Context-aware analysis for adaptive unified authentication platform

Context-aware user authentication has become a necessary tool to serve as an additional security perimeter to protect online identities.By learning about user’s online behavior over time,authentication system are able to establish user behavior profile. Any substantial deviation on login context from the profile would indicate a high risk login attempt. Such adaptive authentication system has been developed in production server where user login records for more than six months have been collected. In this paper, the analysis of the user login context is presented

A Model of Electronic Customer Relationship Management System Adoption In Telecommunication Companies

Employee satisfaction is key to electronic–customer relationship management (E-CRM) systems in telecommunication companies. The purpose of this study is to investigate the direct and indirect effect of technological factors, individual factors, and organizational factors on employees' level of satisfaction. For this study, data was collected from 300 employees' workings in Malaysian telecommunication companies; and the data was analyzed using PLS-SEM. The findings revealed that technological, organizational, and individual factors are positively and significantly related to satisfaction and perceived usefulness. The results also supported the direct and positive relationship between perceived usefulness between employees' job satisfaction. The study has contributed to the body of literature by exploring the implications of various significant factors in terms of employee satisfaction. Besides, the management of the telecommunication companies may benefit from this study by adopting strategies that not only employee satisfaction but may also enhance the companies' performance. The limitations and the direction for future research are discussed in the end

Enhanced Buffer Management Policy and Packet Prioritization for Wireless Sensor Network

Limited storage of the sensor node is one of the main causes of packet drop in the Wireless sensor network (WSN).   Frequent link disconnection is also another cause of packet drop.  Due to lack of continues end-to-end connection; two nodes may not be able to communicate with one another. Thus, communication may be established with the help of store and forward approach between the source and destination node. In that case, the sensor node may not be capable of storing a chunk of data since the buffer is available in a small amount. In order to store the data packets in the buffer when the link is down, an effective buffer management scheme is highly needed to keep the data packets for a long time until the link is re-established. This paper proposes a new buffer management scheme called Packet Priority Heterogonous Queue (PPHQ), which based on prioritizing and classifying the packets into different categories to minimize the loss of important packets. Unlike the existing Multi-layer WSN, that treats the data packets differently; we considered the data packets such as; temperature, humidity, and pressure to be same. However, the classification of different packet types is based on the sensor’s information value.  We completely divide the whole buffer into different queues, and thus the newly arrived packets are inserted in their corresponding queue. The buffer will then prioritize and schedule on which packet to be stored or transmit first when the buffer is overloaded. Our result exhibits that PPHQ scheme indeed provides minimum packet drop as well as maximum throughput compared to existing Multi-layer WSN buffer management schemes

A New Method for Battery Lifetime Estimation Using Experimental Testbed for Zigbee Wireless Technology

Many Zigbee-based wireless sensor networks have been developed for outdoor applications such as agriculture monitoring. The main attractiveness of Zigbee wireless module is in its potential to set up self-organizing network that requires no network backbone and extremely low cost with low-power wireless networking. Many simulations have been performed for testing the capabilities of wireless communication device and the battery lifetime. However, the results from the simulation do not capture the actual environment effects and the simulators allow users to isolate certain factors by tuning to different parameters. This paper provides experimental results on actual voltage drop using Zigbee protocol devices when communicating temperature, humidity and soil moisture data using a 900mAh battery both in indoor and outdoor environments. It is observed that the wireless nodes are capable of relaying data up to 143 meters on unobstructed line of sights in an outdoor environment with some observation of packet drop. The results differ from previous researches that perform the experiments on shorter range which only covers 50 cm distance between transmitter node and receiver node for 2 bytes of data transfer. The paper proposes a new method for battery lifetime estimation which is derived from number of times data packet can be transmitted. This study also suggests to conduct experiment by including the environmental factors to capture the actual performance of wireless device and the impact to packet drop. The experiment concludes the suitability of Zigbee wireless communication for short-range applications of up to 143 meters which is significantly farther than other reported experiments

