• Journal of environmental and Sanitary engineering
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• v.21 no.1 s.59
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• pp.1-11
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• 2006

This study was to investigate concentration characteristics of atmospheric PCBs in soil sample and pine needle at rural area. Profiles of PCB congener detected in pine needle and soil sample have a difference that low molecular PCBs mainly existed in pine needle, whereas high molecular PCBs were mainly existed in soil sample because of their different vapor pressure and octanol-air partitioning coefficient($K_{OA}$) of each congeners. Correlation coefficients(r) of PCB congeners simultaneously detected in soil and pine needle were significant (r>0.71, p<0.01), which showed that PCB congeners patterns of atmosphere could be estimated in using pine needle and soil sample indirectly. The contributions(%) of higher molecular PCBs(>penta-CB) to total PCBs in soil sample were higher than those of pine needle and the contribution of lower molecular PCBs(

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.7
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• pp.3268-3283
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• 2018

With the advent of the Information Age, the source identification of digital images, as a part of digital image forensics, has attracted increasing attention. Therefore, an effective technique to identify the source of digital images is urgently needed at this stage. In this paper, first, we study and implement some previous work on image source identification based on sensor pattern noise, such as the Lukas method, principal component analysis method and the random subspace method. Second, to extract a purer sensor pattern noise, we propose a sample selection method to improve the random subspace method. By analyzing the image texture feature, we select a patch with less complexity to extract more reliable sensor pattern noise, which improves the accuracy of identification. Finally, experiment results reveal that the proposed sample selection method can extract a purer sensor pattern noise, which further improves the accuracy of image source identification. At the same time, this approach is less complicated than the deep learning models and is close to the most advanced performance.

• Journal of the Society of Disaster Information
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• v.17 no.4
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• pp.897-903
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• 2021

Purpose: Recently, ransomware damage that encrypts victim's data through hacking and demands money in exchange for releasing it is increasing domestically and internationally. Accordingly, research and development on various response technologies and solutions are in progress. Method: A secure storage area and a general storage area were created in the same virtual environment, and the sample data was saved by registering the access process. In order to check whether the stored sample data is infringed, the ransomware sample was executed and the hash function of the sample data was checked to see if it was infringed. The access control performance checked whether the sample data was accessed through the same name and storage location as the registered access process. Result: As a result of the experiment, the sample data in the secure storage area maintained data integrity from ransomware and unauthorized processes. Conclusion: Through this study, the creation of a secure storage area and the whitelist-based access control method are evaluated as suitable as a method to protect important data, and it is possible to provide a more secure computing environment through future technology scalability and convergence with existing solutions.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.3
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• pp.53-59
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• 1994

A new fully differential sample-and-hold circuit which can effectively compensate the offset voltage of an operational amplifier and the charge injection of a MOS switch is presented. The proposed circuit shows a true sample-and-hold function without a reset period or an input-track period. The prototype fabricated using a 1.2$\mu$m double-polysilicon CMOS process occupies an area of 550$\mu$m$\times$288$\mu$m and the error of the sampled ouput is 0.056% on average for 3V input at DC.

• Journal of Acupuncture Research
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• v.23 no.5
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• pp.187-198
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• 2006

Objectives : The purpose of this study is to assess the effect of Daekumeumja herb-acupuncture on neural cell proliferation and nitric oxide synthase(NOS) expression in hippocampus of ethanol-intoxicated Sprague-Dawley(SD) rats. Methods : SD rats were randomly assigned into 5 groups ; the normal group, the alcohol-treated(control) group, the alcohol- and 1 mg/kg Daekumeumja- treated(sample A) group, the alcohol- and 5mg/kg Daekumeumja-treated (sample B) group, the alcohol- and 10 mg/kg Daekumeumja-treated (sample C) group(n = 6 in each group). Normal group were received with Saline, while control group were injected intraperitoneally with alcohol(2 g/kg) once per day for 5 days. Sample groups were treated Daekumeumja herb-acupuncture on Chungwan(CV12) for 5 consecutive days. Bromo-deoxyuridine(BrdU) was injected into all animals once per day for 5 days. For the detection of BrdU-positive cells and NADPH-d- positive cells in hippocampus, immunohistochemistry was performed. Results : 1. In the dentate gyrus area, the number of BrdU-positive cells in the sample $B(278.08{\pm}6.46)$, $C(331.33{\pm}16.68)$ groups was significantly(p<0.05) increased compared with the control group. 2. In the dentate gyrus area, the number of NADPH-d-positive cells in the sample $C(86.50{\pm}10.02)$ groups was significantly(p<0.05) increased compared with the control group. 3. In the CAI area, the number of NADPH-d-positive cells in the sample $A(63.90{\pm}2.69)$, $B(75.70{\pm}3.01)$, $C(97.70{\pm}4.06)$ groups was significantly(p<0.05) increased compared with the control group. 4. In the CA 2-3 area, the number of NADPH-d-positive cells in the sample $B(30.20{\pm}1.89)$, $C(62.70{\pm}2.08)$ groups was significantly(p<0.05) increased compared with the control group. Conclusion : These results indicate that, neural cell proliferation and NOS expression in hippocampus was reduced in ethanol-intoxicated group. Treatment of Daekumeumja herb-acupuncture increased this diminution. Daekumeumja could be able to effect on the prevention of the amnesia and learning disability in alcoholism.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1449-1454
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• 2013

