Characterisation and modelling of pedestrian flows in hospital and academic environments

This paper examined pedestrian characteristics in two urban facilities namely a teaching hospital and a university campus. The aim was to determine if pedestrian flow features in these facilities differed from those in downtown areas. The objectives were to measure pedestrian flow rates and model their walking behaviour. Eleven sites located within these facilities were selected for study. The results indicated that the male walked faster than the female in the university campus while the female was faster in the hospital environment. Also the university campus saw more groups of pedestrians in the traffic mix than was the case in the hospital environment where 93% of the pedestrians were in single files. The male walked faster than the female by 7% in the university environment while the female were faster by 4% in the hospital environment. The modelling effort showed that the free walking speed in the university environment was 68.052 m/min with a critical density of 3.15 ped/m2. That of the hospital environment was 75.099 m/min and a critical density of 4.36 ped/m2. Since the speed-density relationships for the two facilities revealed a highly randomized plot, the data was fit to the normal distribution and pdf and cdf were used to assess the quality of the flow. For the university environment the results showed that 15% of the combined pedestrians walked below 56.88 m/min while 50% of the pedestrians walked below 66.67m/min and 85% walked below 72.50 m/min. Similarly, the results of the hospital environment showed that 15th percentile of the combined pedestrians walked below 69.75 m/min. The median speed of pedestrians was 72.50 m/min while 85% of the pedestrians walked below 75.25 m/min. In both cases, the 15 percentile speeds were 14% and 18.5% less than the median speeds in both facilities respectively. Thus flow breakdowns are unexpected in the two facilities

Defending Against Firmware Cyber Attacks on Safety-Critical Systems

In the past, it was not possible to update the underlying software in many industrial control devices. Engineering teams had to ‘rip and replace’ obsolete components. However, the ability to make firmware updates has provided significant benefits to the companies who use Programmable Logic Controllers (PLCs), switches, gateways and bridges as well as an array of smart sensor/actuators. These updates include security patches when vulnerabilities are identified in existing devices; they can be distributed by physical media but are increasingly downloaded over Internet connections. These mechanisms pose a growing threat to the cyber security of safety-critical applications, which are illustrated by recent attacks on safety-related infrastructures across the Ukraine. Subsequent sections explain how malware can be distributed within firmware updates. Even when attackers cannot reverse engineer the code necessary to disguise their attack, they can undermine a device by forcing it into a constant upload cycle where the firmware installation never terminates. In this paper, we present means of mitigating the risks of firmware attack on safety-critical systems as part of wider initiatives to secure national critical infrastructures. Technical solutions, including firmware hashing, must be augmented by organizational measures to secure the supply chain within individual plants, across companies and throughout safety-related industries

A study of nanoparticles as a drug carrier on the wall of Stenosed Arteries

The influences of nanoparticles as drug carriers on the walls of stenosed arteries are presented. In this study, three nanoparticles namely Fe3O4 , TiO2 and Cu were used. It is observed that the addition of Fe3O4 nanoparticles tends to reduce the resistance impedance of blood temperature in bell shaped stenosed arteries. The blood temperature increases slightly in the streamwise direction before the throat region. Thereafter, the blood temperature increases at a higher rate and reaches its maximum value at the stenosis throat. It is found that the temperature distribution is heavily dependent on parameters such as periodic body acceleration and Prandtl number

Audit quality and accounting conservatism

This objective of this study is to examine the impact of audit quality on accounting conservatism in Turkey. Using three different measures of accounting conservatism, we report that audit quality, in terms of brand name auditor and industry specialist auditor, is positively related to conservatism. Our results hold after controlling for operating cash flow, leverage, firm age and sales growth. Overall, the evidence is consistent that accounting conservatism complements firms in the Turkish business environment that engage with high quality auditors to mitigate agency costs.peer-reviewe

Optimal power demand curve: a case study in Universiti Putra Malaysia

The necessitation in the optimal power demand model, make it an impetus to present this work as a glaring path in determining the optimum power demand curve, using the available data of a substation. The data are used to find the equation and its coefficients of determination that can give the best-fit curve of the power demand of a substation, based on the available data. This will produce a model that can be validated by comparing the data and figured out the equation

Effect of fractional crystallyzation on composition and thermal behavior of coconut oil

This study was aimed to fractionate coconut oil into its high- and low-melting fractions and determine the compositional and thermal property changes. A sample of coconut oil was dissolved in acetone, and allowed to crystallize isothermally at a desired temperature to separate into the low- and high-melting components. The isolated fractions were compared to the original sample with respect to fatty acid and triacylglycerol compositions as well as thermal behavior. There were considerable deviations in the fatty acid and triacylglycerol compositions of the two components with respect to those of the original sample. As a consequence, the overall melting behaviors of the two components differed considerably from that of the original sample. In the high-melting fraction, the onset and endset were shifted toward the higher temperature region with a concurrent reduction in its melting range, and vice-versa, the onset and endset of the low-melting fraction had shifted toward the low-temperature region with an increase in its melting range. The reduction of the melting range of the high-melting fraction could make it a specialty fat for applications in confectionery

Medium access prioritizing in the heterogeneous low-rate wireless PANs

Coping with customer interests to employ Wireless Sensor Networks (WSN) in the new applications requires dealing with the fact of nodes variety that implies the heterogeneous nature of the traffic. This necessitates employing differentiation techniques that lead in the end to implementing prioritization in some processes of the system. The medium access controlling process plays a main role in the WSN work life cycle and the QoS provisioning is mainly based on the MAC efficiency. In this paper, we introduce the main techniques of WSN medium access prioritizing in the cluster-based Low-PANs. We propose using the prioritizing source as the categorizing factor. Furthermore, this study analyzes the impact of applying the MAC prioritization on the performance of the WSN. The simulation results prove that prioritizing nodes improves the system performance in terms of the access delay and the throughput metrics

A novel low complexity high efficiency hybrid PAPR reduction for OFDM systems

In this paper, we propose a novel hybrid multiplicative-additive technique to reduce the peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. This technique consists of two inverse fast Fourier transform (IFFT) blocks. The input symbols of the first IFFT are the mapped symbols, whereas the input symbols of the second IFFT are the summations of the absolute value of the real part of the outer signal constellation points and zeros symbols. First, the output of the two IFFT blocks is partitioned into four subblocks, which are subsequently used to rearrange the subblocks with padding zeros in a specific manner. Then, a new optimization scheme is introduced, in which only a single two-phase sequence and four iterations needs to be applied. Numerical analysis shows that the hybrid proposed technique achieves better bit error rate (BER) and PAPR reduction performance than partial transmit sequences (PTS) multiplicative technique and tone reservation (TR) additive PAPR technique. The other salient feature of this scheme is that no side information (SI) is needed which increases transmission efficiency

Decentralized time domain muting for interference mitigation in LTE-advanced heterogeneous networks

User equipments (UEs) offloaded from the MeNBs to the PeNBs via cell range extension (CRE) bias in a co-channel deployment suffered severe interference. The severity of the downlink interference varies significantly with the change in the CRE bias. The baseline approach for Interference mitigation technique based on time domain muting (TDM) of resources by MeNBs used trial and error technique which is causing resource wastage and is practically not feasible. Proposed here is a Model for TDM based on estimated cell load conditions and symbol efficiency (SE) as metrics to determine the muting ratio of resources. System level simulation was conducted to validate the throughput performances and the MeNBs- PeNBs resource trade-offs of the proposed method. Compared to the baseline (centralized) approach, the proposed decentralized TDM algorithm exhibited optimal throughput performance and adapted to the change in CRE bias with better trade-offs