A QoS-Aware CAC with bandwidth reservation and degradation scheme in IEEE 802.16e networks

Call admission control (CAC) schemes play a critical role in providing quality-of-service (QoS) guarantees for various classes of traffic with diverse QoS requirements in IEEE 802.16e networks. The dynamic CAC and bandwidth reservation scheme is one of the current schemes that simultaneously provides efficient utilization of network resources and guarantees QoS for admitted connections. However, its admission criteria starved high and low service classes due to its linear adaptation policy to accommodate more users into the network under moderate-to-heavy traffic load conditions. Its adaptive threshold for handoff connections is adjusted based on the arrival of new and handoff connections, that results in a waste of resources when the new and handoff connection arrival rate occurs frequently. In this paper, a new CAC scheme for Mobile WiMAX networks is proposed to prevent starvation of service classes and enhance the efficient utilization of network resources. The scheme determines a new admission criteria based on a scheduling service class. In the admission criteria, bandwidth degradation policy is used to admit more users when there is no available bandwidth to admit a more users. The adaptive threshold has been introduced dynamically to adjust the quantity of reserved bandwidth for handoff connections based on the traffic intensity of handoff requests. In addition, an analytical model for the proposed scheme is also developed. Extensive simulation experiments have been conducted to evaluate the performance of our proposed approach. The simulation results illustrate that the proposed scheme significantly improves the network efficiency compared to other schemes in terms of accepting more connections into the network and assuring QoS for all service classes. The numerical results have shown similar performance to the simulation results

An efficient battery lifetime aware power saving (EBLAPS) mechanism in IEEE 802.16e networks

The IEEE 802.16e standard is an emergent broadband wireless access technology that added the mobility feature to the original standard. This feature made battery life of an operated mobile subscribe station (MSS) a bigger challenge because an MSS is powered by a rechargeable battery. The battery lifetime mechanism has to be created in order to prolong the battery-life of an MSS. The battery lifetime-aware power saving (BLAPS) scheme has been created to prolong the battery life of an MSS by adaptively adjusting the three-sleep parameters named idle threshold, initial sleep window, and final sleep window according to the residual energy and the traffic load. However, the scheme minimized the energy consumption of the MSS at the expense of the average response delay due to the effect of the remaining energy. It also used the standard sleep mode algorithm where the MSS frequently goes to listening mode when the traffic is low which leads to the high-energy consumption. In this paper, a new energy mechanism called efficient battery life-aware power saving scheme has been proposed to enhance the parameters of BLAPS. The three-sleep parameters in BLAPS mechanism are analytically enhanced according to the downlink stochastic traffic arrival pattern of an MSS. Moreover, an improved sleep mode control algorithm has been introduced to reduce the frequent transition to listening mode in case of low traffic. The simulation has been extensively used to evaluate the proposed scheme. The results have shown that the proposed scheme outperforms the BLAPS significantly in terms of both the average response delay and the average energy consumption

Fabrication of titania nanotube and its application for palmitic acid determination by electrochemical technique

Fabrication of titania nanotubes (TNTs) through electrochemical anodization and its application for the determination of palmitic acid has been explored. In this work, self-organized oxide tube or pore arrays of TNT has been achieved by adjusting the voltage and time of anodization. The TNTs prepared at 30 V for 2 hours resulted in highly ordered nanotubular structure. Type of electrolyte such as glycerol employed for electrochemical anodization of TNT affected the morphology which showed better result as compared to aqueous electrolyte. The application of the prepared TNTs towards palmitic acid has also been evaluated. The electrochemical detection of palmitic acid was based on the electrochemical reduction of quinone (2-methyl-1,4-naphthaquinone, VK3) to form corresponding hydroquinone. The developed method showed good linearity towards concentration of palmitic acid in the range of 2.3 mM to 6.2 mM (R 2 = 0.9862) with the detection limit of 1.006 mM

Inorganic-based phytohormone delivery vector of 2-chloroethylphosphonate nanohybrid, a new stimulating compound with controlled release property to increase latex production.

