• Title/Summary/Keyword: channel morphology

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Pace and Facial Element Extraction in CCD-Camera Images by using Snake Algorithm (스네이크 알고리즘에 의한 CCD 카메라 영상에서의 얼굴 및 얼굴 요소 추출)

  • 판데홍;김영원;김정연;전병환
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2002.11a
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    • pp.535-542
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    • 2002
  • 최근 IT 산업이 급성장하면서 화상 회의, 게임, 채팅 등에서의 아바타(avatar) 제어를 위한 자연스러운 인터페이스 기술이 요구되고 있다. 본 논문에서는 동적 윤곽선 모델(active contour models; snakes)을 이용하여 복잡한 배경이 있는 컬러 CCD 카메라 영상에서 얼굴과 눈, 입, 눈썹, 코 등의 얼굴 요소에 대해 윤곽선을 추출하거나 위치를 파악하는 방법을 제안한다. 일반적으로 스네이크 알고리즘은 잡음에 민감하고 초기 모델을 어떻게 설정하는가에 따라 추출 성능이 크게 좌우되기 때문에 주로 단순한 배경의 영상에서 정면 얼굴의 추출에 사용되어왔다 본 연구에서는 이러한 단점을 파악하기 위해, 먼저 YIQ 색상 모델의 I 성분을 이용한 색상 정보와 차 영상 정보를 사용하여 얼굴의 최소 포함 사각형(minimum enclosing rectangle; MER)을 찾고, 이 얼굴 영역 내에서 기하학적인 위치 정보와 에지 정보를 이용하여 눈, 입, 눈썹, 코의 MER을 설정한다. 그런 다음, 각 요소의 MER 내에서 1차 미분과 2차 미분에 근거한 내부 에너지와 에지에 기반한 영상 에너지를 이용한 스네이크 알고리즘을 적용한다. 이때, 에지 영상에서 얼굴 주변의 복잡한 잡음을 제거하기 위하여 색상 정보 영상과 차 영상에 각각 모폴로지(morphology)의 팽창(dilation) 연산을 적용하고 이들의 AND 결합 영상에 팽창 연산을 다시 적용한 이진 영상을 필터로 사용한다. 총 7명으로부터 양 눈이 보이는 정면 유사 방향의 영상을 20장씩 취득하여 총 140장에 대해 실험한 결과, MER의 오차율은 얼굴, 눈, 입에 대해 각각 6.2%, 11.2%, 9.4%로 나타났다. 또한, 스네이크의 초기 제어점을 얼굴은 44개, 눈은 16개, 입은 24개로 지정하여 MER추출에 성공한 영상에 대해 스네이크 알고리즘을 수행한 결과, 추출된 영역의 오차율은 각각 2.2%, 2.6%, 2.5%로 나타났다.해서 Template-based reasoning 예를 보인다 본 방법론은 검색노력을 줄이고, 검색에 있어 Feasibility와 Admissibility를 보장한다.매김할 수 있는 중요한 계기가 될 것이다.재무/비재무적 지표를 고려한 인공신경망기법의 예측적중률이 높은 것으로 나타났다. 즉, 로지스틱회귀 분석의 재무적 지표모형은 훈련, 시험용이 84.45%, 85.10%인 반면, 재무/비재무적 지표모형은 84.45%, 85.08%로서 거의 동일한 예측적중률을 가졌으나 인공신경망기법 분석에서는 재무적 지표모형이 92.23%, 85.10%인 반면, 재무/비재무적 지표모형에서는 91.12%, 88.06%로서 향상된 예측적중률을 나타내었다.ting LMS according to increasing the step-size parameter $\mu$ in the experimentally computed. learning curve. Also we find that convergence speed of proposed algorithm is increased by (B+1) time proportional to B which B is the number of recycled data buffer without complexity of computation. Adaptive transversal filter with proposed data recycling buffer algorithm could efficiently reject ISI of channel and increase speed of convergence in avoidance burden of computational complexity in reality when it was experimented having the same condition of

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The Morphological Changes of Deltaic Barrier Islands in the Nakdong River Estuary after the Construction of River Barrage (하구둑 건설 이후 낙동강 하구역 삼각주 연안사주의 지형변화)

