• Journal of the Korea Concrete Institute
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• v.17 no.4 s.88
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• pp.513-520
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• 2005

The uniform truss mechanism is widely accepted as a shear transfer mechanism in reinforced concrete members. However, the uniform truss action cannot be expected when the bond stress distribution is not constant along longitudinal bars. A test method in which only the truss action takes place is developed and conducted to investigate the truss actions under various bond contributions. Based on the experimental results and analysis, the following findings can be obtained: 1) The bond stress distribution depends on the axial compression force, the amount of shear reinforcement and loading conditions. 2) The analysis using the combined truss model consisting of uniform and fan-shape trusses can predict the experimental results

• Journal of the Korea Concrete Institute
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• v.27 no.3
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• pp.299-309
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• 2015

Ultra High Performance Fiber Reinforced Concrete (UHPFRC) is distinguished from the normal concrete by outstanding compressive and tensile strength. Cracked normal concrete resists shear by aggregate interlocking while clamped by transverse reinforcement, which is called as shear friction theory. Cracked UHPFRC is expected to have a different shear transfer mechanism due to rather smooth crack face and post-cracking behavior under tensile force. Twenty-four push-off specimens with transverse reinforcement are tested for four different fiber volume ratio and three different ratio of reinforcement along the shear plane. The shear friction strength for monolithic concrete are suggested by limit analysis of plasticity and verified by test results. Plastic analysis gives a conservative, but reasonable estimate. The suggested shear friction factor and effectiveness factor of UHPFRC can be applied for interface shear transfer design of high-strength concrete and fiber reinforced concrete with post-cracking tensile strength.

• Fire Science and Engineering
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• v.18 no.3
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• pp.51-56
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• 2004

A fire outbreak in a reinforcement concrete structure looses the organism by the different contraction and expansion of hardened cement pastes and aggregate, and causes cracks by thermal stress, leading to the deterioration of the durability. So concrete reinforcement structure is damaged partial or whole structure system. Therefore diagnosis of deterioration is needed based on mechanism of fire deterioration in general concrete structures. Fundamental information and data on the properties of concrete exposed to high temperature are necessary for accurate diagnosis of deterioration. In this study, it was presented data for the accurate diagnosis and selection of repair and reinforcement system for the deteriorated concrete heated highly, various concrete such as standard design compressive strength, fine aggregate and admixture were exposed to a high temperature environment. And fundamental data were measured engineering properties such as explosive spatting, ultrasonic pulse velocity and compressive strength.

• Asia-Pacific Journal of Business
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• v.4 no.2
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• pp.21-30
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• 2013

Ethics involves distinguishing between what is right or wrong thereby making a correct choice. An organization should treat its internal as well as external stakeholders ethically. This research gives valuable insights on the prevailing ethical climate and potential organizational challenges in institutionalizing ethics and its management in the manufacturing sector. The present study is designed to analyze four parameters of ethical climate in the manufacturing sector with reference to different managerial levels, to identify the critical factor of the ethical code of conduct and to find correlations between four parameters of ethical climate. Descriptive research has been used and data are collected from 200 employees of three Indian companies of manufacturing sector using a well designed questionnaire. Analyzing data with SPSS, It has been found that overall good number of people believe that MBE (Management of Business Ethics) process is well implemented. People are well aware and trained and involved in the ethical process. Senior management is very much committed to promote the ethical environment in the organization and thus company values are well communicated to the employees. Concern resolution mechanism is well established in the organization. MBE in the organization is more prevalent in higher-level employees. Senior management commitment and reinforcement is very critical for CoC (code of conduct). Correlation between all the 4 parameters is positive and significant. But the parameters are not highly correlated with each other. Organizations need to work upon these parameters to promote an ethical climate in the organization by awarding or felicitating exemplary ethical behavior. More emphasis should be given on senior management commitment and reinforcement of the ethical behavior across all levels.

