• 제목/요약/키워드: Fiber Selection

검색결과 183건 처리시간 0.024초

인력비행기의 소재선정 및 구조설계 (HPA(Human Powered Aircraft) Material Selection and Structural Design)

  • 윤성찬;허현우;유새롬;이재홍;김두만;오장근;이희우
    • 항공우주시스템공학회지
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    • 제3권1호
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    • pp.42-46
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    • 2009
  • The 1st development of "Human Powered Aircraft(HPA)" in Korea has been conducting by KAFA(Korea Air Force Academy) from Aug. 2008 to now. HPA is an aircraft powered by directly human energy. The thrust provided by the human power may be the only source and that is weak. Therefore, light weight and strong structure is first requirement. In this paper, treating a basic conceptual design of HPA and material property and material choice for HPA. Also analysing the structure and checking the safety of HPA.

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Simultaneous Burst and Burst Control Packet Transmission Protocol for Optical Burst Switching Ring Networks

  • Park, Joon-Pyo;Lee, Man-Seop
    • ETRI Journal
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    • 제29권1호
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    • pp.116-119
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    • 2007
  • In this letter, we design a collision resolution protocol for optical burst switching ring networks to avoid burst collision. We define the offset time condition for no burst transmission collision and manage the free time list of nodes for no burst reception collision. In order to improve the throughput, we use a fiber delay line, void-filling, and void-compression. This protocol does not require any additional procedures for bandwidth reservation such as centralized assignment of bandwidth, lightpath setup of WDM ring networks, or token capturing for the burst transmission. The simulation results show that the proposed protocol can achieve high throughput while saving 70% of wavelengths when compared to round robin with random selection, round robin with persistent, and round robin with non-persistent with only destination delay.

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좌립형 폴리머 지지애자의 기계적 강도 해석 (Mechanical Strength Analysis of Station Type Polymer Insulator)

  • 조한구;박기호;한동희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.85-88
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    • 2000
  • FRP has been used very much as high strength core materials for insulators because of its high strength and good insulation properties. In this study cantilever, tension and torsion stress were simulation along to the unidirection glass fiber. In addition, FRP was made by pultrusion method. This paper proposed the procedure of the finite element model updating and pretest using the commercial finite element code MSC. Nastran. To enhance the efficiency of experimental modal analysis, we proposed the process which is the selection of the locations and the number of measurement points for pre-test.

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200 Gbps WDM 시스템에서 Mid-Span Spectral Inversion 기법을 이용한 채널 왜곡의 보상 특성 (Compensation Characteristics of Distorted Channels in 200 Gbps WDM Systems using Mid-Span Spectral Inversion Method)

  • 이성렬
    • 한국전자파학회논문지
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    • 제14권8호
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    • pp.845-854
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    • 2003
  • 광섬유의 색 분산과 비선형 효과에 의해 왜곡된 채널 신호를 보상하기 위한 방법으로 고비선형 분산 천이 광섬유의 광 위상 공액기를 이용한 경로 평균 강도 근사 MSSI(Mid-Span Spectral Inversion)를 채택한 채널 전송률 40 Gbps의 5-채널 WDM시스템의 시뮬레이션을 통하여 채널 각각의 MSSI 보상 특성을 다양한 광섬유 분산 계수에 따라 분석해 보았다. 채널별 보상 특성의 분석은 1 dB 기준 눈 열림 패널티, 수신단에서의 비트 에러율 특성, $10^{-9}$ BER에서의 채널 간 파워 패널티 등을 이용했다. 시스템 전송 길이, 광섬유의 분산 계수, 광 위상 공액기 펌프 광 파장, 광 위상 공액기에서의 WDM신호 파장에 따른 공액파 변환 효율 등에 관계하여 광 위상 공액기를 중심으로 한 첫 번째 전송 링크에서의 신호 평균 전력과 두 번째 전송 링크에서의 공액파 평균 전력을 동일하게 만드는 펌프 광 전력을 적절히 선택하면 고비선형 분산 천이 광섬유가 MSSI 보상을 통한 광대역 WDM 시스템을 위한 광 위상 공액기에서의 비선형 매질로 매우 적합하다는 것을 확인할 수 있었다.

