• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.14 no.1
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• pp.17-26
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• 1984

The purpose of this study was radiographic analysis of the morphology of maxillary sinus in adolescents and adults. In order to analize the morphology of maxillary sinus in view point of anteroposterior width of medial wall, vertical distance between antral floor and nasal floor level, anterior extension, distance between antral floor and maxillary 1st molar apex, and types of lower border of maxillary sinus, specialized maxillary projection and periapical view with paralleling technique was taken. The author examined orthopantomograms and intraoral standard views taken from 400 adolescents and adults ranged 15-65 year-old. The obtained results were as follows: 1. The antero-posterior width of medial wall of maxillary sinus was 32.80mm in 15-19 year-old group, 33.86㎜ in 20-24 year-old group, 34.09㎜ in 25-29 year-old group, and 33.67㎜ in 30-65 year-old group, and the left maxillary sinus was somewhat smaller than the right. 2. The vertical distance between antral floor and nasal floor level was 8.49㎜ in 15-19 year-old group, 9.05㎜ in 20-24 year-old group, 8.95㎜ in 25-29 year-old group, and 8.32㎜ in 30-65 year-old group. 3. The order of anterior extension of maxillary sinus were distal half of canine, mesial half of canine, mesial half of 1st premolar, and distal half of 1st premolar. 4. The distance between antral floor and maxillary 1st molar were 4.36㎜ in 15-19 year-old group, 4.77㎜ in 20-24 year-old group, 3.58㎜ in 25-29 year-old group, and 2.33㎜ in 30-65 year-old group. 5. The order of the types of lower border of maxillary sinus were entire downward type, close type, partially downward type, waving type, separating type, and indistinct. In the types of antral floor, there was a tendency to increase the seperating type with age.

• Structural Engineering and Mechanics
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• v.68 no.2
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• pp.215-226
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• 2018

In this article, the theory of fractional order two temperature generalized thermoelasticity is employed to study the wave propagation in a fiber reinforced anisotropic thermoelastic half space in the presence of moving internal heat source. The whole space is assumed to be under the influence of gravity. The surface of the half-space is subjected to an inclined load. Laplace and Fourier transform techniques are employed to solve the problem. Expressions for different field variables in the physical domain are derived by the application of numerical inversion technique. Physical fields are presented graphically to study the effects of gravity and heat source. Effects of time, reinforcement, fractional parameter and inclination of load have also been reported. Results of some earlier workers have been deduced from the present analysis.

• Korean Journal of Applied Biomechanics
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• v.23 no.4
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• pp.395-402
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• 2013

The purpose of this study was to investigate change of mechanical energy before and after training of half vinyasa yoga. Thirteen subjects (height: $163.4{\pm}3.9$ cm, body mass: $54.9{\pm}7.3$ kg, age: $20.0{\pm}0.49$ yrs) participated in this experiment. The motions of half vnyasa yoga were captured with Vicon system and parameters were calculated with Visual-3D. After training of half vinyasa yoga, the mechanical energies of body segments were increased and increments of mechanical energies in the lower segments were greater than the upper segments. The phase increments of mechanical energies increased phase 1, phase 2, and phase 3 in order. After training of half vinyasa yoga, phase contributions of body segments were similar before training of half vinyasa yoga. The contribution of mechanical energy on trunk segment in body was the greatest contribution of upper segments; also that of mechanical energy on thigh segment in body was the greatest contribution of lower segments. Before training, the coefficient of correlation between vertical center of gravity (CoGz) and mechanical energy of phase 3 was a -.559, but after training, the coefficient of correlation between CoGz and mechanical energy of phase 2 was a .587. These findings suggest that the training of half vinyasa yoga may be increasing the mechanical energies of body segments.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.1
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• pp.62-69
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• 1998

