Ahmed Hassan | Cairo University (original) (raw)

Papers by Ahmed Hassan

2012 16th European Conference on Software Maintenance and Reengineering, 2012

Companion Proceedings of the 36th International Conference on Software Engineering - ICSE Companion 2014, 2014

Empirical Software Engineering, 2015

ABSTRACT Release notes are an important source of information about a new software release. Such ... more ABSTRACT Release notes are an important source of information about a new software release. Such notes contain information regarding what is new, changed, and/or got fixed in a release. Despite the importance of release notes, they are rarely explored in the research literature. Little is known about the contained information, e.g., contents and structure, in release notes. To better understand the types of contained information in release notes, we manually analyzed 85 release notes across 15 different software systems. In our manual analysis, we identify six different types of information (e.g., caveats and addressed issues) that are contained in release notes. Addressed issues refer to new features, bugs, and improvements that were integrated in that particular release. We observe that most release notes list only a selected number of addressed issues (i.e., 6-26 % of all addressed issues in a release). We investigated nine different factors (e.g., issue priority and type) to better understand the likelihood of an issue being listed in release notes. The investigation is conducted on eight release notes of three software systems using four machine learning techniques. Results show that certain factors, e.g., issue type, have higher influence on the likelihood of an issue to be listed in release notes. We use machine learning techniques to automatically suggest the issues to be listed in release notes. Our results show that issues listed in all release notes can be automatically determined with an average precision of 84 % and an average recall of 90 %. To train and build the classification models, we also explored three scenarios: (a) having the user label some issues for a release and automatically suggest the remaining issues for that particular release, (b) using the previous release notes for the same software system, and (c) using prior releases for the current software system and the rest of the studied software systems. Our results show that the content of release notes vary between software systems and across the versions of the same software system. Nevertheless, automated techniques can provide reasonable support to the writers of such notes with little training data. Our study provides developers with empirically-supported advice about release notes instead of simply relying on adhoc advice from on-line inquiries.

9th ASME International Conference on Radioactive Waste Management and Environmental Remediation: Volumes 1, 2, and 3, 2003

ABSTRACT

... 45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE; RADIOISOTOPES; SIMULATION; TRANSPORT;... more ... 45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE; RADIOISOTOPES; SIMULATION; TRANSPORT; GROUND WATER; CONTAMINATION; NUCLEAR TEST SITES; UNDERGROUND. Description/Abstract, Groundwater flow and radionuclide transport at the ...

Proceedings of the 36th International Conference on Software Engineering - ICSE 2014, 2014

ABSTRACT Object-Relational Mapping (ORM) provides developers a conceptual abstraction for mapping... more ABSTRACT Object-Relational Mapping (ORM) provides developers a conceptual abstraction for mapping the application code to the underlying databases. ORM is widely used in industry due to its convenience; permitting developers to focus on developing the business logic without worrying too much about the database access details. However, developers often write ORM code without considering the impact of such code on database performance, leading to cause transactions with timeouts or hangs in large-scale systems. Unfortunately, there is little support to help developers automatically detect suboptimal database accesses. In this paper, we propose an automated framework to detect ORM performance anti-patterns. Our framework automatically flags performance anti-patterns in the source code. Furthermore, as there could be hundreds or even thousands of instances of anti-patterns, our framework provides sup- port to prioritize performance bug fixes based on a statistically rigorous performance assessment. We have successfully evaluated our framework on two open source and one large-scale industrial systems. Our case studies show that our framework can detect new and known real-world performance bugs and that fixing the detected performance anti- patterns can improve the system response time by up to 98%.

Proceedings of the 20th ACM international conference on Information and knowledge management - CIKM '11, 2011

Workshop Proceedings of Textgraphs 7 on Graph Based Methods For Natural Language Processing, Jul 13, 2012

ABSTRACT Most of the research on social networks has almost exclusively focused on positive links... more ABSTRACT Most of the research on social networks has almost exclusively focused on positive links between entities. There are much more insights that we may gain by generalizing social networks to the signed case where both positive and negative edges are considered. One of the reasons why signed social networks have received less attention that networks based on positive links only is the lack of an explicit notion of negative relations in most social network applications. However, most such applications have text embedded in the social network. Applying linguistic analysis techniques to this text enables us to identify both positive and negative interactions. In this work, we propose a new method to automatically construct a signed social network from text. The resulting networks have a polarity associated with every edge. Edge polarity is a means for indicating a positive or negative affinity between two individuals. We apply the proposed method to a larger amount of online discussion posts. Experiments show that the proposed method is capable of constructing networks from text with high accuracy. We also connect out analysis to social psychology theories of signed network, namely the structural balance theory.

