines theconcept of Temporal Coordination. Then, based on in-depth studies of thesocio-temporal aspects of coordinating cooperative work at hospitals, thepaper explores this notion of temporal coordination. This analysis identifiessome of the highly intertwined temporal problems, constraints, interests,and conflicts, which arise when work subject to temporal limits is to becoordinated. The paper then introduces the PATIENT SCHEDULER, which isa prototype designed during this project to illustrate how aspects oftemporal coordination can be supported by computer technology.     

混杂系统滚动时域状态反馈预测控制研究与实现

分析了混杂系统混合逻辑动态建模机理,提出混杂系统基于滚动时域状态反馈预测控制策略,并对滚动时域状态估计器的收敛性进行了研究.仿真实例验证了滚动时域状态反馈预测控制策略的有效性.     

事件本体中动作程度词的形式化研究

针对事件本体中动作程度词的形式化作了深入研究.首先从大量文本中提取程度词,进而根据其特征将其分为三类;然后找到一种完全覆盖此三类程度词的统一表示方法,用模糊逻辑将其形式化;最后通过实验验证其可行性.通过对三个分别代表各类的程度词进行形式化,验证了此方法的可行性.     

基于虚拟样机的机械臂动力学建模与仿真*

基于多刚体动力学的原理,在分析机械臂的运动学和拉格朗日动力学方程的基础上求解其雅可比矩阵,并采用虚拟样机技术建立了机械臂的三维仿真模型,进行了动力学分析,获得了机械臂的动态特性。通过将获得的动态特性还原到模型中,建立了基于可视化技术的机械臂运动姿态的计算机动画,逼真地模拟了机械臂的整个运动过程,检验了机械臂动力学模型的相关性能。     

Analysis of assembly operations difficulty: a fuzzy expert system approach

Typical mechanical products can be assembled in various sequences of assembly operations. These sequences have high impact on the assembly time, machine utilization and even on the product quality. In order to select the best sequence of assembly operations, proper evaluation of the various sequences of assembly operations is required. This, in turn, requires the consistent evaluation of each assembly operation in the sequence. The assembly operations can be evaluated for various criteria, of which the operation difficulty is the most meaningful. This paper describes a methodology to analyse the assembly operations and calculates an operation's degree of difficulty using an expert system. This analysis consists of two steps: the first one identifies the main parameters that affect the assembly difficulty and assigns fuzzy triangular values to these parameters. The second step assigns weights to the parameters in order to maximize the agreement with a domain expert. The expert system analyses the difficulty of the assembly operation performed in two orientations: horizontal and vertical. The expert system then assigns a triangular fuzzy number as the aggregate measure of the operation's difficulty.     

动力学积分保辛的数学根据

用最小作用量变分原理来解释保辛,对于连续时间系统、离散时间系统、有限元法、结构力学、最优控制和动力学计算等,可以通用的.     

A quiver approach to studying orbit spaces of linear systems

Orbit spaces associated to linear actions are of particular interest in control theory. Their geometrical properties can be naturally investigated by using the representations of quivers as an abstract framework. The aim of the paper is to bring into attention an application of this approach and to show how the use of quivers makes it easy handling concepts arising in control theory. Specifically, the natural duality between controllable and observable systems, as well as the construction of compactifications for the associated orbit spaces is interpreted in terms of opposite quivers.     

A methodology to design a fuzzy logic based supervision of Hybrid Renewable Energy Systems

Hybrid Renewable Energy Systems (HRES) are increasingly used to improve the grid integration of wind power generators. The goal of this work is to propose a methodology to design a fuzzy logic based supervision of this new kind of production unit. A graphical modeling tool is proposed to facilitate the analysis and the determination of fuzzy control algorithms adapted to complex hybrid systems. To explain this methodology, the association of wind generators, decentralized generators and storage systems are considered for the production of electrical power. The methodology is divided in six steps covering the design of a supervisor from the system work specifications to an optimized implementation of the control. The performance of this supervisor is shown with the help of simulations. Finally, the application of this methodology to the supervision of different topologies of HRES is also proposed to bring forward the systematic dimension of the approach.     

Compositional verification of real-time systems with Explicit Clock Temporal Logic

To specify and verify real-time systems, we consider a real-time version of temporal logic called Explicit Clock Temporal Logic. Timing properties are specified by extending the classical framework of temporal logic with a special variable which explicitly refers to a global notion of time. Programs are written in an Occam-like real-time language with synchronous message passing. To show that a program satisfies a specification, we formulate a proof system which is proved to be sound and relatively complete. The proof system is compositional, which makes it possible to decompose the design of a large system into the design of subsystems. This is shown by the verification of a small part of an avionics system.This research was supported by ESPRIT-BRA project 3096 Formal Methods and Tools for the Development of Distributed and Real-Time Systems (SPEC).