• 한국멀티미디어학회논문지
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• 제17권12호
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• pp.1430-1436
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• 2014

We propose an algorithm which detects the touch of the fingertip on a general wall using the shadow information. Nowadays, there is a demand for presentation systems which can perceive the presenter's action so that the presenter can use natural movements without extra interface hardware. One of the most fundamental techniques in this area is the detection of the fingertip and the recognition of the touch of the fingertip on the screen. The proposed algorithm recognizes the touch of the fingertip without using the depth information, and therefore needs no depth or touch sensing devices. The proposed method computes the convex hull points of both the fingertip and the shadow of the fingertip, and then computes the distance between those points to decide whether a touch event has occured. Using the proposed method, it is possible to develop a new projector device which can perceive a fingertip touch on a general wall.

• Journal of Computational Design and Engineering
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• 제1권4호
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• pp.289-297
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• 2014

Although big-sized markers are good for accurate marker recognition and tracking, they are easily occluded by other objects and deteriorate natural visualization and level of immersion during user interaction in AR environments. In this paper, we propose an approach to exploiting the use of rectangular markers to support tangible AR interaction based on fingertip touch using small-sized markers. It basically adjusts the length, width, and interior area of rectangular markers to make them more suitably fit to longish objects like fingers. It also utilizes convex polygons to resolve the partial occlusion of a marker and properly enlarges the pattern area of a marker while adjusting its size without deteriorating the quality of marker detection. We obtained encouraging results from users that the approach can provide better natural visualization and higher level of immersion, and be accurate and tangible enough to support a pseudo feeling of touching virtual products with human hands or fingertips during design evaluation of digital handheld products.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.319-320
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• 2006

In this paper, we propose a vision based system employing two cameras to provide effective touch screen function. The two main processes - determining touch (or no-touch) and contact location of screen plane - are essential for enabling touch screen function. First region of interest is found by using color characteristic and histogram for determining the contact mode. Second, if the hand touches the mirror, the fingertip point in image is found using the correlation coefficient based on the mirror attribute. Subsequently, the fingertip coordinate in image is transformed to the location in mirror plane by using four predefined points (termed as four-point method) and bilinear transform. Representative experimental results show that the proposed system is suited to touch screen.

• 정보처리학회논문지B
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• 제17B권4호
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• pp.287-294
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• 2010

TOF(Time of Flight) 기술은 물체의 3차원 깊이 정보 추출을 가능케 하는 기술 중의 하나이다. 하지만, TOF의 카메라의 출력인 깊이 영상을 이용한 물체의 3차원 위치 추출은 몸이나 손 등 크기가 큰 물체의 경우에는 비교적 신뢰성 있는 결과를 얻을 수 있는데 비하여 크기가 작은 손 끝의 경우에는 신뢰할 수 있는 값을 얻기 힘들다. 본 논문에서는 TOF 카메라에서 육면체 손 모델을 이용하여 수정된 손의 영상에서의 위치 정보와 팔 모델을 이용하여 손 끝의 3차원 좌표를 추정한다. 제안된 방법으로 실험을 한 결과 TOF 카메라의 깊이 영상만을 사용하여 인식한 손 끝의 3차원 위치정보와 비교하여 훨씬 더 향상된 결과를 얻을 수 있었다.

• 한국CDE학회논문집
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• 제18권5호
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• pp.374-383
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• 2013

Various interaction techniques have been studied for providing the feeling of touch and improve immersion in augmented reality (AR) environments. Tangible AR interaction exploiting two types (product-type and pointer-type) of simple objects has earned great interest for cost-effective design evaluation of digital handheld products. When the sizes of markers attached to the objects are kept big to obtain better marker recognition, the pointer-type object frequently and significantly occludes the product-type object, which deteriorates natural visualization and level of immersion in an AR environment. In this paper, in order to overcome such problems, we propose tangible AR interaction using fingertip touch combined with small-sized markers. The proposed approach facilitates the use of convex polygons to recover the boundaries of AR markers which are partially occluded. It also properly enlarges the pattern area of each AR marker to reduce the sizes of AR markers without sacrificing the quality of marker detection. We empirically verified the quality of the proposed approach, and applied it in the process of design evaluation of digital products. From experimental results, we found that the approach is comparably accurate enough to be applied to the design evaluation process and tangible enough to provide a pseudo feeling of manipulating virtual products with human hands.

• Archives of Plastic Surgery
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• 제35권4호
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• pp.483-486
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• 2008

Purpose: Fingertip injuries are the most common hand injuries and may lead to significant disability. Knowledge of fingertip anatomy is mandatory to treat these injuries effectively. All surgical techniques used for coverage of fingertip injuries must be based on the nature of the injury and the patient's age. Many authors have studied the method of fingertip reconstruction because goals of these treatments should include maintaining length, sensibility, motions, and appearance. The purpose of this study is to evaluate the effect of digital artery perforator flap for fingertip reconstruction without aesthetic and functional problems. Methods: From November 2006 to March 2007, the authors performed fingertip reconstruction on 3 fingers of 3 patients, aged between 41 to 54 years (average age, 47 years) using digital artery perforator flap. Results: All fingers recovered successfully and there were no necrosis of the flap. We followed up 3 cases more than 5 months. Light touch and temperature sensation could be detected in all flaps and the static two-point discrimination test was 8 mm. Conclusion: This flap is an alternative choice for coverage of fingertip defects. This method also takes short time to procedure and to recovery. The digital artery perforator flap has never been reported in Korea, however it is considered as a useful method for treatment of fingertip injury.

