• Structural Engineering and Mechanics
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• v.52 no.3
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• pp.485-505
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• 2014

This study aimed to develop an approach to accurately predict the wind models and wind effects of large wind turbines. The wind-induced vibration characteristics of a 5 MW tower-blade coupled wind turbine system have been investigated in this paper. First, the blade-tower integration model was established, which included blades, nacelle, tower and the base of the wind turbine system. The harmonic superposition method and modified blade element momentum theory were then applied to simulate the fluctuating wind field for the rotor blades and tower. Finally, wind-induced responses and equivalent static wind loads (ESWL) of the system were studied based on the modified consistent coupling method, which took into account coupling effects of resonant modes, cross terms of resonant and background responses. Furthermore, useful suggestions were proposed to instruct the wind resistance design of large wind turbines. Based on obtained results, it is shown from the obtained results that wind-induced responses and ESWL were characterized with complicated modal responses, multi-mode coupling effects, and multiple equivalent objectives. Compared with the background component, the resonant component made more contribution to wind-induced responses and equivalent static wind loads at the middle-upper part of the tower and blades, and cross terms between background and resonant components affected the total fluctuation responses, while the background responses were similar with the resonant responses at the bottom of tower.

• Coupled systems mechanics
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• v.9 no.2
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• pp.163-182
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• 2020

Coupled thermo-mechanical analysis of reinforced concrete slab at elevated temperatures from a fire accounting for nonlinear thermal parameters is carried out. The main focus of the paper is put on a one-way continuous reinforced concrete slab exposed to fire from the single (bottom) side as the most typical working condition under fire loading. Although contemporary techniques alongside the fire protection measures are in constant development, in most cases it is not possible to avoid the material deterioration particularly nearby the exposed surface from a fire. Thereby the structural fire resistance of reinforced concrete slabs is mostly influenced by a relative distance between reinforcement and the exposed surface. A parametric study with variable concrete cover ranging from 15 mm to 35 mm is performed. As the first part of a one-way coupled thermo-mechanical analysis, transient nonlinear heat transfer analysis is performed by applying the net heat flux on the exposed surface. The solution of proposed heat analysis is obtained at certain time steps of interest by α-method using the explicit Euler time-integration scheme. Spatial discretization is done by the finite element method using a 1D 2-noded truss element with the temperature nodal values as unknowns. The obtained results in terms of temperature field inside the element are compared with available numerical and experimental results. A high level of agreement can be observed, implying the proposed model capable of describing the temperature field during a fire. Accompanying thermal analysis, mechanical analysis is performed in two ways. Firstly, using the guidelines given in Eurocode 2 - Part 1-2 resulting in the fire resistance rating for the aforementioned concrete cover values. The second way is a fully numerical coupled analysis carried out in general-purpose finite element software DIANA FEA. Both approaches indicate structural fire behavior similar to those observed in large-scale fire tests.

• The Journal of Natural Sciences
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• v.5 no.1
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• pp.87-93
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• 1992

A robotically assisted field material handling system designed for loading and unloading of a planar pallet with a forklift in unstructured field environment is presented. The system uses combined acoustic/visual sensing data to define the position/orientation of the pallet and to determine the specific locations of the two slots of the pallet, so that the forklift can move close to the slot and engage it for transport. In order to reduce the complexity of the material handling operation, we have developed a method based on the integration of 2-D range data of Poraloid ultrasonic sensor along with 2-D visual data of an optical camera. Data obtained from the two separate sources complements each other and is used in an efficient algorithm to control this robotically assisted field material handling system . Range data obtained from two linear scannings is used to determine the pan and tilt angles of a pallet using least mean square method. Then 2-D visual data is used to determine the swing angle and engagement location of a pallet by using edge detection and Hough transform techniques. The limitations of the pan and tilt orientation to be determined arc discussed. The system developed is evaluated through the hardware and software implementation. The experimental results are presented.

• Korean Journal of Optics and Photonics
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• v.25 no.5
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• pp.273-278
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• 2014

We present an algorithm for surface reconstruction from the second-derivative data for free-form aspherics, which uses a subaperture scanning system that measures the local surface profile and determines the three second-derivative values at those local sampling points across the free-form surface. The three second-derivative data were integrated to get a map of x- and y-slopes, which went through a second Southwell integration step to reconstruct the surface profile. A synthetic free-form surface 200 mm in diameter was simulated. The simulation results show that the reconstruction error is 19 nm RMS residual difference. Finally, the sensitivity to noise is diagnosed for second-derivative Gaussian random noise with a signal to noise ratio (SNR) of 16, the simulation results proving that the suggested method is robust to noise.

