• Investigative Magnetic Resonance Imaging
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• v.17 no.4
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• pp.275-285
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• 2013

Purpose : The objective of this study was to investigate effects of different smoothing kernel sizes on brain tissue-masked susceptibility-weighted images (SWI) obtained from normal elderly subjects using voxel-based analyses. Materials and Methods: Twenty healthy human volunteers (mean $age{\pm}SD$ = $67.8{\pm}6.09$ years, 14 females and 6 males) were studied after informed consent. A fully first-order flow-compensated three-dimensional (3D) gradient-echo sequence ran to obtain axial magnitude and phase images to generate SWI data. In addition, sagittal 3D T1-weighted images were acquired with the magnetization-prepared rapid acquisition of gradient-echo sequence for brain tissue segmentation and imaging registration. Both paramagnetically (PSWI) and diamagnetically (NSWI) phase-masked SWI data were obtained with masking out non-brain tissues. Finally, both tissue-masked PSWI and NSWI data were smoothed using different smoothing kernel sizes that were isotropic 0, 2, 4, and 8 mm Gaussian kernels. The voxel-based comparisons were performed using a paired t-test between PSWI and NSWI for each smoothing kernel size. Results: The significance of comparisons increased with increasing smoothing kernel sizes. Signals from NSWI were greater than those from PSWI. The smoothing kernel size of four was optimal to use voxel-based comparisons. The bilaterally different areas were found on multiple brain regions. Conclusion: The paramagnetic (positive) phase mask led to reduce signals from high susceptibility areas. To minimize partial volume effects and contributions of large vessels, the voxel-based analysis on SWI with masked non-brain components should be utilized.

• Journal of the Korean Ceramic Society
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• v.41 no.2
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• pp.125-130
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• 2004

The effect of SiC particle size on the microstructures and mechanical properties of A1$_2$O$_3$-SiC composite was investigated. Two types of SiC powders having average particle sizes of 0.15 ${\mu}{\textrm}{m}$ and 3 ${\mu}{\textrm}{m}$ were used. The grain growth in the specimen containing 0.15 ${\mu}{\textrm}{m}$ SiC was effectively inhibited due to the fine SiC particles. However, after the formation of some abnormal grains, fast and exaggerated grain growth occurred which led to the microstructure of large grains with irregular shape. Fracture strength decreased due to the abnormal large grains. On the other hand, for specimen containing 3 ${\mu}{\textrm}{m}$ SiC showed normal grain growth behavior from initial sintering stage. Large SiC particles, however, effectively inhibited exaggerated grain growth after nucleation of a few abnormal grains. As a consequence, microstructure consisted of homogeneous elongated grains. In the A1$_2$O$_3$-2.5SiC(0.15 ${\mu}{\textrm}{m}$)-2.5SIC(3 ${\mu}{\textrm}{m}$) composite fabricated by mixing the two types of SiC powder, abnormal grain growth occurred. However, the good fracture strength was maintained regardless of microstructural changes in this specimen.

• Journal of Yeungnam Medical Science
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• v.14 no.1
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• pp.227-236
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• 1997

발꿈치는 신체의 다른부위에 비하여 엄청난 하중을 지탱하고 있으며, 주행시에는 막대한 전단력을 받으므로 그 재건에 있어서 어려운 점이 있다. 그 동안 발꿈치의 연부조직 결손을 재건하기 위한 많은 방법들이 개발되어 왔지만, 비교적 큰 발꿈치의 연부조직 결손을 재건하는 것은 아직도 쉬운 일이 아니다. 이처럼 큰 결손의 재건에는 주로 유리 피판술을 이용한 재건술을 사용하는데, 그 중에서도 광배근, 복직근, 대퇴박근 등의 근육을 이용하는 방법이 최근에 많이 이용되고 있다. 이와 같은 유리 근 피판에 피부이식을 이용하는 발꿈치 재건술은 표재성 감각기능을 재건하지 못하는 것이 단점으로 지적되고 있으나, 보행 또는 주행시 발꿈치에 가해지는 압력과 전단력을 효과적으로 견디어 낼 뿐아니라, 외관상으로도 정상에 가까운 발꿈치를 재건할 수가 있어서 좋은 방법으로 인정되고 있다. 특히, 대퇴박근은 피판을 비교적 쉽게 채취할 수 있고, 공여부에 기능적인 장애나 심한 변형을 남기지 않아서 좋은 방법이라 생각된다. 다만 크기가 비교적 작아서, 발등이나 족관절 상부에까지 이르는 광범위한 연부조직 결손에서는 사용할 수 없는 점이 아쉽다. 저자는 비교적 가늘고 긴, 대퇴박근의 형태적 특징을 최대한 이용하여, 결손부의 다양한 형태 및 크기에 따라 대퇴박근을 말발굽형, 나선형, S-자형 등으로 적절히 형상화하여 발꿈치 결손을 효과적으로 재건하는 방법을 고안하였다. 또한, 공여부에 긴 선상 반흔이 남는 것을 피하기 위하여 두 개의 작은 절개를 통해서 대퇴박근을 채취하였다. 이 방법을 이용하여 영남대학교 의과대학 성형외과학 교실에서는 1993년 이후부터 7명의 비교적 큰 발꿈치의 연부조직 결손 환자를 대상으로 유리 대퇴박근 피판술을 이용한 재건술로 성공적인 결과를 얻을 수 있었다.

