• Journal of Korean Society of Transportation
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• v.28 no.5
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• pp.141-153
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• 2010

The study is about the development of operating speed prediction models aimed for an evaluation of design consistency of four lane rural roads. The main differences of this study relative to previous research are the method of data collection and classification of road alignments. The previous studies collected speed data at several points in the horizontal curve and approaching tangent. This method of collection is based on the assumption that acceleration and deceleration only occurs at horizontal tangents and the speed is kept constant at horizontal curves. However, this assumption leads to an unreliable speed estimation, so drivers' behavior is not well represented. Contrary to the previous approach, speed data were collected with one and data analysis using a speed profile is made for data selection before building final models. A total of six speed prediction models were made according to the combination of horizontal and vertical alignments. The study predicts that the speed data analysis and selection for model building employed in this study can improve the prediction accuracy of models and be useful to analyze drivers' speed behavior in a more detailed way. Furthermore, it is expected that the operating speed prediction models can help complement the current design-speed-based guidelines, so more benefits to drivers as real road users, rather than engineers or decision makers, can be achieved.

• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.247-261
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• 1995

The purpose of this study was to quantitate differences in the nature of the correction of Angle's Class II div 1 malocclusion dependent on the patient's age at the time of treatment. The sample consisted of 27 female patients in the adolescent group with a mean initial records age of 11.8 years and 25 female patients in the adult group with a mean starting age of 21.1 yrs. Lateral cephalometric head films were taken before and after orthodontic treatment with four bicuspid extraction. The results were obtained as follows. 1. None of maxillary skeletal parameters exhibited a significantly different in treatment change between adolescents and adults. But, in mandibular skeletal measurements, there were significant differences between two groups. (P<0.05) 2. Measures of vertical dimension in the adults remained unchanged during treatment, reflecting the effective absence of growth. 3. The steepness of occlusal plane in the adults changed significantly.(P<0.05) In contrast, the adolescents displayed stability of the occlusal plane. 4. According to the Johnston analysis, there was a significant difference in the total molar correction between two groups.(P<0.05) 5. According to the Johnston analysis, differential mandibular growth in the adolescents contrubuted $63\%$ of the total molar correction, with orthodontic tooth movement accounting for the remaining $37\%$. In the adults, dental movement comprised $99\%$ of the correction.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.426-432
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• 2008

We introduce a method of rendering a scene lying 3D objects which is like that artist draw on a canvas by brushing. Painting is the art area presenting something created by color and line on 2D plane. We are brushing on billboards on screen space for the 2D brushing effect according to the definition of "Painting". Brushing orientation is haven to rotate for preventing the orientation in the first scene in the case that object or camera are moving. If the brushing isn't rotated, shower-door effect is watched on the scene as undesirable result We present a brushing rotating method for keeping the orientation changing the direction of view and object rigid animation. The brushing direction is computed with Horn's 2D similarity transform by least-square solution. We watched the changing brushing to track the motion of object and view.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.24 no.2
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• pp.83-93
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• 1988

Recent Experimental results show that the J integral can be effectively used to obtain a valid parameter for predicting plane strain and plane stress fracture. However, only a few research results have been reported for the effect of thickness where the plane strain state can not be assumed. A purpose of this study is to find the behavior of fracture touhness and tearing modulus varing the specimen thickness. The type of specimen in the present study is compact tension (CT). The thicknesses of the low carbon steel specimens that are used in the experiments are 5, 10, 15, 20 and 25mm. The measurement of crack length is taken by optical measurements method. From the study, the followings are found; 1) The fracture toughness and the tearing modulus which are obtained by using Yoon's and Simpson's formula show more conservative than that by using Rice's and Merkel's. 2) The fracture toughness is increase in specimen thickness which is reached 15mm. Beyond this thickness the fracture toughness is decreased in specimen thickness. 3) In the case of CT specimen with the thickness ranging from 5 to 25mm, the tearing modulus which is applied the same J integral equation is almost constant. 4) By using Yoon's formula, the correlation of the plane slress fracture toughness J sub(C) with specimen thickness B is expressed as the following formula. J sub(C)/J sub(IC)=1.7-15.1(B/W)+112.9(B/W) super(2) -301.3(B/W) super(3) +260.6(B/W) super(4)

• Tunnel and Underground Space
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• v.20 no.6
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• pp.455-464
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• 2010

The variations of the uniaxial compressive strength, the strains and the elastic constants with respect to the angle of anisotropy are analyzed in order to investigate the characteristics of a transversely isotropic rock experimentally. Total 35 specimens of 7 different angles from a large block of rhyolite presenting the flow structure obviously are used in tests. This study is composed of two reports; the elastic constants are mainly analyzed for the every individual angle in the report No. 1 and they will be discussed synthetically in the report No. 2. From the specimens of 0 and 90 degree, 4 independent elastic constants which can directly be obtained without the help of any other suggested equations, may be referred to the true values. Data variation in the strain measurements differs on the angle is analyzed. That of small angle specimens tends higher than that of large angle specimens. The relation of apparent Young’s modulus and angle is found to be M- or U-shaped. For small angle specimens, Saint-Venant approximation cannot be applied successfully on account of showing the non-monotonous increase, and E1 is analyzed out of the true value range. In the specimen of $\phi$ = 75, the deviation of strain measurement and strength are smallest and 4 all constants are analyzed in the true value range. Therefore, specimen of the angle of around 75 may become preferable if only one specimen should be used in test of a transversely isotropic rock.

