• Cement Symposium
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• no.31
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• pp.198-204
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• 2004

온라인 분쇄입도 조절 콘트롤(Insitec) 시스템은 시멘트의 생산공정상에 시멘트입도를 직접 측정하고 측정된 데이터를 이용하여 공정을 제어할수 있는 새로운 방법으로서, 세계적으로 50여개의 시멘트 생산 현장에 이러한 시스템이 설치되어 있다. 시멘트의 생산공정은 일반적인 분쇄공정과는 차별되는 나름데로의 특성이 있으므로 이를 개발한 Malvern Instrument사(영국)에서는 시멘트 공장의 특성에 적합한 시스템을 개발해왔다. 우선 가장 이상적인 Instec 시스템의 설치를 위해서는 다음과 같이 3단계의 절차가 필요하다. 첫 단계로서 공정상의 변수로 적용되어야 될 변화를 찾아 모니터링하고 연관시키는 것이다. 그 다음 단계에서, 시멘트 생산공정을 24시간 동안 모니터링하여 설정 값과 측정 값과의 차이점과 원인을 찾아내어 요인을 결정하게 되고, 마지막 단계에서는 현장에 장비를 설치, 상기의 반복과정을 마무리하고 공정을 제어할 수 있게 하는 것이다. 시멘트 생산공정에서 분쇄기, 분급기 및 송풍기 등의 회전수 증가와 감소, 시멘트조성의 변화와 같은 중요한 공정상의 변화가 있을 경우, 이로 인해 생기는 입도의 영향은 Insitec 시스템의 입도관리에 기록되게 된다. 본 논문에서는 스페인의 Jerez에 있는 Holcim 플랜트에 설치된 Insitech를 이용하여 운전상의 변수 등을 측정하고 제어하며 시멘트 공정에 활용하는 방안에 대한 연구를 소개한 것이다.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.1027-1029
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• 2009

The aim of this research was to study the structural and rheological properties of gels formed by ferulated maize bran arabinoxylans (MBAX) at different concentrations. MBAX was cross-linked by a laccase leading to the formation of dimers and trimers of ferulic acid (di-FA, tri-FA) as covalent cross-link. An increase in MBAX gels elasticity (from 11 to 20 Pa) as well as lower mesh size (from 80 to 48 nm) were obtained by augmenting the MBAX concentration from 2.5 to 3.5%(w/v), respectively, but no increase in di-FA and tri-FA content was obtained (0.03 and 0.014 ${\mu}$g/mg MBAX, respectively).

• Journal of the Korean Mathematical Society
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• v.48 no.1
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• pp.159-167
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• 2011

We consider a curve $\alpha$= $\alpha$(s) in Minkowski 3-space $E_1^3$ and denote by {T, N, B} the Frenet frame of $\alpha$. We say that $\alpha$ is a slant helix if there exists a fixed direction U of $E_1^3$ such that the function is constant. In this work we give characterizations of slant helices in terms of the curvature and torsion of $\alpha$. Finally, we discuss the tangent and binormal indicatrices of slant curves, proving that they are helices in $E_1^3$.

• Journal of Power Electronics
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• v.14 no.6
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• pp.1130-1138
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• 2014

This study analyzes a ladder multilevel converter (double ladder topology) with the use of a new averaging modeling technique. This technique introduces an analytical method to compute for the switching losses and is used to conduct an in-depth analysis of the influence of the switching frequency and parasitic resistance of components on converter efficiency. The obtained results enable the selection of switches and switching frequency to minimize losses. Moreover, simulation results and experimental measurements validate the analytical calculations.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.377-377
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• 2006

Alkoxyamine and thiocarbonyl thio end capped polyethylene (PE) chains were synthesized using a direct and simple approach consisting in reacting di(polyethylenyl)magnesium (PE-Mg-PE) chains with a range of nitroxides and disulfides of thiocarbonyl thio compounds. PE-Mg-PE compounds were prepared by a catalyzed chain growth reaction of ethylene on nbutyloctylmagnesium (BOMg) with a neodymocene complex $(C_{5}Me_{5})_{2}NdCl_{2}Li(OEt_{2})_{2}$. Complete characterizations confirm the introduction of the desired end groups. The controlled radical polymerization (NMP and RAFT) of butyl acrylate mediated by these functional polyethylenes was successful.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.1
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• pp.118-125
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• 2016

This paper presents a new high-efficient algorithm and architecture for an elliptic curve cryptographic processor. To reduce the computational complexity, novel modified Lopez-Dahab scalar point multiplication and left-to-right algorithms are proposed for point multiplication operation. Moreover, bit-serial Galois-field multiplication is used in order to decrease hardware complexity. The field multiplication operations are performed in parallel to improve system latency. As a result, our approach can reduce hardware costs, while the total time required for point multiplication is kept to a reasonable amount. The results on a Xilinx Virtex-5, Virtex-7 FPGAs and VLSI implementation show that the proposed architecture has less hardware complexity, number of clock cycles and higher efficiency than the previous works.

• ETRI Journal
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• v.28 no.6
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• pp.732-738
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• 2006

In this paper, novel CMOS pseudo-exponential circuits operating in a class-AB mode are presented. The pseudo-exponential approximation employed is based on second order equations. Such terms are derived in a straightforward way from the inherent nonlinear currents of class-AB transconductors. The cells are appropriate to be integrated in portable equipment due to their compactness and very low power consumption. Measurement results from a fabricated prototype in a 0.5 ${\mu}m$ technology reveal a range of 45 dB with errors lower than ${\pm}0.5$ dB, a power consumption of 100 ${\mu}W$, and an area of 0.01 $mm^2$.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.1
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• pp.340-367
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• 2018

Storage services integration can be done for achieving high availability, improving data access performance and scalability while preventing vendor lock-in. However, multiple services environment management and interoperability have become a critical issue as a result of service architectures and communication interfaces heterogeneity. Storage federation model provides the integration of multiple heterogeneous and self-sufficient storage systems with a single control point and automated decision making about data distribution. In order to integrate diverse heterogeneous storage services into a single storage pool, we are proposing a storage service federation framework named BoxBroker. Moreover, an automated decision model based on a policy-driven data distribution algorithm and a service evaluation method is proposed enabling BoxBroker to make optimal decisions. Finally, a demonstration of our proposal capabilities is presented and discussed.

• Archives of Plastic Surgery
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• v.40 no.6
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• pp.779-782
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• 2013

Chondroblastomas are rare entities accounting for approximately 1% of all primary bone tumors. We describe a case of a 7-year-old girl with a giant chondroblastoma of the maxilla, treated with bilateral class III maxillectomy and reconstruction with a double-barreled and double skin paddle fibular free flap. We show evidence of an excellent aesthetic outcome at 6 months' follow up with no evidence of tumor recurrence.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.891-894
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• 2013

The present study was performed to assess the activity of the botulinum toxin A on breast cancer cells. The T47D cell line was exposed to diverse concentrations of the botulinum toxin A and cell viability and apoptosis were estimated using MTT and propidium iodine/annexin V methods, respectively. Botulinum toxin A exerted greater cytotoxic activity in T47D cells in comparison with MCF10A normal cells; this appeared to be via apoptotic processes caspase-3 and -7. In conclusion, botulinum toxin A induces caspase-3 and -7 dependent apoptotic processes in the T47D breast cancer cell line.