  • Kim, Sung-Hwan
    • Journal of the Korean Geographical Society
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    • v.40 no.4 s.109
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    • pp.416-427
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    • 2005
  • This paper aims to investigate morphological changes of deltaic barrier islands in the Nakdong Estuary and especially their spatial variations after barrage construction. We analyzed shorelines, geometrical centroids, and areas to reveal the changes of barrier islands. Here, we suggest three interesting points from this study. First, each individual barrier island in the Nakdong estuary goes through a different stage of the geomorphic cycle. The frontal barrier islands such as Sinja-do and Doyo-deung grow because they are located in front of the gates of the barrage. Sediments in water out of the gates are moved to offshore and then reworked by coastal processes such as waves and tides. Second, on the contrary, Baekhap-deung located behind Doyo-deung now diminishes indicating that sediments mainly move to the frontal growing island. Third, there is no morphological change in several barrier islands far away from the main flow of the Nakdong river such as Jinwoo-do, Daema-deung, and Jangja-do. In conclusion, barrier islands in the Nakdong estuary show distinct spatial variations. As a barrier island is closer to the main channel or is in the frontal location, there happens a very dynamic change in the morphology of the island.

Tidal depositional processes and late Quaternary (Holocene and pre Holocene) stratigraphy in the western coasts of Korea (한국 서해안 조수 퇴적과정과 제4기 후기(현세와 선현세) 층서)

  • 박용안
    • 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.

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ON THE MORPHOLOGY OF POST-LARVAL AND YOUNG STAGES OF OMOBRANCHUS ELEGANS(STEINDACHNER) (앞동갈베도라치 Omobranchus elegans (STEINDACHNER)의 자치어기의 형태)

  • KIM Yong Uk
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.12 no.4
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    • pp.297-303
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    • 1979
  • Early morphological changes of Omobranchus slogans (STEINDACHNER) (Family Blennidae) were studied based on the samples of 125 individuals collected from Changseon channel of Nam-hae in June 1973 and May 1979. Descriptions were made with particular emphasis on developmental changes of supraorbital region, fin rays, development of chromatophores and the preopercular spine. In the early stages the lateral profile of the supraorbital region is perpendicular to tile sagittal plane, however, in the later stages it becomes curved. In the early stage of 5.55 mm in total length the number of soft rays of dorsal fin is 18, and that of the anal fin 15. Ventral fin first appears as a premoidal proturberance. It fully developes into a fin composed of two soft rays in the stages of 12.9 mm in total length. The caudal fin rays first appear in the ventral part and in the stages of 6.15 mm in total length it gets one or two soft rays which bear 1-2 segments. In the later stages each ray bears more than 5 segments. Melanophores first appear as two black spots on the central part of the head. They are distributed on the opercle and the antero-dorsal surface of the trunk in the stage of 18mm in total length. At this stage the general chromatophore. pattern is identical to the adult stage. The anal fin bears melanophores at the basal part of the rays, and it is one of the remarkable morphological characters of this species. In early stages the preopercular spine develops reaching the basal part of the pectoral fin. In the later stages of 15 mm in total length relative length of the spine decreases to total length, and ie reaches only the distal margin of the opercular.

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Surface Apatite Growth of NaOH and SBF Treated CP-Ti, Ti-6Al-4V and ECAP-Ti (NaOH처리와 SBF침적에 따른 CP-Ti, Ti-6Al-4V 및 ECAP-Ti의 표면 아파타이트 성장)

  • Oh Seok-Jin;Ruy Jae-Gyeoung;Lee Seung-Woo;Kim Yun-Jong;Han Man-So;Kim Chang-Hyu
    • Korean Journal of Materials Research
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    • v.14 no.12
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    • pp.893-899
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    • 2004
  • Even though Ti-6Al-4V has gained popularity as an implant material, the possible dissolution of Al and V ions in body fluids remains a matter of concern. Though commercially pure Ti (Cp-Ti) overcomes this problem, the mechanical strength of pure titanium remains very low. Thus, in this experiment Cp-Ti was processed by Equal channel angular processing (ECAP), in order to increase the mechanical strength. The biocompatibility of ECAP-Ti, Cp-Ti and Ti-6Al-4V was examined by the apatite formation on each sample surface, after treating the surface with 5M NaOH and soaking in Simulated body fluids (SBF). Initially, the samples were mechanically polished on silicone carbide paper (#2000). The polished samples were treated with 5M NaOH solution at $60^{\circ}C$ for 24 hours. The NaOH treated samples were washed gently with distill water and dried at $40^{\circ}C$ for 1 day. The dried samples were heat treated in air at $600^{\circ}C$ for 1 hour. The surface morphology of these samples were studied using SEM and XRD. The SEM studies showed network of pores in all samples. The XRD showed oxide layer formation on Cp-Ti and Ti-6Al-4V. samples. However the oxide layer in ECAP-Ti was not substantial. These samples were immersed in SBF, kept at $36.5^{\circ}C$ for seven days period. At the end of 7 days, the apatite formation was confirmed only on Cp-Ti and was not observed in Ti-6Al-4V and ECAP-Ti. These observations of apatite formation relate to the fact that Cp-Ti showed greater oxide layer than other samples. The apatite examined was confirmed as tricalcium phosphate (TCP) using EDS and XRD.

