• International Journal of Reliability and Applications
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• 제18권2호
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• pp.65-82
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• 2017

Abstract. Camilo Dagum proposed several variants of a new model for the size distribution of personal income in a series of papers in the 1970s. He traced the genesis of the Dagum distributions in applied economics and points out parallel developments in several branches of the applied statistics literature. The main aim of this paper is to define a bivariate Dagum distribution so that the marginals have Dagum distributions. It is observed that the joint probability density function and the joint cumulative distribution function can be expressed in closed forms. Several properties of this distribution such as marginals, conditional distributions and product moments have been discussed. The maximum likelihood estimates for the unknown parameters of this distribution and their approximate variance-covariance matrix have been obtained. Some simulations have been performed to see the performances of the MLEs. One data analysis has been performed for illustrative purpose.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2002년도 Join Meetings of Korean Society of Sericultural Science and Japanse Society of Sericultural Science
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• pp.146-146
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• 2002

No Abstract, See Full Text

• International Journal of Reliability and Applications
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• 제14권2호
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• pp.97-105
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• 2013

A stress-strength model is formulated for a multi-component system consisting of k identical components. The k components of the system with random strengths ($X_1$, $X_2$, ${\ldots}$, $X_k$) are subjected to one of the r random stresses ($X_{k+1}$, $X_{k+2}$, ${\ldots}$, $X_{k+r}$). The estimation of system reliability based on maximum likelihood estimates (MLEs) and Bayes estimators in k component system are obtained when the system is either parallel or series with the assumption that strengths and stresses follow exponential distribution. A simulation study is conducted to compare MLE and Bayes estimator through the mean squared errors of the estimators.

• 무역상무연구
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• 제20권
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• pp.387-421
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• 2003

On the above, a comparison between preliminary draft conventions and comments by the Int'l Chamber of Commerce, contents of preliminary draft convention, problems and alternative are discussed. The conclusions are as follows thereof : The laws of MLEC and MLES made preparation for electronic era of CISG. But electronic circumstances are more changed than the time of regulation of them. Therefore the business world needs a stand-alone convention dealing broadly with the issues of contract formation in electronic commerce. At last, preliminary draft convention delivered a second round. But the base of the instrument was also MLEC and MLES. The revised preliminary draft convention is much amended beyond preliminary draft convention. At its forty-one sessions, the working group reviewed articles 1-11 of the revised preliminary draft convention presented by the secretariat. The remainder was pending until the time of its forty-two sessions. Therefore, on the base of deliberations and decisions of that sessions and them of thirty-six sessions of UNCITRAL, which will be held on comming november, the draft convention which will be prepared by the secretariate, be re-revised preliminary draft convention. According to review of working group on them, preliminary draft convention will officially be draft convention or revise by secretariate. Under these situations, my points of view on draft convention are as follows : As though e-UCP is used carring out side by side with UCP, after e-CISG making in order to adjust CISG to "on" transaction, it is very easy and prompt for business worked to use CISG with e-CISG. This will facilitate ratification of the CISG. For this case, I already presented contents of e-CISG. It is very important for the preliminary draft convention to deal specially with issues related to electronic contracting or to electronic transaction, because according to which way, its contents and scope of application will be different. But the revised draft convention is regretably compromising both them. Consequently, its contents are very confusing and we could not expect its success. If e-CISG will regulate, it is desirable that, if possible, working group has to make the general rule, and the making of useful, practical, affordable rule for electronic commerce, for example Uniform Customs and Practices for Electronic Commerce(e-UEC) in order to solve the specific practical problems, if any, which business currently faces regarding electronic contracting, has to entrust ICC. If working group want to make e-CISG, it is important not to hesitate and take a significant amount of time.

• Journal of the Korean Data and Information Science Society
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• 제27권3호
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• pp.587-598
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• 2016

각종 선거를 앞두고 여러 여론조사 기관들은 다양한 방법으로 선거 결과를 예측한다. 조사를 통한 선거 예측을 수행하는 데 있어서 발생할 수 있는 문제점 중 하나는 무응답이며 무응답 대체 방법에 따라 예측 결과는 완전히 다른 결과를 생산해 낼 수 있다. 본 연구에서는 무응답 대체의 방법으로 모형을 기반으로 한 대체 방법에 대하여 연구하였다. 특히, 최대 우도 추정 방법을 적용했을 때 무시할 수 없는 무응답 (non-ignorable non-response) 체계 하에서 발생할 수 있는 변방 값 문제를 해결하기 위해 Wei와 Tanner (1990)가 제안한 Monte Carlo EM 알고리즘을 적용하였다. 모의 실험을 통하여 MCEM 방법과 기존의 최대 우도 추정 방법, 베이지안 추정 방법 사이의 비교 연구를 진행하였고 그 결과 MCEM 방법이 기존 방법들에 대한 대안 방법으로 이용될 수 있음을 보였다. 또한 2012년에 시행된 제18대 대통령 선거 당일의 출구조사 자료를 적용하여 실증 분석을 수행하였다. 예측 결과를 비교하기 위해 Bautista 등 (2007)이 제안한 MWPE (modified within precinct error)를 이용하였다.

