• Imaging Science in Dentistry
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• v.48 no.2
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• pp.111-119
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• 2018

Purpose: This study was conducted to evaluate the accuracy of linear measurements of 3-dimensional (3D) images generated by cone-beam computed tomography (CBCT) and facial scanning systems, and to assess the effect of scanning parameters, such as CBCT exposure settings, on image quality. Materials and Methods: CBCT and facial scanning images of an anthropomorphic phantom showing 13 soft-tissue anatomical landmarks were used in the study. The distances between the anatomical landmarks on the phantom were measured to obtain a reference for evaluating the accuracy of the 3D facial soft-tissue images. The distances between the 3D image landmarks were measured using a 3D distance measurement tool. The effect of scanning parameters on CBCT image quality was evaluated by visually comparing images acquired under different exposure conditions, but at a constant threshold. Results: Comparison of the repeated direct phantom and image-based measurements revealed good reproducibility. There were no significant differences between the direct phantom and image-based measurements of the CBCT surface volume-rendered images. Five of the 15 measurements of the 3D facial scans were found to be significantly different from their corresponding direct phantom measurements(P<.05). The quality of the CBCT surface volume-rendered images acquired at a constant threshold varied across different exposure conditions. Conclusion: These results proved that existing 3D imaging techniques were satisfactorily accurate for clinical applications, and that optimizing the variables that affected image quality, such as the exposure parameters, was critical for image acquisition.

• Journal of Korean Clinical Nursing Research
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• v.23 no.2
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• pp.189-201
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• 2017

Purpose: The aim of this study was to develop the nursing management core task and competency matrix for hospital unit managers. The perceived level of importance and performance of identified core competencies by unit managers were also investigated. Methods: Literature review and expert survey identified nursing management core task and competencies. Subsequently, the core task and competency matrix was developed and validated by expert panel. A survey of 196 nurse managers from 3 cities identified perceived importance and performance of core competiences. Results: Thirty-eight nursing management core task and thirty-seven nursing management core competencies were identified comprising five categories; Clinical practice knowledge, Evidence-based practice, Employee development, Strategic planning and Initiative. Based on the core task and competencies, the task and competency matrix for unit managers was developed. In the analysis of importance and performance of core competencies, the mean score of importance ($3.50{\pm}0.30$) was higher than the mean score of performance ($3.03{\pm}0.34$). Conclusion: The development of core task and competencies for unit managers in hospitals provides a guide for the development and evaluation of programs designed to increase competence of unit managers.

• Physical Therapy Rehabilitation Science
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• v.6 no.1
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• pp.45-51
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• 2017

Objective: This study aimed to identify the area with greatest effect using self-myofascial release technique (self-MFR) in the hamstring, suboccipital, and plantar regions. Design: Cross-sectional study. Methods: Twenty-two adult subjects were evaluated for flexibility and hamstring pain threshold after self-MFR. Based on the superficial back line, the self-MFR application areas were the suboccipital region, hamstring, and plantar regions. Self-MFR was applied to each area using a wooden pole for a total of 4 minutes. Self-MFR was applied for 3 days at the same time of day, which was randomly assigned for each subject. Treatment was applied to one area each day. The sit and reach test (SRT), active range of motion (AROM), and passive ROM (PROM) were used to determine changes in flexibility, and an algometer was used to determine pain threshold. Pre/post-self-MFR effectiveness was tested using a paired t-test. Repeated measurement was used to compare self-MFR effects in the suboccipital, hamstring, and plantar regions. Results: When the self-MFR technique was applied to the 3 areas, the SRT showed significant improvement over baseline (p<0.05). Bilateral AROM and PROM showed significant improvements (p<0.05). When the self-MFR technique was applied to the hamstring, the semimembranosus showed a significant change in pain threshold (p<0.05). Conclusions: Our findings suggest that indirect application based on the Anatomy Trains could be effective for those who need to improve muscle flexibility. Moreover, self-MFR easily alleviates myofascial pain while maintaining flexibility, and can be performed at any time and place.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.5
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• pp.173-182
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• 2007

e-Learning can be seen as not only one of Internet based information systems which can provide education services, but also one of teaching-learning methods which can implement self-directed learning. This paper tests factors affecting the e-Learning performance based on information systems success model and self-efficacy theory using a field study. Questionnaires are collected from 216 students who are enrolling a e-learning class using online survey. The results are following: first, the service quality and self-efficacy are significant predictors of use intention, but system quality and information quality are not. second, the system quality, information quality, service quality and self-efficacy are significant predictors of user satisfaction. Third, use intention and user satisfaction are found to be a strong predictor of the learning performance.

• The KIPS Transactions:PartA
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• v.9A no.1
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• pp.1-8
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• 2002

Most of the traditional embedded web server systems have been designed for monitoring and controlling some dedicated equipments. Hence, not only they have no generality and flexibility but also they are too expensive for the lower-cost domestic equipment. To cope with these difficulty, we suggest a lower-cost ${\mu}$-embedded web server model which is suitable for monitoring and controlling the industry or house equipments by using the internet. The suggested model is based on an one-chip ${\mu}$-processor in which the ISP (In-System Programming) function and flash ROM are embedded basically to minimize the cost of H/W and S/W. Also it allows to add an new function dynamically to provide the generality and flexibility. Finally, to evaluate the feasibility of the suggested model, we have manufactured a test-board based on the ATMega103 ${\mu}$-processor and programmed the control program and tested it on the MS Explorer 5.0 environment.

