• Journal of Internet Computing and Services
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• v.5 no.1
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• pp.67-84
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• 2004

Real-time database systems (RTDBS) are database systems whose transactions are associated with timing constraints such as deadlines. Therefore transaction needs to be completed by a certain deadline. Besides meeting timing constraints, a RTDBS needs to observe data consistency constraints as well. That is to say, unlike a conventional database system, whose main objective is to provide fast average response time, RTDBS may be evaluated based on how often transactions miss their deadline, the average lateness or tardiness of late transactions, the cost incurred in transactions missing their deadlines. Therefore, in RTDBS, transactions should be scheduled according to their criticalness and tightness of their deadlines, even If this means sacrificing fairness and system throughput, And It always must guarantee preceding process of the transaction with the higher priority. In this paper, we propose an efficient real-time scheduling algorithm (Multi-level EFDF) that alleviates problems of the existing real-time scheduling algorithms, a real-time concurrency control algorithm(2PL-FT) for firm and soft real-time transactions. And we compare the proposed 2PL F[ with AVCC in terms of the restarting ratio and the deadline missing ratio of transactions. We show through experiments that our algorithms achieve good performance over the other existing methods proposed earlier.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.12
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• pp.149-158
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• 2005

This paper proposes a congestion avoidance algorithm which provides stable throughput and transmission rate regardless of buffer size by limiting the TCP congestion window in fixed bandwidth networks. Additive Increase, Multiplicative Decrease (AIMD) is the most commonly used congestion control algorithm. But, the AIMD-based TCP congestion control method causes unnecessary packet losses and retransmissions from the congestion window increment for available bandwidth verification when used in fixed bandwidth networks. In addition, the saw tooth variation of TCP throughput is inappropriate to be adopted for the applications that require low bandwidth variation. We present an algorithm in which congestion window can be limited under appropriate circumstances to avoid congestion losses while still addressing fairness issues. The maximum congestion window is determined from delay information to avoid queueing at the bottleneck node, hence stabilizes the throughput and the transmission rate of the connection without buffer and window control process. Simulations have performed to verify compatibility, steady state throughput, steady state packet loss count, and the variance of congestion window. The proposed algorithm can be easily adopted to the sender and is easy to deploy avoiding changes in network routers and user programs. The proposed algorithm can be applied to enhance the performance of the high-speed access network which is one of the fixed bandwidth networks.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.2
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• pp.16-27
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• 2017

IEEE 802.15.6 standard, a Wireless Body Area Network, aims to transfer not only medical data but also non-medical data, such as physical activity, streaming, multimedia game, living information, and entertainment. Services which transfer those data have very various data rates, intervals and frequencies of continuous access to a medium. Therefore, an efficient anti-collision operations and medium assigning operation have to be carried out when multiple nodes with different data rates are accessing shared medium. IEEE 802.15.6 standard for CSMA/CA medium access control method distributes access to the shared medium, transmits a control packet to avoid collision and checks status of the channel. This method is energy inefficient and causes overhead. These disadvantages conflict with the low power, low cost calculation requirement of wireless body area network, shall minimize such overhead for efficient wireless body area network operations. Therefore, in this paper, we propose a medium access scheduling scheme, which adjusts the time interval for accessing to the shared transmission medium according to the amount of data for generating respective sensor node, and a priority control algorithm, which temporarily adjusts the priority of the sensor node that causes transmission concession due to the data priority until next successful transmission to ensure fairness.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.1 s.343
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• pp.111-120
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• 2006

In this paper, a node architecture of WDM metro network for connecting broadband access networks to converge wire/wireless networks. In consideration of the proposed node architecture and network requirements we proposed and evaluated medium access control protocols. We review WDM related technologies of sub-carrier multiplexing and optical components in order to resolve the bottleneck between optical backbone networks md access networks, and a access node architecture sharing common wavelength is introduced. Source-stripping (SS) MAC protocol Is evaluated under the proposed functional node architecture. DS+IS (Destination-Stripping and Source-Stripping) and DS+IS (Destination-Stripping and Intermediate-Stripping) MAC protocols are described to increase the slot-reuse factor which is low on SS MAC protocol. The key function of new MAC protocols regards the optical switch module of proposed node architecture and helps intermediate or source access nodes for dropping slots to destinations of different wavelength group. Thus, slot-reuse factor increases as the MAC protocols reduce the unnecessary ring-rotation of transferred slots. We use a numerical analysis to expect bandwidth efficiency and maximum throughput by slot-reuse factor Throughput network simulation, the verification of throughput, queuing delay, and transmission fairness are compared among MAC protocols.

