319 research outputs found

    The vendor and user organizations characteristics for COTS software evaluation and selection

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    Since the Commercial off-the-shelf (COTS) software become widespread components in the market for building the systems with less time and cost, the COTS evaluation and selection becomes a non-trivial task. There are many models attempted to propose a set of characteristics for evaluating and selecting COTS software.However, these models have concentrated on the functional and quality characteristics of COTS software, leaving other effective characteristics related to vendor (the organization that developed, support, and realized COTS software) and user (the organization that integrated and used COTS software) organizations. Therefore, this paper proposed a set of important characteristics relevant to the vendor and user organizations that play important role to discriminate between COTS alternatives in COTS evaluation and selection process.Most of the related studies have been analyzed and carefully studied in the literature to identify and propose these characteristics together with their attributes and associated metrics

    Software Engineering Laboratory Series: Proceedings of the Twentieth Annual Software Engineering Workshop

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    The Software Engineering Laboratory (SEL) is an organization sponsored by NASA/GSFC and created to investigate the effectiveness of software engineering technologies when applied to the development of application software. The activities, findings, and recommendations of the SEL are recorded in the Software Engineering Laboratory Series, a continuing series of reports that includes this document

    The consequences of spatial environmental variability on dispersal and on the spatial distribution of species

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    A central goal in ecology is to identify and understand causal factors that lead to the expansion or contraction of species ranges. Spatio - temporal population dynamics depend on biotic and abiotic environmental conditions, local demography, dispersal behaviour, and phenotypic variation. In particular understanding dispersal behaviour turns out to be a tough problem, because complex feedback loops between dispersal, local demography, and individual variations can arise. Furthermore, previous attempts to understand dispersal by reducing the complexity either in space or time have often resulted in a disregard of these feedbacks. The aim of this thesis was to investigate the influence of dispersal on spatio-temporal population dynamics with models and experiments that explicitly consider the multi causality of dispersal. The thesis is composed of three different studies: Firstly, for an active dispersing species, a plausible factor affecting dispersal behaviour could be personal information. Birds, for example, might gather information on future nest sites and, as a result, individuals differ in the amount and quality of information they possess for use in reaching a dispersal decision. We manipulated the information available to flycatchers (Ficedula hypoleuca) in a field experiment and we found that individuals which were longer exposed to the information altered dispersal behaviour to a greater extent, but only at a local spatial extent. Secondly, models of sex-biased dispersal rarely take space into account. With a computer simulation model, we showed that acknowledging the spatial distribution of the sexes has consequences for the evolutionary outcome of the model leading to selection of more similar dispersal behaviour among the two sexes. Thirdly, models of invasion spread rate often ignore the dependency of dispersal on environmental heterogeneity. We expanded on a reaction-diffusion model to improve this deficit and show that the invasion dynamics of an ecto-parasite (deer ked, Lipoptena cervi) is dependent on the local density of its main host, moose (Alces alces), across its Finnish range. In conclusion, these studies point at the necessity to consider interactions between dispersal and environmental variability, feedbacks between causal factor of dispersal, and realistic assumptions about space and time in order to solve the conundrum of factors determining the spatio-temporal distribution of species.Ei saatavill

    Movement of forest-dependent dung beetles through riparian buffers in Bornean oil palm plantations

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    ABSTRACT Fragmentation of tropical forests is increasing globally, with negative impacts for biodiversity. In Southeast Asia, expansion of oil palm agriculture has caused widespread deforestation, forest degradation, and fragmentation. Persistence of forest-dependent species within these fragmented landscapes is likely to depend on the capacity of individuals to move between forest patches. In oil palm landscapes, riparian buffers along streams and rivers are potential movement corridors, but their use by moving animals is poorly studied. We examined how six dung beetle species traversed riparian buffers connected to a continuous forest reserve area within an oil palm plantation in Sabah, Malaysian Borneo. We used a mark-release-recapture study and a new Bayesian Joint Species Movement Modelling (JSMM) approach, extended to a continuous capture process model. Dung beetle species were fairly generalist in their habitat use, but two species showed a statistically-supported preference for riparian buffer forest over oil palm, and one species showed a strong preference for forest reserve over riparian buffer, indicating the importance of forested areas within oil palm landscapes for some species. A land-use change simulation indicated that the loss of riparian buffers in oil palm will result in reduced movement by forest-dependent species. Synthesis and applications: Our results provide evidence for the use of riparian buffers in oil palm plantations for forest-dependent dung beetle species, strengthening the case for their retention, restoration, and re-establishment. Furthermore, our study demonstrates the wider applicability of the Joint Species Movement Modelling (JSMM) framework to assess movement behaviour of species in fragmented landscapes, a vital tool for future forest and landscape management and conservation prioritisation exercises.Peer reviewe

