• Steel and Composite Structures
• /
• v.36 no.4
• /
• pp.383-398
• /
• 2020

This paper investigates the progressive collapse behavior of 3D steel-framed gravity buildings under fires with a cooling phase. The effect of fire protections and bracing systems on whether, how, and when a gravity building collapses is studied. It is found that whether a building collapses or not depends on the duration of the heating phase, and it may withstand a "short-hot" fire, but collapses under a mild fire or a "long-cool" fire. The collapse time can be conservatively determined by the time when the temperature of steel columns reaches a critical temperature of 550 ℃. It is also found that the application of a higher level of fire protection may prevent the collapse of a building, but may also lead to its collapse in the cooling phase due to the delayed temperature increment in the heated members. The tensile membrane action in a heated slab can be resisted by a tensile ring around its perimeter or by tensile yielding lines extended to the edge of the frame. It is recommended for practical design that hat bracing systems should be arranged on the whole top floor, and a combination of perimeter and internal vertical bracing systems be used to mitigate the fire-induced collapse of gravity buildings. It is also suggested that beam-to-column connections should be designed to resist high tensile forces (up to yielding force) during the cooling phase of a fire.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.22 no.2
• /
• pp.372-379
• /
• 1998

A new 6 degrees-of-freedom micro stage, based on parallel mechanisms and actuated by using piezoelectric elements, has been developed for the application of micro positioning such as semiconductor manufacturing devices, high precision optical measurement systems, and high accurate machining. The micro stage structure consists of a base platform and an upper platform(stage). The base platform can effectively generates planar motion with yaw motion, while the stage can do vertical motion with roll and pitch motions with respect to the base platform. This separated structure has an advantage of less interference among actuators. The forward and inverse kinematics of the micro stage are discussed. Also, through linearization of kinematic equations about an operating point on the assumption that the configuration of the micro stage remains essentially constant throughout a workspace is performed. To maximize the workspace of the stage relative to fixed frame, an optimal design procedure of geometric parameter is shown. Hardware description and a prototype are presented. The prototype is about 150mm in height and its base platform is approximately 94mm in diameter. The workspace of the prototype is obtained by computer simulation. Kinematic calibration procedure of the micro stage and its results are presented.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.31 no.2
• /
• pp.173-180
• /
• 2013

In this paper, we studied on measurement of soil deformation around the tip of model pile by close-range photogrammetry. The rigorous bundle adjustment method was utilized to monitor the soil deformation in the laboratory model pile-load test as function of incremental penetration of the pile. Control points were installed on the frame of the laboratory model box case and more than 150 target points were inserted inside the soil around the model pile and on the surface. Four overlapping images including three horizontal and one vertical image were acquired by a non-metric camera for each penetration step. The images were processed to automatically locate the control and target points in the images for the self-calibration and the bundle adjustment. During the bundle adjustment, the refraction index of the acrylic case of the laboratory model was accounted for accurate measurement. The experiment showed the proposed approach enabled the automated photogrammetric monitoring of soil deformation around the tip of model pile.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.9
• /
• pp.2294-2301
• /
• 1998

The aim of this paper is to extract features from each news scenes for example, symbol icon which can be distinct each broadcasting corp, icon and caption which are has feature and important information for the scene in respectively, In this paper, we propose extraction methods of caption that has important prohlem of news videos and it can be classified in three steps, First of al!, we converted that input images from video frame to YIQ color vector in first stage. And then, we divide input image into regions in clear hy using equalized color histogram of input image, In last, we extracts caption using edge histogram based on vertical and horizontal line, We also propose the method which can extract news icon in selected key frames by the difference of inter-histogram and can divide each scene by the extracted icon. In this paper, we used comparison method of edge histogram instead of complex methcxls based on color histogram or wavelet or moving objects, so we shorten computation through using simpler algorithm. and we shown good result of feature's extraction.

• The Journal of Internal Korean Medicine
• /
• v.38 no.6
• /
• pp.917-929
• /
• 2017

Objectives: The objective of this study was to investigate the validity of the preliminary critical pathway of integrative medicine to improve the quality of life of lung cancer patients who received chemotherapy. Methods: The vertical axis of the preliminary critical pathway of integrated medicine consisted of nine domains: assessment, treatment, activity, consult, diet, medication, Korean medical examination, education, and others. The frame of the horizontal axis was the date from hospitalization to discharge. A total of 105 items in this preliminary critical pathway were validated by an expert group from October 28, 2016 to November 4, 2016. A total of ten experts from two different medical institutions participated in the validity test, using the four-point Content Validity Index (CVI) scale. The items with validity of greater than 80% were considered as significant. Results: The analysis of the content validity of 105 items showed 102 items with greater than 80% agreement. Assessment, treatment, consult, diet, medication, and education showed 100% agreement. Only three items showed a low validity (62.5%). Based on additional comments, the preliminary critical pathway of integrative medicine has been supplemented. Conclusions: This study suggests the possibility of using the integrated medical critical pathway for patients with lung cancer who received chemotherapy.

