• The Korean Journal of Applied Statistics
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• v.32 no.4
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• pp.631-642
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• 2019

Many methods have been developed to solve problems found in sample surveys involving a large number of item non-responses that cause inaccuracies in estimation. However, the non-response adjustment method used under the assumption of random non-response generates a bias in cases where the response rate is affected by the variable of interest. Chung and Shin (2017) and Min and Shin (2018) proposed a method to improve the accuracy of estimation by appropriately adjusting a bias generated when the response rate is a function of the variables of interest. In this study, we studied a case where the response rate function is linear and the error of the super population model follows normal distribution. We also examined the effect of the number of stratum population on bias adjustment. The performance of the proposed estimator was examined through simulation studies and confirmed through actual data analysis.

• Journal of Preventive Medicine and Public Health
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• v.31 no.1 s.60
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• pp.49-58
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• 1998

The study was done to determine the reliability and validity of a life style questionnaire for the elderly. The questionnaires were sent to 16,524 elderly people who were beneficiaries of Korean Medical Insurance Corporation in Pusan. Among the completed 9,139 questionnaires, 200 were randomly sampled and retested. finally, 110 duplicates were collected. Weighted kappa-value and Pearson correlation coefficients were estimated to measure the reliability. Validity coefficient was estimated by using reliability coefficient. In self-self responses, reliability coefficients of the most of items were over 0.6 except some physical activity related item. Relatively high reliability was observed in smoking, alcohol related items and anthropometric items. In self-proxy responses, most of the physical activity related items were found to be less reliable than self-self responses. Smoking and alcohol related items were consistently reliable. Male showed higher validity in food related item than female. On the other hand, some of the physical activity related items and smoking and alcohol related items were less valid in male than female. With regard to bias of proxy respondents, offsprings tended to underestimate the frequency of house cleaning' and 'kitchen work' and overestimate the height of them. In conclusion, the life style questionnaire was found to be reliable in the most of items. But, some items related with physical activity were found to be somewhat less reliable. Sexual difference on the validity was identified in some items. With regard to bias of proxy respondents, offsprings tended to have bias in part of items of housework and anthropometry.

• Survey Research
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• v.7 no.2
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• pp.71-95
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• 2006

This article presents strengths of Computer-Assisted Personal Interviewing(CAPI) in social surveys with complicated questionnaires, from examples of a pilot and the first year surveys of the Korean Longitudinal Study of Ageing(KLoSA). This study focuses on how to improve the quality of data by using CAPI and finds five strengths among others. First of all, CAPI can contribute to reducing response errors by structuring the logic and path of questionnaires, setting a response range, and maintaining response consistency. Second, CAPI enhances convenience of interviewing by allowing customized questions and automatic calculation and scoring. It also allows the 'help' function. Third, its random arrangement of questions prevents response order effect and/or questions order effect. Fourth, CAPI can raise the response rate by reducing item non-responses. Fifth, it makes it easy monitoring interviewing, thus helps supervising interviewers and modifying questionnaires when necessary. These merits of CAPI contribute to reducing possible errors in the process of interviewing, therefore improve the data quality.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.2
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• pp.215-227
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• 2004

Purpose: The prevalence of childhood obesity has increased dramatically. It is important to know about life style and dietary habits of the obese children because the treatment of childhood obesity focuses on using behavioral modification techniques. We aimed to develop a questionnaire for the purpose of providing convenient and useful guidance to pediatricians who evaluate and treat obese children. Methods: Previously developed questionnaire was given to 94 obese children and their parents who had visited clinic for obese children and adolescents. We analyzed response rates on questions and reliability between children and their parents. Results: The response rates on questions were somewhat high. Agreement of paired questions of both parents and children was also moderately high (63~92%). It is acceptable to complete questions by either parents or children alone. Items for hours of playing video games or computer, maternal job, kind of consuming beverage and food outside home were added. Conclusion: We concluded that some questions are not needed to be given to both parents and their children. It would be better to have parents record life style of their children and to have children record their food intake with physical activity outside home.

• Journal of Korean Library and Information Science Society
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• v.42 no.4
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• pp.375-393
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• 2011

As small libraries are now considered as public libraries, it is time to discuss a policy decision for institutional complement, supporting policy frame, and activating management of small libraries. There is a need to improve statistical indicators of small libraries, as an effort to improve library statistics as a whole. Small libraries in National Library Statistics have been using an altered version of 2008 library statistiscal frame, which was solely designed for public libraries. However, due to the inadequacy of indicators, results show 91.3% of missing values and high rates of errors in collected data. This research select the key statistical indicators for small libraries by analyzing 4 researches of present states and 7 researches of measuring indicators. The research, therefore, proposed an improved version of statistical indicators, by advising of the professional groups in the small library statistics and estimation and investigating of 108 small libraries in GyeongGi-Do Area. There are 7 categories and 37 items in the proposed statistics.

• The Korean Journal of Applied Statistics
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• v.32 no.6
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• pp.889-898
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• 2019

The problem of missing value imputation for variables in surveys that include item missing becomes complicated if outliers and logical boundary conditions between other survey items cannot be ignored. If there are outliers and boundaries in a variable including missing values, imputed values based on previous regression-based imputation methods are likely to be biased and not meet boundary conditions. In this paper, we approach these difficulties in imputation by combining various robust regression models and multiple imputation methods. Through a simulation study on various scenarios of outliers and boundaries, we find and discuss the optimal combination of robust regression and multiple imputation method.

