• The Journal of Information Technology
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• v.5 no.4
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• pp.173-183
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• 2002

In this paper, we propose an efficient forecasting methodology of the mid and long-term frequency demand in Korea. The methodology consists of the following three steps: classification of basic service group, calculation of effective traffic, and frequency forecasting. Based on the previous studies, we classify the services into wide area mobile, short range radio, fixed wireless access and digital video broadcasting in the step of the classification of basic service group. For the calculation of effective traffic, we use the measures of erlang and bps. The step of the calculation of effective traffic classifies the user and basic application, and evaluates the effective traffic. Finally, in the step of frequency forecasting, different methodology will be proposed for each service group.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.5
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• pp.285-294
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• 2022

Using the ARDL approach, this study examined the impact of macro factors on Vietnam's stock market in the short and long run from 2010 to 2021. The State Bank of Vietnam and the International Monetary Fund provided time series data for this study. Research results show that in the long run, money supply and exchange rate respectively affect the stock market. The money supply had a positive effect on the VN-Index, while the exchange rate showed the opposite effect. However, the study did not find a relationship between world oil price and interest rates on VN-Index in the long run. On the other hand, in the short term, there are relationships between variables; specifically, interest rates and exchange rates have a negative impact on the VN-Index, while the world oil price and the fluctuation of money supply M2 of the previous one and two months showed an impact in the same direction on this index. The differences in the regression results on the impact of exchange rate and oil price on the VN-Index compared to previous studies come from the characteristics of Vietnam's stock market, with the large capitalization of companies in the oil and gas sector, and the structure of Vietnam's economy with export heavily depends on FDI sector.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.2
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• pp.126-131
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• 2010

Objectives: This study is aimed to determine any differences in the postoperative stability between absorbable and titanium plate systems for fixation in orthognathic surgery with simultaneous maxillomandibular procedures especially including maxillary posterior impaction and advancement. Study Design: Forty patients with dentofacial deformities were randomly assigned into titanium (4 males and 6 females) and absorbable (17 males and 13 females) fixation group. All patients had undergone surgical alterations of maxilla with posterior impaction and advancement. A comparison study of the change in the maxillary position after the simultaneous surgery was performed with 1-day, 6-months postoperative lateral cephalograms compared to preoperative lateral cephalogram by tracing. Wilcoxon rank sum test was used for statistical analysis. Result: The position of the maxilla was stable after surgery and was not changed significantly from 1 day to 6 month after the simultaneous maxillomandibular surgery both in the experimental (absorbable plates) and control (titanium plates). Conclusion: This study suggests that application of absorable plating system in the fixation of maxillary segment in the simultaneous maxillomandibular procedures, leads to a predictable short-term postoperative skeletal stability comparable to the titanium plating system. Long term follow-up and further studies will be needed.

• Journal of Chest Surgery
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• v.28 no.11
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• pp.1038-1044
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• 1995

We have been used cryopreserved homograft valves for right ventricular outflow tract[RVOT reconstruction since November 1993. The homograft valves were harvested from the hearts of brain dead patients or hearts of transplant recipients. There were 12 male and 10 female patients. Their ages ranged from 5 months to 13 years[mean age,39.2 $\pm$ 37.4 months and the weight ranged from 5 to 48kg [mean weight, 13.7$\pm$ 9. l kg . The diagnoses included pulmonary atresia with ventricular septal defect [n=14 , tetralogy of Fallot[n=4 , truncus arteriosus[n=3 , and double outlet right ventricle with pulmonic stenosis[n=l .Monocuspid homograft patches were used for RVOT widening or REV[reparation l`etage ventriculaire operations in 4 patients. We also used homograft as valved conduits for RVOT reconstruction in 17 patients and left ventricular outflow tract reconstruction in anatomically corrected transposition in 1 patient. Among them size-reducing technique [converting a tricuspid valved conduit into a bicuspid valved conduit were applied to six patients for the correction of size mismatching. The mean follow-up period was 10.6 $\pm$ 5.4 months. There was one operative death[4.5% due to bleeding and one reoperation for removal of vegetation on the homograft leaflet. Postoperative echocardiography documented no significant homograft insufficiency and RVOT obstructions.In short-term, the homograft valves provide excellent hemodynamic characteristics, even though further studies are necessary to evaluate the long-term results.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.3
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• pp.3-13
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• 2005

The conceptual rainfall-runoff models are used to predict complex hydrological effects of a basin. However, to obtain reliable results, there are some difficulties and problems in choosing optimum model, calibrating, and verifying the chosen model suitable for hydrological characteristics of the basin. In this study, Genetic Algorithm and SCE-UA method as global optimization methods were applied to compare the each optimization technique and to analyze the application for the rainfall-runoff models. Modified TANK model that is used to calculate outflow for watershed management and reservoir operation etc. was optimized as a long term rainfall-runoff model. And storage-function model that is used to predict real-time flood using historical data was optimized as a short term rainfall-runoff model. The optimized models were applied to simulate runoff on Pyeongchang-river watershed and Bocheong-stream watershed in 2001 and 2002. In the historical data study, the Genetic Algorithm and the SCE-UA method showed consistently good results considering statistical values compared with observed data.

