• Journal of the Korean Society of Safety
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• v.22 no.5
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• pp.1-6
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• 2007

Vibro-impacts in manual transmissions result due to several nonlinearities such as multi-staged clutch characteristics and gear backlashes. For the sake of understanding the torsional system, one specific manual transmission with front engine and front wheel drive configuration is investigated with a linear model under the several assumptions substituting the nonlinear factors. First, this system is examined with the mathematical approaches by expressing the governing equations to find out the torsional motions. Second, this system is analyzed using the linear model in order to understand its modal and frequency response characteristics using eigensolution method and the FRF(Frequency Responses Function) analysis. Third, with the given results from the eigensolutions, several mode shapes are investigated related to the torsional motion characteristics. Fourth, the system characteristics with the FRFs are studied with the basic approach, with which the several key parameters will be suggested based upon the results in the further studies.

• IE interfaces
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• v.23 no.2
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• pp.108-117
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• 2010

Wireless sensor network may be installed where it is hard to access or where one has to constantly gather data without any human's monitoring. Sensors which compose a sensor network are usually small with poor battery capacities and thus energy-efficient usage is very important because of difficulties in replacing or recharging the batteries to make the lifetime of the whole sensor network longer. LEACH protocol, a well-known hierarchical routing protocol, may resolve this problem by distributing the role of cluster header evenly to the sensor nodes in the whole area of network at each round. In this thesis, we introduce a variant of LEACH protocol which considers the distance between base station and sensors in the way that if a node is far from the base station then the probability that this node becomes a cluster header is low. Experiments to evaluate the energy efficiency and the ability to collect the information show that the proposed method in this paper has maintained much wider sensing area while keeping the energy efficiency same as LEACH.

• Journal of Crop Science and Biotechnology
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• v.11 no.1
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• pp.63-68
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• 2008

The induced genetic divergence was estimated in 44 mutant lines of finger millet variety GPU 26, developed by single and combination treatments with gamma rays, EMS and NG using three multivariate analyses. The mutant lines were grouped into eight genetically diverse clusters by multivariate D2 and canonical analyses and 11 clusters by dendrogram grouping through Gower's similarity coefficient. The clustering pattern in these three methods was almost similar. Twelve mutant lines in D2 and 13 in the dendrogram grouping method were grouped in the parental cluster(Cluster I) indicating that they did not possess enough divergence from the parent to be classified as micromutant lines. However a large proportion of mutant lines showed divergence from the parent variety and also among themselves. No definite relationship of mutagenic origin and clustering of mutant lines were observed. The mutant lines developed from the same mutagenic treatments often grouped into different clusters indicating that each mutagenic treatment was effective in inducing diverse types of changes in the nine traits studied. The hybridization program between the divergent mutant lines GE 2-2 or GE 3-4 with GG 3-1 is expected to give promising and desirable segregants in subsequent generations. Traits such as days to 50% flowering and days to maturity had major contributions to the induced genetic divergence.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.1
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• pp.25-37
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• 2002

The purpose of the study was to survey the distribution patterns of inorganic elements of PM-10 in the various indoor environments and analyze the pollution patterns of aerosol in various places of indoor environment using a pattern recognition method based on cluster analysis and disjoint principal component analysis. A total of 40 samples in the indoor had been collected using mini-vol portable samplers. These samples were analyzed for their 19 bulk inorganic compounds such as B, Na, Mg, Al, K, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, As, Se, Cd, Ba, Ce, and Pb by using an ICP-MS. By applying a disjoint principal component analysis, four patterns of the indoor air pollutions were distinguished. The first pattern was identified as a group with high concentrations of PM-10, Na, Mg, and Ca. The second pattern was identified as a group with high concentrations B, Mg, At, Ca, Fe, Cu, and Ba. The third pattern was a group of sites with high concentrations of K, Zn. Cd. The fourth pattern was a group with low concentrations PM-10 and all inorganic elements. This methodology was found to be helpful enough to set the criteria standard of indoor air quality, corresponding pollutants, and classification of indoor environment categories when making an indoor air quality law.

