• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 1부
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• pp.280-285
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• 2008

ZigBee는 저전력 저속 근거리 무선 통신 프로토콜로서 센서 네트워크에 많은 적용이 되는 프로토콜이다. ZigBee가 PAN을 구성하는 방법은 Beacon Enabled PAN과 Non Beacon Enabled PAN의 두 가지가 존재 한다. Non Beacon Enabled PAN에서 데이터 전송방식은 End-Device가 원하는 시점에 Active 상태에 진입하여 데이터를 보내는 방법으로 저전력을 지원한다. 그러므로 Router는 End-Device가 데이터를 보내는 시간을 정확히 알 수 없게된다. 이런 문제를 해결하기 위해서 Router는 항상 Active 상태로 존재해야 한다. 이로 인해 Non Beacon Enabled PAN을 사용하는 센서 네트워크에서 Router는 별도의 상시 전원을 공급 받아야한다. 그러나 Non Beacon Enabled PAN의 ZigBee Router가 건전지와 같은 한정적인 전력 공급원을 가지게 되는 상황에서는 안정적인 네트워크 구축이 불가능하게 된다. 본 논문에서는 이를 해결하기 위해서 PAN Time을 통한 네트워크 동기화를 사용한 저전력 알고리즘을 제안한다. End-Device는 PAN Time을 사용하여 PAN의 동기화를 수행하며, PAN Time을 통해 Router의 저전력 진입을 지원한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 전력전자학술대회 논문집
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• pp.351-352
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• 2016

Since anti-islanding scheme of grid-connected inverter is a key function of standards compliance, unintentional islanding results in safety hazards, reliability, and many other issues. Therefore, many anti-islanding schemes have been researched, however, existing anti-islanding schemes show poor power quality and non-detection zone issues. Besides, most of them have problems which deteriorate performance of islanding detection under parallel-operation. Therefore, this paper proposes a new anti-islanding scheme that has both negligible power quality degradation, no non-detection zone and precise islanding detection under parallel-operation. Finally, both simulation and experimental results validate the proposed scheme.

• 한국표면공학회지
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• 제29권6호
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• pp.857-861
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• 1996

The influence of rf-plasma operation on the thin film formation containing small particles for Al-Li alloys mainly have been studied as a function of Ar gas pressure and plasma power by means of a 200kV transmission electron microscope (TEM). Under the non-plasma operation, the transition from continuous thin films to clusters of grape-like small particles occurred at Ar gas pressures above 20Pa. Particles were single crystals with clear crystal habit planes. Under the plasma operation, the influence of gas pressures on the film formation at a plasma power of 5W was also examined. Thin films containing particles below 30Pa and the films containing mainly particles above 40Pa were formed. The prominent change of the average particle size was not recognized. The increase of the plasma powers at 20Pa, which formed particles under non-plasma, suppressed growth of particles, and homogeneous films containing very small particles were fabricated. The electric conductivity showed slight decrease with an increase of plasma power.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권2호
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• pp.485-499
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• 2021

Although non-binary low-density parity-check (NB-LDPC) codes have better error-correction capability than that of binary LDPC codes, their decoding complexity is significantly higher. Therefore, it is crucial to reduce the decoding complexity of NB-LDPC while maintaining their error-correction capability to adopt them for various applications. The extended min-sum (EMS) algorithm is widely used for decoding NB-LDPC codes, and it reduces the complexity of check node (CN) operations via message truncation. Herein, we propose a low-cost CN processing method to reduce the complexity of CN operations, which take most of the decoding time. Unlike existing studies on low complexity CN operations, the proposed method employs quick selection algorithm, thereby reducing the hardware complexity and CN operation time. The experimental results show that the proposed selection-based CN operation is more than three times faster and achieves better error-correction performance than the conventional EMS algorithm.

• 한국군사과학기술학회지
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• 제24권2호
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• pp.151-164
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• 2021

With the gradual increase in the ROK naval power, it is an undeniable fact that the time of operation in the ice-infested area will be necessary in the near future. Recently, cases of ice formation around Korean waters in wintertime have been frequently reported. However, in the case of the ROK naval vessels to date, it is a fact that the ice-strengthened perspective has not been considered from the design stage. In this study, the capability of operation in the ice-infested area of the ROK naval vessels, which did not take into account the ice-strengthened design, was reviewed through the evaluation of the vessel's structural integrity in accordance with the sea ice conditions.

• 한국수자원학회논문집
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• 제30권3호
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• pp.257-268
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• 1997

홍수시 최적의 방류량을 목표로 하는 댐 운영자의 경우 방류량을 결정하는데 있어 댐의 안전과 저수지의 운영효율을 고려한 이해할 만한 근거를 제시할 필요가 있다. 본 연구에서는 예측된 홍수수문곡선을 댐 규정에 명시된 무피해방류량을 기준으로 분할하여 무피해방류량으로 조절되는 부분과 홍수조절용량을 이용하여 조절되는 부분으로 구분하였다. 홍수조절용량을 이용하는 경우 예측홍수를 판단하는 기준을 마련하여 저수지 운영의 안전과 효율을 고려한 홍수조절계획을 수립하는 방안 ("저수지 홍수변환법")을 강구하였다. 본 연구에서는 연구범위를 단일 댐의 홍수시 저수지 운영 방안으로 제한하여 대청 다목적 댐을 적용하고 그 결과를 분석하였다.

