• The korean journal of orthodontics
• /
• v.27 no.2
• /
• pp.259-272
• /
• 1997

This study was performed to locate the anteroposterior position of the center of resistance of upper anterior teeth when intrusive forces are acted on them by applying segmented arch mechanics. Three-dimensional finite element model of upper six anterior teeth, periodontal ligament and alveolar bone was constructed The locations of the center of resistance were compared according to the three variables, which are number of teeth contained in anterior segment, axial inclination of anterior teeth, and degree of alveolar bone loss. The following conclusions were drawn from this study; 1. When the axial inclination and alveolar bone height were normal, the locations of center of resistance of anterior segment according to the number of teeth contained were as follows; 1). In 2 teeth segment, the center of resistance was located in the distal area of lateral incisor bracket 2) In 4 teeth segment, the center of resistance was located in the distal 2/3 of the distance between the brackets of lateral incisor and canine. 3) In 6 teeth segment, the center of resistance was located in 3mm distal of canine bracket, which is interproxirnal area. between canine and 1st premolar. 4) As the number of teeth contained in anterior segment increased, the center of resistance shifted to the distal side. 2. As the labial inclination of incisors increased, the center of resistance shifted to the distal side. 3. As the alveolar bone loss increased, the center of resistance shifted to the distal side.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.28 no.4
• /
• pp.475-485
• /
• 2004

This paper was studied to investigate and compare the effects of inclined baffle plate on the turbulent flow characteristics of a gun-type gas burner through X-Y plane and Y-Z plane respectively by using X-probe from hot-wire anemometer system. For this purpose, two burner models with a cone-type baffle plate and a flat-type one respectively were used. The fast jet flow spurted from slits plays a role such as an air-curtain because it encircles rotational flow by swirl vanes and drives mixed main flow to axial direction regardless of the inclination of baffle plate. The inclined baffle plate causes axial mean velocity component and turbulent intensities etc. to be greatly concentrated towards the central part of a burner, and its effect especially appears in the range of about X/R=1.0-2.0. Also, it gives much larger size to axial mean velocity component and turbulent intensities etc formed near the slits in the range of X/R=1.4103. Especially the inclined baffle plate shifts more the Reynolds shear stress uw to the central region of a burner(Y/R=${\pm}$0.75) than the flat-type one, moreover it develops more strongly than uv.

• Tunnel and Underground Space
• /
• v.26 no.2
• /
• pp.100-109
• /
• 2016

This study suggests three spatial distribution functions of strength parameters, which can be adopted in the derivation of failure conditions for transversely isotropic rocks. All three proposed functions, which are the oblate spheroidal function, the exponential function, and the function based on the directional projection of the strength parameter tensor, consist of two model parameters. With assumption that the cohesion and friction angle can be described by the proposed distribution functions, the transversely isotropic Mohr-Coulomb criterion is formulated and used as a failure condition in the simulation of the conventional triaxial tests. The simulation results confirm that the failure criteria incorporating the proposed distribution functions could reproduce the general trend in the variations of the axial stress at failure and the directions of failure planes with varying inclination of the weankness planes and confining pressure. Among three distribution functions, the function based on the directional projection of the strength parameter tensor yields the highest axial strength, while the axial strength estimated by the oblate spheroidal distribution function is the lowest.

• Journal of Power System Engineering
• /
• v.5 no.2
• /
• pp.22-29
• /
• 2001

This paper represents axial mean velocity, turbulent kinetic energy and swirl number based on momentum flux measured in the X-Y plane and Y-Z plane respectively of a cone type gas swirl burner by using X-probe from the hot-wire anemometer system. This experiment is carried out at flow rates 350 and $450{\ell}/min$ respectively, which are equivalent to the combustion air flow rate necessary for heat release 15,000 kcal/hr in gas furnace, in the test section of a subsonic wind tunnel. Axial mean velocities and turbulent kinetic energies show that their maximum values exist centering around narrow slits situated radially on the edge of and in the forefront of a burner until $X/R{\fallingdotseq}1.5$, but they have a peculiar shape like a starfish diffusing and developing into inward and outward of a burner by means of the mixing between flows ejected from narrow slits, an inclination baffle plate and swirl vanes respectively according to downstream regions. Moreover, they show a relatively large value in the inner region of 0.5$S_m$ obtained by integration of velocity profiles shows a characteristic that has an inflection point composing of the maximum and minimum value until X/R<3, but shows close agreement with the geometric swirl number after a distance of X/R=3.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.32 no.1
• /
• pp.52-59
• /
• 2006

