• Interaction and multiscale mechanics
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• 제3권4호
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• pp.365-372
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• 2010

Station is an important building in high-speed railway, and its vibration and noise may significantly affect the comfort of waiting passengers. A coupling vibration model for train-structure system is established to analyze and evaluate the vibration level of a typical waiting hall under dynamic train load. The motion of a four-axle vehicle with two suspension system is modeled in multi-body dynamics with linear springs and dampers employed. The station is modeled as a whole finite element structure which is 113 m in longitudinal and 163.5 m in lateral, and the stiffness of the station foundation is considered. According to the assumptions that both wheel and rail are rigid bodies and keep contact to each other in vertical direction, and the wheel/rail interaction and displacement coordination in horizontal direction is defined by the simplified Kalker creep theory, the vehicle spatial vibration model has 27 degrees-of-freedom. An overall analysis procedure is made of the train moving through the station, by which the dynamic responses of the train and the station are calculated. According to the comparison between analysis and test results, the actual connection status between different parts of the station is estimated and the vibration level of the waiting hall is evaluated.

• 한국유체기계학회 논문집
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• 제18권3호
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• pp.5-11
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• 2015

Ocean waves have huge amounts of energy, even larger than wind or solar, which can be extracted by some mechanical device. This can be done by creating a system of reacting forces, in which two or more bodies move relative to each other, while at least one body interacts with the waves. This moves the floater up and down. The floaters are connected to an arm structure, which are mounted on a fixed hull structure. Hence, the structure of the floater is very important. A static structural analysis with FSI (Fluid-Structure Interaction) analysis is conducted. To achieve the pressure load for the FSI analysis, the floater is simulated on a wave generator using rigid body motion. The structural analysis is done to examine the stresses on the whole system, and four types of flange and floater are optimized. The result shows that the structure of floater with wood support is the safest.

• Asian-Australasian Journal of Animal Sciences
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• 제20권11호
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• pp.1729-1737
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• 2007

A CRD experiment was conducted to evaluate the effects of different exogenous betaine levels (0.000, 0.075, 0.150 and 0.225 percent) on 576 one-day-old male broiler chicks (Ross) under water salinity stress. Different levels of water salinity were made by adding 3 levels of NaCl (0, 1,000 and 2,000 mg/L) to drinking water. Feed and water were available ad libitum. Betaine increased body weight, improved feed conversion ratio, and decreased packed cell volume (p<0.05). Water salinity promoted body weight over the whole period, increased feed intake (11 to 21 and 29 to 42-d) and also improved feed conversion ratio in grower and finisher periods (p<0.01). Breast weight, water consumption (28-d and 42-d) and excreta moisture (28-d) were increased by elevating the level of water salinity (p<0.01). Interaction between dietary betaine and water salinity was significant on plasma osmolarity as well as epithelial osmolarity of the duodenum at 28-d. Epithelial osmolarity was decreased from duodenum to ileum. The data imply that betaine is involved in the protection of intestinal epithelia against osmotic disturbance which can be caused by saline water, but further research is needed to investigate the effects of betaine with higher levels of water salinity.

• 한국해양공학회지
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• 제9권1호
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• pp.161-172
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• 1995

A numerical procedure is described fro predicting the motion and structural responses of tension leg platforms(TLPs) in waves. The developed numerical approach is based on a combination of a three dimensional source distribution method and the dynamic response analysis method, in which the superstructure of TLPs is assumed flexible instead of the rigid body assumption used in tow-step analysis method. Both the hydrodynamic interactions among TLP members, such as columns and pontoons, and the structural whole structure are formulated using element-fixed coordinate systems which have the origin at the node of the each hull element and move parallel to a space-fixed coordinate system. Numerical results are compared with the experimental and numerical ones, which are obtained in the literature, concerning the motion and structural responses of a TLP in waves. The results of comparison confirmed the validity of the proposed approach.

