• Title/Summary/Keyword: change of load

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FEM simulations of load cell weighing sensor (Load cell 중량센서의 FEM simulation)

  • 박찬원
    • Electrical & Electronic Materials
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    • v.7 no.3
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    • pp.200-205
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    • 1994
  • The FEM technique was applied to simulate the change of stress characteristics for various structural parameters and loading positions of the load cell. The output voltage of the load cell was then computed to compare with the manufactured load cell. The tendency of the stress variations of the load cell was well agreed with the basic formula of the single fixed. beam. Also, the stress characteristics according to the change of loading positions showed respective featured results as different structure. The calculated output voltages of the load cell were very close to those of the real manufactured ones.

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Relationship between Leg Stiffness and Kinematic Variables According to the Load while Running

  • Hyun, Seung Hyun;Ryew, Che Cheong
    • Korean Journal of Applied Biomechanics
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    • v.27 no.2
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    • pp.109-116
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    • 2017
  • Objective: This study aimed to investigate the relationship between leg stiffness and kinematic variables according to load while running. Method: Participants included eight healthy men (mean age, $22.75{\pm}1.16years$; mean height: $1.73{\pm}0.01m$; mean body weight, $71.37{\pm}5.50kg$) who ran with no load or a backpack loaded with 14.08% or 28.17% of their body weight. The analyzed variables included leg stiffness, ground contact time, center of gravity (COG) displacement and Y-axis velocity, lower-extremity joint angle (hip, knee, ankle), peak vertical force (PVF), and change in stance phase leg length. Results: Dimensionless leg stiffness increased significantly with increasing load during running, which was the result of increased PVF and contact time due to decreased leg lengths and COG displacement and velocity. Leg length and leg stiffness showed a negative correlation (r = -.902, $R^2=0.814$). COG velocity showed a similar correlation with COG displacement (r = .408, $R^2=.166$) and contact time (r = -.455, $R^2=.207$). Conclusion: Dimensionless leg stiffness increased during running with a load. In this investigation, leg stiffness due to load increased was most closely related to the PVF, knee joint angle, and change in stance phase leg length. However, leg stiffness was unaffected by change in contact time, COG velocity, and COG displacement.

Change in Magnetic Flux in the Air Due to Load (하중에 의한 공기중 자속의 변화)

  • Lee, Jeong-Hee
    • Journal of the Korean Society for Nondestructive Testing
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    • v.29 no.1
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    • pp.21-26
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    • 2009
  • In order to determine the effective way of measuring the Mode I stress intensity factor($K_1$) by means of the alternating current potential drop(ACPD) technique for a material containing a two-dimensional surface crack, the change in magnetic flux in the air due to load was studied theoretically and experimentally. The magnetic flux in the air between crack surfaces is uniform and is not changed by increasing the load in the specimen and experimental results are the same as those obtained from theoretical analysis. Therefore, the change in potential drop due to load in the measuring system which was designed to induce a large amount of electro-motive force was caused by the change in internal inductance of material and the change in the mutual inductance concerned with internal inductance of material.

Evaluation of Furrow Mulching Methods for Controlling Non-Point Source Pollution Load from a Sloped Upland (경사밭 고랑멀칭 방법에 따른 비점오염 저감효과 평가)

  • Yeob, So-Jin;Kim, Min-Kyeong;Kim, Myung-Hyun;Bang, Jeong-Hwan;Choi, Soon-Kun
    • Journal of The Korean Society of Agricultural Engineers
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    • v.64 no.3
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    • pp.33-43
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    • 2022
  • South Korea's agricultural nitrogen balance and phosphorus balance rank first and second, respectively, among OECD countries, and proper nutrient management is required to preserve the water quality of rivers and lakes. This study evaluates the effects of furrow mulching on the reduction of non-point source pollution (NPS) load from a sloped upland. The study site was Wanju-gun, Jeollabuk-do, and the survey period was from 2018 to 2019. The slope of the testbed was 13%, and the soil type was sandy loam. The cropping system consisted of maize-autumn Chinese cabbage rotation. The testbed was composed of bare soil (bare), control (Cont.), furrow vegetation mulching (FVM), and furrow nonwoven fabric mulching (FFM) plots. Runoff was collected for each rainfall event with a 1/100 sampler, and the NPS load was calculated by measuring the concentrations of SS, T-N, and T-P. The NPS load was then analyzed for the entire monitoring and crop cultivation periods. During the monitoring period, the effect of reducing the NPS load was 1.5%~44.5% for FVM and 13.1%~55.2% for FFM. During the crop cultivation period, it was 1.2%~80.5% for FVM and 27.0%~65.1% for FFM, indicating that FFM was more effective than FVM. As the NPS load was fairly high during the crop conversion period, an appropriate management method needs to be implemented during this period.

