• Journal of Information Processing Systems
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• v.5 no.1
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• pp.33-40
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• 2009

Ever since the network-based malicious code commonly known as a 'worm' surfaced in the early part of the 1980's, its prevalence has grown more and more. The RCS (Random Constant Spreading) worm has become a dominant, malicious virus in recent computer networking circles. The worm retards the availability of an overall network by exhausting resources such as CPU capacity, network peripherals and transfer bandwidth, causing damage to an uninfected system as well as an infected system. The generation and spreading cycle of these worms progress rapidly. The existing studies to counter malicious code have studied the Microscopic Model for detecting worm generation based on some specific pattern or sign of attack, thus preventing its spread by countering the worm directly on detection. However, due to zero-day threat actualization, rapid spreading of the RCS worm and reduction of survival time, securing a security model to ensure the survivability of the network became an urgent problem that the existing solution-oriented security measures did not address. This paper analyzes the recently studied efficient dynamic network. Essentially, this paper suggests a model that dynamically controls the RCS worm using the characteristics of Power-Law and depth distribution of the delivery node, which is commonly seen in preferential growth networks. Moreover, we suggest a model that dynamically controls the spread of the worm using information about the depth distribution of delivery. We also verified via simulation that the load for each node was minimized at an optimal depth to effectively restrain the spread of the worm.

• Journal of Welding and Joining
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• v.28 no.1
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• pp.41-46
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• 2010

The low alloy-steel material(1.0Cr-0.5Mo, SA213T12), which has widely been used for the waterwall tube in the conventional power plant, do not have enough creep rupture strength for waterwall tubes of the Ultra-supercritical(USC) boilers. According to this reason, the high-strength low alloy-steel(2.25Cr-1.0Mo, SA213T22) has newly been adopted for the waterwall tube in the USC boilers. This paper presents failure analysis on weld-joint of the waterwall tubes in USC boilers. Visual inspections were performed to find out the characteristics of the fracture. Additionally both microscopic characteristics and hardness test were carried out on failed tube samples. Failures seem to happen mainly because the welding process has not been conducted strictly.(preheating, P.W.H.T and so forth). Thus, this paper has the purpose to describe the main cause of the poor welding process and to explain how to prevent similar failures in those weld-joints.

• Development and Reproduction
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• v.16 no.1
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• pp.19-29
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• 2012

The ultrastructural characteristics of germ cell differentiations during spermatogenesis and mature sperm morphology in male $Atrina$ ($Servatrina$) $pectinata$ were evaluated via transmission electron microscopic observation. The accessory cells, which contained a large quantity of glycogen particles and lipid droplets in the cytoplasm, are assumed to be involved in nutrient supply for germ cell development. Morphologically, the sperm nucleus and acrosome of this species are ovoid and conical in shape, respectively. The acrosomal vesicle, which is formed by two kinds of electron-dense or lucent materials, appears from the base to the tip: a thick and slender elliptical line, which is composed of electron-dense opaque material, appears along the outer part (region) of the acrosomal vesicle from the base to the tip, whereas the inner part (region) of the acrosomal vesicle is composed of electron-lucent material in the acrosomal vesicle. Two special characteristics, which are found in the acrosomal vesicle of A. ($S$) $pectinata$ in Pinnidae (subclass Pteriomorphia), can be employed for phylogenetic and taxonomic analyses as a taxonomic key or a significant tool. The spermatozoa were approximately $45-50{\mu}m$ in length, including a sperm nucleus (about $1.43{\mu}m$ in length), an acrosome (about $0.51{\mu}m$ in length), and a tail flagellum (about $46-47{\mu}m$). The axoneme of the sperm tail evidences a 9+2 structure.

• Parasites, Hosts and Diseases
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• v.23 no.2
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• pp.313-323
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• 1985

Boophilus microplus (Canestrini, 1887) female specimens were subjected to scanning electron microscopy for the observation of surface fine structures. Morphological characteristics observed were summarized as follows: 1. The palpi were wider than long, and compressed, ridged dorsally and laterally. There were usually four pairs of ventro-internal setae on the articles. 2. The hypostome dentition was usually 4/4 but occasionally 5/5. 3. The basis capituli were hexagonal dorsally and the porose area was distinct with the holes developed well. 4. There were numerous folds resembling finger prints around the female genital pore. 5. A pair of anal lobes with specified setae on them was also rocognized as one of the morphological characteristics.

• Korean Journal of Veterinary Research
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• v.32 no.1
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• pp.77-82
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• 1992

A noncytopathic bovine viral diarrhea virus(NC BVDV) strain isolated and purified from persistently infected primary bovine fetal lung(BFL) cells was studied by biophysical methods. The buoyant density of particles of the NC BVDV strain was shown to be between 1,090 and $1,114g/cm^3$ and the maximum virus infectivity occured at $1,098g/cm^3$. Immunoelectron microscopic examination by using the partially purified virus revealed regular spherical particles 30~80nm in diameter. Differences in the genomic size of cytopathic and noncytopathic BVDV from infected cells were not found. A comparison of viral proteins of a noncytopathic and cytopathic strain(NADL) by immunoprecipitation using monoclonal antibody indicated that NC BVDV, compared to cytopathic NADL, was cell associated.

