• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1107-1114
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• 2004

System Packet Interface Level 4 Phase 2(SPI-4.2) is an interface for packet and cell transfer between a physical layer(PHY) device and a link layer device, for aggregate bandwidths of OC-192 ATM and Packet Over Sonet/SDH(POS), as well as 10Gbps Ethernet applications. SPI-4.2 core consists of Tx and Rx modules and supports full duplex communication. Tx module of SPI-4.2 core writes 64-bit data word and 14-bit header information from the user interface into asynchronous FIFO and transmits DDR(Double Data Rate) data over PL4 interface. Rx module of SPI-4.2 core operates in vice versa. Tx and Rx modules of SPI-4.2 core are designed to support maximum 256-channel and control the bandwidth allocation by configuring the calendar memory. Automatic DIP4 and DIP-2 parity generation and checking are implemented within the designed core. The designed core uses Xilinx ISE 5.li tool and is described in VHDL Language and is simulated by Model_SIM 5.6a. The designed core operates at 720Mbps data rate per line, which provides an aggregate bandwidth of 11.52Gbps. SPI-4.2 interface core is suited for line cards in gigabit/terabit routers, and optical cross-connect switches, and SONET/SDH-based transmission systems.

• The Transactions of the Korea Information Processing Society
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• v.4 no.2
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• pp.531-542
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• 1997

In this paper,we propose applicable methodology using simple scenarios for the architecture and its procedure of sibnalling at the NNI for B-ISDN in Korea.By the recent technologies,the flexible and intergrated networks of the future are designed, and the infrastructure hardware and software of those networks are sdsigned based on the modular concepts.Also the ATM-based B-ISDN must be able to support the broadband transmission function for providing various services with diverse bandwidths such as multimedia serivce and the function for controlling services and bandwidth is necessaty.Currently,the trquirements at the NNI for B-ISDN in korea atr based on the network mode connection type which is connection setup strucuture.They must show the upper/lower layer conformance to have the flexibility in new services and guarantee the interoperability between the network functions.But,network functions and protocol specifications described in this paper are limity to the first stage target system in korea.Therefore,we present the modular architecture which is corresponding to the B-ISUP of HAN/B-ISDN with those characteristics.Currently applicable architecture and procedure for B-ISUP and the functions of expandable modular architecture are also proposed.

• Spatial Information Research
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• v.12 no.2
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• pp.151-163
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• 2004

This study aims to develop a standard protocol by which users can exchange data information efficiently between KOSDIC and GIS. The ultimate goal from this study is to propose a data exchange format using KOSIC. The background of this study is that GIS industry sector is vigorously developing linked to spatial information construction such as UIS, LIS, EIS, AM/FM through supporting by regional government institution. According to do, the format of data transformation becomes major issue. GIS data can easily transfer to CAD version but when CAD data convert to GIS format (DWG->DXF->SHP) cannot get high success rate due to errors and problems. In addition, CAD data feature is made from oriental structure which is made of point and line faeture so that GIS system is impossible to data transformation. In the reason, the biggest problem is discordance of symbolization in integration and standard of data format. By investigation the usability of this study, conclusion are drawn efficient alternative plan in data transformation. Though this wort we will be able to provide a better transformation of data conversion between CAD format and GIS format. Accordingly, it is of important to enrich the integrated construction information infrastructure, which accommodates ever-changing constructions environment.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.2
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• pp.28-37
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• 2017

Multipath TCP (MPTCP), which is a layer 4 protocol that can get the reliability and the efficiency of the transmission by using multipath transfer, was standardized by the IETF. MPTCP provides superior performance when compared to a single TCP when used in a homogeneous network with similar network characteristics. However, MPTCP degrades performance when used in heterogeneous networks with different network characteristics. In this paper, we propose 'Delay-alerted path-blocking scheduler'. It measures the delay of each path and blocks the path with a long delay to reduce the order of packets in the receive buffer. If the duplicated packet is sent to the blocked path to measure the delay and the congestion on the blocking path is reduced, the blocked path is unblocked. For performance analysis, the proposed scheduler was implemented in the Linux kernel and improved performance was obtained in the test bed. We also confirmed that the proposed scheduler reduces the degradation of MPTCP performance in real wireless networks with heterogeneous path characteristics.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.3
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• pp.233-240
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• 1994

