• Journal of Biosystems Engineering
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• v.35 no.1
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• pp.21-30
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• 2010

This study was performed to develop an active tire pressure control system that can adjust tire pressure to the optimum level according to traveling and working condition of agricultural tractor. For the development of active tire pressure control system, pneumatic supplier, solenoid valve block including pneumatic supply line, infinite rotation type pneumatic supplier with rotary joint unit, tire pressure transceiver module and control algorithm were developed. Also, tire simulator was developed. Using this tire simulator, the feasibility of each part constructing actual system was tested by checking the performance. The average communication success ratio was 98.3% between tire pressure transmitter and receiver module according to the various tire rotational speed and data receipt position of receiver module. The communication performance of the developed transmitter and receiver module was very stable in any condition. The tire pressure control system was accomplished by using the proportional control algorithm in this study. Also tire pressure control performance of developed control system was analyzed by using the tire simulator. As a result of control performance analysis to the developed system, the developed control system took 307 seconds to inflate agricultural tractor's tire from 50 kPa to 180 kPa. In opposite case, it took 210 seconds. Also it was able to control the tire pressure accurately under ${\pm}0.9%$ (FS) in any condition.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.4
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• pp.645-651
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• 2006

This paper discusses computer system performance evaluation and analysis by employing a simulator which able to execute a symmetric multiprocessor in machine simulation environment. We also perform a multiprocessor system analysis using SPLASH-2, which is a suite of multi-program benchmarks for multiprocessors, to perform the behavior study of the symmetric multiprocessor OS kernel, IRIX5.3. To validate the scalability of symmetric multiprocessor system, we demonstrate structure and evaluation methods for symmetric multiprocessor as well as a functionality-based software simulator, SimOS. In this paper, we examine cache miss count and stall time on the symmetric multiprocessor between the local instruction and local data, using the multi-program benchmarks such as RADIX sorting algorithm and Cholesky factorization.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.5
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• pp.818-823
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• 2010

Exploiting models and simulations are encouraged among the defense acquisition society, as now enforced by the Defense Aquisition Program Administration's regulations. They are useful and, sometimes, inevitable especially in an earlier phase of system development. Computer-simulation-based experimentation technique for the system operational performance analysis for a torpedo defense system is introduced in this paper. Problem definition for the torpedo defense system analysis and engineering efforts for models and simulations development are presented here, including defining measures of performance and effectiveness for the torpedo defense system, conceptual modeling for torpedo engagement and defense simulation, design of experimentation, design of simulator and experimentor, and hardware and software implementation of an analysis support tool - a system operations demonstration and experimentation simulator.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.337-342
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• 2011

A roller rig has been widely used in the study about dynamic stability and railway safety. However, the cost for constructing the roller rig and the difficulty in adjusting the design parameters for vehicle systems lead to the development of a small scale simulator which is cheaper than the large scale test systems and easy to control the parameters affecting dynamic characteristics of the railway vehicle. For the operation of the small scale test system called a small scale simulator, it is required to investigate the performance and characteristics of the system. This could be achieved by a comparative study between an analysis and an experiment. This paper presented the analytical model which could be used for verifying of the test results and understanding of the physical behavior of the dynamic system comprising the small scale bogie and the simulator.

• The Journal of the Acoustical Society of Korea
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• v.21 no.1E
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• pp.18-24
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• 2002

This paper discusses the development of an acoustic vector channel simulator for the performance analysis of an acoustic digital communication system. The channel simulator consists of transmission module, acoustic channel model, receiver, beamformer, and adaptive equalizer. The source signal (QPSK) is generated by the specified parameters. The transmitted signal generates multipath signals which have a different delay, amplitude and doppler frequency. The paper presents in details the approach to the performance analysis of an acoustic digital communication system according to the antenna structure and the various baseband signal processing techniques.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2600-2608
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• 2011

The dynamic stability of railway vehicle has been one of the important issues in railway safety. The dynamic simulator has been used in the study about the dynamic stability of railway vehicle and wheel/rail interface. Especially, a small scale simulator has been widely used in the fundamental study in the laboratory instead of full scale roller rig which is not cost effective and inconvenient to achieve diverse design parameters. But the technique for the design of the small scale simulator for the fundamental study about the dynamic characteristics of the wheel-rail system and the bogie system has not been well developed in Korea. Therefore, the research about the development of the small scale simulator and the bogie has been conducted. As this paper, To predict the dynamic behavior of railway vehicle, we studied running stability test of 1/5 scaled bogie that similarity laws is applied using small scale derailment simulator. For the operation of the small scale derailment simulator, it is required to investigate the performance and characteristics of the system. This could be achieved by a comparative study between an analysis and an experiment. This paper presented the analytical model which could be used for verifying of the test results and understanding of the physical behavior of the dynamic system comprising the small scale bogie and the simulator.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.5
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• pp.666-674
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• 2013

