• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제3권8호
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• pp.329-334
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• 2014

본 논문에서는 마이크로 CT 영상에서 해면뼈의 형태학적 분석을 위하여 해면뼈를 자동 분할하는 방법을 제안한다. 제안된 방법에서는 임계값을 이용하여 뼈 영역을 추출하고 뼈의 바깥쪽 경계선을 검출한다. 뼈 영역의 각 복셀에 대하여 구 정합을 적용하여 해당 복셀을 중심으로 하는 최대 크기의 구를 구한다. 이 구에 뼈의 바깥쪽 경계선이 포함되면 이 구에 포함된 복셀들은 치밀뼈로 분류되고 그렇지 않으면 해면뼈로 분류된다. 제안된 방법을 쥐의 15개 대퇴골 원위부 영상에 적용하였으며 사람이 수작업으로 분할한 결과와 비교 실험을 수행하였다. 분할된 해면뼈에 대하여 BV/TV, Tb.Th, Tb.Sp, Tb.N의 네 가지 형태학적 지표자를 측정하였다. 회귀분석과 Bland-Altman 방법으로 비교해본 결과 BV/TV, Tb.Th, Tb.Sp, Tb.N 모두 신뢰할 만한 수준의 범위 안에 있었다. 또한 구 정합 방법은 단순하게 구현할 수 있으면서도 3차원 정보를 이용함으로써 해면뼈를 정확하게 분할할 수 있음을 알 수 있었다.

• The Journal of Advanced Prosthodontics
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• 제8권2호
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• pp.101-109
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• 2016

PURPOSE. To investigate the void parameters within the resin cements used for fiber post cementation by micro-CT (${\mu}CT$) and regional push-out bonding strength. MATERIALS AND METHODS. Twenty-one, single and round shaped roots were enlarged with a low-speed drill following by endodontic treatment. The roots were divided into three groups (n=7) and fiber posts were cemented with Maxcem Elite, Multilink N and Superbond C&B resin cements. Specimens were scanned using ${\mu}CT$ scanner at resolution of $13.7{\mu}m$. The number, area, and volume of voids between dentin and post were evaluated. A method of analysis based on the post segmentation was used, and coronal, middle and apical thirds considered separately. After the ${\mu}CT$ analysis, roots were embedded in epoxy resin and sectioned into 2 mm thick slices (63 sections in total). Push-out testing was performed with universal testing device at 0.5 mm/min cross-head speed. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests (${\alpha}=.05$). RESULTS. Overall, significant differences between the resin cements and the post level were observed in the void number, area, and volume (P<.05). Super-Bond C&B showed the most void formation ($44.86{\pm}22.71$). Multilink N showed the least void surface ($3.51{\pm}2.24mm^2$) and volume ($0.01{\pm}0.01mm^3$). Regional push-out bond strength of the cements was not different (P>.05). CONCLUSION. ${\mu}CT$ proved to be a powerful non-destructive 3D analysis tool for visualizing the void parameters. Multilink N had the lowest void parameters. When efficiency of all cements was evaluated, direct relationship between the post region and push-out bonding strength was not observed.

• 전자통신동향분석
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• 제38권6호
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• pp.119-127
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• 2023

Market-oriented networks support various tasks in the market domain. We analyze trends in structural changes of such networks to adapt to preferences in general market movements. This analysis is different from conventional ones that focus on specific technologies. Instead, we focus on the paradigm shift of network technology from connectivity functionalities to platforms supporting business domains for direct modeling. Moreover, we analyze current development efforts of technologies based on popular and realistic solutions such as FIWARE, 5GinFIRE, IBN, IDN, and HNSP. Remarkably, we detail HNSP as an open research and development platform to experiment with business models and enable co-building with developers. We observe a clear paradigm shift of communications technology from a closed to an open job-shop style.

• 한국정보통신학회논문지
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• 제23권12호
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• pp.1673-1678
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• 2019

산업 통신에는 다양한 네트워크가 있으며 여러 가지 통신 방식을 사용한다. 기업에서는 생산 라인 확장, 공장 업그레이드, 네트워크 세분화, 시스템 통합 등을 위하여 산업용 장치와 네트워크 간에 통신 변환이 필요하다. 이것은 많은 제조회사가 제작한 설계자가 다른 다양한 기계 장치를 네트워크에 연결하고 전송하기 위하여 데이터 또는 프로토콜 변환을 위한 통신 장비가 제공되어야함을 의미한다. 본 논문에서는 적층형 통신 모듈을 사용하여 산업 통신 프로토콜 변환을 지원할 수 있는 산업용 통신 게이트웨이를 설계하였다. 제작된 게이트웨이는 RS485 시리얼 통신을 이용하는 개별 통신 모듈을 다층으로 연결하는 구조를 가지고 있다. 각각의 통신 모듈은 아날로그 데이터 카드, 디지털 데이터 카드, CAN 및 LAN 지원 카드로 구성하였다. 메인 보드 프로세서는 Atmega micro-processor를 사용하였고, RS485 시리얼 슬롯을 배치하여 적층형 통신 모듈 구조를 가지도록 하였다. 본 논문에서 제작된 적층형 산업용 통신 게이트웨이는 아날로그 및 디지털 I/O 기능과 CAN과 LAN을 지원할 수 있기 때문에 산업용 통신 제어 및 모니터링에 폭넓게 활용될 수 있다.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.718-725
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• 2017

