• 한국산학기술학회:학술대회논문집
• /
• 한국산학기술학회 2003년도 Proceeding
• /
• pp.211-215
• /
• 2003

Network security should be first considered in a distributed computing environment with frequent information interchange through internet. Clear classification is needed for information users should protect and for information open outside. Basically proper encrypted database system should be constructed for information security, and security policy should be planned for each site. This paper describes access control, user authentication, and User Security and Encryption technology for the construction of database security system from network users. We propose model of network encrypted database security system for combining these elements through the analysis of operational and technological elements. Systematic combination of operational and technological elements with proposed model can construct encrypted database security system secured from unauthorized users in distributed computing environment.

• 한국산학기술학회:학술대회논문집
• /
• 한국산학기술학회 2003년도 Proceeding
• /
• pp.243-246
• /
• 2003

This system is unionized form about GPS and a pocket game machine. This game machine of the use only for the game with an existing system but the function of various purposes which carries out service relevant to a user's position information. This system have the game function, the function to offer space guidance service by the theme interlocked with a user's position, and the traffic safety education function.

• Communications for Statistical Applications and Methods
• /
• 제27권2호
• /
• pp.163-175
• /
• 2020

We consider a wide class of general weakly-dependent processes, called ψ-weak dependence, which unify almost all weak dependence structures of interest found in statistics under natural conditions on process parameters, such as mixing, association, Bernoulli shifts, and Markovian sequences. For detecting the tail behavior of the weakly dependent processes, change point tests are developed by means of cumulative sum (CUSUM) statistics with the empirical distribution functions of sample extremes. The null limiting distribution is established as a Brownian bridge. Its proof is based on the ψ-weak dependence structure and the existence of the phantom distribution function of stationary weakly-dependent processes. A Monte-Carlo study is conducted to see the performance of sizes and powers of the CUSUM tests in GARCH(1, 1) models; in addition, real data applications are given with log-returns of financial data such as the Korean stock price index.

• 품질경영학회지
• /
• 제26권1호
• /
• pp.126-142
• /
• 1998

Traditional statistical process control(SPC) assumes that consective observations from a process are independent. In industrial practice, however, observations are ofter serially correlated. A common a, pp.oach to building control charts for autocorrelatd data is to a, pp.y classical SPC to the residuals from a time series model fitted. Unfortunately, one cannot completely escape the effects of autocorrelation by using charts based on residuals of time series model. For the detection of variance change in the process we propose a CUSUM of squares control chart which does not require the model identification. The proposed CUSUM of squares chart and the conventional control charts are compared by a Monte Carlo simulation. It is shown that the CUSUM of squares chart is more effective in the presence of dependency in the processes.

• 대한산업공학회지
• /
• 제31권4호
• /
• pp.341-348
• /
• 2005

This paper is concerned with the question of servicing warranties for repairable items. During the warranty period, each time an item fails the manufacturer has the obligation to restore the item to operational condition either by repairing the item or by replacing it with a new item. In this paper, we consider repair-replacement strategies based on the condition of the failed item. For products with phase-type lifetime distributions where the phases represent the condition of the item, we develop algorithms to determine the expected cost of servicing a warranty and use it in making the repair-replacement decision. Illustrative numerical examples are presented. We also propose a dynamic strategy by taking the expected remaining warranty cost into consideration.

• 산업경영시스템학회지
• /
• 제24권69호
• /
• pp.87-92
• /
• 2001

A significant number of all reported accidents in Korea involved education and training Based on the Labor Ministry data, statistics, show the education cause was directly involved in 38% of major accidents, Since safety managers have in charge of safety education at the factory, occupational safety curriculum must be studied to train safety manager effectively. In this study an analysis on relative importance of industrial safety curriculum for a good safety manager was performed by Analytic Hierarchy Process(AHP) The results showed that relative importance of industrial safety curriculum by AHP was safety management(w=0.240) ergonomics and system safety(w=0.201) construction safety(w=0.182) mechanic safety(w=0.139) electronic safety(w=0.134) and chemical safety(w=0.104) in order. The results could be used for industrial safety curriculum planning in university and safety organization such as Korea Occupational safety and Health Agency.

• 한국안전학회지
• /
• 제14권1호
• /
• pp.141-149
• /
• 1999

At present time, industrial accidents statistics are used as the basic data of the policy to prevent industrial accidents and the plan to applicate the industrial accident insurance. But this statistical data is not sufficient for the effective safety management because it is the expression of the itemized distribution and the frequency for the whole cases. This study tried to correlational analysis for each causes by defining investigational items as their accident parameters. The correlational analysis, between the unsafe action and status and their relational causes, was performed to analyze the occurrence causes of industrial accident. And to assume the severity of accident, the correlativity and independency between causes and direct causes which are defined hospital days subordinate parameter were analyzed. In addition, this study expressed numerically the effectiveness of subordinate parameters depended on the level of independent parameter by presenting the predictive model between dependent parameter and independent parameter, which have the categorical parameter, through the Logit analysis method.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2003년도 춘계학술대회
• /
• pp.149-159
• /
• 2003

In this paper, I analyzed the industrial system and agriculture system about safety between korea and australia. An agriculture which is one of the national security industry, has recognized the importance. International country have attention to the automatization of machine for the improvement of agriculture. However, because of modernization of agriculture, the rate of accurrence about agriculture accident has increased dramatically. Especially the rate of accurence of agricultural accident is higher than the other industrial accident in the developed country. Because of these reasons, developed country has efforted to the agriculture systemabout safety. Australia law for the safety system of agriculture is very well and the rate of accident in the self-management agriculture is included in the statistics of industrial but The rate of accident in self-management agriculture is very higher. Korea has many middle size factory to make new goods and factory accurre very many accident. Because Korea government research the theory and practical affairs for the industrial system about safety and health to protect industrial accident In future we have to try new method about Agriculture Safety of Korea.

• Industrial Engineering and Management Systems
• /
• 제11권2호
• /
• pp.176-182
• /
• 2012

This paper presents a new approach to risk comparison in uncertain environment. Based on the uncertainty theory, some uncertain risk measures and risk comparison rules are proposed. Afterward the bridges are built between uncertain risk measures and risk comparison rules. Finally, several comparable examples are given.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제3권2호
• /
• pp.99-106
• /
• 1999

In this paper, the spline hazard rate model to the randomly censored data is introduced. The unknown hazard rate function is expressed as a linear combination of B-splines which is constrained to be linear(or constant) in tails. We determine the coefficients of the linear combination by maximizing the likelihood function. The number of knots are determined by Bayesian Information Criterion. Examples using simulated data are used to illustrate the performance of this method under presenting the random censoring.