226 research outputs found

    Improving Automated Software Testing while re-engineering legacy systems in the absence of documentation

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    Legacy software systems are essential assets that contain an organizations' valuable business logic. Because of outdated technologies and methods used in these systems, they are challenging to maintain and expand. Therefore, organizations need to decide whether to redevelop or re-engineer the legacy system. Although in most cases, re-engineering is the safer and less expensive choice, it has risks such as failure to meet the expected quality and delays due to testing blockades. These risks are even more severe when the legacy system does not have adequate documentation. A comprehensive testing strategy, which includes automated tests and reliable test cases, can substantially reduce the risks. To mitigate the hazards associated with re-engineering, we have conducted three studies in this thesis to improve the testing process. Our rst study introduces a new testing model for the re-engineering process and investigates test automation solutions to detect defects in the early re-engineering stages. We implemented this model on the Cold Region Hydrological Model (CRHM) application and discovered bugs that would not likely have been found manually. Although this approach helped us discover great numbers of software defects, designing test cases is very time-consuming due to the lack of documentation, especially for large systems. Therefore, in our second study, we investigated an approach to generate test cases from user footprints automatically. To do this, we extended an existing tool to collect user actions and legacy system reactions, including database and le system changes. Then we analyzed the data based on the order of user actions and time of them and generated human-readable test cases. Our evaluation shows that this approach can detect more bugs than other existing tools. Moreover, the test cases generated using this approach contain detailed oracles that make them suitable for both black-box and white-box testing. Many scienti c legacy systems such as CRHM are data-driven; they take large amounts of data as input and produce massive data after applying mathematical models. Applying test cases and nding bugs is more demanding when we are dealing with large amounts of data. Hence in our third study, we created a comparative visualization tool (ComVis) to compare a legacy system's output after each change. Visualization helps testers to nd data issues resulting from newly introduced bugs. Twenty participants took part in a user study in which they were asked to nd data issued using ComVis and embedded CRHM visualization tool. Our user study shows that ComVis can nd 51% more data issues than embedded visualization tools in the legacy system can. Also, results from the NASA-TLX assessment and thematic analysis of open-ended questions about each task show users prefer to use ComVis over the built-in visualization tool. We believe our introduced approaches and developed systems will signi cantly reduce the risks associated with the re-engineering process. i

    Elements of Gallows Humor in Vonnegut's Slaughter House Five

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    This study analyzes the outstanding satirist Kurt Vonnegut's novel Slaughter-house-five to demonstrate how the elements of Gallows Humor are applied to provide a better understanding of the author's worldview and of his narrative process. This is an anti-war book in which Vonnegut has attempted to blend the serious theme with humor. Through the choice of his protagonist- Billy Pilgrim- and the manipulation of black humor, Vonnegut exposes the atrocities of war from a new viewpoint. The focal point is to extract the phrases containing gallows humor, a sort of black humor, to be studied and explained by details, accordingly some literary terms are to be precisely defined and the unique style of writing is indispensable. Keywords: Anti-war, Black Humor, Gallows Humor, Satire, Humor, Vonnegu

    CROSS-DISCIPLINARY COLLABORATIONS IN DATA QUALITY RESEARCH

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    Data Quality has been the target of research and development for over four decades, and due to its cross-disciplinary nature has been approached by business analysts, solution architects, database experts and statisticians to name a few. As data quality increases in importance and complexity, there is a need to motivate the exploitation of synergies across diverse research communities in order to form holistic solutions that span across its organizational, architectural and computational aspects. As a first step towards bridging gaps between the various research communities, we undertook a comprehensive literature study of data quality research published in the last two decades. In this study we considered a broad range of Information System (IS) and Computer Science (CS) publication outlets. The main aims of the study were to understand the current landscape of data quality research, create better awareness of (lack of) synergies between various research communities, and, subsequently, direct attention towards holistic solutions. In this paper, we present a summary of the findings from the study that outline the overlaps and distinctions between the two communities from various points of view, including publication outlets, topics and themes of research, highly cited or influential contributors and strength and nature of co-authorship networks

    HealthXAI: Collaborative and explainable AI for supporting early diagnosis of cognitive decline

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    Our aging society claims for innovative tools to early detect symptoms of cognitive decline. Several research efforts are being made to exploit sensorized smart-homes and artificial intelligence (AI) methods to detect a decline of the cognitive functions of the elderly in order to promptly alert practitioners. Even though those tools may provide accurate predictions, they currently provide limited support to clinicians in making a diagnosis. Indeed, most AI systems do not provide any explanation of the reason why a given prediction was computed. Other systems are based on a set of rules that are easy to interpret by a human. However, those rule-based systems can cope with a limited number of abnormal situations, and are not flexible enough to adapt to different users and contextual situations. In this paper, we tackle this challenging problem by proposing a flexible AI system to recognize early symptoms of cognitive decline in smart-homes, which is able to explain the reason of predictions at a fine-grained level. Our method relies on well known clinical indicators that consider subtle and overt behavioral anomalies, as well as spatial disorientation and wandering behaviors. In order to adapt to different individuals and situations, anomalies are recognized using a collaborative approach. We experimented our approach with a large set of real world subjects, including people with MCI and people with dementia. We also implemented a dashboard to allow clinicians to inspect anomalies together with the explanations of predictions. Results show that our system's predictions are significantly correlated to the person's actual diagnosis. Moreover, a preliminary user study with clinicians suggests that the explanation capabilities of our system are useful to improve the task performance and to increase trust. To the best of our knowledge, this is the first work that explores data-driven explainable AI for supporting the diagnosis of cognitive decline

