• 제목/요약/키워드: re-estimation

검색결과 357건 처리시간 0.034초

The Removal of Trembling Artifacts for FORMOSAT-2

  • Chang Li-Hsueh;Wu Shun-Chi;Cheng Hsin-Huei;Chen Nai-Yu
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.142-145
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    • 2005
  • Since the successful launch of FORMOSAT -2 satellite by National Space Organization of Taiwan in May 2004, the Remote Sensing Instrument (RSI) on- board the FORMOSAT -2 has continuously acquired images at one panchromatic and four multi-spectral bands (http://www.nspo.org.tw). In general, the RSI performs well and receives high quality images which proved to be very useful for various applications. However, some RSI panchromatic products exhibit obvious trembling artifact that must be removed. Preliminary study reveals that the trembling artifact is caused by the instability of the spacecraft attitude. Though the magnitude of this artifact is actually less than half of a pixel, it affects the applicability of panchromatic products. A procedure removing this artifact is therefore needed for providing image products of consistent quality. Due to the nature of trembling artifact, it is impossible to describe the trembling amount by employing an analytic model. Relied only on image itself, an algorithm determining trembling amount and removing accordingly the trembling artifact is proposed. The algorithm consists of 3 stages. First, a cross-correlation based scheme is used to measure the relative shift between adjacent scan lines. Follows, the trembling amount is estimated from the measured value. For this purpose, the Fourier transform is utilized to characterize random shifts in frequency domain. An adaptive estimation method is then applied to deduce the approximate trembling amount. In the subsequent stage, image re-sampling operation is applied to restore the trembling-free product. Experimental results show that by applying the proposed algorithm, the unpleasant trembling artifact is no longer evident.

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SIFT 특징을 이용하여 중첩상황에 강인한 AAM 기반 얼굴 추적 (Robust AAM-based Face Tracking with Occlusion Using SIFT Features)

  • 엄성은;장준수
    • 정보처리학회논문지B
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    • 제17B권5호
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    • pp.355-362
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    • 2010
  • 얼굴추적은 3차원 공간상에서 머리(head)와 안면(face)의 움직임을 추정하는 기술로, 얼굴 표정 감정인식과 같은 상위 분석단계의 중요한 기반기술이다. 본 논문에서는 AAM 기반의 얼굴추적 알고리즘을 제안한다. AAM은 변형되는 대상을 분할하고 추적하는데 광범위하게 적용되고 있다. 그러나 여전히 여러 가지 해결해야할 제약사항들이 있다. 특히 자체중첩(self-occlusion)과 부분적인 중첩, 그리고 일시적으로 완전히 가려지는 완전중첩 상황에서 보통 국부해에 수렴(local convergence)하거나 발산하기 쉽다. 본 논문에서는 이러한 중첩상황에 대한 AAM의 강인성을 향상시키기 위해서 SIFT 특징을 이용하고 있다. SIFT는 일부 영상의 특징점으로 안정적인 추적이 가능하기 때문에 자체와 부분중첩에 효과적이며, 완전중첩의 상황에도 SIFT의 전역적인 매칭성능으로 별도의 재초기화 없이 연속적인 추적이 가능하다. 또한 추적과정에서 큰 자세변화에 따른 움직임을 효과적으로 추정하기 위해서 다시점(multi-view) 얼굴영상의 SIFT 특징을 온라인으로 등록하여 활용하고 있다. 제안한 알고리즘의 이러한 강인성은 위 세 가지 중첩상황에 대해서 기존 알고리즘들과의 비교실험을 통해서 보여준다.