To remove nitrogen from wastewater, ammonia nitrogen has to be oxidized to nitrate nitrogen before denitrification reaction which converts nitrate nitrogen to nitrogen gas. In order to understand nitrification, several mathematical models had been proposed and Monod type model has been accepted internationally. Since Monod type model consists of maximum substrate utilization rate, substrate concentration and half-saturation coefficient, these values have to be addressed before using Monod type model. Several experimental procedures to determine half-saturation coefficient have been developed, however, Infinite dilution method was known to be time saving procedure. In this study, the mathematical equations and experimantal procedures for Infinite dilution method are presented and this method is used to determine half-Saturation coefficient for nitrifying bacteria. As results, Infinite dilution method is proved that this coefficient can be determined within 8 hours and the values of half-saturation coefficient has a range of 0.728 and $0.455gNH_4{^+}-N/m^3$ and the average has $0.580gNH_4{^+}-N/m^3$ through 5 sets of experiments.

• The Research Journal of the Costume Culture
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• v.8 no.2
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• pp.261-271
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• 2000

In order to investigate the function and feature of western men's underclothes in the second half of the 19C, in this study, the historical changes of western men's underclothes are compared the first half of the 19C with the second half of the 19C. In the second half of the 19C, the useful function to ease for body was important. In the 1860's, for day-shirt, the tucked panels was disappeared and the front was pain. But the evening dress-shirt continued to show an expansive front tucked. Coloured shirts was used for country and sporting occasions. Ready-made underwear was used. In the 1870's, the plain breast was introduced and the Gladstone collar was used. Paper collars and dickeys were unfashionable. The drawers was composed a gusset at the back of the waistband. The dress of one generation was became the livery of the next. In the 1880's, a new feature was one stud and the use of pique for the breast. Coloured shirt was composed of stripes across the breast. In the 1890's, height of the collar steadily increased. The coat-shirt and regatta shirt became popular. The nice choice of shirt, collar and tie was a matter of supreme importance .The social status of the white shirt was further threatened by fancy coloured shirts. The mode of relaxation affected sports shirts. By the close of this period, both sexes accepted the hygienic rule of wool next the skin.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.2 s.95
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• pp.135-147
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• 2005

As automobile technology advances, a smoother ride with less noise is desired. In order to achieve these purposes, a study on the vibration and noise produced by a moving automobile was carried out and a model for tire vibration characteristics which influence the ride performance was developed. The model was verified through simulations and experiments. The developed model was then applied to a half car model and automobile vibrations were analyzed. The effects of tire design parameters on the automobile vibration energy were investigated. The results from laboratory and field tests confirm the validity of the analytical model. The 17-DOF half-car model was built to analyze automobile vibration. The characteristics of the nonlinear model for a shock absorber were applied to this model. The results from the present 17-DOF half car model incorporating the analytical tire model with tire design parameters, were compared with the 5-DOF half car model where the tire was modeled with linear springs. The results of the 17-DOF model are close to the experimental results. Using the 17-DOF model, the influence of tire design parameter were considered. According to the analysis results, the vibrations at seat/body/wheel were predicted by simulation and experiment.

• Journal of the Korean Society of Safety
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• v.34 no.5
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• pp.103-110
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• 2019

In order to reduce the accidents occurring at construction sites, it is necessary to approach with harmonious measures considering various aspects such as systems, training, facilities, and protection equipments. Suggestion of safe construction method can be a good alternative. In the previous study, the half-depth precast deck with RC rib panel was proposed as an alternative method for safe bridge deck construction, and the performance required by the design code was verified through a four-point bending test. But the actual bridge deck is subjected to the repetitive action of the wheel load rather than the bending condition due to the four-point load. In this study, fatigue test was performed by repeating the wheel load $2{\times}10^6$ cycles to verify the safety of the half-depth precast deck with RC rib panel under actual conditions. As a result, fatigue effect due to repetition of wheel load was not significant in terms of serviceability such as crack width and deflection. In the residual strength test conducted after the fatigue test, the half-depth precast deck with RC rib panel failed by punching shear which is typical failure mode of bridge decks and the residual strength was similar to the punching strength of the RC and PSC bridge decks in spite of the fatigue effects.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.7
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• pp.995-1006
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• 2004

