• Title/Summary/Keyword: Frames

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Hierarchical Keyframe Selection from Video Shots using Region, Motion and Fuzzy Set Theory (비디오 셧으로부터 영역, 모션 및 퍼지 이론을 이용한 계층적 대표 프레임 선택)

  • Kang, Hang-Bong
    • Journal of KIISE:Software and Applications
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    • v.27 no.5
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    • pp.510-520
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    • 2000
  • For content-based video indexing and retrieval, it is necessary to segment video data into video shots and then select key frames or representative frames for each shot. However, it is very difficult to select key frames automatically because the task of selecting meaningful frames is quite subjective. In this paper, we propose a new approach in selecting key frames based on visual contents such as region information and their temporal variations in the shot. First of all, we classify video shots into panning shots, zooming shots, tilting shots or no camera motion shots by detecting camera motion information in video shots. Then, in each category, we apply appropriate fuzzy rules to select key frames based on meaningful content in frame. Finally, we control the number of key frames in the selection process by adjusting the degree of detail in representing video shots.

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Response modification factor of suspended zipper braced frames

  • Abdollahzadeh, Gholamreza;Abbasi, Mehdi
    • Steel and Composite Structures
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    • v.18 no.1
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    • pp.165-185
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    • 2015
  • The suspended zipper bracing system is suggested to reduce the flaws of ordinary zipper braced and concentric inverted V braced frames. In the design procedure of suspended zipper bracing systems, columns and top story truss elements are strengthened. This bracing system show different performances and characteristics compared with inverted V braced and ordinary zipper frames. As a result, a different response modification factor for suspend zipper frames is needed. In this research paper, the response modification factor of suspended zipper frames was obtained using the incremental dynamic analysis. Suspended zipper braced frames with different stories and bay lengths were selected to be representations of the design space. To analyze the frames, a number of models were constructed and calibrated using experimental data. These archetype models were subjected to 44 earthquake records of the FEMA-P695 project data set. The incremental dynamic analysis and elastic dynamic analysis were carried out to determine the yield base shear value and elastic base shear value of archetype models using the OpenSEES software. The seismic response modification factor for each frame was calculated separately and the values of 9.5 and 13.6 were recommended for ultimate limit state and allowable stress design methods, respectively.

Design and analysis of non-linear space frames with semi-rigid connections

  • Sagiroglu, Merve;Aydin, Abdulkadir Cuneyt
    • Steel and Composite Structures
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    • v.18 no.6
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    • pp.1405-1421
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    • 2015
  • Semi-rigid connections are the actual behavior of beam-to-column connections in steel frames. However, the behavior of semi-rigid connections is not taken into account for the simplicity in the conventional analysis and design of steel frames. A computer-based analysis and design has been studied for the three-dimensional steel frames with semi-rigid connections. The nonlinear analysis which includes the effects of the flexibility of connections is used for this study. It is designed according to the buckling and combined stress constraints under the present loading after the joint deformations and the member end forces of the space frame are determined by the stiffness matrix method. The semi-rigid connection type is limited to the top and bottom angles with a double web angle connection. The Frye-Morris polynomial model is used to describe the non-linear behavior of semi-rigid connections. Various design examples are presented to demonstrate the efficiency of the method. The results of design and analysis of unbraced semi-rigid frames are compared to the results of unbraced rigid frames under the same design requirements.

Seismic performance of concrete frame structures reinforced with superelastic shape memory alloys

  • Alam, M. Shahria;Nehdi, Moncef;Youssef, Maged A.
    • Smart Structures and Systems
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    • v.5 no.5
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    • pp.565-585
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    • 2009
  • Superelastic Shape Memory Alloys (SMAs) are gaining acceptance for use as reinforcing bars in concrete structures. The seismic behaviour of concrete frames reinforced with SMAs is being assessed in this study. Two eight-storey concrete frames, one of which is reinforced with regular steel and the other with SMAs at the plastic hinge regions of beams and regular steel elsewhere, are designed and analyzed using 10 different ground motion records. Both frames are located in the highly seismic region of Western Canada and are designed and detailed according to current seismic design standards. The validation of a finite element (FE) program that was conducted previously at the element level is extended to the structure level in this paper using the results of a shake table test of a three-storey moment resisting steel RC frame. The ten accelerograms that are chosen for analyzing the designed RC frames are scaled based on the spectral ordinate at the fundamental periods of the frames. The behaviour of both frames under scaled seismic excitations is compared in terms of maximum inter-storey drift, top-storey drift, inter-storey residual drift, and residual top-storey drift. The results show that SMA-RC frames are able to recover most of its post-yield deformation, even after a strong earthquake.

Comparison of Nonlinear Analysis Programs for Small-size Reinforced Concrete Buildings I (소규모 철근콘크리트 건축물을 위한 비선형해석 프로그램 비교 I)

  • Yoo, Changhwan;Kim, Taewan
    • Journal of the Earthquake Engineering Society of Korea
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    • v.19 no.5
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    • pp.219-228
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    • 2015
  • For small-size reinforce-concrete buildings, Midas Gen, OpenSees, and Perform-3D, which are structural analysis programs that are most popularly used at present, were applied for nonlinear static pushover analysis, and then difference between those programs was analyzed. Example buildings were limited to 2-story frames only and frames with one or more rectangular walls. Analysis results showed that there was not much difference for frames only based on capacity curves. There were some differences for frames with rectangular walls, but it was not so significant. The global behaviors represented by the capacity curve were not so different, but the feature of each analysis program appeared when the results were analyzed in more detail. Therefore, the program users should understand the feature of the program well, and then conduct performance assessment. The result of this study is limited to low-story frames only and frames with rectangular walls so that it should be noted that it is possible to get different results for frames with non-rectangular walls or mid- to high-rise buildings.

