• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.137-138
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• 2012

• 한국정밀공학회지
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• 제29권12호
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• pp.1290-1295
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• 2012

Oblique astigmatism according to the rotation of the eye has to be removed for obtaining peripheral clear vision in ophthalmic lenses. For this reason, we calculated tangential and sagittal power using third-order approximation theory and then controlled conic constant for the difference of the two powers to converge to 0 regardless of the rotation angle of the eye. As a result, an aspherical ophthalmic lens without oblique astigmatism was designed. Also, we found optimal machining condition to the lens material using factorial design and finally fabricated the designed lens through ultra-precision machining with that condition.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(5)
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• pp.17-20
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• 2001

This study is regarding the autonomous navigation of the mobile robot which operates through a sensor, the Omnnidirectional Vision System which makes it possible to retrieve the real-time movements of the objects and the walls accessing the robot from all directions and to shorten the processing time. After attempting to extend the field of view by using the reflection system and then learning the point of all directions of 2$\pi$ from the robot at the distance, robot recognizes three-dimensional world through the simple image process, the transform procedure and constant monitoring of the angle and distance from the peripheral obstacles. This study consists of 3 parts: Part 1 regards the process of designing Omnnidirectional Vision System and part 2 the image process, and part 3 estimates the implementation system through the comparative study process and three-dimensional measurements.

• 한국안광학회지
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• 제19권1호
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• pp.99-104
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• 2014

목적: 중심외주시 훈련 전후 대비감도를 검사하여 망막 주변부의 기능적 개선 여부를 알아보고자 하였다. 방법: 정상 시각을 가진 14명의 성인 남녀의 우안을 대상으로 중심와에서 $20^{\circ}$ 이측으로 떨어진 망막 주변부의 대비감도를 검사했다. 60분간 영상을 21일 동안 중심외주시 훈련 후 대비감도를 다시 검사하여 사후 검정했다. 결과: 시간적 가중에 따른 임계점 분석에서 중심외주시 훈련 전 0.7 cpd에서 임계점은 2.67(467 ms)이었으며 훈련 후 2.79(616 ms)로 증가했다 (p<0.05). 훈련 전 3.0 cpd에서 임계점 역시 2.53(341 ms)이었으며 훈련 후 3.04(1102 ms)로 증가했다(p<0.05). 결론: 중심외주시 훈련시 선명하고 작은 글씨체의 문자로 훈련하는 것을 권장하며 짧은 시간동안 자주 반복하는 것이 보다 효과적이다. 아울러, 저시력 환자에 대한 각 병변별 시재활훈련을 할 수 있는 기준에 대한 연구가 절실하다.

• 한국산학기술학회논문지
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• 제10권11호
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• pp.3412-3417
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• 2009

본 연구는 저시력 환자와 정상인의 삶의 만족도를 상호 객관적으로 비교하고자 시행하였다. 다인성 저시력환자 20명과 그들의 나이와 유사하며 신체 건강한 정상인 20명을 대상으로 시기능설문지 NEI VFQ-25를 사용하여 구두로 평가하였다. 참가자 연령은 25세에서 78세까지 고루 분포하였으며 저시력 실험군의 평균값은 55.88$\pm$14.76이었으며 정상 대조군은 94.47$\pm$3.78로 나타났다. 저시력 실험군의 나이는 근거리 활동성과 가장 관련이 높았으며(r=-0.584) 그들의 시력은 주변시력과 관련이 가장 높은 것으로 나타났다(r=0.527). 저시력 환자의 삶의 만족도는 정상인에 비해 현저히 낮았으며 안구진탕이 일상생활에 큰 영향을 미칠 것으로 생각된다.

