88 research outputs found
Parameters of Motion for Hydraulic Vertical No-Anvil Hammers
an analytical solution for equations of motion for the head of no - anvil hydraulic hammer is achieved , dependence for determination the maximum value of force acting on the hammer head from the site of actuator is determined
Analytical Method for Calculating the Exact Value of Friction Coefficient for Crank-Connecting Rod Sheet Metal Forming Press Mechanism
In the present literature as well as in text books of by pressure metal forming machines, the calculations of energy losses due to friction for crank- connecting rod stamping machines are carried out by calculating the torque resulting from friction force ,which contains the value of friction coefficient
Vibrations of Systems with One Degree- of- Freedom in the Presence of Coulomb Friction
An analytical solution for the motion equations of a single-mass mechanical system damped by Coulomb friction force is derived
Formal Analysis of A Novel Mutual Authentication and Key Agreement Protocol
This research work analyzes the universal mobile telecommunication system (UMTS) authentication and key agreement (AKA) protocol, which suffers from the traffic bottleneck at home location register and authentication center (HLR/AuC). In addition, serving network has no capability to authenticate mobile station. To overcome these problems a new security scheme has been proposed which provides a more efficient and a secure authentication between mobile station and home networks, the proposed protocol called Efficient AKA (E-AKA). The E-AKA uses a temporary key to enable visitor location register and serving network (VLR/SN) to authenticate mobile station (MS) without intervention of HLR/AuC. To analyze and validate the security of the proposed protocol, the BAN (Burrows, Abadi and Needham) logic is used. The results show that the E-AKA protocol is more robust than the current AKA protocol.Facultad de Informátic
Fine-tuning U-net for medical image segmentation based on activation function, optimizer and pooling layer
U-net convolutional neural network (CNN) is a famous architecture developed to deal with medical images. Fine-tuning CNNs is a common technique used to enhance their performance by selecting the building blocks which can provide the ultimate results. This paper introduces a method for tuning U-net architecture to improve its performance in medical image segmentation. The experiment is conducted using an x-ray image segmentation approach. The performance of U-net CNN in lung x-ray image segmentation is studied with different activation functions, optimizers, and pooling-bottleneck-layers. The analysis focuses on creating a method that can be applied for tuning U-net, like CNNs. It also provides the best activation function, optimizer, and pooling layer to enhance U-net CNN’s performance on x-ray image segmentation. The findings of this research showed that a U-net architecture worked supremely when we used the LeakyReLU activation function and average pooling layer as well as RMSProb optimizer. The U-net model accuracy is raised from 89.59 to 93.81% when trained and tested with lung x-ray images and uses the LeakyReLU activation function, average pooling layer, and RMSProb optimizer. The fine-tuned model also enhanced accuracy results with three other datasets
Leadership Pattern in Uncertainty Conditions and Its Impact on the Organizational Identification: Comparative Applied Study on Government Sector in the Hashemite Kingdom of Jordan
The study aimed to investigate leadership styles in uncertainty conditions and its impact on organizational identification in government sector in the Hashemite Kingdom of Jordan .The study used the descriptive analytical approach, through a questionnaire that was designed in accordance with study objectives and hypotheses .The study population consisted of employees in all ministries and government institutions amounting (254442) employees.ِِ A stratified sample amounting (500) employees was select, 500 questionnaires were distributed to sample's subjects. The study concluded a set of findings: The results showed that the leadership democratic style is the most commonly used in government ministries and public institutions.. While transactional style was the less common one. Sample’s subjects attitudes regarding organizational identification were medium Results showed that there is a medium perception among workers for importance of readiness for uncertainty, also results showed public institutions superiority ministries in of leadership styles implementation, with surpass of democratic leadership style on both. There was a significant impact of leadership styles on organizational identification. Laissez-faire, and transactional; have the most prominent impact on organizational identification; finally results indicate that uncertainty increase leadership styles ability in explaining the difference in organizational identification upon studying leadership styles collectively and individually. The study recommended that leaders need to adopt the powers authorization principle, and to empower employees to take decisions, and to involve employees in action plans preparations in order to improve their performance
