13 research outputs found

    Improving Pedestrian Safety with the Implementation of the Demand-Responsive Transverse Rumble Strip as a New Traffic Safety Countermeasure

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    The traditional TRS has been extensively used as a traffic calming device to provide cognitive alerts in the form of sound and vibration to drivers. However, TRS always remains fixed on the road and thus exerts cognitive alerts, irrespective of any potential downstream hazards. Moreover, the continuous exposure to rumble strips has been identified as a source of discomfort and annoyance for drivers, which limits its application to potentially useful scenarios. This study explores a rumble strip design with dynamic behavior named as Demand-Responsive Transverse Rumble Strip (DRTRS) in order to address the limitations of static TRS. The study incorporates DRTRSā€™ appropriate design dimensions and operation scheme, sound and vibration effect, speed-reducing effect, and pedestrian demand-based activation. In methodological procedures, the study explored four main aspects of DRTRS for designing and evaluating its effectiveness, which includes identification of optimum design dimensions, quantitative experimentation of in-vehicle sound and vibration, quantitative analysis of DRTRS effectiveness on driversā€™ speed reductions, and prediction of the pedestrian demand for the activation mechanism of the DRTRS system. The study identified and selected the optimum width and depth of the rumble units of the DRTRS system prototype. The system was found to be effective in engaging the auditory and haptic senses of drivers, by generating discernible in-vehicle sound and vibration. Thereafter, the engagement of driversā€™ cognitive senses yielded by the system had a significant effect on reducing vehicle speeds. In addition, the system can be set for flexible activation length based on the need from the crosswalks identified by pedestrian presence and prediction algorithms

    The Relationship between Human Resource Management (HRM) Practices and Employee Selected Outcomes within the Organization: Empirical Evidence from Cement Manufacturing Company Limited in Bangladesh perspective

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    This is a compendium of the entire object which seeks to examine the association between human resource management practices and employee selected outcomes within the organizations. Data were collected through questionnaire from 100 employees. SPSS-16 was used to analyze the collected data. In this study, descriptive statistics, correlations, and multiple regression analysis have been applied to determine the contribution of each independent variable in human resource management practices within the organizations. The study shows that there is a significant relationship between independent and dependent variables. The result of the analysis revealed that HRM practices have a significant influence on employee selected outcomes like perceived organizational support, employee attitudes and behavior, affective and normative commitment and discretionary behavior within the organization. Furthermore, findings of this research paper emphasis on the presence and appearance of HR internal experts in the organizations which helps to achieve competitive advantage and improving organizational performance. Keywords: HR Practices, Employee Attitudes, Employee Commitment, Discretionary Behavior

    Design and Preliminary Testing of Demand-Responsive Transverse Rumble Strips

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    Transverse rumble strips are common practice to alert drivers by engaging their auditory and tactile senses in addition to visual senses by traffic signals. However, continuous exposure to noise and vibration by transverse rumble strips often results in diminished effectiveness and erratic behaviors, leading to additional safety challenges. In response, demand-responsive transverse rumble strips were developed as traffic safety countermeasures that reduce unnecessary noise and vibration associated with transverse rumble strips by incorporating active control of the rumble strips. Rather than staying static, demand-responsive transverse rumble strips are activated based on the presence of pedestrians, at predesignated times, or in response to abrupt changes in traffic flow. To evaluate the effectiveness of demand-responsive transverse rumble strips, the research team assessed noise and vibration data, both inside the vehicles and on the roadside, for various types of vehicles traveling at different speeds. The test data indicate that demand-responsive transverse rumble strips produced noticeable in-vehicle noise and vibration that could alert drivers to downstream events. Furthermore, demand-responsive transverse rumble strips generated sufficient noise to alert roadside pedestrians to vehicle presence but at low enough level to be considered as acceptable for a residential neighborhood use. Accordingly, demand-responsive transverse rumble strips could address the challenges that static transverse rumble strips face, by providing a design with relatively limited noise while enhancing safety

    Can We Use Functional Annotation of Prokaryotic Taxa (FAPROTAX) to Assign the Ecological Functions of Soil Bacteria?

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    FAPROTAX is a promising tool for predicting ecological relevant functions of bacterial and archaeal taxa derived from 16S rRNA amplicon sequencing. The database was initially developed to predict the function of marine species using standard microbiological references. This study, however, has attempted to access the application of FAPROTAX in soil environments. We hypothesized that FAPROTAX was compatible with terrestrial ecosystems. The potential use of FAPROTAX to assign ecological functions of soil bacteria was investigated using meta-analysis and our newly designed experiments. Soil samples from two major terrestrial ecosystems, including agricultural land and forest, were collected. Bacterial taxonomy was analyzed using Illumina sequencing of the 16S rRNA gene and ecological functions of the soil bacteria were assigned by FAPROTAX. The presence of all functionally assigned OTUs (Operation Taxonomic Units) in soil were manually checked using peer-reviewed articles as well as standard microbiology books. Overall, we showed that sample source was not a predominant factor that limited the application of FAPROTAX, but poor taxonomic identification was. The proportion of assigned taxa between aquatic and non-aquatic ecosystems was not significantly different (p > 0.05). There were strong and significant correlations (σ = 0.90–0.95, p < 0.01) between the number of OTUs assigned to genus or order level and the number of functionally assigned OTUs. After manual verification, we found that more than 97% of the FAPROTAX assigned OTUs have previously been detected and potentially performed functions in agricultural and forest soils. We further provided information regarding taxa capable of N-fixation, P and K solubilization, which are three main important elements in soil systems and can be integrated with FAPROTAX to increase the proportion of functionally assigned OTUs. Consequently, we concluded that FAPROTAX can be used for a fast-functional screening or grouping of 16S derived bacterial data from terrestrial ecosystems and its performance could be enhanced through improving the taxonomic and functional reference databases

