• 제목/요약/키워드: Depth of Field

검색결과 3,058건 처리시간 0.037초

담수심 처리가 논의 증발산량에 미치는 영향 (Effects of ponding depth treatment on evapotranspiration in paddy fields)

  • 손성호;박기중;정상옥
    • 한국농공학회:학술대회논문집
    • /
    • 한국농공학회 2002년도 학술발표회 발표논문집
    • /
    • pp.9-12
    • /
    • 2002
  • The purpose of this study was to investigate the effects of ponding depth treatment on evapotranspiration in paddy fields. Three poding depth treatments, very sallow, shallow, and deep were used. The experimental plots were three $80m{\times}8m$ rectangular plots. Daily values of rainfall amount, ponding depth, irrigation water, drainage water, evapotranspiration, and infiltration were measured in the field. The ponding depth was continuously observed by observed nstaff during the growing season. The ET was measured by 1m diameter PVC lysimeters. Irrigation water volume was measured by 75 mm pipe flow-meters and the drainage water volume by 75 mm pipe flow-meters and a recording parshall flume. The results showed that irrigation water depths were 688.9 mm, 513.6 mm, and 624.4 mm in 2001, and 356.9 mm, 428.6 mm, and 513.2 mm in 2002 in very shallow, shallow, and deep ponding, respectively. The evapotranspiration were 465.0 mm, 484.1 mm, and 415.1 mm in 2001 and 461.3 mm, 476.3 mm, and 470.6 mm in 2002 in very shallow, shallow, and deep ponding, respectively.

  • PDF

DEPTH AND LAYOUT OPTIMIZATIONS OF A RADIOACTIVE WASTE REPOSITORY IN A DISCONTINUOUS ROCK MASS BASED ON A THERMOMECHANICAL MODEL

  • Kim, Jhin-Wung;Koh, Yong-Kwon;Bae, Dae-Seok;Choi, Jong-Won
    • Nuclear Engineering and Technology
    • /
    • 제40권5호
    • /
    • pp.429-438
    • /
    • 2008
  • The objective of the present study is the depth and layout optimizations of a single layer, high level radioactive waste repository in a discontinuous rock mass with special joint set arrangements. A single layer repository model, considering variations in the repository depths, pitches, and tunnel spacings, is used to analyze the thermomechanical interaction behavior. It is assumed that the repository is constructed in saturated granite with joints; the PWR spent fuel in a disposal canister is installed in a deposition drift which is then sealed with compacted bentonite; and the backfill material is filled in the repository tunnel. The decay heat generated by the high level radioactive wastes governs the thermomechanical behavior of the near field rock mass of the repository. The temperature and displacement behavior of the repository is influenced more by the pitch variations than the tunnel spacing and repository depth. However, the stress behavior is influenced more by the repository depth variations than the pitch and tunnel spacing. For the final selection of the tunnel spacing, pitch, and repository depth, other aspects such as the nuclide migration through a groundwater flow path, construction costs, operation costs, and so on should be considered.

우리나라 중.소 하천의 세굴특성 조사연구(2) (Field Investigation of Bridge Scours in Small and Medium Streams(2))

  • 여운광;강준구
    • 한국수자원학회논문집
    • /
    • 제32권1호
    • /
    • pp.49-59
    • /
    • 1999
  • 우리 나라의 세굴현황을 파악하고 교량설계에 대한 기초자료를 제공하기 위하여 중부지방의 중·소하천에 위치한 교량에 대하여 실시한 세굴조사 자료를 분석하였다. 현장실측은 주로 세굴에 영향을 미치는 물리량들, 즉 수심, 유속, 교각폭, 및 길이, 세굴깊이, 접근각 등을 중심으로 이루어졌다. 지역적으로는 경기도 용인·광주지역, 홍천강의 서면지역, 청평·포천지역, 연천지역, 청주북일지역으로 구분하였으며 교각도 타원과 원형으로 구분하였다. 이들로부터 세굴깊이와 수심, 접근각 도는 Fuoude수 등주요 인자들과의 관계를 도출하였으며 또한 기존의 제안된 세굴공식에 이들을 적용시켜 세굴깊이를 산정하였다. 또한 실측된 세굴깊이와 비교하여 우리 나라에 적용가능한 세굴공식을 제안하였다.