• Structural Engineering and Mechanics
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• v.81 no.4
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• pp.411-428
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• 2022

This paper presents the Campbell diagram analysis of the rotordynamic system using the full order model (FOM) and the reduced order model (ROM) techniques to determine the critical speeds, identify the stability and reduce the computational time. Due to the spin-speed-dependent matrices (e.g., centrifugal stiffening matrix), several model order reduction (MOR) techniques may be considered, such as the modal superposition (MS) method and the Krylov subspace-based MOR techniques (e.g., Ritz vector (RV), quasi-static Ritz vector (QSRV), multifrequency quasi-static Ritz vector (MQSRV), multifrequency/ multi-spin-speed quasi-static Ritz vector (MMQSRV) and the combined Ritz vector & modal superposition (RV+MS) methods). The proposed MMQSRV method in this study is extended from the MQSRV method by incorporating the rotational-speed-dependent stiffness matrices into the Krylov subspace during the MOR process. Thus, the objective of this note is to respond to the question of whether to use the MS method or the Krylov subspace-based MOR technique in establishing the Campbell diagram of the shaft-disc-blade assembly systems in three-dimensional (3D) finite element analysis (FEA). The Campbell diagrams produced by the FOM and various MOR methods are presented and discussed thoroughly by computing the norm of relative errors (ER). It is found that the RV and the MS methods are dominant at low and high rotating speeds, respectively. More precisely, as the spinning velocity becomes large, the calculated ER produced by the RV method is significantly increased; in contrast, the ER produced by the MS method is smaller and more consistent. From a computational point of view, the MORs have substantially reduced the time computing considerably compared to the FOM. Additionally, the verification of the 3D FE rotordynamic model is also provided and found to be in close agreement with the existing solutions.

• Journal of Aerospace System Engineering
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• v.18 no.2
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• pp.71-78
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• 2024

During the initial thermal design process, determining the thermal effect of various design variables in a complex orbital thermal environment is time-consuming. To save time in the initial design phase, it is necessary to quickly derive optimal design parameters and predict the temperature. To address these challenges, Veritrek, a software specialized in optimal design using a reduced-order model (ROM), was released in 2018. In this paper, we utilized the Veritrek software to build a reduced-order model, conduct sensitivity analysis, and perform optimal design analysis for a graphite sheet-based cryogenic cooler thermal control system. The goal was to determine the optimal design values for the number of graphite sheet layers, radiator area, and thickness that would meet the allowable temperature of the cryogenic cooler.

• The Journal of the Acoustical Society of Korea
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• v.29 no.3
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• pp.209-215
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• 2010

Recently portable terminal is received attention by wireless networks and mass capacity ROM. In this result, TTS(Text to Speech) system is inserted to portable terminal. Nevertheless high quality synthesis is difficult in portable terminal, users need high quality synthesis. In this paper, we proposed Distributed TTS (DTTS) that was composed of server and terminal. The DTTS on corpus based speech synthesis can be high quality synthesis. Synthesis system in server that generate optimized speech concatenation information after database search and transmit terminal. Synthesis system in terminal make high quality speech synthesis as low computation using transmitted speech concatenation information from server. The proposed method that can be reducing complexity, smaller power consumption and efficient maintenance.

• The Journal of the Acoustical Society of Korea
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• v.27 no.3
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• pp.154-162
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• 2008

Signals in an underwater channel get distorted by multipath propagation. In this paper, pre-coding method is suggested which helps comprehending the signals with minimum equalization. The signals are transformed based on the knowledge of the impulse response of the channel. Proposed pre-coding method is tested by simulations based on the ray theory and through water tank experiments. In weak multipath environment, in case of an SNR of about 20 dB, BER is $10^{-3}{\sim}10^{-4}$, while in strong multipath environment, similar BER is achieved with SNR of about 30 dB. In order for the pre-coding method to be used for underwater vehicles, channel prediction method utilizing the waveguide invariant is suggested and tested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6099-6111
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• 2015

This study was a systematic review and meta-analysis comparing the effects of aquatic exercise and land-based exercise in the treatment of knee osteoarthritis. 7 studies (n=449) met selection and exclusion criteria out of 287 potential studies obtained from the literature search via Ovid-Medline, Cochrane Library CENTRAL, CINAHL, RISS and KISS. The overall risk of bias of selected studies using SIGN (Scottish Intercollegiate Guidelines Network) checklist for randomized controlled trials (RCT) was regarded as low. As a result of meta analysis, Standardized Mean Difference (SMD) for pain was -0.26(95% CI -0.49, -0.03, p=0.03, $I^2=14%$), which implies that aquatic exercise groups had significant less pain than land-based exercise groups. On the other hand, there was no significant difference between aquatic exercise groups and land based exercise groups for flexion Range of Motion (ROM) (-0.12, 95% CI -0.51, 0.27, p=0.53, $I^2=0%$), extension ROM (-0.04, 95% CI -0.55, 0.48, p=0.89, $I^2=43%$), physical function (-0.12, 95% CI -0.44, 0.19, p=0.44, $I^2=0%$), Quality of Life (QOL) (-0.15, 95% CI -0.54, 0.24, p=0.46, $I^2=0%$). This study has some limitations due to few RCTs comparing aquatic exercise groups and land-based exercise groups in the treatment of knee osteoarthritis. Therefore, further RCTs should be conducted along with long-term outcomes.