• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3472-3484
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• 2023

The objective of this research is to assess the seismic performance of different types of electrical cabinets in nuclear power plants. The cabinets under investigation are: (a) Case 1: a short single cabinet; (b) Case 2: a tall single cabinet; (c) Case 3: separated cabinets; and (d) Case 4: a combined cabinet with coupling effects. To accurately capture the real behavior of the cabinet, three-dimensional finite element models are developed using ANSYS with connection non-linearity. Frequency domain decomposition (FDD) is used to determine the dynamic properties of the cabinets from shaking table testing data, and these results are utilized to validate the numerical model. The close match between the experimental and numerical results obtained from the modal analysis demonstrates the accuracy of the numerical model. Subsequently, transient structural analysis is performed on the validated models to explore seismic performance. The results show that the acceleration response of the combined cabinet is lower than the single cabinet and the separated cabinet. This observation suggests that top anchors used to combine two different types of cabinets play a crucial role in assessing the efficiency and seismic resistance of electrical cabinets in a nuclear power plant.

• Journal of the Korean Geographical Society
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• v.43 no.2
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• pp.235-252
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• 2008

Many cartographers have for many years searched for a way to construct cartograms in which the sizes of geographic areas such as states, counties or census tracts are reseated in proportion to their population or some other socio-economic properties. While many techniques and algorithms for creating cartograms have been proposed, some of them are still extremely complex to generate in a proper manner, and many of them suffer either from this lack of readability or from seamless integration with GIS software. This paper, therefore, presents a simple population cartogam technique based on the Circular Cartogram Algorithm(CCA) by Dorling(1996) to tackle these drawbacks by drawing the areas as simple circles for use as a base map and linking the construction with GIS mapping processes. For an automated approach in the cartogram generation, this paper proposes a close coupling method of ArcView GIS 3.3. package in order for users to access to the cartopam algorithm. Then, they will be available through an interface that the ArcView GIS system allows user-written routines to be accessed easily. The CCA and its coupling architecture ensure to improve the potential applicability of the use of cartograms to census mapping at practical levels. As the cartogram examples, cartograms of population and property types in 2005 Korea census data sets are illustrated in the end, by which viewers can easily identify the residential concentration and their relative ratio in Seoul metropolitan area.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.9
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• pp.823-828
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• 2009

A small UHF RFID tag antenna for a key-chain installed inside of a metallic key-management cabinet has been designed. The tag antenna has been designed as small size as $66\;mm{\times}6\;mm$ with consideration of coupling among the tag antennas and metallic parts of key-chain and cabinet. The tag antenna is fabricated with a meander line dipole using T-matching method with FR-4 substrate. One tag antenna has been designed with consideration of coupling of adjacent tag antennas, and the other has been designed for the location close to the metallic part in the cabinet. The characteristics of tag antennas and reading distance have been analyzed based on the different numbers of adjacent tag antennas. As a results, the 360 tag antennas installed in the cabinet have been successfully recognized.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.1
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• pp.30-38
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• 2015

In this paper, the design of a compact triple-mode bandpass filter using a high-Q cylindrical dielectric resonator is proposed. In detail, the triple $TE_{01{\delta}}$ modes along three orthogonal axes are used and novel coupling structure in the metallic enclosure is adopted to introduce the coupling between the resonant modes. Due to the cross coupling, the proposed bandpass filter has an asymmetric frequency response with flexible three transmission zeros, one of which can be located very close to the passband edge to provide an extremely sharp skirt characteristic with low insertion loss. The proposed filter is about 60 % miniaturized compared with conventional single-mode dielectric resonator filter. The proposed bandpass filter design is validated by the circuit and 3D EM simulations and measurements compared to the target specifications.

• Journal of the Korea Convergence Society
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• v.8 no.7
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• pp.39-46
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• 2017

Dongguan City of Guangdong province, one of the core areas of the Pearl River Delta, has also pursued economic development through the geographical advantage close to Hong Kong. In the early 1980s, small and medium-sized multinational corporations related to home appliances industry from Hong Kong invested to the Dongguan area and set up a production factory. In the mid-1990s, as Taiwanese PC manufacturers invested, local industrial clusters have developed in Dongguan with core of the IT, PC components and electronic industries. The case of the IT industrial cluster in Dongguan is a typical example of the development of Chinese manufacturing industry after the reform of China. This paper focused on the coupling strategy case of Dongguan City industrial cluster in Guangdong province, and theoretically compared the endogenous growth factor analysis(NMID) of regional industrial development with the regional differentiation of industry based on external linkage with global production network(GPN).

