• Journal of Korean Society of Environmental Engineers
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• v.31 no.4
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• pp.256-262
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• 2009

The use of hydrodynamic separator is becoming increasingly popular for suspended solids reduction in urban storm runoff. This study is a laboratory investigation of the use of Vortex Screen to reduce the solids concentration of synthesized storm runoff. The synthesized storm runoff was made with water and addition of particles; manhole sediment, road sediment, fly ash, and ployvinyl chloride powder. Vortex Screen was made of acryl resin with 250 mm of diameter and height of 700 mm. To determine the removal efficiency for various influent concentrations of suspended solids (SS) and chemical oxygen demand (COD), tests were performed with different operational conditions. The samples were taken simultaneously at the influent storage tank and effluent tank, and measured SS and COD concentrations. The ranges of surface loading rate were 110 to 1,550 $m^3/m^2$/day, and influent SS concentrations were varied from 141 to 1,986 mg/L. This paper was intended to evaluate the effect of inlet baffle and the ratio of underflow to overflow ($Q_U/Q_O$) on particle separation efficiency for various particle size using Vortex Screen. It was found that when increase of $Q_U/Q_O$ from 10% to 20%, SS removal efficiency was increased about 6%. The range of SS and COD removal efficiencies of road sediment particle size 125<$d_p$<300 ${\mu}m$ were 68.0~81.0%, 53.1~71.9%, respectively. Results showed that SS removal efficiency with inlet baffle improved by about 10~20% compared without inlet baffle.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.174-178
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• 1999

Recently, the computer vision has been applied to many automation fields. Especially, this paper presents a maritime traffic detection system using computer vision since the high level information can be obtained using obtained area information. The high level informations are obtained such as speed, queueing length, queueing time, ship size, and ship kind. To get ship speed, the two detection lines are set on the predetermined screen position. The speed is obtained the passing time and the predetermined distance between the first and second detection line on the screen. Also, queueing length and time are gotten using screen position of ship. Furthermore, the size and kind of ship are calculated using the ship database and camera calibration data. This developed system contributes to reduce the traffic accidents on the coast. Futhermore, the more information can be extracted using obtained area information.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.10
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• pp.989-994
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• 2011

This study aims to demonstrate the feasibility of a visual servoing-based paired structured light (SL) robot for estimating structural displacement under various external loads. The former paired SL robot, which was proposed in the previous study, was composed of two screens facing with each other, each with one or two lasers and a camera. It was found that the paired SL robot could estimate the translational and rotational displacement each in 3-DOF with high accuracy and low cost. However, the measurable range is fairly limited due to the limited screen size. In this paper, therefore, a visual servoing-based 2-DOF manipulator which controls the pose of lasers is introduced. By controlling the positions of the projected laser points to be on the screen, the proposed robot can estimate the displacement regardless of the screen size. We performed various simulations and experimental tests to verify the performance of the newly proposed robot. The results show that the proposed system overcomes the range limitation of the former system and it can be utilized to accurately estimate the structural displacement.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.9
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• pp.724-727
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• 2009

We have fabricated (Ba,Sr)TiO3$TiO_3$ thick films doped with various amount of ZnBO dopants (1, 3, and 5 wt%) by screen printing method on the alumina substrates, which were sintered at the temperature below $1200^{\circ}C$. With increasing the amount of ZnBO dopants, the relative dielectric permittivity of ZnBO doped (Ba,Sr)$TiO_3$ was decreased, while loss tangent was increased. 1 wt% ZnBO doped (Ba,Sr)$TiO_3$ thick film has relative dielectric permittivity of 759 at 1 MHz, while 3 and 5 wt% of ZnBO doped (Ba,Sr)$TiO_3$ thick films have 624 and 554, respectively. By introducing ZnBO dopants to the (Ba,Sr)$TiO_3$ thick films, leakage current densities were decreased. The decreased leakage current with increasing ZnBO dopants can be explained by increased density and grain size of thick film on alumina substrate. We believe this decreased leakage current density probably come from the increased grain size and increased density.

• The Journal of Industrial Distribution & Business
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• v.15 no.3
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• pp.11-20
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• 2024

Purpose: This study focuses on the Chinese smartphone market to estimate product attributes influencing Chinese customers' preference for developing new smartphones through conjoint analysis. Research design, data and methodology: The online questionnaire survey is processed among Chinese potential smartphone customers. Conjoint analysis including traditional conjoint analysis (TCA) and choice-based conjoint analysis (CBCA), is used to analyze the useful data of 500. Results: Results indicate that price is the most important predictor while screen size is the least for Chinese customers' preference whether the method is TCA or CBCA. However, the importance of brand, capacity, CPU, and screen design is different. Moreover, based on each smartphone attribute level's utility, the new products with the best combinations are different compared with both methods. Finally, the predicted market shares of the top 3 products are the same with maximum utility rule model between TCA and CBCA. However, when considering with the new best combined product, they are significantly different. Conclusions: Managers should recognize the differences between TCA and CBCA and select the best method to develop new smartphones for sustainable business in the Chinese competitive market based on the important attributes of price, brand, capacity, CPU, screen design, and size.

