Challenge-response trust assessment model for personal space IoT

© 2016 IEEE. Internet of Things (IoT) embraces the interconnection of identifiable devices that are capable of providing services through their cooperation. The cooperation among devices in such an IoT environment often requires reliable and trusted participating members in order to provide useful services to the end user. Consequently, an IoT environment or space needs to evaluate the trust levels of all devices in contact before admitting them as members of the space. Existing trust evaluation models are based on resources such as historical observations or recommendations information to evaluate the trust level of a device. However, these methods fail if there is no existing trust resource. This paper introduces a specific IoT environment called personal space IoT and proposes a novel trust evaluation model that performs a challenge-response trust assessment to evaluate the trust level of a device before allowing it to participate in the space. This novel challenge-response trust assessment model does not require the historical observation or previous encounter with the device or any existing trusted recommendation. The proposed challenge-response trust assessment model provides a reliable trust resource that can be used along with other resources such as direct trust, recommendation trust to get a comprehensive trust opinion on a specific device. It can also be considered as a new method for evaluating the trust value on a device

Initial trust establishment for personal space IoT systems

© 2017 IEEE. Increasingly, trust has played a crucial role in the security of an IoT system from its inception to the end of its lifecycle. A device has to earn some level of trust even before it is authenticated for admission to the system. Furthermore, once the device is admitted to the system, it may behave maliciously over time; hence its behavior must be evaluated constantly in the form of trust to ensure the integrity of the system. Currently, no mechanism exists to establish an initial trust on a device, without prior knowledge, before its admission to an IoT system. Even when trust is applicable, trust evaluation models require direct/indirect observations over time, historical data on past encounters, or third party recommendations. However, this type of past data is not available in the first encounter between the system and the device. The question is how to establish whether a device can be trusted to a level that merits further evaluation for admission into a mobile and dynamic IoT system when it encounters the system for the first time? This paper addresses this challenge by proposing a challenge-response method and a trust assessment model to establish, without prior knowledge, the initial trust that a device places on another in a mobile and dynamic environment called personal space IoT. The initial trust is established before further interaction can take place and under the assumption that only a limited window of time is available for the trust assessment. The paper describes and evaluates the proposed model theoretically and by simulation. It also describes a practical scheme for realizing the proposed solution

Miniaturized triaxial optical fiber force sensor for MRI-guided minimally invasive surgery

Proceedings of: 2010 IEEE International Conference on Robotics and Automation (ICRA'10), May 3-8, 2010, Anchorage (Alaska, USA)This paper describes the design and construction of a miniaturized triaxial force sensor which can be applied inside a magnetic resonance imaging (MRI) machine. The sensing principle of the sensor is based on an optical intensity modulation mechanism that utilizes bent-tip optical fibers to measure the deflection of a compliant platform when exposed to a force. By measuring the deflection of the platform using this optical approach, the magnitude and direction of three orthogonal force components (Fx, Fy, and Fz) can be determined. The sensor prototype described in this paper demonstrates that it can perform force measurements in axial and radial directions with working ranges of +/- 2 N. Since the sensor is small in size and entirely made of nonmetallic materials, it is compatible with minimally invasive surgery (MIS) and safe to be deployed within magnetic resonance (MR) environments.European Community's Seventh Framework Progra

C1 inhibitor deficiency: 2014 United Kingdom consensus document

C1 inhibitor deficiency is a rare disorder manifesting with recurrent attacks of disabling and potentially life-threatening angioedema. Here we present an updated 2014 United Kingdom consensus document for the management of C1 inhibitor-deficient patients, representing a joint venture between the United Kingdom Primary Immunodeficiency Network and Hereditary Angioedema UK. To develop the consensus, we assembled a multi-disciplinary steering group of clinicians, nurses and a patient representative. This steering group first met in 2012, developing a total of 48 recommendations across 11 themes. The statements were distributed to relevant clinicians and a representative group of patients to be scored for agreement on a Likert scale. All 48 statements achieved a high degree of consensus, indicating strong alignment of opinion. The recommendations have evolved significantly since the 2005 document, with particularly notable developments including an improved evidence base to guide dosing and indications for acute treatment, greater emphasis on home therapy for acute attacks and a strong focus on service organisation. This article is protected by copyright. All rights reserved

Biochemical expression of exudes of a fungal-bacterial bio film during growth and maturation

