460 research outputs found
Effects of municipal smoke-free ordinances on secondhand smoke exposure in the Republic of Korea
ObjectiveTo reduce premature deaths due to secondhand smoke (SHS) exposure among non-smokers, the Republic of Korea (ROK) adopted changes to the National Health Promotion Act, which allowed local governments to enact municipal ordinances to strengthen their authority to designate smoke-free areas and levy penalty fines. In this study, we examined national trends in SHS exposure after the introduction of these municipal ordinances at the city level in 2010.MethodsWe used interrupted time series analysis to assess whether the trends of SHS exposure in the workplace and at home, and the primary cigarette smoking rate changed following the policy adjustment in the national legislation in ROK. Population-standardized data for selected variables were retrieved from a nationally representative survey dataset and used to study the policy action’s effectiveness.ResultsFollowing the change in the legislation, SHS exposure in the workplace reversed course from an increasing (18% per year) trend prior to the introduction of these smoke-free ordinances to a decreasing (−10% per year) trend after adoption and enforcement of these laws (β2 = 0.18, p-value = 0.07; β3 = −0.10, p-value = 0.02). SHS exposure at home (β2 = 0.10, p-value = 0.09; β3 = −0.03, p-value = 0.14) and the primary cigarette smoking rate (β2 = 0.03, p-value = 0.10; β3 = 0.008, p-value = 0.15) showed no significant changes in the sampled period. Although analyses stratified by sex showed that the allowance of municipal ordinances resulted in reduced SHS exposure in the workplace for both males and females, they did not affect the primary cigarette smoking rate as much, especially among females.ConclusionStrengthening the role of local governments by giving them the authority to enact and enforce penalties on SHS exposure violation helped ROK to reduce SHS exposure in the workplace. However, smoking behaviors and related activities seemed to shift to less restrictive areas such as on the streets and in apartment hallways, negating some of the effects due to these ordinances. Future studies should investigate how smoke-free policies beyond public places can further reduce the SHS exposure in ROK
Accurate quantum transport modelling and epitaxial structure design of high-speed and high-power In0.53Ga0.47As/AlAs double-barrier resonant tunnelling diodes for 300-GHz oscillator sources
Terahertz (THz) wave technology is envisioned as an appealing and conceivable solution in the context of several potential high-impact applications, including sixth generation (6G) and beyond consumer-oriented ultra-broadband multi-gigabit wireless data-links, as well as highresolution imaging, radar, and spectroscopy apparatuses employable in biomedicine, industrial processes, security/defence, and material science. Despite the technological challenges posed by the THz gap, recent scientific advancements suggest the practical viability of THz systems. However, the development of transmitters (Tx) and receivers (Rx) based on compact semiconductor devices operating at THz frequencies is urgently demanded to meet the performance requirements calling from emerging THz applications.
Although several are the promising candidates, including high-speed III-V transistors and photo-diodes, resonant tunnelling diode (RTD) technology offers a compact and high performance option in many practical scenarios. However, the main weakness of the technology is currently represented by the low output power capability of RTD THz Tx, which is mainly caused by the underdeveloped and non-optimal device, as well as circuit, design implementation approaches. Indeed, indium phosphide (InP) RTD devices can nowadays deliver only up to around 1 mW of radio-frequency (RF) power at around 300 GHz. In the context of THz wireless data-links, this severely impacts the Tx performance, limiting communication distance and data transfer capabilities which, at the current time, are of the order of few tens of gigabit per second below around 1 m.
However, recent research studies suggest that several milliwatt of output power are required to achieve bit-rate capabilities of several tens of gigabits per second and beyond, and to reach several metres of communication distance in common operating conditions. Currently, the shortterm target is set to 5−10 mW of output power at around 300 GHz carrier waves, which would allow bit-rates in excess of 100 Gb/s, as well as wireless communications well above 5 m distance, in first-stage short-range scenarios. In order to reach it, maximisation of the RTD highfrequency RF power capability is of utmost importance. Despite that, reliable epitaxial structure design approaches, as well as accurate physical-based numerical simulation tools, aimed at RF power maximisation in the 300 GHz-band are lacking at the current time.
