• 한국통신학회논문지
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• 제24권10B호
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• pp.1824-1831
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• 1999

본 논문에서는 연속 패킷 손실 환경에서 systematic erasure code를 적용하였을 경우의 손실 복구율에 관하여 분석하고 손실 특성에 따른 부가 전송량의 추정방법에 대하여 제시한다. 연속 패킷 손실환경은 Gilbert 모델로 설정하였고, 기존의 연속 손실 환경에서의 erasure code의 손실 복구율 분석방안을 이용하여 systematic erasure code를 사용하였을 경우의 성능을 분석하고, 평균 패킷 손실율, 손실의 평균 길이 등의 주어진 패킷 손실 특성으로부터 주어진 손실 특성을 만족시키는 부가 전송량의 추정 방법을 제시한다.

• 전기전자학회논문지
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• 제19권1호
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• pp.94-100
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• 2015

본 논문에서는 U-MOSFET 내부의 기생 body 다이오드(PN diode)를 쇼트키 body 다이오드(Schottky body diode)로 대체한 50V급 전력 U-MOSFET을 제안하였다. 쇼트키 다이오드는 PN 다이오드와 비교 시, 역 회복 손실(reverse recovery loss)을 감소시킬 수 있는 장점을 가지고 있다. 따라서 전력 MOSFET의 기생 body 다이오드를 쇼트키 body 다이오드를 대신함으로써 역 회복 손실을 최소화 할 수 있다. 제안된 쇼트키 body 다이오드(Schottky body diode) U-MOSFET(SU-MOS)를 conventional U-MOSFET(CU-MOS)와 전기적 특성을 비교한 결과, 전달(transfer) 및 출력(output)특성, 항복(breakdown)전압 등 정적(static) 특성의 변화 없이 감소된 역 회복 손실을 얻을 수 있었다. 즉, 쇼트키 다이오드의 폭(width)이 $0.2{\mu}m$, 쇼트키 장벽 높이(Schottky barrier height)가 0.8eV일 때 첨두 역전류(peak reverse current)는 21.09%, 역 회복 시간(reverse recovery time)은 7.68% 감소하였고, 성능지수(figure of merit(FOM))는 35% 향상되었다. 제안된 소자의 특성은 Synopsys사의 Sentaurus TCAD를 사용하여 분석되었다.

• 동력기계공학회지
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• 제16권3호
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• pp.5-9
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• 2012

Novel mechanisms for Energy Recovery Devices are proposed to diminish the pressure loss in the high-pressure reverse-osmosis system. In the beginning, the state-of-the-art in the design of Energy Recovery Devices is reviewed and the features of each model are investigated. The direct-coupled axial piston pump(APP) and axial piston motor(APM) showed 39% energy recovery at operating pressure of reverse osmosis desalination systems, 60 bar. Meanwhile, the developed PM2D model, in which APM pistons are arranged parallel to those of APP, is more compact and showed higher efficiency in a preliminary test. Loss-reduction mechanisms employing rod piston and double raw valve port are additionally proposed to enhance the efficiency and durability of the device.

• 한국통신학회논문지
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• 제29권7B호
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• pp.660-666
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• 2004

처리율로 대표되는 전반적인 TCP의 성능은 패킷 손실이 발생했을 때 이를 복구하는 과정의 효율성에 의해 크게 좌우된다. 특히, 무선 링크를 통한 전송 과정에서의 비트 오류로 인해 발생하는 비 혼잡 패킷 손실은 TCP의 손실 복구 성능을 크게 저하시키는 문제점이 있다. 본 논문에서는 무선 채널에 존재하는 다중 경로 페이딩(multipath fading)에 의해서 상호 연관성을 가지고 연속적으로 발생하는 패킷 손실(correlated packet Losses)에 대해 TCP 손실 복구 과정의 성능을 모델링을 통해서 분석한다. Markov 프로세스를 이용한 분석 결과를 바탕으로 전체적인 패킷 손실 확률이 매우 낮더라도 패킷 손실의 연속성이 손실 복구 차원에서의 TCP의 성능을 크게 저하시킬 수 있음을 보인다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권9호
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• pp.4572-4586
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• 2019

Mobile Edge Computing (MEC) and Information-Centric Networking (ICN) are essential network architectures for the future Internet. The advantages of MEC and ICN such as computation and storage capabilities at the edge of the network, in-network caching and named-data communication paradigm can greatly improve the quality of video streaming applications. However, the packet loss in wireless network environments still affects the video streaming performance and the existing loss recovery approaches in ICN does not exploit the capabilities of MEC. This paper proposes a Deep Learning based Loss Recovery Mechanism (DL-LRM) for video streaming over MEC based ICN. Different with existing approaches, the Forward Error Correction (FEC) packets are generated at the edge of the network, which dramatically reduces the workload of core network and backhaul. By monitoring network states, our proposed DL-LRM controls the FEC request rate by deep reinforcement learning algorithm. Considering the characteristics of video streaming and MEC, in this paper we develop content caching detection and fast retransmission algorithm to effectively utilize resources of MEC. Experimental results demonstrate that the DL-LRM is able to adaptively adjust and control the FEC request rate and achieve better video quality than the existing approaches.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.239-242
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• 2005

