• 제어로봇시스템학회논문지
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• 제22권3호
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• pp.186-191
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• 2016

This paper addresses the development of 3D data acquisition system (3D scanner) based laser structured-light image. The 3D scanner consists of a stripe laser generator, a conventional camera, and a rotation table. The stripe laser onto an object has distortion according to 3D shape of an object. By analyzing the distortion of the laser stripe in a camera image, the scanner obtains a group of 3D point data of the object. A simple semiconductor stripe laser diode is adopted instead of an expensive LCD projector for complex structured-light pattern. The camera has an optical filter to remove illumination noise and improve the performance of the distance measurement. Experimental results show the 3D data acquisition performance of the scanner with less than 0.2mm measurement error in 2 minutes. It is possible to reconstruct a 3D shape of an object and to reproduce the object by a commercially available 3D printer.

• Current Optics and Photonics
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• 제2권6호
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• pp.554-562
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• 2018

This study presents a color 3D scanner based on the laser structured-light imaging method that can simultaneously acquire 3D shape data and color of a target object using a single camera. The 3D data acquisition of the scanner is based on the structured-light imaging method, and the color data is obtained from a natural color image. Because both the laser image and the color image are acquired by the same camera, it is efficient to obtain the 3D data and the color data of a pixel by avoiding the complicated correspondence algorithm. In addition to the 3D data, the color data is helpful for enhancing the realism of an object model. The proposed scanner consists of two line lasers, a color camera, and a rotation table. The line lasers are deployed at either side of the camera to eliminate shadow areas of a target object. This study addresses the calibration methods for the parameters of the camera, the plane equations covered by the line lasers, and the center of the rotation table. Experimental results demonstrate the performance in terms of accurate color and 3D data acquisition in this study.

• 경영과학
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• 제17권1호
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• pp.17-30
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• 2000

This paper addresses the effect of protective capacity on the lead time and throughput of a re-entrant line where statistical fluctuations exist in the form of variation in processing times and machine breakdowns. The specific framework employed in the paper is a five station re-entrant line structured as a closed network mode. This paper argues that protective capacity can be used in conjunction with WIP inventory in order to reduce the lead time and to increase the increase the throughput of a line. Simulation analyses are included to give insight into the effectiveness of protective capacity.

• Journal of Communications and Networks
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• 제13권6호
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• pp.602-611
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• 2011

The inter-domain routing scalability issue is a major challenge facing the Internet. Recent wide deployments of multihoming and traffic engineering urge for solutions to this issue. So far, tunnel-based proposals and compact routing schemes have been suggested. An implicit assumption in the routing community is that structured address labels are crucial for routing scalability. This paper first systematically examines the properties of identifiers and address labels and their functional differences. It develops a simple Internet routing model and shows that a binary relation T defined on the address label set A determines the cardinality of the compact label set L. Furthermore, it is shown that routing schemes based on flat address labels are not scalable. This implies that routing scalability and routing stability are inherently related and must be considered together when a routing scheme is evaluated. Furthermore, a metric is defined to measure the efficiency of the address label coding. Simulations show that given a 3000-autonomous system (AS) topology, the required length of address labels in compact routing schemes is only 9.12 bits while the required length is 10.64 bits for the Internet protocol (IP) upper bound case. Simulations also show that the ${\alpha}$ values of the compact routing and IP routing schemes are 0.80 and 0.95, respectively, for a 3000-AS topology. This indicates that a compact routing scheme with necessary routing stability is desirable. It is also seen that using provider allocated IP addresses in multihomed stub ASs does not significantly reduce the global routing size of an IP routing system.

• 품질경영학회지
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• 제43권1호
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• pp.103-124
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• 2015

Purpose: This paper proposes a structured approach based on Quality Function Deployment (QFD) for service development in the banking industry. Methods: SERVQUAL is modified and adopted as a tool to understand customer requirements for the QFD. Fuzzy theory is used to resolve the subjectivity and ambiguity of customer requirements and satisfaction. This research also uses the importance- satisfaction model to construct an additional House of Quality (HOQ). A pair of houses of quality provides a confluence of results to avoid a risk of depending solely on the results of a single HOQ. Results: A case study is introduced with three domestic banks. Conclusion: The proposed approach effectively addresses a service development problem.