  • PDF

Magnetic field distribution in steel objects with different properties of hardened layer

  • Byzov, A.V.;Ksenofontov, D.G.;Kostin, V.N.;Vasilenko, O.N.
    • Advances in Computational Design
    • /
    • 제7권1호
    • /
    • pp.57-68
    • /
    • 2022
  • A simulation study of the distribution of magnetic flux induced by a U-shaped electromagnet into a two-layer massive object with variations in the depth and properties of the surface layer has been carried out. It has been established that the hardened surface layer "pushes" the magnetic flux into the bulk of the magnetized object and the magnetic flux penetration depth monotonically increases with increasing thickness of the hardened layer. A change in the thickness and magnetic properties of the surface layer leads to a redistribution of magnetic fluxes passing between the poles of the electromagnet along with the layer and the bulk of the steel object. In this case, the change in the layer thickness significantly affects the magnitude of the tangential component of the field on the surface of the object in the interpolar space, and the change in the properties of the layer affects the magnitude of the magnetic flux in the magnetic "transducer-object" circuit. This difference in magnetic parameters can be used for selective testing of the surface hardening quality. It has been shown that the hardened layer pushes the magnetic flux into the depth of the magnetized object. The nominal depth of penetration of the flow monotonically increases with an increase in the thickness of the hardened layer.

Relationship between Progressive Changes in Lamina Cribrosa Depth and Deterioration of Visual Field Loss in Glaucomatous Eyes

  • Kim, You Na;Shin, Joong Won;Sung, Kyung Rim
    • Korean Journal of Ophthalmology
    • /
    • 제32권6호
    • /
    • pp.470-477
    • /
    • 2018
  • Purpose: To investigate the relationship between the progression of visual field (VF) loss and changes in lamina cribrosa depth (LCD) as determined by spectral-domain optical coherence tomography (SD-OCT) enhanced depth imaging in patients with primary open angle glaucoma (POAG). Methods: Data from 60 POAG patients (mean follow-up, $3.5{\pm}0.7$ years) were included in this retrospective study. The LCD was measured in the optic disc image using SD-OCT enhanced depth imaging scanning at each visit. Change in the LCD was considered to either 'increase' or 'decrease' when the differences between baseline and the latest two consecutive follow-up visits were greater than the corresponding reproducibility coefficient value ($23.08{\mu}m$, as determined in a preliminary reproducibility study). All participants were divided into three groups: increased LCD (ILCD), decreased LCD (DLCD), and no LCD change (NLCD). The Early Manifest Glaucoma Trial criteria were used to define VF deterioration. Kaplan-Meier survival analysis and Cox's proportional hazard models were performed to explore the relationship between VF progression and LCD change. Results: Of the 60 eyes examined, 35.0% (21 eyes), 28.3% (17 eyes), and 36.7% (22 eyes) were classified as the ILCD, DLCD, and NLCD groups, respectively. Kaplan-Meier survival analysis showed a greater cumulative probability of VF progression in the ILCD group than in the NLCD (p < 0.001) or DLCD groups (p = 0.018). Increased LCD was identified as the only risk factor for VF progression in the Cox proportional hazard models (hazard ratio, 1.008; 95% confidence interval, 1.000 to 1.015; p = 0.047). Conclusions: Increased LCD was associated with a greater possibility of VF progression. The quantitative measurement of LCD changes, determined by SD-OCT, is a potential biomarker for the prediction of VF deterioration in patients with POAG.

