• 제목/요약/키워드: Weight Adjustments

검색결과 36건 처리시간 0.025초

Wing weight estimation considering constraints of structural strength and stiffness in aircraft conceptual design

  • Bai, Chen;Mingqiang, Luo;Zhong, Shen;Zhe, Wu;Yiming, Man;Lei, Fang
    • International Journal of Aeronautical and Space Sciences
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    • 제15권4호
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    • pp.383-395
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    • 2014
  • According to the requirement of wing weight estimation and frequent adjustments during aircraft conceptual design, a wing weight estimation method considering the constraints of structural strength and stiffness is proposed to help designers make wing weight estimations rapidly and accurately. This method implements weight predictions on the basis of structure weight optimization with stiffness constraints and strength constraints, which include achievement of wing shape parametric modeling, rapid structure layout, finite element (FE) model automated generation, load calculation, structure analysis, weight optimization, and weight computed based on modeling. A software tool is developed with this wing weight estimation method. This software can realize the whole process of wing weight estimation with the method and the workload of wing weight estimation is reduced because much of the work can be completed by the software. Finally, an example is given to illustrate that this weight estimation method is effective.

A Study on Adapting Patterns to Stable Knit Fabrics in Relation to Drapability

  • Song, Mi-Ryong;Yang, Soo-Yung
    • The International Journal of Costume Culture
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    • 제2권2호
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    • pp.80-96
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    • 1999
  • This research focused on pattern adjustments of the stable knit garment for women. Fourteen different types of the knitted fabrics by 12 gauge, computerized flat bed machines were cut in as one half of the torso front, one half of the torso back, and one side of the sleeves for each of them. Guidelines such as the center front, the center back, the armhole, the bust-line, the waistline, the hip-line the hemline were basted on the torso patterns in the knitted fabrics. Also the grain-line, the elbow-line, and the hemline were basted on the one side of the sleeves in the same as above knitted fabrics. The torso patterns in the knitted fabrics were exhibited on the dress-forms on top of the torso patterns in Muslin, which also have the same guidelines drawn on. The distances between the guidelines on Muslin and those on the knitted fabrics for each set of the sample fabrics were measured every three days for two weeks. The fabric properties of the fourteen knitted fabrics such as fiber contents, stitch density both in the wale and course directions, weight, thickness, stretch & recovery, residual shrinkage, relaxation and drapability were laboratory tested for how these were related to finished appearance of 12 gauge, computerized flat knit garments and also in order to prove the fourteen knitted fabrics fall to a category of such as the stable knit. The results from the investigation revealed that six fabric properties such as stitch density, thickness, stretch recovery, residual shrinkage and relaxation were not so much significant factors as weight and drapability. In conclusion, fabric weight, and drapability of the fabric resulting from fiber contents were the cause of final appearance distortion of garment. When adapting patterns for stabilized, 12 gauge, computerized flat knitted fabrics, the fiber contents of the fabrics should be taken into consideration to reduce the production cost and produce better-fit garments.

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다중근접사진측량에 의한 구조물 내부전면의 3차원 해석 (Three Dimensional Analysis of the Whole Interior-Surface of Structures by Multiple Close-Range Photogrammetry)

  • 이진덕;강준묵
    • 한국측량학회지
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    • 제11권1호
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    • pp.7-18
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    • 1993
  • 비지형대상물의 전면해석을 위한 다중지점 사진측량강의 설계에는 촬영점의 기하학적 배치, 영상의 기하학적 조건, 기준점 배치 및 조정의 경중률 등 많은 문제들이 복합적으로 포함되어야 하며, 특히 좁고 긴 구조물의 내부를 측량할 경우에는 특수한 사진측량망을 필요로 한다. 본 연구에서는 구조물 내부의 전면해석에 수반되는 주요 난점들의 해결안을 제시하고 결과의 정확도 및 신뢰도의 향상을 기하고자 하였다. 이를 위해 내부의 형상과 크기에 적합한 다중사진측량망을 구성하고 광속조정법에 의하여 3차원 자료를 취득, 강의 구성요소에 따른 정확도에 미치는 영향을 고찰하였다. 아울러 본 연구에서 개발된 과대오차의 검출연산법은 사진측량 해의 신뢰도 향상에 그 활용이 기대된다.