New inorganic-based phytohormone delivery system, a stimulating compound to increase latex production was developed through hybridisation of 2-chloroethylphosphonic acid (ethephon) into the interlayer of Zn–Al-layered (ZAL) double hydroxide. The hybridisation product, ZADO, was synthesised using co-precipitation technique at pH 7.5, 0.08 M ethephon and initial molar ratio of Zn to Al, R = 4. The resulting material has a basal spacing of 11.5 Å and Fourier transform infrared spectra further supported the hybridisation episode of ethephon into the ZAL. The release behaviour of the active agent, ethephon from the nanohybrid was found to be of controlled manner, governed by pseudo-second order kinetics. These results indicate that it is possible to design and develop a new delivery system of a phytohormone, [ethephon (2-chloroethylphosphonate)] with controlled release property to increase latex production of rubber tree (Hevea brasiliensis)

Theoretical and experimental models for the synthesis of single-walled carbon nanotubes and their electrochemical properties

A major challenge in the field of selective synthesis of single-walled carbon nanotubes (SWCNTs) via chemical vapor deposition (CVD) method is lack of established theoretical model for direct selection of metal/support catalyst to grow the corresponding SWCNTs. This has limited the application of these materials, especially, in electronics. In this report, we introduced circumferential and axial distortions in the Extended Tight Binding (ETB) equations to generate our model equations which correlated the numerical magnitude of chiral index (n, m) of SWCNTs directly with mass fractions of metal/support catalyst matrix, respectively. Theoretical predictions of our model equations showed acceptable deviations with ETB model, and two Fe2O3/Al2O3 catalysts were prepared according to this model to grow corresponding SWCNTs (10, 7) and (8, 8) via CVD pyrolysis of C6H14/N2 feedstock. High-resolution transmission electron microscopy analysis revealed bundled SWCNTs while analysis of their Raman profiles showed consistency with the radial breathing modes, diameter and energy band gaps of SWCNTs (10, 7) and (8, 8). Electrochemical analysis of the samples suggested potentials as pseudocapacitor electrodes. If fully explored and optimized, this model may complement or augment the existing in-situ epitaxial growth model

Inter- and intra-observer reliability and agreement of O2Pulse inflection during cardiopulmonary exercise testing: a comparison of subjective and novel objective methodology.

Cardiopulmonary exercise testing (CPET) is the 'gold standard' method for evaluating functional capacity, with oxygen pulse (O2Pulse) inflections serving as a potential indicator of myocardial ischaemia. However, the reliability and agreement of identifying these inflections have not been thoroughly investigated. This study aimed to assess the inter- and intra-observer reliability and agreement of a subjective quantification method for identifying O2Pulse inflections during CPET, and to propose a more robust and objective novel algorithm as an alternative methodology. A retrospective analysis was conducted using baseline data from the HIIT or MISS UK trial. The O2Pulse curves were visually inspected by two independent examiners, and compared against an objective algorithm. Fleiss' Kappa was used to determine the reliability of agreement between the three groups of observations. The results showed almost perfect agreement between the algorithm and both examiners, with a Fleiss' Kappa statistic of 0.89. The algorithm also demonstrated excellent inter-rater reliability (ICC) when compared to both examiners (0.92-0.98). However, a significant level (P ≤0.05) of systematic bias was observed in Bland-Altman analysis for comparisons involving the novice examiner. In conclusion, this study provides evidence for the reliability of both subjective and novel objective methods for identifying inflections in O2Pulse during CPET. These findings suggest that further research into the clinical significance of O2Pulse inflections is warranted, and that the adoption of a novel objective means of quantification may be preferable to ensure equality of outcome for patients

Electrocardiographic ECG characteristics among Malaysian athletes

The electrocardiogram (ECG) is a graphic representation of the heart’s electrical activity. Although it has some limitations as a diagnostic or prognostic tool, it contains a wealth of information necessary for the proper care of a patient with a potential cardiovascular disease. Understanding the ECG changes among athletes would allow medical practitioners to distinguish between normal physiological adaptations and abnormal changes. However, there is limited data on the ECG characteristics among multi-ethnic athletes such as in Malaysia. This study aimed to determine the ECG characteristics and its associated factors among Malaysian national athletes. Malaysian national athletes annual preparticipation medical records were retrieved. Information on sociodemographic, sports and medical history including the 12-lead resting ECG tracings were extracted. ECG were assessed and categorised into normal, physiological adaptation changes, and abnormal ECG using the standardised ‘Seattle criteria’. Differences in ECG characteristics between genders, ethnic background, and type of sports was investigated. Additionally, factors associated with the ECG characteristics were assessed using multiple logistic regression. Majority of Malaysian national athletes had physiological adaptation ECG changes (61%). The most frequent changes were early repolarization, sinus bradycardia and isolated left ventricular hypertrophy. We found significantly higher prevalence of physiological adaptation changes among men (χ2 (2,371) = 18.9; p = 0.001) and athletes of Chinese ethnicity (both genders) (χ2 (2,356) = 13.8; p = 0.002). Factors associated with physiological ECG changes were men (OR=2.67; 95% CI= 1.68, 4.27; p<0.001) and Chinese ethnicity (OR=2.92; 95% CI=1.68, 4.27; p=0.039). Most athletes had physiological adaptation ECG changes which were significantly associated with male gender and Chinese ethnicity. This information would facilitate the development of a specific guideline in interpreting ECG among Malaysian athletes

