• 한국군사과학기술학회지
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• 제20권1호
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• pp.148-157
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• 2017

Miniature guided-bullet is an advanced military technology of developing guided missile which is designed to hit a target precisely while having easily carriable miniature size. A key issue of developing such system involves size reduction of the original guided missile system, and this in turn arouses stiffness issue regarding small and thin sized control surface. In this study, procedures on how to calculate the critical flutter speed of special type of control surface with the change of its dimension or material property is arranged. During this procedure, design parameters related to critical flutter speed are abridged to help preliminary design of similar structure even faster than time-consuming, and cumbersome computer analysis.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 추계학술대회 논문집
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• pp.63-64
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• 2013

Induction motors' faults detection is almost a popular topic among researchers. Monitoring the output of motors is a key factor in detecting these faults. (Short-time) Fourier, (continuous, discrete) wavelet, and extended Park vector transformations are among the methods for fault detection. One major deficiency of these methods is not being able to detect the severity of faults that carry low energy information, e.g. in ball bearing system failure, there is absolutely no way to detect the severity of fault using Fourier or wavelet transformations. In this paper, the authors have applied the Discrete Wavelet Transform (DWT) frequency-domain analysis to detect bearing faults in an induction motor. In other words, in discrete transform which the output signal is decomposed in several steps and frequency resolution increases considerably, the frequency-band analysis is performed and it will be verified that first of all, fault sidebands become more recognizable for detection in higher levels of decomposition, and secondly, the inner race bearing faults turn out easier in these levels; and all these matter because of eliminating the not-required high energy components in lower levels of decomposing.

• 한국건축시공학회지
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• 제8권1호
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• pp.97-102
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• 2008

The report of the Korean Board of Audit and Inspection(BAI) on May 2007 indicates the problems of Life Cycle Cost (LCC) analysis and evaluation in the Design-Build(Turn-Key) and alternative bidding system. The point which the report indicates is that the cost estimation system for LCC analysis has nothing in common each other and there's no consistency among the repair cycle and ratio per facilities parts. For solving these problems, BAI demands the establishment of the guidelines for LCC analysis and evaluation from the competent authority Korean Ministry of Construction And Transportation(MOCT). The objective of this study is to develop the improvement directions for LCC analysis and evaluation which are suitable to the public construction projects especially for the Design-Build and alternative bidding system in Korea. For this study, the LCC related raws and regulations, LCC analysis guidelines of public cooperations, actual condition of LCC analysis and evaluation which include, the elements of LCC, the estimation rules of the initial cost and the maintenance cost, the analysis standards of time value of money, etc. are investigated to provide the improvement directions for LCC analysis and evaluation.

• BMB Reports
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• 제48권4호
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• pp.200-208
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• 2015

The field of redox proteomics focuses to a large extent on analyzing cysteine oxidation in proteins under different experimental conditions and states of diseases. The identification and localization of oxidized cysteines within the cellular milieu is critical for understanding the redox regulation of proteins under physiological and pathophysiological conditions, and it will in turn provide important information that are potentially useful for the development of novel strategies in the treatment and prevention of diseases associated with oxidative stress. Antioxidant enzymes that catalyze oxidation/reduction processes are able to serve as redox biomarkers in various human diseases, and they are key regulators controlling the redox state of functional proteins. Redox regulators with antioxidant properties related to active mediators, cellular organelles, and the surrounding environments are all connected within a network and are involved in diseases related to redox imbalance including cancer, ischemia/reperfusion injury, neurodegenerative diseases, as well as normal aging. In this review, we will briefly look at the selected aspects of oxidative thiol modification in antioxidant enzymes and thiol oxidation in proteins affected by redox control of antioxidant enzymes and their relation to disease. [BMB Reports 2015; 48(4): 200-208]

• 복식
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• 제65권1호
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• pp.76-88
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• 2015

Excessive spending and the ever-changing fashion trends lead to an increase in material production to meet consumers' needs, which also in turn, increase the amount of industrial waste and many harmful pollutants. To address this problem, this study aimed to utilize discarded jeans' parts, reconstructing them into edgy and functional designs for everyday products. Six pairs of discarded jeans were collected and were used to create six types of functional products -three types of baskets, a bag, a slipper, and a key-holder. The benefits of up-cycling outweigh recycling because it not only increases the recycling rate, but also decreases the amount of energy and cost, thereby increasing the efficiency in recreating new innovative products. These proposed up-cycling ideas will serve as a great alternative for consumers to actively participate in reducing carbon emission, water usage, and waste to landfill by utilizing used clothing. This will guide how consumers can extend the life of their used clothing, utilize recyclable items more thoroughly, and keep used clothing out of landfills.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.357_358
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• 2009

