• Kyungpook Mathematical Journal
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• v.61 no.1
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• pp.111-137
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• 2021

Higson proved that every homotopy invariant, stable and split exact functor from the category of C⁎-algebras to an additive category factors through Kasparov's KK-theory. By adapting a group equivariant generalization of this result by Thomsen, we generalize Higson's result to the inverse semigroup and locally compact, not necessarily Hausdorff groupoid equivariant setting.

• Communications of the Korean Mathematical Society
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• v.37 no.1
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• pp.269-277
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• 2022

We define and study the notion of 𝜇-countably compact spaces in generalized topology and 𝜇𝓗-countably compact spaces which are considered with respect to a hereditary class 𝓗. Some interesting properties and relations are provided in the paper. Moreover, some preservation of functions properties are studied and investigated.

• ETRI Journal
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• v.36 no.2
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• pp.286-292
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• 2014

This paper presents a compact structure composed of an upper high-impedance transmission line, a middle extended parallel coupled line, and a pair of inter-coupled symmetrical stepped impedance stubs. Detailed investigation into this structure based on an equivalent circuit analysis reveals that this proposed structure exhibits a quasi-elliptic low-pass filtering response with three transmission zeros. Moreover, the positions of the three transmission zeros can be tuned and reallocated flexibly by choosing the proper circuit parameters. Finally, the design concept is validated through the design, fabrication, and measurement of two exemplary low-pass filters (LPFs) with one single unit and two cascaded asymmetric units. The measured results agree well with the simulated results. In addition, in the range of $1.42f_c$ to $7.03f_c$, the fabricated quasi-elliptic LPFs experimentally demonstrate a very wide upper-stopband of 20 dB using a compact size of only $0.0089{\lambda}_g{^2}$, where ${\lambda}_g$ is the guided wavelength of a $50{\Omega}$ transmission line at the central frequency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.2872-2877
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• 2012

This paper discusses the development of the wearable personal cooling system for reducing thermal stress in hot environment. The personal cooling system is operated with the compact refrigeration system by compressing refrigerant. The compact refrigeration system is applied with the miniaturization and weight reduction for portable and wearable cooling system. The body heat is reduced by heat conduction with evaporator in direct cooling type. The cooling capacity of the wearable personal cooling system is approximately 100W and, the system could maintain the inside temperature of approximately 12-$13^{\circ}C$ lower than the ambient temperature. The weight of the wearable cooling system is about 3kg including vest, case, battery and all parts.

• Nuclear Engineering and Technology
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• v.53 no.9
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• pp.3112-3121
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• 2021

One of the major factors affecting the life span of a Reactor Pressure Vessel (RPV) is the Pressurised Thermal Shock (PTS). PTS is a thermo-mechanical load on the RPV wall due to steep temperature gradients and structural load created by internal pressure of the fluid within the RPV. Safe operating life of a nuclear power plant is ensured by carrying out fracture analysis of the RPV against thermal shock. Carrying out fracture tests on RPV/large scale components is not always feasible. Hence, studies on laboratory level specimens are necessary to validate and supplement the prototype results. This paper aims to study the fracture behaviour of standard Compact Tension [C(T)] specimens, made of RPV steel 20MnMoNi55, subjected to thermal shock through experimental and numerical investigations. Fracture tests have been carried out on the C(T) specimens subjected to thermal transient load and tensile load to quantify the effect of thermal shock. Crack resistance curves are obtained from the fracture tests as per ASTM E1820 and compared with those obtained numerically using XFEM and a good agreement was found. A quantitative study on the crack tip plastic zone, computed using cohesive segment approach, from the numerical analyses justified the experimental crack initiation toughness.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.835-839
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• 2004

For factory automation using force/torque control, we need a networked-force management system as well as good force sensing and force generation. In this paper, we present a web-based force management system including 6-axis force/torque sensing system. Performance of the force-torque sensor is affected significantly by analog noise that is included in a sensor signal, and the noise should be reduced appropriately to obtain an adequate performance of the sensor. Moreover, the sensor itself should be convenient to install to a real application system. It should be compact in size and also easy to wire in real situation. In this viewpoint, we developed usb-based compact sensor system which is well communicated using web between two computers that exist far away. Software is programmed using LabVIEW and CCS-C. PIC microcontrollers are used for implementing a compact hardware. The proposed system is verified through experimental works.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.191-193
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• 2008

This paper describes a compact Iron-cored Electronic Current Transformer(ECT) based on IEC 61850. The ECT developed in this study has the feature of designing the current transformer with a compact iron-core, compensating error due to the nonlinear characteristic of Iron-core, and applying IEC 61850 9-2 for sampled value(SMV). We verify the performance of the innovative product developed in the study in KERI and test the performance of digital communication in the lab.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.342_343
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• 2009

This paper describes a compact Iron-cored Electronic Current Transformer(ECT) based on IEC 61850 9-2. The ECT developed in this study has the feature of designing the current transformer with compact iron-core, compensating error due to the nonlinear characteristic of iron-core, and applying IEC 61850 9-2 for sampled value(SMV). We test the performance of the product developed in the study in KERI, KEPRI.

• 한국연소학회:학술대회논문집
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• 2004.06a
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• pp.248-255
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• 2004

For the compactness of regenerative combustion, self regenerative combustion and embedding regenerator inside furnace are proposed. The Self Regenerative burner system was developed to enhance thermal efficiency and Low Nox emission. In the twin regenerative system, two burner heads are generally used for preheating and exhausting combustion mode. But self regenerative burner system use only single nozzle body for regenerative combustion. Also two kind of regenerator, internal and external type, were designed to operate conveniently in both large and small furnace. According to test result, the self regenerative combustion system gives strong internal exhaust gas recirculation that reduce NOx emission significantly. NOx was measured as 50ppm(5% O2, 1290C furnace temperature). Also it is found that the fuel saving rate due to the self regenerative burner system reach to 30-40%. Thus it can be concluded that self regenerative mild combustion system appears to provide a reasonable regenerative burner for compactness and high performance as compared with conventional twin regenerative burner system. Also in the RT Application , compact twin regenerative burner was developed with the help of embedding regenerator inside furnace.

• Journal of the Korean Mathematical Society
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• v.31 no.3
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• pp.467-475
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• 1994

In 1983 Harmand and Lima [5] proved that if X is a Banach space for which K(X), the space of compact linear operators on X, is an M-ideal in L(X), the space of bounded linear operators on X, then it has the metric compact approximation property. A strong converse of the above result holds if X is a closed subspace of either $\elll_p(1 < p < \infty) or c_0 [2,15]$. In 1979 J. Johnson [7] actually proved that if X is a Banach space with the metric compact approximation property, then the annihilator K(X)^\bot$ of K(X) in $L(X)^*$ is the kernel of a norm-one projection in $L(X)^*$, which is the case if K(X) is an M-ideal in L(X).