19672 research outputs found
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Enhanced weight-based clustering algorithm to provide reliable delivery for VANET safety applications
No full textA vehicular ad hoc network (VANET) is an emerging and promising wireless technology aimed to improve traffic safety and provide comfort to road users. However, the high mobility of vehicles and frequent topology changes pose a considerable challenge to the reliable delivery of safety applications. Clustering is one of the control techniques used in VANET to make the frequent topology changes less dynamic. Nevertheless, research has shown that most of the existing clustering algorithms focus on cluster head (CH) election with very few addressing other critical issues such as cluster formation and maintenance. This has led to unstable clusters which could affect the timely delivery of safety applications. In this study, enhanced weight-based clustering algorithm (EWCA) was developed to address these challenges. We considered any vehicle moving on the same road segment with the same road ID and within the transmission range of its neighbour to be suitable for the cluster formation process. This was attributed to the fact that all safety messages are expected to be shared among the vehicles within the vicinity irrespective of their relative speedto avoid any hazardous situation. To elect a CH, we identified some metrics on the basis of the vehicle mobility information. Each vehicle was associated with a predefined weight value based on its relevance. A vehicle with the highest weight value was elected as the primary cluster head (PCH). We also introduced a secondary cluster head (SeCH) as a backup to the PCH to improve the cluster stability. SeCH took over the leadership whenever the PCH was not suitable for continuing with the leadership. The simulation results of the proposed approach showed a better performance with an increase of approximately40%– 45% in the cluster stability when compared with the existing approaches. Similarly, cluster formation messages were significantly minimized, hence reducing the communication overhead to the system and improving the reliable delivery of the safety applications. © 2019 Bello Tambawal et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Microstructural and Strength Characteristics of High-Strength Mortar Using Nontraditional Supplementary Cementitious Materials
No full textThis paper presents the investigation of the strength characteristics and microstructural analysis of cement composite mortar developed using nontraditional cement replacement materials. Three types of materials, namely palm oil fuel ash (POFA), treated palm oil fuel ash (TPOFA), and bottom ash (BA) were used as partial cement replacement materials at replacement levels of 0%, 10%, 20%, and 30% by weight. The water to binder ratio (w/b) of 0.32 was used for all mortars. The chemical composition and morphology of binder materials were examined by X-ray florescence (XRF) and scanning electron microscope (SEM) techniques. The fresh and hardened properties of mortar were determined in accordance with ASTM standards and the microstructure of mortar was investigated using X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The results showed pozzolanic activity through formation of C-S-H and CH as confirmed by XRD, TGA, and FTIR. Partial replacement of cement with 10%, 20%, and 30% of TPOFA produced higher compressive strengths of 101.4, 88.4, and 83.6 MPa, respectively, which is slightly closer to 110.0 MPa obtained for control specimen at 90 days. Moreover, higher strength activity index for TPOFA and BA specimens showed better pozzolanic activity as compared to POFA-based mortar. Overall, the use of 10% of POFA, TPOFA, and BA is recommended as a cement replacement in the development of high-strength mortar of strength range of 60 to 100 MPa. © 2019 American Society of Civil Engineers
Personality traits and internet addiction among selected financial institution employees
No full textPurpose: The purpose of this study is to investigate the relationship between personality traits and internet addiction behavior. Within the same industry background, job satisfaction was measured to test whether there is any mediating effect toward the relationship between personality traits and internet behavior. Design/methodology/approach: A sample of 271 employees from financial institutions was selected, and IBM SPSS was used to perform descriptive statistic, correlation analysis and partial regression analysis, to test out three main hypotheses developed in this study. Findings: The results indicate that personality traits, namely, agreeableness and emotional stability are negatively related to internet addiction behavior. However, job satisfaction does not mediate the influence of personality traits toward internet addiction behavior, even though the results indicated personality traits, namely, agreeableness, conscientiousness and emotion stability are positively related to job satisfaction. Research limitations/implications: The main implication includes better understanding on internet addiction behavior in local context and to predict internet addiction behavior through personality traits for better outcome of awareness and prevention toward this psychological disorder. Originality/value: The study contributes in understanding internet addiction behavior in Malaysia occupational context, as most of the local researches focused in validation of measurement tools. Hence, the finding provides an empirical evidence for organizational psychology study in recognition of internet addiction as part of occupational hazards. © 2019, Emerald Publishing Limited
A new species of the Simulium (Gomphostilbia) (Diptera: Simuliidae) from Thailand, with its phylogenetic relationships with related species in the Simulium asakoae species-group