• Strategy21
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• 통권44호
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• pp.323-351
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• 2018

Adopted in Western Pacific Naval Symposium(WPNS) 2014, Code for Unplanned Encounters at Sea(CUES) has been the most valuable output of WPNS history. Written and suggested by Australian Navy in 1999, the goal of CUES is to decrease the possibility of the naval conflict by establishing the code among international navies in the Western Pacific region. Facing many oppositions and requirement of People's Liberation Army Navy(PLAN) in WPNS 2012 and 2013, but it finally adopted in WPNS 2014, with many changes in detailed provisions. From then, navies in the Western Pacific region have followed CUES to prevent maritime conflicts in the region, CUES, however, sometimes does not work correctly. Contents of CUES is the mixture of the parts of Multinational Maritime Tactical Signal and Maneuvering Book(MTP) and International Regulations for Preventing Collision at Sea 1972(CORLEGs). There are means of radio communications such as frequency and signals, instructions for maneuvering and so on. Thus, it is not a new document for the U.S. Navy and its allies, but it requires training to implicate at sea for navies other than U.S. allies, like PLAN. Lots of provisions in CUES were changed because of the opposition of PLAN, and CUES has many shortcomings and practical limitations. First, since CUES is non-legally binding, and there are no methods to force the naval assets on the sea to follow. Second, CUES is only applied to naval assets; naval ships - warships, naval auxiliaries, and submarines - and naval aircraft. Third, the geographical scope in CUES is not clear. Fourth, there is no provision for submerged submarines. Finally, CUES has no time-based framework or roadmap for training. In this regard, there would be six recommendations for improvement. First, CUES should be reviewed by WPNS or other international institutions, while keeping non-binding status so that WPNS could send signals to the navies which do not answer CUES on the sea. Second, the participation of Maritime Law Enforcements(MLEs) such as coast guard is inevitable. Third, navies would use full text of MTP rather than current CUES, which extracts some parts of MTP. Fourth, CUES needs provisions with respect to submerged submarines, which recognizes as offensive weapons themselves. Fifth, the geographic scope of CUES should be clear. Since there are some countries in which claim that a rock with a concrete structure is their territory, CUES should be applied on every sea including EEZ and territorial seas. Finally, the detailed training plan is required to implicate CUES at sea. Rim of the Pacific (RIMPAC) is a good exercise to train CUES, because almost all WPNS member countries except six countries are participating in RIMPAC. CUES is a meaningful document not only for navies but also for nation-states in the region. To prevent escalation of conflict in the region, potentially caused by an unplanned collision at sea, CUES should be applied more strictly. CUES will continue to be in subsequent WPNS and therefore continue to improve in the effectiveness as both an operational and diplomatic agreement.

• 대한치과보철학회지
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• 제36권2호
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• pp.302-322
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• 1998

This study was accompolished to analyze and compare the number and area of the occlusal contact points in healthy volunteers and athletes with normal occlusion. For this study, 15 athletes(13 amles and 2 females with average age 20) and 21 healthy volunteers(14 mles and 7 females with average age 20.09) were selected. The visual display acquired by scanning of occlusal record in maximal intercuspation was converted into 16 gray value image. Then, using computer program(J & Lee Occlusal Analyser), the pixel which was in definite range of the gray value was recognized, and the numbers of recognized pixel were calculated to area. The results were as follows ; 1. The average numbers of total occlusal contact feints were 31.05 in control group, and 34.67 in athlete group. The average area of total occlusal contacts was $100.25mm^2$ in control group, and $127.78mm^2$ in athlete group. 2. In control group, the average numbers of occlusal contact points were revealed in order as follows ; the first molar(8.48), the second molar(8.24), the second premolar(4.71), the lateral incisor(2.90), the first premor(2.43), the central incisor(2.19), and the canine(2.1). The least average in canine(2.1) was similar to the average(2.19) in central incisor and (2.09) in lateral incisor. In athlete group, the average numbers of occlusal contact points were revealed in order as follows ; the first molar(8.97), the second molar(8.47), the second premolar(5.60), the canine(3.80), the lateral incisor(3.33), the first premolar(2.67), and the central incisor(1.93). 3. In control group, the average areas of occlusal contact surface were revealed in order as follows ; the first molar($39.47mm^3$), the second molar($37.54mm^3$), the second premolar($9.54mm^3$) the first premolar($6.18mm^3$), canine($3.49mm^3$), the central incisor($2.76mm^3$), and the lateral incisor($1.28mm^3$). In athlete group, the average areas of occlusal contact surface were revealed in order as follows ; the first molar($44.11mm^3$), the second molar($40.69mm^3$), the second premolar($16.50mm^3$), the first premolar($9.39mm^3$), the canine($5.08mm^3$), the lateral incisor($3.7mm^3$), and the central incisor($2.25mm^3$). 4. With aging in both control and athlete group, there was a decreasing tendancy in average number of occlusal contact point, and was an increasing tendancy in average area of occlusal contact surface. In comparison at each age, both the numbers and area of occlusal contact were greater in athlete group than in control group. It was not significant in the numbers of occlusal contact points beween athlete and control group(p>0.1), but significant in the area of occlusal contact surface(p<0.03). 5. In comparision as to the kind of sports(Gymnastics : 2, Rugby : 3, Soccor : 5, Ice hocky : 5), the numbers of occlusal contact points were the most in ice hocky, and the area of occlusal contact surface was the greatest in gymnastics. With increasing a career in athlete group, there was a decreasing tendancy in average numbers of occlusal contact points and was an increasing tendancy in average area of occlusal contact surface. 6. By T-scan analyzing, the contact numbers on the anterior teeth were greater in control group than in athlete group, and on the posterior teeth were greater in athlete group than in control group. And the results acquired by T-scan were lesser than that caquired by the silicone bite records. It was not significant in the posterior teeth, but significant in the anterior teeth. In T-scan records, the numbers of occlusal contact points on second molar were the greatest, but in the silicone records, the numbers on first molar were the greatest.

