Anomaly Detection in Cloud Components

Cloud platforms, under the hood, consist of a complex inter-connected stack of hardware and software components. Each of these components can fail which may lead to an outage. Our goal is to improve the quality of Cloud services through early detection of such failures by analyzing resource utilization metrics. We tested Gated-Recurrent-Unit-based autoencoder with a likelihood function to detect anomalies in various multi-dimensional time series and achieved high performance.Comment: Accepted for publication in Proceedings of the IEEE International Conference on Cloud Computing (CLOUD 2020). Fix dataset descriptio

MICROFILTRATION MEMBRANE PORE FUNCTIONALIZATION APPROACHES FOR CHLORO-ORGANIC REMEDIATION TO HEAVY METAL SORPTION

Microfiltration polyvinylidene fluoride (PVDF) membranes have distinct advantage for open structure in terms of high internal surface area and ease of access in the pore domain. Functionalization of PVDF membranes with different functional groups (-COOH, -OH, -SH) enables responsive (pH, temperature) properties to membrane, tuning of effective pore size, controlling permeate flux. PVDF microfiltration membrane functionalization with suitable responsive polymer such as poly acrylic acid (PAA) to incorporate carboxyl (-COOH) group enables further modification of functionalized PAA-PVDF membranes for different application ranging from catalysis, bio reactor to heavy metal sorption platform. As a catalytic reactor bed, this PAA-PVDF membranes are very desirable platform for in-situ synthesis of catalytic nanoparticles for conducting a wide range of reactions. As a bio reactor, PAA-PVDF membrane with a net charge have been used to electrostatically immobilize enzymes for conducting catalytic reactions. Functionalization of PVDF membrane also allow for the development of high capacity heavy metal sorbents by modifying existing functional groups (-COOH) to other functional groups (-SH) to adsorb heavy metal cations from contaminated water. Hydrophilic polymers with carboxylic (-COOH) groups are studied in different functionalization processes especially in preparation of responsive (pH) membranes. To understand the role of membrane pore polymerization condition on the properties of functionalized membrane a systematic study has been conducted, specifically, the effects of polymerization on the membrane mass gain, water permeability, Pd-Fe nanoparticle (NP) loading, of pore functionalized polyvinylidene fluoride (PVDF) membranes. In this study, monomer (acrylic acid (AA)) and cross-linker (N, N′- methylene-bis (acrylamide)) concentrations were varied from 10 to 20 wt% of polymer solution and 0.5-2 mol% of monomer concentration, respectively. Results showed that responsive behavior of membrane could be tuned in terms of water permeability over a range of 270-1 Lm-2 h-1 bar-1, which is a function of water pH. The NP size on the membrane surface was found in the range of 16-23 nm. NP loading was found to vary from 0.21 to 0.94 mg per cm2 of membrane area depending on the variation of available carboxyl groups in membrane pore domain. The NPs functionalized membranes were then tested as a platform for the degradation of 3,3\u27,4,4\u27,5-pentachlorobiphenyl (PCB 126) and understand the effect of NP loading of the rate of degradation of PCB 126. The observed batch reaction rate (Kobs) for PCB 126 degradation for per mg of catalyst loading was found 0.08-0.1 h-1. Degradation study in convective flow mode shows 98.6% PCB 126 is degraded at a residence time of 46.2 s. The corresponding surface area normalized reaction rate (Ksa) is found about two times higher than Ksa of batch degradation; suggesting elimination of the effect of diffusion resistance for degradation of PCB 126 in convective flow mode operation. A layer-by-layer approach to immobilize laccase enzyme into PAA functionalized PVDF microfiltration membranes for degradation of 2,4,6-trichlorophenol (TCP) from water was demonstrated to offer bioinspired remediation. Over 80% of the initial TCP was degraded at optimum flow rate under an applied air pressure of about 0.7 bar or lower. This corresponds to degrading a substantial amount of the initial substrate in only 36 seconds residence time, which in a batch reaction take hours. This, in fact, demonstrates an energy efficient flow through system with potential large-scale applications. Comparison of the stability of the enzyme in solution phase vs. immobilized on membrane phase showed a loss of some 65% of enzyme activity in the solution phase after 22 days, whereas the membrane-bound enzyme lost only a negligible percentage of activity in comparable time span. Finally, the membrane was exposed to rigorous cycles of TCP degradation trials to study its reusability. The primary results reveal a loss of only 14% of the initial activity after four cycles of use in a period of 25 days, demonstrating its potential to reuse. Regeneration of the functionalized membrane was also validated by dislodging the immobilized enzyme followed by immobilization of fresh enzyme on to the membrane. A multi-enzyme functionalized membrane reactor for bioconversion of lignin model compound involving enzymatic catalysis was also developed. Layer-by-layer approach was used to immobilize three different enzymes (glucose oxidase, peroxidase and laccase) into pH-responsive membranes. This novel membrane reactor couples the in-situ generation of hydrogen peroxide (by glucose oxidase) to oxidative conversion of a lignin model compound, guaiacylglycerol-B-guaiacylether (GGE). Preliminary investigation of the efficacy of these functional membranes towards GGE degradation is demonstrated under convective flow mode. Over 90% of the initial feed could be degraded with the multienzyme immobilized membranes at a residence time of approximately 22 seconds. GGE conversion product analysis revealed formation of oligomeric oxidation products with peroxidase, which might be potential hazard to membrane bioreactors. These oxidation products could be further degraded by laccase enzymes in the multi-enzymatic membranes explaining the potential of multienzyme membrane reactors. The multi-enzyme incorporated membrane reactors were active for about a month time of storage at 4 oC, and retention of activity was demonstrated after repetitive use. Further, PAA functionalized PVDF membranes are immobilized with thiol (-SH) groups for metal sorption from industrial effluent water. The sorption capacity of mercury for CysM immobilized membrane is 2446 mg/g PAA and the efficiency of Hg removal is 99.1±0.1% respectively from synthetic water. For 1300 minutes CysM-PAA-PVDF membrane is used to remove Hg2+ cations from effluent water. The adsorption efficiency in this long-term study is around 97%. In presence of Ca2+ cations adsorption efficiency drops to 82% for CysM-PAA-PVDF membrane and to 40% for Cys-PAA-PVDF membrane. A mathematical model on heavy metal adsorption by thiol (-SH) functionalized membrane was developed to predict experimental results over a wide range of operating conditions. These diverse functional approaches of microfiltration membranes and its application towards water remediation offer superior performance over traditional treatment process thus anticipates immediate industrial application. Finally, hollow Fe-Pd nanoparticles were synthesized for the application towards degradation of chlorinated compounds. This fabricated Fe hollow spheres have 2.6 times higher surface area and 4.28 times pore volume compare to commercial Fe catalyst. Initial investigation reveals in presence of palladium, these prepared hollow NPs can completely degrade polychlorinated biphenyl (PCB-1) anticipating future potential for water remediation application

