• International conference on construction engineering and project management
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• 2009.05a
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• pp.1081-1087
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• 2009

An automatic construction system in Korea is now at the stage of the full automation like in Japan, and an actual pilot project is going to be built in 2009. However, in developing a new construction system that has never been implemented before, there is a need to assess the performance and to consider the uncertainty of the system. The program evaluation and review technique (PERT) allows dealing with this uncertainty. Thus, this paper implements an analysis of the process of steel fabrication and makes suggestions for time-related problems arising from the analysis. The time required for steel erection by the automatic system was compared with that in the traditional method. In the result, finding out another construction process and improving robot performance were proposed to resolve the problems. The results will contribute to promoting the development of an efficient system for the new automatic construction system.

• Journal of the Korean Solar Energy Society
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• v.26 no.3
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• pp.111-117
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• 2006

Song-do City is a newly constructed city built on land reclaimed from the seaside and the surrounding area. Its development involved a long process since the basic plans for reclamation of the publicly owned seaside area in Song-do were drawn up in September 1979. However, if we take a look at the overall status of the project as it is carried on at present, it is hard to deny that the project is trapped inside the same legal restrictions as are all other existing cities, which permits Song-do City to meet only very minimum standards. This study intends to analyze and assess the Song-do City's environmentally friendly construction and to rate its current development status, exposing any problems and offering alternative solutions. In this paper, the current state of constructions in Song-do City were reviewed. Then a quantitative analysis and assessment for the Song-do City constructions of apartments, complex buildings, office buildings, and school facilities were conducted by using green building certification criteria. Finally the synthetic results of environmental performance evaluation for Song-do city constructions and follow-up suggestions were described.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.3
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• pp.181-190
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• 2016

The objective of this study is to apply performance-based seismic design to high-rise apartment buildings in Korean considering collapse prevention level. The possible issues during its application were studied and the suggestions were made based on the findings from the performance-based seismic design of a building with typical residential multi-unit layout. The lateral-force-resisting system of the building is ordinary shear walls system with a code exception of height limit. In order to allow the exception, the serviceability and the stability of the ordinary shear wall structure need to be evaluated to confirm that it has the equivalent performance as the one designed under the Korean Building Code 2009. The structure was evaluated whether it satisfied its performance objectives to withstand Service Level and Maximum Considered Earthquake.

• Smart Structures and Systems
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• v.33 no.2
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• pp.133-143
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• 2024

Piezoelectric (PZT) actuators have been widely used in precision positioning fields for their excellent displacement resolution. However, due to the inherent characteristics of piezoelectric actuators, hysteresis has been proven to greatly reduce positioning performance. In this paper, five mathematical hysteretic models based on activation function are proposed to characterize the nonlinear hysteresis characteristics of piezoelectric actuators. Then the performance of the proposed models is verified by particle swarm optimization (PSO) algorithm and the experiment data. Thirdly, the fitting performance of the proposed models is compared with the classical Bouc-Wen model. Finally, the performance of the five proposed models in modelling hysteresis nonlinearity of piezoelectric drivers is compared, in terms of RMSE, MAPE, SAPE and operation efficiency, and relevant suggestions are given.

• Journal of Power Electronics
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• v.15 no.6
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• pp.1489-1498
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• 2015

Gallium nitride (GaN)-based power switching devices, such as high-electron-mobility transistors (HEMT), provide significant performance improvements in terms of faster switching speed, zero reverse recovery, and lower on-state resistance compared with conventional silicon (Si) metal-oxide-semiconductor field-effect transistors (MOSFET). These benefits of GaN HEMTs further lead to low loss, high switching frequency, and high power density converters. Through simulation and experimentation, this research thoroughly contributes to the understanding of performance characterization including the efficiency, loss distribution, and thermal behavior of a 160-W GaN-based synchronous boost converter under various output voltage, load current, and switching frequency operations, as compared with the state-of-the-art Si technology. Original suggestions on design considerations to optimize the GaN converter performance are also provided.

• International Journal of High-Rise Buildings
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• v.1 no.3
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• pp.221-228
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• 2012

Shanghai Tower is a super high-rise building of 632 m height with 'mega frame-core- outrigger truss' structure system. Due to the complexity and irregularity of structure, shaking table test was carried out to investigate its seismic performance. A 1/40 scaled test model was designed, built and tested on shaking table under earthquake of small, moderate and large levels. The experimental results showed that the structure can meet the requirements of Chinese codes and reach scheduled performance objectives. Elastic and plastic time-history analysis on the structure were carried out and the results were compared to experimental results. Based on the research results some suggestions were proposed to contribute favorable effect on the seismic capacity of the structure.

