• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2003.04a
• /
• pp.87-90
• /
• 2003

In this paper, the electromechanical displacements of curved actuators such as THUNDER are calculated by finite element method to design the optimal configuration of curved actuators. To predict the pre-stress in the device due to the mismatch in coefficients of thermal expansion, the adhesive as well as metal and PZT ceramic is also numerically modeled by using hexahedral solid elements. Because the modeling of these thin layers causes the numbers of degree of freedom to increase, large-scale structural analyses are performed in a cluster system in this study. The curved shape and pre-stress in the actuator are obtained by the cured curvature analysis. The displacement under the piezoelectric force by an applied voltage is also calculated to compare the performance of curved actuator. The thickness of metal and adhesive, the number of metal layer are chosen as design factors.

• Asia pacific journal of information systems
• /
• v.14 no.4
• /
• pp.147-162
• /
• 2004

A major difference between on-line services and off-line services is in the quality of the service they provide. On-line services lack of dynamic interface between customers and service providers. Traditional studies on personalizing web services do not consider the intimacy level of customers to web services. This study suggests a web personalizing method to satisfy customers in on-line using intimacy theory, cluster analysis, and data mining. The goal of this study is to support customers in web with more intimate service. It also offers improved services to customers by personalizing web services dynamically.

• Korean Journal of Adult Nursing
• /
• v.24 no.5
• /
• pp.454-465
• /
• 2012

Purpose: The aim of this study was to understand the nurses' experiences of caring for demented older persons in geriatric in care facilities. Methods: The subjects were ten nurses employed in geriatric care facilities. Open in-depth interviews were used to collect data from January, 2010 to October, 2010. The Colaizzi phenomenological method was used for data analysis. Results: The experiences of nurses' caring for patients with dementia were divided into the following six categories: 'new encounter', 'understanding of intention and satisfying', 'dilemma of caring', 'contriving of comfort', 'comprehensive coordinator', and 'being present'. There were 15 clusters of themes. The subjects stated that the best caring for the demented older persons were 'encounter, knowing, and being with them'. Conclusion: Nurses' caring could improve the quality of life for demented older patients in geriatric care facility. These results suggest that institutional, administrational strategies and schemes need to cluster around the relationship with patients who would include encounter knowing and being with them.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.11a
• /
• pp.5-6
• /
• 2005

ZnO nanowlres (NWs) were fabricated using Au as catalyst for a method combining laser ablation cluster formation and vapor-liquid-solid (VLS) growth. The target used in synthesis was pure ZnO ceramics. Two different substrates were used; (0001)-oriented sapphires and Au-coated sapphires. The Au thin film was deposited by thermal evaporation and the thickness was about 50 ${\AA}$. ZnO NWs were only formed in case of that used catalyst metal. Field effect scanning electron microscopic (FESEM) investigation showed that the average diameter of ZnO NWs was about 70 nm and the typical lengths varied from $3{\sim}4{\mu}m$.

• Journal of Information Science Theory and Practice
• /
• v.6 no.3
• /
• pp.45-60
• /
• 2018

Research performance evaluation in Korean universities follows strict guidelines that specify scoring systems for publication venue categories and formulas for co-authorship credit allocation. To find out how the standards differ across universities and how they differ from bibliometric research evaluation measures, this study analyzed 25 standards from major Korean universities and rankings produced by applying standards and bibliometric measures such as publication and citation counts, normalized impact score, and h-index to the publication data of 195 tenure-track professors of library and information science departments in 35 Korean universities. The study also introduced a novel impact score normalization method to refine the methodology from prior studies. The results showed the university standards to be mostly similar to one another but quite different from citation-driven measures, which suggests the standards are not quite successful in quantifying the quality of research as originally intended.

• Journal of the Korean Society for information Management
• /
• v.14 no.2
• /
• pp.7-45
• /
• 1997

The purpose of this study was to find the conflict levels of the public librarians in Korea. To accomplish this, questionnaire study was done by selecting 311 librarians selected by cluster sampling method from the 11 public libraries in Seoul. The data of intrapersonal, intraorganizational and intrasocial conflicts of the public librarians were analyzed by SAS/pc routine.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.6 no.4
• /
• pp.153-160
• /
• 2010

MANET composed mobile nodes without central concentration control like base station communicate through multi-hop route among nodes. Accordingly, it is hard to maintain stability of network because topology of network change at any time owing to movement of mobile nodes. MANET has security problems because of node mobility and needs intrusion detection system that can detect attack of malicious nodes. Therefore, system is protected from malicious attack of intruder in this environment and it has to correspond to attack immediately. In this paper, we propose intrusion detection system based on rules in order to more accurate intrusion detection. Cluster head perform role of monitor node to raise monitor efficiency of packet. In order to evaluate performance of proposed method, we used jamming attack, selective forwarding attack, repetition attack.

• Korean Management Science Review
• /
• v.26 no.3
• /
• pp.55-65
• /
• 2009

The objective of this paper is to propose an ant colony optimization (ACO) for clustering design in wireless sensor network problem. This proposed ACO approach is designed to deal with the dynamics of the sensor nodes which can be adaptable to topological changes to any network graph in a time. Long communication distances between sensors and a sink in a sensor network can greatly consume the energy of sensors and reduce the lifetime of a network. We can greatly minimize the total communication distance while minimizing the number of cluster heads using proposed ACO. Simulation results show that our proposed method is very efficient to find the best solutions comparing to the optimal solution using CPLEX in 100, 200, and 400 node sensor networks.

• Communications for Statistical Applications and Methods
• /
• v.27 no.5
• /
• pp.569-578
• /
• 2020

Various graph clustering methods have been introduced to identify communities in social or biological networks. This paper studies the entropy-based and the Markov chain-based methods in clustering the undirected graph. We examine the performance of two clustering methods with conventional methods based on quality measures of clustering. For the real applications, we collect the mathematical subject classification (MSC) codes of research papers from published mathematical databases and construct the weighted code-to-document matrix for applying graph clustering methods. We pursue to group MSC codes into the same cluster if the corresponding MSC codes appear in many papers simultaneously. We compare the MSC clustering results based on the several assessment measures and conclude that the Markov chain-based method is suitable for clustering the MSC codes.

• Korean Journal of Human Ecology
• /
• v.2 no.1
• /
• pp.110-113
• /
• 1999

Clothing shape is principally described in seven factors that are composed of clothing design, clothing material, clothing size, pattern design, sewing method and body motion etc. The aims of this study was to measurement out-line space-shape variation of clothing fitness with body by using the image processing. The subjects for direct anthropometric measurements were 248 female college students aged from 19 to 22. The data were statistically analyzed by principal analysis and cluster analysis. The results selected one somatotype. for the out-line space-shape variation of clothing fitness with body, there dimensional clothing shapes measured. and cross-sectional clothing shape obtained by the measurement was considered to be space wave form. The out-line space-shape variation of clothing fitness with body was observed between the node number and amplitudes of clothing wave form, and node number was determined at the maxim of space-shape amplitude, and the space-shape amplitudes have related with aspect ratio of cross-sectional shape. (Korean J of Human Ecology 2(1) :110-113, 1999)