• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.16 no.4
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• pp.225-234
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• 2012

We present two high-order potential flow models for the evolution of the interface in the Rayleigh-Taylor instability in two dimensions. One is the source-flow model and the other is the Layzer-type model which is based on an analytic potential. The late-time asymptotic solution of the source-flow model for arbitrary density jump is obtained. The asymptotic bubble curvature is found to be independent to the density jump of the fluids. We also give the time-evolution solutions of the two models by integrating equations numerically. We show that the two high-order models give more accurate solutions for the bubble evolution than their low-order models, but the solution of the source-flow model agrees much better with the numerical solution than the Layzer model.

• Information Systems Review
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• v.3 no.1
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• pp.83-101
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• 2001

Studies about wireless internet have been focused on technology issues and few studies were shown in the adoption of wireless internet services. This study uses Technology Acceptance Model in order to understand influencing factors in acceptance of wireless internet services. Reviewing by TAM related studies, this study regards the influencing factors as personal and social environmental dimensions in the case of wireless internet services, and these two factors are used. Two dependent variables-intention and current usage-are adopted for analyzing the effects of the two factors on two dependent variables via mediating variables. The results of this study show that age, frequency of mobile phone usage, occupation, and the recognition level of wireless internet services affected the intention and current usage of these services.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.11
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• pp.1398-1406
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• 2004

The nonlinear signals from an impedance meter for the area average void fraction in two-phase flow have been analyzed to construct a phase space trajectory. The pseudo phase space was constructed with the time delay and proper dimensions. The time delay and the embedding dimension were chosen by the average mutual information and by the false nearest neighborhood, respectively. The attractor-density-map of projected states was used to produce the two dimensional probability distribution functions (2D-PDF). Since the developed 2D-PDF showed clear distinction of the flow patterns, the flow regime identification was made with three rules and with the 2D-PDF. Also, the transition criteria of Mishima-Ishii agree well with the present results.

• Kyungpook Mathematical Journal
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• v.59 no.3
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• pp.563-589
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• 2019

Let W and V be manifolds of dimension m + 2, M a locally flat submanifold of V whose dimension is m. Let $f:W{\rightarrow}V$ be a homotopy equivalence. The problem we study in this paper is the following: When is f homotopic to another homotopy equivalence $g:W{\rightarrow}V$ such that g is transverse regular along M and such that $g{\mid}g^{-1}(M):g^{-1}(M){\rightarrow}M$ is a simple homotopy equivalence? $L{\acute{o}}pez$ de Medrano (1970) called this problem the weak h-regularity problem. We solve this problem applying the codimension two surgery theory developed by the author (1973). We will work in higher dimensions, assuming that $$m{\geq_-}5$$.

• Nuclear Engineering and Technology
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• v.15 no.2
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• pp.98-109
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• 1983

A two-step alternating direction explicit method is developed to solve the space-dependent reactor kinetics equations in two space dimensions. As a special case in the general class of alternating direction implicit methods, this method is analysed for accuracy and stability. To test the validity of this method it is compared with the implicit-difference method used in the TWIGL program. It is shown that the two methods are closely related. The time dependent neutron fluxes of the pressurized water reactor (PWR), during control rod insertion, and, of the CANDU-PHW reactor, in case of postulated loss of coolant accident, are obtained from the numerical calculation results.

• The Journal of Korean Academic Society of Nursing Education
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• v.4 no.2
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• pp.220-235
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• 1998

The revolution of nursing curriculum has been focused on clinical competency for nursing graduates to flexibly respond to changes in societal health needs and disciplinary requirements. In this trend, the study was designed to identify basic concepts of nursing education that reflects the changes in societal needs and nursing discipline, and to develop the instrument to measure performance level in each dimension of clinical competency. The study was conducted in two phases. In phase 1, principal concepts consisted of nursing education were determined through literature review as well as series of discussion sessions on nursing philosophies and educational objectives among researchers. Though the process, the conceptual framework of competency based nursing curriculum was constructed with nursing process and professional role as horizontal threads, client, health needs, and nursing interventions as vertical threads. Then, items were developed to represent each dimension of competency : client and health need, nursing process, professional role, and nursing interventions. The total of 273 items were included as to represent clinical competency required for BSN graduates. In phase 2, questionnaires were distributed to nursing faculties of 41 BSN programs to validate the 273-item Instrument developed to measure competency. The total of 34 subjects returned the questionnaire with 81% of response rates. The subjects of the study had an average of 42 months of clinical experience and 13 years of education experience in various nursing areas with an age range of 30 to 52 years. The data were analyzed by utilizing SPSSWIN and the results are as follows. 1) The mean score of the nursing process dimension was supported most with the mean of 3.60(SD=0.32) compared to client and health need dimension(M=3.49, SD=.40), professional role(M=3.41, SD=.44), and nursing interventions(M=3.57, SD=.34). 2) The dimensions of competency were moderately correlated to each other with a range of r=.433 to r=.829, confirming that four dimensions of competency were related but distinct concepts. 3) The items of each dimension were analyzed based on its appropriateness. 'Assessing risk factors of the clients' were most highly supported in client and health need dimension. Most items of nursing process dimension were considered appropriate, while items related to efficient communication were well supported in professional role dimension. In nursing intervention dimension, items on basic nursing skills were highly supported while items on specific nursing interventions such as music therapy or art therapy were considered relatively inappropriate to competency for BSN graduates. The findings clearly showed that the current nursing education more emphasizes nursing interventions based on nursing process than other dimensions of competency. There is a need to reconceptualize nursing curriculum that is able to reflect more of nursing professional role and client/health need dimensions. Further research to validate the instrument by confirming competency dimensions of nursing graduates who are currently working at the hospital has been suggested.