• Journal of the Korean Applied Science and Technology
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• v.20 no.2
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• pp.94-100
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• 2003

We studied electrochemical characteristics of Langmuir-Blodgett(LB) films by using cyclic voltammetry with a three-electrode system. An Ag/AgCl as a reference electrode, a platinum wire as a counter electrode and LB film-coated indium tin oxide(ITO) as a working electrode were used to study electrochemical characteristics at a various concentration of $NaClO_4$ solution. LB films were reduced from initial potential to -1350 mV, continuously oxidized to l650mV and returned to the initial point. The scan rate was l00mV/s. The monolayer surface morphology of the LB film have been measured by Atomic Force Microscope(AFM). As a result, We comfirmed that the microscopic properties of LB film by AFM showed the good orientation of momolayer molecules and the thickness of monolayer was 3.5-4.lnm. The cyclic voltammograms(CV) of the ITO-coated glass showed the peak potentials for the reduction-oxidation reation. LB films of 4-octyl-4'-(5-carboxypentamethyleneoxy) azobenzene(8A5H) / L-${\alpha}$-phosphayidyl choline, dilauroyl(DLPC) seemed to be irreversible process caused by only the oxidation current from the cyclic voltammogram. The current of oxidatation increased at cyclic voltammogram by increasing 8A5H density in LB films. The diffusivity(D) of LB films increased with increasing of a 8A5H amount and was inversely proportional to the concentration of $NaClO_4$ solution.

• Journal of Technologic Dentistry
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• v.34 no.3
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• pp.227-235
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• 2012

Purpose: This study compared the surface hardness (Vickers) and microstructural characteristics between a type IV stone with and without die hardening treatment, a polyurethane die material. Methods: Materials used were a type IV stone(MG Crystal Rock), two die hardeners (Hardening bath, Epox-it), and a polyurethane resin material(Polyluck). Six specimens per group were prepared according to manufacturer's directions. The prepared specimens were tested by means of hardness test, one-way ANOVA analysis, scanning electron microscopic(SEM) observations and energy dispersive spectroscopic(EDS) analysis. Results: In the hardness test and its statistical analysis, there was no significant difference in the surface hardness between a type IV stone and type IV stone with die hardener coating, type IV stone mixed with an epoxy like material instead of water. In contrast, polyurethane resin material exhibited significantly greater surface hardness than other specimen groups (p<0.05). Conclusion: By considering the results of the hardness test, SEM observations and EDS analysis, although the die hardeners on type IV stone did not show remarkable improvement in surface hardness, the die hardener coating on the surface of type IV stone material did show decrease of microporous and improvement of surface defects.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.6
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• pp.2795-2799
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• 2016

Purpose: To study histomorphological and immunohistochemical patterns of gastro-intestinal stromal tumours (GISTs) in Malaysia. Materials and Methods: A total of 29 GIST cases from Hospital Tuanku Ja'afar, Seremban, were studied retrospectively over a period of 10 years from January 2002 to December 2011. Patient demographic data like age, sex and etnicity were collected. Tumour characteristics like site, maximum dimension and specimen type were analysed. Evaluation was according to established criteria into very low, low, intermediate and high-risk categories. Immunohistochemical characteristics were also analysed. Results: The mean age of patients was 59.7 years. Males (59%) were found to be more commonly affected than females (41%). The Chinese (45%) were commonly affected than Malays (41%), and Indians (10%). The most common symptom was pain in the abdomen (13.8%). More than half of the cases were seen in stomach (53%). The tumour size ranged from 1.5 cm to 17 cm with a mean of 6.94cm. Microscopic findings revealed that the spindle cell type was the most common (76%). It was observed that the majority of the cases (48%) were categorised in the intermediate risk group. Immunohistochemical staining showed positivity for CD117 (78.6%), CD34 (71.4%), vimentin (86.2%), S-100 (27.6%), SMA (35.7%), PKC THETA (46.4%) and PDGRFA (67.9%).

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.130-145
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• 2021

As part of the Smart Seoul policy, the importance of using big urban data is being highlighted. Furthermore interest in the impact of transportation-related urban environmental factors such as PM10 and noise on citizen's quality of life is steadily increasing. This study established the integrated DB by matching IoT big data with transportation data, including traffic volume and speed in the microscopic Spatio-temporal scope. This data analyzed the impact of a spatial unit in the road-effect zone on environmental risk level. In addition, spatial units with similar characteristics of road traffic and environmental factors were clustered. The results of this study can provide the basis for systematically establishing environmental risk management of urban spatial units such as PM10 or PM2.5 hot-spot and noise hot-spot.

• The Korean Journal of Mycology
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• v.46 no.4
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• pp.359-367
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• 2018

As an effort to explore fungal diversity, fungal survey was undertaken in 2017 in the vicinity of demilitarized zone (DMZ) located in Yeoncheon-gun, Gyeonggi-do, Korea. For the survey, wild plants and soils were sampled and subjected to fungal isolation. A total of 18 genera and 23 species including five unrecorded fungal species, Mortierella sclerotiella, M. sossauensis, M. verticillate, Eupenicillium saturniforme, and Trichoderma hispanicum, were obtained from the survey. This study described their morphological characteristics including colony features formed on media, light microscopic images and molecular characteristics of nucleotide sequences of the internal transcribed spacer (ITS) region, 18S and 28S rDNA, ${\beta}-tubulin$ gene, calmodulin, and translation elongation factor $1{\alpha}$ ($tef1{\alpha}$) nDNA genes.