Analyzing repetitiveness in big code to support software maintenance and evolution

Software systems inevitably contain a large amount of repeated artifacts at different level of abstraction---from ideas, requirements, designs, algorithms to implementation. This dissertation focuses on analyzing software repetitiveness at implementation code level and leveraging the derived knowledge for easing tasks in software maintenance and evolution such as program comprehension, API use, change understanding, API adaptation and bug fixing. The guiding philosophy of this work is that, in a large corpus, code that conforms to specifications appears more frequently than code that does not, and similar code is changed similarly and similar code could have similar bugs that can be fixed similarly. We have developed different representations for software artifacts at source code level, and the corresponding algorithms for measuring code similarity and mining repeated code. Our mining techniques bases on the key insight that code that conforms to programming patterns and specifications appears more frequently than code that does not. Thus, correct patterns and specifications can be mined from large code corpus. We also have built program differencing techniques for analyzing changes in software evolution. Our key insight is that similar code is likely changed in similar ways and similar code likely has similar bug(s) which can be fixed similarly. Therefore, learning changes and fixes from the past can help automatically detect and suggest changes/fixes to the repeated code in software development. Our empirical evaluation shows that our techniques can accurately and efficiently detect repeated code, mine useful programming patterns and API specifications, and recommend changes. It can also detect bugs and suggest fixes, and provide actionable insights to ease maintenance tasks. Specifically, our code clone detection tool detects more meaningful clones than other tools. Our mining tools recover high quality programming patterns and API preconditions. The mined results have been used to successfully detect many bugs violating patterns and specifications in mature open-source systems. The mined API preconditions are shown to help API specification writer identify missing preconditions in already-specified APIs and start building preconditions for the not-yet-specified ones. The tools are scalable which analyze large systems in reasonable times. Our study on repeated changes give useful insights for program auto-repair tools. Our automated change suggestion approach achieves top-1 accuracy of 45%-51% which relatively improves more than 200% over the base approach. For a special type of change suggestion, API adaptation, our tool is highly correct and useful

FPT HCM University Parental Attitudes and Behavior Towards their Children's ``Coming Out''

The research team carried out a study of parental’ attitudes and behaviors towards their children’s ”coming-out” and gender identity. The study was conducted in Ho Chi Minh City in Vietnam with a group of respondents who are parents of the FPT students. The study was conducted through quantitative methods using questionnaires modified from previous qualitative studies of the researchers. The results show that the group of respondents had low rates of shock or devastation because of their children’s sexual orientation, but they still had a worried attitude. While their behavior is largely non-violent towards their children, they still try to encourage their children to conform to the biological sex they were born with. Parents are also more inclined to accept their children’s sexual orientation if society and its laws accept it. The research results have and will contribute to the implementation of many campaigns and activities related to the topic of LGBT parents and children. Keywords: parents, students, attitude, behavior, LGBT, coming out, FPT HCM universit

Kinematic and dynamic modelling for a class of hybrid robots composed of m local closed-loop linkages appended to an n-link serial manipulator

Recently, more and more hybrid robots have been designed to meet the increasing demand for a wide spectrum of applications. However, development of a general and systematic method for kinematic design and dynamic analysis for hybrid robots is rare. Most publications deal with the kinematic and dynamic issues for individual hybrid robots rather than any generalization. Hence, in this paper, we present a novel method for kinematic and dynamic modelling for a class of hybrid robots. First, a generic scheme for the kinematic design of a general hybrid robot mechanism is proposed. In this manner, the kinematic equation and the constraint equations for the robot class are derived in a generalized case. Second, in order to simplify the dynamic modelling and analysis of the complex hybrid robots, a Lemma about the analytical relationship among the generalized velocities of a hybrid robot system is proven in a generalized case as well. Last, examples of the kinematic and dynamic modelling of a newly designed hybrid robot are presented to demonstrate and validate the proposed method

What Do Developers Ask About ML Libraries? A Large-scale Study Using Stack Overflow

