• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2535-2538
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• 2012

$SnO_2@carbon$ tube-core nanowire was synthesized via a facile self-organized method, which was in situ by one step via Chemical Vapor Deposition. The resulting composite was characterized by scanning electron microscopy, X-ray diffraction and transmission electron microscope. The diameter of the single nanowire is between 5 nm and 60 nm, while the length would be several tens to hundreds of micrometers. Then X-ray diffraction pattern shows that the composition is amorphous carbon and tin dioxide. Transmission electron microscope images indicate that the nanowire consists of two parts, the outer carbon tube and the inner tin dioxide core. Meanwhile, the possible growth mechanism of $SnO_2@carbon$ tube-core nanowire is also discussed.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.3085-3094
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• 2022

The design concept of a Small High-flux Multipurpose LBE(Lead Bismuth Eutectic) cooled Fast Reactor (SHMLFR) was proposed in the paper. The primary cooling system of the reactor is forced circulation, and the fuel element form is arc-plate loaded high enrichment MOX fuel. The core is cylindrical with a flux trap set in the center of the core, which can be used as an irradiation channel. According to the requirements of the core physical design, a series of physical design criteria and constraints were given, and the steady and transient parameters of the reactor were calculated and analyzed. Regarding the thermal and hydraulic phenomena of the reactor, a simplified model was used to conduct a preliminary analysis of the fuel plates at special positions, and the temperature field distribution of the fuel plate with the highest power density under different coolant flow rates was simulated. The results show that the various parameters of SHMLFR meet the requirements and design criteria of the physical design of the core and the thermal design of the reactor. This implies that the conceptual design of SHMLFR is feasible.

• Advanced Composite Materials
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• v.17 no.1
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• pp.41-56
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• 2008

In this research, optical fiber sensors and shape memory alloys (SMA) were incorporated into sandwich panels for development of a smart honeycomb sandwich structure with damage detection and shape recovery functions. First, small-diameter fiber Bragg grating (FBG) sensors were embedded in the adhesive layer between a CFRP face-sheet and an aluminum honeycomb core. From the change in the reflection spectrum of the FBG sensors, the debonding between the face-sheet and the core and the deformation of the face-sheet due to impact loading could be well detected. Then, the authors developed the SMA honeycomb core and bonded CFRP face-sheets to the core. When an impact load was applied to the panel, the cell walls of the core were buckled and the face-sheet was bent. However, after the panel was heated over the reverse transformation finish temperature of the SMA, the core buckling disappeared and the deflection of the face-sheet was relieved. Hence the bending stiffness of the panel could be recovered.

• Journal of Korean Library and Information Science Society
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• v.40 no.3
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• pp.225-247
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• 2009

The values of a organization generate belief and activate participation of community members. Accordingly, it is necessary to find new core values of the school library in addition to access and assistance which are the library's traditional values. This study analyzed the central keywords in the contents of mission and vision appeared in the International School Library Standards and acquired core values being composed of 5 fields such as education, collaboration, access, cultural awareness and sensitivity, and democratic citizenship. As a result of analyses of missions and visions in America, Australia, UK, and Canada School Library Standards, it seems that life-long learning skills, physical access and social responsibility are common core values. America and UK School Library Standards which were revised recently are underlining technology skills, multiple literacies and integrated information literacy curriculum particularly. Ultimately, these core values will be utilized as the directions and basic materials for the establishment of missions and visions for the school library in Korea.

• Journal of the Korea Society of Computer and Information
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• v.18 no.9
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• pp.1-10
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• 2013

In this paper, we implement the SIFT(Scale-Invariant Feature Transform) algorithm for feature point extraction using a many-core processor, and analyze the performance, area efficiency, and system area efficiency of the many-core processor. In addition, we demonstrate the potential of the proposed many-core processor by comparing the performance of the many-core processor with that of high-performance CPU and GPU(Graphics Processing Unit). Experimental results indicate that the accuracy result of the SIFT algorithm using the many-core processor was same as that of OpenCV. In addition, the many-core processor outperforms CPU and GPU in terms of execution time. Moreover, this paper proposed an optimal model of the SIFT algorithm on the many-core processor by analyzing energy efficiency and area efficiency for different octave sizes.

