• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2623-2626
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• 2012

A series of functionalized furans were synthesized by way of a palladium-catalyzed coupling reaction of 2,3,5-trisubstituted furans with aryl chlorides through C-H bond cleavages at C-4 position. The feature of the reaction was facilitative preparation of furan derivatives with good functional group tolerance. All reactions gave the desired products in moderate to good yields in the presences of $BuAd_2P$ and t-BuOK in DMF at $120^{\circ}C$ after 15 h.

• 한국의류산업학회지
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• 제17권4호
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• pp.604-612
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• 2015

This study investigates preferred bicycle wear designs that can satisfy active senior consumers. A survey was conducted on 50-60's women who periodically rode bicycles. The results indicated a preference for slim designs and red colors. Jacket designs preferences were for a tight fit for size tolerance, stand collar style, and elastic band details for cuff styles. Pants design preferences were for a whole band waist belt type with a tight fit style such as leggings in pants silhouette, zipper details on the side line and ankle length. They also preferred styles with pads attached to underpants in the pad style and the part of the back waist in the pocket position. The survey showed four kinds of jacket design drawings on an ordinal scale rating. Results indicated a preference for set-in variation jackets with the red and gray color combination. Finally, we demonstrated bicycle wear design suggestions. The jacket applied different armhole line colors connected to the sleeve to make the waist slimmer; in addition, stretchable material helped improve armpit part functionality.

• 인터넷정보학회논문지
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• 제9권3호
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• pp.103-117
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• 2008

일반 고객이 대기업 혹은 중소기업, 증권, 금융, 은행권 등의 서비스를 제공받기 위해서는 보편적으로 인터넷, SMS(Short Message Service), ATM(Automated Teller Machine), DM(Direct Mail), 텔레포니 서비스 등을 사용한다. 특히, 화재 보험사 및 증권, 금융, 은행권의 경우는 QoS(Quality of Service) 보장을 통한 실시간성 제약 조건을 만족해야 한다. 본 논문에서는 고객의 최초 접점으로 이용될 수 있는 CRM(Customer Relationship Management) 환경 하에서 다중 채널 서비스를 위한 결함허용 IVR(Interactive Voice Response)을 설계 구현하였다. 제안한 모델은 대 고객 응대 CRM 모델로 효율적으로 이용될 것으로 사료된다.

• 한국소음진동공학회논문집
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• 제15권1호
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• pp.12-19
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• 2005

This paper proposed a dual actuator using Bimorph PZT for information storage device based on prove array NSOM(near-field scanning optical microscopy). The gap between the media and the optical head should be maintained within the optical tolerance. Therefore, a new actuator having high sensitivity is required. Bimorph PZT, which has fast access time and high sensitivity characteristic, is suitable for this precise actuating system. This paper is focused on derivation of mathematical model of dual Bimorph PZT actuator and control algorithm. Hamilton's principle was used for mathematical model. The model is verified by FEA(finite element analysis), and compared with experimental results. Different control algorithms were used for two Bimorph PZT actuating same direction and opposite direction. The gap between recording media and optical head was controlled within 20nm in experiment.

• Journal of Plant Biotechnology
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• 제43권4호
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• pp.444-449
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• 2016

Deep rooting, which enables plants to extract water from greater soil depths, is a critical strategy for improving plant survival under water-deficient conditions. However, as it is difficult to observe intact root systems belowground, several techniques have been developed to screen deep- and shallow-rooting phenotypes in rice. Here, we introduce a simple and convenient method for deep- and shallow-rooting phenotyping using a unique combination of sand, soil, and plastic mesh netting. Vandana, a drought-tolerant rice variety, and Dongjin, a Korean japonica rice variety, were used to analyze root phenotypes. No significant differences in root length were observed in rice grown under irrigated conditions regardless of net position, whereas roots were significantly longer, and ratio of deep root (RDR) values were significantly higher in Vandana rice grown under semi-drought conditions. In summary, this simple and useful method represents a low-cost means of phenotyping the roots of rice and other crops grown in various-sized pots and at multiple plant growth stages.

