• The KIPS Transactions:PartD
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• v.9D no.6
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• pp.1063-1070
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• 2002

With a remarkable growth and expansion of Internet, the security issues emerged from intrusions and attacks such as computer viruses, denial of services and hackings to destroy information have been considered as serious threats for Internet and the private networks. To protect networks from intrusions and attacks, many vendors have developed various security systems such as firewalls and intrusion detection systems. However, managing these systems individually demands too much work and high cost. Thus, integrated and autonomous security management for various security products has become more important. In this paper, we present the architecture of the WISMSF (Web-based Integrated Security Management System for Firewalls) and the merits of centralized approach for managing heterogeneous firewalls and implement the prototype of the central policy database that is a component of the WISMSF engine. The WISMSF engine supports an integrated view for policies, the integrity of polities and the easy recovery and addition of policies. And also, we define the policy conflicts of WISMSF and present the policy recovery process to support to the policies consistence.

• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.356-366
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• 2007

In this paper a methodology is developed to prioritize replacement of water distribution pipes according to the economical efficiency of replacement and assess the long-term effects of water main replacement policies on water distribution systems. The methodology is implemented with MATLAB to develop a computer algorithm which is used to apply the methodology to a case study water distribution system. A pipe break prediction model is used to estimate future costs of pipe repair and replacement, and the economically optimal replacement time of a pipe is estimated by obtaining the time at which the present worth of the total costs of repair and replacement is minimum. The equation for estimating the present worth of the total cost is modified to reflect the fact that a pipe can be replaced in between of failure events. The results of the analyses show that about 9.5% of the pipes in the case study system is required to be replaced within the planning horizon. Analyses of the yearly pipe replacement requirements for the case study system are provided along with the compositions of the replacement. The effects of water main replacement policies, for which yearly replacement length scenario and yearly replacement budget scenario are used, during a planning horizon are simulated in terms of the predicted number of pipe failures and the saved repair costs.

• Journal of Information Processing Systems
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• v.7 no.2
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• pp.299-320
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• 2011

The overhead of processing fine-grain tasks on a grid induces the need for batch processing or task group deployment in order to minimise overall application turnaround time. When deciding the granularity of a batch, the processing requirements of each task should be considered as well as the utilisation constraints of the interconnecting network and the designated resources. However, the dynamic nature of a grid requires the batch size to be adaptable to the latest grid status. In this paper, we describe the policies and the specific techniques involved in the batch resizing process. We explain the nuts and bolts of these techniques in order to maximise the resulting benefits of batch processing. We conduct experiments to determine the nature of the policies and techniques in response to a real grid environment. The techniques are further investigated to highlight the important parameters for obtaining the appropriate task granularity for a grid resource.

• Smart Structures and Systems
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• v.22 no.2
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• pp.151-159
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• 2018

Maintenance activities are regarded as a key part of the repairable deteriorating system because they maintain the equipment in good condition. In practice, many maintenance policies are used in engineering fields to reduce unexpected failures and slow down the deterioration of the system. However, in traditional maintenance policies, maintenance activities have often been assumed to be performed at the same time interval, which may result in higher operational costs and more system failures. Thus, this study presents two non-periodic preventive maintenance (PM) policies for repairable deteriorating systems, employing the failure rate of the system as a conditional variable. In the proposed PM models, the failure rate of the system was restored via the failure rate reduction factors after imperfect PM activities. Operational costs were also considered, which increased along with the operating time of the system and the frequency of PM activities to reflect the deterioration process of the system. A numerical example was provided to illustrate the proposed PM policy. The results showed that PM activities performed at a low failure rate threshold slowed down the degradation of the system and thus extended the system lifetime. Moreover, when the operational cost was considered in the proposed maintenance scheme, the system replacement was more cost-effective than frequent PM activities in the severely degraded system.

