• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.370-377
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• 2006

This study was conducted to develop an efficient method of sampling design appropriate for the sustainable forest management. For this, data were collected in Yangpyung-Gun, Gyunggi Province based on three different sampling designs such as systematic design, systematic cluster design, and stratified cluster design. Based on evaluation statistics, the sampling designs were compared to select a sampling method fitted to sustainable forest management. It was found that the systematical cluster sampling is the most efficient sampling method in terms of feasibility for sustainable forest management. It was also recommended that the sample plots should be made as a cluster of triangle-shape. The clusters should be consisted of a main plot and three sub-plots. And the sub-plots should be arranged with a distance of 50m from the main plot in the center of cluster.

• The Korean Journal of Applied Statistics
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• v.13 no.2
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• pp.457-476
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• 2000

In this study, we have proposed a sampling method and an estimation method for efficiently estimating the mean of a population which has a linear trend. These methods involve drawing a sample by the so-called "centered balanced systematic sampling", which is an extension of systematic sampling, and then estimating the population mean with an adjusted estimator, not with the sample mean itself. We used the concept of interpolation in determining the adjusted estimator.\Ve compared the efficiency of the proposed estimator with those of the estimators from existing methods, under the expected mean square error criterion based on the infinite superpopulation model introduced by Cochran(1946). The proposed method is for use in the case when the sample size n(2 5) is an odd number and k(the reciprocal of the sampling fraction) is an even number. A good result was also obtained in an example using computer simulation. simulation.

• The Korean Journal of Applied Statistics
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• v.17 no.1
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• pp.105-117
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• 2004

In this paper, a new method is developed for estimating the mean of a population which has a linear trend. This method involves drawing a sample by the modified systematic sampling, and then estimating the population mean with an adjusted estimator, not with the sample mean itself. We use the method of least squares in determining the adjusted estimator. The proposed method is shown to be more and more efficient as the linear trend becomes stronger. It turns out to be relatively efficient as compared with the conventional methods if $\sigma$$^2$the variance of the random error term in the infinite superpopulation model, is not very large.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.36-36
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• 2019

본 연구는 한라산국립공원 동사면에 위치한 구상나무숲 장기생태 모니터링 5ha 조사지역 ($20{\times}20m$, 125개 방형구)에서 구상나무의 유묘 및 치수 발생 현황을 파악하기 위하여 수행되었다. 조사는 2016년 6~8월 사이에 $5{\times}5m$ 방형구 125곳에 대해 계통추출법을 적용하여 실시하였다. 조사한 전체 125개 방형구 중에서 54개에서만 유묘가 관찰되었으며, 그 내용은 유묘 615개체 및 치수 1개체로 총 616개체가 발견되었다. 그러나 과반수의 71개 방형구에서 치수뿐만 아니라 유묘도 출현하지 않았다. 심지어 전체 125개 방형구에서 유묘가 가장 많이 관찰된 방형구(2-6지역, 95개체)를 제외하면, 나머지 124개 방형구의 평균 유묘 개체수는 4.2개로 매우 적었고 높이도 35cm 이하에 불과했다. 이와 함께 장기생태 모니터링 조사 지역 내에서 $1{\times}1m$ 방형구 183곳에 대해 단순 무작위 추출법으로 발생지 조사를 수행하였다. 발생지 조사 결과 유묘 2,518개체, 치수 2개체 및 유목 2개체 등 총 2,522개체가 발견되어 계통추출법을 적용한 조사와 유사한 결과가 나타났다. 본 연구를 통해 한라산국립공원 동사면 구상나무숲 내에서 구상나무 유묘의 발생은 어느 정도 이루어지고 있으나, 교란으로 인하여 치수로의 발달이 제한되는 것으로 판단된다. 여러 교란 요인 중에서 조사된 총 3,138개체 중 12.1%, 381개체에서 유제류인 노루에 의한 섭식이 확인되어 노루의 섭식이 유묘 발생 및 치수 발달에 교란을 야기하는 가장 중요한 요인으로 추정해볼 수 있다. 한반도 특산식물 구상나무의 보전 대책 수립을 위한 유묘 및 치수 교란 원인에 대한 지속적인 모니터링이 진행되어야 한다고 사료된다.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11a
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• pp.347-350
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• 2003

표면정보 기반 영상정합기법은 대상기관에서 추출된 표면정보를 기반으로 변환을 추정하여 서로 다른 영상의 전체적 형태의 유사성 정도를 최대화함으로써 정합을 수행하는 방법이다. 정합 수행에 있어 전체 객체를 가장 잘 대표하는 특정 개수의 표면점을 추출하고, 이 대표점으로부터 변환 값을 계산하는 것이 영상정합의 합리적인 최적화 단계를 위해 필수적이다. 대표점 추출결과에 따라 전체 정합의 결과가 달라지게 되므로 정합의 변환요소 값을 정확하게 구해낼 수 있는 대표점을 추출하기 위해 적절한 샘플링 기법의 선택이 요구된다. 본 연구에서는 효율적인 표면정보 기반 다중 모달리티 영상정합을 위해 계통추출법 기반 샘플링 기법과 특징점 탐지 기법 기반 샘플링 기법의 성능을 비교 분석하였다.

