6,146 research outputs found
M-ATTEMPT: A New Energy-Efficient Routing Protocol for Wireless Body Area Sensor Networks
In this paper, we propose a new routing protocol for heterogeneous Wireless
Body Area Sensor Networks (WBASNs); Mobility-supporting Adaptive
Threshold-based Thermal-aware Energy-efficientMulti-hop ProTocol (M-ATTEMPT). A
prototype is defined for employing heterogeneous sensors on human body. Direct
communication is used for real-time traffic (critical data) or on-demand data
while Multi-hop communication is used for normal data delivery. One of the
prime challenges in WBASNs is sensing of the heat generated by the implanted
sensor nodes. The proposed routing algorithm is thermal-aware which senses the
link Hot-spot and routes the data away from these links. Continuous mobility of
human body causes disconnection between previous established links. So,
mobility support and energy-management is introduced to overcome the problem.
Linear Programming (LP) model for maximum information extraction and minimum
energy consumption is presented in this study. MATLAB simulations of proposed
routing algorithm are performed for lifetime and successful packet delivery in
comparison with Multi-hop communication. The results show that the proposed
routing algorithm has less energy consumption and more reliable as compared to
Multi-hop communication.Comment: arXiv admin note: substantial text overlap with arXiv:1208.609
A Mechanism for Securing IoT-enabled Applications at the Fog Layer
The Internet of Things (IoT) is an emerging paradigm branded by heterogeneous technologies composed of smart ubiquitous objects that are seamlessly connected to the Internet. These objects are deployed as Low power and Lossy Networks (LLN) to provide innovative services in various application domains, such as smart cities, smart health, smart communities. The LLN is a form of a network where the interconnected devices are highly resource-constrained (i.e., power, memory, and processing) and characterized by high loss rates, low data rates and instability in the communication links. Additionally, IoT devices produce a massive amount of confidential and security-sensitive data. Various cryptographic-based techniques exist that can effectively cope with security attacks, but are not suitable for IoT as they incur high consumption of resources (i.e., memory, storage and processing). One way to address this problem is by offloading the additional security-related operations to a more resourceful entity such as a fog-based node. Generally, fog computing enables security and analysis of latency-sensitive data directly at the network’s edge. This paper proposes a novel Fog Security Service (FSS) to provide end-to-end security at fog layer for IoT devices, using two well-established cryptographic schemes, identity-based encryption and identity-based signature. The FSS provides security services, such as authentication, confidentiality, and non-repudiation. The proposed architecture is implemented and evaluated in OPNET simulator using a single network topology with different traffic loads. The FSS performed better when compared with the APaaS and the legacy method
Oil palm leaf fibre and its suitability for paper-based products
Due to the shortage of wood as origin materials for paper-based production, agro-residue materials have been explored in the quest of finding the best alternative fibre. Oil palm leaf (OPL) is one of agro-residue that has potential due to its comparable characteristics with wood fibre. Studies on chemical compositions, fibre morphology, and mechanical property of OPL have been carried out aiming to evaluate its potential as a substitute raw material for pulp and paper-based production. The chemical compositions were analysed according to the TAPPI standard, Kurscher-Hoffner and chlorite methods accordingly. The mechanical property (tensile, tearing and bursting strengths) were determined as described in TAPPI test methods. Fibre dimensions were determined using Franklin method and analysed under the optical microscope. The content of cellulose in the OPL is determined to be 43.8%. Although, this result is lower than wood fibre (53%), OPL has higher hemicellulose content (36.4%) than the wood fibre (27.5%). In addition, the lignin content (19.7%) of OPL is in the low range of those in wood resources (18 - 25%). These parameters are important components to produce good quality pulp and will provide high mechanical strength of the paper-based products. The measured fibre length of oil palm leaf (1.13 mm) is shorter than the wood fibre (1.90 mm). Meanwhile, the mechanical property of OPL showed lower indexes than wood resources, however, tear (1.80 mN.m2/g) and burst (0.95 kPa.m2/g) indexes of OPL are higher than other published and successful wood resources (Eucalyptus). Based on the analyses, the oil palm leaf is indeed a suitable alternative of raw material for pulp and paper-based industries
Newly Discovered RR Lyrae Stars in the SDSSXPanXSTARRS1XCatalina Footprint
We present the detection of 6,371 RR Lyrae (RRL) stars distributed across
~14,000 deg^2 of the sky from the combined data of the Sloan Digital Sky Survey
(SDSS), the Panoramic Survey Telescope and Rapid Response System 1 (PS1), and
the second photometric catalogue from the Catalina Survey (CSDR2), out of
these, ~2,021 RRL stars (~572 RRab and 1,449 RRc) are new discoveries. The RRL
stars have heliocentric distances in the 4--28 kpc distance range. RRL-like
color cuts from the SDSS and variability cuts from the PS1 are used to cull our
candidate list. We then use the CSDR2 multi-epoch data to refine our sample.
