• 스마트미디어저널
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• 제2권4호
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• pp.51-59
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• 2013

백본망의 지속적인 고속화는 충분한 가용대역폭을 제공하고 있지만 장거리 대용량 데이터 전송에서 이를 잘 활용하지 못하고 있다. 이는 대부분 응용들이 TCP를 사용하는데서 원인을 찾을 수 있으며 TCP는 전송메커니즘 특성상 고속네트워크에서 신속한 가용대역폭 확보가 어렵다. UDT는 응용계층 전송프로토콜로써 고속네트워크에서 용을 목표 설계된 잘 알려진 프로토콜이다. 본 논문에서는 네트워크 혼잡상태에 적응적인 UDT 병렬전송기법에 대해 제안하고 다음 두 가지 관점에서 성능을 평가한다. 첫째, UDT Rate 혼잡제어에 따른 전송성능을 측정하고 UDT의 성능과 비교한다. 둘째, 네트워크 상태에 적응적인 UDT 병렬전송기법의 전송성능에 대해 분석한다. 실험결과 UDT Rate 혼잡제어의 경우 jitter를 30ms로 설정한 경우 RTT 100ms 구간에서 UDT에 비해 106%의 성능향상을 보였다. 또한 Rate 혼잡제어를 적용한 병렬전송의 경우 jitter를 20ms로 설정한 경우 RTT 400ms 구간에서 UDT 병렬전송에 비해 107% 성능향상을 실험을 통해 확인하였다.

• Nuclear Engineering and Technology
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• 제51권8호
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• pp.1905-1915
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• 2019

This paper investigated the influence of simple support girds on flow, irrespective of having mixing vanes, in a 1 × 3 array rod bundle by using CFD methodology and the most accurate turbulence model which could reflect the actual physics of the flow was determined. In this context, a CFD model was created simulating the experimental studies on a single-phase flow [1] and the results were compared with the experimental data. In the first part of the study, influence of mesh was examined. Tetra, hybrid and poly type meshes were analyzed and convergence study was carried out on each in order to determine the most appropriate type and density. k - ε Standard and RSM LPS turbulence models were used in this section. In the second part of the study, the most appropriate turbulence model that could reflect the physics of the actual flow was investigated. RANS based turbulence models were examined using the mesh that was determined in the first part. Velocity and turbulence intensity results obtained on the upstream and downstream of the spacer grid at -3d_h, +3d_h and +40d_h locations were compared with the experimental data. In the last section of the study, the behavior of flow through the spacer grid was examined and its prominent aspects were highlighted on the most appropriate turbulence model determined in the second part. Results of the study revealed the importance of mesh type. Hybrid mesh having the largest number of structured elements performed remarkably better than the other two on results. While comparisons of numerical and experimental results showed an overall agreement within all turbulence models, RSM LPS presented better results than the others. Lastly, physical appearance of the flow through spacer grids revealed that springs has more influence on flow than dimples and induces transient flow behaviors. As a result, flow through a simple support grid was examined and the most appropriate turbulence model reflecting the actual physics of the flow was determined.

• 한국주거학회논문집
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• 제26권4호
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• pp.33-44
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• 2015

The fast and competitive urbanization has accelerated unbalanced land utilization and housing, thereby producing large number of decaying areas and socially disadvantaged population, while generally promoted citizen's quality of life. Since rental housing policy, therefore, has emerged as a major important issue to solve these ever increasing problems, new concepts in leading examples need to be explored to stimulate creative ideas for future housing improvement. The purpose of this research is to extract successful factors of a leading rental housing 'Manhattan Plaza' in New York city, expecting useful implications for housing improvement in Korea. Field visit and in-depth interview for data collection and qualitative approach for analysis were carried out. As results, its successful sustainability and fame were found to be attributable to following concepts, such as, socially integrative mix of diverse residents, residents' participation in management, privacy respect administration, considerate planning and design features of physical environment. The latter, especially, were prominent in peripheral spaces, indoor and outdoor community spaces, and private spaces. Based on the results, suggestions were made for future Korean rental housing development.

• 대한세포병리학회지
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• 제7권2호
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• pp.197-201
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• 1996

Glassy cell carcinoma is an unusual neoplasm of the uterine cervix that accounts for $1{\sim}2%$ of all cervical malignancy. It is a rapidly progressive and biologically aggressive disease with poor response to therapy. This tumor is considered to be a poorly differentiated mixed adenosquamous carcinoma. The cytologic findings are characterized by tumor cells arranged predominantly in syncytial like aggregates and an inflammatory background. The tumor cells have moderate amounts of eosinophilic or amphophilic cytoplasm, which is often finely granular. The nuclei are relatively large and have fine chromatin with prominent eosinophilic nucleoli. Cytologically, glassy cell carcinoma is most likely to be confused with large cell nonkeratinizing squamous cell carcinoma and with atypical reparative cells. Herein, we report three cases of glassy cell carcinoma of the uterine cervix diagnosed by cervicovaginal smear and confirmed by histologic section with review of literatures.

• 한국초등과학교육학회지:초등과학교육
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• 제37권3호
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• pp.296-308
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• 2018

The purpose of this study is to analyze the characteristics and differences of gesture between career teachers and novice teachers in elementary science class. In order to analyze the gesture of elementary science teachers, gesture analysis framework was developed. The teachers who participated in the experiment were 2 beginner teachers and 2 career teachers. We analyzed 'bones and muscles', 'digestion', 'breathing', and 'excretion' of 'body' section in the second semester of 5th grade. The video recording of the class scene with the camcorder was recorded and analyzed by Observer XT. The results of this study are summarized as follows. First, the career teacher lessens unnecessary gestures than the novice teacher. During the class, the career teachers lessened the gestures not related to the context of the class. These differences were more prominent in the activities of the group with many unexpected situations than those of the teachers who prepared the class contents. Second, career teachers have more communication control act than novice teachers. Career teachers have often made adjustments to induce learner presentations or control unnecessary utterances. Third, career teachers efficiently interacted with learners using gestures that can enhance communication.

