• Journal of Digital Convergence
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• v.20 no.2
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• pp.339-344
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• 2022

It is about how much fine dust can be efficiently removed with respect to the electric dust collector used in factories and large facilities. The results of evaluating the fine dust removal efficiency are as follows. At 10,000 V, Efficiency method I showed 68.1 %, and Efficiency method II was 58.6 %, which was lower than that of Efficiency method I. At 5,000 V, Efficiency method I showed 57.6%, and Efficiency method II showed 51.6%, which was lower than Efficiency method I. At 2,500 V, Efficiency method I showed 50.3%, and Efficiency method II showed 24.4%, which was lower than Efficiency method I. In case of Efficiency method I, it is the efficiency calculated by using the dust concentration before and after passing through the filter. Efficiency method II calculated Efficiency method II to measure the efficiency a little more accurately in the environment where the air after the filter and the polluted air are mixed. Efficiency method II showed lower efficiency than Efficiency method I. As a result of the electrostatic precipitator test, the dust collecting performance was highest at 10,000 V, followed by 5,000 V and 2,500 V in that order.

• Journal of applied mathematics & informatics
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• v.35 no.1_2
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• pp.121-130
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• 2017

This study is concerned with the existence of positive solution for the following nonlinear elliptic system $$\{-M_1(\int_{\Omega}{\mid}x{\mid}^{-ap}{\mid}{\nabla}u{\mid}^pdx)div({\mid}x{\mid}^{-ap}{\mid}{\nabla}u{\mid}^{p-2}{\nabla}u)\\{\hfill{120}}={\mid}x{\mid}^{-(a+1)p+c_1}\({\alpha}_1A_1(x)f(v)+{\beta}_1B_1(x)h(u)\),\;x{\in}{\Omega},\\-M_2(\int_{\Omega}{\mid}x{\mid}^{-bq}{\mid}{\nabla}v{\mid}^qdx)div({\mid}x{\mid}^{-bq}{\mid}{\nabla}v{\mid}^{q-2}{\nabla}v)\\{\hfill{120}}={\mid}x{\mid}^{-(b+1)q+c_2}\({\alpha}_2A_2(x)g(u)+{\beta}_2B_2(x)k(v)\),\;x{\in}{\Omega},\\{u=v=0,\;x{\in}{\partial}{\Omega},$$ where ${\Omega}$ is a bounded smooth domain of ${\mathbb{R}}^N$ with $0{\in}{\Omega}$, 1 < p, q < N, $0{\leq}a$ < $\frac{N-p}{p}$, $0{\leq}b$ < $\frac{N-q}{q}$ and ${\alpha}_i,{\beta}_i,c_i$ are positive parameters. Here $M_i,A_i,B_i,f,g,h,k$ are continuous functions and we discuss the existence of positive solution when they satisfy certain additional conditions. Our approach is based on the sub and super solutions method.

• Journal of the Korea Society of Computer and Information
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• v.20 no.2
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• pp.63-70
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• 2015

In the absence of a polynomial time algorithm capable of obtaining the exact solutions to it, the domatic number problem (DNP) of dominating set (DS) has been regarded as NP-complete. This paper suggests polynomial-time complexity algorithm about DNP. In this paper, I select a vertex $v_i$ of the maximum degree ${\Delta}(G)$ as an element of a dominating set $D_i,i=1,2,{\cdots},k$, compute $D_{i+1}$ from a simplified graph of $V_{i+1}=V_i{\backslash}D_i$, and verify that $D_i$ is indeed a dominating set through $V{\backslash}D_i=N_G(D_i)$. When applied to 15 various graphs, the proposed algorithm has succeeded in bringing about exact solutions with polynomial-time complexity O(kn). Therefore, the proposed domatic number algorithm shows that the domatic number problem is in fact a P-problem.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.6
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• pp.21-34
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• 2011

VANET offers variety of services to allow safe and comfortable driving through V2V and V2I communications in transportation systems. To use these services, safe and reliable V2V and V2I communications must be guaranteed. In this regards, many RSU-based studies have been carried out to meet certain issues such as: efficiency of frequent communication between RSU and vehicles, security of stored information in RSU, and invasion on vehicle's privacy. In this paper, a scheme is proposed to reduce the dependency on RSU and to enhance the vehicle privacy by using signature-based authentication protocol. The proposed protocol is more efficient than existing protocol with group signature, and satisfies all the requirements of VANET.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.7
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• pp.35-40
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• 2011

In u-TSN environment, the communication between vehicle terminal and roadside equipment is very important to support prompt service and to secure road traffic information in real-time upon organizing traffic system. This study suggested V2I or I2V communication service scenario for performance test on vehicle communication system as well as V2V inter-vehicle communication service scenario for emergency information transmission which requires rapidity and accuracy. After implementing real inter-vehicle communication system, we performed vehicle communication experiment following suggested communication service scenario to test the performance. Consequently, we could draw out the optimal transmission mode setup condition, and the result can be applied to the development of stable and efficient u-TSN vehicle communication system.

