• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.1
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• pp.117-117
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• 1992

Pubilc utility industries including the electric utility industry are facing a new stream of privatization com-petition with the private sector and deregulation. The necewssity to solve now and in the future power supply and demand problems has been increasing through the sophisticated generation expansion plan(GEP) approach con-sidering not only KEPCo's supply-side resources but also outside resources such as non-utility generation(NUG) demand-side management (DSM). Under the environmental situation in the current electric utility industry a new approach is needed to acquire multiple resources competitively. This study presents the development of a modified electric generation expansion analysis system(EGEAS) model with avoided cost based on the existing EGEAS model which is a dynamic program to develope an optimal generation expansion plan for the electric utility. We are trying to find optimal GEP in Korea's case using our modified model and observe the difference for the level of reliabilities such as the reserve margin(RM) loss of load probability(LOLP) and expected unserved energy percent(EUEP) between the existing EGEAS model and our model. In addition we are trying to calculate avoided cost for NUG resources which is a criterion to evaluate herem and test possibility of connection calculation of avoided cost with GEP implementation using our modified model. The results of our case study are as follows. First we were able to find that the generation expansion plan and reliability measures were largely influenced by capacity size and loading status of NUG resources, Second we were able to find that avoided cost which are criteria to evaluate NUG resources could be calculated by using our modified EGEAS model with avoided cost. We also note that avoided costs were calculated by our model in connection with generation expansion plans.

• The Journal of the Acoustical Society of Korea
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• v.15 no.2
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• pp.21-32
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• 1996

The performance of the energy density control algorithm for controlling a broadband noise is evaluated in a one-dimensional enclosure. To avoid noncausality problem of a control filter, which often happens in a frequency domain optimization, analyses presented in this paper are undertaken in the time domain. This approach provides the form of the causally constrained optimal controller. Numerical results are presented to predict the performance of the active noise control system, and indicate that imp개ved global attenuation of the broadband noise can be achieved by minimizing the energy density, rather than the squared pressure. It is shown that minimizing the energy density at a single location yields global attenuation results that are comparable to minimizing the potential energy. Furthermore, unlike the squared pressure control, the energy density control does not demonstrate any dependence on the error sensor location for this one-dimensional field. A practical implementation of the energy-based control algorithm is presented. Results show that the energy density control can be implemented using the two sensor technique with a tolerable margin of performance degradation.

• Journal of Wetlands Research
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• v.6 no.1
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• pp.167-178
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• 2004

The southern tidal flat of Kanghwa Island is one of the biggest flats on the west coast of Korea. Tide is typically a semidiurnal with maximum range of about 10m. The tidal flat receives large amount of sediments from Han River system. Surface sediments for sedimentary analyses were sampled at 83 stations in the study area in August 2003. The surface sediments consisted of five sedimentary facies. Generally, sandy mud sediments dominated in the southern tidal flat of Kanghwa Island, whereas sand sediments dominated in channel and subtidal zones of the western part of Kanghwa Island. The area of sandy mud sediment extended to eastward tidal flat compared to sedimentary facies in August 1997. Sedimentary facies analysis of three core sediments from the tidal flat to the south of the Kangwha Island revealed three sedimentary facies: trough-cross-bedded sand, laminated silt, and bioturbated silt. Distribution of the facies in the cores suggested that sedimentation rates has been generally high in the margin of main tidal channel, especially in the east of the Donggeum Island. Twelve-and-half-hour anchoring survey was carried out for measurements of hydrodynamic parameters at Yeomha channel near Choji Bridge(K1) and channel near Donggeum Island(K2) in June 2003. Residual flows indicated strong ebb-dominated tidal currents. Depth-integrated net suspended sediment loads for one tidal cycle were seaward movement with 309,217.9kg/m and 128,123.1kg/m at station K1 and K2, respectively. The higher value of net suspended sediment loads at station K1 suggested that lots of suspended sediments from Han River deposited in the eastern part of tidal flat.

