• Journal of Korean Society for Quality Management
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• v.44 no.3
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• pp.527-540
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• 2016

Purpose: The purpose of this study was to propose contrast metric which is based on the human visual perception and thus it can be used to improve the quality of digital images in many applications. Methods: Previous literatures are surveyed, and then the proposed method is modeled based on Human Visual System(HVS) such as multiscale property of the contrast sensitivity function (CSF), contrast constancy property (suprathreshold), color channel property. Furthermore, experiments using digital images are shown to prove the effectiveness of the method. Results: The results of this study are as follows; regarding the proposed contrast measure of complex images, it was found by experiments that HVS follows relatively well compared to the previous contrast measurement. Conclusion: This study shows the effectiveness on how to measure the contrast of complex images which follows human perception better than other methods.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.7
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• pp.694-699
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• 2009

This paper presents the implementation of the real-time object tracking control of the ROBOKER head. The visual servoing technique is used to track the moving object, but suffers from ill-estimated Jacobian of the virtual link design. To improve the tracking performance, the RBF(Radial Basis Function) network is used to compensate for uncertainties in the kinematics of the robot head in on-line fashion. The reference compensation technique is employed as a neural network control scheme. Performances of three schemes, the kinematic based scheme, the Jacobian based scheme, and the neural network compensation scheme are verified by experimental studies. The neural compensation scheme performs best.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.3
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• pp.103-109
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• 2015

Objectives The objective of this study si to report clinical effect of korean medical treatments and Buteyko breathing technique for asthma patient with pneumonia. Methods The patient was treated by korean medical treatment including acupunture, moxibustion, herbal medication and Buteyko breathing technique. The improvement of clinical symptoms was observed by visual checking and X-ray, Pulmonary Function Test that index include TV, FVC, FEV1. Results After treatments, the patient was improved in visual checking and X-ray on chest, TV, FVC, FEV1. Conclusions We suggest that korean medical treatment and Buteyko breathing technique could be an effective method to improve the asthma patient with pneumonia.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.4
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• pp.59-68
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• 2015

PURPOSE: The purpose of this study was to determine the comparison of visual and auditory biofeedback during sit-to-stand training in patients with stroke. METHODS: Thirty-five subjects with chronic stroke were divided into three groups: a visual feedback group (12 subjects), an auditory feedback group (12 subjects) and a control group (11 subjects). All Groups received neurodevelopmental treatment, and sit-to-stand training for 30minutes three times a week for four weeks. During the sit to stand training, the experimental groups received visual feedback and auditory feedback, whereas the control group performed sit-to-stand training without feedback. Five times sit-to-stand test (FTSST), motion analysis and postural sway during sit-to-stand were used to evaluate sit to stand performance ability. In addition, Berg balance scale (BBS) was performed for evaluation of balance function in participants. RESULTS: All groups showed significant increase on FTSST and BBS between pre- and post-intervention. The BBS scores in visual feedback group was significant increase than control group. The motion analysis and postural sway, more improvement was observed in the visual and auditory feedback groups compared with the control group. The only visual feedback group was a better performance of midline excursion during sit-to-stand than control group. CONCLUSION: These findings suggest that sit-to-stand training using a biofeedback may help to improve sit to stand performance and balance ability of stroke patients.

• Journal of the Korea Society of Computer and Information
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• v.25 no.10
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• pp.15-22
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• 2020

In this study, we propose an improvement method that can create U-Net model which detect fine concrete cracks by applying a weighted loss function. Because cracks in concrete are a factor that threatens safety, it is important to periodically check the condition and take prompt initial measures. However, currently, the visual inspection is mainly used in which the inspector directly inspects and evaluates with naked eyes. This has limitations not only in terms of accuracy, but also in terms of cost, time and safety. Accordingly, technologies using deep learning is being researched so that minute cracks generated in concrete structures can be detected quickly and accurately. As a result of attempting crack detection using U-Net in this study, it was confirmed that it could not detect minute cracks. Accordingly, as a result of verifying the performance of the model trained by applying the suggested weighted loss function, a highly reliable value (Accuracy) of 99% or higher and a harmonic average (F1_Score) of 89% to 92% was derived. The performance of the learning improvement plan was verified through the results of accurately and clearly detecting cracks.

• Journal of Korea Entertainment Industry Association
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• v.14 no.6
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• pp.191-199
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• 2020

Younger generations use a variety of visual media, such as smartphones, televisions, and computers. Due to the development of visual media, the health of eye was weakening. Therefore, this study aimed to investigate the effects of eye health and dynamic visual activity on eye muscle stimulation with eye movement and therapeutic massage in university students. 38 university students in their 20s were divided into a control group(18) and an experimental group(20). The experimental group performed eye movement and therapeutic massage every 30 minutes for 5 times a week for 4 weeks. Ocular fatigue, maximal blinking interval, ocular surface temperature, and dynamic visual activity were measured before and after 4 weeks. Ocular fatigue was decreased significantly after 4 weeks (p<.05), and maximal blinking interval was increased significantly after 4 weeks (p<.05). Ocular surface temperature was not showed a significant difference after 4 weeks (p>.05), and dynamic visual activity was increased significantly after 4 weeks (p<.05). Therefore, eye movement and therapeutic massage are recommended for the improvement of eye function and eye health. It is expected to be used as research data to restore and prevent for eye health.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.4 s.37
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• pp.331-338
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• 2005

