• Title/Summary/Keyword: Biased report

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Misclassification Adjustment of Family History of Breast Cancer in a Case-Control Study: a Bayesian Approach

  • Moradzadeh, Rahmatollah;Mansournia, Mohammad Ali;Baghfalaki, Taban;Ghiasvand, Reza;Noori-Daloii, Mohammad Reza;Holakouie-Naieni, Kourosh
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8221-8226
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    • 2016
  • Background: Misreporting self-reported family history may lead to biased estimations. We used Bayesian methods to adjust for exposure misclassification. Materials and Methods: A hospital-based case-control study was used to identify breast cancer risk factors among Iranian women. Three models were jointly considered; an outcome, an exposure and a measurement model. All models were fitted using Bayesian methods, run to achieve convergence. Results: Bayesian analysis in the model without misclassification showed that the odds ratios for the relationship between breast cancer and a family history in different prior distributions were 2.98 (95% CRI: 2.41, 3.71), 2.57 (95% CRI: 1.95, 3.41) and 2.53 (95% CRI: 1.93, 3.31). In the misclassified model, adjusted odds ratios for misclassification in the different situations were 2.64 (95% CRI: 2.02, 3.47), 2.64 (95% CRI: 2.02, 3.46), 1.60 (95% CRI: 1.07, 2.38), 1.61 (95% CRI: 1.07, 2.40), 1.57 (95% CRI: 1.05, 2.35), 1.58 (95% CRI: 1.06, 2.34) and 1.57 (95% CRI: 1.06, 2.33). Conclusions: It was concluded that self-reported family history may be misclassified in different scenarios. Due to the lack of validation studies in Iran, more attention to this matter in future research is suggested, especially while obtaining results in accordance with sensitivity and specificity values.

The Cultural Analysis of 2010-2011 Foot and Mouth Disease Massacre in Korea (2010-2011년도에 발생한 구제역 살처분 원인에 대한 문화 분석)

  • Kim, Seon-Kyung;Kim, Ji-Eun;Paek, Do-Myung
    • Journal of Environmental Health Sciences
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    • v.37 no.2
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    • pp.165-169
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    • 2011
  • Between January 2010 and March 2011, there were three outbreaks of foot and mouth disease (FMD) in South Korea. Over 3.45 million animals (5,660 farms) were slaughtered, which was 33.3% of the existing pigs, 8.4% of dairy cows and 3.4% of cattle. FMD disaster costs were estimated at around three billion Korean won. Nine civil servants were killed, over 150 people were wounded and 4,788 landfills were confronted with a pollution problem. Vaccination and slaughter are the two basic alternatives for eradication of FMD. Altho ugh slaughter is more violent, risky and expensive than vaccination, the Korean government had chosen only slaughter eradication by the end of 2010. Even though over three million animals were killed, FMD spread out over most of the country. Finally, the government chose to begin vaccination. Following vaccination, outbreaks decreased dramatically. The purpose of this report is a cultural analysis of the related decision-making process, laws and systems. For the culture analysis, we utilize interviews, symposiums, laws, FMD manual, government reports and press releases. In conclusion, we found that the FMD massacre was influenced by cultural and organizational factors. The cultural factors were economism, cheapening of the value of life, biased perceptions and fears. The organizational factors were a closed process of decision-making, monopoly system, a small homogeneous group and group-think. Therefore, more studies will be needed for those factors of FMD disasters in national-scale cases.

Rapid and Accurate Measurement of Diffusion Length of Minority Carriers of CIGS Solar Cells (CIGS 태양전지의 소수캐리어 확산 거리에 대한 새로운 측정 방안 연구)

  • Lee, Don Hwan;Kim, Young Su;Mo, Chan Bin;Nam, Jung Gyu;Lee, Dong Ho;Park, Sung Chan;Kim, Byoung June;Kim, Dong Seop
    • Current Photovoltaic Research
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    • v.2 no.2
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    • pp.59-62
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    • 2014
  • Minority carrier diffusion length is one of the most important parameters of solar cells, especially for short circuit current density (Jsc). In this report, we proposed the calculating method of the minority carrier diffusion length ($L_n$) in CIGS solar cells through biased quantum efficiency (QE). To verify this method's reliability, we chose two CIGS samples which have different grain size and calculated $L_n$ for each sample. First of all, we calculated out that $L_n$ was 56nm and 97nm for small and large grain sized-cell through this method, respectively. Second, we found out the large grain sized-cell has about 7 times lower defect density than the small grain sized-cell using drive level capacitance profiling (DLCP) method. Consequently, we confirmed that $L_n$ was mainly affected by the micro-structure and defect density of CIGS layer, and could explain the cause of Jsc difference between two samples having same band gap.