• The Journal of Korean Physical Therapy
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• 제24권2호
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• pp.134-142
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• 2012

Purpose: This study examined the effect on postural control during the stimulation of haptic touch with fingertip on the stable surface at quiet standing posture, squat flexion stage, 60 degrees squat stage and squat extension stage. Methods: The postural sway was measured on the force platform, while 30 subjects were squatting, under three different haptic touch conditions (No Touch [NT], Light Touch [LT], Heavy Touch [HT]), above the touch pad in front of their body midline. Three different haptic touch conditions were divided into 1) NT condition; squatting as right index fingers held above the touch pad, 2) LT condition (<1N); squatting as the touch pad was in contact with right index fingers pulp with a pressure not exceeding 1N and 3) HT condition; squatting as subjects were allowed to use the touch pad for mechanical support by transmitting onto it with as much force, choosing with their index fingers. Results: There was significant decrease in LT, rather than that of NT (p<0.01), and in HT, rather than that of LT (p<0.01), as the results of the distance and velocity of center of pressure (COP) in mediolateral direction at quiet standing position. In anteroposterior direction, the distance and velocity of COP in LT and HT showed significant decrease, when compared to that of the data of NT (p<0.01). There was no significant difference between the 3 conditions (NT, LT, and HT), with respect to the distance and velocity of COP in mediolateral direction, during dynamic balance (squat flexion stage, squat extension stage) (p>0.05). In anteroposterior direction, the results of the distance and velocity of COP in HT showed significant decrease when compared to that of the data of NT (p<0.05). Conclusion: Light touch, during the task, decreased the postural sway at static balance. The results suggest that haptic touch should be applied, appropriately, because it varies the effects according to different conditions.

• The Journal of Korean Physical Therapy
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• 제5권1호
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• pp.3-8
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• 1993

The purpose of this study was to investigate the specificity of the effort of massage on hamstring muscles extensibility a9 measured by fingertip to floor test. The participant were healthy young men(n=25). Manual massage was applied to the posterior aspects of the both thigh (hamsting portion) during 20 mins. We measured four times ; that is, after rest 20 mins-before massage, immediately after massage, immediately after massage and 20 mins. after massage. As the middle fingers are reaching beyond the floor level, the level was considered as ( + ) level. And the middle fingers did not touch the 리oor, the level was considered as ( - ) level. Results were as fellows : 1) There was significant difference between group 1 and group 2(P<0.05), 2) There was no significant difference between group 2 and group 3(P>0.05). 3) There was no significant difference between group 3 and group 4(P>0.05). Therefore, the extensibility of hamstring muscles was increased after massage more than rest during 20 mins, before massage, and the effects of massage application were prolonged during 20 mins, after massage.

• 한국멀티미디어학회논문지
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• 제13권2호
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• pp.316-323
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• 2010

본 논문에서는 증강현실 응용을 위한 손 끝점 추출과 손 동작 인식 기법을 제안한다. 먼저 RGB 컬러 영역에서 HSV 컬러 영역으로 영상을 변환하고, H, S 값에 대한 이중 임계값과 영역 확장 기법, 연결 요소 분석을 이용한 손을 분할한다. 다음으로 가상 키보드와 마우스의 입력을 위해서 모폴로지 연산과 감산을 통하여 검지와 엄지 손가락 끝점을 추출한다. 마지막으로 마우스 버튼 클릭의 역할을 하기 위하여 손바닥의 무게중심점에 대한 엄지와 검지 손가락 끝점의 각도를 계산하여 엄지와 검지 손가락의 떨어지고, 붙는 동작을 인식한다. 다양한 입력 영상들에 대한 실험 결과는 제안 기법이 고속으로 정확하게 손을 분할하고, 손 끝점을 추출하여 손 동작을 인식할 수 있음을 보여주었다. 제안 기법은 증강 현실 응용을 위한 정보 입력 인터페이스로 사용될 수 있다.

• Physical Therapy Rehabilitation Science
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• 제5권3호
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• pp.138-142
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• 2016

Objective: The purpose of this study was to investigate how light touch with a finger affects balance ability when a posture is maintained in the condition of visual information blockage and to provide a fundamental material for developing balance ability in the process of rehabilitation treatment. Design: Cross-sectional study. Methods: The study subjects were 17 healthy men and women in their twenties and thirties who were studying at S University in Seoul. The system was comprised of an equilateral triangular force platform. Subjects were asked to step on the foot position of the force platform (Good Balance, Finland) barefooted for 30 seconds, with eyes closed, hands hanging down loosely, and feet comfortably apart. It was connected to a laptop by using Bluetooth technology. An experiment was conducted in the following three circumstances: 1) no-touch trial, 2) light touch to the back (T7 area), and 3) light touch to the middle finger of the left hand. Each subject was given a 10-minute break between consecutive measurements. The experimental circumstances were performed randomly. Anteroposterior sway (APSV), mediolateral sway velocity (MLSV), and velocity moment (VM) were measured. Results: The APSVs (mm/s) were $9.32{\pm}3.37$ and $5.45{\pm}2.98$; the MLSVs (mm/s), $6.39{\pm}3.35$ and $3.31{\pm}2.48$; and VM ($mm^2/s$), $17.13{\pm}11.75$ and $6.76{\pm}8.31$ in the first and second experimental circumstances, respectively. APSV, MLSV, and VM values were significantly improved with the 1) no-touch trial and 2) light touch to the back trail conditions compared with the 3) light touch to the middle finger of the left hand condition (p<0.05). Conclusions: This study revealed that the balance ability for maintaining a body posture was influenced more by light touch to the back (T7) than by light touch with the sensitive fingertip and body sway diminished after visual information was blocked.