• Journal of Korean Foot and Ankle Society
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• v.24 no.2
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• pp.37-41
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• 2020

Many articles on operative treatment strategies for osteochondral lesions of the talus (OLT) have been published. On the other hand, there are only a few reports on the conservative treatment of OLT. Understanding the natural history of OLT is essential to establishing the correct treatment. Conservative treatment might lead to comparable clinical outcomes compared to the current options of the operative treatment in isolated OLT lesions. OLT lesions can be divided into two (or possibly three) types. Hence, the prognosis and outcome of certain operative treatments should be evaluated further. The prognosis of OLT combined with instability or malalignment appears poorer than that of isolated OLT lesions. Therefore, concomitant pathologies should be evaluated together when treating patients with OLT.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.2C
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• pp.160-169
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• 2002

An ATM-PON (Passive Optical Network) system consists of an OLT (Optical Line Termination), multiple ONUs (Optical Network Units) and the optical fiber which has a PON (Passive Optical Network)configuration with a passive optical splitter. To avoid cell collisions on the upstream transmission, an elaborate procedure called as ranging is needed when a new ONU is installed. The ONU can send upstream cells according to the grant provided by the OLT after the procedure. To prevent collisions being generated by the variation of several factors, OLT must performs continuously the cell phase monitoring. It means that the OLT predicts the expected arrival time, monitors the actual arrival time for all upstream cells and calculates the error between the times. Accordingly, TC (Transmission Convergence) chip in the OLT needs a predictor which predicts the time that the cell will arrive for the current grant. In this paper, we implement the predictor by using shift registers of which the length is equivalent to the equalized round trip delay. As each register consists of 8 bit, OLT can identify which ONU sends what type of cell (ranging cell, user cell, idle cell, and mini-slot). Also, TC chip is designed to calculate the effective bandwidth for all ONUs by using the function of predictor. With the time simulation and the measurement of an implemented optical board, we verify the operation of the predictor.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.5C
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• pp.454-464
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• 2002

In the ATM-PON (Asynchronous Transfer Mode-Passive Optical Network), the downstream cell transmitted by an OLT is broadcast to all ONUs. The ONU receives selectively its own cells by VP filtering. On the other hand, the upstream cell can be transmitted by ONU in the case of receiving a grant from the OLT. After providing the grant to an ONU, the OLT expects the arrival of a cell after an elapse of the equalized round trip delay. ITU-T G.983.1 recommends that one bit error is allowed between the expected arrival time and the actual arrival time at the OLT. Because the ONU processes the different delay to each type of grant (ranging, user cell, and mimi-slot grant), it is not simple to design the transmission part of ONU. In this paper, we implement a grant processor which provides the delay accurately in the ONU TC chip with the FPGA. For the given equalized delay, it deals with the delay for the cell, the byte, and the bit unit by using the shift register, the byte counter, and the D flip-flop, respectively. We verify the operation of the grant processor by the time simulation and the measurement of the optical board output.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.10B
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• pp.1143-1149
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• 2011

A multi-OLT PON architecture is proposed to accommodate several types of services or multiple service providers economically in a single PON. The operation protocol and a dynamic bandwidth allocation scheme appropriate for two-OLT structure are proposed. Performance analysis shows that the proposed system is very efficient and can be used in the upcoming higher speed PON system.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.4
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• pp.853-860
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• 2006

This study was performed to investigate genes which are differently expressed in human blood by administrating of OLT-2. OLT-2 was medical precipitation composed of three medicinal herbs, Ginseng Radix, Astragali Radix, Glycyrrhizae Radix, and anti-leukemia effect of it was evaluated from Byung Hun Jeon of Wonkwang University this study was approved by Institutional Review Board of Korea Institute of Oriental Medicine (Taejeon, Korea) and four male subjects participated in this study. Gene expressions were evaluated by cDNA chip, in which 24,000 genes were spotted. Hierarchical cluster and biological process against the genes, which expression changes were more than 1.6 fold, were constructed by cluster 3.0 providing Stanford University and EASE(http://apps1 .maid.nih.gov/DAVID). Five groups were clustered according to their expression patterns. Group A contained gene decreased by OLT-2 and increased genes by OLT-2 were involved in Group B, C, D. In biological process, expression of genes involved in cytokine or cell calcium signaling, such as interleukin 18 and G-protein beta 4 were increased, but protein tyrosine phosphatase receptor type c, which function is cell adhesion between antigen-presenting cell and T or B-cell, was decreased by OLT-2. This study provides the most comprehensive available survey of gene expression changes in response to anti-leukemia effect of OLT-2 in human blood.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.6
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• pp.77-88
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• 2008

This paper addresses the implementation of FTTH system based on G-PON technology. This system supports the duplication function that can switchover both TDM and data routes within 10msec. This system consists of OLT and ONU/ONT. G-PON OLT supports the maximum 32 2.5Gbps interfaces, and then has the flexibility and the scalability for supplying digital communication and broadcasting convergence service in the near future. OLT system consists switch module, subscriber module, processor module, and G-PON link module, and has the operating system based on Linux. ONU is installed in customer premise to supply TPS (Triple Play Service). Also ONT has the dedicated interface for IP-TV to improve the transmission characteristics of IP-TV signal.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.1
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• pp.57-64
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• 2004

Passive optical network that use passive component is economical network, and can provide service of high speed to subscribers. The function of VPN which is operated like private network is needed to many companies. There are two methods to implement VPN over ATM-PON. One is located at ONU and OLT system and another is located at core network. In this paper, we implemented to SCB and P2P adding VPN function to ONU and OLT of ATM-PON system. We knew that the proposed method has more fast transmission and more small traffic than other method in the field of the performance.

• Journal of the Korea Society of Computer and Information
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• v.17 no.8
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• pp.51-60
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• 2012

I propose the 5Gbps/1.25Gbps WDM/TDM hybrid Passive Optical Network(PON) with inverse RZ(Return to Zero) code coded downstream and NRZ(Non Return to Zero) upstream re-modulation and analyze its performance by performing simulation with MATLAB. The results have shown that an optical line termination (OLT) can be connected to 8, 16 optical network unit (ONU)s with the Bit Error Rate(BER) of $10^{-9}$ when the distance between OLT and ONU is 10Km and transmitted optical powers are more than -3.8, -0.9dBm, respectively. The proposed WDM/TDM hybrid PON system can solve the problem of data rate limit in upstream which happened in the conventional TDM PON because the upstream data rate is proportional to ONU and does not require a light source in ONU and its control circuits in OLT, thus can be a useful technology for asymmetric optical subscriber networks.

• Journal of Korean Foot and Ankle Society
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• v.24 no.2
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• pp.42-47
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• 2020

Increased loading in a localized area is a possible cause of pain-related osteochondral lesions of the talus (OLT), but the reported effects of realignment surgery for OLT have been anecdotal. Moreover, no report of realignment surgery for OLT could be found in the English literature. This study reviewed previous articles on lower extremity alignment and OLT to determine if OLT can be treated with realignment surgery.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.705-706
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• 2014

This paper proposes a new dynamic bandwidth allocation algorithm for an XG-PON (10-Gbps-capable passive optical network) system. In the XG-PON system, an ONU (optical network unit) does not explicitly send it request to an OLT (optical line termination). The OLT monitors the upstream bandwidth usage of the ONU to estimate the request of the ONU. Then the OLT performs a dynamic bandwidth allocation process based on the estimated requests.