• KIEAE Journal
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• v.13 no.1
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• pp.47-55
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• 2013

This study aims to evaluate the correlation between vertical solar radiation and the level of heating load according to the location and type of housing in multi-family apartments. This study shows that heating load is related with factors such as wall loss, window loss, ventilation loss and solar radiation gain. The heating load increases in the order of the middle floors, the highest floors and the lowest floors. The lowest and the highest floors are the most vulnerable floors, and it should be as emphasized as the middle floors. The heating load saving proposal contains 52 Alt. that shows heating load savings from min. 4% to max. 49%. The goal is to reduce the heating load of the highest and the lowest floors to the level of the middle floors. The result showed that there are 3 Alt. for the lowest floors and 16 Alt. for the highest floors as the heating load saving proposal. This study suggests integrated application to compose saving elements of heating load. so it could be utilized as a data for the construction of passive houses.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.9
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• pp.1186-1191
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• 2014

Weekly and monthly electric load forecasting are essential for the generator maintenance plan and the systematic operation of the electric power reserve. This paper proposes the weekly maximum electric load forecasting model for 104 weeks with the multiple regression model. Input variables of the multiple regression model are temperatures and GDP that are highly correlated with electric loads. The weekly variable is added as input variable to improve the accuracy of electric load forecasting. Test results show that the proposed algorithm improves the accuracy of electric load forecasting over the seasonal autoregressive integrated moving average model. We expect that the proposed algorithm can contribute to the systematic operation of the power system by improving the accuracy of the electric load forecasting.

• Journal of Aerospace System Engineering
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• v.13 no.5
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• pp.57-64
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• 2019

Recently, avionics systems are being developed as integrated modular architecture applying the modular integration design of the functional unit to reduce maintenance costs and increase operating performance. Additionally, a partitioning operating system based on virtualization technology was used to process various mission control functions. In virtualization technology, the CPU processing load distribution is a key consideration. Especially, the uncertainty of the I/O processing time is a risk factor in the design of reliable avionics systems. In this paper, we examine the influence of the I/O processing method by comparing and analyzing the CPU processing load by the I/O processing method through use of case analysis and applying it to the example of spatial-temporal partitioning.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.55-62
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• 2005

In this paper, a CAB/CAE integrated optimal design system is developed, in which design and analysis process is automated using CAD/CAE softwares, for a complicated model for which parametric modeling provided by CAD software is not possible. CAD modeling process is automated by using UG/OPEN API function and UG/Knowledge Fusion provided by Unigraphics. The generated model is transferred to the analysis code ANSYS in parasolid format. Visual DOC software is used for optimization. The system is developed for PLS(Plasma Lighting System), which is a next generation illumination system that is used to illuminate stadium or outdoor advertizing panel. The PLS system consists of more then 20 components, which requires a lot of human efforts in modeling and analysis. The analysis for PLS includes static load, wind load and impact load analysis. As a result of analysis, it is found that the most critical component is a tilt assembly, which links lower & upper body assembly. For more reliable analysis, experiment is conducted using MTS and compared with the Finite element analysis result. The objective in the optimization is to minimize the material volume under allowable stresses. The design variables are three parameters in the tilt assembly that are chosen to be the most sensitive in stress values of twelve parameters. Gradient based method and RSM(Response Surface Method) are used for the algorithm and the results are compared. As a result of optimization, the maximum stress is reduced by 57%.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.6
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• pp.796-801
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• 2011

The objective of this work presented here was focused on analysis of development trend for the integrated power system of naval vessels to perform the high-power and energy mission load platform. These mission loads are affected by the high level of military technologies, digitalization of the ocean battlefield, high power sensor system for maximization of the ship survivability. All electric power including propulsion power for ship should be controlled by integrated single system in order to carry various high power density weapon system such as Electromagnetic Aircraft Launch System, Electromagnetic Rail Gun[feasible precision striking at long distance 200NM(370km) or over]. As the analyzing the present state of things, mechanical propulsion system is shifted into hybrid or fully electric propulsion systems to realize integrated power system at the developed countries. Such challenges include reduced dependency on foreign-supplied fossil fuel, increasing demand for installed ship power, controlling life-cycle costs.

• Journal of Drive and Control
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• v.19 no.4
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• pp.29-35
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• 2022

In this paper, we developed a workload index for monitoring the durability test using operation information of an excavator. First, the acceleration and cylinder pressure were selected as load factors by analyzing operation data. Through load correlation analysis according to each load factor, Root Mean Square (RMS) and Work Load Range (WLR) were respectively derived as a load feature representing mechanical load. In addition, the workload index was used to quantify load features. For applying the workload index to monitoring, a real-time monitoring system consisting of sensors and embedded controller was installed on the excavator and the system was integrated with a remote monitoring environment using a wireless network. Results of load monitoring and analysis verified that the developed workload index was effective from the viewpoint of the relative comparison of the workload.

• Composites Research
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• v.32 no.5
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• pp.216-221
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• 2019

Piecewise integrated composite (PIC) beam has different stacking sequences for several regions with respect to their superior load-resisting capabilities. On the interest of current research is to improve bending characteristics of PIC beam, with assigning specific stacking sequence to a specific region with the help of machine learning techniques. 240 elements of from the FE model were chosen to be reference points. Preliminary FE analysis revealed triaxialities at those regularly distributed reference points to obtain learning data creation of machine learning. Triaxiality values catagorise the type of loading i.e. tension, compression or shear. Machine learning model was formulated by learning data as well as hyperparameters and proper load fidelity was suggested by tuned values of hyperparameters, however, comparatively higher nonlinearity intensive region, such as side face of the beam showed poor load fidelity. Therefore, irregular distribution of reference points, i.e., dense reference points were distributed in the severe changes of loading, on the contrary, coarse distribution for rare changes of loading, was prepared for machine learning model. FE model with irregularly distributed reference points showed better load fidelity compared to the results from the model with regular distribution of reference points.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.712-718
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• 2005

In this study, a translator for transferring structural analysis data among commercial structural analysis programs was developed. The translator adopted the neutral format type based on ISO standard STEP AP 209 not only for the international standardization and robustness but also for the efficient management of structural analysis data Additional load entity is developed and added to AP 209 for the prevention of loss of information in retrieving exact loading condition. A modulization which is needed for efficient management and extension of the translator was made for the encapsulation of file format of each commercial code. Pilot tests peformed with 3-D frame analysis data of Sung-su bridge show that the developed translator guarantees the integrated management of analysis information as well as the exact transferring and retrieving of analysis data and related information.

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.326-329
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• 2001

The main purpose of HITES(Highly Integrated Total Energy System) is to build and develop an integrated energy system for power system operational planning and analysis which consists of load forecast, economic generation schedule, stability analysis and relational database system. The HITES can be utilized to supply a stable electric power and operate KEPCO's power system facilities economically. This system was put into operation in 1999. This paper describes the present condition for operation of HITES and proposes the plan to improve this system after installation.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1042-1045
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• 1998

The main purpose of HITES(Highly Integrate Total Energy System) is to build and develop an integrated energy system for power system operational planning and analysis which consists of load forecast, economic generation schedule, stability analysis and relational database system. The integrated energy system can be utilized to supply a stable electric power and operate KEPCO power system facilities economically. This system will be put into operation in 1999. This paper describes the main feature of the HITES, system main functions, numerical methods adopted this system, and network configuration.