Wide Measurement Range Research Articles

Asset and Factor Risk Budgeting: a balanced approach

Portfolio optimization methods have evolved significantly since Markowitz introduced the mean-variance framework in 1952. While the theoretical appeal of this approach is undeniable, its practical implementation poses important challenges, primarily revolving around the intricate task of estimating expected returns. As a result, practitioners and scholars have explored alternative methods that prioritize risk management and diversification. One such approach is Risk Budgeting, where portfolio risk is allocated among assets according to predefined risk budgets. The effectiveness of Risk Budgeting in achieving true diversification can, however, be questioned, given that asset returns are often influenced by a small number of risk factors. From this perspective, one question arises: is it possible to allocate risk at the factor level using the Risk Budgeting approach? First, we introduce a comprehensive framework to address this question by introducing risk measures directly associated with risk factor exposures and demonstrating the desirable mathematical properties of these risk measures, making them suitable for optimization. Then, we propose a novel framework to find portfolios that effectively balance the risk contributions from both assets and factors. Leveraging standard stochastic algorithms, our framework enables the use of a wide range of risk measures to construct diversified portfolios.

DROPLET SIZE DISTRIBUTION OF HIGH-PRESSURE WATER MIST NOZZLES

Determining the particle size distribution of water mist is necessary for a wide range of industrial applications or experimental measurements. Particle size defines the ability of water mist to absorb heat, absorb or scatter heat radiation, inertize the environment, reduce environmental dust, regulate odor, etc. The paper presents the principle of measuring droplet size distribution using laser diffraction and the measurement procedure for four hollow cone water mist nozzles with orifice 400 µm, 500 µm, 600 µm and 1000 µm. The measurements were performed at distances of 25 mm, 50 mm, 75 mm, 100 mm, 125 mm, 150 mm, 175 mm, 200 mm and 225 mm from the orifice of the individual nozzles in the middle of the water mist cone. Further measurements were made 25 mm, 50 mm and 75 mm from the nozzle orifices on the edge of the fog cones. All measurements were performed at a working pressure of 70 bar in a water mist system.

Liberalisation of alcohol policy in Lithuania and the role of public health coalitions: change in policy beliefs and strategy

Purpose This study aims to investigate the role of the public health advocacy coalition (PHC) in the context of policy change. Using the “advocacy coalition framework” theory, this study examines how new ideas and the transformation of the policy subsystem influenced the adaptation of strategy, framing and messaging used by PHC actors. Design/methodology/approach A detailed policy case study was conducted based on a range of primary documents and individual semi-structured interviews (n = 34) with key decision-makers, civil servants, NGO leaders, public health experts and AI representatives. Findings In 2020, the Lithuanian PHC coalition became involved in policy-making with a slightly re-framed strategy, which was based on public health priorities and scientific research evidence. The priorities and relevant activities were aimed at maintaining a wide range of regulative measures. The PHC advocates focused on and prioritised arguments pertaining to the social and economic harms of alcohol. This framework created some ground for policy-influencing action and was important for debates with AI actors. The PHC put a great deal of pressure on Members of Parliament to continue the implementation of evidence-based policies. Originality/value Over two decades, Lithuanian alcohol policy has shifted in waves, from liberalisation to stricter control interventions. The previous wave of strict alcohol policy was effective from the perspective of the measures implemented, and it also reduced alcohol-related harm. In 2020, two liberal and conservative parties focused on a laissez-faire approach to the elimination of some unfavourable restrictions for the alcohol industry (AI).

A hundred years of Pacific halibut management in the context of global events and trends in fisheries management

The Convention for the Preservation of the Halibut Fisheries of the Northern Pacific Ocean, signed between Canada and the United States of America on 2 March 1923 and ratified on 21 October 1924, established the International Fisheries Commission, renamed in 1953 to the International Pacific Halibut Commission (IPHC). It was the first international agreement for joint management of a marine fishery resource and a major milestone for development of modern standards for marine conservation. The IPHC’s centennial year is an opportunity to celebrate a remarkable history of the Commission, but also reflect on challenges that shaped its mission. Born from alarms about overfishing during World War I, the Commission gradually gained authority to implement a wide range of conservation measures through established public confidence in its basis for decisions. This paper explores the evolution of management measures applied to Pacific halibut commercial fishing shaped not only by the changing stock conditions and growing demand for seafood, but also global events and trends in fisheries management. It examines the impact of rapid commercialization of fisheries driven by population growth and technological improvements, establishment of exclusive economic zones and altered access to fishing grounds, and adoption of Agenda 21, which highlighted the importance of balancing environmental, economic, and social aspects in fisheries management. It concludes by discussing the lessons learned over the past century and their implications for future fisheries management, emphasizing the importance of international cooperation, adaptive strategies, and science-based policies in sustaining transboundary fish stocks like the Pacific halibut.

