• The Journal of Advanced Prosthodontics
• /
• 제5권1호
• /
• pp.58-66
• /
• 2013

PURPOSE. The purpose of this study was to decide the most appropriate point on tragus to be used as a reference point at time of marking ala tragus line while establishing occlusal plane. MATERIALS AND METHODS. The data was collected in two groups of subjects: 1) Dentulous 2) Edentulous group having sample size of 30 for each group with equal gender distribution (15 males, 15 females each). Downs analysis was used for base value. Lateral cephalographs were taken for all selected subjects. Three points were marked on tragus as Superior (S), Middle (M), and Inferior (I) and were joined with ala (A) of the nose to form ala-tragus lines. The angle formed by each line (SA plane, MA plane, IA plane) with Frankfort Horizontal (FH) plane was measured by using custom made device and modified protractor in all dentulous and edentulous subjects. Also, in dentulous subjects angle between Frankfort Horizontal plane and natural occlusal plane was measured. The measurements obtained were subjected to the following statistical tests; descriptive analysis, Student's unpaired t-test and Pearson's correlation coefficient. RESULTS. The results demonstrated, the mean angle COO (cant of occlusal plane) as $9.76^{\circ}$, inferior point on tragus had given the mean angular value of IFH [Angle between IA plane (plane formed by joining inferior point-I on tragus and ala of nose- A) and FH plane) as $10.40^{\circ}$ and $10.56^{\circ}$ in dentulous and edentulous subjects respectively which was the closest value to the angle COO and was comparable with the values of angle COO value in Downs analysis. Angulations of ala-tragus line marked from inferior point with occlusal plane in dentulous subject had given the smallest value $2.46^{\circ}$ which showed that this ala-tragus line was nearly parallel to occlusal plane. CONCLUSION. The inferior point marked on tragus is the most appropriate point for marking ala-tragus line.

• PNF and Movement
• /
• 제14권2호
• /
• pp.131-137
• /
• 2016

Purpose: The purpose of this study was to compare muscle activities in the frontal plane and scapular plane of the middle fiber and lower fiber of the trapezius muscle at different shoulder abduction angles. Methods: Twenty male and female students in their 20s participated in this study. Each subject maintained shoulder abduction at $75^{\circ}$, $90^{\circ}$, $125^{\circ}$, and $160^{\circ}$ in a standing position and repeated motions three times each in the frontal plane and the scapular plane. While maintaining the motions for 10 seconds in each posture, surface electromyography (EMG) was used to measure muscle activity of the middle fiber and lower fiber of the trapezius muscle. The collected EMG data were normalized using maximal voluntary isometric contraction (MVIC). Differences in muscle activity of the middle fiber and lower fiber of the trapezius muscles according to the angles at each plane were statistically processed using repeated measured analysis of variance, and an independent t-test was used to examine the differences between the two planes at each angle. Results: Muscle activity of the middle and lower trapezius during shoulder abduction in the frontal plane and scapular plane significantly increased as the angles increased (p<.05). However, muscle activity of the middle trapezius was significantly lower in the scapular plane than in the frontal plane for all shoulder abduction angles (p<.05). Conclusion: The results of this study suggest that during shoulder abduction, angles should be different according to the goals, and for training during an acute phase or early phase for functional recovery, it is more efficient to perform the training in the scapular plane than in the frontal plane.

• 제어로봇시스템학회논문지
• /
• 제21권11호
• /
• pp.1050-1056
• /
• 2015

In this paper, we use the characteristics of electromagnetic waves underwater attenuation for estimating linear distance between a transmitting node and receiving node, and research underwater vertical plane attenuation model for constructing the underwater localization system. The underwater localization of 2 dimensional with the plane attenuation model in the horizontal plane (H-plane) was proposed previous research. But for the 3 dimensional underwater localization, the additional vertical plane (E-plane) model should be considered. Because the horizontal plane of omnidirectional antenna has the same attenuation tendency in x-y plane according to the distance, whereas in vertical plane shows an irregular pattern in x-z plane. For that reason, in the vertical plane environment, the attenuation should be changed by the position and inclination. Hence, in this paper the distance and angle between transmitting and receiving node are defined using spherical coordinate system and derive an antenna gain pattern using half power beam width (HPBW). The HPBW is called a term which defines antenna's performance between isotropic and other antennas. This paper derives omnidirectional antenna's maximum gain and attenuation pattern model and define vertical plane's gain pattern model using HPBW. Finally, experimental verifications for the proposed underwater vertical plane's attenuation model was executed.

