• 제목/요약/키워드: Improvement depth

검색결과 1,320건 처리시간 0.041초

파력발전용 직접구동터빈의 성능에 미치는 수심의 영향 (Effect of Water Depth on the Performance of a Direct Drive Turbine for Wave Energy Converter)

  • 최영도;김창구;조영진;김유택;이영호
    • 한국유체기계학회 논문집
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    • 제11권6호
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    • pp.38-45
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    • 2008
  • Development of high efficiency turbine with good performance is one of the main topics in the field of developing wave energy converter. For the development and improvement of the turbine performance, the effect of wave condition on the turbine performance should be considered in detail. Also, water depth is an important factor because incident wave power to the turbine is considerably influenced by the wave particle amplitude of motion and the amplitude is closely related with the water depth. Therefore, in this study, the effect of water depth on the performance of a direct drive turbine(DDT) for wave energy converter is investigated using the DDT which is installed in two types of wave channel. The experimental results show that the DDT captures more wave energy under the condition of relatively shallow water depth. When the water depth is shallow, the horizontal water particle amplitude of motion becomes wider and thus, the water power toward the turbine becomes larger.

Polylactic/Polyglycolic copolymer 차단막의 이개부 병소의 치유 효과 (Effects of the Guided Tissue Regeneration Using Polylactic/Polyglycolic Copolymer Membrane in the Furcation Involvement)

  • 허지선;김현영;김창성;최성호;조규성;채중규;김종관
    • Journal of Periodontal and Implant Science
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    • 제31권2호
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    • pp.345-356
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    • 2001
  • The purpose of the present study was to evaluate the clinical efficacy of guided tissue regeneration(GTR) using resorbable polylactic/polyglycolic copolymer(PLA/PGA) membrane in mandibular class II furcation involvement and to compare it to the clinical efficacy of only flap operation. Both procedures were conducted in 5 patients with class II furcation involvements. After 6 months of follow up, the probing pocket depth, clincial attachment level, bone probing depth, and radiographic changes were compared, and the following results were obtained: 1. GTR using PLA/PGA demonstrated a statistically significant reduction in probing pocket depth and bone probing depth, and the control group demonstrated a statistically significant reduction in bone probing depth. 2. The comparison between the experimental and control group failed to demonstrate statistically significant difference in clinical improvement, but more reduction in probing pocket depth and bone probing depth were observed in the experimental group. The probing pocket depth and the bone probing depth were $2.2{\pm}1.6mm$ and $2.4{\pm}1.1mm$ respectively in the control group, while they were $2.4{\pm}1.3mm$ and $3.0{\pm}1.2mm$ respectively in the experimental group. 3. Radiographic change was not detectable for the both groups during the 6 months of follow up. 4. Sites with deeper probing pocket depth at baseline examination showed greater amount of clinical improvement in both groups. Other clinical factors didn't have any significant effect on the treatment results. It is concluded that though there are some limitations, PLA/PGA membrane is effective for the treatment of mandibular class II furcation involvement.

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전문가집단 심층평가를 통한 사회주택 건축단계별 친환경적 계획요소 추출에 관한 연구 (The Extraction for each Design phase using Environment-Friendly Design Factors by In-depth Evaluation of Experts in social housing)

  • 최영오;최무혁
    • 한국주거학회논문집
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    • 제21권1호
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    • pp.1-9
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    • 2010
  • Housing problems in city have being caused social contradiction that contains social discord and conflict between poor and rich. And they have raised one of social problems including a disequilibrium of demand and supply, a housing trouble, and a poor residential environment. Therefore, the purpose of this study is to suggest to the improvement of social housing that exposes to a poor environment for social integration. For this, this study is to extract environmental-friendly design factors for each building phase by in-depth evaluation of experts, and to analyze the problems of domestic social housing and environment-friendly design factors considered prior literature. The results as follow. It might be considered highly phase of schematic design, The building construction, and performance management having factors. Specially, it analyzed to 'Living Environment', 'Economic Efficiency', and 'renewable Energy Systems' should be considered highly. Ultimately, this study would be reconsidered the improvement of social housing proposed by the Government for the social outcast.

