Modeling of insulated CFRP-strengthened reinforced concrete T-beam exposed to fire

The use of Fiber Reinforced Polymer (FRP) has been established as one of the possible techniques to strengthen concrete beams in flexure and shear. Carbon Fiber Reinforced Polymer (CFRP) has been identified as the material of choice in civil infrastructure applications. The fire performance of such CFRP-strengthened members and their resistance to heat transfer and to various environmental exposure factors need to be investigated. In this paper, a detailed finite element model of a CFRP-strengthened reinforced concrete T-beam is developed. The model accounts for the variation in thermal and mechanical parameters of the beams’ constituent materials with temperature, including CFRP and insulation materials. Nonlinear time domain transient thermal-stress finite element analysis is performed using the commercial software ANSYS to study the heat transfer mechanism and deformation within the beam for fire conditions initiating at the bottom of the beam. To relate the simulation to an actual case, a reinforced concrete T-beam strengthened with CFRP and fire-tested by other investigators is modeled. The progression of temperature in the beam, CFRP, reinforcing steel, and along the CFRP–concrete interface is compared to the observed fire test data. Overall, the predicted temperature results are in good agreement with the measured ones. In addition, the mid-span deflection increases nonlinearly during the fire exposure time due to the increase in the total strain on the tension side of the beams and due to concrete cracking. Successful FE modeling of this structure provides an economical, alternative solution to expensive experimental investigations.     

Technique for order performance by similarity to ideal solution for solving complex situations in multi-criteria optimization of the tracking channels of GPS baseband telecommunication receivers

Global positioning system (GPS) has undergone intensive development, starting as an advanced specialized tool to a general-purpose gadget used in our daily lives. GPS exists in new technologies, applications, and consumer products, especially in smartphones and tablets. In a GPS receiver design, power consumption and localization accuracy are critical factors that affect the outcome of a GPS receiver system. Theoretically, increasing the number of required tracking channels in a GPS baseband receiver increases the design complexity and size of this system. Thus, power consumption can significantly increase. The receiver should acquire and track numerous satellites to improve the location accuracy of a position, thereby indicating that the receiver requires a high number of tracking channels. Thus, optimizing these tracking channels to balance the conflict among performance parameters is a difficult and challenging task. This paper presents a technique for order performance by similarity to ideal solution (TOPSIS) for solving complex situations for multi-criteria optimization of the tracking channels of GPS baseband telecommunication receiver. Nine operation modes of GPS receiver were evaluated by each design parameter, such as power consumption, localization accuracy, and time with no position available for static and dynamic positioning. Then, the TOPSIS was utilized and implemented to measure and rank the overall performance of tracking channel selection. Results of this study indicate that (1) multi-objective optimization is a reliable strategy for visualizing the trade-off among the GPS design parameters and providing a dynamic power consumption planning. (2) The best aggregated performance of the GPS receiver occurs when the number of tracking channels equals five and six for static and dynamic positioning, respectively. (3) The most frequent number of available satellites is eight, whereas the other number of satellites is a rare case to acquire. However, GPS standards require that available GPS satellites are constantly 12 at any time and place.     

A new algorithm of modified binary particle swarm optimization based on the Gustafson-Kessel for credit risk assessment

Neural Computing and Applications - To increase the quality of loans provision and reduce the risk involved in this process, several credit scoring models have been developed and utilized to...     

Conceptual framework for the security of mobile health applications on Android platform

Mobile Health (mHealth) applications are readily accessible to the average user of mobile devices, and despite the potential of mHealth applications to improve the availability, affordability and effectiveness of delivering healthcare services, they handle sensitive medical data, and as such, have also the potential to carry substantial risks to the security and privacy of their users. Developers of applications are usually unknown, and users are unaware of how their data are being managed and used. This is combined with the emergence of new threats due to the deficiency in mobile applications development or the design ambiguities of the current mobile operating systems. A number of mobile operating systems are available in the market, but the Android platform has gained the topmost popularity. However, Android security model is short of completely ensuring the privacy and security of users’ data, including the data of mHealth applications. Despite the security mechanisms provided by Android such as permissions and sandboxing, mHealth applications are still plagued by serious privacy and security issues. These security issues need to be addressed in order to improve the acceptance of mHealth applications among users and the efficacy of mHealth applications in the healthcare systems. Thus, this paper presents a conceptual framework to improve the security of medical data associated with Android mHealth applications, as well as to protect the privacy of their users. Based on the literature review that suggested the need for the intended security framework, three-distinct and successive phases are presented, each of which is described in a separate section. First, discussed the design process of the first phase to develop a security framework for mHealth apps to ensure the security and privacy of sensitive medical data. The second phase is discussed who to achieve the implementation of a prototypic proof-of-concept version of the framework. Finally, the third phase ending discussed the evaluation process in terms of effectiveness and efficiency for the proposed framework.     

Computer control of a powered two degree freedom reciprocating gait orthosis

The design of a motion control system for a powered reciprocating gait orthosis is considered. Models for the orthosis are obtained using least squares identification. The control system design is based on pole-placement techniques and a restricted Youla parametrization of the controller. Experimental results are included.     

