• Journal of information and communication convergence engineering
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• 제1권4호
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• pp.169-173
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• 2003

The performance of modern mainframe computers keeps increasing due to the advances in the semiconductor technology. However, the quest for the faster computer has never been satisfied. To overcome the discrepancy in the supply and demand, we studied a high performance computer architecture utilizing a three-dimensional Holographic Data Storage Systems (HDSS) as a secondary storage system. The HDSS can achieve a high storage density by utilizing the third dimension. Furthermore, the HDSS can exploit the parallelism by processing the two-dimensional data in a single step. To compare the performance of the HDSS with the conventional hard disk based storage system, we modeled the HDSS using the DiskSim simulation engine and performed the simulation study. Results showed that the HDSS can improve the access time by 1.7 times.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.616-617
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• 2015

Demand is increasing for large, high-rise, and complex buildings, which is leading to advances in the development of high-performance structural systems. In this context, precast concrete (PC) technology has received a large amount of attention owing to its benefits in terms of schedule reduction, high quality, and easy installation. In addition, advanced methodologies that improve the PC performance by the addition of various materials have recently been reported. Research on analyzing the effects of such high-performance PC on the construction process and productivity is very limited. This makes it difficult for decision-makers to apply PC to particular projects. Thus, the aim of this research was to analyze the work productivity of the high-performance PC slab installation process by using a construction simulation tool to resolve critical issues. In this study, a real construction project that adopted PC slab installation work was analyzed, and a sensitivity analysis was performed to confirm the reliability of the analysis results.

• Structural Engineering and Mechanics
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• 제85권2호
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• pp.265-274
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• 2023

The spherical steel bearings (SSBs) has been gradually replaced traditional rubber bearings and extensively applied to high-speed railway (HSR) bridges in China, due to their durability and serviceability. Nevertheless, SSB is generally simplified to the ordinary constraints in the finite element model, which cannot reflect its detailed mechanical characteristics, especially its seismic performance. To provide a more precisely simulation, an innovative and simplified finite element simulation method is proposed and the combined element group is developed in ANSYS. The primary parameters were determined by means of the performance test of SSB. The finite element model of SSB applied to a single-span HSR simply supported girder bridge was established through the proposed method. The seismic performance of the SSB was further investigated. A shake table test was conducted to evaluate the accuracy of the proposed simulation method. It is found that the numerical results could have a good agreement with the experiment, namely, the proposed method is feasible and efficient.

• 한국군사과학기술학회지
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• 제9권3호
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• pp.25-32
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• 2006

Weapon systems composed of several subsystems execute various engagement missions in distributed combat environments in cooperation with a large number of subordinate/adjacent weapon systems as well as higher echelons through tactical data links. Such distributed weapon systems require distributed real-time simulation test beds to integrate and test their operational software, analyze their performance and effects of cooperated engagement, and validate their requirement specifications. These demands present significant challenges in terms of real-time constraints, time synchronization, complexity and development cost of an engagement simulation test bed, thus necessitate the use of high-performance distributed real-time simulation architectures, and modeling and simulation techniques. In this paper, in order to meet these demands, we presented a distributed real-time simulation system based on High Level Architecture(HLA) and Discrete Event System Specification(DEVS). We validated its performance by using it as a test bed for developing the Engagement Control System(ECS) of a surface-to-air missile system. The proposed technique can be employed to design a prototype or model of engagement-level distributed real-time simulation systems.

• 대한기계학회논문집A
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• 제24권1호
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• pp.134-143
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• 2000

A train performance simulation (TPS) software is a computer program that simulates the operation of a train system over a specified railway route and it is widely used in railroad operation and research applications. Numerical and graphical results from the simulation software, which is developed in this study, provide information on such performance variables as travel time. running speed, energy consumption at a specific time interval and in overall service time as the train moves along the route. Three types of input data are required for a computer simulation: track information, train information, and running conditions. The simulation of train performance starts with several simple mathematical models including train configuration. traction efforts, running resistance. and braking requirements. Based on the basic specifications of Korean High Speed Railway, System. this study, puts a focus on the estimation and assessment of train performance comparing. the specific train configurations of KEST20/11. CPLE20/10. PROP20/10, which are proposed from the previous G7 projects.

