• Title/Summary/Keyword: Re-Estimation

Search Result 357, Processing Time 0.027 seconds

The Removal of Trembling Artifacts for FORMOSAT-2

  • Chang Li-Hsueh;Wu Shun-Chi;Cheng Hsin-Huei;Chen Nai-Yu
    • Proceedings of the KSRS Conference
    • /
    • 2005.10a
    • /
    • pp.142-145
    • /
    • 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.

  • PDF

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

  • Eom, Sung-Eun;Jang, Jun-Su
    • The KIPS Transactions:PartB
    • /
    • v.17B no.5
    • /
    • pp.355-362
    • /
    • 2010
  • Face tracking is to estimate the motion of a non-rigid face together with a rigid head in 3D, and plays important roles in higher levels such as face/facial expression/emotion recognition. In this paper, we propose an AAM-based face tracking algorithm. AAM has been widely used to segment and track deformable objects, but there are still many difficulties. Particularly, it often tends to diverge or converge into local minima when a target object is self-occluded, partially or completely occluded. To address this problem, we utilize the scale invariant feature transform (SIFT). SIFT is an effective method for self and partial occlusion because it is able to find correspondence between feature points under partial loss. And it enables an AAM to continue to track without re-initialization in complete occlusions thanks to the good performance of global matching. We also register and use the SIFT features extracted from multi-view face images during tracking to effectively track a face across large pose changes. Our proposed algorithm is validated by comparing other algorithms under the above 3 kinds of occlusions.

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
    • Biomedical Science Letters
    • /
    • v.22 no.4
    • /
    • pp.199-206
    • /
    • 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.

Re-estimation of Radiation Stress (라디에이션 응력의 재평가)

  • 김경호;조재희;유동훈
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.7 no.4
    • /
    • pp.305-312
    • /
    • 1995
  • In general, the radiation stresses based on the linear wave theory are overestimated which result in the discrepancy between the computed results and laboratory data of mean water level in the surf zone. Oh (1995) estimated the mean water level by using Svendsen's radiation stress model (1984) and compared with the experimental data. In this study. the computed results showed good agreements with the experimental data in the case of small wave steepness. while the results were overestimated in the case of large wave steepness. In this paper. the dimensionless radiation stress proposed by Svendsen (1984) is expressed in terms of relative water depth at breaking point and deep water wave steepness. The computed results are compared with the results calculated by d linear wave theory, Stive's model (1984). Sawaragi et al's model (1984) based on the spectrum of breaking wave components. and published laboratory data. The computed results of the modified Svendsen's model arc favourably compared with the laboratory data.

  • PDF

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

  • Sim, Seonghyun;Nam, Jongoh
    • Ocean and Polar Research
    • /
    • v.39 no.4
    • /
    • pp.301-318
    • /
    • 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.

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

  • Kim, Sang-Hwan;Park, In-Joon;Chang, Soo-Ho
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.15 no.3
    • /
    • pp.321-331
    • /
    • 2013
  • This paper describes the evaluation of shield TBM disc cutter penetration depth in practice. In this study the disc cutter penetration depth used to design the excavation speed of tunnel is reviewed. The characteristics of ground encountered in the investigation site are analysed and evaluated. The shield TBM used in the field is reviewed to verify the applicability of machine in the site. The thrust and torque capacities of each TBM disc cutter are also evaluated. Based on the field data, the excavation volume and speed are re-analysed to evaluate the disc cutter penetration depth used in the design stage. It is clearly found that the design value of disc cutter penetration depth needs to modify when estimation of the TBM capacities in very hard rock formation ($S_c$ >150 MPa).

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
    • /
    • v.28 no.9
    • /
    • pp.1226-1234
    • /
    • 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.

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

  • 김은미
    • Journal of Nutrition and Health
    • /
    • v.29 no.3
    • /
    • pp.251-259
    • /
    • 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.

  • PDF

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
    • /
    • v.9 no.4
    • /
    • pp.400-403
    • /
    • 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.

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

  • Noh Joon-Woo;Kim Soo-Jun;Kim Jeong-Kon;Koh Ick-Hwan
    • Journal of Korea Water Resources Association
    • /
    • v.39 no.7 s.168
    • /
    • pp.627-636
    • /
    • 2006
  • This study estimates adequate discharge to meet the specified target water quality concentration using the pollutant load of the Geum river basin given in TMDL (Total Maximum Daily Load) report. During the 1st phase, BOD is chosen as a target water quality constituent under regulation of the Ministry of Environment in Korea. BOD, TN, and TP loads estimated based on the TMDL and provincial zones were re-distributed for 10 major tributaries, and the remaining areas along the main river are classified as 15 incremental flow areas. Water quality modeling was conducted using Qual2E for the low flow period of a year (i.e. $March{\sim}April$). The results of the model simulation showed that about 30 cms from the Daechung dam would be sufficient to satisfy the target water quality in the Geum river downstream of the Daechung multipurpose Dam.