• Korean Journal of Mathematics
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• v.22 no.1
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• pp.151-167
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• 2014

Let M, N be modules over a ring R and $[M,N]=Hom_R(M,N)$. The concern is study of: (1) Some fundamental properties of [M, N] when [M, N] is regular or semipotent. (2) The substructures of [M, N] such as radical, the singular and co-singular ideals, the total and others has raised new questions for research in this area. New results obtained include necessary and sufficient conditions for [M, N] to be regular or semipotent. New substructures of [M, N] are studied and its relationship with the Tot of [M, N]. In this paper we show that, the endomorphism ring of a module M is regular if and only if the module M is semi-injective (projective) and the kernel (image) of every endomorphism is a direct summand.

• Current Photovoltaic Research
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• v.6 no.3
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• pp.81-85
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• 2018

The photovoltaic modules installed in the actual field are affected by various external environments and the electrical performance output value is generally lowered compared to initial output value. The most of photovoltaic modules consists of low iron glass, encapsulant (EVA), back sheet, frame and junction box assembly based on the solar cells. In this paper, the characteristics of encapsulant which is an important constituent material of photovoltaic module were verified by maximum power determination, electro luminescence images, yellowness index measurement, and gel content measurement after ultraviolet (UV) irradiation exposure. The most commonly installed 72 cells crystalline photovoltaic modules were tested after various UV exposure of 0, 15, 30, and $60kWh/m^2$ and compared with the reference module. After UV exposure of $15kWh/m^2$, which is the current international test condition, a small amount of change was observed in yellowness index and electroluminescence, while a gell content rapidly increased. At a cumulative dose of $60kWh/m^2$, which will be a new international test condition in the near future, however, the yellowness index increased sharply and showed the greatest output power drop.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.7
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• pp.1022-1030
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• 2002

The experiments were performed with a $31{\times}31{\times}7mm^3$ simulated 3-dimensional module on the thermal conductive board of a parallel plate channel. The convective thermal conductance for the path from the module surface directly to airflow and conjugate thermal conductance for the path leading from the module to the floor by way of a module support, then, to the airflow were determined with several combinations of module-support-construction(210, 0.32, 0.021 K/W)/floor-material(398, 0.236W/mK) and channel height(15-30mm). As the result, it was found that the conjugate thermal conductance and the temperature distribution around the module depend on the thermal resistance of the module support, and the channel height. These configurations were designed to investigate on the feasibility of using the substrate as an effective heat spreader in the forced convective air-cooling of surface mounted heat source. The experimental results were discussed in the light of interactive nature of heat transfer through two paths, one directed from the module to the airflow and the other via the module support and the floor to the air.

• The Journal of Sustainable Design and Educational Environment Research
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• v.20 no.3
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• pp.1-10
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• 2021

Before long the number of Elementary School students per class will be 20 in Korea, but the current Area and Module of Elementary School are planned for 30 students. Therefore, necessary Area and Module for less than 20 students should be prepared. The purpose of this research is to find out necessary Area and Module for less than 20 students in Elementary School Classroom. I researched 60 Classrooms of 10 Elementary Schools before 2 researches of mine, and researched the sizes of every path in the classrooms. With the Plans for 20 students, I found the conclusion as follows: First, the one-way class requires a minimum of 5.4m×8.1m (43.74m²), a maximum of 5.4m×8.7m (48.6m²). Second, the 3-row alignment class requires a minimum of 7.2m×7.2m (51.84m²), a maximum of 7.5m×7.5m (56.25m²). Third, the group study class requires a minimum of 6.0m×8.7m (52.2m²), a maximum of 6.3m×9.3m (58.59m²). Fourth, the group study class requires a minimum of 2.34m², a maximum of 14.85m² more than the one-way class. Fifth, the suitable module which fits both 2-row alignment class and group study class except the 3-row alignment class is 6.0m×8.7m (52.2m²).

• Journal of IKEEE
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• v.23 no.3
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• pp.1082-1087
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• 2019

In this study, ECG signal amplifier, wireless transmitter/receiver circuit, signal processing filter circuit and A/D converter circuit design required for the development of small sized ECG module for wireless transmission/ reception were performed. In order to verify the performance of ECG sensors, the measurement was performed from 1 m to 3 m to measure the signal noise ratio according to the gateway distance. Experimental results showed that the signal noise ratio at 2 m distance was 17.18 dB on average, which fulfilled the requirements for commercialization. The experimental results obtained in this study are expected to contribute to the low cost, high efficiency mobile health field where remote monitoring diagnosis can be applied to small biometric devices for chronic disease management.

• Journal of the Korean Mathematical Society
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• v.33 no.4
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• pp.747-761
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• 1996

Thoughout this paper, R will be a commutative ring (with non-zero identity) and M will denote an R-module.

• The Pure and Applied Mathematics
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• v.29 no.3
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• pp.207-230
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• 2022

In this article, we investigate several aspects of (R, S)-hyper bi-modules and describe some their properties. The concepts of fundamental relation, completes part and complete closure are studied regarding to (R, S)-hyper bi-modules. In particular, we show that any complete (R, S)-hyper bi-module has at least an identity and any element has an inverse. Finally, we obtain a few results related to the heart of (R, S)-hyper bi-modules.

• Membrane Journal
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• v.8 no.1
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• pp.50-58
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• 1998

Protein affinity membranes were prepared via coating of chitosan gel on the porous flat and hollow-fiber polysulfone membranes, followed by the immobilization of the reactive dye (Cibacron Blue 3GA) to the chitosan gel. Maximum protein binding capacity of these affinity membranes was about 70 $\mu{g/cm}^2$. Using the affinity flat membrane module, the elution chromatography of human serum albumin (HSA) was performed to determine the optimum condition of eluent buffer. The optimum condition of eluent was the universal buffer solution of 0.06 M concentration containing 1 M KCl at pH 10. For the frontal chromatography of HSA using the flat module, the dynamic protein binding capacity was rapidly decreased from the equilibrium values with increasing flow rate and HSA concentration of the loading solution. However, in the case of hollow-fiber module, the dynamic binding capacity was maintained an equilibrium value without depending on the operating conditions. These results showed that the hollow-fiber module was more effective than the flat module as an affinity chromatography column.

• Honam Mathematical Journal
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• v.28 no.4
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• pp.499-511
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• 2006

It is well-known that every finitely generated torsion-free module over a principal ideal domain is free. This will be generalized. We deal with ideals of the finite, external direct product of certain rings. Finally, if M is a torsion-free, finitely generated module over a reduced, Noetherian ring A, then we prove that Ms is a projective module over As, where $S=A{\setminus}(A)$.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.181-183
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• 2003

This paper presents an operator training simulator for power system restoration against massive black-out. The system is designed especially focused on the generality and convenient setting up for initial condition of simulation. The former is accomplished by using on line calculation methodology, and PSS/E data is used to define the initial situation. The proposed simulator consists of three major components - the Power flow(PF) module, data conversion(CONV) module and CUI subsystem. PF module calculates power flow, and then checks overvoltage of buses and overflow of lines. CONV module composes an Y-Bus array and a data base at each restoration action. The initial Y-Bus array is constructed from PSS/E data. The user friendly GUI module is developed including graphic editor and built-in operation manual. As a result, the maximum processing time for one step operation is 15 seconds, which is adequate for training purpose. Comparison with PSS/E simulation proves the accuracy and reliability of the training system.