• Survey Research
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• v.11 no.1
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• pp.123-144
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• 2010

In new sample design for Korea Housing Survey to research about housing policy, total strata are forty five because individual results of sixteen regions are estimated. The sample size is determined by sample errors of several variables which are the living area, family income, householder income, and living expenses. The sample size of each region is determined by relative standard error of existing result, and the strata sample size is to use the square root proportion allocation. Enumeration districts are sampled by the probability proportion to size systematic sampling in proportion to the enumeration district size, and the systemic sampling to use assortment characteristics. We considered a new apartment complex because of variation reflections which are rebuilder and redevelopment of houses. To get estimators of mean and variance, we used the design weighting, non-response adjusting, and post-stratification. In order to consider estimation efficiency, we calculate the design effect using estimators of variance.

• Communications for Statistical Applications and Methods
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• v.15 no.6
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• pp.883-897
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• 2008

This paper provides correct informations inflecting the present situation using the sample design in population that the National Statistical Office puts in operation of the mining and manufacturing industry statistical survey in 2006. This paper proposes new sampling design which is able to grasp business fluctuations and provide basic data for the rearing policy and management of the material industry and components industry. These sample design are the modified cut-off method and multivariate Neyman allocation using principal components and sampling method is the probability proportional systematic sampling.

• Journal of Korean Society of Forest Science
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• v.46 no.1
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• pp.29-43
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• 1980

The sampling methods selected for this area was (1) Simple random sampling (2) Systematic sampling and (3) Sub-sampling. For the calculation of the number of sampling plot, 10 % coefficient of variation was adapted. As a result, 57 plots each for simple random sampling and systematic sampling was calculated. In the sub-sampling method, however, total of 40 plots, which were consisted of 5 Blocks, secondary 4 major units and tertiary 2 minor units, were examined. The reuslts obtained are summarized as follows : 1. The rate of expected error was 9.24% for simple random sampling, 8.36% for systematic sampling and 7.54% for sub-sampling, respectively. Therefore, the sub-sampling was proved to be the most accurate method among the test. 2. The volume calculated by each sampling method was compared to the volume of all stand. The rate of expected error was also lowest in the sub-sampling (0.39%), followed by systematic sampling (4.18%) and simple random sampling (7.92%). 3. Comparing the various reuslts and analysis of these results, the sub-sampling was regarded as the most rapid and economical method because this method had not only the least number of plots but also the least expected error among the tested sampling methods Therefore the sub-sampling is proved to be an ideal sampling method for forest survey.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.6
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• pp.542-547
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• 1994

To find out the most reasonable analysis conditions of paeoniflorin, different paeoniflorin extraction methods and various UV detector wavelengths were conducted with paeonia radix of 4-year old Euisung local variety. The most reasonable paeoniflorin extraction time by reflux apparatus was 1hr. and by ultrasonic apparatus was 3hrs. and those methods were completed only once. Concentration of paeoniflorin by reflux apparatuses at 1hr. and 2hrs. of extracting time were higher than those of ultrasonic apparatus, and the differences were highly significant. However, the differences of paeoniflorin concentration at 3hrs. and 4hrs. in two methods were not significant. In comparing paeoniflorin concentration of many lines, ultrasonic extracting apparatus was more simple and effective than the reflux apparatus. Paeoniflorin was more reasonable sensitivity at 240nm, and albiflorin was 254nm by HPLC. When paeoniflorin and albiflorin were analyzed simultaneously, 254nm was more stable than any other wavelength.

• The Korean Journal of Applied Statistics
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• v.21 no.4
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• pp.675-694
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• 2008

We propose a new sampling design for the Korean Livestock Production Cost Survey. In this sampling design, the survey population is derived from the 2005’s agricultural census of Korea. And coefficient of variation(CV) is estimated from the current livestock production cost survey data, and the estimated CV’s are used to find the optimal sample size which satisfies the predetermined precision of estimation. In order to save the enumeration cost, the agriculture enumeration districts are used as a primary sampling unit(psu). Final sample is selected by double sampling. Also, we propose the estimator which is able to reflect the change of the population of livestock production households.