• 한국정보통신학회논문지
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• 제19권4호
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• pp.954-964
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• 2015

본 연구는 균일한 조명을 얻기 위해 자유 형상 렌즈(freeform lens)를 제작하였으며, 이를 위해 중첩 조명 모델(overlapped illumination model)을 제안하였고, 제작한 LED 렌즈들의 특성을 분석하였다. 제작한 렌즈는 LED 빛 세기 분포의 중심 방향, 반치각 (half angle) 및 LED 광원의 위치변화를 바탕으로 그 성능을 평가하였다. 아울러 조명영역은 평균 조도 (average illuminance)와 조도 균일도 (illuminance uniformity) 변화 값으로 수행하였다. 광도 분포의 중심 방향 변화에 대해서는 제안된 모델과 발산 모델이 대체로 비슷한 공차 특성을 보였으며, 특히 제작한 렌즈에서 반치각 변화는 기존 방법에 비해 조도 균일도 공차 특성은 현저히 개선됨을 확인하였다.

• 한국항공우주학회지
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• 제31권9호
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• pp.55-63
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• 2003

본 연구에서는 다수의 추력기를 이용한 발사체 상단 RCS 자세 제어 시스템에 대해 다룬다. 이때 추력기 배치 위치와 부착 각도에 따라 시스템 응답 특성, 연료소모량, 추력 분배로직에 의한 유효 토크량, 고장대응 용이성이 달라진다. 최적화 기법을 이용하여 27개의 명령에 대해 명령 방향과 일치하면서 최대 응답 토크량을 갖도록 하는 최적의 배치를 찾는 방법을 제안하였다. 기존에 주어진 추력기 배치 형상과 제안된 추력기 배치 형상에 대한 수치 해석 결과를 비교함으로서 제안된 추력기 배치 형상에 정당성을 찾고자 한다.

• 한국안전학회지
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• 제31권2호
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• pp.90-97
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• 2016

The objective of this study is to evaluate the operator's safety for the risk assessment method of impulsive noise division. Literature reviews on the basis of the impulsive noise study, the measuring methods and procedures, based on the results of the analysis process presents a risk assessment methods. In this study, analysis of the MIL-STD-1474D, B-duration graph for the peak noise level to cross the line from the measurement results is limited by the risk retracted. It is possible to determine whether there is quick can be determined whether the risk. Measurement positions measured by the microphone is installed on the risk of applying results are so located within the tolerance impulsive noise in the measurement position can interpret subjective safety is ensured. In addition, Proportional Dose technology was the proposed by the Patterson with the risk assessment method was applied to the indoor-impulsive noise. As results of this study, results for the same value of applying the technique of Proportional Dose technology results calculated by MIL-STD-1474D methods allows 1 count once increased in comparison to the result obtained.

• KSTLE International Journal
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• 제4권2호
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• pp.37-42
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• 2003

One of the obstacles for a magnetic bearing to be used in the wide range of industrial applications is the failure modes associated with magnetic bearings, which we don't expect for conventional passive bearings. These failure modes include electric power outage, power amplifier faults, position sensor faults, and the malfunction of controllers. Fault-tolerant magnetic bearing systems have been proposed so that the system can operate in spite of some faults in the system. In this paper, we designed a fault-tolerant magnetic bearing system for a turbo-molecular vacuum pump. The system can cope with the actuator/amplifier faults which are the most common faults in a magnetic bearing system. We implemented the existing fault-tolerant algorithms to experimentally prove the adequacy of the algorithms for industrial applications. As it turns out, the system can operate even with three simultaneously failing poles out of eight actuator poles.

• 대한기계학회논문집A
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• 제20권5호
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• pp.1508-1515
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• 1996

The method of utilizing sensitivity linkages for the analysis of mechanical errors are proposed. As sources of the mechanical error, tolerances in the link length and clearances in thejoints are considered. It is demonstrated that the problem of calculating mechanical errors of a 4-bar mechanism can be transformed into a problem of conventeional velocity analysis of a sensitivity linkage. As a result of the present study, it is found and proved that the mechanical error of the output angle in the 4-Bar mechaism is represented as a simple harmonic function with respect to the relative position of the pin on the clearance circle. Also the vector representing the mechanical error of a coupler point makes, in general, an ellipse as the relative angle varies on the clearance circle. With these results we can better identify the characteristic of the mechanical errors in linkages.