• Title/Summary/Keyword: Confidence Region

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Moving Target Tracking Algorithm based on the Confidence Measure of Motion Vectors (움직임 벡터의 신뢰도에 기반한 이동 목표물 추적 기법)

  • Lee, Jin-Seong;Lee, Gwang-Yeon;Kim, Seong-Dae
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.38 no.2
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    • pp.160-168
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    • 2001
  • Change detection using difference picture has been used to detect the location of moving targets and to track them. This method needs the assumption of static camera, and the global motion compensation is required in case of a moving camera. This paper suggests a method for finding a minimum bounding rectangles(MBR) of moving targets in the image sequences using moving region detection, especially with a moving camera. If the global motion parameter is inaccurately estimated, the estimated locations of targets will be accurate either To alleviate this problem, we introduce the concept of the confidence measure and achieve more accurate estimation of global motion. Experimental results show that the proposed method successfully removes background region and extracts MBRs of the targets. Even with a moving camera, the new global motion estimation algorithm performs more precise]y and it reduces the background compensation errors of change detection.

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Development of a Magnetoencephalograph System for Small Animals (소동물용 뇌자도 측정 시스템 개발)

  • Kim, J.E.;Kim, I.S.;Kang, C.S.;Kwon, H.;Kim, J.M.;Lee, Y.H.;Kim, K.
    • Progress in Superconductivity
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    • v.13 no.1
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    • pp.18-23
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    • 2011
  • We developed a four-channel first order gradiometer system to measure magnetoencephalogram for mice. We used double relaxation oscillation SQUID (DROS). The diameter of the pickup coil is 4 mm and the distance between the coils is 5 mm. Coil distance was designed to have good spatial resolution for a small mouse brain. We evaluated the current dipole localization confidence region for a mouse brain, using the spherical conductor model. The white noise of the measurement system was about 30 fT/$Hz^{1/2}$/cm when measured in a magnetically shielded room. We measured magnetic signal from a phantom having the same size of a mouse brain, which was filled with 0.9% saline solution. The results suggest that the developed system has a feasibility to study the functions of brain of small animals.

Assessment of Noise Exposure and Hearing Loss Among Workers in Textile Mill (Thamine), Myanmar: A Cross-Sectional Study

  • Zaw, Aung K.;Myat, Aung M.;Thandar, Mya;Htun, Ye M.;Aung, Than H.;Tun, Kyaw M.;Han, Zaw M.
    • Safety and Health at Work
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    • v.11 no.2
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    • pp.199-206
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    • 2020
  • Background: In a wide range of industries, noise-induced hearing loss remains one of the most prevalent occupational problems. This study aimed to assess the noise exposure level and associated factors of hearing loss among textile workers in Yangon Region, Myanmar. Methods: A cross-sectional study was conducted at a Textile mill (Thamine), Yangon Region, from April to December 2018. In total, 226 workers who were randomly selected from 3 weaving sections participated in face-to-face interviews using a structured questionnaire. A digital sound level meter and pure-tone audiometer were used for the assessment of noise exposure level and hearing loss, respectively. Logistic regression analysis was performed to assess the associated factors of hearing loss. Results: In total workers, 66.4% were exposed to ≥85 dB(A) of noise exposure, and the prevalence of hearing loss was 25.7%. Age ≥35 years, below high school education, hearing difficulty, tinnitus, hypertension, > 9 years of service duration in a textile mill were positively associated with hearing loss. After adjusting confounding factors, age ≥35 years (adjusted odds ratio = 6.90, 95% confidence interval = 3.45-13.82) and tinnitus (adjusted odds ratio = 2.88, 95% confidence interval = 1.13-7.37) were persistently associated with hearing loss. Conclusion: Providing occupational hazard education and enforcement of occupational safety regulations should be taken to decrease the noise exposure level. The regular audiometry test should be conducted for assessment of hearing threshold shift. The employer needs to implement a hearing conservation program in workplace when noise exposure reaches or exceeds 85 dB(A) for 8 hours.

