• Korean Journal of Environmental Biology
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• v.18 no.2
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• pp.269-277
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• 2000

When Persicaria thunbergii and Rumex crispus were treated with Cd($NO_3$)$_2$ and Pb($NO_3$)$_2$ of 5 or 10 mM for 5 days, the amount of bioaccumulation of $Pb^{2+}$ in the leaf of P. thunbergii was 2.87-8.08$\mu\textrm{g}$/g and that of $Cd^{2+}$ was 0.82-2.79$\mu\textrm{g}$/g. In the case of P. thunbergii, the concentration of $Pb^{2+}$ in the leaf was higher than that of $Cd^{2+}$. On the other hand, in R. crispus, the concentration of $Cd^{2+}$ and $Pb^{2+}$ were similar as follows ; 1.49$\mu\textrm{g}$/g in $Cd^{2+}$ 5mM, 2.90$\mu\textrm{g}$/g in Cd2+ 10mM, 1.83$\mu\textrm{g}$/g in $Pb^{2+}$ 5mM and 2.73$\mu\textrm{g}$/g in $Pb^{2+}$ 10mM. The remaining rate of heavy metals and the variation of pH in the cultured soil decreased as compared with control (100 % and pH 6.48) after 5 days as follows; to 77.l% and pH 6.39 in $Cd^{2+}$ 5mM, 90.2% and pH 5.79 in $Cd^{2+}$ 10 mM, 81.1% and pH 6.00 in $Pb^{2+}$ 5mM, and 85.7% and pH 5.80 in $Pb^{2+}$ 10 mM. The result of size exclusion chromatography, several phytochelatins were seperated from the extract of the leaf of both plants treated with heavy metals. The molecular mass of these phytochelatins were estimated as follows; in the case of P. thunbergii, about 4,300-8,600 da by $Cd^{2+}$ and about 3,200-9,700 da by $Pb^{2+}$, and in R. crispus, about 4,300 da by $Cd^{2+}$ and about 3,200-7,500 da by $Pb^{2+}$. In addition, $A_{254}$ of these phytochelatins were higher than $A_{280}$. [Phytochelatin, Persicaria thunbergii, Rumex crispus]

• Korean Journal of Mathematics
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• v.17 no.3
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• pp.271-281
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• 2009

We define injective and projective representations of a quiver $Q={\bullet}{\rightarrow}{\bullet}{\rightarrow}{\bullet}$. Then we show that a representation $M_1\longrightarrow[50]^{f1}M_2\longrightarrow[50]^{f2}M_3$ of a quiver $Q={\bullet}{\rightarrow}{\bullet}{\rightarrow}{\bullet}$ is projective if and only if each $M_1,\;M_2,\;M_3$ is projective left R-module and $f_1(M_1)$ is a summand of $M_2$ and $f_2(M_2)$ is a summand of $M_3$. And we show that a representation $M_1\longrightarrow[50]^{f1}M_2\longrightarrow[50]^{f2}M_3$ of a quiver $Q={\bullet}{\rightarrow}{\bullet}{\rightarrow}{\bullet}$ is injective if and only if each $M_1,\;M_2,\;M_3$ is injective left R-module and $ker(f_1)$ is a summand of $M_1$ and $ker(f_2)$ is a summand of $M_2$.

• Nuclear Engineering and Technology
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• v.16 no.2
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• pp.58-63
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• 1984

Paper electrophoretic separation of octahedrally bonded (Ruc $l_{6}$ )$^{3-}$ has been carried out by using the specially designed migration apparatus. The supporting electrolyte solutions are as follows: 0.1M-HCl $O_4$, 0.05 M-HCl+0.09M-KCl, 0.1M-HCl, 5$\times$10$^{-3}$ M-NTA, 0.01M-HCl, 0.01M-HCl $O_4$, 0.01M-citric acid, 0.01M-K $H_2$P $O_4$+0.01M-N $a_2$HP $O_4$, 0.05M-borax, 0.025M-N $a_2$C $O_3$+0.025M-NaHC $O_3$, 0.01M-N $a_3$P $O_4$, 0.01M-NaOH and 0.1 M-NaOH. The (Ruc $l_{6}$ )$^{3-}$ appears in 2 to 4 peaks and is found in several chemical species such as (RuCl ($H_2O$)$_{5}$ )$^{2+}$, cis and trans (RuC $l_2$($H_2O$)$_4$)$^{1+}$, (RuC $l_3$($H_2O$)$_3$)$^{0}$ , (RuC $l_4$($H_2O$)$_2$)$^{1-}$, (RuC $l_{5}$ ($H_2O$))$^{2-}$ and (RuC $l_{6}$ )$^{3-}$. The retention value has been found to be highest in the 0.025M-N $a_2$C $O_3$+0.025M-NaHC $O_3$ electrolyte solution.n.

• Journal of Software Assessment and Valuation
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• v.16 no.2
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• pp.53-62
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• 2020

In the end-user domain of an IoT environment, there are more and more intelligent M2M devices that provide resources to create and share application services. Therefore, it can be very useful to manage trust by transferring the role of the existing centralized service provider to end users in a P2P environment. However, in a decentralized M2M computing environment where end users independently provide or consume services, mutual trust building is the most important factor. This is because malicious users trying to build malfunctioning services can cause security problems in M2M computing environments such as IoT. In this paper, we provide an integrated analysis and approach for trust evaluation of M2M application services, and an optimized trust evaluation model that can guarantee reliability among users of the M2M community.

