• Physical Therapy Rehabilitation Science
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• 제5권1호
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• pp.15-21
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• 2016

Objective: The purpose of this study was to see the changes in muscle activity of the upper limb in persons using a smartphone. Design: Cross-sectional study. Methods: An experiment was conducted to target 15 right-handed university students. Experiments were carried out for students using cell phones for more than a year. In this study, experiments were carried out with one-handed and both handed operation of smartphone use in a sitting position, the same parameters with smartphone use in a standing position. The experiments were carried out by having the subjects write a text message in Korean on the smartphone for 3 minutes repeated 3 times with a rest period of 10 seconds given between each 3 minute period. Electromyography (EMG) was used to record the muscle activity of the upper trapezius (UT), extensor carpi radialis (ECR), and abductor pollicis (AP) during phone operation. Results: The muscle activity of the AP and ECR were significantly higher during single handed compared to double handed in both sitting and standing position (p<0.05). The muscle activity of the ECR was significantly higher in standing position compared to sitting position with double handed use of the smartphone (p<0.05). UT muscle activity of the right has been activated more than twice compared to the left UT in a sitting position (p<0.05). And UT muscle activity on the right has been activated more than five times compared to the left in a standing position (p<0.05). Conclusions: Using smartphone with double hand is useful for the prevention of musculoskeletal disorders.

• 대한전자공학회논문지TC
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• 제44권12호
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• pp.16-21
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• 2007

본 논문에서는 Composite Right/Left-Handed (CRLH) 전송 선로 (TL)와 pin 다이오드를 이용한 조절 가능한 부성 저항을 이용한 이중 대역 전압 제어 발진기에 대하여 연구하였다. CRLH 전송 선로는 이중 대역 주파수 조절 특성을 갖는 metamaterial 전송 선로를 만들 수 있다. CRLH 전송 선로의 이중 대역 동작은 CRLH 전송 선로의 주파수 오프셋과 위상 기울기에 의해서 얻어지고, 두 개의 동작 주파수들의 주파수 비율은 정수 배가 아닐 수 있다. 전압 제어 발진기의 각각의 주파수 대역은 독립적으로 동작해야 하므로 pin 다이오드를 이용한 조설 가능한 부성 저항을 사용하였다. 정전압을 pin 다이오드에 인가하였을 때, 전압 제어 발진기의 위상 잡음은 주파수 조절 범위 $2.423\sim2.597$ GHz에서 $-108.34\sim-106.67$ dBc/Hz @ 100 kHz이며, 역전압을 pin diode에 인가하였을 때는, 전압 제어 발진기의 위상 잡음이 주파수 조절 범위 $5.137\sim5.354$ GHz에서 $-114.16\sim-113.33$ dBc/Hz @ 100 kHz이다.

• 대한전자공학회논문지TC
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• 제45권8호
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• pp.53-59
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• 2008

본 논문에서는 composite right/left-handed (CRLH) 전송 선로를 이용하여 하나의 RF Si LDMOSFET으로 새로운 이중 대역 고효율 class-F 전력증폭기를 구현하였다. CRLH 전송 선로는 이중 대역 조절 특성을 갖는 메타물질 전송 선로를 만들 수 있다. CRLH 전송 선로의 이중 대역 동작은 전력증폭기의 정합 회로 구현을 위하여 주파수 오프셋과 CRLH 전송 선로의 비선형 위상 기울기에 의해서 얻을 수 있다. 이중 대역에서 모든 고조파 성분을 조절하는 것은 매우 어렵기 때문에, CRLH 전송 선로를 이용하여 이중 대역에서 고효율 특성을 얻도록 오직 2차, 3차 고조파 성분만을 조절하였다. 또한, 제안된 전력증폭기의 효율을 더욱 더 향상시키기 위하여 출력 정합 회로뿐만 아니라, 입력 정합 회로도 고조파 조절 회로를 이용하여 구현하였다. 두 동작 주파수는 880 MHz와 1920 MHz로 정하였다. 전력증폭기의 측정된 출력 전력은 각각 880 MHz에서 39.83 dBm, 1920 MHz에서 35.17 dBm이다. 이 지점에서 얻은 전력 효율, PAE는 880 MHz에서 79.536 %, 1920 MHz에서 44.04 %이다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1991년도 춘계학술대회
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• pp.71-73
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• 1991

