• Advances in nano research
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• v.10 no.5
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• pp.471-479
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• 2021

In the framework of the density functional theory combined with the method of non-equilibrium Green functions (DFT + NEGF), the electric transport properties of a one-dimensional nanodevice consisting of telescoping polyprismanes with various types of electrical conductivity were studied. Its transmission spectra, density of state, current-voltage characteristic, and differential conductivity are determined. It was shown that C_[14,17], C_[14,11], C_[14,16], C_[14,10] show a metallic nature, and polyprismanes C_[14,5], C_[14,4] possess semiconductor properties and has a band gap of 0.4 eV and 0.6 eV, respectively. It was found that, when metal C_[14,11], C_[14,10] and semiconductor C_[14,5], C_[14,4] polyprismanes are coaxially connected, a Schottky barrier is formed and a weak diode effect is observed, i.e., manifested valve (rectifying) property of telescoping polyprismanes. The enhancement of this effect occurs in the nanodevices C_[14,17] - C_[14,11] - C_[14,5] and C_[14,16] - C_[14,10] - C_[14,4], which have the properties of nanodiode and back nanodiode, respectively. The simulation results can be useful in creating promising active one-dimensional elements of nanoelectronics.

• Journal of the Korean Ceramic Society
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• v.19 no.1
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• pp.51-57
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• 1982

The clinckers were obtained when a raw mixture consisted of limestone, slags and gypsum was burned at 134$0^{\circ}C$ for 30 minutes, and 128$0^{\circ}C$ for 30 minutes adding $CaF_2$ as a flux. The principal compounds of these clinkers were $C_3S_2$, $\beta-C_2S$, $C_1A_3{\bar{S}}$. To investigate hydration behavior, cements were made and hydrated at constant humidity cabinet (W/C=0.5 20$\pm 1^{\circ}C$). X-ray diffractometer, SEM, and conduction calorimeter were employed to examine the hydration behavior. The hydrates were mainly C-S-H, ettringite, $Ca(OH)_2$. By the hydration of $C_3S$ and $C_4A_3\bar{S}$, the needle-like ettringite filling the inner vacant spaces of the hardened body might contribute to the rapid-hardening and high-strength phenomena. Furthermore, the hardened body became stronger due to the hydration of $C_2S$ at later period. The addition of granulated blastfurnace slags have a potential to be a blended cement.

• The KIPS Transactions:PartA
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• v.18A no.1
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• pp.25-32
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• 2011

NoC is actively being studied recently in order to overcome the limitations of shared-bus architecture. We proposed an NoC architecture which employs a buffer that plays a similar role of a proxy server in a computer network to enhance the communication efficiency of NoC architecture. In the proposed NoC architecture, whenever the master has a difficulty in communicating with the slave directly, the master communicates with the proxy server which is able to communicate with the slave on behalf of the master. With the proposed scheme in NoC, we can increase the speed and the bandwidth of communication channel. The experimental results showed that overall communication efficiency was significantly improved by sending the packets to the proxy server rather than holding them in the switch buffer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.274-274
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• 2008

This paper describes on the fabrication and characteristics of a 3C-SiC (Silicon Carbide) micro pressure sensor for harsh environment applications. The implemented micro pressure sensor used 3C-SiC thin-films heteroepitaxially grown on SOI (Si-on-insulator) structures. This sensor takes advantages of the good mechanical properties of Si as diaphragms fabricated by D-RIE technology and temperature properties of 3C-SiC piezoresistors. The fabricated pressure sensors were tasted at temperature up to $250^{\circ}C$ and indicated a sensitivity of 0.46 mV/V*bar at room temperature and 0.28 mV/V*bar at $250^{\circ}C$. The fabricated 3C-SiC/SOI pressure sensor presents a high-sensitivity and excellent temperature stability.

• Journal of Powder Materials
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• v.6 no.1
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• pp.18-35
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• 1999

Phase equilibria in the system Si3N4-TiC-TiCxN1-x-C-N were determined by thermodynamic calculations (CALPHAD-method). The reaction peaction paths for Si3N4-TiC and SiC-TiC composites in the Ti-Si-C-n system were simulated at I bar N2-pressure and varying terpreatures. At a temperature of 1923 K two tie-triangles (TiC0.34N0.66+SiC+C and TiC0.13N0.87+SiC+Si3N4) and two 2-phase fieds (TiCxN1-x+SiC; 0.13

• Korean Journal of Mathematics
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• v.27 no.2
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• pp.437-444
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• 2019