Journal of Software: Evolution and Process, 2013

The Journal of Chemical Physics, 2015

The addition of carbon nanotubes (CNTs) and graphene sheets (GSs) into polymeric materials can gr... more The addition of carbon nanotubes (CNTs) and graphene sheets (GSs) into polymeric materials can greatly enhance the conductivity and alter the electromagnetic response of the resulting nanocomposite material. The extent of these property modifications strongly depends on the structural parameters describing the CNTs and GSs, such as their shape and size, as well as their degree of particle dispersion within the polymeric matrix. To model these property modifications in the dilute particle regime, we determine the leading transport virial coefficients describing the conductivity of CNT and GS composites using a combination of molecular dynamics, path-integral, and finite-element calculations. This approach allows for the treatment of the general situation in which the ratio between the conductivity of the nanoparticles and the polymer matrix is arbitrary so that insulating, semi-conductive, and conductive particles can be treated within a unified framework. We first generate ensembles of CNTs and GSs in the form of self-avoiding worm-like cylinders and perfectly flat and random sheet polymeric structures by using molecular dynamics simulation to model the geometrical shapes of these complex-shaped carbonaceous nanoparticles. We then use path-integral and finite element methods to calculate the electric and magnetic polarizability tensors (αE, αM) of the CNT and GS nanoparticles. These properties determine the conductivity virial coefficient σ in the conductive and insulating particle limits, which are required to estimate σ in the general case in which the conductivity contrast Δ between the nanoparticle and the polymer matrix is arbitrary. Finally, we propose approximate relationships for αE and αM that should be useful in materials design and characterization applications.

2012 19th Working Conference on Reverse Engineering, 2012

ABSTRACT While some developers like to work on multiple code change requests, others might prefer... more ABSTRACT While some developers like to work on multiple code change requests, others might prefer to handle one change request at a time. This juggling of change requests and the large number of developers working in parallel often lead to files being edited as part of different change requests by one or several developers. Existing research has warned the community about the potential negative impacts of some file editing patterns on software quality. For example, when several developers concurrently edit a file as part of different change requests, they are likely to introduce bugs due to limited awareness of other changes. However, very few studies have provided quantitative evidence to support these claims. In this paper, we identify four file editing patterns. We perform an empirical study on three open source software systems to investigate the individual and the combined impact of the four patterns on software quality. We find that: (1) files that are edited concurrently by many developers have on average 2.46 times more future bugs than files that are not concurrently edited; (2) files edited in parallel with other files by the same developer have on average 1.67 times more future bugs than files individually edited; (3) files edited over an extended period (i.e., above the third quartile) of time have 2.28 times more future bugs than other files; and (4) files edited with long interruptions (i.e., above the third quartile) have 2.1 times more future bugs than other files. When more than one editing patterns are followed by one or many developers during the editing of a file, we observe that the number of future bugs in the file can be as high as 1.6 times the average number of future bugs in files edited following a single editing pattern. These results can be used by software development teams to warn developers about risky file editing patterns.

Bioorganic & medicinal chemistry letters, Jan 5, 2015

We described here the synthesis and biological evaluation of picolinamides and thiazole-2-carboxa... more We described here the synthesis and biological evaluation of picolinamides and thiazole-2-carboxamides as potential mGluR5 antagonists. We found that a series of thiazole derivatives 6 showed better inhibitory activity against mGluR5. Compounds 6bc and 6bj have been identified as potent antagonists (IC50=274 and 159nM) showing excellent in vitro stability profile. Molecular docking study using the crystal structure of mGluR5 revealed that our compounds 6bc and 6bj fit the allosteric binding site of mavoglurant well.

