• Hwankyungkyoyuk
• /
• v.11 no.2
• /
• pp.177-211
• /
• 1998

This paper presents the development of standardized modules and an integrated program which will be used for social environmental education. The study objectives are to develop modules which are based on various environmental topics, to relate the regional environmental topics to the educational modules and program, and to include the demand of students in the modules and program. Literature and questionary surveys, as well as, module development method were utilized as research tools. The titles of developed modules are “The Green Planet Earth, “Unexpected Resources: Save Resources and Recycle”, “Water as the Mother of All Lives”, “The Blue Sky with Clean Air”, and “Soil as the Home of All Living and Non-living Things”. It is hoped that the developed modules and program are utilized as course materials and curriculum for social environmental education in various educational institutes. The study results will be materialized as multimedia in near future.

• Kyungpook Mathematical Journal
• /
• v.47 no.1
• /
• pp.21-30
• /
• 2007

We say a module $M_R$ a semicommutative module if for any $m{\in}M$ and any $a{\in}R$, $ma=0$ implies $mRa=0$. This paper gives various properties of reduced, Armendariz, Baer, Quasi-Baer, p.p. and p.q.-Baer rings to extend to modules. In addition we also prove, for a p.p.-ring R, R is semicommutative iff R is Armendariz. Let R be an abelian ring and $M_R$ be a p.p.-module, then $M_R$ is a semicommutative module iff $M_R$ is an Armendariz module. For any ring R, R is semicommutative iff A(R, ${\alpha}$) is semicommutative. Let R be a reduced ring, it is shown that for number $n{\geq}4$ and $k=[n=2]$, $T^k_n(R)$ is semicommutative ring but $T^{k-1}_n(R)$ is not.

• Proceedings of the KIEE Conference
• /
• 1998.07b
• /
• pp.614-616
• /
• 1998

Control systems used in power plants consist of some control modules which are operated independently. A failure of control system mainly depends on a failure of control modules. So, it is important to estimate lifetimes of control modules in order to assess the reliability of control systems. In this paper, three methods for estimating lifetimes of control modules are presented and control modules' lifetimes of boiler control system used in a thermal power plant are estimated applying the three methods. Also, advantage and disadvantage of three methods are presented.

• Bulletin of the Korean Mathematical Society
• /
• v.51 no.1
• /
• pp.253-266
• /
• 2014

Commutative rings in which every prime ideal is an intersection of maximal ideals are called Hilbert (or Jacobson) rings. We propose to define classical Hilbert modules by the property that classical prime submodules are intersections of maximal submodules. It is shown that all co-semisimple modules as well as all Artinian modules are classical Hilbert modules. Also, every module over a zero-dimensional ring is classical Hilbert. Results illustrating connections amongst the notions of classical Hilbert module and Hilbert ring are also provided. Rings R over which all modules are classical Hilbert are characterized. Furthermore, we determine the Noetherian rings R for which all finitely generated R-modules are classical Hilbert.

• Bulletin of the Korean Mathematical Society
• /
• v.57 no.6
• /
• pp.1567-1579
• /
• 2020

Let R ⊂ S be a Frobenius extension of rings and M a left S-module and let 𝓧 be a class of left R-modules and 𝒚 a class of left S-modules. Under some conditions it is proven that M is a 𝒚-Gorenstein left S-module if and only if M is an 𝓧-Gorenstein left R-module if and only if S ⊗_R M and Hom_R(S, M) are 𝒚-Gorenstein left S-modules. This statement extends a known corresponding result. In addition, the situations of Ding modules, Gorenstein AC modules and projectively coresolved Gorenstein flat modules are considered under Frobenius extensions.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.10
• /
• pp.1411-1417
• /
• 2015

The installation of PV system to the power distribution system is being increased as one of solutions for environmental pollution and energy crisis. However, the efficiency of PV system is getting decreased because of the aging phenomenon and several operation obstacles. Therefore, The technology development of aging diagnosis of PV modules are required in order to improve operation performance of PV modules. This paper proposes evaluation algorithm for aging state in PV modules by using the electrical characteristics of PV modules and environmental factors. And also, this paper presents a operation evaluation system of PV modules based on the proposed aging diagnosis algorithm of PV modules. From the simulation results of proposed evaluation system, it is confirmed that the proposed algorithm is a useful tool for aging diagnosis of PV systems.