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Kalman Filter-Based Ensemble Timescale with 3- Hydrogen Masers

  • Lee, Ho Seong;Kwon, Taeg Yong;Lee, Young Kyu;Yang, Sung-hoon;Yu, Dai-Hyuk
    • Journal of Positioning, Navigation, and Timing
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    • 제9권3호
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    • pp.261-272
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    • 2020
  • A Kalman filter algorithm is used for the generation of an ensemble timescale with three hydrogen masers maintained in KRISS. Allan deviation curves of three pairs of clocks were obtained by a three-cornered hat method and were used as reference curves for determination of parameters of the Kalman filter-based timescale. The ensemble timescale equation of a 3-clock system was established, and the clocks' phases estimated by the Kalman filter were used as the prediction time of each clock in the equation. The weight of each clock was determined inversely proportional to the Allan variance calculated with the clocks' phases. The Allan deviation of the weighted mean was 1.2×10-16 at the averaging time of 57,600 s. However when we made fine adjustments of the clocks' weight, the minimum Allan deviation of 2×10-17 was obtained. To find out the reason of the great improvement in the frequency stability, additional researches are in progress theoretically and experimentally.

개선된 낙찰자 결정방식에 의한 토목 턴키.대안입찰공사 수주현황 분석 (Orders Status Analysis on the Successful Bidder Decision Method of Civil Turnkey.Alternative Tendering Construction)

  • 박홍태;이양규
    • 한국재난정보학회 논문집
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    • 제9권2호
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    • pp.164-177
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    • 2013
  • 2010년부터 2013년까지 낙찰자 선정방식이 설계적합 최저가방식, 종합평가방식(입찰가격 조정, 설계점수조정, 가중치기준), 확정금액 최상 설계방식으로 변경되었다. 따라서 이 연구는 국내에서 시행된 변경된 방식에 의한 토목부분 턴키 대안입찰공사의 발주현황, 건수, 수주실적, 낙찰률 범위, 공종별 발주기관별 수주실적, 가중치 낙찰자 수주실적 등의 분석을 통해 국내 낙찰자 결정방식이 건설산업에 미치는 영향, 심의 발주방식 및 운영상의 문제점을 분석하여 제시하였다.

최소제곱법에 의한 TRAVERSE망의 이론적 조정법 (A Study on the Theoretical Adjustment of Traverse Networks by the Method of Least Squares)

  • 이계학;성수련;박복봉
    • 한국측량학회지
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    • 제11권2호
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    • pp.1-5
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    • 1993
  • 본 연구에서는 traverse측량에 있어서 여러 개의 환으로 이루어진 강을 측각과 측거의 중량을 동시에 고려하여 정밀하게 조정할 수 있는 이론적 조정법을 제시하였다. 또한, 본 이론적 조정법으로 조정한 각과 거리를 다른 조정법들과 비교 검토한 결과 본 이론적 조정법의 타당성이 입증되었다.

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다층 신경망을 위한 Multi-gradient 학습 알고리즘 (Multi-gradient learning algorithm for multilayer neural networks)

  • 고진욱
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1999년도 하계종합학술대회 논문집
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    • pp.1017-1020
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    • 1999
  • Recently, a new learning algorithm for multilayer neural networks has been proposed 〔1〕. In the new learning algorithm, each output neuron is considered as a function of weights and the weights are adjusted so that the output neurons produce desired outputs. And the adjustment is accomplished by taking gradients. However, the gradient computation was performed numerically, resulting in a long computation time. In this paper, we derive the all necessary equations so that the gradient computation is performed analytically, resulting in a much faster learning time comparable to the backpropagation. Since the weight adjustments are accomplished by summing the gradients of the output neurons, we will call the new learning algorithm “multi-gradient.” Experiments show that the multi-gradient consistently outperforms the backpropagation.

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한국인(韓國人) 칼로리 권장량(勸?量) (The Calorie Allowances for Koreans)

  • 김동준
    • Journal of Nutrition and Health
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    • 제1권1호
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    • pp.49-51
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    • 1968
  • The Calorie allowances for a reference man (25 years, 60kg, moderate work) and a reference woman (25 years, 52kg, moderate work) were given by the formulae which were recommended by the Food and Agricultural Organization(FAO). E=152 W 0.73 3,000 Calories(man) E=123.4 W 0.73 2,200 Calories (woman) The appropriate adjustments were made for age, body weight (Table 1) and activity (Table 2) of adults other than a 'reference man' and 'reference woman' based on our report of 'Studies of Basal Metabolism and Energy Expenditure of Koreans in Daily Life' supported partly by the U.S. Department of Agriculture. The recommendation of FAO for the calorie requirements for children, the additional allowances for pregnancy, lactation and environmental temperature were adopted.