Empirical Software Engineering, 2015

Essential Notes in Psychiatry, 2012

2009 IEEE International Conference on Software Maintenance, 2009

Current Opinion in Pharmacology, 2015

Intestinal inflammation is a major health problem which impairs the quality of life, impacts ment... more Intestinal inflammation is a major health problem which impairs the quality of life, impacts mental health and is exacerbated by stress and psychiatric disturbances which, in turn, can affect disease prognosis and response to treatment. Accumulating evidence indicates that the immune system is an important interface between intestinal inflammation and the enteric, sensory, central and autonomic nervous systems. In addition, the neuroimmune interactions originating from the gastrointestinal tract are orchestrated by the gut microbiota. This article reviews some major insights into this complex homeostatic network that have been achieved during the past two years and attempts to put these advances into perspective with novel opportunities of pharmacological intervention.

SPE Annual Technical Conference and Exhibition, 2009

Hasan, A., McCormack, SJ, Huang, MJ, Norton, B., 2007. Experimental design for integrating phase ... more Hasan, A., McCormack, SJ, Huang, MJ, Norton, B., 2007. Experimental design for integrating phase change materials into building integrated photovoltaics for thermal control. Proceedings of the 3rd Photovoltaic Science, Applications and Technology Conference (PVSAT-3), ...

2012 9th IEEE Working Conference on Mining Software Repositories (MSR), 2012

Many devices are used to deliver aerosol in NIV. 3 spacers and 3 vibrating mesh nebulisers were c... more Many devices are used to deliver aerosol in NIV. 3 spacers and 3 vibrating mesh nebulisers were compared to Sidestream jet nebulizer (SIDE). Device was placed proximal to a breathing simulator in a standard NIV circuit with 500 ml tidal volume, 15 breaths/min, 20 : 5 cm H2O inspiratory (I) : expiratory (E) pressures and 1 : 3 I : E ratio. 2 ml of sulbutamol solution containing 12100 lg was nebulised using Aeroneb Pro (AERO), Aeroneb Solo (SOLO), NIVO and SIDE. 16 MDI doses containing 100 lg sulbutamol each were delivered using AeroChamber MV (AC), AeroChamber Vent (VC) and AeroChamber Mini (MC). Total emitted dose (TED) and its percentage were determined. Aerodynamic droplet characteristics were measured using cooled Andersen Cascade Impactor (1). Differences and superiorities of all tested nebulisers and spacers over jet nebuliser were found. Hence device used to deliver aerosol in NIV should be chosen with care.

2012 16th European Conference on Software Maintenance and Reengineering, 2012

Companion Proceedings of the 36th International Conference on Software Engineering - ICSE Companion 2014, 2014

Empirical Software Engineering, 2015

ABSTRACT Release notes are an important source of information about a new software release. Such ... more ABSTRACT Release notes are an important source of information about a new software release. Such notes contain information regarding what is new, changed, and/or got fixed in a release. Despite the importance of release notes, they are rarely explored in the research literature. Little is known about the contained information, e.g., contents and structure, in release notes. To better understand the types of contained information in release notes, we manually analyzed 85 release notes across 15 different software systems. In our manual analysis, we identify six different types of information (e.g., caveats and addressed issues) that are contained in release notes. Addressed issues refer to new features, bugs, and improvements that were integrated in that particular release. We observe that most release notes list only a selected number of addressed issues (i.e., 6-26 % of all addressed issues in a release). We investigated nine different factors (e.g., issue priority and type) to better understand the likelihood of an issue being listed in release notes. The investigation is conducted on eight release notes of three software systems using four machine learning techniques. Results show that certain factors, e.g., issue type, have higher influence on the likelihood of an issue to be listed in release notes. We use machine learning techniques to automatically suggest the issues to be listed in release notes. Our results show that issues listed in all release notes can be automatically determined with an average precision of 84 % and an average recall of 90 %. To train and build the classification models, we also explored three scenarios: (a) having the user label some issues for a release and automatically suggest the remaining issues for that particular release, (b) using the previous release notes for the same software system, and (c) using prior releases for the current software system and the rest of the studied software systems. Our results show that the content of release notes vary between software systems and across the versions of the same software system. Nevertheless, automated techniques can provide reasonable support to the writers of such notes with little training data. Our study provides developers with empirically-supported advice about release notes instead of simply relying on adhoc advice from on-line inquiries.

