• The Journal of the Korean dental association
• /
• v.44 no.12 s.451
• /
• pp.816-829
• /
• 2006

The purpose of this study was to determine the level of perception and preference between dentists and lay people to altered facial profile. The assessors consisted of 40 dentists and 54 lay people, the survey was performed using questionnaire asking the order of perception and preference. The profiles presented in the questionnaire were based on the profile of one man and one woman, each morphed according to anterior or posterior direction of maxilla and mandible. The results were as follows. 1. In antero-posterior change of man and woman s profile, both dentists and lay people were sensitive to relatively skeletal profile (convex profile) changes than skeletal profile (concave profile) changes. 2. At least dentists needed to be perceived a 2 mm change in convex profile and a 3 mm change in concave profile and lay people needed to be perceived a 2 mm change in convex profile and a 3 mm change in concave profile for profile view. 3. Dentists are more sensitive in perception of man s profile change than lay people, but there is no significant differences between dentists and lay people in sensitivity of detection for woman s profile changes . 4. It seems that there is a general concordance between dentists and lay people in there perception of man s and woman s facial profile. This information might be clinician in comprehensive perception and preference of dentists and lay people to altered facial profile.

• The korean journal of orthodontics
• /
• v.21 no.1 s.33
• /
• pp.113-130
• /
• 1991

This study was undertaken to investigate soft tissue profile changes by orthodontic treatment in female patients. Traditional cephalometric appraisal yields data of dubious scientific value, the soft tissue profile forms were evaluated by finite element method. The subject was divided into three groups according to Angle's classification and each group was composed of 25 female patients averaged aged 12-14 years at the start of treatment. The changes in soft tissue form were evaluated by computing the degree of distortion in each triangle after treatment compared with the triangle before treatment. The conclusions were as follows; 1. The soft tissue profile forms were evaluated by finite element method and independent evaluation of each element by local changes was possible. 2. Maximum and minimum principal strains showed marked variability depending on the particular finite element and each group and Class II, III sample was greater than Class I sample. 3. Soft tissue size changes as a result of orthodontic treatment was not related to those of shape. 4. Soft tissue changes by orthodontic treatment were variable in individual patient, and were not related to Angle's classification.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.191-192
• /
• 2006

The deformation under radial pressure of rectangular dies for metal powder compaction has been investigated by FEM. The explored variables have been: aspect ratio of die profile, ratio between diagonal of the profile and die height, insert and ring thickness, radius at die corners, interference, different insert materials, i. e. conventional HSS, HSS from powders, cemented carbide (10% Co). The analyses have ascertained the unwanted appearance of tensile normal stress on brittle materials, also "at rest", and even some dramatic changes of stress patterns as the die height increases with respect to the rectangular profile dimensions. Different materials behave differently, mainly due to difference of thermal expansion coefficients. Profile changes occur when the dies are heated up to the temperature required for warm compaction. The deformation patterns depend on compaction temperature and thermal expansion coefficients.

• The korean journal of orthodontics
• /
• v.24 no.1 s.44
• /
• pp.135-147
• /
• 1994

Facial esthetics is one of the most important goal of the orthodontic treatment and main concern of many patients. Facial esthetics should be considered in orthodontic diagnosis and treatment planning. Prediction of soft tissue profile changes after orthodontic tooth movement should be considered as well. The purpose of this study was to find out the effect of orthodontic treatment on lip profile in adult patient. The pre and post treatment cephalometric roentgenograms of 87 female adult with bimaxillary protrusion were used to analyze lip profile change. All subjects were treated with four bicuspids extraction. Obtained results were as follows . 1. Lip thickness changes after incisor retraction showed different patterns according to areas of the lip. The thickness of the red lip area showed 2.78 mm increase in average. In contrast the thickness of the cutaneous area showed 0.65 - 0.7 mm decrease according to the different cutaneous areas. 2. The length of the red lip area decreased(1.3mm) after incisor retraction. 3. The length of the cutaneous lip area increased(2.9mm) after incisor retraction.

• Journal of Environmental Science International
• /
• v.9 no.1
• /
• pp.35-42
• /
• 2000

In this study, the movable bed model testing was carried out so as to analyze bed profile changes including predicting scouring and deposition of bed profile and to solve hydraulic problems affecting with bed and both-bank between upstream and downstream of intake weir in the Nakdong river channel. The movable bed model testing consists of fundamental test, movable model test and numerical analysis method respectively. The fundamental test was enforced to analyze relationship of discharge and sediment load in the tilting flume. When the movable model test was worked, it was shown that sediment budget between input sediment load and output sediment load was balanced exactly. As a result of movable model test, it was presented that scouring and deposition changes in quantities between the upstream and downstream of modification weir were less than those of nature and planning weir. Finally, numerical analysis method was operated by 1-dimensional bed profile changes model ; HEC-6 model so as to complement unsolving hard problems during movable model test. So, modification weir will sustained the stable bed profile changes than any other weirs in the study channel.