There are many methods for measuring the difference between two location parameters. In this paper, statistics are proposed in order to estimate the difference of two location parameters. The statistics are designed not using the means, variances, signs and ranks, but with the cumulative distribution functions. Hence these are measured as the differences in the area between two univariate cumulative distribution functions. It is found that the difference in the area between two empirical cumulative distribution functions is the difference of two sample means, and its integral is also the difference of two population means.

• Journal of Digital Contents Society
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• v.5 no.4
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• pp.257-263
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• 2004

This paper is related to the object-based stereo matching algorithm which makes it possible to estimate inner-region disparities for each segmented region. First, several sample points are selected for effectively representing the segmented region, Next, stereo matching is applied to the small area within segmented region which existed in the neighborhood or each sample point. Finally, inner-region disparities are interpolated using a plane equation with disparity of each selected sample. According to the proposed method, the problem of feature-based method that the depth estimation is possible only in the feature points can be solved through the propagation of the disparity in the sample point into the inside of the region. Also, as selecting sample points in contour of segmented region we can effectively suppress obscurity which is occurred in the depth estimation of the monotone region in area-based methods.

• Journal of the Korean housing association
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• v.18 no.5
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• pp.93-102
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• 2007

The purpose of this study is to explore the changes in space structure in urban residential areas, based on the historical and cultural background of Gyeongju area. In order to clarify its residential and cultural properties, the residential patterns and living characteristics identifying its historical context were analysed. This study was carried out with the data of the Hwango-dong area that has maintained its original form since the creation as a urban residential area during the 1960s and 1970s, the data of the Dongbang village area that was developed as one of residential area projects during the 1970s, and the data of the Seonggeon-dong area that was developed as a residential area during the 1970s and 1980s. The analyses on previous studies and statistical data, referring to building administration registers, field survey and photographing of house types, and exploration of living characteristics by house types were used to perform this study. Four hundred and five sample houses were used in this study, having forty one sample houses which were used for living survey and actual plane measurement. The result of this study can be used as basic information for designing the house to meet Gyeongju citizens' desire for living environments, and to maintain the cultural and historical contexts.

• Communications for Statistical Applications and Methods
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• v.17 no.3
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• pp.337-347
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• 2010

Most sample surveys are designed to estimate reliable statistics for the whole population and for some large subpopulations. However, the research for small area estimation have been increasing in recent years because users demand to reliable estimates for smaller subpopulations like small areas or specific domains. In Korea, the Economically Active Population Survey(EAPS) is the main household survey that produces monthly unemployment rates for nationwide and 16 large areas (7 metropolitans and 9 provinces) in Korea. For county level estimation, direct estimators are not reliable because of the small sample sizes. We consider small area estimation of the county level unemployment ratesfrom the sample observations in EAPS. To do this, we use an area level model to "borrow strength" from the auxiliary information, such as administrative data and census data. The proposed method is based on the assumption of normality of the model errors in the area level model. The proposed method is compared with the other alternatives in terms of the estimated mean squared errors.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.2
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• pp.215-219
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• 1999

This study aims to make detail examination of smallholder dairy farming systems in the Nongpho Dairy Cooperative. Forty-three dairy farms were selected from three geographical areas i.e. irrigated area, municipality area, and factory area. Within each area some number of sample farms were selected from each of the three levels of farm and animal crowdedness (very crowded, crowded, and not crowded farms). Detail data were collected during 1996 to 1997, they were socio-economic conditions of the sample farms and farmers, dairy production systems and management of resources (animals, bam, feeds, stocking rates, herd structure, animal body conditions, milk yield and milk quality, manure and farm wastes management, and other related items). Detail information useful for the improvement of farm production efficiency were discussed. It was very clear that much improvement of smallholder dairy production can be achieved if the recommendations given by this study were implemented.