• The Journal of the Korea Contents Association
• /
• v.2 no.2
• /
• pp.17-26
• /
• 2002

In this paper, we suggest a method to acquire the moving object centered video by panning and tilting a camera automatically according to motion vectors calculated by detecting the motion of a moving object on video steam. We create a difference image by estimating the intensity difference at the grid points of neighboring frames. And we detect the motion using both horizontal projection histogram and vertical projection histogram and decide the center of motion part. Then we calculate a new direction and degree of the motion by comparing coordinates at the center of current motion and the center of previous motion. By controling the RCM using these Motion vectors, we can get video stream positioned unwire object on the center of video frame. Through the experiments, we could get a moving object centered video stream continuously arid monitor remotely by implementing sever/client architecture based on the web.

• Earthquakes and Structures
• /
• v.8 no.5
• /
• pp.1215-1240
• /
• 2015

In this paper, the Theory of Plastic Mechanism Control (TPMC) is applied to the seismic design of dual systems composed by moment-resisting frames and Chevron braced frames. The application of TPMC is aimed at the design of dual systems able to guarantee, under seismic horizontal forces, the development of a collapse mechanism of global type. This design goal is of primary importance in seismic design of structures, because partial failure modes and soft-storey mechanisms have to be absolutely prevented due to the worsening of the energy dissipation capacity of structures and the resulting increase of the probability of failure during severe ground motions. With reference to the examined structural typology, diagonal and beam sections are assumed to be known quantities, because they are, respectively, designed to withstand the whole seismic actions and to withstand vertical loads and the net downward force resulting from the unbalanced axial forces acting in the diagonals. Conversely column sections are designed to assure the yielding of all the beam ends of moment-frames and the yielding and the buckling of tensile and compressed diagonals of the V-Braced part, respectively. In this work, a detailed designed example dealing with the application of TPMC to moment frame-chevron brace dual systems is provided with reference to an eight storey scheme and the design procedure is validated by means of non-linear static analyses aimed to check the actual pattern of yielding. The results of push-over analyses are compared with those obtained for the dual system designed according to Eurocode 8 provisions.

• Geomechanics and Engineering
• /
• v.12 no.4
• /
• pp.689-705
• /
• 2017

The present study deals with the Pressure-settlement behavior of square and rectangular skirted footing resting on sand and subjected to a vertical load through a laboratory experimental study. A series of load tests were conducted in the model test tank to evaluate the improvement in pressure-settlement behavior and bearing capacity of square and rectangular model footings with and without structural skirt. The footing of width 5 cm and 6 cm and length/width ratio of 1 and 2 was used. The relative density of sand was maintained at 30%, 50%, 70%, and 87% respectively. The depth of skirt was varied from 0.25 B to 1.0 B. All the tests were carried out using a strain controlled loading frame of 50 kN capacity. The strain rate for all test was kept 0.24 mm/min. The results of present study reveal that, the use of structural skirt improves the bearing capacity of footing significantly. The improvement in bearing capacity was observed almost linearly proportional to the depth of skirt. The improvement in bearing capacity of skirted footings over footing without skirt was observed in the range of 33.3% to 68.5%, 68.9% to 127% and 146.7% to 262% for a skirt depth of 0.25 B, 0.50 B and 1.0 B respectively. The skirted footings were found more effective for sand at relative density of 30% and 50% than at relative density of 70% and 87%. The bearing capacity was found to increase linearly with footing width for footings with and without skirts. This observation was found to be consistent for footings with different skirt depths and for relative density of sand i.e., 30%, 50%, 70%, and 87%. The obtained results from the study for footing with and without skirts were comparable with available solutions from literature.

• Journal of Broadcast Engineering
• /
• v.8 no.3
• /
• pp.306-316
• /
• 2003

When a cinema being composed of 24 frames/sec is converted to NTSC video or TV program, several fields we repeated to have 60 fields/sec, which is called the telecine or 3:2 pull-down. Hence, when encoding the telecine NTSC video into MPEG format, if we convert it into the original 24 frames/sec Progressive cinema, then we can save 20% of bits compared to the case of encoding all the 60 fields. In this Paper, we propose an algorithm for performing the inverse telecine by using the properties of the frames. Specifically, the algorithm exploits the fact that there Is much Inconsistency between the even and odd fields in the case of telecine frame, which results in high magnitude at the Nyquist frequency In the vertical direction. The experiment shows that the proposed algorithm performs very well regardless of the quality of video with a very few computations, whereas the conventional motion based method requires much computational complexity and its performance is degraded when the video is of low (eg. VHS) quality.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.10 no.5
• /
• pp.27-33
• /
• 2010

In this study, a monotonic loading test to estimate structural capacity of 12 meter long full scale precast pre-stressed concrete beam specimen was performed with a 2,000 kN dynamic actuator. A couple of embedded steel plate was installed at the ends of the beam and specimens were connected to steel girder frame with high tension bolts. Nominal compressive strength of pre-stressed concrete beam and slab were 50 MPa and 24 MPa respectively. Two HD25 tensile steel reinforcements were welded on vertical plate of embedded steel plate. Pre-stressed concrete beam specimen was loaded by displacement control method with a certain loading pattern which was repeated loading and unloading with 10mm increment displacement. About 88.34%, 86.97% and 66.83% of displacement restoration ratios were evaluated at elastic, inelastic and plastic behavior region of specimen respectively.