• Journal of Biomedical Engineering Research
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• v.25 no.1
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• pp.49-55
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• 2004

In this paper, we investigated the effects of the photodynamic therapy(PDT) for the tumor mass in mice. In the experimental method, we divided the mice into two control and test group which HepG2 and HeLa cell line induced cancer mass in mice. Photofrin was administered to the tumor-bearing mouse, followed 30 hours later by 630nm and 650nm laser light exposure. After photodynamic therapy we analyzed the two mice group for the tumor mass size, tumor growth, tumor cell necrosis, pathological anatomy change. According to the results, tumor cell necrosis was shown in the tissues which the reduce size of tumor and tumor cell necrotic change according to the irradiation time and light dose amount. The considerable difference, however, between the 630nm and 650nm wavelength was not found for the tumor cell necrotic change and other damage of normal tissue was not found.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.539-541
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• 2016

소프트웨어 중심 사회에서 소프트웨어의 개발과 운영에 대한 효율성을 극대화하기 위해 운영 조직과 개발 조직을 통합한 개발운영조직 통합관리 방법론을 적용하고 있다. 클라우드 환경을 이용하여 서비스를 중단 없이 운영하는 지속적 배포 시스템에서 개발운영조직 통합관리를 적용 하였을 때, 운영 조직의 요구사항과 사용자의 요구사항 등으로 인한 작은 규모 크기의 배포가 빈번하게 발생하게 된다. 이와 같은 시스템은 다양한 보안 위협으로부터 안전하지 않다. 따라서, 본 연구에서는 클라우드 환경에서 지속적 배포시스템의 개발운영조직 통합관리에서 발생할 수 있는 문제점과 보안에 대한 개선사항을 제시하고자 한다.

• The Korean Journal of Zoology
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• v.38 no.1
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• pp.115-124
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• 1995

한국산 거머리 각배obdeffo linea약의 상피조직을 배부상피(dorsal epithelium), 복부 상피(ventral epithelium) 측부상피(lateral epithelium) 별로 3부위를 광학현미경과 전자현미경으로 관찰한 결과 다음과 같은 결론을 얻었다. 전자현미경 관찰에서 거머리 상피조직은 3부위 모두 불규칙한 세포로 구성되었으며, 그들은 전자밀도가 높은세포와 중등도인세포 그리고 투명한세포 등 3종류로 구분되었다. 거머리의 불규칙한 상피조직 사이에서 두 종류의 분비성 과립인 a 및 b형과립과 색소성 과립인 D형과립이 관찰되었다 배부상피조직에서 관찰된 a형과립(66$\times$83 Um)은 복부와 측부에서 관찰된 과립(33H66 Um) 보다 형태가 훨씬 크고 그 수 도 두배정도 많이 관찰된 반면, b형과립은 모든 상피조직에서 동일한 크기와 형태를 보였지만 그 수는 배부와 복부에 비해 측부상피조직에서 두배정도 많이 관찰되었다 이상 분비성 과립들은 PAS-alcian blue(pH 2.5) 반응에서 모두 PAS에 강한 양성반응을 나타내어 중성점액다당류로 확인되었다. 거머리 몸마디를 이루는 체절은 배부와 복부에서 그 주름의 깊이와 넓이가 각각 다르게 나타나서(배부, 40 Um와 330 urn, 복부 100 urn와 150 urn), 복부의 깊은 체절이 발(foot)의 역활을 수행 하였다.

