• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.494-496
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• 2006

There are several types of communication method which is used for the supply of electric power stably. But the communication methods used in KEPCO have weak points in the viewpoint of economy, technology and management. The Satellite communication systems have competitive rover in price and technology for national wide utility owing to its wide area coverage and stability. For better practical use of satellite communication in power industry, we developed the portable satellite communication terminal. This paper presents various functions and composition of the portable terminal for rower industry.

• 대한임베디드공학회논문지
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• 제2권1호
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• pp.1-8
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• 2007

In this paper, we developed a file system architecture for portable multimedia devices. To enhance user convenience, the information about the stored files should be easily retrieved and organized. We defined NMD (Networked MetaData), which can organize the files in networked fashion by attaching user-defined attributes and relation between files. The NMD is stored in flash memory to utilize its nonvolatile property and low-power consumption, while multimedia files are stored in hard disk, an inexpensive mass storage. The experimental implementation showed that this architecture was able to save about 10% power compared to the hard disk NMD-store.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2005년도 추계 종합학술대회 논문집
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• pp.596-600
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• 2005

In High-speed Portable Internet system to improve performance of whole system, adaptive modulation and coding technology is used, this technology changes modulation and encoding techniques depending on wireless channel environment. Modulation technology that is used in High-speed Portable Internet system is BPSK, QPSK, 16QAMs and 64QAMs. If terminal is distant from base station transceiver system, BPSK or QPSK technology Is used and 16QAMs or 64QAM technology is used if is near in the base station transceiver system. In this paper, number of sub-channel in each modulation technology minimized total transmitting number of PDU is analyzed for efficient radio resources usage. For this, simulation is conducted and the results are presented at High-speed Portable Internet system environments.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2004년도 수소연료전지공동심포지움 2004논문집
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• pp.37-42
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• 2004

To maintain proper operating conditions is important to get optimal output power of a PEMFC stack. The air cooled fuel cell stack is widely used in sub kW PEMFC systems. A 500W air cooled PEMFC stack was experimentally investigated to evaluate the design performance and to get optimal operating conditions for the portable application. The relationship between the operating conditions and the performance was analyzed. The results can be used as design criteria for portable PEMFC under various conditions.

• 전기학회논문지
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• 제65권4호
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• pp.622-627
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• 2016

This paper describes the development of a portable potentiostat which can perform square wave voltammetry on electrochemical sensors and wireless transmission of the measured data to a smartphone using Bluetooth. The potentiostat consists of a square wave potential pulse generation circuit for applying the potential pulse to the electrochemical sensor, a reduction/oxidation (or redox) current measurement circuit, and Bluetooth for wireless data transmission to an Android-based smartphone. The measured data are then processed to show the output graph on the smart phone screen in real time. This data transformation into a graph is carried out by developing and installing a simple transformation application software in the Android-based smartphone. This application software also enables the user to set and change the measurement parameters such as the applied voltage range and measured current range at user's convenience. The square voltammetry output data measured with the developed portable potentiostat were almost same as the data of the commercial potentiostat. The measured oxidation peak current with the commercial potentiostat was $11.35{\mu}A$ at 0.26 V and the measured oxidation peak current with the developed system was $12.38{\mu}A$ at 0.25 V. This proves that performance of the developed portable measurement system is comparable to the commercial one.

• 한국지능시스템학회논문지
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• 제24권5호
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• pp.489-494
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• 2014

본 논문에서는 무인차량용 다중채널 무선원격 제어시스템의 설계방안을 제안한다. 기존의 무선원격 제어시스템은 단일 제어채널로 구성되어 제어채널에 고장이 발생하였을 때 응급대처가 불가능한 문제점이 있다. 따라서 휴대용 무선원격 제어기와 스테이션용 무선원격 제어로 구성되는 다중채널 무선원격시스템을 제안한다. 무인차량용 다중채널 무선원격 제어시스템을 개발하기 위하여 휴대용 무선원격 제어기와 휴대용 무선원격 제어기를 설계 및 개발하였다. 개발한 무선원격 제어시스템의 성능을 확인하기 위하여 무인차량에 적용하여 주행 실험을 실시하였다. 무선원격제어기의 고장 시 휴대용 무선원격제어기를 이용한 비상정지 실험과 휴대용 무선원격제어기의 고장 시 스테이션용 원격제어시스템을 이용한 비상정지 실험을 실시한 결과 모두 만족하는 비상정지 성능을 발휘함을 검증하였다.

• 한국산학기술학회논문지
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• 제21권6호
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• pp.618-624
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• 2020

병사용 휴대형 전원은 전투원의 작전 수행 능력을 해치지 않는 범위의 휴대 하중을 지님과 동시에 전투장비의 소비전력에 대응하는 전기에너지를 공급할 수 있어야 한다. 특히 미래병사체계의 경우 전투장비의 고성능화에 따라 장비의 총 요구전력이 증가하고 있으므로 경량 고효율 특성을 가지는 휴대형 전원 개발이 필수적이다. 연료전지는 군용 전원으로 주로 적용되던 종래의 리튬 전지에 비해 중량 대비 에너지밀도가 높아 경량 소형화가 가능하여 휴대형 전원 시스템으로 활발한 연구개발이 진행되고 있다. 본 논문에서는 휴대형 전원으로 적용되는 연료전지의 특성을 살펴보고, 국내·외 군용 휴대형 연료전지 개발 현황을 조사한 후, 국외 선진 기술국의 개발 수준 대비 국내 기술 현황에 대해 분석한다. 또한, 미래병사체계용 전원으로의 적용을 위한 휴대형 연료전지 개발 시 고려해야할 주요 요소를 전력 공급 안정성, 휴대 용이성, 비용 절감 세 가지로 분류하고, 이와 관련된 기술을 중심으로 발전방안을 제시하여 향후 연료전지 기반 개인병사 체계용 휴대형 전원 기술 발전방안 수립 시 활용할 수 있도록 한다.

• 한국멀티미디어학회:학술대회논문집
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• 한국멀티미디어학회 2003년도 추계학술발표대회(상)
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• pp.445-448
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• 2003

During a time when cellular systems are being deployed in massive scale worldwide, international roaming is becoming increasingly important. This paper presents UIM (User Identification Module) for mobility support, authentication, and service portability between different mobile systems. We also introduce network model based on PASM(Portable Authentication and Mobility Service Machine) which will support signaling protocol and user information conversions with database for roaming between different mobile networks. Stored data types and elements in UIM, logical data structure and configuration, and registration procedures are described here in the case of DCN (Digital CDMA (Code Division Multiple Access) Network System) and GSM (Global System for Mobile Communications).

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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• pp.43-45
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• 2000

In this paper, portable and vehicle-mounted generators grounding methods of low-voltage systems is compared to each other. Ungrouded system is better for the safety operation than solidly grounding system. This paper also determined the magnitude and duration of the permissible body current limit and step voltage for the solidly-grounding and ungrounded system.

• 제어로봇시스템학회논문지
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• 제13권8호
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• pp.735-742
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• 2007

The importance of the interaction capability of a robot increases as the application of a robot is extended to a human's daily life. In this paper, a portable mediate interface Handybot is developed with various interaction channels to be used with an intelligent home service robot. The Handybot has a task-oriented channel of an icon language as well as a verbal interface. It also has an emotional interaction channel that recognizes a user's emotional state from facial expression and speech, transmits that state to the robot, and expresses the robot's emotional state to the user. It is expected that the Handybot will reduce spatial problems that may exist in human-robot interactions, propose a new interaction method, and help creating rich and continuous interactions between human users and robots.