• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.2
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• pp.269-286
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• 2011

In this paper, we study a problem that is concerning how to construct a delay-constrained multicast tree on a wireless mesh network (WMN) such that the number of serviced clients is maximized. In order to support high-quality and concurrent interference-free transmission streams, multiple radios are implemented in each mesh node in the WMNs. Instead of only orthogonal channels used for the multicast in the previous works, both orthogonal and partially overlapping channels are considered in this study. As a result, the number of links successfully allocated channels can be expected to be much larger than that of the approaches in which only orthogonal channels are considered. The number of serviced subscribers is then increased dramatically. Hence, the goal of this study is to find interference-free and delay-constrained multicast trees that can lead to the maximal number of serviced subscribers. This problem is referred as the MRDCM problem. Two heuristics, load-based greedy algorithm and load-based MCM algorithm, are developed for constructing multicast trees. Furthermore, two load-based channel assignment procedures are provided to allocate interference-free channels to the multicast trees. A set of experiments is designed to do performance, delay and efficiency comparisons for the multicast trees generated by all the approximation algorithms proposed in this study.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.1-8
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• 2020

The influence of growth regulators (NAA and BA) and sucrose concentrations (0, 3, 5, 7, 9%) on in vitro rapid-propagation of virus-free sweet potato [Ipomoea batatas (L.) Lam.] was investigated with single-node or shoot-tip culture of two cultivars ('Matnami' and 'Shinhwangmi'). The survival rate and growth of shoot-tip explant was also investigated under the presence or absence of light (blue and red LED = 7:3, 150±5 μmol·m^-2·s^-1 PPFD) during minimal-growth in vitro conservation at 15℃. Vine length, vine diameter, fresh weight and dry weight were enhanced without callusing of explant in the MS medium supplemented with 0.2-0.5 mg·L^-1 BA. The growth of single-node and shoot-tip explants were significantly enhanced with the increase of vine length, number of leaf, number of root, fresh weight, and dry weight in the solid medium containing 5% sucrose and 0.2 mg·L^-1 BA. Vine elongation of shoot-tip explants were highest in the liquid medium containing 3% sucrose than the solid medium. The survival rate of minimal-growth in vitro conservation was 100% in 5 months under the presence of light (LED, 150±5 μmol·m^-2·s^-1 PPFD) at 15℃, but the explants in dark condition died in 3 months. The light was absolutely necessary for the in vitro conservation under minimal-growth conditions of virus-free sweet potato plantlets at 15℃, and the high density of explants (10 plantlets per Petri Dish) was increased the efficiency of mass conservation.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.686-693
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• 2012

To develop a technique for mass-propagation of virus-free sweet potato [Ipomoea batatas (L.) Lam.] plant using nutrient film technique (NFT), the growth characteristics of 4 cultivars as affected by nutrient solution composition and cutting size were investigated. 72 cells (35 mL/cell) plug trays filled with vermiculite and perlite (1:1, v/v) were used. Vine length, fresh and dry weights of virus-free plants were the greatest in the nutrient solution recommended by National Horticultural Research Station in Japan, followed by that recommended by National Institute of Horticultural & Herbal Science in Korea, and Yamazaki's nutrient solution for lettuce. The growth of uppershoot cuttings was the best among 4 subsections of cutting. Vine length, and fresh and dry weights increased in the longer cutting treatments, and were better in 'Shinzami' and 'Yeonhwangmi' than those in 'Mannami' and 'Shincheonmi'. Vine diameter and length of the longest root were not significantly affected by the cutting size and cutting source. The growth characteristics of the single node cutting were not significantly different from those in 2-node cutting. The efficiency of rapid mass-propagation could be promoted with single node cuttings and uppershoot cuttings grown in NFT system.

• Journal of Chest Surgery
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• v.46 no.1
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• pp.49-55
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• 2013

