• The Journal of the Acoustical Society of Korea
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• 제18권2E호
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• pp.45-52
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• 1999

This paper presents the integrated speech enhancement system for hands-free mobile communication. The proposed integrated system incorporates both acoustic echo cancellation and engine noise reduction device to provide signal enhancement of desired speech signal from the echoed plus noisy environments. To implement the system, a delayless subband adaptive structure is used for acoustic echo cancellation operation. The NLMS based adaptive noise canceller then applied to the residual echo removed noisy signal to achieve the selective engine noise attenuation in dominant frequency component. Two sets of computer simulations are conducted to demonstrate the effectiveness of the system; one for the fixed acoustical environment condition, the other for the robustness of the system in which, more realistic situation, the acoustic transmission environment change. Simulation results confirm the system performance of 20-25dB ERLE in acoustic echo cancellation and 9-19 dB engine noise attenuation in dominant frequency component for both cases.

• Annals of Clinical Neurophysiology
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• 제13권1호
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• pp.38-43
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• 2011

Background: In the brain, the dominant primary motor cortex (M1) has a greater hand representation area, shows more profuse horizontal connections, and shows a greater reduction in intracortical inhibition after hand exercise than does the non-dominant M1, suggesting a hemispheric asymmetry in M1 plasticity. Methods: We performed a transcranial magnetic stimulation (TMS) study to investigate the hemispheric asymmetry of paired associative stimulation (PAS)-induced M1 plasticity in 9 right-handed volunteers. Motor evoked potentials (MEPs) were measured in the abductor pollicis brevis (APB) muscles of both hands, and MEP recruitment curves were measured at different stimulation intensities, before and after PAS. Results: MEP recruitment curves were significantly enhanced in the dominant, but not the non-dominant M1. Conclusions: These results demonstrate that the dominant M1 has greater PAS-induced plasticity than does the non-dominant M1. This provides neurophysiological evidence for the asymmetrical performance of motor tasks related to handedness.

• 한국융합학회논문지
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• 제12권12호
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• pp.323-330
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• 2021

본 연구에서는 10명의 건강한 성인을 대상으로 기능적 근적외선 분광법(fNIRS)을 이용하여 우세손과 비우세손에 따른 뇌 활성화도의 차이를 알아보고자 하였다. 우세손, 비우세손 총 2가지 조건에서 상자와 나무토막검사(BBT)를 실시하였다. 실험을 진행하는 동안 fNIRS을 이용하여 뇌 활성도를 측정하였으며, 실험이 종료된 후 nirsLAB v2019.04 소프트웨어를 사용하여 신호를 분석하였다. 그 결과 우세손을 사용한 경우 10명 중 6명이 우세손과 관련 있는 대뇌반구의 활성화를 보였고, 비우세손을 사용한 경우는 10명 중 3명만이 비우세손과 관련 있는 대뇌반구의 활성화를 보였다. 즉, 우세손, 비우세손 모두 우세손과 관련 있는 대뇌반구가 좀 더 활성화되었음을 확인하였다. 따라서 우세손을 알기 어려운 감각처리장애를 가진 아동들에게 fNIRS을 적용할 수 있는 기초적 자료로 사용될 수 있으리라 사료된다.

• ETRI Journal
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• 제38권2호
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• pp.366-375
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• 2016

This paper describes an algorithm to suppress composite noise in a two-microphone speech enhancement system for robust hands-free speech communication. The proposed algorithm has four stages. The first stage estimates the power spectral density of the residual stationary noise, which is based on the detection of nonstationary signal-dominant time-frequency bins (TFBs) at the generalized sidelobe canceller output. Second, speech-dominant TFBs are identified among the previously detected nonstationary signal-dominant TFBs, and power spectral densities of speech and residual nonstationary noise are estimated. In the final stage, the bin-wise output signal-to-noise ratio is obtained with these power estimates and a Wiener post-filter is constructed to attenuate the residual noise. Compared to the conventional beamforming and post-filter algorithms, the proposed speech enhancement algorithm shows significant performance improvement in terms of perceptual evaluation of speech quality.

• 한국전문물리치료학회지
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• 제14권4호
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• pp.91-98
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• 2007

In this study, 1,933 Korean male and female subjects ranging in age from 10 to 82 were selected to investigate the various statistics about hand dominance and employment characteristics of preferred hand in handling diverse products and facilities. The statistics show that 5.6% are left-handed and 7.6% are ambidextrous. The average left-hander has a strong tendency to use his or her left hand more often when taking a forceful action than one that requires accuracy. On the contrary, the average ambidextrous or right-handed person generally uses his or her right hand more with action that requires accuracy than force. Derived from such results, the conclusion is that depending on which hand is the dominant one, people seem to use their hands differently when they handle objects and is a point that should be considered in designing hand control devices.

