• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.392.2-392.2
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• 2016

본 연구에서는 인버티드 유기 태양전지에 적용하기 위한 버퍼 하이브리드 투명 캐소드를 RF/DC magnetron 스퍼터를 이용하여 제작하고 그에 대한 특성평가와 적용 가능성에 대해 연구하였다. 버퍼-캐소드 하이브리드 투명 전극은 ZnO, Ag, ITO를 이용하였고, Ag와 ITO의 두께는 고정한 상태에서 버퍼 역할을 하는 ZnO의 두께를 변수(25 nm ~ 45 nm)로 하여 ZnO두께에 따른 광학적, 전기적, 구조적, 표면 특성을 분석하였다. ZnO/Ag/ITO 하이브리드 투명전극의 최적의 조건에서 92%의 높은 투과도와 7.6 Ohm/square의 낮은 면저항을 갖는 버퍼-캐소드 하이브리드 투명전극을 구현하였다. 제작한 ZnO/Ag/ITO 버퍼 하이브리드 투명전극을 인버티드 유기 태양전지에 적용한 결과 버퍼 ZnO층을 스핀 코팅으로 제작한 인버티트 유기 태양전지에 비해 현저하게 낮은 효율을 나타내는 것을 확인 하였다. 이러한 이유를 규명하기 위해 스핀 코팅한 ZnO박막과 스퍼터 한 ZnO박막의 구조적, 표면적 특성을 비교 분석 하였고, UPS 분석 결과 스핀 코팅한 ZnO 박막의 일함수(3.3 eV)에 비해 스퍼터 한 ZnO박막의 일함수(4.4 eV)가 더 큰 것을 확인 할 수 있었다. 이를 통해 인버티드 유기 태양전지 소자의 효율을 높이기 위해서는 광학적 전기적 특성뿐 아니라 적절한 일함수와 공정방법의 중요성을 확인 하였다.

• Journal of Digital Contents Society
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• v.8 no.1
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• pp.85-91
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• 2007

This paper proposes a new hybrid anti-aliasing method for reducing aliasing appearing on an implicit surface using the point sampling. The hybrid anti-aliasing method is a method that finds differences in the values of pixel shown in Z-buffers for an implicit surface and thereby uses each of three types of Z-buffer. After determining the level of differences, it expresses a 3 dimensional object by using a multi Z-buffer if the level is severe, a double Z-buffer for a middle level, and only the original Z-buffer for a negligible difference. In comparison with the existing method in which multi Z-buffers have been entirely used for enhancing the anti-aliasing effect, the hybrid anti-aliasing method is an efficient method demonstrating an effect similar to the one using a multi Z-buffer while reducing the number of Z-buffers to be used.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.93-96
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• 2013

모바일 환경에서 전력 손실이 중요한 문제 중 하나가 됨에 따라, MRAM과 플래시메모리와 같은 비 휘발성 메모리가 차세대 모바일 컴퓨터에 널리 사용될 것이다. 본 논문에서는 DRAM/MRAM 하이브리드 메인 메모리의 제한적인 쓰기 연산 성능을 고려한 효율적인 버퍼 캐시 기법을 연구했다. 제안한 기법은 MRAM 의 제한적인 쓰기 연산 성능을 고려하고 플래시 메모리 저장 장치의 삭제 연산 횟수를 최소화한다.

• Journal of KIISE
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• v.42 no.11
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• pp.1314-1321
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• 2015

Mobile devices employ buffer cache mechanisms, just as in computer systems such as desktops or servers, to mitigate the performance gap between main memory and secondary storage. However, DRAM has a problem in that it accelerates battery consumption by performing refresh operations periodically to maintain the stored data. In this paper, we propose a novel buffer cache scheme to increase the battery lifecycle in mobile devices based on a hybrid main memory architecture consisting of DRAM and non-volatile PCM. We also suggest a new buffer cache policy that allocates buffers based on process states to optimize the performance and endurance of PCM. In particular, our algorithm allocates each page to the appropriate position corresponding to the state of the application that owns the page, and tries to ensure a rapid response of foreground applications even with a small amount of DRAM memory. The experimental results indicate that the proposed scheme reduces the elapsed time of foreground applications by 58% on average and power consumption by 23% on average without negatively impacting the performance of background applications.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.411-413
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• 1999

본 논문에선느 ATM 통신망을 위한 여러 ATM 스위치 모델들 중에서, 내부적으로 블록킹(blocking)이 없고 입출력 단에 각각 버퍼가 할당되어 있는 입출력 버퍼형 교환기에 대하여 연구하였다. 기존에서 스위치 스피드-업(Switch Speed-up) 기법하에서 주로 연구가 이루어졌다. 따라서, 본 논문에서는 유니폼 트래픽하에서 Output-port Expansion 기법을 사용한 귀환.손실 모드 및 하이브리드 모드하에서의 셀 손실률을 비교 분석하였다. Output-port Expansion 기법은, 한 타임 슬롯동안에 입력포트 당 하나의 셀만 교환되며, 만약 하나 이상의 셀들이 같은 출력포트로 향하면, 최대 교환되는 셀 수를 K(Output-port Expansion Ratio)개로 제한하는 방식이다. 유니폼 트래픽(uniform random traffic) 하에서 각 모드에 따른 셀 손실률을 비교 분석한 결과, 로드 0.9를 기점으로, 0.9이하의 로드에서는 하이브리드 모드가, 0.9이상의 로드에서는 손실모드가 가장 낮은 셀 손실률을 보인다.

