• 로봇학회논문지
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• 제7권1호
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• pp.20-28
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• 2012

In spite of the difficulties and uncertain characteristic of cable driven method, surgical robot instrument has adopted it as driving mechanism for various reasons. To overcome the problem of cable system, previous research applied SMCSPO (sliding mode control with sliding perturbation observer) algorithm as robust controller to control the instrument and found that the value of SPO (sliding perturbation observer) followed force disturbance, reaction force loaded on the tip very similarly. Thus, this paper confirms that the perturbation observer is sufficient estimator which finds out the mount of loaded force on the surgical robot instrument. To prove the proposition, simulation using the similar model with an actual instrument and experimental evaluation are performed. The results show that it is possible to substitute SPO for sensors to measure the reaction force. This estimated reaction force will be used to realize haptic function by sending the reaction force to a master device for a surgeon. The results will contribute to create surgical benefit such as shortening the practice time of a surgeon and giving haptic information to surgeon by using it as haptic signal to protect an organ by making force boundary.

• 한국농공학회지
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• 제32권E호
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• pp.80-87
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• 1990

Energy balance equations Were developed to describe the heat transfer mechanisms in a double layer plastic greenhouse with a water curtain system. Heat transfer variables were determined by using various temperature data measured in a conventional prototype semicircular cross-section greenhouse over a range of water temperatures and water flow rates. The heat transfer coefficient between flowing water and greenhouse air was independent of water flow rates. But the heat transfer coefficient between water surface and the stagnant air space within the double plastic layer was dependent on water flow rates. Substituting the heat transfer coefficients, determined from the energy balance equations in the heat transfer equations, demonstrated various relationships among ambient air temperature, greenhouse air temperature, water temperature, and water flow rates. The heating benefits were linearly related to not only the inside and outside air temperatures but also to the water temperature. The energy conservation effects of the water curtain system were found even initial water temperatures were considerably lower than the greenhouse setting temperatures. Sensitivity analysis for heat transfer coefficients demonstrated that the heat transfer coefficient between greenhouse air and the stagnant air within the plastic layers was the most significant coefficient in the estimation of heating effects.

• 기술혁신학회지
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• 제5권2호
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• pp.245-256
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• 2002

Measurement standards, as being widely recognized, is necessary for national economic development and advanced industrialization. Also measurement standards give reliability and fair trade to the producers and consumers. Macro-effect of measurement standards using estimation of cost function has four effects: 1) value-added causing effect, 2) effect of employment, 3) reduction effect transaction cost, 4) reduction effect defect rates. In this study, to investigate the impacts between specific and the other industries, we used I-O Table of Korea Bank. The relation between the value-added produced by original production factors and final use is determined through production level, and the relation can be investigated with production causing coefficient matrix. In this study, it was showed that the measurement standards investments including measurement only man power of industries were increased from 1995 rapidly. The establishment and maintenance of measurement standards contributes to reduce the defect rate of products in production process and improve the confidence of the product quality. The results from this study show that measurement technology contributes to improve quality, decrease defect rate, improve production process, develope new products, reduce prime cost and increase the consumer's confidence on the firms. Since these results indicate that measurement standards are very important in the point of their vast contribution, we hope our findings can contribute to encourage measurement activities in industries.

• 한국항해학회지
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• 제25권2호
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• pp.97-106
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• 2001

이 연구는 항만교통정보센터의 시스템 확충 및 연안 선박교통관리제도의 도입에는 많은 비용이 소요되기 때문에 비용과 편익을 비교하여 타당성을 조사하고자 한다. 따라서 비용과 편익을 분석하는데 중요한 기초자료가 되는 사고예방효과를 추정하고자 한다. 추정의 방법은 거제해역에서 발생한 해양사고를 분석하여 원인요소를 도출한 후 이를 설문문항으로 구성하여 항만교통정보센터의 운영요원을 대상으로 설문을 실시한다. 연안 선박교통관리제도의 도입에 의한 사고예방효과는 충돌사고에서 55.572%, 좌초사고에서 51.667%로 추정되었다. 또한 인적요소와 환경요소에 의한 효과는 높지만 기술적 요소에 의한 효과는 미미한 것으로 분석되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.196-197
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• 2006

Preventive maintenance can avail the generation utilities to reduce cost and gain more profit in a competitive supply-side power market. So, it is necessary to perform reliability analysis on the systems in which reliability is essential. In this paper, RCM (Reliability -Centered Maintenance) analytical method is adopted using real historical failure data in Korean power plants. Therefore, the reliability -based Probability model for predicting the failures of components in the power plant is also established, and application to FMECA(Failure Mode Effects and Critical Analysis) consideration of failure probability, Based on the weighting ranking of generating equipments which status to be probability estimation by FMECA. The FMECA is an engineering analysis and a core activity performed by reliability engineers to review the effects of probable failure modes of generating equipments and assemblies of the power system on system performance. The results of this paper show that application of FMECA with stochastic approach to the preventive maintenance can efficiently avail decreasing the cost on maintenance and hence improve the total benefit.