    A Prototype CVNS Distributed Neural Network

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    Artificial neural networks are widely used in many applications such as signal processing, classification, and control. However, the practical implementation of them is challenged by the number of inputs, storing the weights, and realizing the activation function.In this work, Continuous Valued Number System (CVNS) distributed neural networks are proposed which are providing the network with self-scaling property. This property aids the network to cope spontaneously with different number of inputs. The proposed CVNS DNN can change the dynamic range of the activation function spontaneously according to the number of inputs providing a proper functionality for the network.In addition, multi-valued CVNS DRAMs are proposed to store the weights as CVNS digits. These memories scan store up to 16 levels, equal to 4 bits, on each storage cell. In addition, they use error correction codes to detect and correct the error over the stored values.A synapse-neuron module is proposed to decrease the design cost. It contains both synapse and neuron and the relevant components. In these modules, the activation function is realized through analog circuits which are far more compact compared to the digital look-up-tables while quite accurate.Furthermore, the redundancy between CVNS digits together with the distributed structure of the neuron make the proposal stable against process violations and reduce the noise to signal ration

    Seroprevalence of varicella zoster virus antibody among young women before marriage in Sanandaj, Iran

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    Background and Objectives: Varicella Zoster Virus (VZV) infection in pregnant women can cause complications for the mother and fetus. The aim of this study was to assess the immunity against VZV among young women before marriage. Materials and Methods: In this cross-sectional study 250 women attending health centers in Sanandaj, Iran, for pre-marital medical check-up were randomly selected. The VZV IgG measured by ELISA and demographic characteristics of participants including their age, place of residence, number of siblings, occupation, education and history of chickenpox were also recorded. Data were analyzed using R statistical software. Association between VZV infection and participants� characteristics was assessed using Chi-square and Fisher's exact tests. Results: Out of 250 participants, 178 individuals (71.2) diagnosed as antibody positive and 72 (28.8) negative. Our findings revealed that the immunity against VZV increased with individuals� age (P<0.0001) and their number of siblings (P= 0.03). Significant association was found between history of chickenpox and immunity (P <0.001). Positive and negative predictive values of self-reported history of chickenpox obtained by 94.60 and 49.25, respectively. Conclusion: A notable percentage of women were found to be susceptible to VZV, hence they are at risk of getting infected during pregnancy which in turn may result in fetus abnormalities. Screening the immunity and further studies on the need of vaccination before marriage are recommended. © 2016, Tehran University of Medical Science. All rights reserved

    Preventive and Curative Effect of Omega-3 Supplementation on Bone Mineral Density in People Aged 60 Years and Older: A Review Article

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    Osteoporosis and osteopenia are common worldwide problems leading to potentially life-threatening consequences. Omega-3 supplementation for treating osteoporosis is less studied and less valued by physicians. We aimed to ascertain the appropriate dosage of omega- 3 supplementation to prevent osteoporosis. Google scholar database was searched in May 2017 using the keywords: n-3 fatty acids, omega-3 polyunsaturated fatty acids, essential fatty acids, eicosapentaenoic fatty acids, docosahexaenoic acid, docosapentaenoic acid, alpha-linolenic acid, linoleic acid, osteopenia, osteoporosis, bone density, and fracture. We reviewed English language reports of randomized controlled trials with intake of omega-3 polyunsaturated fatty acids, in which subjects were over 60 years and supplemented with a quantified dosage of omega-3; and outcome was indicated by bone mineral densitometry medical record of fractures and radiological imaging, and serum biomarker to evaluate bone metabolism. We reviewed 110 papers, which only eight articles met our conclusion criteria and concluded with curative effects. Three articles came up with no prophylactic or curative effect of omega-3 supplementation, three articles suggested a dosage of omega-3 supplement that non significantly increased bone mineral densitometry or decreased absorption, and thus, had prophylactic effects. One article just concluded the positive effects, not defining the exact results. It is suggested that a dosage of 4.5 to 6 g/d of eicosapentaenoic acid and docosahexaenoic acid can have curative effects, while 900-1000 mg/d can have prophylactic outcomes. N-3 fatty acids have positive effects on bone density, but to confine definitive dosage and formulation of omega-3 supplementation for reducing the risk of osteoporosis, further investigations are required

    Modulation of the Expression of the GABAA Receptor β1 and β3 Subunits by Pretreatment with Quercetin in the KA Model of Epilepsy in Mice -The Effect of Quercetin on GABAA Receptor Beta Subunits-

