• 한국컴퓨터정보학회논문지
• /
• 제11권1호
• /
• pp.243-250
• /
• 2006

모바일 단말기 장치가 발전하면서 컴퓨터로만 할 수 있었던 게임, 인터넷, 금융 서비스 등을 이동 단말기를 이용하여 처리할 수 있다. 본 논문에서는 펜티엄급 PC에서 유행하던 게임을 이동 단말기에서 재생가능성 하도록 재구성하고, 자동화 가능한 재구성 요소를 정리하여 아바타 변환기로 개발하고자 한다. 즉, 기존의 자원을 최대한 재활용하여 이동 단말기용 컨텐츠 개발 속도를 향상시킬 수 있는 방법을 제안하고자 한다. 플랫폼의 제약사항을 고려하여 기존의 컴퓨터의 아키텍처를 모바일 플랫폼에서 동작 가능한 로직과 리소스로 구분하여 변환하는 동작이 아바타 변환기의 주 기능이다. 이동 통신 사업자의 플랫폼 종류에 따른 다수의 컨텐츠 개발에 공용의 로직과 리소스를 변환함으로써 개발 속도를 향상시킬 수 있다.

• 정보통신설비학회논문지
• /
• 제10권1호
• /
• pp.1-6
• /
• 2011

The Underground pipeline facility is a general but most important facility in modern world, but its maintainability has been left behind. An automated and intelligent management technology is needed to prevent the wast of social resource and security. In this paper, we introduce Pipeline Health Monitoring(PHM) with Ubiquitous Sensor Network(USN) for inexpensive structure safety monitoring system, and improve its utility by inventing the advanced impedance converter.

• 전력전자학회논문지
• /
• 제27권1호
• /
• pp.74-79
• /
• 2022

This paper proposes a DC-DC converter that satisfies a wide output voltage of 150 V-1000 V for the battery voltage of various electric vehicles and can be controlled in both directions for the demand resource of electric vehicles. The proposed converter is a two-stage structure in which an insulated converter and a non-isolated converter are combined and operates as constant current or constant power depending on the voltage of the connected battery. Experimental results from a 20 kW prototype are provided to validate the proposed charger, and a maximum efficiency of 97% is obtained.

• 한국멀티미디어학회논문지
• /
• 제14권5호
• /
• pp.681-690
• /
• 2011

국내 이동통신사들이 서로 다른 모바일 플랫폼을 채택하여 사용함으로 인해 개발자는 하나의 모바일 게임 콘텐츠를 서비스하기 위하여 각각의 스마트폰 플랫폼 특성에 맞추어 변환 작업을 하여야 한다. 하지만, 기존의 모바일 게임 콘텐츠를 스마트폰 플랫폼으로 이식하기 위한 변환 작업에 많은 시간과 비용이 소모되고 있다. 이는 다양한 콘텐츠가 제공되지 못하고 있는 원인이기도 하다 본 논문에서는 이런 문제를 해결하기 위해 기존의 WIPI나 GNEX와 같은 모바일 플랫폼의 게임 콘텐츠를 Android나 iOS와 같은 스마트 플랫폼의 콘텐츠로 자동 변환해주는 모바일 콘텐츠 자동 변환기 시스템의 콘텐츠 분석기와 리소스 변환기를 구현하였다. 모바일 콘텐츠 자동 변환기 시스템은 단시간 내에 스마트 플랫폼으로 콘텐츠를 이식할 수 있도록 하여 동일 콘텐츠를 다른 이동통신사에 서비스하는데 소모되는 시간과 비용을 최소화해준다 또한, 기존 콘텐츠를 자동 변환하여 타 플랫폼에 서비스함으로써 콘텐츠의 재사용성을 높이고, 신규 콘텐츠의 생산성을 높여 사용자에게는 다양한 모바일 게임 콘텐츠를 제공할 수 있도록 지원한다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2010년도 추계학술대회
• /
• pp.74-75
• /
• 2010

As global warming due to burning fossil fuels and natural resource depletion issues have emerged, the development of renewable energy sources such as photovoltaics (PV) has been brought to recent interest. Amongst the vast efforts to harvest and convert solar energy into electricity, the module integrated converters (MIC) has become a worthy topic of research for grid-connected photovoltaic systems. Due to the required high-boosting qualities, only a restricted amount of DC/DC converter topologies can be applied to MICs. This paper investigates the possibility of a tapped-inductor boost converter as a candidate for PV MICs. A dual-inductor interleaving scheme operating slightly above the boundary of the two conduction modes (BCM) is suggested for reduction of input current ripple and minimization of component stress. A digital controller is used for implementation, assuring maximum power tracking and transfer while providing sufficient computational space for other grid connectivity applications, etc. For verification, a 200W converter is designed and simulated via computer software including component losses. High efficiency over a wide power range proves the feasibility of the proposed PV MIC system.

