• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.6
• /
• pp.2529-2539
• /
• 2013

The Korean construction industry has led the miraculous economic boost of Korea by providing solid domestic infrastructures such as highway, roads, and airports. It also played a critical role in global construction market and eaned more than 500 billions dollars in terms of their accumulated international orders. However, domestic construction market has significantly decreased in recent years due to the domestic political environments and global economic crisis. Therefore, the importance of international construction market cannot be more emphasized to the Korean construction market in order for the sustainable growth. There has been, however, little research in the area of identifying required competency elements for the Korean construction industry to stay successful in the global market. The main purpose of this study is to identify elements of core competency to increase global competitiveness for Korean construction industry. Core global construction competency elements were derived from the internal and external environmental analyses along with the extensive literature review, expert interviews and a survey. This study utilized the Importance-Performance Analysis (IPA) and a gap analysis in providing insights on the status competitiveness of the Korean construction industry in terms of required global core competency elements. The analysis shows that project management and financial management are the main areas for improvements required to engineering contractors while construction contractors need to take a more balanced approach among technical, project management, and financial management in order to increase their global competencies.

• Journal of applied mathematics & informatics
• /
• v.25 no.1_2
• /
• pp.315-327
• /
• 2007

Mathematical aspects of the electromagnetic surface-wave propagation are examined for the dielectric core consisting of multiple sub-layers, which are embedded in the gap between the two bounding cladding metals. For this purpose, the linear problem with a partial differential wave equation is formulated into a nonlinear eigenvalue problem. The resulting eigenvalue is found to exist only for a certain combination of the material densities and the number of the multiple sub-layers. The implications of several limiting cases are discussed in terms of electromagnetic characteristics.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.48 no.2
• /
• pp.56-62
• /
• 1999

This paper is concerned with the design and the construction of a moving magnet type linear DC motor(MM type LDM) for instrumentation. A mathematical model for the design of a LDM is developed and a permeance method is used to calculate the effective flux density in the air gap. The flux distribution in the air gap is analyzed and the width of iron core should be determined in order not to saturate the iron core by caluclating maxmum flux density. The design data culculated by a permeance method are compared with the analyzed results using FEM(MAXWELL 2D). The errors between two results are corrected. The tested LDM is constructed using the corrected design data. The results of experiment for thrust characteristics are compared with simulation.

• Transactions of The Korea Fluid Power Systems Society
• /
• v.7 no.4
• /
• pp.44-49
• /
• 2010

This paper represents solenoid design of control valve for incline angle control in variable compressor. Some theoretical and numerical analysis were performed to analyse solenoid and compared with experimental results. Maxwell program was used for numerical analysis. Through redesigns of housing body, plunger, core, and disk in control valve, the needed force was gotten. Reduction of core groove and housing body air-gap had a large influence on magnetic force. But increasing of disk thickness had little effect on magnetic force. Control valve efficiency could be improved through solenoid redesign.

• Nuclear Engineering and Technology
• /
• v.33 no.3
• /
• pp.298-306
• /
• 2001

As fuel burnup proceeds, thermal gradients, differential swelling, and inter-assembly loading may induce assembly duct bowing. Since duct bowing affects the reactivity, such as long or short term power-reactivity-decrement variations, handling problem, caused by top end deflection of the bowed assembly duct, and the integrity of the assembly duct itself. Assembly duct bowing were first observed at EBR-ll in 1965, and then several designs of assembly ducts and core restraint system were used to accommodate this problem. In this study, NUBOW-2D KMOD was used to analyze the bowing behavior of the assembly duct under the KALIMER(Korea Advanced Liquid MEtal Reactor) core restraint system conditions. The mechanical behavior of assembly ducts related to several design parameters are evaluated. ACLP(Above Core Load Pad) positions, the gap distance between the ducts, and the gap distance between the duct and restraint ring were selected as the sensitivity parameter for the evaluation of duct deflection.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.52 no.7
• /
• pp.320-326
• /
• 2003