• Wind and Structures
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• 제18권5호
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• pp.529-548
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• 2014

This article presents the unsteady aerodynamic performance of crosswind stability obtained numerically for the ATM train. Results of numerical investigations of airflow past a train under different yawing conditions are summarized. Variations of occurrence flow angle from parallel to normal with respect to the direction of forward train motion resulted in the development of different flow patterns. The numerical simulation addresses the ability to resolve the flow field around the train subjected to relatively large yaw angles with three-dimensional Reynolds-averaged Navier-Stokes equations (RANS). ${\kappa}-{\varepsilon}$ turbulence model solved on a multi-block structured grid using a finite volume method. The massively separated flow for the higher yaw angles on the leeward side of the train justifies the use of RANS, where the results show good agreement with verification results. A method of solution is presented that can predict all aerodynamic coefficients and the wind characteristic curve at variety of angles at different speed.

• 센서학회지
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• 제21권2호
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• pp.96-102
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• 2012

This paper addresses photometric distortion problems of a compact 3D scanning sensor which is composed of a micro-size and inexpensive camera-projector system. Recently, many micro-size cameras and projectors are available. However, erroneous 3D scanning results may arise due to the poor and nonlinear photometric properties of the sensors. This paper solves two inherent photometric distortions of the sensors. First, the response functions of both the camera and projector are derived from the least squares solutions of passive and active calibration, respectively. Second, vignetting correction of the vision camera is done by using a conventional method, however the projector vignetting is corrected by using the planar homography between the image planes of the projector and camera, respectively. Experimental results show that the proposed technique enhances the linear properties of the phase patterns that are generated by the sensor.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.356-365
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• 2007

The development in the design process is usually based on the choice of a method for designing the system, in which this method is frequently faced with tightening environmental requirements, reducing development cycle times and growing complexity. To tackle such factors, the paper proposes a comprehensive approach focusing on applying systems engineering approach to the building design support. In particular, this paper addresses all capabilities of using some available systems engineering standards (like EIA-632) in the design process. Then, a methodological approach is proposed for the practice of requirements engineering by applying quality assessment and control to design in early phase. The paradigm used, here is to extend and particularly to adapt the work carried out in military and space systems to modern building services by taking into account the semantics of buildings in terms of different engineering fields and architecture issues.

• 대한간호학회지
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• 제39권3호
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• pp.446-457
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• 2009

Purpose: The aim of this study was to construct a structural equation model that would further explain the continuously increasing substance use disorder in Korean adolescents. Methods: Survey visits using a structured questionnaire were conducted with 3,885 students in 2 middle schools and 2 high schools in Busan. A total of 13 instruments were used in this model. The analysis of data was done with both SPSS 14.0 for descriptive statistics and AMOS 5.0 for covariance structure analysis. Results: Based on the constructed model, belief on substance use was found to have a significantly direct effect in influencing adolescent substance use. In addition, other factors such as family environment, satisfaction with school life, self-concept, social support, and personality vulnerability indirectly affected substance use. The final modified model yielded Chi-square=2,987(p<.001), df=121, ${\chi}^2$/df=22.1, GFI=.96, AGFI=.93, NFI=.91, PNFI=.72, PGFI=.72, RMSEA=.07 and exhibited fit indices. Conclusion: This study constructed a model that addresses the factors related to adolescent substance use and explains the relationship of these factors in influencing substance use among Korean adolescents. Findings from this study can contribute to designing appropriate prevention strategies to reduce substance related disorders in adolescents.

• 보건행정학회지
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• 제4권2호
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• pp.111-125
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• 1994

In developing total hospital information system, large amount of time and expense are to be spent while its results are likely to lead itself to end-users' dissatisfaction. Some of the main complaints on the part of end-users come from insufficient consideration of end-users environment as well as inappropriate representation of their requirement in the system alalysis and design. This papre addresses some advantages of Essential Logical Modeling Process for better analysis and design, explaining by example the developmental process of the Patent Management and Accounting System for a tertiary care hospital. In the case, the Essential Model, suggested by McMenamin and Palmer, proved to be an effective tool for clear separation of analysis and design phase and for better communication among system developers and with end-users. The modeling process itself contributed to better program modularity as well, shown in a Structured Chart. Difficulties in learning how to identify' essential activities' for the modeling practice were experienced in the beginnins stage, which were, however, overcome by elaborating some heuristic guideling and by rdferring to necessary tools including State Transition Diagram, Control Flow Diagram, and so many. While full evaluation of the Essential Model usag remains to wait till the completion of the case project, its strengt in making clear distinction between analysis and design phase was enough to be attractive to system analysts. The model concepts are open to many further application fields, particularly such areas as business re engineering, process remodeling, office automation, and organizational restructuring.