• 한국해양공학회지
• /
• 제20권2호
• /
• pp.46-51
• /
• 2006

Moonpool characteristics of a cleaning skip related with the performance of a skip are experimentally investigated. Resistance performances of the ship and flow patterns in the moonpool are observed, in order to determine the effect of different shaped moonpool. The ways to reduce ship pithing motion caused by force in the moonpool are examined. Experimental results, using a scale model of cleaning ship with moonpool, show that the step arranged in tier under water leads to significant improvements in performance, such us resistance and ship pithing motion. Depending upon the shape of step in the moonpool, the results indicate that the increment of resistance performance may be up to 35%, especially in the case of no step or high step.

• Restorative Dentistry and Endodontics
• /
• 제45권2호
• /
• pp.22.1-22.10
• /
• 2020

Objectives: This study investigated the influence of glide path size and operating kinetics on the time to reach the working length and the fracture resistance of Twisted File (TF) and Endostar E3 files. Materials and Methods: A total of 120 mandibular single-rooted premolars were selected. Two methods of kinetic motion (TF adaptive and continuous rotary motion) and file systems (TF and Endostar E3) were employed. The files were used in root canals prepared to apical glide path sizes of 15, 20, and 25. The time taken to reach the working length and the number of canals used before the instrument deformed or fractured were noted. Fractured instruments were examined with scanning electron microscopy. Results: The TF system took significantly more time to reach the working length than the Endostar E3 system. Both systems required significantly more time to reach the working length at the size 15 glide path than at sizes 20 and 25. A greater number of TFs than Endostar E3 files exhibited deformation, and a higher incidence of instrument deformation was observed in adaptive than in continuous rotary motion; more deformation was also observed with the size 15 glide path. One TF was fractured while undergoing adaptive motion. Conclusions: No significant difference was observed between continuous rotary and adaptive motion. The TF system and adaptive motion were associated with a higher incidence of deformation and fracture. Apical glide path sizes of 20 and 25 required significantly less time to reach the working length than size 15.

• 성인간호학회지
• /
• 제28권5호
• /
• pp.491-500
• /
• 2016

Purpose: The purpose of this study was to examine the effect of resistive exercise using an elastic band on range of motion, function and shoulder pain. Methods: Forty two subjects who had rotator cuff surgery were assigned either to a treatment or a comparison group, twenty one each. Following a six week period after surgery those in the treatment group participated in resistant exercise using an elastic band for four weeks. The subjects in the comparison group did not participate in the exercise program. The goniometer measured range of motion, a modified tool measured function, and a self report numerical rating scale measured pain. The data were analyzed using $x^2$ test, Fisher's exact, t-test and the Mann-Whitney Test. Results: Although not statistically significant, there was a trend that more subjects in the treatment group had increased range of motion. There was a statistically significance among the treatment group in terms of increased function (p=.015). Further the treatment group reported less pain that those in the comparison group (p<.001). Conclusion: The findings support that resistance exercise is an effective strategy for patients with rotator cuff repair.

• 대한간호학회지
• /
• 제50권2호
• /
• pp.286-297
• /
• 2020

Purpose: This study aimed to identify the effects of myofascial pain syndrome on shoulder pain, range of motion, and body composition around the shoulder in middle-aged women. Methods: A total of 72 women participated in the randomized controlled trial. The subjects were grouped into an experimental group (n=39) and a control group (n=33). The experimental group received a resistance exercise program using an elastic band for 8 weeks, 3 days a week. The control group followed a normal daily for 8 weeks. Measurements were conducted three times; before the experimental treatment (pre-test), the 2nd and 8th weeks after treatment. Results: Regarding the general characteristics and homogeneity of the dependent variables, there were no significant differences between the two groups, except for the thickness of the left and right muscles and the left fat. After treatment, shoulder pain was significantly different between the two groups (F=18.54, p<.001) and the range of shoulder motion was significantly different (left, F=86.70, p<.001; right, F=98.66, p<.001). Furthermore, there were a significant differences in the thickness of muscles between the two groups (left, F=40.20, p<.001; right, F=29.57, p<.001); however, the thickness of fat was not significantly different. Conclusion: The resistance exercise program reduces shoulder pain and improves the range of motion of the shoulder joint and increases muscle mass on around the shoulder. It suggests to conduct a study to confirm the long-term exercise effect.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
• /
• pp.369-378
• /
• 1996

A Lugged steel wheel was operated with two kinds of travel reduction on a sandy clay. " Small -sized transucers of the three-surfaced lug type " were installed to the wheel for the measurement of normal and tangential forces acting on a trailing lug side, lug face and a leading lug side separately . The external results acting on each surface were calculated from those measured forces. This results proved qualitatively that the relationships between external forces and lug surfaces obtained from mathematical analyses were external forces and lug surfaces obtained from mathematical analyses were correct. The traction, the motion resistance and the dynamic load were changing at the three lug surface under various operating conditions . Therefore, total analyses of three surface were indispensable to discuss the performance of the wheel lug.

