• Title/Summary/Keyword: dynamic modification

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A Controller Design and Performance Evaluation for 6 DOF Driving Simulator (6자유도 주행 시뮬레이터 구동을 위한 제어기 설계 및 성능평가)

  • Kang, Jin Gu
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.8 no.1
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    • pp.1-7
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    • 2012
  • In this paper Vehicle driving simulator have been used in the development and modification of models. A real-time simulation system and washout algorithm for an excavator have been developed for a driving simulator with six degrees of freedom. An interesting question, "how the 6 DOF Driving Simulator can be controlled optimally for the various tasks?" is not easy to be answered. This paper presents the hardware and software developed for a driving simulator of construction vehicle. A simulator can reduce cost and time a variety of driving simulations in the laboratory. Using its 6 DOF Simulator can move in various modes, and perform dexterous tasks. Driving simulators have begun to proliferate in the automotive industry and the associated research community. This effort involves the real-time dynamic of wheel-type excavator the design and manufacturing of the Stewart platform an integrated control system of the platform and three-dimensional graphic modeling of the driving environments.

Light-Adaptive Vision System for Remote Surveillance Using an Edge Detection Vision Chip

  • Choi, Kyung-Hwa;Jo, Sung-Hyun;Seo, Sang-Ho;Shin, Jang-Kyoo
    • Journal of Sensor Science and Technology
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    • v.20 no.3
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    • pp.162-167
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    • 2011
  • In this paper, we propose a vision system using a field programmable gate array(FPGA) and a smart vision chip. The output of the vision chip is varied by illumination conditions. This chip is suitable as a surveillance system in a dynamic environment. However, because the output swing of a smart vision chip is too small to definitely confirm the warning signal with the FPGA, a modification was needed for a reliable signal. The proposed system is based on a transmission control protocol/internet protocol(TCP/IP) that enables monitoring from a remote place. The warning signal indicates that some objects are too near.

Vibration Reduction of Electric-powered Hand Grinder (전동 핸드그라인더의 진동 저감)

  • 조성진
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.831-836
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    • 2004
  • Vibration of electric-powered hand grinder comes from the parts of motor, gear, bearing, and fan. Excessive vibration can be harmful to workers. To reduce vibration of a hand grinder we analyzed the frequency components from the routing electric-powered grinder and did modal test to find the natural frequencies of the each part. It shows that the vibration is due to the resonance of the case. To remove the resonance, the case structure is modified and the bearing cap is replaced on a basis of the results from the rotor dynamic analysis using SAMCEF. As a result the vibration of the hand grinder is reduced greatly.

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Vibration reduction of provision crane in a ship by structural dynamic modification (구조변경을 통한 선박용 Provision Crane의 진동저감)

  • 김극수;조성재;최수현
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.433-437
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    • 2004
  • A provision crane is generally installed on the upper deck to the rear of the accommodation of the ship in order to load and unload engine part or something heavy. There are two types of provision cranes: one is jib-type and the other is monorail-type. So the natural frequency of the jib-type crane equipment is low, therefore, there are some possibility of resonance between crane structure and the main excitation sources of the ship in normal operating range. This study describe a vibration reduction technique for provision crane by applying a proper countermeasure through finite element analysis and modal test. In order to find out weak point in design of provision crane, a sensitive analysis has been performed.

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Case study on Remodeling Clearwell Hydraulic Structure using Transient CFD Simulation Technique (Transient CFD 모사기법을 이용한 정수지 최적설계 사례연구)

  • Kim, Seon-Jin;Kim, Seong-Su;Park, No-Suk;Cha, Min-Whan;Wang, Chang-Keun
    • Journal of Korean Society of Water and Wastewater
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    • v.24 no.4
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    • pp.425-432
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    • 2010
  • From the results of tracer test for the existing clearwell in Y water treatment plant, $T_{10}$ and T10/T were calculated as 150 min and 0.24, respectively. Therefore it required the modification schemes for improving hydraulic efficiency, surrogated by $T_{10}$ and $T_{10}$/T, and disinfection performance. In this study, using transient CFD(Computational Fluid Dynamics) simulation technique, tracer tests on dynamic condition for the suggested schemes were simulated. From the results of simulation, it was revealed that 8~6 baffles are necessary to guarantee the disinfection ability in the existing clearwell. Also, installing orifice baffle in the vicinity of inlet could increase plug flow fraction within clearwell.

