• Journal of Biosystems Engineering
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• v.3 no.2
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• pp.34-34
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• 1978

To find out the power tiller's travel and tractive characteristics on the general slope land, the tractive p:nver transmitting system was divided into the internal an,~ external power transmission systems. The performance of power tiller's engine which is the initial unit of internal transmission system was tested. In addition, the mathematical model for the tractive force of driving wheel which is the initial unit of external transmission system, was derived by energy and force balance. An analytical solution of performed for tractive forces was determined by use of the model through the digital computer programme. To justify the reliability of the theoretical value, the draft force was measured by the strain gauge system on the general slope land and compared with theoretical values. The results of the analytical and experimental performance of power tiller on the field may be summarized as follows; (1) The mathematical equation of rolIing resistance was derived as $$Rh=\frac {W_z-AC \[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\] sin\theta_1}} {tan\phi \[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\]+\frac{tan\theta_1}{1}$$ and angle of rolling resistance as $$\theta _1 - tan^1\[ \frac {2T(AcrS_0 - T)+\sqrt (T-AcrS_0)^2(2T)^2-4(T^2-W_2^2r^2)\times (T-AcrS_0)^2 W_z^2r^2S_0^2tan^2\phi} {2(T^2-W_z^2r^2)S_0tan\phi}\] $$and the equation of frft force was derived as$$P=(AC+Rtan\phi)\[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\]cos\phi_1 ? \frac {W_z ?{AC\[ [1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\]sin\phi_1 {tan\phi[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\]+ \frac {tan\phi_1} { 1} ? W_1sin\alpha $$The slip coefficient K in these equations was fitted to approximately 1. 5 on the level lands and 2 on the slope land. (2) The coefficient of rolling resistance Rn was increased with increasing slip percent 5 and did not influenced by the angle of slope land. The angle of rolling resistance Ol was increasing sinkage Z of driving wheel. The value of Ol was found to be within the limits of Ol =2? "'16?. (3) The vertical weight transfered to power tiller on general slope land can be estim ated by use of th~ derived equation: $$R_pz= \frac {\sum_{i=1}^{4}{W_i}} {l_T} { (l_T-l) cos\alpha cos\beta ? \bar(h) sin \alpha - W_1 cos\alpha cos\beta$$The vertical transfer weight $R_pz$ was decreased with increasing the angle of slope land. The ratio of weight difference of right and left driving wheel on slop eland,$\lambda= \frac { {W_L_Z} - {W_R_Z}} {W_Z} $, was increased from ,$\lambda$=0 to$\lambda$=0.4 with increasing the angle of side slope land ($\beta = 0^\circ~20^\circ) (4) In case of no draft resistance, the difference between the travelling velocities on the level and the slope land was very small to give 0.5m/sec, in which the travelling velocity on the general slope land was decreased in curvilinear trend as the draft load increased. The decreasing rate of travelling velocity by the increase of side slope angle was less than that by the increase of hill slope angle a, (5) Rate of side slip by the side slope angle was defined as $ S_r=\frac {S_s}{l_s} \times$ 100( %), and the rate of side slip of the low travelling velocity was larger than that of the high travelling velocity. (6) Draft forces of power tiller did not affect by the angular velocity of driving wheel, and maximum draft coefficient occurred at slip percent of S=60% and the maximum draft power efficiency occurred at slip percent of S=30%. The maximum draft coefficient occurred at slip percent of S=60% on the side slope land, and the draft coefficent was nearly constant regardless of the side slope angle on the hill slope land. The maximum draft coefficient occurred at slip perecent of S=65% and it was decreased with increasing hill slope angle $\alpha$. The maximum draft power efficiency occurred at S=30 % on the general slope land. Therefore, it would be reasonable to have the draft operation at slip percent of S=30% on the general slope land. (7) The portions of the power supplied by the engine of the power tiller which were used as the source of draft power were 46.7% on the concrete road, 26.7% on the level land, and 13~20%; on the general slope land ($\alpha = O~ 15^\circ ,\beta = 0 ~ 10^\circ$) , respectively. Therefore, it may be desirable to develope the new mechanism of the external pO'wer transmitting system for the general slope land to improved its performance.