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.239-249
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• 1999

In orthognathic surgery to obtain proper functional and esthetic form after skeletal discrepancy treatment, precise diagnosis and treatment plan are essential. Especially in two jaw surgeries that have serious upper and lower jaw problems, maxilla and mandible are arranged in three dimensions. Based on the maxillary rearrangement, mandibular sagittal and transverse positions are determined, and thus new occlusal plane is established. The object of this study is to evaluate the stability of the indiviual ideal occlusal plane based on the architectural and structural craniofacial analysis of Delaires. The subjects of this study were 48 patients who underwent two jaw surgeries, and they were equally divided into two groups, A and B. A group was operated with ideal occlusal plane and B group was not. Two groups were compared at the preoperative, immediate postoperative (average 4.3days), and long-term postoperative (average 1.3years) lateral cephalometric radiographs. The following results were obtained: 1. ANS was lower than that of PNS for both A and B after the surgery. That is, maxilla and mandible are rotated in posterior and superior direction. 2. Significances were found between $T_2$ and $T_3$ for both A and B are HRP-Me at vortical measurements, articular angle(p<0.01), gonial angle(p<0.01), and Mn. plane angle(p<0.05) at angular measurement. Mn. plane angle is increased at HRP-Me is decreased for both A and B. 3. There is no significance in skeletal stability aster the surgery between group A and B. 4. Horizontal movements of B and Pog by surgery have statistically significant inverse correlations with horizontal relapse of B and Pog, and vertical relapse of PNS, as well as Mn. Plane angle, and gonial angle after the surgery.

• Korean Institute of Interior Design Journal
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• no.16
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• pp.36-41
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• 1998

This study is mainly intended to understand on the plan change of a public room in the apartment. This study is summarized as follows; First how the plane type of an apartment public room in the Capital region has been changed since 1970's in which industrialization has seriously started. Second according to the adjoining types how the features of an apartment plan would be divided into some categories. Third how usable area and public area in an apartment has been changed, The scop of this study is limited to the national standard houses of which usable area is 40-85m2(12.1-25.7pyong) built in Seoul and five new cities from 1970's to the half of 1990's The study is based on documents of 1378 samples extracted classified and analysed the plan in the chronical order. The analysis scope is confined to family's public rooms in an apartment such as a living room a dining room and a kitchen. In conclusion the public rooms such as a living room a dining room, and a kitchen become stereotyped with no specific difference in Korean apartments. Especially LDK type, L/DK type is the most general plan in Korean apartments, and the demand of that type is continuously increasing lately.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.2
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• pp.111-118
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• 2003

Notch Antenna is a travelling wave type antenna and can provide multioctave operation in phased arrays that scan over wide angle. In this paper, we designed a wideband E-plane phased array antenna using E-plane waveguide simulator which has a bandwidth of 3 : 1 and a scan volume of $\pm$45$^{\circ}$ in E-plane. We compared impedance of single antenna and infinite array antenna using equivalent circuit modeling. We analyzed full structure of 1$\times$9 phased array antenna and we evaluated active reflection coefficient with variation of beam scan angle through mutual coupling coefficient acquired from simulation and investigated the variation of antenna gain with variation of active element pattern as beam scan angle is varied.

• Journal of Korean Society of Steel Construction
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• v.21 no.5
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• pp.483-492
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• 2009

In this study, nonlinear analysis of steel plane frame was performed using the refined plastic hinge method of advanced analysis techniques. In deterioration of stiffness in plastic zone, influences by flexural bending, residual stress, geometrical non-linearity, and semi-rigid connection are considered. And also, further reduced tangent modulus was used for geometrical non-linearity, top and seat angle were chosen for semi-rigid connection. Furthermore, 3 parameter power model was used for moment-rotation behaviour of beam to column connection. The loading conditions are combined with axial and lateral force and the inverse triangle distribution of lateral and eight type of analytical models were used in analysis. The results of analyses were compared with semi-rigid and rigid connection on behaviour of numerical analysis models. And also, the behaviors of frame with changes of semi-rigidity were analyzed by using the results obtained from MIIDAS-GENw.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.3C
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• pp.323-330
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• 2007

Performance indicators such as output SNR, SIR, SINR for rectangular smart antennas in CDMA basestations have been derived. Simulations have been carried out to find the rectangular smart antenna performance while varying the input SNR, number of antenna elements, and the interferers' spatial distributions. Simplified Conjugate Gradient Method was chosen as the underlying beam forming algorithm. It has been shown that the performance of a rectangular smart antenna is similar to that of the linear one having the same number of elements when the interferers are randomly distributed over the whole azimuth angle range.