• Geomechanics and Engineering
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• v.28 no.6
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• pp.613-624
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• 2022

A study of the evolution of overburden fractures under the solid-fluid coupling state was conducted based on the geological and mining characteristics of the coal seam depth, weak strata cementation, and high-intensity mining in the mining areas of West China. These mining characteristics are key to achieving water conservation during mining or establishing groundwater reservoirs in coal mines. Based on the engineering background of the Daliuta Coal Mine, a non-hydrophilic simulation material suitable for simulating the weakly cemented rock masses in this area was developed, and a physical simulation test was carried out using a water-sand gushing test system. The study explored the spatial distribution and dynamic evolution of the fractured zone in the mining overburden under the coupling of stress and seepage. The experimental results show that the mining overburden can be vertically divided into the overall migration zone, the fracture extension zone and the collapse zone; additionally, in the horizontal direction, the mining overburden can be divided into the primary fracture zone, periodic fracture zone, and stop-fracture zone. The scope of groundwater flow in the overburden gradually expands with the mining of coal seams. When a stable water inrush channel is formed, other areas no longer generate new channels, and the unstable water inrush channels gradually close. Finally, the primary fracture area becomes the main water inrush channel for coal mines. The numerical simulation results indicate that the overlying rock breaking above the middle of the mined-out area allows the formation of the water-conducting channel. The water body will flow into the fracture extension zone with the shortest path, resulting in the occurrence of water bursting accidents in the mining face. The experimental research results provide a theoretical basis for the implementation of water conservation mining or the establishment of groundwater reservoirs in western mining areas, and this theoretical basis has considerable application and promotion value.

• Wind and Structures
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• v.18 no.4
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• pp.443-456
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• 2014

A popular modern architectural form for tall buildings is two (or more) towers which are structurally linked through such features as a shared podium or sky-bridges. The fundamental features of the wind loading and the structural links of such buildings can be studied by measuring load components on the individual unlinked towers along with their correlations. This paper describes application of dual high frequency force balance (DHFFB) in a wind tunnel study of the base wind loading exerted on generic tall twin buildings in close proximity. Light models of two identical generic tall buildings of square plan were mounted on DHFFB and the base wind loading exerted on the buildings was simultaneously acquired. The effects of the relative positions of the buildings on the correlations and coherences involving loading components on each building and on the two buildings were investigated. For some relative positions, the effects of the building proximity on the wind loading were significant and the loading was markedly different from that exerted on single buildings. In addition, the correlations between the loadings on the two buildings were high. These effects have potential to significantly impact, for example, the modally-coupled resonant responses of the buildings to the aerodynamic excitations. The presented results were not meant to be recommended for direct application in wind resistant design of tall twin buildings. They were intended to show that wind loading on tall buildings in close proximity is significantly different from that on single buildings and that it can be conveniently mapped using DHFFB.

• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.37-37
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• 2003

Electron whistlers frequently excite proton whistlers. The proton whistlers appear on the dynamic spectrum as rising tones, which start after the reception of a short electron whistler, asymptotically approaching the local proton gyro-frequency. The proton whistlers are dispersed forms of lightning impulses and their dispersion can be explained by the effects of heavy ions such as H+ and He+ on the propagation of an electromagnetic wave in the ionosphere. In the ionosphere, a right-handed circularly-polarized electron whistler becomes coupled to a left-handed circularly-polarized proton whistler when the frequency becomes close to a cross-over frequency. By adopting the multi-fluid numerical wave model, we examine how the mode coupling varies as the ion composition changes along altitude in the mid-latitude ionosphere. The time histories and dynamic spectra of electric fields are presented. In addition, we compare our results with the previous theoretical and observational studies.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.34-39
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• 1993

Presented in this paper is a complete error covariance analysis for strapdown inertial navigation system(SDINS). We have found that in SDINS the cross-coupling terms in gyrocompass alignment errors can significantly influence the SDINS error propagation. Initial heading error has a close correlation with the east component of gyro bias erro, while initial level tilt errors are closely related to accelerometer bias errors. In addition, pseudo-state variables are introduced in covariance analysis for SDINS utilizing the characteristics of gyrocompass alignment errors. This approach simplifies the covariance analysis because it makes the initial error covariance matrix to a diagonal form. Thus a real implementation becomes easier. The approach is conformed by comparing the results for a simplified case with the covariance analysis obtained from the conventional SDINS error model.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1376-1378
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• 1999

Most conventional protection relays are based on processing information in the spectrum that is close to or at power frequency. It is, however, widely known that faults on transmission lines produce frequency components of a wide range In this respect, this paper describes the basis of a Protection technique for transmission lines which utilises high-frequency components. Fault-generated signals caused by post-fault and the signal derived from stack tuner is connected to the coupling capacitor of CVT. Digital signal processing is then applied to the captured information to determine whether the fault is inside or outside the Protected zone, and to discriminate the fault type on transmission line.