Periods were measured using the Analysis of Variance technique while the
classification process is performed with the Template Fitting Method in
addition to the visual inspection of the light curves. A cross-match of our RRL
star discoveries with previous published catalogs of RRL stars yield
completeness levels of ~50% for both RRab and RRc stars, and an efficiency of
~99% and ~87% for RRab and RRc stars, respectively. We show that our method for
selecting RRL stars allows us to recover halo structures. The full lists of all
the RRL stars are made publicly available.Comment: 14 pages, 11 figures. Accepted 2014 March 30. Received 2014 March 12;
in original form 2013 November 2
Scale-free equilibria of self-gravitating gaseous disks with flat rotation curves
We introduce exact analytical solutions of the steady-state hydrodynamic
equations of scale-free, self-gravitating gaseous disks with flat rotation
curves. We express the velocity field in terms of a stream function and obtain
a third-order ordinary differential equation (ODE) for the angular part of the
stream function. We present the closed-form solutions of the obtained ODE and
construct hydrodynamical counterparts of the power-law and elliptic disks, for
which self-consistent stellar dynamical models are known. We show that the
kinematics of the Large Magellanic Cloud can well be explained by our findings
for scale-free elliptic disks.Comment: AAS preprint format, 21 pages, 8 figures, accepted for publication in
The Astrophysical Journa
PERAN PANGKALAN PENDARATAN IKAN (PPI) INENGO TERHADAP PENDAPATAN NELAYAN DI DESA HUANGOBOTU KECAMATAN KABILA BONE KABUPATEN BONE BOLANGO
This research was conducted in February to August 2023 in PPI Inengo, Huangobotu village, Kabila Bone sub district, Bone Bolango Regency. The sample that applied in this research are 34 fisherman with sampling technique purpose sampling which sampling technique taking based on specific criteria or targets. This research aimed to knows the role of the fish landing station (PPI) Inengo of fishing revenues in Huangobotu Village, Kabila bone sub-district, Bone Bolango Regency. However, the author in method of this research used the survey method and observation directly. In addition, the data obtained then analyzed the data in descriptive qualitative and quantitative. The research result was showed that the incidental landfill (PPI) has important role in fisherman income. Hence, based on Likert scale showed that 116 rating scores in 91-120 rating score which means that the presence of PPI Inengo was very influential on fisherman income.
 
Stretching a Surface Having a Layer of Porous Medium in a Viscous Fluid
The present analysis deals with the steady, incompressible flow of a viscous fluid over a stretching sheet having a layer of porous medium of uniform thickness. The two-dimensional flow equations are derived in a Cartesian coordinate system. The semi-infinite region filled with a viscous fluid is divided into two regions namely, a clear fluid region and a region having a uniform pores. Darcy\u27s law has been used for the flow of fluid in the porous medium region. An exact similar solution of the problem is obtained. The obtained solution is constrained by a relation between the porosity parameter and the parameter representing the viscosity ratios between the two regions. Our interest lies in determining the influence of porosity parameter, viscosities ratio parameter and thickness of the porous layer on the fluid velocity and the skin friction coefficient. The results for the Crane\u27s problem in a complete clear and a complete porous region are retrieved as special cases of the present solution
Experimental assessment of the performance of reinforced concrete beams strengthened with carbon fiber reinforced polymer laminates
In this study, experimental research is carried out to assess the flexural performance of RC beams strengthened with different amount of CFRP laminates at the tension face. Twelve rectangular RC beams were fabricated and three are un-strengthened and used as reference beams and the remaining nine are strengthened with different amount of CFRP varying from single to triple layers and all are tested to failure under three points bending test. The increase of ultimate strength provided by the bonded CFRP laminates is assessed and failure modes is identified and compared to the un-strengthened RC beams. The results indicated that the flexural capacity of the beams was significantly improved as the amount of the laminates increases that ranged from 20% to 52% increased for single to triple layers laminates. It is concluded that the attachment of CFRP laminates has substantial influence on the performance of CFRP strengthened RC beams. Based on the observed results, recommendations are made that externally application of CFRP laminates can be used for a significant enhancement of the strength deficient RC beams in increasing the ultimate load carrying capacity.
Keywords: CPRP laminate, Reinforced concrete, ductility, index, epoxy resin, flexural strengthenin
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