Exploring first-time nascent entrepreneurs’ on-going entrepreneurial opportunity recognition : a case study of London Metropolitan University’s preincubator

Extant literature lacks the integrative theory of first-time (pure) nascent entrepreneurs’ ongoing opportunity recognition. There is an academic consensus that the investigation of ongoing opportunity recognition may provide new insights into entrepreneurs’ behaviours and cognitive processes, i.e. what they do and how they do it. This study has responded to this knowledge gap by addressing the following research question: how do pre-incubator supported nascent entrepreneurs recognise entrepreneurial opportunities? The objectives of this study were: (1) to explore the process by which they come up with opportunity ideas; (2) to explore behavioural actions that shape opportunity ideas into opportunities; (3) to understand the role of the pre-incubator on their cognitive and behavioural process; and (4) to provide recommendations for effective opportunity-recognition practice. A single qualitative case study was adopted for the study of 13 lead graduates who were supported through the pre-incubator’s business start-up programme. Data were collected through semi-structured interview, mind-mapping and participants observation, and analysed by adopting an inductive thematic analysis method. Findings show that nascent entrepreneurs’ opportunity recognition comprises two discreet, interrelated components: opportunity awareness and opportunity search. Opportunity awareness is an intentional process by which they translate their experiential problems and perceived gaps into demand- or supply-driven opportunity ideas. It drives their opportunity search behaviour. They rely on various social networks to test the veracity of their opportunity ideas and search for opportunity-related information. They prioritise their social network reliance according to their social relationships. This behaviour is guided by their emotional attachment to opportunities. It is found that pre-incubator managers moderate their emotional attachment and subsequent search behaviours. As they (nascent entrepreneurs) rely on various social networks, their confirmation bias mediates opportunity recognition belief reinforcement and the input factors provided by social network members. The findings are significant to pre-incubator managers. They provide revelatory insights into their supported nascent entrepreneurs’ emotions, behaviours, and cognition in relation to opportunity recognition. This study also makes noteworthy contributions to entrepreneurship literature by providing new theoretical insights into the opportunity recognition of first-time (pure) nascent entrepreneurs

