• Journal of Korean Ophthalmic Optics Society
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• v.10 no.3
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• pp.241-246
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• 2005

The aim of the study was performed the wave analysis of P-VEP on the development of visual function using Netspeg lens in monocular of refraction error subjects. The P-VEP of three channels were recorded by the Bausch Lomb system. Ten adults (five males, five females, mean=22 years, range=19 to 23) subjects were recorded. The subjects were researched the history including the systemic health, medication, genetics, allergy, ocular disease, and so on. Visual acuity and refraction test were performed for each subject with mono vision by using the Netspeg lens. Also subjects viewed the P-VEP stimulus with mono vision through the corrected visual acuity with Netspeg lens during VEP test. The results of study suggest that the mono vision using Netspeg lens is better than with non-Netspeg lens on the visual acuity and image symptom. On the other hand, the analysis of P-VEP suggest that the amplitude of wave is larger when the eye using Netspeg lens receives the P-VEP stimulus compared with the non Netspeg lens. Also, on the wave style of P-VEP, the eye of Netspeg lens was more stable compared with the naked eye. However, on latency period of P-VEP, the eye of non Netspeg lens was more longer than the eye of Netspeg lens. But, on the other hand, the right and left eye have similar results. In conclusion, this study indicated that the visual acuity and visual function of eye of Netspeg lens used have a better than the eye of non-Netspeg lens in Mono Vision.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.2
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• pp.330-343
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• 1997

Extraoral maxillofacial prostheses are essential for restoring facial structures that are lost as a result of congenital missing, injuries from accidents, surgical treatments of head and neck cancer. Recently, silicone is the most useful material for this purpose and is more advantageous than other maxillofacial prosthetic materials. However, there are some problems for long-term usage of silicone prostheses due to tear and color change. These are major contributing environmental factors to those problems that are such as ultraviolet light, cleansing agents, changes in humidity and successive adhesion and removal. The aim of this study is to evaluate the physical properties and color changes of maxillofacial prosthetic silicone material by those environmental factors using A-2186 silicone material (Factor II, USA) and two pigments, cadmium yellow medium and cosmetic red. Aluminium molds were fabricated according to the ASTM No. D412 & D624 specifications and resulted specimens from molds were fabicated and treated as follows. Control group and experimental I group were fabricated with 0.1% wt. pigment mixing in silicone elastomer and II-1 group, II-2 group of experimental II group were fabricated with 0.2%, 0.3% wt. pigment mixing in silicone elastomer, respectively. Control group was kept in darkroom at room temperature, I-1 group was kept under natural sunlight during 1week, I-2 group was soaked in 20% soap water during 1wk. I-3 group was successively adhered and removed 200 times on inner region of arm using Daro adhesive-33. Experimental II groups were kept in darkroom at room temperature. Instron universal testing machine was used to measure the % elongation, tensile strength, tear strength of control, experimental I, II groups and reflectance spectrophotometer(COLOR EYE-3000, Macbeth, USA) was used to measure the color differences between control group and experimental I group. The results were as follows : 1. When compared with control group, natural weathering group and 20% soap-water soaking group had no significant differences in % elongation(p>0.05). 2. 200 times successive adhesion and removal group, 0.2% wt. pigment group and 0.3% wt. pigment group had significant decreases in % elongation(p<0.05). 3. Natural weathering group, 20% soap-water soaking group and 200 times successive adhesion and removal group had no significant differences in tensile strength (p>0.05). 4. 0.2%, 0.3% wt. pigment groups had significant decreases in tensile strength(p<0.05). 5. Values of all experimental groups were decreased in tear strength. and 200 times successive adhesion and removal group had significant decrease in tear strength(p<0.05). 6. Natural weathering group and 20% soap-water soaking group had significant color differences(${\Delta}E$) and it could be detectable to naked eye(p<0.05). 7. Color differences between control group and 200 times adhesion and removal group were not detectable to the naked eye (${\Delta}E<1.0$).

• Journal of the Korean Wood Science and Technology
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• v.38 no.5
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• pp.391-398
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• 2010

In this study, the figure of domestic hardwood was observed using the naked eye and the possibility of substituting imported wood with domestic one in the making woodcraft or furniture was investigated. It was known from the investigation on 8 different hardwoods that there were various figures such as cloud-shaped figure, blister figure, crotch figure, bird's eye figure, etc. in Zelkova serrata wood and the beautiful pigment figure in Diospyros Kaki wood. There were the unusual figures such as wavy grain figure, fiddle back figure, etc. in Cedrela sinensis wood and was clear ray-fleck figure in Quercus variabilis wood. There were also various figures such as wavy grain figure, blister figure, pigment figure, etc. in Sophra japonica, Tilia amurensis, Castanea crenata, Kalopanax septemlobus wood, etc. It is thus that distinguished figures appeared in each kind of wood can be used for craft, sculpture, furniture, and interior material. These kinds of figures can also be used for instrument, toy, stationery, life article material and souvenir, etc. And it can be expected that they will replace the imported wood has been mainly used to make the woodcraft or furniture until now.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2004.05a
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• pp.11-14
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• 2004