• The Journal of Fisheries Business Administration
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• v.34 no.2
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• pp.1-25
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• 2003

During the past 100 years, Korean fisheries management policies have enforced the license system, it is the most typical regulation system in Korean fisheries. Even now, it has caused resource management failure, it has also invited economic inefficiency and inequity. Accordingly, the Korean government has recently introduced the self-regulatory management system for fishermen with the TAC system. These systems are one of the most market-oriented regulation systems in fisheries management systems. It is defined as regulatory policy tools other than regulations with command and control approach. It is also called “alternatives” which is composed of regulatory alternatives and non-regulatory alternatives. The self-regulatory management system and the ITQ system are cooperative-based co-management between government and fishermen as an alternative management strategy ; it is gaining the increasing attention to improve the effectiveness of fisheries management in Korea. It is expected not only to positively improve function in fisheries regulation, but also to decrease inefficiency in fisheries policies. However, these systems have many problems. The monopolization of rent is one of the typical examples. As solutions for the problem in the aspect of fishery management, fisheries policy is need of approach to industrial organization. For instance, Contestable market theory is one of the good theoretical background, it mean that market is able to free entry and free exit. Thus, fisheries management carry out policies such as revitalization of the used market of capital goods in fisheries, organize of the self-regulatory management group. Conclusively, as the exploiters and managers, fishers and the government should put emphasis on improving economic efficiency so that fishery would grow as an industry that contributes to the increase of social welfare, and the change to that direction will be the only way for our fisheries to preserve its importance.

• Journal of the Korean Professional Engineers Association
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• v.37 no.6
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• pp.54-57
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• 2004

This study attempts to review the theories and systems related to the policy for scientific and engineering human resources, to delve into the relevant documents and case studies, to carry out a survey, and to compare the Korean situation with those of advanced countries. This will verify the problems in current policies and help draw up the plans for future policies.

• Journal of applied mathematics & informatics
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• v.29 no.1_2
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• pp.469-474
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• 2011

In a M/G/I queue where the server alternates between busy and idle periods, we assume that firstly customers arrive at the system according to a Poisson process and the arrival process and customer service times are mutually independent, secondly the system has infinite waiting room, thirdly the server utilization is less than 1 and the system has reached a steady state. With these assumptions, we analyze waiting times on the systems where some vacation policies are considered.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.41
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• pp.243-254
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• 1997

The fast changes of business environment make the enterprise filled with many problems which have to be solved. Productivity is a measure of the organizational performance, especially in manufacturing activities. The purpose of this paper is to measure the value-added productivity of the firms, to identify the characteristics and the relationship between key variables which affect the value-added productivity and also to study the alternative policies of productivity improvement elements which increase productivity effectiveness.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.138-143
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• 1989

In considering the singularities of robot, singularity avoidance control of robot wrist is very important. Because it is more difficult structurally to exclude the wrist singularity than the arm singularity. Since control policies with Jacobian may bring about mathematical singularities, control policies with Euler parameters that never cause mathematical singularities are necessary. In this research, singular status of robot wrist was analyzed and control algorithms for 3 and 4 axes robot wrist were proposed. Application results of the proposed control algorithms to the path including singularity showed us usefulness and validity.

• Journal of Digital Contents Society
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• v.1 no.1
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• pp.23-37
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• 2000

EDI is basically the concept of computer-to-computer exchange of messages relating to various types of activities or business areas, such as banking, trade, medicine, publishing, etc. Therefore, security, reliability and special functionality will be implicit requirements of EDI systems. We will design access control model to content security of these requirements. Access controls in information systems are responsible for ensuring that all direct access to the entities occur exclusively according to the access modes and rules fixed by security policies. On this paper, security policies for access control model are presented from the viewpoints of identity-based, rule-based, role-based policy. We give a design of access control model for secure EDI service based on the derived access control rules and operations to enforce the defined security policies. The proposed access control model provides integrity, confidentiality and a flow control of EDI messages.