• Korean Journal of Optics and Photonics
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• v.15 no.4
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• pp.361-368
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• 2004

We separated the multilayer structure of CD-R(compact disk-recordable) and investigated optimal spot marking conditions and physical and chemical transitions in response to various laser beam energh levels. Spot marking(80 ${\mu}{\textrm}{m}$ spot size) was produced on the surface of each layer using a Q-switched Nd:YAG laser between 27 mJ and 373mJ. By investigating resulting pit formation with Optical Microscopy(OM) and Optical Coherence Tomography(OCT), we analyzed the formation process of spot marking in the multilayer structure of different chemical composition. The localized heating of the substrate in the multilayer thin film caused the short temporal thermal expansion, and absorbed optical energy between reflective and dye interfaces melted dye and increased the volume. During the cooling phase, formation of pit and surrounding rim can be explained by three distinct processes; effect of surface tension, evaporation by spontaneous temperature increase due to laser energy, and mass flow from the recoil pressure. Our results shows that the spot marking formation process in the multilayer thin film is closely related to the layers' physical, chemical, and optical properties, such as surface tension, melt viscosity, layer thickness, and chemical composition.

• Laser Solutions
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• v.7 no.2
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• pp.11-18
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• 2004

We propose a novel application of optical coherence tomography (OCT) to monitor pit formation in laser irradiated optical storage materials. A multilayer optical storage recordable compact disk, is composed of multiple layers, each of different structure. Disks were irradiated with aQ-Switched Nd:YAG laser with an energy of 373 mJ. Post-irradiated disks were evaluated by OCT and those images were compared with optical microscopy. Our results indicate that OCT is a useful instrument to investigate pit formation in multilayer optical storage disks and might also provide information to optimize optical memory technology.

• Journal of the Society of Disaster Information
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• v.4 no.2
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• pp.68-91
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• 2008

Our country is consuming huge source of revenue to improve geometric structure of road with a view to improve safety of the road. However, it is more efficient to provide high-quality pavement markings to the road users. For this purpose, in this study, it is considered the optical theory related to retroreflectivity of pavement marking along with the our country's study literature and foreign. And also considered ur country standard related to pavement marking, made pavement marking sample and measured retroreflectivety. For the experiment, it is selected colors of normal temperature-type paints, grading and content of glass bead as experiment factors. After it is made the same conditions like construction spot, measured retroreflectivity according to the combination of factors and analyzed the optimization of factors.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.4
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• pp.685-694
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• 2016

Visibility of lane marking is impaired at night, or in case of rain, and thereby threatens traffic safety. Recently, various studies and technology have been developed to improve lane marking visibility, such as the extension of lane marking life expectancy (up to 1.5 times), improvement of lane marking equipment, improvement of lane marking visibility (32.7%) by applying phosphorescent material mixed paint, and expressway lane design standards alternative (length 6m, gap 12m, width 13cm: 27.8% of painted surface are reduced) adoption with ergonomic analysis. In this study, a set of cost-benefit analyses was performed for the cases where such techniques were applied. Based on the literature review, 26.9% of traffic accidents would be prevented by improving lane marking visibility by 32.7%; accident reduction benefit was calculated as much as 12.5 billion KRW. Meanwhile, total increased cost when introducing phosphorescent material mixed paint and lane design standards alternative is calculated as 30.6 billion KRW. However, economic feasibility could not be secured with 0.41 of cost-benefit ratio when applied to the expressway network as a whole. Additionally, cost-benefit (B/C) analysis was applied to each of the top 20 night accident hot spots and the results of B/C ratios were between 0.67 and 4.20, showing that 11 out of 20 spot sections of expressway can have economic feasibility. This results indicate, with this kind of pavement marking applied to accident hot spots in rural expressway, better visibility and economic feasibility can be guaranteed through traffic accident reduction. Some limitations and future research agenda have also been discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.5
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• pp.815-825
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• 2017

