• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6B
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• pp.403-410
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• 2008

In this paper, we investigate the performance of MMR system in Non-transparent mode. The IEEE 802.16j MMR system has two node of operation, Single-frame (in band) and Multi-frame (out band) mode. In the analysis, we assume that channel interference between MR-BS and RS, or between RSs anywhere in the given area is ignored. The performance is presented in terms of the delay and the frame efficiency by varying number of RS and BS coverage to RS coverage ratio and the maximum coverage area of a BS by varying traffic density. Analytical results show that the Single-frame is more efficient than Multi-frame in frame efficiency and coverage extension.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1993.05a
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• pp.93-93
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• 1993

We analyzed retrospectively 100 cases of floor of mouth cancer, treated at Korea Cancer Center Hospital from Jan. 1985 to Dec, 1992. The most prevalent age group were 6th, 1th decades, the sex ratio was M:F =4.6:1. 95 patients were smoker, 73 patients smoked more than 1 pack per day. 51 patients were heavy drinker (So-ju more than 1 B/day). Histopathologically, the squamous cell carcinoma (95 cases) was most common, followed by the adenoid cystic carcinoma (4 cases), mucoepidermoid carcinoma (1 case). The most common clinical staging was stage IV, and lymph node metastasis were 71 cases, histopathologically. Distant metastasis were 2 cases, multiple primary cancer was 1 case. 5 years survival rates according to treatment modality were 71.4% in operation only group that were almostly in early stage, 0% in radiation therapy group that were almostly in advanced stage, 32.5 % in combination therapy with operation and radiation therapy.

• Journal of Haehwa Medicine
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• v.16 no.2
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• pp.251-265
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• 2007

Yanhyeoljeseuptang(YHJST) is a traditional herbal medicine used for the treatment of dermatitis. The aim of this study was to confirm whether or not YHJST has a preventive effect on development of atopic dermatitis in dinitrochlorobenzene(DNCB)-applied Nc/Nga mouse. This study was undertaken to develop a reliable mouse model demonstrating similar immunologic phenomena as human atopic dermatitis characterized with predominance of type-2 immune response. NC/Nga mouse were sensitized with $200\;{\mu\ell}$ of 1% 2,4-dinitrochlorobenzene(DNCB) (acetone : olive oil = 3 : 1 mixture) and challenged twice or three times with $150\;{\mu\ell}$ of 0.2% DNCB in a week for the following 4 weeks. YHJST was administered orally to Nc/Nga mouse for 8 weeks, which led to the remarkable suppression on the development of dermatitis, as determined by various immune factors related to pathogenesis of atopic dermatitis in splenocytes and DLN cells. In this study, YHJST selectively suppressed T ce11 (CD4+, CD3+/CD69+, CD4+/CD25+) activation, which may be essential for ratio of IL-4 versus INF-$\gamma$ produced in the splenic T cell culture supernatants was approximately 3-fold higher in the mouse treated with DNCB than their control mouse respectively. Immunologic studies showed down-regulated that the capacity of spleen T cells to produce IL-4, but IFN-$\gamma$ was up-regulated by means of oral intake of these YHJST. These results strongly suggest that YHJST is a promising candidate for treatment of human atopic dermatitis.

• Journal of Haehwa Medicine
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• v.16 no.2
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• pp.267-280
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• 2007

Gupoongjeseuptang(GPJST) is a traditional herbal medicine used for the treatment of dermatitis. The aim of this study was to confirm whether or not GPJST has a preventive effect on development of atopic dermatitis in dinitrochlorobenzene(DNCB)-applied Nc/Nga mouse. This study was undertaken to develop a reliable mouse model demonstrating similar immunologic phenomena as human atopic dermatitis characterized with predominance of type-2 immune response. NC/Nga mouse were sensitized with $200\;{\mu\ell}$ of 1% 2,4-dinitrochlorobenzene(DNCB) (acetone : olive oil = 3 : 1 mixture) and challenged twice or three times with $150\;{\mu\ell}$ of 0.2% DNCB in a week for the following 4 weeks. GPJST was administered orally to Nc/Nga mouse for 6 weeks, which led to the remarkable suppression on the development of dermatitis, as determined by various immune factors related to pathogenesis of atopic dermatitis in splenocytes and DLN cells. In this study, GPJST selectively suppressed T ce11 (CD4+, CD3+CD69+, CD4+CD25+) activation, which may be essential for ratio of IL-4 versus INF-$\gamma$ produced in the splenic T cell culture supernatants was approximately 3-fold higher in the mouse treated with DNCB than their control mouse respectively. Immunologic studies showed down-regulated that the capacity of spleen T cells to produce IL-4, but IFN-$\gamma$ was up-regulated by means of oral intake of these GPJST. These results strongly suggest that GPJST is a promising candidate for treatment of human atopic dermatitis.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.9-16
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• 2011