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도시철도 차량별 혼잡도 개선 방안 (A study on the improvement of the congestion level for each car in urban railways)

  • 이기수;차관봉;윤인영
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.1946-1954
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    • 2008
  • In urban railways operated by 10 cars or 8 cars per trainset, passengers split up and board a train. On-board passengers for each car are not aware of congestion level of other cars of the train. Passengers waiting at stations can not predict congestion rate of the car which they get on. Therefore, the number of passengers is not equally distributed. The cars with a relatively low congestion level and the ones with a high level coexist in the train. The objective of this paper is to enhance passenger convenience and improve train operational efficiency through operational headway adjustments according to congestion level of each car. It also aims to spread passengers out evenly and assess the degree of congestion on each car by measuring the weight of each car including passengers during peak and off-peak hours.

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Genetic Parameters of Pre-adjusted Body Weight Growth and Ultrasound Measures of Body Tissue Development in Three Seedstock Pig Breed Populations in Korea

  • Choy, Yun Ho;Mahboob, Alam;Cho, Chung Il;Choi, Jae Gwan;Choi, Im Soo;Choi, Tae Jeong;Cho, Kwang Hyun;Park, Byoung Ho
    • Asian-Australasian Journal of Animal Sciences
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    • 제28권12호
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    • pp.1696-1702
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    • 2015
  • The objective of this study was to compare the effects of body weight growth adjustment methods on genetic parameters of body growth and tissue among three pig breeds. Data collected on 101,820 Landrace, 281,411 Yorkshire, and 78,068 Duroc pigs, born in Korean swine breeder farms since 2000, were analyzed. Records included body weights on test day and amplitude (A)-mode ultrasound carcass measures of backfat thickness (BF), eye muscle area (EMA), and retail cut percentage (RCP). Days to 90 kg body weight (DAYS90), through an adjustment of the age based on the body weight at the test day, were obtained. Ultrasound measures were also pre-adjusted (ABF, EMA, AEMA, ARCP) based on their test day measures. The (co)variance components were obtained with 3 multi-trait animal models using the REMLF90 software package. Model I included DAYS90 and ultrasound traits, whereas model II and III accounted DAYS90 and pre-adjusted ultrasound traits. Fixed factors were sex (sex) and contemporary groups (herd-year-month of birth) for all traits among the models. Additionally, model I and II considered a linear covariate of final weight on the ultrasound measure traits. Heritability ($h^2$) estimates for DAYS90, BF, EMA, and RCP ranged from 0.36 to 0.42, 0.34 to 0.43, 0.20 to 0.22, and 0.39 to 0.45, respectively, among the models. The $h^2$ estimates of DAYS90 from model II and III were also somewhat similar. The $h^2$ for ABF, AEMA, and ARCP were 0.35 to 0.44, 0.20 to 0.25, and 0.41 to 0.46, respectively. Our heritability estimates varied mostly among the breeds. The genetic correlations ($r_G$) were moderately negative between DAYS90 and BF (-0.29 to -0.38), and between DAYS90 and EMA (-0.16 to -0.26). BF had strong $r_G$ with RCP (-0.87 to -0.93). Moderately positive $r_G$ existed between DAYS90 and RCP (0.20 to 0.28) and between EMA and RCP (0.35 to 0.44) among the breeds. For DAYS90, model II and III, its correlations with ABF, AEMA, and ARCP were mostly low or negligible except the $r_G$ between DAYS90 and AEMA from model III (0.27 to 0.30). The $r_G$ between AEMA and ABF and between AEMA and ARCP were moderate but with negative and positive signs, respectively; also reflected influence of pre-adjustments. However, the $r_G$ between BF and RCP remained non-influential to trait pre-adjustments or covariable fits. Therefore, we conclude that ultrasound measures taken at a body weight of about 90 kg as the test final should be adjusted for body weight growth. Our adjustment formulas, particularly those for BF and EMA, should be revised further to accommodate the added variation due to different performance testing endpoints with regard to differential growth in body composition.