In this study electrical impedance plethysmograph was developed and each ten digital blood flow was measured for eight normal males and a patint with digital arterial reconstruction surgery. Blood flow of the digit with surgery was approximately fourty percent compared to that of the other normal digit. For the normal subjects, right-handed subjects generally have larger blood flow in right fingers than that in left fingers while it was reverse for the left-handed subjects. The relative average magnitude of the digital blood flow is the third, first, second, fourth, and fifth digit in descending order for the left and right hand, respectively. Blood flow of the fifth digit for all subjects except one was the smallest among the five digits.

• 대한의용생체공학회:의공학회지
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• 제12권1호
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• pp.23-28
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• 1991

In this study electrical impedance plethysmograph was developed and each ten digital blood flow was measured for eight nomal males and a patient tvith digital arterial reconstruction surgery. Blood flow of the digit with surgery was approximately fourty percent compared to that of the other normal digit. For the normal subjects, right - handed subjects generally have larger blood flow in right fingers than that in left fingers while it was reverse for the left - handed subjects. The relative average magnitude of the digltal blood flow Is the third, first, second, fourth, and fifth digit in descending order for the left and rich hand, respectively. Blood flow of the fifth digit for all subjec!s except one was the smallest among the five digits.

• Journal of Electrical Engineering and Technology
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• 제11권4호
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• pp.943-950
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• 2016

In this paper, we propose to analyze the physical characteristics of a planar dual-composite right-left handed transmission line by a common application of Bond Graph approach and Scattering formalism (Methodology S.BG). The technique, we propose consists, on the one hand, of modeling of a dual composite right-left metamaterial transmission line (D-CRLH-TL) by Bond Graph approach, and, it consists of extracting the equivalent circuit of this studied structure. On the other hand, it consists to exploiting the scattering parameters (Scattering matrix) of the DCRLH-TL using the methodology which we previously developed since 2009. Finally, the validation of the proposed and used technique is carried out by comparisons between the simulations results with ADS and Maple (or MatLab).

• 대한인간공학회지
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• 제30권1호
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• pp.259-264
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• 2011

Does preferred hand show better performance than non-preferred hand in smart phone text entry using one hand. Is the performance of subjects who use left-preferred hand in smart phone text entry worse than that of others who use right preferred hand among the right handed. This study tried to address these two questions. Thirty young male undergraduate students typed a text using a smart phone which has a touch-based QWERTY keyboard two times with both hands, right and left hand, respectively. The completion time, errors were measured in the text entry tasks. All of participants were right handed, but half of them preferred right hand if they have to use one hand in smart phone text entry and other half preferred left hand. The percentage that preferred hand has better performance than non-preferred hand in smart phone text entry using one hand is less than 90% for right-preferred hand and less than 70% for left-preferred hand. The performance of left hand preferred students is not worse than that of the right hand preferred in one hand text entry of smart phone.

• 한국전자파학회논문지
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• 제25권2호
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• pp.156-163
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• 2014

