• Journal of Communications and Networks
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• v.16 no.2
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• pp.130-139
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• 2014

Due to the unpredictable nature of channel availability, carrying delay-sensitive traffic in cognitive radio networks (CRNs) is very challenging. Spectrum leasing of radio resources has been proposed in the so called coordinated CRNs to improve the quality of service (QoS) experienced by secondary users (SUs). In this paper, the performance of coordinated CRNs under fixed-rate with hard-delay-constraints traffic is analyzed. For the adequate and fair performance comparison, call admission control strategies with fractional channel reservation to prioritize ongoing secondary calls over new ones are considered. Maximum Erlang capacity is obtained by optimizing the number of reserved channels. Numerical results reveal that system performance strongly depends on the value of the mean secondary service time relative to the mean primary service time. Additionally, numerical results show that, in CRNs without spectrum leasing, there exists a critical utilization factor of the primary resources from which it is not longer possible to guarantee the required QoS of SUs and, therefore, services with hard delay constraints cannot be even supported in CRNs. Thus, spectrum leasing can be essential for CRN operators to provide the QoS demanded by fixed-rate applications with hard delay constraints. Finally, the cost per capacity Erlang as function of both the utilization factor of the primary resources and the maximum allowed number of simultaneously rented channels is evaluated.

• Journal of Families and Better Life
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• v.20 no.3
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• pp.49-61
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• 2002

It is shown about the victims of domestic violence in this study that how for them to have made a marriage, what to have been forced them to endure it hitherto and their way to betterment after attending at a institution. In addition, this study approached the side of their family history with a viewpoint of life courses. Some digested stuffs of the results are followed below with the main problems proposed in this research. 1. Most of the female victims for this research had been brought up under normal home conditions besides one of ten victims having lived in their own violent home. On the other hand, many of husbands had been in a poor circumstance, as five of ten ones had grown up with the domestic violence. And it is appeared that anyone of them are not well off now. 2. They were hesitant to break through the wall of violence because of the responsibility of a remarriage(3cases), for their children(4cases), and for fear of divorce(3cases). It was appeared that most of the first violence of them were occurred in six months earlier before marriage and most victims didn't cope with it adequately. 3. The total of 10 women victims, of the former 6 cases, 3 women victims returned to their home with their husbands'authentication of violence-free. Their decision was based on the same reason as they had endured for. And the others were to be out since a termination of the sheltering term, in the course of the divorce suit.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.1
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• pp.12-18
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• 1983

An ecological survey of early childhood nutrition was conducted from January 23 to February 18, to study the feeding method and weaning practice in Whaseong-gun, Kyonggi-do. This study covered a total of 283 children. Seventy three percent of the subjects had been breast-fed; 10% had been bottle-fed; others had been combination-fed before the introduction of supplementary foods. Only 26.9% of the subjects began to be fed supplementary food before the age of 6 months. The supplementary food used most frequently by the majority of children at the beginning of weaning was plain cooked rice; rarely special preparation, or different from the food eaten by the family. As for age of termination of breast feeding, 42.7% of the subjects were before 12 months; 32.8% were between 13 and 18 months of age; 24.5% were more than 19 months old. As for methods of stopping breast feeding, 44.5% of the subjects were naturally terminated while 38.5% were forced to terminate by the application of sticking plaster or medicines to the mother's nipples. The results indicate a need for nutrition and hygiene intervention to improve the weaning practice of rural area through the community nutrition education.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.1
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• pp.67-74
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• 2009

This paper presents a method of improving the service availability by distributing the traffic of voice/data calls over the multi-layer cells in a mobile communication network. The traffic model is described and the call handling performance is analyzed. In our method, a fast moving call is moved to and serviced in the upper layer cell. A call is also moved upward when an overflow occurs. But unlike other methods, the call that is moved upward in the overflow case is the one which has the longest sojourn time in the cell. Moreover, when the call that was moved upward due to overflow condition stays longer than a certain period of time in the upper layer cell, the system moves the call back to the lower layer in order to save the more expensive resources of the upper layer cell. Call handling performance of this method evaluated from M/M/C/K models shows clear improvement with respect to call blocking probability and forced termination probability.

