The Application of Fuzzy Logic Controller to Compute a Trust Level for Mobile Agents in a Smart Home

Agents that travel through many hosts may cause a threat on the security of the visited hosts. Assets, system resources, and the reputation of the host are few possible targets for such an attack. The possibility for multi-hop agents to be malicious is higher compared to the one-hop or two-hop boomerang agents. The travel history is one of the factors that may allow a server to evaluate the trustworthiness of an agent. This paper proposes a technique to define levels of trust for multi-hop agents that are roaming in a smart home environment. These levels of trust are used later to determine actions taken by a host at the arrival of an agent. This technique uses fuzzy logic as a method to calculate levels of trust and to define protective actions in regard to those levels

The metabolic dynamics of cartilage explants over a long-term culture period

INTRODUCTION: Although previous studies have been performed on cartilage explant cultures, the generalized dynamics of cartilage metabolism after extraction from the host are still poorly understood due to differences in the experimental setups across studies, which in turn prevent building a complete picture. METHODS: In this study, we investigated the response of cartilage to the trauma sustained during extraction and determined the time needed for the cartilage to stabilize. Explants were extracted aseptically from bovine metacarpal-phalangeal joints and cultured for up to 17 days. RESULTS: The cell viability, cell number, proteoglycan content, and collagen content of the harvested explants were analyzed at 0, 2, 10, and 17 days after explantation. A high percentage of the cartilage explants were found to be viable. The cell density initially increased significantly but stabilized after two days. The proteoglycan content decreased gradually over time, but it did not decrease to a significant level due to leakage through the distorted peripheral collagen network and into the bathing medium. The collagen content remained stable for most of the culture period until it dropped abruptly on day 17. CONCLUSION: Overall, the tested cartilage explants were sustainable over long-term culture. They were most stable from day 2 to day 10. The degradation of the collagen on day 17 did not reach diseased levels, but it indicated the potential of the cultures to develop into degenerated cartilage. These findings have implications for the application of cartilage explants in pathophysiological fields

Effects of combined exposure to aluminum chloride and γ-radiation on histological and ultrastructure of intestinal Paneth cells

AbstractPurposeThe use of aluminum chloride (AlCl3) as in purification of water and the exposure to ionizing radiation (IR) in therapeutic treatments are believed to be relatively safe. However, their combined effects remain unclear. The aim of the present study is to investigate the effects of concomitant exposure to aluminum chloride and gamma radiation on the histological and ultra-structural pattern of the crypt Paneth cells (PC) of the small intestine in albino rats.Materials and methodsForty male albino rats were divided randomly into four groups (n = 10). Group 1: Control group, Group 2: Aluminum treated group (Rats received a daily a dose of 0.5 mg of AlCl3 per kg of body weight/day), Group 3: γ-Radiation group (rats are exposed to a total dose of 8 Gy in 4 fractions of 2 Gy/week) and Group 4 Rats exposed to AlCl3 and exposed to γ-Radiation. Animals were sacrificed after 4 weeks, one day after the last radiation dose.ResultsHistological and ultra-structural studies in small intestine showed that exposure to γ-rays induced alterations in PC including apoptotic nuclei, presence of injury in secretory granules and completely damaged organelles at the sites of bacterial translocation in the crypt of lumens. Aluminum exposure during irradiation potentiate the damage notified by abnormal PC morphology, dilation the crypt's lumen and erosions of its villi with increased apoptosis in the crypt cells and appearance of homogenously electron-lucent granules.ConclusionsIt is concluded that concomitant exposure to aluminum and IR increased detrimental structural changes in PC of rat intestine due to their combined effect. It is thus recommended to limit the intake of aluminum when human are at risk of over exposure to ionizing radiation

Membrane electrode assembly with high efficiency and stability: effect of solvent type and membrane composition

Membrane electrode assembly (MEA) method is being widely considered in proton exchange membrane fuel cell (PEMFC) preparation. This work describes for the first time how PEMFC performance can be enhanced, while using relatively low temperature processing for the MEA, by choosing the suitable solvent and suitable ionomer (nafion) content. Three dispersion solvents (water, ethylene glycol and ethanol) have been examined here, and ethanol (with lowest boiling point) showed best PEMFC performance. In addition to its non-hazardous nature, the low boiling point ethanol allowed manufacturing the working membrane at 130°C or lower besides using a safe solvent to use. In each solvent system, different nafion concentrations were used (10%, 20% and 30%). The 30% nafion concentration in ethanol showed highest performance (Open circuit potential of 0.88 V and output working potential of 0.67 V at 20 mA/cm2 current density) among the series. The anode and cathode, of the MEA, were both fabricated using same catalyst material (Platinum) and same nafion sheet thickness (50 μm). The spray method was employed. The electrochemical performance for the prepared MEA fuel cells was assessed by linear sweep voltammetry to evaluate the open circuit voltage

Effect of cutting parameters on surface roughness in dry drilling of AISI D2 tool steel by using Taguchi Method