• 한국운동역학회지
• /
• 제32권4호
• /
• pp.147-152
• /
• 2022

Objective: The purpose of this study was to analyze the effects of club head and golf ball kinematics and body alignment according to the swing plane during golf driver swing. Method: Sixteen college golfers participated in this study. Kinematic data of the club head and golf ball were collected using golf swing analysis system (Trackman Ver. 3e). The body alignment variables were collected using 8 motion capture system. An Independent samples t-test was used for comparison between the Out-to-In group and In-to-Out group, and the statistical significance level was set at .05. Results: For the club head related variables, club path and club face angle showed higher values in Out-to-In swing plane than In-to-Out swing plane. For the kinematic variables of the golf ball, the total distance showed a higher value in the In-to-Out swing plane than that of the Out-to-In swing plane. For the body alignment, the In-to-Out swing plane showed higher values than the Out-to-In swing plane for the pelvis rotation angle and trunk rotation angle. Conclusion: This study suggest that it would be more effective to use the In-to-Out swing plane for increasing the total distance during the golf driver swing.

• Geomechanics and Engineering
• /
• 제9권1호
• /
• pp.115-124
• /
• 2015

Determination of mobilized shear strength parameters (that identify stresses on the failure plane) is required for analyzing the stability by limit equilibrium method. Generalized Hoek-Brown (GHB) and Mohr-Coulomb (MC) failure criteria are usually used for obtaining stresses on the plane of failure. In the present paper, the applicability of these criteria for determining the stresses on failure plane is investigated. The comparison is based on stresses on the real failure plane which are obtained from the Mohr stress circle. To do so, 18 sets of data (consist of principal stresses and angle of failure plane) presented in the literature are used. In addition, the values account for (VAF) and the root mean square error (RMSE) indices were calculated to check the determination performance of the obtained results. Values of VAF and RMSE for the normal stresses on the failure plane evaluated from MC are 49% and 31.5 where for GHB are 55% and 30.5, respectively. Also, for the shear stresses on failure plane, they are 74% and 36 for MC, 76% and 34.5 for GHB. Results show that the obtained stresses and angles of failure plane for each criterion differ from real ones, but GHB results are closer to the empirical results. Also, it is inferred that results are affected by the failure envelope not real failure plane. Therefore, obtained shear strength parameters are not mobilized. Finally, a multivariable regressed relation is presented for determining the stresses on the failure plane.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2004년도 춘계학술대회논문집
• /
• pp.164-168
• /
• 2004

The vibration analysis of an axially moving membrane are investigated when the membrane has the two sets of in-plane boundary conditions, which are free and fixed constraints in the lateral direction. Since the in-plane stiffness is much higher than the out-of-plane stiffness, it is assumed during deriving the equations of motion that the in-plane motion is in a steady state. Under this assumption. the equation of out-of\ulcornerplane motion is derived, which is a linear partial differential equation influenced by the in-plane stress distributions. After discretizing the equation by using the Galerkin method, the natural frequencies and mode shapes are computed. In particular, we put a focus on analyzing the effects of the in-plane boundary conditions on the natural frequencies and mode shapes of the moving membrane.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제39권2호
• /
• pp.71-76
• /
• 2013

Objectives: In three-dimensional computed tomography (3D-CT), the cant is evaluated by measuring the distance between the reference plane (or line) and the tooth. The purpose of this study was to determine the horizontal skeletal reference plane that showed the greatest correlation with clinical evaluation. Materials and Methods: The subjects were 15 patients who closed their eyes during the CT image taking process. The menton points of all patients deviated by more than 3 mm. In the first evaluation, clinical cant was measured. The distance from the inner canthus to the ipsilateral canine tip and the distance from the eyelid to the ipsilateral first molar were obtained. The distance between the left and right sides was also measured. In the second evaluation, skeletal cant was measured. Six reference planes and one line were used for the evaluation of occlusal cant: 1) FH plane R: Or.R - Or.L - Po.R; 2) FH plane L: Or.R - Or.L - Po.L; 3) F. Ovale plane R: Rt.F.Ovale - Lt.F.Ovale - Or.R; 4) F. Ovale plane L: Rt.F.Ovale - Lt.F.Ovale - Or.L; 5) FZS plane R: Rt.FZS - Lt.FZS - Po.R; 6) FZS plane R: Rt.FZS - Lt.FZS - Po.L, and; 7) FZS line: Rt.FZS - Lt.FZS. Results: The clinical and skeletal cants were compared using linear regression analysis. The FH plane R, FH plane L, and FZS line showed the highest correlation (P<0.05). Conclusion: The FH plane R and FH plane L are the most appropriate horizontal reference plane in evaluation of occlusal cant on 3D-CT.