• Information Systems Review
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• v.18 no.3
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• pp.1-29
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• 2016

The radical changes in the business environment have motivated firms to exert serious efforts in managing sustainable development. This study identified the effects of sustainable development on the perceived performance of firms from the viewpoint of the balanced scorecard. Independent variables include economic efforts (of efficiency and ethic of accounting and fairness), environmental efforts (management and energy control), and social efforts (consumer protection and contribution for local community). The result from the analysis of data collected in this research suggests that sustainable development efforts are the critical sources of the incorporated performance of firms. The consumer protection efforts of the local community determine the competitiveness of a firm in managing social responsibility and creating value and social activities. Efforts to reconsider efficiency determine the competitiveness of a firm, becoming the critical factors that determine sustainable performance. Energy control facilitates value creation for the environment through cooperation and harmonization with nature, resulting in sustainable business performances through the vitalization of practical establishments and operations. Sustainable management needs to meet international standards, cooperation, and harmony. These standards are based on the economic, environmental, and social efforts that enable firms to adopt sustainable management efforts that are suitable for their own systems.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.15 no.1
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• pp.38-53
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• 2007

In a seminal judgment of November 2002 (Case C-476/98) relating to the compatibility with Community laws of the 'nationality clause' in the 1996 amending protocol to the 1955 U.S.-German Air Services Agreement, the European Court of Justice(ECJ) decided that the provision constituted a measure of an intrinsically discriminatory nature and was thus contrary to the principle of national treatment established under Art. 52 of the EC Treaty. The Court, rejecting bluntly the German government' submissions relying on public policy grounds(Art. 56, EC Treaty), seemed content to declare and rule that the protocol provision requiring a contracting state party to ensure substantial ownership and effective control by its nationals of its designated airlines had violated the requirement of national treatment reserved for other Community Members under the salient Treaty provision. The German counterclaims against the Commission, although tantalizing not only from the perusal of the judgment but from the perspective of international air law, were nonetheless invariably correct and to the point. For such a clause has been justified to defend the 'fundamental interests of society from a serious threat' that may result from granting operating licenses or necessary technical authorizations to an airline company of a third country. Indeed, the nationality clause has been inserted in most of the liberal bilaterals to allow the parties to enforce their own national laws and regulations governing aviation safety and security. Such a clause is not targeted as a device for discriminating against the nationals of any third State. It simply acts as the minimum legal safeguards against aviation risk empowering a party to take legal control of the designated airlines. Unfortunately, the German call for the review of such a foremost objective and rationale underlying the nationality clause landed on the deaf ears of the Court which appeared quite happy not to take stock of the potential implications and consequences in its absence and of the legality under international law of the 'national treatment' requirement of Community laws. Again, while US law limits foreign shareholders to 24.9% of its airlines, the European Community limits non-EC ownership to 49%, precluding any ownership and effective control by foreign nationals of EC airlines, let alone any foreign takeover and merger. Given this, it appears inconsistent and unreasonable for the EC to demand, $vis-{\grave{a}}-vis$ a non-EC third State, national treatment for all of its Member States. The ECJ's decision was also wrongly premised on the precedence of Community laws over international law, and in particular, international air law. It simply is another form of asserting and enforcing de facto extraterritorial application of Community laws to a non-EC third country. Again, the ruling runs counter to an established rule of international law that a treaty does not, as a matter of principle, create either obligations or rights for a third State. Aside from the legal problems, the 'national treatment' may not be economically justified either, in light of the free-rider problem and resulting externalities or inefficiency. On the strength of international law and economics, therefore, airlines of Community Members other than the designated German and U.S. air carriers are neither eligible for traffic rights, nor entitled to operate between or 'free-ride' on the U.S. and German points. All in all and in all fairness, the European Court's ruling was nothing short of an outright condemnation of established rules and principles of international law and international air law. Nor is the national treatment requirement justified by the economic logic of deregulation or liberalization of aviation markets. Nor has the requirement much to do with fair competition and increased efficiency.

• Journal of Korean Academy of Nursing Administration
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• v.5 no.3
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• pp.425-444
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• 1999

