Simulation analysis may be the essential means to either evaluate performance of systems or optimize system parameters for new design. Including many variations for design and implementation, MANET (Mobile Ad-hoc NETwork) is one target area of such an analysis. Since every node, however, included in the network has mobility, one MANET could be overlapped or merged with another one which use a different transport protocol. In order to communicate among nodes in this case, the new merged network should configure paths and addresses in advance. Configuring paths and addresses generates much overheads which ultimately cause delay in communicating data. Performance analysis is required to improve the data transport performance by minimizing overheads. This paper proposes a sound address auto-configuration method which is based on an on-demand manner and then presents modeling and performance analysis of the method. NS-2 simulation results verify that the proposed method can not only alleviate overheads, which are inevitably generated for address auto-configuration processes, and but also decentralize them in time.

In this paper, we propose an ambient light control method based on the difference of image frames in video. The proposed method is composed of three steps. 1) The first step is to extract a dominant color of a current frame. 2) The second step is to compute the amount of change and the representative color in the changed region using the difference image. 3) The third step is to make a new representative color. The difference image is created from two images transformed into the YUV color space. The summed color difference of each pixel is used for the amount of change. The new representative color is created by synthesizing the current color and the changed color in proportion to the amount of change. We compare the variations of the light effect according to time with and without the proposed method for the same video. The result shows that the new method generates more dynamic light effects.

It is necessary for the ship dynamic models to realize ship dynamics and to achieve the real-time analysis in the manoeuvring simulation. Generally, simple dynamic models, such as 1st-order differential equation models of turning angle, turning rate, and forward speed, are used in the manoeuvring simulation for multiple ships. Ship dynamic modeling and parameter estimation methods based on its turning test results are proposed in this paper. Parameter estimation methods for the constant speed model and the speed-changing model are mathematically developed and verified by comparing with turning test results of a real ship.

War-games using C4I systems have been used to improve the command ability of commanders and the fighting power of combat forces. During a war-game simulation, a commander makes a plan for the movement of a combat force and issues orders to the combat force according to the plan. If it is possible to minimize damages from the artillery of enemy forces and take the advantage position where is effective for attack/defense, we can hold a dominant position of the battlefield. Therefore, this papers proposes a genetic algorithm-based optimal path searching method. The proposed method creates an optimal path of a combat force by taking into consideration dangerous conditions of the battlefield in which the combat force is. This paper also shows the process of creating an optimal path by using a discrete event specification modeling and simulation method.

In field, one can observe without difficulties that two flocks are intersected or combined with each other. For example, a fish flock in a stream separates into two part by obstacles (e.g. stone) and rejoins behind the obstacles. The dynamics of two flocks guided by their leader were studied in the situation where the flocks cross each other with a crossing angle, , between their moving directions. Each leader is unaffected by its flock members whereas each member is influenced by its leader and other members. To understand the dynamics, I investigated the order parameter, , defined by the absolute value of the average unit velocity of the flocks' members. When the two flocks were encountered, the first peak in was appeared due to the breaking of the flocks' momentum balance. When the flocks began to separate, the second peak in was observed. Subsequently, erratic peaks were emerged by some individuals that were delayed to rejoin their flock. The amplitude of the two peaks, (first) and (second), were measured. Interestingly, they exhibited a synchronized behavior for different . This simulation model can be a useful tool to explore animal behavior and to develop multi-agent robot systems.

The inherent complexity of semiconductor fabrication processes makes it hard to solve well-known job scheduling problems in analytical ways, which leads us to rely practically on discrete event modeling simulations to learn the effects of changing the system's parameters. Meanwhile, unpredictable disturbances such as machine failures and maintenance diminish the productivity of semiconductor manufacturing processes with fixed scheduling policies; thus, it is necessary to adapt job scheduling policy in a timely manner in reaction to critical environmental changes (disturbances) in order for the fabrication process to perform optimally. This paper proposes an adaptive job control framework for a wafer fabrication process in a control system theoretical approach and implements it based on a DEVS modeling simulation environment. The proposed framework has the advantages in view of the whole systems understanding and flexibility of applying new rules compared to most ad-hoc software approaches in this field. Furthermore, it is flexible enough to incorporate new job scheduling rules into the existing rule set. Experimental results show that this control framework with adaptive rescheduling outperforms fixed job scheduling algorithms.

This paper studies the problem seeking an efficient operational scheduling for battle ships in the Republic of Korea's navy. The ships' availability means that their main systems such as weapons, navigation and propulsion are in full operational readiness. If some of the major systems are not ready, then the ships should not be available for operations. It is required to maintain a high level availability under the limited resources as it determines the strength of ROK's navy. However, it will result in inefficiencies if some ships are operated without proper maintenance only to improve their availability. Thus, this study suggests the operational scheduling for two squadron ships that considers multiple objectives such as availability, overlapping maintenance, and deviation from available ships in a particular week. We applied NSGA-II algorithm to find better solutions for more efficient scheduling. The experiment result reached an efficient solutions after 1,500 generations. Two efficient operational schedules were compared on the basis of three multiple objectives among them.

