• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3C
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• pp.293-298
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• 2008

Recently, with the development of mobile techniques and the consideration to conveniency of using, the research on Mobile RFID Reader technique is getting more and more attentions. Until now, all security authentication algorithms of RFID are algorithms about range between Tag and Reader. The range between Reader and backend DB is composed by wired networks, so it's supposed to be secure range. But it must be taken account of the problem of information security and privacy in wireless range during the design of Mobile RFID Reader. In this paper we design an blind signature scheme based on weil-paring finite group's ECC encryption scheme, and by using this blind signature we propose the anonymous authorization scheme to Mobile RFID Reader's users.

• Magazine of the Korea Concrete Institute
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• v.2 no.3
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• pp.65-72
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• 1990

Theoretical expressions were dcrived for the numher of fibers per unit cross-sectional area in fiber reinforced concrete, with due consideration given to the effects of the surrounding boundaries. The number of fibers per unit cross-sectional area in steel fiber reinforced concrete was also measured experimentally for the specimens incorporating various volume fractions of fibers of different types. Statistical evaluation of the measured value was then performed in order to assess the differences in fiber concentration at different location on tbe cross section. Degree of reorientation of steel fibers in concrete occuring during vibration was examined by com¬paring the differences in the computed and measur'ed values of the number of fibers per unit cross-sectional area.

• Journal of Korea Multimedia Society
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• v.13 no.1
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• pp.76-82
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• 2010

Reversible watermarking hides some information in a digital image in such a way that an authorized party could decode the hidden information and also restore the image to its original state. In this paper, a high capacity reversible watermarking method using histogram shifting is proposed. In order to increase embedding capacity, the proposed method divides the image into $2{\times}2$ blocks and uses a paring(horizontal, vertical, diagonal) inside each block, then finds a maximum embedding bin which has the most frequent difference values among the parings. Also, the proposed method removes the overflow and underflow by using location map which including the maximum embedding bin and increases the embedding capacity by embedding iteratively. The experimental results show that the proposed method provides a high embedding capacity and good visual quality compared with the conventional reversible watermarking methods.

• The Journal of the Korea Contents Association
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• v.6 no.12
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• pp.12-20
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• 2006

In this paper, we propose electronic payment protocol using GDHP blind signature scheme to activate e-business in the wire/wireless integrated environment. The protocol applied elliptic curve algorithm on the GDHP base and improved the efficiency of the existing blind signature technique on the basis of communication frequency and calculation number. And the protocol accelerated speed and strengthened safety against man-in-the-middle attacks and forward secrecy because the certification between individuals is performed by the session key created by Weil paring using elliptic curve cryptosystem in the limited entity $F_q$ instead of the certification used in the existing PayWord protocol.

• Archives of Pharmacal Research
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• v.19 no.5
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• pp.396-399
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• 1996

High-performance liquid chromatographic method with UV detecction was developed for the determination of theophylline and its metabolites in human urine using ${beta}$-hydroxyethyl theophylline$({beta} -HET)$ as an internal standard. For extraction of urine sample, quality control sample and xanthine-free blank urine were mixed with decylamine (ion-paring reagent) and ${beta}$-HET. After saturation with ammonium sulfate, the mixture was then extracted with organic solvent at pH values of 4.0-4.5. All separations were performed with ion-pair chromatography using decylamine as an ion-pairing reagent and 3mM sodium acetate buffered mobile phase (pH 4.0) containing 1% (v/v) acetonitrile and 0.75 mM decylamine. The detection limits of theophylline, 1, 3-DMU, 1-MU, 3-MX and 1-MX in human urine were 0.17, 0.17, 0.39, 0.19 and 0.19 ${\mu}g$/ml, based on a signal-to-noise ratios of 3.0. The mean intraday coefficients of variation (C.V.s) of each compound on nine replicates were lower than 2.0%, while mean interday C.V.s on three days were lower than 1.6%. All separations were finished within 40miutes.

