• Current Optics and Photonics
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• 제5권6호
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• pp.699-710
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• 2021

In this study, we propose a biomimetic optical structure design methodology for investigating micro-optical mechanisms associated with the compound eyes of insects. With these compound eyes, insects can respond fast while maintaining a wide field of view. Also, considerable research attention has been focused on the insect compound eyes to utilize these benefits. However, their nano micro-structures are complex and challenging to demonstrate in real applications. An effectively integrated design methodology is required considering the manufacturing difficulty. We show that photorealistic ray-traced visualization is an effective method for designing the biomimetic of a micro-compound eye of an insect. We analyze the image formation mechanism and create a three-dimensional computer-aided design model. Then, a ray-trace visualization is applied to observe the optical image formation. Finally, the segmented images are stitched together to generate an image with a wide-angle; the image is assessed for quality. The high structural similarity index (SSIM) value (approximately 0.84 to 0.89) of the stitched image proves that the proposed MATLAB-based image stitching algorithm performs effectively and comparably to the commercial software. The results may be employed for the understanding, researching, and design of advanced optical systems based on biological eyes and for other industrial applications.

• 한국전문물리치료학회지
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• 제15권1호
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• pp.30-37
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• 2008

This study was designed to examine the effects of temporary immobilization of the ankle and knee joints on standing in healthy young adults with the use of a postural control mechanism. The subjects were twenty-four college students (12 males and 12 females, aged between 20 and 28). A Biodex balance system SD 950-302 and its software were used to measure indirect balance parameters in standing. Each subject underwent postural stability tests in 4-different joint conditions: free joints, ankle immobilization only, knee immobilization only, and ankle and knee immobilization. In addition, the postural stability test was conducted once with the subject's eyes open and once with the eyes closed conditions. For data analysis of the postural stability tests, the overall stability index, antero-posterior stability index, and medio-lateral stability index were recorded. The overall stability index (p=.000) and medial-lateral index (p=.003) were significantly greater different conditions with eyes closed in postural stability. Therefore, the eyes closed condition is expected to be used as an effective postural stability training for treatment planning in patients with unstable postures. In addition, training based on the dynamic multi-segment model can improve postural stability and is available to therapeutic programs, helping people with unstable balance to reduce their risk of falling.

• 한국소음진동공학회논문집
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• 제21권1호
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• pp.3-8
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• 2011

This paper introduces a robot eye module, of which two degree-of-freedom motions, i.e. panning and tilting, are driven by a pair of wires. The main feature of the module is that each wire can generate push-pull motion without buckling. It is thanks to a Teflon tube which guides the path of the moving wire. End points of the tube and wire have pivot elements so that a smooth push-pull motion is produced even when the end point of wire is moved by eye rotation. This mechanism helps the eye module to be very compact. In this paper, the structure of the robot eye module is introduced in detail, and the required motor angles for a certain direction of eye line are investigated analytically and experimentally.

• Journal of Yeungnam Medical Science
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• 제11권1호
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• pp.55-62
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• 1994

녹내장 누공수술의 대표적 수술인 섬유주절제술의 주된 실패요인인 여과포의 섬유화를 막아 수술성공율을 향상시키기 위해 항대사 물질인 Mitomycin C를 수술실패 위험이 높은 녹내장 환자 20명 25안을 대상으로 섬유주절제술중에 사용하여 섬유주절제술의 보조제로서의 Mitomycin C의 효과를 알아보았다. 전체 대상안의 수술전 평균 안압은 $38.6{\pm}6.6mmHg$였으며 수술 후 최종 평균안압은 $11.7{\pm}3.8mmHg$로 26.9mmHg의 안압감소를 나타내었다. 수술 성공율은 40세 이하의 원발광우각녹내장에서는 8안중 7안 (88%), 포도막염에 의한 속발 녹내장에서는 6안중 5안(83%), 신생혈관녹내장에서는 5안중 4안(80%)에서 성공하였고 유년녹내장과 과거 수술 기왕력이 있는 녹내장 및 무수정체녹내장에서는 6안 모두 (100%)에서 성공함으로서 전체적으로는 25안중 22안에서 성공하여 88%의 성공율을 나타내었다. 수술 후 시력 변화는 25안중 24안(96%)에서 수술전 시력에 비해 변함이 없거나 다소 호전되었으며 1안(4%)에서 시력 소실을 보였다. 술후 합병증은 전방출혈이 5안(20%), 얕은 전방이 4안(16%), 저안압증이 4안(16%), 점상각막염이 3안(12%), 결막봉합파열이 2안(8%), 낭포화된 여과포가 1안(4%), 맥락막 박리 1안(4%)에서 발생하였다. 결론적으로 섬유주절제술에서 Mitomycin C의 부가적 사용은 수술 실패 위험이 높은 녹내장에서 효과적이고 비교적 안전하게 사용할 수 있으나 장기간 경과 관찰을 통하여 안전하고 효과적인 사용법에 대한 다양한 연구가 필요할 것으로 사료된다.

