• 한국디지털정책학회:학술대회논문집
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• 2004.05a
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• pp.705-717
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• 2004

본 연구는 '01.3.19-'03.11.21 까지의 국채 현 선물 장기간 데이터를 이용하여 두 변수간의 관계를 분석해 본 결과 두 변수가 상당히 높은 양(+)의 관계를 갖는 것으로 나타남. 변수간에 장기안정관계 즉 공 적분관계가 존재하는 것으로 나타나 오차수정모형 (ECM)을 통해서 분석을 시도했다. 두 기간 사이에 국채 현 선물 가격간의 관계 변화가 있었는지 알아보기 위해 실증분석 기간을 반분한 후 분석을 실시한 결과국채 선물의 현물에 대한영향력이 최근들어 더 커지고 있는 것으로 나타남. 두 변수간의 원인과 결과관계를 분석하기 위해 실시한 인과관계분석에서는 두 변수간에 통계적으로 유의한 인과관계를 발견할 수 없었다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1893-1896
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• 2003

This research aimed to fabricate a micro structure using micro electrochemical machining (${\mu}$-ECM). with a view to that the theory of ${\mu}$-ECM is established accurately in a different way of conventional electrochemical machining. In details, if the impedance is existed in the system, it is difficult to analyze the micro electrochemical reaction efficiently in polarization curve using a potentiodynamic test. Hence, this research investigates the relationships between impedance and electric current measuring with a potentiostatic test applying to a pair or electrode as a constant potential. And this paper examines the influence of temperature of electrolyte on polarization curve for the quantitative analysis of electrochemical reactions.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.3
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• pp.308-314
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• 2011

In micro electrochemical machining (micro ECM), machining conditions have been determined to maintain a small side gap and to machine a workpiece stably However, machining speed is slow. To improve machining speed while maintaining the form accuracy, the paper investigates machining parameters such as pulse amplitude, duty ratio, pulse on-time, and the electrolyte's temperature and concentration. The experiment in this study shows that the electrolyte's concentration is the key factor that can reduce machining time while maintaining the form accuracy Micro square columns were fabricated to confirm the machining parameters' effects.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.1
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• pp.49-53
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• 2008

A fuzzy inference logic system is proposed for gas turbine engine fault isolation. The gas path measurements used for fault isolation are exhaust gas temperature, low and high rotor speed, and fuel flow. The fuzzy inference logic uses rules developed from a model of performance influence coefficients to isolate engine faults while accounting for uncertainty in gas path measurements. Inputs to the fuzzy inference logic system are measurement deviations of gas path parameters which are transferred directly from the ECM(Engine Control Monitoring) program and outputs are engine module faults. The proposed fuzzy inference logic system is tested using simulated data developed from the ECM trend plot reports and the results show that the proposed fuzzy inference logic system isolates module faults with high accuracy rate in the environment of high level of uncertainty.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1455-1457
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• 2008

Cell adhesion is a coordinated process involving initial binding of integrin receptors to extracellular matrix (ECM), recruitment of adhesion proteins, and focal adhesion assembly. The formation of mechanically stable focal adhesion assembly of cells within surrounding ECM is a key parameter to direct numerous cellular functions including cell migration, differentiation, and apotosis. With current cell adhesion assays, it is difficult to understand contributions of each coordinated event on evolution of cell adhesion strengthening since cells spontaneously spread upon their adhesion to the substrate, thus remodeling their cytoskeletal structure. In this presentation, novel approaches for analysis of cell adhesion strengthening process based on the combination of mechanical device, micro-patterned substrates, and molecular biological techniques will be discussed.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3043-3051
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• 2016

Controlled remodeling of the extracellular matrix (ECM) is essential for cell growth, invasion and metastasis. Matrix metalloproteinases (MMPs) are a family of secreted, zinc-dependent endopeptidases capable of degradation of ECM components. The expression and activity of MMPs in a variety of human cancers have been intensively studied. They play important roles at different steps of malignant tumor formation and have central significance in embryogenesis, tissue remodeling, inflammation, angiogenesis and metastasis. However, increasing evidence demonstrates that MMPs are involved earlier in tumorigenesis. Recent studies also suggest that MMPs play complex roles in tumor progression. MMPs and membrane type (MT)-MMPs are potentially significant therapeutic targets in many cancers, so that designing of specific MMP inhibitors would be helpful for clinical trials. Here, we review the pleiotropic roles of the MMP system in hematological malignancies in-vitro and in-vivo models.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.5
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• pp.496-501
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• 2009

In micro electrochemical machining(micro-ECM), it is important to measure and control the potential of a tool electrode and a workpiece electrode because electrochemical reaction rate depends on the potential of the electrodes. When the electrode potential was measured against a reference electrode, the error of measured electrode potential could be minimized by proper tool electrode design. In this paper, multi-function electrodes consisting of a tool electrode and a reference electrode was fabricated by micro fabrication techniques. The machining conditions in micro-ECM using multi-function electrodes, such as pulse voltage parameters and electrode potential, were investigated.

• The Korean Journal of Applied Statistics
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• v.16 no.2
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• pp.305-319
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• 2003

This paper provides a non-Bayesian method based on the expanded EM algorithm for segmenting the magnetic resonance images degraded by bias field. For the images with the intensity as a pixel value, many segmentation methods often fail to segment it because of the bias field(with low frequency) as well as noise(with high frequency). Our contextual approach is appropriately designed by using normal mixture model incorporated with Markov random field for noise-corrective segmentation and by using the penalized likelihood to estimate bias field for efficient bias filed-correction.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.320-325
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• 2000

This study was performed to investigate the electro-chemical-machining (ECM) characteristic of Ni-Ti Shape Memory Alloy (SMA). From the experimental results, we could gain optimal electro-chemical conditions to bound with lesser machining effect and better surface roughness than any other machining methods to workpiece at the same time. At these conditions, current efficiency was, for especially ECM working of Ni-Ti SMA, approximately 100% and high frequency pulse current was detected.

• Environmental and Resource Economics Review
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• v.11 no.1
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• pp.81-97
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• 2002

Unlike the existing supply-centered water policy, demand management policy of water has become an increasingly important issue in Korea. This paper attempts to analyse the demand for domestic water in Seoul. We employed Engle-Granger's error correction model(ECM) to deduced the price and income elasticities of the water demand. Particularly, we used accounted water amounts instead of supplied water amounts as representative variable of water demand. The result indicates that ECM set up is appropriate and short-run and long-run price elasticities derived by the model are -0.145 and -1.414. In contrast with other studies, we can conclude that the water demand for the water price is elastic. Besides, we can infer from this result that the water price policy with respect to a decrease of leakage ratio is more effective.