• 천문학회보
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• 제42권2호
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• pp.86.4-87
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• 2017

Symbiotic stars are binary systems composed of a hot white dwarf and a mass losing giant. Many symbiotic stars are known to exhibit broad wings around Balmer emission line. We show high resolution spectra of S-type symbiotic stars, Z Andromedae and AG Draconis, obtained with the ESPaDOnS and the 3.6 m Canada-France-Hawaii Telescope, in which we find prominent broad wings around Balmer lines. We adopt Monte-Carlo technique to consider two types of wing formation mechanisms, which are Thomson scattering by free electron in H II region and Raman scattering by atomic hydrogen in H I region. We find that Thomson wings of $H{\alpha}$ and $H{\beta}$ have the same widths in the Doppler space due to the cross section independent of wavelength. In contrast, Raman $H{\alpha}$ wings are 3 times broader widths than $H{\beta}$ counterparts, which is attributed to the different cross sections and branching ratios. Our CFHT data show that $H{\alpha}$ wings of Z Andromedae and AG Draconis are broader than $H{\beta}$ wings, lending strong support to the Raman scattering origin of Balmer wings in these objects.

• Asian Journal of Business Environment
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• 제3권2호
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• pp.17-22
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• 2013

Purpose - This dissertation is based on previous research, and analyzes processing trade, which constitutes a major section of foreign trade in Shandong Province. Research design, data, and methodology - The study uses the survey data on polarization, which is a vital index reflecting the unbalanced growth of regional economic development. The article introduces the processing trade polarization index, and the processing trade polarization fluctuation rate, to predict the geographical polarization posture and development trends in Shandong Province. Results -The development of processing trade in Shandong Province shows the level of gradient from east to west. The first-line growth pole has been formed and developed, and the initial formation of the diffusion mechanism has taken place. However, coordination problems in accompanying regional development have become increasingly prominent. Conclusions - This study focuses on the development of processing trade strategy and suggests overall coordination of development objectives, using non-balanced development goals. According to regional characteristics and development objectives of the processing trade in Shandong Province, the region around the city is divided into innovation diffusion region, enhanced growth areas, areas expected to undertake development, and areas to upgrade in four levels, given the different policy proposals.

• Nuclear Engineering and Technology
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• 제49권1호
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• pp.103-112
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• 2017

Application of the supercritical condition in reactor core cooling needs to be properly justified based on the extreme level of parameters involved. Therefore, a numerical study is presented to compare the thermalhydraulic performance of supercritical and single-phase natural circulation loops under low-to-intermediate power levels. Carbon dioxide and water are selected as respective working fluids, operating under an identical set of conditions. Accordingly, a three-dimensional computational model was developed, and solved with an appropriate turbulence model and equations of state. Large asymmetry in velocity and temperature profiles was observed in a single cross section due to local buoyancy effect, which is more prominent for supercritical fluids. Mass flow rate in a supercritical loop increases with power until a maximum is reached, which subsequently corresponds to a rapid deterioration in heat transfer coefficient. That can be identified as the limit of operation for such loops to avoid a high temperature, and therefore, the use of a supercritical loop is suggested only until the appearance of such maxima. Flow-induced heat transfer deterioration can be delayed by increasing system pressure or lowering sink temperature. Bulk temperature level throughout the loop with water as working fluid is higher than supercritical carbon dioxide. This is until the heat transfer deterioration, and hence the use of a single-phase loop is prescribed beyond that limit.

• 대한세포병리학회지
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• 제4권1호
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• pp.57-61
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• 1993

Endodermal sinus tumor of the mediastinum is a very rare malignant tumor, usually affecting young adolescents, and its histologic findings are characteristic as that of gonadal germ cell origin. We describe the cytologic finding of fine needle aspiration of mediastinal endodermal sinus tumor in a 19-year-old male patient, comparing with tissue section. The tumor cells in smears were usually in tight clusters with large overlapping cells, which were arranged in a papillary or microacinar pattern, suggesting carcinoma. The tumor cells were large, round or oval with a small amount of cytoplasm which was occasionally vacuolated and had indistinct border. The nuclei were large, pleomorphic, and vesicular with large prominent nucleoli. The tissue sections showed typical findings of endodermal sinus tumor. Careful correlation of cytological findings and the serum alpha -fetoprotein level would be helpful to confirm the diagnosis.

• 농촌계획
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• 제24권4호
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• pp.81-88
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• 2018

With the increase of the number of riverfront development projects an objective and systematized survey and assessment tool is required to understand and identify the characteristics and potentials of river environment for human uses. The purpose of this study was to develop an assessment system for the investigation and evaluation of the water-friendly environment and to examine its effectiveness by applying the system to the selected study sites. Literature reviews, expert consultation, and preliminary survey were conducted to select highly relevant indexes to evaluate water-friendliness in rivers and, as a result, an assessment system of ten items in four areas was established. The assessment system were applied to 139 reaches of six rivers including Bykgye Cheon, Seom River, Gap Cheon, Yudeng Cheon, Naesung Cheon, and Kumho River. The scores and grade of water-friendliness were calculated per rivers and reaches, and their differences were prominent according to urban river, rural river, mountainous area and city area. Bykgye Cheon and Naesung Cheon got high scores in visual quality and Kumho River and Gap Cheon in community needs and potential uses. The scores of each section in the same river can be used as a basic data for the selection of appropriate sites for the development of hydrophilic space. In addition, it is expected that identifying the characteristics of each river help establish an appropriate management plan for the river.