• Journal of Korean Institute of Industrial Engineers
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• v.20 no.4
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• pp.65-72
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• 1994

An independent set of nodes is a set of nodes no two of which are joined by an edge. An independent set is called maximal if no more nodes can be added to the set without destroying its independence. The greatest number of maximal independent set is the maximum possible number of maximal independent set of a graph. We consider the greatest number of maximal independent set in connected graphs with fixed numbers of edges and nodes. For arbitrary number of nodes with a certain class of number of edges, we present the connected graphs with the greatest number of maximal independent set. For a given class of number of edges, the structure of graphs with the greatest number of maximal independent set is that the two components are completely joined; one consists of disjoint triangles as many as possible and the other is the complete graph with remaining nodes.

• Journal of Gastric Cancer
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• v.3 no.3
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• pp.134-138
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• 2003

Purpose: The lymph node (N) classification in the International Union Against Cancer (UICC) TNM staging system for gastric adenocarcinomas has been revised from the anatomic sites of metastatic lymph nodes to the number of metastatic lymph nodes. The purpose of this study was to investigate the proper number of retrieved lymph nodes for applying the new TNM staging system. Materials and Methods: We retrospectively studied 267 patients who had undergone a curative resection performed by one surgeon for gastric adenocarcinomas from March 1993 to December 1996 at Korea University Guro Hospital. We compared the old staging system to the new one and analyzed the number of retrieved and metastatic lymph nodes. We also analyzed the number of retrieved and metastatic lymph nodes according to the operative procedure and the extent of the lymphadenectomy, as well as the correlation of lymph-node metastasis to the number of retrieved lymph nodes. Results: The mean number of retrieved lymph nodes was $34.27\pm14.18$, of those $6.85\pm6.24$ were metastatic. According to the extent of the lymphadenectomy, these numbers were $17.8\pm9.3\;and\;7.0\pm5.3$ in D1, $33.1\pm14.6\;and\;3.0\pm3.0$ in $D1+\alpha$, $33.9\pm13.8\;and\;7.5\pm6.2$ in D2, and $40.6\pm13.3\;and\;7.9\pm7.5$ in $D2+\alpha$. There was no correlation between the percentage of the specimen with positive lymph nodes and the number of retrieved lymph nodes, but a logistic regres sion analysis showed that the probability of lymph-node metastasis increased as the number of retrieved lymph nodes increased. Conclusion: The mean number of retrieved lymph nodes was about 34. Although by logistic regression analysis, the probability of lymph-node metastasis increased as the number of retrieved lymph nodes increased, we failed to determine the minimum number of nodes retrieved during a lymphadenectomy needed for accurate staging in a gastric adenocarcinoma. Further study is required to identify the optimum number of lymph nodes that need to be retrieved.

• Journal of the Korea Society of Computer and Information
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• v.18 no.12
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• pp.27-34
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• 2013

In wireless sensor networks, sensors need to communicate with each other to send their sensing data to the administration node and so they are susceptible to many attacks like garbage packet injection that cannot be prevented by using traditional cryptographic approaches. A behavior-based detection is used to defend against such attacks in which some specialized monitoring nodes overhear the communications of their neighbors to detect bad packets. As monitoring nodes use more energy, it is desirable to use the minimal number of monitoring nodes to cover the whole or maximal part of the network. The monitoring nodes can either be selected among the deployed normal nodes or differ in type from normal nodes. In this study, we have developed an algorithm for selecting the predefined number of monitoring nodes needed to cover the maximum number of normal nodes when the different types of normal nodes and monitoring nodes are deployed. We also have investigated experimentally how the number of monitoring nodes and their transmission range affect the connection ratio of the monitoring nodes and the coverage of the normal nodes.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1181-1185
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• 2016

Background: The aim of this study is to compare the numbers of axillary lymph nodes (ALN) taken out by dissection between patients with breast cancer operated on after having neoadjuvant chemotherapy (NAC) treatment and otherswithout having neoadjuvant chemotherapy, and to investigate factors affecting lymph node positivity. Materials and Methods: A total of 49 patients operated due to advanced breast cancer after neoadjuvant chemotherapy and 144 patients with a similar stage of the cancer having primary surgical treatment without chemotherapy at the general surgery clinic of Ondokuz Mayis University Medicine Faculty between the dates 01.01.2006 and 31.10.2012 were included in the study. The total number of lymph nodes taken out by axillary dissection (ALND) was categorized as the number of positive lymph nodes and divided into <10 and ${\geq}10$. The variables to be compared were analysed using the program SPSS 15.0 with P<0.05 accepted as significant. Results: Median number of dissected lymph nodes from the patient group having neoadjuvant chemotherapy was 16 (16-33) while it was 20 (5-55) without chemotherapy. The respective median numbers of positive lymph nodes were 5 (0-19) and 10 (0-51). In 8 out of 49 neoadjuvant chemotherapy patients (16.3%), the number of dissected lymph nodes was below 10, and it was below 10 in 17 out of 144 primary surgery patients. Differences in numbers of dissected total and positive lymph nodes between two groups were significant, but this was not the case for numbers of <10 lymph nodes. Conclusions: The number of dissected lymph nodes from the patients with breast cancer having neoadjuvant chemotherapy may be less than without chemotherapy. This may not always be attributed to an inadequate axillary dissection. More research to evaluate the numbers of positive lymph nodes are required in order to increase the reliability of staging in the patients with breast cancer undergoing neoadjuvant chemotherapy.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.8
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• pp.62-67
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• 2007

