• Journal of Microbiology and Biotechnology
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• v.13 no.3
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• pp.473-476
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• 2003

The effect of oxidation-reduction potential (ORP) level on the denitrification by Ochrobactrum anthropi SY509 was investigated under nongrowing condition. The maximum ORP level of nitrate-containing buffer solution was -70∼-80 mV, under which the denitrification took place. By decreasing the initial ORP level, denitrifying enzyme activity was greatly enhanced, which led to higher denitrification efficiency.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.143-150
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• 2013

Solid-state disks (SSDs) have been widely used by high-performance personal computers or servers due to its good characteristics and performance. The NAND flash-based SSDs, which take large portion of the whole NAND flash market, are the major type of SSDs. They usually integrate a cache buffer which is built from DRAM and uses the write-back policy for better performance. Unfortunately, the policy makes existing scheduling methods less effective at the I/F level of SSDs Therefore, in this paper, we propose a scheduling method for the I/F with consideration of the cache buffer. The proposed method considers the hit/miss status of cache buffer and gives higher priority to the read requests. As a result, the requests whose data is hit on the cache buffer can be handled in advance and the read requests which have larger effects on the whole system performance than write requests experience shorter latency. The experimental results show that the proposed scheduling method improves read latency by 26%.

• The Transactions of the Korea Information Processing Society
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• v.3 no.4
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• pp.947-960
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• 1996

The primary goal for developing high performance ATM switching systems is to minimized the probability of cell loss, cell delay and deterioration of throughput. ATM switching element that is the most suitable for this purpose is the shared buffer memory switch executed by common random access memory and control logic. Since it is difficult to manufacture VLIS(Very Large Scale Integrated circuit) as the number of input ports increased, the used of switching module method the realizes 32$\times$32, 150 Mb/s switch utilizing 8$\times$8, 600Mb/s os 16$\times$16, 150Mb/s unit switch is latest ATM switching technology for small and large scale. In this paper, buffer capacity satisfying total-memory-reduction effect by buffer sharing in a shared buffer memory switch are analytically evalu ated and simulated by computer with cell loss level at traffic conditions, and also features of switching network utilizing the switching module methods in small and large-capacity ATM switching system is analized. Based on this results, the structure in outline of 32$\times$32(4.9Gb/s throughput), 150Mb/s switches under research in many countries is proposed, and eventually, switching-network structure for ATM switching system of small and large and capacity satisfying with above primary goals is suggested.

• The KIPS Transactions:PartA
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• v.18A no.4
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• pp.135-142
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• 2011

This research is to design an effective buffer structure and its management for flash memory based high performance SSDs (Solid State Disks). Specifically conventional SSDs tend to show asymmetrical performance in read and /write operations, in addition to a limited number of erase operations. To minimize the number of erase operations and write latency, the degree of interleaving levels over multiple flash memory chips should be maximized. Thus, to increase the interleaving effect, an effective buffer structure is proposed for the SSD with a hybrid address mapping scheme and super-block management. The proposed buffer operation is designed to provide performance improvement and enhanced flash memory life cycle. Also its management is based on a new selection scheme to determine random and sequential accesses, depending on execution characteristics, and a method to enhance the size of sequential access unit by aggressive merging. Experiments show that a newly developed mapping table under the MBA is more efficient than the basic simple management in terms of maintenance and performance. The overall performance is increased by around 35% in comparison with the basic simple management.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.188-193
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• 1998

Soil pH change is an important factor which determines soil chemical properties. It is an indicator of the effect of urban environmental pollution on soils and plant growth. The objective of this study was to assess the effect of air pollution on the soil of Seoul urban forests during the course of the air pollution being dipersed toward suburb area. Study sites were divided into four sections of concentric circles with 5km interval. Soil samples were collected from A and B horizons in the urban forests, and analyzed for soil pH, soil buffer capacity, cation exchange capacity, and base saturation. Soil pH ranged from 3.96 to 5.08 for A horizon and from 4.10 to 5.25 for B horizon, which were not significantly different among the sections. However, there was a trend of soil pH lowered at the sections close to the urban center. Soil buffer capacity was lower at 0-5km and 5-10km sections compared to that at the outer sections. Cation exchange capacity and base saturation were not different significantly among the sections. Following the pattern of air pollutants being dispersed from urban center to suburb, soil acidification was observed at the urban forests in Seoul area. Low level of soil buffer capacity toward the urban center was an indicator of soil acidification at the urban forests.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.3
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• pp.329-338
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• 2019

Suction of unsaturated bentonite buffers is a very important input parameter for hydro-mechanical performance assessment and design of an engineered barrier system. This study analyzed suction measurement techniques and constitutive models of unsaturated porous media reported in the literature, and suggested suction measurement techniques and constitutive models suitable for bentonite buffer in an HLW repository. The literature review showed the suction of bentonite buffer to be much higher than that of soil, as measured by total suction including matric suction and osmotic suction. The measurement methods (RH-Cell, RH-Cell/Sensor) using a relative humidity sensor were suitable for suction measurement of the bentonite buffer; the RH-Cell /Sensor method was more preferred in consideration of the temperature change due to radioactive decay heat and measurement time. Various water retention models of bentonite buffers have been proposed through experiments, but the van Genuchten model is mainly used as a constitutive model of hydro-mechanical performance assessment of unsaturated buffers. The water characteristic curve of bentonite buffers showed different tendencies according to bentonite type, dry density, temperature, salinity, sample state and hysteresis. Selection of water retention models and determination of model input parameters should consider the effects of these controlling factors so as to improve overall reliability.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06d
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• pp.38-40
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• 2012

비디오 서버는 다수의 비디오 요청을 동시에 서비스하기 때문에 통신망 대역폭을 공평하고 효율적으로 활용하는 것이 중요하다. 모바일 통신망에서 클라이언트들의 재생 버퍼 수준을 이용하여 VBR 비디오 스트림을 전송하는 스케쥴링 알고리즘들이 본 논문에서 제시되었다. 요청된 비디오 재생시 서비스 품질과 실시간적 성능을 향상시키기 위하여 비디오 서버는 일시적으로 버퍼 수준이 낮은 비디오 요청 작업을 우선적으로 서비스하고자 더 많은 대역폭을 할당하는 실시간 스케쥴링 알고리즘을 수행한다. 버퍼 수준이 상이한 모바일 클라이언트들에게 공평한 서비스와 부하 균형이 제공되는 시뮬레이션 결과가 나타났다.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1094-1096
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• 1987

Zero-crossing analysis techniques have been applied to speech recognition. Zero-crossing rate, level-crossing rate and differentiated zero-crossing rate in time domain we used in analyzing speech signals. Speech samples could be stored in memory buffer in real time.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.365-368
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• 2002

WSW(Wrap Side Wall) is proposed to decrease junction electric field in this paper. WSW process is fabricated after first gate etch, followed NMI ion implantation and deposition & etch nitride layer New WSW structure has buffer layer to decrease electric field. Also we compared the hot carrier characteristics of WSW and conventional. Also, we design a test pattern including pulse generator, level shifter and frequency divider, so that we can evaluate AC hot carrier degradation on-chip.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.353-357
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• 1992

This paper constitutes the simulator of the serial production line using Extended Petri Nets. We analyze each operations and effect of machine down, calculating the performance measures for improving the capability of manufacturing system. The performance measures are system efficiency, average utilization of machines, average buffer level, and so on. We intend to present the information of the operation states and various problem occurring in the systems.