• Journal of the Korea Society for Simulation
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• v.17 no.2
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• pp.21-29
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• 2008

The High Level Architecture(HLA) specifies a framework for interoperation between heterogeneous simulators, and Run-Time Infrastructure(RTI) is a implementation of the HLA Interface Specification. The Data Distribution Management(DDM) services, one category of IEEE 1516 HLA/RTI management services, control filters for data transmission and reception of data volume among simulators. In this paper, we propose design concept of DDM and show its implementation for light-weighted RTI. The design concept of DDM is to minimize total amount of message that each federate and a federation process generate using the rate of RTI service execution. The design of our proposed DDM follows that a data transfer mechanism is differently applied as the rate of RTI service execution. A federate usually publishes or subscribes data when it starts. The federate constantly updates the data and modifies associated regions while it continues to advance its simulation time. Therefore, the proposed DDM design provides fast update or region modification in exchange of complex publish and subscribe services. We describe how to process the proposed DDM in IEEE 1516 HLA/RTI and experiment variable scenarios while modifying region, changing overlap ratio, and increasing data volume.

• Development and Reproduction
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• v.2 no.1
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• pp.89-99
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• 1998

This study was carried out to investigate the morphological changes of gonadotropes in pituitary gland and spermatogenic cells in testis, obtained from 150 of 3-year-old immature and mature male rainbow trout (Oncorhynchus mykiss) during the reproductive cycles from March to February in the following year. In the maturation cycle of the pituitary gonadotropes of cultured rainbow trout, three periods can be distinguished i.e. a period of resting(March-August), a period of full spermatogenesis (September-November), and a period of breeding (December-February). The ultrastructures of the gonadotropes largely parallel the cyclical changes in the tests. The seminiferous tubules contain all spermatogenetic stages and sperm cells in a period of early maturation. At first, the size of the nucleus and cytoplasm decrease gradually at every stages from spermatogonia to spermatids. In the secondary spermatocytes, the small mitochondria are located over the outer cytoplam. In spermatids, the cytoplasmic masses move toward the posterior part of the nucleus. In spermatids, the two large mitochondria are located over the cytoplasm. In spermatids, the cytoplasmic masses move towark the posterior part of the nucleus. In spermatids, the two large mitochondria are located over the cytoplasm and begin to elongate. In spermatozoa, the surface of the nucleus devreases in volume. Examination by TEM shows that the nuclear envelope and plasma membrane are slightlywrinkled and closely adhered to the nucleus of spermatozoa. Two oval mitochondria are quite separated and the flagellum is inserted into the base of the spermatozoa head.The axoneme in this fish has the typical pattern such as nine peripheral doublets and a central doublet(9+2). there are remarkable individual differences in the size and morphology of spermatozoa head as observed by transmission and scanning electron microscopy.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.705-713
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• 2017

A novel material, $Bi_2WO_6-GO-TiO_2$ composite, was successfully synthesized using a facile hydrothermal method. During the hydrothermal reaction, the loading of $Bi_2WO_6$ and $TiO_2$ nanoparticles onto graphene sheets was achieved. The obtained $Bi_2WO_{6-GO-TiO2}$ composite photo-catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), Raman spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy (UV-vis-DRS), and X-ray photoelectron spectroscopy (XPS). The $Bi_2WO_6$ nanoparticle showed an irregular dark-square block nanoplate shape, while $TiO_2$ nanoparticles covered the surface of the graphene sheets with a quantum dot size. The degradation of rhodamine B (RhB), methylene blue trihydrate (MB), and reactive black B (RBB) dyes in an aqueous solution with different initial amount of catalysts was observed by UV spectrophotometry after measuring the decrease in the concentration. As a result, the $Bi_2WO_6-GO-TiO_2$ composite showed good decolorization activity with MB solution under visible light. The $Bi_2WO_6-GO-TiO_2$ composite is expected to become a new potential material for decolorization activity. Photocatalytic reactions with different photocatalysts were explained by the Langmuir-Hinshelwood model and a band theory.

• Applied Microscopy
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• v.17 no.1
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• pp.131-160
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• 1987

