Adaptive relevance feedback method of extended Boolean model using hierarchical clustering techniques

The relevance feedback process uses information obtained from a user about a set of initially retrieved documents to improve subsequent search formulations and retrieval performance. In extended Boolean models, the relevance feedback implies not only that new query terms must be identified and re-weighted, but also that the terms must be connected with Boolean And/Or operators properly. Salton et al. proposed a relevance feedback method, called DNF (disjunctive normal form) method, for a well established extended Boolean model. However, this method mainly focuses on generating Boolean queries but does not concern about re-weighting query terms. Also, this method has some problems in generating reformulated Boolean queries. In this study, we investigate the problems of the DNF method and propose a relevance feedback method using hierarchical clustering techniques to solve those problems. We also propose a neural network model in which the term weights used in extended Boolean queries can be adjusted by the users’ relevance feedbacks.     

The design of a nuclear reactor

The aim of this largely pedagogical article is to employ pre-college physics to arrive at an understanding of a system as complex as a nuclear reactor. We focus on three key issues: the fuel pin, the moderator, and lastly the dimensions of the nuclear reactor.     

Search result diversification on attributed networks via nonnegative matrix factorization

Search result diversification is an effective way to tackle query ambiguity and enhance result novelty. In the context of large information networks, diversifying search result is also critical for further design of applications such as link prediction and citation recommendation. In previous work, this problem has mainly been tackled in a way of implicit query intent. To further enhance the performance on attributed networks, we propose a novel search result diversification approach via nonnegative matrix factorization. Our approach encodes latent query intents as well as nodes as representation vectors by a novel nonnegative matrix factorization model, and the diversity of the results accounts for the query relevance and the novelty w.r.t. these vectors. To learn the representation vectors of nodes, we derive the multiplicative updating rules to train the nonnegative matrix factorization model. We perform a comprehensive evaluation on our approach with various baselines. The results show the effectiveness of our proposed solution, and verify that attributes do help improve diversification performance.     

Temporal Trends of Malondialdehyde in Stored Human Plasma

Malondialdehyde (MDA) is widely used as oxidative stress biomarker in biomedical research. Plasma is stored in deep freezers generally till analysis. Effect of such storage on MDA values, which may be variable and prolong, was incidentally observed in the ongoing study which is to estimate oxidative stress with oral iron. Plasma from blood samples of pregnant women (20–30 years age) in third trimester of singleton pregnancy (n = 139), consuming oral iron tablets was stored at −20 °C with intention of MDA estimation, as soon as possible. However logistic problems led this storage for prolonged and variable period (1–708 days). When values of MDA estimated using “Ohkawa” 79 method and readings were plotted against time to check the temporal effect, it showed a hyperbolic curve. Standard deviation (SD) was lowest when samples were tested within 3 weeks time. The samples analyzed within 3 weeks had mean ± SD value of 31.59 ± 26.11 μmol/L, while 123.7 ± 93.97 and 366.5 ± 189.8 μmol/L for samples stored for 1–3 and 4 months to 1 year respectively. Mean ± SD were 539.9 ± 196.8 in the samples store for more than a year. Rate of change in values was also lowest (0.0433 μmol/L/day) in the samples tested within first 3 weeks, which rose to 1.2 μmol/L/day during 3 month’s storage. This rate peaked at storage of 120 days (1.87 μmol/L/day) and fell to 0.502 μmol/L/day in the second year of storage. It is concluded that at −20 °C, only 3 weeks of storage time should be considered valid for fairly acceptable stability in MDA values.     

175 Years of linear programming

The theory of flows in networks began to evolve in the early 1950’s.The various linear optimisation questions that could be asked of flows in conserving networks turned out to be neat combinatorial specialisations of linear programming. The simplex method (and its variants) turned out to have very pretty combinatorial interpretations on networks. The algebraic dexterity of linear programming duality led to a unified treatment of many deep theorems in graph theory and combinatorics. In this part, the last of the series on linear programming, we will see glimpses of the theory of network flows through a specific flow optimisation problem — the maximum flow problem.     

Knowledge for sale – the benefits and effects of off-shoring knowledge-based jobs in engineering,design, and R&D – a case study

A framework consisting of a conceptual model and a closed-loop knowledge work outsourcing decision model is developed. A process flow model of a medical device company's product development function is analysed, where this framework is applied to understand various outsourcing options for the company. The conceptual framework describes major attributes related to outsourcing decisions, parameters associated with various attributes and the relationship intensity of parameters with three knowledge work outsourcing options – in-house, near-shoring, and off-shoring. The proposed model is closed loop, emphasizing the importance of regular re-evaluation needed for an off-shored function. The modeling framework contributes to a company's decision whether or not a particular knowledge-based function should either be kept in-house, near-sourced or off-shored. The general perception of off-shoring is to reduce costs but, the proposed model takes into account additional factors such as, market accessibility, strategic partnership, reduced time to regional market, access to overseas talent pool, and governmental incentives, etc. These factors play a vital role in determining an outsourced function. The paper discusses various options and makes recommendations for tapping into technological advancements around the world, their effects on supply chain management and other competitive advantages presented by off-shoring.     

The health information seeking behaviour and needs of community health workers in Chandigarh in Northern India

This article represents two‐firsts for the feature – it is the first to report on a study outside the UK and the first to examine the health information needs of community health workers. Sonika Raj is pursuing PhD at the Centre for Public Health, Panjab University, Chandigarh, in India and she conducted her research in Chandigarh. The article outlines the important role that health workers at community level play in determining health outcomes in the developing world, including Chandigarh. It demonstrates that while those workers recognise their information needs, there are many issues affecting their ability to access health information effectively, not least their limited access to appropriate technology and training. AM     

Activated Carbon Fabric Mask Reduces Lead Absorption and Improves the Heme Biosynthesis and Hematological Parameters of Battery Manufacturing Workers

Activated carbon fabrics (ACF) mask prevents the absorption of lead and reduce its adverse effects of human health. Aim of this study to know the blood lead level and its effects on heme biosynthesis and hematological parameters after using 2 months activated carbon fabric mask of battery manufacturing workers (BMW). Blood lead level, heme biosynthesis and hematological parameters were measured by using standard method. Blood lead level (P < 0.001, − 13.5%) was significantly decreased, activated δ-aminolevulinic acid dehydratase (P < 0.001, 11.97%) and non-activated δ- aminolevulinic acid dehydratase (P < 0.001, 23.17%) enzyme activity were significantly increased, however, the ratio of activated to Non-activated δ- ALAD (P < 0.001, − 10.13%) was significantly decreased, urinary excretion of δ- aminolevulinic acid (P < 0.001, − 10.49%) and porphobilinogen (P < 0.001, − 7.38%) were significantly decreased after using 2 months ACF mask as compared to before using mask of BMW. Hematological parameters i.e Hb (P < 0.05, 13.42%), PCV (P < 0.05, 7.23%), MCV (P < 0.05, 1.9%) were significantly increased and total WBC count (P < 0.05, − 5.18%) was significantly decreased after using 2 months ACF mask as compared to before using mask of BMW. Two months using ACF mask reduces the blood lead level and improves the δ-ALDH activity and hematological parameters, decreases the urinary excretion of δ-ALA, PBG of battery manufacturing workers. Therefore, the regular using of ACF mask is beneficial to prevent the lead absorption and its adverse effects on human health.