• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.4
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• pp.517-525
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• 1996

A Simple AC complex circuit analysis for LCL type series resonant converter with phase shift control is proposed. Based on these analyses, a set of characteristic curves which allows a optimal design procedure for this converter is shown, without increasing the volt-ampere rating of tank circuit Especially, inverter output peak current can be minimized in both full load and partial load conditions. The presented design considerations can make the load range wide from full loads to light loads achieving turn-on with zero voltage switching (ZVS) operation. The detailed analysis and experimental results show the effectiveness of the proposed design algorithms. (author). refs., figs., tab.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.94-96
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• 2009

This paper deals with the design considerations of electro-magnet (EM)-permanent magnet (PM) hybrid levitation and propulsion device for magnetically levitated (maglev) vehicles. Several design considerations such as machine structure, manufacturing, and control strategy are described. In order to verify the design scheme and feasibility of control strategy, dynamic test set is implemented and tested.

• Journal of the Korean Society of Combustion
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• v.18 no.2
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• pp.23-31
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• 2013

Compact steam boiler is a useful heat exchanger in a space-intensive system. There are some constraints in terms of sizing and designing the space confined in the system which is usually used in vessels. In this study, design considerations for heavy duty heat exchangers of compact steam boilers are presented and evaluated. Especially, evaporator tubes of marine boiler which are exposed to a high temperature environment are considered. Also, extended surface designs with a high temperature are examined. In order to determine the criteria with considerations of both heat transfer rate and pressure drop in the heat exchanger, they are evaluated with major variables, such as the tube diameter, the number of tubes, and the tube length. Finally, the design parameters are estimated as the bare tubes are installed instead of the finned tubes.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.791-798
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• 2001

As the form factor of the disk drive is decreased, many mechanical issues that are negligible in larger form factors, should be considered for the design of the miniature drives. This paper deals with basic research on vibration characteristics and design considerations of small disks and actuators. The natural frequencies of micro-sized disks with polycabonate and glass substrates are experimentally measured, being compared to FEM results. In order to investigate the effects of rotating speeds, airflow and disk size on power consumption. we measure power imposed to spindle motor when different optical disks are spins in vacuum chamber. Finally, The vibration characteristics of the micro actuator used in a IBM Microdrive are experimentally studied for the application to the basic design of micro optical disks.

• Journal of the Korean Society of Industry Convergence
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• v.15 no.4
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• pp.117-124
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• 2012

Recent years, many industries acknowledge that environmental substantiality of products must be an essential role and it is one of the major importances for industries to consider the environmental impacts of products at the early stages of product development. This study investigated eco-design parameters and $CO_2-eq$. emissions in each stage of raw material acquisition, manufacturing, transportation, use and disuse in life cycle of touch monitor stand based on Eco-Design. In this study, to fulfill of Eco-Design, the environmental impact assessment of through LCA(Life cycle assessment) was carried out with benchmarking monitor stand and we suggested the direction of new design of touch monitor stand mechanism based on eco-friendly considerations. New design based on LCT(Life Cycle Thinking) showed that the following eco-friendly considerations at the early stage of design to be helpful to reduce GWP(Global Warming Potential) [kg $CO_2-eq$.] in new monitor stand development and it is necessary for Eco-Design process of the product.

• Earthquakes and Structures
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• v.1 no.4
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• pp.391-410
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• 2010

There are several important considerations that need to be made in the capacity design of RC frame-wall structures. Capacity design forces will be affected by material overstrength, higher mode effects and secondary loadpaths associated with the 3-dimensional structural response. In this paper, the main issues are identified and different means of predicting capacity design forces are reviewed. In order to ensure that RC frame-wall structures perform well it is explained that the prediction of the peak shears and moments that develop in the walls is particularly important and unfortunately very challenging. Through examination of a number of case study structures it is shown that there are a number of serious limitations with capacity design procedures included in current codes. The basis and potential of alternative capacity design procedures available in the literature is reviewed, and a new simplified capacity design possibility is proposed. Comparison with the results of 200 NLTH analyses of frame-wall structures ranging from 4 to 20 storeys suggest that the new method is able to predict wall base shears and mid-height wall moments reliably. However, efforts are also made to highlight the uncertainty with capacity design procedures and emphasise the need for future research on the subject.

