bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simultaneous estimation of several percentiles
Authors: Raatikainen Kimmo E. E. 
Published: March 2008

In many simulation studies the performance of the modeled system is characterized only by mean values of the performance indices. However, the percentiles are more informative in sum marizing the performance. Several simultaneous percentiles, pre sented for example in the form of the boxplot, provide the analyst with better understanding of the system's behaviour. The simultaneous estimation of several percentiles is a cumber some task. The extended P2-algorithm proposed in this study significantly reduces the computation of the estimation. The algorithm simultaneously estimates several percentiles without storing and sorting the observations. Empirical validation studies indicate the algorithm can be used in simulation studies.
Radar target signal modeling and validation
Authors: Bertolini A. , Long J.H. 
Published: March 2008

The performance of a radar system is greatly affected by the elec tromagnetic scattering properties of the targets to be tracked. A key target parameter is the radar cross section, defined as an effective area that scatters incident power in the direction of the radar receiver. Two target modeling approaches used at Raytheon and their validation are described. One of the methods computes a com posite signal and equivalent cross section and glint from a num ber of discrete point scatterers. The other method, a statistical model, combines filtered and scaled noise sources from a ran dom number generator to produce the desired results. The outputs presented include plots of sample radar cross sec tion, glint and angle tracking error histories as functions of target aspect and target aspect rate. There are also comparisons of results computed by the two methods, as well as with actual flight data.
A simulation study of hardwood rootstock populations in young loblolly pine plantations
Authors: Weise David R. , Glover Glenn R. 
Published: March 2008

A computer program to simulate spatial distribution of hard wood rootstock populations is presented. Nineteen 3 to 6 year- old loblolly pine (Pinus taeda L.) plantations in Alabama and Georgia were measured to provide information for the simula tor. Spatial pattern, expressed as Pielou's nonrandomness index (PNI), ranged from 0.47 to 2.45. Scatterplots illustrated no rela tionship between pattern, species relative density, site prepara tion, or stand age. Newnham's point pattern generator was modified to reduce execution time. Equations to predict program inputs as a func tion of PNI and desired number of points were developed for uniform, random, and randomly clumped populations. Total rootstock height distribution was fitted using a two-parameter, left- and right-truncated Weibull function. Crown area was de termined conditionally by total rootstock height. The simulator may be used to generate populations for evaluating different sampling methods for hardwood rootstock attributes or in in dividual tree growth and yield models.
A statistical expert system for simulation analysis
Authors: Mellichamp Joseph M. , Park Young H. 
Published: March 2008

Efforts on a number of fronts are being made to enhance the usefulness of simulation as a tool for analysis. Graphical input, animation, automated program generation, model management utilities, and user interactive environments all address the issue of ease of use. Even with the current emphasis in this regard, simulation suffers from several shortcomings which preclude even greater application of the methodology. One of the more signifi cant limitations is the dependence of simulation on statistical methodologies. Practically every phase of simulation analysis in volves one or more statistical issues. And the fact of the matter is that many simulation practitioners have neither the statistical skills nor the access to qualified statisticians to effectively address these crucial issues. The obvious solution to this problem would be to have an ex pert statistician available during every simulation study to answer any questions concerning statistical issues. A more practical alter native is to make available an expert system which could func tion as a statistical advisor to simulation analysts. This option seems ideally suited for expert system techniques since it is well- defined and narrowly bounded and an appropriate body of statistical knowledge exists. The objective of this research was to develop such an expert statistical consultant. The system would be able to advise as well as perform appropriate computations for a variety of statistical issues including input data analysis, design of experiments, and output analysis. An overview of the proposed system is given and illustrations of the capabilities of the system are presented.
A User-Friendly Interactive Turbo Pascal Simulation Toolkit
Authors: Tavernini Lucio 
Published: March 2008

A Turbo Pascal-based simulator specifically designed for continuous-time models with time delays and hysteretic phenomena is presented and its use illustrated with examples. Delays can be time- and state-dependent. For models with hysteretic (multi-valued) behavior, use is made of a recently introduced mathematical paradigm: the differential automaton. For models defined by differ ential or delay-differential equations with jumps in the derivatives, the differential automaton formalism can be bypassed by using a switch function to indicate points of low differentiability in the model. The switch function interacts with the simulator to approximate each point of discontinuity where the numerical integrator is to be reini tialized. This interaction, transparent to the user and implemented via side effects of the switch function, replaces the explicit scheduling of state events by the user. For models with time delays, a global approximation is constructed for each delayed state variable. Each global ap proximation is partitioned into sufficiently smooth seg ments and a smoothness index is associated with the boundary separating any two such segments. Whenever a delay crosses between two adjacent segments, should the value of the smoothness index require it, the time of crossing is approximated iteratively, the numerical integra tor is reinitialized, and a new segment is started in the partition. A new segment is also started whenever a switching takes place. The simulator graphical output interface is self-config uring at execution time with respect to the video display adapter-display combination in use. Interactive plotting programs with on-line documentation are also provided to retrieve, then plot, problem data from save files generated during a simulation.
Law Enforcement Simulation System
Authors: McDonald Craig J. 
Published: March 2008

