• Physical Therapy Korea
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• v.24 no.1
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• pp.1-8
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• 2017

Background: The multiple hop test is an active performance test that has been commonly used to assess individuals with functional ankle instability. Previous studies have suggested that insufficiency of dynamic postural stability and passive stability during dynamic activities can have an influence on performance in the multiple hop test. However, no study has investigated the effects of dynamic postural stability training and ankle bracing on multiple hop test performance in individuals with functional ankle instability. Objects: The purpose of this study was to compare the immediate effects of dynamic postural stability training versus ankle bracing in the performance of the multiple hop test for participants with functional ankle instability. Methods: Twenty-nine participants with functional ankle instability who scored below 24 in the Cumberland Ankle Instability Tool were selected. The participants were randomly divided into two groups: a dynamic postural stability training group (n1=14) and an ankle bracing control group ($n_2=15$). The multiple hop tests were performed before and after applying each intervention. Dynamic postural stability training was performed using visual-feedback-based balance-training equipment; participants in this group were asked to perform a heel raise in a standing position while watching the centering of their forefoot pressure to prevent excessive ankle inversion. Ankle bracing was applied in the control group. Results: When comparing the pre- and post-intervention period for both groups, both methods significantly improved the results of the multiple hop test (p<.05). However, no significant differences were shown between the dynamic postural stability training and ankle bracing groups (p>.05). Conclusion: Both dynamic postural stability training and ankle bracing showed significant improvement (2.85 seconds and 2.05 seconds, respectively) in test performance. Further study is needed to determine the long-term effects of dynamic postural stability training and to determine whether insufficient dynamic postural stability is a causative factor for functional ankle instability.

• The Journal of Korean Physical Therapy
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• v.28 no.4
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• pp.254-258
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• 2016

Purpose: This study was conducted to identify the effects of dual task training on balance and functional performance in high school soccer players with functional ankle instability. Methods: Twenty high school soccer players with functional ankle instability were randomly assigned to a single task training group and a dual task training group. One participant who did not participate regularly in the training was excluded. The single task training group (n=9) received balance training on an unstable surface. The dual task training group (n=10) received balance training on an unstable surface and had to catch thrown balls during the balance training. Both groups were trained for 4 weeks, 3 days a week. The balance and functional performance of both groups was measured before and after training. Balance was measured using an anterior-posterior and medio-lateral balance. Functional performance was measured based on a figure-of-8 hop test, up-down hop test, and a single hop test. All data were analyzed by repeated two-way ANOVA tests. Results: A time by group interaction effect was not observed in the medio-lateral balance test, figure-of-8 hop test, or single hop test (p>0.05). A time by group interaction effect was observed in the anterior-posterior balance and up-down hop test (p<0.05). Conclusion: These results suggest that dual task training improved balance and functional performance better than single task training for some items.

• Journal of Korean Orthopaedic Sports Medicine
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• v.4 no.2
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• pp.109-115
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• 2005

Purpose: The purpose of this study was to evaluate the effectiveness of three functional performance tests and one-legged hop test and to establish the reference data of the three functional performance tests of the active young Korean men. Materials and methods: We performed five tests on 40 normal subjects such as one-legged hop test (single hop, triple hop) and the three functional performance tests (carioca test, co-contraction test, shuttle run test). The mean age was 28.4 years. The mean score of Tegner activity scale was 6.2 and Lysholm score 98.2 Mean value and standard deviation were obtained. The correlation of age, height and weight with the results, the relationship between FPT and one-legged hop test and the mean difference between dominant and non-dominant limbs were statistically calculated. Results: All data obtained were normally distributed and there were no significant relationship between age, height and weight. The paired t-test of one legged hop test showed no statistical significance between dominant and non-dominant limbs. The results of one legged hop test had strong relationship with functional performance test. Conclusion; The three functional performance tests can be a useful functional test in ACL-insufficient athletes. Our results can be used as normal reference data of the normal active Korean men.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.3
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• pp.187-192
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• 2012

In the present study, the antinociceptive profiles of hop extract were characterized in ICR mice. Hop extract administered orally (from 25 to 100 mg/kg) showed an antinociceptive effect in a dose-dependent manner as measured in the acetic acid-induced writhing test. Antinociceptive action of hop extract was maintained at least for 60 min. Moreover, cumulative response time of nociceptive behaviors induced with intraplantar formalin injection was reduced by hop extract treatment during the 2nd phases. Furthermore, the cumulative nociceptive response time for intrathecal injection of substance P ($0.7{\mu}g$) or glutamate ($20{\mu}g$) was diminished by hop extract. Intraperitoneal pretreatment with naloxone (an opioid receptor antagonist) attenuated antinociceptive effect induced by hop extract in the writhing test. However, methysergide (a 5-HT serotonergic receptor antagonist) or yohimbine (an ${\alpha}_2$-adrenergic receptor antagonist) did not affect antinociception induced by hop extract in the writhing test. Our results suggest that hop extract shows an antinociceptive property in various pain models. Furthermore, the antinociceptive effect of hop extract may be mediated by opioidergic receptors, but not serotonergic and ${\alpha}_2$-adrenergic receptors.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.9
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• pp.1320-1330
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• 2002

The purpose of this study was to classify Y generation according to Hip Hop mania elements and to investigate the differences in psychological characteristics (self-consciousness, egocentrism) and buying behavior of Hip Hop fashion among the classified groups. The subjects were 500 middle and high school students living in Seoul and Kyonggi area.46g data were analysed using cluster analysis, ANOVA and Duncan's multiple range test. The results were as (follows : As a result of classifying Y generation with Hip Hop mania element including behavior and attitude aspect they were classified into three groups; Hip Hop mania group, Hip Hop interesting group, Hip Hop uninterested group. Among groups there were significant differences in public and private self-consciousness, self-centeredness, evaluative criteria of Hip Hop fashion, information sources and clothing store patronage. Hip Hop Mania group showed significantly higher level in both public and private self-consciousness, thus the members of the group were so egocentric in their thinking and behavior. When they purchased Hip Hop fashion, they regarded both aesthetic appreciation and practicality as import information.

