• BMB Reports
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• v.41 no.4
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• pp.310-315
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• 2008

BirA ligase is a prokaryotic ortholog of holocarboxylase synthetase (HCS) that can biotinylate proteins. This study tested the hypothesis that BirA ligase catalyzes the biotinylation of eukaryotic histones. If so, this would mean that recombinant BirA ligase is a useful surrogate for HCS in studies of histone biotinylation. The biological activity of recombinant BirA ligase was confirmed by enzymatic biotinylation of p67. In particular, it was found that BirA ligase biotinylated both calf thymus histone H1 and human bulk histone extracts. Incubation of recombinant BirA ligase with H3-based synthetic peptides showed that lysines 4, 9, 18, and 23 in histone H3 are the targets for the biotinylation by BirA ligase. Modification of the peptides (e.g., serine phosphorylation) affected the subsequent biotinylation by BirA ligase, suggesting crosstalk between modifications. In conclusion, this study suggests that prokaryotic BirA ligase is a promiscuous enzyme and biotinylates eukaryotic histones. Moreover the biotinylation of histones by BirA ligase is consistent with the proposed role of human HCS in chromatin.

• Journal of Communications and Networks
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• v.13 no.4
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• pp.319-326
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• 2011

Beamforming techniques have been successfully utilized for traffic channels in order to solve the interference problem. However, their use for control channels has not been sufficiently investigated. In this paper, a (semi-) centralized beamforming strategy that adaptively changes beam patterns and controls the total transmit power of cells is proposed for the performance enhancement of the common channel in hierarchical cell structure (HCS) networks. In addition, some examples of its practical implementation with low complexity are presented for two-tier HCS networks consisting of macro and pico cells. The performance of the proposed scheme has been evaluated through multi-cell system-level simulations under optimistic and pessimistic interference scenarios. The cumulative distribution function of user geometry or channel quality has been used as a performance metric since in the case of common control channel the number of outage users is more important than the sum rate. Simulation results confirm that the proposed scheme provides a significant gain compared to the random beamforming scheme as well as conventional systems that do not use the proposed algorithm. Finally, the proposed scheme can be applied simultaneously to several adjacent macro and pico cells even if it is designed primarily for the pico cell within macro cells.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.2
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• pp.123-128
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• 2010

Hydriding combustion synthesis (HCS) can produce full hydrides of alloys and in a short time. The conventional process based on ingot metallurgy cannot produce Mg-based alloy easily with the desired composition and the cast product needs a ling activation process for the practical use of hydrogen storage. In this study, the hydriding properties of Mg-xNi (x=5, 13.5, 54.7wt.%) alloys prepared by hydriding combustion synthesis were evaluated. The hydrogen storage capacity and kinetics of HCS Mg-xNi alloys were strongly dependent on the content of Ni. The HCS Mg-13.5wt.%Ni alloy shows the hydriding behavior to reach the maximum capacity within 30 min. and the reversible $H_2$ storage of 5.3wt.% at 623 K.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.4
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• pp.391-397
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• 2009

In this paper, longitudinal static stability is investigated, which is an essential requirement for the safety and the performance of the human powered hydrofoil boat (HPHB). In case a disturbance changes the trim angle of the boat, the derivative of the moment about the center of gravity must be negative in order to make the boat to be stable. The equation to evaluate the longitudinal static stability of the EPISODE, a HPHB of Chungnam National University with a height controlling system(HCS) is derived. From the derivative it is confirmed that a longitudinal and vertical position of the center of gravity is important for a HPHB. The range of a trim angle while the boat is foil-born was found with a HCS under the condition of mechanical restraint. And it is confirmed that the longitudinal static stability is satisfied for EPISODE in certain range of a trim angle. It is also shown that the longitudinal static stability and a range of the trim angle can be determined from the principal dimensions of a HPHB, therefore, it can be applied from the stage of the conceptual design of HPHB.

