• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1403-1406
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• 2002

Environmental impact of human activities has become a great concern in most of the countries world-wide, and for years. It has recently focused on potential climate changes due to the increase of green house gases content in the atmosphere. One of these gases is $SF_6$, which is an essential material in electrical applications having excellent dielectric and arc-quenching properties. Though the actual contribution of $SF_6$ to global warming is negligible at present, the control of $SF_6$ emissions seems to be nevertheless imperative. Actually, it is listed in the Kyoto protocol that emissions should not only be duly reported but also the electrical industry which is now the major user of this gas must be able to show that it is possible to use this gas and at the same time preserve the environment. For the development of environmentally-benign electric power equipment and systems, novel gases or gas mixtures are strongly required as the alternatives of $SF_6$ gas. Until now, most research work is focused on the $SF_6/N_2$ mixed gas which is suitable for application in the electrical apparatus with slightly non-uniform fields. Recently, $SF_6/CO_2$ mixed gas also is expected to be promising as a $SF_6$ alternative, especially in highly non-uniform fields and in a gas-impregnated film insulation system. Including these results, the author reviews the research trend or reducing the environmental impact of $SF_6$ gas in this paper.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.2
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• pp.147-154
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• 2012

In head sea, a ship has mainly the longitudinal motion such as vertical acceleration and pitch. In that case, the motion characteristics of a ship will have changed as the location different from each of place vertically and horizontally on board. The author carried out an experiment about the ship's vertical acceleration and pitch according to the location for the head sea, and analyzed the data with the aid of the statistical and spectral analyzing method to get the motion characteristics of the vessels. The response of vertical acceleration and pitch not deeply depend on the decks vertically, but displayed the relative big different value horizontally even if same deck. The biggest response of vertical acceleration and pitch among the accommodations was shown at scientist room, but the value of it not reached to the minimum requirement of ISO 2631-1 for working on board.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.2
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• pp.257-264
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• 2015

This study is intended to provide navigator with specific information necessary to assist the avoidance of collision and the operation of ships to evaluate the maneuverability of dead weight tonnage 8,000 tons Oil/Chemical tanker. The actual maneuvering characteristics of ship can be adequately judged from the results of typical ship trials. Author carried out sea trials based full scale for turning test, Z" maneuvering test, man overboard rescue maneuver test, inertia stopping test. Consequently, $2^{st}$ Overshoot yaw angle of the semi balanced rudder and flap rudder in ${\pm}20^{\circ}$ zig-zag test showed $22.2^{\circ}$ and $18.0^{\circ}$, respectively. The maneuverability of the vessel was good in the flap rudder. The man overboard rescue maneuver maneuverability test was most favorable in the flap rudder and the full load condition. The results from tests could be compared directly with the standards of maneuverability of IMO and consequently the maneuvering qualities of the ship is full satisfied with its.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.2
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• pp.245-256
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• 2015

This study is intended to provide navigator with specific information necessary to assist the avoidance of collision and the operation of ships to evaluate the maneuverability of dead weight tonnage 8,000 tons Oil/Chemical tanker. The actual maneuvering characteristics of ship can be adequately judged from the results of typical ship trials. Author carried out sea trials based full scale for turning test in ballast condition and full load condition, semi balanced rudder and flap rudder. The turning circle maneuvering were performed on the starboard and port sides with $35^{\circ}$ rudder angle at the normal continuous rating. The results from tests could be compared directly with the standards of maneuverability of IMO and consequently the maneuvering qualities of the ship is full satisfied with its.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.1
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• pp.50-63
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• 2015

Explosive bolts are one of pyrotechnic release devices, which are highly reliable and efficient for a built-in release. Among them, ridge-cut explosive bolts which utilize shock wave generated by detonation to separate bolt body produce minimal fragments, little swelling and clean breaks. In this study, separation phenomena of ridge-cut explosive bolts or ridge-cut mechanism are computationally analyzed using Hydrocodes. To analyze separation mechanism of ridge-cut explosive bolts, fluid-structure interactions with complex material modeling are essential. For modeling of high explosives (RDX and PETN), Euler elements with Jones-Wilkins-Lee E.O.S. are utilized. For Lagrange elements of bolt body structures, shock E.O.S., Johnson-Cook strength model, and principal stress failure criteria are used. From the computational analysis of the author's explosive bolt model, computational analysis framework is verified and perfected with tuned failure criteria. Practical design improvements are also suggested based on a parametric study. Some design parameters, such as explosive weights, ridge angle, and ridge position, are chosen that might affect the separation reliability; and analysis is carried out for several designs. The results of this study provide useful information to avoid unnecessary separation experiments related with design parameters.

