• Journal of the Optical Society of Korea
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• v.20 no.5
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• pp.607-613
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• 2016

The pleura is known as an end target organ of exposure to toxic environmental materials such as fine particulate matter and asbestos. Moreover, long-term exposure to hazardous materials can eventually lead to fatal lung disease such as diffuse pleural fibrosis or mesothelioma. Chest computed tomography (CT) and ultrasound are gold standard imaging modalities for detection of advanced pleural disease. However, a diagnostic tool for early detection of pleural reaction has not been developed yet due to difficulties in imaging ultra-fine structure of the pleura. Optical coherence tomography (OCT), which provides cross-sectional images of micro tissue structures at a resolution of 2-10 μm, can image the mesothelium with a thickness of ~100 μm and therefore enables investigation of the early pleural reaction. In this study, we induced the early pleural reaction according to a time sequence after pleurodesis using talc, which has been widely used in the clinical field. The pleural reaction in talc grouped according to the time sequence (1st, 2nd, 4th weeks) showed a significant thickening (average thickness: 45 ± 7.5 μm, 80 ± 10.7 μm, 90 ± 12.5 μm), while the pleural reaction in sham and normal groups showed pleural change from normal to minimal thickening (average thickness: 16 ± 5.5 μm, 17 ± 4.5 μm, 15 ± 6.5 μm, and 12 ± 7.5 μm, 13 ± 2.5 μm, 12 ± 3.5 μm). The measurement of pleural reaction by pathologic examinations was well-matched with the measurement by OCT images. This is the first study for measuring the thickness of pleural reactions using a biophotonic modality such as OCT. Our results showed that OCT can be useful for evaluating the early pleural reaction.

• Journal of Astronomy and Space Sciences
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• v.15 no.2
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• pp.359-371
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• 1998

We present the design specifications and the performance estimation of the FUVS (Far Ultraviolet Spectrograph) proposed for the observations of aurora, day/night airglow and astronomical objects on small satelltes in the spectral range of $900~1750AA$. The design of FUVS is carried out with the full consideration of optical characteristics of the grating and the aspheric substrate. Two independent methods, ray-tracing and the wave front aberration theory, are employed to estimate the performance of the optical design and it is verified that both procedures yield the resolution of $2~5AA$ in the entire spectral range. MDF (Minimum Detectable Flux) is also estimated using the known characteristics of the reflecting material and MCP, to study the feasibility of detection for faint emission lines from the hot interstellar plasmas. The results give that the observations from 1 day to 1 week, depending on the line intensity, can detect such faint emission lines from diffuse interstellar plasmas.

• KIEAE Journal
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• v.8 no.1
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• pp.53-60
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• 2008

The daylighting affects on the human biological cycles and physiological alterations. Daylighting is also an important element in visual comfort and it sometimes influences the quality of vision. Therefore the absence of natural light during the day brings contradictory result. To solve the problems of natural light lack and provide sufficient daylight in interior spaces, it might be necessary to apply some daylighting systems. One of these systems, light pipe system, which is simple, cheep and easily constructed, is very useful to apply for small buildings. The light pipe is simple means of directing daylighting (diffuse and direct lighting)into interior space. In order to application of light pipe system in Korea, it is necessary to optical data of light pipe system. This study aims to evaluate preliminary experiment of the daylighting environment of light pipe system. Light pipe system, that aspect ratio is 1:2(diameter and length), was installed in a windowless mock-up with $27m^2$. The mock-up model was constructed as a prototype of Korean office surface. Illuminance was measured with a Topcon IM-5 Luxmeter to evaluate the distribution of the illuminance on a floor. The indoor and outdoor illuminance and the internal/external illuminance ratio are compared to discuss with in the graphs. Luminance was measured with Radiant imaging Promertric 1400 that is digital photometer to evaluate the distribution of luminance on interior surface. The contrast of luminance is discussed with table and graphs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6227-6235
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• 2015

The HUD has recently been downsized due to the development of micro display and LED technology as a see through information display device, gradually expands the application areas. In this paper, using a DLP micro display device designed a compact head-up display(HUD) optical system for biocular observation of the image exhibition area 5 inches. It was analyzed for each design element of the optical system in order to design a compacted HUD. DLP, projection optical system and concave image combiner were discussed the design approach and the characteristics. Through a connection structure analysis of each optical system, detailed design specifications were set up and designed the optical system in detail. Put a folded configuration in the form of a white diffuse reflector between the projection lens and concave image combiner was designed to be independent, respectively. Distance of the projected image is adjustable up to approximately 2m ~ infinity and observation distance is 1m. Resolution could be recognized by 1 ~ 2pixels in HD($1,280{\times}720pixels$) class, various characters and symbols could be read. In addition, color navigation map, daytime video camera and thermal imaging cameras can be displayed.

• Journal of Astronomy and Space Sciences
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• v.17 no.1
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• pp.77-86
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• 2000

There have been a few attempts to measure diffuse line emission between 900 $\AA$ and 1200 $\AA$, and only in a limited number of sight lines has it been detected. The main contributions to the equilibrium radiative cooling curve between $10^{4.5}K\;to\;10^6K$ are from the doublet of Ovi ${lambda}{lambda}1032;and;{lambda}{lambda}1038$ in the FUV spectral region. There are several bright airglow lines which could interfere with attempts to observe the OVI lines. The nearest lines HI 1025 $\AA$, OI 1027 $\AA$ have a combined intensity of about $10^{5.5}$ photons/s/$cm^2$/sr. In the present study, the detectability simulation of OVI doublet is performed using a Monte-Carlo technique and chi-square statistics. The analysis results are compared with the previous observations and with the predictions of several interstellar medium models, and are used to limit manufacturing and alignment errors of FIMS optical system.