• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.5
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• pp.53-59
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• 2019

Solid fuel reacts with an oxidizer during combustion of a propellant to increase performance. Representative solid fuels are aluminum, cyclotrimethylenetrinitramine (RDX) and octahydro-1, 3,5,7-tetra nitro-1,3,5,7-tetrazocin (HMX). During combustion, these compounds generate white smoke by reacting with moisture and produce materials that are harmful to the environment, such as carbon monoxide, carbon dioxide, and methane gas. This study prepared a high-nitrogen-containing energetic material, hydrazinium 5-aminotetrazolate (HAT), which could be applied as a solid fuel. The compound was characterized by nuclear magnetic resonance (NMR) spectroscopy, and a thermal analysis was measured by differential scanning calorimetry (DSC). Also, the specific impulses and volumes of detonation gases were calculated using the EXPLO5 program.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.46-51
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• 2012

This study aims to develop the performance analysis program on the staged combustion cycle of the liquid rocket engine using liquid oxygen(LOx) as oxidizer, liquid hydrogen(LH2) and RP-1 as fuel. The developed analysis program can obtain the propellant mass flow rate, the specific impulse, and representative design values of engine components for the required thrust satisfying pressure, mass flow, and energy balance conditions. The analysis results show that the the specific impulses (Isp) compared to those of the real engines have been less than 1%. With additional constraints, the program will be improved for the system optimization.

• Cross-Cultural Studies
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• v.24
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• pp.32-45
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• 2011

This paper addresses some issues on the Northern Nigerian traditional garments and caps. We observed that most of the Northern Nigerian garments and caps, particularly those of the Kanuri people, have their origin in the culture and traditions of the people. In very significant ways, the garments and the caps depict the belief systems, political metaphysics, and the general consciousness of the people including their creative impulses. But as more and more people move from rural areas to the cities, travel abroad and as more and more cultures intermingle, inevitable changes catch up with the culture and tradition of the people. We observed that it is hard to find in the Northern Nigeria scene, particularly among the Kanuri people, clothes that have assumed new nomenclature other than garments and caps. We realized that, the culture and tradition of the Kanuri people wearing longer, voluminous and roomy garments preferably with cap have witnessed changes due to the blend with foreign culture. This and many other issues are discussed in this paper. The purpose of this research is to show that inspite of the Kanuri people's strong adherence to their beliefs and culture which hardly encourage any changes, the use of their traditional garments and caps have exhibited the flexibility of their beliefs, culture and traditions. The use of the garments and caps discussed in this paper are those observed among the Kanuri people of Northern Nigeria.

• Journal of Drive and Control
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• v.15 no.4
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• pp.74-80
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• 2018

A damper is a hydraulic device designed to absorb or eliminate shock impulses which is acting on the sprung mass of vehicle. It converting the kinetic energy of the shock into another form of energy, typically heat. In a vehicle, a damper reduce vibration of car, leading to improved ride comfort and running stability. Therefore, a damper is one of the most important components in a vehicle suspension system. Conventionally, the design process of vehicle suspensions has been based on trial and error approaches, where designers iteratively change the values of the design variables and reanalyze the system until acceptable design criteria are achieved. Therefore, the ability to tune a damper properly without trial and error is of great interest in suspension system design to reduce time and effort. For this reason, a many previous researches have been done on modeling and simulation of the damper. In this paper, we have conducted optimal design process to find optimal design parameters of damping force which minimize a acceleration of sprung mass for a given suspension system using genetic algorithm.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.26 no.1
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• pp.72-80
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• 2019

Purpose: This study aimed to measure health-related quality of life (HRQoL) and investigate the relevant factors for middle aged women using the 2014 Korea Health Panel data. Methods: The Korea Health Panel data 2014 were collected from February to August 2014 by the Korea Institute for Health and Social Affairs and the National Health Insurance Corporation and included 2,075 people who responded to the questionnaire. Using SPSS WIN program, the data were analyzed by t-test, ANOVA, Pearson correlation coefficient, and multiple regression analysis. Results: Limited activity was the most influential factor for the health-related quality of life of middle-aged women. For health behavior, the factors affecting HRQoL were drinking, sleeping time, and physical activity. For physical health, factors affecting HRQoL were vision problems, eating problems, and hearing problems. For mental health, the factors affecting HRQoL were suicidal impulse, stress, and frustration. Conclusion: These results indicated that to improve HRQoL for middle-aged women, limited activity and suicidal impulses should be addressed.