• International Journal of Fluid Machinery and Systems
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• v.10 no.1
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• pp.1-8
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• 2017

Bifurcation refers to wye division of penstock to divide the flow symmetrically or unsymmetrically into two units of turbine for maintaining economical, technical and geological substrates. Particularly, water shows irrelevant behavior when there is a sudden change in flow direction, which results into the transition of the static and dynamic behavior of the flow. Hence, special care and design considerations are required both hydraulically and structurally. The transition induced losses and extra stresses are major features to be examined. The research on design and analysis of bifurcation is one of the oldest topics related to R&D of hydro-mechanical components for hydropower plants. As far as the earlier approaches are concerned, the hydraulic designs were performed based on graphical data sheet, head loss considerations and the mechanical analysis through simplified beam approach. In this paper, the multi prospect approach for design of Bifurcation, incorporating the modern day's tools and technology is identified. The hydraulic design of bifurcation is a major function of dynamic characteristics of the flow, which is performed with CFD analysis for minimum losses and better hydraulic performances. Additionally, for the mechanical design, a simplified conventional design method as pre-estimation and Finite Element Method for a relevant result projections were used.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.2
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• pp.161-177
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• 2017

This paper presents the design considerations and field applications on inflatable structure system to protect rapidly flooding damages in large section tunnel. This inflatable structure system is very valuably used to protect passively and rapidly the possibilities of tunnel damages by flooding threats and unusual leakage to be occurred during and after underground infrastructure. In particular, this system should be necessary in subsea tunnel. The predominant factors in the design of inflatable structure system are the leakage and friction characteristics between the inflater and tunnel liner. The analytical and experimental studies are performed to develop the design considerations and to examine the design parameters of the inflatable structure system. The analytical solutions are developed using membrane theory to suggest the design considerations. The relative friction tests of several fabric materials are also carried out to determine the friction characteristics according to the different friction conditions between inflater and tunnel surface. The test results show that the friction coefficients in wet surface condition are about 20% lower than the values in dry surface condition. In addition, virtual design of tunnel protection system for two virtual subsea tunnel sites which is under reviewing in Korea, is carried out based on this research. It is expected that the results of this research will be very useful to understand the inflater structure design and development the technology of tunnel protection structures in the future.

• Journal of the Korean Society of Combustion
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• v.17 no.3
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• pp.30-45
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• 2012

An existing unit of power plant is considered to refurbish it for possible application of carbon capture and storage(CCS). Conceptual design of the plant includes basic considerations on the national and international situation of energy use, environmental concerns, required budget, and time schedule as well as the engineering concept of the plant. While major equipment of the recently upgraded power plant is going to be reused, a new boiler for air-oxy fired dual mode operation is to be designed. Cryogenic air separation unit is considered for optimized capacity, and combustion system accommodates flue gas recirculation with multiple cleaning and humidity removal units. The flue gas is purified for carbon dioxide separation and treatment. This paper presents the background of the project, participants, and industrial background. Proposed concept of the plant operation is discussed for the possible considerations on the engineering designs.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.9-14
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• 2005

The Burj Dubai Project will be the tallest structure ever built by man; when completed the tower will be more than 700 meter tall and more than 160 floors. The early integration of aerodynamic shaping and wind engineering considerations played a major role in the architectural massing and design of this residential tower, where mitigating and taming the dynamic wind effects was one of the most important design criteria. This paper presents a brief overview of the structural system development and considerations of the tower and discusses the construction planning of the key structural components of the tower.