• Geomechanics and Engineering
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• v.14 no.4
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• pp.345-354
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• 2018

Currently, layered geogrid method (LGM) is the commonly practiced technique for reinforcement of slopes. In this paper the geogrid-box method (GBM) is introduced as a new approach for reinforcement of rock-soil slopes. To achieve the objectives of this study, a laboratory setup was designed and the slopes without reinforcements and reinforced with LGM and GBM were tested under the loading of a circular footing. The effect of vertical spacing between geogrid layers and box thickness on normalized bearing capacity and failure mechanism of slopes was investigated. A series of 3D finite element analysis were also performed using ABAQUS software to supplement the results of the model tests. The results indicated that the load-settlement behavior and the ultimate bearing capacity of footing can be significantly improved by the inclusion of reinforcing geogrid in the soil. It was found that for the slopes reinforced with GBM, the displacement contours are widely distributed in the rock-soil mass underneath the footing in greater width and depth than that in the reinforced slope with LGM, which in turn results in higher bearing capacity. It was also established that by reducing the thickness of geogrid-boxes, the distribution and depth of displacement contours increases and a longer failure surface is developed, which suggests the enhanced bearing capacity of the slope. Based on the studied designs, the ultimate bearing capacity of the GBM-reinforced slope was found to be 11.16% higher than that of the slope reinforced with LGM. The results also indicated that, reinforcement of rock-soil slopes using GBM causes an improvement in the ultimate bearing capacity as high as 24.8 times more than that of the unreinforced slope.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.736-744
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• 2009

The abrupt failure of slope caused by a concentrated rainfall would be a disaster in this country. Specially, the soil slope may be collapsed by the rainfall seepage, however, there is not much information for the mechanism of slope failure during rainfall. As analyzing the stability of slope by rainfall, the conventional method is to put the ground-water level on the surface of slope. However, it may provide the over-reinforcement for the slope stability. Futhermore, although over-reinforcement for the slope was fulfilled, the possibility of potential slope failure still exists. In this study, the slope stability by the conventional design method and the causes of unstable slope during rainfall were investigated. To analyze the slope stability by rainfall, the computer program SEEP/W for the analysis of seepage was used. As changing the intensity and duration of rainfall in SEEP/W, the analysis were performed. After completion of analysis, the porewater pressure data from SEEP/W was applied to SLOPE/W. As a results of this analysis, it is not reasonable that the groundwater level is going up to the surface of slope during rainfall. Therefore, the conventional reinforcement for the slope stability is not obvious to satisfy the criterion safety factor during rainfall. The reasonable counterplan is to install drainage hole on the surface of slope in order to prevent erosion and debris flow.

• Structural Engineering and Mechanics
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• v.74 no.3
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• pp.351-363
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• 2020

Based on the dynamic tests of recycled aggregate concrete (RAC) short columns confined by the hoop reinforcement, the dynamic failure mechanism and the mechanical parameters related to the constitutive relation of confined recycled aggregate concrete (CRAC) were investigated thoroughly. The fracturing sections were relatively flat and smooth at higher strain rates rather than those at a quasi-static strain rate. With the increasing stirrup volume ratio, the crack mode is transited from splitting crack to slipping crack constrained with large transverse confinement. The compressive peak stress, peak strain, and ultimate strain increase with the increase of stirrup volume ratio, as well as the increasing strain rate. The dynamic confining increase factors of the compressive peak stress, peak strain, and ultimate strain increase by about 33%, 39%, and 103% when the volume ratio of hoop reinforcement is increased from 0 to 2%, but decrease by about 3.7%, 4.2%, and 9.1% when the stirrup spacing is increased from 20mm to 60mm, respectively. This sentence is rephrased as follows: When the stirrup volume ratios are up to 0.675%, and 2%, the contributions of the hoop confinement effect to the dynamic confining increase factors of the compressive peak strain and the compressive peak stress are greater than those of the strain rate effect, respectively. The dynamic confining increase factor (DCIF) models of the compressive peak stress, peak strain, and ultimate strain of CRAC are proposed in the paper. Through the confinement of the hoop reinforcement, the ductility of RAC, which is generally slightly lower than that of NAC, is significantly improved.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.7
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• pp.2496-2512
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• 2021