낮추베기 뽕나무 뿌리와 몇몇 토양화학성 분포에 관한 조사연구 (Distribution of Root System and Several Chemical Components of Soil on Low-Cutting Mulberry Field)

  • 이원주
    • 한국잠사곤충학회지
    • /
    • 제22권1호
    • /
    • pp.52-58
    • /
    • 1980
  • 20년생 낮추베기 개양서반의 뽕밭에서 휴간 1.8m을 7등분으로, 2주간 1.2m를 7등분으로 각각 분할하고, 표토로부터 10cm씩 40cm 깊이의 토양을 구분 채취하여 총 196점에 대한 뿌리와 토양화학성분포를 조사 분석한바 그 결과는 다음과 같다. 1. 뿌리의 분포는 그루주변으로 갈수록 증가하늘 반면 pH 유효인산, Ca, Mg등은 이와 대조적으로 휴간에서 높았다. 2. 주간의 뿌리 및 토양화학성(pH, 유효인산, K, Ca, Mg등)은 비교적 균일한 분포를 보였다. 3. 층위별 뿌리의 분포는 10~20cm부위에서 가장 높은데 비해 0~10cm부에서는 20~30, 30~40에서 보다도 낮으며 pH, 유효인산, Ca, Mg, K등은 0~10cm부위에서 가장 높으며 심층으로 갈수록 낮아서, 사실상 양분의 효율적인 흡수가 극대점에 이르지 못한 것으로 판단되었다.

  • PDF

지역사회기반 참여연구 방법에 입각한 단기집중 방문재활프로그램 질적 평가: 치료사와 대상자 심층면담을 중심으로 (A Qualitative Evaluation of Short-Term Intensive Home-Based Rehabilitation Program for Disabilities Through In-Depth Interview: Community-Based Participatory Research Approach)

  • 이민영;김은성;윤범철
    • 한국전문물리치료학회지
    • /
    • 제23권2호
    • /
    • pp.44-56
    • /
    • 2016
  • Background: The Community-Based Participatory Research (CBPR) approach is recognized in the field of health promotion as a way to optimize intervention for promoting health by taking into account specific social, economical, and institutional situations of the community. However, the CBPR approach has not been applied in the field of community-based rehabilitation. Objects: This study was conducted to explore the self-perceived satisfaction of therapists and disabilities on the Short-term Intensive Home-based Rehabilitation (SIHR) program developed using the CBPR approach as well as determine the points that need improvement. Methods: This research was conducted through in-depth interviews. The SIHR program was developed, applied, and evaluated by both the researchers and four therapists on the basis of the CBPR approach. The SIHR program was administered to four disability for 1 hour a day, 2 or 3 times a week, for 8 weeks, and their self-rehabilitation was monitored once a week for 4 weeks. After all intervention periods, in-depth interviews were conducted by using a semi-structured questionnaire for the therapists and disability. Results: The therapists were satisfied with the contents of the SIHR program, such as behavioral change technique and goal-directed training. They were also satisfied with the process of developing the program through a community network. Disabilities were satisfied with the therapists' persuasive and emotionally interactive way of delivering the SIHR program as well as the individually customized rehabilitation training and physical improvement. The short period (8 weeks) of the SIHR program was noted by both therapists and disabilities as the part that needs improvement. Conclusion: The SIHR program developed using the CBPR approach was feasible and satisfying to therapists and disabilities. However, a longer SIHR program should be developed. Community networks could help therapists effectively utilize community resources and thereby provide more rehabilitation program for persons with disability.

