• Advances in nano research
• /
• v.13 no.3
• /
• pp.247-257
• /
• 2022

Extraordinary properties of nanocomposites make them a primary replacement for many conventional materials. Anterior cruciate ligament (ACL) reconstruction, which is a frequent surgery in sport activities, is one of the fields in which nanocomposites could be utilized. In the present study, the mechanical properties of different porous scaffolds made from graphene nano-composites are presented ad load bearing capacity of these materials is calculated using finite element method. The numerical results are further compared with experimental published data. In addition, several geometrical and material parameters are analyzed to find the best configuration of nanocomposite scaffolds in reconstruction of ACL. Moreover, coating of detoxification chemicals are extremely easier on the nano-structured materials than conventional one. Detoxification potential of nano-composites in the injured body are also discussed in detail. The results indicated that nano-composite could be successfully used in place of auto- and allografts and also instead of conventional metallic screws in reconstruction of ACL.

• Advances in nano research
• /
• v.14 no.2
• /
• pp.179-193
• /
• 2023

Physical activities enhance blood flow in the vessels, which may increase the quality of medicine delivery. The emergence of revolutionary technologies such as nanoscience, made it possible to treat the incurable illnesses such as cancer. This paper investigates the impact of sport and physical exercises on the quality and quantity of the drug-delivery based on the mathematical modeling of a nanomotor made by nanotubes carrying the nano-drug capsules. Accordingly, the mathematical equations of rotating nanomotor are generated by considering the both of higher-order beam model and nonlocal strain gradient model, as a comprehensive continuum theory. Next, through the generalized differential quadrature together with Newmark-beta methods, the differential relations are discretized and solved. Finally, the impact of varied parameters on the dynamical behavior of the nanomotor is examined in detail. The outcomes of this investigation can be useful to achieve an excellent design of nanomotors carrying nano-drugs.

• Journal of Global Scholars of Marketing Science
• /
• v.16 no.2
• /
• pp.95-108
• /
• 2006

The major objective of this study is to test if an Olympic Games sponsorship program can influence investors' behavior: stock returns, stock volatility and transaction volumes. The paper deals with stock market reaction on Olympic sponsorship announcement for service organizations using event study method. Our research intention is to test 440 daily stock prices and transaction volumes, in order investigate the potent influence between the announcement of a grand sport sponsorship program and investors' behavior. For this study we examined the announcement data of three grand sponsors of Olympic Games of Athens 2004 (Alpha Bank. Delta and G.T.O) The main contribution of this study is to examine how stock investors' behavior is influenced by the sponsorship program of companies and to extend research scope of marketing field toward stock market. They authors suggest that organizations interested in influencing investors' behavior should invest in sponsorship activities at the sports' sector.

• Journal of the Korea Convergence Society
• /
• v.8 no.12
• /
• pp.397-405
• /
• 2017

The purpose of this study was to empirically reveal the causal relationship between ethics management, organizational trust, organizational identification, and organizational citizenship behavior perceived by members of public sports organizations. For this purpose, a survey was conducted on the employees of Korea sports promotion foundation, the city and county sports association, and the federation of sports associations in Kyoung-In and Kangwon area. The results were as follows : First, ethics management has been found to influence organizational trust. Second, ethics management has been found to influence organization identification. Third, organizational trust has been found to influence organizational identification. Fourth, organizational trust has been found to influence organizational citizenship behavior. Fifth, organizational identification has been found to influence organizational citizenship behavior. This study confirmed that the ethical management activities of public sports organizations were positively influencing the various pro-social behaviors of the members who voluntarily perform outside of their jobs for the development of organization by trusting and identifying the organization.

• Korean Journal of Applied Biomechanics
• /
• v.18 no.1
• /
• pp.179-190
• /
• 2008

The purpose of this study was to identify whether or not in one-leg vertical jump of each limb asymmetry between both sides is present and to identify how the discrepancies between both limbs affect two-leg jumping performance, that is bilateral deficit. We had 13 healthy subjects perform one-leg jump for both sides and two-leg countermovement jump. The result of biomechanical analysis showed significantly difference of 4-7% in net impulses and work output between dominant and non-dominant one-leg jump and bilateral deficit of 24% when sum of those of each one-leg jump was compared with two-leg jump. But asymmetry in lower extremity was not significantly correlated with bilateral deficit. Two-leg jump could be characterized by relatively short propulsion time, long propulsion distance and high joint angular velocity compared with one-leg jump. These factors seemed to contribute to decreased performance in two-leg jump. Furthermore bilateral deficit was attributed to lower activities of extensor muscles found in two-leg jump.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.1
• /
• pp.207-219
• /
• 2005

The purpose of this study was to determine the effect of the foot rotation on the lower limb muscles. Fourteen subjects performed step-up/step-down at a cadence of 80 beats/min, exercises with the foot neutral, $35^{\circ}$ internally rotated, and $35^{\circ}$ externally rotated, respectively. For each variable, a one-way analysis of variance (ANOVA) was used to determine whether there were significant differences between genders and among the eight types of jump. When a significant difference was found in jump type, post hoc analyses were performed using the Tukey procedure. A confidence level of p < .05 was used to determine statistical significance. The results showed that significant changes in averaged IEMG values occurred with the internal rotation of the foot in the lateral gastrocnemius during the knee extension, and in the semitendinosus during the knee flexion. During the knee extension, however, the internal rotation of the foot produced a significantly lower Averaged IEMG values than the neutral foot position in the medial gastrocnemius. The results also found that the peak IEMG activity of the rectus femoris during the knee extension for the external rotation of the foot was Significantly higher than the corresponding values in the neutral position of the foot, while the intenal rotaion of the foot exhibited a significant difference with the neutral position of the foot in the semitendinosus during the knee flexion. In general, the foot rotation position did not influence the average IEMG and Peak IEMG values of most muscles. The practice of adopting foot rotation to selectively strengthen individual muscles of the lower limb was not supported by this study. The external rotation of the foot produced high muscle activities in the quadriceps during the knee extension. For the knee extension, therefore, maintaining a laterally rotated position should be need for stable and comfortable position.