• Journal of Industrial Convergence
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• v.18 no.6
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• pp.33-39
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• 2020

The multi-screen image system could make the audiences appreciate contents without special devices by expansively composing the images played on a single screen to many facets suitable for the use, which could provide the great immersiveness to the audiences. Based on the recent interest in realistic images, it is produced as films through the multi-projection technology such as Screen X or Escape, and it is developed into the media that could deliver stories and information. Also, the size of display tends to gradually get larger while the image quality is improved to high definition. Thus, the development is accelerated in the form of Digital Signage that could play the high definition image contents by solidly composing many HD or UHD display screens. Moreover, through the convergence of digital technologies, it is developed into the higher value-added industry that could have two-way communication. This study aims to understand the developmental history of multi-screen image from 1950 to the present, technical analysis, and the production method, and then to research how to minimize the image degradation when playing the contents, in various platforms using the multi-screen image.

• International Journal of Air-Conditioning and Refrigeration
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• v.12 no.1
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• pp.21-29
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• 2004

This paper is to study the heat transfer performance of the copper-water heat pipe with screen wicks. Recently, the semiconductor capacity of an electronic unit becomes larger, but its size becomes much smaller. As a result, a high- performance cooling system is needed. Experimental variables are inclination angles, temperatures of cooling waters and the mesh number of screen wicks. The distilled water was used as a working fluid. Based on the experimental results, when the copper-water heat pipe of 6mm diameter is used at the top heat mode, the heat transfer performance of 100 mesh 2 layers heat pipe is better than that of 150 and 200 mesh. The thermal resistance of the two layers with the 100-mesh screen was 0.7-$0.8^{\circ}C$/W.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.4
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• pp.834-848
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• 2013

To effectively use these functions many kinds of human-phone interface are used such as touch, voice, and gesture. However, the most important touch interface cannot be used in case of hand disabled person or busy both hands. Although eye tracking is a superb human-computer interface method, it has not been applied to smartphones because of the small screen size, the frequently changing geometric position between the user's face and phone screen, and the low resolution of the frontal cameras. In this paper, a new eye tracking method is proposed to act as a smartphone user interface. To maximize eye image resolution, a zoom lens and three infrared LEDs are adopted. Our proposed method has following novelties. Firstly, appropriate camera specification and image resolution are analyzed in order to smartphone based gaze tracking method. Secondly, facial movement is allowable in case of one eye region is included in image. Thirdly, the proposed method can be operated in case of both landscape and portrait screen modes. Fourthly, only two LED reflective positions are used in order to calculate gaze position on the basis of 2D geometric relation between reflective rectangle and screen. Fifthly, a prototype mock-up design module is made in order to confirm feasibility for applying to actual smart-phone. Experimental results showed that the gaze estimation error was about 31 pixels at a screen resolution of $480{\times}800$ and the average hit ratio of a $5{\times}4$ icon grid was 94.6%.

• Korean Journal of Materials Research
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• v.28 no.12
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• pp.714-718
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• 2018

Anti-reflection thin films are fabricated on glass substrates using the screen printing method. Tetra ethyl silicate(TEOS) and methyl tri methoxy silane(MTMS) are used as starting materials and buthyl carbitol acetate(BCA) and buthyl cellusolve(BC) are mixed to improve the viscosity of the solution. Anti-reflection thin films are fabricated according to the number of the screen mesh and the characteristics improve as the mesh size increases. The transmittance and reflectance of the coated thin film using 325 mesh are about 94 % and 0.43 % in the visible wavelength. The thickness and refractive index of the AR thin film are 107 nm and n = 1.26, respectively.

• Journal of Fisheries and Marine Sciences Education
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• v.17 no.1
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• pp.67-75
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• 2005

Mobile devices compared with personal computers on the desktop have low bandwidths, small screens, and relatively slow speeds. These systems have practical problems with information searches in a web environment. Information searching of various web contents on the small size screen has especially severe limitations. We propose a filtering technique of web contents which can overcome the limitations of small size screens and meet the user requirements in a PDA environment. For these constructions, we first divide the screen into segment blocks and then extract content blocks according to the user requirements, so that only filtered web contents will be shown. The performance evaluation of the proposed technique saves an average time of about 30% by displaying only the extracted information instead of the whole web page.