The method of stator segmentation is generally taken to enhance the electromagnetic performance of surface-mounted permanent magnet (SPM) machine and reduce its production cost. Based on the model with single slot, the expressions of cogging torque in machine with uniform or non-uniform segmentations are deduced and the optimal combination is given. Moreover, this paper discusses a structured skewing method and put forward a novel stator structure model to reduce the cogging torque in segmented permanent magnet machine. The model can reduce the cogging torque amplitude by shifting a proper angle of slot-opening. The shifting angle formula for analysis can also be suitable for other permanent machine with segmented stator. Finally the results of finite element simulation are given to prove that the method is effective and feasible.

• Journal of Species Research
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• 제6권spc호
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• pp.185-214
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• 2017

The genus Phyllopodopsyllus T. Scott, 1906 is nearly cosmopolitan and contains around 60 valid species, but has not been previously recorded in Korea. One of the reasons is probably the paucity of research in marginal habitats, such as marine interstitial. I describe two new species here. Numerous specimens of both sexes of P. kitazimai sp. nov. were collected from a beach near Yeongdeok, while only two females of P. busanensis sp. nov. were collected from a beach near Busan. The new species differ in numerous macro-morphological characters, such as the segmentation and armature of the antennula, armature of the mandibula, maxillula, maxilliped, and the first three swimming legs, as well as the shape of the caudal rami and the female genital field. However, they show very little difference in the number and position of cuticular organs (pores and sensilla) on all somites, which might prove these rarely used micro-characters to be useful in the reconstruction of phylogenetic relationships in this group of harpacticoids. Both species have their closest relatives in Japan. Phyllopodopsyllus kitazimai is morphologically most similar to P. punctatus Kitazima, 1981, but can be distinguished by much longer third exopodal segments of the third and fourth swimming legs. Phyllopodopsyllus busanensis shares the largest number of morphological similarities with P. setouchiensis Kitazima, 1981, but can be distinguished by shorter caudal rami. A key to species is also provided.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.77-78
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• 2020

In Korea, more than 30,000 tons of waste Styrofoam are produced every year. Styrofoam is spent more than 500 years decomposing during the reclamation process, so it needs to be recycled. The recycling rate of waste styrofoam continues to be the third highest in the world, but it is lower than that of Germany and Japan. Therefore, measures are needed to increase the recycling rate of waste Styropol. Another problem is that cement is mainly used in existing lightweight foam concrete. However, large amounts of CO2 from cement-producing processes cause environmental pollution. Currently, Korea is increasing its greenhouse gas reduction targets to cope with energy depletion and climate change, and accelerating efforts to identify and implement reduction measures for each sector. In 2013 alone, about 600 million tons of carbon dioxide was generated in the cement industry. Therefore, this study replaces CO2 generation cement with furnace slag fine powder, uses crude steel cement for initial strength development of bubble concrete, and manufactures hardening materials to study its properties using waste styrofoam. As a result of the experiment, the hardening agent replaced by micro powder of furnace slag was less intense and more prone to absorption than cement using ordinary cement. Further experiments on the segmentation and strength replenishment of furnace slag are believed to contribute to the manufacture of environmentally friendly lightweight foam concrete.

• Nuclear Engineering and Technology
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• 제56권6호
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• pp.1975-1988
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• 2024

It is important to maintain cladding integrity in spent nuclear fuel management. This study proposes a numerical analysis method to evaluate the fracture resistance of irradiated zirconium alloy cladding under pinch load known to cause Mode-III failure. The mechanical behavior and fracture of the cladding under pinch loading can be evaluated by a Ring Compression Test (RCT). To simulate the fracture of hydride precipitates, zirconium matrix, and Zr/hydride interfaces under the stress field generated by RCT, a micro-structure crack propagation simulation method based on Continuum Damage Mechanics (CDM) has been proposed. Our RCT simulation model was constructed from microscopic images of irradiated cladding. In this study, we developed an automated process to generate a pixel-based finite element model by separating the hydride precipitates, zirconium matrix, and interfaces using an image segmentation method. The appropriate element size was selected to ensure the efficiency and accuracy of a crack propagation simulation. The load-displacement curves and strain energies from RCT were compared and analyzed with the simulation results of different element sizes. The finalized RCT simulation model can be used to establish the failure criterion of fuel rods under pinch loading. The advantages and limitations of the proposed method are fully discussed here.