According to the 4th BPE(Basic Plan for long-term Electricity Supply and Demand), Electricity demand of Jeju island in 2012 will be reached to 682MW. Jeju island will be faced with severe shortage of electricty, also needed to find transport route to supply green energy which will be made from "Carbon free island" energy policy toward land at that time. For that reason, The plan which construct 400MW size HVDC connection line was decided for potential supply stabilization and transportation of green energy. KEPCO organized special construction office not only to observe the successful project completion which aims 2011 December but also to build up professional manpower. KEPCO is putting spur to the HVDC project these days. Construction site of converter stations has been already confirmed and contracts of cable, converter have done as per turn-key early this year. On this report, we would like to discuss about project scheme, main characteristics of system, and the furture progress plan of "Jindo~Jeju HVDC construction project expecially converter station part" which is being pushed by KEPCO.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.41-46
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• 2004

This study deals with the friction and wear characteristics of C-N coated spur gear. The PSII apparatus was built and a SCM415 test piece and test gear with steel substrate was treated with carbon nitrogen by this apparatus. The composition and structure of the surface layer were analyzed and compared with that of PVD coated TiN layer. It was found that both of friction coefficients of C-N coating and TiN coaling decreased with increasing load, however, C-N coating showed relatively lower friction coefficient than that of TiN coating. We was investigated the effect of C-N coating on hardness, friction and wear. The TiN coated gear showed more serious friction phenomena than that of C-N coated gear. It was considered that coating of TiN, which was conducted at a vacuum chamber at about $500^{\circ}C$ results in a tempering of base material that causes microstructure change, which in turn resulted in decreasing of hardness. The C-N coated gear and pinion had higher wear resistance that of TiN coated gear and pinion. C-N coating significantly improved the friction and wear resistance of the gear.

• 기술사
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• 제32권1호
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• pp.122-141
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• 1999

Groupware is a new emerging research field, involving increasing numbers of institutions in the USA, Europe, and Asia such as Korea and Japan, etc., as an interdisciplinary research and development area with a strong computer science component. It grew from fairly unsystematic attempts by various developers to generate software that would increase the competence of people working together. This in turn was partly a response to: failures of and problems inherited from Office Automation and Management Information System ; some sociological intuitions about ways people might work together; and a search for uses of new interfacing, networking, and multi-media technologies. In this paper, groupware that has been configured to meet the needs of groups at work is defined as computer-based systems which support working groups of people engaged in common task in a shared environment. The basic concepts, origin, and historic research of the groupware are described. Specially, groupware relies on the approaches and contributions of many disciplines in computer science as well as sociology that is concerning human, social, and cultural activities. So, nine key disciplines of them upon which successful groupware depends are described briefly. Some state-of-the-art implementations and developments are reviewed through classifying and analyzing the current available groupware applications in the field or market.

• Computers and Concrete
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• 제11권1호
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• pp.1-20
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• 2013

There is an abundance of research on the strengthening of reinforced concrete (RC) structural elements such as beams, columns and slabs with fibre reinforced polymer (FRP) composites. Less research by comparison has been conducted on the strengthening of RC beam-column connections and the majority of such research has been predominantly experimental to date. Few existing experimental studies have reported extensive instrumentation of test specimens which in turn makes understanding the behavior of the connections and especially the contributions made by the FRP difficult to ascertain. In addition, there has been even more limited research on the analytical and numerical modelling of FRP-strengthened connections. In this paper, detailed descriptions of key strategies to model FRP-strengthened RC connections with finite elements are provided. An extensively instrumented and comprehensively documented set of experiments on FRP-strengthened connections is firstly presented and finite element models are then constructed using ANSYS. The study shows that the finite element approach is able to capture the overall behavior of the test specimens including the failure mode as well as the behavior of the FRP which will most importantly lead to a detailed understanding of the FRP and the future development of rational analytical models. The finite element models are, however, unable to model the stiffness of the connections with accuracy in the ultimate load range of response.

• 천문학회보
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• 제39권2호
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• pp.43.1-43.1
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• 2014

We report on the optical spectroscopic analysis of a Low Luminosity Quasi Stellar Objects (LLQSOs) sample at $z{\leq}0.06$ based on the Hamburg/ESO QSO survey (HES). To better relate the low-redshift Active Galactic Nucleus (AGN) to the QSO population it is important to study samples of the latter type at a level of detail similar to that of the low-redshift AGN. Powerful QSOs, however, are absent at low redshifts due to evolutionary effects and their small space density. Our understanding of the (distant) QSO population is, therefore, significantly limited by angular resolution and sensitivity. The LLQSOs presented here offer the possibility to study the faint end of this population at smaller cosmological distances and, therefore, in greater detail. This, in turn, provides information about the key ingredients with respect to fueling and feedback of QSOs, and their relative importance/strength. Here, we present results of the analysis of visible wavelength spectroscopy provided by the HES and the 6 Degree Field Galaxy Survey (6dFGS). Interesting differences in the taxonomy of the sources having both types of spectra have been noticed and will be discussed.