Anatomical features of the renal papilla and pelvis and ultrastructures of the epithelium covering these areas in four species of mammals were studied by means of light, scanning and transmission electron microscopy. In terms of the morphology of mammalian kidney types distinguished by Sperber(1944), Pfeiffer(1968) and Schmidt-Nielsen(1977), the kidneys of animal species used in this experiment were; 1) the mouse kidney with the fornix between a long conical papilla and the funnel-shaped pelvis, 2) the guinea pig kidney with the peripelvic column and pelvic pouch between a short conical papilla and the funnel-shaped pelvis, 3) the dog kidney with the peripelvic column and pelvic pouch between the crest-shaped papilla and the funnel-shaped pelvis, and 4) the cattle kidney which is divided into multiple renculi with minor and major calyces and pelvis. The renal papilla was lined with the simple or pseudostratified columnar epithelium which covered the inner zone of the renal medulla. The epithelial cells with numerous short microvilli on the surface contained a few organelles. In the mouse, the fornix was lined with one to two cell-layered cuboidal epithelium which covered the outer zone of the renal medulla and a part of the cortex. The epithelial cells of the fornix with numerous short microvilli or microridges on the surface had well-developed organelles. In the guinea pig, the peripelvic column was lined with the simple cuboidal or low columnar epithelium which covered the outer zone of the renal medulla. The epithelial cells with numerous short microvilli on the surface contained well-developed organelles. The pelvic pouch was lined with the pseudostratified columnar epithelium which was composed of four kinds of cells; the secretory cell with small electron-dense granules (310 nm), the secretory cell with large granules (720 nm) showing various electron densities, the mitochondria-rich cell with a single cilium, and the basal cell. Pelves of the mouse and guinea pig, peripelvic column, pelvic pouch and pelvis of the dog, and minor and major calyces and pelvis of the cattle were lined with the transitional epithelium. The fusiform vesicles in the superficial cells of the epithelium were highly developed in the dog, relatively well developed in the mouse and guinea pig, and poorly developed in the cattle. From the above findings, it is suggested that the transport of solutes and water of the urine in the pelvic cavity can take place through the epithelia covering the renal papilla and fornix of the mouse, papilla and peripelvic column of the guinea pig, and papillae of the dog and the cattle. And specialized cell types in the epithelium of the guinea pig pelvic pouch, two kinds of secretory cells and mitochondria-rich cell with a single cilium, could have peculiar functions in the renal pelvis, respectively.

• Applied Microscopy
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• v.38 no.3
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• pp.205-212
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• 2008

In this study morphological changes of the testes of golden hamsters treated with 6-aminonicotinamide (6-AN, 10 mg/kg body weight) in every two days were investigated using light and transmission electron microscopes. After the 7th injection of 6-AN, body weights of hamsters were significantly reduced, and the weight of testes were markedly reduced in the group of hamsters after 5th injections. Degeneration of seminiferous epithelium appeared first in the group receiving 5th injections, which were followed by severe degenerations after the 9th injection. In the degenerated seminiferous epithelium, deep vacuolization, and destruction of spermatogenic cells and Sertoli cells were also oberved. Multinuclear giant cells were also observed in the lumen of destructed seminiferous epithelium. But there were no edematous changes in the interstitial tissue, and the Leydig cells were found to be relatively intact. Therefore, these results show that 6-AN trigger severe morphological alteration of the spermatogenic cells and Sertoli cells, however Leydig cells are unaltered by 6-AN.

• Applied Microscopy
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• v.38 no.1
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• pp.29-34
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• 2008

Small amounts of zinc ions regulate a plentitude of enzymatic proteins, receptors and transcription factors, thus cells need accurate homeostasis of zinc ions. Some neurons have developed mechanisms to accumulate zinc in specific membrane compartment ("vesicular zinc"), which can be evidenced using histochemical techniques. These neurons are the socalled zinc enriched (ZEN) neurons, which accumulate glutamate and zinc inside their synaptic vesicles and release it during synaptic transmission. In the present paper we have studied the distribution of the ZEN terminals in the rat hippo-campus using ZnSe autometallography, Neo-Timm staining, ZnT3 immunohistochemistry and TSQ fluorescence staining.

• Parasites, Hosts and Diseases
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• v.22 no.2
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• pp.259-266
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• 1984

Present study was undertaken to elucidate the changes of the ultrastructure of Naegleria fowleri trophozoite in brain tissue of mice and culture medium. Naegleria fowleri, 0359 strain, which used in this study was cultured in axonic liquid medium, CGVS medium. Each mouse was inoculated with amoebas intranasally under secobarbital anesthesia, and sacrificed on 7th day after the infection. Comparative observation of the ultrastructure of the amoebas in axonic culture and experimentally infected mice brain was done with transmission electron microscope. The results are summarized as follows: 1. The amoebas in mouse brain tissue were round in outline, whereas those of amoebas from axonic culture showed irregular appearance. 2. Mitochondria in the amoebas from axonic culture was oval, round and cylindrical shape and darkly stained, whereas those of the amoebas from mouse brain tissue showed dumbbell shape together with above forms. The stain was not unique, but light and/or dark. 3. Rough endoplasmic reticulum of amoebas in brain tissue was tubular, but from culture it was vesicular or tubular in shape. 4. Emity vacuoles were demonstrated in amoebas from culture, while food vacuoles with myelinated structures were abundant in those from tissue, suggesting a strong phagocytic activity. 5. Mouse brain tissue in ected were extensively destroyed, and Polymorphonuclear leukocytes were infiltrated predominantly with inflammatory lesion. Amoebas were observed in the vicinity of the capillary.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.3
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• pp.122-126
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• 2012

