• Steel and Composite Structures
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• v.20 no.3
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• pp.487-500
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• 2016

In order to investigate the flexural bearing capacity of panel zone of diaphragm-through joint between concrete filled square steel tubular column and steel beam, four specimens were tested under static tension loads to study the mechanical properties and bearing capacity of diaphragm-through joints with a failure mode of panel zone. Finite element models of these specimens were developed to simulate the test and compare the predicted failure modes, load-displacement curves and bearing capacities with the experimentally observed. It was found that the tensile load from the steel beam flange is mainly shared by the square steel tube and the diaphragm. The diaphragm plastic zone appears along the cross-section lines enclosed by the square steel tube and the influence of steel beam web on the plastic zone of the steel tube is significant and cannot be neglected. Computational models of yield lines on square steel tube and diaphragm are established based on the distribution pattern of the plastic zone, and an analytical method for the evaluation of the bearing capacity of the joint is proposed. The theoretical results and the experimental data are compared and found in good agreement.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.7
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• pp.23-30
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• 2014

"Cut off line" in automotive passing beam has very important safety function because it serves for headlamp aiming. Headlights that are aimed incorrectly will not only perform poorly but also offend oncoming traffic. In addition, an objective definition of cut off line in low beam is necessary, since a requirement for correct aiming of the beams is specified within all the existing regulations. Accordingly, headlight regulations are requirements that automobiles must satisfy in order to be sold in a particular country. In this study, a more advanced recognition method for the cut off lines of the various headlamps commonly used in Europe, North America, and domestic is suggested and a headlamp testing system is developed to adjust the beam to the country-specific regulation. This system uses image processing technology to detect the cut off lines in the beam patterns of halogen headlamps, high-intensity discharge headlamps, and light-emitting diode headlamps as well.

• Wind and Structures
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• v.23 no.3
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• pp.253-273
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• 2016

Ice accretions on stay cables may result in the instable vibration of galloping, which would affect the safety of cable-stayed bridges. A large number of studies have investigated the galloping vibrations of transmission lines. However, the obtained aerodynamics in transmission lines cannot be directly applied to the stay cables on cable-stayed bridges. In this study, linear and nonlinear single degree-of-freedom models were introduced to obtain the critical galloping wind velocity of iced stay cables where the aerodynamic lift and drag coefficients were identified in the wind tunnel tests. Specifically, six ice shapes were discussed using section models with geometric scale 1:1. The results presented obvious sudden decrease regions of the aerodynamic lift coefficient for all six test models. Numerical analyses of iced stay cables associated to a medium-span cable-stayed bridge were carried out to evaluate the potential galloping instability. The obtained nonlinear critical wind velocity for a 243-meter-long stay cable is much lower than the design wind velocity. The calculated linear critical wind velocity is even lower. In addition, numerical analyses demonstrated that increasing structural damping could effectively mitigate the galloping vibrations of iced stay cables.

• Proceedings of the Korea Society for Simulation Conference
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• 2003.11a
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• pp.185-192
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• 2003

Digital Manufacturing-based production could be very effective in shipbuilding in order to save costs and time, to increase safety for workers, and to prevent bottleneck processes in advance. Digital shipbuilding system, a simulation-based production tool, is being developed to achieve such aspects in Korea. To simulate material flow in a subassembly line at a shipyard, the product, process and resources was modeled for the subassembly process which consisted of several sub-processes such as tack welding, piece alignment, tack welding, and robot welding processes. The analysis and modeling were carried out by using the UML(Unified Modeling Language), an object-oriented modeling method as well as IDEF(Integration DEFinition), a functional modeling tool. Initially, the characteristics of the shop resources were analyzed using the shipyard data, and the layout of the subassembly line was designed with the resources. The production process modeling of the subassembly lines was performed using the discrete event simulation method. Using the constructed resource and process model, the productivity and efficiency of the line were investigated. The number of workers and the variations In the resource performance such as that of a new welding robot were examined to simulate the changes in productivity. The bottleneck process floated according to the performance of the new resources. The proposed model was viewed three-dimensionally in a digital environment so that interferences among objects and space allocations for the resources could be easily investigated

• Journal of the Korean Society of Visualization
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• v.19 no.1
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• pp.18-27
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• 2021

As the photo-voltaic (PV) industry grows, the floating PV has been suggested to resolve current environmental destruction and a lack of installation area. Currently, various floating PV systems have been developed, but there is a lack of studies on how the shape of the floating body and other compositions are affecting structural behavior. In this study, the behavior of the floating PV was investigated at the various length of mooring lines, stiffness of connecting hinges, and size of floating bodies. The shortest mooring lines with the distributed type floating PV showed the least force on the floating body and corresponding motion. A frictionless hinge is safer at the regular and low-height wave, while a stiff hinge is safer at irregular and high-height wave. In addition, due to the bi-axial distribution of the connecting hinge, 45° direction wave was found to be the most dangerous.

