• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.1
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• pp.26-36
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• 2013

This paper presents a simple and cost-effective stand-alone rapid battery charging system of 30kW for electric vehicles. The proposed system mainly consists of active front-end rectifier of neutral point clamped 3-level type and non-isolated bi-directional dc-dc converter of multi-phase interleaved half-bridge topology. The charging system is designed to operate for both lithium-polymer and lithium-ion batteries. The complete charging sequence is made up of three sub-interval operating modes; pre-charge mode, constant-current mode, and constant-voltage mode. The pre-charge mode employs the stair-case shaped current profile to accomplish shorter charging time while maintaining the reliable operation of the battery. The proposed system is specified to reach the full-charge state within less than 16min for the battery capacity of 8kWh by supplying the charging current of 78A. Owing to the simple and compact power conversion scheme, the proposed solution has superior module-friendly mechanical structure which is absolutely required to realize flexible power expansion capability in a very high-current rapid charging system.

• The Journal of the Korea Contents Association
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• v.11 no.3
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• pp.36-47
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• 2011

The main issue in the current software development is the development of a reusable and flexible software. Already many successful software development experiences have been proposed to extract patterns of common look, depending on the software environment or depending on the nature of the module you want to implement. Can develop the software quickly and accurately to select fit for the purpose of developing and reuse using experienced patterns. These developments are depending on the success and failure become a new experience and reuse again. Apply design pattern in software development is required, was not an option. In this paper, design and implement to a common framework applied design patterns for the development of reusable software using .NET Remoting in one of the technologies of distributed communication services.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.4
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• pp.873-892
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• 1998

In this paper, we propose an architecture of multimedia communication terminal that can e used in broadband ISDN environments. To design and implement the multimedia communication terminal, we analyzed the structure of multimedia terminals and the types of services which is recommended by public and private standard or ganization, such as ITU-T, Digital Audio-Visual Council(davic) and ATM Forum. The multifunctional communication terminal designed in this paper could allow inter-working between existing communication terminals on the heterogeneousnetwork and accept current and advanced multimedia communication application flexible. An implemented terminal is consisted of the multimedia processing board and the ATm interface board that is installed in PCI bus on personal computer. The integrated service multimedia communication terminal that is implemented supports retrieval, distributive and conversational communication service simultaneously. And then we performaned functional module test according to the individual communication services.

• KIEE International Transactions on Power Engineering
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• v.4A no.3
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• pp.129-133
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• 2004

This paper deals with the design and implementation of a TCSC (Thyristor Controlled Series Capacitor) simulator, which is a module for an analog type power system simulator. Principally, it presents configuration of controller hardware/software and its experimental results. An analog type power system simulator consists of numerous power system components, such as various types of generator models, scale-downed transmission line modules, transformer models, switches and FACTS (Flexible AC Transmission System) devices. It has been utilized for the verification of the control algorithm and the study of system characteristics analysis. This TCSC simulator is designed for 50% line compensation rate and considered for damping resister characteristic analysis. Its power rate is three phase 380V 20kVA. For hardware extendibility, its controller is designed with VMEBUS and its main CPU is TMS320C32 DSP (Digital Signal Processor). For real time control and communications, its controller is applied to the RTOS (Real Time Operation System) for multi-tasking. This RTOS is uC/OS-II. The experimental results of capacitive mode and inductive mode operations verify the fundamental operations of the TCSC.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.4
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• pp.16-23
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• 2012

At present, the significance of a new manufacturing system that can shift from 'mass production' and consider life cycles of a product is pointed out and extremely expected. In such a situation, it is recognized that the modular design, often called 'unit design,' is the important design methodology which realizes the new production system enabling 'cost reduction,' 'flexible production of a multi-functional artifact,' 'settlement of an environmental issue,' and so on. A module (unit) of a product is generally defined as 'the parts group made into the sub-system from a certain specific viewpoint.' So far, there have been many researches related to the modular design. However, they are often limited to a certain viewpoint (objective). This paper proposes a simple but effective method for multi-objective modular design. In the proposed method, a new design metric, called similarity index, is proposed to evaluate the modular design candidates from the multiple viewpoints.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.323-324
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• 2013