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Pharmacological evaluation of the inhibition of polysialyltransferases as a therapeutic strategy in cancer. Characterisation of models for evaluating polysialic acid as a potential therapeutic target and pharmacological assessment of novel polysialyltransferase inhibitors
Mu'tah University and Jordan Armed Forces, Hashemite Kingdom of Jordan.The full text will be available at the end of the extended embargo: 2nd Feb 202
Cold-curing mixtures based on biopolymer lignin complex for casting production in single and small-series conditions
This study proves that lignin-based biopolymer materials can be employed as starting materials for the synthesis of novel casting binders that fulfill the current level of characteristics. The optimal concentration of the binder in the mixture was experimentally determined to be 5.8%–6.2%. It has been demonstrated in practice that the employment of ammonium salts as a technical lignosulfonate (TLS) modifier can result in the provision of cold (room temperature) curing of a mixture based on them. It was proposed to use as a technological additive that boosts the strength characteristics of a mixture of substances carboxymethyl cellulose (CMC). In a variety of adhesive materials, it is utilized as an active polymer base. The concentration limits for using CMC in the mixture are set at 0.15%–0.25%. To improve the moldability of the combination, it was suggested that kaolin clay be used as a plasticizing addition. The concentration limits for using a plasticizing additive are set at 3.5%–4.0%. The produced mixture was compared to the analog of the alpha-set method in a comparative analysis. It was discovered that the proposed composition is less expensive, more environmentally friendly, and enables the production of high-quality castings. In terms of physical, mechanical, and technological properties, the created composition of the cold curing mixture is not inferior to analogs from the alpha-set method. For the first time, a biopolymer-based binder system containing technical lignosulfonate with the addition of ammonium sulfate and carboxymethyl cellulose was used in the production of cast iron castings on the case of a cylinder casting weighing 18.3 kg from gray cast iron grade SCh20. Thus, it has been proved possible for the first time to replace phenol-based resin binders with products based on natural polymer combinations. For the first time, a cold-hardening mixture based on technological lignosulfonates has been developed without using hardeners made of very hazardous and cancer-causing hexavalent chromium compounds. But is achieved through a combination of specialized additives, including kaolin clay to ensure the mixture can be manufactured, ammonium sulfate to ensure the mixture cures, and carboxymethyl cellulose to enhance the strength properties of the binder composition. The study's importance stems from the substitution of biopolymer natural materials for costly and environmentally harmful binders based on phenolic resins. This development's execution serves as an illustration of how green technology can be used in the foundry sector. Reducing the amount of resin used in foundry manufacturing and substituting it with biopolymer binders based on technological lignosulfonates results in lower product costs as well as the preservation of the environment. Using lignin products judiciously can reduce environmental harm by using technical lignosulfonates, or compounds based on technical lignin. The combination is concentrated on businesses with single and small-scale manufacturing because it is presumable that this is merely the beginning of the investigation. This study confirms the viability of creating a cold-hardening combination based on technical lignosulfonates in practical applications and supports this with the castings produced, using the creation of a gray cast iron cylinder casting as an example
Ecotourism Intention in Jordan: The Role of Ecotourism Attitude, Ecotourism Interest, and Destination Image
The goal of this research was to check the impact of eco-tourism attitude, eco-tourism interest, and destination image on eco-intention. The sample size of this study was 309, gathered using convenience sampling. The data collection instrument was developed using five-point Likert scale. The data was analyzed by using PLS-SEM. The findings of data analysis showed that the ecotourism attitude was positively affecting the ecotourism interest. However, ecotourism attitude was not significantly affecting the ecotourism intention. The ecotourism interest was positively affecting the ecotourism intention. The destination image was also significantly affecting ecotourism intention. Ecotourism service operators may work with tourism community members for creating projects targeting domestic people and provide them with learning experiences regarding nature, ecological and cultural heritage protection attempts and initiatives, and how ecotourism will support such efforts and initiatives and conserve them
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