• Journal of Arbitration Studies
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• v.19 no.2
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• pp.49-72
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• 2009

Korea Fair Trade Commission (KFTC), one of the Government agencies, has been preparing a standard model form of Exclusive Contract for Entertainment Management (hereinafter referred to as "Exclusive Contract") to eliminate some types of unfairness that placed entertainers at disadvantage such as forced PR activities or activities without payment, excessive privacy infringement, and exemption of payment after the termination of the exclusive contract. The said Exclusive Contract was drafted by The Korean Commercial Arbitration Board (the "KCAB") in association with the Korean Entertainment Law Society (the "KELS") and KCAB has persistently persuaded Corea Entertainment Management Association (the "CEMA"; mainly actors management) and Korea Entertainment Producers' Association (the "KEPA"; mainly singers management) to adopt the above-mentioned Exclusive Contract, respectively, and especially arbitration clause instead of litigation. After KCAB's tens of meetings and persuasion, they finally decided to accept KCAB's offer and they have submitted the Exclusive Contract drafted by KCAB and KELS to KFTC on April 17, 2009. The arbitration clause drafted by KCAB was already accepted by unfair contract examination division and unfair contract advisory committee and the final standard model contract was supposed to be publicly announced on June 30, 2009 after final examination of unfair contract standing committee, but the announcement has been delayed owing to severe controversies between the concerned parties, such as CEMA, KAU (Korea Artists' Union), KEPA and KSA (Korea Singers' Association) related to delicate issues like contract period and ownership of intellectual properties, etc. But it is expected the announcement will be made very soon by which the contract will include the originally drafted arbitration clause by KCAB. Therefore, it is very timely to examine the various legal issues which can be arisen out of disputes, and arbitration appropriateness with Exclusive Contract of Entertainment Management on this paper.

• Toxicological Research
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• v.8 no.2
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• pp.265-272
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• 1992

Effects of repeated physical exercise on the carbon tetrachloride ($CCl_4$) hepatotoxicity were examined in adult female rats. Rats were introduced into a cylindrical rotating cage and forced to exercise for 1 hr each day, 6days/week, for 5 consecutive weeks at a speed starting from 10m/min, increased by 1m/min per day until the speed reached 27m/min. Significantly less body weight gain was observed in the exercise group suggesting that physical fitness had been induced in these animals. Eighteen hours following termination of the last exercise bout rats were treated with $CCl_4$(2 mmol/kg.ip). The $CCl_4$-induced heptotoxicity was significantly potentiated in the repeated exercise group compared to the resting sedentary animals as determined by changes in serum sorbitol dehydrogenase (SDH), glutamic oxaloacetic transaminase(GOT), glutamic pyruvic transaminase (GPT), and glucose-6-phosphatase(G-6-Pase) activities when measured 24hrs following the $CCl_4$ treatment. Hepatic drug metabolizing activity was determined in order to elucidate the underlying mechanism of potentiating action of the $CCl_4$ hepatotoxicity induced by repeated physical exercise. Repeated exercise increased the hepatic microsomal cytochrome P-450 contents and aminopyrine N-demethylase activity. The results suggest that the potentiation of $CCl_4$ hepatotoxicity by repeated exercise is associated with induction of the mixed function oxidase (MFO) enzyme system mediating the metabolism of $CCl_4$ to its active metabolite(s).