9th ASME International Conference on Radioactive Waste Management and Environmental Remediation: Volumes 1, 2, and 3, 2003

ABSTRACT

... 45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE; RADIOISOTOPES; SIMULATION; TRANSPORT;... more ... 45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE; RADIOISOTOPES; SIMULATION; TRANSPORT; GROUND WATER; CONTAMINATION; NUCLEAR TEST SITES; UNDERGROUND. Description/Abstract, Groundwater flow and radionuclide transport at the ...

Proceedings of the 36th International Conference on Software Engineering - ICSE 2014, 2014

ABSTRACT Object-Relational Mapping (ORM) provides developers a conceptual abstraction for mapping... more ABSTRACT Object-Relational Mapping (ORM) provides developers a conceptual abstraction for mapping the application code to the underlying databases. ORM is widely used in industry due to its convenience; permitting developers to focus on developing the business logic without worrying too much about the database access details. However, developers often write ORM code without considering the impact of such code on database performance, leading to cause transactions with timeouts or hangs in large-scale systems. Unfortunately, there is little support to help developers automatically detect suboptimal database accesses. In this paper, we propose an automated framework to detect ORM performance anti-patterns. Our framework automatically flags performance anti-patterns in the source code. Furthermore, as there could be hundreds or even thousands of instances of anti-patterns, our framework provides sup- port to prioritize performance bug fixes based on a statistically rigorous performance assessment. We have successfully evaluated our framework on two open source and one large-scale industrial systems. Our case studies show that our framework can detect new and known real-world performance bugs and that fixing the detected performance anti- patterns can improve the system response time by up to 98%.

Proceedings of the 20th ACM international conference on Information and knowledge management - CIKM '11, 2011

Workshop Proceedings of Textgraphs 7 on Graph Based Methods For Natural Language Processing, Jul 13, 2012

ABSTRACT Most of the research on social networks has almost exclusively focused on positive links... more ABSTRACT Most of the research on social networks has almost exclusively focused on positive links between entities. There are much more insights that we may gain by generalizing social networks to the signed case where both positive and negative edges are considered. One of the reasons why signed social networks have received less attention that networks based on positive links only is the lack of an explicit notion of negative relations in most social network applications. However, most such applications have text embedded in the social network. Applying linguistic analysis techniques to this text enables us to identify both positive and negative interactions. In this work, we propose a new method to automatically construct a signed social network from text. The resulting networks have a polarity associated with every edge. Edge polarity is a means for indicating a positive or negative affinity between two individuals. We apply the proposed method to a larger amount of online discussion posts. Experiments show that the proposed method is capable of constructing networks from text with high accuracy. We also connect out analysis to social psychology theories of signed network, namely the structural balance theory.

Journal of Software: Evolution and Process, 2013

The Journal of Chemical Physics, 2015

The addition of carbon nanotubes (CNTs) and graphene sheets (GSs) into polymeric materials can gr... more The addition of carbon nanotubes (CNTs) and graphene sheets (GSs) into polymeric materials can greatly enhance the conductivity and alter the electromagnetic response of the resulting nanocomposite material. The extent of these property modifications strongly depends on the structural parameters describing the CNTs and GSs, such as their shape and size, as well as their degree of particle dispersion within the polymeric matrix. To model these property modifications in the dilute particle regime, we determine the leading transport virial coefficients describing the conductivity of CNT and GS composites using a combination of molecular dynamics, path-integral, and finite-element calculations. This approach allows for the treatment of the general situation in which the ratio between the conductivity of the nanoparticles and the polymer matrix is arbitrary so that insulating, semi-conductive, and conductive particles can be treated within a unified framework. We first generate ensembles of CNTs and GSs in the form of self-avoiding worm-like cylinders and perfectly flat and random sheet polymeric structures by using molecular dynamics simulation to model the geometrical shapes of these complex-shaped carbonaceous nanoparticles. We then use path-integral and finite element methods to calculate the electric and magnetic polarizability tensors (αE, αM) of the CNT and GS nanoparticles. These properties determine the conductivity virial coefficient σ in the conductive and insulating particle limits, which are required to estimate σ in the general case in which the conductivity contrast Δ between the nanoparticle and the polymer matrix is arbitrary. Finally, we propose approximate relationships for αE and αM that should be useful in materials design and characterization applications.