Seismic performance of RC frames retrofitted with haunch technique

  • Akbar, Junaid;Ahmad, Naveed;Alam, Bashir;Ashraf, Muhammad
    • Structural Engineering and Mechanics
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    • v.67 no.1
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    • pp.1-8
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    • 2018
  • Shake table tests performed on five 1:3 reduced scale two story RC moment resisting frames having construction defects, have shown severe joint damageability in deficient RC frames, resulting in joint panels' cover spalling and core concrete crushing. Haunch retrofitting technique was adopted herein to upgrade the seismic resistance of the deficient RC frames. Additional four deficient RC frames were built and retrofitted with steel haunch; both axially stiffer and deformable with energy dissipation, fixed to the beam-column connections to reduce shear demand on joint panels. The as-built and retrofitted frames' seismic response parameters are calculated and compared to evaluate the viability of haunch retrofitting technique. The haunch retrofitting technique increased the lateral stiffness and strength of the structure, resulting in the increase of structure's overstrength. The retrofitting increased response modification factor R by 60% to 100%. Further, the input excitation PGA was correlated with the lateral roof displacement to derive structure response curve that have shown significant resistance of retrofitted models against input excitations. The technique can significantly enhance the seismic performance of deficient RC frames, particularly against the frequent and rare earthquake events, hence, promising for seismic risk mitigation.

Performance-based seismic design of eccentrically braced steel frames using target drift and failure mode

  • Li, Shen;Tian, Jian-bo;Liu, Yun-he
    • Earthquakes and Structures
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    • v.13 no.5
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    • pp.443-454
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    • 2017
  • When eccentrically braced steel frames (EBFs) are in the desired failure mode, links yield at each layer and column bases appear plastically hinged. Traditional design methods cannot accurately predict the inelastic behavior of structures owing to the use of capacity-based design theory. This paper proposes the use of performance-based seismic design (PBSD) method for planning eccentrically braced frames. PBSD can predict and control inelastic deformation of structures by target drift and failure mode. In buildings designed via this process, all links dissipate energy in the rare event of an earthquake, while other members remain in elastic state, and as the story drift is uniform along the structure height, weak layers will be avoided. In this condition, eccentrically braced frames may be more easily rehabilitated after the effects of an earthquake. The effectiveness of the proposed method is illustrated through a sample case study of ten-story K-type EBFs and Y- type EBFs buildings, and is validated by pushover analysis and dynamic analysis. The ultimate state of frames designed by the proposed method will fail in the desired failure mode. That is, inelastic deformation of structure mainly occurs in links; each layer of links involved dissipates energy, and weak layers do not exist in the structure. The PBSD method can provide a reference for structural design of eccentrically braced steel frames.

Cyclic tests of steel frames with composite lightweight infill walls

  • Hou, Hetao;Chou, Chung-Che;Zhou, Jian;Wu, Minglei;Qu, Bing;Ye, Haideng;Liu, Haining;Li, Jingjing
    • Earthquakes and Structures
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    • v.10 no.1
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    • pp.163-178
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    • 2016
  • Composite Lightweight (CL) insulated walls have gained wide adoption recently because the exterior claddings of steel building frames have their cost effectiveness, good thermal and structural efficiency. To investigate the seismic behavior, lateral stiffness, ductility and energy dissipation of steel frames with the CL infill walls, five one-story one-bay steel frames were fabricated and tested under cyclic loads. Test results showed that the bolted connections allow relative movement between CL infill walls and steel frames, enabling the system to exhibit satisfactory performance under lateral loads. Additionally, it is found that the addition of diagonal steel straps to the CL infill wall significantly increases the initial lateral stiffness, load-carrying capacity, ductility and energy dissipation capacity of the system. Furthermore, the test results indicate that the lateral stiffness values of the frames with the CL infill wall are similar to those of the bare steel frames in large lateral displacement.

A Study for necessity that console game machines materialize high frames per second (콘솔 게임기에서 고 프레임 구현 필요성에 관한 고찰)

  • Cho, Hyung-ik
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.533-535
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    • 2014
  • As technology advances, console game machines have developed the abilities to materialize high frames per second. And that have enabled console games machines to implement more active and natural moving. In general moving pictures, 30 frames per second is enough for people to enjoy motion contents. But In the game field, the need for implementation of more than 60 frames are being raised, and there is the controversial that is necessary or not. This paper will analyze that high frames per second (E.g. more 30fps) is really necessary or not in the console game machines, and that is efficient in game playing.

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A Study on the frame within a frame as a Digital Game Design Tool (디지털 게임 설계 장치로서의 다중 프레임 연구)

  • Kim, Da-In;Sung, Jung-Hwan
    • Journal of Korea Game Society
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    • v.21 no.6
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    • pp.111-124
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    • 2021
  • Starting with painting, it is the frame that plays the main role in movies, cartoons, and games as well as the act of attracting the audience's attention. Knowing about a frame is to be able to read and use the frame. Therefore, this paper deals with frames of digital games, especially multiple frames that complement the limited configuration of primary frames. In this paper, frame within frames are classified into structural frames, which are the basic components of the game, temporal frames, which reflect player behavior, and surface frames representing the characteristics of existing visual media. Through this, we examine the aspects of frame within a frame as digital game design equipment. This paper is meaningful in that it derives the possibility of using frame within a frame of games in the future and provides a mechanism for frame within a frame analysis.