• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.85-91
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• 1998

Many of the newest network suers are gaining their fist network experience as users of the Internet. Because of the universal nature of this exciting new experience, millions of new users are driving the demand for increasingly multimedia oriented applications, especially in communication area. Since the communication via the Internet can use various media forms including audio, video and graphics, it can e very efficient communication system on the Internet, which allows Internet users to communicate, collaborate, and associate with others. Webber provides various communication services, like ACS(Audio Conference System), VCS(Video Conference System) and Virtual Space, in an integrated environment. Webber consists of Service-PUBs(Processing Unit Plug-in), which process each service, and Framework, which manages these PUPs. PUP is so highly independent of each other that it's easy to add, maintain, delete services and also optimally configure the system to user's terminal performance or network status.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2156-2159
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• 1998

This paper describes a Battery Checking & Monitoring System for monitoring battery cell and power system in Uninterruptible Power Supplies(UPS). The system is capable of measuring, in a matter of setting time, float and discharge voltage of up to 240 cells in a single installation, and has the memory capacity to store battery's alarm data information on up to 200 separate sites. This system are easy to maintain and attain cost effectively, so that prepared for meeting the customer's service needs immediately. The system is additionally programmed with a each model, that will enable to accurately determine the remain battery capacity in a UPS system following a short discharge test. It is also equipped with remote interrogation and control facilities.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1180-1184
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• 2004

There are two types of controller between railway and train. those are the Continuous Message Controller and the Intermittent Message Controller using for KHSR. The conventional Intermittent Message Controller board used a variable resister for setting the phase, but the variable resister affected some environmental facts, such as temperature, humidity, and vibration, etc. This study suggests how to solve the environmental problem described above. Using FPGA is quite profitable. It's easy to use and maintain, flexible with the New algorithm to fix up the problem.

• International Journal of Control, Automation, and Systems
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• v.2 no.4
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• pp.435-449
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• 2004

In this paper, a novel anti-sway control system that uses an inclinometer as a sway sensor is investigated. The inclinometer, when compared with a vision system, is very cheap, durable, and easy to maintain, while providing almost the same performance. A number of observers to estimate the angular velocity of the load and the trolley velocity are presented. A state feedback controller with an integrator is designed. After a time-scale analysis, a 1/4-size pilot crane of a rail-mounted quayside crane was constructed. The performance of the proposed control system was verified with a real rubber-tired gantry crane at a container terminal as well as with the constructed pilot crane. Experimental results are provided.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.370-371
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• 2018

Recently, interest in renewable energy is increasing due to energy depletion and environmental problems. Among them, solar energy is the most popular feature for its infinite, eco-friendly, easy to maintain and high utilization. In these solar power systems, solar cells have either a current-voltage characteristic curve or a power-voltage characteristic curve with non-linear properties. Therefore, the Maximum Power Point Tracking (MPPT) technique is important to control this. In this thesis, we will discuss MPPT techniques using a boost converter and demonstrate their behavior using the PSIM program. Also, the MPPT control algorithm for solar energy generation will be proposed.

• Genomics & Informatics
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• v.13 no.3
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• pp.90-92
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• 2015

Biological diversity, also known as biodiversity, is an important criterion for measuring the value of an ecosystem. As biodiversity is closely related to human welfare and quality of life, many efforts to restore and maintain the biodiversity of species have been made by government agencies and non-governmental organizations, thereby drawing a substantial amount of international attention. In the fields of biological research, biodiversity is widely measured using traditional statistical indices such as the Shannon-Wiener index, species richness, evenness, and relative dominance of species. However, some biologists and ecologists have difficulty using these indices because they require advanced mathematical knowledge and computational techniques. Therefore, we developed VBioindex, a user-friendly program that is capable of measuring the Shannon-Wiener index, species richness, evenness, and relative dominance. VBioindex serves as an easy to use interface and visually represents the results in the form of a simple chart and in addition, VBioindex offers functions for long-term investigations of datasets using time-series analyses.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.8
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• pp.629-635
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• 2008

Recently, microturbines have received attention as a small-scale distributed power generator. Since the exhaust gas carries all of the heat release, the microturbine CHP (combined heat and power) system is relatively compact and easy to maintain. Generating hot water or steam is usual method of heat recovery from the microturbine. In this work, a heat recovery unit producing hot water was installed at the exhaust side of a 30 kW class microturbine and its performance characteristics following microturbine power variation was investigated. Heat recovery performance has been compared for different operating conditions such as constant hot water temperature and constant water flow rate. In particular, the influence of water flow rate and hot water temperature on the recovered heat was analyzed.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.8
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• pp.689-695
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• 2004

This paper presents a robot system that combines computer network and an autonomous mobile robot where RTOS is installed. We propose a wireless communication protocol, and also implement it on the RTOS of the robot system. Main controller of the robot processes the control program as a task type in the real-time operating system. Peripheral devices are driven by the device driver functions with the dependency of the hardware. Because the client and server program was implemented to support the multi-platforms by Java SDK and Java JMF, it is easy to analyze programs, maintain system, and correct the errors in the system. End-user can control a robot with a vision showing remote sight over the Internet in real time, and the robot is moved keeping away from the obstacles by itself and command of the server received from end-user at the local client.

• The Transactions of the Korea Information Processing Society
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• v.6 no.10
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• pp.2693-2706
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• 1999

Reengineering to object-oriented system is needed to maintain the system and satisfy requirements of structure change. Target systems which should be reengineered to object-oriented system are difficult to change because these systems have no design document or their design document is inconsistent of source code. Using design document to identifying objects for these systems is improper. There are several researches which identify objects through procedural source code analysis. In this paper, we propose automatic object identification method based on clustering of VTFG(Variable-Type-Function Graph) which represents relations among variables, types, and functions. VTFG includes relations among variables, types, and functions that may be basis of objects, and weights of these relations. By clustering related variables, types, and functions using their weights, our method overcomes limit of existing researches which identify too big objects or objects excluding many functions. The method proposed in this paper minimizes user's interaction through automatic object identification and make it easy to reenginner procedural system to object-oriented system.

• Journal of the Korean Institute of Navigation
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• v.24 no.4
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• pp.299-312
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• 2000

Because shore(ship) to ship(shore) communication service via INMARSAT pay expensive cost, satellite service typically use two stage service that land users dial up LES(Land Earth Station) for sending or receiving message. In order to send and receive message, land users must maintain online state with LES on dedicated line. Also, two stage INMARSAT communication service must consume long time that processes step by step. In case of large company, they have own communication system, but small companys communicate simple messages with only telex. This paper describes the design and implementation of an integrated communication services via INMARSAT-C. This system uses inexpensive INMARSAT-C for transmission between ship and land. Because this system provides web and E-Mail interface, users send and receive messages easily and quickly. This system provides most users with inexpensive and easy communication facilities between ship and land.