Gas–liquid two-phase flow measurement by using electrical tomography sensors and Venturi

Gas–liquid two-phase flow is characterized by complexity, non-homogeneity and difficulty in modeling. Therefore, traditional measurement methods often struggle to simultaneously meet the requirements of high precision and a wide measurement range. In this context, this study aims to explore an innovative multi-sensor fusion technique to achieve accurate measurement of gas–liquid two-phase flow under full operating conditions. In this study, a combination of three sensors, Venturi, ERT (Electrical Resistance Tomography) and ECT (Electrical Capacitance Tomography), is used to propose a new method based on the fusion of LVF (Liquid-phase Volume Fraction) calculations with flow results. Firstly, the high sensitivity characteristics of ECT and ERT sensors are utilized to obtain spatial distribution information of the flow, which is then used to calculate the LVF. Subsequently, the calculated LVF is combined with the total flow rate measured by the Venturi. Through an established mathematical model, the individual flow rates of the gas and liquid phases are inversely calculated. The results show that the method exhibits high measurement accuracy in different LVF ranges with the relative error controlled within 10%, especially in wet and non-wet gas conditions, which fills the gap of the traditional methods in this field. In addition, the method not only improves the measurement accuracy, but also broadens the measurement range, which meets the diversified needs of complex two-phase flow measurement in the oil and gas industry.

Dual-mode AT-cut quartz resonant pressure sensor for wide pressure and temperature measurement ranges

In this paper, a dual-harmonic-mode excited resonant pressure sensor with an AT-cut all-quartz sensing element was developed to synergistically achieve a wide measurement range for both temperature and pressure, along with a fast transient response. In this device, the excited third overtone mode indicated the applied pressure, while the beat frequency generated by the overtone and fundamental modes was used for self-temperature compensation. At the same time, the sandwiched all-quartz sensitive structure design effectively addressed the limitations associated with narrow pressure and temperature ranges. Especially, the dual-mode self-temperature sensing mechanism has been validated in the subzero temperature range for the first time. Quartz crystal processing techniques were employed to manufacture the sensor, and key performance metrics were characterized. The experimental results demonstrated that the sensor achieved an accuracy of ± 0.015 % full scale (FS) under a pressure range of 0–120 MPa and a temperature range of −40 to 150 °C. The pressure sensitivity of the overtone frequency was quantified as 365 Hz/MPa, and the beat frequency provided a temperature accuracy of 0.4 °C. Additionally, the developed sensor exhibited fast transient response under dynamic pressure and temperature conditions attributed to its self-temperature compensation capability. Thus, this study provides a practical solution for high-pressure measurements across a wide temperature range, combined with excellent transient performance.

Simultaneous Vibration and Temperature Real-Time Monitoring Using Single Fiber Bragg Grating and Free Space Optics

Simultaneous monitoring of temperature and vibration of electromechanical systems, public buildings, and volcanic terrain is an important indicator of preventing accidents. This work showcases the simultaneous temperature and vibration measurement using a single-fiber Bragg grating (FBG) sensor. The concurrent interrogation of vibration and temperature by the FBG sensing system can be integrated with free space optics (FSO), which saves on the costs associated with fiber optic cables and overcomes terrain barriers. Furthermore, the real-time measured vibration frequencies and different temperature levels can be recognized by a deep neural network (DNN) sequential model. In addition to the FSO support, the sensing system can be arranged in multiple sensing locations to form a wide range of measurements, offering a highly cost-effective solution.

Unravelling age-related gait decline in cerebral palsy: insights into physiological changes and functional implications through an observational study—a French study protocol in a laboratory setting

IntroductionCerebral palsy (CP) presents a complex neurodevelopmental disorder with a spectrum of motor impairments stemming from early brain injury. Whereas CP is traditionally viewed as a non-progressive condition, emerging evidence...

The Impact of Human Activities on Corals

Coral reef ecosystems are one of the most vital and dynamic ecosystems on earth, teeming with a diverse array of marine life and playing a crucial role in maintaining the health of the oceans. By delving into the multifaceted impacts of human activities on coral reef ecosystems, this paper examines the devastating consequences of various anthropogenic factors, such as the booming tourism industry, the pervasive microplastic pollution problem, and oil spills and other forms of marine pollution. The protection and restoration of coral reef ecosystems through a wide range of measures provides a safer and healthier habitat for coral reefs, thereby ensuring that coral reefs can continue to play an important role in the marine ecosystem. Only by adopting such a comprehensive and proactive approach can humankind ensure the sustainable use of coral reefs. Furthermore, this article proposes a series of protective measures and strategic improvement plans designed to rehabilitate and restore coral reef ecosystems to their former glory, ensuring their survival for future generations to marvel at and benefit from.

Universal Design in Sustainable Tourism Certification Schemes.