The purpose of this study is to survey evaluation of the nurse on the current Performance Appraisal System. the need for future performance of the nurse and the opinions about the job rotation, and suggest the direction of improvement by obtaining basic data to improve personnel management of the nurse in a hosipial, the subject of the investigation. The study was conducted self-reporting questionniare survey of 330 nurses working at C hospital located in Chonbuk Province and the data was collected from May 4. 1999 through May 14. The research used measuring instrument developed by researcher for evalution about the present performance appraisal. the need for the future performanc appraisal system and the opinion of job rotaion. The analysis of the collected data was computerized using SPSS/PC+ program, calculated frequency, percentage, the mean and standard deviation and used Pearson, s Correlation Coefficients, t-test, chi- square test. Major findings are as follows. 1) As for the purpose of the current performanc appraisal, the appraiser recognized it as a security of promotion standard, while the employee saw it as a means for control as guidance and supervison of work. 2) With regard to use the result of the present performance appraisal, appraiser picked ambiguous appraisal standard, employees recognized unilateral evaluation of superior eliminated the participation of them as the highest priority. 3) In relation to the current criteria for promotion of the nurse, both appraisers and employees placed more weight on the length of clinical than performance appraisal score. 4) There is much possibility of the appraiser making an error to evaluate considering the length of performance appraisal. 5) Both appraisers and employees indicated that prospective result of performance appraisal should be used for the ability development & motivation of the individual. 6) Concerning employee's participation for performance appraisal both sides wanted by far more participation. 7) Regarding the most ideal appraisal method, both parties favored most the way added up the evaluation of the head nurse and peer review and followed by the manner the revaluation of the head nurse by considering self-evaluation. 8) As to the individual interview after the appraisal, more than 60% of appraisers responded it's not necessary, while above 88.5% of employees answered it is essential so that it is showed significantly difference between the appraisers and the employees. 9) As far as open of the evaluation result is concerned. 75% of the appraiser were against it but 80% of the employee were for it so that it showed significantly between them. The most principal reason that the employee want is that it motivates the individual's ability development and the fairness of the appraisal increases. 10) Whether the periodical rotation is necessary or not, 80% of appraisers and employees answered it's necessary, however, over 70% of them did not want the rotation. 11) Work-group Cohesiveness level within the nursing unit was attentive different from desire of the rotation, that is, the work group cohesiveness level of nurses wanting rotation was significantly lower than that of the group not desiring it.

• Korean Security Journal
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• no.59
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• pp.161-188
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• 2019

Not much is known about the factors of North Korean refugees willingness to report crime. Based on the survey of 800 North Korean refugees living in the metropolitan area of South Korea, this study examined the theoretical factors influencing North Korean refugees' willingness of reporting crime. Focusing on the legal cynicism, procedural justice, and the behavior of law theory, this research verified that procedural justice model is most important in explaining their willingness to report crime. Variables under procedural justice model(i.e., perceived fairness of the law, confidence in the law, and perceived necessity of the law) were significant in an expected direction. On the other hand, most of the hypotheses based on social conditions derived from the five types of stratification, morphology, culture, organization, and social control presented by Donald Black (1974) showed no significant effects on the intent to report crime among North Korean refugees. Implications for research and policies were discussed based on the findings.

• Korean journal of communication and information
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• v.81
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• pp.122-152
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• 2017

The media movement is a movement to separate from the political power and to dismantle the media power and to seek the control of citizens' media. Political power is the biggest factor that violates the fairness and independence of the media in the public domain. On the other hand, the factor that interferes with the healthy and responsible media of the press in the private sector is the media power originating from the owner. Citizens 'media campaign emphasizes citizens' mobility as a subject that monitors the political power and media power that have the sovereignty of the media belonging to the citizen and may infringe on this sovereignty.In the Lee Myung Bak - Park Geun Hye regime, the civil press movement was a period of resistance and struggle. Citizen media campaigns have completely collapsed with governance. As a result, the intellectuals who have expertise in the media have lost their place in the discussion and presentation of the policy alternatives in which the policy production is centered. The influence of citizen media organizations, which are centered on activists rather than citizen's direct action, is limited. In order to strengthen the power of the media reform, it is necessary to reconstruct social forces such as civil society, media unions, media organizations and political forces. We should also look for various ways in which citizens can participate actively in the agenda and activities of the movement. In addition, it is necessary to expand the movement of the media.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.6B
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• pp.588-603
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• 2003

In this paper, we propose an Aggregate Three Color Marker without per flow management which is required for an Edge router to improve End-to-End QoS of Assured Service in DiffServ. Proposed Aggregate Three Color Marker is used with the Adaptive RIO-DC scheme to achieve the minimum rate guarantee without per flow management. Assuming that the admission control for Assured Service has been performed, proposed Aggregate Three Color Marker measures incoming In-profile traffic rate at the output link of an edge router using a token-bucket with a token rate equal to the sum of contracted rates of admitted flows passing the edge router. If there are token losses from the token bucket, out-of-profile packets are promoted to Yellow packets within the aggregate traffic profile. And yellow packets are demoted to out-of-profile packets at the input link to an Edge router fer the purpose of fairness maintenance. In-profile packets and Yellow packets are processed identically at the RIO-DC buffer management scheme in our proposed method. Simulation results show that through using proposed Aggregate Three Color Marker with the Adaptive RIO-DC scheme, the minimum rate guarantee for Assured Service can be achieved without per flow management at multiple DiffServ domains.