• 산업경영시스템학회지
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• 제25권4호
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• pp.46-53
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• 2002

Push-pull strength has been found to be associated with various work factors such as height, distance, repetition, duration, posture and individual factors. Therefore, this study was performed to investigate the effect of various work factors on push-pull strength and muscle recruitment pattern. Work factors were consisted of grip height(elbow, shoulder), grip distance(100%, 50%, and 25% of maximum grip distance) and shoulder angle(neutral($90^{\cire}$), and abduction($45^{\cire}$, $0^{\cire}$)) during sitting work. The results showed that the normalized strength and EMG value were higher at the elbow height than the shoulder height, and increased with grip distance and shoulder adduction. The results of ANOVA showed that there was significant difference on muscle recruitment patterns among the task conditions. Therefore, it is necessary to consider work factors as well as strength to prevent workers from work-related injuries.

• 국제물리치료학회지
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• 제4권1호
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• pp.532-538
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• 2013

The purpose of this study is to analyze the grip strength by the girth of upper arm and forearm and their muscle activities by duration of grip strength. The subjects were consisted of 20 healthy adults(10 males & 10 females) who had no medical history of neurological and surgical problems with their arms. Girth of upper arm/ forearm and maximum grip strength for 4sec and 30sec were measured. Muscle activity was by wireless electrode EMG system. Co-relation of girth of upper arm/ forearm was significantly high. Upper arm's muscle activity performed for 4sec and 30sec was significantly high. In this study. It suggests that training of upper arm should be performed with the training of grip strength because both of upper arm and forearm affected grip strength.

• 한국지능시스템학회논문지
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• 제26권1호
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• pp.30-36
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• 2016

디지털 도어록 시장이 활성화 되면서 생체인식기술과 스마트폰 등을 인증 수단으로 사용하는 보다 편리한 도어록 시스템이 개발되고 있다. 디지털 도어록의 성능은 보안성과 편리성이라는 두 가지 서로 상충되는 요소에 의해 결정된다. 본 논문에서는 편리성을 유지하면서 보안성을 높일 수 있는 하나의 방법으로 인증 수단을 문고리에 통합하는 원그립 기반 디지털 도어록의 디자인을 제안하고 구현하였다. 제안된 원그립 기반 문고리 통합형 도어록 시스템에서는 사용자가 문을 열기 위해 문고리를 잡는 한 번의 동작만으로 지문인식과 터치 센서를 이용한 그립패턴 인식을 순차적으로 진행하여 보안성을 한 단계 높이면서도 사용상의 편리성은 그대로 유지할 수 있다. 제안된 방법은 디지털 도어록 시스템 자체의 성능 개선 뿐 아니라 앞으로 더욱 활성화 될 것으로 예상되는 스마트 도어록 분야에서 스마트폰을 분실했을 때 발생하는 문제를 해결할 수 있을 것으로 기대한다.

• 대한인간공학회지
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• 제28권2호
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• pp.27-34
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• 2009

The purpose of this study was to evaluate aging (young and old), gender (male and female), and handle shape effects on grip force, finger force, and subjective comfort. Four handle shapes of A, D, I, and V were implemented by a multi-finger force measurement (MFFM) system which was developed to measure every finger force with different grip spans. Forty young (20 males and 20 females) and forty old (20 males and 20 females) subjects participated in twelve gripping tasks and rated their comfort for all handles using a 5-point scale. Grip forces were calculating by summation of all four forces of the index, middle, ring and little fingers. Results showed that young males (283.2N) had larger gripping force than old males (235.6N), while young females (151.4N) had lower force than old females (153.6N). Young subjects exerted the largest gripping force with D-shape due to large contribution of the index and middle fingers and the smallest with A-shape; however, old subjects exerted the largest with I-shape and the smallest with V-shape due to small contribution of the ring and little fingers. As expected, the middle finger had the largest finger force and the little finger had the smallest. The fraction of contribution of index and ring fingers to grip force differed among age groups. Interestingly, young subjects provided larger index finger force than ring finger force, whereas old subjects showed that larger ring finger forces than index finger force in the griping tasks. In the relationship between performance and subjective comfort, I-shape exerting the largest grip force had less comfort than D-shape producing the second largest grip force. The findings of this study can provide guidelines on designing hand tool handle to obtain better performance as well as users' comfort.

• 한국방사선학회논문지
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• 제15권3호
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• pp.321-327
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• 2021