• Communications of the Korean Mathematical Society
• /
• v.33 no.2
• /
• pp.561-569
• /
• 2018

In this paper, we introduce some notions of orthogonality in the setting of Finsler $C^*$-modules and investigate their relations with the Birkhoff-James orthogonality. Suppose that ($E,{\rho}$) and ($F,{\rho}^{\prime}$) are Finsler modules over $C^*$-algebras $\mathcal{A}$ and $\mathcal{B}$, respectively, and ${\varphi}:{\mathcal{A}}{\rightarrow}{\mathcal{B}}$ is a *-homomorphism. A map ${\Psi}:E{\rightarrow}F$ is said to be a ${\varphi}$-morphism of Finsler modules if ${\rho}^{\prime}({\Psi}(x))={\varphi}({\rho}(x))$ and ${\Psi}(ax)={\varphi}(a){\Psi}(x)$ for all $a{\in}{\mathcal{A}}$ and all $x{\in}E$. We show that each ${\varphi}$-morphism of Finsler $C^*$-modules preserves the Birkhoff-James orthogonality and conversely, each surjective linear map between Finsler $C^*$-modules preserving the Birkhoff-James orthogonality is a ${\varphi}$-morphism under certain conditions. In fact, we state a version of Wigner's theorem in the framework of Finsler $C^*$-modules.

• Journal of the Korean Solar Energy Society
• /
• v.37 no.2
• /
• pp.35-45
• /
• 2017

The types of installation of the photovoltaic system applied to domestic residential buildings are classified as follows: Mounted modules with air circulation, semi-integrated modules with air duct behind, integrated modules with fully insulated back. In order to study generation characteristics of PV system, we verified the validity of interpretation program based on long-term measurement data of demonstration house installed in BAPV form and also analyzed the generation characteristics and performance of each installation type. The results are as follows. First, the RMSE of amount of generation and simulation according to annual daily insolation of demonstration system located in Daejeon was 0.98kWh and the range of relative error of monthly power generation was -5.8 to 3.1. Second, the average annual PR of mounted modules was 82%, semi-integrated modules 76.1% and integrated modules 71.9%. This differences were attributed to temperature loss. Third, the range of operating temperature of annual hourly photovoltaic modules was -6.5 to $61.0^{\circ}C$ for mounted modules, $-6.0{\sim}73.9^{\circ}C$ for semi-integrated modules and -5.5 to $88.9^{\circ}C$ for integrated modules. The temperature loss of each installation type was -14.0 to 16.1%, -13.8 to 21.9%, and -13.6 to 28.5%, respectively.

• Kyungpook Mathematical Journal
• /
• v.55 no.2
• /
• pp.289-300
• /
• 2015

In [9], the author extends the definition of lifting and supplemented modules to ${\delta}$-lifting and ${\delta}$-supplemented by replacing "small submodule" with "${\delta}$-small submodule" introduced by Zhou in [13]. The aim of this paper is to show new properties of ${\delta}$-lifting and ${\delta}$-supplemented modules. Especially, we show that any finite direct sum of ${\delta}$-hollow modules is ${\delta}$-supplemented. On the other hand, the notion of amply ${\delta}$-supplemented modules is studied as a generalization of amply supplemented modules and several properties of these modules are given. We also prove that a module M is Artinian if and only if M is amply ${\delta}$-supplemented and satisfies Descending Chain Condition (DCC) on ${\delta}$-supplemented modules and on ${\delta}$-small submodules. Finally, we obtain the following result: a ring R is right Artinian if and only if R is a ${\delta}$-semiperfect ring which satisfies DCC on ${\delta}$-small right ideals of R.

• Journal of the Korean Solar Energy Society
• /
• v.36 no.5
• /
• pp.1-8
• /
• 2016

In this paper, we evaluated the effect of a silica-based Anti-Reflection(AR) coating for PV modules. The coating technique can be easily applied to large-scale PV modules at room temperature with improvements of the optical properties that is qualified by the optical transmission measurements on the coated cover glass of the modules. The power improvement of the large-scale PV modules shows the increasing about 2.4% at standard condition of the coating technique on average. To improve the AR coating effect of the PV modules, we have characterized the individual PV modules by the measurements of DC power output, modified performance ratio(PRm) and the regression. The results show that the significant improvements of the AR coating effect are 6.4%, 5.5% and 4.5% of increasing of the performances by using the measurements of DC power output, modified performance ratio(PRm) and the regression, respectively.