• Journal of the Korean Society for Marine Environment & Energy
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• v.1 no.2
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• pp.40-51
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• 1998

The interaction of contained oil slicks with current was investigated with a two-dimensional experimental setup in the circulating water channel facility. A vertical plate was used to contain the oils against the currents and the evolution of the oil slick, mainly focusing on the water/oil interface, was examined with an aid of a laser sheet. Two different oils - soy bean oil and diesel oil - were studied with varying the current speed (10 cm/sec to 35 cm/sec), the barrier depth (4 cm and 8 cm) and the volume of oil (2 liter to 12 liter). Different types of the interface behavior were observed according to the conditions and their mechanism was discussed based basically on the dimensional analysis. The critical speeds of two types of oil loss mechanism (entrainment failure and drainage failure) were also examined.

• Korean Journal of Optics and Photonics
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• v.18 no.4
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• pp.286-291
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• 2007

We theoretically investigated the far-field radiation pattern of epi-signal from a polystyrene sphere in coherent anti-Stokes Raman scattering (CARS) microscopy with an objective lens of high numerical aperture. We calculated the field distribution of the incident laser beams under the tight-focusing condition and the far-field radiation pattern through coherent addition of radiation from the nonlinear polarizations (Hertzian dipoles) as the origin of CARS signal generation. The epi-radiation patterns for polystyrene spheres of different diameters are calculated, and the pattern of a sphere is also compared with that of a shell fer a diameter of 1100 nm. We finally show how the radiation pattern of the polystyrene sphere changes as the center of the sphere shifts from the focus of the beam.

• Journal of the Optical Society of Korea
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• v.13 no.4
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• pp.468-471
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• 2009

We propose a simple nondestructive method to obtain refractive-index profiles of a graded-index (GRIN) light-focusing rod by means of a diffraction grating. In our proposed method, a laser beam is illuminated through a diffraction grating perpendicular to the axis of the GRIN lens and the separation between the zeroth and first-order diffraction peaks is measured and analyzed. The results demonstrate that the refractive-index profiles of commercially available GRIN lenses can be successfully reconstructed.

• The Research Journal of the Costume Culture
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• v.19 no.1
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• pp.71-82
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• 2011

This paper examined the kinds and characteristics of leather and also analyzed the expression techniques and characteristics of leather in contemporary fashion. The objective of this study lies in re-interpreting the current location of leather in contemporary fashion design, enlarging unlimited potential expression fields of leather, and at the same time, helping create new viewpoints and expression types of leather. For this purpose, this paper examined the kinds and characteristics of leather through the existing literatures, and it also carried out positive analysis of the expression techniques and characteristics of leather clothes through local and foreign fashion magazines and collection papers, such as Gap, Vogue, and Mode & Mode, focusing on the works presented in the fashion collections after 2000. Leather in contemporary fashion is expressed in different colors through dyeing. Through various expression techniques such as wrinkles, ruffle, stitch, embossing, quilting, patchwork, holing, nailing, cutting, laser cutting, fringe, weaving, printing, and collage, leather breaks the fixed ideas of itself and further, it makes the images of fashion design affluent. Leather clothes, which are made through various expression techniques, have some characteristics. First, leather clothes emphasize women's voluptuous beauty. Second, leather clothes create a decorative effect through mixture of materials and various expression techniques. Third, through the feel of materials and the emphasis of shapes, primitive beauty is expressed.

• Journal of KIBIM
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• v.9 no.4
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• pp.10-20
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• 2019

As a result, the areas of knowledge that received the highest score in a positive impact were areas of risk management, while those that received the highest score in a negative impact were items of software management. In addition, each project was rated according to the score obtained. The distribution of grades by project was 71% for projects above middle grade and 29% for projects below middle grade. These results show that interest in BIM technology is increasing compared to the past, actual field application and research are actively being conducted, and that real construction sites also enjoy significant positive effects in terms of project management through BIM. In addition, the company is using BIM by applying advanced digital technologies such as AI technology, laser scanning technology and drone technology in line with the era of the fourth industrial revolution. Such a steady progress in future research on BIM technology development will reduce the number of low-grade projects and many middle-grade projects are expected to be upgraded to higher-level ones.

