A Rule-based Skyline Computation over a dynamic database

Skyline query which relies on the notion of Pareto dominance filters the data items from a database by ensuring only those data items that are not worse than any others are selected as skylines. However, the dynamic nature of databases in which their states and/or structures change throughout their lifetime to incorporate the current and latest information of database applications, requires a new set of skylines to be derived. Blindly computing skylines on the new state/structure of a database is inefficient, as not all the data items are affected by the changes. Hence, this paper proposes a rule-based approach in tackling the above issue with the main aim at avoiding unnecessary skyline computations. Based on the type of operation that changes the state/structure of a database, i.e. insert/delete/update a data item(s) or add/remove a dimension(s), a set of rules are defined. Besides, the prominent dominance relationships when pairwise comparisons are performed are retained; which are then utilised in the process of computing a new set of skylines. Several analyses have been conducted to evaluate the performance and prove the efficiency of our proposed solution

Relative neighborhood graphs uncover the dynamics of social media engagement

© Springer International Publishing AG 2016. In this paper, we examine if the Relative Neighborhood Graph (RNG) can reveal related dynamics of page-level social media metrics. A statistical analysis is also provided to illustrate the application of the method in two other datasets (the Indo-European Language dataset and the Shakespearean Era Text dataset). Using social media metrics on the world’s ‘top check-in locations’ Facebook pages dataset, the statistical analysis reveals coherent dynamical patterns. In the largest cluster, the categories ‘Gym’, ‘Fitness Center’, and ‘Sports and Recreation’ appear closely linked together in the RNG. Taken together, our study validates our expectation that RNGs can provide a “parameterfree” mathematical formalization of proximity. Our approach gives useful insights on user behaviour in social media page-level metrics as well as other applications

Synthesis And Characterization Of Chitosan/Tio2 Nanocomposite For The Adsorption Of Congo Red

Chitosan/TiO2 nanocomposite was fabricated by a film-casting method for the adsorption of Congo red. The nanocomposite film was characterized by Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, powder X-ray diffraction, thermogravimetric analysis, weight-loss test, and adsorption study. Morphological analysis revealed rough and agglomerated filler materials over the film surface. The interaction among components of the composite was proven by powder X-ray diffraction and Fourier-transform infrared spectroscopy. The weight-loss result showed excellent stability of the composite in acidic medium. The adsorption mechanism was supported by both Langmuir and Freundlich isotherm models. The adsorption capacity of the composite film was 32 mg/g

Smart Rocking Armour Units

This paper describes a method to measure the rocking motion of lab-scale armour units. Sensors as found in mobile phones are used. These sensors, data-storage and battery are all embedded in the model units, such that they can be applied without wires attached to them. The technique is applied to double-layer units in order to compare the results to the existing knowledge for this type of armour layers. In contrast to previous research, the gyroscope reading is used to determine the (rocking) impact velocities. Two pioneer measurement series are described. From the readings both the temporal distribution of rocking can be inferred, as well as the spatial distribution. The temporal probability distribution for the rocking events seems logarithmic, with the impact velocity u2% being in the same order of magnitude as those reported earlier. These measurements indicate that for a randomly placed cube in an armour layer most rocking and most violent impact velocities occur about 2Dn under the waterline, instead of around the waterline. Moreover, the wave steepness is seen to have an effect on the rocking intensity. From the measurements with multiple units it can be seen that the measured impact velocity exhibits a large spatial variation among different units at an otherwise equal location.Hydraulic Structures and Flood Ris

A MEMS capacitive pH sensor for high acidic and basic solutions

We have developed a micro-scale chip-based pH sensing system, which can effectively measure the changes in pH ranging from 1 to 4 and 10 to 12. This method relies on fringing field capacitive measurements. A change in pH of the medium results in a permittivity change for the fringing electric field, which in turn affects the capacitance values. Capacitance changes are then converted to resonant frequency shifts via a readout circuit. This technique provides high sensitivity, low hysteresis, and low noise as well as low fabrication cost. Very importantly, the device and the corresponding measurement circuitry have the potential to be integrated in an electronic pill for continuous non-invasive measurement within the body. © 2014 IEEE