사일리지용 우량 보리품종 선발 2. 사료가치 및 TDN 수량 (Selection of Promising Barley Cultivar for Silage 2. Nutrient value and total digestible nutrient yield)

  • 김원호;서성;윤세형;김기용;조영무;박태일;고종민;박근제
    • 한국초지조사료학회지
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    • 제23권4호
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    • pp.283-288
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    • 2003
  • 본 연구는 답리작에서 사일리지용 보리 우량품종 선발을 위해 경기 수원(축산연)에서 1999 ∼ 2001년까지 3년간 생육단계별로 사료가치 및 TDN수량 등을 조사하였다. 총체보리의 유숙기 때의 ADF 함량은 27.3 ∼ 29.1% 이었고 황숙기의 경우 27.4 ∼ 30.4%이었다. 또한 유숙기와 황숙기 때의 NDF 함량은 50.6 ∼ 55.9% 그리고 53.1 ∼ 60.6. 유숙기와 황숙기의 TBN 함량은 65.4 ∼ 67.4% 그리고 64. 3 ∼ 67.7%이었다. 또한 ha 당 TDN 수량은 유숙기 때 4,120 ∼ 5,528kg, 황숙기 때 5,674 ∼ 6,569kg 이었다. 그리고 소화율은 유숙기 65.8 ∼ 74.6% 이었고 황숙기 때 64.6 ∼ 73.9% 이었다. 본 시험에서 수량 및 사료가치를 고려하여 수원지역에서는 총체용 보리 우량 품종은 알보리이며, 작부체계에 있어서 황숙기 때 수확하는 것이 유리하다.

여자 중.고등학생의 화운데이션 교육과 착용실태에 관한 연구 (A Study on the Education & Wearing Behaviors about Foundation for Middle and High School Girls)

  • 신지영;오경화
    • 한국의류학회지
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    • 제32권4호
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    • pp.517-529
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    • 2008
  • The education status of the body make-up foundations for teenage girls was evaluated and their purchase & wearing behaviors and the level of satisfaction were studied to analyze the relationship between education level and wearing satisfaction. The research was conducted for 728 middle and high school girls in Seoul and Incheon area, by the questionnaire method. The collected data was analyzed by SPSS. Frequency, percentage, average, standard deviation, $X^2$-test, t-test, and ANOVA were performed. Among various foundation education contents learned in home economics class, most students were aware of the kind of underwear, the fiber content & management methods, laundry methods, and the kind and function of foundations. While more than 80% of all respondents didn't know about the size of foundations. As a results, most of students realized the influence of foundation wearing on the human body, selection methods for brassiere and girdle according to form and age, and matters to be attended to wear brassiere and girdle. The education standard, practical use, and awareness degree on the side effects, and the need for foundation education were positively related each other. Therefore, it is very important to educate teenage girls in the fast growth period the right selection of foundation and its effect on body health, in order to provide normal growth and healthy body.

Virtual Metrology for predicting $SiO_2$ Etch Rate Using Optical Emission Spectroscopy Data

  • Kim, Boom-Soo;Kang, Tae-Yoon;Chun, Sang-Hyun;Son, Seung-Nam;Hong, Sang-Jeen
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.464-464
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    • 2010
  • A few years ago, for maintaining high stability and production yield of production equipment in a semiconductor fab, on-line monitoring of wafers is required, so that semiconductor manufacturers are investigating a software based process controlling scheme known as virtual metrology (VM). As semiconductor technology develops, the cost of fabrication tool/facility has reached its budget limit, and reducing metrology cost can obviously help to keep semiconductor manufacturing cost. By virtue of prediction, VM enables wafer-level control (or even down to site level), reduces within-lot variability, and increases process capability, $C_{pk}$. In this research, we have practiced VM on $SiO_2$ etch rate with optical emission spectroscopy(OES) data acquired in-situ while the process parameters are simultaneously correlated. To build process model of $SiO_2$ via, we first performed a series of etch runs according to the statistically designed experiment, called design of experiments (DOE). OES data are automatically logged with etch rate, and some OES spectra that correlated with $SiO_2$ etch rate is selected. Once the feature of OES data is selected, the preprocessed OES spectra is then used for in-situ sensor based VM modeling. ICP-RIE using 葰.56MHz, manufactured by Plasmart, Ltd. is employed in this experiment, and single fiber-optic attached for in-situ OES data acquisition. Before applying statistical feature selection, empirical feature selection of OES data is initially performed in order not to fall in a statistical misleading, which causes from random noise or large variation of insignificantly correlated responses with process itself. The accuracy of the proposed VM is still need to be developed in order to successfully replace the existing metrology, but it is no doubt that VM can support engineering decision of "go or not go" in the consecutive processing step.