Hard drilling of AISI D2 reportedly produce accelerated wear to the cutting tool that detrimental to the surface finish. This paper presents the effect of drilling tool and drilling parameters by using Taguchi method to produce minimum surface roughness under dry conditions. The experiments were conducted using high speed steel (HSS) based drilling tools, coated with various coating layer (uncoated, TiN and TiCN) on material AISI D2 tool steel. Two cutting parameters, spindle speed and feed rate, each at three levels were considered. An L9 array, the signal-to-noise (S/N) ratio and the analysis of variance (ANOVA) were employed to analyze the significant and percentage of each parameters for minimum surface roughness. The results revealed that the drilling tools gave main affects the surface roughness based on the highest percentage distribution (95%), followed by the spindle speed (3%) and feed rate (0.4%). Further, the results of ANOVA indicated that the combination of optimum parameter recorded as drilling tools HSS-TiCN with spindle speed of 680 rpm and feed rate of 206.25 mm/min

Epigallocatechin gallate/layered double hydroxide nanohybrids: Preparation, characterization, and in vitro anti-tumor study

In recent years, nanotechnology in merging with biotechnology has been employed in the area of cancer management to overcome the challenges of chemopreventive strategies in order to gain promising results. Since most biological processes occur in nano scale, nanoparticles can act as carriers of certain drugs or agents to deliver it to specific cells or targets. In this study, we intercalated Epigallocatechin-3-Gallate (EGCG), the most abundant polyphenol in green tea, into Ca/Al-NO3 Layered double hydroxide (LDH) nanoparticles, and evaluated its efficacy compared to EGCG alone on PC3 cell line. The EGCG loaded LDH nanohybrids were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy (TEM) and nanosizer analyses. The anticancer activity of the EGCG-loaded LDH was investigated in prostate cancer cell line (PC3) while the release behavior of EGCG from LDH was observed at pH 7.45 and 4.25. Besides enhancing of apoptotic activity of EGCG, the results showed that intercalation of EGCG into LDH can improve the anti-tumor activity of EGCG over 5-fold dose advantages in in-vitro system. Subsequently, the in-vitro release data showed that EGCG-loaded LDH had longer release duration compared to physical mixture, and the mechanism of diffusion through the particle was rate-limiting step. Acidic attack was responsible for faster release of EGCG molecules from LDH at pH of 4.25 compared to pH of 7.4. The results showed that Ca/Al-LDH nanoparticles could be considered as an effective inorganic host matrix for the delivery of EGCG to PC3 cells with controlled release properties. © 2015 Shafiei et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

The first decade of biomedical engineering degree program at the University of Malaya: experiences and achievements

The Department of Biomedical Engineering, at the Faculty of Engineering, University of Malaya was established in the 1997/1998 academic session with an intake of 20 students and five academic staff. The Department has undergone numerous changes in the structure of its degree programme, with each one of them recognised and fully accredited by the Engineering Accreditation Council and Ministry of Higher Education. The Department has played an active role at national and global levels, in the areas of biomedical engineering education and research collaboration. Several initiatives have been planned to ensure the Department stays at the forefront of disseminating biomedical engineering innovations in Malaysia

Effect of Temperature on the Wear Properties of Alloy Steel under Jatropha Curcas Biodiesel

This paper presents the effect of Jatropha curcas biodiesel on the wear properties of mild steel, which was coated by preplacement of TiC particulate and melting it using a conventional TIG torch arc heat source. The aim of the study is to investigate the wear behaviour of surface modified AISI 4340 steel and the uncoated AISI 4340 steel which were performed using CSM tribometer at four different temperatures viz., 100 °C, 120 °C, 140 °C, and 160 °C, with the presence of jatropha biodiesel. At the end of the tests, wear characteristics was investigated by weight loss measurements and changes of the exposed metal surface. Surface morphology was examined by scanning electron microscope and surface profilometry. EDX analysis was performed on the samples’ surface. Results showed that wear of alloy steel increases with increasing temperature. TiC coated alloy steel showed improved wear resistance as this alloy steel demonstrated lower wear volume loss as compared to the uncoated steel in presence of jatropha biodiesel at higher temperature

Acquiring anatomical representation of human maxilla for rapid maxillary expansion

The purpose of the study is to model and provide a better understanding of maxilla bone involved in the treatment for rapid maxillary expander (RME) for dento-facial applications. The treatment is recommended for patients presented with an arch width deficiency named cross bites. Cross bites often cause abnormal physical forces that disrupt the balance of the occlusal relationship. More commonly, the maxilla or the upper jaw appears to be narrow and contributes to significant degree of crowding in the mouth. Early investigators [1-4] discovered that rapid maxillary expansion resulted in a splitting of the median palatal suture. The expansion is possible with the process of bone resorption and new bone deposition thus maintaining the expansion achieved [10]. This preliminary study shows that the FE model has the potential to be a valuable tool for further analysis of dental simulation and the understanding of orthodontic treatment