• International Journal of Automotive Technology
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• 제3권2호
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• pp.57-62
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• 2002

It is well known that the entrained air in oil causes appreciable reduction in the stiffness of hydraulic systems. It makes the response delay of the systems and sometimes destroys the stability. Because the hydraulic systems of automatic transmissions are operated in relatively low pressure and high temperature, it is very important to analyze the effects of the air included in automatic transmission fluid. However, it is difficult to derive the generalized model to describe the effective bulk modulus theoretically or measure it in actual operating conditions of automatic transmissions. This paper reviews previous studies of the air effects in hydraulic systems and the measurement techniques of the effective bulk modulus in operating conditions. Based on this work, the theoretical model with moderate complexity and the measurement technique of the effective bulk modulus considering entrained air effect at real operating conditions are suggested. Our paper also shows that the quantity of the entrained air in the automatic transmission fluid can be estimated from the experimental results.

• 대한임베디드공학회논문지
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• 제6권3호
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• pp.139-148
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• 2011

As the architecture of automotive software is complicated and LOC of software increases, there is an increasing demand for standard operating system. OSEK/VDX defines an industry standard for automotive operating system and middleware. This paper introduces an implementation of RTOS(OSCAR-OSEK) based on OSEK/VDX standard. For better speed of scheduling, we suggest a new method for ready queue implementation considering the characteristic of automotive application software. Also we introduce a method for improving the portability of RTOS on various MCUs. And, we show OSCAR-OSEK implementation and performance test results.

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.266-275
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• 2018

Herein, a novel operating life (OL) test method was evaluated with 200 mAh pouch-type lithium-ion batteries. By combining the calendar life (CL) test with intermediate pulse power cycling, more realistic life prediction was possible, which encompassed real operation of batteries accompanying with thermal acceleration. Larger capacity decrease and resistance increase of pouch cell were observed in the OL test, which was well explained using the SEI film growth model. After dissemble of pouch cell, capacity loss and resistance increase mostly occurred within anode, reflecting that SEI film growth on anode surface was highly attributable to cell degradation.

• 한국산학기술학회논문지
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• 제9권1호
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• pp.59-63
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• 2008

본 논문에서는 복합고조파 전류에 의한 누전차단기의 동작특성에 대해 분석하였다. 정격감도전류 30[mA] 전류형 누전차단기에 대해 복합고조파에 의한 동작특성을 실험하여 고조파에 의한 누전차단기 오동작, 부동작 특성 등을 분석하였다. 실험결과 누전차단기의 동작전류는 복합고조파 전류에 의해 변화하였다.

• 전기학회논문지
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• 제61권6호
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• pp.797-803
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• 2012

In this paper, for minimizing the real-time operating load losses of the power transformer, a SCADA optimum operating system was developed, and the economic analyses on the test operation were performed. Transformer loss DB which reflects the economic integration operation criteria was constructed by referring the transformer manufacturer's loss data(iron loss, copper loss). Based on the loss DB, each substation transformer real-time loss was calculated according to the size of the transformer loads, and if integration or separation transformer operating conditions minimizing the loss are met, then a window pops-up and the dispatcher performs the substation equipments operation according to the procedure provided by this system. With the existing SCADA main program, the relation database of the substation facilities and integration/separation operation algorithm were developed and applied to Auto MTR Processor and pconn Processor Task module. Seven stations test data for seven months were analyzed for the economic analyses, and the results showed that Cost-Benefit ratio was 2.64, and IRR(Internal Rate of Return), 36%, which asserted the economic justification of the proposed system.

• 한국콘텐츠학회논문지
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• 제13권12호
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• pp.291-298
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• 2013

본 연구는 수술실 간호사의 업무스트레스와 피로와의 관계를 규명하기 위한 횡단적 서술적 조사연구이다. 연구대상은 G시와 C도에 소재한 2개 상급종합병원과 5개 종합병원의 수술실 간호사 124명이었고 설문지를 이용하여 자료를 수집하였다. 수집된 자료는 기술통계, t-test, ANOVA, Pearson's correlation으로 분석하였다. 연구 결과 수술실 간호사의 업무스트레스는 3.64(0.45)점, 피로 점수는 3.46(0.60)점이었다. 수술실 간호사의 업무스트레스는 병원 종류에 따라서 통계적으로 유의한 차이가 있었고, 수술실 간호사의 피로 정도는 병원 종류, 근무배경, 주관적 건강상태에 따라서 통계적으로 유의한 차이를 보였으며, 수술실 간호사의 피로는 업무스트레스와 통계적으로 유의한 순상관관계가 있었다(r=0.47, p=<.001). 그러므로 본 연구는 수술실 간호사의 업무스트레스와 피로의 관련성을 파악한 점에서 의의를 지니며, 향후 수술실 간호사를 위한 업무스트레스 중재프로그램의 개발에 있어 기초자료가 될 것으로 기대한다.

