• Proceedings of the Korean Association for Survey Research Conference
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• 2001.04a
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• pp.153-165
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• 2001

In this paper we point out another advantage of systematic sampling over simple random sampling, which have not yet been spelled out in the literature. After a single sample is drawn by a sampling scheme, it is important to check whether the achieved sample represents the pupulation well or out. Therefore, a sampling scheme which avoids the possibility of selecting non-preferred samples is desirable. The simulation results are given to illustrate that, in the ordered population, the possibility of selecting non-preferred sample by systematic sampling is lower than that by simple random sampling.

• Survey Research
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• v.2 no.2
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• pp.153-165
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• 2001

In this paper we point out another advantage of systematic sampling over simple random sampling, which have not yet been spelled out in the literature. After a single sample is drawn by a sampling scheme, it is important to check whether the achived sample represents the population well or not. Therefore. a sampling scheme which avoids the possibility of selecting non-preferred samples is desirable. The simulation results are given to illustrate that, in the ordered population, the possibility of selecting non-preferred sample by systematic sampling is lower than that by simple random sampling.

• Journal of Korean Society of Forest Science
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• v.82 no.2
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• pp.207-219
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• 1993

The study was conducted to discuss the theory and practical application of point sampling method using Spiegel Relaskop that can reduce time and expenses with efficiency in field work for stand inventory. An example of the analysis for real data was given to help practical foresters easily compute basal area, number of trees and volume per hectare even though the theory of point sampling technique is relatively difficult. Also, a SAS program for personal computer and the handling methods of pocket calculator were provided to easily use the point sampling technique in data analysis.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.17-22
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• 2009

In this paper, we discuss two fundamental issues of hybrid scene representation: constructing and rendering. A hybrid scene consists of triangular meshes and point-set models. Consider the maturity of modeling techniques of triangular meshes, we suggest that generate a point-set model from a triangular mesh might be an easier and more economical way. We improve stratified sampling by introducing the concept of priority. Our method has the flexibility that one may easily change the importance criteria by substituting priority functions. While many works were devoted to blend rendering results of point and triangle, our work tries to render point-set models and triangular meshes as individuals. We propose a novel way to eliminate depth occlusion artifacts and to texture a point-set model. Finally, we implement our rendering algorithm with the new features of the shader model 4.0 and turns out to be easily integrated with existing rendering techniques for triangular meshes.

• Journal of the military operations research society of Korea
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• v.11 no.2
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• pp.64-68
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• 1985

This paper considers the following case: (1) the product is paid by the right price for a lot accepted by a given consumer's acceptance sampling plan, and (2) the product is paid by the discounted price for a lot rejected by this plan. In such a case, the producer's sampling plan need not be the same as that of the consumer's. From the producer's view point, the producer need to determine the preliminary sample size which maximizes his revenue. This paper, therefore, determines an optimal preliminary sample size from the producer's view point. This preliminary sample size is affected by the consumer's acceptance sampling plan, percent defective, preliminary inspection cost and the discount rate of the price.

• Journal of Environmental Science International
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• v.21 no.1
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• pp.49-55
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• 2012

In this study, the characteristic of offensive major odorous compound from the Bon-San industrial complex in Gimhae were determined by analytical methods of Gas Chromatography, High Performance Liquid Chromatography and UV/VIS Spectrophotometer. The kind of major odorous compounds examined acetaldehyde, sulfur compounds, ammonia and styrene. The concentration of all odorous compounds at 3 sampling points of industrial complex were lower than those of regulation standard levels of the industrial complex in Korea. The mean concentration of hydrogen sulfide was 0.0235 ppm at sampling point 2, it was higher than other sampling point. Complex odors was lower than regulation standard levels of the industrial complex in Korea.

• Proceedings of the Korean Association for Survey Research Conference
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• 2000.11a
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• pp.157-168
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• 2000

In this paper we point out another advantage of systematic sampling over simple random sampling, which have not yet been spelled out in the literature. After a single sample is drawn by a sampling scheme, it is important to check whether the achived sample represents the population well or not. Therefore, a sampling scheme which avoids the possibility of selecting non-preferred samples is desirable. The simulation results are given to illustrate that, in the ordered population, the possibility of selecting non-preferred sample by systematic sampling is lower than that by simple random sampling.

• Journal of Digital Contents Society
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• v.8 no.1
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• pp.85-91
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• 2007

This paper proposes a new hybrid anti-aliasing method for reducing aliasing appearing on an implicit surface using the point sampling. The hybrid anti-aliasing method is a method that finds differences in the values of pixel shown in Z-buffers for an implicit surface and thereby uses each of three types of Z-buffer. After determining the level of differences, it expresses a 3 dimensional object by using a multi Z-buffer if the level is severe, a double Z-buffer for a middle level, and only the original Z-buffer for a negligible difference. In comparison with the existing method in which multi Z-buffers have been entirely used for enhancing the anti-aliasing effect, the hybrid anti-aliasing method is an efficient method demonstrating an effect similar to the one using a multi Z-buffer while reducing the number of Z-buffers to be used.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.4
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• pp.335-342
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• 2012

3D point cloud is widely used in Architecture, Civil Engineering, Medical, Computer Graphics, and many other fields. Due to the improvement of 3D laser scanner, a massive 3D point cloud whose gigantic file size is bigger than computer's memory requires efficient preprocessing and visualization. We suggest a data structure to solve the problem; a 3D point cloud is gradually subdivided by arbitrary-sized cube grids structure and corresponding point cloud subsets generated by the center of each grid cell are achieved while preprocessing. A massive 3D point cloud file is tested through two algorithms: QSplat and ours. Our algorithm, grid-based, showed slower speed in preprocessing but performed faster rendering speed comparing to QSplat. Also our algorithm is further designed to editing or segmentation using the original coordinates of 3D point cloud.

• The Korean Journal of Applied Statistics
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• v.17 no.2
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• pp.281-301
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• 2004

In this paper we consider the change point problem in a sequence of univariate normal observations. We want to know whether there is any change point or not. In case a change point exists, we will identify its change type. Namely, it can be a mean change, a variance change, or both the mean and variance change. The intrinsic Bayes factors of Berger and Pericchi (1996, 1998) are used to find the type of optimal change model. The Gibbs sampling including the Metropolis-Hastings algorithm is used to estimate all the parameters in the change model. These methods are checked via simulation and applied to the winter average temperature data in Seoul.