Slotless Permanent Magnet Linear Synchronous Motor (PMLSM) has good control ability but thrust density is low. So, this paper proposes inserted core type of slotless PMLSM to improve its thrust density. Inserting the core between windings of each phase, detent force is generated by the difference of magnetic resistance in an air gap. To minimize detent force, this paper applies the neural network to inserted core type of slotless PMLSM. The, Magnetic pole ratio, the width of the inserted core and the width of the coil are selected as a design parameter to minimize detent force. In comparison with inserted core type one, thrust ripple greatly decreases by minimizing detent force and also thrust increases in this optimal model.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.2
• /
• pp.77-81
• /
• 2009

Air-gap was introduced to suppress the saturation of the iron core comprising the flux-lock type superconducting fault current limiter (SFCL) with parallel connection of two coils. However, the air-gap makes the impedance of this SFCL decreased and can result in unusefulness of the SFCL. To analyze the current limiting characteristics of the SFCL with the air-gap, the experimental circuit for short-circuit test was constructed. Through the comparison with the current limiting characteristics of the SFCL without air-gap, the merit and the demerit of the flux-lock type SFCL with the air-gap were discussed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1995.03a
• /
• pp.111-117
• /
• 1995

• Advances in Energy Research
• /
• v.5 no.2
• /
• pp.91-105
• /
• 2017

Thermal hydraulic (TH) analysis of nuclear power reactors is utmost important. In this way, the numerical codes that preparing TH data in reactor core are essential. In this paper, a subchannel analysis of a Russian pressurized water reactor (WWER1000) core with enhanced numerical code is carried out. For this, in fluid domain, the mass, axial and lateral momentum and energy conservation equations for desired control volume are solved, numerically. In the solid domain, the cylindrical heat transfer equation for calculation of radial temperature profile in fuel, gap and clad with finite difference and finite element solvers are considered. The dependence of material properties to fuel burnup with Calza-Bini fuel-gap model is implemented. This model is coupled with Isotope Generation and Depletion Code (ORIGEN2.1). The possibility of central hole consideration in fuel pellet is another advantage of this work. In addition, subchannel to subchannel and subchannel to rod connection data in hexagonal fuel assembly geometry could be prepared, automatically. For a demonstration of code capability, the steady state TH analysis of a the WWER1000 core is compromised with Thermal-hydraulic analysis code (COBRA-EN). By thermal hydraulic parameters averaging Fuel Assembly-to-Fuel Assembly method, the one sixth (symmetry) of the Boushehr Nuclear Power Plant (BNPP) core with regular subchannels are modeled. Comparison between the results of the work and COBRA-EN demonstrates some advantages of the presented code. Using the code the thermal modeling of the fuel rods with considering the fission gas generation would be possible. In addition, this code is compatible with neutronic codes for coupling. This method is faster and more accurate for symmetrical simulation of the core with acceptable results.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.10b
• /
• pp.322-324
• /
• 2004

PLE 방법론은 단일 제품이 아니라 유사한 제품들간의 공통성(Commonality)과 가변성(Variability)을 개발하고 관리하며 소프트웨어 개발 전체 생명주기에 걸쳐 부품을 조립하는 형태로 만들어진다. 또한 PLE 방법론은 재사용 단위가 가장 큰 방법론이기 때문에 최근에는 소프트웨어 업계에서 주목을 많이 받고 있다. 따라서 소프트웨어 재사용 분야가 점점 다양화되면서 어플리케이션의 특성에 적합한 프로세스에 대한 요구가 늘어나고 있다. 어플리케이션 과정은 요구사항 정의에 따라서 설계가 되어야 하고 이렇게 설계가 된 요구사항 정의와 핵심자산의 Gap 분석을 통해 정제된 설계를 얻을 수 있다. 하지만, 현재는 체계적인 절차와 기법에 대한 연구가 많이 미흡한 상태이다. 이렇게 체계적인 절차와 기법이 있다면 어플리케이션을 개발하는데 있어 보다 효율적이고, 보다 완성도 높은 어플리케이션이 개발 될 것이라고 기대한다. 따라서 본 논문에서는 제품계열공학의 핵심자산과 어플리케이션간의 Gap 분석 절차를 제안하고자 한다.