For c > -1, let ${\nu}_c$ denote a weighted radial measure on ${\mathbb{C}}$ normalized so that ${\nu}_c(D)=1$. For $c_1,c_2>-1$ and $f{\in}L^1(D^2,\;{\nu}_{c_1}{\times}{\nu}_{c_2})$, we define the weighted Berezin transform $B_{c_1,c_2}f$ on $D^2$ by $$(B_{c_1,c_2})f(z,w)={\displaystyle{\smashmargin2{\int\nolimits_D}{\int\nolimits_D}}}f({\varphi}_z(x),\;{\varphi}_w(y))\;d{\nu}_{c_1}(x)d{\upsilon}_{c_2}(y)$$. This paper is about the space $M^p_{c_1,c_2}$ of function $f{\in}L^p(D^2,\;{\nu}_{c_1}{\times}{\nu}_{c_2})$ ) satisfying $B_{c_1,c_2}f=f$ for $1{\leq}p<{\infty}$. We find the identity operator on $M^p_{c_1,c_2}$ by using invariant Laplacians and we characterize some special type of functions in $M^p_{c_1,c_2}$.

• Journal of Elementary Mathematics Education in Korea
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• v.23 no.3
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• pp.273-288
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• 2019

This study focuses on understanding proportionality, in particular, what constitutes relational understanding of a:b=c:d, which is called proportional expression. The meanings of a:b=c:d are analyzed and some suggestions are offered for improving the teaching and learning of it. The equation a:b=c:d has three different meanings. First, it represents two different structures in one proportional situation. Second, it represents a common structure in two different proportional situations. Finally, it represents a number or a quantity underlying in different proportional situations. It is important to choose and use a unit flexibly to understand the first and the second meanings of a:b=c:d, Double strip diagram and double number line are useful to visualize the meanings of a:b=c:d. In addition, what a number or a quantity in the third meaning of a:b=c:d refers to in proportional situations should be emphasized in teaching and learning of a:b=c:d.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.752-757
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• 1995

The effect of fermentation temperature on the changes of pH, acidity, salt content, color and vitamin C of mustard leaf kimchi during various storage days was investigated. The conditions of fermentation temperature were set at $4^{\circ}C$ (sample A) and $20^{\circ}C$ (sample B), and $4^{\circ}C$ after keeping at $20^{\circ}C$ for 12 hours(sample C) and $20^{\circ}C$ for 36 hours(sample D). As the fermentation proceeded, pH of sample stored at low temperature(sample A) was drop ped gradually from initial pH of 5.24 but there was great pH drop in the sample stored at high temperature(sample B, D). The salt content of the sample B at high temperature increased remarkably, and then the values showed D > A > C. The Humter values of L and a increased at the optimum ripening period, the higher the initial fermentation temperature(B) and the later the initial fermentation time at $20^{\circ}C$ those values, then decreased. The Hunter value of b constantly increased until day of 108. As fermentation time passed, the content of total vitamin C decreased to the range of 9.0mg% to 14.0mg% up to 24 days of fermentation, and at the optimum ripening period, it increased to the range of 14.0mg% to 22.0mg%, and at the fermentation period(until day 108), it decreased gradually.

• Journal of KIISE:Software and Applications
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• v.31 no.11
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• pp.1551-1559
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• 2004

Java, a platform independent object-oriented programming language, is widely used, however it should be integrated with JNI to use system services or to reuse legacy systems. Though JNI provides the standard APIs which allow Java to be combined with C/$C^{++}$, it is very hard and cumbersome for developers to use JNI APIs. In order to address this problem, we introduce a translator named C2JNI, which converts the embedded C program into a JNI compatible C program. With C2JNI, developers can Integrate Java and C programs without JNI APIs, and it will reduce the complexity caused by JNI APIs.

• Bulletin of the Korean Mathematical Society
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• v.36 no.2
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• pp.337-342
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• 1999

M. Cohen and S. Montgomery showed that a Maschke-type theorem for the smash product, which unlike the corresponding result for group actions, does not require any assumptions about the characterstic of the algebra. Our purpose in this paper is a Maschke-type theorem for the graded smash coproduct C⋊kG: let V be a right C⋊kG-comodule and W a C⋊kG-subcomoduleof V which is a C-direct summand of V. Then W is a C⋊kG-direct summand of V. Also this result is equivalent to the following : let V be a graded right C-comodule and W a graded subcomodule of V which has a complement as a C-subcomodule of V. Then W has a graded complement.