• The Journal of Asian Finance, Economics and Business
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• v.5 no.2
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• pp.73-79
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• 2018

The purpose of this study is to explore how small and medium enterprises in India has identified the opportunities and challenges in adopting the Web 3.0 technologies to improve their productivity and efficiency. After an in-depth literature review, researchers framed a semi-structured questionnaire with open-ended questions for collecting responses from managers working in 40 Indian SME's representing five key economic sectors. The collected data was analyzed, and themes were encoded using the NVivo 11 computer-assisted qualitative data analysis software. Content analysis was used to analyze the data collected with the semi-structured interviews. This study identified five key themes and 12 subthemes illustrating the key advantages and challenges as perceived by the managerial leadership of SMEs. The five key themes identified in this study include integration of data and services, the creation of new functionalities, privacy and security, financial and technological challenges, and organizational challenges. The results of this study will benefit the organizational leadership of SMEs in planning and developing their short-term and long-term information systems strategies and will enable SME leaders to make optimal use of their information technology assets, improving the productivity and competitiveness of the firms. Web 3.0 technologies are considered as emerging technologies, so the advantages and challenges of using these technologies for SMEs have not been explored in the context of emerging economies, such as India.

• Proceedings of the KSRS Conference
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• v.1
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• pp.159-162
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• 2006

This paper describes the ground system for COMS (Communication, Ocean, and Meteorological Satellite), the first Korean multi-purposed geostationary satellite, at MSC (Meteorological Satellite Center) in Korea. The overview of COMS MI (Meteorological Imager) will be introduced as well. KMA would implement mission planning for COMS MI operation and receive, process, interpret, disseminate, and archive MI data operationally for domestic and foreign user groups. Major missions of COMS MI are mitigation of natural hazard such as typhoon, dust storm, and heavy rain, and short-term warning of severe weather to protect human health and commerce. Moreover, research of climate variability and long-term changes will be supported. In accordance with those missions, the concept and design of COMPASS (COMS operation and meteorological products application service system), the ground system for COMS MI in MSC, have been setting up since 2004. Currently, COMPASS design is being progressed and will have finished the end of 2006. The development of COMPASS has three phases: first phase is development of fundamental COMPASS components in 2007, second phase is to integrate and test all of the COMPASS components in 2008, and the last phase is to operate COMPASS after COMS In-Orbit Tests in 2009.

• Journal of Korean Medicine for Obesity Research
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• v.7 no.1
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• pp.1-7
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• 2007

Background : Use of Ma Huang is controversial. Multiple reports of adverse effects led the U.S. Federal Drug Administration (FDA) to announce about prohibiting dietary supplements containing ephedrine alkaloids/Ma Huang. Objective : The objective of the study was to review the evidence from literature and rigorous clinical trials on the dosage, effectiveness, and adverse effects. Methods : Literature searches were conducted in U.S. FDA database after 2003 and digital Uibujeonok(醫部全錄). Hand searches of medical journal and bibliographies of identified articles were conducted. Results : Ma Huang has been used in Korean Oriental Medicine to treatment asthma and other ailments. Recently, Ephedrine/Ma Huang are used for weight loss or to enhance athletic performance in Europe and America, Korea. Ephedrine/Ma Huang are associated with increased risk of psychiatric, autonomic, or gastrointestinal symptoms, and heart palpitations. In addition to that, a risk of serious adverse events, including heart attack, stroke, epilepsy and psychiatric problem are also have been reported. Therefore, max dose of total alkaloids of ephedrine is studied in need of a specialist's part. Conclusion : In most reports, Ma Huang effectively promoted short-term weight loss and enhancement of athletic performance, But, safety with long-term use requires further investigation.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.8
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• pp.77-85
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• 2020

The aim of this study is two-fold. Firstly, it attempts to assess the level of management accounting practices (MAPs) in manufacturing companies in Vietnam. Secondly, it purports to explore the impact of potential contingency factors on the current level of MAPs in the sample of studied companies from the industrial sector in Vietnam. The study examines the hypotheses that MAPs in Vietnamese manufacturing firms are affected by a range of contingent variables. A quantitative research was conducted by sending questionnaires to the target respondents that comprise both accountants and managers in 160 manufacturing enterprises in the north of Vietnam. The first main findings from the study reveal that MAPs in Vietnam are mainly traditional rather than contemporary ones, and oriented toward the short-term rather than the long-term. The second main research findings resulted from multiple regression model show that MAPs in Vietnam are significantly affected by company size, commitment of directors, advanced manufacturing technology, and distinct number of products. However, no significant associations are found between MAPs and intensity of competition from the emerging market as hypothesized in this study. Research findings are bases for recommendations to promote the application of contemporary practices and enhance management accounting functions in manufacturing companies in Vietnam.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.1
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• pp.237-246
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• 2001

This study is to measure the creep coefficient by 3 days, 7 days and 28 days in the age when loading for the quality assessment of $350kgf/cm^2$ in the high-strength concrete. And it is to analyze the behavior of creep coefficient by applying the experimental data though the compressive strength test, the elastic modulus test and the dry shrinkage test to the ACI-209, AASHTO-94 and CEB/FIP-90, the prediction mode, and the basis of concrete structural design. Also it is to analyze the behavior of short-term creep coefficient during 91 days in the age when loading through the experiment by using the regression analysis, the statistical theory. As applying it to the long-term behavior during 365 days and comparing with the creep prediction mode and examining it, the result from the analysis of the quality of the concrete is as follows. As the result of comparison and analysis about the ACI-209, AASHTO-94 and CEB/FIP-90, the prediction mode, and the basis of concrete structural design, the normal Portland cement class 1 shows the approximate value with the prediction of GEE/PIP-90 and the basis of concrete structural design, but in case of the prediction of ACI-209 and AASHTO-94, there would be worry of underestimation in the application.