• Title/Summary/Keyword: DLM

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Flutter characteristics of a Composite Wing with Various Ply Angles (복합재료날개의 적층각에 대한 플러터 특성 연구)

  • Yoo, Jae-Han;Kim, Dong-Hyun;Lee, In
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2000.04a
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    • pp.126-130
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    • 2000
  • In this study, flutter characteristics of a composite wing have been studied for the variation of laminate angles in the subsonic, transonic and supersonic flow regime. The laminate angles are selected by the aspect of engineering practice such as 0, $\pm$45 and 90 degrees. To calculate the unsteady aerodynamics for flutter analysis, the Doublet Lattice Method(DLM) in subsonic flow and the Doublet Point Method(DPM) in supersonic flow are applied in the frequency domain. In transonic flow, transonic small disturbance(TSD) code is used to calculate the nonlinear unsteady aerodynamics in the time domain. Aeroelastic governing equation has been solved by v-g method in the frequency domain and also by Coupled Time-Integration Method(CTIM) in the time domain. from the results of present study, characteristics of free vibration responses and aeroelastic instabilities of a composite wing are presented for the set of various lamination angles in the all flow range.

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Prediction of the number of Tropical Cyclones over Western North Pacific in TC season (여름철 북서태평양 태풍발생 예측을 위한 통계적 모형 개발)

  • Sohn, Keon-Tae;Hong, Chang-Kon;Kwon, H.-Joe;Park, Jung-Kyu
    • 한국데이터정보과학회:학술대회논문집
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    • 2002.06a
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    • pp.9-15
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    • 2002
  • This paper presents the seasonal forecasting of the occurrence of tropical cyclone (TC) over Western North Pacific (WNP) using the generalized linear model (GLM) and dynamic linear model (DLM) based on 51-year-data (1951-2001) in TC season (June to November). The numbers of TC and TY are predictands and 16 indices (the E1 Nino/Southern Oscillation, the synoptic factors over East asia and WNP) are considered as potential predictors. With 30-year moving windowing, the estimation and prediction of TC and TY are performed using GLM. If GLM forecasts have some systematic error like a bias, DLM is applied to remove the systematic error in order to improve the accuracy of prediction.

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Contents of Carotenoids and Chlorophylls in Dolsan Leaf Mustard(Brassica juncea) (돌산갓의 Carotenoids 및 Chlorophyll 함량)

  • Cho, Young-Sook;Ha, Bong-Seuk;Park, Seok-Kyu;Chun, Soon-Sil
    • Journal of the Korean Society of Food Culture
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    • v.8 no.2
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    • pp.153-157
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    • 1993
  • To furnish basic data for the utilization of leaf mustard as a raw material of salted and fermented vegetable food, the contents of carotenoids and chlorophylls of Dolsan Leaf Mustard(DLM) were investigated. Total carotenoid content of DLM was 4.75 mg%, and the compositions were ${\beta}-carotene(80.91%)$, lutein(13.07%), lutein epoxide(3.93%). The contents of chlorophyll a and b were 4.1 and 1.5 mg%, and leaf was 7.4- and 8.1-fold, respectively, higher than leaf stalk. The ratios of chlorophyll a/b in leaf (2.7:1) and leaf stalk(3.0:1) were similar to those of other vegetables.

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Planform Curvature Effects on the Stability of Coupled Flow/Structure Vibration (면내 곡률이 천음속 및 초음속 유체/구조 연계 진동 안정성에 미치는 영향)

  • Kim, Jong-Yun;Kim, Dong-Hyun;Lee, In
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.11
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    • pp.864-872
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    • 2002
  • In this study, the effect of planform curvature on the stability of coupled flow/structure vibration is examined in transonic and supersonic flow regions. The aeroelastic analysis for the frequency and time domain is performed to obtain the flutter solution. The doublet lattice method(DLM) in subsonic flow is used to calculate unsteady aerodynamics in the frequency domain. For all speed range, the time domain nonlinear unsteady transonic small disturbance code has been incorporated into the coupled-time integration aeroelastic analysis (CTIA). Two curved wings with experimental data have been considered in this paper MSC/NASTRAN is used for natural free vibration analyses of wing models. Predicted flutter dynamic pressures and frequencies are compared with experimental data in subsonic and transonic flow regions.

A Study on Local Segmental Motions of Methylene Chain in Poly(Butylene Terephthalate) in Solution Phase

  • NamGung, Hyeon;O, Jeong Rae;Lee, Jo Ung
    • Bulletin of the Korean Chemical Society
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    • v.21 no.11
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    • pp.1071-1076
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    • 2000
  • Temperature dependent data of 13C spin-lattice relaxation times and NOE factors for methylene carbons at 50.3MHz and 125.5 MHz have been used to probe the local chain dynamics of poly(butylene terephthalate) (PBT) in solution phase. The interpretation of the relaxation data for methylene chain carbons in PBT was attempted on the basis of several proposed motional models, among which the DLM model was found to be superior. Analysis based on the DLM model indicated that the motion of the $OCH_2groups$ was more restricted compared with the central methylene carbon, which is consistent with conclusions from solid state experiments reported by other investigators. Librational amplitudes of terminal and central carbon of PBT were estimated to be $29.84^{\circ}$ and $32.01^{\circ}respectively.