• Journal of Home Health Care Nursing
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• v.11 no.1
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• pp.44-56
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• 2004

This study was conducted to investigate the evaluation of students on a practical performance of the home health care and to provide data for practical education on the home care nurse institution. Research was performed from March to December. 2002. 40 Respondents participated in the evaluation four times. The data were analysed by using the SPSS/PC + version 10. 0. The results of this study were as followings: 1. The average age of the subjects was 32. Majority of the subjects were interested in home health care. Majority of the subjects were staff nurse(57.5%) and workers at general hospitals(50%). 2. According to the result of the comparison of practical performances. performance evaluations of 20 items were higher when they admitted special practice than when they admitted any other practice. There was an positive increase in the evaluation of health assessment. nursing documentation. explanation. coping with emergency status. coordination and self assertion. In addition to health assessment. CPR. oxygenation. education & consultation. developmental assessment of child. nursing documentation. mastering nursing practice and consideration of client were significantly different. 3. The subjects were useful for practical circumference where they are working at. From these research findings. the following suggestions have been drawn: it is needed to manage practical curriculum variously and to include not only clinical aspect but also organic or administrational aspect and to reflect on students' needs and to choose to be reasonable items and to develop instruments for evaluation capability of home care nurse.

• Korean Journal of Construction Engineering and Management
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• v.13 no.5
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• pp.76-83
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• 2012

The purposes of this study are both to identify suggestions regarding the evaluation framework of construction policy performance based on the analysis of the 4th Master Plan for Improvement of Construction Technology and to provide recommendations that can be used for developing the 5th Master Plan for Improvement of Construction Technology. In order to achieve this purpose, a questionnaire was distributed to construction industry-related professionals and makes them evaluate the performance of the 4th Master Plan for Improvement of Construction Technology by performance index appropriacy, measurement appropriacy, and target level. In addition, comprehensive literature review was implemented to extract important points, which are related to policy evaluation, that can be considered factors in developing the 5th Master Plan for Improvement of Construction Technology.

• KIEAE Journal
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• v.10 no.1
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• pp.91-96
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• 2010

Incheon Free Economic Zone's Songdo Area is a newly constructed city built on land reclaimed from the seaside and the surrounding area. Yeongjong Area is made after Land reclamation between Yeongjong Island and Yongyou Island began in November 1992. The first phase linking these islands to create the Incheon International Airport (phase 1) and the Airport Town Square community was finished in March 2001. However, if we take a look at the overall status of the project as it is carried on at present, it is hard to deny that the project is trapped inside the same legal restrictions as are all other existing cities, which permits Songdo Area and Yeongjong Area to meet only very minimum standards. This study intends to analyze and assess the Incheon Free Economic Zone's Songdo Area and Yeongjong Area of environmentally friendly construction and to rate its current development status, exposing any problems and offering alternative solutions. In this paper, the current state of constructions in Songdo Area and Yeongjong Area were reviewed. Then a quantitative analysis and assessment for the Songdo Area and Yeongjong Area constructions of apartments, complex buildings, office buildings, school facilities, store and hotel facilities were conducted by using green building certification criteria. Finally the synthetic results of environmental performance evaluation for Incheon Free Economic Zone's Songdo Area and Yeongjong Area constructions and follow-up suggestions were described.

• Korean Management Science Review
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• v.19 no.2
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• pp.25-39
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• 2002

This study suggests a revised TAM (Technology Acceptance Model)-based performance evaluation model in MS (management science) education. Recently, many MS education programs are developed on the basis of computer and Internet communication technology. Previous researchers used TAM as an individual performance evaluation model, and proved that perceived usefulness and perceived ease of use are the substantive successful factors. This study provides a revised TAM-based conceptual framework for understanding what is involved in improving university MS education and what might be implied by conducting research on its improvement. It is argued in this research that three sets of forces and conditions have a direct and indirect impact on MS education ; first, each student has self efficacy and it is a critical determinant of behavior next, the use of Internet-based information system at MS education affects on the renewal of MS education : and finally, perceived usefulness and perceived ease of use have impacts on behavioral intention and actual system usage. This research concludes with suggestions for which direction this framework provides for future research on the premise and limits of efforts to renew MS education in university.