• Journal of Radiation Protection and Research
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• 제42권1호
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• pp.48-55
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• 2017

Background: Simultaneous detection of neutrons and gamma rays have become much more practicable, by taking advantage of good gamma-ray discrimination properties using pulse shape discrimination (PSD) technique. Recently, we introduced a commercial CLYC system in Korea, and performed an initial characterization and simulation studies for the CLYC detector system to provide references for the future implementation of the dual-mode scintillator system in various studies and applications. Materials and Methods: We evaluated a CLYC detector with 95% $^6Li$ enrichment using various gamma-ray sources and a $^{252}Cf$ neutron source, with validation of our Monte Carlo simulation results via measurement experiments. Absolute full-energy peak efficiency values were calculated for gamma-ray sources and neutron source using MCNP6 and compared with measurement experiments of the calibration sources. In addition, behavioral characteristics of neutrons were validated by comparing simulations and experiments on neutron moderation with various polyethylene (PE) moderator thicknesses. Results and Discussion: Both results showed good agreements in overall characteristics of the gamma and neutron detection efficiencies, with consistent ~20% discrepancy. Furthermore, moderation of neutrons emitted from $^{252}Cf$ showed similarities between the simulation and the experiment, in terms of their relative ratios depending on the thickness of the PE moderator. Conclusion: A CLYC detector system was characterized for its energy resolution and detection efficiency, and Monte Carlo simulations on the detector system was validated experimentally. Validation of the simulation results in overall trend of the CLYC detector behavior will provide the fundamental basis and validity of follow-up Monte Carlo simulation studies for the development of our dual-particle imager using a rotational modulation collimator.

• Genomics & Informatics
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• 제14권4호
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• pp.138-148
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• 2016

The success of genome-wide association studies (GWASs) has enabled us to improve risk assessment and provide novel genetic variants for diagnosis, prevention, and treatment. However, most variants discovered by GWASs have been reported to have very small effect sizes on complex human diseases, which has been a big hurdle in building risk prediction models. Recently, many statistical approaches based on penalized regression have been developed to solve the "large p and small n" problem. In this report, we evaluated the performance of several statistical methods for predicting a binary trait: stepwise logistic regression (SLR), least absolute shrinkage and selection operator (LASSO), and Elastic-Net (EN). We first built a prediction model by combining variable selection and prediction methods for type 2 diabetes using Affymetrix Genome-Wide Human SNP Array 5.0 from the Korean Association Resource project. We assessed the risk prediction performance using area under the receiver operating characteristic curve (AUC) for the internal and external validation datasets. In the internal validation, SLR-LASSO and SLR-EN tended to yield more accurate predictions than other combinations. During the external validation, the SLR-SLR and SLR-EN combinations achieved the highest AUC of 0.726. We propose these combinations as a potentially powerful risk prediction model for type 2 diabetes.

• Journal of Nutrition and Health
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• 제31권2호
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• pp.220-230
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• 1998

The purpose of this study was to develop and validate the Food frequency questionnaire (FFQ) for dietary studies of Koreans. One hundred and five food items for the Food frequency questionnaire were selected based on information of frequently consumed foods from National Nutrition Survey Reports and on raw data from a dietary survey on diabetic patients. Frequency of consumption was determined through nine categories ranging from more than three times a day to almost never to indicate how often the specified amount of each food item was consumed during the past month. Three portion sizes were given for each food item(small, medium or large) with respect to a stated medium portion. Seventy-three healthy women served for the validation study. They completed both the FFQ and a 3-day diet record. The FFQ estimate of mean nutrient intake was higher by 10-20% than that of the 3-days diet record and the Spearman correlation coefficients between the two methods ranged from 0.26 to 0.59 . The degree of agreement was from 36% to 38% when nutrients intake assessed by the FFQ and 3day diet record were classified within the same quintile. On the whole , the result of this study seemed to be in good agreement with other studies. Therefore the FFQ developed in this study is considered to be a reliable tool in assessing the dietary habits of Korean.

• 아동학회지
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• 제35권6호
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• pp.111-133
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• 2014

This study was conducted in order to develop a parenting behavior scale for parents of school-age children and to analyze the scale in terms of both reliability and validity. Data were collected from a sample of mothers of $1^{st}$ to 3rd grade students in four elementary schools located in Seoul. 778 mothers were administered a parenting behavior scale with 123 items, and 779 mothers were asked to verify the validity of the developed scale in which 45 items remained after a series of analyses. Data were analyzed by means of exploratory factor analysis, confirmatory factor analysis, and correlation analysis. The results of factor analysis identified five factors, Warmth, Reasoning, Intrusiveness, Coercion, and Neglect. The Cronbach's ${\alpha}$ of each factor demonstrated results of .82~.86, suggesting that the scale had adequate internal consistency. Concurrent validity was established by using correlations between mothers' parenting behaviors and children's social competence. Moreover, cross-validation was also verified for the five factors. Considering the reliability and validity of this scale, it can clearly serve as a useful tool for assessing parenting behavior which is closely related to child development.