• 대한간호
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• 제32권4호
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• pp.48-62
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• 1993

This study was done for the purpose of analyzing the job-satisfaction and its depressive factors in human relation of operating room nurses of university hospital. Therfore, it makes an offer the basic data to help the resolution and prevention of the problems in operating room nurses. Furthermore, this study was conducted in order to find out some kinds of scientific data for the better control of depressive factors of job-satisfaction expressed by the operating room nurses. The structred questionaire reports of 246 operating room nurses who were employed in 5 different university hospitals which have over 1, 000 beds located in Seoul, Korea were used, which wer collected from August 24th to August 30th of 1992. The author visited supervisors of operating room in each university hospital and explained the aim of this study. The most of them(90.0%) answered to the questionaires. Analysis of the collected data were done by mean, standard deviation, percentage, t-test, F-test, Q-test, correlation analysis, one-way ANOVA.and stepwise multiple regression analysis. Major findings of this study were as follows: 1. The job of the operating room nurses were remarkably related with the satisfaction in human relation, which was defined as the behavioral job with thoughtful action rather than with mechanical action. However, the degree of satisfaction in human relation with personnel in other departments was found to be the lowest and its the main depressive factors were appeared due to the absence of interaction and uncooperative attitudes. Therefore, it was required that the members of other job need more cooperative attitude to the actual works in the operating room nurses. 2. The depressive factors in the satisfaction degree of human relation with offical seniors wer significantly related with their irresponsibility and partialness. Moreover, the job attitude of the operating room nurses is abundantly required to be improved, 3. The depressive factors in the satisfaction of human relation with medical doctors were significantly related with their insincerity and the class-consciousness. It is clearly suggested that the medical doctors do more cooperative behaviors for the jobs of the operating room without the suggested that the medical doctors do more cooperative behaviors for the jobs of the operating room without the superiority feeling of class-consciousness. 4. There was a significantly positive association between the satisfaction degree of human relation of the nurses with the following charateristics. (1) The registered nurses which had a tendency to be satisfied about the registered nurses' job. (2) The registered nurses which had a tendency to be a technique-aptitued in the motivation of the registered nurses'job. (3) The registered nurses which had a tendency to be satisfied about the total hospital working carrier and the aspects of old ages. Finally, these findings indicated that the operating room nurses should require the professional education courses associated with a high-development techniques and setisfaction in their jobs.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 춘계 학술대회 논문집
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• pp.62-66
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• 2001

Advanced system architectures or frameworks proposed by researchers are usually verified by implementing their prototype systems, but it is very difficult to integrate them with operating legacy systems to show their applicability. Thus, a test bed approach is widely adopted to provide a system environment that imitates the operations of real legacy systems and their interactions. In this paper, we introduce our experiences to implement a test bed as a system environment on which we have implemented a prototype system to verify our studies for process information sharing. The test bed simulates simultaneously operating workflow systems and their interactions. We also show the result of the prototype system that was Implemented on the test bed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.551-553
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• 2002

The cubicle type GIS rated at 25.8kV has been designed and manufactured by Jinkwang E&C eacently with their own technologies and KERI's assistances. The C-GIS has been tested to check the design capability for reference before conducting the type test. The operating characteristics test, short time withstand current and peak withstand current test, basic short circuit test duty T60 for preconditioning test, cable charging current switching test, capacitor bank current switching test, basic short circuit test duty T100s and T100a, single phase earth fault test, double earth fault test has been conducted. The test results show that the design and the manufacturing of the C-GIS has an enough capability to pass through the type test except the occurrence of 2 NSDDs in the cable charging current switching test and the instability of opening time at the minimum operating voltage. The problems shown in the tests will be improved soon and the successful pass will be expected in the following type test.

• 드라이브 ㆍ 컨트롤
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• 제21권1호
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• pp.22-30
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• 2024

Gearboxes designed for reciprocating motion operating mechanisms operate under conditions where both the load and speed undergo continuous variations. When conducting durability tests on gearboxes designed for such applications, operating the target gearbox under conditions similar to the intended usage is essential. The gearbox must be operated for the required number of cycles to validate its durability under conditions mirroring its intended usage. This study devised an accelerated test method for gearboxes, which reduces operating angles and operational strokes. The reliability of the accelerated test was verified by comparing the stresses imposed on the gears under general and acceleration conditions through multi-body dynamic simulations. The results confirmed that the maximum contact stress levels under normal and accelerated conditions were within a 0.1% error range, indicating a minimal difference in the gear damage rates. However, a difference in the maximum contact stress results between the normal and accelerated conditions was observed when inertial forces acted on the output shaft due to the operational acceleration of the gearbox. Therefore, when conducting this acceleration test, caution should be exercised to ensure that the operational load on the gearbox, which affects inertia, does not significantly deviate from the conditions observed under normal operating conditions.