• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.113-116
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• 2001

In this paper, a new multicasting scheduling is proposed for WDM single-hop broadcast network. The main idea of traditional multicast scheduling algorithms is partitioning the multicast group into several subgroups to reduce the delay time after receiving previous message. Those partitioning algorithms are grouping method of receivers already tuned to transmitters wavelength. However, multicast scheduling shows better performance by considering the previous status of receivers. Thus, in this paper, a new subgrouping method is proposed to minimize delay through collecting the current status of receivers. This method is operated by using the tunable transceiver in WDM single hop broadcasting network and uses fixed control channel for collecting the status of receivers. In addition, we analyzed the performance of proposed method through the computer simulation and then compared with existing multicast scheduling algorithm.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.616-618
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• 2004

기존의 멀티캐스트는 하나의 그룹 주소를 갖고 그 주소를 통해 여러 멤버 노드로의 데이터 송수신을 지원한다. 하지만 서로 연관된 많은 멀티캐스트 그룹이 존재 시 송신자의 각 그룹 관리가 힘들어지고, 노드의 잦은 멀티캐스트 그룹간 참가 및 탈퇴로 인해 지연시간이 생긴다. 또한 멀티캐스트 라우팅 테이블 유지에 많은 자원을 사용한다. 이에 서로 연관된 멀티캐스트 그룹간 불리언 연산을 통해 더 유연성 있는 운용을 가능하게 하는 기법을 제시하고 그에 따른 문제점과 해결방안을 살펴본다.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.541-546
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• 2001

현재 많은 사용자들이 네트워크 게임을 즉시고 있다. 네트워크 게임은 동시에 많은 사용자들이 하나의 서버에 접속하여 게임을 하므로, 많은 사용자특이 접속하는 경우 서버의 부하 증가와 네트워크 트래픽 증가로 인한 데이터 전송 지연이나 데이터 손실이 발생하여 게임을 원활히 진행하지 못하는 문제가 있다. 본 논문에서는 이러한 지연을 줄이기 위해서 그룹화 방법을 이용하여 서버가 전송하는 데이터의 개수를 줄임으로써 서버의 부하 감소 및 네트워크 트래픽을 줄이는 방법을 제안한다.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 1998.07a
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• pp.39-40
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• 1998

수온과 광주기를 조절한 실험구는 대조구에 비해 GSI의 peak가 2개월 늦어졌으며, 난소의 발달도 지연되었다. 암컷 혈중의 $E_{2}$와 T 농도도 성숙 단계의 지연에 따라 peak가 각기 다르게 나타났다. 그러나 수온과 광주기를 조절한 그룹의 일부개체는 성숙이 지연되지 않았으며, 수컷의 GSI나 수컷 혈중의 T 농도도 수온과 광주기의 변화에 영향을 받지 않았다.

• Journal of Digital Contents Society
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• v.15 no.2
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• pp.137-145
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• 2014

In this paper, we focus on end-to-end transfer delay improvement by using erasure coding when delivering expediting message consisting of M packets in networks with high coefficient of variation of transfer time. In the scheme, M packets are divided into b groups with each having g packets. Each group is erasure coded with additional r packets and transmitted. Since the first arrived g packets among g+r packets completes the delivery of the group, the delivery time of the expediting message is reduced. For the scheme, we investigate the optimum group size and number of redundancy packets considering delivery delay reduction and additional transmission cost caused by using erasure coding. From the results of the investigation, we see that the proposed scheme is effective in networks having high variability of transfer time and would be very useful and practical especially for the case that expedited deliveries of messages are needed.

• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.53-62
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• 2023

The purpose of this study is to find an optimized imaging technique and evaluate its usefulness by comparing and analyzing the difference in contrast enhancement of lower extremity artery according to the patient's heart rate during lower extremity Computed Tomography Angiography examination. From January 2022 to August 22nd, 139 outpatients who visited Ajou University Hospital and underwent lower extremity angio CT examination were targeted. According to the heart rate, the groups were divided into four groups: A(HR ≤65), B(65 < HR < 80), C(80≤ HR). In addition, among patients with a heart rate of 65 or less, the heart rate was considered, and the scan was divided into D, E, F group with a delay time. The time of arrival of contrast medium and the average value of contrast enhancement were compared and analyzed. As a result of quantitative evaluation, B and C groups with a heart rate of more than 65 times had better HU values in the popliteal artery than A group (HR ≤ 65), and D group showed better HU improvement effects compared to A group (p<0.001). The comparative analysis with other groups was insignificant. The difference in heart rate affected the angiographic intensity of the lower extremities artery. Therefore, it is effective to apply the appropriate test timing for each patient by using the heart rate during the lower extremity angio CT Scan.

• The KIPS Transactions:PartC
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• v.9C no.6
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• pp.919-926
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• 2002

In this paper, new multicast scheduling algorithms are proposed for the WDM single-hop broadcast-and-select networks. The existing multicast scheduling algorithms are focused on the partitioning a multicast group into several subgroups to reduce the delay time of each receiver. These partitioning algorithms are grouping method of the receivers already tuned to the transmitter's wavelength. However, these algorithms ignore the state of receivers, which leads to increase the number of subgroups and the delay time. Therefore, 1 propose two new multicast scheduling algorithms called H_EAR and PGM that partition a multicast group to subgroups using the tunable transmitter, state information of receivers, and pseudo group concept. The performance of proposed algorithms are evaluated through the computer simulation. They show the better performance comparing with the existing multicast scheduling algorithm.

• The Journal of Korean Academy of Sensory Integration
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• v.19 no.1
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• pp.1-12
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• 2021

Objective : The purpose of this study was to investigate the effects of paired-group sensory integration therapy on sensory processing, peer interaction, and play development of four-year-old children. Methods : This study involved 13 weekly sessions of a four-minute intervention as well as an initial 10 minutes of parental counseling for those without experience of paired-group sensory integration therapy. The intervention consisted of sensory processing activities and various occupational activities, and the children's Short Sensory Profile (SSP), Penn Interactive Peer Play Scale (PIPPS), and Knox Preschool Play Scale-Revised (KPPS-R) were measured before and after the sessions for comparison. The results are presented using visualized data. Results : After the paired-group interventions, all subjects showed improved sensory processing ability according to their SSP scores and improved play development on the KPPS-R. Moreover, the frequency of negative interactions decreased in the PIPPS measure. Conclusion : This paired-group sensory integration therapy had a positive effect on sensory processing, peer interaction, and play for children with developmental delay. In the future, research that applies this kind of paired-group intervention in various age groups would be useful.

• Journal of Internet Computing and Services
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• v.4 no.6
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• pp.87-93
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• 2003

Data Replication makes distributed system and database system improved in availability and performance. But it is difficult to keep strict consistency in data update. Existing algorithms keep strict consistency, but have problems of cost a great deal and delay time. It is to introduce hybrid update propagation algorithm which permits eager update for original copy and propagates lazy update for other copies. Hybrid update propagation algorithm also permits group update in ownership. This algorithm menages replica version in order to control group update consistency. Consistency and performance is improved by combining eager update and lazy update with group ownership. Simulation shows improvement of transaction throughput and response time depending on application and execution environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.7A
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• pp.597-602
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• 2005

This paper proposes an efficient multicast scheme for the hierarchical mobile IPv6(HMIPv6). If a mobility anchor point(MAP) in a new domain does not support multicasting, an entering group member cannot join the multicast group through the new MAP The group member thus keeps receiving multicast packets from its home agent(HA) using Mobile IPv6 (MIPv6). This increases the propagation delay of binding update (BU) messages. However, our scheme enables an entering group member to keep receiving packets from the old multicast MAP. It can also reduce tunneling costs, total delivery costs and handover latency. We simulated the performance of our scheme by comparing it with the seamless multicast handover in a hierarchical mobile Pv6 (M-HMIPv6) using the delivery cost and handover latency factors.