• 한국데이타베이스학회:학술대회논문집
• /
• 한국데이타베이스학회 1997년도 International Conference MULTIMEDIA DATABASES on INTERNET
• /
• pp.515-523
• /
• 1997

Maintaining materialized views and/or replica can basically be considered as a client-sewer architecture that extracts the changes of the distributed source data and transfers them to the relevant target sites. View maintenance and materialized views are considered to be important for suggesting solutions to the problems such as a decision support, active databases, a data warehouse, temporal databases, internet applications, etc. In this paper an analysis is addressed that formulates the cost functions and evaluates them as the propagation subjects, objects, and update policies. The propagation subject can be the client side, sewer side, and the third: and the objects can be base tables, semi-base tables, and delta files: And the update policies can be the immediate, deferred and periodic ones, respectively.

• 한국가구학회지
• /
• 제10권1호
• /
• pp.83-93
• /
• 1999

The purpose of this study is to analyze the issues of today's school furniture systems and propose the new standards for tomorrow's school furniture design. For the improvement of the educational environments, the school furniture need to be reformed very badly. The present educational furniture is very falling behind in safety, function, ergonomics and its aesthetics. The classroom tables and chairs should be comfortable in physical and psychological aspects and accommodates the practical use in order to raise the student's efficiency of learning. In this study, the new design and ergonomic standards of the chairs and tables are proposed by comparing other national standards and analyzing the problems of the present educational facilities.

• 응용통계연구
• /
• 제23권4호
• /
• pp.777-781
• /
• 2010

Yates' continuity correction of the chi-squared test for testing the homogeneity of two binomial proportions in $2{\times}2$ contingency tables is developed to lower the value of the test statistic slightly. The effect of continuity correction is expected to decrease as the sample size increases. However, in extremely unbalanced $2{\times}2$ contingency tables, we find some cases where the effect of continuity correction is eccentric and is larger than expected. In such cases, we conclude that the chi-squared test with continuity correction should not be employed as a test statistic in both asymptotic tests and exact tests.

• 한국정밀공학회지
• /
• 제19권5호
• /
• pp.64-71
• /
• 2002

A new model utilizing a transfer function was proposed in the previous paper fur analizing motion errors of hydrostatic tables. Validity of the proposed method was theoretically verified as the calculated motion errors were compared with the results by conventional multi pad method. In this paper, relationship between form error of rail and motion errors of hydrostatic table is analized theoretically in order to comprehand so-called ‘averaging effect of oil film’. Experiments on the motion errors of hydrostatic table is conducted with 3 different rails, and the results are compared with the results calculated by Transfer Function Method. The results show good agreement. From the results, it is verified that TFM is very effective to analize the motion errors of hydrostatic table.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2004년도 추계학술대회 논문집
• /
• pp.672-676
• /
• 2004

In this paper, measuring system of 5 DOF motion errors are proposed using two capacitive type sensor, a straight edge and a laser interfoerometer. Yawing error and pitching error are measured using the laser interferometer, and rolling error is measured by the reversal method using a capacitive type sensor. Linear motion errors of horizontal and vertical direction are measured using the sequential two point method. In this case, influence of angular motion errors is compensated using the previously measured angular motion errors. In the horizontal direction, measuring accuracy is within 0.05 $\mu$m and 0.27 arcsec, and in the vertical direction, it is within 0.15 $\mu$m and 0.5 arcsec. From these results, it is confirmed that the proposed measureing system is very effective to the measurement of 5 DOF motion errors in the ultra precision feed tables.

• 인지과학
• /
• 제15권1호
• /
• pp.25-33
• /
• 2004

본 논문은 자질기반 문법의 LR 파싱 테이블 생성과 관련된 두 가지 문제점을 논의한다. 먼저 자질기반 문법에 LR 파싱 방법을 적용할 경우 발생하는 비종결성 및 비결정성의 문제를 살펴본 후, 이 문제를 해결할 수 있는 LR 방법을 제시한다. 또한 파싱 테이블을 생성하기에는 충분한 정보를 가지지 못하는 하위명시 규칙의 문제점을 지적하고, 이러한 규칙들을 LR 파싱 방법으로 처리할 수 있도록 하는 규칙추론 알고리듬을 제안한다.

• 한국전자통신학회논문지
• /
• 제8권5호
• /
• pp.751-756
• /
• 2013

본 논문은 다기능 학습 커뮤니티 시스템의 설계와 구현에 대한 내용을 다룬다. 본 논문은 다양한 기능을 갖고 있는 온라인 학습 커뮤니티 시스템의 최신동향 및 관련 연구를 분석하였다. 본 시스템의 설계는 시스템 작업 흐름, 시스템 설계 단계의 기능 구분, 데이터베이스 테이블 설계, 시스템 인터페이스 설계를 하였다. 본 시스템은 관리자 모드와 사용자 모드를 구성하여 구현하였으며, 다른 학습 커뮤니티와 기능을 비교 검토하였다.

• 대한산업공학회지
• /
• 제31권4호
• /
• pp.316-333
• /
• 2005

Although some successful recognition algorithms have been developed, most of them did emphasize on extracting accurate interpretations without considerations of manufacturability. Evaluating the manufacturability for multiple features leads to produce the machining sequences. In this paper, the A* algorithm guarantees the optimal setup sequences with minimizing the machining cost. Also, tolerances including surface roughness are converted to STEP formats to be utilized for more reliable process plans. Finally, decision tables are used to create the detailed operational sequences based on geometric tolerances and surface roughness. Machining parameters such as feed, depth of cut, and cutting speed for each operation are added to the routing sheet. Windows are presented to show how the entire system works for a sample part.

• Journal of Information Processing Systems
• /
• 제2권2호
• /
• pp.67-75
• /
• 2006

In order to acquire a precise and quick response to an analytical query, proper selection of the views to materialize in the data warehouse is crucial. In traditional view selection algorithms, all relations are considered for selection as materialized views. However, materializing all relations rather than a part results in much worse performance in terms of time and space costs. Therefore, we present an improved algorithm for selection of views to materialize using the clustering method to overcome the problem resulting from conventional view selection algorithms. In the presented algorithm, ASVMRT (Algorithm for Selection of Views to Materialize using Reduced Table), we first generate reduced tables in the data warehouse using clustering based on attribute-values density, and then we consider the combination of reduced tables as materialized views instead of a combination of the original base relations. For the justification of the proposed algorithm, we reveal the experimental results in which both time and space costs are approximately 1.8 times better than conventional algorithms.

• 보건의료산업학회지
• /
• 제7권3호
• /
• pp.57-69
• /
• 2013

In these days, the interest on health industry is increasing around the world. This paper attempts to estimate the economic effects of the Cosmetic Industrydusing the Input-Output Analysis. Especially, 78*78 Sector Tables were used as the first analysis tool. So then, 79*79 Sector Tables adjusted were used for that industry. The main analysis tools of this study are comparing and analyzing backward and forward linkage effects, the induced effects of the self industry and other industries and the induced coefficients such as product, value-added, job and employment. According to the result of analysis, the cosmetic industry has great economic impacts which affects the major macroeconomic factors such as product, value added and backward linkage effect. And the induced effects of the self cosmetic industry are significant compared to other industries in aspects of product, value-added, and employment.