• 해양환경안전학회지
• /
• 제19권4호
• /
• pp.397-402
• /
• 2013

본 연구에서는 전장이 26.75 m인 해양플랜트지원선의 선형개발을 위한 수치해석을 수행하였고 수치해석 검증을 위한 1/10의 모형선 시험을 예인수조에서 수행하였다. 또한 운항해역의 해상조건으로 뷰포트 스케일 2, 3 및 4에서 향파, 선수사파 및 횡파에서 선속별 상하동요 및 종동요에 대해서 운동응답특성을 수치 해석하였다. 모형시험과 수치해석의 저항 예측 결과는 상호 일치하였다. 운동응답특성은 선수파에서 상하동요는 조우주파수 1.8~2.0 영역에서 크게 나타났으며, 종동요는 거친 해상에서 선미사파 및 고속영역에서 높은 운동특성을 보였다.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제12권1호
• /
• pp.810-818
• /
• 2020

A moored floating structure may exhibit resonant motion responses to low-frequency excitations. Similar to the resonant responses of many vibration systems, the motion amplitude of a moored floating structure is significantly affected by the damping of the entire system. In such cases, the damping contributed by the mooring lines sometimes accounts for as much as 80% of the total damping. While the damping induced by catenary mooring lines is well-investigated, few studies have been conducted on the damping induced by taut mooring lines, especially one partly embedded in soil. The present study develops a simple but accurate model for estimating the damping contributed by mooring lines. A typical type of taut mooring line was used as the reference and the hydrodynamic drag force and soil resistance were taken into consideration. The proposed model was validated by comparing its predictions with those of a previously developed model and experimental measurements obtained by a physical model. Case studies and sensitivity studies were also conducted using the validated model. The damping induced by the soil resistance was found to be considerably smaller than the hydrodynamic damping. The superposition of the wave frequency motion on the low-frequency motion was also observed to significantly amplify the damping induced by the mooring lines.

• Journal of Advanced Research in Ocean Engineering
• /
• 제4권3호
• /
• pp.135-145
• /
• 2018

This paper deals with the added resistance of a ship in waves using computational fluid dynamics (CFD). The ship added resistance is one of the key considerations in the design of energy-efficient ship. In this study, the added resistance of a LNG carrier in head waves is computed using a CFD code to consider the nonlinearity and the viscous effects. The unsteady Reynolds Averaged Navier-Stokes equation (RANS) is numerically solved and the volume of fluid (VOF) approach is used to simulate the free surface flows. The length of incident wave varies from half the ship length to twice the ship length. To investigate the nonlinearity effect, both the linear wave condition and the nonlinear wave condition are considered. The heave and pitch motions are calculated along with the added resistance, and the wave contours are obtained. Grid convergence test is conducted thoroughly to achieve the converged motion and resistance values. The calculated results are compared and validated with experimental data.

• International journal of advanced smart convergence
• /
• 제12권2호
• /
• pp.167-172
• /
• 2023

In this study, the absolute and relative strength of six upper extremity resistance exercises were measured by classifying resistance exercise experts and non-experts. As a result, the skilled group showed higher absolute and relative muscle strength than the unskilled group in the 6 upper extremity resistance exercises. These results are judged to be the hypertrophy of fast-twith muscles, the mobilization of motor units, and the increase in the speed of nerve conduction while the skilled person consistently performs resistance exercise. Experts use intermuscular coordination efficiently to stably perform the load according to the movement and exercise intensity performed during exercise, whereas the inexperienced person uses relatively large muscle groups rather than efficiently using intermuscular coordination. It is considered that exercise motion and load were performed by mobilizing. In addition, as a result of comparing the absolute and relative muscle strength between the 6 types of upper limb resistance exercises, there was a difference between the 6 types of upper limb resistance exercises in the two groups. It can be judged that greater muscle strength and endurance were created through liver coordination.

• 대한조선학회논문집
• /
• 제51권6호
• /
• pp.459-479
• /
• 2014

This paper considers experimental and numerical studies on added resistance in waves. As the numerical methods, three different methods, strip method, Rankine panel method and Cartesian-grid method, are applied. The computational results of vertical motion response and added resistance are compared with the experimental data of Series 60($C_B=0.8$) hull, S175 containership and KVLCC2 hull. To investigate the influence of above-still water hull form, a Rankine panel method is extended to two nonlinear methods: weakly-nonlinear and weak-scatterer approaches. As nonlinear computational models, three ships are considered: original KVLCC2 hull, 'Ax-bow' and 'Leadge-bow' hulls. Two of the three models are modified hull forms of original KVLCC2 hull, aiming the reduction of added resistance. The nonlinear computational results are compared with linear results, and the improvement of computational result is discussed. As experimental approach, a series of towing-tank experiment for ship motions and added resistance on the three models (original KVLCC2 hull, 'Ax-bow' and 'Leadge-bow') are carried out. For the original KVLCC2 hull, uncertainty analysis in the measurement of vertical motion response and added resistance is performed in three waves conditions: ${\lambda}/L=0.5$, 1.1, 2.0. From the experimental results, the effects of hull form on added resistance are discussed.