가공변질층 깊이의 수학적 모델링 (Mathematical Modeling for the Depth of Deformed Layer in Machining)

  • 박영우
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 추계학술대회 논문집
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    • pp.247-250
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    • 1995
  • The development and empirical validation of a mathematical model for predicting the depth of deformed layer in a machined surface are presented. The main assumption for develioping this model is that there is a linear relationship between plastic strain and the depth to which it extends. The model relates the work required to shear the workpice material to the work needed to compress the workpiece material ahead of the cutting tool. The results show that the percent difference between the calculated and the measured depth of deformed layer ranges form 4 percent to 19 percent. An improvement of the model is suggested through application of actual distribution data of plastic strain.

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상압 저온 플라즈마 전처리한 폴리아미드계 직물의 색농도 (Color Depth of Polyamide Fabrics Pretreated with Low-Temperature Plasma under Atmospheric Pressure)

  • 이문철
    • 한국염색가공학회지
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    • 제5권2호
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    • pp.134-138
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    • 1993
  • Wool, silk and nylon 6 fabrics were treated with low-temperature plasma under atmospheric pressure of acetone/argon or helium/argon for 30 and 180 sec, and then dyed with leveling type acid dye, C.I. Acid Red 18 and milling type acid dye, C.I. Acid Blue 83. In spite of short time of the plasma treatment for thirty seconds, the color depth of wool fabrics was increased remarkably with both of the plasma gases, aceton/argon or helium/argon and with the kinds of dyes i.e., levelin type or milling type. But the atmosperic low-temperature plasmas did not increase the depth of silk and nylon 6 fabrics dyed with both of the acid dyes regardless of the teated time and plasma gases. It seems that low-temperature plasma by atmospheric-pressure discharge is effective for improvement of dyeing of wools as is the same way with the low-temperature plasma by glow discharge. The kinds of plasma gases and treated time did not influnce the depth of wool fabric pretreted with the atmosperic low-temperature plasmas.

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Vacuum distribution with depth in vertical drains and soil during preloading

  • Khan, Abdul Qudoos;Mesri, G.
    • Geomechanics and Engineering
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    • 제6권4호
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    • pp.377-389
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    • 2014
  • The vacuum consolidation method which was proposed by Kjellman in 1952 has been studied extensively and used successfully since early 1980 throughout the world, especially in East and Southeast Asia. Despite the increased successful use, different opinions still exist, especially in connection to distribution of vacuum with depth and time in vertical drains and in soil during preloading of soft ground. Porewater pressure measurements from actual cases of field vacuum and vacuum-fill preloading as well as laboratory studies have been examined. It is concluded that (a) a vacuum magnitude equal to that in the drainage blanket remains constant with depth and time within the vertical drains, (b) as expected, vacuum does not develop at the same rate within the soil at different depths; however, under ideal conditions vacuum is expected to become constant with depth in soil after the end of primary consolidation, and (c) there exists a possibility of internal leakage in vacuum intensity at some sublayers of a soft clay and silt deposit. A case history of vacuum loading with sufficient subsurface information is analyzed using the ILLICON procedure.

분산깊이 우선 탐색 프로토콜의 복잡도 개선을 위한 연구 (Improvement on The Complexity of Distributed Depth First Search Protocol)

  • 최종원
    • 한국정보처리학회논문지
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    • 제3권4호
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    • pp.926-937
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    • 1996
  • 그래프 트래버설(traversal) 기법은 그래프의 노느들을 '방문(visiting)'하는 임의의 패턴이라고 할 수 있으며, 그래프 트래버설 방법 중 하나가 깊이 우선 탐색 기법은 유향 그래프의 강결합 요소나 일반 그래프의 이중 결합 요소를 찾는데 이용 된다. 이러한 깊이 우선 탐색 기법을 분산 네트워크 상에서 구현하기 위한 분산 프로토콜은 통신망의 위상 변화가 없는 고정위상 문제와 시간의 지남에 따라 위상의 변화가 있는 동적 위상 문제로 나누어 볼 수 있다. 본 논문에서는 먼저 고정 위상에 서의 개선된 분산 깊이 우선 탐색 프로토콜을 설계하고 다음으로 이 프로토콜을 동적 위상에 적용하여 링크/노드의 고장/복구에 대처할 수 있는 레질리언트 프로토콜을 설계하였다. 또한, 이들 프로토콜의 메시지와 시간 복잡도를 각각 분석하고,

