• Therapeutic Science for Rehabilitation
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• v.1 no.1
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• pp.29-38
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• 2012

Introduction : This study reviews the main areas of cognitive rehabilitation including executive dysfunction, memory dysfunction, perceptual dysfunction, attention deficit, and dysfunctions in activities of daily living in order to apply to the adaptation of occupational therapy. Body : Cognition programs based on the virtual reality are being used not only to evaluate but to train the overall components of human's cognition. Because the cognitive program is concentrating on the real environment, it is known to bring a remarkable transitional effect to the actual environment, compared to the basic computer-based evaluation and training. Applying virtual reality to the rehabilitation program can develop and advance the high technology and can result in a major effect on the innovative treatment technology. Conclusions : In this process, virtual reality is expected to be researched more in the near future. Particularly in the cognitive realm, it is imperative for researchers to pay attention to the improved transitional effect of the virtual reality toward the actual environment, rather than the already existing method of evaluations. Therefore, application of the virtual reality for the cognitive training should be researched for various types of subjects in the diverse aspects of congnitive function. Application of the virtual reality in the cognitive function has its unlimited potential, thus the rehabilitation program integrated with not only evaluation but training and education is expected extensively in the future.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.133-137
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• 2001

The method to make glass is tried first thing in domestic study for glasses lens. Tg of glass KzFSl was measured by DSC experiment and press method of glass of meniscus shape was studied for minimize the cost. Tg was increased $483^{\circ}C$ to $501^{\circ}C$ with increasing heating rate $2^{\circ}C/min$ to $20^{\circ}C/min$. It shows Arrhenius temperature dependence and the activation energy of Tg is ${\Delta}E$=409 kJ/mole(4.25eV) by using Ozawa method and Tg is near $480^{\circ}C$. The melt of KzFSl powder was poured to concave cast stainless and pressed convex cast stainless. The quenched glass was slow cooled with cooling rate $0.25^{\circ}C/min$ in temperature range $520{\sim}430^{\circ}C$. The glass was made without strain. It has meniscus shape and same size to commercial glasses lens.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.1
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• pp.9-13
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• 2002

It is well known that the maximum amplitude of accommodation decreases with increasing age.(Presbyopia). With single vision lenses presbyopia can be corrected only for one viewing distance. With progressive power lenses presbyopia can be corrected for all viewing distances. But there are some other changes in the visual system with age which can not be corrected by spectacle lenses. Pupillary diameter decreases and the light transmission of the ocular media decreases. Therefore old people need more light, they need better illumination. Cone density in the retina decreases, this is only one example for changes in the sensory system. These changes in the visual system cause changes in visual functions. At the age of 80 visual acuity has decreased to half. Contrast sensitivity for gratings decreases mainly for high spatial frequencies very important is the increase of stray light in the ocular media and therefore the increase of glare. Veiling luminance increases by a multiple of approximately 4, Dark adaptation gets slower and light sensitivity is approximately 2 log units (factor 100) less when the eye is completely dark adapted. Also colour vision gets worse, especially at low luminances. Elderly people have problems with visual tasks which require divided attention between foveal and peripheral vision. An example is the measurement of the useful field of view. This useful field of view be expanded (improved) by visual training.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.77-81
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• 2007

The spherical lens is typically classified by the refractive power into two groups such as (+) diopter lens and (-) diopter lens. The deformation occurred by the external force that is applied to a lens is caused by the increase or the decrease in the diopter of a lens. In this paper, the deformation of the lens was quantitatively measured by using ESPI (Electronic Speckle Pattern Interferometry) which have been used in the optical measurement field for past few years. ESPI has an advantage that the deformation of an object can be measured precisely by using coherence of the light. The experiment was carried out to the totally 16 types of plastic lens. It was confirmed that the deformation was decreased by increasing the diopter of the lens when same displacement was applied to the lens in case of (+) diopter lens and was increased by decreasing the diopter of the lens in case of (-) diopter lens. Also, it was found that the deformation of (+) diopter lens is less than that of (-) diopter lens. Therefore, with these results, it is expected that the possibility of the quantitative measurement for variation of the optical defect caused by the deformation of a lens when the deformation is occurred to the various types of the lens can be presented and that the application in the lens industrial field can be performed.