• Phonetics and Speech Sciences
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• v.13 no.2
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• pp.57-66
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• 2021

This study focuses on the issue of automatic severity classification of dysarthric speakers based on speech intelligibility. Speech intelligibility is a complex measure that is affected by the features of multiple speech dimensions. However, most previous studies are restricted to using features from a single speech dimension. To effectively capture the characteristics of the speech disorder, we extracted features of multiple speech dimensions: voice quality, prosody, and pronunciation. Voice quality consists of jitter, shimmer, Harmonic to Noise Ratio (HNR), number of voice breaks, and degree of voice breaks. Prosody includes speech rate (total duration, speech duration, speaking rate, articulation rate), pitch (F0 mean/std/min/max/med/25quartile/75 quartile), and rhythm (%V, deltas, Varcos, rPVIs, nPVIs). Pronunciation contains Percentage of Correct Phonemes (Percentage of Correct Consonants/Vowels/Total phonemes) and degree of vowel distortion (Vowel Space Area, Formant Centralized Ratio, Vowel Articulatory Index, F2-Ratio). Experiments were conducted using various feature combinations. The experimental results indicate that using features from all three speech dimensions gives the best result, with a 80.15 F1-score, compared to using features from just one or two speech dimensions. The result implies voice quality, prosody, and pronunciation features should all be considered in automatic severity classification of dysarthria.

• International Journal of Concrete Structures and Materials
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• v.8 no.1
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• pp.83-97
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• 2014

This paper presents the results of an investigation aimed at developing reinforced concrete beams consisting of precast permanent U-shaped reinforced mortar forms filled with different types of core materials to be used as a viable alternative to the conventional reinforced concrete beam. To accomplish this objective, an experimental program was conducted and theoretical model was adopted. The experimental program comprised casting and testing of thirty beams of total dimensions $300{\times}150{\times}2,000mm$ consisting of permanent precast U-shaped reinforced mortar forms of thickness 25 mm filled with the core material. Three additional typical reinforced concrete beams of the same total dimensions were also cast to serve as control specimens. Two types of single-layer and double-layers steel meshes were used to reinforce the permanent U-shaped forms; namely welded wire mesh and X8 expanded steel mesh. Three types of core materials were investigated: conventional concrete, autoclaved aerated lightweight concrete brick, and recycled concrete. Two types of shear connections between the precast permanent reinforced mortar form and the core material were investigated namely; adhesive bonding layer between the two surfaces, and mechanical shear connectors. The test specimens were tested as simple beams under three-point loadings on a span of 1,800 mm. The behavior of the beams incorporating the permanent forms was compared to that of the control beams. The experimental results showed that better crack resistance, high serviceability and ultimate loads, and good energy absorption could be achieved by using the proposed beams which verifies the validity of using the proposed system. The theoretical results compared well with the experimental ones.

• Korean Journal of Cognitive Science
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• v.14 no.1
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• pp.41-50
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• 2003

We tested the capability of the pleasure and arousal dimension-based facial expression synthesis system and proposed the most effective interface for it. First, we tried to confirm the adequateness of the dimensional model as a basic structure of the internal states for the system. Fer it, subjects compared the 17 facial expressions on the two axes. The results validated the fundamental hypothesis of the system. Second, we chose 21 representative expressions from the system to test its performance and had subjects rate their similarities. We analyzed these data using multidimensional scaling methods and these results verified the system's reliability. Third, we compared the efficiencies of two interfaces -coordinate values and slide bars- to find the most suitable interface for the system. Subjects synthesise 25 facial expressions with each interface of it. The results showed that the visualization of two dimensional values into Cartesian coordinate is more stable as an input display of facial expression synthesis system based on dimensions.

• The Korean Journal of Applied Statistics
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• v.22 no.3
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• pp.463-477
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• 2009

This study was intended to examine the mediating roles of trust in CEO and supervisor on the relationships between organizational justice and employee behaviors. Data were collected from 4,055 employees across 18 different companies in Korea. Employees were asked to answer on a self-reported questionnaire. The two dimensions of organizational justice (i.e. procedural justice and distributive justice) were used. Employee behaviors were measured using counter-productive behavior and organizational citizenship behavior. Data were analyzed using a structural equation model. The hypothesized fully mediated model better fitted the data. Relative to distributive justice, procedural justice was more strongly related to both trust in CEO and trust in supervisor. But there were no significant differences in the degree of relationships between the two dimensions of trust and the two types of employee behaviors. These results showed that procedural justice is more important in enhancing trust in leader.