• Title/Summary/Keyword: System Calls

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A study of the enhanced ATM cell transmission in satellite communication system using variable-size block interleaving (위성망에서 가변블록 인터리빙 기법을 이용한 ATM 셀 전송 성능향상에 관한 연구)

  • 김은경;김낙명
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.5
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    • pp.1-10
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    • 1998
  • Satellite communication is getting more important in the coming 21st century because of its wide areas sevice capability, ease of access, and fast channel establishment. As such, satellite communication networks will be the basis of the global communication system in cooperation with the ground ATM networks. In this paper, we consider an efficient transmission methodology of ATM cells over the satellite communication channel. We first analyze possible bottlenecks and performance deterioration factors in the case, and then propose an enhanced cell trasmission mechanism. In order to use satellite channel for ATM cell transmission, the application of complicated channel coding is inevitable. However, the forwared error control such as convolutional encoding brings forth burst errors, which calls for the application of some kind of interleaving mechanism to randomize the burst errors at the receiver. Another aspect which should b econsidered in satellite communication system is the inherent transmission delay, which can be very considered in satellite communication system is te inherent transmission delay, which can be very critical to the delay-sensitive ATM traffic. Therefore, we propose that the processing delay at the block interleaving stage should be controlled propose a variable-size block interleaving mechanism which utilizes the predicted transmission delay for each traffic in the queues of the transmitter. According to the computer simulation, the proposed mechanism could improve the overall performance by drastically reducing the ATM cell drop rate owing to the excessive transmission delay.

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Development and Implementation of Training Program for Information System Design Using Material Requirements Planning

  • Yamazaki, Tomoaki;Yin, Rui;Kawaguchi, Seisuke;Hayasaka, Hirotatsu;Matsumoto, Toshiyuki;Ichikizaki, Osamu;Kanazawa, Takashi
    • Industrial Engineering and Management Systems
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    • v.11 no.3
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    • pp.255-265
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    • 2012
  • Environments surrounding production sites have changed greatly in recent years. Accommodating environmental changes calls for the design and development of information systems that center on production lines. There is a need for a training program that teaches learners to understand the particulars of an operation and apply that knowledge to an information system. In this research, we used material requirements planning (MRP) as the subject for which basic skills are to be taught and developed an MRP exercise-based training program. The program is designed for 13 lectures of 90 minutes each, and it consists of MRP exercises, modeling methods to represent them, the use of a programming language for system development, and finally, evaluation of the exercises. Lecture materials are described in 505 lecture slides using Microsoft PowerPoint to allow visualization of topics through graphs and models. The developed training program was then delivered to 86 college students, and its results were measured through quizzes to verify educational effectiveness.

An Empirical Study on Evaluating the Value of Port (항만가치의 평가에 관한 연구)

  • 김태균;문성혁;노홍승
    • Journal of Korean Society of Transportation
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    • v.19 no.6
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    • pp.75-87
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    • 2001
  • Inter-port competition is fiercer than in the past because of technological evolution in transport systems : the increasing side of containerships implies only a few calls in three or four ports at each end of the trade and the rest of the traffic being served by smaller feederships. It is therefore essential for big ports to be selected as one of these calls by the main shipowners, consortia and alliances to avoid rmarginalisation. In order to compete effectively, many ports have been obliged to modernise and extend considerably its existing ports or to build new port facilities. With the advent of major environmental legislation around the world, however, amenities such as fish and wildlife, clean air and water, access to the waterfront, and view protection took on greater importance. Ports are now being forced to incorporate environmental considerations into their planning and management functions in order to avoid additional costs or timing delays. The aim of this paper is to analyse the port value by which port comparison(or selection) will be made with HFP(Hierarchical Fuzzy Process) method. This was done by extracting and grouping the evaluation factors of port value by port experts : facility and location factor, logistics service factor environment and amenity factor, city and economic factor, and human and system factor. For empirical test of this method, 6 major ports in Northeast Asia were chosen and analysed. The order of importance for five evaluation factors were 1) facility and location factor 2) logistics service factor 3) human and system factor, 4) city and economic factor, and 5) environment and amenity factor. This means that geographical location and logistics services are still being considered as the most important factor to call the port by port users. even though environment and amenity factor shows relatively low figure. Among 6 major ports, Port of Kobe was ranked the first position in a comprehensive evaluation, while Ports of Busan and Kwangyang were 4th and 5th respectively. This implies that Port of Busan should make much efforts to enhance the existing facilities as well as management system.

