• Journal of the Korean Ceramic Society
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• v.12 no.4
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• pp.3-8
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• 1975

Hydration processes of the rapid hardening cement clinkers, which were synthesized from domestic alunite for major alumina source, limestone, kaolin and fluorite, were investigated by means of x-ray diffraction analysis, thermal analysis and microscopic observation etc. The clinkers were composed mainly of alite, calcium fluroaluminate (C11A7.CaF2) minerals. While the hydratio processes of the clinkers are altered by concentration of SO3 in the paste, calcium aluminate hydrates such as C4AH13, CAH10 and calcium monosulfate hydrate (C3A.CaSO4.12H2O) are formed at first and then some of them are transformed into ettringite(C3A.3CaSO4.32H2O) within 30~60 min. when the concentration of SO3 in the paste are enough. However the formed ettringite are changed slowly into calcium monosulfate hydrate as the concentration of SO3 become lowered, and the paste is hardened with these close-packed minerals. When the content of SO3 in clinker is so enough, calcium sulfoaluminate hydrates are found without any addition of anhydrite or hemi-hydrite.

• Journal of the Korean Ceramic Society
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• v.13 no.2
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• pp.3-7
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• 1976

Influences of chlorides(CaCl2, MgCl2, NaCl) on the colouring effect of Fe component in white portland cement was investigated. Chlorides enhance the whiteness of the white portland cement owing to volatilization of Fe2O3 and translation of ferrite composition toward C2F. This translation is caused by consumption of alumina at the formation of C12A7, the formation of which is promoted in the presence of chloride. With decrease of p in ferrite composition C6F1-pAp, transfer of Fe3+ from 4 to 6 coordinated cite is occurred, and as a result, whiteness is raised. Hydration process of the cement containing a small amount of chloride differs little from the one without chloride.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1445-1446
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• 2011

ITO 박막의 전기 광학적 특성을 향상시키기 위해 열처리 공정은 필수적이다. 하지만 향후 발전시켜나갈 플렉서블 디스플레이(flexible display)에서는 ITO를 저온에서 증착해야 할 필요성이 대두되었고, 이에 따라 기판의 온도를 상온으로 유지하면서 고품질의 ITO 박막을 제조하고자 하는 연구가 진행되고 있다. 본 연구에서는 상온에서 유리 기판 위에 RF 마그네트론 스퍼터링(magnetron sputtering) 장치의 자기장 분포를 제어하여 ITO 박막을 증착하였다. 제작된 시편의 두께와 투과도 및 이동도를 측정 비교하였다.

• Journal of Advanced Navigation Technology
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• v.11 no.1
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• pp.31-36
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• 2007

TCP (Transmission Control Protocol) is one of the protocols which are widely used from the Internet environments. Through the flow control of TCP, it could be increased efficiency for the loss and a re-transmission of data and the flow control become accomplished through window technique which puts the limit of size. By the flow control, TCP divided in various versions. In this paper, it is analyzed the simulation result which applies the error model in the Newreno which is an improved model of the representative Tahoe, Reno.

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.1047-1052
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• 2011

Various services are created using mobile networks after mobile devices such as smart phones and tablet PCs are propagated rapidly. However, the contents of smart devices are not enough diversity because they depend on games and messaging services primarily. In this paper, we described the study have progressed based on mobile devices and networks using augmented reality technologies about virtual education system.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2607-2609
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• 1999

본 논문에서는 다수대 전동기로 구성된 연속구동 시스템의 속도 및 장력 제어를 위한 연속 부하 분담 제어를 제안한다. 제안된 방법을 이용하여 장력 센서를 사용하지 않고 인접한 전동기의 출력 토오크를 원하는 비율로 조절하는 것에 기존의 장력 센서를 이용한 피드백 제어 특성을 시뮬레이션과 실험을 통해 비교 검토하였다. 4개의 구동롤로 구성된 다중 스팬 축소 모델을 설계, 제작하여 제안된 방법의 유용성을 입증하였다.

• Journal of Advanced Navigation Technology
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• v.15 no.4
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• pp.626-631
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• 2011

In this paper, the methods of designing and implementing user interaction using jQuery in Web Application are suggested. While computing ability of smart devices grows up, web application technology is generalized. So JavaScript is one of noticeable web application technologies, and jQuery is the most popular JavaScript framework. We described basic grammar, scalability and plug-ins of jQuery. We categorized user interactions and animations and described methods to implement it.

• Journal of Drive and Control
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• v.10 no.3
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• pp.14-20
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• 2013

In the study, a control strategy using a feedback linearization compensator and a disturbance observer was suggested and applied to the synchronization control of two hydraulic cylinders. The hydraulic system consists of a proportional directional control valve with overlap characteristic near the neutral position, a conventional hydraulic cylinder and an external load. The control performances of the system were verified through numerical simulations. From the simulations, it was ascertained that excellent control performances were obtained with the suggested control strategy.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.4
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• pp.75-81
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• 2010

Due to the increasing use of smart phones, using Wifi, Wibro of mobile devices spread. Accordingly, Need of using peer-to-peer file sharing between mobile devices is growing. However, common Peer-to-Peer(P2P) system is too complex and is not suitable to be applied to mobile devices. Thus, the need of research has shown to improve way in a mobile environment that has a constraints as mobility and the scope of communication. Among them, there is a Chord as contents look up algorithm. Chord is the issue. Chord as the DHT-based P2P protocol shares files, index-key and distributed key across the network. However, exist Chord doesn't consider the mobility. So, It has a lot of problems in the mobile environment. Thus, in this paper, I will try to explore an appropriate way of Chord in a mobile environment.

• Journal of the Korean Ceramic Society
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• v.30 no.8
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• pp.609-614
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• 1993

Semiconducting Zn-Ti-Ni-O and Zn-Ti-O system were investigated. The specimens sintered at the temperature between 125$0^{\circ}C$ and 145$0^{\circ}C$ exhibited PTCR effect between -5$0^{\circ}C$ and 35$0^{\circ}C$ with resistivity ration exceeding three decades. Semiconducting Zn-Ti-Ni-O is consisted of two phases, one is n-type ZnO and the other is p-type spinel structure. The mechanism of PTCR effect was explained in relation to the piezoelectric property of ZnO and the residual stress caused by thermal expansion difference between two phases during cooling process.