• The KIPS Transactions:PartA
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• v.13A no.6 s.103
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• pp.533-540
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• 2006

This paper describes the design and implementation of a grid system META (Metacomputing Environment using Test-run of Application) which facilitates the execution of a CFD (Computational Fluid Dynamics) analysis program on distributed environment. The grid system META allows the CFD program developers can access the computing resources distributed over the network just like one computer system. The research issues involved in the grid computing include fault-tolerance, computing resource selection, and user-interface design. In this paper, we exploits an automatic resource selection scheme for executing the parallel SPMD (Single Program Multiple Data) application written in MPI (Message Passing Interface). The proposed resource selection scheme is informed from the network latency time and the elapsed time of the kernel loop attained from test-run. The network latency time highly influences the executional performance when a parallel program is distributed and executed over several systems. The elapsed time of the kernel loop can be used as an estimator of the whole execution time of the CFD Program due to a common characteristic of CFD programs. The kernel loop consumes over 90% of the whole execution time of a CFD program.

• Fire Science and Engineering
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• v.18 no.1
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• pp.18-23
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• 2004

This paper describes the minimum ignition limits for propane-air 5.25 Vol.% mixture gases in low voltage inductive circiuts. The improved effects on the ignition limit are studied by parallel safety components(resistors) for propane-air 5.25 Vol.% mixture gas in low voltage inductive circuits. The experimental devices used in this test are the IEC type spark ignition test apparatus. The minimum ignition limits are controlled by the values of current in inductive circuit. Energy supplied from electric source is first accumulated at the inductance, it's extra energy is working as ignition source of the explosive gas. The improved effects on the ignition limit are respectively obtained as the maximum rising rate of 330% by composing parallel circuits between inductance and resistor as compared with disconnecting inductance with the safety components. The more values of inductance increase the higher improved effects of ignition limit rise. The less values of resistor the higher improved effects of ignition limit rise. It is considered that the result can be used for not only data for researches and development of intrinsically safe explosion-proof machines which are applied equipment and detectors used in dangerous areas but also for datum for its equipment tests.

• Journal of the Korean Wood Science and Technology
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• v.50 no.1
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• pp.1-11
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• 2022

To evaluate the bearing strength of red pine cross-laminated timber (CLT) with self-tapping screw (STS), which is widely used as a fastener for connection in CLT building, the bearing test was conducted. Accoring to the STS's diameters (8, 10, 12 mm), the bearing test specimens with half hole were manufactured. Bearing strength was compared and reviewed in consideration of the configuration in STS and the loading direction to the grain of red pine. As a result of the bearing test on the STS's diameter, the yield bearing load increases as the larger diameter of the STS in all directions of the red pine. The bearing strength of the thread part (thread + tip) was higher than the shank part (shank + shank cutter). In compared with the directions to the grain of red pine, the bearing strength of the cross section parallel to the loading direction was the highest, and the tangent section was the lowest bearing strength. The average bearing strength of the loading direction in parallel to the grain was 23.43 MPa, which was about 45% higher than the average 16.16 MPa in perpendicular to the grain. The predicted bearing strength calculated by Eurocode (EN) and Korean Building Code (KBC)'s equation was lower than the experimental value. It is nessesary to propose the new equations of bearing strength reflected the configuration information of STS.

• Journal of Broadcast Engineering
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• v.18 no.2
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• pp.178-184
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• 2013

In this paper, we propose an efficient parallelization technique of PU-level motion estimation (ME) in the next generation video coding standard, high efficiency video coding (HEVC) to reduce the time complexity of video encoding. It is difficult to encode video in real-time because ME has significant complexity (i.e., 80 percent at the encoder). In order to solve this problem, various techniques have been studied, and among them is the parallelization, which is carefully concerned in algorithm-level ME design. In this regard, merge estimation method using merge estimation region (MER) that enables ME to be designed in parallel has been proposed; but, parallel ME based on MER has still unconsidered problems to be implemented ideally in HEVC test model (HM). Therefore, we propose two strategies to implement stable parallel ME using MER in HM. Through experimental results, the excellence of our proposed methods is shown; the encoding time using the proposed method is reduced by 25.64 percent on average of that of HM which uses sequential ME.

