• KIISE Transactions on Computing Practices
• /
• v.22 no.2
• /
• pp.113-118
• /
• 2016

The walking speed of handicapped people generally is slower than that of normal people. So it is difficult for them to cross at crosswalks within the allotted time provided by the traffic light. This problem can be solved by expanding the time of the traffic light. However, if the latency of the traffic light is increased without distinguishing the handicapped among all other pedestrians, the efficiency of traffic signal lights will decrease. In this paper, we propose a smart traffic signal connecting mechanism between the previous pedestrian traffic signal and a pedestrian's device (smartphone). This Smart pedestrian traffic light, through this mechanism, minimizes traffic congestion by providing additional walking time only to the handicapped among pedestrians. This crosswalk traffic light recognizes the handicapped using a technique called Internet of things (IOT). In this paper, we extract the data necessary to build an effective smart crosswalk traffic light mechanism through simulation techniques. We have extracted different kinds of traffic signal times with our virtual simulation environment to verify the efficiency of the smart crosswalk pedestrian traffic light system. This approach can validate the effective delay time of the traffic signal time through a comparison based on number of pedestrians.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.2
• /
• pp.62-69
• /
• 2016

This paper proposes to select Measure of Performance(MOP) for object attainment in the counterfire operation and deduce the reasonable combination of blue force's hitting resources satisfying MOP's optimal value and regression equation for the object achievement time. Also, in the study-methodological perspective, a series of procedures for drawing the regression equation from the real world is presented. Firstly the model was made by simplifying the weapon-system information of red force and blue force, then the time for object attainment was derived from its simulation. Simulating the model for the counterfire operation was divided into three phases-detection, decision and hitting. The probability method by applying the random numbers were used for detection, fixed constant numbers for decision and hitting. The simulation was repeatedly performed to get the minimum time for the object attainment against the fixed enemy, and it was estimated as the optimal value of simulation. From this result, the optimum combination of blue force's weapon system against the red force and finally, the regression equation were obtained by using the response surface analyzing method in MINITAB. Thereafter this equation was completely verified by using 'the 2-sample t-test.' As a result, the regression equation is suitable.

• Journal of the Korea Society for Simulation
• /
• v.24 no.3
• /
• pp.17-26
• /
• 2015

A cluster tool used in many kinds of semiconductor processes for improving the performance and the quality of wafers has a simple configuration, but its schedule is not easy because of its parallel processing module, a lack of intermediate buffers, and time constraints. While there have been many studies on its schedule, most of them have focused on full cycles in which identical work cycles are repeated under constant task times. In this research, we suggest strategies of start-up transient scheduling which satisfies time constraints and converges into a desirable steady schedule for full work cycle. The proposed schedules are expected robust under the stationary stochastic task times. Finally, we show that the strategies make schedules enters the desirable steady schedule and robust using the simulation.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.23 no.7
• /
• pp.791-800
• /
• 2017

For fires in ship accommodation areas, if it is possible to predict the pattern in which fire will spread and suggest proper countermeasures according to a situation using a fire simulation tool, fire damage may be reduced. However, fire simulations have a practical limit: a significant amount of time is required to analyze the results due to the size of the computational domain and the number of grids. Therefore, in this study, applicable grid size for fire simulations to predict fire patterns in ship accommodation areas was analyzed, and a generation method was conducted to predict fire behavior in real time. As a result, a value within 0.25[m] was judged appropriate as an applicable grid size for ship accommodation areas. Also, in comparison with studies using a single mesh generation method, the visibility value was similar, within 4.3 %, as was the temperature value, within 8.3 %, when a multi mesh generation method was used, showing a decline of 80 % in analysis time. Therefore, it was confirmed that composing a grid using multi mesh was effective for reducing analysis time.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2013.01a
• /
• pp.3-6
• /
• 2013

반도체 공정에서 소자의 제조 비용 감소를 위해 제조 공정 검증을 위한 시뮬레이션을 수행하게 된다. 이 시뮬레이션은 반도체 소자 내부의 물리량 계산을 통해 반도체 소자 내부의 불순물의 거동을 해석하게 된다. 이를 위해 사용되는 알고리즘으로 3차원적 형상을 표현하는 물리적 미분 미분방정식을 계산하게 되는데, 정확한 계산을 위해 유한 차분 시간 영역법(이하 FDTD)과 같은 수치해석 기법을 이용한다. 실제적으로 반도체 공정의 시뮬레이션에서 FDTD연산의 실행 시간은 90% 이상을 소요하게 된다. 이러한 연산에서 더욱 빠른 성능을 확보하기 위해 본 논문에서는 기존의 CUDA(Compute Unified Device Architecture)로 구현된 FDTD알고리즘을 OpenMP를 통한 다중 GPU제어를 이용하여 연산 수행시간을 감소하고, 그 결과물을 통하여 성능 향상도를 측정한다.

• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2015.11a
• /
• pp.70-71
• /
• 2015

2011년3월에 발생한 동일본대지진에서는 일부지역에서 대규모 쓰나미 경보 사이렌의 고장 및 긴급시 사용하는 방조제 개폐장치의 고장 등, 상상외의 여러가지 일들이 발생하면서 그 피해가 더 커졌다. 이러한 사태를 바탕으로 대규모 지역에서의 피난 계획 및 시뮬레이션의 필요성이 최근에 대두되고 있다. 본 연구에서는 이러한 광역 피난계획을 풀기 위한 동적 네트워크 흐름 문제(dynamic network flow problem)를 적용한 방법론을 소개하고, 동적 네트워크 흐름 문제를 풀기 위한 일반적인 방법론 중 시간 확대 네트워크 문제 및 시간 확대 네트워크의 문제점인 계산시간을 해결하기 위한 고속연산 휴리스틱 알고리즘을 제시하고자 한다.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1848-1849
• /
• 2007

배전계통과 설비의 부하분석은 계측장치에 의존하여 왔으며, 대규모인 배전설비의 부하감시는 막대한 설치 및 유지보수 비용이 수반된다. 본 논문에서는 계측장치를 설치하지 않고도 정기적으로 취득되는 고객의 검침데이터를 이용하여 배전설비의 시간대별 부하분석 및 시뮬레이션을 수행할 수 있는 모델을 개발하고, 그 과정 및 결과를 제시한다. 이 모델은 고압고객의 원격검침 및 저압고객의 월검침 데이터를 구간계통에 적용하고 조류계산을 수행하여 15분 단위로 회선이하 구간 및 변압기의 부하를 분석할 수 있다. 또한, 특정 시점의 부하를 증감시키거나 다른 설비로 전환하여 시간대별 부하가 어떻게 변화하는지 시뮬레이션을 수행할 수 있다.

• Tunnel and Underground Space
• /
• v.24 no.6
• /
• pp.430-439
• /
• 2014

This study developed a simulation program for truck-loader haulage systems in an underground mine. A limestone underground mine in Korea was selected as a study area and investigated to design the simulation algorithm for truck-loader haulage systems. GPSS/H simulation language was utilized to develop the simulation program. Simulations were conducted to analyze the optimal number of haulage trucks dispatched in the 540 ML loading point by using the developed program. The simulation results showed that 8 trucks can maximize the daily production (2,076 ton). The real production (1,850 ton/day) of limestone ores was very similar to the simulated one (1,850.35 ton/day) when considers 7 trucks dispatched in the 540 ML loading point. In addition, average waiting time at loader were similar (waiting time by time study : 1.39 min, simulated waiting time : 1.35 min).

• Journal of KIISE:Computing Practices and Letters
• /
• v.13 no.6
• /
• pp.358-370
• /
• 2007

Software simulations have been widely used for the design and application development of a wireless sensor network that is an infrastructure of ubiquitous computing. In this study, we develop a sensor network simulator that can verify the behavior of sensor network applications, estimate execution time and power consumption, and simulate a large-scale sensor network. To implement the simulator, we use an instruction-level parallel discrete-event simulation method. Instruction-level simulation uses executable images loaded into a real sensor board as workload, such that it results in the high degree of details. Parallel simulation makes simulation of a large-scale sensor network possible by distributing workload into multiple computers. The simulator can predict the amount of power consumption based on operating time of modules in a sensor node and counting the number of executed instructions by kind. Also it can simulate ubiquitous applications with various scenarios and debug programs. Instruction traces used as workload for simulations are executable images produced by the cross-compiler for ATmega128L microcontroller.

• Journal of the Korea Society for Simulation
• /
• v.20 no.3
• /
• pp.41-48
• /
• 2011

Wireless communication technology developed, portable wireless devices based on wireless network including the smartphone rapidly developed, and products with functions similar to highly efficient computer are being launched. Therefore, active studies to enable performance of works, which were previously held in computers, on portable wireless terminal are being held. Until now, simulation was undertaken using computers which satisfy high performance computing resource. Such contains a problem that it cannot break away the limit of space. Portable wireless terminal has the merit that it can break away from the limit of space by using wireless network in comparison to wired environment. In this paper, it suggests a simulator based on wireless devices for distributed simulation. For such purpose, the performance time of simulation will be compared in regards to the case of performing nodes control simulation in a single highly efficient computer and the case of performing distributed simulation in many wired and wireless network environments. Through the comparison, the possibility for utility of portable wireless terminal as the object of distributed simulation will be verified, and it will be presented that simulation can be performed in a shorter time by performing distributed simulation under various wired and wireless network environments away from the limit of space.