• Steel and Composite Structures
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• v.37 no.3
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• pp.273-289
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• 2020

Due to the unique construction method of modular steel buildings (MSBs) with units prefabricated fully off the site and assembled quickly on the site, the inter-module connection for easy operation and overall performance of the system were key issues. However, it was a lack of relevant research on the system-level performance of MSBs. This study investigated the seismic performance of two-storey modular steel structure with a proposed vertical rotary inter-module connection. Three full-scale quasi-static tests, with and without corrugated steel plate and its combination, were carried out to evaluate and compare their seismic behaviour. The hysteretic performance, skeleton curves, ductile performance, stiffness degradation, energy dissipation capacity, and deformation pattern were clarified. The results showed that good ductility and plastic deformation ability of such modular steel structures. Two lateral-force resistance mechanisms with different layout combinations were also discussed in detail. The corrugated steel plate could significantly improve the lateral stiffness and bearing capacity of the modular steel structure. The cooperative working mechanism of modules and inter-module connections was further analyzed. When the lateral stiffness of upper and lower modular structures was close, limited bending moment transfer may be considered for the inter-module connection. While a large lateral stiffness difference existed initially between the upper and lower structures, an obvious gap occurred at the inter-module connection, and this gap may significantly influence the bending moments transferred by the inter-module connections. Meanwhile, several design recommendations of inter-module connections were also given for the application of MSBs.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.87-92
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• 2011

The heat from PV modules should be removed for better electrical performance, and can be converted into useful thermal energy. A photovoltaic-thermal(PVT)module is a combination of PV module with a solar thermal collector which forms one device that converts solar radiation into electricity and heat simultaneously. The performance of the PV/Thermal combined collector module is directly influenced by solar radiation that also has an effect on PV module temperature. It is also has believe that the energy performance of PV/T collector is related to absorber design as well as PV module temperature. The existing study has been paid to the PV/Thermal combined collector module with circle tube absorbers. The aim of this study is to analyze the experimental performance of the PV/Thermal combined collector rectangular tube absorbers according to solar radiation. The experimental result show that the average thermal and electrical efficiencies of the PVT collector were 43% and14.81% respectively. Solar radiation is one of the most influential factors to determine the energy performance of PVT collector, but from a certain level of solar radiation the PVT collector receives on, its efficiencies began to decrease.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.785-791
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• 2005

Reconfigurability of machine tools is one of the critical factors to realize the responsive manufacturing systems to satisfy the mass-customization production. This paper presents the methods to model and simulate the machine tools on Internet in response to change in the machining requirements. Specifically, a set of module combination rules and a modeling method of the structure of machine tools using connectivity graph are developed. In response to the user requirements, kinematic relations and structures of machine tools can be derived using the module combination rules and connectivity graph relationships. Internet-based simulator of machine tools is implemented and presented. The developed machine tool simulator can be used to verify the structure of machine tools derived from the user requirements.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.2
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• pp.68-74
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• 2004

This paper presents a novel hybrid multilevel inverter using DC-Link voltage combination in order to improve the waveshape of output voltage and reduce harmonics. The proposed multilevel inverter can generate an 11-level output voltage. It employs three H-bridge cell, which consists of single phase full-bridge inverter module. Among them, two modules are used for level generation, and one module performs PWM switching. Nine levels are synthesised by the level inverter, and two levels are added to output by the PWM inverter. As a result, it generates an 11-level. The operational principles are explained in depth, and the validity of the proposed system is verified through the PSpice simulation and experimental results based on a prototype.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.331-335
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• 2012

Many researches have been performed the analysis and experiments on auto-focus lens due to the development of camera module which is used in mobile-phone recently. Various types of voice coil motor are used mostly in the view point of actuators. Various type of magnetic flux flow is made by the combination of magnet, coil and yoke, etc. And the function of auto-focus is made by the proper combination of the lens components. In this research, some of the simple and economic structure is chosen to investigate the characteristics analytically among various types of lens which are used in industries. Desired level of lens module design was achieved by electromagnetic analysis using ANSYS$^{TM}$ finite element analysis program.