• 한국어병학회지
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• 제35권2호
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• pp.167-176
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• 2022

We injected infectious myonecrosis virus (IMNV) to pacific whiteleg shrimp, Litopenaeus vannamei, and observed closely with using light microscope and transmission electron microscope (TEM) for 4-8 days post infection (dpi). As clinical signs, abdominal bodies had mild opaque muscles at 5 dpi. And the mortality was shown at 6 dpi. At 8 dpi, most injected shrimps had severe opaque muscles and humped back that cause of movement disorder. As results of histopathological examinations, local parts of abdominal body muscle had muscle fiber hyalinization, muscle fiber atrophy, rounded muscle fibers, myofibrillar hypertrophy in size, a decrease in number of myofibrils and phagocytosis from the sarcolemmas by multiple hemocytes at 4 dpi. Especially, myofibrillar hypertrophy appeared at the whole or random part of single muscle fiber not in specific locations like the center or edge of muscle fiber. At 6-7 dpi, multiple muscle necrosis, muscle fiber segmentation, myofibril lysis ap- peared and a few hemocytes were infiltrated at lesions. At 8 dpi, extensive muscle necrosis, multiple myofibril lysis and muscle fiber atrophy were shown, and very few hemocytes were infiltrated. In early stage of infection, local viral myositis with zenker's degeneration were shown. These lesions appeared multiply after the early stage. In late stage of infection, extensive coagulative muscle necrosis appeared with few of inflammatory response such as hemocytes infiltration. The lack of hemocytes infiltration response at the late stage might be disadvantage for Litopenaeus vannamei to defense against IMNV and to recover, because hematocytes (granulocyte, semi-granulocyte) eliminate pathogen and damaged tissues from infection sites and help recover. As results of the TEM observation, IMNVs that had nonenveloped icosahedral capsid which was 30-40 nm diameter were in myofibril and beside tubules of sarcoplasmic reticulum and moved to the certain direction. The micro-tears and micro-trau- mas in myofibrils caused muscle fiber necrosis. And semi-granulocytes engulfed IMNVs to eliminate virus.

• 해부∙생물인류학
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• 제31권4호
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• pp.133-142
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• 2018

조직표본의 실제적인 3차원 구조에 대한 정보를 3차원 조직학이라고 하였다. 무른 성분들이 섞여 있고, 물을 포함 하고 있는 조직 내부의 미세구조의 3차원적 분석을 위해 방사광의 X선을 광원으로 하는 위상대조 미세단층 촬영이 활용되고 있다. 하지만, X선 위상대조영상 분석에서 물을 포함하고 있는 조직에서는 위상대조가 제대로 구현되지 않다는 것을 알게 되었다. 이러한 현상을 해결하기 위해 다양한 방법들을 적용하였으며, 표본을 얼렸을 때 위상대조가 강화된다는 사실을 확인하였다. 방사광 전파위상대조 동결미세단층촬영은 포항가속기연구소 X선 영상빔라인에서 수행하였다. 표본을 동결상태로 유지하면서 $0.18^{\circ}$ 간격으로 $180^{\circ}$ 회전하였으며, 표본을 통과한 X선에 의해 섬광기에 맺힌 영상을 광학렌즈로 확대하여 CCD카메라로 모았다. 각 표본 전체 투사영상을 OCTOPUS 소프트웨어로 재구성하여 2차원 단면영상으로 만들고, Amira 소프트웨어를 이용하여 3차원 영상으로 재구성하였으며, 단면영상에서 각 구조에 대한 구역화와 랜더링 작업을 수행하였다. 물에 의한 위상대조 방해 영향을 줄이기 위해 표본을 얼렸을 때 위상대조는 강화되었으나 동결팽창에 의한 조직변형이 관찰되었다. 표본을 막힌 공간에 넣고 주위를 포매제로 채워 급속냉동 동안 표본이 압박되도록 하였을 때 위상대조의 강화와 동결팽창에 의한 조직변형을 줄일 수 있었다. 결론적으로, 생체조직 내부 미세구조의 비파괴, 고해상도 3차원 영상분석에 있어 조직표본을 동결포매제로 포매 후 급속냉동하고, 방사광에서 방출되는 X선을 광원으로 하는 전파위상대조 동결미세단층촬영법은 효과적인 방법이 될 수 있을 것으로 기대한다.