This paper studied about the design and implementation of tactical communication network simulator in order to obtain tactical communication network parameter, such as link capacity and routing plan, and a number of exceptional cases that may occur during actual deployment by conducting simulation of a large-scale tactical communication networks. This tactical communication network simulator provides equipment models and link models of commercial OPNET simulator for tactical communication network. In addition, 6 types of simulation scenario writings convenience functions and traffic generation models that may occur in situations of tactical communication network environment were implemented in order to enhance user friendliness. By taking advantages of SITL(System-In-The-Loop) function of OPNET, the tactical communication network simulator allows users to perform interoperability test between M&S models and actual equipment in operating simulation of tactical communication network, which is run on software. In order to confirm the functions and performance of the simulator, small-scale of tactical communication network was configured to make sure interoperability between SITL-based equipment and a large-scale tactical communication network was simulated and checked how to cope with traffic generated for each network node. As the results, we were able to confirm that the simulator is operated properly.

• International Journal of Railway
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• v.2 no.2
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• pp.50-59
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• 2009

Numerous train operating companies provide training by means of driving simulators. A detailed analysis in the course of the rail research project 2TRAIN has shown that the simulation technology, the purposes of training and the overall concept of simulator-based training are rather diverse (Schmitz & Maag, 2008). A joint factor however are weak assessment capabilities and the fact that the simulator training is often not embedded into the overall competence management. This fact hinders an optimal use of the simulators. Therefore, 2TRAIN aims at the development of enhanced training and assessment tools. Taking into account that several simulators are already in use, the focus lays on the extension of existing simulation technology instead of developing entirely new systems. This extension comprises (1) a common data simulation interface (CDSI), (2) a rule-based expert system (ExSys), (3) a virtual instructor (VI), and (4) an _assessment database (AssDB). The foundation of this technical development is an assessment concept (PERMA concept) that is based on performance markers. The first part of the paper presents this assessment concept and a process model for the two major steps of driver performance assessment, i.e. (1) the specification of exercise and assessment and (2) the assessment algorithm and execution of the assessment. The second part describes the rationale and the functionalities of the simulator add-on tools. Finally, recommendations for further technical improvement and appropriate usage are given. based on the results of a pilot study.

• Publications of The Korean Astronomical Society
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• v.23 no.2
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• pp.73-90
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• 2008

A software simulator is developed for verifying the VLBI Correlation Subsystem (VCS) trial product hardware. This software simulator includes the delay tracking, fringe rotation, bit-jump, FFT analysis, re-quantization, and auto/cross-correlation functions so as to confirm the function of the VCS trial product hardware. To verify the effectiveness of the developed software simulator, we carried out experiments using the simulation data which is a mixed signal with white noise and tone signal generated by software. We confirmed that the performance of this software simulator is similar as that of the hardware system. In case of spectral analysis and re-quantization experiment, a serious problem of the VCS hardware, which is not enough for expressing the data stream of FFT results specified in VCS hardware specification, was found by this software simulator. Through the experiments, the performance of software simulator was verified to be efficient. In future, we will improve and modify the function of software simulator to be used as a software correlator of Korea-Japan Joint VLBI Correlator (KJJVC).

• Journal of Drive and Control
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• v.14 no.4
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• pp.29-36
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• 2017

Electronic control technologies that have long been developed for passenger cars spread to construction equipment and agricultural vehicles because of its outstanding performance achieved by embedded software. Especially, system program of transmission control unit (TCU) plays a crucial role for the superb shift quality, driving performance and fuel efficiency, etc. Since the control algorithm is embedded in software that is rarely analyzed, development of such a TCU cannot be conducted by conventional reverse engineering. Transmission simulator is a kind of electronic device that simulates the electric signals including driver operation command and output of various sensors installed in transmission. Standalone TCU can be run in normal operation mode with the signals provided by transmission simulator. In this research, transmission simulator for the tracked vehicle TCU is developed for the analysis of shift control algorithm from the experiments with standalone TCU. It was confirmed that shift experimental data for the simulator setup conditions can be used for the analysis of control algorithms on proportional solenoid valves and shift map.