This article describes a model (known as COPS, COuntywide Police Simulation System) which simulates the receipt of police, fire, and emergency medical calls at a public safety communications center, with subse quent dispatch of law enforcement officers to police events. The delivery of police services involves the processing of an event, or call-for-service, from the moment that the call is received at an emergency communications center through disposition of the call by police officers. This process involves telecom municators, dispatchers, and police officers. From the telecommunicator perspective, it includes the receipt of a request for police service at a public safety communications center, the assignment of the call to an available telecommunicator, the interview of the calling party by the telecommunicator, and the transfer of the event in formation to a police dispatcher. The dispatcher is then responsible for selecting the most appropriate police unit(s) for dispatch. The police officer must travel to the scene, service the complainant, clear from the call, and return to preventive patrol. The model examines the interaction of external variables, including the type of call, the frequency of calls, the number of telecommunicators on duty, the number of police cars in service, the deployment pattern of the officers, the number of cars to be dispatched, and the dispatch plan. By modifying the values that these variables can hold, the distribution of workload among police officers can be observed, response times and service times can be examined, and dispatching policies can be evaluated. Sensitivity analysis can be performed without disrupting the life-critical nature of the live operation.
Verifying and validating complex simulation models by analogy
Authors: Banks Jerry 
Published: March 2008

This paper describes a procedure used to develop verifi cation and validation techniques for very large simulation models. The procedure uses analogies from other systems to stimulate analogies which can then be implemented in the simulation environment. Sixteen systems were studied and some 64 analogies were developed. Several of the analogies are currently being considered for possible extension and application to complex simulation models.
MOSES: Manufacturing Organization Simulation and Evaluation System
Authors: Pruett James M. , Vasudev Vinay K. 
Published: March 2008

The key to the successful "factory of the future" will be the effective coordination of managerial functions and production operations. The simulation model described in this paper addresses this "coordination" issue, especially in terms of managing the impact of interrelated alternatives and activities in an information-rich environment. An evolutionary simulation modeling program, MOSES (Manufacturing Organization Simulation & Evaluation System), has been developed for the purpose of describing, analyzing, and understanding manufacturing organizations. MOSES is both a program and a concept. As a program, it is a menu-driven, interactive, discrete-simulation modeling tool. MOSES users are able to simulate any discrete-product manufacturing environment. As a concept, MOSES is a blend of simulation modeling and information-based management. It is structured around the idea that all manufacturing organization functions can be categorized into one of four areas—marketing, production, inventory, and accounting—and that organizational success depends on decisions made by managers of those areas. MOSES users manage the organization by observing, experimenting with, and modifying the simulation-driven activities. This user interaction may take place before, during, or after the simulation process. MOSES is evolutionary in several ways: (1) the user is able to build a meaningful manufacturing organization simulation model without writing any computer code; (2) the model spans the entire manufacturing organization, not just the production function; (3) the model includes optimization techniques and heuristics along with traditional logical modeling principles; (4) the model' stores and manipulates data using database technology rather than more traditional file techniques ; (5) the system includes the user as an integral part of the simulation process.
A mathematical model to simulate small boat behaviour
Authors: Browning Andrew W. 
Published: March 2008

The use of mathematical models and associated computer simulation is a well established technique for predicting the behaviour of large marine vessels. For a variety of raisons, mainly related to effects of scale, existing models are unable to ad equately predict the manoeuvring character istics of smaller vessels. The accuracy with which the performance of a boat under autopilot control can be predicted also leaves much to be desired. The paper presents a mathematical model to simulate small boat behaviour and so can assist with the design and testing of boat autopilots. The boat model is presented in six degrees- of-freedom, which, with suitable wave disturbance terms, allows motions such as broaching to be analysed. Instabilities in the performance of an autopilot arising from such sea-induced yaw motions can be assessed with a view to improving the control algorithms and methodology. The research rectifies the glaring omission of a small boat mathematical model, the framework of which could be expanded to encompass other marine vehicles. Initial results are promising and show good agreement with real data.
Real-time simulation of air traffic control radar terminal with trainer interface
Authors: Kornecki A. , Cieplak J. , Schneider A. 
Published: March 2008

