• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.243.1-243.1
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• 2010

Devices based on nanomaterials platforms are emerging as a powerful tool for ultrasensitive sensors for the direct detection of biological and chemical species. In this talk, we will report the preparation and the full characterization of electrochemical polymerization of biopolymers platforms and nano-structure formation for electrochemical detection of enzymatic activity and toxic compound in electrolyte for biosensor applications. Formation of an electroactive polymer film of two different compounds has been quantified by observing new redox peak at higher potentials in cyclic voltammogram measurements. RCT value of at various biopolymer concentration based hybrid films has been obtained from electrochemical impedance spectroscopy analysis and possible mechanism for formation of complexes during electrochemical polymerization on conducting substrates has been investigated. Biosensors developed based on these hybrid biopolymers have very high sensitivity.

• Journal of Astronomy and Space Sciences
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• v.33 no.1
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• pp.63-67
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• 2016

The Korea Institute of Science and Technology Information (KISTI) has been studying the e-Science paradigm. With its successful application to particle physics, we consider the application of the paradigm to astroparticle physics. The Standard Model of particle physics is still not considered perfect even though the Higgs boson has recently been discovered. Astrophysical evidence shows that dark matter exists in the universe, hinting at new physics beyond the Standard Model. Therefore, there are efforts to search for dark matter candidates using direct detection, indirect detection, and collider detection. There are also efforts to build theoretical models for dark matter. Current astroparticle physics involves big investments in theories and computing along with experiments. The complexity of such an area of research is explained within the framework of the e-Science paradigm. The idea of the e-Science paradigm is to unify experiment, theory, and computing. The purpose is to study astroparticle physics anytime and anywhere. In this paper, an example of the application of the paradigm to astrophysics is presented.

• Journal of the Optical Society of Korea
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• v.20 no.2
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• pp.223-227
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• 2016

The impact of optical receiver configuration on in-band crosstalk-induced penalty has been investigated in both theoretical and experimental analyses, for differential phase-shift keying (DPSK) and differential quadrature phase-shift keying (DQPSK) signals. Previously it has been shown that DPSK signals are ~6 dB more tolerant to in-band crosstalk than on-off keying (OOK) signals. However, we find that the tolerance difference between the two signals is reduced to ~3 dB when the decision threshold of the receiver is optimized to minimize the bit-error rate for each signal. Then we derive simple equations for the in-band crosstalk-induced penalty in DPSK and DQPSK signals with two different optical receiver configurations: balanced and single-ended direct-detection receivers. We confirm that the penalties obtained from our simple equations agree well with the measured results.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.6
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• pp.71-77
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• 1999

Monitoring of Cutting tool wear is a critical issue in automated machining system and has been extensively studied for many years. An austempered ductile iron(ADI) exhibits the excellent mechanical properties and the wear resistance. ADI has generally the poor machinability due to the characteristic. This paper presents the in-process detection of flank wear of cutting tools using the acoustic emission sensor and the digital oscilloscope. The amplitude level of AE signal(AErms) is mainly affected by cutting speed and it is proportional to cutting speed. There have been the relationship of direct proportion between the amplitude level of AE signals and the flank wear width of cutting tool. The flank wear with corresponding to the tool life is successfully detected with the monitor-ing system used in this study.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1683-1684
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• 2008

For direct detection of microbes in air, samples have to be collected but environmental particles such as dust are also trapped in such samples. Therefore the isolation of target bacteria from non-biological materials of similar size is of great importance in the identification of such organisms. Dielectrophoresis is an emerging technique that can rapidly separate cells in microfluidics. In this paper we proposed a new method for the separation of airborne microbes using condensation and dielectrophoresis. This system could be used as a continuous flow through separation system for various particles and utilized as a pretreatment technique for microbe detection.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.7
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• pp.1699-1706
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• 1998

This paper presents a threshold decision technique for direct sequence code acquistion employing Pseudo-Noise(PN) matched filter. The probabilities of detection and false alarm are derived as a measure of the system performance in both nonfading and nonselective Rician fading channels. For received PN codes with different SNR, the proposed acquisition scheme is able to detect a desired threshold in the search mode so that this value is utilized as a threshold for the verification mode. Thus, there is no need to determine a threshold by applying the Neyman-Person ciriteron. It is shown that this scheme achieves lower probability of false alarm than the acquisition scheme based on the Neyman-Person criterion, giving comparable performance in terms of the probability of detection.

