• Journal of the Korean Electrochemical Society
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• v.15 no.2
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• pp.67-73
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• 2012

Spherical lithium manganese oxide spinel, $LiMn_{2-x}M_xO_4$ (M = Al, Mg, B) prepared by wet-milling, spray-drying, and sintering process has been investigated as a cathode material for lithium ion batteries. As-prepared powders exhibit various surface morphologies and internal density in terms of boron (B) doping level. It is found that the dopant B drives the growth of the primary particle and minimizes the surface area of the powder. As a result, the dopant enhances the internal density of the particles. Electrochemical tests demonstrated that the capacity of the synthesized material at 5 C could be maintained up to 90% of that at 0.2 C. The cycle performance of the material showed that the initial capacity was retained up to 80% even after 500 cycles under the high temperature of $60^{\circ}C$.

• Journal of KIISE
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• v.42 no.3
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• pp.307-319
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• 2015

Current ontology studies use the Hadoop distributed storage framework to perform map-reduce algorithm-based reasoning for scalable ontologies. In this paper, however, we propose a novel approach for scalable Web Ontology Language (OWL) Horst Lite ontology reasoning, based on distributed cluster memories. Rule-based reasoning, which is frequently used for scalable ontologies, iteratively executes triple-format ontology rules, until the inferred data no longer exists. Therefore, when the scalable ontology reasoning is performed on computer hard drives, the ontology reasoner suffers from performance limitations. In order to overcome this drawback, we propose an approach that loads the ontologies into distributed cluster memories, using Spark (a memory-based distributed computing framework), which executes the ontology reasoning. In order to implement an appropriate OWL Horst Lite ontology reasoning system on Spark, our method divides the scalable ontologies into blocks, loads each block into the cluster nodes, and subsequently handles the data in the distributed memories. We used the Lehigh University Benchmark, which is used to evaluate ontology inference and search speed, to experimentally evaluate the methods suggested in this paper, which we applied to LUBM8000 (1.1 billion triples, 155 gigabytes). When compared with WebPIE, a representative mapreduce algorithm-based scalable ontology reasoner, the proposed approach showed a throughput improvement of 320% (62k/s) over WebPIE (19k/s).

• The Journal of the Korea Contents Association
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• v.14 no.11
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• pp.249-259
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• 2014

This study has analyzed the factors that influence the safety consciousness of school bus drivers at Child Care Centers. To achieve this, 276 directors and drivers of owner-operator who drives the school bus at Child Care Centers in Chungnam, Chungbuk and Daejeon area were selected as study subjects. For the data analysis, PASW Statistics 18.0 was used. The main results of this study are as follows. The level of safety consciousness of directors and drivers of owner-operator were 6.46 and 6.82 respectively showing that drivers of owner-operator were significantly higher. Second, the factors that influence the safety consciousness were shown to be significantly different for each group. The factors that influence the safety consciousness of directors were shown in the order of whether or not the accident was experienced, safety-seeking motivation, sensation-seeking disposition, safety consciousness of caregivers, perception-motor skill. The factors that influence the safety consciousness of drivers of owner-operator were shown in the order of safety-seeking motivation, health status, daily driving hours, economic status, safety consciousness of caregivers. Based on these results, several ways were suggested to improve the safety consciousness of school bus drivers at Child Care Centers and prevent the traffic accidents.

• BMB Reports
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• v.47 no.9
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• pp.512-517
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• 2014

In this study, we showed that Mycobacterium abscessus MAB2560 induces the maturation of dendritic cells (DCs), which are representative antigen-presenting cells (APCs). M. abscessus MAB2560 stimulate the production of pro-inflammatory cytokines [interleukin (IL)-6, tumor necrosis factor (TNF)-${\alpha}$, IL-$1{\beta}$, and IL-12p70] and reduce the endocytic capacity and maturation of DCs. Using $TLR4^{-/-}$ DCs, we found that MAB2560 mediated DC maturation via Toll-like receptor 4 (TLR4). MAB2560 also activated the MAPK signaling pathway, which was essential for DC maturation. Furthermore, MAB2560-treated DCs induced the transformation of $na\ddot{i}ve$ T cells to polarized $CD4^+$ and $CD8^+$ T cells, which would be crucial for Th1 polarization of the immune response. Taken together, our results indicate that MAB2560 could potentially regulate the host immune response to M. abscessus and may have critical implications for the manipulation of DC functions for developing DC-based immunotherapy.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1211-1214
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• 1992

AC servo motor drives, Fara DS series, proposed in this paper can be effectively used in robots, CNC machine tools, and FA system with AC servo motors as actuators. The inverter of the AC servo drive consists of IGBT (Insulated Gate Bipolar Transistor) which have high switching frequency. Noises and vibrations generated in variable speed control of AC servo motors can be greatly reduced due to their high switching frequencies. In the developed servo drive, maximum torque is always generated in the whole speed range by compensating phase shift, which results from the nonlinearies of the AC servo motor during abrupt acceleration and deceleration. Abundant protection functions are provided to prevent abnormal state of the servo motor, and furthermore diverse user options are considered provided for the effective application. The proposed AC servo motor drive is designed to minimize velocity variation with respect to external load, supply voltage, environmental temperature, and humidity, so can be widely used in the fields of factory automation including robots and CNC msachine tools.

