• 한국소음진동공학회논문집
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• 제26권3호
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• pp.331-339
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• 2016

To improve the acoustic performance of sound absorbing materials, the thickness of the material should be increased or the sound absorbing material having an irregular surface shape should be used. In this study, the acoustic characteristics and methods to improve the acoustic performance of a sound absorbing system equipped with double layered polyester sound absorbing materials were investigated. The numerical model was set up and the results obtained from the model were compared with the actual measurement data. And, strategies to improve the acoustic performance of sound absorbing systems with double layered sound absorbing materials made of polyester with different configuration were shown. So, this study is expected to be usefully used at sites that require high acoustic absorption performance with minimal installation thickness to reduce sounds reflection in narrow spaces such as interior of subway tunnels or in noise barriers installed adjacent to rails.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.185-186
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• 2006

Image Guided Surgery(IGS) system has been developed to provide exquisite and objective information to surgeons for surgical operation process. It is necessary that registration technique is important to match between 3D image model reconstructed from image modalities and the object operated by surgeon. Majority techniques of registration in IGS system have been used by recognizing fiducial markers placed on the object. However, this method has been criticized due to its invasive protocol inserting fiducial markers in patient's bone. Therefore, shape-based registration technique using geometric characteristics of the object has been invested to improve the limitation of IGS system. During Total Knee Replacement(TKR) operation, it is challenge to register with high accuracy by using shape-based registration because the area to acquire sample data from knee is limited. We have developed region-based 3D registration technique based on anatomical landmarks on the object and this registration algorithm was evaluated in femur model. It was found that region-based algorithm can improve the accuracy in 3D registration. We expect that this technique can efficiently improve the IGS system.

• Journal of Information Technology Applications and Management
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• 제21권2호
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• pp.31-48
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• 2014

The concept of Health Related Quality of Life and its determinants have evolved since the 1980s. Although many researchers have published articles of technology usage in hospitals and the installation of technology based healthcare system, the research about applying the information technology to improve the patients' perceived quality of healthcare services is still limited. In general, services are deeds, processes and performances that are essentially concerns of the consumer. The healthcare service quality depends on tangible factors, such as equipments, facilities, and the quality of hospital staff and also the intangible ones. The main purpose of this work is to establish new model and find out the contribution of information technology to enhance the patients' perceived quality of healthcare service. We attempted to examine the main information technology related factors in 3 aspects, namely quality of information, the technology accessibility and the community that can improve patients' perceived quality of healthcare services. Offline and online questionnaires were used to measure the patients' perceived quality and were distributed to 384 people in 2 countries, Laos and South Korea. A principle component analysis and multiple regressions were used to verify our model. Results show that the use of information technology has partial positive effect on patient-physician interaction in both countries. However, patient knowledge and patient autonomy which are the 2 dimensions of patient-physician interaction has significant positive effect on patients' perceived quality of healthcare service.

• 대한인간공학회지
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• 제30권6호
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• pp.715-725
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• 2011

Objective: This study is aimed at developing Articulated Human Models(AHM) using superquadrics to improve the geometric accuracy of the body shape. Background: The previous work presents the AHM with geometrical simplification such as ellipsoids to improve analysis efficiency. However, because of the simplicity, their physical properties such as a center of mass and moment of inertia are computed with errors compared to their actual values. Method: This paper introduces a three steps method to present the AHM with superquadrics. First, a 3D whole body scan data are divided into 17 body segments according to body joints. Second, superquadric fitting is employed to minimize the Euclidean distance between body segments and superquadrics. Finally, Fee-Form Deformation is used to improve accuracy over superquadric fitting. Results: Our computational experiment shows that the superquadric models give better accuracy of dynamic analysis than that of ellipsoid ones. Conclusion: We generate the AHM composed of 17 superquadrics and 16 joints using superquadric fitting. Application: The AHM using superquadrics can be used as the base model for dynamics and ergonomics applications with better accuracy because it presents the human motion effectively.

• 한국멀티미디어학회논문지
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• 제25권8호
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• pp.1109-1121
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• 2022

As the demand for quality sleep increases in modern society, the importance of sleep technology has increased. Recently, development of sleep environment improvement products and research on the user's sleep improvement have been activated. Representatively, user sleep pattern analysis research is being conducted through the existing polysomnography, but it is difficult to use it in the sleep environment of daily life. Therefore, in this paper, we propose a system design that can provide a customized deep sleep service to users by detecting sleep disturbance factors in a motion bed environment. In order to improve the user's sleep satisfaction, a logistic regression-based sleep pattern analysis model is proposed and accuracy and significance are verified through experiments. And to improve user's sleep satisfaction, we propose a logistic regression-based sleep pattern analysis model and verify accuracy and significance through experiments. The proposed system is expected to improve the user's sleep quality and effectively prevent and manage sleep disorders.

