• Journal of Mechanical Science and Technology
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• 제15권12호
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• pp.1892-1899
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• 2001

An experimental study was performed for measuring velocity and turbulence intensity in a circular tube for Re= 10,000, 15,000 and 20,000, with swirl and without swirling flow. The velocity fields were measured using PIV techniques and swirl motion was produced by a tangential inlet condition. Some preliminary measurements indicated that over the first 4 diameter, two regions of flow reversal were set up (the so called 2-cell structure). At the highest Reynolds numbers, the maximum values of the measured axial velocity components had moved toward the test tube wall and produce more flow reversal at the conter of the tube. As the Reynolds number increased, the turbulence intensity of swilling flow at the tube inlet also increased.

• 전자공학회논문지A
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• 제28A권10호
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• pp.774-781
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• 1991

A communication network protocol among programable devices built-i manufacturing field, MAP (Manufacturing Automation Protocol), has to provide the job transfer service carrying out a lot of jobs distributively, and the MMS( manufacturing message specification) defines the above application layer protocol. In this paper user software required in job transfer was implemented. So as to provide each service with compatibility and extension, each module was designed according to the functions. A method is selected in double-assigning their domain and program applicable even in complex process, which loads and proceeds several programs sequentially. In order to confirm the logical validity of the designed protocol, local applying test is accomplished for the application layer of response station. Modelling the job flow process, each serice module is verified with the I/O primitives.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1992년도 춘계학술대회 논문집
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• pp.359-363
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• 1992

As the demands of manufacturing automation is increasing, lots of efforts are devoted to the applications of Computer Integrated Manufacturing(CIM) concept in manufacturing shop floor. A workstation is a computer which controls differnet machines in the low level of factory(shop floor). A workstation can be utilized efficiently to enhance the coopetative work of machines. A scheduler is a component program in a workstation and it controls the operation of machines according to a fixed plan. A scheme for the scheduler has been developed for selected machines and software has been made. The fixed plan is stored in a schedule file which keeps machine names, communications methods, information for communications and time for the usages, etc. The scheduler carries out its role by the information in the schedule file. Although the developed software has some Iimitations, the test results show that the scheduler can be applied easily to the automation of the low level of factory.

• Journal of Biosystems Engineering
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• 제25권1호
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• pp.63-70
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• 2000

In Korea, researches for year-round leaf vegetables production system are in progress and the most of them are focused on environment control. Automation technologies for harvesting , transporting and grading need to be developed. This study was conducted to develop harvesting process automation system profitable to a competitive price. 1. Manipulator and end-effector are to be designed and fabricated , and fuzzy logic controller for controlling these are to be composed. 2. The entire system constructed is to be evaluated through a performance test. A robot system for harvesting a lettuce was developed. It was composed of a manipulator with 20DOF (degrees of freedom) an end-effector, a lettuce feeding conveyor , an air blower , a machine vision device, 6 photoelectric sensors and a fuzzy logic controller. A fuzzy logic control was applied to determined appropriate grip force on lettuce. Leaf area index and height index were used as input parameters, and voltage was used as output parameter for the fuzzy logic controller . Success rate of the lettuce harvesting system was 93.06% , and average harvesting time was about 5 seconds per lettuce.

• 한국산업융합학회 논문집
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• 제18권4호
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• pp.241-249
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• 2015

The purpose of this research is to develop the pattern recognition algorithm based on smart camera for inspection automation, and including external surface state of molding parts or optical parts. By performance verification, this development can be applied to establish for existing reflex data because inputting surface badness degree of scratch's standard specification condition directly. And it is pdssible to distinguish from schedule error of badness product and normalcy product within schedule extent after calculating the error comparing actuality measurement reflex data and standard reflex data mutually. The proposed technology cab be applied to test for masearing of the smallest 10 pixel unit. It is illustrated the relibility pf proposed technology by an experiment.

