• Korean Journal of Applied Biomechanics
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• v.25 no.3
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• pp.293-300
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• 2015

Objective : The purpose of this study was to compare the kinematic data of the horizontal rotation movements of shoulder, hip, knee during two-handed backhand drive stroke according to two different ball directions. Methods : The kinematic variables were analyzed such as the joint angles of the lower body, horizontal rotation angles of the shoulder, hip, inter-knee segment, body twist angle and difference in angle of forward swing. Two-handed backhand drive stroke was analyzed through a three-dimensional motion analysis. The collected data were analyzed by a paired t-test, and the statistical significant value was set at ${\alpha}=.05$. Results : The findings of this study were as follows; First, there was no difference in the total angles of lower limb joints from the forward swing position to impact posterior. Second, there was no difference in the horizontal rotation angles of E1 shoulder, hip, and E2 shoulder but the horizontal rotation angles of E1 knee, E2 hip, knee, E3, and E4 shoulder, hip, and knee were different in all events. Third, there was no difference in the body twist angle of the maximum horizontal rotation. In addition, there was no difference in the angle of the body twist by the ball direction in the shoulder-hip, the hip-knee and the shoulder-knee. Conclusion : Horizontal rotation angle determines ball directions.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.1
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• pp.1231-1239
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• 2001

This paper presents a new leveling algorithm that estimates the initial horizontal angles composed of roll angle and pitch angle for a moving or stationary vehicle. The system model of the EKF is designed by linearizing the nonlinear Euler angle differential equation. The measurement models are designed for the moving case and for the stationary case, respectively. The simulation results show that the leveling algorithm is ade-quate not only for acquiring the initial horizontal angles of the vehicle in the motion with acceleration and rotation but also for the stationary one.

• New & Renewable Energy
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• v.4 no.3
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• pp.36-44
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• 2008

This paper discusses about the mathematical modelling of a new conceptual shape of horizontal axis wind turbine. The geometrical characteristic of wind turbine is studied for the variation of azimuthal angles and elevation angles. The projecting trajectories of Cuban-8 blade due to rotation are analyzed on the each plane in the Cartesian coordinate system. Trajectories show several interesting graphical patterns since the geometrical shape is complicated with the rotational motion of two twisted circumferential blades with elevation angles.

• Journal of Korean Dental Science
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• v.14 no.1
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• pp.26-31
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• 2021

Purpose: This study aimed to find a correlation between the occlusal plane and two reference planes that are frequently used in semi-adjustable articulators. Materials and Methods: Sixty-two males and fifty females with normal articulation were recruited and the lateral cephalograms of these patients were taken. The angles between the Frankfort horizontal (FH) and the occlusal planes, the angles between the gnathologic and the occlusal planes, and the angles between the FH and gnathologic planes were measured on the lateral cephalograms. Result: The mean angles between the FH and the occlusal planes was 8.29°±3.62°, with 8.88°±3.09° and 7.63°±4.10° for male and female patients, respectively. The mean angles between the gnathologic and the occlusal planes was 2.77°±3.62°, and the angle between the FH and the gnathologic planes was 5.52°±3.62°. No significant differences were found in the measured angles between the male and female patients (P>0.05). Conclusion: Different guidance angles may be applied to articulators for prosthodontic restoration, depending on the reference planes that the articulators use.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.5
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• pp.415-423
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• 2020

GNSS (Global Navigation Satellite System) is mostly used for high-precise surveys due to its accuracy and efficiency. But this technique does not always fulfill the demanding accuracy in harsh operational environments such as urban canyon and forest. One of the remedies for overcoming this barrier is to compose a heterogeneous surveying network by adopting terrestrial measurements (i.e., distances and angles). Hence, this study dealt with the adjustment of heterogeneous surveying networks consisted of GNSS baseline vectors, distances, horizontal and vertical angles with a view to enhancing their accuracy and so as to derive an appropriate scheme of the measurement combination. Reviewing some technical issues of the network adjustments, the simulation, and experimental studies have been carried out, showing that the inclusion of the terrestrial measurements in the GNSS standalone overall increased the accuracy of the adjusted coordinates. Especially, if the distances, the horizontal angles, or both of them were simultaneously adjusted with GNSS baselines, the accuracy of the GNSS horizontal component was improved. Comparing the inclusion of the horizontal angles with those of the distances, the former has been more influential on accuracy than the latter even though the same number of measurements were employed in the network. On the other hand, results of the GNSS network adjustment together with the vertical angles demonstrated the enhancement of the vertical accuracy. As conclusion, this paper proposes a simultaneous adjustment of GNSS baselines and the terrestrial measurements for an effective scheme that overcomes the limitation of GNSS control surveys.