Comparative Estimation of Exposure Level and Health Risk Assessment of Highly Produced Pesticides to Agriculture Operators by Using Default Dermal Absorption Rate or Actual Measurement Values

  • Kim, Su-Hyeon;Lee, Chang-Hun;Kim, Ki-Hun;Jeong, Sang-Hee
    • 대한의생명과학회지
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    • 제22권4호
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    • pp.199-206
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    • 2016
  • Pesticides are widely used to prevent loss of agricultural production but extensive exposure can induce health problems to pesticide operators. This study was performed to evaluate the health risk of highly produced pesticides used in fruit growing farm land by comparison of estimated exposure level with AOEL using KO-POEM program. AOEL was driven based on NOAEL of each pesticide evaluated by JMPR, EFSA or KRDA. In calculation of exposure level, types of formulation, dilution factors, spraying duration and motor type and exposure protection device were allocated according to actual condition of use. Dermal absorption rate was differently applied among EFSA default values (25% or 75%), general default value (10%) or real test result values to know the plausibility of default values and safety of pesticide to operators in outline. Twenty pesticide ingredients (fungicides and insecticides) were produced more than 30 tons per year, which were mancozeb, chlorothalonil, imidaclopirid and etc in order. Dermal absorption rates obtained from studies were various from 0.07 to 81% but mostly under 10%. The estimated exposure levels showed big differences more than 10 times higher when using EFSA default rate and up to 5 times higher when using general rate of 10% comparing using rates of test results. Mancozeb, chlorthalonil, diazinon and chlorpyrifos presented still higher exposure level than AOEL even when using test absorption rate from study, which suggests that re-evaluation of AOEL or dermal exposure absorption rate or strict management are required for health protection of operators who use those four pesticides in farm land.

라디에이션 응력의 재평가 (Re-estimation of Radiation Stress)

  • 김경호;조재희;유동훈
    • 한국해안해양공학회지
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    • 제7권4호
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    • pp.305-312
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    • 1995
  • 일반적으로 선형파동이론에 의해 산정된 라디에이션 응력은 쇄파대내 및 부근에서 과대 평가되는데, 이것이 평균수위변동의 계산치와 실험치와의 불일치의 원인이 된. 오(1995)는 Svendsen (1984)이 제안한 라디에이션 응력을 이용하여 평균수위변동을 산정하고 실험치와 비교한 결과, 파형경사가 작은 경우에는 잘 일치하고 있으나 파형경사가 큰 경우에는 실험치와 잘 맞지 않는 것을 보였다. 본 연구에서는 Svendsen(1984)이 제안한 무차원 라디에이션 상수를 수정하여 쇄파점에서의 상대수심 및 심해파 파형경사의 함수로 표현하여 계산하고, 그 결과를 선형이론, Stive(1984)모델, 쇄파의 성분파고 스펙트럼에 기초한 Sawaragi 등(1984)의 모델 및 기왕의 실험 데이터와 비교하였다. 수정, 제안된 Svendsen 모델의 결과는 실험치와 매우 양호한 일치를 보여 주었다.

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근해어업 생산함수 추정을 이용한 규모수익 및 한계생산성 분석 (Analysis of Marginal Productivity and Return to Scale Using Estimation of Production Function in Offshore Fisheries)

  • 심성현;남종오
    • Ocean and Polar Research
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    • 제39권4호
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    • pp.301-318
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    • 2017
  • The production of Korean offshore fisheries has been gradually decreasing due to the severe depletion of offshore fisheries resources caused by excessive fishing efforts. The production of the offshore fisheries in 2016 was the lowest since 1975. So the federal and local governments in Korea adopted and implemented various fisheries management plans and policies in order to restore fisheries resources. However, these plans and polices have not been successful in re-establishing fisheries resources. Thus, in order to accurately diagnose the situation with regard to offshore fisheries, this study sought to estimate not only the return to scale by fishing gear of offshore fisheries, but marginal productivity of individual fishing gear based on production factors derived from offshore fisheries production functions. The study was organized in the following manner. First of all, this study estimates production functions of offshore fisheries. The Cobb-Douglas and the translog production functions are adopted as offshore fisheries production functions. Specifically, the functions are estimated by crew, vessels, and offshore resource as production factors. The offshore resource is estimated by the Clarke Yoshimoto Pooley model based on the surplus production model. Secondly, the fisheries production functions are extended to the fixed-effect model and the random-effect model with panel data. Thirdly, this study analyzes the return to scale of offshore fisheries and the marginal productivity of the production factors from the estimated offshore fisheries production function. In conclusion, this study suggests plans and countermeasures for productivity improvement by group (labor intensive or technology intensive) based on the characteristics of individual offshore fishing gear.