Electrocardiographic (ECG) characteristics among Malaysian athletes

The electrocardiogram (ECG) is a graphic representation of the heart’s electrical activity. Although it has some limitations as a diagnostic or prognostic tool, it contains a wealth of information necessary for the proper care of a patient with a potential cardiovascular disease. Understanding the ECG changes among athletes would allow medical practitioners to distinguish between normal physiological adaptations and abnormal changes. However, there is limited data on the ECG characteristics among multi-ethnic athletes such as in Malaysia. This study aimed to determine the ECG characteristics and its associated factors among Malaysian national athletes. Malaysian national athletes annual pre-participation medical records were retrieved. Information on sociodemographic, sports and medical history including the 12-lead resting ECG tracings were extracted. ECG were assessed and categorised into normal, physiological adaptation changes, and abnormal ECG using the standardised ‘Seattle criteria’. Differences in ECG characteristics between genders, ethnic background, and type of sports was investigated. Additionally, factors associated with the ECG characteristics were assessed using multiple logistic regression. Majority of Malaysian national athletes had physiological adaptation ECG changes (61%). The most frequent changes were early repolarization, sinus bradycardia and isolated left ventricular hypertrophy. We found significantly higher prevalence of physiological adaptation changes among men (χ2(2,371) = 18.9; p = 0.001) and athletes of Chinese ethnicity (both genders) (χ2(2,356) = 13.8; p = 0.002). Factors associated with physiological ECG changes were men (OR=2.67; 95% CI= 1.68, 4.27; p<0.001) and Chinese ethnicity (OR=2.92; 95% CI=1.68, 4.27; p=0.039). Most athletes had physiological adaptation ECG changes which were significantly associated with male gender and Chinese ethnicity. This information would facilitate the development of a specific guideline in interpreting ECG among Malaysian athletes

The Effect of Single, Binary and Ternary Anions of Chloride, Carbonate and Phosphate on the Release of 2,4-Dichlorophenoxyacetate Intercalated into the Zn–Al-layered Double Hydroxide Nanohybrid

Intercalation of beneficial anion into inorganic host has lead to an opportunity to synthesize various combinations of new organic–inorganic nanohybrids with various potential applications; especially, for the controlled release formulation and storage purposes. Investigation on the release behavior of 2,4-dichlorophenoxyacetate (2,4-D) intercalated into the interlayer of Zn–Al-layered double hydroxide (ZAN) have been carried out using single, binary and ternary aqueous systems of chloride, carbonate and phosphate. The release behavior of the active agent 2,4-D from its double-layered hydroxide nanohybrid ZANDI was found to be of controlled manner governed by pseudo-second order kinetics. It was found that carbonate medium yielded the highest accumulated release of 2,4-D, while phosphate in combination with carbonate and/or nitrate speeds up the release rate of 2,4-D. These results indicate that it is possible to design and develop new delivery system of latex stimulant compound with controlled release property based on 2,4-D that is known as a substance to increase latex production of rubber tree,Hevea brasiliensis

The pilot study on Down to Earth (D2E) injury prevention program among varsity netball players

BACKGROUND: Sports injuries involving lower extremities have been reported to be very common in netball. We explored the effect of Down to Earth, a program which focuses on safe-landing techniques during sport activities, in reducing lower limbs injuries among varsity netball players. METHODS: This was a single-blinded controlled trial, where 42 varsity netball players were randomly assigned into two groups, the intervention group (N.=17) and the control group (N.=25). The intervention group was instructed to incorporate Down to Earth program in their training, while the control group continued to train using their standard program for 6 weeks. Data on lower extremity injury were collected during training or competition for the period of 6 weeks post intervention. RESULTS: The overall incidence of injuries was 5.9 injuries per 1000 hours of participations throughout the study. The mean exposure hour was 77 hours during training and 32 hours during match. The intention to treat analysis showed that the rate ratio ranges from 0.01-0.71. The number of training injuries were significantly higher in the control group than the intervention group (P<0.05). Based on number to treat, number of players that were needed to prevent one injury during training was three players and 37% of the players in intervention group were protected by the Down to Earth program. The intervention group had 0.01 lower rate of lower limb injury during training than the control group. CONCLUSIONS: This study has shown that Down to Earth program is beneficial in reducing the risk of lower limbs injuries during training among the varsity netball player. As previous study also reported that more training hours are advantageous for athletes to reduce injury risk, this suggests that Down to Earth could be considered as one of the effective programs for sports injuries prevention