This study was conducted to compare the endocrine milieu, and pregnancy rates in In Vitro Fertilization and Embryo Transfer(IVF-ET) program employing combined with gonadotropin releasing hormone agonist(GnRH-a) and pergonal(LH 75lU+FSH 75lU) when either human chorionic gonadotropin(HCG) or progesterone were used for luteal phase support. A total number of 40 IVF-ET treatment cycles were prospectively studied. Ovarian hyperstimulation method was modified ultrashort protocol using GnRH-a. All patients started Decapeptyl at menstrual cycle day # 2, and HMG was started at # 3 days. When leading follicle was ${\geqq}$18mm or at least two follicles were ${\geqq}$14mm in diameter, HCG 10000lU intramuscularly was injected. After 36 hours HCG administration, oocytes were retrieved as usual guided by transvaginal ultrasound. Embryo were transfered 36-48 hours later. The patient's cycles were prospectively randomized to receive HCG(20cycles) or Progesterone (20cycles) for luteal support. The progesterone group received 25mg 1M starting from the day of ET. The HCG group received 1500IU 1M. on days 0, +2, +5 after ET. Estadiol($E_2$) and Progesterone($P_4$) were measured on the day of oocyte aspiration, ET day, and every 6 days thereafter. Results were follows as; 1. Estradiol, progesterone and LH levels on the day of HCG trigger, retrieved oocytes and number of transfered embryo were not significantly different in both groups. 2. On the day of aspiration and embryo transfered day, $E_2$, $P_4$ level were significantly higher in progesterone group than HCG group(p<0.01). 3. $E_2$, $P_4$ level on 6 days after ET were significantly higher in progesterone group than HCG group(p<0.01). But, $P_4/E_2$ ratio was not different in both groups. 4. $E_2$, $P_4$ level 12 days after ET were decreased abruptly in both groups and higher hormonal level appeared in HCG group(P<0.01). 5. The total pregnancy rate in the HCG group was 40% (8/20) and in the progesterone group 15%(3/20). 6. Comparing the pregnant and nonpregnant cases progesterone group was not different the hormonal status. In HCG group, pregnant cases appeared in higher $P_4$, $P_4/E_2$ ratio than nonpregnanct cases(P<0.01).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2B
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• pp.117-128
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• 2006

For the legacy IEEE 802.15.3 WPAN protocol, an unpredictable piconet coordinator(PNC) leaving from a piconet without a proper handoff procedure causes an absence of PNC, and thus the piconet gets collapsed. In addition, several beacons from PNCs in adjacent piconets may be collided on a device(DEV) located between those piconets. This beacon collision eventually makes the DEV leave from the piconet. To remedy these two problems, we here propose an Active Seamless Coordinator Switching(ASCS) scheme and a PNC HB based Beacon Alignment(PHBA) one. In the ASCS scheme, a PNC assigns a number of DEVs as next possible PNCs in sequence for provisioning against the abrupt breakdown of the current active PNC. Each nominated DEV proactively sends a probe frame to confirm the operation status of the active PNC. For the case of no response from the PNC, the nominated DEV tries to become a new PNC immediately. In the second PHBA scheme, each PNC is allow to broadcast a special Heart Beat(HB) frame randomly during a superframe period. When a DEV receives a HB frame from other PNC, it promptly sends the related PNCs a special Hiccup Beat(HCB) frame with the superframe information of its associated PNC. As a result, the HCB frame makes both PNCs align their superframe beginning time in order to yield no more beacon collisions. For these two proposed schemes, we show the performance by simulations. We can confirm the enhancement of throughput for each superframe and average frame transfer delay, since each scheme can reduce the duration of piconet collapse. Finally, it is worth while to note that the proposed schemes can be operated with frames those are permitted in the legacy WPAN standard.

• Archives of Plastic Surgery
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• v.36 no.5
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• pp.611-616
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• 2009