The rapid advances in high power light sources and arrays as encountered in incandescent lamps have induced dramatic increases in die heat flux and power consumption at all levels of high power LED packaging. The lifetime of such devices and device arrays is determined by their temperature and thermal transients controlled by the powering and cooling, because they are usually operated under rough environmental conditions. The reliability of packaged electronics strongly depends on the die attach quality, because any void or a small delamination may cause instant temperature increase in the die, leading sooner or later to failure in the operation. Die attach materials have a key role in the thermal management of high power LED packages by providing the low thermal resistance between the heat generating LED chips and the heat dissipating heat slug. In this paper, thermal transient characteristics of die attach in high power LED package have been studied based on the thermal transient analysis using the evaluation of the structure function of the heat flow path. With high power LED packages fabricated by die attach materials such as Ag paste, solder paste and Au/Sn eutectic bonding, we have demonstrated characteristics such as cross-section analysis, shear test and visual inspection after shear test of die attach and how to detect die attach failures and to measure thermal resistance values of die attach in high power LED package. From the structure function oi the thermal transient characteristics, we could know the result that die attach quality of Au/Sn eutectic bonding presented the thermal resistance of about 3.5K/W. It was much better than those of Ag paste and solder paste presented the thermal resistance of about 11.5${\~}$14.2K/W and 4.4${\~}$4.6K/W, respectively.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.5
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• pp.81-101
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• 2011

This study was conducted to understand the environmental and ecological function of habitat through evaluation of water environment, soil environment, vegetation characteristics, macro-invertebrate characteristics, and visual habits environment evaluation (SVAP) in Hongdong stream located in Hongseong-Gun, Chungnam Province, and hereafter to utilize the results for the habits reconstruction and improvement project. As the results of water quality analysis, BOD, COD, T-P was almost below the standard quality from upper stream to down stream. The construction of small reservoir, wetland and water purification facility, and the management of non-point pollution are proposed to improve these problems. The soil texture was sandy soil, which is unfitted with vegetation development. The construction of shallows and bogs, and induction of soil sedimentation and biotope formation are proposed to improve these problems. In the plant flora, total 90 kinds were observed with 81 species and nine varieties in total 36 families and 85 genera, and the naturalization rate was higher at down area than upper area. As the results of macro-invertebrate fauna survey, total 26 species and 297 individuals in 20 families and 22 genera were collected. Peltodytes sinensis, Chironomidae sp., and Culicidae sp., which are observed at polluted environment, were collected as dominant species. An appropriate vegetation management party idea is necessary, and it is done an idea in consideration of the soil and a physical characteristic. Visual habits environment evaluation (SVAP) result was mostly determined with below normal (Fair) grade. Pollution source interception, purification pond establishment, and various bog establishment are proposed to improve these problems. With the above results, the ecological environment was determined with bad condition, and the improvement of biotope was urgently needed through sustainable monitoring and management of streams habitat in rural area.

• Journal of Korean Neurosurgical Society
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• v.30 no.4
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• pp.518-521
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• 2001

We present a rare case of a pituitary adenoma revealing a sedimentation level on MRI, which has not been previously documented. This 55-year-old woman was referred with the diagnosis of craniopharyngioma. She presented with four-month history of progressive headache and visual dimness. Neurological examination revealed a bitemporal hemianopsia and decreased visual acuity. Laboratory data including endocrine examination were unremarkable. An additional three-dimensional MRI was taken for further evaluation, and demonstrated a sedimentation level within the tumor. The patient underwent transcranial removal of the tumor. About 12cc of dark-red blood was aspirated from the tumor. Histological examination revealed a pituitary adenoma with hemorrhage. Postoperatively, the patient showed gradual improvement of visual function. Considering that the pituitary adenoma is one of more common tumors that cause tumoral bleeding, a cystic sellar tumor that has a sedimentation level should be sought first for a pituitary adenoma rather than a craniopharyngioma. This may have an important impact when deciding surgical approach.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.4
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• pp.428-437
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• 1994

Optic nerve injury serious enough to result in blindness had been reported to occur in 3% of facial fractures. When blindness is immediate and complete, the prognosis for even partial recovery is poor. Progressive or incomplete visual loss may be ameliorated either by large dosage of steroid or by emergency optic nerve decompression, depending on the mechanism of injury, the degree of trauma to the optic canal, and the period of time that elapses between injury and medical intervention. We often miss initial assessment of visual function in management of facial fracture patients due to loss of consciousness, periorbital swelling and emergency situations. Delayed treatment of injuried optic nerve cause permanent blindness due to irreversible change of optic nerve. But by treating posttraumatic optic nerve injuries aggressively, usable vision can preserved in a number of patients. The following report concerns three who suffered visual loss due to optic nerve injury with no improvement after steroid therapy and/or optic nerve decompression surgery.