    Opportunistic Relay Selection over Generalized Fading and Inverse Gamma Composite Fading Mixed Multicast Channels : A Secrecy Tradeoff

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    This work was supported in part by the National Research Foundation of Korea funded by the Korean Government, Ministry of Science and ICT, under Grant ICT-NRF-2020R1A2B5B02002478; and in part by Sejong University through its Faculty Research Program under Grant 20212023.Peer reviewedPublisher PD

    Security at the Physical Layer over GG Fading and mEGG Turbulence Induced RF-UOWC Mixed System

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    This work was supported in part by the National Research Foundation of Korea grant funded by the Korean Government (Ministry of Science and ICT) under Grant 2019R1A2C1083988, in part by the Ministry of Science and ICT, South Korea, under the Information Technology Research Center Support Program supervised by the Institute for Information and Communications Technology Planning and Evaluation, under Grant IITP-2021-2016-0-00313, and in part by Sejong University through its Faculty Research Program under Grant 20202021.Peer reviewedPublisher PD

    Enhancing security of TAS/MRC-based mixed RF-UOWC system with induced underwater turbulence effect

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    Post commercial deployment of fifth-generation (5G) technologies, the consideration of sixth-generation (6G) networks is drawing remarkable attention from research communities. Researchers suggest that similar to 5G, 6G technology must be human-centric where high secrecy together with high data rate will be the key features. These challenges can be easily overcome utilizing PHY security techniques over high-frequency free-space or underwater optical wireless communication (UOWC) technologies. But in long-distance communication, turbulence components drastically affect the optical signals, leading to the invention of the combination of radio-frequency (RF) links with optical links. This article deals with the secrecy performance analysis of a mixed RF-UOWC system where an eavesdropper tries to intercept RF communications. RF and optical links undergo Ī·āˆ’Ī¼ and mixture exponential generalized Gamma distributions, respectively. To keep pace with the high data rate of the optical technologies, we exploit the antenna selection scheme at the source and maximal ratio combining diversity at the relay and eavesdropper, while the eavesdropper is unaware of the antenna selection scheme. We derive closed-form expressions of average secrecy capacity, secrecy outage probability, and probability of strictly positive secrecy capacity to demonstrate the impacts of the system parameters on the secrecy behavior. Finally, the expressions are corroborated via Monte Carlo simulations

    Life on the Rocks: First Insights Into the Microbiota of the Threatened Aquatic Rheophyte Hanseniella heterophylla

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    Little is known about microbial communities of aquatic plants despite their crucial ecosystem function in aquatic ecosystems. Here, we analyzed the microbiota of an aquatic rheophyte, Hanseniella heterophylla , growing at three areas differing in their degree of anthropogenic disturbance in Thailand employing a metabarcoding approach. Our results show that diverse taxonomic and functional groups of microbes colonize H. heterophylla . Proteobacteria, Actinobacteria, Dothideomycetes, and Sordariomycetes form the backbone of the microbiota. Surprisingly, the beneficial microbes reported from plant microbiomes in terrestrial habitats, such as N-fixing bacteria and ectomycorrhizal fungi, were also frequently detected. We showed that biofilms for attachment of H. heterophylla plants to rocks may associate with diverse cyanobacteria (distributed in eight families, including Chroococcidiopsaceae, Coleofasciculaceae, Leptolyngbyaceae, Microcystaceae, Nostocaceae, Phormidiaceae, Synechococcaceae, and Xenococcaceae) and other rock biofilm-forming bacteria (mainly Acinetobacter , Pseudomonas , and Flavobacterium ). We found distinct community compositions of both bacteria and fungi at high and low anthropogenic disturbance levels regardless of the study areas. In the highly disturbed area, we found strong enrichment of Gammaproteobacteria and Tremellomycetes coupled with significant decline of total bacterial OTU richness. Bacteria involved with sulfamethoxazole (antibiotic) degradation and human pathogenic fungi ( Candida , Cryptococcus , Trichosporon , and Rhodotorula ) were exclusively detected as indicator microorganisms in H. heterophylla microbiota growing in a highly disturbed area, which can pose a major threat to human health. We conclude that aquatic plant microbiota are sensitive to anthropogenic disturbance. Our results also unravel the potential use of this plant as biological indicators in remediation or treatment of such disturbed ecosystems

    On effective secrecy throughput of underlay spectrum sharing Ī± - Ī¼/ MĆ”laga hybrid model under interference-and-transmit power constraints

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    The underlay cognitive radio-based hybrid radio frequency/free-space optical (RF/FSO) systems have emerged as a promising technology due to their ability to eliminate spectrum scarcity and spectrum under-utilization problems. The physical layer security of such a network with a primary user, a secondary source, a secondary receiver, and an eavesdropper is therefore examined in this work. In this network, secret communication occurs between two reliable secondary peers over the RF and FSO links simultaneously, and the eavesdropper can only overhear the RF link. In particular, the maximum transmits power limitation at the secondary user as well as the permissible interference power restriction at the primary user are also taken into consideration. All the RF and FSO links are modeled with Ī± - Ī¼ fading and MĆ”laga turbulence with link blockage and pointing error impairments. At the receiver, the selection combining diversity technique is utilized to select the signal with the best electrical signal-to-ratio (SNR). Furthermore, to examine the secrecy performance taking into account the effects of each system parameter, closed-form expressions for the secrecy outage probability and effective secrecy throughput are derived. The resultant expressions are finally verified by Monte-Carlo simulations
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