Assessment of selected herbicides and chelating agents in water using gas chromatography-electron capture detector (GC-ECD)

Water contamination by herbicides and chelating agents is increasing mainly due to the increasing agricultural activities. Water contamination by these compounds has become a concern due to their adverse effects to the environment and humans. Seven sampling sites of water sources in Selangor and Johor were chosen for the study. Contamination level of Mecoprop (MCCP), Nitrilotriacetic acid (NTA) and Ethylenediaminetetraacetic acid (EDTA) in these water body areas was determined by using Gas Chromatography-Electron Capture Detector (GC-ECD). Our results indicated that water samples of Sungai Melot in Selangor showed the highest presence of EDTA. MCCP was detected at a high level at Sungai Sarang Buaya, Johor while NTA showed similar level of concentration at three different sites, Ladang 10, Ladang Sayur and Mardi, Selangor

HYDROTHERMAL GROWTH AND SQUEEGEE METHOD IN THE FABRICATION OF MIXED-PHASE TiO2 NANOSTRUCTURES

In this work, the modification of TiO2 nanostructures based on its morphology and crystallinity phase were fabricated using a simple method. Hydrothermal growth method was used to synthesize nanorods and nanoflowers, while nanoparticles was applied using squeegee method. The average length and diameter of the as-grown nanorods were 3.5 and 46-215 nm, respectively. Meanwhile, the average total thickness and band gap value of mixed-phase TiO2 nanostructures were 15.98-24.54 nm and 2.84 eV, respectively. Based on its structural and electrical properties, the fabricated film has great potential to be applied as photoanode semiconductor layer for dye-sensitized solar cells application. Key words: TiO2, Nanostructures, Mixed-phase, Hydrothermal, Squeege

THE USE OF TRIPLE-TAILS CUSTOM-MADE SURFACTANT IN THE PRODUCTION OF GRAPHENE OXIDE THIN FILM AS TRANSPARENT CONDUCTIVE ELECTRODE

In this work, graphene oxide (GO) and reduced GO (rGO) thin films were fabricated from GO and rGO using the custom-made and commercial surfactants, which were sodium 1,4-bis (neopentyloxy)-3-(neopentyloxycarbonyl)-1,4-dioxobutane-2-sulphonate and sodium dodecyl sulphate, respectively. The GO solution was synthesized using electrochemical exfoliation method followed by reduction process utilizing hydrazine hydrate to produce rGO solution. The GO and rGO transfer process were done using spraying deposition method on fluorine-doped tin oxide substrate. The fabricated GO and rGO thin films consists of several layers resulted in high transparency over 85% with maximum transmittance of 93.69%. Based on several characterizations, the fabricated GO and rGO thin films have potential to be applied as transparent conductive electrode.Key words: Custom-made, Surfactant, Electrochemical, Spraying, Electrode. ABSTRAKDalam penelitian ini, film tipis grafin oksida (GO) dan grafin oksida yang direduksi (rGO) difabrikasi dari GO dan rGO menggunakan surfaktan yang dibuat khusus dan surfaktan komersial yaitu secara berurutan adalah sodium 1,4-bis (neopentyloxy)-3-(neopentyloxycarbonyl)-1,4-dioxobutane-2-sulphonate dan sodium dodecyl sulphate. Larutan GO disintesis menggunakan metode eksfoliasi elektrokimia diikuti dengan proses reduksi menggunakan hidrazin hidrat untuk menghasilkan larutan rGO. Proses transfer GO dan RGO dilakukan dengan menggunakan metode deposisi penyemprotan diatas substrat oksida timah oksida dengan doping florin. Film tipis GO dan rGO yang difabrikasi terdiri dari beberapa lapis dengan transparansi tinggi mencapai 85% dengan transmitansi maksimum sebesar 93,69%. Berdasarkan beberapa karakterisasi, film tipis GO dan rGO ini memiliki potensi untuk diaplikasikan sebagai elektroda konduktif transparan.Kata Kunci: dibuat khusus, surfaktan, elektrokimia, penyemprotan, elektrod

