• Proceedings of the KSRS Conference
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• v.1
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• pp.436-440
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• 2006

Diffuse pollution has been considering as a major source of the quality deterioration of water resources. The establishment of riparian vegetation strips of buffers along those areas of water bodies is used to reduce the threat of diffuse pollution. Remote sensing offers a means by which critical areas could be identified, so that subsequent action toward the establishment of riparian zones can be taken. Even though the principal purpose of this research comes from the feasibility of the imagery of KOMPSAT-2 satellite, Landsat TM satellite data, which has 7 bands, are used to characterize the land cover for the study area on the behalf of KOMPSAT-2. This investigation focuses on the assessment of the existing riparian buffer zones for a portion of the upper Geum river watershed from the viewpoint of pollution mitigation by riparian vegetation strip establishment. Through comparing the delineation of riparian buffer zones developed with the existing zones established by the government, we can find the critical distortion points of the existing riparian buffer zone.

• Journal of Power System Engineering
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• v.11 no.1
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• pp.76-81
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• 2007

The objective of this study is to find the optimum design of a snubber using CFD analysis. Several dimensions such as snubber height(H), snubber diameter(D), buffer width and buffer angle are considered in this study. The present study shows that the CFD can be applied to study the pressure characteristics inside the snubber. The objective of the snubber design optimization are to minimize a pressure loss and the pulsation ratio. Numerical results such as particle track, pressure distribution and turbulent kinetic energy are used to analyze the critical area and pressure behavior inside the snubber. As a result, snubber model with H/D ratio of 3.23 and buffer angle of $40^{\circ}$ has a minimum pressure loss. On the other hand, snubber model with H/D ratio 4.41 and buffer angle $10^{\circ}$ has a minimum pulsation ratio.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.12
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• pp.2366-2373
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• 2007

In this paper, a low-power and small-area asynchronous 1 kilobit EEPROM for passive UHF RFID tag chips is designed with $0.18{\mu}m$ EEPROM cells. As small area solutions, command and address buffers are removed since we design asynchronous I/O interface and data output buffer is also removed by using separate I/O. To supply stably high voltages VPP and VPPL used in the cell array from low voltage VDD, Dickson charge pump is designed with schottky diodes instead of a PN junction diodes. On that account, we can decrease the number of stages of the charge pump, which can decrease layout area of charge pump. As a low-power solution, we can reduce write current by using the proposed VPPL power switching circuit which selects each needed voltage at either program or write mode. A test chip of asynchronous 1 kilobit EEPROM is fabricated, and its layout area is $554.8{\times}306.9{\mu}m2$., 11% smaller than its synchronous counterpart.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.3
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• pp.39-51
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• 2008

This study focuses on the reconstruction of buffer greens which were installed to reduce environmental effects on roadsides constructed in the 1980s, in order to supplement various urban green functions. The subjects were buffer greens installed along the Songpadaero and Nambusunwhanro in Songpa-gu. Planting was suggesting to strengthen the buffer, landscape, shading and ecological function according to the use of the buffer green surroundings. The surroundings of the green axis subjects are high-rise apartment areas, neighboring commercial areas, commercial working areas, transportation facility areas, urban support facility areas, schools, parks, etc. However, the structure of the buffer greens were uniformed with Plantanus occidentalis and Ginkgo biloba and Zelkova serrata in the canopy layer and with Forsythia koreana and Ligustrum obtusifoliumin the shrub layer in lineal or alternate order, functioning only as buffer space. Therefore, the buffer greens need to be reconstructed， supplementing various functions according to land use, in order to improve the pedestrian walk area in terms of landscape and use of greens. In line with that, the planting improvement plans according to the land use patterns, and physical and ecological structure were classified into buffer and landscape, landscape and buffer, buffer and shading, and buffer and ecological function. In addition, improving planting function, species and facilities are suggested.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.2
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• pp.45-58
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• 2006

