• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.24 no.5
• /
• pp.541-547
• /
• 2015

In this study, the performance of a low-floor midsize bus under development is predicted through simulations. To predict the vehicle's acceleration, maximum speed, and uphill driving performance, a forward simulator which calculates the vehicle power is developed. Also we verify the forward simulator by comparing simulations and test result for benchmarking vehicle. To predict the fuel consumption, we use a backward simulator for a specified road cycle. However, to predict the fuel consumption using the backward simulation the engine fuel-consumption map is needed. The engine fuel-consumption map extracting data from a similar sized diesel engine is used by re-scaling the maximum torque. As a result, we simulate the vehicle's forward performance with a new engine. Further, we simulated the backward performance to optimize the fuel efficiency and gearshift timing.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.24 no.5
• /
• pp.576-582
• /
• 2015

Generally, the fuel economy of hybrid electric vehicle (HEV) is effected by the size of each component. In this study the fuel economy for HEV of our own making is evaluated using backward simulator, where dynamic programming is applied. In a competition, the vehicle is running through the road course that includes many speed bumps and steep grade. Therefore, the new driving cycle including road grade is developed for the simulation. The backward simulator is also developed through modeling each component. A performance map of engine and motor for component sizing is made from the existing engine map and motor map adapted to the HEV of our own making. For optimal component sizing, the feasible region is defined by restricting the power range of power sources. Optimal component size for best fuel economy is obtained within the feasible region through the backward simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.497-500
• /
• 1995

In this paper, a program for real time simulation of a vehicle is developed. The program uses relative coordinates and BEF(Backward Difference Formula) numerical integration method. Numerical tests showed that the proposed implicit method is more stable in carring out the numerical integration for vehicl dynamics than the explicit method. Hardware requirements for real time simulation are suggested. Algorithms of parallel processing is developed with DSP (digital signal processor).

• Proceedings of the KIEE Conference
• /
• 2006.04a
• /
• pp.252-254
• /
• 2006

The recent improvement in the performance of digital processor, the application of control technology, which used in the HVDC(High Voltage Direct Current) system with the digital processors, has increased. Having this research development as the basis, this paper presents an achievement of progression by tuning the parameter of PI controller based on Genetic Algorithms(GAs) and by controlling with PI controller with a developed simulator by applying the Matrix operating function, voltage source switching element, modified nodal analysis which can include transformer and the backward Euler which does not create the problem of numerical oscillation. As a result, I expect this development in the simulator HVDC System to bring more application in the field of control technology research with an expanded practicality.

• Journal of Korea Society of Industrial Information Systems
• /
• v.5 no.3
• /
• pp.117-124
• /
• 2000

A systolic array is a parallel processing system which consists of processing elements of basic computation capabilities, connected with regular and local communication lines. It has been known that a systolic array is on of effective systems to solve complicated communication problems occurred between densely connected neurons on ANN(Artificial Neural Network). In this paper, a systolic array simulator for the back-propagation ANN, which automatically constructs the proper systolic array for a given number of neurons of the ANN, is designed and constructed. With animation techniques of the simulators, it is easy for users to be able to examine the execution of the back-propagation algorithm on the designed systolic array step by step. Moreover the simulator can perform forward and backward operations of the back-propagation algorithm either in sequence or in parallel on the designed systolic array. Parallel execution can be performed by feeding continuous input patterns and by executing bidirectional propagations on all of processing elements of a systolic array at the same time.

• Journal of Korea Multimedia Society
• /
• v.19 no.6
• /
• pp.1089-1094
• /
• 2016

A simulation game represented the real world and situation as a video games, In the first time, this simulation game primarily applied to military practice areas and then it's applied areas were extended to strategy, flighting, racing, life areas. In this paper, we developed the driving simulator that operate the 3-axis sensor attached driver's handle which could forward/backward moving, control of direction, and transmit of gear in the virtual space. For more the realities of the situation and accuracy of the location and speed, we adopted the 3-axis sensing informations, Unreal engine4' and Blueprint.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.4
• /
• pp.75-84
• /
• 1995

Fault simulators are used for accurate evaluation of fault coverages of digital circuits. But fault simulation becomes time and memory consuming job because computation time is proportional to wquare of size of circuits. Recently, several approximate algorithms for testability analysis have been published to cope with the problems. COP is very fast but cannot be used for sequential circuits, while STAFAN can ve used for sequential circuits but requires large amount of computation because it utilizes logic simulation results. In this paper EXTASEC(An Extension of Testability Analysis for Sequential Circuits) is proposed. It is an extension of COP in the sense that it is the same as COP for combinational circuits, but it can handle sequential circuits, Xicontrollability and backward line analysis are key concept for EXTASEC. Performance of EXTASEC is proven by comparing EXTASEC with a falut simulator, STAFAN, and COP for ISCAS circuits, and the result is demonstated.

• Journal of Electrical Engineering and Technology
• /
• v.11 no.3
• /
• pp.751-758
• /
• 2016

The modifiable walking pattern generation (MWPG) algorithm can handle dynamic walking commands by changing the walking period, step length, and direction independently. When an infeasible command is given, the algorithm changes the command to a feasible one. After the feasibility of the navigational command is checked, it is translated into the desired center of mass (CM) state. To achieve the desired CM state, a reference CM trajectory is generated using predefined zero moment point (ZMP) functions. Based on the proposed algorithm, various complex walking patterns were generated, including backward and sideways walking. The effectiveness of the patterns was verified in dynamic simulations using the Webots simulator.

• IE interfaces
• /
• v.7 no.3
• /
• pp.171-180
• /
• 1994

Defined is a Multi-level Parallel Machine Flow-Shop (MPMFS) which reflects some real world manufacturing situations. Just-In-Time (JIT) philosophy is applied to the MPMFS scheduling in order to achieve lowering work-in-process inventory level as well as meeting due dates. A schedule generating simulator is developed. The latest start time of each operation is determined by a backward simulation followed by another forward simulation to analyze the schedule feasibility and actual inventory level. Reasonable schedules are available through adjusting some parameters for allowance factors such as set-up times of machines and other environmental changes. The SLAMSYSTEM under Window is employed for this processing with some input/output data handling processes devised under DOS.

• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1346-1348
• /
• 2005

디지털 프로세서의 성능이 크게 향상됨에 따라 HVDC(High Voltage Direct Current) 시스템의 제어에 고급 지능형 제어 기술의 적용이 연구되고 있다. 이러한 연구의 일환으로, 본 논문에서는 MATLAB을 이용한 HVDC 시스템 시뮬레이터의 개발 결과를 소개한다. 시뮬레이터는 MATLAB의 프로그램 언어와 행렬 연산 기능을 이용하였으며, 회로의 수식화는 전압원 및 스위칭 소자, 변압기를 포함할 수 있는 수정된 마디 해석법(modified nodal analysis)을 사용하였고, 적분법은 Backward Euler 적분법을 사용하여 수치적 진동(numerical oscillation) 문제가 발생하지 않도록 하였다. 개발 결과, 본 시뮬레이터가 향후의 HVDC 시스템 지능형 제어 기술 연구에 유용하게 활용될 것으로 기대한다.