Enhancing the performance of self-powered ultraviolet photosensor using rapid aqueous chemical-grown aluminum-doped titanium oxide nanorod arrays as electron transport layer

Aluminum (Al)-doped titanium dioxide nanorod arrays (ATNs) were grown on fluorine-doped tin oxide-coated glass at different Al atomic concentrations ranging from 1 at.% to 5 at.% in a Schott bottle through single-step aqueous chemical growth for self-powered photoelectrochemical cell-type ultraviolet (UV) photosensor applications. X-ray diffraction patterns showed that the grown ATNs exhibited a crystalline rutile structure. The ATNs showed smaller crystallite size and average nanorod diameter and length compared with the undoped sample. The photocurrent measured from the fabricated UV photosensors improved to some extent with increasing Al-dopant concentration. Samples with 2 at.% Al showed the maximum photocurrent of 108.87 μA/cm2 at 0 V bias under UV irradiation (365 nm, 750 μW/cm2). The results show that high-performance UV photosensors can be fabricated and enhanced using ATNs easily prepared in a glass container

Optimisation of silicone-based dielectric elastomer transducers by means of block copolymers – synthesis and compounding

Emerging artificial muscle technology has developed from metal-based robotics to softtype robotics made from soft matter. Research into artificial muscle technology based on soft matter has been conducted mainly in order to mimic soft and robust human muscle. In this regard, dielectric elastomers have been studied. Their actuation occurs when Maxwell stress exceeds elastic stress in the presence of an electrical field, resulting in contraction in thickness and planar expansion in the area. As well as an actuator, dielectric elastomers can be used as generators and sensors. As a dielectric elastomer, silicones have been used extensively in many applications, due to favourable properties such as thermal stability, non-conductivity, high gas permeability and low toxicity. However, silicones have a low dielectric constant and thereby low energy density. In order to enhance actuation performance, it is the aim of this research to develop silicone elastomers with a high dielectric constant and high electrical breakdown strength, as well as a low Young’s modulus. In this Ph.D. thesis, two methods were developed to enhance silicone properties such as the dielectric constant and electrical breakdown strength. The first method was devised to enhance the dielectric constant of silicone elastomers through the use of a polydimethylsiloxane-polyethyleneglycol (PDMS-PEG) copolymer, in order to obtain an elastomer with high electrical energy. PDMS-PEG copolymers were synthesised and blended in commercial silicone and subsequently cross-linked. The relative permittivity of cross-linked silicone with 5 wt% of PDMS-PEG copolymers increased by nearly 50%, without compromising dielectric loss and mechanical properties, compared to the commercial silicone elastomer. The second investigated method involved enhancing the electrical breakdown strength of silicone by using an aromatic voltage stabiliser. Here, polyphenylmethylsiloxane (PPMS), which contained aromatic voltage stabilisers, was bonded covalently to PDMS through a hydrosilylation reaction obtaining PDMS-PPMS copolymers. The synthesised copolymers were subsequently cross-linked with a vinyl cross-linker. The obtained cross-linked PDMS-PPMS copolymers were inherently soft and robust with increased electrical breakdown strength (21%) compared to the reference elastomer without an aromatic voltage stabiliser. The conducting polymer was developed through the use of a multi-walled carbon nanotube (MWCNT) in a PDMS-PEG matrix as a compliant electrode of dielectric elastomers. The conductive PDMS-PEG copolymer was incorporated with surface-treated MWCNT, in order to obtain highly conductive elastomer. The prepared sample with 4 parts per hundred rubber (phr) MWCNT was soft and the resulting conductivity of the cross-linked PDMS-PEG copolymer with the addition of MWCNT was high, at 10-2 S cm-1, nearly equivalent to a commonly used commercial conducting polymer. In this thesis, the elastomer and electrode system is referred to as a ‘dielectrielastome