• Journal of the Korean Magnetics Society
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• v.16 no.1
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• pp.102-106
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• 2006

Magnetic nanoparticles can be used for a variety of biomedical applications. They can be used in the targeted delivery of therapeutic agents in vivo, in the hyperthermic treatment of cancers. in magnetic resonance (MR) imaging as contrast agents and in the biomagnetic separations of biomolecules. We have synthesized magnetite $(Fe_3O_4)$ nanoparticles using chemical coprecipitation technique with sodium oleate as surfactant. Nanoparticle size can be varied from 2 to 8nm by controlling the sodium oleate concentration. Magnetite phase nanoparticles could be observed from X-ray diffraction. Magnetic colloid suspensions containing particles with sodium oleate and chitosan have been prepared. Nanoparticles, both oleate-coated and chitosan-coated, have been characterized by several techniques. Atomic farce microscope (AFM) was used to image the coated nanoparticles. Magnetic hysteresis measurement were performed using a superconducting quantum interference device (SQUID) magnetometer at room temperature to investigate the magnetic properties of the magnetite nanoparticles. The SQUID measurements revealed superparamagnetism of nanoparticles.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.457-469
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• 2014

Purpose: This study was to evaluate students and optometrist in the importance and difficulty of work capability, and the educational needs for optometric duty in order to use them as basic data for the improvement of the curriculum. Methods: 292 ophthalmic optic's college students and 123 optometrists were surveyed in the importance and difficulty of work capability, and the educational needs for the optometric duty, and data was statistically analyzed for the results. Results: The mean of the importance of work capability was higher for the optometrists (3.61) than for the students (3.51) and glasses dispensing was the highest for both students and optometrists. The mean of the difficulty of work capability was higher for the students (2.75) than for the optometrists (2.67), which was the highest in refraction for the students and in prescription for the optometrists. The mean of educational needs was higher for the optometrists (3.53) than for the students (3.45), which was the highest in glasses dispensing for the students and highest in refraction for the optometrists. There were significant differences in some tasks in between the students by gender, grade and desired working place, while between the optometrists by gender, age, work experience, working place and working area (p<0.05). Conclusions: It is necessary to improve a curriculum of the Department of Opthalmic Optics, and develop a standard curriculum reflected the importance and the difficulty of work capability, and the educational needs regarding to optometric duty.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.43-49
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• 2008

Purpose: The current study was conducted to evaluate the compatibility of UV-A blocking contact lens on eye protection with regular contact lens. Methods: The protective activity of regular contact lens (UV-A blocking: 20%) and UV-A blocking contact lens (UV-A blocking: 85%) on the denaturation of RNase A, catalase, and superoxide dismutase (SOD) induced UV-A irradiation were compared by acrylamide gel electrophoresis. The enzyme solutions were irradiated with UV-A for 1, 3, 6, 24 and 96 hours at the wavelength of 365 nm. Covering area with contact lenses were varied as 50%, 70% and 100% according to the calculation of blocking areas of anterior eye that could be covered with RGP lens, soft contact lens, and eye glasses, respectively. Results: Denaturations of RNase, catalase and SOD were exaggerated when they were exposed to UV-A for a longer period. The denaturation was effectively prevented by UV-A blocking contact lens compared to regular contact lens. The capability of UV-A blocking contact lens was considerably reduced when the covering area with contact lens decreased and exposure time to UV-A extended. Conclusion: Therefore, it would be suggested that wearing contact lens for a long time under sunlight is carefully considered since the activity of UV-A blocking contact lens against UV-A irradiation may not be enough to protect enzymes presented in eyes when exposure time to UV-A increased.