This study examines the effects of clothing style and the order effect on impression formation. The instrument of this study consisted of response scales and stimuli. Fifty-one items of 7-point semantic differential scales, 9 items of demographic traits, and 4 items of subjective evaluation scales were developed. Stimuli were color pictures of a model wearing each of two clothing styles(mannish style, feminine style). The sample include 56 male and female subjects in their twenties and thirties. The experimental design was within-subject design and the half of the sample responded to the mannish style first and the other half responded to the feminine style first. Responses to the semantic differential scales were factor analyzed, and seven factors were identified: intellectuality, sensibility, activity, modesty, competence, display, keenness. There were significant differences between mannish style and feminine style in impression of wearer＇s age, job, and physical attractiveness as well as wearer＇s intellectuality and sensibility. It was revealed that the first impression and second impression of wearer＇s intellectuality, sensibility, modesty, competence, display were differed by the function of the order of stimuli shown to the subjects. Both primacy effect and recency effect of order effect were confirmed, and especially negativity effect was influenced prominently on impression formation.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2234-2236
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• 1997

The SIT, a Static Induction Transistor, is a semiconductor switch that is also called the power junction field-effect transistor (power JFET). Its characteristics are similar to a MOSFET except that its power level is higher and its maximum frequency of operation is lower. The normal method to protect against internal circuit transients of the form of di/dt or dv/dt is the use of snubber circuits. However, the limits of di/dt and dv/dt are high enough for the SIT that it is possible to operate without snubber circuits. SITs can be connected in parallel in order to cope with higher load currents that the value of an individual device rating. The purpose of this study is to investigate the parallel operation of SITs. In this experiment, we used a half-bridge inverter, the output of inverter is up to almost 1MHz and 2kW. Experimental results show that the operation of parallel connected SITs are facilitated individually good current sharing. The reason is the positive temperature coefficient of resistance of the SIT.

• YAKHAK HOEJI
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• v.15 no.2
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• pp.41-52
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• 1971

Cu(II) chelates of several sulfanilamide derivatives (Sulfa-Cu) were prepared and their effects on solubility, absorptivity in intestinal lumen, biding tendency with serum protein and erythrocytes, concentration in rabbit blood, and acetylation rate were studied in comparison with their free ligand forms. For solubility concerned, the partition coefficients of Sulfa-Cu are decreased as following order: Sulfadimethoxine Copper chelate (SDM-Cu), Sulfamethoxypyridazine Copper chelate (SD-Cu), Sulfamerazine Copper chelate (SM-Cu), Sulfaisoxazole Copper chelate (SIX-Cu). The partition coefficients of SDM-Cu and ST-Cu were much greater than those of ligands. this phenomenone acounts for the rapid absorption of SDM-Cu and ST-Cu in the rat small intestine (in situ). The Sulfa-Cu were absorbed at the intestinal lumen of a rat in the rate of first order and there was no difference between long acting sulfa drugs and their Cu0chelates in biological half lives. In binding experiments, sulfa-Cu binded with serum protein in lower ratio than their ligands except SIX-Cu. On other hand, acetylation rates of sulfa-Cu were higher than those of free sulfa drugs and the acetylation rate were higher than those of free sulfa drugs and powder. In a experiment on Sulfa-Cu concentration in rabbit blood, the half lives of SD-Cu, SIX-cu, ST-Cu, and SM-Cu were longer than those of their ligands. Above all, the half life of SD-Cu appeared to be approximately 3.5 times logner than that of corresponding ligand, SD. When absorption of sulfa drugs or sulfa-Cu at the small intestinal lumen of a rat and the concentration in rabbit blood after absorption were compared, it was found that there was not always conrrelated.