This study was aimed to propose the plan of creating a biotope reflecting an ecological education as well as its function as the habitats of amphibian in Namsan Urban Natural Park in Seoul. There were Cheonil mineral spring area which was located on the southern side of Namsan, wetlands which was already created on the east valley(800$m^2$) and a buffer area of the circumference(1,100$m^2$) as the biotope sites. Major fields of this study include a survey of the staus, a basic plan, a master plan; a survey of this site was focused on topography, water system, existing vegetation, wildbird, amphibian, trail; a detailed plan was focused on flow plan, planting plan, facility plan. Existing vegetation was classified into 8 types; Pinus densiflora forest, Pinus densiflora planted area, Prunus sargentii-Quercus spp. forest, Pinus rigida forest, Robinia pseudoacacia forest, artificial green space, wetlands, south beltway. There were Pinus densiflora planted area and Prunus sargentii-Quercus spp. forest as major vegetations of this site. 14 species and 33 individuals of wildbirds appeared, Rana temporaria ornativentris and Hynobius leechi were investigated in the wetlands.In particular, habitats of amphibian were divided eco-zone, buffer-zone and restore-zone, and habitats and facilities which would be suitable for the characteristics of each space were planned. As a result, environment elements of good habitats including spawn wetlands of amphibian, harbor of amphibian, water plant of wetland, wild shrubs forest, ecological landscape forest, wetland observation trail, fence of wetland protection and ramp by pebble and log were created at the site. The amphibian biotope of Namsan is rated high as an important space for conserving biodiversity. Accordingly, continuous monitoring of this biotope as a urban habitat is required as the environment changes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4572-4579
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• 2013

South Korea people and government pour growing interest on emergency evacuation shelters due to recent threatening of North Korea provocation. However, survey says the border area suffers lack of 278 shelters compared to population, needless to say the lack of class-2 shelter in case of provocation. Firstly, this study visualized the evacuation buffer area and summarized acceptable population for all class (1~4) shelters in Cheoan neighbor(dong). Specifically, for the class-2 shelter coverage in old downtown neighbor (Sungjung-dong, Jungang-dong, Munsung-dong), this study calculated evacuation excluded population and deficient shelter area through GIS buffer analysis. As a result, the old downtown needs $25,546m^2$ shelter area more that can accommodate 56%(30,657man) of the population.

• 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.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1987.04a
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• pp.31-34
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• 1987

A new efficientcoding system which can transmit video conferenceof viedeophone signals at a 64kbps is proposed. In addition to the interframe and CRC (Conditional Repleni shment Coding) system, BTVQ (Binary Tree searched Vector Quantizer)and RLC (Run Length Coding) methods are incorporated. Couble buffer memory is used for simple comtrol of channel symbol transmission and memory underflow And also buffer memory onerfolw is easily controlled by the thresholds of a MAD (Moving Area Betector)

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.6
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• pp.131-142
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• 2009

The purpose of this study is to detect the protection area around the Geum-buk and Geum-nam Mountains for making a sustainable ecological network. The protection area in the Geum-buk and Geum-nam Mountains was analyzed by using spatial data and a field survey for landscape conservation purposes. A survey scope was fixed using digital elevation model, and the protection area was finally determined based on the parcel map called as the Korea Land Information System (KLIS). Here we have several conclusions in this study. First, spatial data used in this study were a map of ecological and natural degree (MEND), forest distribution map, elevation map, slope map, and several maps for the protection area assigned by laws regarding to the natural resources. Second, we used 4 alternatives to determine the best choice for showing the ecological network in the study area. One alternative (alt. 3) of 4 ones was finally chosen as the best condition for making the ecological network. The condition in elevation and slope was a little modified to a lower level in alt, 3. The result derived from alt, 3 reflected the continuity and connectivity in the ecological network and we estimate that the protection area can protect the core area using the buffer zone around the ecological network. Finally the parcel-based protection area in the Geum-buk and Geum-nam Mountains had $493.92km^2$ of the core area, and $233.99km^2$ of the buffer zone, which means the parcel-based protection area increased by $97.76km^2$ in the core area, but decreased by $76.61km^2$ as of in the topographical map.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.1
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• pp.36-42
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• 2016

In multi-level-cell based storage devices, TLC NAND has been employed solid state drive due to cost effectiveness. Since TLC has slow performance and low endurance compared with MLC, TLC based storage has adopted SLC buffer scheme to improve performance. To improve SLC buffer scheme, this paper proposes page overwriting method in SLC block. This method provides data updates without erase operation within a limited number. When SLC buffer area is filled up, FTL should execute copying valid pages and erasing it. The proposed method reduces erase counts by 50% or more compared with previous SLC buffer scheme. Simulation results show that the proposed SLC buffer overwrite method achieves 2 times write performance improvement.