• International Journal of Automotive Technology
• /
• 제3권1호
• /
• pp.33-40
• /
• 2002

Increasingly stringent emission regulations of EU and CARB (California Air resource Board) require mandatory OBD (On Board Diagnostics) far the catalytic converters of a vehicle. It demands that MIL(Malfunction Indication Light) should be tuned on to inform the driver of catalytic converter failures. Currently dual oxygen sensor method Is widely used for the converter OBD. However, since it works only alter converter light-off, it has a serious limitation when applied to TLEV or more stringent emission regulations where more than 85% of total emission is coming out before converter light-off. In addition, a recent development in catalyst material. coating technology and additive catalysts leads to a much improved OSC (Oxygen Storage Capacity) after converter light-off, current methods are very difficult to determine levels of converter aging. Therefore, it is desired to develop an OSC detecting method before converter light-off to diagnose converter failures with higher reliability. In this study, OSCs of converters are measured by an absolute measuring method and a dynamic measuring method, and some of fundamental ideas are suggested about converter OBD before converter light-off. The converters are aged with two different aging methods; those are a furnace aging and an engine bench aging: to represent aging conditions in actual field applications. Dual oxygen sensor method at the lower temperature than light-off is also studied at a model gas bench with the converters. It is fecund that there is a certain point in temperature lower than light-off where difference due to aging level becomes maximum, thus a proper dynamic method to effectively monitor catalytic converters could be implemented fur the range lower than light-off temperatures. With this result, the aging level of converters is examined at an engine bench.

• Journal of international Conference on Electrical Machines and Systems
• /
• 제1권2호
• /
• pp.70-78
• /
• 2012

Due to the variable nature of renewable energy resources and power demand by consumers, it is difficult to operate a power system installed with only one type of renewable energy resource. Grid-based renewable generation may be the only solution to overcome this problem. The conventional approach based on a low-voltage converter with power frequency transformer is commonly employed for grid connection of offshore renewable energy systems. Because of the heavy weight and large size of the transformer, the system can be expensive and complex in terms of installation and maintenance. In this paper, an 11-kV series connected H-bridge (SCHB) multilevel voltage source converter (VSC) is proposed to achieve a compact and light direct grid connection of renewable energy systems. This paper presents the design, simulation and analysis of a five level (5L)-SCHB and an eleven level (11L)-SCHB VSC for 11-kV grid-based renewable energy systems. The performance, cost, modulation scheme and harmonic spectra of the converter are analyzed.

• Journal of information and communication convergence engineering
• /
• 제7권2호
• /
• pp.107-112
• /
• 2009

Renewable energy resources will be an increasingly important part of power generation in the new millennium. Besides assisting in the reduction of the emission of greenhouse gases, they add the much needed flexibility to the energy resource mix by decreasing the dependence on fossil fuels. Due to their modular characteristics, ease of installation and because they can be located closer to the user, PV system have great potential as distributed power source to the utilities. In this paper, a dc-de power converter scheme with the push-pull based technology is proposed to apply for solar power system which has many features such as high efficiency, stable output, and low acoustic noises, DC-DC converter is used in proposed topology has stable efficiency curve at all load range and very high efficiency characteristics. This paper presents the design of a single-phase photovoltaic inverter model and the simulation of its performance.

• Journal of Electrical Engineering and Technology
• /
• 제6권5호
• /
• pp.605-612
• /
• 2011

As the power grids are integrated into one big umbrella called a "smart grid," communication protocol plays a key role in successful operations. The successful deployment of smart grid interoperability is a major hurdle that must be overcome. The micro grid, a small power system that distributes energy resource, is operated in diverse regions. Different vendors use different communication protocols in the operation of the micro grid. Recently, the IEC 61850 has been legislated to solve the interoperability problems in power utility automation. The present paper presents a micro grid system based on the IEC 61850 protocol. It consists of a micro grid monitoring system, a protocol converter that transforms serial data to IEC 61850 data, and distributed energy resource controllers for diverse DER nodes. A developed communication gateway can be deployed for DER controllers with serial links to exchange data with IEC 61850-based devices. The gateway can be extended to IEC 61850-based distribution automation systems, substation automation systems, or SCADA.

• 한국지구물리탐사학회:학술대회논문집
• /
• 한국지구물리탐사학회 2007년도 공동학술대회 논문집
• /
• pp.291-296
• /
• 2007

We measured potential waveform of load, displacement, micro electric signal generated by rock and mortar fracture using PXI A/D Converter. The rock type used for measurement was used granite, limestone and sandstone, and mortar specimen. we made measuring equipment of physical properties to confirm basic information of physical properties, measured physical properties of rock engineering, electric resistivity and seismic velocity. Potential waveform system was built using PXI A/D Converter and measured potential waveform of load, displacement, micro-electric signal generated using this during uniaxial compressive test by the specimen finished such test of physical properties. Using the saturated rock and mortar specimen, micro electric signal increased, and It didn't increase a signal in dried rock and mortar specimen according as load and strain rate increases. But signal also increased in saturated or dried specimen in case of sandstone. It was possible to check the close correlation relationship the signal and fracture behavior by a compressive load as the signal of fracture position was increased bigger than the other position. It was also possible to check the correlation relationship between physical properties and micro geo-electric signal.