• Healthcare Informatics Research
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• 제24권4호
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• pp.276-282
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• 2018

Objectives: Due to the uncontrolled increase of the mobile health applications and their scarce use by elderly for reason of absence credibility of measurements by lack scientific support, the aim of this study was to evaluate the differences between the biophysical measurements based on standard instrument against a mobile application using controlled experiments with elderly to propose an effective validation model of the developed apps. Methods: The subjects of the study (50 people) were elderly people who wanted to check their weight and cardiac status. For this purpose, two mobile applications were used to measure energy expenditure based on physical activity (Activ) and heart rate (SMCa) during controlled walking at specific speeds. Minute-by-minute measurements were recorded to evaluate the average error and the accuracy of the data acquired through confidence intervals by means of statistical analysis of the data. Results: The experimental results obtained by the Activ/SMCa apps showed a consistent statistical similarity with those obtained by specialized equipment with confidence intervals of 95%. All the subjects were advised and trained on the use of the applications, and the initial registration of data to characterize them served to significantly affect the perceived ease of use. Conclusions: This is the first model to validate a health-app with elderly people allowed to demonstrate the anthropometric and body movement differences of subjects with equal body mass index (BMI) but younger. Future studies should consider not only BMI data but also other variables, such as age and usability perception factors.

• 한국컴퓨터정보학회논문지
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• 제27권9호
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• pp.77-89
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• 2022

본 논문에서는 RML 매핑 방식으로 구축한 RDF 지식 그래프의 구조를 묘사하고 검증할 용도의 SHACL 스키마를 자동으로 생성하는 시스템을 제안한다. 제안하는 시스템은 기존 연구와는 달리 RML 매핑 규칙 뿐만 아니라 RML 매핑의 입력인 CSV, JSON, XML, 데이터베이스와 같은 다양한 포맷의 데이터에서 추출한 메타데이터도 함께 사용하여 스키마를 생성한다. 따라서 기존 연구 기반의 스키마에서는 부재했던 데이터 타입, 문자열 길이, 값의 범위, 차수 관련 제약 조건이 스키마에 포함된다. 그리고 기존 연구에서 간과한 소위 반복된 속성 문제를 제안하는 시스템은 해결한다. 297개의 케이스로 구성된 적합성 테스트를 통해 제안된 시스템이 그래프에 대한 올바른 제약 조건을 생성함을 보여준다. 제안된 시스템은 오류가 발생하기 쉬운 기존 수동 검증 프로세스를 자동화하는 데 기여할 수 있다.

• Steel and Composite Structures
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• 제8권1호
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• pp.19-34
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• 2008

This paper presents the results of a validation and parametric study for the theory presented in the companion paper. The parameters investigated include the stiffness of axial and rotational restraints, load ratio, depth-span ratio of the beam, the yield strength of steel, load type and the temperature distribution in the crosssection of the beam.

• Journal of Preventive Medicine and Public Health
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• 제41권2호
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• pp.74-79
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• 2008

Since the positive listing system for prescription drug reimbursement has been introduced in Korea, the number of pharmacoeconomic evaluation studies has increased. However it is not clear if the quality of pharmacoeconomic evaluation study has improved. Due to the lack of randomized clinical studies in Korean health care setting, Korean economic evaluation studies have typically integrated the local cost data and foreign clinical data. Therefore methodological issues can be raised in regard to data coherence and consistency. But the quality of data was not questiened and the potential bias has not been investigated yet. Even though changes in policy have encouraged the undertaking of pharmacoeconomic evaluations, there is few public-side funding for validation study of cost-effectiveness models and data. Several companies perform economic evaluation studies to be submitted on behalf of their own products, but do not want the study results to be disclosed to the academic community or public. To improve the present conduct of pharmacoeconomic evaluations in Korea, various funding sources need to be developed, and, like other multidisciplinary areas, the experts in different fields of study should collaborate to ensure the validity and credibility of pharmacoeconomic evaluations.

• 아동학회지
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• 제38권3호
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• pp.91-111
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• 2017

Objective: This study aimed to review scales and tests developed for or validated with children and their families that were published in the Korean Journal of Child Studies from 1984 to 2016. Specifically, the purpose of the present study was to analyze the contents and format of the selected instruments, as well as to evaluate their psychometric properties. Methods: Using several databases and journal archives from the Korean Journal of Child Studies, searches were implemented using the key terms: instrument, scale, development, and validation. Instruments from 76 selected studies were reviewed based on several characteristics, such as assessment areas, contents, respondents, responding types, and psychometric properties. Results and Conclusion: First, a majority of the reviewed instruments were developed for infants and children, whereas only one was developed for adolescents. With regard to their specific measurement domains, many instruments focused on social emotional development among children. Second, with a few exceptions, the selected studies provided appropriate evidence for the reliability of the instrument, including its internal consistency, inter-rater reliability, and spilt-half reliability. Many studies also reported on the criterion-related or construct validity of the instrument to establish its validity. Future studies need to develop instruments across diverse developmental areas that collect information from multiple sources and raters. In addition, more evidence on the reliability and validity of the reviewed instruments should be provided to demonstrate their psychometric qualities.

• 아동학회지
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• 제24권3호
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• pp.135-149
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• 2003

This study aimed to develop an observation scale for assessing the quality of day care programs and to examine reliability and validity of the scale. Instruments included 3 self-assessment scales, the Evaluation Scale for Early Childhood Programs and an observation scale completed by 8 trained observers in 89 day care sites. Item analysis indicated that most items were acceptable in terms of item discrimination and item response distribution. Cronbach ${\alpha}^{\prime}s$ and inter-observer reliability were relatively high. Validity of the scale was evidenced by correlations between the observation scale and the criterion measure and inter-correlations among sub-areas of the observation scale. Scores on the observation scale were validated by quality ratings from self-assessment scores.