• Carbon letters
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• 제16권4호
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• pp.223-232
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• 2015

This review presents current progress in the preparation methods of liquid crystalline nano-carbon materials and the liquid crystalline spinning method for producing nano-carbon fibers. In particular, we focus on the fabrication of liquid crystalline carbon nanotubes by spinning from superacids, and the continuous production of macroscopic fiber from liquid crystalline graphene oxide.

• 한국고분자학회지:고분자과학과기술
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• 제25권3호
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• pp.194-200
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• 2014

• BMB Reports
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• 제56권2호
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• pp.56-64
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• 2023

Nitrogen (N) is an essential macronutrient required for plant growth and crop production. However, N in soil is usually insufficient for plant growth. Thus, chemical N fertilizer has been extensively used to increase crop production. Due to negative effects of N rich fertilizer on the environment, improving N usage has been a major issue in the field of plant science to achieve sustainable production of crops. For that reason, many efforts have been made to elucidate how plants regulate N uptake and utilization according to their surrounding habitat over the last 30 years. Here, we provide recent advances focusing on regulation of N uptake, allocation of N by N transporting system, and signaling pathway controlling N responses in plants.

• 전자통신동향분석
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• 제38권1호
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• pp.36-45
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• 2023

The increasing demand for ultra-high efficiency of compact power conversion systems for electric vehicle applications has brought GaN power semiconductors to the fore due to their low conduction losses and fast switching speed. In particular, the development of materials and core device processes contributed to remarkable results regarding the publication of vertical GaN power devices with high breakdown voltage. This paper reviews recent advances on GaN material technology and vertical GaN power device technology. The GaN material technology covers the latest technological trends and GaN epitaxial growth technology, while the vertical GaN power device technology examines diodes, Trench FETs, JFETs, and FinFETs and reviews the vertical GaN PiN diode technology developed by ETRI.

• Molecules and Cells
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• 제45권2호
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• pp.76-83
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• 2022

Neurons-on-a-Chip technology has been developed to provide diverse in vitro neuro-tools to study neuritogenesis, synaptogensis, axon guidance, and network dynamics. The two core enabling technologies are soft-lithography and microelectrode array technology. Soft lithography technology made it possible to fabricate microstamps and microfluidic channel devices with a simple replica molding method in a biological laboratory and innovatively reduced the turn-around time from assay design to chip fabrication, facilitating various experimental designs. To control nerve cell behaviors at the single cell level via chemical cues, surface biofunctionalization methods and micropatterning techniques were developed. Microelectrode chip technology, which provides a functional readout by measuring the electrophysiological signals from individual neurons, has become a popular platform to investigate neural information processing in networks. Due to these key advances, it is possible to study the relationship between the network structure and functions, and they have opened a new era of neurobiology and will become standard tools in the near future.

• Educational Technology International
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• 제12권2호
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• pp.135-151
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• 2011

Recently, a wide variety of studies on future learning have appeared owing to rapid advances in information and communication technology (ICT) and increased discussion about core competencies in twenty-first-century learning. These studies, though insufficient in number, cover various fields such as architecture (design of the learning space), education (learning model), and technology (adaptation of mobile devices). However, these studies focus on mainstream students and do not discuss the future situation of inclusive education with regard to both mainstream and students with physical disabilities. Hence, in order to fill this gap, the present study explores the perceptions and ideas held by special education preservice teachers on the future learning space with regard to school design and peer-to-peer feedback. For this purpose, these preservice teachers' design proposals about future school were collected and analyzed. In conclusion, special education preservice teachers perceive the future learning space as an inclusive environment in which smart technology is incorporated. Future learning environment were categorized in terms of flexible, ubiquitous technology, physical and mental health, safety, and spaces with facilities for students with physical disabilities.