An empirical study of evaluating the Korean firm's technological knowledge assets (한국 기업의 기술지식자산 평가에 대한 실증연구)

  • 윤찬병;하형철;박용태
    • Proceedings of the Technology Innovation Conference
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    • 1999.06a
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    • pp.85-97
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    • 1999
  • Being the new paradigm of "knowledge based economy", knowledge asset get to be the key to evaluate the firm's value. For a instance, Scandia firstly informed the intellectual capital report with its own financial statements in 1994. Some financial institutions have emphasized the roles of knowledge assets in the evaluating firm's value, too. But the concept of knowledge asset is so extensively defined that the result of evaluation is not as much reliable as financial statements. As previous studies examined the firm-specific cases, the sectoral pattern of knowledge asset has been ignored and it cause the difficulty in the empirical study. Moreover, the objectivity of study is ambiguous. Therefore, we regards knowledge asset as a technological knowledge asset. Which is related to R&D(research & development) and technology. Because this definition is more measurable than others and can play a frontier role in evaluating the knowledge asset. We extract the criteria related to the technological knowledge asset through the survey of 'Scandia' and other previous studies and add other criteria, which explain the Korean-specific environments. We gather data from "Technological Innovation"(STEPI, 1997, 1999) and "The bibliography of Korean R&D institutes"(KITA,1998) and "the survey of listed company"(Daewoo Securities, 1998. 1999). As the results of empirical study, the variables which explain the financial value of firms do not reflect the 'technological knowledge asset' well. It results from the factors as followings. Firstly, instead of stock price the proxy measurement related to 'knowledge asset' is needed. Secondly, the sample is biased to the large scale firms so we'll collect samples more broadly. Finally, the concept of 'technological knowledge asset' is too narrow to explain the value of firm. We expect the result of this empirical study gives contribution to the evaluation of firms' value more exactly.

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A Polysilicon Field Effect Transistor Pressure Sensor of Thin Nitride Membrane Choking Effect of Right After Turn-on for Stress Sensitivity Improvement (스트레스 감도 향상을 위한 턴 온 직후의 조름 효과를 이용한 얇은 질화막 폴리실리콘 전계 효과 트랜지스터 압력센서)

  • Jung, Hanyung;Lee, Junghoon
    • Journal of Sensor Science and Technology
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    • v.23 no.2
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    • pp.114-121
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    • 2014
  • We report a polysilicon active area membrane field effect transistor (PSAFET) pressure sensor for low stress deflection of membrane. The PSAFET was produced in conventional FET semiconductor fabrication and backside wet etching. The PSAFET located at the front side measured pressure change using 300 nm thin-nitride membrane when a membrane was slightly strained by the small deflection of membrane shape from backside with any physical force. The PSAFET showed high sensitivity around threshold voltage, because threshold voltage variation was composed of fractional function form in sensitivity equation of current variation. When gate voltage was biased close to threshold voltage, a fractional function form had infinite value at $V_{tn}$, which increased the current variation of sensitivity. Threshold voltage effect was dominant right after the PSAFET was turned on. Narrow transistor channel established by small current flow was choked because electron could barely cross drain-source electrodes. When gate voltage was far from threshold voltage, threshold voltage effect converged to zero in fractional form of threshold voltage variations and drain current change was mostly determined by mobility changes. As the PSAFET fabrication was compatible with a polysilicon FET in CMOS fabrication, it could be adapted in low pressure sensor and bio molecular sensor.