본 논문에서는 composit right-left handed (CRLH) 전송 선로에서 발생하는 -1 모드를 이용하여 십자 개구 결합 급전을 갖는 소형 원형 편파 메타 물질 안테나를 제안한다. -1 모드는 일반적인 패치 안테나의 기본 모드인 $TM_{010}$ 모드와 동일한 성질을 가지고 있기 때문에, 원형 편파의 동작원리를 동일하게 적용할 수 있다. 원형 편파는 두 개의 수직인 모드가 $90^{\circ}$의 위상 차이를 가질 때 형성된다. 두 개의 -1 모드를 얻기 위해서 사각형 형태를 갖는 4개의 버섯 구조를 이용하였고, 모드 간에 $90^{\circ}$의 위상차를 인가하기 위해서 십자형 개구의 폭과 길이를 최적화 하였다. 제작된 안테나의 4개로 배열된 버섯 구조의 면적은 $0.34{\lambda}_g{\times}0.34{\lambda}_g$이며, RT/duroid5880 기판에 설계되었다. 제안된 안테나의 중심 주파수는 좌수 원형 편파 안테나의 경우 1.622 GHz 원형 편파의 3 dB 대역폭은 3 MHz로 측정되었다. 우수 원형 편파 안테나의 경우, 중심 주파수는 1.609 GHz로 원형 편파의 3 dB 대역폭은 3 MHz로 측정되었다. 각각 안테나의 효율은 좌수 원형 편파 안테나의 경우 61.1 %, 우수 원형 편파 안테나의 경우 54.5 %로 측정되었다.

• 한국ITS학회 논문지
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• 제14권6호
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• pp.117-124
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• 2015

본 논문에서는 새로운 기법의 광대역 저손실 CRLH(composit right/left handed) 전송선로와 윌킨슨 전력 분배기에 대해 제안한다. 전송선로는 평형 미엔더 인덕터와 직렬 캐패시터로 구성된 coplanar 도파관 (CPW)으로 구성되며, 전력 분배기는 CRLH 전송선로를 일반 전송선로 부분에 대체하여 설계를 한다. 실험 결과 동작 주파수 대역 8.4 GHz 에서 30.0 GHz내에서 반사손실은 12 dB 이하로써 비교적 만족한 결과를 얻었다. 전력 분배기의 주파수는 12.05에서 13.15 GHz 그리고 16.50에서 19.30 GHz 로써 대역폭은 20 dB 기준으로 8.9 % 및 17.9 % 이며 이는 측정결과와 시뮬레이션 결과와 비교를 하였을 때 상당히 일치하는 것을 알 수 있다.

• 한국전문물리치료학회지
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• 제26권2호
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• pp.24-33
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• 2019

Background: Spontaneous use of the upper extremities on the affected side of patients with stroke is a meaningful indicator of recovery and may vary by the age or dominant hand of patients. No prior study has reported changes in actual amount of use test (AAUT) and motor activity log (MAL)-28 according to age and handedness in healthy adults, and AAUT inter-rater reliability for assessment of healthy adults. Objects: This study aimed to (1) research the differences in AAUT and MAL-28 according to age and handedness in healthy adults, and (2) determine the inter-rater reliability of the AAUT. Methods: Seventy healthy adults participated in this study. The MAL-28 was assessed by dividing 61 subjects into young right-handed ($n_1=20$), young left-handed ($n_2=21$), and older right-handed ($n_3=20$) groups. The AAUT was assessed by dividing 63 subjects into young right-handed ($n_1=25$), young left-handed ($n_2=18$), and older right-handed ($n_3=20$) groups. Student's t-test and the Wilcoxon signedrank test were used for statistical analysis. Results: The Amount of Use (AOU) scale values for each group showed no significant differences between age groups and handedness groups in the MAL-28 (p>.05). The AAUT AOU scale value showed significant differences regarding dominant handedness in the AAUT (p<.05), but no significant differences according to age (p>.05). (2) Inter-rater reliability of the AAUT was excellent, except few items (item 9, 11, and 12). Conclusion: Although both the MAL-28 and the AAUT measured how much participants used their dominant arms in healthy subjects, the AAUT only showed significantly higher dominant arm use in left hander than the right hander. In addition, the inter-rater reliability of the AAUT was excellent. Current results can be utilized as a basic information when clinicians develop rehabilitation strategies, and AAUT was shown to be a reliable evaluation tool for measurement of upper extremity use in Korean adults, based on the reliability demonstrated by this study.