• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.228-231
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• 2002

This paper describes the design and experimental verification of a hybrid fuzzy control system for a BLDC motor drive. The principle of the proposed control system is to use a PI controller which performs satisfactorily in most cases, while a fuzzy controller, which is ready to take over the PI controller. is used when severe perturbations occur. Thus. the PI and fuzzy controller can be managed to take advantage of their positive attributes.

• 한국가금학회:학술대회논문집
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• 한국가금학회 2003년도 국제 심포지움
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• pp.9-20
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• 2003

미래를 예측한다는 것은 기회가 됨과 동시에 도전이 되기도 한다. 다음 시대에 양계산업에서 어떤 변화가 닥칠 것인가를 예상하는 것은 과거를 돌이켜보는 기회가 되며, 다시 이것은 미래를 예측할 수 있는 수단으로 사용할 수 있다. 지난 50∼60 년 동안 양계산업이 상업화된 것을 보면 차기 50 년 동안 일어날 수 있는 발전은 분명 굉장할 것이다. 영양, 육종, 건강, 생산, 사양과 같은 분야에서 기술의 진보는 양계산업의 발달에 이바지하였으며 또한 계속될 것이다. (중략)

• 한국IT서비스학회:학술대회논문집
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• 한국IT서비스학회 2009년도 추계학술대회
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• pp.544-548
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• 2009

The underlying success of logistics depends on the flow of data and information for effective management. Over the last 30 years, we have seen the power of microprocessors double about every 18months. This continuing trend means that computers will become considerably smaller, cheaper, and more abundant; indeed, they are becoming ubiquitous and are even finding their way into everyday objects, resulting in the creation of smart things. In the long term, ubiquitous technologies will take on great economic significance. Industrial products will become smart because of their integrated information processing capacity, or take on an electronic identity that can be queried remotely, or be equipped with sensors for detecting their environment, enabling the development of innovative products and totally new services. The global marketplace runs on logistics, security, speed, agility and flexibility..In this paper we report that pairing these traditional logistics functions with RFID technology can be a huge value-driver for companies. This winning combination yields increased logistics management effectiveness and more efficient visibility into the supply chain management.

• 드라이브 ㆍ 컨트롤
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• 제14권1호
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• pp.29-34
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• 2017

This study analyzed a life test method for a power take-off (PTO) gearbox. An engine transfers mechanical power (rotation and torque) to a hydraulic pump through a PTO Gearbox with one input shaft and three output shafts. PTO gear box durability under high loads over long time periods was tested using dynamometers. In order to reflect the rated operating conditions, power must be distributed to each output shaft, and experiments were conducted under various conditions to verify the characteristics of the distributed power. An accelerated life test was designed using speed and torque as acceleration factors. Also, efficiency tests were conducted under various load conditions. Also, a lubrication oil composition analysis was performed to analyze gearbox wear status.

• International Journal of Computer Science & Network Security
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• 제22권8호
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• pp.323-327
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• 2022

The field of this study is in Islamic jurisprudence. Taking the preferred saying is contrary to the original, and takes it if necessity or need arises. There are reasons for adopting the preferred saying that were mentioned in this research so that the mufti and jurist know when to take the preferred saying, and when to act with the most correct saying. The origin is the work of the jurist and mufti by saying the most correct. If the necessity or the need that prompted the mufti to take the preferred saying ceases, then he returns to work with the most correct saying, and gives it precedence over the most preferred opinion. The researcher recommends that this topic be given more attention from researchers, and that it is taken care of in jurisprudential developments; So that the embarrassment of the nation is lifted, and the jurists clarify the legal ruling on emerging issues.