Wrist PA-grip view는 주변 인대들의 손상을 쉽게 진단할 수 있기 때문에 삼각섬유연골 파열 진단에 시행한다. 그러나 의료장비 기술의 발전에도 불구하고 기하학적 요소에 따른 영상의 왜곡은 아직까지도 많은 제한점이 있다. 본 논문에서는 정확한 Wrist PA-grip view 검사를 위해 현재 사용되고 있는 검사방법에서 발생되는 왜곡을 분석하여 영상의 왜곡을 최소한으로 감소시킬 수 있는 검사방법을 제시하고자 한다. Wrist PA-grip view를 재현하기 위하여 인체모형 팬텀을 사용하였고 source of image distance (SID)는 110 cm와 임의로 정해놓은 130 cm, 150 cm로 설정하였다. 각 SID에 따라서 손목 팬텀을 x축 방향 및 y축 방향으로 각각 0, 2, 4, 6, 8, 10 cm 이동하였다. 정량적 평가를 하기 위해 손목 팬텀의 이동 시 마다 자뼈와 노뼈의 먼쪽관절면의 거리의 차이를 picture archiving and communication system (PACS) system을 통해 측정하였다. 정성적 평가로는 방사선사 20명을 대상으로 설문조사를 실시하였다. SID에 따라 나뉜 세 그룹 간의 x축과 y축 방향의 움직임에 따른 왜곡도를 비교하기 위해 Kruskal Wallis test 통계기법을 시행하였으며 사후검정으로 Tukey test를 시행하였다. 정량적 평가 결과에서 x축 방향으로 이동하여 얻은 측정값은 모든 그룹에서 유의한 차이를 보이지 않았다 (p>0.05). y축 방향으로 이동하여 얻은 측정값은 대부분의 그룹에서 유의한 차이를 보였다 (p<0.05). 영상에서 왜곡이 임상적 진단과 수술에 많은 영향을 미치는 검사의 경우, 보다 정확한 진단을 위해 영상 후처리로 영상의 질을 유지하는 한도 내에서 기존의 SID인 110 cm 보다는 150 cm에서 검사하여 왜곡을 감소시키기를 제안하는 바이다.

• The Journal of Korean Physical Therapy
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• 제15권4호
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• pp.312-318
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• 2003

The purpose of this study were to determine the effect on grip and pinch strength with elbow and wrist angle change. 112 college students, 88 males, and 24 females aged 19 to 34 years, participated in the study. A Grip and pinch strength was measured in two elbow position($0^{\circ}$ and $90^{\circ}$) and three wrist position($80^{\circ},\;0^{\circ},\;23^{\circ}$). The data were analyzed by mean and deviation, and t-test using the PC/SAS system. These results were obtained as follows; 1. There was a more strength grip and pinch power in $0^{\circ}$ than $90^{\circ}$ elbow flexion at three wrist angle. 2. There was a significant high grip and pinch strength in $23^{\circ}$ dorsiflexion among three wrist angle(p<0.01). 3. The grip and pinch strength power was measured higher in male than female every elbow and wrist angle(p<0.01).

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.1038-1042
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• 2003

In order to evaluate dynamic impedance of a hand-arm system it is necessary to measure the hand-transmitted vibration and the reaction force at the same time while gripping the vibrating handle. In the study a device was developed to measure both the vibration and the force. The device consists of a measurement handle with four strain gauge and two accelerometers and a PC based control system with a program for the signal processing and evaluation of the hand-transmitted vibration and reaction force. The handle was installed on the vibration shaker so that it can move by the generated signal from the control system. As an application of the system dynamic reaction force and the frequency weighted acceleration at the handle attached to the shaker were measured at various grip force and feed force. This system will be very useful in the area of impedance measurement and the evaluation of performance of anti-vibration gloves.

• 대한기계학회논문집A
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• 제35권5호
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• pp.459-467
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• 2011

상지 운동기능 장애인의 재활치료에 대한 지속적인 관심과 훈련의 정량적인 평가가 요구되고 있다. 이러한 문제를 해결하기 위해서 햅틱 장치를 개발했다. 피험자가 햅틱 장치의 손잡이를 움직일 때, 가상의 힘을 제시하여 그들의 동작에 대해 어시스트력이나 항력을 제시할 수 있다. 개발한 상지 운동훈련 프로그램과 시스템의 유효성을 검토하기 위해, 5 명의 운동기능 장애인을 대상으로 직선동작 훈련 프로그램을 수행할 때의 손잡이 위치, 수행 속도, 손잡이의 오차 및 상지의 EMG 신호를 측정하였다. 5 명의 피험자의 손잡이의 궤적 및 EMG 활동이 유사함을 보였다. 이러한 결과는 가상 현실의 힘을 손잡이에 제시함으로써 EMG 활동이 증가하였다고 볼 수 있다. 본 실험의 결과, 객관적이며 정량적인 상지 재활치료 시스템의 개발 및 평가 방법이 시사되었다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제6권4호
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• pp.304-313
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• 2006

This paper describes a novel way of applying capacitive sensing technology to a mobile user interface. The key idea is to use grip-pattern, which is naturally produced when a user tries to use the mobile device, as a clue to determine an application to be launched. To this end, a capacitive touch sensing system is carefully designed and installed underneath the housing of the mobile device to capture the information of the user's grip-pattern. The captured data is then recognized by dedicated recognition algorithms. The feasibility of the proposed user interface system is thoroughly evaluated with various recognition tests.

• 한국기계가공학회지
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• 제10권2호
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• pp.96-103
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• 2011

Rotor grip is used as a component of rotor system in unmanned helicopter. Instead of usual machining, hot forging process has been considered to improve its proof stress against repeated loading conditions and crash in the farm-field. Die design and forming analysis have been performed according to the conditions such as billet volume, flash, cavity filling, and the distribution of damage during the forming by using FE analysis. In the results of analysis, the possibility of structural failure in the model has not been found because its maximum effective stress is much lower than yield strength of the titanium alloy. In the forging die design, flash has been allowed because of low production in the industrial field. Preform design was studied by using FE-analysis, and its optimal dimension was obtained in the hot forging of rotor grip with titanium alloy.