    Application of rock mass classification methods for slope stability design in open pit of Otso Gold Oy (Laivan Kaivos)

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    Abstract. Rock Mass Classification systems are used in the mining industry to classify rock types based on their physical and mechanical properties. It is one of the basic requirements on which the development of the mine will be based. Previous geotechnical studies at the Otso Gold Laivan Mine employed the Rock Mass Quality Index (Q-system), Goelogical Strength Index (GSI), Mining Rock Mass Rating (M-RMR) and later Rock Quality Designation Index (RQD) to determine the quality of rocks at the mine for mine planning, designs, and development, including slope stability analysis and design. However, these were done at a time there was less or no pit development. This study aims to classify unexposed sections of the mine Rock Mass Rating (RMR) and perform a Slope Mass Ratings for the stability of rock slopes in the south pit of the mine. RMR results will be used to compare with previously used classification systems. Three slopes are selected for stability analysis. Field measurements and observations were conducted to obtain data for rock classification and kinematic analysis. Kinematic analysis with the information on rock quality and stability of slopes from calculated RMR and SMR, will be used to perform a slope stability analysis on the present slopes and for consideration in future development of the pit. This study will also suggest slope specifications for further development based on present performances of the slopes

    A framework for cots software evaluation and selection for COTS mismatches handling and non-functional requirements

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    The decision to purchase Commercial Off-The-Shelf (COTS) software needs systematic guidelines so that the appropriate COTS software can be selected in order to provide a viable and effective solution to the organizations. However, the existing COTS software evaluation and selection frameworks focus more on functional aspects and do not give adequate attention to accommodate the mismatch between user requirements and COTS software specification, and also integration with non functional requirements of COTS software. Studies have identified that these two criteria are important in COTS software evaluation and selection. Therefore, this study aims to develop a new framework of COTS software evaluation and selection that focuses on handling COTS software mismatches and integrating the nonfunctional requirements. The study is conducted using mixed-mode methodology which involves survey and interview. The study is conducted in four main phases: a survey and interview of 63 organizations to identify COTS software evaluation criteria, development of COTS software evaluation and selection framework using Evaluation Theory, development of a new decision making technique by integrating Analytical Hierarchy Process and Gap Analysis to handle COTS software mismatches, and validation of the practicality and reliability of the proposed COTS software Evaluation and Selection Framework (COTS-ESF) using experts’ review, case studies and yardstick validation. This study has developed the COTS-ESF which consists of five categories of evaluation criteria: Quality, Domain, Architecture, Operational Environment and Vendor Reputation. It also provides a decision making technique and a complete process for performing the evaluation and selection of COTS software. The result of this study shows that the evaluated aspects of the framework are feasible and demonstrate their potential and practicality to be applied in the real environment. The contribution of this study straddles both the research and practical perspectives of software evaluation by improving decision making and providing a systematic guidelines for handling issue in purchasing viable COTS software

    Network reputation-based quality optimization of video delivery in heterogeneous wireless environments

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    The mass-market adoption of high-end mobile devices and increasing amount of video traffic has led the mobile operators to adopt various solutions to help them cope with the explosion of mobile broadband data traffic, while ensuring high Quality of Service (QoS) levels to their services. Deploying small-cell base stations within the existing macro-cellular networks and offloading traffic from the large macro-cells to the small cells is seen as a promising solution to increase capacity and improve network performance at low cost. Parallel use of diverse technologies is also employed. The result is a heterogeneous network environment (HetNets), part of the next generation network deployments. In this context, this thesis makes a step forward towards the “Always Best Experience” paradigm, which considers mobile users seamlessly roaming in the HetNets environment. Supporting ubiquitous connectivity and enabling very good quality of rich mobile services anywhere and anytime is highly challenging, mostly due to the heterogeneity of the selection criteria, such as: application requirements (e.g., voice, video, data, etc.); different device types and with various capabilities (e.g., smartphones, netbooks, laptops, etc.); multiple overlapping networks using diverse technologies (e.g., Wireless Local Area Networks (IEEE 802.11), Cellular Networks Long Term Evolution (LTE), etc.) and different user preferences. In fact, the mobile users are facing a complex decision when they need to dynamically select the best value network to connect to in order to get the “Always Best Experience”. This thesis presents three major contributions to solve the problem described above: 1) The Location-based Network Prediction mechanism in heterogeneous wireless networks (LNP) provides a shortlist of best available networks to the mobile user based on his location, history record and routing plan; 2) Reputation-oriented Access Network Selection mechanism (RANS) selects the best reputation network from the available networks for the mobile user based on the best trade-off between QoS, energy consumptions and monetary cost. The network reputation is defined based on previous user-network interaction, and consequent user experience with the network. 3) Network Reputation-based Quality Optimization of Video Delivery in heterogeneous networks (NRQOVD) makes use of a reputation mechanism to enhance the video content quality via multipath delivery or delivery adaptation

