Studying the Cable Loss Effect on the Seismic Behavior of Cable-Stayed Bridge

As the demand and construction of cable-stayed bridges have increased, research on the safety of cable-stayed bridges in the event of natural disasters such as fires and explosions is actively being conducted. If a cable-stayed bridge is damaged by an unexpected natural disaster or accident, it can cause serious traffic congestion and huge economic losses. This study evaluates the usability of the cable-stayed bridge in the event of cable damage. Additionally, seismic performance and the impact of the damage are evaluated by numerical analysis. To achieve this goal, the cable-stayed bridge is modeled using 3D BEAM elements and two-node cable elements. Then, the impact of the damage was evaluated by gradually damaging the cable. The deflection, axial force of the girder, and cable stress changes under far-field ground motion (El-Centro earthquake) were reviewed. A representative dynamic analysis program LS-DYNA was utilized for the numerical analyses. The results show that the loss of a small number of cables does not affect the usability of the bridge. However, if five or more cables are continuously lost, or if an earthquake occurs when cables are already lost, excessive deflections and changes in the girders’ axial forces can cause usability problems

LOCAL COLLISION SIMULATION OF AN SC WALL USING ENERGY ABSORBING STEEL

This study evaluates the local damage of a turbine in an auxiliary building of a nuclear power plant due to an external impact by using the LS-DYNA finite element program. The wall of the auxiliary building is SC structure and the material of the SC wall plate is high manganese steel, which has superior ductility and energy absorbance compared to the ordinary steel used for other SC wall plates. The effects of the material of the wall, collision speed, and angle on the magnitude of the local damage were evaluated by local collision analysis. The analysis revealed that the SC wall made of manganese steel had significantly less damage than the SC wall made of ordinary steel. In conclusion, an SC wall made of manganese steel can have higher effective resistance than an SC wall made of ordinary steel against the local collision of an airplane engine or against a turbine impact

Evaluation of Seismic Performance and Effectiveness of Multiple Slim-Type Damper System for Seismic Response Control of Building Structures

This paper presents the evaluation of seismic performance and cost-effectiveness of a multiple slim-type damper system developed for the vibration control of earthquake excited buildings. The multiple slim-type damper (MSD) that consists of several small slim-type dampers and linkage units can control damping capacity easily by changing the number of small dampers. To evaluate the performance of the MSD, dynamic loading tests are performed with three slim-type dampers manufactured at a real scale. Numerical simulations are also carried out by nonlinear time history analysis with a ten-story earthquake excited building structure. The seismic performance and cost-effectiveness of the MSD system are investigated according to the various installation configurations of the MSD system. From the results of numerical simulation and cost-effectiveness evaluation, it is shown that combinations of the MSD systems can effectively improve the seismic performance of earthquake excited building structures

Multi-Population Genetic Algorithm for Multilabel Feature Selection Based on Label Complementary Communication

Multilabel feature selection is an effective preprocessing step for improving multilabel classification accuracy, because it highlights discriminative features for multiple labels. Recently, multi-population genetic algorithms have gained significant attention with regard to feature selection studies. This is owing to their enhanced search capability when compared to that of traditional genetic algorithms that are based on communication among multiple populations. However, conventional methods employ a simple communication process without adapting it to the multilabel feature selection problem, which results in poor-quality final solutions. In this paper, we propose a new multi-population genetic algorithm, based on a novel communication process, which is specialized for the multilabel feature selection problem. Our experimental results on 17 multilabel datasets demonstrate that the proposed method is superior to other multi-population-based feature selection methods