This work aims at proposing practical solutions to address the aforementioned issues. First, a physical-based simulation methodology was developed to accurately and reliably simulate the static current-voltage (IV ) characteristic of indium gallium arsenide/aluminium arsenide (In-GaAs/AlAs) double-barrier RTD devices. The approach relies on the non-equilibrium Green’s function (NEGF) formalism implemented in Silvaco Atlas technology computer-aided design (TCAD) simulation package, requires low computational budget, and allows to correctly model In0.53Ga0.47As/AlAs RTD devices, which are pseudomorphically-grown on lattice-matched to InP substrates, and are commonly employed in oscillators working at around 300 GHz. By selecting the appropriate physical models, and by retrieving the correct materials parameters, together with a suitable discretisation of the associated heterostructure spatial domain through finite-elements, it is shown, by comparing simulation data with experimental results, that the developed numerical approach can reliably compute several quantities of interest that characterise the DC IV curve negative differential resistance (NDR) region, including peak current, peak voltage, and voltage swing, all of which are key parameters in RTD oscillator design.
The demonstrated simulation approach was then used to study the impact of epitaxial structure design parameters, including those characterising the double-barrier quantum well, as well as emitter and collector regions, on the electrical properties of the RTD device. In particular, a comprehensive simulation analysis was conducted, and the retrieved output trends discussed based on the heterostructure band diagram, transmission coefficient energy spectrum, charge distribution, and DC current-density voltage (JV) curve. General design guidelines aimed at enhancing the RTD device maximum RF power gain capability are then deduced and discussed.
To validate the proposed epitaxial design approach, an In0.53Ga0.47As/AlAs double-barrier RTD epitaxial structure providing several milliwatt of RF power was designed by employing the developed simulation methodology, and experimentally-investigated through the microfabrication of RTD devices and subsequent high-frequency characterisation up to 110 GHz. The analysis, which included fabrication optimisation, reveals an expected RF power performance of up to around 5 mW and 10 mW at 300 GHz for 25 μm2 and 49 μm2-large RTD devices, respectively, which is up to five times higher compared to the current state-of-the-art. Finally, in order to prove the practical employability of the proposed RTDs in oscillator circuits realised employing low-cost photo-lithography, both coplanar waveguide and microstrip inductive stubs are designed through a full three-dimensional electromagnetic simulation analysis.
In summary, this work makes and important contribution to the rapidly evolving field of THz RTD technology, and demonstrates the practical feasibility of 300-GHz high-power RTD devices realisation, which will underpin the future development of Tx systems capable of the power levels required in the forthcoming THz applications
30th European Congress on Obesity (ECO 2023)
This is the abstract book of 30th European Congress on Obesity (ECO 2023
Energy Concerns with HPC Systems and Applications
For various reasons including those related to climate changes, {\em energy}
has become a critical concern in all relevant activities and technical designs.
For the specific case of computer activities, the problem is exacerbated with
the emergence and pervasiveness of the so called {\em intelligent devices}.
From the application side, we point out the special topic of {\em Artificial
Intelligence}, who clearly needs an efficient computing support in order to
succeed in its purpose of being a {\em ubiquitous assistant}. There are mainly
two contexts where {\em energy} is one of the top priority concerns: {\em
embedded computing} and {\em supercomputing}. For the former, power consumption
is critical because the amount of energy that is available for the devices is
limited. For the latter, the heat dissipated is a serious source of failure and
the financial cost related to energy is likely to be a significant part of the
maintenance budget. On a single computer, the problem is commonly considered
through the electrical power consumption. This paper, written in the form of a
survey, we depict the landscape of energy concerns in computer activities, both
from the hardware and the software standpoints.Comment: 20 page
Efficiency of logistics processes in a distribution system
Diplomová práce se zabývá efektivitou logistických procesů v distribuční soustavě. Jejím cílem je porovnání efektivity příjmu distribučních kanálů a porovnání efektivity metod používaných při příjmu. Práce nejprve specifikuje základní pojmy jako je logistika a logistický systém, distribuce a e-shop. Skrze provedené měření ve vybrané firmě je vyhodnocování dat provedeno porovnáváním efektivnější metody příjmu. Dle zjištěných výsledků jsou poté navrženy kroky ke zlepšení a je vyhodnocen efektivnější distribuční proces.The diploma thesis deals with the efficiency of logistics processes in the distribution system. Its goal is to compare the effectiveness of receiving distribution channels and the methods used in receiving. The work first specifies basic concepts such as logistics and logistics system, distribution and e-shop. Through the measurement carried out in the selected company, the data is evaluated by comparing the more effective reception method. Based on the results found, steps for improvement are then proposed, and a more efficient distribution process is evaluated.