Background: The aim of this study was to determine the survival rate of patients with non-small cell lung cancer (NSCLC) who were preoperatively diagnosed with a negative N2 lymph node, but postoperatively confirmed as a positive N2 node based on a pathological evaluation. Materials and Methods: The hospital records of 248 patients from 1994 to 2009 with resected primary NSCLC who were preoperatively diagnosed with negative N2 lymph node, were retrospectively reviewed. Of these, after surgery, there were 148 (59.7%) patients with pathological N0, 54 (21.8%) with pathological N1 and 46 (18.5%) with pathological N2. Results: The median follow-up period was 24 months (range, 1 to 132 months). The 5-year disease free survival rates were 60% in pN0, 44% in pN1, and 29% in pN2. The 5-year overall survival rates were 63.1% in pN0, 51.9% in pN1, and 33.5% in pN2. There were no statistically significant differences between pN1 and pN2 (p=0.326 and p=0.106, respectively). Thirty-three (71.7%) of the 46 pN2 patients had single-zone metastasis, and 13 patients (28.3%) had multiple-zone metastases over the two nodal zone metastasis. There were no statistical differences in the 5-year disease free survival rate and the 5-year overall survival rates between the two groups. Conclusion: The 5-year disease free survival and the overall survival rate of the patients with unsuspected N2 disease were statistically similar with that of the patients with pathological N1 disease. There was no statistically significant difference between the patients with a single-zone metastasis and a multiple zone metastasis.

• Journal of Korean Association for Spatial Structures
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• v.4 no.2 s.12
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• pp.63-71
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• 2004

The structural space is gradually wide and is wanting agreeable environment by the requirement and necessity of people who lives modem stage. The building coincides with such requirements and is the high rise building actual circumstances which is doing ultra-large. The confirmed report of the technology to organize great merit is becoming currently considerably important issue in constructing a building field. Thus, this paper examine closely for nonlinear unstable taking a picture uneasiness height of prosperity considering to initial imperfection by a numerical method with a space frame structure of discrete system in large space structure. Based on previous investigation method, this paper induce nodal stiffness matrix of solid truss elements considering geometrical nonlinear using finite element method. In this paper, three types of space structure considered; i) 1-free node space structure, ii) 2-free node space structure, iii) multi-free node space structure. It apply the above examples to a nonlinear program, next, grasp the characteristic of an unstable conduct and the result was a clearing low.

• Radiation Oncology Journal
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• v.15 no.4
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• pp.357-367
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• 1997

Purpose : To identify variable prognostic factors and analyse failure patterns in the uterine cervix cancer after radical operation and adjuvant radio-therapy, a retrospective analysis was undertaken. Materals and Methods : I analysed one hundred and twenty four patients with uterine cervix cancer, FIGO stage IB, IIA and IIB, treated with radical hysterectomy and pelvic lymph node dissection followed by adjuvant radio-therapy between May 1985 and May 1994. Minimum follow up period was 24 months. All of them were treated with full dose external radiotherapy with linear accelerator and/or high dese rate intracavitary radiation. Results : Overall 5 year survival rate and relapse free survival rate were $75.4\%,\;73.5\%$, respectively. Significant prognostic factors by relapse free survival were wall involvement thickness, lymph node location and number, parametrium involvement, tumor size, stage, uterine body involvement, vaginal resection margin involvement. By multivariate analysis, lymph node matastasis. tumor size and vaginal resection margin involvement were significant prognostic factos. Treatment related failure were 33 cases. Locoregional failure were more likely in the stage IIB, lymph node positive or vaginal resection margin positive patients whereas distant failures were relatively more frequent in stage IB, IIA and lymph node, vaginal resection negative patients. In stage IIB, 5 year relapse free survival rate was only $56\%$ and nine of twenty two patients recurred. Conculsion : Postoperative radiotherapy results are good for patients with relatively low risk factor. But the results are poor for patients with multiple, high risk factors or stage IIB. To control recurrence for patients with high risk factors, postoperative adjuvant radiotherapy is not sufficient treatment method. To raise control rate adding other methods such as radiosensitizing agent or chemotherapy is necessary and prospectively randomized study is needed for evaluation of postoperative radiotherapy efficacy and /or other methods. And it is reasonable to treat primary radical radiotherapy for patients with stage IIB cervical cancer instead of radical operation and adjuvant radiotherapy and/or chemotherapy regimen.

• The Journal of the Korean bone and joint tumor society
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• v.16 no.2
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• pp.69-73
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• 2010