Transfection of Mesenchymal Stem Cells with the FGF-2 Gene Improves Their Survival Under Hypoxic Conditions

  • Song, Heesang;Kwon, Kihwan;Lim, Soyeon;Kang, Seok-Min;Ko, Young-Guk;Xu, ZhengZhe;Chung, Ji Hyung;Kim, Byung-Soo;Lee, Hakbae;Joung, Boyoung;Park, Sungha;Choi, Donghoon;Jang, Yangsoo;Chung, Nam-Sik;Yoo, Kyung-Jong;Hwang, Ki-Chul
    • Molecules and Cells
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    • v.19 no.3
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    • pp.402-407
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    • 2005
  • Bone marrow mesenchymal stem cells (MSCs) have shown potential for cardiac repair following myocardial injury, but this approach is limited by their poor viability after transplantation. To reduce cell loss after transplantation, we introduced the fibroblast growth factor-2 (FGF-2) gene ex vivo before transplantation. The isolated MSCs produced colonies with a fibroblast-like morphology in 2 weeks; over 95% expressed CD71, and 28% expressed the cardiomyocyte-specific transcription factor, Nkx2.5, as well as ${\alpha}$-skeletal actin, Nkx2.5, and GATA4. In hypoxic culture, the FGF-2-transfected MSCs (FGF-2-MSCs) secreted increased levels of FGF-2 and displayed a threefold increase in viability, as well as increased expression of the anti-apoptotic gene, Bcl2, and reduced DNA laddering. They had functional adrenergic receptors, like cardiomyocytes, and exposure to norepinephrine led to phosphorylation of ERK1/2. Viable cells persisted 4 weeks after implantation of $5.0{\times}10^5$ FGF-2-MSCs into infarcted myocardia. Expression of cardiac troponin T (CTn T) and a voltage-gated $Ca^{2+}$ channel (CaV2.1) increased, and new blood vessels formed. These data suggest that genetic modification of MSCs before transplantation could be useful for treating myocardial infarction and end-stage cardiac failure.

Surface Modification of Li Metal Electrode with PDMS/GO Composite Thin Film: Controlled Growth of Li Layer and Improved Performance of Lithium Metal Battery (LMB) (PDMS/GO 복합체 박막의 리튬 금속 표면 개질: 리튬전극의 성장 제어 및 리튬금속전지(LMB) 성능 향상)

  • Lee, Sanghyun;Seok, Dohyeong;Jeong, Yohan;Sohn, Hiesang
    • Membrane Journal
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    • v.30 no.1
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    • pp.38-45
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    • 2020
  • Although Lithium metal battery (LMB) has a very large theoretical capacity, it has a critical problem such as formation of dendrite which causes short circuit and short cycle life of the LMB. In this study, PDMS/GO composite with evenly dispersed graphene oxide (GO) nanosheets in poly (dimethylsiloxane) (PDMS) was synthesized and coated into a thin film, resulting in the effect that can physically suppress the formation of dendrite. However, PDMS has low ion conductivity, so that we attained improved ion conductivity of PDMS/GO thin film by etching technic using 5wt% hydrofluoric acid (HF), to facilitate the movement of lithium (Li) ions by forming the channel of Li ions. The morphology of the PDMS/GO thin film was observed to confirm using SEM. When the PDMS/GO thin film was utilized to lithium metal battery system, the columbic efficiency was maintained at 87.4% on average until the 100th cycles. In addition, voltage profiles indicated reduced overpotential in comparison to the electrode without thin film.