• 드라이브 ㆍ 컨트롤
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• 제17권1호
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• pp.44-50
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• 2020

For the requirement of accurate tracking control and the safety of physical human-robot interaction, torque control is basically desirable for humanoid robots. Because of the complexity of humanoid robot dynamics, the TDC (time-delay control) is practical because it does not require a dynamic model. However, there occurs a considerable error due to discontinuous non-linearities. To solve this problem, the TDC-FLC (fuzzy logic compensator) is applied to humanoid robots. The applied controller contains three factors: a TDE (time-delay estimation) factor, a desired error dynamic factor, and FLC to suppress the TDE error. The TDC-FLC is easy to execute because it does not require complicated humanoid dynamic calculations and the heuristic fuzzy control rules are intuitive. TDC-FLC is implemented on the whole body of a humanoid, not on biped legs even though it is performed by a virtual humanoid robot. The simulation results show the validity of the TDC-FLC for humanoid robots.

• 드라이브 ㆍ 컨트롤
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• 제15권3호
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• pp.1-7
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• 2018

Humanoid robots have fascinated many researchers since they appeared decades ago. For the requirement of both accurate tracking control and the safety of physical human-robot interaction, torque control is basically desirable for humanoid robots. Humanoid robots are highly nonlinear, coupled, complex systems, accordingly the calculation of robot model is difficult and even impossible if precise model of the humanoid robots are unknown. Therefore, it is difficult to control using traditional model-based techniques. To realize model-free torque control, time-delay control (TDC) for humanoid robot was proposed with time-delay estimation technique. Using optimal walking trajectory obtained by particle swarm optimization, TDC with proposed scheme is implemented on whole body of a humanoid, not on biped legs even though it is performed by a virtual humanoid robot. The simulation results show the validity of the proposed TDC for humanoid robots.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2003년도 International Symposium of Silkworm/Insect Biotechnology and Annual Meeting of Korea Society of Sericultural Science
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• pp.97-98
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• 2003

Current study was aimed to understand an interaction between Dopa decarboxylase (DDC) and proteins that specifically binds to DDC in the silkworm, Bombyx mori. Materials and Methods: Materials-Animal: Bombyx mori Construction of GST fusion protein Preparation of lysates: Protein extracted from whole body of Bombyx mori Methods-In vitro binding assay with lysates, Peptide sequence and RACE-PCR (omitted)

• 한국게임학회 논문지
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• 제4권2호
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• pp.21-28
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• 2004

인간의 경험은 시각적 청각적 자극과 함께 물리적인 상호작용, 즉 직접적인 신체감각의 접촉을 통해 다차원적으로 정보를 인식할 때 보다 효율적이다. 특히 게임분야에서 게임을 즐김으로써 얻을 수 있는 만족감 내지는 몰입감은 사용자에게 전달되는 다양한 신체감각에 대한 피드백이 복합적으로 이루어졌을 때 효과적이다. 이에 본 연구에서는 시각과 청각의 전달에 의존하고 있는 기존의 온라인게임 분야에서 사용자들의 다양한 요구를 충족시킬 수 있는 체감형 시스템에 대해 분석하였으며 적용방법에 대해 연구하였다.

• 한국가금학회지
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• 제35권3호
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• pp.291-302
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• 2008