The Airway Science Simulation Labora tory (ASSL) was established in 1987 at. Embry Riddle Aeronautical University. The objective of this laboratory is to further develop and promote aviation education. One project that has emerged from this laboratory is the described below Air Traffic Control Simulation System (ATCSS). The ATCSS is designed to facilitate an environ ment in which students participate and interact as both pilots and air traffic controllers. This interaction simulates the real-time teamwork between pilots and air traffic controllers. The purpose of this paper is to describe the simulation design concept, its components, and its potential for a variety of aviation uses. This description will include: the methods of interfacing, software and hardware requirements, feasibility of operating in multitasking environment, parallel processing, and ATC requirements with respect to oriented-towards-human- factors aviation training.
Study of modeling and simulation for a chemical production system
Authors: Habchi Georges , Deloule Françoise 
Published: March 2008

The purpose of this paper is to demonstrate the advantages that may be obtained through the use of simulatian tools in the design of a production workshop and more specifically, in validating a structure for production and a logic for control in the field of chemical processes. Such simulation concerns a type of production which is totally different from manufacturing type, as the former are continuous processes that can be rendered discrete. After a rapid presentation of the various theoretical approaches to modeling and simulation tools that may be used in this field, we will describe the system to be designed and its characteristics. Then we will go on to the approach to modeling we have retained and the simulation carried out in order to study the system dynamically. Finally, we will present the results we reached and we will draw some conclusions on the advantages and the limits of the study made. This study, which aims at designing and evaluating the performances of a production unit in an international class plant specializ ing in the production of liquid chemical products, was carried out with the help of the SIMAN-CINEMA (3.5) simulation generator and decision assistance tool widely used in the design and set up of manufacturing type production systems.
The simulation of decentralized control: a hostless resource allocation model
Authors: Gagliano Ross A. , Fraser Martin D. , Schaefer Mark E. 
Published: March 2008

In this article, an alternative approach to control for computing systems, with possible distributed, parallel, or multilprocess application, is proposed and evaluated through simulation. Functions normally handled by centralized controllers, schedulers, arbiters and priority schemes are accomplished through a decentral ized model of control. Resource allocation, one important control function, is resolved within a Challenge Ring (CR) in which individual computing tasks independently (or without a host, hence their interaction is called hostless) exercise algorithms to gain access to computing resources. Simulated system performance is monitored by analyzing individual task processing times, total system times, resource availability, resource utilization, and system efficiency. Our preliminary experimental results indicate that such decentralized (or hostless) models can be superior to some standard centralized (or hosted) versions. Moreover, tasks in CR networks that interact through cooperative strategies in some cases exhibit better performance. Our overall results encourage the further exploration of decentralized control models which could be useful in the continuing pursuit of alternative machine constructs (e.g. non-von Neumann architectures) and new distributed operational schemes (e.g. hostless network operating systems).
Simulation Modelling to Assist Operational Management and Planning in Clinical Laboratories
Authors: Bodtker Karin , Wilson Lynda , Godolphin William 
Published: March 2008

Clinical laboratories must balance staff and equipment utilization with specimen through put and turnaround time while reducing errors, costs and employee health hazards. Simulation can help to anticipate the effect of new technol ogy, alternative operating procedures and lab capacity changes. GPSS/H-386 was used to simulate the analyzer area of a hospital clinical chemistry lab and the time-consuming pre-analytic processes of both a large hospital lab and a commercial laboratory outpatient facility. The processes modelled were the arrival of patients and receipt of specimens into the lab, data entry, blood-drawing, centrifugation and aliquotting. Thegreatest challenge was accurate modelling of a system driven by human decision making with flexible task priorities. Experiments in the outpatient facility indicated that staff resources could be pooled instead of having specific job assignments without a significant effect on performance measures, and that an amalgamation of two outpatient labs could reduce staffing. These conclusions were not intuitively obvious to the lab managers.
A new method for modeling large flexible structures
Authors: Fritchman B.M. , Hammond R.A. 
Published: March 2008