Purpose: The rate of fistulas occuring followed by resection of oral cavity, oropharyngeal, hypopharyngeal, and laryngeal cancer are reported to be 9 ~ 23% according to various documents. Neglected treatment of the fistula can result in a setback in proper treatment with restrictions in oral intake leading to delayed return to daily life. Furthurmore, in severe cases, it may injure important vessels and adjacent structures of the neck area. The author reviewed previously reported cases of treatment methods for fistulas recurring after diverse head and neck operations and with sharing the treatment experiments of our patients, we tried to present a treatment algorism for different fistula types. Methods: Our study was based on retrograde analysis of 64 patients who were clinically diagnosed with fistula after operation for cancer of the head and neck from 1997 to 2008 at Severance Hospital. Their primary sites of cancer were 8 oral cavity, 22 oropharynx, 25 hypopharynx, and 9 larynx. The patients were aged 45 to 75 years and the male to female ratio was 11 to 1. The patient's operation records and progress notes were evaluated for determination of degree of fistula and treatment methods. Results: Most fistulas were clinically suspected after postoperative 5 days and symptoms noted for detection of the fistula were erythema, purulent discharge, edema, tenderness, and fluctuation. The fistula was definitely diagnosed at postoperative 2 weeks with barium test and treatment method ranging from conservative management to operative procedure were applied to each patients. Total 21 patients were managed with conservative protocol. In 15 cases, direct repair of the fistula was done and more stable repair of the fistula was possible with using of TachoComb$^{(R)}$. Pharyngostoma was performed in 14 patients. Among them, 4 patients healed spontaneously, 5 patients were taken direct closure, 4 patients were taken pectoralis major musculocutaneous flap, and one patient was taken esophageal transfer. The other 14 patients were taken 11 pectoralis major musculocutaneous flaps and 3 free flaps without pharyngostoma formation. Conclusion: Fistula is a troublesome complication resulting after resection of head and neck cancer. Early detection and adequate treatment according to the period and condition of the fistula may prevent further complications and reduce the pain of the patient.

• Journal of Internet Computing and Services
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• v.17 no.6
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• pp.33-39
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• 2016

With recent advances in sensor technology, CMOS-based semiconductor devices and networking protocol, the areas for application of wireless sensor networks greatly expanded and diversified. Such diversification of uses for wireless sensor networks creates a multitude of beneficial possibilities for several industries. In the application of wireless sensor networks for monitoring systems' data transmission process from the sensor node to the sink node, transmission through multi-hop paths have been used. Also mobile sink techniques have been applied. However, high energy costs, unbalanced energy consumption of nodes and time gaps between the measured data values and the actual value have created a need for advancement. Therefore, this thesis proposes a new model which alleviates these problems. To reduce the communication costs due to frequent data exchange, a State Prediction Model has been developed to predict the situation of the peripheral node using a geographic autocorrelation of sensor nodes constituting the wireless sensor networks. Also, a Risk Analysis Model has developed to quickly alert the monitoring system of any fatal abnormalities when they occur. Simulation results have shown, in the case of applying the State Prediction Model, errors were smaller than otherwise. When the Risk Analysis Model is applied, the data transfer latency was reduced. The results of this study are expected to be utilized in any efficient communication method for wireless sensor network monitoring systems where all nodes are able to identify their geographic location.

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.17-23
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• 2020

In this paper, collecting real-time data frames that occur during RS232 communication between an HMI and PLC of automation equipment by sniffing real-time information data frames through MCU without modification of the HMI or PLC, a method is proposed that allows users to collect data without being dependent on the modification of PLC and HMI systems. The user collects necessary information from the sniffing data through the parsing operation, and the original communication interface is maintained by transmitting the corresponding sniffing frame to the destination. The MCU's UART communication interface circuit is physically designed according to the RS232 communication standard, and this additionally improves efficiency more so than an interrupt-based system by using the DMA device inside the MCU. In addition, the data frame IO operation is performed by logically separating the work of the DMA interrupt service routine from the work of the main thread using the circular queue. Through this method, the user receives the sniffing data frame between the HMI and PLC in RS232 format, and the frame transfer between PLC and HMI arrives normally at the original destination. By sniffing the data frame without further modification of the PLC and HMI, it can be confirmed that it arrives at the user system normally.

• Journal of the Korea Society of Computer and Information
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• v.14 no.11
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• pp.105-111
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• 2009

The study aims to propose the intelligent clustering technique that calculates the distance by improving the problems of multi-hop clustering technique for inter-vehicular secure communications. After calculating the distance between vehicles with no connection for rapid transit and clustering it, the connection between nodes is created through a set distance vale. Header is selected by the distance value between nodes that become the identical members, and the information within a group is transmitted to the member nodes. After selecting the header, when the header is separated due to its mobility, the urgent situation may occur. At this time, the information transfer is prepared to select the new cluster header and transmit it through using the intelligent cluster provided from node by the execution of programs included in packet. The study proposes the cluster technique of the intelligent distance estimation for the mobile Ad-hoc network that calculates the cluster with the Store-Compute-Forward method that adds computing ability to the existing Store-and-Forward routing scheme. The cluster technique of intelligent distance estimation for the mobile Ad-hoc network suggested in the study is the active and intelligent multi-hop cluster routing protocol to make secure communications.