• Geomechanics and Engineering
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• v.14 no.3
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• pp.257-269
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• 2018

Analysis of slope stability failures, as one of the complex natural hazards, is one of the important research issues in the field of civil engineering. Present paper adopts and investigates four soft computing-based techniques for this problem: Patient Rule-Induction Method (PRIM), M5' algorithm, Group Method of data Handling (GMDH) and Multivariate Adaptive Regression Splines (MARS). A comprehensive database consisting of 168 case histories is used to calibrate and test the developed models. Six predictive variables including slope height, slope angle, bulk density, cohesion, angle of internal friction, and pore water pressure ratio were considered to generate new models. The results of test studies are used for feasibility, effectiveness and practicality comparison of techniques with each other, and with the other available well-known methods in the literature. Results show that all methods not only are feasible but also result in better performance than previously developed soft computing based predictive models and tools. It is shown that M5' and PRIM algorithms are the most effective and practical prediction models.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.11a
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• pp.589-598
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• 2006

The rectilinear Steiner tree problem is to find a minimum-length rectilinear interconnection of a set of terminals in the plane. It is well known that the solution to this problem will be the minimal spanning tree (MST) on some set Steiner points. A hybrid evolutionary algorithm is introduced based upon the Prim algorithm. The Prim algorithm for the fitness evaluation requires heavy calculation time. The fitness value of parents is inherited to their child and the fitness value of child is estimated by the inherited structure of tree. We introduce four alternative evolutionary algorithms, Experiment result shows that the calculation time is reduced to 25% without loosing the solution quality by using the fitness estimation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.2
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• pp.33-39
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• 2015

Power supplying capacity of the distribution feeder should be maintained within thermal capacity of the wire. This paper presents the minimum spanning tree based load balancing technique to release multiple overloading of distribution feeders. In order to minimize number of involved backup feeders, Dijkstra and Prim algorithm are adopted to construct minimum spanning tree. Simulation testing result based on part of KEPCO's commercial distribution systems shows effectiveness of proposed scheme.

• Journal of the Korean Geographical Society
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• v.49 no.4
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• pp.601-614
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• 2014

The purpose of this study is to investigate high school students' geographic misconceptions and their mechanisms of formation. Three main theories explaining why students develop misconceptions exist: 1) framework theory, 2) p-prim(phenomenological primitive) theory, and 3) categorization theory. This study chose three target geographic concepts, or, 1st and 2nd mountain ranges, secondary central business district and satellite city, and the Nopsae wind and the F$\ddot{o}$hn phenomenon. Then, this research explored students' typical misconceptions regarding these concepts and attempted to examine which theory explains the misconception forming processes most well. As a result, the following misconceptions were found. First, students understood that the numbers 1 and 2 denote the order of the formation of mountain ranges. Second, despite differences in their main functions, students tended to subsume the secondary central business district and satellite city under one functional category. Third, students believed that the Nopsae wind and the F$\ddot{o}$hn phenomenon are identical in hierarchy. This study explained students' creation of these misconceptions by applying the categorization theory in which students located a concept in an inappropriate location of an ontology tree.

• Natural Product Sciences
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• v.11 no.2
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• pp.79-84
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• 2005

Thirteen compounds were isolated from the roots of Angelica genuflexa through repeated silica gel column chromatography. Nine coumarins, isoimperatorin (1), osthol (2), demethylsuberosin (3), oxypeucedanin (4), heraclenin (5), pabulenol (7), umbelliferone (8), oxypeucedanin hydrate (9) and marmesinin (11), and four chromones, hamaudol (6), cimifugin (10), sec-O-glucosylhamaudol (12) and prim-O-glucosylcimifugin (13), were identified by physicochemical and spectroscopic analysis. Among these, compounds 3, 5, 6, 8, 12, and 13 were isolated for the first time from the roots of Angelica genuflexa. These coumarins and chromones were examined for their anticomplement activity. Demethylsuberosin (3) showed a weak anticomplement activity with an $IC_{50}$ value of $390\;{\mu}M$.