In this paper, field application of mass concrete using setting time difference of super retarding agent is reported to reduce hydration heat of concrete placed at newly constructed apartment house in Busan. Horizontal placing lift is applied. According to test results. slump and air content meets the requirement of target values. For compressive strength, it exceeds the nominal strength ordered by the costumer. Compressive strength of concrete cured in place is achieved more than the values of nominal strength at l4days. For temperature history, maximum temperature of center at top section shows 58.5$^{\circ}C$, and at bottom section, 62.6$^{\circ}C$. According to naked eye's investigation, no hydration heat crack is observed at the surface of concrete.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1647-1653
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• 2011

In the case of an urban rail chopper type subway train, varistors have been installed for protecting usual electronic equipments, semiconductor devices(diodes, transistors, thyrister, etc.) communications, measuring, control device and absorbing opening & closing surge of electromagnetic valve. These varistors were steadily reduced dielectric strength as becoming superannuated. Thus there is a problem that reacts more sensitive at the same surge in the general control operation. On existing maintenance, there is not specific standard to replace superannuated varistor. So when maintaining chopper type subway train, all varistors or old varistors that workers checked a discoloration & crack with the naked eye and noticed degradation smell by deterioration are replaced. This study suggests detail standards for judgement that varistors are good or bad chopper type subway train, and it draw a efficient maintenance which efficient maintenance can check more easy the degradation properties variation.

• Electronics and Telecommunications Trends
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• v.35 no.6
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• pp.37-47
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• 2020

Today, the volume of international trade by airplanes and ships is rapidly increasing, and the volume of trade over land is expected to increase as inter-Korean relations change. In customs processes, humans inspect using the naked eye; therefore, computer vision technology can be used to assist customs inspectors responsible for X-ray security screening. In particular, because of recent advances in deep learning technology, algorithms for image understanding and object detection performance are improving, and studies on their application to X-ray screening have been published. This manuscript describes trends in artificial intelligence X-ray image-reading technology to detect prohibited items. X-ray inspection AI technology is similar to the Sphinx, which was the guardian of the pyramids in ancient Egyptian mythology.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.3
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• pp.283-292
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• 2015

This paper presents the development of the automatic safety inspection technique for the ammunition fuzes using radiography images. The technique inspects 49-ammunition fuze by detecting the X-ray or neutron radiographic images to check whether the fuze is unintendedly armed or/and some major assembled parts are at right place. To execute the program, we loads the image(s) for under test. After reading images, the program conducts a series of pre-image processing, and then starts inspecting input images by using the detection algorithms which are designed distinctively for each fuze. After completing the detection process, the program displays the final result of the fuze status: "safety or danger." Through this program, we can cut off the fuzes which have any doubt about safety, and can only provide absolutely safe fuzes, compared with the current naked eye inspection method.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1553-1556
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• 2006

A diazatetrathia crown ether derivative that has two appended nitrobenzoxadiazolyl moieties showed selective OFF-ON type fluoroionophoric signaling properties toward Hg2+ ions over other transition metal ions. The compound also exhibited a pronounced chromogenic behavior toward Hg2+ ions by changing the solution color from light orange to yellow, which can easily be detected with naked-eye. The detection limit for the analysis of Hg2+ ions in 90% aqueous acetonitrile was found to be 4.8??10-6 M, which suggests that the compound may be used as a chemosensor for analyzing sub-millimolar Hg2+ ions in aqueous environments.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.676-678
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• 2004

In order to develop new yellow phosphor that emit efficiently under the 450 - 470 nm excitation range, we have synthesized a $Eu^{2+}$-activated $Sr_3SiO_5$ yellow phosphor and investigated an attempt to develop white LEDs by combining it with a InGaN blue LED chip (460 nm). Two distinct emission bands from the InGaN-based LED and the $Sr_3SiO_5$:Eu phosphor are clearly observed at 460 nm and at 570 nm, respectively. These two emission bands combine to give a spectrum that appears white to the naked eye. Our results showed that InGaN (460 nm chip)-based $Sr_3SiO_5$:Eu exhibits a better luminous efficiency than that of the industrially available product InGaN (460 nm chip)-based YAG:Ce.

• Journal of the Korean Society of Safety
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• v.23 no.3
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• pp.12-16
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• 2008

For industrial centrifuges, the state of their welding areas, even with a naked-eye observation, offers potential safety problems such as inconsistent bead formation. STS304, which is used mainly in centrifuges, is made of metal alloys with chrome and nickel as the main ingredients, offering excellent corrosion resistance, thermal resistance, and high strength, and thus allowing it to be used for diverse purposes. This paper conducted tensile and fatigue tests of STS304 to improve the safety of centrifuges. In the findings, for the static behavior of the STS304 material, welded specimens increased their yield and tensile strength compared with the base test specimens, but decreased their elongation ratio. Also, the data dispersion phenomenon of welded specimens remarkably increased.