• Kyungpook Mathematical Journal
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• v.46 no.2
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• pp.255-260
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• 2006

Let $m$ and $k$ be any positive integers, let $\mathbb{Z}_k$ the ring of integers of modulo $k$, let $G_m(\mathbb{Z}_k)$ the group of all $m$ by $m$ nonsingular matrices over $\mathbb{Z}_k$ and let ${\phi}_m(k)$ the order of $G_m(\mathbb{Z}_k)$. In this paper, ${\phi}_m(k)$ can be computed by the following investigation: First, for any relatively prime positive integers $s$ and $t$, $G_m(\mathbb{Z}_{st})$ is isomorphic to $G_m(\mathbb{Z}_s){\times}G_m(\mathbb{Z}_t)$. Secondly, for any positive integer $n$ and any prime $p$, ${\phi}_m(p^n)=p^{m^2}{\cdot}{\phi}_m(p^{n-1})=p{^{2m}}^2{\cdot}{\phi}_m(p^{n-2})={\cdots}=p^{{(n-1)m}^2}{\cdot}{\phi}_m(p)$, and so ${\phi}_m(k)={\phi}_m(p_1^n1){\cdot}{\phi}_m(p_2^{n2}){\cdots}{\phi}_m(p_s^{ns})$ for the prime factorization of $k$, $k=p_1^{n1}{\cdot}p_2^{n2}{\cdots}p_s^{ns}$.

• Bulletin of the Korean Mathematical Society
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• v.43 no.3
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• pp.619-626
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• 2006

Let m be any positive integer, R be a ring with identity, $M_m(R)$ be the matrix ring of all m by m matrices eve. R and $G_m(R)$ be the multiplicative group of all n by n nonsingular matrices in $M_m(R)$. In this pape., the following are investigated: (1) for any pairwise coprime ideals ${I_1,\;I_2,\;...,\;I_n}$ in a ring R, $M_m(R/(I_1{\cap}I_2{\cap}...{\cap}I_n))$ is isomorphic to $M_m(R/I_1){\times}M_m(R/I_2){\times}...{\times}M_m(R/I_n);$ and $G_m(R/I_1){\cap}I_2{\cap}...{\cap}I_n))$ is isomorphic to $G_m(R/I_1){\times}G_m(R/I_2){\times}...{\times}G_m(R/I_n);$ (2) In particular, if R is a finite ring with identity, then the order of $G_m(R)$ can be computed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.10C
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• pp.959-964
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• 2007

In this paper, for a positive integer M and a prime p such that $M|p^n-1$, families of M-ary sequences using the M-ary Sidel'nikov sequences with period $p^n-1$ are constructed. The family has its maximum magnitude of correlation values upper bounded by $3\sqrt{p^{n}}+6$ and the family size is $(M-1)^2(2^{n-1}-1)$+M-1 for p=2 or $(M-1)^2(p^n-3)/2+M(M-1)/2$ for an odd prime p.

• Information and Communications Magazine
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• v.20 no.11
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• pp.1550-1559
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• 2003

The convergence of fixed and wireless networks in data communication is providing the necessary driver for M2M commerce to take-off. The opportunities provided by M2M Commerce areonly limited by imagination. Automotive Fleet and Freight, Tolling, Water and Power Metering, Supply Chain Management including Asset Management, Remote Monitoring and Diagnostics, Energy Management and Access Control and Security are among the many M2M applications that are currently getting rolled out. ARC Group expects the worldwide solutions market to be worth in excess of US$ 100 billion by 2007. In addition, operator revenues worldwide from the transport of Telematics data alone will rise from US$ 3.5 billion in 2002 to US$ 78 billion by 2007. This paper discusses some of the lifestyle and business opportunities provided by M2M Commerce in the new ear of network convergence. It also provides some case studies to demonstrate the benefits of M2M Commerce across the supply chain. The key focus of the paper is on achieving enhanced lifestyle, cost reduction, improved profitability and enhanced customer relationship management through M2M Commerce.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.603-606
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• 2012

M2M 서비스를 통한 통신 모델은 MTC 디바이스와 MTC 서버 통신 모델 기반으로 이루어졌다. 하지만 최근 이동통신 시스템 기반으로 M2M 서비스가 개발되면서 다양한 M2M 서비스 개발을 위해 디바이스간 직접 통신 및 게이트웨이 기반 M2M 서비스 통신 모델에 관한 기술표준이 3GPP SA1에서 추진 중이다. 이와 관련된 기술은 3GPP SA1 TR 22.888(MTCe: Study on Enhancements for MTC) 문서를 통해 개발 중이며 주요 내용은 MTC capillary network 구축 및 MTC 게이트웨이 디바이스 역할 등을 기술하고 있다. MTC capillary network 구성의 목적은 non-3GPP M2M 디바이스를 이동통신 시스템을 통해서 M2M 서비스를 제공하기 위함이다. 본 논문에서는 이와 관련된 표준기술 및 use case를 분석한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.1
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• pp.106-113
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• 2014

This work proposes an analytic framework to estimate the capacity of the link in an M2M gateway that multiplexes a massive number of machine type communication devices. First, we specify the network architecture for M2M communications. Next, we summarize the characteristics of M2M traffic, from which we extract an area about the problem that has to be resolved in the dimensioning of the link capacity. After that we propose a new method to determine the capacity of the link in an M2M gateway. Via numerical experiment reflecting the realistic environment of M2M traffic, we illustrate the validity of the proposed model.