Purpose: The purpose of this study was to evaluate the influence of apical-coronal implant position on the stress distribution after occlusal and oblique loading. Materials and Methods: The cortical and cancellous bone was assumed to be isotropic, homogeneous, and linearly elastic. The implant was apposed to cortical bone in the crestal region and to cancellous bone for the remainder of the implant-bone interface. The cancellous core was surrounded by 2-mm-thick cortical bone. An axial load of 200 N was assumed and a 200-N oblique load was applied at a buccal inclination of 30 degrees to the center of the pontic and buccal cusps. The 3-D geometry modeled in Iron CAD was interfaced with ANSYS. Results: When only the stress in the bone was compared, the minimal principal stress at load Points A and B, with a axial load applied at 90 degrees or an oblique load applied at 30 degrees, for model 5. The von Mises stress in the screw of model 5 was minimal at Points A and B, for 90- and 30-degree loads. When the von Mises stress of the abutment screw was compared at Points A and B, and a 30-degree oblique load, the maximum principal stress was seen with model 2, while the minimum principal stress was with model 5. In the case of implant, the model that received maximum von Mises stress was model 1 with the load Point A and Point B, axial load applied in 90-degree, and oblique load applied in 30-degree. Discussion and Conclusions: These results suggests that implantation should be done at the supracrestal level only when necessary, since it results in higher stress than when implantation is done at or below the alveolar bone level. Within the limited this study, we recommend the use of supracrestal apical-coronal positioning in the case of clinical indications.

• Journal of Astronomy and Space Sciences
• /
• v.12 no.1
• /
• pp.1-13
• /
• 1995

We carried out photometric and spectroscopic observatious of the blue compact dwarf galaxy Haro 6 in the Virgo Cluster of Galaxies. The long-slit spectroscopy was employed at three position angles, $\Phi$=$0^{\circ}$, $\Phi$=$30^{\circ}$, and $\Phi$=$120^{\circ}$with CCD camera mounted on the Cassegrain Spectrograph. Based on the mean intrinsic axial ratio < $q_0$ >=0.3, we derived inclination I of the system as $44^{\circ}$using our composite V-band CCD image. Careful analysis on the velocity field of the system shows an asymptotically fiat rotation curve with the maximum rotational velocity $V(r)_{max}$ reaches about 12km/sec. The calculation of the dynamical mass of Haro 6 with a simple mass model is briefly discussed with emphasis on the mass to luminosity ratio. From the IRAS Point Source Cataloque, we derived dust-to-gas ratio which indicates relatively low dust content, thus tempting us to conjecture the youth of the system.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.24 no.3
• /
• pp.651-659
• /
• 1997

This report presents a case of adolescent patient who had multiple impacted teeth and no systemic disease, and was treated with removable and fixed orthodontic appliances. The results obtained through these cases were summarized as follows : 1. Even in the case without systemic disease, there can be the delayed eruption of multiple teeth 2. If the root formation is not completed, root have no excessive curvature, axial inclination of the tooth is not excessive, and there is eruption space, the tooth can be induced to normal occlusion. 3. Since esthetically proper occlusion and dentition was acquired by recovery of the impacted teeth to normal occlusion, the prosthodontic treatment after extraction of the impacted teeth was less needed. 4. This treatment brought psychological stability to pubertal patient who was interested in his facial profile.

• The korean journal of orthodontics
• /
• v.16 no.2
• /
• pp.107-114
• /
• 1986

This study was undertaken to determine the adequate bracket position in Korean. The subjects were consisted of casts and photographs of 30 males & 30 famales. They had acceptable profile, normal occlusion, no loss of teeth and no experience of dental treatment. The following conclusions were obtained. 1. In case of no necessity of the posterior teeth movement, bracket angulation was made automatically by paralleling the bracket slot with occlusal plane. 2. Axial inclination of all teeth were measured, and those of canine & premolar were much variable. 3. Adequate bracket position of Korean occlusion were obtained.

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.7-12
• /
• 2003

heat pipe with screen meshed wick. The heat pipe was designed in 200 screen meshs, 500 mm length and 12mm O.D tube of copper, water as working fluid and nitrogen as non-condensible gas. Heat pipe used in this study has evaporator, condenser and adiabatic section, respectively. Experimental data of wall temperature distribution along axial length is presented for heat transport capacity, condensor cooling water temperature change, degrees of an inclination angle, and operating temperature.

• Journal of Astronomy and Space Sciences
• /
• v.3 no.1
• /
• pp.53-66
• /
• 1986

Isophotes and surface brightness distribution were obtained for the late type normal spiral galaxy NGC 7793 (morphological type SA(s)d) which is one of the Sculptor group. The calculated total luminosity $M_{T}$ is obtained as 9.44 and the corrected face on magnitude ${B_T}^{circ}$ is 9.10. The revised distance to this galaxy $\Delta$=3.1 Mpc (de Vaucouleurs and Davoust 1980) is used for calculating the absolute magnitude ${M_T}^{circ}$ = -18.36. From the isophotes, the position angle to the major axis is $101^{circ}$, the mean axial ratio is q=b/a =0.65, and the inclination is i=50$^{circ}$. The concentric indices $C_{21}$=1069 and $C_{32}$ =1.50 are well agreed to the average value of Sd type galaxies.