• 한국세라믹학회지
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• 제51권2호
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• pp.97-102
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• 2014

In order to improve the refresh rate of old newspaper(ONP), PCC shape-controlling experiments were carried out. The effect of a PCC polymorph on improving the quality of old newspaper was studied for a transformation from waste paper to eco-friendly paper. The synthesis of PCC consists of an in-situ process and a loading process to enhance the refresh rate of old newspaper. The characteristics between the in-situ process and the loading process could be analysed by SEM analyses of coated fiber surfaces. The retention rate ranges from 65 to 67% after the application of the in-situ process, and that after the loading process ranges from 55 to 58%. The retention rates thus show a difference of about 7-10%. In addition, the whiteness and ERIC characteristics of the in-situ process gave more efficient results than those of the loading process.

• 한국시뮬레이션학회논문지
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• 제9권4호
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• pp.51-58
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• 2000

The control of the data retention time is a main issue for realizing future high density dynamic random access memory. The novel junction process scheme in sub-micron DRAM cell with STI(Shallow Trench Isolation) has been investigated to improve the tail component in the retention time distribution which is of great importance in DRAM characteristics. In this' paper, we propose the new implantation scheme by gate-related ion beam shadowing effect and buffer-enhanced ${\Delta}Rp$ (projected standard deviation) increase using buffered N-implantation with tilt and 4X(4 times)-rotation that is designed on the basis of the local-field-enhancement model of the tail component. We report an excellent tail improvement of the retention time distribution attributed to the reduction of electric field across the cell junction due to the redistribution of N-concentration which is Intentionally caused by ion Beam Shadowing and Buffering Effect using tilt implantation with 4X-rotation. And also, we suggest the least requirements for adoption of this new implantation scheme and the method to optimize the key parameters such as tilt angle, rotation number, Rp compensation and Nd/Na ratio. We used MEDICI Simulator to confirm the junction device characteristics. And measured the refresh time using the ADVAN Probe tester.

• JSTS:Journal of Semiconductor Technology and Science
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• 제12권1호
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• pp.41-45
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• 2012

We observed that in chemical vapor deposition (CVD) tungsten silicide (WSix) poly gate scheme, the gate oxide thickness decreases as gate length is reduced, and it intensifies the roll-off properties of transistor. This is because the fluorine diffuses laterally from WSix to the gate sidewall oxide in addition to its vertical diffusion to the gate oxide during gate re-oxidation process. When the channel length is very small, the gate oxide thickness is further reduced due to a relative increase of the lateral diffusion than the vertical diffusion. In DRAM cells where the channel length is extremely small, we found the thinned gate oxide is a main cause of poor retention time.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.485-486
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• 2006

This paper proposes a novel low-cost CMOS temperature sensor for controlling the self-refresh period of a mobile DRAM. In this temperature sensor, ring oscillators composed of cascaded inverter stages are used to obtain the temperature of the chip. This method is highly area-efficient, simple and easy for IC implementation as compared to traditional temperature sensors based on analog bandgap reference circuits. The proposed CMOS temperature sensor was fabricated with 80 nm 3-metal DRAM process. It occupies a silicon area of only about less than $0.02\;mm^2$ at $10^{\circ}C$ resolution with under 5uW power consumption at 1 sample/s processing rate. This area is about 33% of conventional temperature sensor in mobile DRAM.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2005년도 춘계학술발표대회
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• pp.55-58
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• 2005

In multi-level storage system with snapshot data, some snapshots which are from selection portions of the base tables are kept in main memory. So how to efficiently refresh snapshots in response to changes on their base tables for preserving consistency which requires snapshots reflect the current state of the base tables referenced by the snapshot query is a very import research issue. In this paper, a method for efficiently refreshing snapshots is proposed. In this method, it uses a data structure to store metadata which contains some necessary information of every snapshot and an updating log that records the history of changes on its base tables. Synchronization process scans the metadata and refreshing process is executed using appropriate logs after it finds anyone of the snapshot need to be refreshed.

• 한국정보통신학회논문지
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• 제13권4호
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• pp.720-726
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• 2009

대규모 데이터베이스 시스템에는 다양한 종류의 데이터들이 공존하고 있으며, 사용자에게 정확하고 유용한 정보를 제공하기 위해 데이터의 신선도를 유지하는 문제는 중요한 이슈로 등장하고 있다. 대부분의 이런 문제의 해결책은 적절한 시간내에 요청된 갱신질의어를 얼마나 효율적으로 수행하는가 하는 것이 관건이다. 본 논문에서는 데이터의 신선도 유지와 기아상태의 공정성을 유지하기 위한 갱신 스케줄링 알고리즘을 제안한다. 제안된 알고리즘은 요청된 갱신질의어 실행시간 할당을 위해 목표 갱신 비율을 일정한 스케줄링 주기마다 재 계산한다. 본 논문에서 제안된 알고리즘을 사용함에 따라 데이터들의 공정성과 신선도를 유지 할 수 있다. 동적, 반-동적, 정적 데이터의 갱신처리 결과를 보여주기 위해 통합 웹사이트를 구현하였다.