No full textA new species of black fly, Simulium (Gomphostilbia) rampae, is described, based on adult male, its pupal exuviae and mature larvae collected from Doi Inthanon National Park, northern Thailand. This new species is placed in the Simulium asakoae species-group, and is characterized in the male by the high number of upper-eye facets in 17 vertical columns and 18 horizontal rows, in the pupa by the gill with a long common basal stalk, cone-shaped terminal hook, and cocoon with an anterodorsal projection, and in the larva by the medium-long postgenal cleft. A DNA analysis using COI gene supported its assignment to the S. asakoae species-group and showed its close relationship to S. (G.) udomi Takaoka & Choochote and S. (G.) chiangdaoense Takaoka & Srisuka. This is the fourth member of the S. asakoae species-group recorded from Thailand. © 2019 Elsevier B.V
The notion of animism: Some views from prophetic tradition and western anthropologist perspectives
No full textPurpose of Study: The prophetic tradition (al-Sunnah) as the second authentic source for Muslims includes guidance that touches all aspects of life, from economics, politics, laws, anthropology, etc. Some Western anthropologists stressed on debating the notion of animism which is a belief that everything exists in the universe has soul, spirit and must be respected. In fact, animism had been revered by all religions, and this theory was introduced by Edward Burnett Tylor (1832-1917) in the 19th century. Methodology: This article discusses on animism from the perspectives of prophetic traditions and Western Anthropologist. By applying content analysis method, this article found that both parties have some similarities and differences. In lieu of this, Islam concluded that animism or the belief in the power of invisible spirits of people’s ancestors and the spirits of nature to influence the fortunes of humans on earth are blasphemous and deviant. While in view of Anthropologist, animism puts more emphasis on the uniqueness of each individual soul. Animists see themselves on roughly equal footing with other animals, plants, and natural forces, and subsequently, have a moral imperative to treat these agents with respect. Implications/Applications: The implications for this kind of studies will open to discussions about anthropology through multi background and methods of data collection. © Usman et al
How much of Raymond Vernon's product cycle thesis is still relevant today: evidence from the integrated circuits industry
No full textVernon's product cycle thesis has increasingly been questioned as industries experienced differentiation and dispersal of production stages, while the need for proximity for interactions to take place between scientists and engineers, and consumers ended following the introduction of computerised inventory and production, and planning systems. This paper re-examines this thesis using the integrated circuits (IC) industry. The results show that IC multi-nationals have continued to retain frontier R&D and wafer fabrication activities at locations endowed with strong human capital and research centers. However, IC firms are attracted to relocate frontier R&D activities in distant host-sites, such as USA, Japan, Spain, Germany, Russia and Israel that are endowed with sophisticated science, technology and innovation infrastructure, and scientists and engineers. Also, IC manufacturing is too knowledge-intensive to be attracted to the least developed countries. Copyright © 2019 Inderscience Enterprises Ltd
The Prevalence of Smoking, Determinants and Chance of Psychological Problems among Smokers in an Urban Community Housing Project in Malaysia
No full textObjective: This study was conducted to assess the prevalence, pattern of smoking and sociodemographic factors among Kerinchi residents in Kuala Lumpur, as well as to identify the association between smoking, stress, anxiety and depression. Methods: This study was carried out at four community housing projects in the Lembah Pantai area in Kuala Lumpur. Data was collected between 3 February 2012, and 29 November 2012. Data collectors made house visits and used interviewer administered questionnaires containing questions on demographic data and smoking patterns. Depression anxiety stress scale (DASS) was used to assess psychological symptoms. Alcohol smoking and substance involvement screening tool (ASSIST) scale was used to assess nicotine use. Results: Data from 1989 individuals (833 households) showed the age of respondents ranged from 18 to 89 years and the mean age was 39.12 years. There were 316 smokers indicating the prevalence of smoking was 15.85%, with 35.5% among males and 1.8% among females. Further, 86.6% of smokers were Malay and 87% were Muslims. Divorce was associated with smoking. Unemployment and housewives were less associated with smoking. Depression and anxiety were significantly associated with smoking (OR = 1.347. 95% CI: 1.042-1.741) and (OR = 1.401. 95% CI: 1.095-1.793) respectively. Conclusion: Screening for depression and anxiety should be routinely performed in the primary care setting and in population-based health screening to intervene early in patients who smoke. © 2019 by the authors. Licensee MDPI, Basel, Switzerland
Perceptions of complementary/alternative medicine use and influence on evidence-based asthma medicine adherence in Malaysian children