Purpose: Sentinel lymph node (SLNB) is the first confronted lymph node from primary lesion of tumor through lymphatic drainage, which is important for determining early metastasis and setting guidelines for treatment. We reported significant of sentinel lymph node biopsy in malignant melanoma (MM) and squamous cell carcinoma (SCC) of lower extremities. Materials and Methods: Twenty-five cases of surgically treatment and being possible for follow up more than 1 year among the patients who were diagnosed as MM and SCC in this institution from Sep. 2005 to Jan. 2009, and 10 cases of them were performed SLNB. Average age was 64 years old, and 15 cases of male and 10 cases of female were in this group. Results: 3 years overall survival rate was 100% and 3 years disease-free survival rate was 76%. Metastasis occurred in total 6 patients, 4 cases of inguinal lymph nodes, 1 case of soft tissue around knee, 1 case of left achilles tendon. In 15 cases of not performing SLNB, overall survival rate was 93.3% and disease-free survival rate was 73.3%. In 10 cases of performing SLNB, overall survival rate was 100% and disease-free survival rate was 90%. And only 1 case showed positive finding in the biopsy, and none of the 10 cases showed metastasis in follow-up. Conclusion: SLNB leads simpler and less complications compared to prior elective lymph node dissection, and shows high degree of accuracy. Throughout the SLNB, setting guidelines for treatment by accurate staging is thought to be helpful for increasing the survival rate in the patient with MM and SCC.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.4
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• pp.351-361
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• 2014

Compared to a terrestrial communication, the high BER(Bit Error Ratio) and low channel bandwidth are the major factor of throughput degradation due to characteristics of underwater channel. Therefore, a MAC protocol must be designed to solve this problem in UWASNs(Underwater Acoustic Sensor Networks). MAC protocols for UWASNs can be classified into two major types according to the contention scheme(Contention-free scheme and Contention-based scheme). In large scale of sensor networks, a Contention-based scheme is commonly used due to time-synchronize problem of Contention-free scheme. In the contention-based scheme, Each node contends with neighbor nodes to access network channel by using Back-off algorithm. But a Slot-Time of Back-off algorithm has long delay times which are cause of decrease network throughput. In this paper, we propose a new scheme to solve this problem. The proposed scheme uses variable Slot-Time instead of fixed Slot-Time. Each node measures propagation delay from neighbors which are used by Slot-time. Therefore, Slot-Times of each node are optimized by considering node deployment. Consequently, the wasted-time for Back-off is reduced and network throughput is improved. A new mac protocol performance in throughput and delay is assessed through NS3 and compared with existing MAC protocol(MACA-U). Finally, it was proved that the MAC protocol using the proposed scheme has better performance than existing MAC protocol as a result of comparison.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5365-5369
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• 2014

Background: The lymph node ratio (LNR) has been shown to be an important prognostic factor for colorectal cancer. However, studies focusing on the prognostic impact of LNR in rectal cancer patients who received neoadjuvant chemoradiotherapy (CRT) followed by curative resection have been limited. The aim of this study was to investigate LNR in rectal cancer patients who received neoadjuvant chemoradiotherapy (CRT) followed by curative resection. Materials and Methods: A total of 131 consecutive rectal cancer patients who underwent neoadjuvant CRT and total mesorectal excision were included in this study. Patients were divided into two groups according to the LNR (${\leq}0.2$ [n=86], >0.2 [n=45]) to evaluate the prognostic effect on overall survival (OS) and disease-free survival (DFS). Results: The median number of retrieved and metastatic lymph node (LN) was 14 (range 1-48) and 2 (range 1-10), respectively. The median LNR was 0.154 (range 0.04-1.0). In multivariate analysis, LNR was shown to be an independent prognostic factor for both overall survival (hazard ratio[HR]=3.778; 95% confidence interval [CI] 1.741-8.198; p=0.001) and disease-free survival (HR=3.637; 95%CI 1.838-7.195; p<0.001). Increased LNR was significantly associated with worse OS and DFS in patients with <12 harvested LNs, and as well as in those ${\geq}12$ harvested LNs (p<0.05). In addition, LNR had a prognostic impact on both OS and DFS in patients with N1 staging (p<0.001). Conclusions: LNR is an independent prognostic factor in ypN-positive rectal cancer patients, both in patients with <12 harvested LNs, and as well as in those ${\geq}12$ harvested LNs. LNR provides better prognostic value than pN staging. Therefore, it should be used as an additional prognostic indicator in ypN-positive rectal cancer patients.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.461-465
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• 2007

MANET(Mobile Ad hoc Networks) is free-mobility formation of mobile nodes in the wireless networks. Generally, wireless networks has two main type of structures which Tree and Mesh. These general structure is difficult to do which connectivity, redundancy transmit and network continuant. In this paper, we would suggest a new ODDMRP(Ontology Doppler effect-based Dynamic Multicast Routing Protocol) technology for effective MANET which Ontology Doppler effect-based. ODDMRP consist of the parameters for node entropy when using Doppler effect which moving position of round node, moving time, and distribution chart in velocity also it express distance of destination node and property structure organization. It would be used to provide improvement to keep the optimal communication routing and also could be improve network stabilization, and continuation durability of connectivity.