• Composites Research
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• v.22 no.2
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• pp.30-36
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• 2009

In this paper, we propose the design method for the composite torque link of a landing gear for a helicopter. The composite torque link has to be light weighted and very stiff to keep the shock absorber in the landing gear of helicopter. The configuration and structural shape has to be designed in consideration of the RTM (Resin Transfer Molding) manufacturing process which is adopted to minimize the manufacturing cost. The mechanical properties are obtained through the coupon tests with the specimens made by the same manufacturing process for the composite structure. The optimal design process was performed through iterative modifications of the models which were verified by stress analysis using FEM. The composite torque link has lug-shaped parts and is very thick, so 3D Layered solid elements of ABAQUS were used to get the stress field including the stress components in thickness direction and non-linear static analysis using contact B.C. of rigid-deform condition was used to get the optimal design.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.4
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• pp.641-650
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• 2008

One of the most important the success of a food service organization. As a matter of fact, menu functions as a list of product restaurant and a communication tool that facilitates the communication between a restaurant and its customers. Accordingly, many scholars and practitioners have suggested various for menu analysis. Among others, menu analysis methods proposed by Miller, Kasavana & Smith, and Pavesic have been frequently and repeatedly published in the academic literature. However, methods common limitation utilize a two-dimensional approach quadrants. Focusing on this problematic of traditional menu analysis methods, Hayes & Huffman suggested a new menu analysis method goal value analysis. The of this study to the menu analysis technique suggested by Hayes & Huffman using goal value. In this research, the goal value analysis adopted wine restaurant.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.7
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• pp.48-56
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• 2011

Recently, new storage device SSD(Solid State Disk) based on NAND flash memory is gradually replacing HDD(Hard Disk Drive) in mobile device and thus a variety of research efforts are going on to find the cost-effective ways of performance improvement. By increasing the NAND flash channels in order to enhance the bandwidth through parallel processing, DRAM buffer which acts as a buffer cache between host(PC) and NAND flash has become the bottleneck point. To resolve this problem, this paper proposes an efficient low-cost scheme to increase SSD performance by improving DRAM buffer bandwidth through scheduling techniques which utilize DRAM multi-banks. When both host and NAND flash multi-channels request access to DRAM buffer concurrently, the proposed technique checks their destination and then schedules appropriately considering properties of DRAMs. It can reduce overheads of bank active time and row latency significantly and thus optimizes DRAM buffer bandwidth utilization. The result reveals that the proposed technique improves the SSD performance by 47.4% in read and 47.7% in write operation respectively compared to conventional methods with negligible changes and increases in the hardware.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.2
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• pp.19-24
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• 2007

With recent advancement of high-speed, multi-gigabit data transmission capabilities, serial links have been more widely adopted in industry than parallel links. Since the parallel link design forces its transmitter to transmit both the data and the clock to the receiver at the same time, it leads to hardware's intricacy during high-speed data transmission, large power consumption, and high cost. Meanwhile, the serial links allows the transmitter to transmit data only with no synchronized clock information. For the purpose, clock and data recovery circuit becomes a very crucial key block. In this paper, a 5.4Gbps half-rate bang-bang CDR is designed for the applications of high-speed graphic DRAM interface. The CDR consists of a half-rate bang-bang phase detector, a current-mirror charge-pump, a 2nd-order loop filter, and a 4-stage differential ring-type VCO. The PD automatically retimes and demultiplexes the data, generating two 2.7Gb/s sequences. The proposed circuit is realized in 66㎚ CMOS process. With input pseudo-random bit sequences (PRBS) of $2^{13}-1$, the post-layout simulations show 10psRMS clock jitter and $40ps_{p-p}$ retimed data jitter characteristics, and also the power dissipation of 80mW from a single 1.8V supply.

