• Journal of Korean Society of Environmental Engineers
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• v.28 no.2
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• pp.150-157
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• 2006

Spatially resolved remote identification and quantification of trace gases in the atmosphere is desirable in various fields of scientific research as well as in public security and industrial contexts. Environmental observations investigating causes, extent md consequences of air pollution are of fundamental interest. We present an Imaging-DOAS system, a ground based remote sensing instrument that allows spatially resolved mapping of atmospheric trace gases by a differential optical absorption spectroscopy(DOAS) with sun scattered light as the light source. A passive DOAS technique permits the identification and quantification of various gases, e.g., $NO_2,\;SO_2,\;and\;CH_2O$, from their differential absorption structures with high sensitivity. The Imaging-DOAS system consists of a scanning mirror, a focusing lens, a spectrometer, a 2-D CCD, ad the integral control software. An imaging spectrometer simultaneously acquires spectral information on the incident light in one spatial dimension(column) and sequentially scans the next spatial dimension with a motorized scanning mirror. The structure of the signal acquisition system is described in detail and the evaluation method is also briefly discussed. Applications of imaging of the $NO_2$ contents in the exhaust plumes from a power plant are presented.

• Korean Journal of Optics and Photonics
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• v.28 no.5
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• pp.194-202
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• 2017

The purpose of this study is to analyze how optics concepts and activities have changed according to the revision of the national science curriculum. For this purpose, the optics achievement standards presented in the middle-school science curriculum of the 7th curriculum, 2007 revised curriculum, 2009 revised curriculum, and 2015 revised curriculum, and the optics content presented in the textbooks developed for each curriculum, were compared and analyzed. The optics content is classified into four concepts: the process of viewing an object; light and color; reflection and refraction; and the image from a mirror and a lens. The main results are as follows: First, according to the revision of curriculum, some optics concepts have been added or removed. In particular, big changes have appeared in the concepts of "process of viewing the object", "dispersion", "reflection and refraction" and so on. Second, the content for 'image formation by a mirror and a lens' was gradually reduced, according to the revision of curriculum, and the level of activity was also adjusted. Third, attempts to present the content of textbooks in conjunction with the phenomena and tools that students can experience in everyday life have increased gradually. In addition, based on the analysis of the content of curriculum and textbooks, the implications for optics education have been discussed.

• Journal of The Korean Astronomical Society
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• v.55 no.4
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• pp.123-130
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• 2022

We present the analysis of a planetary microlensing event OGLE-2019-BLG-0362 with a shortduration anomaly (~0.4 days) near the peak of the light curve, which is caused by the resonant caustic. The event has a severe degeneracy with ∆𝜒² = 0.9 between the close and the wide binary lens models both with planet-host mass ratio q ≃ 0.007. We measure the angular Einstein radius but not the microlens parallax, and thus we perform a Bayesian analysis to estimate the physical parameters of the lens. We find that the OGLE-2019-BLG-0362L system is a super-Jovian-mass planet $M_p=3.26^{+0.83}_{-0.58}M_J $ orbiting an M dwarf $M_h=0.42^{+0.34}_{-0.23}M_{\odot}$ at a distance $D_L=5.83^{+1.04}_{-1.55}kpc$. The projected star-planet separation is ${\alpha}_{\bot}= 2.18^{+0.58}_{-0.72}AU$, which indicates that the planet lies beyond the snow line of the host star.

• Journal of The Korean Association For Science Education
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• v.27 no.5
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• pp.456-464
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• 2007

The aims of this research are to analyze the representations and conceptual sequence of eye vision in Korean science textbooks and to suggest a contents construct about eye vision where the conceptual sequence is considered. Research method was literature review, and the literatures that were used for analysis were the 7th Korean science curriculum which was revised in 1997, and the science and physics textbooks developed based on the 7th Korean science curriculum. The research results are as follows: 1) Although the science curriculum seems to have no problem on sequence in the eye vision concepts, the science and physics textbooks based on the curriculum reveal problems on the sequence in the eye vision concepts; 2) Some Korean science textbooks explain retinal image formation according to the Alhazen's idea, except in inverse image; 3) Some Korean science textbooks explain about the reasons of near- and far-sightedness without consistency between the textbooks for 7th and 8th grade students; 4) A few Korean science textbooks give an inappropriate explanation about the principle of eye sight correction by eye glasses; 5) According to the analysis result, the concepts related to eye vision should be presented in the order of explanation about light refraction phenomena, image formation process by convex lens, structure of human eye and retinal image formation process, correction of eye sight using lens.

