• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.213-223
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• 2007

In this paper, we carry out a cyber group consultation by means of the video-based education system, and verify the effects. For the verification of this study, two assumptions were set up. These assumptions were inspected by selecting 45 students of D elementary school located in a big city, and coming up with a test utilizing one of video-based education systems. Following up, a self-respect test form and a questionnaire were made to verify of the group consultation to the video-based education system, and by analyzing the test form and the questionnaire, the conclusion of this study was finally drawn. The conclusion gained through the process adove is as follows: It turned out that real-time video-based cyber group consultation promoted self-respect and enthusiastic participation of consulters as well as formed emotinal stability and a close affinity between the consultant and the consulter through active interaction. The results of this video-based education system operation will be helpful to broaden the area of elementary school cyber group consultation. Further, it is thought that it will contribute to the basic investigation to verify the educational effects of Multi-point imaging system in the run-up to the operation of full-scale real-time video-based education systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.4
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• pp.795-804
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• 2009

An HSS(Home Subscriber Server) system requires a main-memory database on main-memory unit for the real-tine management of the subscriber information in the mobile communication service, in that the system controls not only basic data for handling calls of users, but also additional service data related to user authentication and operational data. Nonetheless, HSS-DBS system, requiring the reliability and stability, need more secure data store method and a back-up technique because the system have a long startup time and the big problem on the failures of main-memory. This paper proposes an efficient back-up replication technique, on the basis of enhancing the stability and performance of HSS system. The proposed shadowing back-up technique adopting the delayed recovery process, can help minimize the real-time back-up overloads by location registration, while the proposed backup replication method enables more stable system operations with replicating the data to remote server in real time.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.4
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• pp.243-250
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• 2011

Noise levels of the three subway lines of Busan city have been investigated. Averaged cabin noise of the train has been measured during the train trip for each station. It has been measured with separation of day time (9:00~18:00) and night time (18:00~22:00) measurements but there was no big difference on the measured data. Repeating for the measured data has been confirmed with twice measurements in May and June 2010. Several noise effects to the subway noise levels of Busan are explained. Those are screen door effect, rail road surface condition, subway train type and curvature of railway. Among three subway lines of Busan city, the line 2 is relatively noisy and its reasons are studied. It has been shown that the screen door effect is 10 dB(A) and S shape of sharp curve contributes in high noise level.

• Journal of Computing Science and Engineering
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• v.11 no.4
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• pp.142-151
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• 2017

Spontaneous intracerebral hemorrhage (sICH) has a high mortality rate. Research has demonstrated that sICH occurrence is related to weather conditions; therefore, this study used the decision tree method to explore the impact of climatic risk factors on sICH at different ages. The Taiwan National Health Insurance Research Database (NHIRD) and other open-access data were used in this study. The inclusion criterion was a first-attack sICH. The decision tree algorithm and random forest were implemented in R programming language. We defined a high risk of sICH as more than the average number of cases daily, and the younger, middle-aged and older groups were calculated as having 0.77, 2.26 and 2.60 cases per day, respectively. In total, 22,684 sICH cases were included in this study; 3,102 patients were younger (<44 years, younger group), 9,089 were middle-aged (45-64 years, middle group), and 10,457 were older (>65 years, older group). The risk of sICH in the younger group was not correlated with temperature, wind speed or humidity. The middle group had two decision nodes: a higher risk if the maximum temperature was >$19^{\circ}C$ (probability = 63.7%), and if the maximum temperature was <$19^{\circ}C$ in addition to a wind speed <2.788 (m/s) (probability = 60.9%). The older group had a higher risk if the average temperature was >$23.933^{\circ}C$ (probability = 60.7%). This study demonstrated that the sICH incidence in the younger patients was not significantly correlated with weather factors; that in the middle-aged sICH patients was highly-correlated with the apparent temperature; and that in the older sICH patients was highly-correlated with the mean ambient temperature. "Warm" cold ambient temperatures resulted in a higher risk of sICH, especially in the older patients.

• Journal of Advanced Navigation Technology
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• v.13 no.1
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• pp.1-10
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• 2009

In this study, what effects corporate culture of airlines' flight attendants has on job satisfaction was analyzed and the following results were derived. First, it showed that flight attendants of airlines feel job satisfaction with the ability of handling works by themselves before supervisors order something, with the faith of supervisors that subordinates will be able to work well, and with being able to talk about difficulties of the company open-minded. Second, flight attendants inairlines showed different levels of recognition about corporate culture based on age, married or not, position and how long they have worked in the company. Especially, it showed a big difference by their positions. Third, looking into the effect demographical characters have on job satisfaction, it indicated that the higher the positions were, the higher job satisfaction was, and especially, compared that job satisfaction of flight attendants having 4-7 years' careers is low, that of the flight attendantsmore than 8 years is high.