Visibility of lane marking is impaired at night or in the rain, which thereby threatens traffic safety. Recently, various studies and technologies have been developed to improve lane marking visibility, such as the extension of lane marking life expectancy (up to 1.5 times), improvement of lane marking equipment productivity, improvement of lane marking visibility by applying phosphorescent material mixed paint. Cost-benefit analysis was performed with considering various benefit items that can be expected. About 45% of traffic accidents would be prevented by improving lane marking visibility. Additionally, accident reduction benefit and traffic congestion reduction benefit were calculated as much as 246 billion KRW per year and 12 billion KRW per year, respectively, by reducing repaint cycle due to enhanced durability. 45 billion KRW per year is expected to reduced with improved lane detection performance of autonomous vehicle. Meanwhile, total increased cost when introducing phosphorescent material mixed paint to 91,195km of nationwide road is identified as 1922 billion KRW per year. However, economic feasibility could not be secured with 0.16 of cost-benefit ratio when applied to the road network as a whole. In case of "Accident Hot Spot" analyzing section window (400m), one or more fatality or two or more injured (one or more injured in case of less than 2 lanes per direction) per year were caused by pavement marking related accident, economic feasibility was secured. In detail, 3.91 of cost-benefit ratio is estimated with comparison of the installation cost for 5,697 of accident hot spot and accident reduction benefit. Some limitations and future research agenda have also been discussed.

• Animal Systematics, Evolution and Diversity
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• v.38 no.4
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• pp.214-221
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• 2022

Six species in five families of Lepidoptera were newly recorded from Korea. The adult specimens of these six species were obtained during the rearing caterpillars collected across Korea. Agonopterix omelkoi Lvovsky (Depresariidae) can be distinguished by the ochreous forewing with a dark brown slanted line, a dark brown triangular spot, and a blackish discal dot, and the whitish hindwing. Dichomeris ferruginosa Meyrick (Gelechiidae) can be diagnosed by the light brown forewing with two relatively large blackish dots and suffusion of dark brown along the dorsum and subtermen, and the grayish hindwing. Pseudohedya satoi Kawabe (Tortricidae) can be diagnosed by the dark ochreous forewing with several medially curved dark ochreous medial lines, and the large light grayish tornal marking, and the dark grayish hindwing. Rhodoneura hyphaema (West) (Thyrididae) can be diagnosed by the reddish forewing with a relatively thick postmedial band, and the reddish hindwing with a narrow dark reddish straight medial band. Comibaena subprocumbaria (Oberthür) (Geometridae) can be diagnosed by the greenish forewing with a whitish apical marking that bordered with a brownish or dark reddish line that connected to the termen, and the distal abdominal segments with whitish and dark reddish dots. Perixera absconditaria (Walker) (Geometridae) can be diagnosed by the light brownish forewing with a relatively thick, slanted, dentate brownish postmedial line, and the light brownish hindwing with a small white discal spot. We provide the diagnosis and figures of adults and larvae, and DNA barcoding data.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.6
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• pp.130-138
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• 2007

To protect the surface of ground-cutting slopes occurring at the national road substitute detour [roundabout road]construction jobsite between Munduk and Wubokgu within the jurisdiction of Pohang-si and environment-friendly road construction, a test execution of re-vegetation measures on the major slopes was done and the results are as follows : As a result of finding out the number of sprouting individuals on the test construction site, the average number of sprouting individuals on the three test spots by the method of revegetation measures D, revegetation measures A, and revegetation measures B was 1,292 number of per square meter, 1,190 number of per square meter, and 1,095 number of per square meter respectively, which statistics were higher than those of test spot by the revegetation measures C. As a result of finding out living plant's breeding index [weight in dried state], the average dried weight of living plant at the test spot by the method of revegetation measures B, in case of foreign herbal species, was the highest marking 8.96 grams per square meter, and the next was 6.86grams per square meter by the method of revegetation measures D, and the next after was 6.80 grams per square meter by the method of revegetation measures A, and the last 5.93 grams per square meter by the method of revegetation measures C. As a result of finding out the covering degree on the slopes, the same average covering degree of 80% and 77.5% in revegetation measures A and revegetation measures D individually, which showed a somewhat higher covering degree than those of revegetation measures B and revegetation measures C. As a result of finding out appearing plants on the test construction site, seeding plant life was found to be sprouting on all test spot while native and foreign herbal species and herbaceous plant as well as shrubs were growing in good harmony with each other. However, in case of revegetation measures B and revegetation measures C method, foreign plant species are dominantly growing. As a result of inspecting rifts on the slopes and the excavated state by water, there existed cracks in some of base materials only in revegetation measures C method applied spot.

• Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.313-316
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• 2012

Two unrecorded species of the snapper, Lutjanus malabaricus (296.0 mm standard length [SL]) and L. stellatus (350.0 mm SL) belonging to the family Lutjanidae, were first collected from the western coastal waters of Jeju Island, Korea. L. malabaricus is characterized by having a dark marking on the upper half of the caudal peduncle, a band of vomerine teeth that does not protrude posteriorly at the middle, and nine anal soft rays. Compared to its Korean relative, L. malabaricus is distinguishable by having rows of scales that run obliquely in the dorsal-posterior direction above the lateral line (vs. parallel to the lateral line in L. argentimaculatus). L. stellatus can be identified by the absence of wavy blue lines on the head (vs. many blue lines in L. rivulatus) and presence of a white spot above the lateral line (vs. a black blotch on the lateral line in L. rivulatus). We propose new Korean names, "Jin-hong-tung-dom" and "Huin-jeom-tung-dom," for L. malabaricus and L. stellatus, respectively.

• Physical Therapy Rehabilitation Science
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• v.4 no.1
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• pp.49-54
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• 2015

Objective: Cervical stabilization exercises are frequently to improve strength and endurance of cervical muscles. The purpose of this study was to identify changes in head repositioning accuracy (HRA) and neck proprioception through cervical stabilization exercises in healthy adults. Design: One group pretest-posttest design. Methods: Thirteen participants with no previous history of neck pain or injury to the cervical spine were recruited. HRA was measured by equipment including laser pointer, helmet, eye patch and marking pens. The distance between the spot where the beam had stopped and the center of the graph paper was measured three times with the averaged value used as the head repositioning accuracy. Neck proprioception was measured by a cervical range of motion device (CROM). Subjects wore the CROM tester and were to look straight ahead while bending his/her neck. Subjects were instructed to perform extension, lateral flexion and rotation, and the values were then measured and recorded. The measurements were performed pre-intervention, and after cervical stabilization exercise. Results: There was no significant difference on HRA after intervention. In addition, there was no significant difference on neck proprioception compared with pre-intervention. Conclusions: The present study did not identify any effect on HRA and neck proprioception of cervical stabilization exercise. Further investigations are required to elucidate this in old aged participants and patients with neck pain.

• Journal of Ecology and Environment
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• v.43 no.4
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• pp.385-389
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• 2019

Knowledge of abundance, or population size, is fundamental in wildlife conservation and management. Camera-trapping, in combination with capture-recapture methods, has been extensively applied to estimate abundance and density of individually identifiable animals due to the advantages of being non-invasive, effective to survey wide-ranging, elusive, or nocturnal species, operating in inhospitable environment, and taking low labor. We assessed the possibility of using coat patterns from images to identify an individual leopard cat (Prionailurus bengalensis), a Class II endangered species in South Korea. We analyzed leopard cat images taken from Digital Single-Lense Relfex camera (high resolution, 18Mpxl) and camera traps (low resolution, 3.1Mpxl) using HotSpotter, an image matching algorithm. HotSpotter accurately top-ranked an image of the same individual leopard cat with the reference leopard cat image 100% by matching facial and ventral parts. This confirms that facial and ventral fur patterns of the Amur leopard cat are good matching points to be used reliably to identify an individual. We anticipate that the study results will be useful to researchers interested in studying behavior or population parameter estimates of Amur leopard cats based on capture-recapture models.