This paper presents a simple and cost-effective stand-alone rapid battery charging system of 30kW for electric vehicles. The proposed system mainly consists of active front-end rectifier of neutral point clamped 3-level type and non-isolated bi-directional dc-dc converter of multi-phase interleaved half-bridge topology. The charging system is designed to operate for both lithium-polymer and lithium-ion batteries. The complete charging sequence is made up of three sub-interval operating modes; pre-charge mode, constant-current mode, and constant-voltage mode. The pre-charge mode employs the stair-case shaped current profile to accomplish shorter charging time while maintaining the reliable operation of the battery. The proposed system is specified to reach the full-charge state within less than 16min for the battery capacity of 8kWh by supplying the charging current of 78A. Owing to the simple and compact power conversion scheme, the proposed solution has superior module-friendly mechanical structure which is absolutely required to realize flexible power expansion capability in a very high-current rapid charging system.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.3
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• pp.193-200
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• 2012

Mobility is one of the most important issues for search and rescue robots. To increase mobility for small size robot we have focused on the mechanism and algorithm inspired from centipede. In spite of small size, using many legs and flexible long body, centipede can overcome high obstacles and move in rough terrains stably. This research focused on those points and imitated their legs and body that are good for obstacle negotiation. Based on similarity of a centipede's legs and tracks, serially connected tracks are used for climbing obstacles higher than the robot's height. And a centipede perceives environments using antennae on its head instead of eyes. Inspired from that, 3 IR sensors are attached on the front, top and bottom of the first module to imitate the antenna. Using the information gotten from the sensors, the robot decides next behavior automatically. In experiments, the robot can climb up to 45 cm height vertical wall and it is 600 % of the robot's height and 58 % of the robot's length.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.201-202
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• 2012

This paper presents a simple and cost-effective stand-alone rapid battery charging system of 30kW for electric vehicles. The proposed system mainly consists of active front-end rectifier of neutral point clamped 3-level type and non-isolated bi-directional dc-dc converter of multi-phase interleaved half-bridge topology. The charging system is designed to operate for both lithium-polymer and lithium-ion batteries. The complete charging sequence is made up of three sub-interval operating modes; pre-charging mode, constant-current mode, and constant-voltage mode. Each mode is operated according to battery states: voltage, current and State of Charging (SOC). The proposed system is able to reach the full-charge state within less than 16min for the battery capacity of 8kWh by supplying the charging current of 67A. The optimal discharging algorithm for Vehicle to the Grid (V2G) operation has been adopted to maintain the discharging current of 1C. Owing to the simple and compact power conversion scheme, the proposed solution has superior module-friendly mechanical structure which is absolutely required to realize flexible power expansion capability in a very high-current rapid charging system. Experiment waveforms confirm the proposed functionality of the charging system.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.5
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• pp.38-45
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• 2004

As optical communication is being substituted for telecommunication, the demand of a large variety of fiber optic components is increasing. V-groove substrates, one of the module components, are used to connect optical fibers to optical planar circuits and to arrange fibers. Their applications are multi-channel optical connectors and optical waveguide fiber coupling, etc. Because these substrates are a critical part of the splitter in a multiplexer and a multi fiber connector, precise and reliable fabrication process is required. For precisely aligning core pitch between fibers, machined core pitch tolerance should be within sub-microns. Therefore, these are generally produced by state-of-the-art micro-fabrication like MEMS. However, most of the process equipment is very expensive. It is also difficult to change the process line for custom designs to meet specific requirements using various materials. For various design specifications such as different values of the V angle and low-priced process, the fabrication method should be flexible and low cost. To achieve this goal, we have suggested a miniaturized machine tool with high accuracy positioning system. Through this study, it is shown that this cutting process can be applied to produce V-groove subtracts. We also show the possibility of using a miniaturized machining system for producing small parts.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.9
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• pp.32-40
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• 2004

This paper deals with an automated computer-aided process planning and die design system by which designer can determine operation sequences even if they have a little experience in process planning and die design for axisymmetric products. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM softwares, DEFORM and ANSYS, to form a useful package. The system is composed of four main modules. The process planning and the die design modules consider several factors, such as the complexities of preform geometry, punch and die profiles, specifications of available multi former, and the availability of standard parts. They can provide a flexible process based on either the reduction in the number of forming sequences by combining the possible two processes in sequence, or the reduction of deviation of the distribution on the level of the required forming loads by controlling the forming ratios. Especially in die design module an optimal design technique and horizontal split die were investigated for determining appropriate dimensions of components of multi-former die set. It is constructed that the proposed method can be beneficial for improving the tool life of die set at practice.