• 항공우주시스템공학회지
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• 제17권5호
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• pp.11-18
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• 2023

The architecture of the Fuel Thermal Management System (FTMS) in a commercial aircraft engine was built to model and simulate the fuel system. The study shows the thermal interactions between the fuel and engine lubrication oil through the mission profile of a high bypass ratio, two-spool turbofan engine. Fuel temperature was monitored as it flowed through each sub-component of the fuel system during the mission. The heat load in the fuel system strongly depended on the fuel flow rate, and was significantly increased for the periods of cruise and descent with decrease of fuel flow rate, rather than for the periods of take-off. Due to the thermal interaction in the pump housing, the fuel temperature at the outlet of the low-pressure pump was increased (4.0, 9.2, and 30.0) % over the case without thermal interaction for take-off, cruise, and descent, respectively.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2005년도 가을 학술발표논문집 Vol.32 No.2 (1)
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• pp.280-282
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• 2005

In this paper we propose several mapping schemes for streaming video generated by state-of-the-art H.264 codec over IEEE 802.11e enabled wireless LANs. The schemes take advantage of both 802.11e's QoS mechanism and some novel features of the H.264 codec, so as to protect the most important information in terms of visual quality and reduce distortion under network congestion. The proposed methods are evaluated by means of the H.264 reference software codec, network simulation, and objective video quality measurements. Results show that the proposed methods achieve a robust and error resilient H.264 video streaming over wireless LANs than traditional best-effort streaming.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 E
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• pp.1871-1873
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• 1997

The conventional current transformers are often take faults and out of order that for detect to over current of electric power lines because electromagnetic interference. But, it is possible to implement protection relay of high reliability using optical magnetic field sensor which are immunity and small size. The optical magnetic field sensor is possible to rapidly detect to over current and recover when electric power line have fault. And it is not necessary to make with capacitance of electric power lines as optical magnetic field sensor is have linearity from 0 to about 20kA. In this study, we designed and constructed compensative feedback circuit in order to minimize of optical power intensity variation with environ- mental variations(temperature, drive current) of light source. And this system have highest optical advantages and reliability.

• 대한지역사회영양학회지
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• 제14권2호
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• pp.206-215
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• 2009

The purpose of this study was to investigate the current status of foodservice management in organizations delivering meal boxes for low-income children during summer vacation. A survey was conducted with persons in charge of meal box production and service of these organizations via mail. Out of 114 questionnaires distributed nationwide, 100 were analyzed(87.8% analysis rate). Over half(53%) of the organizations delivered meal boxes consisting of rice and side dishes while the rest delivered side dishes only. About 81% of the organizations received KRW 3,000 per meal from their local governments and the rest received KRW 3,500. Only 28% of organizations had employed a dietitian. Over one-third(38%) of the respondents were unaware of the official nutritional standard of the foodservice program for low-income children during vacation. Most of the organizations(94%) had menu planned in advance. The average percentage of food cost was 84.1%. Over 40% of the organizations did not keep food samples for sanitation test(43%) and did not take any measures for keeping food temperature during delivery(45%). The organizations delivering rice and side dishes were more likely to be located in cities rather than rural areas and received higher reimbursement rate. The organizations receiving reimbursement of KRW 3,500 or hiring a dietitian were more likely to use standardized recipes, keep food samples for sanitation test, or take measures for keeping food temperature during delivery compared to the counterparts. Respondents reported that increasing reimbursement rate was the most necessary for improving the quality of meal box. This study results showed that the meal box delivery service for low-income children was not properly managed during the vacation, with regards to menu planning and food production. It is recommended that reimbursement rate for meal boxes should be adjusted depending on meal box types and local conditions.

• Nuclear Engineering and Technology
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• 제49권4호
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• pp.838-849
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• 2017

This paper proposes penalty factor equations that take into consideration the weld strength over-match given in the classified form similar to the revised equations presented in the Code Case N-779 via cyclic elastic-plastic finite element analysis. It was found that the $K_e$ analysis data reflecting elastic follow-up can be consolidated by normalizing the primary-plus-secondary stress intensity ranges excluding the nonlinear thermal stress intensity component, $S_n$ to over-match degree of yield strength, $M_F$. For the effect of over-match on $K_n{\times}K_{\nu}$, dispersion of the $K_n{\times}K_{\nu}$ analysis data can be sharply reduced by dividing total stress intensity range, excluding local thermal stresses, $S_{p-lt}$ by $M_F$. Finally, the proposed equations were applied to the weld between the safe end and the piping of a pressurizer surge nozzle in pressurized water reactors in order to calculate a cumulative usage factor. The cumulative usage factor was then compared with those derived by the previous $K_e$ factor equations. The result shows that application of the proposed equations can significantly reduce conservatism of fatigue assessment using the previous $K_e$ factor equations.