• Journal of Korean Library and Information Science Society
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• v.47 no.4
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• pp.443-464
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• 2016

A great number of institutions around the world have been building digital repositories to communicate scholarly information. Meanwhile, digital repositories have been struggling with how to preserve increased volume of digital contents for the long term and how to build a sustainable information environment. The HathiTrust partnership was established to meet the need of a sustainable collaborative model of digital repositories in research libraries, mainly in North America, and has been expanded globally by signing with other libraries around the world. This paper is dealt with the establishment, operation and policy, construction status, and user service of the HathiTrust. The results presented in this paper include the benefits and potential opportunities of the HathiTrust as a participating member. Partnership in HathiTrust would allow each member institution to provide more cost-effective operations, shared management and long-term preservation of digital content, ease of copyright management, and increased accessibility. In the future it is expected to provide a shared storage of printed materials and to facilitate a big data research center.

• Journal of the Korean Society for Railway
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• v.15 no.1
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• pp.88-95
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• 2012

Presently, because making process of train service plan consist of various constraint condition, for example structure of track, structure of track in station, train maintenance time and others for considering to be necessary of train management, it has been had extremely complex structure problems. For these reasons, it has big problems to compare analysis for various train service time-table. A study suggest methodology to choice service the most effective schedule and plan of train put before comparative analysis on making train diamond picture's expected effect of established possible various train time-table in making process of train service schedule for improving effectiveness and organization of train service schedule establishment. A study uses Line-Blocking theory for analyzing train service time-table and analyze example for regional train Sadang to Ansan section in 4line.

• Korean Journal of Optics and Photonics
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• v.21 no.6
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• pp.235-240
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• 2010

We fabricate highly birefringent photonic crystal fiber with new structure using a stack and draw method. Fabricated fiber has two big air holes, one at each side of the outside air cladding region, leading to core ellipticity during the drawing process. Birefringence of the fabricated Hi-Bi PCF is measured to be $2.29{\times}10^{-4}$ (at 1550 nm).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.1
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• pp.21-26
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• 2013

Objectives: Full thickness skin grafts (FTSG) offer several advantages; they are esthetically superb, have less postoperative shrinkage, and offer minimal postoperative pain and scar formation at the donor site. As a donor site of FTSG, the groin offers a relatively large area of skin with high elasticity. The aim of this study was to evaluate FTSG from the groin for reconstruction in oral and maxillofacial surgery. Materials and Methods: In a retrospective study, 50 patients (27 males, 23 females) who received FTSG from the groin were evaluated for their operation records, clinical photography, and medical records. Results: The width of skin from the groin was distributed from 2-8 cm (mean: 5.1 cm) at the donor site, while the long axis length was distributed from 3-13 cm (mean: 7.4 cm). A high number of patients, 47 patients (94%) out of 50, showed good healing at the donor site. Wound impairment was seen in 3 patients (6%), minor wound dehiscence in 2 patients, and severe wound dehiscence in 1 patient. In the recipient site, delayed healing was observed in 2 patients (4%). Conclusion: FTSG from the groin to repair soft tissue defects in reconstruction surgery is a good method due to the relatively big size of the graft, decreasing morbidity at the donor site, and higher graft survival rates.

• The Journal of the Acoustical Society of Korea
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• v.22 no.7
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• pp.612-621
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• 2003

As the use of MP3 audio compression increased, the demand for the insertion of additive data about copyright or information on music contents has been groved and the related research has been progressed actively. When an additive data is inserted into MP3 bitstream, it should not to happen any distortion of music quality or the change of file size, due to the modification of MP3 bitstream structure. In our study, to make these conditions satisfied, we inserted some additive data to bitstream by modifying some bits of linbits among the quantized integer coefficients having big values. At this time, we consider the characteristics of linbits and their distributions. As a result of subjective sound quality test through MOS test, we confirmed that the quality of MOS 4.6 can be achieved at the data insertion rate of 60 bytes/sec. Using the proposed method, it is possible to effectively insert an additive data such as copyright information or information about media itself, so that various applications like audio database management can be realized.