轮胎模电火花机床的数控改造研究

针对普通型轮胎模电火花机床,应用数控技术进行数控改造。研究了轮胎模数控电火花机床的硬件电路、软件构成、机械改造和显示信息的功能,具有较强的实用价值。     

车铣削方式加工的车床数控改造

使用三坐标数控系统或串联使用两套二坐标数控系统,均能在改造的卧式车床上实现零件的车铣削方式加工.在扩展机床功能的前提下,介绍了对卧式车床的数控改造以及实现数控加工的各种方法.     

A Review of Smart Contract Blockchain Based on Multi-Criteria Analysis: Challenges and Motivations

A smart contract is a digital program of transaction protocol (rules of contract) based on the consensus architecture of blockchain. Smart contracts with Blockchain are modern technologies that have gained enormous attention in scientific and practical applications. A smart contract is the central aspect of a blockchain that facilitates blockchain as a platform outside the cryptocurrency spectrum. The development of blockchain technology, with a focus on smart contracts, has advanced significantly in recent years. However, research on the smart contract idea has weaknesses in the implementation sectors based on a decentralized network that shares an identical state. This paper extensively reviews smart contracts based on multi-criteria analysis, challenges and motivations. Therefore, implementing blockchain in multi-criteria research is required to increase the efficiency of interaction between users via supporting information exchange with high trust. Implementing blockchain in the multi-criteria analysis is necessary to increase the efficiency of interaction between users via supporting information exchange and with high confidence, detecting malfunctioning, helping users with performance issues, reaching a consensus, deploying distributed solutions and allocating plans, tasks and joint missions. The smart contract with decision-making performance, planning and execution improves the implementation based on efficiency, sustainability and management. Furthermore, the uncertainty and supply chain performance lead to improved users’ confidence in offering new solutions in exchange for problems in smart contacts. Evaluation includes code analysis and performance, while development performance can be under development.     

Morphological and molecular pathology of CCL4‐induced hepatic fibrosis in connexin43‐deficient mice

Gap junction channels, formed by connexins (Cx), are involved in the maintenance of tissue homeostasis, cell growth, differentiation, and development. Several studies have shown that Cx43 is involved in the control of wound healing in dermal tissue. However, it remains unknown whether Cx43 plays a role in the control of liver fibrogenesis. Our study investigated the roles of Cx43 heterologous deletion on carbon tetrachloride (CCl₄)‐induced hepatic fibrosis in mice. We administered CCl₄ to both Cx43‐deficient (Cx43^+/?) and wild‐type mice and examined hepatocellular injury and collagen deposition by histological and ultrastructural analyses. Serum biochemical analysis was performed to quantify liver injury. Hepatocyte proliferation was analyzed immunohistochemically. Protein and messenger RNA (mRNA) expression of liver connexins were evaluated using immunohistochemistry as well as immunoblotting analysis and quantitative real‐time PCR. We demonstrated that Cx43^+/? mice developed excessive liver fibrosis compared with wild‐type mice after CCl₄‐induced chronic hepatic injury, with thick and irregular collagen fibers. Histopathological evaluation showed that Cx43^+/? mice present less necroinflammatory lesions in liver parenchyma and consequent reduction of serum aminotransferase activity. Hepatocyte cell proliferation was reduced in Cx43^+/? mice. There was no difference in Cx32 and Cx26 protein or mRNA expression in fibrotic mice. Protein expression of Cx43 increased in CCl₄‐treated mice, although with aberrant protein location on cytoplasm of perisinusoidal cells. Our results demonstrate that Cx43 plays an important role in the control and regulation of hepatic fibrogenesis. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.     

A new digital watermarking evaluation and benchmarking methodology using an external group of evaluators and multi‐criteria analysis based on ‘large‐scale data’

Digital watermarking evaluation and benchmarking are challenging tasks because of multiple evaluation and conflicting criteria. A few approaches have been presented to implement digital watermarking evaluation and benchmarking frameworks. However, these approaches still possess a number of limitations, such as fixing several attributes on the account of other attributes. Well‐known benchmarking approaches are limited to robust watermarking. Therefore, this paper presents a new methodology for digital watermarking evaluation and benchmarking based on large‐scale data by using external evaluators and a group decision making context. Two experiments are performed. In the first experiment, a noise gate‐based digital watermarking approach is developed, and the scheme for the noise gate digital watermarking approach is enhanced. Sixty audio samples from different audio styles are tested with two algorithms. A total of 120 samples were evaluated according to three different metrics, namely, quality, payload, and complexity, to generate a set of digital watermarking samples. In the second experiment, the situation in which digital watermarking evaluators have different preferences is discussed. Weight measurement with a decision making solution is required to solve this issue. The analytic hierarchy process is used to measure evaluator preference. In the decision making solution, the technique for order of preference by similarity to the ideal solution with different contexts (e.g., individual and group) is utilized. Therefore, selecting the proper context with different aggregation operators to benchmark the results of experiment 1 (i.e., digital watermarking approaches) is recommended. The findings of this research are as follows: (1) group and individual decision making provide the same result in this case study. However, in the case of selection where the priority weights are generated from the evaluators, group decision making is the recommended solution to solve the trade‐off reflected in the benchmarking process for digital watermarking approaches. (2) Internal and external aggregations show that the enhanced watermarking approach demonstrates better performance than the original watermarking approach. © 2016 The Authors. Software: Practice and Experience published by John Wiley & Sons Ltd.