• Archives of Plastic Surgery
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• v.43 no.1
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• pp.32-37
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• 2016

Background We conducted this study to analyze the values of the key cephalometric angular measurements of the mandible using 3-dimensional (3D) computed tomography scans. Methods In the 106 enrolled patients, a 3D cephalometric analysis was performed to measure the angular variables of the mandible. These values were compared between the two sides and between the two sexes. Results The frontal measurements revealed that the mandibular body curve angle was larger on the left (Lt) side (right [Rt], $141.24{\pm}7.54$; Lt, $142.68{\pm}6.94$; P=0.002) and the gonial angle was larger on the right side (Rt, $134.37{\pm}8.44$; Lt, $131.54{\pm}7.14$; P<0.001). The sagittal measurements showed that the gonial angle was larger on the right side (Rt, $134.37{\pm}8.44$; Lt, $131.54{\pm}7.14$; P>0.05). Further, the transverse measurements revealed that the mandibular body curve angle was larger on the right side (Rt, $140.28{\pm}7.05$; Lt, $137.56{\pm}6.23$; P<0.001). Conclusions These results provide an average of the mandibular angular measurements for the Korean population, establishing a standard for determining surgical patient groups and outcome evaluations in the field of mandible contour surgery.

• Journal of Advanced Navigation Technology
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• v.25 no.5
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• pp.384-389
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• 2021

An optimal ground station (GS) antenna pattern design method for network-based UAV command and control communication systems considering complexity and performance is presented. The GS antenna consists of multiple side sectors and one upward sector. The antenna gain for each vertical/horizontal angle of the GS antenna according to the change of antenna design parameters such as the number of sectors, horizontal and vertical beam-width, and tilt-angle is modeled, and the effect of the parameter changes on the signal-to-noise ratio (SNR) distribution in the virtual three-dimensional space is analyzed. It is observed that the tilt-angle of the side sectors has the greatest effect on the performance, and the longer the distance between GSs, the higher the maximum altitude and the smaller the number of side sectors, the tilt-angle should be lower. In addition, it is observed that the wider vertical beam-width of the side sector is advantageous in maximizing the lowest SNR, but narrow vertical beam-width is advantageous in maximizing the average SNR.

• Journal of Korean Physical Therapy Science
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• v.1 no.1
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• pp.175-185
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• 1994

The purpose of this study was to evaluate and compare the biceps muscles activity at the different angle and direction of the base of support on sitting position in hemiplegic patients. The biceps muscles activity was measured at the $0^{\circ},\;10^{\circ}$ of posterior tilt, $10^{\circ}$ of anterior tilt, $10^{\circ}$ of affected side tilt and $10^{\circ}$ of sound side tilt of the base of support by EMG biofeedback (MYOMED 432. ENLAF NONIUS CO.) In this study, 24 out-patients were evaluated who were treated at Yonsei University Medical College Rhabilitation Hospital. This study was carried out from December 5. 1993 to March 30. 1994. In order to determine the statistical significance of result, the ANOVA, and t-test were applied at the 0.05 level of significance. The results were as follows : 1. The biceps muscles activity of the sound side was no significantly difference at the different angle and direction of the base of support on sitting position(p>0.05). 2. The biceps muscles activity of the affected side was significantly increased at the 100 of sound side tilt and $10^{\circ}$ of posterior tilt of the base of support on sitting position(p<0.05). 3. There was no significantly difference in the change of the biceps muscles activity of the affected side between the affected group and the intact group of propriocetive sense(p>0.05). 4. The change of the biceps muscles activity of the affected side was significantly higer in the group of G 2 spasticity compared to that of G 1, G 1+ spasticity(p<0.05). These results showed that the biceps muscles activity of affected side was significantly increased when the base of support was tilted toward the sounde side and posterior direction on sitting position. In order to prevent the increment of biceps muscle activity, the patients must avoid to sit toward sound side and posterior tilt.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.1-10
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• 2008

This study analyzed the rear foot angle of the supporting leg and the anatomical rotation angle of the kicking angle in soccer instep kick and drew conclusions as follows. When the supporting leg was landing on the ground, the valgus angle of the ankle joint reached the maximum peak, and plantar flexion was slightly different in the timing of the maximum peak between the two groups. The flexion angle of the rear foot was statistically significantly different between the two groups, and the movement of the crus on the landing of the supporting foot did not show a statistically significant difference between the groups. The crus leaned backward most before the impact, and the side to side gradient of the crus on impact was $22^{\circ}$. The flexion/extension of the hip joint of the kicking leg reached the maximum peak when the supporting foot was landing on the ground, and at the moment, the maximum extension angle of the hip joint was over $30^{\circ}$. The flexion angle of the knee joint of the kicking leg was largest after landing. While the maximum plantar flexion angle and maximum valgus angle of the ankle joint were not significantly different between the two groups, the maximum external rotation angle was significantly different.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1585-1587
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• 1997