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Modeling and Simulation of Scheduling Medical Materials Using Graph Model for Complex Rescue

  • Lv, Ming;Zheng, Jingchen;Tong, Qingying;Chen, Jinhong;Liu, Haoting;Gao, Yun
    • Journal of Information Processing Systems
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    • 제13권5호
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    • pp.1243-1258
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    • 2017
  • A new medical materials scheduling system and its modeling method for the complex rescue are presented. Different from other similar system, first both the BeiDou Satellite Communication System (BSCS) and the Special Fiber-optic Communication Network (SFCN) are used to collect the rescue requirements and the location information of disaster areas. Then all these messages will be displayed in a special medical software terminal. After that the bipartite graph models are utilized to compute the optimal scheduling of medical materials. Finally, all these results will be transmitted back by the BSCS and the SFCN again to implement a fast guidance of medical rescue. The sole drug scheduling issue, the multiple drugs scheduling issue, and the backup-scheme selection issue are all utilized: the Kuhn-Munkres algorithm is used to realize the optimal matching of sole drug scheduling issue, the spectral clustering-based method is employed to calculate the optimal distribution of multiple drugs scheduling issue, and the similarity metric of neighboring matrix is utilized to realize the estimation of backup-scheme selection issue of medical materials. Many simulation analysis experiments and applications have proved the correctness of proposed technique and system.

Selection of Low Lignin-high Biomass Whole Crop Silage Rice Elite Line for the Improvements of Forage Digestibility and Fermentation

  • Eok-Keun Ahn;Jeom-Ho Lee;Hyang-Mi Park;Yong-Jae Won;Kuk-Hyun Jeong;Ung-Jo Hyun;Yoon-Sung Lee
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2022년도 추계학술대회
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    • pp.277-277
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    • 2022
  • Lignin modification has been a breeding target for the improvements of forage digestibility and fermentation in whole crop silage(WCS) rice. In rice, gold hull and internode 2 (gh2) was identified as a lignin-deficient mutant. gh2 exhibits a reddish-brown pigmentation in the hull and the internode is located on the short arm of chromosome 2 and codes for cinnamyl-alcohol dehydrogenase (CAD). To develop WCS rice variety improved digestibility and fermentation, we measured acid detergent fiber (ADF), lignin and total digestible nutrient (TDN) calculated from ADF (TDN=88.9-(0.79% × ADF) and performed marker-assisted selection using CAD(Os2g0187800) gene first intron region specific marker with 55 Jungmo1038/J.collection lines. Those lines had lignin content range from 0.82 to 6.61%, ADF from 15.8 to 45.8%, TDN from 52.7 to 78.8 compared to 'Jungmo1038'(1.53,20.7,72.6), 'J.collection'(0.98,12.8,78.8%) and gh2 were introgressed into 44 lines. Considering on these genotype and low-lignin phenotype, we finally selected 2 elite lines(Suweon668, Suweon669). Suweon668 and Suweon669 line are high biomass-low lignin lines that the ADF content is relatively low, even though the dry matter weight is high. Also they have lodging and shattering resistance and glabrous leaf and hull important to improve cattle palatability. Our results will provide that rice can be improved for forage digestibility and fermentation with low lignin concentration.

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고혈압 역학연구를 위한 음식중심 식품섭취빈도 조사표 개발: 2001년 국민건강영양조사 자료 이용 (Developing Dish-based Food Frequency Questionnaire for the Epidemiology Study of Hypertension Among Korean)

  • 김미경;윤영미;김영옥
    • 대한지역사회영양학회지
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    • 제13권5호
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    • pp.701-712
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    • 2008
  • The purpose of the present study was aimed to identify dish items applicable in developing dish?based food frequency questionnaire (DFFQ) for a hypertension study of Koreans. The 24-hour recall data of 4,401 subjects aged $20{\sim}65$ years from the 2001 Korean National Health and Nutrition Examination Survey were used for the analysis. Logistic regression model was used to identify the nutrient related with hypertension. Energy, fiber, sodium, calcium, carotene, vitamin B1 and vitamin C were associated with hypertension. Selection the top 30 dish items for these seven nutrients was performed based on their degree of contribution in supplying nutrients in terms of the cumulative percent contribution (cPC), as well as on their degree of explanation for between?person variation, in terms of the cumulative regression coefficient (cMRC). Rice supplied 43% of total energy consumption. Korean cabbage and radish kimchi were two major sources of sodium and it also covered the 27% of between person variation of sodium intake. Soybean paste soup and single item of orange?colored fruits supplied 43% of total vitamin C intake for Koreans and it covered the almost 79% of between person variation among the Korean population. Korean cabbage kimchi was the major source of fiber, calcium, sodium, carotene, and vitamin C for Koreans. In summary, the top 30 selected dish items supplying the 78% to 89% of the 7 nutrients. Those items also covered the 79% to 94% of between person variation of the 7 nutrients consumption. Therefore, the selected 30 dish items in each categories of nutrient could be applicable in developing dish based food frequency questionnaire for hypertension study.