• KIISE Transactions on Computing Practices
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• v.22 no.7
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• pp.326-331
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• 2016

The proportion of video content consumption is growing dramatically but some users avoid it. The reasons are initial time to load, lack of the time to watch video content, and particularly a traffic issues on mobile devices. The proposed Video-to-Images(V2I) technology offers a new user experience to end users through converting video into images without content providers' or users' effort. Using the V2I technology, consumption methods of video content with new type of content by users and the advantages of the new user experience will be introduced. Furthermore, the overall architecture of the V2I will be explained.

• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.2
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• pp.79-99
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• 2010

Pulsed current-voltage (I-V) methods are introduced to evaluate the impact of fast transient charge trapping on the performance of high-k dielectric transistors. Several pulsed I-V measurement configurations and measurement requirements are critically reviewed. Properly configured pulsed I-V measurements are shown to be capable of extracting such device characteristics as trap-free mobility, trap-induced threshold voltage shift (${\Delta}V_t$), as well as effective fast transient trap density. The results demonstrate that the pulsed I-V measurements are an essential technique for evaluating high-$\kappa$ gate dielectric devices.

• Bulletin of the Korean Mathematical Society
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• v.22 no.1
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• pp.11-15
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• 1985

Manddelberg [9] has shown that a Clifford algebra of a free quadratic space over an arbitrary semi-local ring R in Brawer-Wall group BW(R) is determined by its rank, determinant, and Hasse invariant. In this paper, we prove a corresponding result when R is a full ring.Throughout this paper, unless otherwise specified, we assume that R is a commutative ring having 2 a unit. A quadratic space (V, B, .phi.) over R is a finitely generated projective R-module V with a symmetric bilinear mapping B: V*V.rarw.R which is non-degenerate (i.e., the natural mapping V.rarw.Ho $m_{R}$(V,R) induced by B is an isomorphism), and with a quadratic mapping .phi.: V.rarw.R such that B(x,y)=1/2(.phi.(x+y)-.phi.(x)-.phi.(y)) and .phi.(rx) = $r^{2}$.phi.(x) for all x, y in V and r in R. We denote the group of multiplicative units of R by U9R). If (V, B, .phi.) is a free rank n quadratic space over R with an orthogonal basis { $x_{1}$,.., $x_{n}$}, we will write < $a_{1}$,.., $a_{n}$> for (V, B, .phi.) where the $a_{i}$=.phi.( $x_{i}$) are in U(R), and denote the space by the table [ $a_{ij}$ ] where $a_{ij}$ =B( $x_{i}$, $x_{j}$). In the case n=2 and B( $x_{1}$, $x_{2}$)=1/2 we reserve the notation [a $a_{11}$, $a_{22}$] for the space. A commutative ring R having 2 a unit is called full [10] if for every triple $a_{1}$, $a_{2}$, $a_{3}$ of elements in R with ( $a_{1}$, $a_{2}$, $a_{3}$)=R, there is an element w in R such that $a_{1}$+ $a_{2}$w+ $a_{3}$ $w^{2}$=unit.TEX>=unit.t.t.t.

• Journal of applied mathematics & informatics
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• v.16 no.1_2
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• pp.525-532
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• 2004

For two vertices u and v of an oriented graph D, the set I(u, v) consists of all vertices lying on a u-v geodesic or v-u geodesic in D. If S is a set of vertices of D, then I(S) is the union of all sets 1(u, v) for vertices u and v in S. The geodetic number g(D) is the minimum cardinality among the subsets S of V(D) with I(S) = V(D). In this paper, we give a partial answer for the conjecture by G. Chartrand and P. Zhang and present some results on orient able geodetic number.

• Journal of the Institute of Convergence Signal Processing
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• v.13 no.3
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• pp.162-165
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• 2012

In this paper, the method of controlling velocity between joining vehicles at the point of bottleneck using information and communications technology of WAVE method based V2V and V2I are proposed for the driving with high fuel efficiency. Using the derived fuel-efficiency comparative analysis model, it was shown that the proposed method's fuel efficiency is better than traffic light method demanding periodically vehicle's stop. Also, this method provides the derivation algorithm for deceleration and acceleration for controlling velocity between vehicles approaching bottleneck area.