• Asian-Australasian Journal of Animal Sciences
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• 제12권1호
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• pp.84-92
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• 1999

The rumen microbial ecosystem is coming to be recognized as a rich alternative source of genes for industrially useful enzymes. Recent advances in biotechnology are enabling development of novel strategies for effective delivery and enhancement of these gene products. One particularly promising avenue for industrial application of rumen enzymes is as feed supplements for nonruminant and ruminant animal diets. Increasing competition in the livestock industry has forced producers to cut costs by adopting new technologies aimed at increasing production efficiency. Cellulases, xylanases, ${\beta}$-glucanases, pectinases, and phytases have been shown to increase the efficiency of feedstuff utilization (e.g., degradation of cellulose, xylan and ${\beta}$-glucan) and to decrease pollutants (e.g., phytic acid). These enzymes enhance the availability of feed components to the animal and eliminate some of their naturally occurring antinutritional effects. In the past, the cost and inconvenience of enzyme production and delivery has hampered widespread application of this promising technology. Over the last decade, however, advances in recombinant DNA technology have significantly improved microbial production systems. Novel strategies for delivery and enhancement of genes and gene products from the rumen include expression of seed proteins, oleosin proteins in canola and transgenic animals secreting digestive enzymes from the pancreas. Thus, the biotechnological framework is in place to achieve substantial improvements in animal production through enzyme supplementation. On the other hand, the rumen ecosystem provides ongoing enrichment and natural selection of microbes adapted to specific conditions, and represents a virtually untapped resource of novel products such as enzymes, detoxificants and antibiotics.

• 문화기술의 융합
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• 제4권4호
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• pp.349-354
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• 2018

인류는 과학기술의 발전과 함께 의학기술도 눈부신 발전을 거듭해왔다. 그러나 과거에도 난치성 질환은 여전히 존재하였듯이 지금도 난치성 질환이 존재하는데, 그 중 턱관절장애가 있다. 현재 의료선진국이라 불리는 대한민국 의료진들의 진단은 환자의 발언, 의사의 청음진단과 자를 이용한 진단, X-ray 촬영 진단 방식을 고수하며 시대에 뒤떨어지고 있다. 그렇기 때문에 환자의 정확한 증상 여부, 의사 본인의 진단 실력과 경력이 중요하고, 증상의 경중에 따른 진단 횟수의 증가와 이로 인해 발생하는 의료비용은 막대하다. 본 연구에서는 이를 해결하기 위해 저작운동(최대폐구)시 교근에서 발생되는 근전도 신호를 %MVC를 통해 정량화하였다. 정량화된 근전도는 Cortex로 비교, 평가하여 턱관절 상태 평가 기준 지표를 확립할 것이다.

• Structural Engineering and Mechanics
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• 제85권5호
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• pp.593-605
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• 2023

This work presents a comparison between analytical and finite element analysis for bending of porous sandwich functionally graded material (FGM) plates. The plate is rectangular and simply supported under static sinusoidal loading. Material properties of FGM are assumed to vary continuously across the face sheets thickness according to a power-law function in terms of the volume fractions of the constituents while the core is homogeneous. Four types of porosity are considered. A refined higher-order shear with normal deformation theory is used. The number of unknowns in this theory is five, as against six or more in other shear and normal deformation theories. This theory assumes the nonlinear variation of transverse shear stresses and satisfies its nullity in the top and bottom surfaces of the plate without the use of a shear correction factor. The governing equations of equilibrium are derived from the virtual work principle. The Navier approach is used to solve equilibrium equations. The constitutive law of the porous FGM sandwich plate is implemented for a 3D finite element through a subroutine in FORTRAN (UMAT) in Abaqus software. Results show good agreement between the finite element model and the analytical method for some results, but the analytical method keeps giving symmetric results even with the thickness stretching effect and load applied to the top surface of the sandwich.

• 소성∙가공
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• 제23권2호
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• pp.75-81
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• 2014

Progressive dies are used for metal stamping during which multiple operations are performed in a sequence. Material is fed automatically from a coil into the press and advances from one die station to the next with each press stroke. Transfer dies are used in high-volume manufacturing for round, deep-drawn, and medium-to-large parts. Several different operations may be incorporated within a transfer die such as blanking, bending, piercing, trimming, and deep drawing. The main challenge in the current study is how to deform a seat cushion panel meeting the design specifications without any defects. A complex automation die manufacturing technology for the automotive seat cushion panel, mixing both semi-progressive die and transfer die for continuous production, was developed.