No full textComplementary and alternative medicine (CAM) is widely used especially in Asia including for childhood asthma. The use of CAM could influence adherence to evidence-based (E-B) medicine. We explored the views of carers of Malaysian children with asthma regarding the use of CAM for childhood asthma, and its relationship with self-reported adherence to E-B medicine. We used a screening questionnaire to identify children diagnosed with asthma from seven suburban primary schools in Malaysia. Informed consent was obtained prior to the interviews. We conducted the interviews using a semi-structured topic guide in participants’ preferred language (Malay, Mandarin, or Tamil). All interviews were audio-recorded, transcribed verbatim and coded using Nvivo. Analysis was performed thematically, informed by the Necessity-Concerns Framework. A total of 46 carers (16 Malays, 21 Indians, 9 Chinese) contributed to 12 focus groups and one individual interview. We categorised participants’ as ‘Non-CAM’; ‘CAM’; or ‘combination’ user. Cultural practices and beliefs in the efficacy of CAM resulted in widespread use of CAM. Most carers used CAM as ‘complementary’ to E-B medicine. Concerns about dependence on or side effects of E-B treatment influenced carers’ decisions to rely on CAM as an ‘alternative’, with an important minority of accounts describing potentially harmful CAM-use. Healthcare professionals should discuss beliefs about the necessity for and concerns about use of both E-B medicine and CAM, and provide balanced information about effectiveness and safety. The aim is to improve adherence to regular E-B preventer medication and prevent delays in seeking medical advice and harmful practices associated with CAM. © 2019, The Author(s)
Temperature-dependent symmetry energy of neutron-rich thermally fissile nuclei
No full textBackground: The density-dependent symmetry energy coefficient plays a crucial role in understanding a variety of issues in nuclear physics as well as nuclear astrophysics. It is quite interesting and crucial to determine the symmetry energy coefficient and its related observables for neutron-rich thermally fissile nuclei at finite temperature. Purpose: We evaluate the symmetry energy coefficient, neutron pressure, and symmetry energy curvature of a finite nucleus from the corresponding quantities of infinite nuclear matter. Moreover, we correlate an effective symmetry energy coefficient and its related observables with the neutron skin thickness of neutron-rich thermally fissile nuclei at a finite temperature. Methods: The temperature-dependent relativistic mean field model (TRMF) is used to obtain the ground and excited state bulk properties of finite nuclei and the energy density, pressure, and the symmetry energy for infinite nuclear matter. The TRMF model with FSUGarnet, IOPB-I, and NL3 parameter sets is used for the present analysis. The effective nuclear matter properties are used to estimate the corresponding quantities of finite nuclei by using the local density approximation. Results: Nuclear bulk properties such as binding energy, quadrupole deformation, root-mean-square charge radius of the nuclei, and the equation of state and symmetry energy for infinite symmetric nuclear matter are estimated within the TRMF model. The nuclear matter observables at the local density of the nuclei serve as an input to obtain the effective symmetry energy coefficient, neutron pressure, and the symmetry energy curvature of U234,236,250 and Pu240 nuclei. The influence of temperature and density on these properties for neutron-rich thermally fissile nuclei is observed. A correlation is established between the neutron skin thickness and the neutron pressure of the nuclei. Conclusions: The studied properties of nuclei such as effective symmetry energy coefficient, neutron pressure and symmetry energy curvature can be used in the synthesis of neutron-rich thermally fissile nuclei. The method presented here (fully microscopic) can be used further to study the properties of exotic and superheavy nuclei from the corresponding quantities of nuclear matter and vice versa. © 2019 American Physical Society
Effectiveness of poly-γ-glutamic acid in maintaining enamel integrity
No full textObjective: The aim of the study was to determine demineralisation inhibition and remineralisation potential of poly-γ-glutamic acid with its possible mechanism of action on human dental enamel. Methodology: Three sodium-fluoride(NaF) concentration(0.01%w/v,0.1%w/v and 0.5%w/v respectively)and two poly-γ-glutamic acid(PGGA)concentration(1%w/v and 2%w/v respectively)were prepared in 0.1 M acetic acid(pH4.0)and deionized distilled water.For de/re-mineralisation study, tooth samples (18 teeth varnished, leaving a 2 mm2 window on the mid-buccal surfaces) were immersed in respective acidified NaF and PGGA solutions. The Ca2+ release/uptake was monitored with ISE over 72-hr with increasing pH every 24-h from 4.0 to 6.0.These teeth were later subjected to cross-sectional microhardness to determine integrated mineral recovery of enamel on increasing pH of respective acidified solution.In order to determine mechanism of PGGA,two concentrations of PGGA in deionized-water-solutions were used for tooth samples immersion followed by overnight drying then later subjected to Fourier Transform Infra-Red(FT-IR) analysis.The FT-IR analysis was also carried out on PGGA powder.For control,the experiment was repeated using hydroxyapatite(HAp)pellets.The density of PGGA solutions(1%and2%)was also measured to determine their dynamic viscosities. Results: The ISE and microhardness testing revealed statistically significant (ρ ≤ 0.05) dissolution inhibition and remineralisation potential for tooth sample treated with acidified 2%PGGA. From the FT-IR spectra, it was observed that the profiles of the enamel and HAp surfaces treated with 1%-and 2%-PGGA solutions were similar to those of PGGA powder.It was found that the viscosity of PGGA increases with increasing concentration. Conclusion: The study implies that 2% PGGA is more effective than NaF as forms a coating layer to protect from demineralisation and promote remineralisation of the tooth surface. © 2019 Elsevier Lt