• Journal of IKEEE
• /
• v.22 no.4
• /
• pp.907-915
• /
• 2018

This paper proposes a method to improve the performance of low cost infrared distance sensor. Infrared distance sensor measures the intensity of reflected light and converts it into distance. The proposed method improves the sensing distance of the sensor and makes it operate robustly in various lighting environments. This is achieved by extracting the characteristic curves of the sensor and applying the HDR (High Dynamic Range) technique. The output value of the sensor was obtained by varying the intensity of the infrared input and the exposure time, and the characteristic curve of the sensor was extracted from it.

• Journal of Sensor Science and Technology
• /
• v.32 no.2
• /
• pp.100-104
• /
• 2023

In this study, a device was fabricated to check the possibility of a memory device by controlling the oxygen functional groups in graphene oxide formed with a 45-second exposure time. We discovered that graphene oxide can be formed using the ultraviolet (UV) light treatment method with different exposure times. Moreover, Raman spectroscopy measurement revealed that the oxygen functional groups can be moved by controlling the voltage. We further studied the change in the local graphene oxide region, which was found to be related to the modulation of the electrical properties of the device. Therefore, the fabricated graphene oxide device can be used as a wettability switching membrane and graphene-based ion transport device.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.10 no.1
• /
• pp.63-68
• /
• 1980

The purpose of this article is to re-examine the roentgenographic appearance of alveolar osseous in an effort to determine the value of the orthopantomogram in the diagnosis of periodontal disease. A total of 158 osseous lesions from 13 human dry skulls were studied. 14 Ultra-speed periapical films, 2 bitewing films and Kodak panoramic film are used to obtain radiographs of all defects. The bisecting technic was used, with a target-film distance of. 8 inches and exposure factors of 70 kVp, 10MA and 0.4 sec. at anterior teeth, 0.6 see at posterior teeth in exposure time. For orthopantomogram, Panoura Eight-C was used with a exposure factors of 90kVp, 10MA. and 15sec. exposure time. All films were developed in a light. tight darkroom at 68°F for 4½ minutes. Comparison of orthopantomogram and intraoral films on the view-box was carefully studied in relation to the types of osseous defect visually evident; Proximal intraosseous defects, Interproximal craters, Interproximal hemisepta, Furcal defects on multirooted teeth, and Facial or Lingual one-walled defects. The results obtained were as follows; 1. Proximal osseous defects throughout the dental arches and furcal defects on facial and lingual surfaces of multirooted teeth can be identified with a high degree of accuracy from their orthopantomographic appearances. 2. Lesions on facial or lingual surface of the alveolar arches are rather difficult to locate or recognize on the dental radiographs. 3. In determining whether the proximal and furcal lesions are located facially or lingually, Orthopantomogram is superior to the conventional film Orthopantomogram obtained with standardization of head in proper position revealed the complete visualization of alveolar bone without showing occlusal surface of molars and proximal superimposition of teeth. Thus, on the standardized orthopantomograms, The roentgenographic characteristics of each defect were determined.

• Ocean and Polar Research
• /
• v.32 no.4
• /
• pp.397-409
• /
• 2010

Herein, we compared the production rate of UV-absorbing compounds (mycosporine-like amino acids) and carotenoids in two phytoplankton species--Phaeocystis pouchetii and Porosira glacialis--which are the dominant species in Polar Regions under artificial UV radiation conditions. P. pouchetii exposed to UVR and PAR evidenced reductions in the carbon fixation rate, and was not significantly influenced by differing light conditions. However, the concentrations of UV-absorbing compounds and photo-protective pigments of P. pouchetii were increased with increasing exposure time, but P. glacialis maintained constant levels during the UVR exposure experiment. The production rates of MAAs showed a reverse phase between the two phytoplankton species. The carbon fixation rate of P. pouchetii cells was inhibited by exposure to UV radiation, but the production rates of MAAs in P. pouchetii were increased under UV radiation exposure. The carbon fixation rate and production rate of MAAs in P. glacialis were simultaneously inhibited under UV radiation exposure conditions. These results provide us with new information regarding the processes involved in the production of UV-absorbing compounds and photoprotective pigments in two phytoplankton species.

• Textile Coloration and Finishing
• /
• v.23 no.4
• /
• pp.241-249
• /
• 2011

Cotton fabrics was treated with persimmon juice by padding and their dyeability and functionality were assessed including antibacterial activity and deodorization ratio. The merit of padding-based dyeing was easier color reproduction over traditional hand dyeing where various colors and color fastness to light and laundering are hard to obtain. With larger number of padding, the dyed fabrics showed deeper red-yellow colors, which had low brightness and high chromatic colors. The dyed cotton fabrics had a perspiration fastness of 4~5 rating, a rubbing fastness of 3~4 rating, and a washing fastness of 4 rating, As the number of padding and exposed time to sunlight or UV light increase, the values of K/S and ${\Delta}E$ increased and the colors became much deeper gradually. The color development had completed about 70 hours exposure to UV. Among the light sources, the dyed fabrics exposed to UV light showed deeper yellow-red color than those of exposed to sunlight. The cotton fabrics treated with premordants like Al, Cr, Cu, and Sn revealed strong yellow colors, especially the fabrics treated with Fe mordant showed greenish red-yellow colors. As the padding times of dyeing with persimmon juice increased, stiffness and water repellent property were enhanced in warp and weft directions, respectively. Also, the dyed fabrics have good antibacterial activity and deodorization.

