The diagnosis of coronoid impingement using computed tomography

Baik, Jee-Seon,Huh, Kyung-Hoe,Park, Kwan-Soo,Park, Moo-Soon,Heo, Min-Suk,Lee, Sam-Sun,,Choi, Soon-Chul 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.4

Coronoid impingement can cause limitation of mouth opening. In many cases, it appears to be related to the coronoid hyperplasia. We present a case of mouth opening limitation caused by coronoid impingement on the posterior surface of the zygomatic bone without coronoid hyperplasia. The bony changes in coronoid and zygoma including surface irregularity and discontinuity of the cortex and sclerotic change of inner medullary space were noted on computed tomography (CT) scans in different level of axial planes. Through another CT scans in open mouth position could demonstrate that those bony changes were caused by the contact of both surfaces against each other. In case coronoid impingement is suspected of the many possible causes, the open mouth CT scans will be needed to reveal the direct impingement of coronoid on zygoma even without coronoid hyperplasia.

선행강우지수를 고려한 저수유출해석

許彰桓,金知學 충주대학교 산업과학기술연구소 2002 産業科學論文集 Vol.10 No.-

This study is aimed at the development of a deterministic runoff model which can be used for low flow runoff. The model is formulated by the watershed runoff model. Based on the assumptions that runoff system is nonlinear, the proposed watershed runoff models are the conceptual model and tank model. In the model structures, the conceptual and tank model divide the runoff system into a surface structure and a subsurface structure corresponding to the surface flow, and inter flow and ground water flow respectively. The lag time effect of surface can be represented by the sub-tank of surface structure in the conceptual model and by the 2rd-tank in the tank model. The parameter calibration of inter flow and ground water flow in the subsurface structure of the conceptual model is made by separating the components with numeric filter. The runoff coefficient(α_2, K_1) is expressed as the function of antecedent precipitation index(API) in the conceptual and tank model. The parameters related to the surface flow can be calibrated with the runoff coefficient(α_1, α_11, C1, C2) in the conceptual and tank model. In the conceptual and tank model an algorithm are developed to calibrate the parameters automatically based on efficiency criteria. The tank model shows more closely to the observed hydrograph than conceptual model.

용수공급용 저수지의 월유입량 추정

金知學,許彰桓,張仁洙 충주대학교 1997 한국교통대학교 논문집 Vol.32 No.2

This study focused on estimating the monthly inflows for impounding reservior. Data used in the monthly estimated inflows calculation were the monthly rainfalls and the monthly observed inflows of the Sayeon dam with the record length from 1986 to 1995 in Taewha river basin. For the model verification, the values of Model Efficiency(ME), Root Mean Square Error (RMSE),Bias,Volume error (VER) and Correlation Coefficient(R)were calculated to the observed and the estimated inflows. As a result, Tank model was superior to Kajiyama model in accuracy, and the monthly estimated inflows by Tank model could be used to the various water resources planning

都市 流域의 尖頭洪水量 算定

金知學,許彰桓 충주대 산업과학기술연구소 1996 産業科學論文集 Vol.4 No.-

Numerous methods are available for estimating the peak flow required for design apllications in urban watersheds. Some incorporate the rainfall - runoff process, whereas others are completely empiric or correlative in that they predict peak flow by correlating the flow with simple drainage basin characterstic such as area or slpoe. In this study, the rational formula is identified as the most effective method of peak flow estimation for designing drainage facitities in urban watersheds.

충주댐 유역의 수위-유량관계 곡선식의 개발

金知學,許彰桓 충주대 산업과학기술연구소 2000 産業科學論文集 Vol.8 No.-

The importance of discharge measurement in river basins is more increasing with requiring domestic, industrial and agriculture water demand as population and industrialization. It is important to measure a correct and reliable river discharge for water resources study related with investigation, water quality management, water resources distribution and rainfall-runoff relationship. This study developed a methodology to measure stream discharge as well as stage-discharge relationship derivation and application at 6 gauging stations in chungju dam watershed.