• 한국산업융합학회 논문집
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• 제27권3호
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• pp.693-699
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• 2024

The main cause of scattering dust generated by transportation equipment such as automobiles was largely due to exhaust gas from internal combustion engines in the past, but it was generally recognized that non-exhaust causes such as abrasion of the tires or brake pads were low. Accordingly, scattering dust generated by exhaust gas has consistently existed in many studies, such as technological progress and related regulations, but research on non-exhaust is relatively insignificant, and the need for research on scattering dust generated by non-exhaust is emerging. In this study, a dust collector that can be easily mounted on a caliper to collect scattering dust generated by pad wear during the brake operation of an automobile was manufactured. In this study, we developed a dust collector that is easy to mount on calipers to collect scattering dust caused by pad wear during brake operation of automobiles. According to the installation of the manufactured dust collector, the performance of scattering dust by brake operation and the temperature change characteristics of calipers according to the structure of the dust collector were evaluated.

• 복식문화연구
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• 제14권5호
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• pp.715-727
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• 2006

The purposes of this study are to investigate the job satisfaction, customer satisfaction and revisiting intention to beauty shops, and to examine the difference of the job satisfaction, customer satisfaction, and revisiting intention between franchised and non-franchised beauty shops. Data were obtained via questionnaire, which developed by results of pretest and previous studies, from workers and consumers of beauty shops in Busan. They were analyzed by factor analysis, t-test and regression. The results were as follows; First, the job satisfaction of beauty shops workers was composed of Adaptation, Operation and Instruction. For both of franchised and non-franchised beauty shops, the operation of beauty shops greaty influenced the job satisfaction of workers, and job satisfaction is not significantly different. Second, consumer satisfaction related to services of beauty shops is composed of three factors: Policy, Personal service, and Physical environment. Regardless of shop types, the policy of shop influenced the consumer satisfaction. Consumers' revisiting intentions to beauty shops are influenced by consumer satisfaction. Third, consumers in franchised beauty shops is less likely to be satisfied and to have the intentions to revisit than those of non-franchised beauty shops. Resulted provide some insights to develop strategies for franchised and non-franchised beauty shops. Limitations and future research directions have been discussed.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제14권6호
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• pp.599-603
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• 2008

플래시 메모리는 기존 저장 매체와는 달리 읽기 연산에 비해 쓰기 연산의 수행비용이 매우 크고, 저장된 데이타에 대한 직접 갱신이 불가능한 고유의 특성이 있다. 본 논문에서는 플래시 메모리 환경이 클러스터링 방법과 비클러스터링 방법에 미치는 영향을 분석한다. 이를 통해 디스크 환경과는 달리 플래시 메모리 환경에서는 비 클러스터링 방법이 더 적합하다는 것을 보인다. 또한, 플래시 메모리 환경에서 비 클러스터링 방법이 가진 문제점을 지적하고, 이를 기반으로 플래시 메모리 환경에서 레코드 관리방법의 설계 시 고려해야 할 사항들을 제안한다.

• 간호행정학회지
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• 제8권1호
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• pp.123-135
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• 2002

Purpose: In this study, the critical pathway for laparoscopic cholecystectomy patients was developed and applied for clinical study. The effectiveness of the critical pathway was analyzed. Method: The subjects with no critical pathway services of this study were 30 laparoscopic cholecystectomy operation patients, who were hospitalized in B General Hospital in Busan from Nov. 28. 2000 to May 2. 2001. The subjects with critical pathway services of this study were 30 laparoscopic cholecystectomy operation patients, who were hospitalized in B General Hospital in Busan from June. 11. 2001 to Oct. 31. 2001. Results: 1. Development for critical pathway Preliminary critical pathway for the laparoscopic cholecystectomy patients was developed though analysis of the reference and 34 case of medical record. The items on the y-axis were assessment, test, treatment, diet, fluid, consult, medication, activity and education and the items on the x-axis were till 3days after operation. The developed critical pathway was applied in clinical field. 2.　Effectiveness of application on developed critical pathwayPost operational complication was not found in neither the critical pathway using Group nor Non-using Group. Hospitalization period mean was 4.63 days for the using Group and 5.93 days for the Non-using Group(P=.001). The mean cost for medical examination and treatment for the using Group was 786,270 won, 117,454 won(12.9%) less than that of the Non-using Group, 903,724 won(P=.000). The degree of satisfaction for the using group was 3.7 points, for the Non-using Group, 3.15 points. The degree of satisfaction for the used Group was 0.55 points higher than that for the Non-using Group and there was a statistically significant difference(P=.000). Concousion: From results of this study, Using the critical pathway in the laparoscopic cholecystectomy operational patients was effective in decreasing the hospitalization period and cost, and increasing the satisfaction about the medical service.