• Journal of The Korean Association For Science Education
• /
• v.21 no.5
• /
• pp.795-821
• /
• 2001

This Qualitative study investigated a preservice teacher's developing views of learning with the influence of constructivist epistemology taught in the Math, Science, and Technology Education (MSAT) Master of Education (M. Ed.) preservice teacher education program. The MSAT teacher education program employs constructivist aspects of teacher education and generates applications of constructivism to the practice of teaching, as revealed by faculty interview data. It is important at this point to emphasize that there are significant epistemological and ontological differences between different versions of educational constructivism (i.e., individual, radical, and social constructivism) and that these differences imply different pedagogical practices. For the 16 preservice teachers included in a larger study, the epistemological and ontological characteristics for each teacher's developing views of learning were identified through four in-depth interviews. Data from interviews were used to construct a constructivist profile for each preservice teacher's views of learning (i.e., a profile containing ontological beliefs, epistemological commitments, and pedagogical beliefs). Of the sixteen participants in the larger study, five significantly changed ontological and epistemological beliefs and eleven did not. Profile changes for the five who did change also resulted in changes in their conceptions of science teaching and learning (CSTL). In this article, one of the five teachers case was presented with rich quotes. This case study documents how a preservice teacher transferred his ontological and epistemological beliefs to his pedagogical beliefs and maintained the consistency between his philosophical beliefs and CSTL. It also demonstrated implications that changes in components for an educational constructivist profile have for a preservice teacher's view of himself as teacher. Data indicated the possibility that a constructivist-oriented preservice teacher education program can influence students' conceptions of science teaching and learning by explicitly introducing constructivism as an epistemology rather than as a specific method of instruction. Implications for both instructional practices of teacher education programmes and research are discussed.

• Tribology and Lubricants
• /
• v.31 no.5
• /
• pp.205-212
• /
• 2015

In this research, effects of profile changes of stem section of the plunger on the lubrication characteristics of a fuel injection pump (FIP) were evaluated by hydrodynamic lubrication analysis. The clearance between plunger and barrel was divided into two regions, head and stem. The head was not involved in preventing a decrease of fuel oil pressure. So, research efforts were focused on both edges of the plunger’s stem. The two -dimensional Reynolds equation was used to evaluate lubrication characteristics with variations in viscosity, clearance and profile for a laminar, incompressible, unsteady-state flow. Moreover, the equilibrium equation of moment and forces in the vertical and horizontal directions were used to determine the motion of the plunger. The equations were discretized using the finite difference method. Lubrication characteristics of the FIP were investigated by comparing the dimensionless minimum film thickness, or film parameter, which is the ratio of minimum film thickness to surface roughness. Through numerical analyses, we showed that the profile of the lower edge of the stem had no effect on lubrication characteristics, but the profile of the upper edge had a significant influence on lubrication characteristics. In addition, changes in the profile were more effective in improving lubrication characteristics under low viscosity conditions.

• Journal of KSNVE
• /
• v.5 no.2
• /
• pp.257-264
• /
• 1995

We designed the cutter profile for symmetric screw rotor and did vibration experiment of screw rotor manufactured by the designed cutter profile. The results of this study are summarized as follows. (1) We designed the cutter profile of screw rotor (4-6)(5-6) by using numerical analysis program. (2) The maximum amplitude and variation of amplitude of 5-6 profile rotor are about 30 - 36.7% and 10 - 25% smaller than those of 4-6 profile rotor, respectively. (3) As the angular velocity of rotor changes from 100 to 300 rpm, the vibration of X, Y axis in driving shaft of 5-6 profile rotor is about 10 - 20% smaller than that of 4-6 profile rotor.

• Restorative Dentistry and Endodontics
• /
• v.35 no.2
• /
• pp.88-95
• /
• 2010

The purpose of this study was to compare the root canal shaping ability of 4 rotary NiTi instruments in simulated root canals. For the preparation of thirty two curved root canals, Mtwo instruments using "single length"technique, and Profile, ProTaper Universal, and K3 using crown-down technique (N = 8) were used. All canal samples were prepared by reaching an apical canal size of #30. Pre- and post-instrumentation digital images were recorded and an assessment of canal shape was determined using a computer image analysis program SigmaScan Pro (Systat Software Inc., San Jose, CA, USA). The changes of the dimension of inner walls of canals, (2) the changes of the dimension of outer walls of canals, and (3) the centering ratio were measured at 7 measuring points, and then data were statistically analyzed using one-way ANOVA and Duncan's test. The results were as below; 1. The root canal shaping ability of Profile was significantly faster than that of other rotary NiTi instruments (p < 0.05). 2. The deformation and fracture of all instruments used for this study were not experienced. 3. In the degree of changes of the dimension of inner walls of canals, Profile demonstrated the lowest changes of the dimension of inner walls of canals except at the measuring points of the 1 and 2 mm (p < 0.05). However, the ProTaper Universal showed the highest changes of the dimension of inner walls of canals at all measuring points (p < 0.05). 4. In the degree of changes of the dimension of outer walls of canals, Mtwo demonstrated the lowest changse of the dimension of outer walls of canals except at the measuring point of the 1 mm (p < 0.05). However, Profile exhibited the highest changes of the dimension of outer walls of canals at the measuring points of 3 and 4 mm and ProTaper Universal and K3 showed the largest changes of the dimension of outer walls of canals at the measuring points of 1, 2, 6, and 7 mm (p < 0.05). 5. In degree of centering ratio, Profile demonstrated the least centering ratio comparing with the centering ratio shown by other NiTi instruments at the measuring points of 1, 4, 5, and 6 mm. Results suggest that in the coronal part of canal preparation, active cutting files such as ProTaper Universal may efficiently flare the canal orifice and form a better taper, and in the apical part of the canal, files which have a better centering ability such as Profile may maintain the original canal curvature and reduce the shaping time.

• The Journal of the Korean dental association
• /
• v.23 no.6 s.193
• /
• pp.527-538
• /
• 1985

The purpose of this study is to evaluate the chronologic changes of the soft tissue profile in 6 to 11 years children. The author analyzed 174 cephalometric roentgenograms of 13 boys and 16 girls taken from the ages of 6 to 11 to assess the growth changes of the soft tissue profile. The results were obtained as follow: 1. Means, standard deviation and coefficient of variation of children were obtained. 2. Items which showed difference between males and females in longitudinal study were prn. Sn. A', and Ls that were greater than females variation. 3. With age, thickness of the soft tissue were increased except Ls. 4. Nasolabial angle and facial convexity had no significant change with age and sex.