• Environmental and Resource Economics Review
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• v.17 no.4
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• pp.691-717
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• 2008

The Kyoto Mechanisms allows a supplementary means for compliance, CDM(Clean Development Mechanism) and JI(Joint Implementation) projects. The investment in CDM projects is increasing rapidly as the first implementation period began in 2008. This paper seeks to determine factors affecting the price of primary CER using UNFCCC CDM Project Development Document(PDD) data. This study employs the Cluster analysis and the GLS(Generalized Least Squares) method.

• The Journal of the Korea Contents Association
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• v.7 no.9
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• pp.127-138
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• 2007

Due to the development of internet technology and the steady increase of turnover at B2C market many companies put a lot of work into maintaining a good relationship with internet customers. Particularly, analyzing and understanding specific customer groups are essential for effective CRM and marketing strategy Thus, this paper proposes the method to define the customers of online bookstore into several meaningful groups. Five important factors and factor scores for each respondent are obtained by Factor Analysis. Six groups are classified by Cluster Analysis and Analysis of Variance(ANOVA) is used to verify the difference between each group.

• Journal of KIISE:Information Networking
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• v.36 no.2
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• pp.98-107
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• 2009

In this paper, we propose a novel centralized energy-efficient clustering algorithm, called "MCCA : Max k-Cut based Clustering Algorithm for Wireless Sensor Networks." The algorithm does not use location information and constructs clusters via a distributive Max k-Cut based cluster-head election method, where only relative and approximate distance information with neighbor nodes is used and nodes, not having enough energy, are excluded for cluster-heads for a specific period. We show that the energy efficiency performance of MCCA is better than that of LEACH, EECS and similar to BCDCP's by simulation studies.

• The Transactions of the Korea Information Processing Society
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• v.7 no.11
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• pp.3427-3437
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• 2000

In this paper,we propose an method of core sciences extractionusing word cooccrrence graph in order to summarize a document. For automatic extraction of core sentenees, we construct a mean cluster from word cooccurrence graph, and find insistence which corresponds a porposed of author. And then we extract keywords by using relationship between mean cluster and isistence. Finally, core senrences are sclected based on keywords and insitances. The esults are evaluated by comparing with manual extraction, and show that the extraction performance is improved about 10%.

• Journal of the Ergonomics Society of Korea
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• v.34 no.3
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• pp.235-245
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• 2015

Objective: The purpose of this study is to develop visual complexity metrics based on theoretical bases. Background: With the development of IT technologies, drivers process a large amount of information caused by automotive human-machine interface (HMI), such as a cluster, a head-up display, and a center-fascia. In other words, these systems are becoming more complex and dynamic than traditional driving systems. Especially, these changes can lead to the increase of visual demands. Thus, a concept and tool is required to evaluate the complicated systems. Method: We reviewed prior studies in order to analyze the visual complexity. Based on complexity studies and human perceptual characteristics, the dimensions characterizing the visual complexity were determined and defined. Results: Based on a framework and complexity dimensions, a set of metrics for quantifying the visual complexity was developed. Conclusion: We suggest metrics in terms of perceived visual complexity that can evaluate the in-vehicle displays. Application: This study can provide the theoretical bases in order to evaluate complicated systems. In addition, it can quantitatively measure the visual complexity of In-vehicle information system and be helpful to design in terms of preventing risks, such as human error and distraction.

• Korean Journal of Environment and Ecology
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• v.8 no.2
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• pp.135-141
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• 1995

To investigate the structure and the conservation strategy of natural forest at Nature Conservation Area in Chuwangsan, 21 plots(20$\times$20m) set up with random sampling method. Two groups were classified by cluster analysis. High positive correlations was proved between Carpinus laxiflora and Fraxinus rynchophylla, Quercus serrata and Quercus variabilis, Lindera obtusiloba and Stephanandra incisa and High negative correlations was proved between Acer mono and Fraxinus sieboldana, Acer pseudo-sieboldianum and Quercus variabilis. Species diversity(H') of investigated area was calculated 1.1306~1.2688.