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Flexural Experiment of PSC-Steel Mixed Girders and Evaluation for Analyses on Tangentional Stiffness of Connection (프리스트레스트 콘크리트-강 혼합거더의 휨 실험 및 경계면 수평계수 분석)

  • Kim, Kwang-Soo;Jung, Kwang-Hoe;Sim, Chung-Wook;Yoo, Sung-Won
    • Journal of the Korea Concrete Institute
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    • v.20 no.2
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    • pp.231-237
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    • 2008
  • This study was performed to evaluate joint behavior of prestressed concrete(PSC)-steel mixed girders through the flexural test of 14 beams according to embedded length, amount of reinforcing steel, stud arrangement, and prestressing force. All test beams were failed by turns of desertion of reinforcing steel, stud, and steel plate. From test results, prestressing force was more effective on performance of connection than stud arrangement and reinforcing steel. And the spacing of stud is also more effective than embedding length. This paper also presented 3D nonlinear analysis considering the slip of composite section as well as the static load tests of PSC-steel mixed girders. According to the slip modulus, the nonlinear analysis showed that the behavior of hybrid girders could be divided into three parts as full-composite, partial-composite and non-composite. However, the experimental results showed that the PSC-steel hybrid girders with shear connectors took the part of partial composite action in ultimate load stage. In addition, it was founded that stud shear connectors and welded reinforcements were contributed to improve the ultimate strength of hybrid girders for about 20%.

An Evaluation of Applicable Feature of Structural Member Using High Volume Fly-Ash Concrete (다량치환된 플라이애시 콘크리트의 구조부재 적용성 평가)

  • Kim, Gyung-Tae;Yoo, Sung-Won
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.3 no.2
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    • pp.109-114
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    • 2015
  • Recently, numerous studies were dedicated on the HVFA concrete using high volume CCPs. In initial studies, main topics are dependent on material properties of HVFA concrete, but several studies were dedicated on the structural behavior of HVFA concrete such as elasticity modulus, stress-strain relationship and structural behavior nowadays. Therefore, in this paper, on the basis of recent studies on the structural behavior, 2 large-scale test members were manufactured with 7.5m span length and fly ash replacement ratio 50%, concrete compressive strength 50MPa in order to apply to the practical structure and evaluate possibility of application. From the test results, although there were small differences between test results and existing research results on the stress-strain relationship, the application to practical structure is not hard. In flexural test, as the produced pattern of displacement and strain were similar to those of general concrete without fly ash, the difference between 50% fly ash concrete and general concrete is very small. And the concrete shear strength obtained by test was similar to that of design code, so existing design code will be also able to apply.

Design of Optimized pRBFNNs-based Face Recognition Algorithm Using Two-dimensional Image and ASM Algorithm (최적 pRBFNNs 패턴분류기 기반 2차원 영상과 ASM 알고리즘을 이용한 얼굴인식 알고리즘 설계)

  • Oh, Sung-Kwun;Ma, Chang-Min;Yoo, Sung-Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.6
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    • pp.749-754
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    • 2011
  • In this study, we propose the design of optimized pRBFNNs-based face recognition system using two-dimensional Image and ASM algorithm. usually the existing 2 dimensional face recognition methods have the effects of the scale change of the image, position variation or the backgrounds of an image. In this paper, the face region information obtained from the detected face region is used for the compensation of these defects. In this paper, we use a CCD camera to obtain a picture frame directly. By using histogram equalization method, we can partially enhance the distorted image influenced by natural as well as artificial illumination. AdaBoost algorithm is used for the detection of face image between face and non-face image area. We can butt up personal profile by extracting the both face contour and shape using ASM(Active Shape Model) and then reduce dimension of image data using PCA. The proposed pRBFNNs consists of three functional modules such as the condition part, the conclusion part, and the inference part. In the condition part of fuzzy rules, input space is partitioned with Fuzzy C-Means clustering. In the conclusion part of rules, the connection weight of RBFNNs is represented as three kinds of polynomials such as constant, linear, and quadratic. The essential design parameters (including learning rate, momentum coefficient and fuzzification coefficient) of the networks are optimized by means of Differential Evolution. The proposed pRBFNNs are applied to real-time face image database and then demonstrated from viewpoint of the output performance and recognition rate.