소수의 협소화각 RGBD 영상으로부터 360 RGBD 영상 합성 (360 RGBD Image Synthesis from a Sparse Set of Images with Narrow Field-of-View)

  • 김수지;박인규
    • 방송공학회논문지
    • /
    • 제27권4호
    • /
    • pp.487-498
    • /
    • 2022
  • 깊이 영상은 3차원 공간상의 거리 정보를 2차원 평면에 나타낸 영상이며 다양한 3D 비전 연구에서 유용하게 사용된다. 기존의 많은 깊이 추정 연구는 주로 좁은 FoV (Field of View) 영상을 사용하여 전체 장면 중 상당 부분이 소실된 영상에 대한 깊이 정보를 추정한다. 본 논문에서는 소수의 좁은 FoV 영상으로부터 360° 전 방향 RGBD 영상을 동시에 생성하는 기법을 제안한다. 오버랩 되지 않는 4장의 소수 영상으로부터 전체 파노라마 영상에 대해서 상대적인 FoV를 추정하고 360° 컬러 영상과 깊이 영상을 동시에 생성하는 적대적 생성 신경망 기반의 영상 생성 모델을 제안하였으며, 두 모달리티의 특징을 공유하여 상호 보완된 결과를 확인한다. 또한 360° 영상의 구면 특성을 반영한 네트워크를 구성하여 개선된 성능을 보인다.

인공신경망을 이용한 피어의 국부세굴 평가 (Estimation of Local Scour at Piers Using Artificial Neural Network)

  • 박현일;신종현
    • 한국지반공학회논문집
    • /
    • 제24권11호
    • /
    • pp.17-24
    • /
    • 2008
  • 하천 교각에서 유발되는 국부세굴은 교량의 붕괴를 유발하는 요인들 가운데 하나로 알려져 있다. 그러나, 교각주위 하천 흐름은 매우 복잡하기 때문에 국부세굴을 정확하게 산정하는 경험식을 도출하기가 쉽지 않다. 따라서, 기존의 경험식들은 특정 세굴 자료에는 좋은 상관 관계를 보이지만 다양한 현장 세굴자료들에 대해 신뢰성 있는 예측 정도를 갖기는 어렵다. 본 연구에서는 많은 현장 계측자료를 바탕으로 국부세굴심을 산정할 수 있는 인공신경망 모델을 제안하고자 하였다. 제안된 산정식은 교각 형상, 교각 폭, 교각 길이, 흐름 입사각, 흐름 속도, 수심 및 $D_{50}$의 총 7개의 변수의 함수로 구성되었다. 인공신경망 모델의 학습과 검증에 총 426개의 현장 계측자료들이 사용되었으며, 인공신경망 모델이 기존 경험 식들에 비하여 개선된 예측정도를 보임을 확인하였다.

우리나라 중.소 하천의 세굴특성 조사연구(1) (Fied Investigation of Bridge Scours in Small and Medium Streams(1))

  • 여운광;강준구
    • 한국수자원학회논문집
    • /
    • 제32권1호
    • /
    • pp.41-47
    • /
    • 1999
  • 현재 국내에서는 매년 평균 100여개의 교량이 붕괴되거나 심각한 피해를 입고 있다. 이들의 대부분은 홍수시 기초지반이 유실됨으로써 발생되며 다라서 세굴에 의한 피해를 줄이기 위하여는 우선 이에 대한 기초적 연구와 함께 교량설계시 예상되는 세굴깊이를 정확히 산정하고 이를 설계에 합리적으로 반영시키는 것이 필요하다. 그러나 세굴이 발생되는 물리적 현상은 많은 인자들이 서로 복잡하게 연계되어 해석하기에 쉽지 않으며 실측된 자료 또한 찾아보기 힘들다. 본 연구에서는 좀 더 합리적인 설계와 세굴에 대한 기초적인 자료를 제공하기 위하여 교각세굴에 대해 현장실측을 수행하였다. 실측대상은 주로 접근하기 쉬운 중·소하천을 대상으로 하였으며 세굴깊이, 교각폭 및 길이, 수심, 유속 및 유량, 접근각 등 세굴에 영향을 미치는 물리량들을 관측하고 측정하였다. 이들 자료로부터 현재의 국내 세굴현황을 파악할 수 있었으며 교량의 안정성에 영향을 미치는 인자들에 대한 분석을 행하였다.

  • PDF