• Child Health Nursing Research
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• 제25권4호
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• pp.496-506
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• 2019

Purpose: The purpose of this study was to examine the effects of a virtual reality simulation and a blended simulation on nursing care for children with asthma through an evaluation of critical thinking, problem-solving processes, and clinical performance in both education groups before and after the educational intervention. Methods: The participants were 48 nursing students. The experimental group (n=22) received a blended simulation, combining a virtual reality simulation and a high-fidelity simulation, while the control group (n=26) received only a virtual reality simulation. Data were collected from February 25 to 28, 2019 and analyzed using SPSS version 25 for Windows. Results: The pretest and posttest results of each group showed statistically significant improvements in critical thinking, problem-solving processes, and clinical performance. In a comparison of the results of the two education groups, the only statistically significant difference was found for critical thinking. Conclusion: Simulation-based education in child nursing has continued to involve high-fidelity simulations that are currently run in many programs. However, incorporating a new type of blended simulation, combining a virtual reality simulation and a high-fidelity simulation, into the nursing curriculum may contribute to the further development of nursing education.

• 한국군사과학기술학회지
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• 제7권2호
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• pp.13-21
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• 2004

GPS is widely used in various applications since GPS receivers are capable of measuring precise position and velocity in any weather condition for a relatively low cost. However, GPS requires more than four simultaneously visible GPS satellites for optimal performance. In high-motion, high-attitude-changing applications, there exist some situations where less than four satellites are visible or where the dilution of precision (DOP) is high. In this paper, we propose a simulation algorithm that predicts the performance of GPS navigation according to changes in vehicle attitude. We have compared simulation results with experimental results, where simulation results of the proposed algorithm are shown to closely match actual experimental data. This algorithm could be used to predict GPS navigational performance and to determine optimal GPS antenna position.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.275-277
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• 2003

Computer aided simulation is becoming an essential part in planning, design, and operation of railway systems. To determine the adequate performance and specification of railway system, it is necessary to calculate rolling stock's performance such as distance, speed, power etc when train's running. This paper presents result of train performance simulation using the program that developed in advance for Korea high speed train. To verify result of simulation, we have compared that with experiment data.

• 대한기계학회논문집
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• 제19권1호
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• pp.231-239
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• 1995

This paper describes a computer simulation of the triple effect, water-lithium bromide absorption cooling cycles. The performance of the absorption systems is investigated through cycle simulation to obtain the system characteristics with the cooling water inlet temperature, the working solution concentrations, the ratio of the amount of the weak solution to the high, middle and low temperature generators, and the temperature difference of each solution heat exchanger. The efficiency of different cycles has been studied and the simulation results show that higher coefficient of performance could be obtained for the parallel cycle of constant solution distribution rate. As a result of this analysis, the optimum designs and operating conditions were determined based on the operating conditions and coefficient of performance.

• 한국시뮬레이션학회논문지
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• 제12권2호
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• pp.45-53
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• 2003

This paper presents a retargetable compiled assembly simulation technique for fast ASIP(application specific instruction processor) simulation. Development of ASIP which satisfies design requirements in various fields of applications such as telecommunication, wireless network, etc. needs formal design methodology and high-performance relevant software environments such as compiler and simulator In this paper, we employ the architecture description language(ADL) named ${HiXR}^2$ to automatically synthesize an instruction-level compiled assembly simulator. A compiled simulation has benefit of time efficiency to interpretive one because it performs instruction fetching and decoding at compile time. Especially, in case of assembly simulation, instruction decoding is usually a time-consuming job(string operation), so the compiled simulation of assembly simulation is more efficient than that of binary simulation. Performance improvement of the compiled assembly simulation based on ${HiXR}^2$ is exemplified with an ARM9 architecture and a CalmRISC32 architecture. As a result, the compiled simulation is about 150 times faster than interpretive one.