The emergence of electronic flight-control systems into commercial aircraft designs has precipitated an immediate need for nonlinear, discrete-time analyses in both frequency and time-domains, for both the aircraft Structural Dynamic Loads and the Flight Controls communities. This paper presents and demonstrates a methodology by which the large-scale, linear aircraft structural models produced by the Structural Dynamic Loads community can be easily reformulated using EASY5x*. EASY5x then provides an environment for incorporating nonlinearities and discretization; and moreover, it provides an intuitive and tractable environment for engineers who are not well versed in linear analysis techniques to manipulate and analyze both the plant and its interactions with a nonlinear, discrete-time control system. The paper then goes on to present a method for transforming the large- scale linear plant into the z-domain using EASY5x. The resulting state-transition matrices propagate the exact solution to structural model equations of motion so simulation accuracy is greatly increased while run-time for statistically significant simulated time intervals is dramatically reduced. Furthermore, the analysis is brought into the efficient, graphically driven environment of the engineering workstation.
Characteristics and the Role of the Place Graphics System in Simulation of a Flexible Manufacturing System
Authors: Kamisetty Krishnaprasad V. , McDermott Kevin J. 
Published: March 2008

The purpose of this paper is to present the advantages of using computer simulation for designing an FMS workcell. Simulation of the FMS at New Jersey Institute of Technology (NJIT) has demonstrated that it is easier to achieve effective coordination among the various components of the FMS by first simulating the FMS workcell. In addition, simulation of the FMS at NJIT has consistently increased the success of the design providing insights into the workcell at various stages of the process. McAuto's PLACE [1] software has been used to simulate the NJIT FMS. Simulation helps in the design of the FMS cell by leading the user to the most appropriate workable solution to various cell design problems such as collision, exceeding joint reach etc., by utilizing detailed and graphical workcell layouts and the cell performance data. In addition, design changes can be made using the simulation software while the production of parts is taking place on the FMS cell. Other commercial FMS and robot simulation tools are described in this paper while comparing and contrasting them with the PLACE system.
Dynamic Terrain
Authors: Moshell J. Michael , Blau Brian , Li Xin , Lisle Curtis 
Published: March 2008

While many are familiar with flight simulators, there is also a growing body of ground-based simulation training systems. The Army/DARPA sponsored SIMNET project (Nelms 1988) involved over 200 armor and aircraft simulators in a complex network, designed to teach combined arms combat skills. The follow-on Close Combat Tactical Trainer (CCTT) project will be the largest training simulator acquisition in history. In addition, realtime interactive simula tion is moving beyond military training into the potentially much larger market of commercial, entertainment and educational applications currently being called "Virtual Reality" (Furness 1988). However, no existing realtime simulation supports a truly interactive world. In particular, the terrain (soil, water and vegetation) is nearly or completely immutable in today's simula tors. In a word, the terrain is not dynamic. This Project explores the hypothesis that it is economically feasible to construct networked realtime simulators which incorporate useful simulations of dynamic terrain phenomena. The authors have evaticated the computational requirements of realtime graphical dynamic terrain simula tion with both theoretical models and prototypes, and conclude that useful levels of terrain dynamics can be incorporated in the next generation of low-cost, high-volume training simulators and virtual environ ments.
Strategies for Implementing a Promotores-Led Diabetes Self-management Program Into a Clinic Structure
Authors: Sixta Constance S. , Ostwald Sharon 
Published: March 2008

Purpose The purpose of this article is to describe a process for integrating promotores who teach diabetes self-management into a community clinic structure. Methods The Donbedian structure, process, and outcome method- ology was used to integrate promotores into a community clinic. Results The model described here resulted in (1) employment of promotores (community health workers) to teach diabetes self-management courses, (2) integration of provider and nurse oversight of course design and implementation, (3) management of promotora training and the development of teaching competencies and skills, (4) coordination of care through communication and documentation policies and procedures, (5) use of quality control mechanisms to maintain patient safety, and (6) promotion of a culturally competent approach to the educational process. Conclusions The model presented here provides a systematic approach to safely address the educational needs of large numbers of patients with type 2 diabetes who live in communities that suffer from a lack of health care professionals.
Opioid withdrawal syndrome on switching from hydromorphone to alfentanil
Authors: McMunnigall F , Welsh J 
Published: March 2008

Opioid switching is increasingly practiced. This patient did not tolerate morphine, oxycodone or hydromorphone due to opioid toxicity. Finally switch to alfentanil was performed. The patient developed classical opioid withdrawal symptoms and signs from discontinuation of the hydromorphone. Administration of small aliqouts of this drug reversed the symptoms. The existance of incomplete cross tolerance between hydromorphone and alfentanil is demonstrated.