Effect of Clamping Pressure on Surface Properties of Gas Diffusion Layer in PEFCs (체결압이 고분자연료전지 기체확산층의 표면성질에 미치는 영향)

  • Ahn, Eun-Jin;Park, Gu-Gon;Yoon, Young-Gi;Park, Jin-Soo;Lee, Won-Yong;Kim, Chang-Soo
    • Journal of the Korean Electrochemical Society
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    • v.10 no.4
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    • pp.306-310
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    • 2007
  • Characteristics of GDL (Gas Diffusion Layer) mainly determine the gas diffusion and water removal in a cell, thereby changing the performance and affecting durability of PEFC. To optimize the water management and understand the two phase flow in a GDL, it is important to study the behaviors of GDL micro structure under the real operating condition. In the clamped condition of cell, the GDL beneath the rib is more compressed than beneath the channel. Many researches on physical, electrochemical, mechanical behaviors of gas diffusion layer has been conducted. However, changes in surface properties under clamped condition have rarely studied. In present study, the morphology of broken connections of carbon fibers and detachment of PTFE coatings on the fibers were shown from the microscopic observations. In addition, changes in wetting properties of GDL by compression were investigated by using XPS and liquid uptake methods. The hydrophobic characteristics of GDL surface beneath the rib of the flow field plate are changed due to the deformation of micro structure.

Origin and Distribution of Cut and Fill Structures in the Southwestern Margin of Ulleung Basin, East Sea (동해 울릉분지 남서주변부에 발달하는 침식충전구조의 기원 및 분포)

  • Park, Yong Joon;Kang, Nyeon Keon;Yi, Bo Yeon;Yoo, Dong Geun
    • Geophysics and Geophysical Exploration
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    • v.18 no.2
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    • pp.39-53
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    • 2015
  • Analysis of multi-channel seismic reflection profiles acquired from the southwestern margin of Ulleung Basin reveals that the cut and fill structures, which show U-shaped or V-shaped morphology, occur on variable size. The cut and fill structure mostly consists of fine-grained sediments on the well data and is characterized by transparent or semitransparent seismic facies on the seismic section. Such cut and fill structures dominantly occur in the syn-compressional megasequence (MSQ3), which was deposited during basin deformation of late Miocene, among the four megasequences of the study area. These cut and fill structures can be divided into three groups based on their size and formation time. The cut and fill structures of Group I were formed when Dolgorae structure was active, and occurred on a small scale. The cut and fill structures of group II were formed when both Dolgorae structure and Gorae V structure were active, and the number and size of those increased compared with group I. The cut and fill structures of group III were formed when Dolgorae structure was weaken gradually but Gorae V structure kept active, and the number and size of those decreased in comparison with group II. Consequently the cut and fill structures in the southwestern margin of Ulleung basin are interpreted as submarine canyon based on spatial distribution, size and fill sediment. They were controlled by the tectonic movement in response to basin closure and tectonic-induced sediment supply variation.

Analysis of Morphological Characteristics of Farm Dams in Korea (한국 농업용 저수지의 형태학적 특성 분석)

  • Yoo, Chul-Sang;Park, Hyun-Keun
    • Journal of the Korean Geographical Society
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    • v.42 no.6
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    • pp.940-954
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    • 2007
  • This study was to analyze a total of 18,068 farm reservoirs in Korea with their basic measures, and estimate their average characteristics. These characteristics have also been compared with those of foreign countries. Histograms of seven measures(approval area, beneficial area, watershed area, effective storage, full water area, dam length, and dam height) of reservoirs are made to characterize their distributions and to apply the Pareto analysis with the power law to evaluate their inequalities. The histogram analysis shows that the measures of dam(channel cross-section) characteristics follow the log-normal distributions, on the other hand, those of the basin characteristics the exponential-type distributions. Pareto analysis was done for the five measures of having exponential distribution. The Pareto exponents estimated are 0.38 for the approval area, 0.42 for the beneficial area, -0.19 for the effective storage, 0.30 for the watershed area, and 0.22 for the full water area, so the inequality of the beneficial area is the highest and that of the effective storage is the lowest. Analysis of morphology index versus watershed area shows that most reservoirs are categorized into deep or normal ones. These characteristics are also found to be similar to those of foreign countries.