• Journal of Computational Design and Engineering
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• 제1권4호
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• pp.243-255
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• 2014

The present study describes the development of control hardware and software for a mobile welding robot. This robot is able to move and perform welding tasks in a double hull structure. The control hardware consists of a main controller and a welding machine controller. Control software consists of four layers. Each layer consists of modules. Suitable combinations of modules enable the control software to perform the required tasks. Control software is developed using C programming under QNX operating system. For the modularizing architecture of control software, we designed control software with four layers: Task Manager, Task Planner, Actions for Task, and Task Executer. The embedded controller and control software was applied to the mobile welding robot for successful execution of the required tasks. For evaluate this imbedded controller and control software, the field tests are conducted, it is confirmed that the developed imbedded controller of mobile welding robot for shipyard is well designed and implemented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1603-1605
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• 2001

Eight 300kJ modularized capacitor-banks have been constructed. These modules have been installed and assembled to make a 2.4MJ pulse power system (PPS). This 2.4MJ PPS was developed to be used as a driver of an electrothermal-chemical (ETC) gun. Each capacitor bank has six 22kV, 50kJ capacitors connected in parallel. A triggered vacuum switch (TVS-43) was adopted as a main pulse power-closing switch in each module. The module also contains a crowbar circuit made of three high-voltage diode-stacks, a multi-tap inductor and an energy-dumping resistor. Various current shapes have been formed by a sequential firing of multiple capacitor banks. Resistive dummy load has been used and various combinations of experimental parameters, such as charging voltage, trigger time and inductance, were tested to make flexible current shapes.

• 천문학회보
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• 제42권1호
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• pp.34.3-35
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• 2017

Spectral energy distribution camera for QUasars in EArly uNiverse (SQUEAN) is a successor of Camera for Quasars in EArly uNiverse (CQUEAN) which was developed by Center for the Exploration of the Origin of the Universe and operated at the 2.1 m Otto Struve Telescope in the McDonald Observatory, USA, since 2010. The software of SQUEAN controls a science camera, a guiding camera, and a filter wheel, and communicates with the telescope control system (TCS). It has been constantly revised and modularized according to the upgrades of the TCS and the hardware changes. Recently we have implemented the stable network communication and the semi-automatic focusing modules to enhance observational convenience. In this presentation we describe the current status of the SQUEAN control software and introduce a software architecture which is optimized on efficient astronomical observations.

• 한국음향학회:학술대회논문집
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• 한국음향학회 2001년도 추계학술발표대회 논문집 제20권 2호
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• pp.21-24
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• 2001

본 논문은 신경 회로망을 이용하여, 전화망 대역의 음성, 즉, narrowband 음성에서 wideband 음성을 복원하고자 했다. BP 알고리즘을 사용하는 기존의 신경 회로망의 경우에는 음성과 같이 복잡하고 크기가 큰 훈련데이터에 대해서는 훈련이 제대로 되지 않는 단점이 있다. 그러므로 븐 논문에서는 이를 해결하기 위해 입력으로 들어온 LPC 켑스트럼 벡터를 k-means 알고리즘을 이용하여 미리 정한 개수의 cluster로 나눈 다음, 각각의 cluster에 대해 독립적인 신경 회로망을 적용했다 이로 인해 각각의 신경 회로망은 제한되고 서로 상관관계가 많은 음성들만 훈련하면 되므로, 기존의 신경 회로망에서 생기는 훈련의 정체를 개선할 수 있었다. 또 clustering 과정에서 생기는 오류를 보완하기 위해 후보신경 로망들의 출력에 fuzzy 개념을 적용해서 최종 출력을 내도록 했다 실험 결과에서, 제안한 알고리즘은 기존의 codebook mapping 알고리즘보다 스펙트럼 거리척도에 의한 비교 및 주관적인 음질 평가 양쪽에서 개선된 성능을 보였다.

• 로봇학회논문지
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• 제11권3호
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• pp.163-171
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• 2016

A modular manipulator in serial-chain structure usually consists of a series of modularized revolute joint and link modules. The geometric shapes of these modules affect the number of possible configurations of modular manipulator after assembly. Therefore, it is important to design the geometry of the joint and link modules that allow various configurations of the manipulators with minimal set of modules. In this paper, a new 1-DoF(degree of freedom) joint module and simple link modules are designed based on a methodology of joint configurations using a series of Rotational(type-R) and Twist(type-T) joints. Two of the joint modules can be directly connected so that two types of 2-DoFs joints could be assembled without a link module between them. The proposed geometries of joint and link modules expand the possible configurations of assembled modular manipulators compared to existing ones. Modular manipulator system of this research can be a cornerstone of user-centered markets with various solution but low-cost, compared to conventional manipulators of fixed-configurations determined by the provider.