Formulation of functional materials for inkjet printing: A pathway towards fully 3D printed electronics
Inkjet printing offers a facile route for manufacturing the next generation of electronic devices, by combining the design freedom of additive manufacturing technologies with tuneable properties of functional materials and opportunities for their integration into heterostructures. However, to fully realise this potential, the library of functional materials available for additive manufacturing technologies needs to be expanded. In this review, we summarise current developments in ink formulation strategies, approaches for tailoring the functional properties of inks, and multi-material processing. Material – process – property relationships are reviewed for emerging functional materials, such as polymers, nanomaterials, and composites, with examples of current state-of-the-art devices. The flexibility of combining inkjet deposition with other existing technologies and a variety of substrates is also discussed reviewing current trends in electronics and optoelectronics, including wearable electronics, sensing, and energy applications. The review offers a comprehensive and systematic overview of ink formulations for inkjet deposition of electronic devices, summarising the challenges and perspectives in the advancement of 3D and multi-functional electronic devices and smart electronics
An odontometric biodistance analysis of the Rong and the A'chik
Thesis (M.A.) University of Alaska Fairbanks, 2023Little is known about the population history and genetic affinities of many of the tribal groups of northeastern India, including the Rong and the A'chik. Previous linguistic and genetic studies have suggested that these non-Hindu tribal groups may be descendants of East Asian immigrants. Due to the linguistic and genetic research, cultural differences between the groups, and geographic barriers it was hypothesized that members of these two tribal groups share a population history different from that of ethnic groups of other regions of the subcontinent. This study employs tooth size allocation analysis to test hypotheses concerning the origins of the Rong and the A'chik as well as the nature and extent of odontometric variation found among members of both tribes. The author took measurements of the mesiodistal and buccolingual dimensions of the permanent teeth among 166 A'chik and 185 Rong individuals. The author compared the aforementioned data with measurements obtained among 1,151 members of seven ethnic groups from other regions of South Asia. Group centroids from canonical variates analysis were plotted in three dimensions to assess patterns of similarities among samples. Canonical variates, from both sex-pooled and non-pooled analyses, identify the Rong and A'chik as possessing closer affinities to each other than to members of the other groups, thereby supporting the hypothesis of separate population origins from members of other South Asian ethnic groups. Overall, the results suggest the Rong and A'chik have a different geographic origin than, and little admixture with, the other population groups from elsewhere on the subcontinent.UAF Graduate School, the UAF College of Liberal Arts, and the Alaska NSF EPSCoRChapter 1: Introduction -- Chapter 2: Rationale -- 2.1 Genetic background -- 2.1.1 Genetic variation -- 2.1.2 Heritability -- 2.1.3 Gene flow -- 2.1.4 Genetic drift -- 2.1.5 Mutation -- 2.1.6 Natural selection -- 2.2 Dental anthropology -- 2.2.1 Dental development -- 2.2.2 Field theory and clone model -- 2.2.3 Mouse models -- 2.2.4 Dental genetic variance -- 2.2.5 Fluctuating asymmetry -- 2.2.6 Sexual dimorphism -- 2.3 Biodistance analysis -- 2.3.1 A history and overview of statistical approaches (dentition) -- 2.3.2 Tooth size apportionment. Chapter 3: History and ethnography -- 3.1 Population history -- 3.1.1 Background -- 3.1.2 Early population history of the subcontinent -- 3.1.3 Tibeto-Burman population history of the Northeast -- 3.2 The Rong -- 3.2.1 The People and habitation -- 3.2.2 Kinship and marriage systems -- 3.2.3 Language and religion -- 3.2.4 Economy -- 3.2.5 History of migration -- 3.2.6 Recent history -- 3.3 The A'chik -- 3.3.1 The people and habitation -- 3.3.2 Kinship and marriage systems -- 3.3.3 Language and religion -- 3.3.4 Economy -- 3.3.5 History of migration -- 3.3.6 Recent history. Chapter 4: Description of materials and methods -- 4.1 Materials -- 4.1.1 Exclusions -- 4.2 Methods -- 4.2.1 Data collection -- 4.3 Statistical analysis -- 4.3.1 Inter- and Intra-observer reliability -- 4.3.2 Odontometrics. Chapter 5: Results -- 5.1 Paired-samples t-test and antimeres -- 5.2 Descriptive statistics -- 5.3 EM estimation -- 5.4 Levene's test -- 5.5 Principal components analysis -- 5.6 MANOVA -- 5.7 Canonical variate analysis -- 5.8 Classification matrices -- 5.9 Correlation matrices. Chapter 6: Discussion -- 6.1 Sexual dimorphism -- 6.2 Dental correlations -- 6.3 Tooth size -- 6.4 Residence patterns and limitations -- 6.5 Genetic studies -- 6.6 Linguistic evidence -- 6.7 Rong and A'chik origins. Chapter 7: Conclusions -- 7.1 Future research -- Appendices -- Bibliography
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