• Korean Journal of Applied Biomechanics
• /
• v.18 no.4
• /
• pp.143-149
• /
• 2008

The purpose of this study was to investigate the muscle activities of pectoralis major, upper serratus, lat dorsi, anterior deltoid, rhomboids, infraspinatus, and posterior deltoid using Noraxon 8 channels EMG system during T-ball swing in children with Down syndrome. Five Down syndrome, one healthy children, and one baseball adult player were participated in the study. Down syndrome's children showed higher muscle activity than one healthy children and one baseball adult player during address to backswing and backswing to impact swing phase. While Down syndrome's children showed lower muscle activity than one healthy children and one baseball adult player during impact to follow swing phase. The strength of the pectoralis major and upper serratus muscle may help to improve T-ball swing movement during impact to follow swing phase.

• Journal of Mushroom
• /
• v.13 no.3
• /
• pp.181-184
• /
• 2015

Mushroom have long been valued as highly nutritious and tasty foods in many societies throughout the world. It is known for biological activities including anti-inflammatory and anti-oxidative potential. However little is known about anti-cancer property. In this study, we investigated the anti-prostate cancer activity of mushrooms. For that, eight kinds of mushrooms such as, T. matsutake, S. crispa, G. lucidum-US, G. lucidum-AS, C. cardinalis-BR, G. frondosa, P. linteus, U. esculenta were extracted with hot water. Among them, three kinds of mushrooms including T. matsutake, G. lucidum-US and C. militaris-BR extracts inhibited prostate specific antigen (PSA) expression in prostate cancer cell, LNCaP. These results demonstrate that some of mushrooms inhibited PSA expression suggesting that the mushrooms might be a candidate for the treatment of prostate cancer.

• Korean Journal of Applied Biomechanics
• /
• v.27 no.2
• /
• pp.83-90
• /
• 2017

Objective: To investigate the effect of short-term vibration frequencies on muscle force generation capabilities. Method: Six healthy participants were recruited for this study and only their dominant leg was tested. The subjects were tested under five conditions of vibration frequencies with constant amplitude: 0 Hz (no vibration), 30 Hz, 60 Hz, and 90 Hz, and the vibration amplitude was 10 mm for all frequency conditions. The vibration was applied to the rectus femoris (RF). The subjects were then instructed to maintain a steady-state isometric knee joint torque (100 Nm) for the first 6 s. After the steady-state torque production, the subjects were required to produce isometric knee joint torque by leg extension as hard as possible with a start signal within the next 3 s. The vibration was applied for ~4 s starting from 1 s before initiation of the change in the steady-state knee joint torque. Results: The results showed that the maximum voluntary torque (MVT) of the knee joint increased with the vibration frequencies. On average, the MVTs were 756.47 Nm for 0 Hz (no vibration) and 809.61 Nm for 90 Hz. There was a significant positive correlation (r = 0.71) between the MVTs and integrated electromyograms (iEMGs). Further, the co-contraction indices (CCIs) were computed, which represent the ratio of the iEMGs of the antagonist muscle to the iEMGs of all involved muscles. There was a significant negative correlation (r = 0.62) between the CCIs and MVTs, which was accompanied by a significant positive correlation (r = 0.69) between the iEMGs of the vibrated muscle (RF). There was no significant correlation between the MVTs and iEMGs of the antagonist muscle. Conclusion: The results of this study suggest that the short-term vibration on the muscle increases the level of muscle activation possibly owing to the increased Ia afferent activities, which enhances the muscle force generation capability.

• Nutritional Sciences
• /
• v.7 no.4
• /
• pp.241-246
• /
• 2004

This study investigated the influence of weight perception on weight management strategies including diet and exercise in Korean female adolescents. Junior (J) and senior (S) high school girls were divided in two groups; those who had $\leq$100% (BI) and > 100% (AI) of ideal weight (J-BI, n=376, 14.8 yr, 46.1 kg; J-AI, 11=128, 15.0 yr, 57.4 kg; S-BI, n=325, 17.4 yr, 50.1 kg; and S-AI, n=133, 17.5 yr, 58.2 kg, mean values). Questionnaires to assess weight perception, desire to lose weight, body image, eating behavior, weight control strategies and physical activity (PPA) were administered J-AI(9.4 kg) and S-AI(9.8 kg) desired to lose weight more than J-BI(2.5 kg) and S-BI(3.6 kg), respectively (p < 0.001). 85% of J-AI and 93% of S-AI perceived their weight being above average and 23% of J-BI and 34% of S-BI responded similarly (p < 0.001). Body dissatisfaction index (BDI) and eating attitude (EAT26) scores were lower in J-BI(9.7, 12.0) vs. J-AI(16.4, 14.7) and S-BI(12.4, 12.4) vs. S-AI(19.5, 15.4) (p < 0.001). However, PPA was not different for J-BI vs. J-AI, and S-BI vs. S-AL Only 17, 18, 9, and 15% of J.BI, J.AI, S-BI, and S-AI, respectively, exercised regularly. PPA and BDI were only slightly correlated in J-BI(r=0.194, p < 0.005) and S-BI(r=0.220, p < 0.005). Even that the majority of Korean female adolescents perceived they were heavy and desired to lose weight, appropriate exercise and physical activities were not practiced.