• Journal of Welding and Joining
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• 제26권6호
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• pp.59-66
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• 2008

Recently, automobile parts progress with modularization, which a great many allied products are modularized. Therefore, the purpose of this study is to develope modular housing for modularization of steering gear. Generally, steering gear housing is composed of valve housing and rack housing, it is important to combine two housings. However, housing having the pipe shape is very sensitive to welding distortion, and welding trajectory is very complicated. In order to solve this subject, cooperative control by using robots was constructed. Further, we developed the dedicated system to suit modular housing based on it, and applied laser welding to there. Moreover, welding speed was controlled in the rapid curve section so that the defect in trajectory of housing was reduced to obtain sound weldment. Accordingly, produced housing by this way is presented enough withstanding pressure to $100kg/cm^2$, and roundness and straightness are measured about 10/100 and 0.9/100 respectively.

• 한국재난정보학회 논문집
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• 제13권2호
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• pp.130-138
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• 2017

본 연구는 부상식 기초가 사용되는 오일샌드 플랜트의 하부기초에 소형강관 말뚝이나 마이크로 파일 등을 마찰말뚝개념으로 사용할 경우 발생할 수 있는 말뚝의 개별 침하나 부상을 1개의 군으로 연결하여 복합거동이 가능하도록 하는 복합거동 연결체에 관한 것이다. 이에 기존의 무리말뚝과 파일드 래프트(piled raft) 기초의 장점을 오일샌드 플랜트에 적용하기 위한 복합거동 연결체의 형상을 검증하기 위하여 축소모형을 제작, 하중에 대한 거동을 계측하고 이를 통해 장치의 안정성 및 취약 부위를 선정하여 연결체의 형태를 결정하였다.

• 대한안전경영과학회지
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• 제16권4호
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• pp.11-19
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• 2014

Modern systems development becomes more and more complicated due to the need on the ever-increasing capability of the systems. In addition to the complexity issue, safety concern is also increasing since the malfunctions of the systems under development may result in the accidents in both the test and evaluation phase and the operation phase. Those accidents can cause disastrous damages if explosiveness gets involved therein such as in weapon systems development. The subject of this paper is on how to incorporate safety requirements in the design of safety-critical systems. As an approach, a useful system structure using the method of design structure matrix (DSM) is studied while reflecting the need on systems safety. Specifically, the effects of system components failure are analyzed and numerically modeled first. Also, the system components are identified and their interfaces are represented using a component DSM. Combining the results of the failure analysis and the component DSM leads to a modified DSM. By rearranging the resultant DSM, a modular structure is derived with safety requirements incorporated. As a case study, application of the approach is also discussed in the development of a military UAV plane.

• 대한의용생체공학회:의공학회지
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• 제36권6호
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• pp.264-270
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• 2015

A mock circulatory loop system has been developed to construct a simulator for trainees in cardiopulmonary bypass systems or to simulate a test environment for cardiac-assist devices. This paper proposes a computerized mock circulatory loop system whose node is modularized by using a servo control flow regulator to simulate dynamic change of the hemodynamic status. To observe the effect of time-varying resistance, one with hemodynamic properties, the proposed system replicates the planned cross-sectional areas of the outlet of a ventricular assist device in terms of voltage input of a servo valve. The experiment is performed (1) for steady-input commands of selected area sizes and (2) for dynamic commands such as monotonous increase and decrease, and oscillatory functions of the voltage input, and a computer program based on LabVIEW (National Instruments, Austin, USA) processes every measured data and control command to the servo valve. The results show that the pressure and flow at the target points with respect to time-varying resistance match intuitive estimation: the pressure at the outlet and the pressure drop between both sides of the valve increased and the flow at the outlet decreased for increased resistance.

• 전력전자학회논문지
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• 제20권5호
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• pp.389-394
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• 2015

This paper proposes a series-connected power conversion system that integrates a photovoltaic power conditioner and a charge-balancing circuit. In conventional methods, a photovoltaic power conditioner and a cell-balancing circuit are needed for photovoltaic systems with energy storage devices, which results in a complex configuration and high cost. To overcome these problems, a series-connected DC-DC power conditioning system that integrates a photovoltaic power conditioner with a charge-balancing circuit is proposed. During the generation, the system operates as power conditioner only, whereas it operates as a cell balancing circuit during the rest time. For the analysis, the operating principle of the circuit and the controller design are done by PSIM simulation. For verification, a hardware prototype with 48-W photovoltaic modules has been implemented. Results verified that the modularized photovoltaic power conversion system with a series-connected storage successfully works with the proposed method.