• Economic and Environmental Geology
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• v.39 no.1 s.176
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• pp.1-7
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• 2006

This paper attempts to locate and define a quartzite deposit in Geochang, Kyongsangnam Province in order to establish its commercial viability. The quartzite deposit (Poongwon Mine) occurs as lens or boudinage at the contact between mica schist of the Deogyusan formation and granite gneiss. During Precambrian, regional metamorphism and granitization may have caused the formation ot quartzite layers through recrystallization and rearrangement of silica components derived from older sedimentary rocks, probably chert and/or sandstone. The deposit is composed of fine-grained milky, or light yellowish quartz showing weak laminations with fairly dense and rough appearance in outcrop. It reaches about $60\;m(height)\times140\;m(length)\times35m(width)$ with attitude of $N57^{\circ}E-N8^{\circ}4E\;and\;51^{\circ}-60^{\circ}NW$. The average grade of the quartzite samples is $SiO_2=94.4\;wt\%,\;A1_2O_3=3.3\;wt\%,\; Fe_2O_3=0.8\;wt\%,\;K_2O=0.7\;wt\%$, which can be used for foundry, constructional materials, or concrete making. The proved reserve was estimated as 200,811 tonnage.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.4
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• pp.317-326
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• 2011

QLF-D system composed with DSLR(digital single-lens reflex) camera, and the images of natural enamel caries and artificial caries was developed from 2 days to 14 days captured by QLF-D system. The correlation between lesion depth of the polarized microscope and luminosity ratio of QLF-D image was analyzed and the results were summarized as follows: 1. The Pearson correlation value between the lesion depth of polarized microscope images and luminosity ratio of QLF-D images was 0.969(p<0.01). 2. From Regression analysis of lesion depth from polarized image by demineralized period, the equation was y = 8.67x - 1.16(p<0.05). 3. From Regression analysis of luminosity ratio from QLF-D image by demineralized period, the equation was y = 3.53x + 6.42(p<0.05). From the results, QLF-D system can detect the enamel caries at the very early stage and can monitor the progression of demineralization and remineralization. For the convenient use of QLF-D system in the laboratory, the image analysing software was needed to analyze of interest site of enamel caries lesion.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.253-263
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• 2013

Frequency Scanning Interferometry(FSI) system, one of the most promising optical surface measurement techniques, generally results in superior optical performance comparing with other 3-dimensional measuring methods as its hardware structure is fixed in operation and only the light frequency is scanned in a specific spectral band without vertical scanning of the target surface or the objective lens. FSI system collects a set of images of interference fringe by changing the frequency of light source. After that, it transforms intensity data of acquired image into frequency information, and calculates the height profile of target objects with the help of frequency analysis based on Fast Fourier Transform(FFT). However, it still suffers from optical noise on target surfaces and relatively long processing time due to the number of images acquired in frequency scanning phase. 1) a Polarization-based Frequency Scanning Interferometry(PFSI) is proposed for optical noise robustness. It consists of tunable laser for light source, ${\lambda}/4$ plate in front of reference mirror, ${\lambda}/4$ plate in front of target object, polarizing beam splitter, polarizer in front of image sensor, polarizer in front of the fiber coupled light source, ${\lambda}/2$ plate between PBS and polarizer of the light source. Using the proposed system, we can solve the problem of fringe image with low contrast by using polarization technique. Also, we can control light distribution of object beam and reference beam. 2) the signal processing acceleration method is proposed for PFSI, based on parallel processing architecture, which consists of parallel processing hardware and software such as Graphic Processing Unit(GPU) and Compute Unified Device Architecture(CUDA). As a result, the processing time reaches into tact time level of real-time processing. Finally, the proposed system is evaluated in terms of accuracy and processing speed through a series of experiment and the obtained results show the effectiveness of the proposed system and method.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.279-286
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• 2013