• Journal of IKEEE
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• v.23 no.4
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• pp.1208-1217
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• 2019

The life-cycle prediction of the sub-module which is the unit system of MMC is very important from the viewpoint of maintenance and economic feasibility of HVDC system. However, the life-cycle prediction that considers only the type, number and combination of parts is a generalized result that does not take into account the operating condition of the sub-module, and may significantly differ from the life-cycle of the actual one. Therefore, we design a fault tree for the purpose of reflecting the operation characteristics of the full-bridge sub-module and apply the MIL-HDBK-217F to the failure rate of the basic event to predict the life-cycle of the full-bridge sub-module. It compares the life-cycle expectancy of the conventional failure rate analysis with the proposed fault-tree analysis and compares the lifetime according to whether the redundancy of the full-bridge sub-module is considered.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.6
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• pp.343-349
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• 2014

It is summarized that potential causes of performance degradations and failure mechanisms of crystalline silicon photovoltaic (PV) modules installed in Middle East area. In addition, we also reviewed current PV module qualification test (IEC 61215) and the methods for detection of wear-out fault. The failure of PV modules in the extreme environmental conditions such as deserts is mainly due to high temperature, humidity, and dust storms. In particular, cementation phenomenon caused by combination of sand and moisture leads to rapid degradation in the performance of PV modules. In order to evaluate and guarantee the long term reliability of PV modules, specific qualification tests such as sand dust test, salt mist test and potential induce degradation test considering operating environment of PV module should be carried out.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.3
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• pp.105-112
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• 2008

Solar energy, which is one of renewable energy, would be the most useful resources that can be applied to making energy recycling villages without using fossil energy. This study analyzed energy potential on solar energy considering weather condition in three traditional villages and compared with energy consumption surveyed. A photovoltaic system having 3.0kWp capacity of unit module can generate 182.5%, 96.1% and 170.9% of the yearly mean consumption of electric power in Makhyun, Boojang, and Soso, respectively. A flat-plate solar collector having $2.64m^2$ area of unit module can generate warm water of $142{\ell}$/day, $89{\ell}$/day, and $173{\ell}$/day, respectively in three study villages. In Makhyun and Soso, photovoltaic power and warm water produced by solar energy were sufficient to supply required amount of electric power and warm water. However, both electric power and warm water produced by unit solar module were not sufficient in Boojang area, and so it is required to increase the module area by more than 50%. According to the results of this study, the appropriate combination of energy resources can be applied to rural green-village planning if the characteristic of energy potential for each local area is considered.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.9
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• pp.621-628
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• 2013

This paper presents a framework for context-aware smart phone applications based on Android. The mobile context-aware system is composed of a low level context collection module, a high level context generation module and a service provision module. Existing android system cannot provide an appropriate application framework to integrate these independent modules. In this paper, we provide an application framework which make each module a component, and provide appropriate services to each component. This framework hides the Android platform, so that the complexity for organical combination can be minimized and the application developers can make the mobile context-aware applications easily.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.882-883
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• 2013

With the development of the society, pure electric vehicles will be surely important of the future. Electric vehicle requires various technology like motor driving, battery management, operational efficiencies and so on. Battery management is indeed the most important to enhance battery's performance and life. This paper has deeply discussed and studied on the lithium-polymer battery management system of pure electric vehicle. First of all we have analyzed the characteristic of the lithium-polymer batteries and the factors influenced on the state of charge. Then a logical SOC measuring method has been raised, which is the combination of open circuit voltage and Ah integration. The next we will introduce the design of battery management system, the battery management system performs many functions, such as inspecting the whole process, when it's running cell equalization protecting and diagnosing the battery, estimating the state of charge. The module design style including microcontroller, data aquisition module, charging control module and serial communication module. To arrive at conclusions, the battery management system which this paper has introduced is reliable and economical.