• Journal of Information Processing Systems
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• 제16권6호
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• pp.1447-1458
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• 2020

This paper describes a structured overlay network scheme based on multiple different time intervals. Many types of data (e.g., sensor data) can be requested at specific time intervals that depend on the user and the system. These queries are referred to as "interval queries." A method for constructing an overlay network that efficiently processes interval queries based on multiple different time intervals is proposed herein. The proposed method assumes a ring topology and assigns nodes to a keyspace based on one-dimensional time information. To reduce the number of forwarded messages for queries, each node constructs shortcut links for each interval that users tend to request. This study confirmed that the proposed method reduces the number of messages needed to process interval queries. The contributions of this study include the clarification of interval queries with specific time intervals; establishment of a structured overlay network scheme based on multiple different time intervals; and experimental verification of the scheme in terms of communication load, delay, and maintenance cost.

• 대한산업공학회지
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• 제25권1호
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• pp.47-55
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• 1999

This paper develops an efficient heuristic algorithm for scheduling workforce level that can accommodate all the requested maintenance jobs. Each job has its own release and due dates as well as man-day requirement, and must be scheduled in a non-interrupted time interval, namely, without preemption. Duration of each job is not fixed, but to be determined within given specific range. The objective is to minimize workforce level to complete all the requested maintenance jobs. We show that the problem can be seen as a variant of the two-dimensional bin-packing problem with some additional constraints. A non-linear mixed integer programming model for the problem is developed, and an efficient heuristic algorithm based on bin-packing algorithms is proposed. In order to evaluate goodness of the solution obtained from the proposed algorithm, a scheme for getting a good lower bound for the optimum solution is presented and analyzed. The computational experiment shows that the proposed algorithm performs quite satisfactorily.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권5호
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• pp.1963-1978
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• 2015

With the advancement of mobile web environments, identification and analysis of the user behavior play a significant role and remains a challenging task to implement with variations observed in the model. This paper presents an efficient method for mining optimized user behavior prediction model using genetic algorithm on mobile web structure. The framework of optimized user behavior prediction model integrates the temporary and permanent register information and is stored immediately in the form of integrated logs which have higher precision and minimize the time for determining user behavior. Then by applying the temporal characteristics, suitable time interval table is obtained by segmenting the logs. The suitable time interval table that split the huge data logs is obtained using genetic algorithm. Existing cluster based temporal mobile sequential arrangement provide efficiency without bringing down the accuracy but compromise precision during the prediction of user behavior. To efficiently discover the mobile users' behavior, prediction model is associated with region and requested services, a method called optimized user behavior Prediction Model using Genetic Algorithm (PM-GA) on mobile web structure is introduced. This paper also provides a technique called MAA during the increase in the number of models related to the region and requested services are observed. Based on our analysis, we content that PM-GA provides improved performance in terms of precision, number of mobile models generated, execution time and increasing the prediction accuracy. Experiments are conducted with different parameter on real dataset in mobile web environment. Analytical and empirical result offers an efficient and effective mining and prediction of user behavior prediction model on mobile web structure.

• 한국컴퓨터정보학회논문지
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• 제15권10호
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• pp.113-120
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• 2010

본 논문에서는 비디오 프록시 서버의 제한된 저장 공간을 효율적으로 활용하기 위한 시간 제약 다중 요청 기법을 제안한다. 제안하는 기법은 요청된 동영상 데이터를 전송받아 사용자에게 전송하고 비디오 프록시 서버에 일시적으로 저장한다. 이때 일시적으로 저장된 동영상 데이터는 설정된 시간 내에서 발생되는 사용자의 요청의 상태에 따라 저장장치에서 삭제되거나 저장된다. 또한 새롭게 요청된 동영상의 저장 공간을 확보하기 위해서 저장장치에 저장되어 있는 동영상 세그먼트 중 요청 가능성이 가장 낮은 세그먼트를 선정하고 제거한다. 이를 위해 사용자에 의해 주로 요청되는 동영상 세그먼트 부분인 전방 클래스와 요청되지 않았거나 요청될 가능성이 적은 세그먼트 부분인 후방 클래스로 분리한다. 분리된 클래스 중 후방 클래스에서 가장 오래전에 요청된 세그먼트를 선정하여 삭제함으로써 제한된 공간을 효율적으로 활용한다. 실험을 통해 제안하는 방법이 기존의 방법들 보다 높은 적중률을 보이는 동시에 보다 적은 삭제 횟수를 보인다는 것을 확인한다.

