• Korean Journal of Psychosomatic Medicine
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• v.9 no.2
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• pp.174-181
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• 2001

Objectives : The author investigated the rate of diagnostic agreement between consultants and consultees and concordance ratings on the consultees' recommendation to examine the interactive collaborativeness and find the factors that influence the reflectiveness on treatment. Methods : The subjects were 54 patients with delirium selected from 583 cases referred from other departments who were admitted to Hanyang University Kuri Hospital from July 1, 1995 to Dec. 31, 1997. The information on demographic data, diagnostic impression, symptoms, management before consultation, psychiatric recommendation, management after consultation, diagnoses at the referring departments and the psychiatric department on delirium was obtained by medical records and consultation papers retrospectively. The reflectiveness of the psychiatric recommendation was divided into complete concordance, partial concordance, and nonconcordance and among them the complete and partial concordance were considered for concordance. The reflectiveness was compared among all the departments and between medical unit and surgery unit. Results: The rate of diagnostic agreement on the cause of delirium was highest(85.7%) in organic brain syndrome and lowest in general medical condition(0%). There was no statistically significant differences between medical unit and surgery unit. Neither differences were there among all the departments. In comparing symptoms affecting the reflectiveness, it was 73.5% in impulsive and aggressive behavioral changes, whereas 40.0% in behavioral changes. Reflectiveness of psychiatric recommendation showed higher scores in the case of behavioral changes. The cases of sleep problem showed higher scores of reflectiveness. When these two symptoms of behavioral change and sleep problem were compared as one factor, the results suggested that there were significant differences. The cases with both two symptoms showed 80% in reflectiveness, and the cases with only one symptom or no symptoms showed 44.8% in reflectiveness. There were no statistical significances between concordance ratings and symptoms such as disturbance of consciousness, disorientation, and hallucination that cannot be easily evaluated at the referring departments. Conclusions : The rate of diagnostic agreement on the cause of delirium was highest in the case of organic brain syndrome in which lesions can be easily recognized. The factors that influence the reflectiveness of psychiatric recommendation were behavior changes and sleep disorders in the symptoms of evaluated cases.

• Journal of Digital Convergence
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• v.20 no.5
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• pp.525-535
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• 2022

The purpose of this study is to identify the factors influencing the user's continuous usage intention of computer games. A research model was developed which shows that the independent variables of value, expectation confirmation, perceived enjoyment affect user satisfaction and continuous usage intention. To test the six hypotheses, survey data were collected from 104 respondents, and hypotheses tests as well as a confirmatory factor analysis were conducted using a partial least square analysis tool. The statistical analysis result showed that expectation confirmation had a significant positive effect on satisfaction, and satisfaction also had a strong positive effect on the game user's continuous usage intention. Perceived enjoyment showed a highly strong positive effect on satisfaction. In addition, satisfaction was found to have full mediation effects in the relationship between expectation confirmation and continuous usage intention, and perceived enjoyment and continuous usage intention respectively. This result provides an important implication that continuous usage intention occurs through user satisfaction, and also indicates the contribution of this study for the game industry. Another contribution of this study is to introduce critical independent variables from the marketing and information technology domains in order to explain continuous usage intention of computer games.

• The Korean Journal of Applied Statistics
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• v.26 no.5
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• pp.697-712
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• 2013

When analyzing repeated binary data, the generalized estimating equations(GEE) approach produces consistent estimates for regression parameters even if an incorrect working correlation matrix is used. However, time-varying covariates experience larger changes in coefficients than time-invariant covariates across various working correlation structures for finite samples. In addition, the GEE approach may give biased estimates under missing at random(MAR). Weighted estimating equations and multiple imputation methods have been proposed to reduce biases in parameter estimates under MAR. This article studies if the two methods produce robust estimates across various working correlation structures for longitudinal binary data with time-varying covariates under different missing mechanisms. Through simulation, we observe that time-varying covariates have greater differences in parameter estimates across different working correlation structures than time-invariant covariates. The multiple imputation method produces more robust estimates under any working correlation structure and smaller biases compared to the other two methods.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.9 s.351
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• pp.59-63
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• 2006

With the increasing complexity of VLSI devices, more complex faults have appeared. Many methods for diagnosing the single stuck-at fault have been studied. Often multiple defects on a foiling chip better reflect the reality. So, we propose an efficient diagnosis algorithm for multiple stuck-at faults. By using vectorwise intersections as an important metric of diagnosis, the proposed algorithm can diagnose multiple defects using single stuck-at fault simulator. In spite of multiple fault diagnosis, the number of candidate faults is also drastically reduced. For fault identification, positive calculations and negative calculations based on variable weights are used for the matching algorithm. Experimental results for ISCAS85 and full-scan version of ISCAS89 benchmark circuits prove the efficiency of the proposed algorithm.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.3
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• pp.291-299
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• 2008

The present study is to estimate the effects of diffracted wave fields in a harbor and around harborentrance due to random waves, when a navigation channel is dredged in the vicinity of the a harbor entrance. The cross sections of harbor boundary are considered to be partial or full reflection in this study. The numerical simulation has been performed by the boundary element method, which is to discrete segments of pit- and harbor- boundary with the algorism of auto generated elements. The incident wave conditions are specified using discretized forms of the Mitsuyasu's frequency spectrum and directional function. The results of the present numerical simulation agreed well with those of the published experimental data. It is shown that the ratios of wave height reduction are about 20% for the case of fully reflecting boundary, and 10% for the case of partially reflecting boundary by the effect of placing a pit, respectively.