Rehabilitation of Holwerd

Holwerd is a village located at the coast of the Wadden Sea. Decisions made in the past have affected the town in a negative manner leading to an impoverishment of the region. Therefore, we were tasked with rehabilitating the city of Holwerd by establishing the connection with the sea and making the goal (Holwerd aan Zee) of the inhabitants come into a reality. In order to prioritize the different actions required to achieve the objective, a survey was conducted. Hence, a clearer view of what people are attracted to when choosing a destination is obtained. It was found that the most attractive option is the one that includes recreational elements (proximity to the sea restaurants and bars, hotels...), natural elements (parks, open spaces...) as well as cultural elements (museums, architecture…). Due to the high cost of this alternative, the project is divided into phases. In addition, an environmental impact assessment was conducted to ensure a well-balanced project implementation. In this multidisciplinary project, the focus is mainly on the construction of the navigational channel through the dike connecting to a buffer lake. Together with the channel, the implementation of a sluice in the opening of the dike is also analysed. Through a multi-criteria evaluation each alternative of channel alignment and gates is assessed. These multi-criteria analyses determined that the optimal solution is to connect the navigational channel to a fresh water source where a canal and a small marina were already present. Regarding the type of gate, it resulted that the folding gate made of timber was the most suitable to be installed both in the dike side and in the inner side blocking the salt water flowing further into the fresh water. The design of the channel was developed in such a way that an ebb-dominance tendency is present. The exporting of sediment was checked by using a one-dimensional model with a sinusoidal symmetric tide. The gate prototype was also modelled to ensure the structure can resist the different water levels. Regarding the dredged material of the channel, two proposals are evaluated in order to find a beneficial use of the remaining volume. A nourishment and development of salt marshes in Visbuurt (adjacent town of Holwerd) as well as the creation of the silt islands and development of salt marshes in Holwerd are studied. The dredging operation is also described. Finally, additional research and data collection are recommended prior to further action.Civil Engineering and GeosciencesHydraulic EngineeringMasterproject CiTG CEG 4061 - 0

Design and Analysis of GO Coated High Sensitive Tunable SPR Sensor for OATR Spectroscopic Biosensing Applications

In this paper, we numerically debrief an ultra-high sensitive surface plasmon resonance (SPR) biosensor utilizing thin layers of graphene oxide (GO) that have not been addressed adequately till now. By the deposition of GO on top of the metal-dielectric heterostructure, our proposed sensor can achieve higher sensitivity and higher Quality Factor (QF) simultaneously which has not been possible by the existing models to our knowledge. Because of its large surface area and sp2 inside of an sp3 matrix which is capable of confining π electrons, GO can form strong covalent bonds with biomolecules and hence enhanced light-material interaction that made researchers contemplate to achieve increased sensitivity and figure of merit. Both the transfer matrix method and finite element method are exploited to perform extensive numerical analysis for optimizing the structure considering its sensitivity, full width half maximum (FWHM), and QF. This paper examines six different configurations of multilayer heterostructure containing prism-adhesive-metal-BaTiO3/BP-Gr/GO/MXene-sensing medium, and a noticeably enhanced performance is achieved using GO with a maximum sensitivity of 372 deg/RIU and QF of 88.11 RIU−1 in the range of refractive index (RI) 1.330 to 1.353. Moreover, the possibility of designing a tunable SPR sensor to operate at a broader range of analyte’s RI is investigated, and 414 deg/RIU with 119.27 RIU−1 QF at 1.407 RI is achieved. The Electric field distribution, effects of different layers, and fabrication feasibility of the proposed sensor are explored, it is envisaged that this can be an appropriate apparatus for highly sensitive, rapid, and noninvasive label-free biosensing useful in experimental sensing protocols