• Title/Summary/Keyword: Weight Adjustments

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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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    • v.15 no.4
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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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    • v.2 no.2
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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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Three Dimensional Analysis of the Whole Interior-Surface of Structures by Multiple Close-Range Photogrammetry (다중근접사진측량에 의한 구조물 내부전면의 3차원 해석)

  • 이진덕;강준묵
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.11 no.1
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    • pp.7-18
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    • 1993
  • In analyzing whole surface of non-topographic objects, the design of multi-station photogrammetric network must involve a number of questions such as geometric configuration of exposure stations, imaging geometry, control point configuration or weight allowance of adjustments. Above all, the surveying of the interior of narrow longitudinal structures needs the design of special photogrammetric network. The main objective of this paper is to suggest the schemes for solving difficult problems attendant upon whole inside-surface analysis of structure and to improve the accuracy and reliability of final measurements. For it, the multi-station exposure network suitable to shape and size of the inside of the structure was designed. Then three dimensional data were acquired by bundle adjustments derived from multi-station photos and the effects of network design factors on accuracy of measurements were contemplated. Also, the algorithm for detection of blunders was developed here is expected to lead to improvement of the reliability of photogrammetric solutions.

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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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    • v.9 no.3
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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.

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

  • Park, Hong Taea;Lee, Yang Kyu
    • Journal of the Society of Disaster Information
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    • v.9 no.2
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    • pp.164-177
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    • 2013
  • From 2010 years to 2013, the selection method of successful bidder has been changed design suitable lowest method, comprehensive evaluation method(bid price adjustment, design score adjustments, weight standards), fixed amount best design method. Therefore this study was presented by analyzing the impact on the domestic construction industry according the way to determine the successful bidder, the evaluation order method and the operational issues through the analysis of order status, order number, results of acceptance an order, success rate range, results of acceptance an order according to weight success rate, results of acceptance an order by work type and order institution of a turnkey alternative tendering construction performed in domestic civil part.

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

  • 이계학;성수련;박복봉
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.11 no.2
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    • pp.1-5
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    • 1993
  • This paper dealt with the theoretical adjustment of the closed nets with the various links by weight of the observed angles and distances. In addition to the results of checking between this theoretical adjustment method, the compass rule and transit rule, the theoretical adjustment method is more accurate than other adjustments.

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

  • 고진욱
    • Proceedings of the IEEK Conference
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    • 1999.06a
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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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The Calorie Allowances for Koreans (한국인(韓國人) 칼로리 권장량(勸?量))

  • Kim, D.J.
    • Journal of Nutrition and Health
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    • v.1 no.1
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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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A study on the improvement of the congestion level for each car in urban railways (도시철도 차량별 혼잡도 개선 방안)

  • Lee, Gi-Su;Cha, Gwan-Bong;Yoon, In-Young
    • Proceedings of the KSR Conference
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    • 2008.06a
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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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    • v.28 no.12
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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.