• 척추신경추나의학회지
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• 제12권1호
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• pp.57-70
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• 2017

Objectives : The purpose of this study is to find out the factors affecting the cervical angle with kyphosis. Methods : We investigated 340 cases of patients who had cervical kyphosis. We used cervical angle, flexion malposition angle, odontoid process cline angle, axis-atlas cline angle, odontoid process-atlas cline angle and occiput-atlas cline angle. Correlations between cervical angle and flexion malposition angle, odontoid process cline angle, axis-atlas cline angle, odontoid process-atlas cline angle, occiput-atlas cline angle were analyzed by pearson correlation analysis. Results : The correlation between cervical angle and flexion malposition angle was p-value 0.007, and odontoid process cline angle was p-value 0.002, and axis-atlas cline angle was p-value 0.000, and odontoid process-atlas cline angle was p-value 0.000, and occiput-atlas cline angle was p-value 0.012. Conclusions : Flexion malposition angle, odontoid process cline angle are inversely proportional to cervical angle. And correlation is statistically significant(p<0.01). Axis-atlas cline angle, odontoid process-atlas cline angle are proportional to cervical angle. And correlation is statistically significant(p<0.01). Occiput-atlas cline angle is proportional to cervical angle. And correlation is statistically significant(p<0.05).

• 한국의류산업학회지
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• 제3권5호
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• pp.473-478
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• 2001

The newly developed cone drum twister is one of the outer surface contacting friction-twisting devices in false-twist texturing. An investigation of the drag angle for the newly developed cone drum twister texturing mechanism is reported. An analysis is given from which equations can be derived that relate to the conical angle of cone drum, wrapping angle, drag angle, and yam helix angle. Theoretical values of drag angle are calculated and discussed. It is shown that, as the helix angle and the projected wrapping angle increases, the drag angle also increases slowly until the helix angle of $40^{\circ}$ but after the helix angle of $40^{\circ}$ the drag angle increases rapidly. Furthermore the higher the projected wrapping angle and conical angle, the higher the drag angle of friction surface.

• 대한수학교육학회지:학교수학
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• 제3권1호
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• pp.25-44
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• 2001

The purpose of the study is to investigate multifaced aspects of angle concepts and the developments of angle concept and to examine textbooks in relation to above investigation. In this study, we obtain the following results. First, angle concepts have static and dynamic aspects and develop situated angle concepts, contextual angle concepts, abstract angle concepts, through formal angle concepts. Second, our textbooks emphasize abstract angle concepts and formal angle concepts but lack situated angle concepts and contextual angle concepts.

• 한국전문물리치료학회지
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• 제6권1호
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• pp.23-34
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• 1999

The purposes of this study were to investigate biomechanical variables of the lumbar spine for women who enjoy recreational exercises regularly, and to determine the factors that influence these variables. These variables were determined by the X-ray pictures of the lumbar area of 80 housewives who visited the department of rehabilitation at the Y Hospital from October 1997 to March 1998. The sacral inclination angle, the sacrohorizontal angle, the lumbosacral joint angle, and the lumbar lordotic angle were analysed. The t-test, correlation analysis, and multiple regression analysis were used to determine the significant differences and relationships among variables. The result were as follows: 1) There was a significant difference in the sacral inclination angle (p<0.01), the sacrohorizontal angle (p<0.05) and the lumbar lordotic angle (p<0.05) between the bilateral and the unilateral exercise group. 2) With the sacral inclination angle, the sacrohorizontal angle, the lumbosacral joint angle and the lumbar lordotic angle, correlation was found between the sacral inclination angle and the sacrohorizontal angle (p<0.01), the sacral inclination angle and the lumbosacral joint angle (p<0.05), the sacral inclination angle and the lumbar lordotic angle (p<0.05), and the sacrohorizontal angle and the lumbosacral joint angle (p<0.01). 3) In the bilateral exercise group, the sacral inclination angle correlated with age (p<0.01). The sacrohorizontal angle correlated with age (p<0.01) and exercise time (p<0.01). The lumbar lordotic angle correlated with age (p<0.05) and exercise duration (p<0.05). In the unilateral exercise group, the sacral inclination angle correlated with age (p<0.01), while the sacrohorizontal angle correlated with age (p<0.01) and exercise duration (p<0.05). The lumbar lordotic angle correlated with age (p<0.05).

• The Journal of Korean Physical Therapy
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• 제8권1호
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• pp.33-47
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• 1996

This study was performed to examine the correlation between calcaneus to tibia angle and Q-angle, and the effects of step width and toe out angle on the calcaneus to tibia angle and Q-angle. The age of participated subjects was from 19 to 29 years(Mean=22.95, SD=2.23) who have no significant orthopedic and neurological dysfunction. The marking tapes for measurement of Q-angle and calcaneus to tibia angle were placed on seven location of each subject. Video data were collected while the subject walked on a walking grid. The result as follows : 1. There were significant differences in the step width, toe out angle, and Q-angle but not calcaneus to tibia angle between male and female. 2. There were significant differences in toe calcaneus to tibia angle and Q-angle n step width increased, respectively. 3. There were significant differences between tee out angle and calcaneus to tibia angle but not toe out angle and q-angle. 4. There was statistically significant correlation between calcaneus to tibia angle and Q-angle.

