Density and sound speed contrasts (g and h , respectively), and swimming angle were measured for sandfish (Arctoscopus japonicus) without swimbladder. The density contrast was measured by the volume displacement method while the sound speed contrast was measured by the acoustic measurements of travel time (time-of-flight method). The swimming angle was measured by dividing it into daytime, nighttime, daytime feeding and nighttime feeding. The g was 1.001 to 1.067 with an average (± standard deviation) of 1.032 (± 0.017), and the h was 1.007 to 1.022 with an average (± standard deviation) of 1.015 (± 0.003). The swimming angles (mean ± standard deviation) were 16.8 ± 10.3° during the daytime, 1.9 ± 12.3° during the nighttime, 30.2 ± 12.6° in the daytime feeding and 35.0 ± 13.2° in the nighttime feeding. These results will provide important parameters input to calculate theoretical scattering models for estimating the acoustic target strength of sandfish.

The seismic behaviors of the arch structure vary according to the rise-span ratio of the arch structure. In this study, the rise-span ratio (H/L) of the example arch structure was set to 1/4, 1/6, and 1/8. And the installation angle of the seismic isolator was set to 15°, 30°, 45°, 60° and 90°. The installation angles of the seismic isolator were set by analyzing the horizontal and vertical reaction forces according to the rise-span ratio of the arch structure. Due to the geometrical and dynamic characteristics of the arch structure, the lower the rise-span ratio, the greater the horizontal reaction force of the static load, but the smaller the horizontal reaction force of the dynamic load. And if the seismic isolator is installed in the direction of the resultant force of the reaction forces caused by the seismic load, the horizontal seismic response becomes small. Also, as the installation angle of the seismic isolator increases, the hysteresis behavior of the seismic isolator shows a plastic behavior, and residual deformation appears even after the seismic load is removed. In the design of seismic isolators for seismic response control of large space structures such as arch structures, horizontal and vertical reaction forces should be considered.

This study proposes a low-cycle fatigue life derived from measurement points on pipe elbows, which are components that are vulnerable to seismic load in the interface piping systems of nuclear power plants that use seismic isolation systems. In order to quantitatively define limit states regarding leakage, i.e., actual failure caused by low-cycle fatigue, in-plane cyclic loading tests were performed using a sine wave of constant amplitude. The test specimens consisted of SCH40 6-inch carbon steel pipe elbows and straight pipes, and an image processing method was used to measure the nonlinear behavior of the test specimens. The leakage lines caused by low-cycle fatigue and the low-cycle fatigue curves were compared and analyzed using the relationship between the relative deformation angles, which were measured based on each of the measurement points on the straight pipe, and the moment, which was measured at the center of the pipe elbow. Damage indices based on the combination of ductility and dissipation energy at each measurement point were used to quantitatively express the time at which leakage occurs due to through-wall cracking in the pipe elbow.

Noise is a sound that humans do not want. In this study, Based on the Rotax 912 engine, which is most commonly used in Korea, we will look at noise and thrust changes by changing the propeller blade angle by 1 degree for the two-blade Sensenich Propeller and the three-blade Wrap drive Propeller. Through this, we want to check which part of the propeller angle produces the least noise and the least thrust loss for each propeller, and propose a propeller operation plan in a noisy area based on the value.

In this study, the experiment was conducted on a fire door(W × H = 0.98 m × 2.19 m) installed on the vestibule. The effective leakage area for each opening angles and closing forces derived from the impulse-momentum equation was compared and analyzed with the experimental results. As a result of the experiment, the major factors affecting the door closing forces were the pressure difference and the area of the door. The difference of door closing forces between measured and calculated values by the impulse-momentum equation showed a deviation of less than ±15% at the opening angles of 5°to 10°. At the door opening angle of 2.5°, the dynamic pressure was much higher than the measured static pressure, and this pressure difference is estimated to be air resistance acting to prevent the door from being completely closed.