The purpose of this paper is to propose a methodology that can measure the combat effectiveness of attack helicopter which Korea army will be operating in the near future. To measure the combat effectiveness, firstly, we use a wargame model, AAsim (Army Aviation simulation), as a analytic simulation model which is used to analyze DOTMLPF and operation in army aviation field, secondly we use an Analytic Hierarchy Process by opinion of experts. For simulation and AHP, we consider anti armored corps operation reflecting attack helicopter's combat effectiveness. As a result of this study, the combat effectiveness per each attack helicopter can be measured and this combat effectiveness is useful for reasonable decision making such as selection helicopter type, quantity when acquiring new weapon system.

The simulator models for 500MW fossil power plant have been developed, and interconnected with the turbine control system to test and validate the digital instrumentation & control (I&C) systems before they are implemented in operating power plants. When the performance of a selected digital I&C system is tested, the corresponding simulator model is replaced by the plant digital I&C systems which is considered as a non-tunable system. The input/out variables of simulator models and control systems were mapped using the LabView in interface systems. This paper describes the interconnection method between the simulator model and the digital I&C system, and summarizes the validation test results performed at the condition of steady-state operation, normal evolution, and malfunction. The integrated validation method of digital I&C systems using the simulator models showed that the simulator can be used as a test bed for the implementation of digital I&C systems in power plants.

Recent modeling and simulation technology is being used in various fields. Especially in the field of military, Simulation-Based Acquisition (SBA) is recognized as a essential policy. To effectively carry out SBA, modeling and simulation techniques should be applied in the whole life-cycle for the weapon system development, and simulation architecture framework which provides easily reusable and interoperability is needed. Through reusability and interoperability, the costs of constructing the integrated collaborate environment for simulation based acquisition can be minimized. In this study, we define requirements, issues for enhancing reusability and interoperability, and propose simulation framework as a solution of the problem including structural design. Proposing simulation framework provides common functions for producing simulator as reusable units and easily changeable structure on user's purpose. In addition, we provide the result for applying simulation framework to our project.

This paper is on the research result for analyzing the performance of GLORY(GLobal Resource management sYstem) used for Web Server Cluster system, which was developed at ETRI(Electronic and Telecommunication Research Institute). The paper includes the definition of Web Server Cluster System, the characteristics of the system, user oriented system performance, current performance enhancement methods, computer simulation model for GLORY and its experimental results for the performance of GLORY. GLORY is composed of 2048~1,000,000 units of PCs, and is used for Internet servers. From the results of the simulation experiments, we notice that GLORY has enough capacity to fully serve the appropriate level of Internet services. Also, the results show that Web server service time is longer than that for network transmission time but requires more DNS than expected, and that 100Mbps LAN is good enough for directly connecting Internet to the Web servers while not affecting the total system performance.

The main contents of this paper is to develope effective measures for Internet Web service attack, classifying vulnerability of Web Service by network layer and host unit and researching classification method by attack range of type of services. Using this paper, we can accumulate analyzed Web service attack information which is key information of promote Web security strengthening business, and basis of relevant security research for detect and response Web site attack which can contribute to activation information security industry.

In this study, we consider stationary waiting times in a simple fork-and-join type queue which consists of three single-server machines, Machine 1, Machine 2, and Assembly Machine. We assume that the queue has a renewal arrival process and that independent service times at each node are either deterministic or non-overlapping. We also assume that the Machines 1 and 2 have an infinite buffer capacity whereas the Assembly Machine has two finite buffers, one for each machine. Services at each machine are given by FIFO service discipline and a communication blocking policy. We derive the explicit expressions for stationary waiting times at all nodes as a function of finite buffer capacities by using (max,+)-algebra. Various characteristics of stationary waiting times such as mean, higher moments, and tail probability can be computed from these expressions.

The moving block bootstrap, the stationary bootstrap, and the threshold bootstrap are methods of simulation output analysis, which are applicable to autocorrelated data. These bootstrap methods assume the stationarity of data. However, bootstrap methods cannot work if the stationary assumption is not guaranteed because of seasonality or trends in data. In the simulation output analysis, threshold bootstrap method is the best in describing the autocorrelation structure of original data set. The threshold bootstrap makes the cycle based on threshold value. If we apply the bootstrap to seasonality data, we can get similar accuracy of the results. In this paper, we verify the possibility of applying the bootstrap to seasonal data.

Modern marine navigation requires officers on the bridge to monitor a torrent of data on both the insides and outsides of the ship from numerous useful devices. But despite these tools, navigators can still find it difficult to make a safe decision for two reasons: one is that too much data if provided too quickly tends to cause fatigue and overwhelm the officer, and the other is that any inconsistency across data from several different types of devices can lead to confusion. Indeed, the fact remains that the many marine accidents can be attributed to human error, and hence there is a strong need for decision-support tools for marine navigation. One technique of providing decision support is through the use of simulation to evaluate or predict system dynamics over time using an accurate model. This paper, as a simulation method for risk prediction for a navigation safety information system of ship, suggests a navigation prediction simulation system using various knowledge bases and discrete event simulation methodology, and supports the validity of the system through the examples of components in a restricted navigation situation scenario.