• Title/Summary/Keyword: blind estimation

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Verification of Harmonization of Dose Assessment Results According to Internal Exposure Scenarios

  • Kim, Bong-Gi;Ha, Wi-Ho;Kwon, Tae-Eun;Lee, Jun-Ho;Jung, Kyu-Hwan
    • Journal of Radiation Protection and Research
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    • v.43 no.4
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    • pp.143-153
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    • 2018
  • Background: The determination of the amount of radionuclides and internal dose for the worker who may have intake of radionuclides results in a variation due to uncertainty of measurement data and ingestion information. As a result of this, it is possible that for the same internal exposure scenario assessors could make considerably different estimation of internal dose. In order to reduce this difference, internal exposure scenarios for nuclear facilities were developed, and intercomparison were made to determine the harmonization of dose assessment results among the assessors. Materials and Methods: Seven cases on internal exposures incidents that have occurred or may occur were prepared by referring to the intercomparison excercise scenario that NRC and IAEA have carried out. Based on this, 16 nuclear facilities concerned with internal exposure in Korea were asked to evaluate the scenarios. Each result was statistically determined according to the harmonization discrimination criteria developed by IDEAS/IAEA. Results and Discussion: The results were evaluated as having no outliers in all 7 cases. However, the distribution of the results was spread by various causes. They can be divided into two wide categories. The first one is the distribution of the results according to the assumption of the intake factors and the evaluation factors. The second one is distribution due to misapplication of calculation method and factors related to internal exposure. Conclusion: In order to satisfy the harmonization criteria and accuracy of the internal exposure dose evaluation, it is necessary that exact guidelines should be set on low dose, and various intercomparison cases also be needed including high dose exposure as well as the specialized education. The aim of the blind test is to make harmonization evaluation, but it will also contribute to securing the expertise and high quality of dose evaluation data through the discussion among the participants.

Blind Super-Resolution Kernel estimation using two images (두 장의 이미지를 활용한 이미지 화질 저하 커널 예측)

  • Cho, Sunwoo;Cho, Nam Ik
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2021.06a
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    • pp.303-306
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    • 2021
  • 이미지 초해상도는 영상 취득 과정에서 센서와 렌즈의 물리적인 한계 등으로 인하여 의해 화질이 저하된 이미지를 더 높은 배율로 복원하는 문제이다. 이미지 초해상도는 딥러닝을 통해 놀라운 성능향상을 이루었지만, 카메라로 촬영된 실제 이미지에서는 좋은 성능을 내지 못하였다. 이는 딥러닝에서는 'bicubic' 커널로 down-sampling된 합성 이미지 데이터를 사용하였던 것과 달리 실제 이미지에서는 'bicubic' 커널을 통한 화질 저하와는 다른 화질 저하, 즉 다른 커널을 통한 화질 저하가 발생하기 때문이다. 따라서 실제 이미지에 대한 성능을 높이기 위해서는 이에 대한 정확한 커널 예측이 필요하다. 최근 주목받기 시작한 이미지 초해상도를 위한 커널 예측은 초해상도를 잘 시켜주는 커널을 직접 찾는 방법[10, 13]과 이미지의 분포와 커널을 통해 다운샘플된 이미지에 대한 분포를 일치시켜주면서 커널을 예측하는 방법[14]으로 나누어져 있다. 그러나 두 방법 모두 ill-posed problem 인 커널 예측 문제를 한 장의 이미지만으로 해결하려는 것이기 때문에 정확한 예측에는 어려움이 발생한다. 따라서 본 논문에서는 두 장의 이미지를 활용한 이미지 화질 저하 커널 예측 방법을 제안한다. 제안된 방법은 두 장의 이미지가 같은 카메라를 통해 촬영되었으며 이때 이미지 화질 저하는 카메라에 의해서만 영향을 받는다는 가정을 기반으로 한다. 즉, 두 장의 이미지는 같은 커널을 통해 저하된 이미지라는 가정을 한다. 제안된 방법은 [14]에서처럼 이미지 분포를 기반으로 한 커널 예측을 진행하며, 이미지 초해상도를 진행하고자 하는 이미지 외에 참고 이미지 또한 같은 커널에서 화질 저하를 시켰을 때 본래의 이미지와 같은 분포에 있도록 학습을 진행한다. 결과적으로 본 논문에서는 두 장의 이미지를 사용하였을 때 더욱 정확하게 커널을 찾을 수 있음을 보여준다. 두 장의 이미지를 활용하는 방식이 한 장의 이미지만을 활용하는 기존의 최고 수준의 방법에 비해 합성된 다양한 커널 데이터셋[14]에서 약 0.17dB 성능 향상이 있었다.