• 한국산업정보학회논문지
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• 제12권3호
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• pp.10-18
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• 2007

인터넷의 사용자가 증가함에 따라 사용자의 인터넷 작업부하 유형을 파악하고 이를 수리적으로 표현하여 웹사이트에서 송수신되는 트래픽의 형태를 모델링하는데 적합한 통계적 분포를 제시할 필요가 있다. 독립적이고 불규칙적인 트래픽 추세를 고려할 때 어떤 t 시점에서 임의의 외부적 개입이 주어질 경우 파레토 분포를 이용한 수정된 모델을 가지고 트래픽 발생에 어느 정도 영향을 주는지를 알아본다.

• Journal of Acupuncture Research
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• 제20권5호
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• pp.107-117
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• 2003

Objective: This study was examined for effects of acupuncture of Zusanli(ST36) on the facial thermography in health subjects. Methods: The voiunteers who participating in this study had taken rest for 15 mins in room temperature ($19-21^{\circ}C$) before the examination and informed them what to prohibit smoking. drinking and administration of drug for the previous day. The thermography of face was taken using Digital Infrared Thermographic Imaging (D.I.T.I.: Dorex. DTI-16UT1. U.S.A.) by time interval of 35 minutes at 15 min before and 20 min after acupuncture stimuiation. Thermal temperature of Daying(ST5). Juliao(ST3) and Quanliao(SI18) was measured and compared. Results: The results showed that acupuncture of Zusanli(ST36) significantly decreased the Absolute defference of temperature between Daying(ST5) and Juliao(ST3) (p<0.05, Data were represented meant ${\pm}$S.E.M.(n=33)). The results showed that acupuncture of Zusanli(ST36) significantly decreased the Absolute defference of temperature between Quanliao(SI18) and Juliao(ST3)(p<0.01, Data were represented mean${\pm}$S.E.M. (n=33)). But, acupuncture of Zusanli(ST36) particularly decreased the absolute defference of temperature between Daying(ST5) and Quanliao(SI18). Also. it was observed that acupuncture of ST36 decreased variety of the color tone of thermographic contour line and decreased thermal distribution. Conclusions: The results showed that acupuncture of Zusanli(ST36) significantly decreased the absolute defference of temperature of partial facial surface. Hereafter. study about if acupuncture of Zusanli(ST36) significantly decrease the absolute defference of temperature of all the areas of facial surface is requested. Also. continued study of effects of acupuncture of other meridian on the facial thermography is requested.

• 동의생리병리학회지
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• 제17권6호
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• pp.1493-1499
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• 2003

This study was examined for effects of acupuncture of Chok-Samni(ST36) on the facial thermography in health subjects, The volunteers who participating in this study had taken rest for 15 mins in room temperature (19-21 ℃) before the examination and informed them what to prohibit smoking, drinking and administration of drug for the previous day, The thermography of face was taken using Digital Infrared Thermographic Imaging (D.I.T.I. : Dorex, DTI-16UT1, U.S.A.) by time interval of 35 minutes at 15 min before and 20 min after acupuncture stimulation. Thermal temperature of Yangbaek(GB14), Myon-koryo(ST3) and Chichang(ST4) was measured and compared, The results showed that acupuncture of Chok-Samni(ST36) decreased the Absolute difference of temperature between Myon-koryo(ST3) and Chichang(ST4) (p<0,05, Data were represented mean±S,E.M.(n=33)), But, acupuncture of Chok-Samni(ST36) particularly decreased the absolute difference of temperature between Yangbaek(GB14) and Chichang(ST4) and particularly decreased the absolute difference of temperature between Vangbaek(GB14) and Myon-koryo(ST3) (p<0,05, Data were represented mean±S,E.M.(n=33)). Also, it was observed that acupuncture of Chok-Samni(ST36) decreased variety of the color tone of thermographic contour line and decreased thermal distribution. The results showed that acupuncture of Chok-5amni(ST36) significantly decreased the absolute difference of temperature of partial facial surface. Hereafter, study about if acupuncture of Chok-Samni(ST36) significantly decrease the absolute difference of temperature of all the areas of facial surface is requested. Also, continued study of effects of acupuncture of other meridian on the facial thermography is requested.