• BMB Reports
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• 제45권12호
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• pp.693-699
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• 2012

Together with protein tyrosine kinases (PTKs), protein tyrosine phosphatases (PTPs) serve as hallmarks in cellular signal transduction by controlling the reversible phosphorylation of their substrates. The human genome is estimated to encode more than 100 PTPs, which can be divided into eleven sub-groups according to their structural and functional characteristics. All the crystal structures of catalytic domains of sub-groups have been elucidated, enabling us to understand their precise catalytic mechanism and to compare their structures across all sub-groups. In this review, I describe the structure and mechanism of catalytic domains of PTPs in the structural context.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.319-320
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• 2006

In this paper, automatic sunvisor system is introduced for driver's safety and convenience. This system has the mechanism which keeps the sun off without obstruction of driver's sight. The mechanism can make the sunvisor move forward or rotate left while remaining inside inner roof. The control system consists of a CPU, a motor driver, light sensors, and the algorithm that can control the movement of sunvisor efficiently. When the light sensors take the sun light, they give the signal to the CPU and the CPU calculates the best position of the sunvisor with the information of driver's eyes height. Then, the CPU gives the signal to motors that can move the sunvisor.

• International Journal of Internet, Broadcasting and Communication
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• 제15권2호
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• pp.168-174
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• 2023

In the current world, with the massive scale of SOC construction, it is difficult to diagnose and check all of a bridge's abnormal states with even the experts' eyes for maintenance. It is because we should spend huge costs and time on maintenance. Still, there are not many alternative ways to inspect bridges remotely regarding accuracy or reality. Therefore, we remark on the advantages and disadvantages of previous methods through practices in SOC maintenance. To inspect the abnormal state of the Bridge, we suggest inspecting bridges with an Augmented Reality (AR) mechanism to reduce cost, human resource consumption, and the risk of work. Through the proposed approach, we expect that it provides ways to solve massive construction problems with software-based technologies.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.209-214
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• 2003

We developed a new type of human-sized BWR (biped walking robot), named KUBIR1 which is driven by the closed-chain type of actuator. A new type of the closed-chain actuator for the robot is developed, which is composed of the four-bar-link mechanism driven by the ball screw which has high strength and high gear ratio. Each leg of the robot is composed of 6 D.O.F joints. For front walking, three pitch joints and one roll joint at the ankle. In addition to this, one yaw joint for direction change, and another roll joint for balancing the body are attached. Also, the robot has two D.O.F joints of each hand and three D.O.F. for eye motion. There are three actuating motors for stereo cameras for eyes. In all, a 18 degree-of-freedom robot was developed. KUBIR1 was designed to walk autonomously by adapting small 90W DC motors as the robot actuators and batteries and controllers are on-boarded. The whole weight for Kubir1 is over 90Kg, and height is 167Cm. In the paper, the performance test of KUBIR1 will be shown.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.699-702
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• 2004

This paper discusses about the mechanism of catching an image through an optical manipulation of each organizations in the eye, more specifically, mechanism of catching an image on a retina through a Camera and a Crystal Lens. In the retina, the macula roles as a fovea contrails and it leads the image which is about 3 mm to be shaped on there. However, even the macula may not properly function, our eyes still can catch the image by shifting the optical path to around of the macula, even if the sensitivity of the image is generally lower than the image on the macula. This paper proposes a method of shifting the shaped image on the retina by refracting the optical path through a prism located on the rear of a screen which consists of a 0.7' TFT LCD. Applying this method that throwing an image around on the macula, central visual disturbance patients among retinitis pimentos patients can expect to recover such a mechanism to catch an image.

• 한국지구과학회지
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• 제35권6호
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• pp.467-483
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• 2014

이 연구는 예비과학교사들의 암석에 대한 이해수준에 따른 육안분류 능력을 알아보기 위한 것이다. 이를 위하여 광물과 암석에 대한 비과학적 개념과 관련된 설문지를 개발한 후 예비 과학교사 132명에게 응답하게 하였고, 수집된 자료는 라쉬 모형을 이용하여 암석에 대한 이해수준에 따라 숙달 집단과 미숙달 집단으로 구분하였다. 이렇게 구분된 집단의 육안분류 능력을 알아보기 위해 17종(화성암 6종, 퇴적암 5종, 변성암 6종)을 제시한 후 각자의 기준에 따라 암석을 분류하도록 하였다. 분석 결과 예비 과학교사들은 주로 조직, 색깔, 입자 크기 등을 분류기준으로 사용하였다. 또한 화성암을 분류하는 것은 비교적 쉽게 해결하였지만 퇴적암과 변성암은 동일한 기준을 사용하여 분류하는데 혼동하고 있었다. 한편 암석에 대한 이해수준과 생성원인에 따른 분류능력은 유의미한 상관관계를 보였지만 암석명을 정확하게 분류하는 능력과는 유의미한 상관관계가 없었다. 하지만 생성원인에 따른 분류 능력과 암석명을 정확하게 분류하는 능력과는 높은 상관관계를 보였다.