The requirements for powerful computing capability, high capacity, low latency and low energy consumption of emerging services, pose severe challenges to the fifth-generation (5G) network. As a promising paradigm, mobile edge networks can provide services in proximity to users by deploying computing components and cache at the edge, which can effectively decrease service delay. However, the coexistence of heterogeneous services and the sharing of limited resources lead to the competition between various services for multiple resources. This paper considers two typical heterogeneous services: computing services and content delivery services, in order to properly configure resources, it is crucial to develop an effective offloading and caching strategies. Considering the high energy consumption of 5G base stations, this paper considers the hybrid energy supply model of traditional power grid and green energy. Therefore, it is necessary to design a reasonable association mechanism which can allocate more service load to base stations rich in green energy to improve the utilization of green energy. This paper formed the joint optimization problem of computing offloading, caching and resource allocation for heterogeneous services with the objective of minimizing the on-grid power consumption under the constraints of limited resources and QoS guarantee. Since the joint optimization problem is a mixed integer nonlinear programming problem that is impossible to solve, this paper uses deep reinforcement learning method to learn the optimal strategy through a lot of training. Extensive simulation experiments show that compared with other schemes, the proposed scheme can allocate resources to heterogeneous service according to the green energy distribution which can effectively reduce the traditional energy consumption.

• Steel and Composite Structures
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• v.51 no.2
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• pp.153-172
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• 2024

Due to the fast development of constructions in recent years, there has been a rapid consumption of fresh water and river sand. In the production of concrete, alternatives such as sea water and sea sand are available. The near surface mounted (NSM) technique is one of the most important methods of strengthening. Aluminum alloy (AA) bars are non-rusting and suitable for usage with sea water and sand concrete (SSC). The goal of this study was to enhance the shear behaviour of SSC-beams strengthened with NSM AA bars. Twenty-four RC beams were cast from fresh water river sand concrete (FRC) and SSC before being tested in four-point flexure. All beams are the same size and have the same internal reinforcement. The major factors are the concrete type (FRC or SSC), the concrete degree (C25 or C50 with compressive strength = 25 and 50 MPa, respectively), the presence of AA bars for strengthening, the direction of AA bar reinforcement (vertical or diagonal), and the AA bar ratio (0, 0.5, 1, 1.25 and 2 %). The beams' failure mechanism, load-displacement response, ultimate capacity, and ductility were investigated. Maximum load and ductility of C25-FRC-specimens with vertical and diagonal AA bar ratios (1%) were 100,174 % and 140, 205.5 % greater, respectively, than a matching control specimen. The ultimate load and ductility of all SSC-beams were 16-28 % and 11.3-87 % greater, respectively, for different AA bar methods than that of FRC-beams. The ultimate load and ductility of C25-SSC-beams vertically strengthened with AA bar ratios were 66.7-172.7 % and 89.6-267.9 % higher than the unstrengthened beam, respectively. When compared to unstrengthened beams, the ultimate load and ductility of C50-SSC-beams vertically reinforced with AA bar ratios rose by 50-120 % and 45.4-336.1 %, respectively. National code proposed formulae were utilized to determine the theoretical load of tested beams and compared to matching experimental results. The predicted theoretical loads were found to be close to the experimental values.

• Journal of IKEEE
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• v.28 no.3
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• pp.390-396
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• 2024

Vision Transformer (ViT) learns relationships between patches, but it may overlook important features such as color, texture, and boundaries, which can result in performance limitations in fields like medical imaging or facial recognition. To address this issue, this study proposes the Pairwise Attention Reinforcement (PAR) model. The PAR model takes both the training image and a reference image as input into the encoder, calculates the similarity between the two images, and matches the attention score maps of images with high similarity, reinforcing the matching areas of the training image. This process emphasizes important features between images and allows even subtle differences to be distinguished. In experiments using clock-drawing test data, the PAR model achieved a Precision of 0.9516, Recall of 0.8883, F1-Score of 0.9166, and an Accuracy of 92.93%. The proposed model showed a 12% performance improvement compared to API-Net, which uses the pairwise attention approach, and demonstrated a 2% performance improvement over the ViT model.