Loading Effect on ACPD of a Crack in Paramagnetic Material (균열을 가진 상자성체의 교류전위차에 미치는 하중의 영향)

  • Lee, Jeong-Hee
    • Journal of the Korean Society for Nondestructive Testing
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    • v.19 no.1
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    • pp.1-7
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    • 1999
  • In order to determine the mode I stress intensity factor ($K_I$) by means of the alternating current potential drop(ACPD) technique, the change in potential drop due to load for a paramagnetic material containing a two-dimensional surface crack was examined. The cause of the change in potential drop and the effects of the magnetic flux and the demagnetization on the change in potential drop were clarified by using the measuring systems with and without removing the magnetic flux from the circumference of the specimen. The change in potential drop was linearly decreased with increasing the tensile load and was caused by the change in conductivity near the crack tip. The reason of decreasing the change in potential drop with increasing the tensile load was that the increase of the conductivity near the crack tip due to the tensile load caused the decreases of the resistance and internal inductance of the specimen The relationship between the change in potential drop and the change in $K_I$ was not affected by demagnetization and was independent of the crack length.

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A Study on the Compensation Algorithm for Tension of Belt which is used as the Force Transfer Media Induction Motor (유도 전동기의 동력전달매체로 사용되는 벨트의 장력 보상 알고리즘에 관한 연구)

  • 김승환;임무생
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.9
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    • pp.1126-1130
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    • 1999
  • This paper persents an algorithm compensating for the change of tension acting on a belt which is used as a force transfer media of the induction motor that drives a washing machine. The induction motor adopted in a washing machine is operated not only for the power-transmission device, but also for the detection of clothes load. The load of clothes is determined by the duration of inertial rotation which is occurred by the induction motor during a specific time. The tension of belt also affects the determination of clothes load as another load and this change of the tension is a significant disturbance for accurate determination. This paper mentions the algorithm compensating for the amount of change in tension and the application of the algotithm proved to be effectively increasing the washing performance and reducing the noise and the vibration.

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A Study on the Vibration Characteristics by the Change of Impact Load Direction in the Collecting Plates of Electrostatic Precipitator (충결하중의 방향에 따른 정전집진기 집진판의 진동 특성 연구)

  • 나종문;이기백;양장식
    • Journal of KSNVE
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    • v.5 no.2
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    • pp.247-256
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    • 1995
  • In this paper, double exposure holographic interferometry using ruby pulse laser is formed in order to investigate the propagation of transient waves. The vibration characteristics according to the change of impact load direction, i.e., impacted in the shear direction and in the normal direction are analyzed. It was observed that the macroscopic trends of transient wave generation and propagation in the assembly of precipitator plates were almost similar regardless of the change of impact load direction. But the propagation and mixing of transient wave was advanced relatively slowly when impacted in the normal direction.

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Operating Characteristics of 5MW Class Gas Turbine Engine for Power Generation (5MW급 발전용 가스터빈 엔진의 작동 특성)

  • Park, Jun-Cheol;Hong, Sung-Jin;Bograd, Alexander;Ryu, Je-Wook
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.331-334
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    • 2010
  • Operating characteristics of DGT-5 being developed by Doosan Heavy Industries & Construction Co., Ltd. for power generation service was evaluated. Starting behavior was improved by a series of tests to investigate the effect of various fuel schedule and several combination of bleed valve control. The engine showed stable operation without any instability of compressor in the full operating regime covering from start-up to load conditions. If there is a rapid change of load in the condition of synchronization to Grid, the engine can be controlled stably based on the analysis of dynamic responses of the engine to an rapid load change and a sudden load rejection.

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A Study on the Control of Apartment House Design Factors considering Energy, Environment and Economical Efficiency (에너지, 환경 및 경제성을 통합 고려한 공동주택 설계요소 제어에 관한 연구)

  • Choi, Doo-Sung;Do, Jin-Seok
    • KIEAE Journal
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    • v.12 no.6
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    • pp.29-38
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    • 2012
  • The current building energy efficiency rating certification regulation on apartment houses evaluates only the saving rate of energy consumed during operation, i.e. use, of a building, but doesn't consider the energy consumptions and environmental load($CO_2$) emissions occurring during the whole lifetime of a building. So this study calculated the energy consumptions and environmental load emissions occurring during the whole lifetime of a building, selected reference schemes and alternative items by design variables to present a design draft considering energy efficiency and environmental performance, and evaluated the total cost by combining and calculating its direct cost(material and heating cost) and indirect cost(environmental cost), for an existing apartment house as an evaluation object. As a result of analysis, the change of heating cost by alternative items of design variables showed a 4~8% change rate compared to the reference scheme, and the material cost of design variable 7 showed a maximum 4.4 times change rate in the alternative plan 6 compared to the reference scheme. The environmental cost showed a similar change rate to the material cost change rate in general, but showed a similar environmental cost change rate to the heating cost change rate in case of design variables 4-1, 4-2, 7.

A Study on Simulation Analysis of Fatigue Deformation at Automotive Arm (자동차 암에 있어서의 피로 변형의 시뮬레이션 해석에 관한 연구)

  • Cho, Jae-Ung;Han, Moon-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.3
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    • pp.427-431
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    • 2007
  • The safety and the durability of the arm as an automotive chassis part under the fatigue can be predicted in this study. The fatigue life is sharply decreased from 0.5 to 0.75 at the change of load which is the amplitude load divided by average load. But its life is slightly decreased at the change of load from 0.75 to 1.5. The influence of fatigue life according to the change of load can be predicted by these results. As the value of maximum damage is 2.2 and the value of maximum compressive strain or stress is $-6.93{\times}10^{-3}$ or 349 Mpa at the connected part of rod end applied by concentrated load respectively, there is the greatest possibility of destruction due to the compression at this part.

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