937 research outputs found

    Hygrothermal performance of building envelopes in the tropics under operative conditions : condensation and mould growth risk appraisal

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    Poor indoor hygrothermal performance increases the risk of indoor moisture problems and deterioration due to mould growth, corrosion and damage to archival materials. Hence, proper control of indoor thermohygric intensity abates indoor moisture and its associated problems. This paper presents the results of envelopes hygrothermal performance assessments in a hot and humid climate building with varying operational profile between adjacent spaces. The case-studied building runs on 24hrs cooling mode in one part against natural and/or mechanical supply-exhaust fan means on the other. In-situ experiments were combined with hygrothermal analytical methods to assess the envelope thermal quality together with the operative conditions against condensation and mould growth risks. The results show that the building is overcooled leading to poor envelope hygrothermal performance with associated condensation and mould growth problems on non-airconditioned sides of the envelopes

    Ultrasonic Testing of HPC with Mineral Admixtures

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    Role of membrane surface charge and complexation-ultrafiltration for heavy metals removal: a mini review

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    Membrane technology is a promising water purification unit operation from household use to industrial application owing to its simplicity of operation, efficient recovery and minimum need for chemical and space allocation. Due to that reason, study on the membrane applications have becoming more popular among scientific community nowadays and one of the applications is removal of heavy metal using ultrafiltration (UF). However, a stand-alone UF will be not able to carry out the removal of heavy metals effectively. Certain modification is required in order to enhance its rejection via unique facilitated mechanism. Thus in this review, role of surface charge interaction as well as the method of complexation-ultrafiltration were discussed

    Generic Taxonomy of Social Engineering Attack

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    Social engineering is a type of attack that allows unauthorized access to a system to achieve specific objective. Commonly, the purpose is to obtain information for social engineers. Some successful social engineering attacks get victims’ information via human based retrieval approach, example technique terms as dumpster diving or shoulder surfing attack to get access to password. Alternatively, victims’ information also can be stolen using technical-based method such as from pop-up windows, email or web sites to get the password or other sensitive information. This research performed a preliminary analysis on social engineering attack taxonomy that emphasized on types of technical-based social engineering attack. Results from the analysis become a guideline in proposing a new generic taxonomy of Social Engineering Attack (SEA)

    Landslides and lineament mapping along the Simpang Pulai to Kg Raja highway, Malaysia

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    Geological structural features, such as the discontinuities that may be detected on satellite imagery as lineaments, in many cases control landslide occurrences. Lineament may represent the plane of weakness where the strength of the slope material has been reduced, eventually resulting in slope failure. The main objective of this study is to assess the relationship between lineament and landslide occurrences along the Simpang Pulai to Kg Raja highway, Malaysia. Lineament mapping was undertaken utilizing Landsat imagery and landslide distributions were identified based on field mapping and historical records. Lineament density maps of length, number and intersections were generated and compared with landslide distributions. The lineaments were also visually compared with the landslide occurrences. The results showed that there is an association between the lineaments and landslide distribution. Thus, lineament mapping is essential for the early stages of planning to prevent hazard potential from landslides

    Factors affecting endoglucanase production by Trichoderma reesei RUT C-30 from solid state fermentation of oil palm empty fruit bunches using Plackett-Burman design

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    A study was conducted to screen parameters affecting the production of endoglucanase by Trichoderma reesei RUT C-30 on solid state fermentation of oil palm empty fruit bunch using the Plackett-Burman design. Factors involved in the screening process were peptone concentration, urea concentration, ammonium sulfate concentration, calcium nitrate concentration, yeast extract concentration, tween 80 concentration, pH, incubation time, initial moisture content, inoculum size and substrate amount. Through analysis of variance (ANOVA), it was found that initial moisture content (p= 0.001), incubation time (p= 0.001), inoculum size (p= 0.032) and ammonium sulfate concentration (p= 0.023) have been recognized as significant factors affecting endoglucanase activity in solid state fermentation (SSF) of oil palm empty fruit bunch (OPEFB) by T. reesei RUT C-30. The model established from the ANOVA analysis have a significant value of Pmodel>F= 0.0008 and R2 of 0.9132. The preoptimized media showed 2.6 fold increased of endoglucanase activity.Key words: Cellulase, oil palm empty fruit bunches, solid state fermentation, Trichoderma reesei RUT C-30, Plackett-Burman design

    Alert Correlation Technique Analysis For Diverse Log

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    Alert correlation is a process that analyses the alerts produced by one or more diverse devices and provides a more succinct and high-level view of occurring or attempted intrusions. The objective of this study is to analyse the current alert correlation technique and identify the significant criteria in each technique that can improve the Intrusion Detection System IDS) problem such as prone to alert flooding, contextual problem, false alert and scalability. The existing alert correlation techniques had been reviewed and analysed. From the analysis, six capability criteria have been identified to improve the current alert correlation techniques which are capability to do alert reduction, alert clustering, identify multi-step attack,reduce false alert, detect known attack and detect unknown attack and technique’s combination is proposed

    A novel approach of multimedia instruction applications in engineering education

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    Effective use of educational technology depends on knowledge of why and how to utilize technology to solve teaching and learning problems. The present study first conducts a systematic literature review of the limited studies undertaken on multimedia instruction applications for engineering education to critique the current status of knowledge in this area. The conventional qualitative content analysis method was employed for data analysis. The results highlighted the incompatibility of three basic educational elements i.e. engineering curriculum, educational resources and engineering students’ learning characteristics all of which posed major challenges in teaching and learning engineering courses. Multimedia instruction enhances engineering students’ understanding of engineering concepts, procedures, problems and solutions through direct visualization. Furthermore, it could indirectly assist students in achieving higher order learning levels and skills through enhancing or supporting educational resources and increasing students’ motivation. Mobile multimedia instruction and a student-generated multimedia learning approach to improve engineering education are suggested for future research

    A study of frequency and pulses for stepper motor controller system by using programmable logic controller

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    The stepper motor movement process produced different frequency and pulses. This research explained about the frequency and pulses for the stepper motor movement by using Programmable Logic Controller (PLC) as research method. The study was done to find the suitable frequency and pulses for stepper motor movement by developing a prototype stepper motor controller system. The pulse frequency used did not affected the distance of moving load in the stepper motor operations. The increasing number of pulse frequency only will affect the time taken for the stepper motor to complete its operations. The result showed that number of pulse frequency at high operation was 5000 Hz. Pulse number reacted as a manipulated variable that affected both factor which is time taken of stepper motor operation and the distance of moving load

    Threshold Verification Technique for Network Intrusion Detection System

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    Internet has played a vital role in this modern world, the possibilities and opportunities offered are limitless. Despite all the hype, Internet services are liable to intrusion attack that could tamper the confidentiality and integrity of important information. An attack started with gathering the information of the attack target, this gathering of information activity can be done as either fast or slow attack. The defensive measure network administrator can take to overcome this liability is by introducing Intrusion Detection Systems (IDSs) in their network. IDS have the capabilities to analyze the network traffic and recognize incoming and on-going intrusion. Unfortunately the combination of both modules in real time network traffic slowed down the detection process. In real time network, early detection of fast attack can prevent any further attack and reduce the unauthorized access on the targeted machine. The suitable set of feature selection and the correct threshold value, add an extra advantage for IDS to detect anomalies in the network. Therefore this paper discusses a new technique for selecting static threshold value from a minimum standard features in detecting fast attack from the victim perspective. In order to increase the confidence of the threshold value the result is verified using Statistical Process Control (SPC). The implementation of this approach shows that the threshold selected is suitable for identifying the fast attack in real tim
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