• 한국산업융합학회 논문집
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• 제13권4호
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• pp.205-209
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• 2010

Even the domestically small-and medium-sized companies progressed development in the monitoring equipment of inspecting run out in steel wheel aiming to supply and generalize through developing the monitoring equipment for securing quality technology and enhancing quality-test level. Run-Out value in vehicle wheel was measured with Computer & Servo system by using Low-Point marking machine control system, which is this development product. Low-Point value was operated and calculated. It marked by revolving wheel as much as the demanded measurement value based on 1ST harmony curve. Thus, the shipment of inferior product, which occurs in the measurement by the existing worker, could be blocked in advance. In the existing case, 60 sec. was required for inspecting 1 product. However, it came to bring about a rise in production volume through shortening inspection time to 8 seconds and improving workers' operating environment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.902-904
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• 1993

This paper contains the terminal developement for the feeder remote unit in Korea Distribution Automation System. This terminal unit has serval functions in order to do feeder auotmation as following, the open/close controls and gathering status informations of switchgears, getting line currents and voltages, distribution fault. So FRU has four modules to do those functions-Logic Controller, Relay Controller, Data Acquisition, Display, Power Supply etc. The FRU should be on allays, so AC power is supplied before & behind the switchgear. Power Supply is made up with AC/DC, DC/DC, Battery and/or SOLAR CELLS & CONTROLLER. It is important for the supply to protect against some Surges, because surges are happened so many times. Surge test is fellowing the standard IEC 801-5 or IEEE 587.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2019년도 춘계학술발표대회
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• pp.331-334
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• 2019

일반적인 키워드 기반 테스트는 기능 위주의 키워드를 작성하여 테스트를 자동화하여 비용은 적게 들지만 활용도가 높은 테스트를 자동화기 어렵다. 한편 탐색적 테스트는 리스크 기반으로 차터를 작성하여 짧은 시간동안 많은 에러를 탐지하는 장점이 있으나, 문서화가 미흡하다는 단점이 있다. 위와 같은 단점을 보완하기 위하여 탐색적 테스트의 기본 원리를 고수하면서 효율적 키워드 기반 자동화가 가능한 RAKTA(Record And Keyword-based Test Automation) 방법론을 제안한다. RAKTA는 오픈 소스 키워드 기반 자동화 프레임워크인 로봇 프레임워크의 기술을 사용하여, 키워드 기반과, 탐색적 테스트의 장점을 뽑아 효율적으로 테스트 자동화하여 비용을 줄이고 많은 에러를 탐지할 수 있다. 또한 본 논문에서는 RAKTA 방법론을 활용한 여러 가지 키워드 재사용 사례와 기존 조직에서 사용하던 테스트 스크립트를 혼합하여 통합 테스트, 인수 테스트, 설치 테스트를 자동화하는 방법을 제안한다.

• Journal of Power Electronics
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• 제19권5호
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• pp.1289-1302
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• 2019

In this paper, an optimal allocation method of a hybrid active power filter in an active distribution network is designed based on the differential evolution algorithm to resolve the harmonic generation problem when a distributed generation system is connected to the grid. A distributed generation system model in the calculation of power flow is established. An improved back/forward sweep algorithm and a decoupling algorithm are proposed for fundamental power flow and harmonic power flow. On this basis, a multi-objective optimization allocation model of the location and capacity of a hybrid filter in an active distribution network is built, and an optimal allocation scheme of the hybrid active power filter based on the differential evolution algorithm is proposed. To verify the effect of the harmonic suppression of the designed scheme, simulation analysis in an IEEE-33 nodes model and an experimental analysis on a test platform of a microgrid are adopted.

• Journal of Information Processing Systems
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• 제19권5호
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• pp.563-575
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• 2023

Trajectory planning is a key technology for unmanned aerial vehicles (UAVs) to achieve complex flight missions. In this paper, a terminal constraints conversion-based Gauss pseudospectral trajectory planning optimization method is proposed. Firstly, the UAV trajectory planning mathematical model is established with considering the boundary conditions and dynamic constraints of UAV. Then, a terminal constraint handling strategy is presented to tackle terminal constraints by introducing new penalty parameters so as to improve the performance index. Combined with Gauss-Legendre collocation discretization, the improved Gauss pseudospectral method is given in detail. Finally, simulation tests are carried out on a four-quadrotor UAV model with different terminal constraints to verify the performance of the proposed method. Test studies indicate that the proposed method performances well in handling complex terminal constraints and the improvements are efficient to obtain better performance indexes when compared with the traditional Gauss pseudospectral method.