• Journal of Korean Academy of Nursing
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• v.35 no.7
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• pp.1238-1247
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• 2005

Purpose: This study aimed at developing integrated clinical performance indicators(CPIs) through the analysis of quality improvement(QI) activities of a hospital and literature review about performance measures. Method: The CPIs were developed through the following three stages; 1)Identifying preliminary CPIs 2)A staff validity test in preliminary CPIs 3)Developing final CPIs. Result: One hundred twenty-three preliminary CPIs were developed through QI activities of the target hospital for 8 years and literature review. The results of the validity test for the preliminary CPIs supported ninety-one items. Sixty-two CPIs were selected through integration, reclassification and renaming. Then, eighteen items were deleted on account of an imprecise calculation method. Finally, forty-four CPIs were confirmed. They consisted of twenty-six items at the hospital level and eighteen items at the department level. Conclusion: CPIs can be used as criteria to evaluate the performance of healthcare organizations, and to decide the quality of healthcare for customers. This study may contribute to establishing an integrated system between QI activities and performance measurement of healthcare organizations.

• Journal of Digital Convergence
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• v.11 no.9
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• pp.189-194
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• 2013

Semantic Web is what supports a search, data integration, and automated web service by developing technology of giving help so that a computer can understand information a little more on the web. As amount of information gets growing and diverse, there is a problem of offering by efficiently extracting and processing only information proper for users' demand. Semantic Web isn't what is distinguished completely from the existing web. It gives a meaning, which was well defined, to information of being inserted on web by expanding the current web. Through this, a computer and a person come to perform work cooperatively. To implement Semantic Web, the limit of HTML needs to be overcome. The existing access authorization has not taken information and semantics into account due to the limitations of HTML. It is difficult to expand or integrate many relevant documents by using HTML. Program or software agent, not a person, cannot extract a meaning of document automatically. This study suggests a method of Access Authorization Policy Management that is in the Semantic Web configuration. Accordingly, the policy, which was designed in this study, improved the authorization process more than the existing method.

• Journal of the Korea Society of Computer and Information
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• v.13 no.2
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• pp.19-29
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• 2008

In case of unit testing, White-box test can be used to closely check source code and to analyze logic and statement errors. On the other hand, in case of function testing of system level, Black-box test can be mainly used to compare actual and expected results by inputting test data because the scale of function is large. This Black-Box test in system testing level has problem in tracing errors in source code when we find errors. Moreover applying White-box test is not easy for system testing level because the levels of test target are different. Therefore this paper suggests the vertical test method of a practical and integrated system level which can checks up to source code level using White-box test style although it aims to test the highly abstract level like a system function. In addition, the experiment explains how to apply the vertical test by displaying an example which traces from UML specification model to the source code and also shows efficiency of error trace.

• Journal of the Korea Society of Computer and Information
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• v.13 no.2
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• pp.211-220
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• 2008

The home network technology which used USN is developing quickly. Use yet line to a lot of part as home network technology. Recently be leap into prominence to technology core of home network as wireless technology a ZigBee. ZigBee Perceive with cognition from tag and sensor as use USN, and processing, save, integration, and provide information. Implement the access control system which used technology BigBee with design at these papers. The wireless-based construction that used ZigBee. The influence that can let you implement early a Ubiquitous society is technology there being. Also, show by a large spinoff in an allied industry field, and improve the quality of life, and invention calls value added of leading edge IT service and product. The implementation of mobile base on access control system using zigbee method is expected to be helpful for the convenience in home network use.

• Journal of the HCI Society of Korea
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• v.6 no.2
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• pp.11-20
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• 2011

The mass collaboration, one of the newest solutions for web-related tasks, has been recognized to be an effective tool for the R&D sectors of the corporates, since the key advantages of crowdsourcing is that the industrial challenges can be shared with the public entities to find proper solutions. This research approaches to the possibility of the design adoption with participation thorough the Internet will positively effect to its process. This research tried to look around the current trend of web 2.0 based services which support the Mass Collaboration method and results of paper related to the Crowdsourcing and design integration. Following to the analysis of web research, we meet the conclusion as just a small number of users' opinion has helped designing new product and service. And we compared it to the conventional design process detail functions, less number of websites support it. However, the result of paper research shows optimistic results of collective design activity. Several cases emphasize that participants were very active to support their thoughts, memories and novel design idea, therefore designer and researchers got enormous help from them and it was better than conventional participatory design in some perspective.

• Korean Journal of Construction Engineering and Management
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• v.5 no.5 s.21
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• pp.117-125
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• 2004

Recently, the word 'outsourcing' is used frequently in the corporation circumstance. Continuous recession with IMF caused restructuring measures which made unnecessary organization be downsized, and offered opportunity to breakup structure of $^{\circ}A$EHigh cost and Low efficiency, which is inefficient and uneconomic production method' in our corporation. Due to the effect of such circumstance change, the construction industry have already introduced and implemented outsourcing in many parts. For successful outsourcing in the construction industry, close relation and mutual cooperation should be preceded and JIT system is needed to improve the relation. In this study, the importance and proportion in which outsourcing is occupied in the construction industry are recognized, and the method for improving the productivity is suggested through evaluating the factors and usefulness of JIT system which can be applied to the construction industry.