Summary Type 1 diabetes is a chronic autoimmune disease characterised by insulin deficiency and resultant hyperglycaemia. Knowledge of type 1 diabetes has rapidly increased over the past 25 years, resulting in a broad understanding about many aspects of the disease, including its genetics, epidemiology, immune and β-cell phenotypes, and disease burden. Interventions to preserve β cells have been tested, and several methods to improve clinical disease management have been assessed. However, wide gaps still exist in our understanding of type 1 diabetes and our ability to standardise clinical care and decrease disease-associated complications and burden. This Seminar gives an overview of the current understanding of the disease and potential future directions for research and care.

Type 1 diabetes

The integration of social networking concepts into the Internet of things has led to the Social Internet of Things (SIoT) paradigm, according to which objects are capable of establishing social relationships in an autonomous way with respect to their owners with the benefits of improving the network scalability in information/service discovery. Within this scenario, we focus on the problem of understanding how the information provided by members of the social IoT has to be processed so as to build a reliable system on the basis of the behavior of the objects. We define two models for trustworthiness management starting from the solutions proposed for P2P and social networks. In the subjective model each node computes the trustworthiness of its friends on the basis of its own experience and on the opinion of the friends in common with the potential service providers. In the objective model, the information about each node is distributed and stored making use of a distributed hash table structure so that any node can make use of the same information. Simulations show how the proposed models can effectively isolate almost any malicious nodes in the network at the expenses of an increase in the network traffic for feedback exchange.

/pdf/trustworthiness-management-in-the-social-internet-of-things-12e9rj0kz4.pdf

Trustworthiness Management in the Social Internet of Things

A topical review of numerical and experimental studies of supercontinuum generation in photonic crystal fiber is presented over the full range of experimentally reported parameters, from the femtosecond to the continuous-wave regime. Results from numerical simulations are used to discuss the temporal and spectral characteristics of the supercontinuum, and to interpret the physics of the underlying spectral broadening processes. Particular attention is given to the case of supercontinuum generation seeded by femtosecond pulses in the anomalous group velocity dispersion regime of photonic crystal fiber, where the processes of soliton fission, stimulated Raman scattering, and dispersive wave generation are reviewed in detail. The corresponding intensity and phase stability properties of the supercontinuum spectra generated under different conditions are also discussed.

Supercontinuum generation, photonic crystal fiber

A novel highly sensitive porous core-photonic crystal fiber (PC-PCF) has been designed and analyzed for detection of chemical analytes in the terahertz frequency range. The PC-PCF is designed using rectangular structured air holes in the core with a kagome structured cladding. The full vectorial finite-element method is used to tune the geometrical parameters and to characterize the fiber. Our results demonstrate a high relative chemical sensitivity with significantly lower confinement loss for different analytes. Moreover, the PCF shows near zero dispersion variation, high modal effective area, high birefringence, and high numerical aperture. The practical realization of the fiber is feasible with present fabrication techniques. Our optimized PCF has commercial applications in chemical sensing as well as applications in terahertz systems that require guided polarization preserving transmission.

A Novel Approach for Spectroscopic Chemical Identification Using Photonic Crystal Fiber in the Terahertz Regime

Online Social Networks (OSNs) are becoming a popular method of meeting people and keeping in touch with friends. OSNs resort to trust evaluation models and algorithms to improve service quality and enhance user experiences. Much research has been done to evaluate trust and predict the trustworthiness of a target, usually from the view of a source. Graph-based approaches make up a major portion of the existing works, in which the trust value is calculated through a trusted graph (or trusted network, web of trust, or multiple trust chains). In this article, we focus on graph-based trust evaluation models in OSNs, particularly in the computer science literature. We first summarize the features of OSNs and the properties of trust. Then we comparatively review two categories of graph-simplification-based and graph-analogy-based approaches and discuss their individual problems and challenges. We also analyze the common challenges of all graph-based models. To provide an integrated view of trust evaluation, we conduct a brief review of its pre- and postprocesses (i.e., the preparation and validation of trust models, including information collection, performance evaluation, and related applications). Finally, we identify some open challenges that all trust models are facing.

