• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.10a
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• pp.175-181
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• 2005

This paper describes the development of on-line computer vision laboratories to teach the detailed image processing and pattern recognition techniques. The computer vision laboratories include distant image acquisition method, basic image processing and pattern recognition methods, lens and light, and communication. This study introduces a case study that teaches computer vision in distance learning environment. It shows a schematic of a distant loaming workstation and contents of laboratories with image processing examples. The study focus more on the contents of the vision Labs rather than internet application method. The study proposes the ways to improve the on-line computer vision laboratories and includes the further research perspectives

• Journal of the Ergonomics Society of Korea
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• v.11 no.1
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• pp.3-12
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• 1992

To put the binocular 3-D images system into practical use, it is required to investigate the relationship between the system and men and to make ergonomic evaluation of the system. In this study, we perform a comparative analysis of the changes in the accommodation and pupil functions before and afer observing binocular 3-D images a sthe visual distance varies. From the experiment, we obtained the following results: (1) The discordance in the distance informatioons on the accommodation and pupil functions when obwerving 3-D images is compensated by the miosis and altering the focal depth. (2) From the consideration of the effect of the visual distance condition on the visual functions, it is thoughth that the visual functions are stabilized at the dark focus in the sense that the changes in the tension and relazation afer observing the 3-D images are minimized.

• The Journal of Korea Robotics Society
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• v.1 no.2
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• pp.151-157
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• 2006

This paper is concerned with the template-based face recognition from robot camera images with illumination and distance variations. The approaches used in this paper consist of Eigenface, Fisherface, and Icaface which are the most representative recognition techniques frequently used in conjunction with face recognition. These approaches are based on a popular unsupervised and supervised statistical technique that supports finding useful image representations, respectively. Thus we focus on the performance comparison from robot camera images with unwanted variations. The comprehensive experiments are completed for a databases with illumination and distance variations.

• The Journal of Korean Society for Radiation Therapy
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• v.6 no.1
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• pp.89-93
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• 1994

Authors have measured virtual source distance of electron beam from CL/1800 medical linear accelerator, with newly designed method. Beam scanning was performed with the direction of beam axis in the air. Compared results between this study and well established in phantom measurement shows good agreement with in experimental error. And we have found that build-up cap plays very important role in air measurement because of charge build up. The method of in-air measurement of virtual source distance is very easy to set-up and generate accurate results.

• Korean Journal of Cognitive Science
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• v.15 no.1
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• pp.13-24
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• 2004

This paper deals with the anaphoric usage of demonstratives when they refer to what are already mentioned in the context. We examine syntactic, semantic and pragmatic factors that contribute to the choice of demonstratives. As for anaphoric usage, English and Spanish show the even distribution between proximal and distal demonstratives with the meaning of their deictic counterparts. Korean and Russian, however, show the uneven distribution of the more prevalent form (unmarked on) and the lesser one (market one). This study aims at a typological explanation for the anaphoric usage of demonstratives through comparison and contrast with such factors as the distance to the antecedent, cognitive status, psychological distance and the center of attention.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.5
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• pp.203-211
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• 2002

In this paper, the implementation of a new AF(Automatic Focusing) system for a digital still camera is introduced. The proposed system operates in real-time while adjusting focus after the measurement of distance to an object using a passive sensor, which is different from a typical method. In audition, measurement errors were minimized by using the data acquired empirically, and the optimal measuring time was obtained using EV(Exposure Value) which is calculated from CCD luminance signal. Moreover, this system adopted an auxiliary light source for focusing in absolute dark conditions, which is very hard for CCD image Processing. Since this is an open-loop system adjusting focus immediately after the distance measurement, it guarantees real-time operation. The performance of this new AF system was verified by comparing the focusing value curve obtained from AF experiment with the one from the measurement by MF(Manual-Focusing). In both case, edge detector was used for various objects and backgrounds.

