• Advances in concrete construction
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• v.11 no.1
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• pp.33-43
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• 2021

A new type of composite insulated concrete sandwich wall (ICS-wall), which is composed of a triangle truss steel wire network, an insulating layer, and internal and external concrete layers, is proposed. To study the mechanical properties of this new ICS-wall, tensile, compression, and shearing tests were performed on 22 specimens and tensile strength and corrosion resistance tests on 6 triangle truss joints. The variables in these tests mainly include the insulating plate material, the thickness of the insulating plate, the vertical distance of the triangle truss framework, the triangle truss layout, and the connecting mode between the triangle truss and wall and the material of the triangle truss. Moreover, the failure mode, mechanical properties, and bearing capacity of the wall under tensile, shearing, and compression conditions were analyzed. Research results demonstrate that the concrete and insulating layer of the ICS-wall are pulling out, which is the main failure mode under tensile conditions. The ICS-wall, which uses a graphite polystyrene plate as the insulating layer, shows better tensile properties than the wall with an ordinary polystyrene plate. The tensile strength and bearing capacity of the wall can be improved effectively by strengthening the triangle truss connection and shortening the vertical distances of the triangle truss. The compression capacity of the wall is mainly determined by the compression capacity of concrete, and the bonding strength between the wall and the insulating plate is the main influencing factor of the shearing capacity of the wall. According to the tensile strength and corrosion resistance tests of Austenitic stainless steel, the bearing capacity of the triangle truss does not decrease after corrosion, indicating good corrosion resistance.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1287-1294
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• 2021

This paper is a study on the implementation of a sensor-based smart compression system for improving home and street environments. Since modernization, the amount of garbage has been increasing every year, and this has seriously adversely affected not only people but also ecosystems such as marine pollution and soil pollution. In particular, in large cities with large floating populations, garbage is dumped on the streets without proper measures to deal with the amount of waste generated. In order to improve this problem, this paper intends to implement a system with automatic compression and opening/closing functions using sensors. This system is designed to activate automatic opening/closing function through an infrared sensor, and automatically opening and closing when the inclination is changed using an impact sensor. In addition, by installing a distance sensor, the amount of internal waste can be easily monitored from the outside, and a manual compression switch and a manual opening/closing switch is separately designed to enable opening and closing and compression as needed to increase the effectiveness.

• Steel and Composite Structures
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• v.42 no.5
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• pp.617-631
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• 2022

To study the eccentric compressive performance of the basalt-fiber reinforced recycled aggregate concrete (BFRRAC)-filled circular steel tubular stub column, 8 specimens with different replacement ratios of recycled coarse aggregate (RCA), basalt fiber (BF) dosage, strength grade of recycled aggregate concrete (RAC) and eccentricity were tested under eccentric static loading. The failure mode of the specimens was observed, and the relationship curves during the entire loading process were obtained. Further, the load-lateral displacement curve was simulated and verified. The influence of the different parameters on the peak bearing capacity of the specimens was analyzed, and the finite element analysis model was established under eccentric compression. Further, the design-calculation method of the eccentric bearing capacity for the specimens was suggested. It was observed that the strength failure is the ultimate point during the eccentric compression of the BFRRAC-filled circular steel tubular stub column. The shape of the load-lateral deflection curves of all specimens was similar. After the peak load was reached, the lateral deflection in the column was rapidly increased. The peak bearing capacity decreased on enhancing the replacement ratio or eccentric distance, while the core RAC strength exhibited the opposite behavior. The ultimate bearing capacity of the BFRRAC-filled circular steel tubular stub column under eccentric compression calculated based on the limit analysis theory was in good agreement with the experimental values. Further, the finite element model of the eccentric compression of the BFRRAC-filled circular steel tubular stub column could effectively analyze the eccentric mechanical properties.

• Advances in concrete construction
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• v.13 no.2
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• pp.199-213
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• 2022

Experimental and discrete element approaches were used to examine the effects of F shape non-persistent joints on the failure behaviour of concrete under uniaxial compressive test. concrete specimens with dimensions of 200 cm×200 cm×50 cm were provided. Within the specimen, F shape non-persistent joint consisting three joints were provided. The large joint length was 6 cm, and the length of two small joints were 2 cm. Vertical distance between two small joints change from 1.5 cm to 4.5 cm with increment of 1.5 cm. In constant joint lengths, the angle of large joint change from 0° to 90° with increments of 30°. Totally 12 different models were tested under compression test. The axial load rate on the model was 0.05 mm/min. Concurrent with experimental tests, numerical simulation (Particle flow code in two dimension) were performed on the models containing F shape non-persistent joint. Distance between small joints and joint angles were similar to experimental one. the results indicated that the failure process was mostly governed by both of the Distance between small joints and joint angles. The axial loading rate on the model was 0.05 mm/min. The compressive strengths of the samples were related to the fracture pattern and failure mechanism of the discontinuities. Furthermore, it was shown that the compressive behaviour of discontinuities is related to the number of the induced tensile cracks which are increased by increasing the joint angle. In the first, there were only a few acoustic emission (AE) hits in the initial stage of loading, and then AE hits rapidly grow before the applied stress reached its peak. Furthermore, a large number of AE hits accompanied every stress drop. Finally, the failure pattern and failure strength are similar in both approaches i.e., the experimental testing and the numerical simulation approaches.