This paper represents an interworking architecture for keeping the VLC audio quality between Worldwide Interoperability for Microwave Access (WiMAX) and IEEE 802.11 Mobile Ad hoc Network (MANET) where both mobile routers and mobile nodes are moving dynamically. Systematic performance analysis on the interworking architecture has been conducted by using OPNET simulator to show the results such as Packet Delivery Ratio (PDR) and throughput. Based on simulation results, when the number of MANET nodes is small, PDR remains relatively stable even though data packets increase. However, with the many MANET nodes, PDR decreases as data traffic increases. Throughput is affected by the number of MANET nodes. Especially when the MANET node density has increased further, throughput is much higher, but it is not affected by the mobility speed. However, FTP download and upload response time is not affected much by both the number of MANET nodes and the mobility speed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7B
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• pp.536-549
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• 2012

An ad hoc network consists of nodes with limited energy. Therefore, the data transmission can fail abruptly due to lack of energy of transmitting node. A previous work PAMP proposed to build multiple low-energy paths to support stable packet delivery exploiting the nodes with low energy. It has energy-reservation scheme and multi-path selection scheme for stationary wireless ad hoc networks. In this paper, we propose an extended version of PAMP by incorporating network coding opportunity in path selection process. The simulation results show that our proposed scheme shows better packet delivery ratio and lower energy consumption compared with PAMP and a legacy energy-aware multipath routing protocol REAR.

• Journal of Gastric Cancer
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• v.16 no.2
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• pp.98-104
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• 2016

Purpose: The incidence of gallstones after gastrectomy for gastric cancer is higher than in the general population. However, the causes and mechanisms of post-gastrectomy gallstones are unclear. The aim of this study was to evaluate the incidence of gallstone formation and the risk factors for their development after gastrectomy for gastric cancer. Materials and Methods: Of 1,744 gastric cancer patients who underwent gastrectomy at Seoul National University Bundang Hospital between January 2010 and December 2012, 1,284 were included in this study and retrospectively reviewed. Patients' age, sex, body mass index (BMI), tumor location, stage, type of gastrectomy, type of reconstruction, and extent of node dissection were evaluated. Results: The incidence of gallstones after gastrectomy for gastric cancer was significantly higher in men than in women (P=0.019). Exclusion of the duodenum during reconstruction was associated with a significantly higher incidence of gallstones (P=0.003). Overweight and obese patients with BMI ${\geq}23kg/m^2$ had significantly higher incidence of gallstones than those with a lower BMI (P=0.006). Multivariate analysis showed that obesity (hazard ratio, HR=1.614; 95% confidence interval, CI: 1.135~2.296; P=0.008), male sex (HR=1.515, 95% CI: 1.029~2.231, P=0.033), and exclusion of the duodenum (HR=1.648, 95% CI: 1.192~2.280, P=0.003) were significant, independent risk factors for gallstones after gastrectomy. Conclusions: The cumulative incidence of gallstones for 5 years after gastrectomy was 15.3%. Male sex, obesity, and exclusion of the duodenum were risk factors for gallstone formation after gastrectomy. Careful surveillance will be required for these patient groups after gastrectomy.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2771-2778
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• 2014

In this paper, we propose an algorithm that select efficient relay nodes using information of network environment and nodes. The proposed algorithm can be used changeable weight factors as following network environment in node density. The routing protocols adopting store-carry-forward method are used for solving network problems occurred by unstable end-to-end connection in Delay Tolerant Networks(DTNs). Exiting DTN routing algorithms have problems that large latency and overhead because of deficiency of network informations. The proposed algorithm could be provide a solution this problems using changeable weight factor and prediction of network environment. Thus, selected relay nodes work efficiently in unstable and stressed network environment. Simulation results show that enhancement performance as overhead, delivery ratio, average latency compared to exiting DTN routing algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6B
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• pp.583-591
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• 2011

We presents the architecture of the 2.5 Gbps hybrid PON link which can increase of the transmission distance and link capability, and split ratio by using a colorless DWDM-PON and O/E/O based reach extender into an existing G-PON link. A RSOA based DWDM-PON to apply the feeder fiber can provide a link capacity of 32 larger that of a legacy G-PON. The reach extender converts the wavelength of DWDM-PON to G-PON through GTC frame regeneration at the remote node, and can provide a burst reset signal in order to extract upstream burst signal, simultaneously. The proposed hybrid PON enable a legacy G-PON to operate over the maximum 60 km distance with a 128-way split per WDM wavelength.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.20-27
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• 2013

In recently years, with the growth of social media and the development of mobile devices, the data have been significantly increased. MapReduce is an emerging programming model that processes large amount of data. However, since MapReduce evenly places the data in the dedicated distributed computing environment, it is not suitable to the non-dedicated distributed computing environment. The data replacement algorithms were proposed for performance optimization of MapReduce in the non-dedicated distributed computing environments. However, they spend much time for date replacement and cause the network load for unnecessary data transmission. In this paper, we propose an efficient data replacement algorithm for the performance optimization of MapReduce in the non-dedicated distributed computing environments. The proposed scheme computes the ratio of data blocks in the nodes based on the node availability model and reduces the network load by transmitting the data blocks considering the data placement. Our experimental results show that the proposed scheme outperforms the existing scheme.