• The Korean Journal of Applied Statistics
• /
• v.21 no.1
• /
• pp.177-182
• /
• 2008

There are times when we need more sample to achieve a more accurate estimator. Since these two sets of sample have the information about the same population, it is necessary to treat both as a single combined data. In this paper we present the unpooled sample variance for the combined data when we just know a sample mean and variance for the each data set without the raw data. It is shown that the pooled variance $s^2_p$ is always greater than the exact variance $s^2_t$ when ${\bar{x}}_n\;=\;{\bar{y}}_m$. And the difference of means for two data, ${\bar{x}}_n-{\bar{y}}_m}$, is larger, the difference of $s^2_p$ and $s^2_t$ is larger.

• Journal of the Korea Society for Simulation
• /
• v.26 no.3
• /
• pp.95-104
• /
• 2017

This study focuses on resolving traffic congestion caused by a large scale event based on the case of ROK Joint Officer Commissioning Ceremony, and it was conducted through literature review as well as Arena Simulation. The study purpose is to appropriately allocate and disperse the traffic by utilizing nearby parking lots of facilities. The annual event draws about 7,400 vehicles to a limited number of parking lots, and all vehicles leave the parking lots concurrently, causing a severe bottleneck near the exit and a few roads. In order to resolve the issue, the optimal number of cars in the event area was analyzed. After the analysis, the study found that the overflow of cars in the event area should be allocated to nearby parking lots of facilities with shuttle buses operating to transport the attendees. As the proposed result of the simulation, the traffic congestion time was reduced from 150 minutes to 64 minutes, a total reduction of 86 minutes.

• Review of KIISC
• /
• v.4 no.2
• /
• pp.23-39
• /
• 1994

본 논문은 예전의 방법들에서 일어나고 있는 수행 속도 문제점들을 향상하기 위하여 병렬 처리를 이용하여 난수를 발생하는 방법중에서 가장 보편적이고 빠른 방법으로 알려진 저차 합동 다항식에 기초한 새로운 고속 디지탈 서명방식에 대한 병렬 알고리즘을 제안한다. 새로운 디지탈 서명 방식은 비밀키로써 큰 소수 p,q를 이용하여, 공개 정보로써 n=$p^2$ * q를 이용한다. 난수는 서명을 생성할때 이용되며, 서명을 검증하기 위하여 부등식을 이용하며 병렬 알고리즘을 이용하여 서명을 생성하는 처리속도의 향상된 성능을 위하여 전처리와 디지탈 서명을 구축하는 계산방법의 새로운 병렬 알고리즘을 작성하였다. 본 논문에서 새로 제안한 서명방식에 대한 병렬 알고기즘을 검증하고 비도를 산출할 것이며, 시뮬레이션을 통하여 예전의 방식들과 비교 분석한다. 본 논문은 공개키를 이용한 병렬 암호와 시스템과 신호 처리에 대한 병렬 알고리즘으로 응용될 수 있을 것이며, 병렬과 분산 처리 환경하에서 개발되는 정보서비스 특히 메세지 처리 시스템 서비시, 전자교환 서비스 등의 디지탈 서명에 유용될 수 있을 것이다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2021.05a
• /
• pp.6-8
• /
• 2021

최근 COVID-19의 백신이 개발되어 접종을 시작했다. 정부는 집단면역 생성을 위해 접종 목표치를 설정하고, 민관합동신속대응팀을 설립하는 등의 조치를 취하고 있다. 하지만 COVID-19의 백신이 다른 백신에 비해 개발 기간이 훨씬 짧을뿐더러, 효과가 입증되지 않아 신뢰를 얻지 못하고 있다. 블록체인은 거래 당사자 간의 거래정보를 네트워크에 참여하는 모든 구성원들이 공동으로 기록, 검증, 저장하는 분산장부 기술로 공인된 제3자 없이도 무결성 및 신뢰성을 확보할 수 있다. 이에 본 논문에서는 COVID-19 백신의 신뢰도를 제고하기 위해 블록체인을 기반으로 한 백신 접종 이력 관리 시스템을 설계하고, 향후 QR코드 등의 방식과 연동하여 백신 여권 등으로의 확장 가능성을 제시한다.

• Journal of Korean Institute of Fire Investigation
• /
• v.11 no.1
• /
• pp.155-166
• /
• 2007

This study is to deduce problems and grope for its solution by investigating the general operation status about the present fire investigation in Korea. As for the problems, this study is to point out that they are application of diversion by the function of law for fire investigation, execution of individualized fire investigation by each institution, total lack of information sharing system for fire investigation, and weakness of cause investigation for arson. The reform measures are as follows: the unity of law for fire investigation, joint investigation by the related institutions, early introduction of civil fire investigation expert system, extension of special research institutes for fire investigation, introduction of system for sharing information of fire investigation, and operation of fire investigation team for cause investigation for arson.