Relationship Between the Prohibitin 3' Untranslated Region C > T Gene Polymorphism and Cancer Susceptibility - Results of a Meta-analysis

  • Zhou, Tian-Biao;Yin, Sheng-Sheng;Huang, Jian-Jian;Ou, Chao
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.7
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    • pp.3319-3323
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    • 2012
  • Objective: The results from the published studies on the association between prohibitin 3' untranslated region C > T gene polymorphism and cancer risk are conflicting. This meta-analysis was performed to evaluate the relationship with cancer susceptibility overall, and to explore whether the T allele or TT genotype could become a predictive marker for cancer risk. Methods: Association studies were identified from the databases of PubMed, Embase, and Cochrane Library as of March 1, 2012, and eligible investigations were synthesized using the meta-analysis method. Results were expressed with odds ratios (OR) for dichotomous data, and 95% confidence intervals (CI) were also calculated. Results: Six investigations were identified for the analysis of association between the prohibitin 3' untranslated region C > T gene polymorphism and cancer risk, covering of 1,461 patients with cancer and 1,197 controls. There was a positive association between the T allele and cancer susceptibility (OR=1.20, 95% CI: 1.03-1.39, P=0.02), and CC homozygous might play a protective role (OR=0.80, 95% CI: 0.68-6.11, P=0.95). In the sub-group analysis, prohibitin 3' untranslated region C > T gene polymorphism and cancer risk appeared associated with the risk of breast cancer, but not ovarian cancer. Conclusions: Our results indicate that T allele is a significant genetic molecular marker to predict cancer susceptibility and CC genotype is protective, especially for breast cancer. However, more investigations are required to further clarify the association of the prohibitin 3' untranslated region C > T gene polymorphism with cancer susceptibility.

Relationship between residential district and health-related quality of life in Chungnam industrial complex area

  • Kim, Heechan;Roh, Sangchul
    • Environmental Analysis Health and Toxicology
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    • v.31
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    • pp.17.1-17.7
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    • 2016
  • Objectives This study aimed to evaluate the relationship between residential district of people, such as power plant, steel-mill and petrochemical industries, and health-related quality of life (HRQoL). Methods Using a cross-sectional study design, we randomly recruited participants for our study from industrial areas (thermoelectric power plant, steel-mill, petrochemical industry) and rural areas. Logistic regression analysis was used to identify the relationships between Euro quality of life-5 dimension (EQ-5D) scores and living region, while controlling for sociodemographic characteristics. Results In adjusted model, quality of life decreased with increasing category of age and were lower for females than males. EQ-5D scores of people living in the vicinity of thermoelectric power plant were significant lower than those of people living the vicinity of comparison region (odds ratio, 1.59; 95% confidence interval, 1.00 to 2.53). Conclusions Living region of thermoelectric power plant, was strongly associated with scores on the EQ-5D. More research is needed to elucidate the mechanisms which makes the relationship with the living regions and HRQoL.

The analysis of groundwater table variations in Sylhet region, Bangladesh

  • Zafor, Md. Abu;Alam, Md. Jahir Bin;Rahman, Md. Azizur;Amin, Mohammad Nurul
    • Environmental Engineering Research
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    • v.22 no.4
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    • pp.369-376
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    • 2017
  • The trend analysis of the study was acquired by selecting multiyear monthly groundwater table data and monitors the wells in each sub-district under the study area. The intention of this research was to analyze the outcome of the non-parametric Mann-Kendall test at greater than the significance level which is 95% of groundwater level in Sylhet. The aptitude is effective at two conjunctures where the confidence bounds are 95% and it meets the estimate line of Sen's. To calculate and assess the spatial differences in the inanition of groundwater table, geostatistical methods was applied based on data from 27 groundwater wells during the period from January 1975 to December 2011 which were obtained from a secondary source, Bangladesh Water Development Board. The geographic information system was used to assess the spatial change in order to find the level of groundwater. Cross-validation errors were found within an advisable level in estimating the groundwater depth with different interpolation models of ordinary kriging methods. Finally, surface maps were generated with the best-fitted model. The southeast region was found highly vulnerable from groundwater level point of view. Northern region was detected highest hazard prone area for diverge groundwater using kriging method.