• Journal of the Korea Society of Computer and Information
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• v.17 no.6
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• pp.1-11
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• 2012

As the process technology scales down, multi-core processors cause serious problems such as increased interconnection delay, high power consumption and thermal problems. To solve the problems in 2D multi-core processors, researchers have focused on the 3D multi-core processor architecture. Compared to the 2D multi-core processor, the 3D multi-core processor decreases interconnection delay by reducing wire length significantly, since each core on different layers is connected using vertical through-silicon via(TSV). However, the power density in the 3D multi-core processor is increased dramatically compared to that in the 2D multi-core processor, because multiple cores are stacked vertically. Unfortunately, increased power density causes thermal problems, resulting in high cooling cost, negative impact on the reliability. Therefore, temperature should be considered together with performance in designing 3D multi-core processors. In this work, we analyze the temperature of the cache in quad-core processors varying cache organization. Then, we propose the low-temperature cache organization to overcome the thermal problems. Our evaluation shows that peak temperature of the instruction cache is lower than threshold. The peak temperature of the data cache is higher than threshold when the cache is composed of many ways. According to the results, our proposed cache organization not only efficiently reduces the peak temperature but also reduces the performance degradation for 3D quad-core processors.

• The Journal of Sustainable Design and Educational Environment Research
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• v.16 no.3
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• pp.37-50
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• 2017

The Ministry of Education selected and implemented 'science core school' since 2009 as a policy to strengthen science education to produce talented science students. This study judged that it is necessary to examine the current management practice and diagnose problems to propose improvement measures for more successful management of science core school in the future. To this end, we interviewed and observed teachers and students at a high school specialized in science based in Gyeonggi province which was selected as a science core school, as qualitative study methods such as interview and observation to survey and analyze the current management practice of the school. The management outcome was that the school contributed to fostering talented students in natural sciences and engineering because more varied activities were implemented at the school to develop scientific knowledge of students including experiment, excursion, and circle activity. Identified problems were increased amount of private education due to intense competition over school achievement, negligence of extracurricular activities, burdensome workload for teachers of specific subjects, and lack of expertise of math and science teachers. In conclusion, the following improvement measures are suggested for sustainable management of science core schools: greater liberty should be granted to science core schools; more training opportunities should be given to teachers; college admission program should be improved for science core school students; and it is necessary to introduce courses taught by external teachers, and provide systematic support such as increasing administration staff.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.659-662
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• 2005

A parameterized FFT/IFFT core generator (PFFT_CoreGen) is designed, which can be used as an essential IP (Intellectual Property) in various OFDM modem designs. The PFFT_CoreGen generates Verilog-HDL models of FFT cores in the range of 64 ${\sim}$ 2048-point. To optimize the performance of the generated FFT cores, the PFFT_CoreGen can select the word-length of input data, internal data and twiddle factors in the range of 8-b ${\sim}$ 24-b. Some design techniques for low-power design are considered from algorithm level to circuit level.

• Structural Monitoring and Maintenance
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• v.5 no.2
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• pp.189-204
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• 2018

This paper examines the seismic responses of a reinforced concrete (RC) frame core-tube building with pre-pressed spring self-centering energy dissipation (PS-SCED) braces. The PS-SCED brace system consists of friction devices for energy dissipation, pre-pressed combination disc springs for self-centering and tube members as guiding elements. A constitutive model of self-centering flag-shaped hysteresis for PS-SCED brace is developed to better simulate the seismic responses of the RC frame core-tube building with PS-SCED braces, which is also verified by the tests of two braces under low cyclic reversed loading. Results indicate that the self-centering and energy dissipation capabilities are well predicted by the proposed constitutive model of the PS-SCED brace. The structure with PS-SCED braces presents similar peak story drift ratio, smaller peak acceleration, smaller base shear force and much smaller residual deformations as compared to the RC frame core-tube building with bucking-restrained braces (BRBs).

• Journal of the Korea Society of Computer and Information
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• v.21 no.10
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• pp.183-190
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• 2016

In this paper, we have looked at through core competences and contents of Informatics curriculum in middle school by expert questionnaire and Focus Group Interview(FGI). Among nine core competences of Informatics subject in curriculum, abstraction and automation were easily found, but creative harmony and cooperation were indirectly confirmed in the statements of teaching and assessment sections of Informatics curriculum in middle school. It was also identified that some core competency elements are redundant or hardly to found in the contents of Informatics curriculum. In addition, various opinions about Informatics curriculum have been put forward over the FGI. The results of this study will be the case that can be consulted on new revised Informatics curriculum to be developed further.