• Journal of Oral Medicine and Pain
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• v.25 no.2
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• pp.173-189
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• 2000

The purpose of this study was to evaluate the effect of specific head positions on the mandibular rotational torque movements in maximum mouth opening, protrusion and lateral excursion. Thirty dental students without any sign or symptom of temporomandibular disorders(TMDs) were included as a control group and 90 patients with TMDs were selected and examined by routine diagnostic procedure for TMDs including radiographs and were classified into 3 subgroups : disc displacement with reduction, disc displacement without reduction, and degenerative joint disease. Mandibular rotational torque movements were observed in four head postures: upright head posture(NHP), upward head posture(UHP), downward head posture(DHP), and forward head posture(FHP). For UHP, the head was inclined 30 degrees upward: for DHP, the head was inclined 30 degrees downward: for FHP, the head was positioned 4cm forward. These positions were adjusted with the use of cervical range-of-motion instrumentation(CROM, Performance Attainment Inc., St. Paul, U.S.A.). Mandibular rotational torque movements were monitored with the Rotate program of BioPAK system (Bioresearch Inc., WI, U.S.A.). The rotational torque movements in frontal and horizontal plane during mandibular border movement were recorded with two parameters: frontal rotational torque angle and horizontal rotational torque angle. The data obtained was analyzed by the SAS/Stat program. The obtained results were as follows : 1. The control group showed significantly larger mandibular rotational angles in UHP than those in DHP and FHP during maximum mouth opening in both frontal and horizontal planes. Disc displacement with reduction group showed significantly larger mandibular rotational angles in DHP and FHP than those in NHP during lateral excursion to the affected and non-affected sides in both frontal and horizontal planes(p<0.05). 2. Disc displacement without reduction group showed significantly larger mandibular rotational angles in FHP than those in any other head postures during maximum mouth opening as well as lateral excursion to the affected and non-affected sides in both frontal and horizontal planes. Degenerative joint disease group showed significantly larger mandibular rotational angles in FHP than those in any other head postures during maximum mouth opening, protrusion and lateral excursion in both frontal and horizontal planes(p<0.05). 3. In NHP, mandibular rotational angle of the control group was significantly larger than that of any other patient subgroups. Mandibular rotational angle of disc displacement with reduction group was significantly larger than that of disc displacement without reduction group during maximum mouth opening in the frontal plane. Mandibular rotational angle of disc displacement without reduction group was significantly larger than that of disc displacement with reduction group or degenerative joint disease group during maximum mouth opening in the horizontal plane(p<0.05). 4. In NHP, mandibular rotational angles of disc displacement without reduction group were significantly larger than those of the control group or disc displacement with reduction group during lateral excursion to the affected side in both frontal and horizontal planes. Mandibular rotational angle of disc displacement without reduction group was significantly smaller than that of the control group during lateral excursion to the non-affected side in frontal plane. Mandibular rotational angle of disc displacement without reduction group was significantly larger than that of disc displacement with reduction group during lateral excursion to the non-affected side in the horizontal plane(p<0.05). 5. In NHP, mandibular rotational angle of the control group was significantly smaller than that of disc displacement with reduction group or disc displacement without reduction group during protrusion in the frontal plane. Mandibular rotational angle of disc displacement without reduction group was significantly larger than that of the disc displacement with reduction group or degenerative joint disease group during protrusion in the horizontal plane. Mandibular rotational angle of the control group was significantly smaller than that of disc displacement without reduction group or degenerative joint disease group during protrusion in the horizontal plane(p<0.05). 6. In NHP, disc displacement without reduction group and degenerative joint disease group showed significantly larger mandibular rotational angles during lateral excursion to the affected side than during lateral excursion to the non-affected side in both frontal and horizontal planes(p<0.05). The findings indicate that changes in head posture can influence mandibular rotational torque movements. The more advanced state is a progressive stage of TMDs, the more influenced by FHP are mandibular rotational torque movements of the patients with TMDs.