쉴드TBM의 현장 디스크커터 관입깊이에 대한 연구 (Evaluation of disc cutter penetration depth of shield TBM in practice)

  • 김상환;박인준;장수호
    • 한국터널지하공간학회 논문집
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    • 제15권3호
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    • pp.321-331
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    • 2013
  • 이 연구는 TBM의 디스크커터 관입깊이에 대하여 실질적인 현장을 통하여 평가한 것이다. 연구를 위하여 설계시 적용되는 디스크커터 관입깊이에 대하여 검토하였다. 또한 대상 현장에 대한 지반특성에 대하여 검토하고 현장에 투입된 장비에 대한 적용성에 대하여 분석하였다. 특히 장비의 용량분석을 실시하여 적합성에 대하여 평가하였다. 이러한 평가결과와 현장 공사자료를 근거로 실질적인 TBM의 공사량과 굴진속도를 분석하였다. 이 결과로부터 설계시 적용된 TBM의 디스크커터 관입깊이에 대하여 재평가 하였다. 연구 결과로부터 설계시 적용되는 디스크커터 관입깊이는 특히 극경암 지반($S_c$ >150 MPa)에 있어서 적용값의 변경이 필요하다는 것을 명백히 보여주었다.

Genetic Analysis of Milk Yield in First-Lactation Holstein Friesian in Ethiopia: A Lactation Average vs Random Regression Test-Day Model Analysis

  • Meseret, S.;Tamir, B.;Gebreyohannes, G.;Lidauer, M.;Negussie, E.
    • Asian-Australasian Journal of Animal Sciences
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    • 제28권9호
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    • pp.1226-1234
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    • 2015
  • The development of effective genetic evaluations and selection of sires requires accurate estimates of genetic parameters for all economically important traits in the breeding goal. The main objective of this study was to assess the relative performance of the traditional lactation average model (LAM) against the random regression test-day model (RRM) in the estimation of genetic parameters and prediction of breeding values for Holstein Friesian herds in Ethiopia. The data used consisted of 6,500 test-day (TD) records from 800 first-lactation Holstein Friesian cows that calved between 1997 and 2013. Co-variance components were estimated using the average information restricted maximum likelihood method under single trait animal model. The estimate of heritability for first-lactation milk yield was 0.30 from LAM whilst estimates from the RRM model ranged from 0.17 to 0.29 for the different stages of lactation. Genetic correlations between different TDs in first-lactation Holstein Friesian ranged from 0.37 to 0.99. The observed genetic correlation was less than unity between milk yields at different TDs, which indicated that the assumption of LAM may not be optimal for accurate evaluation of the genetic merit of animals. A close look at estimated breeding values from both models showed that RRM had higher standard deviation compared to LAM indicating that the TD model makes efficient utilization of TD information. Correlations of breeding values between models ranged from 0.90 to 0.96 for different group of sires and cows and marked re-rankings were observed in top sires and cows in moving from the traditional LAM to RRM evaluations.

주요 당류 및 해조류의 대사 에너지 함량 평가에 관한 연구 (A study on estimation of metabolizable energy content in starch-foods and seaweeds)