The Influence of Fibre Processing and Treatments on Hemp Fibre/Epoxy and Hemp Fibre/PLA Composites

In recent years, due to growing environmental awareness, considerable attention has been given to the development and production of natural fibre reinforced polymer (both thermoset and thermoplastic) composites. The main objective of this study was to reinforce epoxy and polylactic acid (PLA) with hemp fibre to produce improved composites by optimising the fibre treatment methods, composite processing methods, and fibre/matrix interfacial bonding. An investigation was conducted to obtain a suitable fibre alkali treatment method to: (i) remove non-cellulosic fibre components such as lignin (sensitive to ultra violet (UV) radiation) and hemicelluloses (sensitive to moisture) to improve long term composites stability (ii) roughen fibre surface to obtain mechanical interlocking with matrices (iii)expose cellulose hydroxyl groups to obtain hydrogen and covalent bonding with matrices (iv) separate the fibres from their fibre bundles to make the fibre surface available for bonding with matrices (v) retain tensile strength by keeping fibre damage to a minimum level and (vi) increase crystalline cellulose by better packing of cellulose chains to enhance the thermal stability of the fibres. An empirical model was developed for fibre tensile strength (TS) obtained with different treatment conditions (different sodium hydroxide (NaOH) and sodium sulphite (Na2SO3) concentrations, treatment temperatures, and digestion times) by a partial factorial design. Upon analysis of the alkali fibre treatments by single fibre tensile testing (SFTT), scanning electron microscopy (SEM), zeta potential measurements, differential thermal analysis/thermogravimetric analysis (DTA/TGA), wide angle X-ray diffraction (WAXRD), lignin analysis and Fourier transform infrared (FTIR) spectroscopy, a treatment consisting of 5 wt% NaOH and 2 wt% Na2SO3 concentrations, with a treatment temperature of 120oC and a digestion time of 60 minutes, was found to give the best combination of the required properties. This alkali treatment produced fibres with an average TS and Young's modulus (YM) of 463 MPa and 33 GPa respectively. The fibres obtained with the optimised alkali treatment were further treated with acetic anhydride and phenyltrimethoxy silane. However, acetylated and silane treated fibres were not found to give overall performance improvement. Cure kinetics of the neat epoxy (NE) and 40 wt% untreated fibre/epoxy (UTFE) composites were studied and it was found that the addition of fibres into epoxy resin increased the reaction rate and decreased the curing time. An increase in the nucleophilic activity of the amine groups in the presence of fibres is believed to have increased the reaction rate of the fibre/epoxy resin system and hence reduced the activation energies compared to NE. The highest interfacial shear strength (IFSS) value for alkali treated fibre/epoxy (ATFE) samples was 5.2 MPa which was larger than the highest value of 2.7 MPa for UTFE samples supporting that there was a stronger interface between alkali treated fibre and epoxy resin. The best fibre/epoxy bonding was found for an epoxy to curing agent ratio of 1:1 (E1C1) followed by epoxy to curing agent ratios of 1:1.2 (E1C1.2), 1: 0.8 (E1C0.8), and finally for 1:0.6 (E1C0.6). Long and short fibre reinforced epoxy composites were produced with various processing conditions using vacuum bag and compression moulding. A 65 wt% untreated long fibre/epoxy (UTLFE) composite produced by compression moulding at 70oC with a TS of 165 MPa, YM of 17 GPa, flexural strength of 180 MPa, flexural modulus of 10.1 GPa, impact energy (IE) of 14.5 kJ/m2, and fracture toughness (KIc) of 5 MPa.m1/2 was found to be the best in contrast to the trend of increased IFSS for ATFE samples. This is considered to be due to stress concentration as a result of increased fibre/fibre contact with the increased fibre content in the ATFE composites compared to the UTFE composites. Hygrothermal ageing of 65 wt% untreated and alkali treated long and short fibre/epoxy composites (produced by curing at 70oC) showed that long fibre/epoxy composites were more resistant than short fibre/epoxy composites and ATFE composites were more resistant than UTFE composites towards hygrothermal ageing environments as revealed from diffusion coefficients and tensile, flexural, impact, fracture toughness, SEM, TGA, and WAXRD test results. Accelerated ageing of 65 wt% UTLFE and alkali treated long fibre/epoxy (ATLFE) composites (produced by curing at 70oC) showed that ATLFE composites were more resistant than UTLFE composites towards hygrothermal ageing environments as revealed from tensile, flexural, impact, KIc, SEM, TGA, WAXRD, FTIR test results. IFSS obtained with untreated fibre/PLA (UFPLA) and alkali treated fibre/PLA (ATPLA) samples showed that ATPLA samples had greater IFSS than that of UFPLA samples. The increase in the formation of hydrogen bonding and mechanical interlocking of the alkali treated fibres with PLA could be responsible for the increased IFSS for ATPLA system compared to UFPLA system. Long and short fibre reinforced PLA composites were also produced with various processing conditions using compression moulding. A 32 wt% alkali treated long fibre PLA composite produced by film stacking with a TS of 83 MPa, YM of 11 GPa, flexural strength of 143 MPa, flexural modulus of 6.5 GPa, IE of 9 kJ/m2, and KIc of 3 MPa.m1/2 was found to be the best. This could be due to the better bonding of the alkali treated fibres with PLA. The mechanical properties of this composite have been found to be the best compared to the available literature. Hygrothermal and accelerated ageing of 32 wt% untreated and alkali treated long fibre/PLA composites ATPLA composites were more resistant than UFPLA composites towards hygrothermal and accelerated ageing environments as revealed from diffusion coefficients and tensile, flexural, impact, KIc, SEM, differential scanning calorimetry (DSC), WAXRD, and FTIR results. Increased potential hydrogen bond formation and mechanical interlocking of the alkali treated fibres with PLA could be responsible for the increased resistance of the ATPLA composites. Based on the present study, it can be said that the performance of natural fibre composites largely depend on fibre properties (e.g. length and orientation), matrix properties (e.g. cure kinetics and crystallinity), fibre treatment and processing methods, and composite processing methods

