• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.3
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• pp.137-147
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• 2020

This paper proposes printed bow-tie antennas with 3 ~ 5 GHz broadband characteristics were proposed for testing the electromagnetic immunity of automotive electrical components in the 5G frequency band. The antenna get -10 dB bandwidth in the 2.75 ~ 6 GHz frequency band and the broadside radiation pattern with S₁₁ characteristic of -16.2 dB at resonant frequency. In testing electromagnetic immunity in the 5G mobile communication frequency band, the VSWR characteristic remained below 2.1, forming a level of 1 W as proposed by international standards. As a result, it is confirmed that the proposed antenna can be applied to antenna testing for electromagnetic immunity verification in the 5G mobile communication frequency band.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.425-436
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• 2014

Although the strut-tie model approaches of current design codes are regarded as the valuable methods for designs of structural concretes with D-regions, the approaches have to be improved because of the uncertainties in terms of the concepts and provisions for designs of 3-dimensional structural concretes. To improve the uncertainties, a new strut-tie model approach is proposed in this study. In the proposed approach, the concepts of employing a 3-dimensional grid element allowing load transfers in all directions at a node to construct a strut-tie model, a numerical analysis approach to determine the effective strengths of concrete struts and nodal zones by reflecting the effects of reinforcing bars and 3-dimensional stress state, and maximum areas of struts and ties to examine their load carrying capacities are integrated into the strut-tie model approaches of current design codes.

• Ocean Systems Engineering
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• v.6 no.2
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• pp.143-159
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• 2016

Cargo, such as a Tension Leg Platform (TLP), Semi-submersible platform (Semi), Spar or a circular Floating Production Storage and Offloading (FPSO), are frequently dry-transported on a Heavy Lift Vessel (HLV) from the point of construction to the point of installation. The voyage can span months and the overhanging portions of the hull can be subject to frequent wave slamming events in rough weather. Tie-downs or sea-fastening are usually provided to ensure the safety of the cargo during the voyage and to keep the extreme responses of the cargo, primarily for the installed equipment and facilities, within the design limits. The proper design of the tie-down is dependent on the accurate prediction of the wave slamming loads the cargo will experience during the voyage. This is a difficult task and model testing is a widely accepted and adopted method to obtain reliable sea-fastening loads and extreme accelerations. However, it is crucial to realize the difference in the inherent stiffness of the instrument that is used to measure the tri-axial sea fastening loads and the prototype design of the tie-downs. It is practically not possible to scale the tri-axial load measuring instrument stiffness to reflect the real tie-down stiffness during tests. A correlation method is required to systematically and consistently account for the stiffness differences and correct the measured results. Direct application of the measured load tends to be conservative and lead to over-design that can reflect on the overall cost and schedule of the project. The objective here is to employ the established correlation method to provide proper high-frequency responses to topsides and hull design teams. In addition, guidance for optimizing tie-down design to avoid damage to the installed equipment, facilities and structural members can be provided.

• Structural Engineering and Mechanics
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• v.57 no.4
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• pp.657-680
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• 2016

Reinforced concrete (RC) deep beams are structural members that predominantly fail in shear. Therefore, determining the shear strength of these types of beams is very important. The strut-and-tie method is commonly used to design deep beams, and this method has been adopted in many building codes (ACI318-14, Eurocode 2-2004, CSA A23.3-2004). In this study, the efficiency of artificial neural networks (ANNs) in predicting the shear strength of RC deep beams is investigated as a different approach to the strut-and-tie method. An ANN model was developed using experimental data for 214 normal and high-strength concrete deep beams from an existing literature database. Seven different input parameters affecting the shear strength of the RC deep beams were selected to create the ANN structure. Each parameter was arranged as an input vector and a corresponding output vector that includes the shear strength of the RC deep beam. The ANN model was trained and tested using a multi-layered back-propagation method. The most convenient ANN algorithm was determined as trainGDX. Additionally, the results in the existing literature and the accuracy of the strut-and-tie model in ACI318-14 in predicting the shear strength of the RC deep beams were investigated using the same test data. The study shows that the ANN model provides acceptable predictions of the ultimate shear strength of RC deep beams (maximum $R^2{\approx}0.97$). Additionally, the ANN model is shown to provide more accurate predictions of the shear capacity than all the other computed methods in this study. The ACI318-14-STM method was very conservative, as expected. Moreover, the study shows that the proposed ANN model predicts the shear strengths of RC deep beams better than does the strut-and-tie model approaches.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.2
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• pp.355-370
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• 2014

