Location-Based Service Provisioning for Next Generation Wireless Networks

We study how the wireless network infrastructure can support location-based services (LBSs). We assume that each mobile is equipped with self-geolocation capability. The wireless network can provide geolocation information of mobiles to an application services provider (ASP) so that the ASP can customize services based on the geolocation of the users. The main challenge in wireless networking is to keep track of the geolocation of mobile users such that the application service can maintain a certain quality of service (QoS). In general, the quality of service depends on how often mobiles update their geolocation. Because geolocation updates require battery power, radio resources, and signaling in the wired network, optimization of the geolocation update frequency is critical. In this paper, we present geolocation update schemes in which we can minimize the update frequency while satisfying the QoS of application service. For case study, we consider location-based traffic report service (LBS-TR) and location-based navigation service (LBS-NS). In LBS-TR, each mobile user about to enter a heavily jammed highway is informed in a timely manner so that the user can avoid traffic congestion. In LBS-NS, a mobile user is given navigation instructions custom-tailored to the geolocation of the user. The granularity of navigation instructions changes as the user moves from highway to local street and from local street to building complex.     

Template-directed synthesis of silica nanotubes for explosive detection

Fluorescent porous organic-inorganic thin films are of interest of explosive detection because of their vapor phase fluorescence quenching property. In this work, we synthesized fluorescent silica nanotubes using a biomineralization process through self-assembled peptidic nanostructures. We designed and synthesized an amyloid-like peptide self-assembling into nanofibers to be used as a template for silica nanotube formation. The amine groups on the peptide nanofibrous system were used for nucleation of silica nanostructures. Silica nanotubes were used to prepare highly porous surfaces, and they were doped with a fluorescent dye by physical adsorption for explosive sensing. These porous surfaces exhibited fast, sensitive, and highly selective fluorescence quenching against nitro-explosive vapors. The materials developed in this work have vast potential in sensing applications due to enhanced surface area.     

Mussel Inspired Dynamic Cross‐Linking of Self‐Healing Peptide Nanofiber Network

A general drawback of supramolecular peptide networks is their weak mechanical properties. In order to overcome a similar challenge, mussels have adapted to a pH‐dependent iron complexation strategy for adhesion and curing. This strategy also provides successful stiffening and self‐healing properties. The present study is inspired by the mussel curing strategy to establish iron cross‐link points in self‐assembled peptide networks. The impact of peptide‐iron complexation on the morphology and secondary structure of the supramolecular nanofibers is characterized by scanning electron microscopy, circular dichroism and Fourier transform infrared spectroscopy. Mechanical properties of the cross‐linked network are probed by small angle oscillatory rheology and nanoindentation by atomic force microscopy. It is shown that iron complexation has no influence on self‐assembly and β‐sheet‐driven elongation of the nanofibers. On the other hand, the organic‐inorganic hybrid network of iron cross‐linked nanofibers demonstrates strong mechanical properties comparable to that of covalently cross‐linked network. Strikingly, iron cross‐linking does not inhibit intrinsic reversibility of supramolecular peptide polymers into disassembled building blocks and the self‐healing ability upon high shear load. The strategy described here could be extended to improve mechanical properties of a wide range of supramolecular polymer networks.     

A new MILP model proposal in feed formulation and using a hybrid-linear binary PSO (H-LBP) approach for alternative solutions

Large-scale feed factories may have multiple production and storage facilities. Any production facility uses its own available raw materials while performing feed formulation. However, ensuring a reasonable cost is achieved, and the desired quality criteria are met, may require obtaining a certain amount of raw material from other facilities. Selecting a specific amount of raw materials among many raw materials in different facilities requires many combinations to be tried out. Providing solutions, especially when there is a large amount of the raw material, may be costly and take more time. A new mixed-integer linear programming (MILP) model that specifies the type of material and the amount of the material to be selected from external facilities has been proposed in this study. When deterministic methods like MILP are used, only one solution result is obtained. However, when the decision-maker would like to see alternative results, solution constraints can be mitigated and a solution provided within the same or similar time. A new method named hybrid-linear binary PSO (H-LBP) has been proposed in this study for the problems that the decision-maker had limited time for and for which the solution results were required in a shorter time. Continuous particle swarm optimization, which works as a hybrid with linear programming, has been used in this method. The new model proposed in this study was tested on the mixed feeds for sheep, cattle and rabbit species by using both MILP and the proposed H-LBP methods. Raw materials determined by the model were added to the mixture, and the cost in each of the three species was observed to go down. In addition, different alternative solutions at reasonable cost and similar quality were presented to the producer/decision-maker in a shorter time.