In some wireless sensor networks, the sensor nodes are required to be located sparsely at designated positions over a wide area, introducing the problem of adding minimum number of relay nodes to interconnect the sensor nodes. The problem finds its form in literature: the Minimum number of Steiner Points. Since it is known to be NP-hard, this paper proposes an approximation scheme to estimate the minimum number of relay nodes through the properties of the abstract from. Reducing the number of nodes in a sensor network, the amount of data exchange over the net will be far decreased.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7559-7562
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• 2014

Currently the most important prognostic factor in lung cancer is the stage. In the current lung TNM classification system, N category is defined exclusively by anatomic nodal location though, in other type of tumours, number of lymph nodes is confirmed to be a fundamental prognostic factor. Therefore we evaluated the number of mediastinal lymph nodes as a prognostic factor in locally advanced NSCLC after multimodality treatment, observing a significant effect of the number of lymph nodes in terms of OS (p<0.01) and DFS (p<0.001): patients with a low number of positive mediastinal nodes have a better prognosis.

• Journal of Industrial Technology
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• v.18
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• pp.195-202
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• 1998

The effect of the number of nodes on the heat loss from a rectangular fin for a finite difference method is studied. There are two ways for selecting nodes for the upper half fin in this finite difference method. In the first place, all the ${\Delta}x$ are the same and all the ${\Delta}y$ are the same for the entire upper half fin. Incremental length of x (i.e. ${\Delta}x$) is divided by two near the fin tip while all the ${\Delta}y$ are the same for another way. The results show that 1) About 30 nodes are enough to obtain the satisfactory exact analysis (relative error < 5%) on the heat loss for a given range of Biot number in case of short fin (i.e. $L{\leq}2$). 2) Under usual circumstances (Bi<0.1), the relative error of heat loss between using 30 nodes and 90 nodes is within 4% for given range of non-dimensional fin length. 3) The relative error of the calculated heat loss (the number of node=90) as compared to the expected exact heat loss is less then 1.5% for Bi=0.1 and L=10 while that is over 13% for Bi=1.0 and L=10.

• Journal of Korea Multimedia Society
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• v.10 no.1
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• pp.94-101
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• 2007

Partial dominant pruning(PDP) is regarded as the most practical scheme, reducing redundant messages arisen in broadcasting over ad hoc networks, in such a way that only part of nodes are allowed to forward the received broadcast message. In this paper we propose an extend PDP version called DPDP(directional PDP) such that it reduces not only the number of selected forward nodes, but also the number of antenna elements deployed by the forward nodes. It turns out through simulation that as the number of antenna elements increases, the number of selected forward nodes by DPDP slightly outnumbers that obtained using PDP but both the number of antenna elements deployed by the forward nodes and the redundancy ratio of the received message per node always outperform respectively those given by PDP.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.929-935
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• 2017

All sensor nodes generally determine their positions using anchor nodes that are located in underwater sensor networks. This paper proposes a Tabu search algorithm to determine the minimum number of anchor nodes for the location of all sensor nodes in underwater sensor networks. As the number of the sensor nodes increases in the network, the amount of calculation that determines the number of anchor nodes would be too much increased. In this paper, we propose a Tabu search algorithm that determines the minimum number of anchor nodes within a reasonable computation time in a high dense network, and propose an efficient neighborhood generating operation of the Tabu search algorithm for efficient search. The proposed algorithm evaluates those performances through some experiments in terms of the minimum number of anchor nodes and execution time. The proposed algorithm shows 5-10% better performance than the conventional algorithm.

• Journal of the Korea Society of Computer and Information
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• v.10 no.5 s.37
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• pp.209-216
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• 2005

In wireless sensor networks, an estimation method is proposed for distances between nodes within two hops. The method uses only proximity information of nodes without physiccal distance measurements. It drastically improves the performance of localization algorithms based on Proximity information. In addition, it is the first method that estimates distances between nodes exactly in two hops. The distances are estimated from the number of common neighbors under an assumption that the number of common neighbors is proportional to the intersection of two unit disks centered at the two nodes. Simulation analysis shows that the estimation error is roughly from 10 to 20 percent of real distances. Meanwhile, the number of messages required by a distributed algorithm realizing this method is only two times the number of nodes.