Background: The serratus posterior inferior (SPI) muscle originates from the spinous process of T11-L2 and inserts at the lower border of the 9–12th ribs. This muscle is involved in thoracolumbar rotation and stability. Several positions can be used to improve trunk stability; the quadruped position is a good position for easily maintaining a neutral spine. In particular, during one arm lifting, various muscles act to maintain a neutral trunk position, and the SPI is one of these muscles. If trunk stability is weakened, uncontrolled trunk rotation may occur at this time. Tape can be used to increase trunk stability. There have been no studies on the effect of taping applied to the SPI muscle on thoracolumbar junction (TLJ) stability. Objects: This study compared the TLJ rotation angle between three different conditions (without taping, transverse taping, and SPI muscle direction taping). Methods: Thirty subjects were recruited to the study (18 males and 12 females). The TLJ rotation angle was measured during one arm lifting in a quadruped position (ALQP). Two taping methods (transverse and SPI muscle direction taping) were applied, and the TLJ rotation angle was measured in the same movement. Results: SPI muscle direction taping significantly reduced TLJ rotation compared to that without taping (p < 0.001) and with transverse taping (p < 0.001). There was a significant difference in the TLJ rotation angle between transverse taping and SPI muscle direction taping (p < 0.017). Conclusion: SPI muscle direction taping reduces the TLJ rotation angle during ALQP. Therefore, SPI muscle direction taping is one method to improve TLJ stability and reduce uncontrolled TLJ rotation during ALQP.

The effects of different spray angles (90°, 85°, 80°) on the microstructure and mechanical properties of a Y2O3 coating layer prepared using the atmospheric plasma spray (APS) process were studied. The powders employed in this study had a spherical shape and included a cubic Y2O3 phase. The APS coating layer exhibited the same phase as the powders. Thickness values of the coating layers were 90°: 203.7 ± 8.5 μm, 85°: 196.4 ± 9.6 μm, and 80°: 208.8 ± 10.2 μm, and it was confirmed that the effect of the spray angle on the thickness was insignificant. The porosities were measured as 90°: 3.9 ± 0.85%, 85°: 11.4 ± 2.3%, and 80°: 12.7 ± 0.5%, and the surface roughness values were 90°: 5.9 ± 0.3 μm, 85°: 8.5 ± 1.1 μm, and 80°: 8.5 ± 0.4 μm. As the spray angle decreased, the porosity increased, but the surface roughness did not show a significant difference. Vickers hardness measurements revealed values of 90°: 369.2 ± 22.3, 85°: 315.8 ± 31.4, and 80°: 267.1 ± 45.1 HV. It was found that under the condition of a 90° angle with the lowest porosity exhibited the best hardness value. Based on the aforementioned results, an improved method for the APS Y2O3 coating layer was also discussed.

In this paper, the dynamic response was analyzed by performing linear dynamic analysis using historic earthquake loads on twisted-shaped structures and fixed structure among free-form high-rise structures with atypical elevation shape following prior studies. In addition, the dynamic characteristics of the analysis models according to the plane rotation angle of the twisted structure were compared and analyzed. As a result of the analysis, as the plane rotation angle of the twisted structure increased, the interlayer deformation rate increased in the high-rise part of 50th floors or more. The story shear force and the story absolute acceleration were similar in the entire structure. In the case of the story shear force, the response of the twisted shape model was rather reduced in the middle part. As a result of analyzing the dynamic response, the vulnerable layer where the response amplification of the twisted structure occurs was found to be 31st story.

Background: Backpacks are one of the most widely used accessories in modern society. However, previous studies have shown that carrying a backpack can cause various musculoskeletal problems. Objectives: To investigate the effects of a body-adhesive backpack on craniovertebral angle, sagittal shoulder angle and the muscle fatigue in the upper extremity. Design: Randomized cross-over design. Methods: For this study, 36 healthy university students participated in this study. The experiment was conducted three times using common backpack, and body-adhesive backpack condition. The angles of the cervical spine and shoulder joints of the subjects were calculated without the backpack. Electrodes were placed at upper trapezius, lower trapezius, rectus abdominis and erector spinae to check for muscle fatigue. Subjects carried a backpack and walked on a treadmill for 15 minutes at 4 km/h. The muscle fatigue signal was also measured while walking. After walking, the craniovertebral and sagittal shoulder angles were measured again while subjects carried backpack. Results: As a result of this study, body-adhesive backpack condition showed significant decrease and significant increase in craniovertebral angle and sagittal shoulder angle than common backpack (P<.05). Body-adhesive backpack condition showed significant decrease in upper trapezius, lower trapezius, erector spinae, and rectus abdominis when compared to a common backpack (P<.05). Conclusion: This study suggests that a body-adhesive backpack is more beneficial in correcting body posture than a common backpack.

