• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.33.1-33.10
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• 2017

Dental implants are a common treatment for the loss of teeth. This paper summarizes current knowledge on implant surfaces, immediate loading versus conventional loading, short implants, sinus lifting, and custom implants using three-dimensional printing. Most of the implant surface modifications showed good osseointegration results. Regarding biomolecular coatings, which have been recently developed and studied, good results were observed in animal experiments. Immediate loading had similar clinical outcomes compared to conventional loading and can be used as a successful treatment because it has the advantage of reducing treatment times and providing early function and aesthetics. Short implants showed similar clinical outcomes compared to standard implants. A variety of sinus augmentation techniques, grafting materials, and alternative techniques, such as tilted implants, zygomatic implants, and short implants, can be used. With the development of new technologies in three-dimension and computer-aided design/computer-aided manufacturing (CAD/CAM) customized implants can be used as an alternative to conventional implant designs. However, there are limitations due to the lack of long-term studies or clinical studies. A long-term clinical trial and a more predictive study are needed.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.1
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• pp.17-24
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• 2019

In this paper, we analyzed the effect of power system load model on the short-term voltage stability analysis results. First, we introduced common load models. We also confirmed that some load models can not represent actual system phenomena even if the model parameters are optimized. Also, we studied about the influences of load parameters and regional characteristics of load model on the sort-term voltage stability of KEPCO power system considering the contingency. The results showed that the importance of selecting a load model was confirmed again. And we recognized about it can be understood that it should reflect the load characteristics of the area near the assumed contingency more accurately.

• Korea Trade Review
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• v.44 no.1
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• pp.17-30
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• 2019

This study is to investigate the effect of real exchange rate on bilateral trade balance between Korea and ASEAN 10 countries. Using quarterly data from 1991 to 2017 the paper analyzes whether or not the real depreciation of Korea's won could improve the trade balance in the short and long term. Based on Autoregressive Distributed Lag(ARDL) model, the empirical results show that trade balance, GDP, and real exchange rate are all cointegrated, representing the long-run relationship among variables. In the consideration of long-run relationship, the increases in ASEAN countries' GDP could have a negative impact and Korea's GDP positive impact on trade balance between Korea and ASEAN countries unexpectedly. For the main variable, the paper did not find the long-term effect of real exchange rate on the trade balance, for the short-term effect of the real exchange rate it was found that there exists the J-curve effect only in the case of Vietnam and Brunei. Therefore, these results imply that the intended policy concerning the exchange rate in the free-floating exchange rate system could be limited to improve the trade balance between Korea and ASEAN countries.

• Journal of information and communication convergence engineering
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• v.5 no.2
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• pp.171-176
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• 2007

To give a guarantee a consistently high level of quality and reliability of Telematics traffic service, traffic flow forecasting is very important issue. In this paper, we proposed an adaptable integrated prediction model to predict the traffic flow in the future. Our model combines two methods, short-term prediction model and long-term prediction model with different combining coefficients to reflect current traffic condition. Short-term model uses the Kalman filtering technique to predict the future traffic conditions. And long-term model processes accumulated speed patterns which means the analysis results for all past speeds of each road by classifying the same day and the same time interval. Combining two models makes it possible to predict future traffic flow with higher accuracy over a longer time range. Many experiments showed our algorithm gives a better precise prediction than only an accumulated speed pattern that is used commonly. The result can be applied to the car navigation to support a dynamic shortest path. In addition, it can give users the travel information to avoid the traffic congestion areas.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.6
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• pp.85-93
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• 2020

The paper investigates the impact of the statement of cash flows of listed companies on lending decisions of commercial banks in the context of Vietnam. Survey data for the research were collected from 160 credit officers of Vietnamese commercial banks for short-term and long-term lending decisions, whether the cash flow statement includes complete information or has a lack of information. The cash flow statement, in which the information on the cash flow is completely contrary to the profit information on the income statement is examined. This paper employed T-tests to address the research issues in a market considered to be ineffective, like Vietnam. The research results show: (1) the information on the cash flow statement affects both the short-term and long-term lending decisions of credit officers, and (2) the lack of information on the cash flow statement in both cases of positive and negative profits affects the comfort and confidence of credit officers in making decisions. The research findings also indicate that cash flow statements are important for lending decisions of credit institutions in Vietnam. Therefore, this paper provides a new insight to managers on how to improve the quality of cash flow statement to meet the needs of lenders.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.2
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• pp.179-189
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• 2003

The concentration of gaseous elemental mercury (Hg) was measured concurrently with relevant environmental parameters from Yang-Jae monitoring station in Seoul during Sept. 1997 to June 2002. Although data collection was disrupted for certain periods, the grand mean concentration of Hg for this five year period was found at 5.32 $\pm$ 3.53 ng m$^{-3}$ (N = 27,170). Because of short resolution of data acquisition, we were able to examine the temporal variability of Hg at varying time scale. The diurnal variability of Hg, when investigated for each of those five years, indicated consistently the dominance of nighttime over daytime. If examined at seasonal scale, Hg level was systematically higher during winter/spring than summer/fall period. The results of this short-term variability were best explained by the combined effects of such factors as meteorological conditions (formation of inversion layer and seasonal changes) and anthropogenic source processes. However, examination of long-term variation Pattern was much more complicated to explain. Thus, extension of our study is needed to diagnose the future direction in long-term trend of Hg behavior.

