• International conference on construction engineering and project management
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• 2013.01a
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• pp.300-303
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• 2013

On BIPV systems, especially roof-top PV systems, the power generation is easier to be reduced due to the shades of facilities nearby, or roof itself. To secure profitability of roof-top PV systems, the optimal design of solar arrays through the precise shading analysis is an important item of design considerations. In this paper, an optimization system for array design of roof-top PVs is to be developed using three-dimensional Geospatial Information System(GIS). The profitability of income and expense is considered through the shading analysis of entire roofs. By applying the system to project for validation, the adequacy and the improvement of NPV of the system were verified compared to expert's design. The system has significance by reason that PV modules are placed through rules established with expert knowledge and geometric rules were applied to reflect the constructability and maintainability.

• Korean Journal of Remote Sensing
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• v.38 no.3
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• pp.311-326
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• 2022

The Compact Advanced Satellite 500-4 (CAS500-4) is under development to efficiently manage and monitor forests in Korea and is scheduled to launch in 2025. The National Institute of Forest Science is developing 36 types of forestry applications to utilize the CAS500-4 efficiently. The products derived using the remote sensing method require validation with ground reference data, and the quality monitoring results for the products must be continuously reported. Due to it being the first time developing the national forestry satellite, there is no official calibration and validation site for forestry products in Korea. Accordingly, the author designed a calibration and validation site for the forestry products following international standards. In addition, to install calibration and validation sites nationwide, the authors selected appropriate sensors and evaluated the applicability of the sensors. As a result, the difference between the ground observation data and the Sentinel-2 image was observed to be within ±5%, confirming that the sensor could be used for nationwide expansion.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.9
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• pp.739-748
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• 2021

This paper discusses the prediction and validation of design loads of satellite components using modal mass acceleration curve (Modal MAC). To calculate the acceleration upper bound of the satellite components subjected to the launch environment by the Modal MAC, the parameters of SpaceX Falcon 9 launch vehicle were used, and the acceleration upper bound curve in the modal domain was derived. After that, the maximum acceleration loads applied to the satellite components were predicted by combining Modal MAC with the spacecraft interface loads of the satellite/launch vehicle and modal information of the satellite. In addition, the accuracy of the Modal MAC was validated through comparison with the results of the coupled loads analysis using a simple satellite and launch vehicle model.

• Korean Management Science Review
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• v.11 no.3
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• pp.87-102
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• 1994

Conceptual database design is an important activity because the performance of a DBMS heavily depends on the proper design of the database, and view integration is one of the most important phases of conceptual database design. During this phase, the individual views designed by separate user groups are integrated into a global view for the entire system. After the view integration, a database schema must be validated before it becomes a stable product of the design. In this paper, a methodology for view integration an validation is suggested. The individual views are modeled by entity-relationship model. The entities are integrated according to their name and domain information. After that, the relationships are merged by their constraints. We also present a methodology for checking redundant relationships which has an algorithmic description.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.5
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• pp.199-204
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• 2006

To develop a safety-critical network in nuclear power plants that puts more stringent requirements than the competitive commercial ones do, we establish four design criteria - deterministic communication, explicit separation/isolation structure, reliability, verification & validation. According to those design criteria, the fundamental design elements are chosen as follows - a star topology, point-to-point physical link, connection-oriented link control and fixed allocation access control. After analyzing the design elements, we also build a communication architecture with TDM (Time Division Multiplexing) bus switching scheme. Finally, We develop a DDCNet (Deterministic Data Communication Network) based on the established architecture. The DDCNet is composed of 64 nodes and guarantees the transmission bandwidth of 10Mbps and the delay of 10 msec for each node. It turns out that the DDCNet satisfies the aforementioned design criteria and can be adequately utilized for our purpose.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.335-338
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• 2006

A Numerical study of the cavitation within a centrifugal pump is carried out using CFD commercial code, FLUENT. The objective of this study is to predict the onset of cavitation within the pump blade and the degradation in the pressure rise due to the generation and transport of vapor. A pump designed for the study is a six bladed, one-circular arc impeller design suggested by A.J. Stepanoff et al. The Steady-state calculations are performed for a wide range of flow rate without the cavitation to investigate the pump performance. The design head and efficiency show a very good agreement with the numerical results at the design flow rate. After the validation with the numerical results, the pump performance and the onset of cavitation within the blade is predicted by changing NPSH at the design flow rate.

• CDE review
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• v.4 no.2
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• pp.30-35
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• 1998

Recently, many enterprises wish to preoccupy competitive positions in the market by motivating themselves towards CALS(Commerce At Light Speed) and try hard to achieve system implementation with the use of new concept-based backbone systems such as ERP(Enterprise Resource Planning) or PDM(Product Data Management). However, unfortunately there is an inevitable discrepancy during implementation period between package vendors and customers due to lack of clear methodology and misunderstanding about system. In some cases, consensus on partially verified system design invokes customers'continuous change demands and often it tends to result in unnecessary project delays. PDM application system implementation project of the company L has been studied here to solve these sorts of problems. The major yields of this work are achievement of a willing approval from customers and rapid system design under a time-limited and conceptually defined project scope and finally, through fully verified system design, we were able to reach successful system implementation.

• Journal of Digital Contents Society
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• v.13 no.3
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• pp.413-420
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• 2012

In this paper, PBL-based design education(PBDE) techniques for effective engineering design education to assess the infrastructure and outcome of creative engineering education which has been recognized as an important target in accreditation system of engineering education and a case of contents development as PBDE application to the logic circuit design that is essential integrant course of IT division of universities is presented. Because integrant design is based on compositional technologies with restricted realistic constraints, design components and the application of realistic constraints are different from those of capstone design. PBL technique must be carefully considered as it is used for creative design education. We applied the developed content to real design classes for validation of its performance and effectiveness.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.4
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• pp.445-452
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• 2004

Intermittent deep draw artificial circulation system is one of the most widely used destratification systems to control algal bloom in reservoirs in Korea. However, there have been neither theoretical background of design criteria nor operation guide line for efficient application of the system available for such systems. A design method was developed to calculate required compressor capacity and number of circulation units considering physical interactions between stratified water layers and plumes induced by the intermittent deep draw artificial circulation system. The program was tested with data observed in Yeoncho Lake. The results indicated that the developed method can applied in the fields successfully. Further validation processes would improve design and operation methods.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.83-85
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• 2008

This paper deals with design and dynamic analysis of electromagnets for levitation applications. On the basis of equivalent magnetic circuit (EMC) method and 3-D finite element analysis (FEA) model, initial and detailed design for electromagnets are performed. Using the state equation for the closed-loop control, the dynamic analysis of electromagnets is also performed. Finally, this paper investigates the variation of levitation force according to current under fixed nominal air-gap, and the variation of required current according to load weight in order to maintain the nominal air-gap. From these results, the validation of design and dynamic analysis of electromagnets is confirmed. In particular, the influence of winding temperature on levitation control is discussed in detail.