• 한국ITS학회 논문지
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• 제8권4호
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• pp.73-83
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• 2009

최근 물류분야를 비롯한 여러 산업분야에서 RFID 도입과 관련된 다양한 연구들이 이루어지고 있다. 본 연구는 일관수송용 파렛트의 RFID 부착에 따른 경제적 효과분석 및 RFID 도입비용 추정모형을 개발을 통하여 향후 물류분야 RFID 도입의 활성화 및 효율성 제고를 위한 기반을 마련하였다. 이를 위하여 50개 물류업체의 RFID 도입에 따른 의식도 조사자료를 이용하였으며, 경제적 효과분석결과 B/C 2.766, NPV 26억 원의 효과가 있는 것으로 분석되어 기업물류차원에서 상당한 편익을 가져올 것으로 나타났다. 이는 기존의 정성적인 기대효과 제시에 머무르고 있는 현시점에서 본 연구의 결과가 의미하는 부분이 상당히 크다.

• 한국조리학회지
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• 제12권3호
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• pp.17-31
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• 2006

There have not been the best method for improving the management system of an enterprise. Its management system must be changed according to new environment. Therefore, the food service industry had to accept outsourcing strategies to reduce cost and construct the core-capability of enterprise. In this respect, we studied the introduction and the satisfaction in outsourcing strategies for family restaurants, including a post of enterprise, decision on the supply-enterprises, contract preparation, cost of outsourcing, recontract items and outsourcing result estimation. The results of this study were as follows; First, 90.5% of managers for 7 family restaurants felt that outsourcing is needed. Second, the post of the outsourcing for 7 family restaurants was from 1 to 8; supply for raw food material, cleaning and equipment repair. The introduction of outsourcing for 7 family restaurants started in 1995 and it had constantly made progress up to 2003. Thirdly, the advantages of the outsourcing for 7 family restaurants were increase of benefit, improvement of controllable-power for family restaurants and improvement of employees' satisfaction. Fourthly, 42.9% of managers were satisfied and 4.8% of them were not satisfied. 36 to 40 year old vice-managers were very satisfied with the result of the outsourcing. Fifth, 90.5% of family restaurant managers found the outsourcing to be needed and especially managers in their late thirties realized the outsourcing.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.491-498
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• 2004

In recent years, as an effort to grasp the leading position in the field of maritime trading, new ports and container terminals arc now under construction. Old ports are extended. At the beginning, stones were thrown down to form stone embankments, that is stone-dams, in the outer and inner boundaries of the planned reclamation-land. S.C.P(Sand Compaction Pile) works are often needed to improve the stability of stone-dams, where marine sediments arc relatively thick. Here, interests are centered on the shape of stone body. In this, drilling work won't provide a sufficient resolution. In addition, the result corresponds to only one borehole point information. Thus, the aim of this paper is to introduce an affordable technology, that is, a combined geophysical method(seismic tomography + Televiewer) enables to get the whole information about stone-dam section. The measuring and evaluating procedure is described in detail with an emphasis on dealing with the use of seismic detonator, proper borehole deployment and integrated data analysis. Examples of field experiments at Busan new port are illustrated, which will prove the benefit of combined geophysical method.

• 한국환경과학회지
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• 제20권3호
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• pp.395-404
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• 2011

Weather forecasting is one of the key elements to improve health through the prevention and mitigation of health problems. Health forecasting is a potential resource creating enormous added value as it is effectively used for people. The purpose of this study is to estimate 'Willingness to Pay' for health forecasting. This survey was carried out to derive willingness to pay from 400 people who lived in Busan and Kyungnam Province and over 30 years of age during the period of July 1-31, 2009. The results showed that a 47.50% of people had intention to willingness to pay for health forecasting, and the pay was 7,184.21 won per year. Willing to pay goes higher depending on 'tax burden as to benefit of weather forecasting', 'importance of the weather forecasting in the aspect of health', 'satisfaction to the weather forecasting', and 'frequency of health weather index check'. This study followed the suggestion of the Korea Meteorological Administration generally and the values derived through surveys could be reliable. It can be concluded that a number of citizens who are willing to pay for health forecasting are high enough to meet the costs needed to provide health forecasting.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 추계학술대회
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• pp.611-614
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• 2012

시공간 블록 부호화(STBC: Space-Time Block Code) 기법은 단순하면서도 효과적인 다이버시티 기법으로 WCDMA, HSDPA 및 LTE 이동통신 표준에 채택되었다. 이러한 STBC 기법은 페이딩 채널의 추정 정확도에 따라 그 성능이 좌우된다. 채널 추정을 위한 기준 심볼의 오버헤드를 수용할 수 없거나 고속으로 이동하는 모바일의 경우 채널 추정이 힘든 경우가 있다. 이러한 문제를 해결하기 위하여 차등 시공간 블록 부호화(DSTM: Differential Space-Time Modulation) 기법들이 제안되어 왔다. 이 기법들은 채널 추정을 필요로 하지 않기 때문에 위와 같은 고속 이동 환경에 적합한 장점이 있다. 본 논문에서는 다양한 속도로 이동하는 모바일 채널에 LTE 파라미터를 적용하여 기존의 STBC 및 DSTM의 성능을 고찰해 보고, 단말에 적용 가능한 적응적 DSTM 복호 기법을 제안하여 그 성능을 고찰하였다.