A high speed address recovery technique for AC plasma display Panel(PDP) is proposed. By removing the GND switching operation, the recovery speed can be increased and switching loss due to GND switch also becomes to be reduced. The proposed method is able to perform load-adaptive operation by controlling the voltage level of energy recovery capacitor, which prevents increasing inefficient power consumption caused by circuit loss during recovery operation. Thus, the technique shows the minimum address power consumption according to various displayed images, different from Prior methods operating in fixed mode regardless of images. Test results with 50" HD single-scan PDP(resolution = 1366$\times$768) show that less than 350ns of recovery time is successfully accomplished and about 54% of the maximum power consumption can be reduced, tracing minimum power consumption curves.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권9호
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• pp.450-453
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• 2005

A high speed address recovery technique for AC plasma display panel(PDP) is proposed. Replacing GND switch by clamping diode. the recovery speed can be increased by saving GND hold-time and switching loss due to GND switch also becomes also be reduced. The proposed method is able to perform load-adaptive operation by controlling the voltage level of energy recovery capacitor, which prevents increasing inefficient power consumption caused by circuit loss during recovery operation. Test results with 50' HD single-scan PDP(resolution = 1366$\times$768) show that less than 3sons of recovery time is successfully accomplished and about$54\%$ of the maximum power consumption can be reduced, tracing minimum power consumption curves.

• Journal of Power Electronics
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• 제6권3호
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• pp.205-213
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• 2006

A cost-effective magnetic-coupled AC-PDP sustain driver with low switching loss is proposed. The transformer reduces current stress in the energy recovery switches which affects circuit cost and reliability. The turns-ratio can be used to adjust the sustain pulse slopes which affect gas discharge uniformity. Dividing the recovery paths prevents abrupt changes in the output capacitance and thereby switching losses of the recovery switches is reduced. In addition, the proposed circuit has a more simple structure because it does not use the recovery path diodes which also afford a large recovery current. By reducing the current stress and device count in the energy recovery circuit, the proposed driver may have decreased circuit cost and improved circuit reliability.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권4호
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• pp.368-371
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• 2006

The standard procedure outlined by the United States Environmental Protection Agency (US EPA) in Method 1623 for analyzing Giardia lamblia cysts and Cryptosporidium parvum oocysts in water samples consists of filtration, elution, centrifugal concentration, immunomagnetic separation (IMS), and immunofluorescence assay (IFA) followed by microscopic examination. In this study, the extent of (oo)cyst loss in each step of this procedure was evaluated by comparing recovery yields in segmented analyses: (i) IMS + IFA, (ii) concentration + IMS + IFA, and (iii) filtration/elution + concentration + IMS + IFA. The complete (oo)cyst recovery by the full procedure was $52{\sim}57%$. The (oo) cyst loss in the IMS step was only $0{\sim}6%$, implying that IMS is a fairly reliable method for (oo)cyst purification. Centrifugal concentration of the eluted sample and pellet collection before IMS resulted in a loss of $8{\sim}14%$ of the (oo)cysts. The largest (oo)cyst loss occurred in the elution step, with $68{\sim}71%$ of the total loss. The permeated loss of (oo)cysts was negligible during filtration of the water sample with a $1.0-{\mu}m$ pore polyethersulfone (PES) capsule. These results demonstrated that the largest fraction of (oo)cyst loss in this procedure occurred due to poor elution from the filter matrix. Improvements in the elution methodology are therefore required to enhance the overall recovery yield and the reliability of the detection of these parasitic protozoa.

• 한방안이비인후피부과학회지
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• 제23권1호
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• pp.289-299
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• 2010

Back ground & Objectives : Bilateral sudden sensorineural hearing loss(SSNHL) is very rare disease. This is the first case report in the oriental medical literature. This study describes a case of bilateral SSNHL with incomplete recovery. Methods : We treated 1 patient who had SSNHL sequentially in both ears. He received oriental and western medical treatments for more than 2 weeks and measured the hearing recovery. For diagnosis on this case, pure tone audiometry was used. The degree of improvement was evaluated by Siegel's Criteria. Results & Conclusions : This patient discharged without hearing improvement. For bilateral SSNHL patients, the result of treatment is important for their qualities of life. But the recovery rate of hearing in bilateral SSNHL is lower than unilateral SSNHL. The oriental medical therapy had some theraputic effects on SSNHL and the theraputic effects on bilateral SSNHL requires further study.