Uncertainty and Sensitivity Analyses of Human Aggregate Risk Assessment of Benzene using the CalTOX Model (CalTOX 모델을 이용한 벤젠 종합위해성평가의 불확실성 분석과 민감도 분석)

  • Kim, Ok;Lee, Minwoo;Song, Youngho;Choi, Jinha;Park, Sanghyun;Park, Changyoung;Lee, Jinheon
    • Journal of Environmental Health Sciences
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    • v.46 no.2
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    • pp.136-149
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    • 2020
  • Objectives: The purpose of this study was to perform an aggregate human risk assessment for benzene in an industrial complex using the CalTOX model and to improve the reliability and predictability of the model by analyzing the uncertainty and sensitivity of the predicted assessment results. Methods: The CalTOXTM 4.0 beta model was used to evaluate a selected region, and @Risk 7.6 software was used to analyze uncertainty and sensitivity. Results: As a result of performing the aggregate risk assessment on the assumption that 6.45E+04 g/d of benzene would be emitted into the atmosphere over two decades, 3% of the daily source term to air remained in the selected region, and 97% (6.26E+04 g/d) moved out of the region. As for exposure by breathing, the predicted LADDinhalation was 2.14E-04 mg/kg-d, and that was assessed as making a 99.99% contribution to the LADDtotal. Regarding human Riskcancer assessment, the predicted human cancer risk was 5.19E-06 (95% CI; 4.07E-06-6.81E-06) (in the 95th percentile corresponding to the highest exposure level, a confidence interval of 90%). As a result of analyzing sensitivity, 'source term to air' was identified as the most influential variable, followed by 'exposure time, active indoors (h/day)', and 'exposure duration (years)'. Conclusions: As for the results of the human cancer risk assessment for the selected region, the predicted human cancer risk was 5.19E-06 (95% CI; 4.07E-06-6.81E-06) (in the 95th percentile, corresponding to the highest exposure level, a confidence interval of 90%). As a result of analyzing sensitivity, 'source term to air' was found to be most influential.

An Improved Map Construction for Mobile Robot Using Fuzzy Logic and Genetic Algorithm (퍼지 논리와 진화알고리즘을 이용한 자율이동로봇의 향상된 지도 작성)

  • Jin Kwang-Sik;Ahn Ho-Gyun;Yoon Tae-Sung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.3
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    • pp.330-336
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    • 2005
  • Existing Bayesian update method using ultrasonic sensors only for mobile robot map building has a problem of the quality of map being degraded in the wall with irregularity, which is caused by the wide beam distribution. For improving this problem, an infrared sensors aided map building method is presented in this paper. Information of obstacle at each region in ultrasonic sensor beam is acquired using the infrared sensors and the information is used to get the confidence of ultrasonic sensor information via fuzzy inference system and genetic algorithm. Combining the resulting confidence with the result of Bayesian update method, an improve map is constructed. The proposed method showed good results in the simulations and experiments.

Uncertainty Assessment of Regional Frequency Analysis for Generalized Logistic Distribution (Generalized Logistic 분포형을 이용한 지역빈도해석의 불확실성 추정)

  • Shin, Hongjoon;Nam, Woosung;Jung, Younghun;Heo, Jun-Haeng
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6B
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    • pp.723-729
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    • 2008
  • Confidence intervals of growth curves are calculated to assess the uncertainty of index flood method as a regional frequency analysis. The asymptotic variance of quantile estimator for the generalized logistic distribution is introduced to evaluate confidence intervals. In addition, the variances of at-site frequency estimator and regional frequency estimator are used to evaluate an efficiency index. The efficiency indexes for 14 homogeneous regions based on 378 stations show that index flood method estimators are more efficient than at-site frequency estimators. It is shown that the number of sites in a region needs to be limited for regional gain.

On Confidence Intervals of Robust Regression Estimators (로버스트 회귀추정에 의한 신뢰구간 구축)

  • Lee Dong-Hee;Park You-Sung;Kim Kee-Whan
    • The Korean Journal of Applied Statistics
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    • v.19 no.1
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    • pp.97-110
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    • 2006
  • Since it is well-established that even high quality data tend to contain outliers, one would expect fat? greater reliance on robust regression techniques than is actually observed. But most of all robust regression estimators suffers from the computational difficulties and the lower efficiency than the least squares under the normal error model. The weighted self-tuning estimator (WSTE) recently suggested by Lee (2004) has no more computational difficulty and it has the asymptotic normality and the high break-down point simultaneously. Although it has better properties than the other robust estimators, WSTE does not have full efficiency under the normal error model through the weighted least squares which is widely used. This paper introduces a new approach as called the reweighted WSTE (RWSTE), whose scale estimator is adaptively estimated by the self-tuning constant. A Monte Carlo study shows that new approach has better behavior than the general weighted least squares method under the normal model and the large data.