1,050 research outputs found

    Ensemble learning for software fault prediction problem with imbalanced data

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    Fault prediction problem has a crucial role in the software development process because it contributes to reducing defects and assisting the testing process towards fault-free software components. Therefore, there are a lot of efforts aiming to address this type of issues, in which static code characteristics are usually adopted to construct fault classification models.  One of the challenging problems influencing the performance of predictive classifiers is the high imbalance among patterns belonging to different classes. This paper aims to integrate the sampling techniques and common classification techniques to form a useful ensemble model for the software defect prediction problem. The empirical results conducted on the benchmark datasets of software projects have shown the promising performance of our proposal in comparison with individual classifiers

    Travel Intention and Travel Behaviour in the Post-Pandemic Era: Evidence from Vietnam

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    Tourism is on the pathway of returning and contributes to the economic development of many countries. Understanding the decision-making process of tourism customers in the post-pandemic context is crucial for a strong recovery of the tourism sector. The paper aims to identify the determinants of travel intention and the link between travel intention and travel behaviour in the post-COVID-19 pandemic period. A total number of 431 questionnaires regarding the individual behaviour of Vietnamese travellers were collected. The empirical results reveal that electronic word of mouth, crisis management, and destination image in COVID have positive relationships with travel intention. Besides, travel intention is positively linked with the customers’ travel behaviour during the post-pandemic era. By contrast, the results do not support the conclusion regarding the relationship between risk communication, the healthcare system, non-pharmaceutical interventions and the travel intention of customers. Finally, the practical implications are included for enhancing a faster recovery process of the tourism sector

    Survey on Mutation-based Test Data Generation

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    The critical activity of testing is the systematic selection of suitable test cases, which be able to reveal highly the faults. Therefore, mutation coverage is an effective criterion for generating test data. Since the test data generation process is very labor intensive, time-consuming and error-prone when done manually, the automation of this process is highly aspired. The researches about automatic test data generation contributed a set of tools, approaches, development and empirical results. In this paper, we will analyse and conduct a comprehensive survey on generating test data based on mutation. The paper also analyses the trends in this field

    Childhood Acute Poisoning at Haiphong Children\u27s Hospital: A 10-Year Retrospective Study

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    INTRODUCTION: Children are most often harmed by acute poisoning, which may cause disability or even death. This demonstrates the critical necessity for epidemiologic studies specific to each nation and area since they aid in developing plans for the prevention of acute poisoning. There are no data or outdated data on acute poisoning in children in Vietnam. This research would partly fill this existing gap and compare the trend with other places across the globe. METHODS: A retrospective study was conducted in the 10-year period from 2012 to 2021 in Haiphong Children\u27s Hospital, Vietnam. RESULTS: There were 771 children hospitalized due to acute poisoning. Children in the 1-5-year-old group accounted for the highest rate, at 506 (65.6%). The mean age was 4.5 ± 4.1 years old. The male-to-female ratio was 1.2/1. Nonpharmaceutical chemicals were the most common agent in 331 cases (42.9%), including cleaning products 63 (19.0%), rat poison 60 (18.1%), and petrol 42 (12.7%). Medications were the second most common agent in 290 cases (37.6%), mostly paracetamol 60 (20.7%) and sedatives 40 (13.8%). There were 633 (82.1%) children exposed to poisons unintentionally. CONCLUSION: Children between the ages of 1 and 5 are more likely to be exposed to harmful substances. The most common agents were nonpharmaceutical chemicals followed by pharmaceuticals. Most incidents were inadvertent. Finally, our research may provide insights that public health authorities might use to plan practical actions

    Inverse kinematic control algorithm for a welding robot - positioner system to trace a 3D complex curve

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    The welding robots equipped with rotary positioners have been widely used in several manufacturing industries. However, for welding a 3D complex weld seam, a great deal of points should be created to ensure the weld path smooth. This is a boring job and is a great challenge - rotary positioner system since the robot and the positioner must move simultaneously at the same time. Therefore, in this article, a new inverse kinematics solution is proposed to generate the movement codes for a six DOFs welding robot incorporated with a rotary positioner. In the algorithm, the kinematic error is minimized, and the actual welding error is controlled so that it is always less than an allowable limit. It has shown that the proposed algorithm is useful in developing an offline CAD-based programming tool for robots when welding complex 3D paths. The use of the algorithm increases the accuracy of the end-effector positioning and orientation, and reduces the time for teaching a welding robot - positioner system. Simulation scenarios demonstrate the potency of the suggested method

    Improved Color Uniformity In White Light-Emitting Diodes Using LiLu(MoO4)2:Sm3+ Combined SiO2 Composite

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    The research herein concerns the composite of red phosphor of LiLu(MoO4)2:Sm3+ (LMOS), yellow phosphor YAG:Ce3+, SiO2 particles, and silicone gel. The LMOS phosphor is created via the sol-gel procedure and supposed to yields significant heat consistency. The concentration of this LMOS phosphor is fixed at around 10 wt.%  and the concentration of SiO2 particles is modifed. This is to influence the scattering performance of the composite to achieve the better color distribution. After sample creation, we analyzed the luminescence of the LMOS in the composite and the effects of the composite with different SiO2 dosages on the commercial light-emitting diode (LED). When excited via 405-nm ultraviolet, the samples generate red ray under 648 nm matching the shift between 4G5/2 and 6H9/2 for the ion of Sm3+. With high SiO2 amounts, the color difference is reduced, and the luminosity is enhanced. The correlated color temperature is also lower, resulting in a warmer white light for the packed LED. However, the color rendering index declines, which could be attributed to the green and blue color deficiency while the red color is dominant. From the tested outcomes, LiLu(MoO4)2:Sm3+@SiO2­ composite is validated to be effective at improving chromatic uniformity for white-ray diodes

    Parallel Mutant Execution Techniques in Mutation Testing Process for Simulink Models, Journal of Telecommunications and Information Technology, 2017, nr 4

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    Mutation testing – a fault-based technique for software testing – is a computationally expensive approach. One of the powerful methods to improve the performance of mutation without reducing effectiveness is to employ parallel processing, where mutants and tests are executed in parallel. This approach reduces the total time needed to accomplish the mutation analysis. This paper proposes three strategies for parallel execution of mutants on multicore machines using the Parallel Computing Toolbox (PCT) with the Matlab Distributed Computing Server. It aims to demonstrate that the computationally intensive software testing schemes, such as mutation, can be facilitated by using parallel processing. The experiments were carried out on eight different Simulink models. The results represented the efficiency of the proposed approaches in terms of execution time during the testing process

    Synthesis of antiulcer drug esomeprazole.

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    Esomeprazole (Nexium®), the (S)-isomer of Omeprazole, is the first proton-pump inhibitor developed as a single isomer for the treatment of acid-related diseases. It is used for the treatment of peptic ulcers, gastroesophagal reflux disease, and erosive esophagitis. Herein, we report our synthetic study of esomeprazole sodium salt from the starting    2-mercapto-5-methoxybenzimidazole and 2-(chloromethyl)-4-methoxy-3,5-dimethylpyridine hydrochloride reagents. The Esomeprazole sodium salt was obtained from enantioselectivesulfoxidation reaction in moderate yield with high enantioselectivity
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