• Journal of Intelligence and Information Systems
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• v.15 no.2
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• pp.15-31
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• 2009

The next generation IT environment is expected to be an open computing environment based on Grid computing technologies, which allow users to access to any type of computing resources through networks. The open computing environment has benefits in aspects of resource utilization, collaboration, flexibility and cost reduction. Due to the variation in performance of open computing resources, however, resource allocation simply based on users' budget and time constraints often fails to meet the Service Level Agreement(SLA). This paper proposes the Mean-Absolute Deviation(MAD) portfolio optimization approach, in which service brokers consider the uncertainty of performance of resources, and compose resource portfolios that minimize the uncertainty. In order to investigate the effect of this approach, we simulate an open computing environment with varying uncertainty levels, users' constraints, and brokers' optimization strategies. The simulation result concludes threefolds. First, the MAD portfolio optimization improves the success ratio of delivering the required performance to users. Second, the success ratio depends on the accuracy in predicting the variability of performance. Thirdly, the measured variability can also help service brokers expand their service to cost-critical users by discounting the access cost of open computing resources.

• Journal of Internet Computing and Services
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• v.20 no.1
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• pp.17-24
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• 2019

Since the information of $4^{th}$ Industrial Revolution is introduced in WEF (World Economic Forum) in 2016, IoT, AI, Big Data, 5G, Cloud Computing, 3D/4DPrinting, Robotics, Nano Technology, and Bio Engineering have been rapidly developed as business applications as well as technologies themselves. Among the diverse business applications for IoT, wearable devices are recognized as the leading application devices for final customers. This longitudinal study is compared to the results of the 1st study conducted to identify customer needs of activity trackers, and links the identified users' needs with the well-known marketing frame of marketing mix. For this longitudinal study, a survey was applied to university students in June, 2018, and ANOVA were applied for major variables on usable features. Further, potential customer needs were identified and visualized by Word Cloud Technique. According to the analysis results, different from other high tech IT devices, activity trackers have diverse and unique potential needs. The results of this longitudinal study contribute primarily to understand usable features and their changes according to product maturity. It would provide some valuable implications in dynamic manner to activity tracker designers as well as researchers in this arena.

• Journal of the Korean Regional Science Association
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• v.37 no.4
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• pp.49-59
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• 2021

This study aims to identify the characteristics of the cancelled districts of housing redevelopment and housing reconstruction project. The subject of this study is 189 project districts(121 promoted districts, 68 cancelled districts). Both 121 promoted districts and 68 cancelled districts were analyzed by Decision Tree Analysis. The first separation of the release zone influencing factors was made by the Development Actors. In other words, the most important independent variable for determining the release zone influence factor was shown to be the presence or absence of propulsion actors. Of the 89 districts without propellers, 41 were lifted and 48 were promoted, and 9 out of 100 districts with propellers were lifted and 91 were promoted. The second separation of the impact factors on the zone was then made by Land Owners, and the probability of cancellation increased if the number of landowners was less than 468 and 37 out of 62 were removed. On the other hand, four out of 27 districts with more than 468 landowners were lifted and 23 districts were promoted. The third separation was made by the Average Land Assessment, and 35 zones were lifted below the standard of KRW 269.64 million/m² approximately KRW 8.91 million per pyeong, and two zones were lifted at higher official prices. In the second division, the number of landowners was 468 or more, and in node4, four areas were removed from areas with a public land area ratio of 29.43% or more, and no areas less were released. This study used SPSS Statistics 26 S/W for analysis.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.10a
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• pp.267-270
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• 2005

