• Current Optics and Photonics
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• v.5 no.6
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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.

• Physical Therapy Korea
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• v.15 no.1
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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.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.1
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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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• v.11 no.1
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• pp.55-62
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• 1994

The use of intraoperative application of Mitomycin C at the filtration site has been known to improve the surgical outcome in glaucomatous eyes with high risk for failure of trabeculectomy. The author performed trabeculectomies with intraoperative Mitomycin C on 25 eyes of 20 patients with poor surgical prognosis to study the efficacy and safety of this technique in glaucomatous patients with high risk for failure of trabeculectomy. After the preparation of a scleral flap, 0.2mg/ml solution of Mitomycin C was applied between Tenon's capsule and the sclera for 2 minutes. The exposed area was then irrigated with 200 ml of balanced salt solution. The follow-up period was from 1 to 7 months (mean 3.8 months). The mean preoperative intraocular pressure (IOP) was $38.6{\pm}6.6mmHg$. The mean final postoperative IOP was $11.7{\pm}3.8mmHg$. Twenty three (88%) of the 25 eyes were successfully controlled with the IOP of less than or equal to 20 mmHg without glaucoma medication. There were early postoperative complications of hyphema in 5 eyes (20%), shallow anterior chamber in 4 eyes(16%), punctate keratopathy in 3 eyes (12%), aqueous leaking from conjunctival wound in 2 eyes (8%), encapsulated bleb in 1 eye (4%) and choroidal detachment in 1 eye (4%), and 4 eyes had long term hypotony lasting more than 2 months. Although Mitomycin C is simple to use and effective adjunct to trabeculectomy, further study will be needed to determine the mechanism of action, indication, dosage and optimal exposure time of Mitomycin C.

• BMB Reports
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• v.45 no.12
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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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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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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• v.15 no.2
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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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• 2003.10a
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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.

• Proceedings of the IEEK Conference
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• 2004.08c
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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.

• Journal of the Korean earth science society
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• v.35 no.6
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• pp.467-483
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• 2014

This study aimed to investigate the classification ability with naked eyes according to the understanding level about rocks of pre-service science teachers. We developed a questionnaire concerning misconception about minerals and rocks. The participants were 132 pre-service science teachers. Data were analyzed using Rasch model. Participants were divided into a master group and a novice group according to their understanding level. Seventeen rocks samples (6 igneous, 5 sedimentary, and 6 metamorphic rocks) were presented to pre-service science teachers to examine their classification ability, and they classified the rocks according to the criteria we provided. The study revealed three major findings. First, the pre-service science teachers mainly classified rocks according to textures, color, and grain size. Second, while they relatively easily classified igneous rocks, participants were confused when distinguishing sedimentary and metamorphic rocks from one another by using the same classification criteria. On the other hand, the understanding level of rocks has shown a statistically significant correlation with the classification ability in terms of the formation mechanism of rocks, whereas there was no statistically significant relationship found with determination of correct name of rocks. However, this study found that there was a statistically significant relationship between the classification ability with regard to formation mechanism of rocks and the determination of correct name of rocks.