Application of Accrual Basis for Calculation of Prolongation Cost in Construction Projects (공기연장 추가간접비 산정기준의 발생주의방식 적용 연구)

  • Jeong, Kichang;Lee, Jaeseob
    • Korean Journal of Construction Engineering and Management
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    • v.19 no.5
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    • pp.111-120
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    • 2018
  • Recently, Domestic public construction projects are experiencing a great deal of disputes because of the growing uncertainty about the criteria for calculating the prolongation cost. In addition, researchers have been studying various systems and proper cost estimates in an effort to reduce the uncertainty of these systems and the occurrence of disputes. However, there is no standard yet for social consensus. Meanwhile, The study on the classification system according to the recognition standard of accounting has been systematically studied. As a result, the concepts of accrual and cash basis are defined separately. The purpose of this study is to verify the possibility of applying the concept of 'accrual basis' to the Standard for calculation of prolongation cost. Therefore, As a result of analyzing the occurrence pattern of Job-site overhead cost, it is confirmed that actual costs can not be calculated by the cash-basis method. In particular, the implications of the necessity of the accrual-basis method should be more strictly indicated in the case of items such as indirect labor costs and welfare benefits. In addition, the contractor 's claim report and the appraisal report were examined. As a result, it was confirmed that the calculation situations of prolongation costs are biased to the cash-basis method. In this way, it is suggested that necessary to supplement the calculation standard of the actual costs from the point of view of accrual basis.

Population Policy and Population Quality(Report 1. General Review on the Problems of Mental and Physical Handicaps) (인구정책과 인구자질향상을 위한 연구(제 1 보 심신장애자 발생억제대책))

  • Kim, Jong-Kun;Huh, Jung
    • Korea journal of population studies
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    • v.3 no.1
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    • pp.5-41
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    • 1979
  • Vast volumes of studies of the medical and public health aspects of fertility and family planning have been published by the various institutes of health related research and university scholars in Korea. None of them, however, have dealed with the population problems associated with biologically and mentally handicapped people. It must be emphasized that the purpose of Korea's population policy should be to improve the quality of the population rather than to decrease its rate of increase. In this spirit, the first report of this study is to identify problems related with mentally and physically less fitted population, and to attempt to offer the possible solutions to the health planners and policy-makers. Several nation-wide surveys of the handicapped people in Korea have been compared. Each survey shows a wide range of difference in the prevalence of the handicaps(see Table 13). In this study, the data on the handicaps are collected by two independent system ; one by the nation-wide survey and the other by the reporting system existing at the Seoul National University Demonstration Health Project. The Chandrasekar-Deming technique was used to estimate the total number of handicaps. The estimates are summarized in the tables 8, 9 and 10. Estimate of total number of handicapped people in Korea is 601, 400 with the prevalence rate of 16.1 per thousand persons. Even if taking a number of conditions which may result in a biased estimate of the total number of the handicaps into consideration, the proportion of handicapped people in Korea has increased in the past two decade as the result of the rapid decline in fertility and childhood mortality, which consequently prolonged life expectancy of persons with congenital or acquired impediment. An increase in the proportion of handicapped people will eventually bring about serious problems of social welfare, medical care, and population qualities from various aspects including eugenics. To tackle the problem, there must be an increased emphasis on the prevention of handicaps from the government and private sector. Based on the amount and quality of data, and from the practical point of view, this study prepared a set of recommendations for the government to strengthen its programs of the preventive activities during the prenatal period and early childhood, early finding from routine examinations, and proper social and medical rehabilitation.

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FACTORS INFLUENCING PERCEPTIONS OF CHILD SEXUAL ABUSE: VIGNETTE STUDY FINDINGS (아동성폭력 상황인식에 영향하는 요인들에 관한 분석 : Vignettes를 이용한 연구결과를 중심으로 한 고찰)