• 품질경영학회지
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• 제51권4호
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• pp.677-689
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• 2023

Purpose: The purpose of this study is to design a x-ray screening rating system to improve X-ray screening ability, which is a core job competency of security screener at Incheon International Airport, and to verify its effectiveness through empirical analysis to suggest ways to improve the level management system. Methods: In this study, the effectiveness of the research model was analyzed using T-test tests for effect analysis based on the empirical analysis results derived through the competency evaluation model, the screening rating system. Results: The results of this study are as follows. The average score for regular education before the implementation of the x-ray screening rating system was 94.1 points, but after the implementation of the x-ray screening rating system, the average score for regular education was 95.5 points, an average of 1.4 points increased. In addition, the proportion of those with 95 or more points classified as high scorers also increased significantly from 51.1% to 69.3%. Conclusion: The X-ray screening rating system of security inspectors will systematically manage the level of screening ability, which is a key job competency, and play a strong role in improving competency, while preventing security accidents through early identification and intensive training of level-lowers.

• 한국IT서비스학회지
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• 제13권1호
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• pp.253-267
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• 2014

This study explores to identify the characteristics of the business model by comparing and analyzing the value creation between two cases, and to be successful in business model innovation. In order for the pursuit of purposes, domestic and international firm' business model cases are analyzed. Regarding the business model innovation, huge differences are found between two cases. First, a clear customer value proposal is important. Netflix is constantly monitoring the customer's needs and satisfactions to improve value proposition, while Joycube, domestic firm does not adjust to meet the change of the customer's behaviors. Second, the business model innovation should be taking into account the customer's behaviors in the constant changing market environments. For the growth, firms should consider strategic monitoring the market environments, and find a novelty of the markets, and to create the jump through business model innovation.

• International Journal of Aeronautical and Space Sciences
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• 제17권4호
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• pp.491-500
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• 2016

This paper presents a highly efficient aeroelastic optimization method based on a surrogate model; the model is verified by considering the case of a high-aspect-ratio composite wing. Optimization frameworks using the Kriging model and genetic algorithm (GA), the Kriging model and improved particle swarm optimization (IPSO), and the back propagation neural network model (BP) and IPSO are presented. The feasibility of the method is verified, as the model can improve the optimization efficiency while also satisfying the engineering requirements. Moreover, the effects of the number of design variables and number of constraints on the optimization efficiency and objective function are analysed in detail. The accuracy of two surrogate models in aeroelastic optimization is also compared. The Kriging model is constructed more conveniently, and its predictive accuracy of the aeroelastic responses also satisfies the engineering requirements. According to the case of a high-aspect-ratio composite wing, the GA is better at global optimization.

• 음성과학
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• 제10권2호
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• pp.35-43
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• 2003

General speaker verification systems improve their recognition performances by normalizing log likelihood ratio, using a speaker model and its background speaker model that are required to be verified. So these systems rely heavily on the availability of much speaker independent databases for background speaker model design. This constraint, however, may be a burden in practical and portable devices such as palm-top computers or wireless handsets which place a premium on computations and memory. In this paper, new approach for the GMM-based background model design used in portable speaker verification system is presented when the enrollment data is available. This approach is to modify three parameters of GMM speaker model such as mixture weights, means and covariances along with reduced mixture order. According to the experiment on a 20 speaker population from YOHO database, we found that this method had a promise of effective use in a portable speaker verification system.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 1999년도 춘계학술발표대회 논문집
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• pp.133-136
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• 1999

This study intends to develop an evaluation model which could be used as an effective tool for criticizing the model house of multi-family housing. The evaluation model has been developed based on the theoretical framework suggested by previous results of research related on hosing design, which comprises the following four components: 1) the paradigm of future home and life-style, 2) marketing effects of housing developer, 3) goals and principles of housing design, and 4) results of user-preference study. In this study, an evaluation model was suggested as a preliminary form which would be modified in detail after series of tests in the field. The evaluation model will be used provide standardized criteria for the quality of model houses, and eventually help to improve the quality of multi-family housing design by balanced information from theorist, user and developer.