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    Objectives: Quercetin is a flavonoid and an important dietary constituent of fruits and vegetables. In recent years, several pharmacological activities of quercetin, such as its neuroprotective activity and, more specifically, its anti-convulsant effects in animal models of epilepsy, have been reported. This study evaluated the role of quercetin pretreatment on gene expression of γ-amino butyric acid type A (GABAA) receptor beta subunits in kainic acid (KA)-induced seizures in mice. Methods: The animals were divided into four groups: one saline group, one group in which seizures were induced by using KA (10 mg/kg) without quercetin pretreatment and two groups pretreated with quercetin (50 and 100 mg/kg) prior to seizures being induced by using KA. Next, the messenger ribonucleic acid (mRNA) levels of the GABAA receptor β subunits in the hippocampus of each animal were assessed at 2 hours and 7 days after KA administration. Quantitative real-time polymerase chain reaction (RT-PCR) assay was used to detect mRNA content in hippocampal tissues. Results: Pretreatments with quercetin at doses of 50 and 100 mg/kg prevented significant increases in the mRNA levels of the β1 and the β3 subunits of the GABAA receptor at 2 hours after KA injection. Pretreatment with quercetin (100 mg/kg) significantly inhibited β1 and β3 gene expression in the hippocampus at 7 days after KA injection. But, this inhibitory effect of quercetin at 50 mg/kg on the mRNA levels of the β3 subunit of the GABAA receptor was not observed at 7 days after KA administration. Conclusion: These results suggest that quercetin (100 mg/kg) modulates the expression of the GABAA receptor β1 and β3 subunits in the KA model of epilepsy, most likely to prevent compensatory responses. This may be related to the narrow therapeutic dose range for the anticonvulsant activities of quercetin

    Chronic treatment with the nitric oxide synthase inhibitor, L-NAME, attenuates estradiol-mediated improvement of learning and memory in ovariectomized rats

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    INTRODUCTION: The role of ovarian hormones and nitric oxide in learning and memory has been widely investigated. OBJECTIVE: The present study was carried out to evaluate the effect of the nitric oxide synthase (NOS) inhibitor, N (G)-nitro-L-arginine methyl ester (L-NAME), on the ability of estradiol to improve learning in OVX rats using the Morris water maze. METHODS: Forty rats were divided into five groups: (1) ovariectomized (OVX), (2) ovariectomized-estradiol (OVX-Est), (3) ovariectomized-L-NAME 10 (OVX-LN 10), (4) ovariectomized-L-NAME 50 (OVX-LN 50) and (5) ovariectomized-estradiol-L-NAME 50 (OVX-Est-LN 50). The animals in the OVX-Est group were treated with a weekly injection of estradiol valerate (2 mg/kg; i.m.). The OVX-LN 10 and OVX-LN 50 groups were treated with daily injections of 10 and 50 mg/kg L-NAME (i.p.), respectively. The animals in the OVX-Est-LN 50 group received a weekly injection of estradiol valerate and a daily injection of 50 mg/kg L-NAME. After 8 weeks, all animals were tested in the Morris water maze. RESULTS: The animals in the OVX-Est group had a significantly lower latency in the maze than the OVX group (p<0.001). There was no significant difference in latency between the OVX-LN 10 and OVX-LN 50 groups in comparison with the OVX group. The latency in the OVX-Est-LN 50 group was significantly higher than that in the OVX-Est group (p<0.001). CONCLUSION: These results show that L-NAME treatment attenuated estradiol-mediated enhancement of spatial learning and memory in OVX rats, but it had no significant effect in OVX rats without estrogen, suggesting an interaction of nitric oxide and estradiol in these specific brain functions

    Vancomycin dosing in low-flux hemodialysis; Is adjustment of drug dosage necessary?

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    Introduction: Vancomycin is a wide useable antibiotic against gram-positive bacteria species in different clinical setting particularly in hemodialysis patients. Objectives: The present study aimed to assess the serum level of vancomycin before and after hemodialysis. Patients and Methods: This cross-sectional study was performed on patients who were hospitalized and medicated by vancomycin with the loading dose of 1000 mg followed by the maintenance dose of 500 mg after each dialysis session every other day. All patients were dialyzed with a low-flux dialyzer membrane. Half an hour before and immediately after dialysis, 2 mL blood sample was taken and stored at -20°C until assaying the level of vancomycin. Results: The average reduction in the serum level of vancomycin was totally 17.65 ± 1.69. The mean reduction in the serum level of vancomycin was significantly higher in the patients aged higher than 60 years, as compared to other ones. But the level of drug was independent to gender or body mass index. Conclusion: Using low-flux dialyzer membranes, the average reduction in the serum level of vancomycin is expected to be in the range of 12.43 to 21.56 that age was directly associated with the average reduction of the level of vancomycin. Therefore, adjusting and monitoring the serum level of drug in old ages even in the cases of using low-flux dialyzer membranes is recommended. © 2019 The Author(s)
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