• JSTS:Journal of Semiconductor Technology and Science
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• 제10권1호
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• pp.55-60
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• 2010

For battery-powered device applications, which grow rapidly in the electronic market today, low-power becomes one of the most important design issues of CMOS VLSI circuits. A multi-VDD system, which uses more than one power-supply voltage in the same system, is an effective way to reduce the power consumption without degrading operating speed. However, in the multi-VDD system, level converters should be inserted to prevent a large static current flow for the low-to-high conversion. The insertion of the level converters induces the overheads of power consumption, delay, and area. In this paper, we propose a new level converter which can provide the level up/down conversions for the various input and output voltages. Since the proposed level converter uses only one power-supply voltage, it has an advantage of reducing the complexity in physical design. In addition, the proposed level converter provides lower power and higher speed, compared to existing level converters.

• 한국정보통신학회논문지
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• 제20권8호
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• pp.1569-1580
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• 2016

2.4 GHz 능동형 RFID가 보다 활성화되기 위해 개선되어야 할 요인 중 하나는 배터리 수명 문제다. 그러나 현재 까지 소비 전력 예측을 위한 정확한 모델이 존재하지 않는다. 본 연구에서는 태그의 전력 소비를 정확하게 예측 할 수 있는 시뮬레이션 모델을 개발하였다. 충돌 제어와 query 명령어 사용 방법에 따라 6개의 시뮬레이션 모델을 제안 하였다. 예측 정확도를 높이기 위하여 태그의 작동 모드를 몇 개로 분류하고 그에 따른 전력 소비와 작동 시간을 조사하였다. 태그 수집과 응답 확인 과정을 간소화 하는 Query command 명령 방법과 최근에 제안된 충돌 제어 알고리즘을 본 시뮬레이션 모델에 사용하였다. 소비 전력 이외에도 시스템 효율과 다중 태그의 인식 시간, 그리고 인식률과 같은 성능 지표를 구하여 기존의 ISO/IEC 18000-7 시스템과 비교하였다.

• Journal of information and communication convergence engineering
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• 제9권6호
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• pp.695-700
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• 2011

Smartphone has formed a new market and introduced a new environment. They have an operating system like PCs, enabling free installation and removal of application programs. As the number of Smartphone users is increasing, more personal information is also exposed to malicious codes. There are problem of modification and deletion of files, battery consumption, and information leakage due to malicious codes. As the needs of Smartphone antivirus solutions are increasing, the antivirus solutions should be evaluated with quality characteristics. In this paper, we propose an effective evaluation method for functionality and performance of Smartphone antivirus solutions, and the best practices for evaluation.

• 대한전기학회논문지:전력기술부문A
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• 제54권9호
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• pp.441-448
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• 2005

On-line dynamic security assessment is becoming more and more important for the stable operation of power systems as load level increases. The necessity is getting apparent under Electricity Market environments, as operation of power system is exposed to more various operating conditions. For on-line dynamic security assessment, fast transient stability analysis tool is required for contingency selection. The TEF(Transient Energy Function) method is a good candidate for this purpose. The clustering of critical generators is crucial for the precise and fast calculation of energy margin. In this paper, we propose a new method for fast decision of mode of instability by using stability indices. Case study shows very promising results.

• 전자통신동향분석
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• 제29권4호
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• pp.157-167
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• 2014

최근 원도우XP에 대한 기술지원 종료가 사회적 이슈로 대두되고 있다. 우리나라는 다른 나라에 비해 데스크톱 OS 분야에서 원도우 OS를 사용하는 비중이 높은 상황이다. 과거 국산 OS 개발 노력은 있었지만, 원도우 환경의 편리함, 업무환경 등의 동반지원 부족 등으로 원도우 OS 제품을 성공적으로 대체한 사례는 아직까지 없다. 한편, 모바일 OS에서는 바다(Bada), 타이젠(Tizen) 등 상용화 사례가 있다. 윈도우XP 서비스 종료는 특정 솔루션에 대한 의존에서 탈피하기 위한 기회라는 점에서 정부는 오픈소스 기반 OS를 개발하여 행정용 PC에 활용한다는 계획이다. 데스크톱 OS 전환의 선결과제로 OS 자체에 대한 사용자 편리성, 안정성 그리고 보안성이 해결되어야 하며, 관련 기술 생태계가 확보되어야 한다는 지적이다. 본고에서는 먼저 OS 시장의 규모와 국내 시장점유율 현황을 검토하였다. 그리고 찬성론과 신중론 관점에서 윈도우XP 서비스 종료로 불거진 OS 개발 논쟁에 대해 살펴보았다.