• Journal of Information Technology Applications and Management
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• v.24 no.1
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• pp.1-10
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• 2017

Recently, the problem of plagiarism has emerged as a big social issue because not only literature but also thesis become the target of plagiarism. Even the government requires conformation for plagiarism of high-ranking official's thesis as a standard of their ethical morality. Plagiarism is not just direct copy but also paraphrasing, rewording, adapting parts, missing references or wrong citations. This makes the problem more difficult to handle adequately. We propose a plagiarism detection scheme called a bit signature in which each unique word of document is represented by 0 or 1. The bit signature scheme can find the similar documents by comparing their absolute and relative bit signatures. Experiments show that a bit signature scheme produces better performance for document copy detection than existing similar schemes.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.78.1-78.1
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• 2014

Pulsar binaries in tight orbits are considered to emit strong gravitational waves (GWs) during the last stage of their coalescences. They form a subset of compact binary mergers, which consists of white dwarfs (WDs), neutron stars (NSs), or black holes (BHs). One of the most famous example of 'merging' pulsar binaries is the Hulse-Taylor pulsar (PSR B1913+16) discovered in 1974 by Russell Hulse and Joseph Taylor. About ten NS-NS and several tens of NS-WD binaries are known in our Galaxy. Merging binaries are rare and only a few NS-NS and NS-WD have been discovered to date. A pulsar with a black hole companion is also theoretically expected, but there is yet no detection. Within several years, direct detections of GWs from compact binary mergers will be made by laser interferometers. This will pave a way to study physics of compact binaries that cannot be reached by electromagnetic waves (EM). Pulsar binaries are of particular interest as we can use both EM and GW to probe these systems. In this talk, we present a brief overview on the Galactic pulsar populations and discuss their implications for GW detection.

• Structural Engineering and Mechanics
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• v.53 no.2
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• pp.249-260
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• 2015

Damage detection based on a reference set of measured data usually has the problem of different environmental temperature in the two sets of measurements, and the effect of temperature difference is usually ignored in the subsequent model updating. This paper attempts to identify the structural damage including the temperature difference with artificial measurement noise. Both local damages and the temperature difference are identified in a gradient-based model updating method based on dynamic response sensitivity. The sensitivities of dynamic response with respect to the system parameters and temperature difference are calculated by direct integration method. The measured dynamic responses of the structure from two different states are used directly to identify the structural local damages and the temperature difference. A single degree-of-freedom mass-spring system and a planar truss structure are studied to illustrate the effectiveness of the proposed method.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.595-599
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• 2013

The coordination of pyridyl-N to pentacyanoferrate for the detection of small organic antigens in solution is presented. The unique contribution of this paper is the direct conjugation of pyridyl-N in small organic antigens to pentacyanoferrate. Pentacyanoferrate is promising as an electrochemical label owing to its good electro-chemical properties, which can be utilized to generate an electrical signal in homogeneous electrochemical immunoassays. The facilely synthesized pyridyl-N to pentacyanoferrate was characterized by the electrochemical and spectroscopic methods. Hippuric acid (HA) has been detected competitively on the interaction of free HA and pentacyanoferrate-(4-aminomethylpyridine-hippuric acid) (Fe-HA) to its antibody, with the detection limit of 0.50 ${\mu}g\;mL^{-1}$. While pentacyanoferrate-based immunoassay is in its simplicity and infancy, the proposed immunoassay offers attractive opportunities for developing pyridyl-N-based the electrochemical detection of small organic antigens in the health care area.