• The Korean Journal of Quaternary Research
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• v.9 no.1
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• pp.33-42
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• 1995

우리나라의 서해(West Sea)는 일명 황해(Yellow Sea)라고 일컬어지는 약 40여 m의 평균 수심을 갖는 대륙붕 해저지형 분지에 의하여 지배되는 전형적 육연해이다, 그런데 이 바다는 중심부(황해의 중심부)를 기준으로 하여 중국 대륙의 산동반도에서 양가강 하구에 이르는 서부 해안을 가지며 북부에는 발해만의 해안이 있고 동부에는 서해(황해) 특유의 넓 은 조수환경(tidal environment)과 조수해안이 발달한다. 그러나 남쪽으로는 북서태평양과 연결된다. 한국 서해안이 평균 4m 이상의 조차(tidal range)를 나타내는 조간대 조수환경이 며 조간대 해저지형(intertidal morphology)이 전형적인 퇴적층(체)에 의하여 지배되는 여러 가지 특징을 나타낸다. 서해안 조수환경은 네델란드, 독일 또는 지배되는 여러 가지 특징을 나타낸다. 서해안 조수환경은 네델란드 독일 또는 미국의 경우와 같이 연구가 잘되어 세계 적으로 널리 알려진 소위 barrier island system and tidal depositional environments와는 크 게 다른 퇴적과정과 환경이다. 경기도 남양만의 조수 환경의 경우, 조간대 해저지형 요소인 조류로(tidal channel)와 조간대 정규해저(intertidal zone proper)에 관한 동력적 퇴적과정 연 구결과 조간대 특유의 lateral sedimentation 과 vertical sedimentation 2가지 퇴적과정중 후 자의 퇴적과정이 우세한 것으로 밝혀졌고 이러한 퇴적과정의 진행이 매우 안정한 지속성을 가지는 것이 특징이다, 이러한 퇴적과정의 조간대 퇴적물의 쇄설 입자는 약 20% 미만의 모 래(sand) 입자 50~70%의 실트(silt) 와 점토(clay) 입자가 20~30%에 달하는 입자조직 (grain texture)의 퇴적상을 나타낸다. 결과적으로 조간대의 동력적인 조수수괴의 수위(level of tidal water)는 평균 만조선과 평균 저조선으로 한정되며 이것은 퇴적과정과 퇴적작용의 조정(control) 요인으로 조간대 퇴적상의 발달과 분포에 큰 영향을 미친다, 예를들면 남양만 등의 대부분의 서해안 조간대 표층 퇴적상(녁\ulcorner미 sedimentary faci-es)은 만조선에서 간조 선에 가까울수록 조립화현상(coarsening trend)을 나타낸다. 이러한 퇴적상 변화는 저조선에 서 만조선으로의 조간대 지형과 주조수로의 지형.수력학적 특성이 다음과 같기 때문이다. a) a general decrease in width b) a general decrease in depth c) a general decrease in maximum and average current velocities d) a general increase in contents of suspended mud e) a general decrease in grain size of the bottom sand and an increasing abundance of muddy deposits. 우리나라 서해안 조간대 퇴적층(체)의 수직 층서(vertical stratigraphy)는 지난 3여년동안의 수십개의 vibracoring(주상시추)에 의하여 매우 흥미롭고 중요하게 밝혀지고 있는바 이것은 현세(Holocene)와 선현세(preHolocene: 11000 years BP)의 오랜시간 경과에 따른 조수환경 변화의 수직퇴적 과정과 기후 해수면 변화의 현상에 원인이 있다고 해석된다.(박용안 외, 1992-1995)결과적으로 서해안 조수퇴적체(층)의 분지주변(basim margin)진화과정이 밝혀지 고 있다.

• Archives of Plastic Surgery
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• v.37 no.1
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• pp.59-66
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• 2010

Purpose: In the finger, there are three major palmar arches in the arterial system. The location of this arches are constant. The middle and distal transverse arches are consistently large (almost 1 mm) and may be used for arterial vessel repairs either proximally or distally, depending on the length and direction needed. This paper describes our experiences in reconstruction and replantation of the finger using rerouting the transverse digital palmar arch. Methods: 31 patients with injuries according to our classification were treated from March of 2005 to October of 2008. In this study the authors subdivided injuries into those with amputation distal to the insertion of the flexor digitorum profundus (Class I, 31 fingers); those with amputation distal to the insertion of the flexor digitorum superficialis (Class II, 4 fingers). Replantation was performed using the artery-only technique with neither vein nor nerve repair. Because the artery has been damaged, it is still possible to make a direct suture by transposing the arterial arch in an inverted Y to I arterial configuration or converting the arch. Venous drainage was provided by an external bleeding method with partial nail excision, medical leech, and repaired margin. Results: The success rate was 87% (n=27) in class I and 75% (n=4) in class II. The authors conclude that crushing and complete avulsion injuries & amputations are salvageable, with acceptable functional results in select patients, especially those with amputation distal to the insertion of the flexor digitorum superficialis. Conclusion: We performed replantation and reconstruction with only-arterial transposing anastomosis successfully, resulting in good recovery of aesthetic and functional outcome. Three major digital palmar arches, especially distal two branches, give us additional treatment options. In the finger replantation and reconstructive techniques using rerouting healthy the transverse digital palmar arch increase the survival rate of the finger.