• 구강회복응용과학지
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• 제18권4호
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• pp.235-249
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• 2002

This study was accompolished to analyze and compare the number and area of the occlusal contact points in healthy volunteers and athletes with normal occlusion. Before the study, 89 athletes(sports career:8.6 years, average age 20) at Kyung Hee University were selected, and survey was accomplished for athlete's recognition about sports dentistry. For this study, 15 athletes(13 amles and 2 females with average age 20) and 21 healthy volunteers(14 mles and 7 females with average age 20.09) at Kyung Hee University were selected. The visual display acquired by scanning of occlusal record in maximal intercuspation was converted into 16 gray value image. Then, using computer program(J & Lee Occlusal Analyser), the pixel which was in definite range of the gray value was recognized, and the numbers of recognized pixel were calculated to area. The results were as follows : (1) On the survey about sports dentistry, 28% of 89 athletes didn't agree that human occlusion may be important, and 30% didn't have any idea of the influence of human occlusion during their sports activities. (2) The average numbers of total occlusal contact points were 31.05 in control group, and 34.67 in athlete group. The average area of total occlusal contacts was $100.25mm^2$ in control group, and $127.78mm^2$ in athlete group. (3) In control group, the average numbers of occlusal contact points were revealed in order as follows; the first molar(8.48), the second molar(8.24), the second premolar(4.71), the lateral incisor(2.90), the first premor(2.43), the central incisor(2.19), and the canine(2.1). The least average in canine(2.1) was similar to the average(2.19) in central incisor and (2.09) in lateral incisor. In athlete group, the average numbers of occlusal contact points were revealed in order as follows; the first molar(8.87), the second molar(8.47), the second premolar(5.60), the canine(3.80), the lateral incisor(3.33), the first premolar(2.67), and the central incisor(1.93). (4) In control group, the average areas of occlusal contact surface were revealed in order as follows; the first molar($39.47mm^3$), the second molar($37.54mm^3$), the second premolar($9.54mm^3$) the first premolar($6.18mm^3$), canine($3.49mm^3$), the central incisor($2.76mm^3$), and the lateral incisor($1.28mm^3$). In athlete group, the average areas of occlusal contact surface were revealed in order as follows; the first molar($44.11mm^3$), the second molar($40.69mm^3$), the second premolar($16.50mm^3$), the first premolar($9.39mm^3$), the canine($5.08mm^3$), the lateral incisor($3.7mm^3$), and the central incisor($2.25mm^3$). (5). With aging in both control and athlete group, there was a decreasing tendancy in average number of occlusal contact point, and was an increasing tendancy in average area of occlusal contact surface. In comparison at each age, both the numbers and area of occlusal contact were greater in athlete group than in control group. It was not significant in the numbers of occlusal contact points beween athlete and control group(p>0.1), but significant in the area of occlusal contact surface(p<0.05). (6) In comparision as to the kind of sports(Gymnastics:2, Rugby:3, Soccor:5, Ice hocky:5), the numbers of occlusal contact points were the most in ice hocky, and the area of occlusal contact surface was the greatest in gymnastics. With increasing a career in athlete group, there was a decreasing tendancy in average numbers of occlusal contact points, and was an increasing tendancy in average area of occlusal contact surface.