http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
De Chuan Zhou 대한수학회 2020 대한수학회보 Vol.57 No.6
Let $S$ and $T$ be $w$-linked extension domains of a domain $R$ with $S\suse T$. In this paper, we define what satisfying the $w_R$-GD property for $S \subseteq T$ means and what being $w_R$- or $w$-GD domains for $T$ means. Then some sufficient conditions are given for the $w_R$-GD property and $w_R$-GD domains. For example, if $T$ is $w_R$-integral over $S$ and $S$ is integrally closed, then the $w_R$-GD property holds. It is also given that $S$ is a $w_R$-GD domain if and only if $S\suse T$ satisfies the $w_R$-GD property for each $w_R$-linked valuation overring $T$ of $S$, if and only if $S\suse (S[u])_{w}$ satisfies the $w_R$-GD property for each element $u$ in the quotient field of $S$, if and only if $S_{\mathfrak{m}}$ is a GD domain for each maximal $w_R$-ideal $\mathfrak{m}$ of $S$. Then we focus on discussing the relationship among GD domains, $w$-GD domains, $w_R$-GD domains, Pr\"ufer domains, P$v$MDs and P$w_R$MDs, and also provide some relevant counterexamples. As an application, we give a new characterization of P$w_R$MDs. We show that $S$ is a P$w_R$MD if and only if $S$ is a $w_R$-GD domain and every $w_R$-linked overring of $S$ that satisfies the $w_R$-GD property is $w_R$-flat over $S$. Furthermore, examples are provided to show these two conditions are necessary for P$w_R$MDs.
A Novel Hitting Frequency Point Collision Avoidance Method for Wireless Dual-Channel Networks
( Hou-de Quan ),( Chuan-bao Du ),( Pei-zhang Cui ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.3
In dual-channel networks (DCNs), all frequency hopping (FH) sequences used for data channels are chosen from the original FH sequence used for the control channel by shifting different initial phases. As the number of data channels increases, the hitting frequency point problem becomes considerably serious because DCNs is non-orthogonal synchronization network and FH sequences are non-orthogonal. The increasing severity of the hitting frequency point problem consequently reduces the resource utilization efficiency. To solve this problem, we propose a novel hitting frequency point collision avoidance method, which consists of a sequence-selection strategy called sliding correlation (SC) and a collision avoidance strategy called keeping silent on hitting frequency point (KSHF). SC is used to find the optimal phase-shifted FH sequence with the minimum number of hitting frequency points for a new data channel. The hitting frequency points and their locations in this optimal sequence are also derived for KSHF according to SC strategy. In KSHF, the transceivers transmit or receive symbol information not on the hitting frequency point, but on the next frequency point during the next FH period. Analytical and simulation results demonstrate that unlike the traditional method, the proposed method can effectively reduce the number of hitting frequency points and improve the efficiency of the code resource utilization.
A characterization of ω-Artinian modules
권태인,김환구,De Chuan Zhou 강원경기수학회 2020 한국수학논문집 Vol.28 No.4
Let $R$ be a commutative ring with identity and let $M$ be a $w$-module over $R$. Denote by $\mathscr{F}_M$ the set of all $w$-submodules of $M$ such that $(M/N)_w$ is $w$-cofinitely generated. Then it is shown that $M$ is $w$-Artinian if and only if $\mathscr{F}_M$ is closed under arbitrary intersections, if and only if $\mathscr{F}_M$ satisfies the descending chain condition.
On nonnil-exact sequences and nonnil-commutative diagrams
Wei Zhao,De Chuan Zhou 대한수학회 2023 대한수학회지 Vol.60 No.6
In this paper, we investigate the nonnil-exact sequences and nonnil-commutative diagrams and show that they behave in a way similar to the classical ones in Abelian categories.
A homological characterization of Krull domains
Fanggui Wang,De Chuan Zhou 대한수학회 2018 대한수학회보 Vol.55 No.2
Let $R$ be a commutative ring. In this paper, the $w$-projective Basis Lemma for $w$-projective modules is given. Then it is shown that for a domain, nonzero $w$-projective ideals and nonzero $w$-invertible ideals coincide. As an application, it is proved that $R$ is a Krull domain if and only if every submodule of finitely generated projective modules is $w$-projective.
$\tau_w$-Loewy modules and their applications
김환구,임정욱,De Chuan Zhou 대한수학회 2019 대한수학회보 Vol.56 No.6
In this paper, we study a theory for the structure of $\tau_w$-Loewy series of modules over commutative rings, where $\tau_w$ is the hereditary torsion theory induced by the so-called $w$-operation, and explore the relationship between $\tau_w$-Loewy modules and $w$-Artinian modules.
First-principles study of transport properties of endohedral Li@C20 metallofullerene
Yi-Peng An,Chuan-Lu Yang,Mei-Shan Wang,Xiao-Guang Ma,De-Hua Wang 한국물리학회 2010 Current Applied Physics Vol.10 No.1
The transport properties of the endohedral Li@C20 metallofullerene are studied using density functional non-equilibrium Green’s function method. The equilibrium conductance of Li@C20 metallofullerene becomes larger than that of the empty C20 fullerene molecule. The I.V curve under low-bias voltage shows the characteristic of metallic behavior; another, the novel negative differential resistance behavior is also observed. It is found that the doping effect of Li atom significantly changes the transport properties of C20 fullerene.
A HOMOLOGICAL CHARACTERIZATION OF KRULL DOMAINS
Wang, Fang Gui,Zhou, De Chuan Korean Mathematical Society 2018 대한수학회보 Vol.55 No.2
Let R be a commutative ring. In this paper, the w-projective Basis Lemma for w-projective modules is given. Then it is shown that for a domain, nonzero w-projective ideals and nonzero w-invertible ideals coincide. As an application, it is proved that R is a Krull domain if and only if every submodule of finitely generated projective modules is w-projective.