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Stereo Image Blind Watermarking Scheme based-on Discrete Wavelet Transform and adaptive Disparity Estimation (웨이블릿 변환과 적응적 변이 추정을 이용한 스테레오 영상 블라인드 워터마킹)

  • Ko Jung-Hwan;Kim Sung-Il;Kim Eun-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.2C
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    • pp.130-138
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    • 2006
  • In this paper, a new stereo image watermarking scheme based-on adaptive disparity estimation algorithm is proposed. That is, a watermark image is embedded into the right image of a stereo image pair by using the DWT and disparity information is extracted from this watermarked right image and the left image. And then, both of this extracted disparity information and the left image are transmitted to the recipient through the communication channel. At the receiver, the watermarked right image is reconstructed from the received left image and disparity information through an adaptive matching algorithm. a watermark image is finally extracted from this reconstructed right image. From some experiments using CCETT's 'Manege' and 'Friends' images as a stereo image and English alphabet '3DRC' as a watermark image, it is found that the PSNRs of the watermarked image from the reconstructed right images through the adaptive matching algorithm & DWT is improved 2.03 dB, 3.03 dB and robusted against various attacks. These experimental results also suggest a possibility of practical implementation of an adaptive matching also-rithm-based stereo imagewatermarking scheme proposed in this paper.

Detection and Absorbed-Dose Estimation of Irradiated Enzyme Powder Using ESR Spectroscopy (ESR Spectroscopy를 이용한 방사선 조사 효소분말의 검지와 흡수선량 예측)

  • Chung, Hyung-Wook;Jeong, Jae-Young;Kwon, Joong-Ho
    • Korean Journal of Food Science and Technology
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    • v.31 no.5
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    • pp.1159-1163
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    • 1999
  • Along with the increasing demands for food irradiation technology in the food industry, a proper detection means for controlling irradiated foods is required. Enzyme powder, which is permitted to be irradiated in Korea, was subjected to a detection trial by ESR spectroscopy. The high correlation coefficients were observed between the absorbed doses ranging from 2.5 to 15.0 kGy and the corresponding ESR signal intensity, such as $R^2$ = 0.9904 in gamma irradiation and $R^2$ = 0.9696 in electron beam. Pre-established threshold values for both non-irradiated control (1.19) and 2.5 kGy-irradiated samples (6.97 in gamma-ray; 7.36 in electron-beam) were successfully applicable to the detection of 30 coded unknown samples of enzyme powder. The calibration curves obtained from the samples irradiated at 2.5 to 15 kGy were expected to be potentially adopted to estimate absorbed doses ranging front 4 to 7 kGy with a quadratic equation.

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A Clinical Trial of Acupuncture Treatment for Frozen Shoulder (Frozen Shoulder의 침치료에 대한 임상연구)

  • Hong, Kwon-Eui;Kim, Young-Il;Yim, Yun-Kyoung;Ahn, Taek-Won;Kang, Wee-Chang;Choi, Sun-Mi;Lee, Hyun
    • Journal of Acupuncture Research
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    • v.23 no.1
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    • pp.165-177
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    • 2006
  • Objectives : 1. Clinical trial for the efficacy evaluation of Korean acupuncture techniques in treating frozen shoulder. 2. Development of the standard clinical guidelines of the acupuncture treatment for the frozen shoulder. 3. Development of the new clinical protocol for the acupuncture treatments. 4. Verification of the hypothesis that treating at both the remote and the nearby acupoints according to the meridian theory is more effective than treating at only the nearby acupoints. Methods : 1. Research designed as Single blind, Randomized, Sham acupuncture controlled clinical Trial. 2. Assignment of 86 patients to one of three groups treated at nearby acupoints(group A), remote & nearby acupoints(group B), and sham points(group C) respectively. 3. Trial conducted at KIOM CRC of Dunsan oriental medical hospital, Daejeon Univ. 4. Estimation of the recovery rate of the frozen shoulder in subjects aged over 40. 5. Efficacy evaluation using VAS, SPADI, ROM and Improvement rate. Results : 1. There was no significant difference in VAS among the three groups. 2. Pain related scores in SPADI of the group B were significantly lower than those of the group A. 3. There was no significant difference in disability related scores of SPADI among the three groups. 4. External rotation of upper arm in the group B was significantly improved in comparison with that in the group C. 5. Abduction of upper arm in group A was improved with weak statistical significance in comparison with that in the group C. Conclusion : Acupuncture at both the remote and the nearby acupoints according to the meridian theory is effective to improve external rotation of frozen shoulder, and acupuncture at the nearby acupoints is effective to improve adduction of frozen shoulder. However it is not clear that acupuncture treatment at both the remote and the nearby acupoints according to the meridian theory is more effective than treating at only the nearby acupoints in the treatment of frozen shoulder. Since our study was a short term trial, a long term trial for a more precise evaluation of acupuncture treatment for frozen shoulder will be needed in the future.