Inflation Targeting as the Monetary Policy Framework: Bangladesh Perspective

Inflation targeting strategy has become a widely accepted monetary policy framework in many countries all over the world. Our study finds that the central bank of Bangladesh is neither inflation targeting nor does follow any other rule-guided monetary policy, rather the policy is formulated with substantial discretion under the guidelines of donor agencies. This paper provides the evidence that monetary sector of Bangladesh economy has gained considerable degree of maturity and fulfils a number of prerequisites to adopt inflation targeting strategy. Using data over 1980-2010 we estimate an error correction model in order to examine if interest rate policy could fight the inflation. This is evident that deviation in inflation from target can be corrected via the changes in interest rate. Empirical findings jointly with few descriptive statistics provide strong evidence to recommend inflation targeting as the monetary policy strategy for Bangladesh.Bangladesh, Inflation Targeting, Monetary Policy.

Hierarchical Design Based Intrusion Detection System For Wireless Ad hoc Network

In recent years, wireless ad hoc sensor network becomes popular both in civil and military jobs. However, security is one of the significant challenges for sensor network because of their deployment in open and unprotected environment. As cryptographic mechanism is not enough to protect sensor network from external attacks, intrusion detection system needs to be introduced. Though intrusion prevention mechanism is one of the major and efficient methods against attacks, but there might be some attacks for which prevention method is not known. Besides preventing the system from some known attacks, intrusion detection system gather necessary information related to attack technique and help in the development of intrusion prevention system. In addition to reviewing the present attacks available in wireless sensor network this paper examines the current efforts to intrusion detection system against wireless sensor network. In this paper we propose a hierarchical architectural design based intrusion detection system that fits the current demands and restrictions of wireless ad hoc sensor network. In this proposed intrusion detection system architecture we followed clustering mechanism to build a four level hierarchical network which enhances network scalability to large geographical area and use both anomaly and misuse detection techniques for intrusion detection. We introduce policy based detection mechanism as well as intrusion response together with GSM cell concept for intrusion detection architecture.Comment: 16 pages, International Journal of Network Security & Its Applications (IJNSA), Vol.2, No.3, July 2010. arXiv admin note: text overlap with arXiv:1111.1933 by other author