Physicochemical and Functional Properties of Kochujang with Broccoli Leaf Powder (브로콜리잎 분말 첨가 재래식 고추장의 이화학적 및 기능적 특성)

  • Oh, You-Sung;Baek, Jin-Woo;Park, Kyeong-Yeol;Hwang, Joon-Ho;Lim, Sang-Bin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.5
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    • pp.675-681
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    • 2013
  • Home-made broccoli Kochujang (HMBK) was prepared with the addition of 5% broccoli leaf powder. Its physicochemical and functional properties were measured in extracts (80% methanol, 80% ethanol, and distilled water) and compared with home-made Kochujang (HMK) and factory-produced Kochujang (FPK). Total phenolic content (TPC) was 22% higher in methanol extract from HMBK (524.2 GAE/100 g) compared to HMK (431.0 GAE/100 g). TPC was 8% higher in ethanol extract from HMBK (541.9 GAE/100 g) compared to HMK (499.9 GAE/100 g). DPPH radical scavenging activity was 1.6 times higher in the methanol extracts from HMBK than HMK. In contrast there was no difference in DPPH radical scavenging activity between HMBK and HMK. Oxygen radical absorbance capacities in methanol and ethanol extracts from HMBK were similar to HMK, but both were higher than extracts from FPK (55% and 23% higher, respectively). Inhibition of angiotensin I converting enzyme activity in methanol extracts from HMBK was similar to HMK, but it was 2.6 times higher than inhibition activities from FPK. Interestingly, only ethanol extract from HMBK showed a 10.7% and 18.3% inhibition on cell growth of the human colon adenocarcinoma grade II cell line (HT-29) and human lung carcinoma cell line (NCI-H1229), respectively. These results indicate home-made Kochujang with broccoli leaf powder contains high total phenolics, antioxidant activities, and cancer cell growth inhibition activities.

Development of an Underwater Rope-cutter Device and Controller for Removal of Propeller and Shaft Foreign Material for Small Vessel (소형선박용 프로펠러 및 샤프트 이물질 제거를 위한 수중절단기 기구 설계 및 제어기 개발)

  • Lee, Hunseok;Oh, Jin-Seok;Choi, Sun-Hong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.7
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    • pp.927-935
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    • 2019
  • Screw-failure accidents in small ships frequently occur in coastal waters. In particular, vessels' propulsion systems are frequently coiled due to objects such as fish-nets and ropes that float on the sea. The failure of the ship's propulsion system can cause primary accidents such as ship operation delays and drifting due to loss of power; furthermore, the possibility of secondary accidents such as those involving operators in the underwater removal of rope stuck in a propeller. Ships that do not have the proper tools to solve these problems must be either lifted onto land to be repaired or divers must dive directly under the ship to solve the problem. Accordingly, some small vessels have been equipped with rope-cutter devices on the propeller shaft to prevent ship propeller system accidents in recent years; however, they are not being applied efficiently due to the cost and time of installation. To solve these problems, this study develops an underwater rope-cutter device and controller for the removal of propeller and shaft foreign material in small vessels. This device has simple structures that use the principle of a saw. Meteor gears and crank pins were used for the straight-line rotation of saw blades of the underwater rope-cutters to allow for long strokes. Furthermore, the underwater rope-cutting machines can be operated by being connected to the ship battery. The user, a non-professional, can ensure convenience and stability by applying reverse current prevention and a speed control circuit so that it can be used more conveniently and safely.

Development and the Long-Term Test of Anti-Adhesion Surface Coating Technology on Electric Power Distribution Equipment (배전기기 외함 부착방지 및 자기세정 코팅기술 개발 및 현장실증)

  • Shim, Myung Jin;Sohn, Song Ho;Seo, Ji Hoon;Han, Sang Chul
    • KEPCO Journal on Electric Power and Energy
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    • v.6 no.3
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    • pp.285-288
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    • 2020
  • The demand for coating technology on electric power equipment that has arisen from such issues regarding the attaching of illegal advertisements and posters to electric power distribution boxes such as TR, SW, etc. in down town areas seeks to produce functional coating surfaces using polymers and nano-materials that will result in improvements in self-cleaning performance and greater stability even under harsh environmental conditions. KEPCO-coatings consist of copolymerized acrylic resin and methacryl-modified reactive silicone that are able to chemically combine, which results in performance improvement without any leakage of of silicone, thus contributing to its properties of high-stability. Thus, the research team has also started long-term on-site testing on 9 electric power distribution spots around a city center in cooperation with the KEPCO Daeduck-yusung branch. The KEPCO-coating technology could advance the best coating materials and processes to meet appropriate circumstances for a variety of outdoor damage environment. It is also predicted that KEPCO could be possible to expand international electric maintenance markets and to arrange business platforms if KEPCO would achieve its original technology (IPs) by the means of upgrading in self-cleaning coating technology and obtaining long-term on-site test records from nationwide electric facilities.