We investigated the generation of high pretilt angle for nematic liquid crystal (NLC) in the cell with slanted non-polarized ultraviolet (UV) light irradiation on two kinds of the polyimide (PI) film. It was shown that the monodomain alignment in NLC is obtained in the cell with slanted non-polarized UV light irradiation on PI surface. The pretilt angle of NLC is generated about 3 degrees in the cell with slanted non-polarized UV light irradiation with 70 degrees on PI surface without side chain. But, the pretilt angle of NLC is generated about 1 degree in the cell with slanted non-polarized UV light irradiation with 80 degrees on PI surface with side chain. We consider that the pretilt angle generation in NLC is attributted to anisotropic dispersion force between the LC molecular and the PI surface.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.1
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• pp.15-26
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• 2002

The purpose of this study was to classier the somatotype of late middle-aged women and to analyze the characteristics of each somatotype. The subjects were 337 late middle-aged women and their age range os from 45 to 59 fears old. Data were collected through anthropometry and photometry and analyzed by factor analysis, cluster analysis and discriminant analysis. The results were as follows; 1. The result of factor analysis indicated that 9 factors were extracted through factor analysis and those factors comprised 83.56 percent of total valiance. 2. Using factor scores, cluster analysis was carried out and the subject were classified into 4 cluster. Each cluster was classified as their body front and side view contour. Type 1 is tall, slim, and lower balk is flat on the side. Type 2 is standard and lean-back type on the side. Type 3 is standard height and weight, H type in front, and belly-protruded on the side. Type 4 is short, fat, and the side is hip-protruded. 3. According to the stepwise discriminant analysis, the 9 important items in classifying the somatotype of the late middle-aged women are as follows ; lower back tilt angle, hip depth(back) -back waist depth(back), bust depth(fore) - anterior waist depth(fore), jugular fossa point(fore), upper back tilt angle, burst breadth -waist breadth, right shoulder tilt, height of shoulder - height of anterior waist, abdomen breath. The correct classification rate for these items is as exact as 84.62%.

• Journal of Auto-vehicle Safety Association
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• v.13 no.3
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• pp.69-77
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• 2021

Although accident data from the National Police Agency and insurance companies do not know the vehicle safety, the damage level information can be obtained from the data managed by the bus credit association or the bus company itself. So the accident severity was analyzed based on the side impact accidents using accident repair cost. K-means clustering analysis separated the cost of accident repair into 'minor', 'moderate', 'severe', and 'very severe'. In addition, the side impact accident severity was analyzed by using an ordered logit model. As a result, it is appeared that the longer the repair period, the greater the impact on the severity of the side impact accident. Also, it is appeared that the higher the number of collision points, the greater the impact on the severity of the side impact accident. In addition, oblique collisions of the angle of impact were derived to affect the severity of the accident less than right angle collisions. Finally, the absence of opponent vehicle and large commercial vehicles involved accidents were shown to have less impact on the side impact accident severity than passenger cars.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1496-1500
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• 2008

Less than 1 % directional error in the range of 5 meters in the green could cause a stroke or more. Although there are several reasons offsetting the direction of the golf ball, lie angle and sidespin effect are the most crucial factors of the putting game. Simple equation is conformed to the experimental results of the deviation of the directional error in all distance. Also, the experimental results of the putting robot show that there are significant side spin effects.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.97-102
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• 2003

An experimental study is conducted to investigate the effects of duct corrugation angle on heat/mass transfer characteristics in wavy ducts by using a naphthalene sublimation technique. The corrugation angles of the wavy ducts are $145^{\circ}$ , $130^{\circ}$ and $115^{\circ}$ . and the Reynolds numbers based on the duct hydraulic diameter vary from 300 to 3,000. At the low $Re(Re{\leq}1000)$, high heat/mass transfer regions are formed by the secondary vortex flows called Taylor-Gortler vortices on both pressure-side and suction-side walls. At the high $Re(Re{\geq}1000)$, the effects of these secondary flows are vanished. As corrugation angle decreases, the local peak Sh induced by Taylor-Gertler vortices are increased and average Sh also enhanced. More pumping power (pressure loss) is required with the smaller corrugation angle due to the stronger secondary vortex flows.