• 한국전문물리치료학회지
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• 제13권4호
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• pp.23-29
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• 2006

The purpose of the present study was to examine gaze effects on spatial and kinematic characteristics during a pointing task. Subjects were asked to watch and point to an aimed target (2 mm in diameter) displayed on a vertically mounted board. Four gaze conditions were developed as combinations of "seeing-aiming" in terms of the eye movements: Focal-Focal (F-F), Focal-Fixing (F-X), Fixing-Focal (X-F), and Fixing-Fixing (X-X). Both the home target and an aimed target were presented for 1 second and then were disappeared in F-F and X-F. In X-F and X-X, only an aimed target disappeared after 1 second. Subjects were asked to point (with index finger tip) to an aimed target accurately as soon as the aimed target was removed. A significant main effect of gaze was found (p<.01) for normalized movement time. Peripheral retina targets had significantly larger absolute error compared to central retina targets on the x (medio-lateral) and z (superior-inferior) axes (p<.01). A significant undershooting to peripheral retina targets on the x axis was found (p<.01). F-F and X-F had larger peak velocities compared to F-X and X-X (p<.01). F-F and X-F were characterized by more time spent in the deceleration phase compared to F-X and X-X (p<.01). The present study demonstrates that central vision utilizes a form of on-line visual processing to reach to an object, and thus increases spatial accuracy. However, peripheral vision utilizes a relatively off-line visual processing with a dependency on proprioceptive information.

• Annals of Clinical Neurophysiology
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• 제25권1호
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• pp.10-18
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• 2023

The ultimate purpose of eye movement is to maintain clear vision by ensuring that images of observed objects are focused on the fovea in the retina. Accurate evaluation of ocular movements, including nystagmus and saccadic intrusions, provides very useful information for determining the overall function and abnormality of the complex oculomotor system, from the peripheral vestibular system to the cerebrum. Eye movement tests are therefore essential for the accurate diagnosis of patients who complain of dizziness and imbalance. They help to predict lesion locations from the peripheral vestibular system to the central cerebral cortex and play an important role in differentiation from other diseases. The methodology of recording and interpreting ocular movements using video-oculography are described in this review article.

• 제어로봇시스템학회논문지
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• 제3권5호
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• pp.497-502
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• 1997

In this study an automatic rolling-coil labeling system using robot vision system and peripheral mechanism is proposed and implemented, which instead of the manual labor to attach labels Rolling-coils in a steel mill. The binary image process for the image processing is performed with the threshold, and the contour line is converted to the binary gradient which detects the discontinuous variation of brightness of rolling-coils. The moments invariant algorithm proposed by Hu is used to make it easy to recognize even when the position of the center are different from the trained data. The position error compensation algorithm of six degrees of freedom industrial robot manipulator is also developed and the data of the position of the center rolling-coils, which is obtained by floor mount camera, are transferred by asynchronous communication method. Therefore, even if the position of center is changed, robot moves to the position of center and performs the labeling work successfully. Therefore, this system can be improved the safety and efficiency.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.809-812
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• 2006

본 논문은 철강공장의 연주공정에서 만들어진 슬라브 소재의 관리를 위해 사용되는 소재 관리문자를 실시간으로 인식하기 위한 비전시스템 개발 결과에 대해 기술한다. 슬라브 재질의 단면에 마킹된 소재 관리문자는 슬라브가 다음 공정인 열연공정으로 이동하기 전에 공정상에서 실시간으로 인식된다. 문자인식 시스템은 영상획득을 위한 카메라 시스템, 영상을 장거리로 고속 전송하기 위한 영상전송 시스템, 기존 시스템과의 인터페이스를 위한 입 출력 장치로 구성된다. 개발된 문자인식 시스템을 실제 철강공장에 설치하여 운용테스트를 실시했다. 테스트 기간 중에 시스템의 내구성과 신뢰성을 검증하고 최종적으로 문자 인식률을 검증했다. 개발된 시스템에 대해 현장 테스트 결과 실험실 수준과 비슷한 수준의 인식률을 가졌다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1266-1268
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• 1996

In this study an automatic roiling-coli labeling system using robot vision system and peripheral mechanism is proposed and implemented, which instead of the manual labor to attach labels Rolling-coils in a steel miil. The binary image process for the image processing is performed with the threshold, and the contour line is converted to the binary gradient which detects the discontinuous variation of brightness of rolling-coils. The moment invariants algorithm proposed by Hu is used to make it easy to recognize even when the position of the center are different from the trained data. The position error compensation algorithm of six degrees of freedom industrial robot manipulator is also developed and the data of the position of the center rolling-coils, which is obtained by floor mount camera, are transfered by asynchronous communication method. Therefore even if the position of center is changed, robot moves to the position of center and performs the labeling work successfully. Therefore, this system can be improved the safety and efficiency.