• Journal of the Korean Wood Science and Technology
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• v.35 no.3
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• pp.10-21
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• 2007

It is necessary to study about moment performance of glulam-dowel connections which had been applied rotation. To analyze and predict the moment performance, angled to grain load was replaced with parallel to grain load and perpendicular to grain load. The dowel bending strength and dowel bearing strength were tested. And tensile strength test for connections of two different end distances was performed. Specimens of rotation test were composed with different drift pin numbers and drift pin arrangement. Connection deformation was occurred by plastic behavior of drift pin after yield when tensile load applied at connection. And the absorbing drift pin deflection by end distance continued the connection deformation. When rotation applied at connection that 2 drift pins were arranged parallel to grain (b2h), it showed similar performance with tensile perpendicular to grain. And connection that 2 drift pins were arranged perpendicular to grain (b2v) showed similar performance with tensile parallel to grain. Connection capacity that 4 drift pins were arranged rectangular (b4) showed 1.7 times as strong as connection that 2 drift pins were arranged parallel to grain (b2h). These results agreed predicted values and it is available that rotation replaced with tensile load.

• Journal of the Korean Wood Science and Technology
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• v.29 no.4
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• pp.1-8
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• 2001

This study was carried out to investigate the strength and stiffness of drift pinned and bolted joints with steel-plates by the tension-type lateral strength tests. Specimens were solid wood of Pinus densiflora. Bolt and drift pin were jointed with inserted steel plates. Tests were conducted with combinations of two loading directions (parallel to the grain : 0 degree, perpendicular to the grain : 90 degree) and three diameters of fasteners (d = 6 mm, 10 mm, 12 mm). The results obtained were as follow: 1. In the test of the parallel to the grain, maximum loads were increased with increasing of the diameter of bolt and drift pin in the same end distance. In the test of perpendicular to the grain with diameter 10 mm and 12 mm, specimens mostly were failed with horizontal splits in woods reaching the yield load of drift pinned and bolted joints. 2. The ratio of maximum load to the yield load determined by the so-called "5% offset method", was great in bolted joints in the parallel to the grain This trend become more remarkable as the slenderness ratio was increased. 3. The calculated yield strength was agreed well with the experimental results of drift pinned joint(0 degree).

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.3
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• pp.26-33
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• 1984

This paper proposes a new LSI/VLSI logic design structure which improves shift register latches in conventional LSSD. Test patterns are easily generated and fault coverage is enhanced by using the design structure. The new parallel shift register latch can be applied to the design of easily testable PLA's. In this case, the number of test patterns is decreased and decoders which are added to the feedback inputs in conventional PLA's using LSSD are not necessary.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.807-812
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• 1999

Locating of reinforcing bars, in particular to know their accurate depths, is very important thing in radar inspection of concrete structures. By the way, a depth estimation of reinforcing bars in concrete structures by the radar is not easy because micorwave propagation velocity in test area is generally unknown. This problem can be solved by Generalized Hough transformation technique. Using this technique, the micorwave propagation velocity in test area can be detected from the radar image, which appear as hyperbolas conveying the velocity information in their shape. A developed speed-up technique for the computation of the Generalized Hough transformation is also investigated in this study. As a result, although it becomes difficult to locate reinforcing bars when multiple parallel bars lying too close together, there is a possibility of detecting accurate depths of reinforcing bars in test area by the proposed method.

• Journal of the Korea Concrete Institute
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• v.12 no.1
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• pp.23-31
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• 2000

Locating reinforcing bars, in particular to know their accurate depths, is very important in radar inspection of concrete structures. By the way, an accurate depth estimation of reinforcing bars in concrete structures by the radar is not easy because the microwave propagation velocity in test area is generally unknown. This problem can be solved by generalized Hough transformation technique. Using this technique, the microwave propagation velocity in test area can be detected from the radar image, which appear as hyperbolas conveying the velocity information in their shape. A developed speed-up technique for the computation of the Generalized Hough transformation is also investigated in this study. As a result, although it becomes difficult to locate reinforcing bars when multiple parallel bars lying too close together, there is a possibility of detecting accurate depths of reinforcing bars in test area by the proposed method

• Journal of the Korean Society of Industry Convergence
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• v.23 no.1
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• pp.101-106
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• 2020

Along with dust collection efficiency, pressure loss is a very important cyclone operation factor. A severe rise in pressure loss causes the problem of cost. To solve the problem, the method connecting axial-vane type cyclones in parallel is suggested recently. The axial vane type cyclone dust collector applied in this study is a small portable type. Multiple cyclones are installed in a round type. The basic performance test on the axial vane type cyclone dust collector was conducted. As a result, the cut size reduced along with a rise in the wind velocity of the cyclone dust collector inlet. According to the test on dust collection efficiency, the effect of dust collection began to appear in the range of 3㎛ and dust collection efficiency was greatly improved at 5 ㎛. The noise of the cyclone dust collector well met the fan sound power level of KSB 6361.