• Architectural research
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• 제8권1호
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• pp.25-36
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• 2006

Campus core is an essential element in a university's physical environment for symbolic importance of high educational philosophy as well as hierarchical significance of campus structure. Yet, as modern expansion develops into and out of campus core, a challenging design and planning problem for a growing university is how to integrate a new development into the existing core structure and how to expand the fast-growing development beyond the core while maintaining a symbiotic harmony between the campus core and the modern expansion. Such challenge addresses four design frameworks for symbiotic development of the campus core and the modern expansion: (1) building grouping with territorial proximity; (2) building design rules for form and texture; (3) open space network with pedestrian walkway; (4) use-programming for on-campus student community. This study aims to explore these issues with in-depth case study of the Princeton University campus in Princeton, New Jersey in the United States. The study concludes that the Princeton campus is a result from successful synthesis of all the complex design elements, especially in relationship between the old and the new; and adds further that the development of a modern university campus requires a comprehensive plan that takes into account the older buildings when conceiving the new in symbiotic relationship along with open space network as well as functional program distribution.

• 소음진동
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• 제9권4호
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• pp.747-753
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• 1999

This paper presents results of vibration analysis of a generator-stator core for 500 MW fossil power plant. A finite element analysis using a commercial S/W is performed to estimate alternating electromagnetic forces, mainly of 120 Hz in 60 Hz machines, acting on the core, and then to calculate forced response of the core. Results are compared with design requirements.

• Elastomers and Composites
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• 제37권1호
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• pp.21-30
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• 2002

개시제 ammonium persulfate(APS)와 유화제 sodium dodecyl benzene sulfonate(SDBS)를 이용하여 methyl methacrylate(MMA), styrene(St), ethyl acrylate(EA)등의 단량체를 core(내부)와 shell(외부)의 폴리머성분이 다른 core-shell 폴리머를 합성하고 각 core-shell 폴리머에 대한 구조를 연구하였다. 한 입자의 내부와 외부의 고분자 조성이 다른 composite 라텍스는 고분자 블렌딩과 공중합의 물성과는 달리 한 입자 내에서도 상반된 두 가지 물성을 동시에 나타내는 특성으로 인하여 여러 산업 분야에 응용이 가능하다. 그러나, core-shell 라텍스를 제조할 때 반응중입자가 성장하는 과정에서 입자의 응집과 중합율이 떨어지고, 라텍스의 응용시 기계적 안정성이 문제점으로 되고 있다. 따라서 shell 중합시에 새로운 입자의 생성이 적고 중합중 안정성이 우수한 라텍스를 제조하기 위해 유화제농도, 개시제농도, 중합온도가 PMMA/PSt과 PSt/PMMA의 core-shell 구조에 미치는 영향과 중합 후 입도분석기(particle size analyzer; PSA) 및 투과전자현미경(transmission electron microscope; TEM)을 이용하여 실제 입자측정과 입자형태 특성을 확인하였으며 시차주사열량계(differential scanning calorimeter, DSC)를 이용하여 유리전이온도($T_g$)의 측정, 최저성막온도(minimum film formation temperature; MFFT), NaOH 첨가에 의한 가수 분해에 따르는 pH를 측정하여 core-shell의 새로운 특성을 확인하였다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.213-215
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• 2003

Multimedia has to carry data of heterogeous types. Multicast communication techniques can supply the most appropriate infrastructures to such multimedia. Of many multicast protocols, the core based tree (CBT) protocol is the most concentrative studies are conducted on. The CBT places a core router at center of the shared tree and transfers data through the tore router. However, the CBT has two problems due to centralizing all network traffics into a core router. First it can raise bottleneck effect at a core router. Second, it is possible to make an additive processing overhead when core router is distant from receivers. To cope with the problems, this paper proposes an intelligent anycast routing protocol. The anycast routing attempts to distribute the centralized traffic into plural core routers by using a knowledge-based algorithm. The anycast routing estimates the traffic characteristics of multimedia data far each multicast source, and achieves effectively the distributing that places an appropriate core router to process the incoming traffic based on the traffic information in the event that request of receivers are raised. This method prevent the additional overhead to distribute traffic because an individual core router uses the information estimated to multicast sources connected to oneself and the traffic processing statistics shared with other core neuters.

• Bulletin of the Korean Chemical Society
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• 제23권6호
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• pp.872-879
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• 2002

One of the improtant characteristics of core-shell type nanoparticles is the long-term storage and reuse as an aqueous injection solution when required. For this reason, reconstruction of lyophilized core-shell type nanoparticles is considered to be essential . BAB type triblock copolymers differ from AB type diblock copolymers, which contain the A block as a hydrophilic part and the B block as a hydrophobic part. by not being easily redistributed into phosphate-buffered saline (PBS, pH 7.4, 0.1 M). Therefore, lyophilized core-shell type nanoparticles of CEC triblock copolymer were reconstituted using a somication process with a bar-type sonicator in combination with a freezing-thawing process. Soncation for 30s only resuspended CEC nanoparticles in PBS; their particle size distribution showed a monomodal pattern with narrow size distribution. The bimodal size distribution pattern and the aggregates were reduced by further sonication for 120 s but these nanoparticles showed a wide size distribution. The initial burst of drug release was increased by reconstitution process. The reconstitution of CEC core-shell type nanoparticles by freezing-thawing resulted in trimodal distribution pattern and formed aggregates, although freezing-thawing process was easier than sonication . Drug release form CEC nanoparticles prepared by freezing-thawing was slower than from the original dialysis solution. Although core-shell typenanoparticles of CEC triblock copolymers were not easily performed. Cytotoxicity testing of core-shell type nanoparticles of CEC-2 triblock copolymers containing clonazepam (CNZ) was performed using L929 cells. Cytotoxicity of CNZ was decreased by incorporation into nanoparticles.