  • Ko, Chung-Mee
    • Research in Community and Public Health Nursing
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    • v.10 no.2
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    • pp.549-563
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    • 1999
  • This paper is a review of findings from studies that have used vignettes to identify salient characteristics that have been found to influence individuals' perceptions of child sexual abuse. Vignette studies finding avoid to unreliable and biased self-reports. A review of the literature revealed that factors influencing the perception process are divided into two groups. One group of factors relates to the details of the abuse situation including characteristics of sexual act (intrusiveness of the sexual act and the frequency of acts), characteristics of victim (age of victim, the gender of victim and victim resistance), and characteristics of perpetrator (age of perpetrator, gender of perpetrator and the relationship of the perpetrator to the child). The other group of factors focused on in research reflects individuals background variables that affect personal interpretations of the abuse situation. These factors include professional affiliation of the respondent and various other. demographics (e.g., gender of respondents, age, education, marital status, parental status, number of children, the length of experience, etc.), along with respondents own child sexual victimization experiences. Based on theses findings vignette studies have allowed researchers to learn how individuals vary their perceptions of various situational aspects of child sexual abuse situations, and how background characteristics of the respondents as observers may influence these perceptions.

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Science Teachers' Actual and Preferred Cases of Assessment in 'Scientific Inquiries in History' of Science Inquiry Experiment (과학탐구실험의 '역사 속의 과학 탐구'에서 과학교사의 평가 실태와 평가 지향 조사)

  • Minhwan, Kim;Dahae, Park;Taehee, Noh
    • Journal of The Korean Association For Science Education
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    • v.42 no.6
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    • pp.597-610
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    • 2022
  • In this study, we investigated actual cases of assessment science teachers conducted and the cases they preferred in a typical situation based on the curriculum in the context of 'Scientific Inquiries in the History' of Scientific Inquiry Experiment. A questionnaire composed of descriptive questions was developed and a survey was conducted with 70 science teachers with experience in teaching 'Scientific Inquiries in History'. Interviews were conducted with eight of them. The assessment cases were analyzed in terms of the assessment areas and assessment methods, and the results were compared. The analyses of the results revealed that 'scientific inquiry ability' accounted for the highest ratio of the assessment areas in the actual cases of assessment. There were few cases that assessed the core concepts presented in the curriculum, 'the nature of science' and 'scientists' inquiry methods'. The assessment methods were greatly biased toward the report method and various assessment methods were not used. In preferred cases of assessment, the ratio of cases that assessed the core concept increased slightly, however the frequencies remained at a low. As for the assessment methods in preferred cases of assessment, the measurement methods decreased, the performance methods increased, and the informal methods which were not shown in the actual cases appeared. However various assessment methods were still not used. The causes of the survey results were analyzed based on the opinions of the teachers who participated in the interviews. Based on above results, plans to actively conduct NOS assessments in Scientific Inquiry Experiment are discussed.

Characteristics of Process-Focused Assessment in Science Classes from the Research Middle School Reports (연구학교 보고서에 나타난 중학교 과학과 과정중심평가의 특징)

  • Jong-Hee Kim;Jee-young Park;Nan Sook Yu;Min-Seon Joo
    • Journal of the Korean Society of Earth Science Education
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    • v.16 no.2
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    • pp.182-195
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    • 2023
  • The purpose of this study was to analyze reports from research middle schools based on the criteria for process-focused assessment to find out how the characteristics of process-focused assessment were being implemented in middle school science classes. The analysis criteria for the characteristics of process-focused assessment (integration of lessons and assessments, evaluation elements and methods, content and timing of feedback, and learner growth management) were extracted. Using the analysis framework, the result reports of seven research middle schools for process-focused assessment were analyzed. In terms of integration of lessons and assessments, when the process-focused assessment was operated, the class and evaluation plan were well implemented based on the curriculum achievement standards, but the process-focused assessment was recognized as a performance evaluation. In terms of evaluation elements and methods, the evaluation element for knowledge was the main component, and competency was presented in the planning stage, but competency was not dealt with in class execution. The evaluation method was biased toward teacher-centered observation evaluation and written test, and the setting of scoring criteria for each evaluation element was insufficient. In terms of the content and timing of feedback, feedback was mainly provided based on achievement confirmation, but no case was found in which scaffolding was provided at an appropriate time for insufficient parts in the learning process. In terms of the learner's growth management, the competencies cultivated through science classes were included in the detailed subject specialties of the school record. However, little was shown in the report on how to systematically manage the process of developing learners' competencies and reflect the evaluation results to teachers' class improvement.