  • 김은미
    • Journal of Nutrition and Health
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    • 제29권3호
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    • pp.251-259
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    • 1996
  • The validity of the energy data of the starch-foods and seaweeds in Korean food composition tables has been suspected due to possible differences in their chemical compositions from those of western food ingredients. Energy conversion parameters being used currently in nutrition has been derived in countries where food items re quite different from ours. This study was undertaken to determine the metabolizable energy of starch-foods and seaweeds by the method selected in preexperiment20). Cooked starch foods and seaweeds were freeze-dried and fed to Sprague Dawley rat with 200∼300g body weight to measure apparent metabolizable energy (AME) values and nitrogen-corrected AME (AMEn) values for four days after three days of preliminary period for adaptation to the diets. The AME and AMEn values of the wheat noodle were 4554.6, 4584.7, the Starch Vermicelli, 3763.4, 3855.7, the Ra myon, 4916.9, 4876.0, the Buckwheat noodle, 4469.7, 4442.0kcal/kg dry matter, the Potato, 4514.6, 4520.0 and those of the Bread, 3256.9, 3582.6, 3260.5, kcal/kg dry matter, respectively. Those of Sea tangle were 1437.3, 1631.3 and of Laver, 3126.6, 3171.3kcal/kg dry matter, resectively. When the AME values of the starch-foods and seaweeds measureed in present study were compared with energy values calculated by various conversion parameters such as Atwater's Rubner's, Sochun's and FAO's, there appeared dramatic differences indicating that for many of the food items, the latter energy values by conversion factors are hardly acceptable. These data also suggest that the existing energy conversion factors are not applicable to seaweeds and a further study is needed to obtain specific factors for the conversion to biological energy from the chemical composition of seaweeds.

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Evidence-based estimation of health care cost savings from the use of omega-3 supplementation among the elderly in Korea

  • Hwang, Ji-Yun;Kim, Wu Seon;Jeong, Sewon;Kwon, Oran
    • Nutrition Research and Practice
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    • 제9권4호
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    • pp.400-403
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    • 2015
  • BACKGROUND/OBJECTIVES: By the year 2050, thirty-eight percent of the Korean population will be over the age of 65. Health care costs for Koreans over age 65 reached 15.4 trillion Korean won in 2011, accounting for a third of the total health care costs for the population. Chronic degenerative diseases, including coronary heart disease (CHD), drive long-term health care costs at an alarming annual rate. In the elderly population, loss of independence is one of the main reasons for this increase in health care costs. Korean heath policies place a high priority on the prevention of CHD because it is a major cause of morbidity and mortality. SUBJECTS/METHODS: This evidence-based study aims to the estimate potential health care cost savings resulting from the daily intake of omega-3 fatty acid supplementation. Potential cost savings associated with a reduced risk of CHD and the medical costs potentially avoided through risk reduction, including hospitalizations and physician services, were estimated using a Congressional Budget Office cost accounting methodology. RESULTS: The estimate of the seven-year (2005-2011) net savings in medical costs resulting from a reduction in the incidence of CHD among the elderly population through the daily use of omega-3 fatty acids was approximately 210 billion Korean won. Approximately 92,997 hospitalizations due to CHD could be avoided over the seven years. CONCLUSIONS: Our findings suggest that omega-3 supplementation in older individuals may yield substantial cost-savings by reducing the risk of CHD. It should be noted that additional health and cost benefits need to be revisited and re-evaluated as more is known about possible data sources or as new data become available.

금강수계 오염총량관리를 고려한 저수지 방류량산정 (Estimation of Reservoir Discharge to Support TMDL Management in the Geum River Basin)

  • 노준우;김수전;김정곤;고익환
    • 한국수자원학회논문집
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    • 제39권7호
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    • pp.627-636
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    • 2006
  • 본 논문에서는 금강수계 오염총량관리 기본계획에서 제시된 오염부하량 자료를 기반으로 공시된 목표수질을 달성하기 위한 적정방류량을 산정하였다. 오염총량관리의 1단계로 BOD를 대상으로 총량관리가 이루어질 계획이며 향후 질소 및 인 계열로 확대될 전망이다. 총량구역별 및 행정구역별로 산정된 BOD와 TN, TP 부하량을 GIS를 활용하여 10개의 지류수계에 대하여 재분배하였고 지류수계에 해당되지 않는 구역에 대해서는 15개의 소구간으로 처리하여 반영하였다. Qual2E를 사용하여 수질모의를 실시한 결과 2010년에 대하여 산정된 장래수질에 대하여 기준부하량의 경우 약 30 CMS의 유량이 본류구간에 대하여 제시된 수질기준을 만족하기에 적절한 것으로 모의되었다.