Biofilms are often complex communities of multiple microbial species and remain attached to surfaces. Fungal-bacterial biofllms are formed when the fungal surface is colonized by one or more species of bacteria. These biofilms can enhance microbial effectiveness compared to the monocultures. Beneficial biofilms can be developed in vitro and be used for various agricultural and biotechnological purposes. As a recent development in biofertilizer research, fungal-rhizobial biofilms have been developed and these are termed biofilmed biofertilizers (BFBFs). This research was focused to investigate chemical composition of compounds exuded during growth and maturation of the biofilms. A developed fungal-bacterial biofilm using an Azotobacter species and a Colletorichum fungal species was used for the study. Exudates of the biofilm, fungal monoculture and bacterial monoculture in solid and liquid states were extracted separately by using three organic solvents; hexane, ethyl acetate and methanol. Extraction was done weekly for four weeks during growth and maturation of the biofllm. Then extracted exudates dissolved in organic solvents were evaporated by using a vortex evaporator. Thereafter crude was mixed with potassium bromide (KBr) and pellets were made. The KBr pellets were analyzed using Fourier Transform Infrared (FTIR) spectroscopy. To evaluate the effect of the exudates of the fungal-bacterial biofilm on seed germination and plant growth in comparison to bacterial and fungal monocultures, a plant assay was done weekly by using lettuce (Lactuca sativa) seeds (N 48). During all four harvests, the fungal-bacterial biofllm produced more diverse functional groups than the mono cultures. The developed biofilm produced carboxylic acids and carboxylic salts, which are associated with plant growth promoting hormones, especially in first and second harvests. Significantly higher plant height and high germination of lettuce with the biofilm exudates could be attributed to above fact. During third and fourth weeks, the biofllm produced more amines and amides than fungal and bacterial mono cultures. This may have contributed to increased pH in biofilm cultures compared to the mono cultures. Thus, it can be concluded that biochemical expression of exudates of fungal-bacterial biofilms during their growth and maturation is very useful for breaking dormancy of seeds and their germination and growth, contributing to high plant productivit

Miniaturized force-indentation depth sensor for tissue abnormality identification during laparoscopic surgery

Proceedings of: 2010 IEEE International Conference on Robotics and Automation (ICRA'10), May 3-8, 2010, Anchorage (Alaska, USA)This paper presents a novel miniaturized force-indentation depth (FID) sensor designed to conduct indentation on soft tissue during minimally invasive surgery. It can intra-operatively aid the surgeon to rapidly identify the tissue abnormalities within the tissue. The FID sensor can measure the indentation depth of a semi-spherical indenter and the tissue reaction force simultaneously. It make use of with fiber optical fiber sensing method measure indentation depth and force and is small enough to fit through a standard trocar port with a diameter of 11 mm. The created FID sensor was calibrated and tested on silicone block simulating soft tissue. The results show that the sensor can measure the indentation depth accurately and also the orientation of the sensor with respect to the tissue surface whilst performing indentation.European Community's Seventh Framework Progra

Diagnosing evapotranspiration responses to water deficit across biomes using deep learning.

Accounting for water limitation is key to determining vegetation sensitivity to drought. Quantifying water limitation effects on evapotranspiration (ET) is challenged by the heterogeneity of vegetation types, climate zones and vertically along the rooting zone. Here, we train deep neural networks using flux measurements to study ET responses to progressing drought conditions. We determine a water stress factor (fET) that isolates ET reductions from effects of atmospheric aridity and other covarying drivers. We regress fET against the cumulative water deficit, which reveals the control of whole-column moisture availability. We find a variety of ET responses to water stress. Responses range from rapid declines of fET to 10% of its water-unlimited rate at several savannah and grassland sites, to mild fET reductions in most forests, despite substantial water deficits. Most sensitive responses are found at the most arid and warm sites. A combination of regulation of stomatal and hydraulic conductance and access to belowground water reservoirs, whether in groundwater or deep soil moisture, could explain the different behaviors observed across sites. This variety of responses is not captured by a standard land surface model, likely reflecting simplifications in its representation of belowground water storage

Novel miniature MRI-compatible fiber-optic force sensor for cardiac catherization procedures

Proceedings of: 2010 IEEE International Conference on Robotics and Automation (ICRA'10), May 3-8, 2010, Anchorage (Alaska, USA)This paper presents the prototype design and development of a miniature MR-compatible fiber optic force sensor suitable for the detection of force during MR-guided cardiac catheterization. The working principle is based on light intensity modulation where a fiber optic cable interrogates a reflective surface at a predefined distance inside a catheter shaft. When a force is applied to the tip of the catheter, a force sensitive structure varies the distance and the orientation of the reflective surface with reference to the optical fiber. The visual feedback from the MRI scanner can be used to determine whether or not the catheter tip is normal or tangential to the tissue surface. In both cases the light is modulated accordingly and the axial or lateral force can be estimated. The sensor exhibits adequate linear response, having a good working range, very good resolution and good sensitivity in both axial and lateral force directions. In addition, the use of low-cost and MR-compatible materials for its development makes the sensor safe for use inside MRI environments.European Community's Seventh Framework Progra

Pseudo-Haptics for Rigid Tool/Soft Object Interaction Feedback in Virtual Environments

This paper proposes a novel pseudo-haptics soft object stiffness simulation technique which is a marked improvement to currently used simulation methods and an effective low-cost alternative to expensive 3-DOF haptic devices. Soft object stiffness simulation is achieved by maneuvering an indenter avatar over the surface of a virtual soft object by means of an input device, such as a mouse, a joystick, or a touch-sensitive tablet. The alterations to the indenter avatar behavior produced by the proposed technique create for the user the illusion of interaction with a hard inclusion embedded in the soft object. The proposed pseudo-haptics technique is validated with a series of experiments conducted by employing three types of 2-DOF force-sensitive haptic surfaces, including a touchpad, a tablet with an S-pen input, and a tablet with a bare finger input. It is found that both the sensitivity and the positive predictive value of hard inclusion detection can be significantly improved by 33.3% and 13.9% respectively by employing tablet computers. Using tablet computers could produce results comparable to direct hand touch in detecting hard inclusions in a soft object. The experimental results presented here confirm the potential of the proposed technique for conveying haptic information in rigid tool / soft object interaction in virtual environments