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Generation of Finite Automata for Intrusion Detection (침입탐지를 위한 유한상태기계의 생성 기법)

  • Lim, Young-Hwan;Wee, Kyu-Bum
    • The KIPS Transactions:PartC
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    • v.10C no.2
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    • pp.119-124
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    • 2003
  • Although there have been many studies on using finite automata for intrusion detection, it has been a difficult problem to generate compact finite automata automatically. In a previous research an approach to profile normal behaviors using finite automata was proposed. They divided the system call sequence of each process into three parts prefix, main portion, and suffix, and then substituted macros for frequently occurring substrings. However, the procedure was not automatic. In this paper we present algorithms to automatically generate intrusion detection automata from the sequence of system calls resulting from the normal runs of the programs. We also show the effectiveness of the proposed method through experiments.

3D Analysis System for Copper Palate Defect Detection (동판의 결함 검출 위한 3차원 분석 시스템 개발)

  • Oh, Choon-Suk
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.1
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    • pp.55-62
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    • 2013
  • Automatic inspection system is required for increment of copper plate production and demand expansion. Thus 3D surface form and defect detection of copper plate calls for 3D image and GUI analysis. Limitation of 2D analysis, such as error occurrence and decision difficulty makes eye inspection automatic. Automatic inspection is able to raise accurate inspection rate and productivity efficiency elevation. In this paper defect classification is defined and inspection system is implemented. Defect analysis algorithms and GUI for 3D image analysis is developed and tested.

A Study on the System of Litigation and Ideal Dispute Resolution (소송제도와 이상적인 분쟁해결제도에 관한 연구 - 대법원의 상고법원 설치안을 중심으로 -)

  • SHIN, Han-Dong
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.68
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    • pp.43-63
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    • 2015
  • The number of final appeal(the rate of final appeal: 43%) has been on the increase every year over the past ten years in Korea. The number of final appeal cases given to a justice of the Korean Supreme Court amounts to nearly one everyday, which makes it vulnerable to faulty decisions. Reversal rate of final appeal is as low as 10% with most of the cases being dismissed and hence the percentage of people having trust in the judiciary is merely 27%. In this context, the Korean judiciary has announced its plan to set up a final appellate court in the Supreme Court. The establishment of final appellate court, however, is not only against the Constitution but also hardly seen in other nations. It would only overexpand the Supreme Court. Furthermore, the final appellate court would end up deteriorating into the court of fourth instance and impose extra burden on the government as well as on the disputing parties. Therefore, it is necessary to upgrade the quality of the court by increasing the number of judges in the lower court and let them focus on the fact finding process. Facilitating the ADR(Alternative Dispute Resolution) process such as arbitration would help improve the structure of the judiciary. The incompatibility among the four values of the dispute resolution process(equitability, truth, quickness and efficiency) calls for building comprehensive judicial system in which disputes are settled by choosing either jurisprudence or utility.

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Roles of Korean Medicine in Restructuring Public Health Service of Korea ((참여)정부의 보건의료 Infra개편과정에서 한의학의 참여방안 -공공의료를 중심으로-)

  • Lee, Sun-Dong
    • Journal of Society of Preventive Korean Medicine
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    • v.9 no.2
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    • pp.17-41
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    • 2005
  • Current Korean medical system is evaluated as inefficient and the government is planning a new medical development plan to provide guaranteed life-long medical service and more efficient medical system Korean medicine also needs to participate as the primary medical provider and strengthen public recognition. The needs for active participation are essential to prevent irrational medical policies and Korean medicine can exercise medical merits. When the doctors of Korean medicine are recognized as the primary medical provider, not only social rights are served but also provide medical service to less privileged sector of the society. This calls for the establishment of system for attending physician and public health doctor from Korean medicine. Another important issue is the establishment of public medical service at the government level. Doctors of Korean medicine should be posted at the national health center and other public hospitals. Revision of the current policies on Korean medicine must be made to yield concrete outcome of the public Korean medicine service as well as cooperation between the conventional allopathic medical community and the Korean medical community