• Journal of Internet Computing and Services
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• v.10 no.2
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• pp.171-177
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• 2009

Optical packet switching(OPS) is a strong candidate for the next-generation internet, since it has a fine switching granularity at the packet level for providing flexible bandwidth, and provides seamless integration between WDM layer and IP layer. Optical packet switching have been studied in two categories: OPS in synchronous and OPS in asynchronous networks. In this article we are focused on contention resolution of OPS in asynchronous networks. The hybrid buffer have been addressed, to reduce packet loss further as one of the alternative buffer structures for contention resolution of asynchronous and variable length packets, which consists of the FDL buffer and the electronic buffer. The OPS design issue for the limited number of TWCs and internal wavelengths is important in the aspect of switch cost and resource efficiency. Therefore, an hybrid buffer structured optical packet switch and its scheduling algorithm is presented for considering the limited number of TWCs and internal wavelengths, for contention resolution of asynchronous and variable length packets. The proposed algorithm could lead to the packet loss improvement compared to the legacy LAUC-VF algorithm with only the FDL buffer.

• The KIPS Transactions:PartC
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• v.9C no.4
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• pp.531-542
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• 2002

An input and output buffering ATM switch conventionally operates in either Queueloss mode or Backpressure mode. Recently, a new mode, which is called Hybrid mode, was proposed to overcome the drawbacks of Queueloss mode and Backpressure mode. In Hybrid mode, when both the destined output buffer and the originfted input buffer are full, a cell is dropped. This thesis analyzes the cell loss rate and the cell delay of Queueloss, Backpressure and Hybrid modes in a switch adopting output-port expansion scheme under uniform traffic. Output-port expansion scheme allows only one cell from an input buffer to be switched during one time slot. If several cells switch to a same destined output port, the number of maximum transfer cells is restricted to K (Output-port expansion ratio). The simulation results show that if an offered load is less than 0.9, Hybrid mode has lower cell loss rate than the other modes; otherwise, Queueloss mode illustrates the lowest cell loss rate, which is a different result from previous researches. However, the difference between Hybrid and Queueloss modes is comparably small. As expected, the average cell delay in Backpressure mode is lower than those of Queueloss mode and Hybrid mode, since the cell delay due to the retransmission of higher number of dropped cells in Backpressure mode is not considered.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.4
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• pp.324-330
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• 1990

In this paper, the hybrid ARQ system involving the single error correcting and double error detection (127, 119) cyclic Hamming codes and the SR(selective repeat) ARQ schemes with a finite receiver buffer has been designed and constructed. The system performance has been analyzed and simulated. As a result of the simulation, it has been shown that the transmitter retransmitted those data blocks that were detected in errors especially the request signal errors using two retransmission. The system performance was measured by throughput efficiency due to channel error effects.

• The KIPS Transactions:PartA
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• v.15A no.6
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• pp.335-344
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• 2008

We propose an adaptive garbage collection technique for hybrid flash memory which has both SLC and MLC. Since SLC area is fast and MLC area has low cost, the proposed scheme utilizes the SLC area as log buffer and the MLC area as data block. Considering the high write cost of MLC flash, the garbage collection for the SLC log buffer moves a page into the MLC data block only when the page is cold or the page migration invokes a small cost. The other pages are moved within the SLC log buffer. Also it adjusts the parameter values which determine the operation of garbage collection adaptively considering I/O pattern. From the experiments, we can know that the proposed scheme provides better performance compared with the previous flash management schemes for the hybrid flash and finds the parameter values of garbage collection close to the optimal values.

• Journal of the Korean Magnetics Society
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• v.27 no.3
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• pp.82-86
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• 2017

The IrMn based GMR-SV films with three different buffer layers were prepared on Corning glass by using ion beam deposition and DC magnetron sputtering method. The major and minor magnetoresistance curves for three different buffer layers beneath the structure of NiFe(15 nm)/CoFe(5 nm)/Cu(2.5 nm)/CoFe(5 nm)/NiFe(7 nm)/IrMn(10 nm)/Ta(5 nm) at room temperature have shown different magnetoresistance properties. When the samples were annealed at $250^{\circ}C$ in vacuum, the magnetoresistance ratio, the coercivity of pinned ferromagnetic layer, and the interlayer coupling field of free ferromagnetic layer were enhanced while the exchange bias coupling field did not show noticeable changes.