598 research outputs found

    Stakeholder identification in the requirements engineering process

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    Adequate, timely and effective consultation of relevant stakeholders is of paramount importance in the requirements engineering process. However, the thorny issue of making sure that all relevant stakeholders are consulted has received less attention than other areas which depend on it, such as scenario-based requirements, involving users in development, negotiating between different viewpoints and so on. The literature suggests examples of stakeholders, and categories of stakeholder, but does not provide help in identifying stakeholders for a specific system. In this paper, we discuss current work in stakeholder identification, propose an approach to identifying relevant stakeholders for a specific system, and propose future directions for the work

    Trustee: Full Privacy Preserving Vickrey Auction on top of Ethereum

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    The wide deployment of tokens for digital assets on top of Ethereum implies the need for powerful trading platforms. Vickrey auctions have been known to determine the real market price of items as bidders are motivated to submit their own monetary valuations without leaking their information to the competitors. Recent constructions have utilized various cryptographic protocols such as ZKP and MPC, however, these approaches either are partially privacy-preserving or require complex computations with several rounds. In this paper, we overcome these limits by presenting Trustee as a Vickrey auction on Ethereum which fully preserves bids' privacy at relatively much lower fees. Trustee consists of three components: a front-end smart contract deployed on Ethereum, an Intel SGX enclave, and a relay to redirect messages between them. Initially, the enclave generates an Ethereum account and ECDH key-pair. Subsequently, the relay publishes the account's address and ECDH public key on the smart contract. As a prerequisite, bidders are encouraged to verify the authenticity and security of Trustee by using the SGX remote attestation service. To participate in the auction, bidders utilize the ECDH public key to encrypt their bids and submit them to the smart contract. Once the bidding interval is closed, the relay retrieves the encrypted bids and feeds them to the enclave that autonomously generates a signed transaction indicating the auction winner. Finally, the relay submits the transaction to the smart contract which verifies the transaction's authenticity and the parameters' consistency before accepting the claimed auction winner. As part of our contributions, we have made a prototype for Trustee available on Github for the community to review and inspect it. Additionally, we analyze the security features of Trustee and report on the transactions' gas cost incurred on Trustee smart contract.Comment: Presented at Financial Cryptography and Data Security 2019, 3rd Workshop on Trusted Smart Contract

    A PC-based magnetometer-only attitude and rate determination system for gyroless spacecraft

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    This paper describes a prototype PC-based system that uses measurements from a three-axis magnetometer (TAM) to estimate the state (three-axis attitude and rates) of a spacecraft given no a priori information other than the mass properties. The system uses two algorithms that estimate the spacecraft's state - a deterministic magnetic-field only algorithm and a Kalman filter for gyroless spacecraft. The algorithms are combined by invoking the deterministic algorithm to generate the spacecraft state at epoch using a small batch of data and then using this deterministic epoch solution as the initial condition for the Kalman filter during the production run. System input comprises processed data that includes TAM and reference magnetic field data. Additional information, such as control system data and measurements from line-of-sight sensors, can be input to the system if available. Test results are presented using in-flight data from two three-axis stabilized spacecraft: Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) (gyroless, Sun-pointing) and Earth Radiation Budget Satellite (ERBS) (gyro-based, Earth-pointing). The results show that, using as little as 700 s of data, the system is capable of accuracies of 1.5 deg in attitude and 0.01 deg/s in rates; i.e., within SAMPEX mission requirements

    Controller Energy management for hybrid renewable energy system

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    A new modified configuration for the stand-alone photovoltaic- wind ndash diesel generator system with and without battery to electrify a remote area household load in Egypt is presented. The displaying, reenactment, and operational control technique for the framework is produced. The created control intends to enhance the energy flow inside the framework, with the end goal that the heap is fulfilled autonomous on the varieties in insolation, the temperature and the wind speed. Additionally, it means to ensure the battery against overcharging or excessive discharging. Also, it means to secure the worldwide framework against the unpredictable excess or defict of the available energy

    A Sentimental Analysis Tool for Determining the Promotional Success of Fashion Images on Instagram

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    Sentiment Analysis (SA) or Opinion Mining is the process of analysing natural language texts to detect anemotion or a pattern of emotions towards a certain product to make a decision about that product. SA is atopic of text mining, Natural Language Processing (NLP) and web mining disciplines. Research in SA iscurrently at its peak given the amount of data generated from social media networks. The concept is thatconsumers are expressing exactly what they need, want and expect from a product but on the other hand thecompanies don’t have the tools to analyse and understand these feelings to satisfy these consumersaccordingly.One of the applications that generate a high rate of reactions and sentiments in social networks isInstagram. This study focuses on analysing the reactions generated by the top 50 fashion houses on Instagramgiven their top 20 images with the highest number of likes. The approach taken in this study is to qualify thevisual aesthetics of fashion images and to establish why some succeed on social media more than others.The basic question asked in this paper is whether there are certain visual aesthetics that appeal more to theuser and are therefore more successful on social media than others as determined by a measure we introduce,‘Social Value’. To do so, a sentiment analysis tool is developed to measure the proposed social value of eachimage. An input of comments from each image will be processed. Each comment will go through a preprocessingphase; each word will be placed through a lexicon to identify if it is positive or negative. Theoutput of the lexicon is a score value assigned to each comment to identify its degree of positivity, negativity,or it has no effect on the social value. Adding to these results, the number of likes and shares would also betaken into consideration quantifying the image’s value. A cumulative result is then produced to determine thesocial value of an image. Keywords: Sentiment Analysis; Opinion Mining; Instagram; Social Value; Aesthetic