유기셀레늄급원을 달리하여 쇠고기 육색 안정성에 미치는 영향을 분석한 결과는 다음과 같다. Myoglobin의 함량은 대조구와 시험구에서 각각 6.39%, 14.18%로 대조구가 시험구에 비하여 낮은 결과를 보였으며, Oxy-Myoglobin의 함량은 반대로 대조구 89.07%, 시험구 83.47%로 시험구가 대조구에 비하여 낮은 결과를 보였다(p<0.05). 그러나 Met-myoglobin 함량은 대조구가 4.56%이였고 시험구가 2.35%로 대조구가 높은 결과를 보였다. 보다 정확한 결과를 평가하기 위해서는 시료를 Met화 시킨 후 측정해 볼 필요성이 대두되어 도축후 $4^{\circ}C$에서 14일 및 21일간 숙성한 시료를 $20^{\circ}C$에서 48시간 산화시킨 후 측정 육색소 화학적 조성을 비교한 결과, 육색소 화학적 조성을 비교한 결과로 Myoglobin 함량은 저장 14일차와 21일차에서 유의적인 차이를 보이지 않았으나, Oxy- myoglobin은 저장 14일차와 21일차 모두 유기셀레늄 강화 버섯 폐배지 급여구가 대조구와 무기셀레늄 급여구에 비하여 높은 결과를 보였다. Met-myoglobin함량에 있어서는 대조구와 무기셀레늄구가 유기 셀레늄구와 유기셀레늄강화 버섯 폐배지 급여구에 비하여 높은 결과를 보였다(p<0.05). 유기셀레늄 강화 버섯 폐배지 급여구가 대조구나 유기셀레늄구에 비하여 Oxy-myoglobin production이 유의적으로 높았으며, Met-myoglobin Activity는 유기 셀레늄 급여구가 가장 높았으며, 그 다음으로는 유기셀레늄강화 버섯폐배지 급여구가 높았다(p<0.05). 이러한 결과는 소매상품 으로 제조 판매시 Oxy-Mb이 Met-Mb으로의 전환을 억제하여 이상적인 육색을 장시간 유지할 수있을 것으로 판단된다.조직감과 염도에서 매우 좋게 평가되었다. 이러한 결과는 제조 가능한 식염첨가최저수준은 0.5%이상임을 보여주었다. 따라서 로인 햄의 제조에 필요로 되는 식염의 첨가량은 0.5${\sim}$1.5% 범위로 평가된다. 차후의 연구로는 저염 로인 햄의 경우 품질의 저하를 보완할 수 있는 기능성 첨가물이나 가공기법이 필요할 것으로 보인다.97.22로 가장 낮았고, 기타 처리구는 1.19${\sim}$1.59의 처리를 보이고 있는데 비하여, 대조구(100) 대비 증체율에서는 생봉독 처리 2구에서 103.30으로 3.30%가 높았다.양성이 무엇보다 중요하다. 특히 지역자원 활용 소스 중심의 문화관린 산업의 seeds 발굴과 향토상품의 상품화와 네트워크 조직망 구축을 위한 지역중심의 복합 생활문화 공간이 필요할 것이며, 이를 촉진키 위한 mentor academy시스템 접근을 통해 점점 고령화되어 가고 있는 재래시장에 대해 차별적 특성이 반영된 종합적이고 체계적 접근 방법연구가 필요하다./TEX> 자체기술개발, 선진기술 도입, 산업간 및 산업내 기술확산, 국제기술협력 ${\rightarrow}$ 기술혁신의 촉진 ${\rightarrow}$ 총요소생산성과 기업경쟁력(자원 및 역량, 프로세스 경쟁력, 품질경쟁력, 시장경쟁력, 고객성과, 시장성과, 재무성과)의 제고 ${\rightarrow}$ 가격경쟁력(임금, 금리, 물류비용, 환율 등)과 비(非)가격경쟁력(디자인, 에프터서비스, 품질, 운송 등)의 제고 ${\rightarrow}$ 국가경쟁력의 제고 ${\rightarrow}$ 국제수지 흑자 ${\rightarrow}$ 성장 ${\rightarrow}$ 물가 및

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.1926-1934
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• 2013

M2M (Machine-to-Machine Communication) refers to technologies that allow wired and wireless systems to communicate with other devices with similar capabilities. M2M has special features which consist of low electricity consumption, cheap expenses, WAN, WLAN and others. Therefore, it can communicate via a network. Also, it can handle itself without a person's management. However, it has a wireless-communicate weakness because of the machine-communicate request, and also it is difficult to administrate and control each other. So In this Paper, It suggests the safety protocol between Device, Gateway and Network Domain in M2M environment. Proposed protocol is based on ID-Based encryption's certificate and creates session key between the Access Server and the Core Server in the Network Domain. It uses that session key for sending and receiving data in mutual, and adds key renewal protocol so it will automatically update discern result. a comparative analysis of the existing M2M communication technologies and PKI-based certificate technology is compared with the proposed protocol efficiency and safety.