• Korean Journal of Veterinary Research
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• v.33 no.2
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• pp.295-300
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• 1993

Central nervous system of two dogs with natural canine distemper was investigated histopathologically and immunocytochemically with antisera to MBP, MAG and GFAP. Histopathologically, there were neuronal degeneration and diffuse gliosis in the cerebrum, vacuolar degeneration, hypertrophy of astrocytes and demyelination in cerebellar white matter adjacent to the 4th ventricle and optic tracts showing non-inflammatory demyelinating encephalomyelitis (Summers and Appel, 1987). Immunohistochemically, there was a concurrent disappearance of MBP and MAG in the well developed demyelinating lesion in the cerebellar white matter. At the margin of demyelination, Loss of both MBP and MAG varied on the stage of demyelinating process. GFAP-positive astrocytes were hypertrophied and contained canine distemper virus intranuclear inclusions. GFAP-positive fibers were increased at the early stage of demyelination, and then were not immunoreaeted at the well developed demyelination. Hypertrophic astrocytes with intranuclear inclusions were commonly identified in the interfascular layer without myelin vacuolation and demyelination. This is the first study of primary demyelination and astroglial reactions in natural CDE investigated using immunocytochemistry of two myelin proteins and GFAP. Concurrent loss of MBP and MAG suggest that the myelin sheath is the target in the demyelinating process in CDE.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.156-157
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• 2012

단일 셀에서 비휘발성 및 고속의 휘발성 메모리를 모두 구동할 수 있는 다기능 메모리는 모바일 기기 및 embedded 장치의 폭발적인 성장에 있어 그 중요성이 커지고 있다. 따라서 최근 이러한 fusion기술을 응용한 unified RAM (URAM)과 같은 다기능 메모리의 연구가 주목 받고 있다. 이러한 다목적 메모리는 주로 silicon on insulator (SOI)기반의 1T-DRAM과 SONOS기술 기반의 비휘발성 메모리의 조합으로 이루어진다. 하지만 이런 다기능 메모리는 주로 단결정기반의 SOI wafer 위에서 구현되기 때문에 값이 비싸고 사용범위도 제한되어 있다. 따라서 이러한 다기능메모리를 다결정 실리콘을 이용하여 제작한다면 기판에 자유롭게 메모리 적용이 가능하고 추후 3차원 적층형 소자의 구현도 가능하기 때문에 다결정실리콘 기반의 메모리 구현은 필수적이라고 할 수 있겠다. 본 연구에서는 다결정실리콘을 이용한 channel recessed구조의 다기능메모리를 제작하였으며 각 1T-DRAM 및 NVM동작에 따른 memory 특성을 살펴보았다. 실험에 사용된 기판은 상부 비정질실리콘 100 nm, 매몰산화층 200 nm의 SOI구조의 기판을 이용하였으며 고상결정화 방법을 이용하여 $600^{\circ}C$ 24시간 열처리를 통해 결정화 시켰다. N+ poly Si을 이용하여 source/drain을 제작하였으며 RIE시스템을 이용하여 recessed channel을 형성하였다. 상부 ONO게이트 절연막은 rf sputter를 이용하여 각각 5/10/5 nm 증착하였다. $950^{\circ}C$ N2/O2 분위기에서 30초간 급속열처리를 진행하여 source/drain을 활성화 하였다. 계면상태 개선을 위해 $450^{\circ}C$ 2% H2/N2 분위기에서 30분간 열처리를 진행하였다. 제작된 Poly Si MFM에서 2.3V, 350mV/dec의 문턱전압과 subthreshold swing을 확인할 수 있었다. Nonvolatile memory mode는 FN tunneling, high-speed 1T-DRAM mode에서는 impact ionization을 이용하여 쓰기/소거 작업을 실시하였다. NVM 모드의 경우 약 2V의 memory window를 확보할 수 있었으며 $85^{\circ}C$에서의 retention 측정시에도 10년 후 약 0.9V의 memory window를 확보할 수 있었다. 1T-DRAM 모드의 경우에는 약 $30{\mu}s$의 retention과 $5{\mu}A$의 sensing margin을 확보할 수 있었다. 차후 engineered tunnel barrier기술이나 엑시머레이저를 이용한 결정화 방법을 적용한다면 device의 특성향상을 기대할 수 있을 것이다. 본 논문에서는 다결정실리콘을 이용한 다기능메모리를 제작 및 메모리 특성을 평가하였다. 제작된 소자의 단일 셀 내에서 NVM동작과 1T-DRAM동작이 모두 가능한 것을 확인할 수 있었다. 다결정실리콘의 특성상 단결정 SOI기반의 다기능 메모리에 비해 낮은 특성을 보여주었으나 이는 결정화방법, high-k절연막 적용 및 engineered tunnel barrier를 적용함으로써 해결 가능하다고 생각된다. 또한 sputter를 이용하여 저온증착된 O/N/O layer에서의 P/E특성을 확인함으로써 glass위에서의 MFM구현의 가능성도 확인할 수 있었으며, 차후 system on panel (SOP)적용도 가능할 것이라고 생각된다.