• Korea Trade Review
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• v.44 no.4
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• pp.205-220
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• 2019

This article recapitulates the recent changes in trade laws, which may be accentuated due to the intriguing emergence of fortified protectionism and Mega FTAs. It points out the need to formulate not only the corporate strategy for enhancing the product differentiation and architectural capabilities but also the public policy, which comprises the industrial adjustment policy to cope with possible negative impulses caused by the digital trade and foreign direct investment. It is imperative for Korea to facilitate the alignment between corporate strategy and industrial adjustment policy as an effective means of enhancing industrial structure by nurturing those linkage effects between relevant forward and backward industries. Given the drastically volatile trade norms of multi-track trade policies, it may be a pivotal momentum for Korea to pursue a paradigm shift of its trade policy with a prime objective of achieving such an alignment between corporate strategy and industrial adjustment policy, which affords increased value-added and the further development of product or generic technology instead of resorting to the misuses and abuses of economies of scale and production technology for the maximization of export amount.

• Journal of English Language & Literature
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• v.55 no.6
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• pp.937-959
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• 2009

The Queen of the Air, John Ruskin-s highly elliptical publication of 1869, elaborates a complex mythology as a way of responding to the prevalence of scientific thinking, widespread environmental degradation, the pernicious effects of political economy, and mechanistic labor. Benjamin-s desire to rescue human experience from prevailing scientific conceptions is reminiscent of Ruskin-s fear that the peculiar power that shapes the unities of the natural world is simultaneously being "beaten down by the philosophers into a metal or evolved by them into a gas" and obscured by the dreams and theories of philosophers and theologians. As a critic remarks, in Benjamin-s-and, we would add, Ruskin-s-view, "what the modern era lacked was a basis for continuity which would prevent experience from disintegrating into a desultory and meaningless series of events." Despite its frenetic hyper-associativity, then, The Queen of the Air contains a key element that Benjamin believes is necessary for "redemption": the desire for a new form of consciousness that recognizes links to the past and thus to the longings and dreams of our forebears. Thus, although Ruskin most immediately influences Proust, who in turn influences Benjamin, Benjamin-s thought is far more Ruskinian than critics have heretofore observed. Just as Benjamin helps us make sense of the ways in which The Queen of the Air is caught in the grip of the shocking associativity of modern life, so Ruskin assists us in discerning similar impulses in Benjamin-s attraction to a form of archaic consciousness that can, by altering the modern form of perception, reenchant the present.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.181-194
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• 2022

between the Action-image and the Affection-image, there is the Impulse-image. IF the aesthetics of the action-image and Affection-image are realism and idealism, the aesthetics of the impulse - image is naturalism. since the impulse-image has traits of action-image and affection-image, naturalism refers to four co-ordinates: originary world/derived milieu, impulses/modes of behavior. In Deleuze's view, the great directors we call naturalists are Stroheim, Bunuel, and Joseph Losey.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.22 no.2
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• pp.273-282
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• 1992

The purpose of this study was to propose the utility which was evaluated the digital image processing and clinical application of the videodensitomery. The experiments were performed with IBM-PC/16bit-AT compatible, video camera(CCdtr55, Sony Co., Japan), an color monitor(MultiSync 3D, NEC, Japan) providing the resolution of 512×480 and 64 levels of gray. Sylvia Image Capture Board for the ADC(analog to digital converter) was used, composed of digitized image from digital signal and the radiographic density was measured by 256 level of gray. The periapical radiograph(Ektaspeed EP-21, Kodak Co., U. S. A) which was radiographed dried human mandible by exposure condition of 70 kVp and 48 impulses, was used for primary X-ray detector. And them evaluated for digitzed image by low and high pass filtering, correlations between aluminum equivalent values and the thickness of aluminum step wedge, aluminum equivalent values of sound enamel, dentin, and alveolar bone, the range of diffuse density for gray level ranging from 0 to 255. The obtained results were as follows: 1. The edge between aluminum steps of digitized image were somewhat blurred by low pass filtering, but edge enhancement could be resulted by high pass filtering. Expecially, edge enhancement between distal root of lower left 2nd molar and alveolar lamina dura was observed. 2. The correlation between aluminum equivalent values and the thickness of aluminum step wedge was intimated, yielding the coefficient of correlation r=0.9997(p<0.00l), the regression line was described by Y=0.9699X+0.456, and coefficient of variation amounting to 1.5%. 3. The aluminum equivalent values of sound enamel, dentin, and alvolar bone were 15.41㎜, 12.48㎜, 10.35㎜, respectively. 4. The range of diffuse density for gray level ranging from 0 to 255 was wider enough than that of photodenstiometer to be within the range of 1-4.9.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.99-105
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• 2010

The most frequently used noise model for the performance analysis of a communication system is additive white Gaussian noise. However impulsive noise model is more practical for the real communication environments, currently the performance analysis of a communication system in impulsive noise is increasing. In this paper, therefore, the performance of a cooperative system, which is recently one of the most intensive research topics, is derived in impulsive noise. We analytically derive and compare the performance of two opportunistic cooperative diversity systems which have an amplify-and-forward (AF) relaying or a decode-and-forward (DF) relaying. It is noticed that the impulsive noise component is increases with decreasing the average number of impulses in impulsive noise, consequently the performance of two systems is degraded in high SNR region. Also it is shown that the performance of the opportunistic cooperative system with DF relaying is superior to that with AF relaying.