Curing kinetics and effects of fibre surface treatment and curing parameters on the interfacial and tensile properties of hemp/epoxy composites

The curing kinetics of neat epoxy (NE) and hemp fibre/epoxy composites was studied and assessed using two dynamic models (the Kissinger and Flynn-Wall-Ozawa Models) and an isothermal model (the Autocatalytic Model) which was generally supported by the experimental data obtained from dynamic and isothermal differential scanning calorimetry (DSC) scans. The activation energies for the curing of composites exhibited lower values compared to curing of NE which is believed to be due to higher nucleophilic activity of the amine groups of the curing agent in the presence of fibres. The highest tensile strength, σ was obtained with composites produced with an epoxy to curing agent ratio of 1:1 and the highest Young's modulus, E was obtained with an epoxy to curing agent ratio of 1:1.2. Alkali treated hemp fibre/epoxy (ATFE) composites were found to have higher σ and E values compared to those for untreated hemp fibre/epoxy (UTFE) composites which was consistent with the trend for interfacial shear strength (IFSS) values. Composites σ and E were found to be higher for a processing temperature of 70°C than for 25°C for both UTFE and ATFE composites, but were found to decrease as the curing temperature was increased further to 120°C

Effects of Selenium and Zinc in Aflatoxin B1 Poisoning in Broiler

To test the effect of selenium & zinc in aflatoxin B1 poisoning in broiler, day-old broiler chicks (n=80) were divided into 5 treatment groups with 16 birds each, (T0-control; T1-50ppb AFB1 T2-100ppb AFB1, T3-200ppb AFB1, T4-400ppb AFB1), after treating  3 weeks, 8 birds were sacrificed & rest of the birds continued with AFB1 & started a new treatment with Zn & Se supplements at the dose rate Zn (40, 60, 80 mg/kgbwt) and Se (30, 40, 50 µg/kgbwt) respectively  in T2, T3 & T4  from 3rd week to 5th  week. Experiment was conducted from day 1 to 35 days of age. The broilers were weighed, bled, killed by cervical dislocation .Body weights were significantly decreased (643.66±3.17) by 400ppb aflatoxin B1 (P < 0.05) at 21 days compare to control group T0. Higher concentration aflatoxin B1 (400ppb) in T4 group significantly decreased body weight from T1 (50ppb). Aflatoxin B1 induced a significant increase biochemical parameters such as serum alanine transaminase (ALT) & aspartate transaminase (AST).Significantly elevated level (P < 0.05)  of ALT & AST were observed in T4 (58.2±0.7 & 1185±17) respectively. In case of hematological parameters, the study revealed that it also reduced the level of total erythrocyte count (TLC), total leucocyte count (TLC), hemoglobin, lymphocyte, monocyte & basophil, however it accelerated neutrophil & eosinophil level. Aflatoxin B1 raised weight of liver, spleen & diminished weight of pancreas. Higher concentration extended mortality rate upto 15% in T4 group at 3 weeks. After treating with Zn& Se, growth performances had been improved gradually, it depressed these negative effects of AFB1 in broiler. These effects of AFB1 were ameliorated by supplementation of Zn & Se. It was concluded that aflatoxin contamination (50, 100, 200, 400 ppb) in broiler diet impaired the performance in terms of body weight gain, biochemical, hematological parameter, relative organ weights & livability percentage. Supplementation of zinc & Se in the aflatoxin contaminated diet improved the adverse effects of aflatoxicosis on performance of the broiler chickens. Supplementation. In conclusion, the results demonstrated that mineral treatment (Zn & Se) might be used for correction of aflatoxin B1 in broiler