• Journal of KIISE:Computer Systems and Theory
• /
• v.28 no.10
• /
• pp.491-498
• /
• 2001

We present a method of modeling lights from photographs taken with conventional imaging equipment. It does not use both any geometrical information and special apparatus to calculate surface reflection properties. To represent surface reflection properties of the scene, we use BRDFs which are calculated by radiance values of surface elements and light sources. And the BRDF data of each surface is further transformed to the spherical harmonic domain for efficient storage. Thus it allows to reconstruct the photo-realistic scene under different light sources, to manipulate diversely the arbitrary light source and to control exposure time of camera sensor. Moreover we test our algorithm with real image instead of synthetic image.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1158-1162
• /
• 2005

Drug delivery systems have been developed to reduce the side toxicity of drugs by localizing them in the site of action. But it depends on the circulation of the blood and it doesn't have the function of locomotive mechanism of itself for searching for the region of disease. However, this problem could be solved by nanobot which have the locomotive function. So, we mimic the movement of cell that can move in a human body. In this paper, to polymerize the encapsulated actin within the liposome, electroporation technique is employed. In order to optimize polymerization and depolymerization of the liposome, we compare the time of polymerization and depolymerization by concentration of crown ether. we synthesis the liposome which contain azobenzene Linked crown Ether conjugated Actin protein. Azobenze linked crown ether holds the K+ ion by exposure of UV light and this disturbs the actin polymerization. In result, UV light could control the liposome growth. Finally, we could develop the liposome robot and control the growth and degeneration of the liposome by external stimuli such s UV light. The merit of the controlling by UV light doesn't need to inject proteins which induce polymerization and depolymerization of actin protein.

• Current Photovoltaic Research
• /
• v.12 no.2
• /
• pp.41-47
• /
• 2024

CIGS solar cells are thin film solar cells that have excellent light absorption coefficient and can be manufactured with high efficiency through the use of low materials. In Korea, they must pass KS certification for home and commercial installation. KS C 8562 is a standard for evaluating the durability of CIGS and thin film amorphous silicon solar modules and deals with contents such as light, temperature, humidity, and mechanical durability. Unlike general crystalline silicon solar modules, the CIGS solar module has a different behavior of output change through these environmental tests, so if it shows 90% or more of the rated output suggested by the manufacturer after the final test, it is judged to be a suitable product. In this paper, the output before and after individual tests was measured through the test method of KS C 8562 to observe the output change and to discover the vulnerabilities of the CIGS solar module when exposed to various environments. Through this, it was confirmed that humidity exposure was the most vulnerable and that it had output recovery characteristics for light (visible light and ultraviolet rays). This study attempted to present the output behavior characteristics and data of the CIGS module at the time when the high efficiency thin film photovoltaic module market is expected to be created in the future.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.8 no.6
• /
• pp.78-83
• /
• 1999

This study discusses a non-contact optical technique, electronic speckle pattern interformetry(ESPI), that is well suited for in-plane and out-of-plane deformation measurement. However, the existing ESPI methods that are based on dual-exposure, real-time and time-average method have difficulties for accurate measurement of structure, due to irregular intensity and shake of phase. Therefore, phase shifting method has been proposed in order to solve this problem. About the method, the path of reference light in interferometry is shifted and added to least square fitting method to make the improvement in distinction and precision. This proposed method is applied to measure in -plane displacement that is compared with the previous method. Also, Used as specimen AS4/PE따 [30/=30/90]s was analyzed by ESPI based on real-time to determine the characteristics of vibration under no-load and tension. These results are quantitatively compared with those of FEM analysis inmode shapes.

• Journal of Ginseng Research
• /
• v.47 no.1
• /
• pp.65-73
• /
• 2023

Background: Age-related macular degeneration (AMD) is a significant visual disease that induces impaired vision and irreversible blindness in the elderly. However, the effects of ginseng berry extract (GBE) on the retina have not been studied. Therefore, this study aimed to investigate the protective effects of GBE on blue light (BL)-induced retinal damage and elucidate its underlying mechanisms in human retinal pigment epithelial cells (ARPE-19 cells) and Balb/c retina. Methods: To investigate the effects and underlying mechanisms of GBE on retinal damage in vitro, we performed cell viability assay, pre-and post-treatment of sample, reactive oxygen species (ROS) assay, quantitative real-time PCR (qRT-PCR), and western immunoblotting using A2E-laden ARPE-19 cells with BL exposure. In addition, Balb/c mice were irradiated with BL to induce retinal degeneration and orally administrated with GBE (50, 100, 200 mg/kg). Using the harvested retina, we performed histological analysis (thickness of retinal layers), qRT-PCR, and western immunoblotting to elucidate the effects and mechanisms of GBE against retinal damage in vivo. Results: GBE significantly inhibited BL-induced cell damage in ARPE-19 cells by activating the SIRT1/PGC-1α pathway, regulating NF-kB translocation, caspase 3 activation, PARP cleavage, expressions of apoptosis-related factors (BAX/BCL-2, LC3-II, and p62), and ROS production. Furthermore, GBE prevented BL-induced retinal degeneration by restoring the thickness of retinal layers and suppressed inflammation and apoptosis via regulation of NF-kB and SIRT1/PGC-1α pathway, cleavage of caspase 3 and PARP, and expressions of apoptosis-related factors in vivo. Conclusions: GBE could be a potential agent to prevent dry AMD and progression to wet AMD.