• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.4
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• pp.77-83
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• 2006

A PIV(Particle Image Velocimetry) was applied to measure in-cylinder velocity field according to inlet valve angle during compression stroke. Two engines, one is conventional DOHC 4 valve and the other is narrow valve angle, were used to compare real compression flow. The results show that the flow patterns are well arranged compared with intake flow and the basic tumble flow structures are maintained until end compression stage regardless of valve angle. Also the results show that the tumble motion is intensified by momentum conservation during compression in normal engine. In the normal engine, the bulk shape of flow pattern is "Y" type at the top of cylinder and reverse "Y" type at the bottom of cylinder and weak reverse flow exists at the top of cylinder along cylinder center line. Otherwise, the other engine's flow pattern changes from "Y" type to "T" type at the top of cylinder during compression.

• Journal of the Korean Wood Science and Technology
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• v.26 no.2
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• pp.45-50
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• 1998

Tracheid length, microfibril angle, and compression strength were examined in south and north sides of Pinus koraiensis. The sample tree was 57 years old and had been planted in central Korea. Tracheid length on the south side of the tree ranged from 2.87 to 3.40mm and on the north ranged from 3.60 to 3.53mm and mean values were 3.15 mm for the south and 3.26mm for the north. Tracheid length was 0.11 mm longer on the north side than on the south. Microfibril angle on the south side ranged from $12.6^{\circ}$ to $20.3^{\circ}$ and that on the north from $6.8^{\circ}$ to $13.5^{\circ}$; mean values were $16.6^{\circ}$ on the south side and $9.6^{\circ}$ on the north. Microfibril angle was $7.0^{\circ}$ greater on the south side than on the north side. For compression strength on the south and north sides, significant difference at the 95% level was found only at l.3m above the ground level of the sample tree; for compression limit stress, significant difference at this level was found at 1.3 and 5.3m above the ground level. However, compression strength and compression limit stress were greater on the north side than on the south side.

• Journal of Biosystems Engineering
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• v.8 no.1
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• pp.70-74
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• 1983

This study was conducted to determine whether or not the form and angle of the precombustion chamber affected the performance of agricultural diesel engines. Twenty different types of precombustion chambers were designed and tested using a two way classification with four individual tests. The output power and specific fuel consumption ratio at full load were measured and analyzed. The results of the study were summarized as follows; 1. The diameter of main passageway giving the best power output and specific fuel consumption ratio at full load was between 5.8 and 6.1mm. The ratio of area of main passageway bore to that of piston head was from 0.4 to 0.44 percent at the highest engine power. 2. The angle of main passageway giving the best power output and specific fuel consumption ratio at full load was between 41 and 43 degrees. 3. The change of the diameter of main passageway affected the output of engine more significantly than the change of angle, however, on the specific fuel consumption ratio the angle of main passageway had more effect than the diameter.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.8
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• pp.674-681
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• 2001

An experiment is conducted to investigate the effect of the inclination angle on convective boiling heat transfer of a uniformly heated tube. The test section used is a stainless steel tube with10.7mm in inner diameter. The hating length is 3m and is heated directly by an AC current. The test fluid is R-113. Experiment are carried out with mass flow rates of 300, 500 and $700\;kg/m^{2}s$, and heat fluxes varying from 5 to 65 kW/$m^2$. The inclination angles of the tube are $0^{\circ},\;5^{\circ},\;11^{\circ}\;and\;25^{\circ}$. the circumferential temperature variation at low quality region and the location of dryout at high quality region are mainly observed. Circumferential anisothermality occurring at low mass flow rate and low quality conditions is gradually reduced with the increase in the inclination angle and finally disappears at the inclination angle of $25^{\circ}$. Critical quality where dryout is initiated is seriously influenced by the inclination angle. Wall temperature after critical quality is also affected by the inclination angle.

• Advances in aircraft and spacecraft science
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• v.10 no.2
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• pp.141-158
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• 2023

In current research work, the aerodynamics performance of a newly designed large flying V aircraft is numerically investigated. Three Flying V configurations, with V-angles of 50°, 70° and 90° that represent the minimum, moderate, and maximum configurations respectively, were designed and modeled to assess their aerodynamic performance at cruise flight conditions. The unstructured mesh was developed using ICEM CFD and Ansys-Fluent was used as an aerodynamic solver. The developed models were numerically simulated at cruise flight conditions with a Mach number equal to 0.15. K-ω SST turbulence model was chosen to account for flow turbulence.The authors performed steady flow simulations.The results obtained from the experimentation reveal that the maximum main angle configuration of 90° had the highest C_Lmax value of 0.46 compared to other configurations. While the drag coefficient remained the same for all three configurations, the 50° V-angle configuration achieved the maximum stall angle of 35°. With limited stall delay benefits, the flying V possesses no sufficient stability, due to the flow separation detected at whole elevon and winglet suction side areas at AoA equal and higher than 30°.