STRUCTURAL TEST AND ANALYSIS OF RC SLAB AFTER FIRE LOADING

In the present study the behavior of fire and the residual strength of fire-ignited RC slabs are investigated by experimental tests and numerical simulations. The fire tests of RC slabs were carried out in a furnace using the ISO 834 standard fire. The load capacity of the cooled RC slabs that were not loaded during the fire tests was evaluated by additional 3 point bending tests. The influence of the proportion of PP (polypropylene) fibers in the RC slabs on the structural behavior of the RC slabs after the fire loading was investigated. The results of the fire tests showed that the maximum temperature of concrete with PP fiber was lower than that of concrete without PP fiber. As the concrete was heated, the ultimate compressive strength decreased and the ultimate strain increased. The load-deflection relations of RC slabs after fire loading were compared by using existing stress-strain-temperature models. The comparison between the numerical analysis and the experimental tests showed that some numerical analyses were reliable and therefore, can be applied to evaluate the ultimate load of RC slabs after fire loading. The ultimate load capacity after cooling down the RC slabs without PP fiber showed a considerable reduction from that of the RC slabs with PP fiber

Development of Carbon Nanotube/Silicone Pad for Improved Performance of Electromyostimulation Training

We have developed a carbon nanotube (CNT) pad to replace carbon black, which is essential for electric muscle stimulation (EMS) suits that can provide efficient exercise effects in a short time. The optimized CNT pad had 10 times lower concentration but showed 20 times lower resistance than the carbon black pad. In the case of the peak voltage indicating the EMS performance, it was confirmed that the CNT (4.0 wt%) was 25.9 V and the carbon black (40 wt%) was 6.5 V, which was about 4 times better. CNT added increased from 4.0 wt% to 10.0 wt%, and the peak voltage increased from 25.9 V to 26.8 V, but the output voltage was not significantly improved compared to the amount of CNT added. These experimental results are expected to show higher EMS properties than carbon black because carbon nanotubes and silicon are agglomerated to form a particle-like shape

Development of Carbon Nanotube/Silicone Pad for Improved Performance of Electromyostimulation Training

We have developed a carbon nanotube (CNT) pad to replace carbon black, which is essential for electric muscle stimulation (EMS) suits that can provide efficient exercise effects in a short time. The optimized CNT pad had 10 times lower concentration but showed 20 times lower resistance than the carbon black pad. In the case of the peak voltage indicating the EMS performance, it was confirmed that the CNT (4.0 wt%) was 25.9 V and the carbon black (40 wt%) was 6.5 V, which was about 4 times better. CNT added increased from 4.0 wt% to 10.0 wt%, and the peak voltage increased from 25.9 V to 26.8 V, but the output voltage was not significantly improved compared to the amount of CNT added. These experimental results are expected to show higher EMS properties than carbon black because carbon nanotubes and silicon are agglomerated to form a particle-like shape

Multidimensional Aspects of de qi

Background. De qi comprises varied senses depending on the individual. No single method can yet fully measure the multiple dimensions of de qi adequately. Objective. We examined the advantages of implementing multiple questionnaires for de qi measurement. Methods. Fourteen participants completed a preacupuncture questionnaire regarding their perception toward acupuncture treatment. After acupuncture stimulation at the HT7 point, de qi sensations were measured by MASS and ASQ. In groups with different levels of expectation, we compared the subtotal scores of each phase in the ASQ, as well as the VAS de qi intensity and MASS index using Kruskal-Wallis test. For the structural comparison of questionnaires, we first performed Spearman’s rank correlation test between the scores of individual descriptors in MASS and ASQ. The subtotal scores of each phase in ASQ was compared with VAS de qi intensity and MASS index. Results. The subtotal score of the manipulation phase in ASQ strongly correlated with the VAS score of de qi intensity (Spearman’s ρ=0.654, p=0.011) and MASS index (Spearman’s ρ=0.488, p=0.076). MASS and ASQ showed strong correlations in certain analogous descriptors. Unpleasant perceptions toward acupuncture treatment did not significantly correlate with overall de qi intensity. Conclusions. De qi sensations in acupuncture treatment have multidimensional aspects. Intensity of stimulation, ASQ, and MASS index assess somewhat restricted aspects of de qi. Those questionnaires have exclusive differences of sets in spite of their strong intersections. Use of multiple questionnaires may enable a more comprehensive understanding of de qi properties and the elicitation of relevant construction in de qi features of acupuncture