• 융합경영연구
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• 제11권4호
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• pp.31-39
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• 2023

Purpose: This study attempted to systematize a support system that can enhance teaching core competencies by establishing a scale for diagnosing teaching core competencies at University A. Research design, data and methodology : To this end, the first Delphi was conducted With six experts related to university core competency modeling research by extracting factors and designing structured questionnaires through a literature review process that collects and analyzes prior research related to domestic and foreign university teaching competency. The derived questions were diagnosed on 27 professors, and independent sample t-verification and ANOVA were conducted using SPSS 24.0 for analysis by key teaching competency factors. Result: What is the standard suitability of KMO. It was shown as 929 (KMO standard conformity value is close to 1), and Barlett's sphericity verification showed χ2=5773.295, df=1081, p<.It appeared as 001 and confirmed that it was suitable for conducting factor analysis. Conclusions: The core competencies of A University teachers were set based on the educational goals of A University, such as basic teaching competency, creative teaching competency, practical teaching competency, and communication teaching competency. This means that the concept and factors of the core competency of professors are likely to change, and in the end, continuous efforts to upgrade and apply research on core competency of professors are essential to quickly and organically respond to changes in competency required to increase the competitiveness of universities.

• Steel and Composite Structures
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• 제44권4호
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• pp.519-529
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• 2022

Sandwich structures with the superior mechanical properties such as high stiffness and strength-to-weight ratio, good thermal insulation, and high energy absorption capacity are used today in aerospace, automotive, marine, and civil engineering industries. These structures are composed of moderately stiff, thin face sheets that withstand the majority of transverse and in-plane loads, separated by a thick, lightweight core that resists shear forces. In this research, the finite element technique is used to simulate a sandwich panel with a truss core under axial compressive stress using ABAQUS software. A review of past experimental studies shows that the bondline between the core and face sheets plays a vital role in the critical failure load. Therefore, this modeling analyzes the damage initiation modes and debonding between face sheet and core by cohesive surface contact with traction-separation model. According to the results obtained from the modeling, it can be observed that the adhesive stiffness has a significant influence on the critical failure load of the specimens. To achieve the full strength of the structure as a continuum, a lower limit is obtained for the adhesive stiffness. By providing this limit stiffness between the core and the panel face sheets, sudden failure of the structure can be prevented.

• 한국안전학회지
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• 제17권4호
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• pp.133-139
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• 2002

Core-shell polymers of inorganic/organic pair, which are consisted of both core and shell component, were synthesized by sequential emulsion polymerization using ethyl methacrylate (EMA) as a shell monomer and ammonium persulfate as initiator. We found that $CaCO_3$ core should be prepared by adding 2.0wt% SDBS(sodium dodecyl benzene sulfonate), $CaCO_3$ core/PEMA shell polymerization was carried out on the surface of $CaCO_3$ particle during EMA shell polymerization in the core-shell polymer preparation. The structure of core-shell polymer were investigated by measuring the degree on decomposition of $CaCO_3$ by HCI solution, thermal decomposition of polymer composite on thermogravimetric analyzer, glass transition temperature on differential scanning calorimeter, and morphology using scanning electron microscope.

• Nuclear Engineering and Technology
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• 제51권1호
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• pp.54-59
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• 2019

The main objective of nuclear reactor safety is to maintain the nuclear fuel in a thermally safe condition with enough safety margins during normal operation and anticipated operational occurrences. In this research, core flow bypass is studied under the conditions of the unavailability of safety systems. As core bypass occurs, the core flow rate is assumed to decrease exponentially with a time constant of 25 s to new steady state values of 20, 40, 60, and 80% of the nominal core flow rate. The thermal hydraulic code PARET is used through these calculations. Reactor thermal hydraulic stability is reported for all cases of core flow bypass.

• 폴리머
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• 제34권1호
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• pp.38-44
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• 2010

탄산칼슘/유기계 core-shell 입자를 제조하기 위해 core로는 침강성 탄산칼습을 사용하였고, shell로서는 여러 종류의 methyl methacrylate(MMA), ethyl acrylate(EA), n-butyl acrylate(BA), styrene(St), 2-ethylhexyl acylate(2-EHA)을 사용하여, 반응 온도 유화제, 개시제의 종류와 첨가량을 변화시킨 후에 유화중합을 시켜 최적의 유화중합 조건을 구하였다. 생성된 core-shell 입자의 구조는 FT-IR로, 입자크기와 형태는 입도 분석, SEM, TEM으로 각각 측정하였다. 그리고, 이 core-shell 입자에 부직포를 함침시켜 처리전후의 표면변화는 접촉각으로 확인하였다. 또한, 함침 처리 전후의 부직포/부직포 소재와 관능성 단량체 첨가한 부직포/부직포 소재의 박리 접착강도를 측정하여 상호 비교하였다. 탄산칼슘/유기 core-shell 입자 합성의 경우에는 유화제인 SDBS를 0.5 wt% 첨가한 탄산칼슘을 core로 하여 MMA와 0.1 wt% 농도의 APS를 단계적으로 주입하여 중합함으로써 탄산칼슘입자 표면에 단량체의 중합이 잘 유도될 수 있었으며 중합 도중에 새로운 중합체 입자의 생성이 적었다.