• The Korean Journal of Applied Statistics
• /
• v.4 no.1
• /
• pp.1-11
• /
• 1991

It is of great interest to consider the homogeniety of covariance matrices in MANOVA of discriminant analysis. If we lock at the problem of testing hypothesis, H : $\Sigma_1 = \Sigma_2$ from an invariance point of view where $\Sigma_i$ are the covariance matrix of two independent p-variate distribution, the testing problem is invariant under the group of nonsingular transformations and the hypothesis becomes H : $\delta_1 = \delta_2 = \cdots = \delta_p = 1$ where $\delta = (\delta_1, \delta_2, \cdots, \delta_p)$ is a vector of latent roots of $\Sigma$. Bias-corrected estimators of eigenvalues and sampling distribution of the test statistics proposed are obtained. Pooled-bootstrap method also considered for Bartlett's modified likelihood ratio statistics.

• Journal of Broadcast Engineering
• /
• v.16 no.2
• /
• pp.216-225
• /
• 2011

Following the proliferation of three-dimensional video contents and displays, many terrestrial broadcasting companies have been preparing for stereoscopic 3DTV service. In terrestrial stereoscopic broadcast, it is a difficult task to code and transmit two video sequences while sustaining as high quality as 2DTV broadcast due to the limited bandwidth defined by the existing digital TV standards such as ATSC. Thus, a terrestrial 3DTV broadcasting with a heterogeneous video codec system, where the left image and right images are based on MPEG-2 and H.264/AVC, respectively, is considered in order to achieve both high quality broadcasting service and compatibility for the existing 2DTV viewers. Without significant change in the current terrestrial broadcasting systems, we propose a joint rate control scheme for stereoscopic 3DTV service based on the heterogeneous dual codec systems. The proposed joint rate control scheme applies to the MPEG-2 encoder a quadratic rate-quantization model which is adopted in the H.264/AVC. Then the controller is designed for the sum of the left and right bitstreams to meet the bandwidth requirement of broadcasting standards while the sum of image distortions is minimized by adjusting quantization parameter obtained from the proposed optimization scheme. Besides, we consider a condition on maintaining quality difference between the left and right images around a desired level in the optimization in order to mitigate negative effects on human visual system. Experimental results demonstrate that the proposed bit rate control scheme outperforms the rate control method where each video coding standard uses its own bit rate control algorithm independently in terms of the increase in PSNR by 2.02%, the decrease in the average absolute quality difference by 77.6% and the reduction in the variance of the quality difference by 74.38%.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.36 no.4
• /
• pp.100-110
• /
• 2008

The purposes of the study were to analyze the effects of determinants and persuasive messages on the willingness-to-pay cultural & heritage assets' admission fees. Recently visitors have responded to a nationwide boycott of the fees within national parks due to feelings of disapproval and resentment. Data were collected through onsite surveys of 302 visitors in the Mt. Gyeryong National Park. Regression analysis and two-way ANOVA were employed to obtain the results. The results indicate that credit card payment was the most prominent predictor of willingness-to-pay at the .05 level. The second highest coefficient was obtained in the condition levying of admission fees and parking fees at the same time, providing temple interpretive services, followed by free days for everyone on special days each month. In addition, the most persuasive message was the descriptive content, which stated that fees were profoundly committed to the protection of the cultural heritage for future generations. As a result, it is effective to continually persuade visitors to use posters or reminders that stress the preservation of cultural assets at the entrance gate.

• Korean Security Journal
• /
• no.20
• /
• pp.45-69
• /
• 2009

This study is to present effective and rational strategies by comparing and analyzing plans of some nations such as the United States, Britain, Germany and Japan against terrorism. Nations mentioned above have made alliance to prevent the possible terrorism after 9.11 attack and performed various tasks efficiently. The result of this study is summarized as follows. First, it is required that there should be an integrated system which works properly. Each nation has not distinguished natural disaster from man-made one based on the damage and the abilities of authorities to deal with. On the other hand, South Korea tells two disasters according to causes and runs distributed systems in which each government division performs its duties to manage each disaster. Accordingly, in economic terms, it is much more effective to provide integrated counter terrorism, not distributed one. Second, information sharing must be stimulated. To take actions quickly when an accident occurs, the government needs to have united and integrative systems, which make it prepare for various types of terrorism well. In addition, it is necessary for a government-related organization to tie up with other channels for collecting, analyzing and sharing information. For this, integrative systems for terrorism should be taken into consideration.