• Journal of KIBIM
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• v.11 no.4
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• pp.20-30
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• 2021

In the era of the 4th industrial revolution, smart construction is actively researched, in the domestic construction field, and one of the key elements in this field is Building Information Modeling(BIM). In Korea, smart construction is being implemented through BIM-based digitization and intelligence. The geotechnical engineering field should also prepare for the introduction of BIM. In this study, the concept and application status of GeoBIM were identified, and the direction of future research was presented. This study is a part of the study "Establishment of GeoBIM-based Digital Twin Maintenance System" in the current "Technology Development for Establishment of Jeju Ground Collapse Response System for Safe Road Operation". The subject and scope of the study is continuous excavation at caves located under roads in Jeju Island, and initial research is being conducted on Jaeamcheon-gul and Jeonggusu-gul. This study aims to build a digital twin through individual data construction and integration processes such as cave shape modeling using laser scanners, 3D stratum modeling using borehole information and geophysical exploration data, and modeling of surrounding conditions using drones.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.8 no.1
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• pp.1-11
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• 2013

The femto fusion technology refers to not only the technology for femtosecond($10^{-15}$ second) laser and but also the fusion technology of its application. This technology is comparable to the nano technology, the extreme technology on the space, and is of extreme time-domain technology. Now, we need to develop the hyperfine and high-precision femto fusion process technology which allows to miniaturize and highly integrate the products of mobile, semiconductor and display industries, the national main focusing growth industries. However, The femtosecond laser fabrication technology is essential in the development of fusion technology, but only a few of domestic researchers can handle the former. Under this condition, our government plans to develop the "femto fusion technology infrastructure project" as one of the ICT research infrastructure. So the purpose of this study is to analyze the feasibility of this project. We applied AHP(analytic hierarchy process) for this study. The final result shows that all the repondent's score is over 0.55 and the aggregated score is 0.846. And as a consequence, we can conclude that to do this project is feasible.

• Archives of design research
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• v.18 no.2 s.60
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• pp.303-314
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• 2005

This study is intended to promote local woodcraft industry with revitalization of local festival in Inje-county. To do so, we propose the travel souvenir design with local identity and the plan for production and marketing based on the management of 'Design Hospital' and the building of production method through 'laser wood inlaying technique like puzzle style'. Research method is benchmarking analysis of successful cases of travel souvenir which is developed for cultural contents of local festival. The result of this study is the following. First, design outsourcing is done one of support in industry focused on old boy network, Through it, Special brain of design can be supplied without compensation. Also the difficulty of manpower problem is lessened and the ability of product development in short term can be guaranteed. On the basis of this, we are able to apply Mass Customization production by up to date digital production method. This enables us to maintain the production flexibility of cultural goods fit for the traits of local festival. This study is intended to present the best model guananteeing both profit of wood technological industry and the possibility of local cultural.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.270-276
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• 2020

3D printing is an additive manufacturing technology that can produce complex shapes in a single process for a range of materials, such as polymers, ceramics, and metals. Recent 3D printing technology has developed to a level that enables the mass-production through an improvement of the printing speed and the continuous development of applicable materials. In this study, 3D printing technology using a laser was applied to manufacture a heat exchanger for an air compressor in a railway vehicle. First, the optimal design of the heat exchanger was carried out by focusing on weight reduction and compactness as a shape suitable for 3D printing. Based on the design derived, heat exchanger prototypes were made of AlSi10Mg alloy material by applying the SLM technique. Moreover, the manufactured prototypes were attached to an existing air compressor, and the heat exchange performance of the compressed air was tested. The test results of the 3D printed prototypes showed a heat exchange performance of approximately 80% and 85% at low and high-pressure, respectively, compared to the existing heat exchanger. From the 𝓔-NTU method results with an external cooling air condition similar to that of the existing heat exchanger, the calculated heat transfer amount of 3D printed parts showed similar performance compared to the existing heat exchanger. As a result, the 3D printed heat exchanger is lightweight with good performance.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.1
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• pp.35-39
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• 2003

The display technology on the retina is the key role in inspecting the condition of the patients. 2-dimensional retina image is widely used in the eye examination as of today. Recently, 3-dimensional retina image ones have been introduced to this area, but the quality of the image is not fully satisfied to the operator. For the purpose of developing 3-D retina imaging instrument, the optimization of a 3-D retina imaging system using Code-V tool was investigated in this thesis. He-Ne laser having the wavelength 632.8 nm was used to make a power source to detect the retina. Several lenses and mirrors installed on sledge which were developed to perform focus control on 3-D device were designed to make a beam focusing and direct line. Polygon scanner having 24 mirror facets and galvanometer making tilting movement were utilized to make a 2-D laser plane. Also, design of eye ball had been fulfilled to see the focus of the 2-D plane. Reflected ray from retina detected on the sensor array with the same path. All cognitive components were optimized for aberration correction in order to focus on retina. Results of optimization were compared to those of initial designed optics system. On the basis of above results, the result of third aberration has been corrected to stable values to the optical system. MTF evaluating the resolution of an image has been closely correlated to the diffraction limit and PSF indicating the strength distribution of an image has shown the SR value as 0.9998 having high performance. The possibility of new and powerful 3-D retina image instrument was verified by simulating each component of the instrument by Code-V.