    Multi-Criteria Decision Making in software development:a systematic literature review

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    Abstract. Multiple Criteria Decision Making is a formal approach to assist decision makers to select the best solutions among multiple alternatives by assessing criteria which are relatively precise but generally conflicting. The utilization of MCDM are quite popular and common in software development process. In this study, a systematic literature review which includes creating review protocol, selecting primary study, making classification schema, extracting data and other relevant steps was conducted. The objective of this study are making a summary about the state-of-the-art of MCDM in software development process and identifying the MCDM methods and MCDM problems in software development by systematically structuring and analyzing the literature on those issues. A total of 56 primary studies were identified after the review, and 33 types of MCDM methods were extracted from those primary studies. Among them, AHP was defined as the most frequent used MCDM methods in software development process by ranking the number of primary studies which applied it in their studies, and Pareto optimization was ranked in the second place. Meanwhile, 33 types of software development problems were identified. Components selection, design concepts selection and performance evaluation became the three most frequent occurred problems which need to be resolved by MCDM methods. Most of those MCDM problems were found in software design phase. There were many limitations to affect the quality of this study; however, the strictly-followed procedures of SLR and mass data from thousands of literature can still ensure the validity of this study, and this study is also able to provide the references when decision makers want to select the appropriate technique to cope with the MCDM problems

    High-resolution 3D forest structure explains ecomorphological trait variation in assemblages of saproxylic beetles

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    Climate, topography and the 3D structure of forests are major drivers affecting local species communities. However, little is known about how the specific functional traits of saproxylic (wood-living) beetles, involved in the recycling of wood, might be affected by those environmental characteristics. Here, we combine ecological and morphological traits available for saproxylic beetles and airborne laser scanning (ALS) data in Bayesian trait-based joint species distribution models to study how traits drive the distributions of more than 230 species in temperate forests of Europe. We found that elevation (as a proxy for temperature and precipitation) and the proportion of conifers played important roles in species occurrences while variables related to habitat heterogeneity and forest complexity were less relevant. Furthermore, we showed that local communities were shaped by environmental variation primarily through their ecological traits whereas morphological traits were involved only marginally. As predicted, ecological traits influenced species' responses to forest structure, and to other environmental variation, with canopy niche, wood decay niche and host preference as the most important ecological traits. Conversely, no links between morphological traits and environmental characteristics were observed. Both models, however, revealed strong phylogenetic signal in species' response to environmental characteristics. These findings imply that alterations of climate and tree species composition have the potential to alter saproxylic beetle communities in temperate forests. Additionally, ecological traits help explain species' responses to environmental characteristics and thus should prove useful in predicting their responses to future change. It remains challenging, however, to link simple morphological traits to species' complex ecological niches. Read the free Plain Language Summary for this article on the Journal blog

    Alternative measures of trait-niche relationships: A test on dispersal traits in saproxylic beetles

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    Functional trait approaches are common in ecology, but a lack of clear hypotheses on how traits relate to environmental gradients (i.e., trait-niche relationships) often makes uncovering mechanisms difficult. Furthermore, measures of community functional structure differ in their implications, yet inferences are seldom compared among metrics. Community-weighted mean trait values (CWMs), a common measure, are largely driven by the most common species and thus do not reflect community-wide trait-niche relationships per se. Alternatively, trait-niche relationships can be estimated across a larger group of species using hierarchical joint species distribution models (JSDMs), quantified by a parameter Gamma. We investigated how inferences about trait-niche relationships are affected by the choice of metric. Using deadwood-dependent (saproxylic) beetles in fragmented Finnish forests, we followed a protocol for investigating trait-niche relationships by (1) identifying environmental filters (climate, forest age, and deadwood volume), (2) relating these to an ecological function (dispersal ability), and (3) identifying traits related to this function (wing morphology). We tested 18 hypothesized dispersal relationships using both CWM and Gamma estimates across these environmental gradients. CWMs were more likely than Gamma to show support for trait-niche relationships. Up to 13% of species' realized niches were explained by dispersal traits, but the directions of effects were consistent with fewer than 11%-39% of our 18 trait-niche hypotheses (depending on the metric used). This highlights the difficulty in connecting morphological traits and ecological functions in insects, despite the clear conceptual link between landscape connectivity and flight-related traits. Caution is thus warranted in hypothesis development, particularly where apparent trait-function links are less clear. Inferences differ when CWMs versus Gamma estimates are used, necessitating the choice of a metric that reflects study questions. CWMs help explain the effects of environmental gradients on community trait composition, whereas the effects of traits on species' niches are better estimated using hierarchical JSDMs
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