• 인간식물환경학회지
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• 제24권3호
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• pp.277-283
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• 2021

Background and objective: This study was conducted to increase understanding of agriculture through agricultural experience programs for adolescents living in self-reliance residence hall, and to investigate changes in work performance ability through changes in hand function. Methods: There were 11 subjects, and the average age was 18.2 years, all males without disabilities. The agricultural experience program consists of a total of 10 sessions including orientation and watching videos on future agriculture, creating vegetable gardens, planting, managing each crop, harvesting, visiting the processing room, and selling at a local food store. Results: The change in agricultural literacy by the agricultural experience program positively improved from a score of 113.73 to 127.91 (p = .008). The changes by sub-item are as follows. The value and safety of agri-foods (p = .020) and agriculture and natural environment (p = .007) were significantly improved. The function and value of rural areas (p = .050), production of agricultural products (p = .160), processing and distribution of agricultural products (p = .248), and agricultural policies (p = .058) were not significantly changed. The simple function of the hands was measured by the number of pegs inserted during 30 seconds, and the assembly function was measured by the number of pegs inserted during 60 seconds. In the case of simple function, the dominant hand was improved from 14.82 to 15.83 (p = .014), andthe non-dominant hand was also significantly improved from 13.79 to 15.01 (p = .002). There was no significant improvement in the simple function (p = .153) and assembly function (p = .770) of both hands. Conclusion: It is considered that the agricultural experience program will enable youths living in self-reliance residence halls to enhance their understanding of agriculture as an occupation, and enable them to play a role as wise consumers by positively affecting improvements in their agricultural literacy and simple hand functions.

• 한국전문물리치료학회지
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• 제12권4호
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• pp.7-11
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• 2005

The purposes of this study were to investigate the effects of variability of training on the acquisition of motor skill of closed loop type tracking task using Rotary Pursuit, and to determine if there was a bilateral transfer effect to the non-dominant hand following practice with the dominant hand. Twelve healthy volunteer students (5 males and 7 females, aged 25 to 37) were randomly divided into a constant practice group and a variable practice group. A photoelectric rotary pursuit apparatus with stop clock and repeat cycle timer by Lafayette Instrumentation Co. was used for this study. Rotary pursuit is a closed loop task in which a subject attempts to keep a photoelectric stylus on a lighted target in motion. Subjects performed the clockwise circular pursuit task while standing. Experimental procedure was divided into three sessions, namely, pre-test, training, and post-test. The constant group practiced all 60 trials at 30 rpm. Variable practice group did a varied practice session with 15 trials at speeds of 20 rpm, 26 rpm, 34 rpm, and 46 rpm. No one in either group practiced with their non-dominant arm. A Mann-Whitney test and a Wilcoxon Signed Ranks test were used for statistical analyses. The results of this study showed no different training effect between groups on the post-test with the dominant hand. However, bilateral transfer effect of rotary pursuit task between hands was demonstrated. Possible mechanisms are discussed.

• International Journal of Contents
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• 제16권1호
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• pp.57-64
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• 2020

We sought to compare upper extremity muscle activity between handwriting on paper and touchscreen with dominant and non-dominant hands in younger adults (age 23.90±1.12) and the elderly (age 75.55±5.76). Muscle activity (percent of maximum voluntary contraction) in the biceps brachii muscle, triceps brachii muscle, flexor carpi ulnaris muscle, and extensor carpi ulnaris muscle was measured using an electromyography device. As a result, our data indicate that muscle activity is lower in younger adults than the elderly. Besides, muscle activity is lower in the dominant versus non-dominant hand, and lower when writing using a touchscreen than on paper. These results can be used to support recommending touchscreens in the elderly. Also, they can be used as baseline data for comparing the performance of non-paretic side and paretic side in patients relative to the central nervous system.

• 한국안광학회지
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• 제16권3호
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• pp.333-338
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• 2011

Purpose: The aim of this study was to investigate eye dominance and reading performance based on eye movements and reading speed. Methods: The eye dominance of 30 subjects was determined using the sighting test (hole formed by hands). The subjects were asked to read the numerical reading material aloud in English from left to right and from right to left at random. The number of saccades, regressions, and inter-fixations per minute was calculated using Visual-Oculography (VOG) and the reading speed was recorded as number of characters per minute using stopwatch. Results: No significant differences in reading speed among right and left eye dominant subjects as they read from left to right and right to left directions (p>0.05). However, left eye dominant subjects were found to read significantly faster compared to right eye dominant subjects in both directions of reading (p<0.05). In term of eye movement patterns, no significant differences in saccades, regressions, and inter-fixations per minute were found between subjects with right eye dominance and left eye dominance for both reading directions (p>0.05). Conclusions: Reading performance in term of eye movement and speed was not affected by eye dominance, but subjects with left eye dominance read faster than subjects with right eye dominance.

• 대한통합의학회지
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• 제4권2호
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• pp.77-88
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• 2016

Purpose : The purpose of this study was to explore an effect exerted to non-affected hand and affected hand of patients by performing training of chopsticks and grasp strength that are helpful to dexterity and grasp strength of hand together with training method of joint exercise, muscle strength build-up training, delicate hand function training. Method : By targeting 30 normal adult male/females engaged in K university, Busan for one month on April, 2015, 10 persons of hand function build-up training group, that of dexterity training group and 10 persons of control group were randomly selected. For hand function build-up training group, chopsticks training in parallel with total 20 times of grasp strength training for 4 weeks including 5 minutes of dominant hand grasp strength training, 5 minutes of non-dominant hand grasp strength training, 15 minutes of chopsticks training was performed based on 25 minutes/one time, 5 times a week. Result : First, In a comparison of dexterity of both hands by each group depending on training period, hand function build-up group and dexterity training group were represented to be effective compared with control group. Secondly, In a comparison of manipulatory ability of both hands by each group depending on training period, hand function build-up group and dexterity training group were represented to be effective compared with control group. Conclusion : It is considered that diversified and broad research covering patients with musculoskeletal disease and nervous system-related disease would be performed by securing far more test subjects after comparing a correlation between dexterity training and hand function training.