• Journal of Korean Physical Therapy Science
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• v.25 no.3
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• pp.61-67
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• 2018

Background: The purpose of this study is to report the effect of balance training through various ankle inclination on dynamic balance in healthy adults. Methods: This study was participated in 20 healthy subjects. Twenty healthy adults were randomly divided into 10 ankle inclination group and 10 flat group, 3 kinds of exercised were performed in $30^{\circ}$ of the plantar flexion, $0^{\circ}$ of the neutral angle and $30^{\circ}$ of the dorsiflexion. Above 3 kinds of exercises were also performed in the flat group. Dynamic balance of each group was evaluated using a Figure-of-8 hop test, Up-down hop test, and Functional reach test before and after the experiment. Results: In the ankle inclination, the post-experiment showed a significant difference in Figure-of-8 hop test, Up-down hop test, and Functional reach test in comparison to pre-experiment(p<.05). Conclusion: The exercise applied in the ankle inclination is effective in improvement of the dynamic balance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.5785-5804
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• 2019

The information of localization is a fundamental requirement in wireless sensor network (WSN). The method of distance vector-hop (DV-Hop), a range-free localization algorithm, can locate the ordinary nodes by utilizing the connectivity and multi-hop transmission. However, the error of the estimated distance between the beacon nodes and ordinary nodes is too large. In order to enhance the positioning precision of DV-Hop, fast triangle flip bat algorithm, which is based on curve strategy and rank transformation (FTBA-TCR) is proposed. The rank is introduced to directly select individuals in the population of each generation, which arranges all individuals according to their merits and a threshold is set to get the better solution. To test the algorithm performance, the CEC2013 test suite is used to check out the algorithm's performance. Meanwhile, there are four other algorithms are compared with the proposed algorithm. The results show that our algorithm is greater than other algorithms. And this algorithm is used to enhance the performance of DV-Hop algorithm. The results show that the proposed algorithm receives the lower average localization error and the best performance by comparing with the other algorithms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.5
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• pp.2499-2522
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• 2017

Multi-hop networks are a low-setup-cost solution for enlarging an area of network coverage through multi-hop routing. Carrier sense multiple access with collision avoidance (CSMA/CA) is frequently used in multi-hop networks. Multi-hop networks face multiple problems, such as a rise in contention for the medium, and packet loss under heavy-load, saturated conditions, which consumes more bandwidth due to re-transmissions. The number of re-transmissions carried out in a multi-hop network plays a major role in the achievable quality of service (QoS). This paper presents a statistical, analytical model for the end-to-end delay of contention-based medium access control (MAC) strategies. These strategies schedule a packet before performing the back-off contention for both differentiated heterogeneous data and homogeneous data under saturation conditions. The analytical model is an application of Markov chain theory and queuing theory. The M/M/1 model is used to derive access queue waiting times, and an absorbing Markov chain is used to determine the expected number of re-transmissions in a multi-hop scenario. This is then used to calculate the expected end-to-end delay. The prediction by the proposed model is compared to the simulation results, and shows close correlation for the different test cases with different arrival rates.

• Journal of the Korean Society of Food Culture
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• v.19 no.4
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• pp.399-406
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• 2004

The extracts 70% acetone from chestnut inner shell, pine needle and hop flower were added to soybean oil, lard, soybean oil-water emulsion and lard-water emulsion in order to test the antioxidant activity compared with ${\alpha}-tocopherol$, respectively. Induction period was determined by Rancimat and the antioxidant activities were recorded in the order of pine needle>chestnut inner shell>hop>tocopherol in the soybean oil, and in the order of tocopherol>chestnut inner shell>pine needle>hop in the lard treatment. These three extracts showed similar high antioxidant activity by peroxide value test in soybean oil, soybean oil-water emulsion, lard and lard water emulsion, respectively. The chestnut inner shell extract would be the highest antioxidant agent among the extracts tested in this study. Ellagic acid of chestnut inner shell and flavanol of pine needle would increase the antioxidant activity according to analysis result of polyphenol compound, respectively.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.1
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• pp.35-45
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• 2014

The driving environment of the vehicle has characteristics that the change of position, velocity and distance between vehicles is severe. The performance test of system must be carried out in the real road environments with consideration of the driving environment of vehicles to measure the performance correctly because the performance of vehicular communication systems is affected by the driving conditions of the vehicle. In this paper, we propose the test methods of V2V/V2I performance and V2V multi-hop transmission function and present the test results measured by the vehicular communication systems already developed. In the test result, we confirmed the fact that the distance of communication devices and the driving direction of vehicle are affecting the communication performance. We also confirmed the multi-hop transmission function using the driving vehicle in the limited area as the proposed test method.