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Coupling Metrics Including Indirect Dependency for Object-Oriented Systems (객체지향 시스템에서 간접 의존성을 포함한 결합도 메트릭)

  • Yoo, Moon Sung
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.7 no.3
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    • pp.37-42
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    • 2011
  • Nowadays software developers are moving from conventional software process technologies to the object-oriented paradigm. To develope the object-oriented softwares efficiently, various software metrics have been suggested. Coupling refers to the degree of independence between components of the system. It has long been well known that good software practice calls for minimizing coupling interaction. Many researches have been studied coupling metrics of the object- oriented systems. We review Chidamber and Kemerer's work & Li's work. In this paper, we study the coupling of the overall structures of object-oriented systems by analyzing the class diagram of UML. We propose four coupling metrics for object-oriented softwares. First, we use an established coupling metric for object- oriented systems as a basic coupling metric. Then we modify the basic coupling metric by including indirect coupling between classes, We also suggest two relative coupling metrics to measure coupling between subsystems. We investigate the theoretical soundness of the proposed metrics by the axioms of Briand et al. Finally, we apply the presented metrics to a practical case study. This coupling metric will be helpful to the software developers for their designing tasks by evaluating the coupling metric of the structures of object-oriented system and redesigning tasks of the system.

An Empirical Study on the Critical Success Factors of Business to Business e-Procurement System (B2B 전자조달시스템의 핵심성공요인(CSF) 도출을 위한 실증분석)

  • Lee, Sang-Jin;Shin, Seoung-Man
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.47
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    • pp.239-260
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    • 2010
  • The purpose of this study would like to investigate the critical success factors of the e-procurement which means on-line purchase of goods and services for organizations. This action represents one of the largest expense items in a firm's cost structure. In order to draw CSFs of e-procurement system, we have surveyed questionnaire to the related firms. The basic variables used in this survey are taken from many precedent researches in relation to the e-procurement. On the other hand, the research data is collected from companies which had used the MRO e-marketplace. Through factor analysis of those data, four-factor resulted as follows: (1) factor one suggests the rationalization of the firm's management of its suppliers; (2) factor two calls for redesigning affected business processes and influencing end-user/employee procurement-related behaviors; (3) factor three refers to carefully orchestrating an e-procurement technology planning process with one's suppliers and using intelligence in designing the software and mining the data it produces; and (4) factor four relates to selecting an e-procurement solution and/or simultaneously participating in a number of electronic environments supporting e-procurement. In conclusion, these four factors are regarded as critical success factors for the application of e-procurement system and then suppliers should take care the effective planning of e-procurement structure.

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In vitro Nasal Cell Culture Systems for Drug Transport Studies

  • Cho, Hyun-Jong;Termsarasab, Ubonvan;Kim, Jung-Sun;Kim, Dae-Duk
    • Journal of Pharmaceutical Investigation
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    • v.40 no.6
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    • pp.321-332
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    • 2010
  • Growing interest in the nasal route as a drug delivery system calls for a reliable in vitro model which is crucial for efficiently evaluating drug transport through the nasal cells. Various in vitro cell culture systems has thus been developed to displace the ex vivo excised nasal tissue and in vivo animal models. Due to species difference, results from animal studies are not sufficient for estimating the drug absorption kinetics in humans. However, the difficulty in obtaining reliable human tissue source limits the use of primary culture of human nasal epithelial cells. This shortage of human nasal tissue has therefore prompted studies on the "passage" culture of nasal epithelial cells. A serially passaged primary human nasal epithelial cell monolayer system developed by the air-liquid interface (ALI) culture is known to promote the differentiation of cilia and mucin gene and maintain high TEER values. Recent studies on the in vitro nasal cell culture systems for drug transport studies are reviewed in this article.