• Nuclear Engineering and Technology
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• v.49 no.5
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• pp.928-940
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• 2017

An experiment using the $Prim{\ddot{a}}rkreisl{\ddot{a}}ufe$ Versuchsanlage (PKL) was performed for the OECD/NEA PKL-3 Project as a counterpart to a previous test with the large-scale test facility (LSTF) on a cold leg smallbreak loss-of-coolant accident with an accident management (AM) measure in a pressurized water reactor. Concerning the AM measure, the rate of steam generator (SG) secondary-side depressurization was controlled to achieve a primary depressurization rate of 200 K/h as a common test condition; however, the onset timings of the SG depressurization were different from each other. In both tests, rapid recovery started in the core collapsed liquid level after loop seal clearing, which caused whole core quench. Some discrepancies appeared between the LSTF and PKL test results for the core collapsed liquid level, the cladding surface temperature, and the primary pressure. The RELAP5/MOD3.3 code predicted the overall trends of the major thermal-hydraulic responses observed in the LSTF test well, and indicated a remaining problem in the prediction of primary coolant distribution. Results of uncertainty analysis for the LSTF test clarified the influences of the combination of multiple uncertain parameters on peak cladding temperature within the defined uncertain ranges.

• The KIPS Transactions:PartA
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• v.17A no.3
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• pp.159-166
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• 2010

In this paper, to obtain the Minimum Spanning Tree (MST) from the graph with several nodes having the same weight, I applied both Bor$\dot{u}$vka and Kruskal MST algorithms. The result came out to such a way that Kruskal MST algorithm succeeded to obtain MST, but not did the Prim MST algorithm. It is also found that an algorithm that chooses Inter-MSF MWE in the $2^{nd}$ stage of Bor$\dot{u}$vka is quite complicating. The $1^{st}$ stage of Bor$\dot{u}$vka has an advantage of obtaining Minimum Spanning Forest (MSF) with the least number of the edges, and on the other hand, Kruskal MST algorithm has an advantage of always obtaining MST though it deals with all the edges. Therefore, this paper suggests an Hybrid MST algorithm which consists of the merits of both Bor$\dot{u}$vka's $1^{st}$ stage and Kruskal MST algorithm. When applied additionally to 6 graphs, Hybrid MST algorithm has a same effect as that of Kruskal MST algorithm. Also, comparing the algorithm performance speed and capacity, Hybrid MST algorithm has shown the greatest performance Therefore, the suggested algorithm can be used as the generalized MST algorithm.

• Journal of KIISE:Information Networking
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• v.34 no.6
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• pp.458-465
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• 2007

Wireless Sensor Network(WSN) is a special network that collects measured data by sensor nodes in the predefined sensor field and forwards them to the base station in a distance using their own routing scheme. WSN requires routing techniques to maximize energy efficiency because sensor nodes have non-rechargeable and thus limited energy. Characteristics of WSN are various according to applications, many of routing algorithms have been proposed. This paper proposes an algorithm called A-PEGASIS that basically bases on PEGASIS and enhances in two aspects - an elegant chain generation algorithm and periodical update of chains. We compare performance of the previous algorithm of LEACH, PEGASIS, PEDAP and PEDAP-PA with ours through simulation. It confirms that the A-PEGASIS is most superior in terms of average WSN lifetime and high probability of node survival rate during WSN life time.

• Journal of KIISE:Databases
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• v.36 no.4
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• pp.306-313
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• 2009

Top-k queries are issued to find out the highest (or lowest) readings in many sensor applications. Many top-k query processing algorithms are proposed to reduce energy consumption; FILA installs a filter at each sensor node and suppress unnecessary sensor updates; PRIM allots priorities to sensor nodes and collects the minimal number of sensor reading according to the priorities. However, if many sensor reading converge into the same range of sensor values, it leads to a problem that many false positives are occurred. In this paper, we propose a cluster-based approach to reduce them effectively. Our proposed algorithm operates in two phases: top-k query processing in the cluster level and top-k query processing in the tree level. False positives are effectively filtered out in each level. Performance evaluations show that our proposed algorithm reduces about 70% false positives and achieves about 105% better performance than the existing top-k algorithms in terms of the network lifetime.

• Korean Journal of Bronchoesophagology
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• v.2 no.1
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• pp.63-70
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• 1996

Reconstruction for hypopharynx and cervical esophagus after wide resection of extensive hypopharynx and larynx cancers have been used various methods including myocutaneous flaps, gastric pull up, md jejunal or large bowel free graft. Recently, the authors had experienced hypopharynx and larynx cancers with extension to the posterior hypopharyngeal wall and thoracic esophagus. Of course, these reconstructive methods should be selected in accordance with the patient's age, physical status, extend of prim.:W lesion, and defect after on block resection, however, gastric pull up was performed in hypopharynx cancer which had skipped lesion in the thoracic esophagus and jejunal free grafts were performed in case 2, 3 which had a extended lesions to the posterior pharyngeal wall. Some complications were noted, which were successfully stabilized by conservative managements. The gastric pull up and jejunal free graft were considered suitable methods for reconstrunction of hypopharynx and cervical esophagus, however, further studies are necessary about it.