• Journal of Chest Surgery
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• v.43 no.5
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• pp.490-498
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• 2010

Background: A hybrid procedure using an open surgical extra-anatomic bypass of aortic arch vessels and thoracic endovascular aortic repair (TEVAR) is less invasive than open surgery, and provides a suitable proximal landing zone. Here we report our experience with a hybrid TEVAR procedure at a single center. Material and Method: We retrospectively reviewed consecutive patients with thoracic aortic disease who received a hybrid TEVAR procedure between August 2008 and January 2010. Patients' data were prospectively collected and mean follow-up was $10.8{\pm}5.5$ months (range 3~20). Result: Nine patients (7 males and 2 females) with a mean age of $63.8{\pm}15.8$ years (range 38~84) underwent a hybrid procedure. Five patients had an arch or a proximal descending aortic aneurysm, two had a dissecting aneurysm of the descending aorta, and two had an aneurysm of the ascending arch and descending aorta. Mean expected mortality calculated by logistic EuroSCORE was 21%. Six patients underwent debranching and rerouting from ascending aorta to arch vessels, 2 had carotid-carotid bypass grafting, and 1 underwent carotid-axillary bypass grafting. Mean operation time was $221.4{\pm}84.0$ min (range 94~364). Deployment success of endovascular stent grafting was 100% with no endoleak on completion angiography. There was no mortality, and a small embolism in the branch of the right opthalmic artery in one patient. During follow-up, one intervention was required for the endoleak. Actuarial survival at 20 months was 100%. Conclusion: Early and mid-term results are encouraging and suggest that hybrid TEVAR procedures are less invasive and safer and represent an effective technique for treating thoracic aortic disease.

• Journal of Preventive Medicine and Public Health
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• v.25 no.3 s.39
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• pp.247-268
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• 1992

This study was conducted to evaluate the effect of VDT work on eyes and vision among workers in a TV manufacturing plant. The study subjects consisted of 264 screen workers and 74 non-screen workers who were less than 40 years old male and had no history of opthalmic diseases such as corneal opacities, trauma, keratitis, etc and whose visual acuity on pre-employment health examination by Han's test chart was 1.0 or above. The screen workers were divided into two groups by actual time for screen work in a day : Group I, 60 workers, lesser than 4 hours a day and group II, 204 workers, more than 4 hours a day. From July to October 1992 a questionnaire was administered to all the study subjects for the general charateristics and subjective eye symptoms after which the opthalmologic tests such as visual acuity, spherical equivalent, lacrimal function, ocular pressure, slit lamp test, fundoscopy were conducted by one opthalmologist. The proportion of workers whose present visual acuity was decreased more than 0.15 in comparison with that on the pre-employment health examination by Han's test chart was 20.6% in Group II. 15.0% in Group I and 14.9% in non-screen workers. However, the differences in proportion were not statistically significant. The proportion of workers with decreased visual acuity was not associated with the age, working duration, use of magnifying glass and type of shift work (independent variables) in all of the three groups. However, screen workers working under poor illumination had a higher proportion of persons with decreased visual acuity than those working under adequate illumination (P<0.05) . The proportion of workers whose near vision was decreased was 27.5% in Group II, 18.3% in Group I, and 28.4% in non-screen workers and these differences in proportion were not statistically significant. Changes of near vision were not associated with 4 independent variables in all of the three groups. Six out of seven subjective eye symptoms except tearing were more common in Group I than in non-screen workers and more common in Group II than in Group I (P<0.01). Mean of the total scores for seven subjective symptoms of each worker(2 points for always, 1 point for sometimes, 0 point for never) was not significantly different between workers with decreased visual acuity and workers with no vision change. However, mean of the total scores for Group II was higher than those for the Group I and non-screen workers (P<0.01). Total eye symptom scores were significantly correlated with the grade of screen work, use of magnifying glass, and type of shift work. There was no independent variable which was correlated with the difference in visual acuity between the pre-employment health examination and the present state, the difference between far and near visions, lacrimal function, ocular pressure, and spherical equivalent. Multiple linear regression analysis for the subjective eye symptom scores revealed a positive linear relationship with actual time for screen work and shift work(P<0.01). In this study it was not observed that the VDT work decreased visual acuity but it induces subjective eye symptoms such as eye fatigue, blurred vision, ocular discomfort, etc. Maintenance of adequate illumination in the work place and control of excessive VDT work are recommended to prevent such eye symptoms.