• Journal of KIISE:Information Networking
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• v.36 no.1
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• pp.57-67
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• 2009

Packet forwarding in the Internet routers is to find out the longest prefix that matches the destination address of an input packet and to forward the input packet to the output port designated by the longest matched prefix. The IP address lookup is the key of the packet forwarding, and it is required to have efficient data structures and search algorithms to provide the high-speed lookup performance. In this paper, an efficient IP address lookup algorithm using binary search is investigated. Most of the existing binary search algorithms are not efficient in search performance since they do not provide a balanced search. The proposed binary search algorithm performs perfectly balanced binary search using switch pointers. The performance of the proposed algorithm is evaluated using actual backbone routing data and it is shown that the proposed algorithm provides very good search performance without increasing the memory amount storing the forwarding table. The proposed algorithm also provides very good scalability since it can be easily extended for multi-way search and for large forwarding tables

• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.779-788
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• 2002

There are many technically difficult issues in searching multimedia data such as image, video and audio because they are massive and more complex than simple text-based data. As a method of searching multimedia data, a similarity retrieval has been studied to retrieve automatically basic features of multimedia data and to make a search among data with retrieved features because exact match is not adaptable to a matrix of features of multimedia. In this paper, data clustering and its indexing are proposed as a speedy similarity-retrieval method of multimedia data. This approach clusters similar images on adjacent disk cylinders and then builds Indexes to access the clusters. To minimize the search cost, the hashing is adapted to index cluster. In addition, to reduce I/O time, the proposed searching takes just one I/O to look up the location of the cluster containing similar object and one sequential file I/O to read in this cluster. The proposed schema solves the problem of multi-dimension by using clustering and its indexing and has higher search efficiency than the content-based image retrieval that uses only clustering or indexing structure.

• Radiation Oncology Journal
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• v.6 no.2
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• pp.151-154
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• 1988

To answer the question whether last clonogenic cell should be eradicated for the tumor to be controlled, radiation tumor control study was performed using microscopic tumors of variable sizes ranging from 101 to 10s tumor cells. $TCD_{50}'s$ estimated from experimental data were 14.8, 27. 1, 42.4, 49.9 and 65.5 Gy for $10^1,\;10^2,\;10^3,\;10^4\;and\;10^4$ tumor cells, respectively. Theoretical calculations, assuming that all the clonogenic cells should be inactivated, were 15.65, 8.50, 40.97, 53.41 and 65.85 Gy. From this well matched data, it can be concluded that all the clonogenic cells should be eradicated for tumor control, at least in this tumor model.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.7
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• pp.535-543
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• 2014

A computational simulation for a nonslender BWB UCAV configuration with rounded leading edge and span of 1.0m was performed to analyze its aerodynamic characteristics. The freestream is 50m/s over -4 to 26 degree A.o.A.s. Reynolds number based on the mean chord length is $1.25{\times}10^6$. 3D multi block hexahedral grids are used which allow good grid quality and ease to capture boundary layer. ${\gamma}-Re_{\theta}$ model as well as $k-{\omega}$ SST model is employed to assess the effect of transition for flow behavior. Drag and lift of the UCAV were well predicted while $C_M$ is under predicted at high angle of attacks and influenced by the turbulence models strongly. After assessing pressure distribution, skin friction lines and velocity field around the UCAV configuration, it was found that transition effect should be considered to enhance the prediction of aerodynamic behavior by a vortical flowfield.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.3
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• pp.355-362
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• 2003

In this paper, we analyzed the DS/CDMA System with Hybrid SC/MRC diversity, as a method to achieve a good performance by reducing the complexity of system, when PLL gain value was revised a phase gulf among branches to make perfect coherent receive signal. The channel is a multipath Nakagami-m fading channel, we consider user(K), processor gain(N), number of paths(Lp) in DS/CDMA system with hybrid SC/MRC diversity. We found that PLL gain values exist to make perfect coherent receive signal. We verified that DS/CDMA system with Hybrid SC/MRC diversity can improve performance when the proper PLL gain values is used in the system. As a result, we verified that the upper limit of PLL gain value is 5dB to make perfect coherent receive signal in the DS/CDMA system with hybrid SC/MRC diversity.