     

Synthesis and characterization of soluble multi-walled carbon nanotube/poly(organophosphazene) composites

Poor solubility of carbon nanotubes (CNTs) in water and organic solvents offers a significant problem for their applications. Macromolecules can be suitable solubilizing agents and a structural component of composite materials for CNTs. Several polymers were tested for the preparation of CNT dispersions. In this study, a poly[(4-pyridineoxy)(phenoxy)phosphazene] (3) was prepared by sequential treatment of poly(dichlorophosphazene) (2) with sodium 4-pyridineoxy and sodium phenoxide in THF. Multi-walled carbon nanotube/poly(organophosphazene) composites (f-MWCNT/PZS) with different feed ratios [R_feed = 1:1, 1:3, 1:5 and 1:10 (w/w)] were obtained by the treatment of the functionalized multi-walled carbon nanotube (f-MWCNT) with the protonated poly(organophosphazene) (PZS). Excellent dispersions of the f-MWCNT/PZS nanocomposites in water and common organic solvents were achieved. The influence of feed ratio on polymer coating and the stability of composites were investigated by thermal gravimetric analysis (TGA). f-MWCNT/PZS_1:5 nanocomposite was characterized by ³¹P, ¹H NMR, FTIR, XRD, EDX and Raman Spectroscopy. The morphologic characterizations of f-MWCNT/PZS_1:5 were carried out by HRTEM and SEM methods.     

The determination of the total mass attenuation coefficients and the effective atomic numbers for concentrated colemanite and Emet colemanite clay

In this study, the attitude of some photon absorption energy related parameters such as coherent, Compton, photoelectric, pair-nuclear, pair-electronic, the total mass attenuation coefficients, effective atomic number, and electron density are investigated for two the mixtures, concentrated colemanite and Emet colemanite clay. In order to reach some desired conclusions, we calculated many of these parameters ranging from low energy (1 keV) to high energy (100 MeV) by using WinXCom program. Radiation shielding of the materials are compared in terms of B₂O₃ content. One of the most significant promise claimed by this study is that the excess or scarcity of B₂O₃ content in any material may not be a defining parameter alone for environment, construction, radiation shielding, and neutron capture applications. As well as B₂O₃ content, concentration values from quantitative and qualitative analysis of other compounds such as SiO₂, CaO, MgO, Fe₂O₃, Al₂O₃, PbO, K₂O contained in a material, if existed, must be taken into account.     

Dosage planning for type 2 diabetes mellitus patients using Indexing HDMR

Diabetes mellitus type 2 (T2DM), is also named as non-insulin dependent diabetes mellitus (NIDDM) or adult-onset diabetes, is a metabolic disease characterized by high blood glucose. Deficient insulin production or insulin resistance of the body are the causes of T2DM. Drug treatment has a very important role as well as exercise and diet. To keep the body sugar level stable within the accepted range values, drug dosage planning is a part of combinational treatment. In this study, Indexing HDMR method which is a multivariate data partitioning method is used to produce a polynomial based rule structure to manage the drug dosage planning process. For this purpose, 142 diabetic assays, 96 of which as training data and 46 of which as testing data, were used in this study. The Indexing HDMR method worked well in modeling drug dosages and it is obvious that the method is reliable for the purpose.     

A direct touch table-top display as a multi-user information kiosk: Comparing the usability of a single display groupware either by a single user or people cooperating as a group

This study aimed to investigate the usability of a direct touch table-top display (D3TD) application that was designed to be used as a multi-user information kiosk (MUIK). We examined its use by either a single person or multiple user groups to determine the effect of people cooperating as a group on its usability. We compared both groups’ user performance and usability survey results. A one-way MANOVA of overall usability metrics emphasised a significant difference between the groups. Given the significance of the overall test, examining the univariate main effects revealed that the difference between the groups arose in the earlier system use stages due to differences in the success rate. There was no difference in the task completion time between the groups. Participants in the multiple user group achieved a higher task completion rate in the first phase and lower error rates in the following steps. However, the usability survey results did not reveal a significant difference between the groups. We observed that users working on the same individual task tended to help each other when working in a multi-user environment. These mutual aids occurred mostly in the earlier stages, influencing the users’ performance. The results show that a D3TD has a potential to enhance usability in terms of effectiveness when deployed as a MUIK.