• Korean Journal of Bronchoesophagology
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• v.9 no.2
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• pp.60-64
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• 2003

Restenosis frequently develops with granulation and overgrowth of scar following surgical treatment for laryngotracheal stenosis. Various methods such as stenting or CO2 laser application have been used to prevent restenosis, but they were seldom unsatisfactory. Mitomycin is an antineoplastic antibiotics derived from Streptomyces caespitosus; it inhibits fibroblast proliferation and acts as an alkylating agent to inhibit DNA synthesis. This study was desinged to evaluate effectiveness and determine indications of usage of topical mitomycin for laryngotracheal stenosis as a nonsurgical means of reducing postoperative granulation and scar tissue formation. Patients and Method : A retrospective study was performed on eight cases of laryngotracheal stenosis with topical mitomycin application. The author analyzed clinical outcomes of operative treatment with topical mitomycin. Patients underwent laryngotracheal reconstruction, endoscopic granulation removal, or bronchoscopic bougienage followed by topical application of mitomycin (0.4 mg/$m{\ell}$, 4minuntes) on the lesion intraoperatively. Result : Overall success rate of decannulation was 38% ($\frac{3}{8}$). Successful decannulation was possible in 75% ($\frac{3}{4}$) of laryngeal stenosis patients, 75% ($\frac{3}{4}$) of children, 60% ($\frac{3}{5}$) of the patients without previous surgery, and 75% ($\frac{3}{4}$) of bronchoscopic bougienage. Conclusion : The topical application of mitomycin in laryngotracheal stenosis was effective in untreated pediatric laryngeal stenosis which underwent bronchoscopic bougienage. Our results show that the topical mitomycin application for laryngotracheal stenosis could be a effective adjuvant treatment.

• Corrosion Science and Technology
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• v.19 no.2
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• pp.66-74
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• 2020

In this paper, the author's team has carried out a comparative experimental study on the corrosion characteristics of Q235 steel commonly used in large-scale storage tanks under the specific bottom water environment found with Russian and Daqing crude oil. It was found that there is a certain degree of uniform or local corrosion on the tank floor depending on the kind of bottom water. The bottom water corrosion of Daqing crude oil is a uniform corrosion caused by carbon dioxide. While the Russian crude oil bottom water corrosion is clearly local corrosion caused by co-corrosion of carbon dioxide and hydrogen sulfide, here the corrosion rate is obviously higher than that caused by Daqing crude oil. There are two modes of storage tank inspection and maintenance that have been currently adopted by Chinese refining and chemical enterprises: a regular inspection mode and a API581-2016 risk-based detection mode. These modes have been effectively combined to form an intelligent tank inspection and maintenance mode, software tools to support this intelligent inspection and maintenance management have been developed.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.1
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• pp.26-37
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• 2008

Objective : The present study was carried out to investigate the effects of NaisoOkseol-Tang (NOT) on solid tumor in mice in terms of immune-potentiating and direct cytotoxic action of NOT in vitro and vivo study. Methods: The present author investigated thymocyte proliferation and NO production to confirm immune-potentiating activity of NOT and also investigated body/tumor weight and survival rates in tumor bearing mice. In this study, administration of NOT decreased tumor/weight ratio significantly, and prolonged survival duration compared to non-treated control. Treatment with NOT also elevated proliferation rates of thymocytes isolated from tumor bearing mice. Results: In vitro study, treatment with NOT suppressed proliferation rate of Sarcoma 180 (S-180) cells. Contrary, treatment with NOT elevated proliferation rate of thymocytes. These results were co-related with in vivo study. In addition, NO production from abdominal macrophages isolated from normal mice was not affected by treatment with NOT. Conclusion : NOT is useful to treat patient with solid tumor, because NOT has direct toxic action for tumor cell and immune-potentiating action for T cells.

• Journal of Information Science Theory and Practice
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• v.4 no.1
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• pp.6-20
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• 2016

Scholarly communication plays a significant role in the development and dissemination of research outputs in library and information science (LIS). This study presents findings from a survey which examines the key attributes that characterize the publishing by Pakistani LIS scholars, i.e. academics and professionals, in national journals. A pilot-tested, electronic questionnaire was used to collect the data from the target population. 104 respondents (or 69.3% of target) provided feedback on areas such as number of articles published, number of citations, and the nature of any collaboration with other authors. The findings of this survey revealed that, among the various designated regions of Pakistan, the Punjab region was the most highly represented. In articles published in national journals, there was a clear preference among all respondents to collaborate with at least one other author. The citation metrics for LIS articles in national journals were relatively low (30.22%), which aligns with Scimago’s Journal and Country Rankings. The uptake of social scholarly networks mirrors international trends. Respondents were asked to score factors which could impact negatively on their ability to undertake research and/or publish the results. The study recommends that concerned stakeholders work together, as appropriate, to address concerns. In addition, it recommends that further research be undertaken to define patterns of Pakistani co-authorship in the social sciences.

• The Research Journal of the Costume Culture
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• v.21 no.5
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• pp.684-698
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• 2013

Interest and desire for analogue emotion increased with the dazzling development of digital technology. Especially, as analogue emotion got grafted in the design field, analysis through various expression media is being done. This study seeks to propose design of t-shirt using unique advantage of Hangeul calligraphy that can satisfy the modern flow and pattern design's various expressions. Calligraphy is being used in various fields such as advert, package, logo, movie poster, signboard, graphic design, calligraphy and abstract painting. Formative yet effective in readability and conveying meaning as it's expressed in letters, calligraphy is a field of attention with its contribution in extending the new design area. As a method of the study, altogether 8 pieces of t-shirts were proposed through related preceding research, literary research, co-work with calligraphy author, computer graphic program, and heat transfer. As such, the t-shirt designs which were created by suggesting various design and using traditional materials like calligraphy, can be used as novel and sensual factor, where one can get a glimpse at the potential of development as traditional fashion product.