• 정보처리학회논문지B
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• 제8B권5호
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• pp.507-514
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• 2001

VOD(Video-On-Demand) 시스템에서 실시간 서비스 및 대화형 서비스의 제공 여부는 QoS(Suality of Service)를 결정하는 중요한 요소이다. 본 논문에서는 지연이나 단절 업서는 대화형 서비스를 제공하기 위하여 서버로부터 단지 하나의 비디오 스트림만을 수신하여 복수 사용자들에게 서비스를 제공하는 스위칭 에이전트(Switching Agent)의 종단노드(Head-End Node)로 구성된 종단시스템(Head-End System)을 제안한다. VCR 서비스는 클라이언트 및 종단노드의 버퍼가 동적으로 확장되어 비디오 데이터를 저장하기 때문에 사용자에게 제한 없이 제공되어진다. 또한 제안된 알고리듬은 버퍼의 사용 효율을 증대시키는 방법을 제공하며 모든 클라이언트들의 서비스 요청을 지연 없이 즉시 처리하므로 사용자들에게 진정한 대화형 VOD 서비스를 제공하게 된다. 본 논문에서는 종단시스템을 구현하여 서버로부터 단지 하나의 비디오 스트림만을 수신하여 지연이나 단절 없는 VCR 기능을 갖춘 VOD 시스템을 구현하였으며, 시뮬레이션 결과는 제안된 알고리듬이 VCR 서비스 요청수와 시간에 대하여 매우 우수한 성능을 갖고 있음을 보여주고 있다.

• 정보처리학회논문지A
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• 제14A권7호
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• pp.443-450
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• 2007

대용량 무선 인터넷 프록시 캐시 서버 클러스터에서는 성능 및 저장 공간의 확장성이 중요하게 되었다. 여기에서 성능의 확장성은 캐시 서버를 추가함에 따라 클러스터 성능이 선형적으로 증가함을 의미하고 저장 공간의 확장성은 캐시 데이터가 서버들에게 분할 저장되어 있어서 캐시 서버의 수에 상관없이 캐시 데이터를 저장하는 클러스터안의 공간의 합은 일정함을 의미한다. 대용량 서버 클러스터에서 많이 사용되는 라운드로빈 기반 부하분산 방법은 성능의 확장성은 보장되지만, 요청 URL 데이터가 모든 서버에 저장되어야 하므로 저장 공간의 확장성이 없는 단점을 가진다. 해싱기반 부하분산 방법은 모든 요청 URL 데이터가 서버들에 분할 저장되어 있어서 저장 공간의 확장성을 가진다. 그러나 그 방법은 사용자의 요청 패턴 불균형 또는 특정서버로의 요청 집중(Hot-Spot) 시에 성능 확장성이 없다. 본 논문에서는 성능 및 저장 공간의 확장성을 보장하는 새로운 동적 해싱 부하분산기법을 제안한다. 제안된 기법에서는 주기적으로 과부하 상태의 캐시 서버에 할당된 요청들을 찾아서 다른 캐시서버로 동적으로 재할당한다. 제안된 방법을 16대의 컴퓨터를 사용하여 실험을 수행하였고, 실험 결과를 통해 제안된 방법이 기존 방법과는 달리 성능 및 저장 공간의 확장성을 보장함을 확인하였다.

• The Korean Journal of Pain
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• 제27권1호
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• pp.35-42
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• 2014

Background: Epidural steroid injection (ESI) is one of the most common procedures for patients presenting low back pain and radiculopathy. However, there is no clear consensus on what constitutes appropriate steroid use for ESIs. To investigate optimal steroid injection methods for ESIs, surveys were sent to all academic pain centers and selected private practices in Korea via e-mail. Methods: Among 173 pain centers which requested the public health insurance reimbursements for their ESIs and were enrolled in the Korean Pain Society, 122 completed questionnaires were returned, for a rate of 70.5%; also returned were surveys from 39 academic programs and 85 private practices with response rates of 83.0% and 65.9%, respectively. Results: More than half (55%) of Korean pain physicians used dexamethasone for ESIs. The minimum interval of subsequent ESIs at the academic institutions (3.1 weeks) and the private practices (2.1 weeks) were statistically different (P = 0.01). Conclusions: Although there was a wide range of variation, there were no significant differences between the academic institutions and the private practices in terms of the types and single doses of steroids for ESIs, the annual dose of steroids, or the limitations of doses in the event of diabetes, with the exception of the minimum interval before the subsequent ESI.