Evaluation of Street Tree Rootage by Transplanting Methods - Photochemical Response Analysis of Different Cultivation for Sorbus alnifolia - (가로수의 이식방법에 따른 수목 활착 평가 - 재배방법별 팥배나무의 광화학적 반응 해석 -)

  • Yoo, Sung Young;Park, So Hyun;Park, Chung In;Kim, Tae Jin
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.1
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    • pp.132-138
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    • 2015
  • Trees, cultivated in containers, are appropriate in soil deformation such as road sites with cutting and filling. This study tested the effectiveness of trees produced in containers for early rootage in street tree transplantation. For the study, Korean Mountain Ashes(Sorbus alnifolia) were used for experimental groups. The groups were categorized into three categories: trees cultivated in containers with mulching treatment(group A), trees cultivated outdoors with mulching treatment (group B), and trees cultivated in containers with weeding treatment(group C). Each group consisted of ten trees of the same size and transplanted to the experimental site. In order to compare each group's rootage, the study was carried out with the chlorophyll fluorescence method by the analysis of photochemical reaction. As a result of the study, group B had the lowest the maximum fluorescence amount(P). The amount of fluorescence increased by OJ transition of the process, and appeared to reduce the photosystem II electron transport efficiency. In photosystem II, electron transfer energy flux through photosystem I(RE1o/RC, RE1o/CS) was also reduced by more than 20% in group B. These results may imply that transplantation of container-cultivated trees with mulching treatment provides the most rapid rootage among the groups. The weeding treatment is also more effective than mulching treatment for rapid rootage of street trees.

An Experiment of Structural Performance of Expansion Joint with Rotation Finger (가변형 핑거 조인트를 가지는 신축이음장치의 구조 성능 실험)

  • Yoo, Sung won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.6
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    • pp.170-175
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    • 2018
  • For the seismic performance, it is necessary to prevent the destruction of the expansion joint device due to the appropriate deformation of the expansion joint device due to the seismic force. Recently, the hinge is installed on the fingering of the expansion joint device in Korea, New products are being developed. In this paper, we have experimentally evaluated the real scale resistance of the expansion joints with rotational finger joints against load at right angle to the bridge axis. Experimental results show that the maximum horizontal displacement is about 21.1mm for conventional stretch joints and 51.00mm for seismic stretch joints. It is presumed that the existing expansion joint test specimen is resistant to the load in a direction perpendicular to the throat axis, and then the bending and shear deformation of the finger are excessively generated and the fracture phenomenon is likely to occur. On the other hand, in the case of the seismic expansion joint, the deformation of the load due to the load is absorbed by the hinge of the finger with respect to the load in the direction perpendicular to the throat, so that only horizontal deformation in the direction of load action.

The Research Work of Development of Imaging Media and Expansion of The Animation Expression - Focusing on The Expansion of Space for Frozen (영상미디어 기술의 발달과 애니메이션 표현력의 확장에 대한 연구 -<겨울왕국>에서 나타난 공간의 확장 중심으로)

  • Lim, Jae Min;Lee, Jong Han
    • Cartoon and Animation Studies
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    • s.36
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    • pp.325-347
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    • 2014
  • "The art challenges the technology, and the technology inspires the art." By this word John Lasseter expressed Pixar animations main soul of story. Media technology has a close relation with the animation. As media developed more and more, an animation has been widen a lot and have given new visions to the audiences. We can see such this figure from the history of the Disney animation. They had tried to make all the kind of animations such a silent animation, planetary animation, black and white animation and the multi colored animation. Lately Disney had made animation that has traditional style. But the method of making traditional animation stable side story's holdup the audience. So Disney animation decided to change this method. For the result of Disney animation studio effort Frozen had produced after a computer graphics work following Rapunzel. What was the reason for entertain well of Frozen? Not only changing the method of producing traditional to computer graphic is could not make entertain well. We can see from the Frozen concordance of the original idea and modern scenario, OST the perfection of computer graphics work. In this paper work Disney animation has worked from the silent animation to computer graphic works result of "The Frozen". For the contribution of technology development makes able to analyze animations expression and relation. There is a lot shots that hard to analyze in the Frozen. But I will study it with the method named "Expansion in space" to making main analyzing expressive extension that appears on the scene.

The Estimation of Bio-kinetic Parameters using Respirometric Analysis (산소이용률을 이용한 생물학적 동력학 계수 추정)

  • Choung, Youn-Kyoo;Kim, Han-Soo;Yoo, Sung-In
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.1
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    • pp.11-19
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    • 2000
  • In order to predict the performance of biological wastewater treatment plant, the kinetic parameters and stoichiometric coefficient must be known. The theories and experimental procedures for determining the biological kinetic parameters were discussed in this study. Respirometric analysis in the batch reactor was carried out for the experimental assessment of kinetic parameters. A simple procedure to estimate kinetic parameters of heterotrophs and autotrophs under aerobic condition was presented. The difficulties in the interpretation of COD and VSS measurements encouraged the conversion of respirometric data to growth data. Maximum specific growth rate, yield coefficient, half saturation constant and decay rate of heterotrophic biomass were obtained from OUR(Oxygen Uptake Rate) data. Maximum specific growth rate of autotrophic biomass was obtained from the increase of nitrate concentration. The aim of this paper is to estimate the kinetic parameters of heterotrophic and autotrophic biomass by means of the respirometric analysis of activated sludge behavior in the batch reactors. These procedures may be used for the activated sludge modeling with complex kinetic parameters.

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