산지소유역에서의 분포형 단위도의 적용

金知學,許彰桓 忠州大學校 1998 한국교통대학교 논문집 Vol.33 No.2

The aim of this study is to develop the of distributed unit hydrograph in the small mountainous watershed. The distributed unit hydrograph is a unit hydrograph derived from a spatially distributed excess rainfall. It is computed from the time-area diagram of a watershed. The excess rainfall is computed by means of the Soil Conservation Service runoff curve methed. Derivation and application of the distributed unit hydrogarph is illustrated by an example using data from Yogak valley watershed in the Chungju city.

忠州川 水系의 水面形 算定에 關한 硏究

金知學,許彰桓,張仁洙 忠州大學校 1996 한국교통대학교 논문집 Vol.31 No.2

This study aims at the provision of optimal methodology which needs for a stream improvement plan in urban watershed. The study basin is the Chungju river basin, which have the 3 tributary basins. The rational formula applied to estimate peak runoff rates in this study is the most widely used method for designing drainage facilities for small urban and rural watersheds. The HEC-2 model is applied to caculate water surface profiles for steady, gradually varied flow in Chungju river system. The computational procedure is based on solution of the one-dimensional energy equation using the standard step method. The model is applied to floodplain management to evaluate floodway encroachments and to delineate flood hazard zones. The model also is used to evaluate effects on water surface profiles of channel improvement and levees as well as the presence of bridges or other structures in the floodplain.

降雨量의 頻度分析에 關한 硏究

金知學,申桂鍾,許彰桓 충주대 산업과학기술연구소 1994 産業科學論文集 Vol.2 No.-

This study aim at the development of the model of probability rainfall for return period by using frequency analysis. In this study, models of frequency analysis are classified to for lowing models : Two-Parameter lognormal distribution, Three-Parameter lognormal distribution, Pearson Type III distribution, Log-Pearson Type III distribution, Extremal Type I distribution. From the comparison of these models with rainfall data, it is found that Extremal Type I distribution is maximum value and Log-Pearson Type IIIf distribution is minimum value.

선행강우지수를 고려한 저수유출 시뮬레이션 모형

金知學,許彰桓 충주대 2003 産業科學論文集 Vol.11 No.-

This study is aimed at the development of a deterministic runoff model which can be used for low flow runoff. The model is formulated by the watershed runoff model. Based on the assumptions that runoff system is nonlinear, the proposed watershed runoff models are the conceptual model and artificial neural network model. In the model structures, the conceptual model divide the runoff system into a surface structure and a subsurface structure corresponding to the surface flow, and inter flow and ground water flow. The lag time effect of surface can be represented by the sub-tank of surface structure in the conceptual model. Fifteen neural networks models using Quasi-Newton technique were prepared to find the optimum parameters with each of them having different numbers of hidden layers and hidden layers nodes. The parameter calibration of inter flow and ground water flow in the subsurface structure of the conceptual model is made by separating the components with numeric filter. The runoff coefficient(a2,K1) is expressed as the function of antecedent precipitation index(API) in the conceptual model. The parameters related to the surface flow can be calibrated with the runoff coefficient(a1, a11, c1, c2) in the conceptual model. In the conceptual and ann model an algorithm are developed to calibrate the parameters automatically based on efficiency criteria. The conceptual model shows more closely to the observed hydrograph than ann model.

群集分析에 의한 豪雨 圈域區分

金和學,許彰桓 忠州大學校 1995 한국교통대학교 논문집 Vol.30 No.2

This study attempts to classify climatic storm regions of the Nakdong river basin based on heavy rainfall data by the hierarchical Cluster analysis. The data used this study are obtained from 56 T/M rainfall station during the period of 1988-1991 years in the Nakdong river basin. Variables used in the study are deviation and mean of deviation in storm rainfall. Distance used is Euclidean distances. Homogeneity test is based on Variance analysis of basic statistical method.