• Korean Journal of Plant Taxonomy
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• v.45 no.4
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• pp.369-379
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• 2015

The seed morphology of 25 taxa (8 genera) of Alsineae (Alsinoideae, Caryophyllaceae) in Korea was examined using stereo (SM) and scanning electron microscopy (SEM) in order to evaluate their diagnostic values and taxonomic implications. Circular, comma-shaped, ellipsoid, ovate, pyriform, reniform, and sub-circular seed shapes were identified. The seeds of the examined taxa range from 0.28 to 4.10 mm in length and from 0.33 to 3.10 mm in width; the smallest one was found in Sagina japonica, while the largest was in Honkenya peploides var. major. A hilar appendage was found in Cerastium, Honkenya, Moehringia, and strophioles were only observed in the genus Moehringia. Based on the examination of epidermal cells of the seed surface, four micromorphological types can be distinguished, viz., the colliculate-papillate (Col-Pap), colliculate-columellate (Col-Cll), colliculate-simple (Col-Sim), and smooth (Sm) types. Descriptions of the testa shape, margin, and the degree of elevation of the anticlinal cell walls, and the outer periclinal cell walls are summarized for the tribe. Taxonomic implications of the seed micromorphological characters were also discussed, in comparison with an earlier taxonomic system.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.2
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• pp.25-32
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• 2014

The river plan executes the role for prevention of disaster and protection of environment, and requires the surveying results with high accuracies for managing river, dam, reservoir which will be the major infrastructures. The purpose of this study is for comparing and analyzing the results of river surveying which is used widely for disaster management and construction industry support. The results are gathered by using LiDAR which is being used in Korea recently and by using Total station. Study area is chosen at upper area of Bukhan River which is located at Gangwon-do. Total 2 cross-sections of the two methods are extracted from the study area. The standard deviation of land part is about 0.017m which shows little difference between two methods, but the Airborne LiDAR results cannot survey the heights of the points accurately at the singular points with vertical structure and water body part. To overcome the problems through this study, there should be ways to survey the bottom river through transmission of water level within the same margin scope as land part and to survey detailed facilities used by laser exactly through continuous research and experiment. When implementation stage comes, this study expect that this document will be utilized variously for making decision in the area of planning and drawing of business and engineering not just for river regarding the major area or the area that people cannot access.

• Restorative Dentistry and Endodontics
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• v.31 no.5
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• pp.337-343
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• 2006

The purpose of this study was to estimate the relation between techniques used for microleakage from dye penetration and for marginal adaptation from SEM evaluation of the restoration. Using high speed #330 bur class V cavities ($4{\times}3{\times}1.5 mm$ around CEJ) were prepared on the buccal surface of 20 extracted human molars. Six dimples as reference points for SEM and dye penetration evaluation were made with 1/2 round bur. Cavity was bulk filled with microhybrid composite resin (Esthet X) and all-in-one adhesive (Xeno III). Teeth were stored in saline solution for one day, after then, they were finished and polished using Sof-Lex system. Fifty percent silver nitrate dye solution was used for the evaluation of microleakage and resin replica was used for marginal adaptation. All of these were done after 1000 times thermocycling between 5 and $55^{\circ}C$. Vertical sections were made through three dimples of restoration to obtain samples for the evaluation of dye penetration and inner marginal adaptation. Outer adaptational estimation was done with an intact restoration before sectioning. Dye penetration was determined in three degrees and percentage of outer and inner leaky margin was estimated from SEM image The data were analysed statistically: Spearman's rho test were used to check relationships between two methods. The result were as follows : 1. There were significant relationships between degree of dye penetration and inner and outer marginal adaptations each (p < 0.01). 2. However, there was no significant relationship between the results or inner and outer marginal adaptation. Within the results of this study, relationship between the percentage of marginal adaptation and microleakage shows significant relationship. However, inner and outer marginal adaptation did not show any significant relationship mutually.