• Journal of Korea Multimedia Society
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• v.15 no.2
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• pp.215-225
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• 2012

In multimedia database, a multidimensional space-based indexing has been used to increase search efficiency. However, this method is inefficient in terms of ubiquity because it uses Euclidean distance as a scale of distance calculation. On the contrary, a metric space-based indexing method, in which metric axiom is prerequisite is widely available because a metric scale other than Euclidean distance could be used. This paper is attempted to propose a way of improving VP-tree, one of the metric space indexing methods. The VP-tree calculates the distance with an object which is ultimately linked to the a leaf node depending on the node fit for the search range from a root node and examines if it is appropriate with the search range. Because search speed decreases as the number of distance calculations at the leaf node increases, however, this paper has proposed a method which uses the latest interface on query object as the base point of trigonometric inequality for improvement after focusing on the trigonometric inequality-based range compression method in a leaf node. This improvement method would be able to narrow the search range and reduce the number of distance calculations. According to a system performance test using 10,000 video data, the new method reduced search time for similar videos by 5-12%, compared to a conventional method.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.2
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• pp.119-122
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• 2013

Repetitive strings such as periods have been studied vigorously in so diverse fields as data compression, computer-assisted music analysis, bioinformatics, and etc. In bioinformatics, periods are highly related to repetitive patterns in DNA sequences so called tandem repeats. In some cases, quite similar but not the same patterns are repeated and thus we need approximate string matching algorithms to study tandem repeats in DNA sequences. In this paper, we propose a new definition of approximate periods of strings based on distance sum. Given two strings $p({\mid}p{\mid}=m)$ and $x({\mid}x{\mid}=n)$, we propose an algorithm that computes the minimum approximate period distance based on distance sum. Our algorithm runs in $O(mn^2)$ time for the weighted edit distance, and runs in O(mn) time for the edit distance, and runs in O(n) time for the Hamming distance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4A
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• pp.217-225
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• 2012

Structural behavior of built-up compression members with unsymmetric connectors under buckling status has been studied through these experiments. When the distance between adjacent H-300 beams of built-up compression member is 2 m in length, and the H-300 beams are lengthened up to 30 m in length with three-10 m-H-beams by bolts and double arrayed, three specimen having each connector plate, single channel, double channel are experimented for evaluating buckling loads. The buckling loads from the experiments are compared with buckling loads of structural analysis using FEM and buckling loads of Timoshenko Eq. in order to figure out how the connectors' type affects on longitudinal and lateral displacements, also strain of the built-up compression members as well. The result from the experiments show that the buckling loads 4.2% decreases in double channel connectors and 36.6% decreases in single channel connectors than plate connectors.

• The Journal of the Korea Contents Association
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• v.5 no.4
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• pp.188-196
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• 2005

This paper presents a new test data compression and low power scan test method that can reduce test time and power consumption. A proposed method can reduce the scan-in power and test data volume using a modified scan cell reordering algorithm and hybrid adaptive encoding method. Hybrid test data compression method uses adaptively the Golomb codes and run-length codes according to length of runs in test data, which can reduce efficiently the test data volume compare to previous method. We apply a scan cell reordering technique to minimize the column hamming distance in scan vectors, which can reduce the scan-in power consumption and test data. Experimental results for ISCAS 89 benchmark circuits show that reduced test data and low power scan testing can be achieved in all cases. The proposed method showed an about a 17%-26% better compression ratio, 8%-22% better average power consumption and 13%-60% better peak power consumption than that of previous method.

• Physical Therapy Rehabilitation Science
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• v.7 no.2
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• pp.78-82
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• 2018

Objective: The purpose of this study was to determine the effect of wearing a pelvic compression belt on ball speed and accuracy in instep shoots of youth soccer players. Design: Randomized cross-over design. Methods: We included 20 male junior soccer players with experience of more than 5 years. Participants were randomly assigned to two conditions: application of a pelvic compression belt and instep shooting or no application. Instep shooting was performed three times at a distance of 20 meters from the position of the goal post, and the ball speed was measured using a speed gun at a position 5 meters behind the goal post. The shooting accuracy was measured based on a 5-point scale. The shooting accuracy was measured by scoring 5 points at 2.44 meters in the middle of the goal area of area A, 3 points at 2.44 meters in the goal area of area B, and 0 in the case of shooting outside the goal area C. Results: After applying a pelvic compression belt, the mean speed of the ball was significantly increased (p<0.05). The maximum speed of the ball was significantly increased (p<0.05). The accuracy of the ball was significantly increased (p<0.05). Conclusions: Through this study, we expect that the use of the pelvic compression belt can be applied as a training method to improve the shooting ability of soccer players. Clinically, pelvic compression belts are expected to help rehabilitation soccer players to improve their shooting accuracy.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.1
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• pp.53-59
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• 2009

Multi-view video is necessary to develop a new compression encoding technique for storage and transmission, because of a huge amount of data. Layered depth image is an efficient representation method of multi-view video data. This method makes a data structure that is synthesis of multi-view color and depth image. This paper proposed enhanced compression method by presentation of efficient layered depth image using real distance comparison, solution of overlap problem, and interpolation. In experimental results, confirmed high compression performance.