• Imaging Science in Dentistry
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• v.36 no.3
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• pp.131-135
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• 2006

Purpose : To evaluate the true projection angles of film-side mandibular condyles in panoramic and transcranial radiographs. Materials and Methods : 52 panoramic and transcranial radiographs of 4 condyles from two human dry mandibles with gradual horizontal and vertical angle changes were taken. The results were compared with the standard panoramic and transcranial radiographs and the identical pairs were selected. Results and Conclusion : Panoramic radiography projected 10 degrees to the film-sided condyles both horizontally and vertically. Transcranial radiography projected 15 degrees to the film-sided condyles vertically. The medial and lateral poles were not forming the outline of condylar images in both projections when the horizontal angles of condyles were not sufficiently big enough.

• Current Optics and Photonics
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• v.3 no.2
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• pp.154-163
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• 2019

In this study, we developed an optical sighting system capable of shooting at a long-distance target by operating a digital gyro mirror composed of a gyro sensor and an FSM. The optical sighting system consists of a reticle part, a digital gyro mirror (FSM), a parallax correction lens, a reticle-ray reflection mirror, and a partial reflection window. In order to obtain the optimal volume and to calculate the leading angle range according to the driving angle of the FSM, a calculation program using Euler rotation angles and a three-dimensional reflection matrix was developed. With this program we have confirmed that the horizontal leading angle of the developed optical sighting system can be implemented under about ${\pm}8^{\circ}$ for the maximum horizontal driving angle (${\beta}={\pm}12.5^{\circ}$) of the current FSM. Also, if the ${\beta}$ horizontal driving angle of the FSM is under about ${\pm}15.5^{\circ}$, it can be confirmed that the horizontal direction leading angle can be under ${\pm}10.0^{\circ}$. If diagonal leading angles are allowed, we confirmed that we can achieve a diagonal leading angle of ${\pm}10.0^{\circ}$ with a vertical driving angle ${\alpha}$ of ${\pm}7.1^{\circ}$ and horizontal driving angle ${\beta}$ of ${\pm}12.5^{\circ}$.

• Geomechanics and Engineering
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• v.13 no.4
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• pp.701-714
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• 2017

The effect of nearby cohesionless sloping ground on the uplift capacity of horizontal strip plate anchor embedded in sand deposit with horizontal ground surface has been studied numerically. The numerical analysis has been carried out by using the lower bound theorem of limit analysis with finite elements and linear optimization. The results have been presented in the form of non-dimensional uplift capacity factor of anchor plate by changing its distance from the slope crest for different slope angles, embedment ratios and angles of soil internal friction. It has been found that the decrease in horizontal distance between the edge of the anchor plate and the slope crest causes a continuous decrease in uplift capacity of anchor plate. The optimum distance is that distance between slope crest and anchor plate below which uplift capacity of an anchor plate has been found to decrease with a decrease in normalized crest distance from the anchor plate in presence of nearby sloping ground. The normalized optimum distance between the slope crest and the anchor plate has been found to increase with an increase in slope angle, embedment ratio and soil internal friction angle.

• Journal of the Korean Wood Science and Technology
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• v.17 no.3
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• pp.20-27
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• 1989

This experiment was made to find the peripheral variations of annualring widths, the cell dimensions, microfibril angles and bulk densities within each annual-ring of horizontal-growing young tree of beech(Betul a platyphylla var. japonica) and Oak (Quercus variabilis) from the tension to the opposite side. Also a comparision between the features of the obnormal annual ring for horizontal-growing year and normal annual ring for the straight-growing years was made. The dimension of propotion of the element, the microfibril angles and the bulk density decreased or increased continuously toward opposite side which showed minimum or maximum value. The dimension of elements the microfibril angles and the bulk density decreased or increased continuously towards opposite side which showed minimum or maximum value. The dimension of elements. the microfibril angles and the bulk density in the normal annual rings were similar to those in the lateral woods. whereas were significantly more different in the tension wood than in the opposite wood. The features of typical opposite wood in the hardwoods were influenced by the locations within the inclined stems than effects of the decrease in the annual ring width. The oppostie woods in hardwoods did not conform to the tension wood and lateral wood. The abnormal annual ring included the opposite wood, lateral wood similar to normal wood and tension wood having specialized structure even in the same annual ring.