• Computers and Concrete
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• v.13 no.3
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• pp.389-409
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• 2014

Precast hollow core slabs (HCS) are technically advanced products in the precast concrete industry, widely used in the last years due to their versatility, their multipurpose potential and their low cost. Using three dimensional FEM (Finite Element Method) elements, this study focuses on the stresses induced by the prestressing of steel. In particular the investigation of the spalling crack formation that takes place during prestressing is carried out, since it is important to assure the appropriate necessary margins concerning such stresses. In fact, spalling cracks may spread rapidly towards the web, leading to the detachment of the lower part of the slab. A parametric study takes place, capable of evaluating the influence of the tendon position and of the web width on the spalling stress. Consequently, after an extensive literature review on the topic of soft computing, an optimization of the HCS is performed by means of Genetic Algorithms coupled with 3-D FEM models.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.63-64
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• 2006

Chracteristics on evaporating pressure drop of HCs refrigerants inside a horizontal tube were studied experimentally. Experimental results were presented for pressure drops of hydrocarbon refrigerants R-290, R-600a, R-1270 and HCFC refrigerant R-22 inside a horizontal double pipe heat exchanger. Three tubes with a tube diameter of 12.70mm, 9.52mm and 6.35mm were used for this study. Hydrocarbon refrigerants showed higher evaporating pressure drop than that of R-22 in all tubes. The highest pressure drop was founded in R-600a. The highest evaporating perssure drop of all refrigerants was shown in a tube diameter of 6.35mm with same mass flux. The results can be used as the basic data for the design of heat exchanger using hydrocarbon refrigerants as an alternatives.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.617-620
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• 1999

In this paper, a new autofocusing technique which is resistive to noise generated by the CCD of video cameras is proposed. In the proposed scheme, the frequency selective weighted median (FSWM) filter is utilized to estimate the degree of focus and the fast hill-climbing search (HCS) strategy is exploited to determine the best focused image. Since the FSWM filter can not only extract high frequency components from the image, but also eliminate impulsive noise, the proposed autofocusing method employing the FSWM criterion function can estimate the degree of focus precisely. Furthermore, the proposed real-time HCS algorithm enables the video camera to continuously focus on dynamic images. Experimental results demonstrate that the proposed technique outperforms existing techniques by enhancing the accuracy of the focus value of the video camera without the influence of noise.

• Animal cells and systems
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• v.13 no.2
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• pp.97-103
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• 2009

Recently, great advance is achieved in the field of genome-wide functional screening using cell-based assay. Here, we briefly introduce well-established and typical cell-based assays of GPCR and some parameters which should be considered for genome-wide functional screening. Because of characters and importance of GPCR as drug targets, several ways of assay systems were devised. Among them, high-content screening (HCS) that is based on the analysis of image by confocal microscope is becoming favorite choice. The advances in this technology have been driven exclusively by industry for their convenience. Now, it is turn for academy to define more detail signaling networks via HCS using cDNA or siRNA libraries at genome-wide level. By isolating novel signaling mediators using cDNA or siRNA library, and postulating them as new candidates for therapeutic target, more understanding about life science and more increased chances to develop therapeutics against human disease will be achieved.

• Journal of the korean Society of Automotive Engineers
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• v.13 no.5
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• pp.89-94
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• 1991

In the quantitative analysis of oxygenated exhaust emissions (unburned methanol, formal- dehyde) from methanol fueled vehicles, the oxygen contained in oxygenated exhaust gases lowers the FID (Flame Ionization Detector) response factor of conventional THC analyzer and leads to erroneous HC reading. For correct measurement of various HCs including oxygenated HCs emitted from FFV(Flexible Fuel Vehicle), first of all, the measurement technique of real HC emissions should be established. GC and HPLC-DNPH measuring methods specified by the EPA are used in this paper to analyze unburned methanol and formaldehyde components in the exhaust emissions. In emission test of FFV, unburned methanol and formaldehyde are emitted mostly during cold transient period, and it is shown that formaldehyde emission level is proportional to engine displacements. In view of the HC emission level, vehicle using M85 has 40% advantage over gasoline-fueled vehicle in OMHCE and has a good potential of a low emission vehicle.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.9B
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• pp.602-609
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• 2005

In this paper, the performance of HCS (hierarchical cell structure), which consists of macro-cell and micro-cell, has been analyzed by assuming that the cells in HAPS (high altitude plat(on station) are tessellated to provide wide coverage, control the co-channel interference and give the higher spectrum efficiency. Since the outside-cell interference factor is well blown to analyze the effects of interference between cells, the effects of interference from the micro-cells into the macro-cells has been estimated using the factor as a performance estimation of HCS in HAPS. HCS served by HAPS can be realized by permitting the suitable power control and the proper number of users in micro-cell because the interference from the micro-cell into the macro-cell is not a function of the distance between cells but a function of the power control and the number of users.