• The Korean Journal of Applied Statistics
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• v.16 no.2
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• pp.247-259
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• 2003

In Korea, quota sampling is mainly adopted in telephone surveys, instead of random sampling which requires call-back procedure and random selection of respondent within households. The contact mode based on the se $x^{*}$age quotas is economically more advantageous and less time-consuming. However, it lacks theoretical ground for valid statistical inference, so that it is hardly accepted in academic circles despite of widely spread practice. Subsequently, survey theoreticians argued that random sampling-based telephone surveys should be tried. In response, Research & Research (R&R), a private research company in Seoul, executed atelephone survey by random sampling mode for the prediction of 2002 Ulsan City Mayor Election. The aim of this case study is to find out various effects of the call-back rule with random selection of respondents by statistically re-analyzing R&R’s Ulsan Survey Data.s by statistically re-analyzing R&R’s Ulsan Survey Data.

• Survey Research
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• v.3 no.2
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• pp.77-90
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• 2002

This study reports the results of a random sampling telephone survey conducted in the case of the Ulsan mayoral election 2002. We interview at least five times to a respondent who is randomly selected by means of the birthday method from a randomly sampled telephone number list of 1,233 households, We analyze the result of interviewing, such as absence and promise. And we compare the demographic variables of the surveyed sample and those of the population and we also compare the randomly selected sample's voting preference with outcome of the election in various ways. Finally, we discuss difficulty of random sampling with the birthday method and suggest some technical tips to conduct random sampling telephone survey.

• Journal of the Korean Data and Information Science Society
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• v.10 no.1
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• pp.79-89
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• 1999

A counting rule that allows an element to be linked to more than one enumeration unit is called a multiplicity counting rule. Sample designs that use multiplicity counting rules are called network samples. Defining a network to be a set of observation units with a given linkage pattern, a network may be linked with more than one selection unit, and a single selection unit may be linked with more than one network. This paper considers allocation for multivariate stratified random sampling with multiplicity.

• Proceedings of the KSCN Conference
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• 2004.05a
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• pp.408.2-409
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• 2004

조사연구에서 조사대상의 모집단을 대표할 수 있는 표본을 추출하는 것은 조사결과를 그 모집단에 일반화시키기 위해 서는 필수적이다. 국민건강영양조사에서는 확률표출방법을 이용하여 우리나라 국민의 영양실태에 관해 대표성 있는 정보를 얻고 있는 반면, 개개인의 연구자가 일부 지역 주민을 대상으로 하는 소규모의 영양조사에서는 과학적인 표출방법을 이용하여 표본을 추출하는 것이 매우 어렵기 때문에 대부분의 경우 자원자를 대상으로 하거나 임의로 표본을 선정하는 실정이다.(중략)

• KDI Journal of Economic Policy
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• v.31 no.1
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• pp.207-237
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• 2009

One of the main problems in Korea's public assistance program, the NBLS (National Basic Livelihood Security), is that the loophole of welfare system is continuously growing. Living wage program is the largest sub-program of the NBLS, and the most important determinant of amount of living wage for each beneficiary is the level of reported income. Therefore, accurate and effective income detection is essential in improving policy effects and furthermore reducing the leakage of wage expenditure as beneficiaries always have an incentive to underreport their income. Since most of them do not pay income tax, the welfare authority should exert an independent effort to effectively detect their income. Considering that living wage is a special kind of income tax of which marginal tax rate is -1, one can apply a classical theory of tax evasion to understand illegal or excessive receipt of living wage caused by income underreporting. Utilizing a classical theory given by Alingham and Sandmo (1972), this paper provides a theoretical analysis of the optimal income reporting of the beneficiary. Then an optimization problem is constructed from the government's viewpoint to derive optimal income detecting device (auditing). This paper proves that cut-off discriminated auditing outperforms random auditing and cut-off auditing which implies if the government assigns a positive audit probability to every reported income less than a certain level and the probability is inversely proportional to the level of reported income, it can minimize underreporting and then gradually reduce the leakage of wage expenditure.

• Survey Research
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• v.12 no.2
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• pp.77-88
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• 2011

Korean telephone surveys have been based on telephone directory and thus criticized for considerable under-coverage. Now, Korean survey institutions progress to random digit dialing (RDD) very actively. But still most surveys are administered by quota sampling, prone to assign heavier weights to social classes with more hours staying indoor. As a practical remedy, time-balanced quota sampling scheme was proposed by Huh and Hwang (2006). This study compares two telephone surveys on TV audience environment in Korea: RDD with conventional quota sampling versus RDD with time-balanced quota sampling.

• Proceedings of the Korean Association for Survey Research Conference
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• 2002.11a
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• pp.129-139
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• 2002

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.397-400
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• 1999

본 연구에서는 기존의 모드적합법의 단점을 개선하여 각 관에 임의의 모드갯수를 선택할 수 있고, 동심관형 단순확장관의 음향특성뿐만 아니라 입$\cdot$출구가 임의의 위치에 있는 경우에도 모드적합법을 적용할 수 있는 방안을 제시한다. 그리고 제시한 방안으로 프로그램을 작성하여, 각각 임의의 모드와 임의의 입$\cdot$출구의 위치를 가지는 원형 소음기의 4단자 정수를 구하고, 이로부터 임의의 입$\cdot$출구 위치에 따른 소음기의 음향특성을 구하여 유한요소법과 비교하여 제안하는 방법의 유용성을 검증하고 고차모드의 영향을 조사하였다.

• Journal of Korean Society of Forest Science
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• v.109 no.3
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• pp.291-299
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• 2020

The purpose of this study was to propose the most cost-effective sampling method, by analyzing the cost of forest resource investigation per sampling method for the planned harvesting area of in Chunyang-myeon, Byeonghwa-gun, Gyeongsangbuk-do, Korea. For this study, three sampling methods were selected: random sampling method, systematic sampling method, and line transect method. For each method, sample size, hourly wage, number of sample points, survey time, travel time, the sample error rate of the estimated average volume, and the desired sampling error rate were used to calculate the cost of forest resource inventories. Thus, 10 sampling points were extracted for each sampling method, and the factors required for cost analysis were calculated via a field survey. As a result, the field survey cost per ha using the random sampling method was found to be have the lowest cost, regardless of the desired sampling error rate, followed by the systematic sampling method, and the line transect method.

• The Korean Journal of Applied Statistics
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• v.13 no.1
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• pp.81-96
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• 2000

본 논문은 의학분야에서 주로 사용되는 메타분석 중 그룹화 임의효과 모형(grouped random effects model)을 프라빗 연결함수(probit link function)를 이용하여 베이즈적 관점에서 연구하였다. 이때 프라빗 함수를 강요하기 위해 잠재변수를 정의하였고, 사전 분포를 달리한 세가지 모형을 고려하였다. 주어진 세가지 모형들에게서 적합한 모형 선택을 위하여 베이즈 인자(Bayes factor, BF)와 유사베이즈 인자(pseudo-Bayes factor, PsBF)를 이용하였다. 깁스샘플러와 메트로폴리스 알고리즘을 이용하여 베이지안 계산상의 어려움을 해결하였다. 예로써, 새로운 간질약에 대한 효과를 조사하기 위하여 앞에서 제시된 방법으로 해석하였다.