• Smart Structures and Systems
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• v.20 no.5
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• pp.525-537
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• 2017

This paper explores different vibration control strategies for the cancellation of human-induced vibration on a structure with time-varying modal parameters. The main motivation of this study is a lively urban stress-ribbon footbridge (Pedro $G\acute{o}mez$ Bosque, Valladolid, Spain) that, after a whole-year monitoring, several natural frequencies within the band of interest (normal paring frequency range) have been tracked. The most perceptible vibration mode of the structure at approximately 1.8 Hz changes up to 20%. In order to find a solution for this real case, this paper takes the annual modal parameter estimates (approx. 14000 estimations) of this mode and designs three control strategies: a) a tuned mass damper (TMD) tuned to the most-repeated modal properties of the aforementioned mode, b) two semi-active TMD strategies, one with an on-off control law for the TMD damping, and other with frequency and damping tuned by updating the damper force. All strategies have been carefully compared considering two structure models: a) only the aforementioned mode and b) all the other tracked modes. The results have been compared considering human-induced vibrations and have helped the authors on making a decision of the most advisable strategy to be practically implemented.

• Korean Journal of Microbiology
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• v.33 no.2
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• pp.131-135
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• 1997

Several microorganisms capable of producing protopectinase, which catalyzes dissociation of plant tissue to single cells, were isolated from soils. Crude enzymes prepared from culture supernatants of the strains released potato cells as a single cell from potato tissues. One of the isolated strains showing higher activity of protopectinase was selected and identified as Rhizopus sp. from the morphological characteristics. For preparing single cells from potato tissues, optimum enzyme activity of protopectinase, which was prepared from culture filtrate of Rhizopus sp. R2, was obescrved at $40^{\circ}C$ and pH 4.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.5_6
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• pp.250-257
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• 2003

As the memory access time becomes slower relative to the fast processor speed, most systems use cache memory to reduce the gap. The cache performance has an increasingly large impact on the performance of algorithms. Blocking is the well known method to utilize cache and has shown good results in multiplying matrices and search trees like d-heap. But if we use blocking in the data structures which require rotation during insertion or deletion, the execution time increases as the data movements between blocks are necessary. In this paper, we have proposed the extended pairing heap algorithms using block node and shown by experiments that our structure is superior Also in case of using block node, we use less memory space as the number of pointers decreases.

• Bulletin of the Korean Chemical Society
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• v.21 no.6
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• pp.623-627
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• 2000

Aggregation of hydrophobically end-capped poly(ethylene oxide)s: HEURs, denoted as $C_8$$EO_{380}$$C_8$, $C_12$$CO_{600}$$C_{12}$, and $C_{18}$$EO_{860}$$C_{18}$,are described using static fluorescence, dynamic light scattering, and atomic force microscope (AFM) techniques. The CAC (critical aggregation concentration) was determined by com-paring two fluorescent peaks which were influenced by the polarity of the probe dye molecules, pyrene. The aggregation occurs in concentrations higher than 10 g/L of $C_8$$EO_{380}$$C_8$ and the CAC decreases by increasing the side chain length. The dynamic light scattering experiment shows fast mode and slow mode decays, and both are diffusive. The fast mode does not depend on the concentration, but the slow mode shows concentration dependence influenced by the formation of an aggregated structure. The hydrophobic end groups effect more dominantly than the main chains for the formation of HEUR micelles. By increasing the concentration, the HEUR micelles change their structure from spheres to rodlike micelles, and finally make fused structures, which were visualized with atomic force microscopy.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.6
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• pp.74-82
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• 1997

We provide a set of information on technologies to draw meaningful action plans for the internationalization on National R&D activities. In this study, we employed a modiffed Delphi method to evaluate levels of our technological capabilities and developed countries as well. We investigated technology acquis- tion methodologies, technology characteristics and various aspects of international cooperation in terms of technology. Then, we analyzed final responses of participants (i.e., the third round results of Delphe method) to see the correlation among various factors in developing technologies through international R&D cooperation. The technology classification used in this research was developed by STEPI (Science and Technology Policy Institute). In conclusion, levels of our technologies were investigated to be between the stage of imi- tating/absorbing advanced thechnologies and the stage of digesting acquired technologies. Especially, com- paring with other technologies, mechanical engineering was evaluated to be almost near the stage of digesting acquired technology(the middle level stage of technology). Our overal technological capabilities were evaluated to be 40 .approx. 60% of top level countries.