국내에서 사육되는 유색육용계 성장에 적합한 에너지와 단백질 수준을 구명하여 사료 급여 체계 확립에 필요한 기초자료를 제공하고자 두 차례의 사양 실험을 수행하였다. 공시동물은 유색육용계 1일령 암, 수컷 1,404수를 사용하였고, 펜당 26수씩 배치하였다. 사료내 에너지 수준은 사육전기 5주간 3,000, 3,100 kg/kcal이며, 단백질 함량은 $0{\sim}2$주에 20, 21, 22%를 급여하였으며, $3{\sim}5$주에 18, 19, 20, 21, 22%로 처리하였다. 조사 항목은 체중, 사료 섭취량을 측정하여 생산성을 계산하였으며, 실험 종료시 혈액을 채취하여 분석하였다. 실험 1 : $0{\sim}2$주간 사료 ME 함량 차이에 따른 생산 능력은 처리구간에 차이가 없으며 CP 함량 차이에 기인한 증체량과 사료 섭취량도 차이가 없었지만 사료 요구율은 CP 21, 22% 처리구에서 CP 20% 처리구에 비하여 통계적으로 개선되었다(P<0.05). 실험 개시후 $3{\sim}5$주간에 사료 ME 3,100 kcal/kg 처리구에서 ME 3,000 kcal/kg 처리구에 비하여 사료 요구율은 개선되었다(P<0.05). 이 기간에 사료내 CP 22% 처리구는 낮은 수준의 처리구보다 증체량이 유의하게 증가하였고(P<0.05) 사료 요구율은 CP가 높은 수준의 사료를 급여시에 낮은 수준의 CP 처리구에 비하여 개선되었지만 사료 섭취량은 처리구간에 차이가 없었다(P<0.05). 이 기간에 증체량과 사료 요구율은 ME와 CP간 상호 작용하였다(P<0.05). 전 실험기간 5주간에 사료 요구율은 ME 3,100 kcal/kg 처리구에서 ME 3,000 kcal/kg 처리구보다 개선되었으며, CP (20)18% 처리구는 다른 처리구에 비하여 높게 나타났다(P<0.05). 증폐량은 CP (22)22% 처리구에서 CP (21)21%, (20)18% 처리구보다 증가하였으며, ME와 CP간에 상호 작용은 증체량과 사료 요구율에서 나타났다(P<0.05). 혈중 알부민, 총콜레스레롤 함량은 ME 3,100 kcal/kg 처리구에서 ME 3,000 kcal/kg 처리구보다 증가하였지만 중성지방은 감소되었다(P<0.05). 한편 총콜레스테롤은 CP (22)21 처리구에서 CP (22)20, (20)18% 처리구에 비하여 증가하였다(P<0.05). 시험 2 : $0{\sim}2$주간 증체량은 ME 3,000 kcal/kg 처리구에 비하여 ME 3,100 kcal/kg 처리구에서 높게 나타났으며, CP 22% 처리구에서 CP 20% 처리구보다 유의하게 개선되었으며, CP과 ME는 상호 작용을 보였다(P<0.05). 사료 요구율은 CP 21, 22% 처리구에서 CP 20% 처리구보다 개선되었으나(P<0.05), $3{\sim}5$주 및 전체 사육 기간에 처리구간에 생산성은 차이가 없었다. 혈액 성상도 처리구간에 차이를 나타내지 않지만 ME와 CP 처리구간 총콜레스테롤 함량에 대한 상호 작용은 <.0001 수준에서 인정되었다. 따라서 교잡육용계 생리에 적합한 사료내 단백질 수준은 $0{\sim}2$주령에 22% 또는 그 이상의 수준으로 급여하고, $3{\sim}5$주의 단백질 수준은 21, 20% 수준으로 급여가 생산성의 극대화에 효과적일 것으로 생각되며, 사료내 에너지는 부분적으로 처리구간에 생산에 차이를 보였지만 일관성이 없었으므로 에너지 수준을 세분화하여 급여하는 추후의 시험이 필요할 것으로 사료된다.

• 대한조선학회논문집
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• 제59권5호
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• pp.271-279
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• 2022

In order to study the self-propulsion test and analysis techniques for the submerged body with pumpjet propulsors in the Large Cavitation Tunnel (LCT), at the Korea Research Institute of Ships and Ocean Engineering, a set of test equipment was designed and manufactured. The pumpjet propulsor is composed of rotor, stator and duct which results in the strong interaction between the components. To measure the thrust and torque for duct and stator, a ring-shaped sensor was applied. The test equipment including pumpjet is installed on the stern of the submerged body. As the whole pumpjet including duct and stator was considered as the propulsor from pumpjet open-water test, the self-propulsion test was conducted in the same way. The total thrust, combined thrust of rotor, duct and stator was used for the pumpjet self-propulsion test analysis. Accordingly, the self-propulsion test and analysis were conducted in the same way as those of the conventional propeller. The full-scale performances of the pumpjet propulsor were compared with those of the reference propeller. On the basis of the present study, it is thought that the pumpjet propulsor would be designed optimally.