• Journal of the korean Society of Automotive Engineers
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• v.18 no.5
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• pp.53-68
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• 1996

마그네슘이 자동차 경량화에 관심이 되는 이유는 근본적으로 CAFE 규제와 같이 경량화를 통한 화석연료의 소모를 크게 억제해야 한다는 사회적인 규제이나, 지난 10여년간의 기술발전으로 내식성이 나쁘다거나 취급이 위험한 금속이라는 인식이 크게 개선된 데에도 있다. 다른 경량금속에 대한 Mg 지금 가격의 비교조건이 호전되었고 향후 원소 재공급의 다변화가 추진되고 있는 것도 환경을 변화시킨 중요한 요인이다. 그간 중요한 경량화 대체 재료로 연구투자가 많았던 유기고분자 재료 및 FRP 등과 같은 복합재료는 폐기부품의 재활용이 어려움 때문에 호나경친화적인 단점이 부각되어, 이 소재의 증가가 주춤해 있다. 마그네슘의 경우에는 재활용이 가능하고, 진동흡수효과가 매우 커서 소음발생을 크게 줄일 뿐만 아니라, 주행 및 내구성시험에서 치수안정성이 좋고 많은 종류의 전자기기 사용에 의한 전자파 차폐효과도 큰 장점을 가지고 있다. 본 고에서는 Mg 다이캐스팅으로 자동차부품의 경량화 현황과 선진국에서 보는 전망을 미국을 중심으로 정리하고, 이와 관련한 Mg 다이캐스팅으로 자동차부품의 경량화 현황과 선진국에서 보는 전망을 미국을 중심으로 정리하고, 이와 관련한 Mg 기술적인 이슈와 시장전망도 서술하였다. 그리고 현재 우리나라의 연구계와 부품업계에서 추진하고 있는 연구개발 동향을 자동차 업계에 소개하는 의미도 있다. 이처럼 우리나라의 현황을 정리해 보는 것은 국내 자동차 산업이 국제적인 경쟁을 하고 있고 Mg기술과 원료확보에서 일본의 견제를 받고 있는 우리의 현실에서도 필요한 작업으로 생각된다.값들로 구성되는 형상을 내구 성능, 성형성등을 고려하여 최종 형상으로 결정한다. 내구성능의 예측은 금속부품의 내구수명 예측에 널리 이용되고 있는 방법이 방진 고무부품의 경우에도 적용 가능한지를 검토하고, 방진 고무부품에도 일반적으로 적용될수 있는 내구수명 예측방안의 개발 가능성을 타진해 보았다. 본 연구의 목표는 시제품을 제작하기 이전에 설계된 부품에 대한 스프링 상수 및 내구특성을 체계적으로 규명하여 제품 시험의 횟수를 줄이고, 보다 정밀한 제품을 제작할 수 있도록 하기 위한 것이다.세포수는 초기 배반포기배에서 팽윤 배반포기배로 진행됨에 따라 두배에서 세배 정도 증가되었음을 알 수 있었다. 또한, differential labelling과 bisbenzimide기법에서 얻어진 각각의 총세포수를 비교하였을 때 총세포수는 발달의 진행 정도에 따라 증가되며 그와 동시에 동일한 군 간의 세포수도 거의 유사함을 알 수 있었다. 따라서, ICM과 TE를 differential labelling하는 기법은 수정란의 quality를 평가하는데 매우 유용한 기법으로서 착상전 embryo 발달을 연구하는데 효과적으로 이용될 수 있다는 것을 시사한다. 고도의 유의차를 나타낸 반면 비수구, 초생수로구 및 Bromegrass 목초구 간에는 아무런 유의차가 인정되지 않았다. 7. 농지보전 처리구인 배수구와 초생수로구는 비처리구에 비해 낮은 침두 유출량과 낮은 토양유실량을 나타내었다.구보다 14% 절감되는 것으로 나타났다.작용하는 것으로 사료된다.된다.정량 분석한 결과이다. 시편의 조성은 33.6 at%