    Intravenous infusion practices across England and their impact on patient safety: a mixed-methods observational study

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    BACKGROUND: Intravenous (IV) medication administration has traditionally been regarded to be error-prone with high potential for harm. A recent US multisite study revealed surprisingly few potentially harmful errors despite a high overall error rate. However, there is limited evidence about infusion practices in England and how they relate to prevalence and types of error. OBJECTIVES: To determine the prevalence, types and severity of errors and discrepancies in infusion administration in English hospitals, and to explore sources of variation in errors, discrepancies and practices, including the contribution of smart pumps. DESIGN: Phase 1 comprised an observational point-prevalence study of IV infusions, with debrief interviews and focus groups. Observers compared each infusion against the medication order and local policy. Deviations were classified as either errors or discrepancies based on their potential for patient harm. Contextual issues and reasons for deviations were explored qualitatively during observer debriefs, and analytically in supplementary analyses. Phase 2 comprised in-depth observational studies at five of the participating sites to better understand causes of error and how safety is maintained. Workshops were held with key stakeholder groups, including health professionals and policy-makers, the public and industry. SETTING: Sixteen English NHS hospital trusts. RESULTS: Point-prevalence data were collected from 1326 patients and 2008 infusions. In total, 240 errors were observed in 231 infusions and 1489 discrepancies were observed in 1065 infusions. Twenty-three errors (1.1% of all infusions) were considered potentially harmful; one might have resulted in short-term patient harm had it not been intercepted, but none was judged likely to prolong hospital stay or result in long-term harm. Types and prevalence of deviations varied widely among trusts, as did local policies. Deviations from medication orders and local policies were sometimes made for efficiency or to respond to patient need. Smart pumps, as currently implemented, had little effect. Staff had developed practices to manage efficiency and safety pragmatically by working around systemic challenges. LIMITATIONS: Local observers may have assessed errors differently across sites, although steps were taken to minimise differences through observer training, debriefs, and review and cleaning of data. Each in-depth study involved a single researcher, and these were limited in scale and scope. CONCLUSIONS: Errors and discrepancies are common in everyday infusion administration but most have low potential for patient harm. Findings are best understood by viewing IV infusion administration as a complex adaptive system. Better understanding of performance variability to strategically manage risk may be more helpful for improving patient safety than striving to eliminate all deviations. FUTURE WORK: There is potential value in reviewing policy around IV infusion administration to reduce unnecessary variability, manage staff workload and engage patients, while retaining the principle that policy has to be fit for purpose, contextualised to the particular ward situation and treatment protocol, and sensitive to the risks of different medications. Further work on understanding infusion administration as a complex adaptive system might deliver new insights into managing patient safety. FUNDING: This project was funded by the NIHR Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 8, No. 7. See the NIHR Journals Library website for further project information

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    Crystal structure of N'-[2-(benzo[d]thia-zol-2-yl)acet-yl]benzohydrazide, an achiral compound crystallizing in space group P1 with Z = 1.

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    In the molecule of the title compound, C16H13N3O2S, one hydrazinic nitrogen atom is essentially planar, but the other is slightly pyramidalized. The torsion angle about the hydrazinic bond is 66.44 (15)°. Both hydrazinic hydrogen atoms lie anti-periplanar to the oxygen of the adjacent carbonyl group. The mol-ecular packing is a layer structure determined by two classical hydrogen bonds, N-H⋯O=C and N-H⋯Nthia-zole. The space group is P1 with Z = 1, which is unusual for an achiral organic compound

    Training Students on the Pharmacist Patient Care Process using an Electronic Health Record and Simulations

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    Objective: To measure the impact of an electronic health record (EHR) and simulated physician encounters on student knowledge and skills related to the implementation phase of the Pharmacist Patient Care Process (PPCP). Secondary objectives were to measure students’ self-perceived abilities. Methods: Students enrolled in a therapeutics course worked-up patient cases within an EHR. Students entered orders/ prescriptions into the computerised provider order entry (CPOE) platform. Faculty graded student work using a rubric. Students completed an instructor-developed pre-post attitudes survey and knowledge quiz. Results: Two hundred students participated in this study and worked-up seven cases. Scores ranged from 67.7% to 88.2% on the case work-ups and 78.6% to 91.1% on the order/prescription-entry components. Individual scores on the quiz improved from 15.3/20 to 17.3/20 (p\u3c0.001). Aggregate ratings on the attitudes survey increased from 23.2 to 31.0 (p\u3c0.001). Conclusion: Use of an EHR coupled with simulation was well-received and improved student understanding of the PPCP
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