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평면 모델링을 통한 깊이 영상 부호화의 개선 (Improvement of Depth Video Coding by Plane Modeling)

  • 이동석;권순각
    • 한국산업정보학회논문지
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    • 제21권5호
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    • pp.11-17
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    • 2016
  • 본 논문에서는 평면을 모델링하여 깊이 정보를 보정하고 부호화를 개선하는 방법을 제안한다. 먼저 보정하고자 하는 화소를 중심으로 수평, 수직 방향으로 최소 자승법을 이용하여 평면을 모델링한 후 예측 오차에 근거하여 예측된 평면이 적합한지 판단한다. 그 후 모델링된 평면상의 깊이 화소 값으로 보정한다. 제안된 방법을 통해 평면으로 이루어진 깊이 영상뿐만 아니라 다양한 깊이 정보를 가지는 깊이 영상에 대해서도 보정이 가능하다. 제안된 방법을 적용하여 부호화 성능을 나타내는 엔트로피 척도를 측정한 결과, 부호화 성능이 최대 80.2% 개선된 것을 확인하였다.

Multi-view 영상 코딩에서 영상 개선 알고리듬 (An algorithm for the image improvement in the multi-view images coding)

  • 김도현;최동준;양영일
    • 전자공학회논문지S
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    • 제35S권7호
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    • pp.53-61
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    • 1998
  • In this paper, we propose an efficient multi-view images coding algorithm to find the optimal depth and texture from the set of multi-view images. The proposed algorithm consists of two consecutive steps, i) the depth estraction step, and ii) the texture extraction step, comparedwith the traditional algorithem which finds the depth and texture concurrently. The X-Y plane of the normalized object space is divided into traingular paatches and the Z value of the node is determined in the first step and then the texture of the each patch is extracted in the second step. In the depth extraction step, the depth of the node is determined by applying the block based disparity compensation method to the windowed area centered at the node. In the second step, the texture of the traingular patches is extracted from the multi-view images by applying the affine transformation based disparity compensation method to the traingular pateches with the depth extracted from the first step. Experimental results show that the SNR(Singnal-to- Noise Ratio) of images enconded by our algorithm is better than that of images encoded by the traditional algorithm by the amount about 4dB for for the test sets of multi-view images called dragon, kid, city and santa.

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반복적인 격자 워핑 기법을 이용한 깊이 영상 초해상도 기술 (Iterative Deep Convolutional Grid Warping Network for Joint Depth Upsampling)

  • 양윤모;김동신;오병태
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송∙미디어공학회 2020년도 추계학술대회
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    • pp.205-207
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    • 2020
  • 본 논문에서는 딥러닝 기반의 깊이 영상 초해상도 기술에 대해서 제안한다. 기존 깊이 영상의 초해상도 기술은 고해상도의 컬러 영상과 저해상도 깊이 영상을 이용하여 화소 값을 개선시켜 고해상도의 깊이 영상을 예측하였다. 하지만 이라한 방법들은 단순히 화소 값을 증가 또는 혹은 감소시키는 방법으로 언더슈팅 또는 오버슈팅과 문제를 발생시켜 성능 향상을 제한한다. 제안하는 기법에서는 이러한 한계를 극복하기 위해 화소의 위치를 이동하여 영상을 복원하는 격자 워핑 방식을 반복적으로 적용하여 고해상도 깊이 영상을 예측하였다. 실험 결과, 제안한 방식이 기존 방법들에 비해 정량적, 시각적 품질을 개선시켰음을 확인하였다.

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