Modern software systems are increasingly including machine learning (ML) as an integral component. However, we do not yet understand the difficulties faced by software developers when learning about ML libraries and using them within their systems. To that end, this work reports on a detailed (manual) examination of 3,243 highly-rated Q&A posts related to ten ML libraries, namely Tensorflow, Keras, scikit-learn, Weka, Caffe, Theano, MLlib, Torch, Mahout, and H2O, on Stack Overflow, a popular online technical Q&A forum. We classify these questions into seven typical stages of an ML pipeline to understand the correlation between the library and the stage. Then we study the questions and perform statistical analysis to explore the answer to four research objectives (finding the most difficult stage, understanding the nature of problems, nature of libraries and studying whether the difficulties stayed consistent over time). Our findings reveal the urgent need for software engineering (SE) research in this area. Both static and dynamic analyses are mostly absent and badly needed to help developers find errors earlier. While there has been some early research on debugging, much more work is needed. API misuses are prevalent and API design improvements are sorely needed. Last and somewhat surprisingly, a tug of war between providing higher levels of abstractions and the need to understand the behavior of the trained model is prevalent

Social Media Affects the Attitudes of FPT Students From the LGBT Community Towards Coming Out to Their Parents

This study aims to determine the factors from social media and crowd psychology among individuals, a group, or communities on social networks that affect the attitudes of Lesbian, Gay, Bisexual, and Transgender (LGBT) students at FPT University in Ho Chi Minh City toward coming out to their parents. The research desires to determine whether there is any difference in terms of year of admission, major, and the frequency of social media use. The research method is quantitative research (survey - using questionnaire). The sample size of the survey is 154 LGBT students; All respondents are studying at FPT University Ho Chi Minh City. The results showed that searching for information and digital coming out are the two factors that have the most substantial impact on the attitudes of LGBT students at FPT University in Ho Chi Minh City (HCMC) towards disclosing their sexual orientation to their parents

Pre-treatment potential of electro-coagulation process using aluminum and titanium electrodes for instant coffee processing wastewater

This study aimed at investigating the potential of electrocoagulation (EC) process using Al-Al and Al-Ti electrodes for the pre-treatment of instant coffee processing wastewater. Effects of various operating conditions, including cell voltage, time of treatment, inter-electrode distance, pH of solution, solution conductivity and agitation speed on the removals of chemical oxygen demand (COD) and color were considered. The maximum removal of COD and color was achieved at 87% and 99%, respectively, corresponding to COD and color in the effluents of 359-384 mg/L and 58-101 Pt-Co. Biodegradability of treated wastewater was significantly improved since BOD5/COD increased from initial value of 0.42 to 0.65 after treatment. Nether mixing nor adding of electrolyte was recommended. Moreover, the COD removal kinetics during EC process appeared to follow the first-order kinetic model. The operating costs were also determined as a reference for cost assessment of the treatment

HYBRID COMPOSITE BASED ON MAGNETITE/ CHITOSAN FOR 2,4-D AND CHRYSOIDINE REMOVAL

In this study, magnetite nanoparticles, chitosan, a hybrid composite of magnetite/chitosan were prepared through a simple method. The prepared materials were characterized via Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer, Laser diffraction particle size analyzer, and Zeta Potential. Then, the adsorption capacity of these materials for chrysoidine, 2,4-dichlorophenoxyacetic acid (2,4-D) removal were also determined in the same condition. Prepared materials have the ability to adsorb selectivity with Chrysoidine and 2,4-D. There results show the potential application of hybrid composite magnetite/chitosan in the field of environmental treatment

Preparation of some new benzo[d]thiazole derivatives

In this work, four new benzo[d]thiazole derivatives were synthesized successfully from vanillin. Nitration of vanillin gave nitrovanillin followed by cyclization reaction with o-aminothiophenol under microwave irradiation in 4 minutes to give nitroaromatic compound 3. The reduction to convert the nitro group to amino group was optimized. It was found that Fe/ con. HCl in ethanol was the best condition for this case about both yield (~95 %) and simple procedure to give compound 4 as a salt. Acetylation occurs at both phenolic hydroxyl group and amino group of the salt 4 to form N,O-acetyl compound 5. Under mild hydrolysis 5 produces N-acetyl compound 6. The structures of these compounds were established by IR, 1H and 13C NMR and mass spectral analyses. Keywords. benzo[d]thiazole, vanillin, reduction, microwave