Cooperative spectrum sensing has been considered as a promising approach to improve the sensing performance in distributed cognitive radio networks. However, there may exist some selfish secondary users (SUs) who are unwilling to cooperate. The presence of selfish SUs could cause catastrophic damage to the performance of cooperative spectrum sensing. Following the social perspective, we propose a Social Tie-based Incentive Scheme (STIS) to deal with the selfish problem for cooperative spectrum sensing in distributed cognitive radio networks. This scheme inspires SUs to contribute sensing information for the SUs who have social tie but not others, and such willingness varies with the strength of social tie value. The evaluation of each SU's social tie derives from its contribution for others. Finally, simulation results validate the effectiveness of the proposed scheme.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.4
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• pp.672-676
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• 2012

This paper studies the relation between the deformation of platen caused by clamping force, the bending stress and elongation at the tie-bar in injection molding machine of toggle type. These data are analyzed through analytical molding and numerical approach by tensile tester. The effect of bending stress on the stress concentration of teeth and nut system is also analyzed by 2 dimensional numerical approach. The bending stress of tie-bar caused by platen deformation becomes less than 20% of average tensile stress. And the effect of bending stress on stress concentration at teeth and nut system of tie-bar is found to be small.

• KIEE International Transactions on Power Engineering
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• v.2A no.4
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• pp.166-173
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• 2002

Dispersed Generation (DG) units significantly effect the existing distribution protection practices. Therefore, new protection practices of the distribution system interconnected with DG units should be reevaluated and developed. In this paper, a new inter-tie protection scheme of DG units for distribution automatic reclosing is proposed. The impact of DG units on existing radial-sectionaliser coordination is analyzed. And the effects of the distribution reclosing type (radial and passive reclosing) on DG dynamics are analyzed and classified. From the results of the DG dynamic responses by the reclosing type, i.e. radial and passive reclosing, the inter-tie protection schemes of DG are introduced to improve the reliability and availability of utility interactive DG. The proposed schemes are proved and evaluated by a case study using PSCAD/EMTDC simulation.

• Journal of the Korean Society of Hazard Mitigation
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• v.1 no.2 s.2
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• pp.103-114
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• 2001

As the results of comparison with several anchorage design methods of PSC box girder, stress superposition effect by the order of prestressing force can't be considered in the case of multi-anchorage design with existing design methods. In anchorage design by 3-D finite element analysis, estimation of stress concentration region and stress flow are correctly defined, but the estimation of sectional forces in anchorage is very complicated. In the case of anchorage design by strut-tie model method, the stress superposition effect can be considered and sectional forces in anchorage are easily calculated. Therefore, strut-tie model method is remarkably suitable to anchorage design if geometrical conditions of the truss members are carefully considered.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.14 no.1
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• pp.10-15
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• 2003

Background and Objectives : Ankyloglossia, commonly known as tongue-tie, is the result of a short, fibrous lingual frenulum or highly attached geioglossus muscle. This condition may cause sucking and swallowing problems, articulation disorders, interference with the tongue's cleansing action, increased the potential for caries, and inability to lick the lips, play a wind instrument, and 'french kiss' Treatment is surgical procedure. In the most cases, horizontal sectioning and mucosal suture(the conventional procedure) is preferred, but in some cases, the Z-plastic procedure is effective. This study is aimed to compare the result of the two procedures. Materials and Methods : Twenty tongue-tie patients underwent operation. Ten patients were treated with the Z-plastic procedure and ten patients were treated with the conventional method randomly. We checked preoperative mobile tongue length, postoperative mobile tongue length, operation time and postoperative wound states. Results : Among the 20 cases of tongue-tie, 2 cases are excepted due to pre-operative state, thus we compared 18 cases of tongue-tie patients. There is no statistically significant difference between the two procedures except in operation time. The Z-plastic procedure apparently needs a little more operating time. Conclusion : Patients treated with the Z-plastic procedures appeared to have better outcomes, but the data shows no statistical significance except in operating time. Consequently, the Z-plastic procedure is indicated in a limited amount of cases.

• The Research Journal of the Costume Culture
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• v.30 no.1
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• pp.161-171
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• 2022

Traditional tie-dyeing is widely implemented in the clothing handicraft culture in China, South Korea, and Japan. Since it was developed 2,000 years ago, it has become a popular method of fabric making in the world and is highly respected by fashion designers. Based on the existing traditional tie-dyeing methods, this study conducted specific research on the 3D printing technology of the SLS laser method and the micro tool design application method of the clamp-dyeing process. Through the experimental methods of this study, it proposes to use the "7000 Nylon" material, which is commonly used in 3D printing, to develop a new clamp-dyeing tool. This new tool can be widely used in the clamp-dyeing of fabrics, such as cotton, hemp, silk, and some chemical fibers. The applied method and principle can be consistent with the traditional clamp-dyeing method. Therefore, the innovation of tie-dyeing technology is the best protection measure for the development and inheritance of traditional fabric making. The continuation of artistic life needs originality, which is also the best response to market competition. At the same time, this new design of the clamp-dyeing tool has the characteristics of novelty, innovation, and rich changes, which aligns with the new fashion demands of current fabric design.