Background: Incorrect postures of adolescents caused by the use of smart devices have been noted as a factor causing spinal diseases. Objectives: To examine the effect of joint mobilization and stretching on Cobb’s angle and respiratory function in adolescent idiopathic scoliosis (AIS). Design: Cluster-randomized controlled trial. Methods: A total of 22 subjects with AIS were enrolled. They were allocated to two groups: the joint mobilization (n=11) and the stretching (n=11). All interventions were conducted for 30 minutes, three times a week for six weeks. Outcome measures were the Cobb’s angle and respiratory function. The Cobb’s angle and respiratory function measured using the X-ray and Micro- Quark. Results: Joint mobilization group showed significant differences in Cobb’s angle and respiratory function, but stretching group showed significant differences Cobb’s angle. The differences in peak expiratory flow (PEF) between the two groups were significant. Conclusion: This study proved that joint mobilization is a more effective intervention for AIS to improve Cobb’s angle and respiratory function, when compared to stretching.

딸기는 다년생 초본성 식물로 그 과실은 영양 가치가 높고 인기있는 고부가가치 채소작물이다. 본 연구는 딸기 품종 ‘설향’과 ‘매향’의 런너유인각도(RTA)가 절간장과 런너 발생수에 미치는 영향을 조사하여 자묘의 생산성을 높이고 번식효율을 증가시키기 위한 기초 자료를 얻고자 수행되었다. 러너를 0°(상향), 45°, 90°(수평), 135°, 또는 180°(하향)의 각도로 한 달 간 유인하였다. 이 실험은 유리온실에서 주간/야간 온도 29/20°C, 평균 광도 450 μ mol m-2·s-1 PPFD의 자연광 환경에서 수행하였으며, 1일 광주기는 12시간이었다. ‘설향’과 ‘매향’에 있어서 RTA는 런너 수와 절간장에 영향을 주었으며, 자묘 수, 생체중과 건물중에 영향을 미쳤다. RTA 135° 또는 180°에서 두 품종 모두 자묘의 평균 생체중과 건물중이 가장 작았으며, ‘설향’ 품종에서는 런너 길이와 절간장이 짧아졌다. RTA가 두 품종 모두에서 런너의 직경에는 영향을 미치지 않았지만 런너의 형태에는 영향을 미쳤다. RTA중 135°와 비교해서 180°가 가장 많은 자묘를 생산하여 가장 번식효율이 좋았다.

Background: Based on the understanding of the muscle activation relationship between the infraspinatus and posterior deltoid muscles to according to the angle of motion during external rotation on glenohumeral joint, effective shoulder joint strengthening exercise for the prevention and rehabilitation of shoulder injury due to muscle strength imbalance can be performed by achieving the ideal muscle activity ratio during exercise. Objectives: To compare and analyze the muscle activation changes and activity ratio of the infraspinatus and posterior deltoid muscles according to the glenohumeral external rotation angle. Design: Quasi-randomized trial. Methods: The study included 48 healthy male and female adults who provided informed consent for participation in the study. All the subjects performed isometric glenohumeral external rotation by setting the angle of motion to 30°, 45°, and 60° using a 5 kg resistance weight pulley. On surface electromyography, the differences in muscle activation and activity ratio between the infraspinatus and posterior deltoid muscles were investigated. Results: A significant difference in muscle activation was found in the comparison between the infraspinatus and posterior deltoid muscles according to the glenohumeral external rotation angle (P<.05). The muscle activation levels of the infraspinatus and posterior deltoid muscles were highest at the external rotation angles of 30° and 60°, respectively. The muscle activity ratio between the infraspinatus and posterior deltoid muscles also showed a significant difference (P<.05) and was highest at the shoulder external rotation angle of 30°. Conclusion: The findings of this study suggest that muscle activity is the highest at the shoulder external rotation angle of 30° in healthy individuals.

MDPS control has been a difficult problem for the past two decades. Though there are many ways to control steering feeling, the MDPS control logic is still being upgraded or developed for steering feel improvement. A new point of view in MDPS is proposed by evolution logic, which is a new driver friendly improvement based on the analysis of driver’s driving pattern. As a result of the application of evolution logic, this paper shows that drivers behaviour effecting factors among MDPS parameters will efficiently lead to customers’ satisfaction.

Menton (Me) deviation is commonly used for diagnosing facial asymmetry. This study compared angle and distance measurement in determining the severity of Me deviation for facial asymmetry diagnosis. Three-Dimensional Computed Tomographic(3D CT) images of 32 patients (mean age 22.5yrs, SD 3.4yrs; 16 male, 16 female) with facial asymmetry were selected for this study. Angle and distance of Me deviation in each patient were obtained and the severity of Me deviation was determined according to the angle and the distance measurement. The severity of Me deviation by angle and distance measurement was compared and statistical analysis was performed. Eight (25%) showed disagreement in severity of Me deviation between the two measurements. The kappa coefficient on the two measurements was 0.67, showing substantial agreement. It is suggested that both angle and distance measurement be performed in determining severity of Me deivation.