• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.4
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• pp.667-674
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• 1987

In this paper an effective block matching algorithm is proposed to find the motion vector. There are two approaches to the estimation of the motion vector in MCC (motion compensated coding), i.e., pel(pixel element) recursive algorithm and block matching algorithm. The search algorithm in this paper is based on the block matching method. The advantage of a proposed algorithm using integral projections is the reduction of the computation time. While the conventional block matching methods have to be computed in 2-dimensional arrays, the proposed algorithm using integral projections can be computed in 1-dimensional arrays. In comparison with conventional block matching methods, a computer simulation shows that though the prediction error increases 0.23 db, it is not detectable for human eyes and the average reduction ratio of computation time obtained from the proposed algorithm is about 3-4.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.706-711
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• 1998

Structural tests of the PSC Beam bridge using high strength concrete, concrete compressive strength 700kg/$\textrm{cm}^2$, are conducted for the application including durability and serviceability of the bridge. Current design safety factors with respect to the jacking force and the service design load DB-24 are applied to the design of the bridge. Concrete compressive strength 700kg/$\textrm{cm}^2$, girder depth 2.3m, girder space 3.2m, span length 20m, and slab thickness 27cm are selected for the bridge test. The Bulb-Tee section of the girders is applied instead of I section because it is well known more stable to the longer span(40m). Static load test(4 beams) with composite and non-composite section, and fatigue load test(1 beams) with composite section are conducted. Crack moment, ultimate load, deflections with load steps, and strains of the beam section for those bridges are investigated. The structural test results of the bridges showed a good performance for a safety and a serviceability.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.10a
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• pp.357-364
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• 2003

In the conventional reinforced-concrete bridge deck, concrete and steels are likely to be deteriorated and corroded under the influence of noxious environment. To cope with these problems caused in the conventional reinforced-concrete bridge deck, pultruded composite bridge deck having light weight, high strength, corrosion resistance and durability is developed. For the DB24 truck load pultruded composite bridge deck is designed and fabricated. For the fabricated and assembled deck panel, structural testing such as flexural test, local fatigue test, flexural fatigue test are conducted to verify the deck capacity experimentally. In this paper design for deck profile, details of connection and experimental results of composite bridge deck are presented.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.13-17
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• 2004

In recent years, the deterioration of reinforced concrete structures has become a serious problem in civil engineering fields. This situation is mainly due to corrosion of steel reinforcing bars embedded in concrete. Recently, there has been a greatly increased demand for the use of FRP (fiber reinforced plastic) in civil engineering field due to their superior mechanical and physical properties. This paper presents an experimental study on the behavior of concrete bridge deck reinforced with FRP Box, FRP Plate, and FRP Re-bar. In tlIe study, mechanical properties of FRP Box, FRP Plate, GFRP Re-bar, and CFRP Grid have been investigated. Full scale one-way deck slab was tested under four point lateral load (equivalent to actual wheel load of DB-24 including impact). Load-deflection and load-strain data were collected through LVDT's and strain gages attached to the specimen.

• Journal of the Korean Society of Safety
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• v.23 no.6
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• pp.108-114
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• 2008

Although FRP is relatively new material for constructional use, there are several commercial GFRP bridge decks available today. In this paper we first set variables which decide the design of a GFRP deck based on commercial products. Under the assumption of linear elastic behavior under DB24 load, all the conditions of stability and serviceability are considered. We seek the best solution which minimizes the cross section area using genetic algorithm. The optimal solution shows that the shape is close to the ASSET deck with larger angle of the web and smaller area.

• The Journal of Korea Robotics Society
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• v.17 no.3
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• pp.273-281
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• 2022

In this paper, we propose a robot sound recognition system that detects various sound events. The proposed system is designed to detect various sound events in real-time by using a microphone on a robot. To get real-time performance, we use a VGG11 model which includes several convolutional neural networks with real-time normalization scheme. The VGG11 model is trained on augmented DB through 24 kinds of various environments (12 reverberation times and 2 signal to noise ratios). Additionally, based on random forest algorithm, a decision logic is also designed to generate event signals for robot applications. This logic can be used for specific classes of acoustic events with better performance than just using outputs of network model. With some experimental results, the performance of proposed sound recognition system is shown on real-time device for robots.