Fuzzy linguistic control of arc welding process (퍼지 논리 제어기를 이용한 아크용접 공정제어)

  • 부광석;양완행;조형석
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10a
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    • pp.356-361
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    • 1990
  • This paper presents a new self organizing fuzzy linguistic control (SOFLC) strategy for application to an arc welding process control. The proposed SOFLC is based on on-line modification of the control rules according to the extent of deviation of the one step ahead predictive output of the process from the desired output. The Predictive output of the process is estimated by a fuzzy predictor which is updated from the input and output data of the process. The rule base of the fuzzy subsets describing the control rules is modified by the improving mechanism based on the hill climbing approach. Simulation results show that this proposed SOFLC improves the response of the process in presence of the variation of the process dynamic characteristics.

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Precise assembly and regulation of 26S proteasome and correlation between proteasome dysfunction and neurodegenerative diseases

  • Im, Eunju;Chung, Kwang Chul
    • BMB Reports
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    • v.49 no.9
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    • pp.459-473
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    • 2016
  • Neurodegenerative diseases (NDs) often involve the formation of abnormal and toxic protein aggregates, which are thought to be the primary factor in ND occurrence and progression. Aged neurons exhibit marked increases in aggregated protein levels, which can lead to increased cell death in specific brain regions. As no specific drugs/therapies for treating the symptoms or/and progression of NDs are available, obtaining a complete understanding of the mechanism underlying the formation of protein aggregates is needed for designing a novel and efficient removal strategy. Intracellular proteolysis generally involves either the lysosomal or ubiquitin-proteasome system. In this review, we focus on the structure and assembly of the proteasome, proteasome-mediated protein degradation, and the multiple dynamic regulatory mechanisms governing proteasome activity. We also discuss the plausibility of the correlation between changes in proteasome activity and the occurrence of NDs.

A Study on the Fracture Phenomena in Optical Disks due to Increase of the Rotating Speed (회전속도 증가에 의한 광디스크의 파괴현상에 관한 연구)

  • Cho, Eun-Hyoung;Park, Jun-Min;Seo, Young-Sun;Chung, Jin-Tai
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.339-344
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    • 2000
  • In this study, the fracture phenomena of optical disks are discussed and then some recommendations are presented to prevent the fracture. The fracture occurs when disks have crack on the inner radius of the disks. Since the crack growth and the fracture result from the stress concentration on the tip of the crack, a measure should be taken to overcome the stress concentration. This problem can be resolved by the structural modification of a disk. This study proposes 3 types of improved optical disks, which are robust to the disk fracture due to the high spinning speed of a disk. The first type is a disk reinforced by wire rings, the second type is a disk added by texture fibers, and the third type is a rubber-coated disk.

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Performances of Intermittently Aerated and Dynamic Flow Activated Sludge Process (2단간헐폭기 및 유로변경 간헐폭기 활성슬러지 시스템을 이용한 도시하수 처리)

  • 원성연;민경국;이상일
    • Journal of environmental and Sanitary engineering
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    • v.13 no.1
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    • pp.26-31
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    • 1998
  • Removal of nitrogen and phosphate in wastewater is concerned to important for the prevention of eutrophication in receiving water and lake. Conventional activated sludge system designed for organics removal can be retrofitted only by modification of aeration basin to maintain anaerobic and aerobic state. Biological nutrient removal processes(BNR) such as Bardenpho, A$^{2}$/O, UCT, VIP were generally used for the treatment of wastewater. However these BNR processes used in large scale WWTP were not suitable in small scale WWTP(i.e., package type WWTP) due to relatively large fluctuation of flow rate and concentration of pollutants. The purpose of this research was to develop the compact, effective and economical package type WWTP for the removals of carbon and nitrogen in small scale wastewater. Intermittently aerated activated sludge system (IADFAS) were investigated for removal of nitrogen in both domestic wastewater, Bardenpho process was also evaluated. Nitrogen removal of IAAS, IADFAS, Bardenpho were 75, 77 and 67%, respectively.

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Development of a neural-based model for forecating link travel times (신경망 이론에 의한 링크 통행시간 예측모형의 개발)

  • 박병규;노정현;정하욱
    • Journal of Korean Society of Transportation
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    • v.13 no.1
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    • pp.95-110
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    • 1995
  • n this research neural -based model was developed to forecast link travel times , And it is also compared wiht other time series forecasting models such as Box-Jenkins model, Kalman filter model. These models are validated to evaluate the accuracy of models with real time series data gathered by the license plate method. Neural network's convergency and generalization were investigated by modifying learning rate, momentum term and the number of hidden layer units. Through this experiment, the optimum configuration of the nerual network architecture was determined. Optimumlearining rate, momentum term and the number of hidden layer units hsow 0.3, 0.5, 13 respectively. It may be applied to DRGS(dynamic route guidance system) with a minor modification. The methods are suggested at the condlusion of this paper, And there is no doubt that this neural -based model can be applied to many other itme series forecating problem such as populationforecasting vehicel volume forecasting et .

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