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.6
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• pp.1522-1545
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• 2012

Call admission control (CAC) plays an important role in mobile cellular network to guarantee the quality of service (QoS). In this paper, a dynamic hybrid CAC scheme with integrated cutoff priority and handoff queue for mobile cellular network is proposed and some performance metrics are derived. The unique characteristic of the proposed CAC scheme is that it can support any number of service types and that the cutoff thresholds for handoff calls are dynamically adjusted according to the number of service types and service priority index. Moreover, timeouts of handoff calls in queues are also considered in our scheme. By modeling the proposed CAC scheme with a one-dimensional Markov chain (1DMC), some performance metrics are derived, which include new call blocking probability ($P_{nb}$), forced termination probability (PF), average queue length, average waiting time in queue, offered traffic utilization, wireless channel utilization and system performance which is defined as the ratio of channel utilization to Grade of Service (GoS) cost function. In order to validate the correctness of the derived analytical performance metrics, simulation is performed. It is shown that simulation results match closely with the derived analytic results in terms of $P_{nb}$ and PF. And then, to show the advantage of 1DMC modeling for the performance analysis of our proposed CAC scheme, the computing complexity of multi-dimensional Markov chain (MDMC) modeling in performance analysis is analyzed in detail. It is indicated that state-space cardinality, which reflects the computing complexity of MDMC, increases exponentially with the number of service types and total channels in a cell. However, the state-space cardinality of our 1DMC model for performance analysis is unrelated to the number of service types and is determined by total number of channels and queue capacity of the highest priority service in a cell. At last, the performance comparison between our CAC scheme and Mahmoud ASH's scheme is carried out. The results show that our CAC scheme performs well to some extend.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.235-241
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• 2018

The printout management system should analyze the pattern of existence of personal information (resident number, card number) in the output log and users should be provided with functions such as warning message pop-up, forced printing termination, mailing to administrator, independently logs management. Authentication management can also be performed only by registered users by installing an agent on a user PC, and it should have a restriction function to permit or deny work according to user information. In addition, when printing/copying/scanning using this equipment, it is possible to use document printing and multifunction copier after ID card authentication and ID/PW should be input to device when ID card is not used. In this study, we developed these interfaces with WOWSOFT co., Ltd, a security company that has better technology than the existing printout security methods, to construct the printout management system. Also we designed the interface of basic functions necessary for printout management and contributed to the establishment of printout management system.

• Journal of the Korea Society of Computer and Information
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• v.17 no.6
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• pp.57-66
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• 2012

LTE-Advanced network will form the high-speed IP backbone in collaboration with heterogeneous radio access networks for dynamic optimized resource utilization. In order to implement more innovative and attractive services such as U-Cloud streaming, LBS and mobile smart TV, a mobile terminal needs to support multiple sessions simultaneously. Efficient resource allocation schemes are necessary to maintain QoS of multiple sessions because service continuity may be defected by delay and information loss during handover. This paper proposes a resource allocation scheme to accommodate multiple sessions in a mobile terminal on handover period based on session priority mechanism. Simulation is focused on the forced termination probability of handover sessions. Simulation results show that our proposed method provides a better performance than the conventional method.

• Journal of KIISE:Information Networking
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• v.30 no.3
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• pp.316-328
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• 2003

In this paper, we propose and analyze two adaptive channel allocation schemes for supporting multimedia traffics in hierarchical cellular systems. It is guaranteed to satisfy the required quality of service of multimedia traffics according to their characteristics such as a mobile velocity for voice calls and a delay tolerance for multimedia calls. In the scheme 1, only slow-speed voice calls are allowed to overflow from macrocell to microcell and only adaptive multimedia calls can overflow from microcell to macrocell after reducing its bandwidth to the minimum channel bandwidth. In the scheme II, in addition to the first scheme, non-adaptive multimedia calls can occupy the required channel bandwidth through reducing the channel bandwidth of adaptive multimedia calls. The proposed scheme I is analyzed using 2-dimensional Markov model. Through computer simulations, the analysis model and the proposed schemes are compared with the fixed system and two previous studies. In the simulation result, it is shown that the proposed schemes yield a significant improvement in terms of the forced termination probability of handoff calls and the efficiency of channel usage.