• Journal of Welding and Joining
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• v.28 no.3
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• pp.42-48
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• 2010

Polycarbonate (PC) and Acrylonitrile Butadiene Styrene (ABS) were welded by a combination of a diode laser and a CNC machining center. Laser beam delivered through the transparent PC and was absorbed in an opaque ABS. Polymers were melted and joined by absorbed and conducted heat. Experiments were carried out by varying working distance from 44mm to 50mm for the focus spot diameter control, laser input power from 10W to 25W, and scanning speed from 100 to 400mm/min. The weld bead and cross-section were analyzed for weld quality, and tensile results were presented through the joint force measurement. With focus distance at 48mm, laser power with 20W, and welding speed at 300mm/min, experimental results showed the best welding quality which bead size was measured to be 3.75mm. The shear strength at the given condition was $22.8N/mm^2$. Considering tensile strength of ABS is $43N/mm^2$, shear strength was sufficient to hold two materials. A single process was possible in a CNC machining system, surface processing, hole machining and welding. As a result, the process cycle time was reduced to 25%. Compared to a typical process, specimens were fabricated in a single process, with high precision.

• Korean Journal of Digital Imaging in Medicine
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• v.9 no.2
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• pp.23-30
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• 2007

This study attempts to propose an appropriate method of using digital medical imaging equipments, by studying the effects of automatic exposure control(AEC), grid ratio and the change of radiography distance on the patient dose and detertor acquisition dose during the procedure of acquiring image through a digital medical imaging detector. The change of dose following the change of grid ratio's exposure and radiography distance was measured, by using an abdominal phantom organized with tissue equivalent materials in an amorphous silicon thin film transistor detecter installed with AWC. The case to use grid ratio 12 : 1, focal distance 180cm to radiography distance 110cm in AEC, the patient dose increased rather when we used grid ration 10 : 1, focal distance 110cm. When AEC was not used,the dose necessary for image acquisition decreased as the grid ratio became higher and the distance became further. but detector acquisition dose was not reduced when in applied AEC. When purchasing digiral medical imaging equipments, optional items such as AEC and grid shall be accurately selected to satisfy the use of the equipments. Radiography error made by radiation technologist and unnenessary patient dose can be reduced by selecting equipments with a radiography distance marker equipment when it did not apply AEC. These equipments can also be helpful in maintaining high imaging quality, one of the merits of digital detectors.

• Korean Journal of Optics and Photonics
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• v.23 no.5
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• pp.189-196
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• 2012

A floating optical system is a system that moves more than 2 groups to focus at the camera lens. At the camera optics, the floating system that is mainly used is an optical system such as a macro lens which changes magnification very much. When the floating system is assembled and fabricated in the factory, there are differences between the image plane of the sensor and the focal plane of the infinity or macro state. Therefore, in a considerable proportion of cases, the focus adjustment to minimize the difference of BWD(Back Working Distance) is carried out in the process of manufacturing. In this paper, in order to decide the movement of each group in a floating system, we evaluated the rotation angle of CAM for the focus adjustment. We know that the maximum magnification of macro state is corrected by this numerical method for the focus adjustment, too. We investigated the limit of CAM rotation angle of the system by using statistical analysis for CAM rotation angle, which uses the focus adjustment of the floating system with symmetric error factors.

• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.1
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• pp.69-81
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• 2014

Financial products entail either gains or losses, and customers' psychological reaction to these gains and losses affect the selection of the financial products. This study explains the financial customers' behavior by introducing consumers' psychological variables such as regulatory focus and construal levels. According to the regulatory focus theory, there are two distinct motivational orientations called promotion focus and prevention focus. And, construal level theory proposes that people use more abstract and higher levels of construal to represent objects that are more distant on psychological distance. We have incorporated these two psychological variables into financial consumer behaviors. In the experiment 1, the results have showed that promotion focused customers prefer fund products to deposit products, whereas prevention focused customers have showed the opposite result. In the experiment 2, both regulatory focus and construal level were considered. Specifically, under the high level message, promotion focused customers have showed higher preference to fund products than the prevention focused customers, and no significant difference for the deposit products. On the contrary, given the low level message, prevention focused customers have showed higher preference to both fund and deposit products than the promotion focused customers. Therefore, it comes to the conclusion that it will be efficient for the financial companies to use high level messages for the promotion focused customers and low level messages for the prevention focused customers. Implications and limitations are discussed to establish more effective marketing strategies based on the results of this study.