• 한국항공운항학회지
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• 제25권3호
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• pp.135-142
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• 2017

As PED(Personal Electronic Device) market has been rapidly grown, the demand on Lithium battery, which is most commonly used power source of PED, also has been increased. Dew to this trend, the amount of Lithium battery air transportation is also increasing. However, it should be treated very carefully because Lithium is one of very explosive metal. So ICAO, IATA and civil aviation agencies try to enhance the safety of Lithium battery air transportation by aircraft certification and operating regulations. To enhance in-flight safety, the aircraft for transporting Lithium battery should equip certified fire extinguishing system. But recent studies find that Halon, currently used extinguishing agent, is not effective on extinguishing Lithium battery fire. Besides, there is no certified Halon replacement for air use and no acceptable specific minimum performance standard(MPS) for Lithium battery fire. For this issue, a study on characteristics and establishing MPS of Lithium battery fire is needed for safe air transportation of Lithium battery.

• 한국분말재료학회지
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• 제5권4호
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• pp.293-298
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• 1998

In all larger hardmetal workshops furnaces for dewaxing, vacuum sintering or vacuum and overpressure sintering are today's standard. The furnace technology is well established. Equipment specifications such as operating overpressure, determine sintering cost, product quality, safety and reliability of the furnace and ultimately influence the competitiveness of the hard metal procucer in the global market. Essential furnace requirements are an efficient utilization of the furnace, an environmental friendly dewaxing system, high temperature uniformity, metallurgical treatment with process gases, as well as reduced cooling time by means of rapid cooling. Examples of reduced sintering costs are described achieved using a new design of vacuum sintering furnace with an improved rapid cooling device, cooling times are reduced by up to 45%. Additionally, a cost comparison of two different designs of vacuum overpressure sintering furnaces are included.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.74.2-74
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• 2001

The availability of endoscope has been increased not only for observing inner parts of body but also for operating. Nowdays, the market of the endoscope has been widely extended and we presume that the value of marketablity will reach to wide. Most of the endoscope equipment is very expensive and as well, it costs a lot to repair or change the specific parts of equipment when it´s out of order on account of carelessness. About 90 percent of the endoscope equipment in the world is made in Japan. Therefore, to buy or repair the equipment, we can´t help outflowing foreign currency. In domestic, the efforts for localization and manufacturing the endoscope equipment are short. This paper shows that captured image from a CCD miniature carema is managed ...

• 전기학회논문지
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• 제57권7호
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• pp.1123-1128
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• 2008

The necessity of online dynamic security assessment is getting apparent under Electricity Market environments, as operation of power system is exposed to more various operating conditions. For on-line dynamic security assessment, fast transient stability analysis tool is required for contingency selection. The TEF(Transient Energy Function) method is a good candidate for this purpose. The clustering of critical generators is crucial for the precise and fast calculation of energy margin. In this paper, we propose a new method for fast decision of mode of instability by using stability indices and energy margin. The method is a new version of our previous paper.[1] Case studies are showing very promising results.

• 산업공학
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• 제16권1호
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• pp.111-116
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• 2003

Business integration has been considered as one of the most critical success factors that enable the firms to gain competitive edges. Despite this trend, it has also been found among not a few companies that the activities that should be functionally tied with are performed even independently. In this study, an integrated model of production planning and inventory has been developed. Computerization of the production planning activities is proposed and implemented. We also proposed the reasonable inventory levels of each item using historic data of the items, which are composed of safety stock from the given fill-rate, operating stock from the production patterns, and reserved stock from the production planning. This study has helped the firm to have clearer job definition of the related processes, to tightly control the inventory by setting and tracing the reasonable fill rates for every product, and to quickly respond to the market changes through the computerized production planning process.