• Journal of the Korean Society of Radiology
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• v.3 no.4
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• pp.13-21
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• 2009

The Magnetic Resonance Imaging (MRI) systems consist of various parameters. Among them, the image quality can be arguably the most important part of the systems. As the other components in MRI systems have been developed and evolved, the MRI image quality has been advanced remarkably. And, the radiation imaging system is being converted from the Film to the digital method, which drives the computerization of many hospitals. The management of the tremendous radiation images becomes more critical. The data compression is used to store such large data in a network server. When the image files are compressed, the image quality degrades comparing to its original images. Even slight quality degradation of a medical image could cause an erroneous diagnosis, so the images must be handled carefully. This thesis studied the image assessment methods of comparing the quality of the compressed image to its original, and the quality of the original and the displayed images of the MRI systems via PSNR with actual medical images used in hospitals. As a result, no noticeable quality degradation was found comparing the compressed images with various digital compression methods and the original images. However, it was a different story comparing the original images and the displayed images on MRI monitors. Some noise or image distortion was visible using any regular CRT or LCD monitors were used while the special monitors designed for the MRI imaging and medical images displayed high definition images.

• Journal of Korean Society of Transportation
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• v.20 no.3
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• pp.41-52
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• 2002

Most investment evaluations and economic assessments of road transport proposals in Korea omit a valuation of the time spent in transit for loads of freight. These days there were few attempts to estimate value of freight travel-time savings in Korea, but most of them included rail or marine with statewide area so that couldn't obtain unique travel-time savings for road freight transport. This study applied revealed Preference method and associated binominal logit models to estimate the value of travel-time savings in transit from an statewide survey of road freight transport in 1997. Data sets were segmented according to transport areas and business types. The results of this study showed that the value of freight travel-time savings varied wide ranges from 53,449 won per hour in urban transport to 29,397 won per hour in regional transport, that the use of statewide value of freight travel-time savings can drives wrong results into economic assessment, and that the use of adequate value of freight travel-time savings according to assessment area is very important.

• Development and Reproduction
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• v.8 no.1
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• pp.35-42
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• 2004

Oocyte maturation refers to the process that prophase I arrested germinal vesicle(GV) drives the progression of meiosis to metaphase II(MII) to have the capacity for fertilization and embryo development. To better understand the molecular mechanism(s) involved in oocyte maturation, we identified differentially expressed genes(DEGs) between GV and MII mouse oocytes using a new innovative annealing control primer (ACP) technology. Using 20 ACPs, we successfully cloned 32 DEGs between GV and Mll oocytes, and 26 out of these 32 DEGs were functionally known genes. Four genes including Pscd2 were GV-specific, 10 genes including PKD2 and CSN3 were highly expressed in GV oocytes(GV-selective), and 12 genes including Diva were highly expressed in MII oocytes (MII-selective). Ail of the genes identified in this study were first reported in the oocyte expression using ACP system and especially, we could characterize the existence of PKD-CSW signaling pathwayin the mouse oocytes. Results of the present study would provide insight for studying molecular mechanisms regulating oocyte maturation.

• Cartoon and Animation Studies
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• s.27
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• pp.199-219
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• 2012

An innovative narrative film-making always came out of conflict and negotiation between reality and film form. A lesson we learn from their film-making is a certain reality is no more possible to be dealt with by conventional narrative. A dialectic between a real life and a representation drives a certain film-makers to make films. Kore-eda Hirokazu is internationally known as developing his own method of meshing of so-called real life and the artifice of film. As He began his career as a documentary film-maker, made several documentaries for TV and then turned to his feature film-making, documentary film-making defines the basic stance in all of his film-making. He in particular emphasized that he considered the fundamental ethical standpoint of documentary to be filming from the standpoint that one does not - or cannot - know the person one is filming. And therefore even in his fiction films he avoids subjective cinematic structures that offer easy access to the internal states of his characters. He makes his audience observe the internal states of his characters from the outside with his narrative strategy. This article will analyse two documentary films of Koreeda Hirokazu in such a way that his documentaries meshes a real life and the artifice of film and then explores such a fiction film like that changes its documentary methods into narrative strategy for the same effect on the audience.

• Microbiology and Biotechnology Letters
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• v.47 no.4
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• pp.574-580
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• 2019

ATP drives the conformational change of the group II chaperonin from the open lid substrate-binding conformation to the closed lid conformation to encapsulate an unfolded protein in the central cavity. It is thought that the folding activity of group II chaperonin is strongly correlated with the ATP-dependent conformational change ability. In order to confirm the dependence of the reaction temperature and ATP concentration of PhCpn, the ATPase activities were measured under different reaction temperatures and ATP concentrations. The maximal ATPase activity of PhCpn was observed at 80℃ and 3 mM ATP concentration. As a result of ATPase activity according to the type of salt ions, the highest activity was observed at 300 mM LiCl among the univalent cations and 5 mM MgCl₂ among the divalent cations, respectively. The values of Km and Vmax for ATP substrate were estimated as 2.17 mM and 833.3 μM/min, respectively. This results provide the enzymatic information of PhCpn when the prolonged and high activities of pharmaceutical and industrial proteins (or enzymes), by using chaperonin molecules, are required.