• Journal of Labour Economics
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• v.44 no.1
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• pp.169-204
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• 2021

We empirically verified whether there are different educational investment behaviors according to university admissions, using the Korean Education and Employment Panel data. The results are as follows; the average annual private education cost and the average amount of time spent studying alone per week of rolling admission type were lower than those of regular admission type. Also, rolling admission applicants had longer leisure and sleeping hours, such as watching TV and using computers. These results show the possibility that the university admission system will change the educational investment behavior. Furthermore, there is a possibility to induce the human capital investment to be made efficiently.

• Journal of The Korean Society of Emergency Medicine
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• v.29 no.6
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• pp.595-602
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• 2018

Objective: The Korean Triage and Acuity Scale (KTAS), which was implemented in 2016, needs to be assessed for its validity and reliability. Here we evaluate the relevance of emergency level assessment by analyzing the validity of KTAS as a Korean standardized triage system. Methods: We retrospectively analyzed the medical records of adults who presented to a local emergency room (ER) during an 18-month period. We compared medical resources used, life-saving interventions performed, length of stay (LOS) in ER, admission rate, and mortality at each KTAS level. Results: Among a total of 40,339 patients, most patients were at KTAS 4 (n=19,532, 48.4%) and the longest median LOS in ER was 450 minutes at KTAS 2. As the KTAS level increased, the percentage of medical resources used and lifesaving interventions performed increased significantly. The odds of total admission and intensive care unit admission were significantly higher at KTAS 1 through 4 compared to those at KTAS 5. The odds related to admission and mortality were also significantly higher at KTAS 3 than at KTAS 4. Conclusion: We concluded that the KTAS, as a Korean standardized triage system of emergency level assessment, is relevant. Further, KTAS 1-3 and KTAS 4-5 are appropriate criteria to distinguish emergency and non-emergency patients.

• IE interfaces
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• v.25 no.4
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• pp.450-457
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• 2012

This study addresses the call admission control(CAC) problem for OFDMA wireless communication systems in which both subcarriers and power should be considered together as the system resources. To lessen the exccessive allocation of radio resources for protecting handoff calls, the proposed CAC allows the less data rate than their requirements to handoff calls. The CAC problem is formulated as a semi-Markov decision process(SMDP) with constraints on the blocking probabilities of handoff calls. Some extensive experiments are conducted to show the usefulness of the proposed CAC model.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.5
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• pp.546-553
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• 2015

Recently, flash cache is widely adopted as the performance accelerator of legacy storage systems. Unlike other cache media, flash cache should be carefully managed as it has peculiar characteristics such as long write latency and limited P/E cycles. In particular, we make two prominent observations that can be utilized in managing flash cache. First, a serious worn-out problem happens when the working-set of a system is beyond the capacity of flash cache due to excessively frequent cache replacement. Second, more than 50% of data has no hit in flash cache as it is a second level cache. Based on these observations, we propose a cache admission control policy that does not cache data when it is first accessed, and inserts it into the cache only after its second access occurs within a certain time window. This allows the filtering of data disruptive to flash cache in terms of endurance and performance. With this policy, we prolong the lifetime of flash cache 2.3 times without any performance degradations.

• ETRI Journal
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• v.28 no.5
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• pp.593-606
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• 2006

Thanks to the great possibilities of providing different types of telecommunication traffic to a large geographical area, satellite networks are expected to be an essential component of the next-generation internet. As a result, issues concerning the designing and testing of efficient connection-admission-control (CAC) strategies in order to increase the quality of service (QoS) for multimedia traffic sources, are attractive and at the cutting edge of research. This paper investigates the potential strengths of a generic digital-video-broadcasting return-channel-via-satellite (DVB-RCS) system architecture, proposing a new CAC algorithm with the aim of efficiently managing real-time multimedia video sources, both with constant and high variable data rate transmission; moreover, the proposed admission strategy is compared with a well-known iterative CAC mainly designed for the managing of real-time bursty traffic sources in order to demonstrate that the new algorithm is also well suited for those traffic sources. Performance analysis shows that, both algorithms guarantee the agreed QoS to real-time bursty connections that are more sensitive to delay jitter; however, our proposed algorithm can also manage interactive real-time multimedia traffic sources in high load and mixed traffic conditions.