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Risk of Breast Cancer and Total Malignancies in Rheumatoid Arthritis Patients Undergoing TNF-α Antagonist Therapy: a Meta-analysis of Randomized Control Trials

  • Liu, Yang;Fan, Wei;Chen, Hao;Yu, Ming-Xia
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.8
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    • pp.3403-3410
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    • 2014
  • Context: Interest exits in whether TNF-alpha antagonists increase the risk of breast cancer and total malignancies in patients with rheumatoid arthritis (RA). Objectives: To analyze the risk of malignancies, especially breast cancer, in patients with RA enrolled in randomized control trials (RCTs). Methods: A systematic literature search for RCTs from 1 January 1998 to 1 July 2013 from online databases, such as PubMed, WILEY, EMBASE, ISI web of knowledge and Cochrane Library was conducted. Studies included RCTs that compared the safety of at least one dose of the five TNF-${\alpha}$ antagonists with placebo or methotrexate (MTX) (or TNF-${\alpha}$ antagonists plus MTX vs placebo plus MTX) in RA patients for more than 24 weeks and imported all the references into document management software EndNote${\times}6$. Two independent reviewers selected studies and extracted the data about study design, patients' characteristics and the type, number of all malignancies. Results: 28 RCTs from 34 records with 11,741 patients were analyzed. Of the total, 97 developed at least one malignancy during the double-blind trials, and breast cancer was observed in 17 patients (17.5% of total malignancies). However, there was no statistically significant increased risk observed in either the per protocol (PP) model (OR 0.65, 95%CI [0.22, 1.93]) or the modified intention to treat (mITT) model (OR 0.75, 95%CI [0.25, 2.21]). There were also no significant trend for increased risk of total malignancies on anti-TNF-${\alpha}$ therapy administered at approved doses in either model (OR, 1.06, 95%CI [0.64, 1.75], and OR, 1.30, 95%CI [0.80, 2.14], respectively). As to the two models, modified intention to treat model analysis led to higher estimation than per protocol model analysis. Conclusions: This study did not find a significantly increased risk of breast cancer and total malignancies in adults RA patients treated with TNF-${\alpha}$ antagonists at approved doses. However, it cannot be ignored that more patients developed malignancies with TNF-${\alpha}$ antagonists therapy compared with patients with placebo or MTX, in spite of the lack of statistical significance, so that more strict clinical trials and long-term follow-up are needed, and both mITT and PP analyses should be used in such safety analyses.

Detection of Irradiation Treatment for Seasoned-Powdered Foods by Thermoluminescence Measurement (Thermoluminescence 측정에 의한 조미분말식품의 방사선 조사유무 확인)

  • Chung, Hyung-Wook;Kwon, Joong-Ho
    • Korean Journal of Food Science and Technology
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    • v.30 no.3
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    • pp.509-516
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    • 1998
  • Thermoluminescence measurements were applied to the detection of seasoned-powered foods such as shellfish extract powder, seasoned marine products, Ramen soup powder and sardine extract powder whether they are irradiated or not. Correlation coefficients $(R^2)$ between irradiation doses and corresponding TL responses were more than 0.5966 in all samples and 0.9500 in Ramen soup powder. TL threshold value was pre-established for the detection of unknown Ramen soup powders by verifying TL responses with a re-irradiation step. Threshold values were maximum 1.37 for the nonirradiated samples and minimum 6.06 for the 2.5 kGy-irradiated samples. The samples showing values between 1.37 and 6.06 were subjected to a re-irradiation step for their detection, which results were reconfirmed by enumerating the total bacterial load of the detected samples. Pre-established threshold values were successfully applicable to the detection of 167 coded unknown samples, both nonirradiated and irradiated with gamma or electron-beam energy. In the assessment of irradiated doses, three calibration curves were pre-established by plotting TL intensity versus applied doses, of which a quadratic equation was obtained for the potential estimation of irradiated doses with some variations from the real doses.

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Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014 (설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.7
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    • pp.380-394
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    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.