• KEPCO Journal on Electric Power and Energy
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• v.7 no.2
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• pp.285-293
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• 2021

The construction of underground structures such as power supply lines, communication lines, utility tunnels has significantly increased worldwide for improving urban aesthetics ensuring citizen safety, and efficient use of underground space. Those underground structures are usually constructed along with vertical cylindrical shafts to facilitate their construction and maintenance. When constructing a vertical shaft through the open-cut method, the walls are mostly designed to be flexible, allowing a certain level of displacement. The earth pressure applied to the flexible walls acts as an external force and its accurate estimation is essential for reasonable and economical structure design. The earth pressure applied to the flexible wall is closely interrelated to the displacement of the surrounding ground. This study simulated stepwise excavation for constructing a cylindrical vertical shaft through a centrifugal model experiment. One quadrant of the axisymmetric vertical shaft and the ground were modeled, and ground excavation was simulated by shrinking the vertical shaft. The deformation occurring on the entire ground during the excavation was continuously evaluated through digital image analysis. The digital image analysis evaluated complex ground deformation which varied with wall displacement, distance from the wall, and ground depth. When the ground deformation data accumulate through the method used in this study, they can be used for developing shaft wall models in future for analyzing the earth pressure acting on them.

• Structural Engineering and Mechanics
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• v.84 no.6
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• pp.733-741
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• 2022

The amount of natural gas that is used on a worldwide scale is continuously going up. Natural gas and acidic components, such as hydrogen sulfide and carbon dioxide, cause significant corrosion damage to transmission lines and equipment in various quantities. One of the fundamental processes in natural gas processing is the separation of acid gases, among which the safety and environmental needs due to the high toxicity of hydrogen sulfide and also to prevent wear and corrosion of pipelines and gas transmission and distribution equipment, the necessity of sulfide separation Hydrogen is more essential than carbon dioxide and other compounds. Given this problem's significance, this endeavor aims to extend the lifespan of the transmission lines' pipes for gas and oil. Zinc oxide nanoparticles made from the environmentally friendly source of Allium scabriscapum have been employed to accomplish this crucial purpose. This is a simple, safe and cheap synthesis method compared to other methods, especially chemical methods. The formation of zinc oxide nanoparticles was shown by forming an absorption peak at a wavelength of about 355 nm using a spectrophotometric device and an X-ray diffraction pattern. The size and morphology of synthesized nanoparticles were determined by scanning and transmission electron microscope, and the range of size changes of nanoparticles was determined by dynamic light scattering device.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.9
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• pp.3901-3906
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• 2014

Aim: The purpose of this study was to investigate anti-tumor effects and safety of DH332, a new ${\beta}$-carboline alkaloids derivatives in vitro and in vivo. Materials and Methods: The effects of DH332 on human (RAMOS RA.1) and mouse (J558) B lymphoma cell lines were detected using a CCK-8 kit (Cell Counting Kit-8), and apoptosis was detected by flow cytometry with PI/annexinV staining. Western blotting was used to detected caspase-3 and caspase-8. Neurotoxic and anti-tumor effects were evaluated in animal experiments. Results: DH332 exerts a lower neurotoxicity compared with harmine. It also possesses strong antitumor effects against two B cell lymphoma cell lines with low $IC_{50s}$. Moreover, DH332 could inhibit the proliferation and induce the apoptosis of RAMOS RA.1 and J558 cell lines in a dose-dependent manner. Our results suggest that DH332 triggers apoptosis by mainly activating the caspase signaling pathway. In vivo studies of tumor-bearing BALB/c mice showed that DH332 significantly inhibited growth of J558 xenograft tumors. Conclusions: DH332 exerts effective antitumor activity in vitro and in vivo, and has the potential to be a promising drug candidate for lymphoma therapy.

• Fashion & Textile Research Journal
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• v.18 no.4
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• pp.498-508
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• 2016

The purpose of this study is to develop an aesthetic and functional bicycle wear for new senior women in their 50s and 60s. Based on the results of the survey, we developed bicycle wear that is friendly to bicycling posture and reflects the preference of new senior women. The results are as followed: First, emphasis is placed on the simple and functional design of the experimental wear consisting of jacket and pants. Jacket is different from the color scheme with the armhole princess line in order for the waistline to look slim. Pants are designed to hold the leg muscles tightly in order to help reduce the muscle fatigue on the bicycle ride. Second, cutting lines and coloring materials are used for the wearer to look slim and the safety of the wearer is planned to secure by inserting the reflective material along the cutting lines on the bicycle ride. Third, the pattern of the experimental wear is designed in consideration of the riding motion of the bicycle. Jacket is designed to have back length longer than front length as compared to the bicycle wears available on the market. Sewing lines in the armpit are designed to be eliminated in order to move the arms smoothly on the ride. Pants are designed to minimize the seam line in consideration of the movement of muscles and ligaments and the experimental wear is produced by combining the material with the functions of cool comfort and stretch.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.4 s.74
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• pp.369-374
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• 2006

This paper describes dynamic characteristics of a power transmission tower consisting of lots of power lines and insulators. A numerical 3D modeling for the static, dynamic and buckling analyses of the power transmission tower is presented considering the case when the power lines are cut. Eigenvalue analysis indicates that the transmission tower shows different behavior comparing to usual structures governed by several low modes. The transmission tower is governed by lots of modes. It is verified that the transmission tower is structurally safe against the static wind and buckling loads. But the structural and buckling safety is not guaranteed when all power lines are cut, which comes to collapse the transmission tower. Further study is in need to overcome such case. Wind dynamic analysis shows that fluctuating wind loads increase the response of the tower.