• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.29-32
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• 2002

The developed locomotive in coal mine drawn by the parallel drive system of the double Switched Reluctance motors is introduced. The operational principles, the control pattern and the component parts of the traction and the regenerative braking operation are proposed. The drive system contributes to reduce the cost of utilization of the locomotive per ton kilometer.

• 대한전기학회논문지
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• 제40권7호
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• pp.664-669
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• 1991

In order to improve the reliability and the stability of static power conversion system, further to optimize the operational characteristics of the system, it is very important to investigate the effects (output and switching component characteristics) of each parameters in the system. Therefore this paper particualrly deals with the characteristics of a novel ZVS multi-resonant conversion system to duty cycle, resonant capacitance, resonant inductance, and output capacitance. The results show that resonant inductance and output capacitance are dominat factors in the system.

• 한국신뢰성학회지:신뢰성응용연구
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• 제5권4호
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• pp.451-463
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• 2005

This paper describes procedure to build a generic reliability analysis database structure and failure data during the conceptual design phase. Reliability prediction utilizing such supporting database system enable the designer to quantify the effects of varying design and operational constrains on mechanical component's failure rate. This leads to compare competing alternatives to the reliability improvement efforts.

• Bulletin of the Korean Chemical Society
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• 제17권1호
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• pp.39-42
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• 1996

A new oscillator for electrochemical quartz crystal microbalance (EQCM) was developed by using an operational amplifier without any LC component. The home-made EQCM using this oscillator showed only 0.02 Hz frequency noise at 0.3 s gate time when a 6 MHz AT-cut crystal was used. Pb underpotential deposition on gold substrate in nitric acid media was examined to demonstrate the performance of this EQCM. The derivative of frequency change could be obtained without averaging multiple scans.

• Ocean and Polar Research
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• 제31권4호
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• pp.369-377
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• 2009

Performance of the Korea Ocean Research and Development Institute (KORDI) operational storm surge prediction system for the Korean coast is presented here. Results for storm surge hindcasts and forecasts calculations were analyzed. The KORDI storm surge system consists of two important components. The first component is atmospheric models, based on US Army Corps of Engineers (CE) wind model and the Weather Research and Forecasting (WRF) model, and the second components is the KORDI-storm surge model (KORDI-S). The atmospheric inputs are calculated by the CE wind model for typhoon period and by the WRF model for non-typhoon period. The KORDI-S calculates the storm surges using the atmospheric inputs and has 3-step nesting grids with the smallest horizontal resolution of ${\sim}$300 m. The system runs twice daily for a 72-hour storm surge prediction. It successfully reproduced storm surge signals around the Korean Peninsula for a selection of four major typhoons, which recorded the maximum storm surge heights ranging from 104 to 212 cm. The operational capability of this system was tested for forecasts of Typhoon Nari in 2007 and a low-pressure event on August 27, 2009. This system responded correctly to the given typhoon information for Typhoon Nari. In particular, for the low-pressure event the system warned of storm surge occurrence approximately 68 hours ahead.

• 한국군사과학기술학회지
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• 제14권2호
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• pp.222-231
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• 2011

In this paper, we have proposed a method which can make it possible to stably transmit and receive data like the ARC-164 radio frequency hopping environment as a S/W packet modem with PSK modulation. This is a method that the S/W packet modem with PSK digital modulation and the use of PC sound cards change over from data to voice signals and then transmit/receive data. We confirmed not only that it is possible to solve the slow speed communication with the use of sending data through multi-channels and PSK modulation that has the ability to methodically improve transmission rates, but also that it is possible to send the state of frequency hopping stably. In conclusion, we've confirmed both tactical values that though the transmission rate may be a tad slow, a state of frequency hopping of more than 94% confidence plus voice and data can be sent via radio at the same time. In this paper, the proposed S/W packet modem is only an implemented S/W component, so when we apply it to aircraft that we don't consider EMC problems with, then we have the advantage of a wider use of conventional UHF/VHF/HF radio that is possible to voice communication. If we recognize these operational requirements, we can apply for a lot of field equipment efficiently.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2006년도 추계학술대회
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• pp.618-629
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• 2006

This Paper is about optimizing preventive maintenance period of connected (r,s) out of(m,n) : F lattice system that one of multi-component system, (m,n) matrix failure of whole system is occurrence when parts that belong in (r,s) matrix part procession of parts arranged with procession are breakdown all. The preventive maintenance about system is very important viewing from system reliability and operational expense viewpoint. Preventive maintenance that misses a time calls big loss by system failure and expense of frequent full equipment is paid excessively in preventive maintenance itself but expense is paid much in preventive maintenance itself and whole expense escalation can be achieved preferably. Through this research, reliability model is constructed that do expense by smallest under full equipment policy chosen through comparison of each full equipment policy and preventive maintenance expense full equipment cycle and r ,s value are made using simulated annealing algorithm and simulated annealing algorithm that converge fast in multi-component system certified most suitable to optimization decision

• Smart Structures and Systems
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• 제16권3호
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• pp.435-457
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• 2015

The most widely known form of multifunctional aircraft structure is smart structures for structural health monitoring (SHM). The aim is to provide automated systems whose purposes are to identify and to characterize possible damage within structures by using a network of actuators and sensors. Unfortunately, environmental and operational variability render many of the proposed damage detection methods difficult to successfully be applied. In this paper, an original robust damage detection approach using output-only vibration data is proposed. It is based on independent component analysis and matrix perturbation analysis, where an analytical threshold is proposed to get rid of statistical assumptions usually performed in damage detection approach. The effectiveness of the proposed SHM method is demonstrated numerically using finite element simulations and experimentally through a conformal load-bearing antenna structure and composite plates instrumented with piezoelectric ceramic materials.

• 산업경영시스템학회지
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• 제21권46호
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• pp.1-18
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• 1998

The purpose of this study is to identify critical factors facilitating JIT innovation process for Korean component manufacturers. In order to find the answers to this issue, this study has empirically studied the corelations among JIT innovation culture, competitiveness, and incentive factors. Cluster, ANOVA, and regression analyses were performed from 92 collected survey data. It has found that Korean component manufacturers strongly rely on their inner JIT innovation culture to improve competitiveness. It has also found that the organizational resource and managerial priority should be focused on establishing clear goals and objectives for improvement, and creating open atmosphere with respect to operational process.

• Journal of information and communication convergence engineering
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• 제22권2호
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• pp.139-144
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• 2024

In this study, four types of fall detection systems - designed with YOLOPose, principal component analysis (PCA), convolutional neural network (CNN), and long short-term memory (LSTM) architectures - were developed and compared in the detection of everyday falls. The experimental dataset encompassed seven types of activities: walking, lying, jumping, jumping in activities of daily living, falling backward, falling forward, and falling sideways. Keypoints extracted from YOLOPose were entered into the following architectures: RAW-LSTM, PCA-LSTM, RAW-PCA-LSTM, and PCA-CNN-LSTM. For the PCA architectures, the reduced input size stemming from a dimensionality reduction enhanced the operational efficiency in terms of computational time and memory at the cost of decreased accuracy. In contrast, the addition of a CNN resulted in higher complexity and lower accuracy. The RAW-LSTM architecture, which did not include either PCA or CNN, had the least number of parameters, which resulted in the best computational time and memory while also achieving the highest accuracy.