• 한국결정성장학회지
• /
• 제26권3호
• /
• pp.89-94
• /
• 2016

본 연구에서는 HVPE(Hydride Vapor Phase Epitaxy)를 이용하여 각각 다른 V/III ratio를 가지는 multi-step의 성장 시간 변화에 따라 r-plane 사파이어 위에 성장되는 a-plane GaN 에피층의 결정성에 대하여 연구하였다. 또한 이번 연구의 결과를 선행 연구에서 single-step으로 r-plane 사파이어 위에 성장시킨 a-GaN 에피층의 결과와 비교하였다. Multi-step으로 r-plane 사파이어 위에 a-plane GaN 에피층을 성장시켰을 때, source HCl의 유량과 성장 시간이 증가함에 따라 a-plane GaN 에피층에 대한 rocking curve의 FWHM(Full Width at Half Maximum) 값이 감소하였다. 높은 source HCl의 유량을 갖는 first step과 second step의 성장 시간과 source HCl의 유량이 증가할수록 a-plane GaN 에피층 내부의 void가 감소하였다. 결과적으로 first step과 second step의 성장 시간이 가장 긴 조건에서 성장된 a-plane GaN 에피층이 가장 낮은 FWHM 값인 584 arcsec을 가지며, azimuth angle의 의존도가 가장 적은 것으로 확인되었다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2005년도 춘계학술대회논문집
• /
• pp.728-731
• /
• 2005

The objective of this paper is to perform measurements of vibration intensity of a coupled beam. The propagation of flexural waves generates the out of plane vibration of the coupled beam. The longitudinal waves are generated due to the mode conversion at the structural joint of the coupled beam. The propagation of longitudinal waves generates the in plane vibration of the coupled beam. In order to identify the direction of vibrational power on the coupled beam, the in plane vibration intensity as well as the out of plane vibration intensity needs to be measured. The cross spectral method has been implemented to measure the in-plane vibration intensity as well as out of plane vibration intensity. The results shelved that the experimental method can be effectively used to measure the in-plane vibration intensity as well as the out of plane vibration intensity of coupled beams.

• Smart Structures and Systems
• /
• 제26권4호
• /
• pp.435-449
• /
• 2020

To effectively extract the vast wind resource, offshore wind turbines are designed with large rotor and slender tower, which makes them vulnerable to external vibration sources such as wind and wave loads. Substantial research efforts have been devoted to mitigate the unwanted vibrations of offshore wind turbines to ensure their serviceability and safety in the normal working condition. However, most previous studies investigated the vibration control of wind turbines in one direction only, i.e., either the out-of-plane or in-plane direction. In reality, wind turbines inevitably vibrate in both directions when they are subjected to the external excitations. The studies on both the in-plane and out-of-plane vibration control of wind turbines are, however, scarce. In the present study, the NREL 5 MW wind turbine is taken as an example, a detailed three-dimensional (3D) Finite Element (FE) model of the wind turbine is developed in ABAQUS. To simultaneously control the in-plane and out-of-plane vibrations induced by the combined wind and wave loads, another carefully designed (i.e., tuned) spring and dashpot are added to the perpendicular direction of each Tuned Mass Damper (TMD) system that is used to control the vibrations of the tower and blades in one particular direction. With this simple modification, a bi-directional TMD system is formed and the vibrations in both the out-of-plane and in-plane directions are simultaneously suppressed. To examine the control effectiveness, the responses of the wind turbine without control, with separate TMD system and the proposed bi-directional TMD system are calculated and compared. Numerical results show that the bi-directional TMD system can simultaneously control the out-of-plane and in-plane vibrations of the wind turbine without changing too much of the conventional design of the control system. The bi-directional control system therefore could be a cost-effective solution to mitigate the bi-directional vibrations of offshore wind turbines.