• Journal of Korean Society of Transportation
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• v.30 no.5
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• pp.43-59
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• 2012

It is generally assumed about trip distribution estimation model that growth factor model's estimation accuracy is higher than that of other models in short-term and that gravity model's estimation accuracy is higher than that of other models in long-term. For validation of such assumptions, this study compares estimation accuracies of each estimation model using 3year(1988, 1992, 2004) O-D tables from Daegu city. Each estimation model's accuracy were compared by mid-size and large-size zone as well as short-term and long-term target years. The results show that the trip distribution estimation model selection by usual assumption is not always right.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.2
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• pp.44-55
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• 1994

This paper describes the development of real-time irrigation reservoir operation models that adequately allocate available water resources for paddy rice irrigation. Water requirement deficiency index(WRDI) was proposed as a guide to evaluate the operational performance of release schemes by comparing accumulated differences between daily release requirements for irrigated areas and actual release amounts. Seven reservoir release rules were developed, which are constant release rate method (CRR), mean storage curve method(MSC), frequency analysis method of reservoir storage rate(FAS), storage requirement curve method(SRC), constant optimal storage rate method (COS), ten-day optimal storage rate method(TOS), and release optimization method(ROM). Long-term forecasting reservoir operation model(LFROM) was formulated to find an optimal release scheme which minimizes WRDIs with long-term weather generation. Rainfall sequences, rainfall amount, and evaporation amount throughout the growing season were to be forecasted and the results used as an input for the model. And short-term forecasting reservoir operation model(SFROM) was developed to find an optimal release scheme which minimizes WRDIs with short-term weather forecasts. The model uses rainfall sequences forecasted by the weather service, and uses rainfall and evaporation amounts generated according to rainfall sequences.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.3
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• pp.544-556
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• 1997

All ceramic restorations except In-Ceram Alumina system gave a good esthetics and an exellent marginal fidelity. The flexural strength of them had about 150MPa, so the indication is only single crown. By using In-ceram Alumina System(450Mpa), it is thought to be possible to construct bridge for its high flexural strength. But the prognosis is unclear, The purposes of this study are to clear short term prognosis of In-Ceram bridge restorations, to elucidate its clinical significance. Among 22 In-Ceram Bridge restored in our department, 11 In-Ceram bridges with follow up were used. The period of placement is from 1 to 18 months. The results were as follows : 1. Among follow up 11 bridges, 2 bridges were fractured. One is 4 unit in maxillary lateral incisors, the other is 3 unit bridge in maxillary canine and premolar. Including 11 bridge without follow up, failure rate is very low(2/22). 2. The fracture sites are connector areas between abutment and pontic. To maintain In-Ceram bridge for long term period, it is needed to remove the nonphysiologic occlusal force and to have sufficient thickness of alumina core. For estabilishing clinical use of In-Ceram bridges, it is thought to need clinical research during long term period.

• Journal of Korean society of Dental Hygiene
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• v.19 no.4
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• pp.515-524
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• 2019

Objectives: This study aimed to investigate the effects of the amount and duration of smoking on gingival symptoms in adolescents. Methods: We used the web-based survey data of youth health behaviors from 2016 conducted by the Korean Centers for Disease Control and Prevention. The subjects of the study were 67,983 middle and high school students. Data analysis was performed using the SPSS Ver 20.0 program, and complex sample multivariate logistic regression analysis was performed to analyze gingival symptoms according to short- or long-term smoking habits. Results: In subjects with short-term smoking habits, there was no significant difference in gingival symptoms according to the smoking amount. However, after adjusting for socioeconomic characteristics and oral health behaviors in subjects with long-term smoking habits, a heavy smoking amount (${\geq}0.52PY$) had a 1.25 times higher effect than a light smoking amount (<0.52 PY) on gingival symptoms. Long-term heavy smoking (${\geq}0.52PY$) and low daily tooth-brushing frequency in high school students were factors affecting gingival symptoms. Conclusions: When conducting a project on the oral health of adolescents, it is argued that specific investigations and measures should be set up regarding health behavior factors, such as the amount and duration of smoking among adolescents.