2012 19th Working Conference on Reverse Engineering, 2012

ABSTRACT While some developers like to work on multiple code change requests, others might prefer... more ABSTRACT While some developers like to work on multiple code change requests, others might prefer to handle one change request at a time. This juggling of change requests and the large number of developers working in parallel often lead to files being edited as part of different change requests by one or several developers. Existing research has warned the community about the potential negative impacts of some file editing patterns on software quality. For example, when several developers concurrently edit a file as part of different change requests, they are likely to introduce bugs due to limited awareness of other changes. However, very few studies have provided quantitative evidence to support these claims. In this paper, we identify four file editing patterns. We perform an empirical study on three open source software systems to investigate the individual and the combined impact of the four patterns on software quality. We find that: (1) files that are edited concurrently by many developers have on average 2.46 times more future bugs than files that are not concurrently edited; (2) files edited in parallel with other files by the same developer have on average 1.67 times more future bugs than files individually edited; (3) files edited over an extended period (i.e., above the third quartile) of time have 2.28 times more future bugs than other files; and (4) files edited with long interruptions (i.e., above the third quartile) have 2.1 times more future bugs than other files. When more than one editing patterns are followed by one or many developers during the editing of a file, we observe that the number of future bugs in the file can be as high as 1.6 times the average number of future bugs in files edited following a single editing pattern. These results can be used by software development teams to warn developers about risky file editing patterns.

Bioorganic & medicinal chemistry letters, Jan 5, 2015

We described here the synthesis and biological evaluation of picolinamides and thiazole-2-carboxa... more We described here the synthesis and biological evaluation of picolinamides and thiazole-2-carboxamides as potential mGluR5 antagonists. We found that a series of thiazole derivatives 6 showed better inhibitory activity against mGluR5. Compounds 6bc and 6bj have been identified as potent antagonists (IC50=274 and 159nM) showing excellent in vitro stability profile. Molecular docking study using the crystal structure of mGluR5 revealed that our compounds 6bc and 6bj fit the allosteric binding site of mavoglurant well.

Empirical Software Engineering, 2015

Essential Notes in Psychiatry, 2012

2009 IEEE International Conference on Software Maintenance, 2009

Current Opinion in Pharmacology, 2015

Intestinal inflammation is a major health problem which impairs the quality of life, impacts ment... more Intestinal inflammation is a major health problem which impairs the quality of life, impacts mental health and is exacerbated by stress and psychiatric disturbances which, in turn, can affect disease prognosis and response to treatment. Accumulating evidence indicates that the immune system is an important interface between intestinal inflammation and the enteric, sensory, central and autonomic nervous systems. In addition, the neuroimmune interactions originating from the gastrointestinal tract are orchestrated by the gut microbiota. This article reviews some major insights into this complex homeostatic network that have been achieved during the past two years and attempts to put these advances into perspective with novel opportunities of pharmacological intervention.

SPE Annual Technical Conference and Exhibition, 2009

Hasan, A., McCormack, SJ, Huang, MJ, Norton, B., 2007. Experimental design for integrating phase ... more Hasan, A., McCormack, SJ, Huang, MJ, Norton, B., 2007. Experimental design for integrating phase change materials into building integrated photovoltaics for thermal control. Proceedings of the 3rd Photovoltaic Science, Applications and Technology Conference (PVSAT-3), ...

2012 9th IEEE Working Conference on Mining Software Repositories (MSR), 2012

Many devices are used to deliver aerosol in NIV. 3 spacers and 3 vibrating mesh nebulisers were c... more Many devices are used to deliver aerosol in NIV. 3 spacers and 3 vibrating mesh nebulisers were compared to Sidestream jet nebulizer (SIDE). Device was placed proximal to a breathing simulator in a standard NIV circuit with 500 ml tidal volume, 15 breaths/min, 20 : 5 cm H2O inspiratory (I) : expiratory (E) pressures and 1 : 3 I : E ratio. 2 ml of sulbutamol solution containing 12100 lg was nebulised using Aeroneb Pro (AERO), Aeroneb Solo (SOLO), NIVO and SIDE. 16 MDI doses containing 100 lg sulbutamol each were delivered using AeroChamber MV (AC), AeroChamber Vent (VC) and AeroChamber Mini (MC). Total emitted dose (TED) and its percentage were determined. Aerodynamic droplet characteristics were measured using cooled Andersen Cascade Impactor (1). Differences and superiorities of all tested nebulisers and spacers over jet nebuliser were found. Hence device used to deliver aerosol in NIV should be chosen with care.