• 디지털산업정보학회논문지
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• 제6권2호
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• pp.55-69
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• 2010

This article proposed the authentication protocol for peer-to-peer resource sharing community. The proposed protocol does not require a priori information for generating and exchanging authentication key. Also this protocol can provide the delicate access control by allowing the user(authenticator) to assign the trust level to the authentication supplicant, which can be used to decide if the resource providing node will accept the resource sharing request from a resource requesting node. Trust Relationship Chaining provides the environment where trust levels (included in the trust table) of nodes in the resource sharing community are propagated among nodes when trust tables are exchanged between two nodes engaged in mutual authentication process and authentication refresh so that any two nodes which are not directly mutual-authenticated can assign the trust level each other for the access control for resource sharing. In the proposed protocol a node can implements the authentication refresh continuously to verify the effectiveness of authentication after mutual authentication so that the authentication of new node or authentication revocation(effectiveness cancellation) of the departed node can be propagated to the all the nodes in RSC and eventually safe resource sharing community is configured.

• 복식
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• 제31권
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• pp.75-87
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• 1997

The purpose of this study was to investigate the experiential aspects of consumer in the ap-parel buying process especially the affective aspects. An ethnographic approach is a kind of qualitative analysis or naturalistic inquiry be-ing adopted by studies of anthnopology and consumer behavior,. Data were collected via doing participant observation interview field notes and recording for three months from fe-male students of universities in Pusan. Results were as following: First consumers experienced the various kinds of affection in the apparel buying pro-cess such as satisfaction pleasure/refresh-ment interest/attraction pride conspicous-ness impulse neglect prostration anxiety ir-ritation and dispiritedness. Second especially they were felt satis-faction and conspicousness by the atmosphere of store pleasure by the smell of store and impulse by nostalgia in apparel buying process. Also negative affections felt in the process such as neglect prostration anxiety and irri-taton had a great influence to apparel buying behavior. This study was to serve as a pilot study we wished to fortify the methodology of qualitat-ive analysis to identify themes and to de-velop hypothesis for further study.

• 한국전자거래학회지
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• 제11권1호
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• pp.1-23
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• 2006

e-Commerce와 같은 응용 등에 의해 점에서 XML데이터의 양이 많아짐에 따라 XML질의 처리를 신속하게 해주는 기술이 필요하게 되었다. 이를 가능하게 해주는 것이 XML질의 캐슁이다. 자주 제기되는 질의에 대하여 질의 결과를 캐쉬한 후, 동일 질의에 재사용 함으로써 빠른 응답 시간을 보장할 수 있다. 본 논문에서는 XML 질의 결과의 포맷으로 가장 보편적으로 사용되고 있는 노드 식별자 집합(NIS)을 캐쉬하여 XML 질의 성능을 향상시키는 기법을 제안한다. 캐쉬되는 NIS는 질의 결과를 구성하는 소스 XML 엘리먼트들의 식별자 집합이다. 따라서 NIS는 질의 결과의 재구성, 변형, 다른 데이터와의 통합 등 정 응용의 데이터 검색 요건을 충족시키기에 적절하고, XML 소스의 변경에 따른 점진적 갱신에 효율적이다. 그러나 XML문서 형태로 질의 결과를 반환해야 할 경우에는 소스 XML 엘리먼트를 검색하는 실체화 과정을 필요로 한다. 본 논문에서는 세 가지의 서로 다른 NIS의 구성을 고려하여 이들의 생성, 실체화. 점진적 갱신 알고리즘을 제안하고 RD BMS를 이용하여 구현하였다. 다양한 실험을 통한 성능 평가 결과 본 논문에서 제시하는 XML질의 캐쉬 기병의 효율성을 확확하였다.

• 정보과학회 논문지
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• 제42권11호
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• pp.1314-1321
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• 2015

모바일 디바이스는 데스크톱이나 서버 등 일반 컴퓨터 시스템과 마찬가지로 주기억장치와 스토리지와의 성능 차이를 완화시키기 위해 버퍼 캐시를 사용한다. 그러나 DRAM 은 저장된 데이터를 유지하기 위해 주기적인 refresh 연산을 수행함으로써 제한된 크기의 배터리 소모를 가속화하는 문제점을 가지고 있다. 본 논문에서는 모바일 디바이스 환경에서 배터리의 수명을 연장하기 위해 DRAM과 비휘발성 메모리인 PCM으로 구성된 하이브리드 메인 메모리 구조기반의 버퍼캐시 정책을 소개한다. 또한, PCM의 성능 및 내구성 특성을 최적화시키기 위해 프로세스 상태 기반의 새로운 버퍼 캐시 정책을 제안한다. 제안 기법은 포그라운드 및 백그라운드 애플리케이션이 사용하는 페이지를 서로 다른 방법으로 배치함으로써 소량의 DRAM으로도 포그라운드 애플리케이션의 빠른 응답성을 보장한다. 실험 결과, 제안 기법은 포그라운드 애플리케이션의 총 수행시간을 평균 58% 감소시켰으며 전력 소비량도 평균 23% 감소시키는 것을 확인하였다.