The properties of Al-doped ZnO (AZO) films were investigated as a function of $H_2/(Ar+H_2)$ gas ratio using an AZO (2 wt% $Al_2O_3$) ceramic target in a radio frequency (RF) magnetron sputtering system. The deposition process was done at $200^{\circ}C$ and in $2{\times}10^{-2}$ Torr working pressure and with various ratios of $H_2/(Ar+H_2)$ gas. During the AZO film deposition process, partial $H_2$ gas affected the AZO film characteristics. The electron resistivity (${\sim}9.21{\times}10^{-4}\;{\Omega}cm$) was lowest and mobility (${\sim}17.8\;cm^2/Vs$) was highest in AZO films when the $H_2/(Ar+H_2)$ gas ratio was 2.5 %. When the $H_2/(Ar+H_2)$ gas ratio was increased above 2.5 %, the electron resistivity increased and mobility decreased with increasing $H_2/(Ar+H_2)$ gas ratio in AZO films. The carrier concentration increased with increasing $H_2/(Ar+H_2)$ gas ratio from 0 % to 7.5 %. This phenomenon was explained by reaction of hydrogen and oxygen and additional formation of oxygen vacancy. The average optical transmission in the visible light wavelength region over 90 % and an orientation of the deposition was [002] orientation for AZO films grown with all $H_2/(Ar+H_2)$ gas ratios.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.1
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• pp.131-143
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• 2007

Statement of the problem: In case of poor bone quality or immediately loaded implant, various strategies have been developed focusing on the surface of materials to improve direct implant fixation to the bone. The microscopic properties of implant surfaces play a major role in the osseous healing of dental implant. Purpose of study: This study was undertaken to evaluate bone response of ion beam-assisted deposition(IBAD) of hydroxyapatite(HA) on the anodized surface of subperiosteal titanium implants. Material and methods: Two half doughnut shape subperiosteal titanium implants were made. The control group was treated with Anodized surface treatment and the test group was treated with IBAD of HA on control surface. Then two implants inserted together into the subperiosteum of the skull of 30 rats and histological response around implant was observed under LM(light microscope) and TEM(transmission electron microscope) on 4th, 6th and 8th week. Results: Many subperiosteal implants were fixed with fibrous connective tissue not with bony tissue because of weak primary stability. The control group observed poor bone response and there was no significant change at any observation time. However the test group showed advanced bone formation and showed direct bone to implant contact under LM on 8th week. The test group observed much rER in the cell of osteoblast but the control group showed little rER under TEM. Conclusions: The test group showed better bone formation than the control group at the condition of weak primary stability. With these results IBAD surface treatment method on Anodized surface, may be good effect at the condition of weak primary stability.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.4
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• pp.316-333
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• 1998

Obstructive sialadenitis of major salivary glands is a common entity that occurs either in sialolithiasis or in foreign-body obstruction of the excretory ducts. This is characterized histologically by the presence of duct-like structural groups in a highly fibrotic stroma. Although the pathologic features are well recognized, the various cell types involved in the atrophy and subsequent regeneration of the obstructed salivary gland have been controversial. For this reason, an animal model of obstructive sialadenitis that induced atrophy in the salivary gland was used. Experimental study was performed to observe changes of submandibular gland in rabbit and apply the results to clinical activity. Forty-five rabbits each weighing about 3Kg were used and divided into control and experimental group. In the experimental group, ducts of submandibular gland was ligated and cutted divided into each twenty rabbits. Rabbits were serially sacrificed on the 3rd, 5th, 14th, 30th day of experiment. The submandibular glands were dissected out at sacrifice and stained with H&E, MT, immunohistochemical stain and the histological examinations were carried out under the light and transmission electron microscope. After examination and comparison of all specimens, the results of this study were as follows: 1. In the features of H&E stain, moderate infiltration of inflammatory cell were present at 3rd day of experiment. The features of ductal metaplasia was observed after 7th day in the ligation group and destructive changes was continued. In the cutting group, atrophic changes were less severe than ligation group but the small ductule were separated from stroma after 7th day. 2. In the feature of MT stain, apposition of connective tissue was increased in all group, more active in ligation group. 3. In the features of immunohistochemical stain, ligation group showed increased PCNA positive response at 7th day and the higher activity of duct cells was observed. Severance group showed more PCNA positive response than ligation group at 30th day. 4. In TEM features, ductal metaplasia was started at 7th day and degenerative change with margination of nucleus had been severe. Although ductal metaplasia was seen in the severance group, more numerous granule in different size was founded than ligation group. From above results, degenerative change was identified with ductal metaplasia, apically apposition of granule, r-ER destruction in ligation group. Severance of duct elicit degenerative change of grandular cells but the change was less severe than ligation group and more PCNA positive cell was founded at acinar cell.