Modeling the Trend of Apartment Market Price in Seoul (서울시 아파트 가격 추세의 모형화)

  • Hwang, Eun-Yeon;Kwon, Yong-Chan;Jang, Dong-Ik;Lee, Jae-Yong;Oh, Hee-Seok
    • Communications for Statistical Applications and Methods
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    • v.15 no.2
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    • pp.173-191
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    • 2008
  • The goal of this paper is analyzing and modeling the trend of apartment market price in Seoul using the dynamic linear model(DLM). We use the market price per pyeong of 30-pyeong-apartment provided by "KB apartment market price database" of Kookmin bank. The data is collected from June $24^{th}$, 2003 to August $28^{th}$, 2006. The inspection of the data reveals that the trend of apartment market price in Seoul can be divided into two groups and we assume that the price is expressed by the common trend of divided groups. We try to estimate the price of apartment by DLM using the Bayesian method.

A Design and Verification of an Efficient Control Unit for Optical Processor (광프로세서를 위한 효율적인 제어회로 설계 및 검증)

  • Lee Won-Joo
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.43 no.4 s.310
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    • pp.23-30
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    • 2006
  • This paper presents design andd verification of a circuit that improves the control-operation problems of Stored Program Optical Computer (SPOC), which is an optical computer using $LiNbO_3$ optical switching element. Since the memory of SPOC takes the Delay Line Memory (DLM) architecture and instructions that are needless of operands should go though memory access stages, SPOC memory have problems; it takes immoderate access time and unnecessary operations are executed in Arithmetic Logical Unit (ALU) because desired operations can't be selectively executed. In this paper, improvement on circuit has been achieved by removing the memory access of instructions that are needless of operands by decoding instructions before locating operand. Unnecessary operations have been reduced by sending operands to some specific operational units, not to all the operational units in ALD. We show that total execution time of a program is minimized by using the Dual Instruction Register(DIR) architecture.

Effect of degraded flaxseed meals on the growth performance, nutrient digestibility, and health status of broilers

  • Xiaoyu Ji;Xiangyu Liu;Jianping Wang;Ning Liu
    • Animal Bioscience
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    • v.37 no.7
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    • pp.1255-1262
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    • 2024
  • Objective: The present study evaluated the effect of flaxseed meal degraded by a protease, Lactobacillus plantarum, or both on the growth performance, nutrient digestibility, and health status of broilers. Methods: There were four diets containing flaxseed meals in its non-degraded form (control, CON), degraded with 3,000 U/kg of protease (enzymatic, ELM), 1.0×109 CFU/kg of Lactobacillus plantarum (fermented, FLM), or both (dual-degraded, DLM). Each form of flaxseed meals was added at 15% of diet. A total of 480 yellow-feathered broilers at 22 d of age were distributed into 4 groups with 6 replicates of 20 chickens each. The feeding trial lasted for 42 d. Growth performance, apparent fecal digestibility (dry matter, energy, crude protein, and ash), and serum immunoglobins and antioxidases were determined at 42 and 63 d of age. Results: Results showed that ELM, FLM, and DLM increased (p<0.001) the contents of peptides and decreased (p<0.001) cyanogenic glycosides, compared to CON. The diets with degraded flaxseed meals increased (p<0.05) feed intake and body weight gain throughout the feeding trial, and the digestibility of energy, crude protein, and ash at the end of feeding trial. Furthermore, all degraded groups enhanced (p<0.05) broiler health status by increasing serum immunoglobulins A and G. Additinally, DLM showed more pronounced effects (p<0.05) on these parameters than ELM or FLM. Conclusion: Flaxseed meals degraded by enzymolysis, fermentation, or both had improved nutrition and application in broilers.

Time Series Analysis for Traffic Flow Using Dynamic Linear Model (동적 선형 모델을 이용한 교통 흐름 시계열 분석)

  • Kim, Hong Geun;Park, Chul Young;Shin, Chang Sun;Cho, Yong Yun;Park, Jang Woo
    • KIPS Transactions on Computer and Communication Systems
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    • v.6 no.4
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    • pp.179-188
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    • 2017
  • It is very challenging to analyze the traffic flow in the city because there are lots of traffic accidents, intersections, and pedestrians etc. Now, even in mid-size cities Bus Information Systems(BIS) have been deployed, which have offered the forecast of arriving times at the stations to passengers. BIS also provides more informations such as the current locations, departure-arrival times of buses. In this paper, we perform the time-series analysis of the traffic flow using the data of the average trvel time and the average speed between stations extracted from the BIS. In the mid size cities, the data from BIS will have a important role on prediction and analysis of the traffic flow. We used the Dynamic Linear Model(DLM) for how to make the time series forecasting model to analyze and predict the average speeds at the given locations, which seem to show the representative of traffics in the city. Especially, we analysis travel times for weekdays and weekends separately. We think this study can help forecast the traffic jams, congestion areas and more accurate arrival times of buses.