• The Korean Journal of Applied Statistics
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• v.20 no.3
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• pp.499-514
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• 2007

It is a common practice to use the auxiliary variables to impute missing values from item nonresponse in surveys. Sometimes there are few auxiliary variables for missing value imputation, but if spatial and time autocorrelations exist, we should use these correlations for better results. Recently, Lee et al. (2006) showed that spatial autocorrelation could be efficiently used for missing value imputation when spatial autocorrelation existed, using the data from the farm household economy data in Gangwon-do, 2002. In this paper, we present au evaluation of spatial and space-time nonresponse imputation methods when there exist spatial and time autocorrelations using the monthly data during 2000-2002 from the same data previously used by Lee et al. (2006). We show that space-time imputation method is more efficient than the other through the numerical simulations.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.617-620
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• 2006

개방화시대에 제품의 국제경쟁력을 확보하기 위해서는 Unix나 Tandem 환경의 시스템운영관리 측면에서 실시간 모니터링 운영의 효율성이 증대 하고 있고 이를 바탕으로 서비스의 품질 및 기술력 향상과 고객만족 서비스 등 경제성이 필수적으로 요구되고 있다. 기존의 시스템관리 기능의 운영측면에서 보다는 보다 더 다양한 고객의 요구가 반영이 가능한 새로운 형태의 실시간 업무지원이 가능한 모니터링 시스템 개발이 필요한 시점이다. 기존의 시스템관리 기능에서 보다 업무지원이 기능이 강하된 모니터링 툴 이다. 즉 업무(Application) 프로세스의 장애현상에 따른 무응답을 사전 감시하고 System의 자원사용현황을 개발 및 운영자 위주의 실시간으로 감시환경 모니터링 서비스 제공이 가능한 기능으로 설계 따라서 시스템관리에서 보다 안정적인 운영을 제공 할 수 있다. 본 연구에서는 업무 프로세스의 장애를 점검할 수 있는 모니터링 툴 검토하여 실무자를 통하여 업무장애 유형에 따른 감시항목 및 의견 수렴, 요건정의에 따른 업무설명회 수행, 탠덤 시스템 모니터링 프로젝트 수행 필요한 기능을 개발 할 것이다. 또한 시스템 운영자 입장에서 실시간 모니터링 서비스를 통하여 업무(Application)프로그램의 전송지연 및 장애 원인을 한눈에 파악 점검 하도록 하며 각 기능별 시스템(System)별 장애 감시 통하여 사용자에서 현재 상태를 종합음성경보(SMS) 구축 연계하여 지원한다. 따라서, 본 논문에서는 중요한 요소로 기존의 많은 Unix나 Tandem 환경의 시스템관리 기능을 비교 분석을 통하여 보다 효율성이 높은 고객서비스 기능과 업무지원이 가능한 실시간 시스템관리 모니터링 툴을 개발 한다.

• Journal of Hospice and Palliative Care
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• v.8 no.1
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• pp.37-44
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• 2005

Purpose: To provide the basic data in developing the nursing intervention for patients who have symptoms of insomnia after undergoing hemopoietic stem cell transplantation (HSCT). This was achieved through investigating sleep quality and sleep patterns according to admission time, and discharge time. Methods: Data was put together by studying 52 HSCT patients who have been admitted to the department of HSCT from August 2002 to August 2003, in a university hospital. Research instruments used were, PSQI for sleep quality and a specified questionnaire for sleep patterns. Results: The PSQI regarding the past mono which was measured at the last day of hospitalization, was 11.8. This was significantly higher than 5.3, which was a measurement for the past month before the hospitalization (t=11.41, P=0.000). Looking at it with 7 categories-quality of sleep, consistency of sleep, sleep period, effectiveness of sleep, sleeping disorder, usage of sleeping pills, impediment of daily life- the PSQI for a month after admission increased significantly compared to the rate measured for a month before admission. Comparing the subjects sleep pattern before and after admission, it showed a significant difference regarding time attending sleep, time it takes to sleep, wake-up time, total time of sleep, day time sleep, number of times waking up during sleep, number of usage of sleeping pills, actions that are taken during sleep disorder, reasons for insomnia. Conclusion: The PSQI score of patients who undergo hemopoietic stem cell transplantation have increased significantly after hospitalization. Compared to the change of sleep patterns when hospitalized, significant changes were observed. Therefore nursing interventions addressing sleep are needed.

• Journal of Korea Entertainment Industry Association
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• v.14 no.8
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• pp.213-219
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• 2020

The purpose of this study was to investigate the characteristics of error types in naming task for 8 questionable demeatia groups, 9 definite dementia groups, and 10 normal groups. The items of naming error analysis were classified into visual perception errors, semantic association errors, semantic non-correlation errors, phoneme errors, Don't Know, and No Response. For the analysis, descriptive statistics analysis, analysis of variance, and multivariate analysis of variance were conducted using SPSS 21.0. As a result, there was a significant difference in the error rate between groups according to the error type. The errors that showed significant differences between the normal group and the other two groups were visual perception errors and semantic non-related errors. The error of non-response was different from the dementia confirmation group, but there was no significant difference from the dementia suspicion group. These results showed that Alzheimer's patients had a defect in confrontation naming ability. Also, it was found that it is appropriate to provid other clues when the defects caused by the degeneration of a specific step during the information processing process become severe.