• The Journal of the Petrological Society of Korea
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• v.13 no.1
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• pp.1-15
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• 2004

In this study we propose that the ‘enclaves’ which occur in the granites should be translated into ‘Po-yu-am’in Korean. Also we suggest some criteria to discriminate the mafic microgranular enclaves (MME) of igneous origin from the xenoliths, which possibly come from the plutonic, volcanic and sedimentary country rocks. The color of the MME is gray green∼dark gray and the mineral grains are fine and equigranular. The MME are generally of ellipsoidal shape and can be easily found within the granites. They do not show any evidence of contact metamorphism by granite host. On the other hand. the xenoliths are generally of angular shape and are of the same mineral assemblage and texture as the country rocks around the granites. The distribution of the xenoliths is mostly concentrated along the intruding plane of the granites near the country rocks. The xenoliths were partly metamorphosed by the granite intrusion. The xenoliths from the plutonic rocks are easily distinguished from the MME in terms of their angular shape and coarser grain size, but they do not have any metamorphic mineral assemblage and texture. The xenoliths from the tuffaceous rocks show angular shape and porphyritic and pyroclastic textures. Large size xenoliths from the sedimentary rocks specifically preserve bedding structure which are indicative of the sedimentary strata. However, the sedimentary xenoliths of small size are often difficult to distinguish from the MME. Metamorphic minerals and texture are a useful key to discriminate the small-sized sedimentary xenoliths from the MME. In summary the xenoliths in the granites can be megascopic ally distinguished from the MME by comparing their color, shape, grain size and remnant original structure like bedding. Additionally the metamorphic mineral assemblage and texture are microscopic discriminators between the xenoliths and the MME in the granites.

• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.4
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• pp.292-303
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• 1998

Recent study has demonstrated that some magnetic properties are sensitive to the microstructural state of material. The ASTM A 508 Gr. 3 reactor pressure vessel steel has various microstructural changes including martensitic and bainitic phases, and various sizes of grain and precipitates in the weld heat-affected zone (HAZ). To correlate the microstructural state with Barkhausen noise (BN), specimens were prepared through simulating various weld thermal cycles using a thermal simulator. The conventional magnetic properties, i.e. coercive force, remanence and maximum induction, did not change significantly, whereas the BN amplitude and energy during a magnetization cycle changed markedly with microstructural state. The BN increased with increasing grain and carbide sizes, and the tempered bainite structure showed higher BN parameter than tempered martensite.

• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.435-438
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• 2014

An 11-year-old, 2.67 kg female Maltese dog with 3 weeks history of palpable cervical mass near trachea was submitted to a local animal hospital. Radiography and ultrasonography showed radiopaque mass adjacent trachea and vagus nerve. Surgically excised mass was solitary and approximately $3.5{\times}2{\times}0.8cm$ in size. Histopathologically, there were large neoplastic foci admixed with normal thyroid tissues. These neoplastic foci were composed of small to large packets of the neoplastic cells with plasmacytic morphology, and these packets were divided by fine fibrovascular septa. Immunohistochemically, most neoplastic cells in the thyroid mass showed positive reactions for cytokeratin (AE1/AE3), chromogranin A, neuron specific enolase (NSE) and the negative reaction for vimentin. Based on the gross, histopathologic and immunohistochemical characteristics, this dog was diagnosed as medullary thyroid carcinoma.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.1
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• pp.30-42
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• 1986

In order to find out the best media, explants and environmental conditions for induction of calluses and organogeneses of Pinellia ternata (Thunb.) Breit in vitro, various parts of adult have been cultured on Murashige & Skoog's medium containing various levels of 2,4-dichlorophenoxy acetic acid(2,4-D) and kinetin. The results obtained were as follows: Calluses were induced from the surface of apical meristem and leaf tissue. Formation and growth of calluses in petiole ex plants were best on the MS medium complemented with 2,4-D 2.0 mg/l and kinetin 0.2mg/l. But callus formation in stem ex plants of the nearest tuber was not induced at all kinds of media. Plantlets occured at all treatment except absence of growth regulator. Their numbers, size, leaf and fresh weight were promoted by 2,4-D 2.0mg/l and kinetin 0.2mg/l. Root growth was increased on the medium containing higher 2,4-D concentrations. Size and fresh weight of callus were increased at 25$^{\circ}C$ compared with 10, 20 and 30$^{\circ}C$, respectively. Optimal pH value was at 6.0 for growth of callus. Morphological aberrations were observed in plantlets, especially in regenerated leaves. The separation of the broad leaved plantlets and albino were observed in some cultures. Growth of plantlets after transplantation was best in pots with the sterilized vermiculte. But abnormal variants withered up.