• Korean Journal of Agricultural Science
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• v.15 no.1
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• pp.95-113
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• 1988

In order to find out changes of chemical components related to browning of dried jujube, four varieties were subjected to the proximate analysis. Boeun, one of the major varieties in Korea, was sun-dried and stored for 12 months and analyzed periodically for one year. Browning, titrable acidity, pH, contents of ascorbic acid, organic acid, total amino acid, free amino acid, free sugar, hydroxymethylfurfural (HMF) and phenolic compounds were determined and compared with those of fresh jujube. The results obtained are summarized as follows; 1. In comparison with other similar fruits, jujube was high contents of ascorbic acid (62-79mg%) and carbohydrate (22-28%) excluding fiber. 2. Browning was increased in both steam-treated and nontreated plot together as storage period was prolonged. 3. Ascorbic acid content of fresh jujube was as high as 297.4mg% DB, but it was decreased to 20.2mg% DB, after 12 months storage. Therefore, loss of ascorbic acid was very great up to 93% of its original content. 4. Five kinds of organic acid, oxalic, succinic, fumaric, malic and citric acid were identified as major organic acids. It was interesting that only fumaric acid content was increased while others decreased during storage. 5. Seventeen kinds of amino acid were identified in the analysis of total amino acid content. Major amino acids were found to be proline, threonine, glutamic acid and lysine. During 12 months storage, 30% of original total amino acid was decreased and this was mostly accounted for free amino acids. 6. Threonine, proline, alanine and valine were identified as free amino acids which showed 85% decrease after 12 months storage. 7. Free sugars of jujube were composed of fructose, glucose and sucrose. They showed 24% decrease after 12 months storage, Especially sucrose was not detected after 4 months storage. 8. HMF of dried jujube was isolated and identified. Its content was increased up to great extent as storage period prolonged. 9. Caffeic, ferulic and P-coumaric acid were identified as jujube phenolic compounds which were significantly decreased during storage. In conclusion, non-enzymatic browning was thought to be more important than enzymatic reaction in the dried jujube. Amino-carbonyl reaction, ascorbic acid oxidation and reaction between phenolic compounds and sugar or nitrogen compounds were observed to be related to this browning.

• Journal of Internet Computing and Services
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• v.24 no.2
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• pp.19-26
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• 2023

Humans have adapted and evolved to natural light. However, as humans stay in indoor longer in modern times, the problem of biorhythm disturbance has been induced. To solve this problem, research is being conducted on lighting that reproduces the correlated color temperature(CCT) of natural light that varies from sunrise to sunset. In order to reproduce the CCT of natural light, multiple LED light sources with different CCTs are used to produce lighting, and then a control index DB is constructed by measuring and collecting the light characteristics of the combination of input currents for each light source in hundreds to thousands of steps, and then using it to control the lighting through the light characteristic matching method. The problem with this control method is that the more detailed the steps of the combination of input currents, the more time and economic costs are incurred. In this paper, an LED lighting control method that applies interpolation and combination calculation based on the minimum spectral power distribution information for each light source is proposed to reproduce the CCT of natural light. First, five minimum SPD information for each channel was measured and collected for the LED lighting, which consisted of light source channels with different CCTs and implemented input current control function of a 256-steps for each channel. Interpolation calculation was performed to generate SPD of 256 steps for each channel for the minimum SPD information, and SPD for all control combinations of LED lighting was generated through combination calculation of SPD for each channel. Illuminance and CCT were calculated through the generated SPD, a control index DB was constructed, and the CCT of natural light was reproduced through a matching technique. In the performance evaluation, the CCT for natural light was provided within the range of an average error rate of 0.18% while meeting the recommended indoor illumination standard.

• Journal of Korean Society of Steel Construction
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• v.16 no.6 s.73
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• pp.725-736
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• 2004

A new type of girder, called steel-confined prestressed concrete girder (SCP girder), has been developed, which maximizes the structural advantages of concrete, steel, and PS tendon, and improves on the shortcomings of steel plate girder, PSC I-girder, and preflex girder bridge for use in the construction of middle- or long-span bridges. To verify the propriety of design, structural safety, and applicability of this girder, a static load test was carried out (Kim et al.., 2002). Since the main damage typically sustained by steel bridges results from the fatigue caused by the repetition of traffic loads, fatigue safety must therefore be guaranteed in applying the SCP girder in the construction of real bridges. In this study, a fatigue test was carried out to investigate fatigue behavior and provide basic data for fatigue design. Based on the fatigue test, the fatigue safety of the girder was estimated. For the fatigue test, 10-m specimens were designed for a standard-design truckload (DB-24). A static load test was also performed before the fatigue test to analyze the structural behavior of the specimens. After the fatigue test, outer steel plates were removed to observe the condition of the concrete in the girder.

• Journal of The Korean Association of Information Education
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• v.24 no.2
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• pp.157-165
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• 2020

As interest in software education has increased, discussions on teaching, learning, and evaluation method it have also been active. One of the problems of software education teaching method is that the instructor cannot grasp the content of coding in progress in the learner's computer in real time, and therefore, instructors are limited in providing feedback to learners in a timely manner. To overcome this problem, in this study, we developed a software education support system that grasps the real-time learner coding situation under block-based programming environment by applying a learning analysis technique and delivers it to the instructor, and visualizes the data collected during learning through the Hadoop system. The system includes a presentation layer to which teachers and learners access, a business layer to analyze and structure code, and a DB layer to store class information, account information, and learning information. The instructor can set the content to be learned in advance in the software education support system, and compare and analyze the learner's achievement through the computational thinking components rubric, based on the data comparing the stored code with the students' code.