• The korean journal of orthodontics
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• v.14 no.2
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• pp.233-239
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• 1984

The author studied on the tongue position, tongue space and intermaxillary space at 4 groups; normal occlusion 30 cases, Angle's Class I bimaxillary protrusion 29 cases, Angle's Class II malocclusion 26 cases, Angle's Class III malocclusion 26 cases. This study used the data from cephalometric films of female subject aged from 16 to 23 years. Following results were obtained; 1. Dorsal height in Angle's Class III malocclusion was greater than normal occlusion. 2. Anterior Intermaxillary Height in Angle's Class I bimaxillary protrusion and Angle's Class III malocclusion was greater than normal occlusion. 3. Tongue space in Angle's Class I bimaxillary protrusion was greater than normal occlusion. 4. The ratio of the tongue space to the intermaxillary space (T.S./I.S.) in Angle's Class II malocclusion was greater and the ratio in Angle's Class III malocclusion is lesser than normal occlusion.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.04a
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• pp.45-46
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• 2006

We have studied the viewing angle control using a twist nematic liquid crystal display (TN-LCDs). These TK-LCDs have the characteristics, of which is not good image quality, for examples low Contrast ratio and gray scale inversion problems at upper and down viewing direction. TN-LCDs have the function of switching between the wide viewing mode and narrow viewing angle mode using two tilted LC layers. Tilt angles of the two LC layers, $14^{\circ}$ and $60^{\circ}$ were required in both wide viewing angle and narrow viewing angle modes, respectively. Consequently, this device is compatible with two image performances of which the wide viewing angle mode and Narrow viewing angle mode.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.2
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• pp.206-216
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• 2000

Predictional study for lateral change between pre- and post-orthognathic surgery has been emphasized mainly on anterior area of lateral profile; upper lip, lower lip and chin et al. So interest for lateral profile change has been less in posterior area of lateral profile and literature analyzing gonial angle change is rare. The purpose of this study is to make prediction for gonial angle change possible and to offer somewhat treatment guidance for gonial angle to be improved by investigating overall gonial angle change between pre- and post-orthognathic surgery and inquiring into factors influencing on pattern of genial angle change. For this study 35 patients were selected retrospectively. Lateral cephalometric radiographs were taken in just pre-op time, pod 1 day, pod 1 year. They were analyzed and genial angles were measured. The results were as follows : 1. Gonial angle at pod 1 day was decreased about $9.3^{\circ}$ than pre-op and gonial angle at pod 1 year was increased about $4.0^{\circ}$ than pod 1 day. So genial angle at pod 1 year was decreased about $5.3^{\circ}$ than pre-op genial angle(p<0.01). 2. Mean pre-op gonial angle was $129.4^{\circ}$, showing significantly high value than normal and mean gonial angle at pod 1 year was $124.1^{\circ}$, showing value near to normal. 3. Mean gonial angle change between pre-op and pod 1 year was decreased about $5.4^{\circ}$ in female and $5.3^{\circ}$ in male. There was no statistically significant difference between male and female(p>0.05). 4. Principal factor influencing on decreased gonial angle in gonial angle change between pre-op and pod 1 year was amount of mandibular setback. 5. Principal factor influencing on increased gonial angle in gonial angle change between pod 1 day and pod 1 year was % horizontal relapse, and it was thought that resorption and bone remodelling on posterior area in mandibular distal segment also were related to increased gonial angle. 6. It is thought that sagittal split ramus osteotomy in mandibular prognathic patients with high value of gonial angle is effective to improvement of gonial angle, and In patients who have normal range of gonial angle and are required with excessive mandibular setback, short lingual cut method, additional resection of posterior margin of distal segment, Obwegeser II method will be considerd. 7. More prudent operation and careful post-op management will be responsible for maintenance of postoperative stable gonial angle.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.271-278
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• 1999

An alternative panel flutter approach utilizing minimum angle is presented. The minimum angle is the lowest value among the angles between modes i and j at a certain pressure condition. This method utilizes eigenvectors rather than eigenvalues. Cross-ply composite plates are considered in this study. A remarkable result of this investigation is that the angle always dropped gradually to zero for all presented examples

• PNF and Movement
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• v.15 no.3
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• pp.259-266
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• 2017

Purpose: This study aimed to compare muscle activities in the right leg during squatting on an angle-adjustable inclined wooden plate at three different angles. Methods: The subjects were 19 healthy adult men and women. An angle-adjustable inclined wooden plate was used for the experiment, and the subjects performed squatting at three adjusted angles of $0^{\circ}$ ankle angle, $10^{\circ}$ ankle flexion, and $10^{\circ}$ plantar flexion. Squatting was randomly performed without a sequence. The knee angle was set at $45^{\circ}$, and a goniometer was used to measure the angles accurately. Electromyography was employed to measure and compare muscle activity in the right leg in each condition. The measured data were converted to root mean square values to calculate the muscle activities. Results: This study showed no statistically significant difference at a $0^{\circ}$ ankle angle, but a statistically significant difference was found in the vastus medialis at $10^{\circ}$ of ankle flexion. Moreover, statistically significant differences were observed in the vastus medialis and lateralis at $10^{\circ}$ of plantar flexion. Conclusion: This study showed a statistically significant difference in the vastus medialis at $10^{\circ}$ of ankle flexion and statistically significant differences in the vastus medialis and lateralis at $10^{\circ}$ of plantar flexion. Therefore, it may be effective to perform squatting at $10^{\circ}$ of ankle flexion when intending to selectively strengthen the vastus medialis and at $10^{\circ}$ of plantar flexion when intending to strengthen both the vastus medialis and lateralis.