This paper introduces a new method for identification of building energy performance problems. The presented method is based on automated analysis and visualization of deviations between actual and expected energy performance of the building using EPAR (Energy Performance Augmented Reality) models. For generating EPAR models, during building inspections, energy auditors collect a large number of digital and thermal imagery using a consumer-level single thermal camera that has a built-in digital lens. Based on a pipeline of image-based 3D reconstruction algorithms built on GPU and multi-core CPU architecture, 3D geometrical and thermal point cloud models of the building under inspection are automatically generated and integrated. Then, the resulting actual 3D spatio-thermal model and the expected energy performance model simulated using computational fluid dynamics (CFD) analysis are superimposed within an augmented reality environment. Based on the resulting EPAR models which jointly visualize the actual and expected energy performance of the building under inspection, two new algorithms are introduced for quick and reliable identification of potential performance problems: 1) 3D thermal mesh modeling using k-d trees and nearest neighbor searching to automate calculation of temperature deviations; and 2) automated visualization of performance deviations using a metaphor based on traffic light colors. The proposed EPAR v2.0 modeling method is validated on several interior locations of a residential building and an instructional facility. Our empirical observations show that the automated energy performance analysis using EPAR models enables performance deviations to be rapidly and accurately identified. The visualization of performance deviations in 3D enables auditors to easily identify potential building performance problems. Rather than manually analyzing thermal imagery, auditors can focus on other important tasks such as evaluating possible remedial alternatives.

• Cross-Cultural Studies
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• v.23
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• pp.81-100
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• 2011

The term of world literature is now becoming an issue and lens through which we need to rethink the value of literature on a more universal dimension so as to imagine newly the location of the local or regional literature that has been alienated from the field of world literature. This kind of recognition leads us to consider the term world literature in relation to globalization and universality and to locate it on a problematical territory rather than to understand it in the traditional and Western way. Therefore the concept of world literature is now given to us as a task to resolve from our particular, or more precisely, peripheral context. The peripheral context could best operate as a possibility of reforming the West-centered order of world literature particularly in the way in which world literature obtains a more universal value. When we discuss world literature we need to consider the way of practice to re-highlight the possibility of periphery and pre-modernity without neglecting the 'light' of modernity and center. In this respect, the discourse of 'East Asia' may be useful for a transnational approach to world literature which focuses on the criticism of all kinds of centrism by foregrounding the concepts of othering and de-homogenization. For this I emphasize the attitude and methodology of 'post' which includes the power of othering and de-homogenization. The 'posty' theories such as post-colonialism, post-structuralism, post-nationalism and post-humanism allow us to indicate properly and acutely our aim by means of freer play of thought and at the same time more just definition and practice of our thought; that is, only by embracing both indication and play can we maintain the universal value of world literature. Here we can say that the global and local enterprise of ethics is the fundamental basis of world literature.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.16-27
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• 2015

Holography technology which was developed by Dennis Gabor (1900~1979) in 1948 is a technology to record wave planes of actual 3D objects. It is known as the only technology which can express 3D information most perfectly close to human-friendly. Holography technology is widely used in advertisement, architecture and arts as well as science technology areas. Especially, digital holographic print which is an applied area is greatly used in military map, architecture map and cultural asset restoration by printing and reproducing 3D information. Holography is realized by recording and reproducing the amplitude and phase information on high resolution film using coherent light like laser. Recording materials for digital holographic printer are silver halide, photoresist and photopolymer. Because the materials have different diffraction efficiency according to film characteristics of each manufacturer, appropriate guide lines should be suggested through efficiency analysis of each film. This paper suggests appropriate guide lines through the diffraction efficiency measurement of silver halide which is a holographic printer recording medium. And the objective of this study is to suggest appropriate guide lines through diffraction efficiency analysis of Ultimate 08-C and PFG-03C which are commercially used. The experiment was prepared by self-diffraction efficiency system which measures the strength with the defector by penetrating RGB recording medium and concentrating diffracted beams through collimating lens. The experiment showed Geola's PFG-03C which is a silver halide for full color has price/performance advantage in optical hologram recording, but recording angles and reproduction angles are irregular for digital holographic printer recording. Ultimate's Ultimate08-C for full color shows its diffraction efficiency is relatively stable and high according to recording angles and laser wavelength.