• 한방재활의학과학회지
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• 제19권2호
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• pp.227-239
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• 2009

Objectives : The purpose of this study is to investigate the relation of Ferguson's angle, Lumbar lordotic angle, Lumbar IVD angle in traffic accident patients. Methods : Total patients were classified into TA(traffic accident) inpatients and non-TA(lumbago) inpatients. We analyzed the characteristics of each group Ferguson's angle, Lumbar lordotic angle, L4-5 IVD angle, L5-S1 IVD angle on X-ray film. Results : 1. Ferguson's angle and Lumbar lordotic angle were smaller than normal range. Non-TA group's angles were smaller than TA group's angles. 2. L4-5 IVD angle of female showed smaller than that of male in TA groups. The older age was, the smaller L4-5 IVD angle was at non-TA groups. 3. L5-S1 IVD angle of female showed smaller than that of male in total groups. The older age was, the smaller L5-S1 IVD angle was at non-TA groups. 4. Ferguson's angle, Lumbar lordotic angle, Lumbar IVD angle were related with direct proportion in total groups. 5. Non-TA groups showed more effective VAS variation than TA groups. Conclusions : Lumbar angles were intimately related with each others. And lumbar angles have an effect on curative value.

• 한국전산유체공학회지
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• 제21권1호
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• pp.58-63
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• 2016

This research is to investigate the performance analysis for efficient design with four different inlet angles of the centrifugal pump impeller. Assuming that the rotation speed and exit angle are fixed, Four cases of the centrifugal pumps were numerically analyzed using ANSYS FLUENT. According to the numerical results, head and pump efficiency at inlet angle of 20 degrees was highest. There is no big difference of efficiency at inlet angle of 20 degrees compared to the inlet angle 30 degrees. About 15% of efficiency at inlet angle of 20 degrees is higher than inlet angle of 40 degrees and 31% higher than inlet angle oof 50 degrees. Because there is liner functional relationship between speed and flow rate, suction flow rate at inlet angle of 20 degrees is superior to the inlet angle of 30 degrees as much as 0.89%, inlet angle of 40 degrees as 13%, inlet angle of 50 as 28.4%. Head at inlet angle of 20 degrees is superior to the inlet angle of 30 degrees as much as 0.4%, inlet angle of 40 degrees as 2.7%, inlet angle of 50 degrees as 3.2%. There should exist highest efficiency and also optimal design shape at inlet angle of 20 degrees.

• Current Optics and Photonics
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• 제4권6호
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• pp.500-508
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• 2020

The rifling angle of artillery is an important parameter, and its determination plays a key role in the stability, hit rate, accuracy and service life of artillery. In this study, we propose an optical measurement method for the rifling angle based on angle error correction. The method is based on the principle of geometrical optics imaging, where the rifling on the inner wall of the artillery barrel is imaged on a CCD camera target surface by an optical system. When the measurement system moves in the barrel, the rifling image rotates accordingly. According to the relationship between the rotation angle of the rifling image and the travel distance of the measurement system, different types of rifling equations are established. Solving equations of the rifling angle are deduced according to the definition of the rifling angle. Furthermore, we added an angle error correction function to the method that is based on the theory of dynamic optics. This function can measure and correct the angle error caused by the posture change of the measurement system. Thus, the rifling angle measurement accuracy is effectively improved. Finally, we simulated and analyzed the influence of parameter changes of the measurement system on rifling angle measurement accuracy. The simulation results show that the rifling angle measurement method has high measurement accuracy, and the method can be applied to different types of rifling angle measurements. The method provides the theoretical basis for the development of a high-precision rifling measurement system in the future.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제27권1호
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• pp.75-86
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• 2023

The angle of attack is highly sensitive to pitch point in the airfoil shape and the decline of pitch point value induces smaller angle of attack, which implies that airfoil profile possessing closer pitch point to the airfoil tip reacts more sensitively to upcoming wind. The method of conformal transformation functions is employed for airfoil profiles and airfoil surfaces are expressed with a trigonometric series form. Attack angle and ideal lift coefficient distributions are investigated for various airfoil profiles in wind turbine blade regarding conformal transformation and pitch point. The conformed angle function representing the surface angle of airfoil shape generates various attack angle distributions depending on the choice of surface angle function. Moreover, ideal attack angle and ideal lift coefficient are susceptible to the choice of airfoil profiles and uniform loading area. High ideal attack angle signifies high pliability to upcoming wind, and high ideal lift coefficient involves high possibility to generate larger electric energy. According to results obtained pitch point, airfoil shape, uniform loading area, and the conformed airfoil surface angle function are crucial factors in the determination of angle of attack.

• 대한족부족관절학회지
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• 제14권2호
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• pp.161-164
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• 2010

Purpose: The purpose of this study is to find out the normal angles of the talus-1st metatarsal angle, the talo-horizontal angle and calcaneal pitch angle for diagnosis of foot deformity in Korea. This would be helpful as it would provide a basic angular measurement of flat and cavus foot that indicates the need for operation. Materials and Methods: Within a period of four months from January 2007 to April 2007, We have established 600 feet of 300 males without trauma history of foot. The source to image distance is 40 inches and erect weight bearing radiographs are obtained in anteroposterior and lateral projections. The significant angular measurements that define flat or cavus foot are the talus-1st metatarsal angle, the talo-horizontal angle and calcaneal pitch angle. Results: The mean age was 21 years (19-22 years) old. The mean talus-1st metatarsal angle was $0{\pm}6.9{^{\circ}}$, the mean talo-horizontal angle was $25.8{\pm}4.5{^{\circ}}$ and the mean calcaneal pitch angle was $23.9{\pm}5.1{^{\circ}}$. Conclusion: We can consider that mean talus-1st metatarsal angle, talo-horizontal angle and calcaneal pitch angle are $0{\pm}6.9{^{\circ}}$, $25.8{\pm}4.5{^{\circ}}$ and $23.9{\pm}5.1{^{\circ}}$ as an normal angle limit of young age in Korea.