In a multivariate normal production process N_p(µ,Σ), a chart combining three EWMA charts with accumulate-combine method for µ, variance components of Σ, and off-diagonal elements of Σ, into a EWMA (exponentially weighted moving average) chart is considered, which is called a combined EWMA chart. Through simulation work, the proposed combined EWMA chart's numerical performance and properties are examined. The simulation results show that the proposed combined EWMA chart, which is simultaneously monitoring all the process parameters of multivariate normal production process, works effectively in the perspective of means, variances and correlation coefficients. In addition, the combined EWMA chart is extended to VSI chart.

This research examines the power of bootstrap two-sample test, and compares it with the powers of two-sample t-test and Wilcoxon rank sum test, through simulation. For simulation work, a positively skewed and heavy tailed distribution was selected as a population distribution, the chi-square distributions with three degrees of freedom, χ²₃. For two independent samples, the fist sample was selected from χ²₃. The second sample was selected independently from the same χ²₃ as the first sample, and calculated d+ax for each sampled value x, a randomly selected value from χ²₃. The d in d+ax has from 0 to 5 by 0.5 interval, and the a has from 1.0 to 1.5 by 0.1 interval. The powers of three methods were evaluated for the sample sizes 10,20,30,40,50. The null hypothesis was the two population medians being equal for Bootstrap two-sample test and Wilcoxon rank sum test, and the two population means being equal for the two-sample t-test. The powers were obtained using r program language; wilcox.test() in r base package for Wilcoxon rank sum test, t.test() in r base package for the two-sample t-test, boot.two.bca() in r wBoot pacakge for the bootstrap two-sample test. Simulation results show that the power of Wilcoxon rank sum test is the best for all 330 (n,a,d) combinations and the power of two-sample t-test comes next, and the power of bootstrap two-sample comes last. As the results, it can be recommended to use the classic inference methods if there are widely accepted and used methods, in terms of time, costs, sometimes power.

The diarylsilyl compound, C₁₄H₁₂Br₄Si, was prepared from the reaction of 3,5-dibromophenyllithium with dimethyldichlorosilane, (CH₃)₂SiCl₂, at -78 ℃, can be a good synthon for derivatization to produce efficient host materials for organic light emitting diodes (OLEDs). Crystal structure analysis shows a slight deviation from ideal tetrahedral symmetry around the Si atom, whose conformation is effective in ensuring the maximum separation of the two phenyl rings and the two methyl substituents. The directions of the two aromatic rings are almost perpendicular to each other. The molecule exists as a monomer in the solid state.

Metabus, currently represented by Second Life on the Internet, is the next-generation 3DCG Internet world in which the 2D Internet world has evolved, and has grown as a new ICT culture of mankind that can replace real society with virtual society. As such, the reason why the world of metabus has rapidly expanded is that the era of 3D Internet has arrived due to the evolution of the Internet, which only used information, and the spread of 5G communication in user-participating WEB. However, there are many situations in which laws do not exist in this virtual world and various illegal acts occur. As the Internet culture developed earlier, illegal activities by users began to appear, and as the legal responsibility of Internet providers was discussed, mankind quickly passed the Millennium Copyright Act or introduced new copyright protection measures such as technical protection, transmission rights, and rights management information. Therefore, this paper reviews and studies how to accept and further grow this new metabus culture, including the viewpoint of intellectual property.

Metabus, a three-dimensional virtual environment for digital communication, has gained a lot of attention recently. Even so, there are still many unanswered questions about the user's consciousness and behavior. A difference in nature from conventional digital communication is also unclear. This paper aims to study Metabus on a hypothetical premise by organizing the possibility of Metabus for communication activation based on a research project aimed at using Metabus to support the formation of a community of school dormitories and studio rental residents. After reviewing the establishment process and application cases of Metabus, we focus on the character (avatar) used as the user's alter ego within the metabus, which will allow customization of both form and content different from text-based communication. The "physicality" and the "spatiality" of the metaverse and the "immersion" they bring are among the most important, functional innovations. Based on this summary, a case of using metabuses will be reviewed to describe the research plan aimed at supporting community formation.

본 논문은 기존의 도시개발정책에서 경제적 관점에서 가치의 중심을 두었다면 4차산업혁명시대에는 서비스적 가치변환을 추구하고 있다. 시공간을 공유하는 사람 중심의 공간 서비스요, 가치의 용광로가 메타버스라고 한다면, 오징어게임과 같은 게임이론이 접목된 도시의 미래상을 고려할 필요가 있다. 4차산업 기술과 서비스가 사회로 침투되면서 도시의 공간 인프라, 동산 부동산, 객체들을 물리적공간과 가상공간에서 인공지능과 빅데이터 분석이 개입된 각종 형태와 형식의 컨텐츠가 입체적으로 생동감을 얻게 되었다. 특히, 코로나19을 맞아 메타버스기반 서비스가 대중들에게도 접근하기 시작하면서 지금까지 경험하지 못했던 메타버스 시민의 역할에 대한 필요성이 대두하게 되었다. 4차산업혁명시대의 스마트도시, 메타버스와 게임이론을 연구하였다.