• The Journal of Internal Korean Medicine
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• v.33 no.3
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• pp.327-337
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• 2012

Objectives : The purpose of this study was to report the clinical effect of short- term admission program on primary palmar/plantar hyperhidrosis in children and adolescents. Methods : Between January 2011 and January 2012, a total of 11 patients with clinical diagnosis of primary palmar/plantar hyperhidrosis were treated with hospitalization which consisted of iontophoresis, electro-acupuncture, herbal medicine, topical therapy and physical therapy. The effects were evaluated as quality of life with dermatology life quality index (DLQI), severity of discomfort using visual analogue scale (VAS), and the patients' subjective satisfaction. We analyzed the patients' improvement before and after admission treatment, as well as six month later. Results : After treatment, the 11 patients' quality of life and severity of discomfort improved significantly. They also were satisfied with oriental treatments for hyper hidrosis. Six months later, 6 of 11 patients had visited the hyperhidrosis clinic. Their symptoms had improved and remained stable. Conclusions : The short-term admission program is effective on primary palmar/plantar hyperhidrosis. Further studies with a larger number of cases will be needed in the future.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.374-385
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• 2021

The purpose of this study were to examine the high school teachers' and parents' perceptions on the evaluation criteria and standard of the school record-focused selection system, and to provide basic data on the development of college admission systems in order to measure student competencies more fairly and accurately. To this end, 102 high school teachers and 68 parents with high school children nationwide were surveyed online. The online questionnaire was produced based on the student screening criteria of J university and consisted largely of the following three areas: 'document evaluation', 'interview evaluation', and 'demographic survey'. The results are as follows. First, both teachers and parents said that the school record-focused selection system is a college admission format that can contribute to the activation of the 2015 revised curriculum. Second, both teachers and parents responded that personality, aptitude and potential are all important factors in document evaluation and interview evaluation. Third, school record-focused selection systems should continue to be maintained in order to promote the 2015 revised curriculum, but securing fairness in the admission process should precede that. Based on the results of the study, suggestions were made in order to improve the college admission system.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.12
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• pp.1-8
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• 2005

In this paper, we study a call admission control algorithm for supporting multicast service under the BcN environment where broadcasting, communication and Internet are converging to be one. It is necessary to control service requests with a certain criteria in order to guarantee QoS because the system capacity is limited. As a possible solution, we divide one multicast service into 3 classes and set up a threshold per each class to control service request. Especially, for the purpose of system benefit, we define system pay-off rate 'GAIN' with the term 'Reward' and 'Penalty' according to admit and reject service request. And we confine the range of threshold which makes GAIN to be maximized. For the performance analysis, we model the system as M/M/m/m queueing system, investigate GAIN under various conditions and show the effectiveness of the proposed algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.7
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• pp.2512-2531
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• 2014

We propose a new Distributed Denial of Service (DDoS) defense mechanism that protects http web servers from application-level DDoS attacks based on the two methodologies: whitelist-based admission control and busy period-based attack flow detection. The attack flow detection mechanism detects attach flows based on the symptom or stress at the server, since it is getting more difficult to identify bad flows only based on the incoming traffic patterns. The stress is measured by the time interval during which a given client makes the server busy, referred to as a client-induced server busy period (CSBP). We also need to protect the servers from a sudden surge of attack flows even before the malicious flows are identified by the attack flow detection mechanism. Thus, we use whitelist-based admission control mechanism additionally to control the load on the servers. We evaluate the performance of the proposed scheme via simulation and experiment. The simulation results show that our defense system can mitigate DDoS attacks effectively even under a large number of attack flows, on the order of thousands, and the experiment results show that our defense system deployed on a linux machine is sufficiently lightweight to handle packets arriving at a rate close to the link rate.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1998.10a
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• pp.180-180
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• 1998