https://dl.acm.org/doi/pdf/10.1145/2906151

Understanding Graph-Based Trust Evaluation in Online Social Networks: Methodologies and Challenges

Trust network analysis with subjective logic (TNA-SL) simplifies complex trust graphs into series-parallel graphs by removing the most uncertain paths to obtain a canonical graph. This simplification could in theory cause loss of information and thereby lead to sub-optimal results. This paper describes a new method for trust network analysis which is considered optimal because it does not require trust graph simplification, but instead uses edge splitting to obtain a canonical graph. The new method is compared with TNA-SL, and our simulation shows that both methods produce equal results. This indicates that TNA-SL in fact also represents an optimal method for trust network analysis and that the trust graph simplification does not affect the result.

/pdf/optimal-trust-network-analysis-with-subjective-logic-1uabdumstj.pdf

Optimal Trust Network Analysis with Subjective Logic

In this article, a hybrid photonic crystal fiber has been proposed for chemical sensing. A FEM has been applied for numerical investigation of some propagation characteristics of the PCF at a wider wavelength from 0.7 to 1.7 µm. The geometrical parameters altered to determine the optimized values. The proposed PCF contains three rings of circular holes in the cladding where the core is formulated with microstructure elliptical holes. The simulation result reveals that our proposed PCF exhibits high sensitivity and low confinement loss for benzene, ethanol and water than the prior PCFs. We have also shown that our proposed PCF shows high birefringence for benzene 1.544 × 10−3, for ethanol 1.513 × 10−3 and for water 1.474 × 10−3 at λ = 1.33 µm. The proposed PCF is simple with three rings which can be used for the sensing applications of industrially valuable lower indexed chemicals.

/pdf/hybrid-photonic-crystal-fiber-in-chemical-sensing-143vpjx2rs.pdf

Hybrid photonic crystal fiber in chemical sensing.

Impact of photo electrode thickness and annealing temperature on natural dye sensitized solar cell

In this paper, a spiral shape photonic crystal fiber (S-PCF) has been suggested as a gas sensor for detecting toxic or colorless gases as well as monitoring the air pollution by metering gas condensate elements in production facilities. Our reported S-PCF is micro-structured where two layers porous core is encircled by a spiral shape cladding. The geometrical parameters have altered to optimize the parameters of the proposed structure. The numerical analysis of the proposed S-PCF is performed by utilizing finite element method (FEM). The relative sensitivity and birefringence of the proposed S-PCF are 55.10% and 7.23 × 10− 3 respectively at the 1.33 μm wavelength that lies in the absorption line of toxic gases (methane and hydrogen fluoride). Besides, effective area, nonlinear coefficient and V parameters are also described briefly.

Design of single mode spiral photonic crystal fiber for gas sensing applications

Services offered and provided through the Web have varying quality, and it is often difficult to assess the quality of a services before accessing and using it. Trust and reputation systems can be used in order to assist users in predicting and selecting the best quality services. This paper describes how Bayesian reputation systems can be combined with trust modeling based on subjective logic to provide an integrated method for assessing the quality of online services. This will not only assist the user's decision making, but will also provide an incentive for service providers to maintain high quality, and can be used as a sanctioning mechanism to discourage deceptive and low quality services.

/pdf/combining-trust-and-reputation-management-for-web-based-31ya4zqo33.pdf

Touhid Bhuiyan

Papers

Optimal Trust Network Analysis with Subjective Logic

Hybrid photonic crystal fiber in chemical sensing.

Impact of photo electrode thickness and annealing temperature on natural dye sensitized solar cell

Design of single mode spiral photonic crystal fiber for gas sensing applications

Combining Trust and Reputation Management for Web-Based Services