Universal design has played a modest role in Norwegian tourism policy, despite its potential for contributing to a more socially, economically and environmentally sustainable tourism industry. The increased interest in sustainability labeling schemes among tourism actors represents an opportunity to work towards universal design of tourism, provided these schemes encompass universal design criteria. Standards for universal design are important in creating recognizable solutions, not least for visitors who often consume services across different sectors in unfamiliar environments. Against this background, we investigated whether sustainable tourism labeling schemes include suggestions made in standards for universal design. Based on previous research on universal design in the transport sector, a coding structure was constructed and used to analyze a sample of 13 tourism-related standards for universal design and five sustainability labeling schemes used by Norwegian tourism actors. Findings show that labeling schemes for sustainable tourism to a very limited extent incorporate measures described in standards for universal design. Moreover, both labeling schemes and standards are primarily aimed at the physical environment rather than the organizational or social environments, and both dedicate little attention to employees. Nevertheless, standards for universal design comprise a much wider range of measures and user-groups. Integrating them into popular sustainability labeling schemes seems pertinent to raise awareness and foster practices that contribute to improve universal design of tourism.

Wafer-level metal thin film thickness scanning based on multiple probe wavelengths nanosecond transient thermoreflectance

The present metal film thickness (dMetal) measurement methods (e.g., profiler and electron microscope) are not able to simultaneously achieve non-invasion, wide measurement range, high-resolution, and wafer-level scanning. In this work, a dMetal measurement method based on multiple probe wavelengths transient thermoreflectance (MW-TTR) is developed. Through a systematic sensitivity discussion, the guidance for reliable dMetal measurement is illustrated theoretically. The realization of measuring different types of metals (Au, Al, Ni, Ti) is achieved with different wavelengths of probe lights. After the rigorous comparison with profiler and picosecond acoustic measurement, the accuracy of measuring nanosized film is verified (∼1% difference). The fitting uncertainties of dMetal are < 5 % for Au and Al metals. The high-throughput wafer-level scanning measurement, with a spatial resolution of ∼ 50 μm, is also realized by integrating automatic displacement control and deep learning fast predicting model into MW-TTR. Spatial mapping of dMetal is consistent with profiler measurement (∼5% deviation in 2000 μm length).

Intrusion event recognition method for distributed fibre optic sensing systems based on Siamese networks

ABSTRACT Due to its high sensitivity and wide measurement range, the distributed optical fibre sensing system has been widely used in long-distance infrastructure monitoring, where it detects vibration signals caused by external events and provides effective early warnings. Given the complexity and diversity of external intrusion events, traditional closed-set classification methods cannot effectively exclude unknown signals. Open-set recognition methods, on the other hand, involve complex model designs, requiring boundary Algorithms and often the inclusion of information related to unknown classes. In this paper, we combine a Siamese network with a residual network to recognise events in the distributed optical fibre sensing system. Through experiments, by comparing the similarity with data in the database, we not only ensure very high accuracy in closed-set classification but also effectively exclude unknown class signals. Experimental results show that our method successfully rejects unknown class data with a 92% success rate, while maintaining closed-set classification accuracy at an average of 99%. Our approach demonstrates excellent performance.

ACESSIBILIDADE À PESSOA COM DEFICIÊNCIA NOS CARTÓRIOS EXTRAJUDICIAIS

The aim of this article is to discuss the problem of the accessibility for the disabled in extrajudicial notary and registry offices. To fulfill this aim, the article firstly talks about the range of the concept of accessibility, its social relevance, the laws that rules this subject, and the challenges and difficulties faced by people with disabilities. On the other hand, this essay demonstrates that the extrajudicial notary and registry offices have a lot of responsibility towards the Brazilian society, not only because their attributions are public but also due to the relevance of their services – specially in the current moment in which there is a tendency of dejudicialization in Brazil. Therefore, considering the inevitable conclusion that the extrajudicial notary and registry offices must be accessible to people with all kinds of disabilities, the paper will examine the wide range of measures and cautions that these offices should take to achieve this purpose, based on some projects that already exist.

Wheatstone Bridge MEMS Hydrogen Sensor with ppb-Level Detection Limit Based on the Palladium-Gold Alloy.

On some occasions, such as new energy clinics, monitoring the trace hydrogen at the ppb level is necessary. The traditional resistive hydrogen sensors based on the Pd alloys are very difficult to realize such an extremely low detection limit. To achieve a detection limit at the ppb level and also ensure good stability, a MEMS hydrogen sensor was designed in a suspended Wheatstone bridge structure, with all four resistive arms defined on a sputtered Pd-Au alloy thin film. For the Wheatstone bridge sensor, absolute response (Ra) and relative response (Rs) are defined to describe the sensitivity of the sensor, and the effect of annealing temperature on baseline drift is investigated using the baseline zero drift parameter (DBZD). By testing the sensors across a hydrogen concentration range of 20 ppb to 3 v/v%, the optimal annealing temperature (250 °C) and operating temperature (60 °C) were identified. Under these conditions, the sensor exhibited a detection limit as low as 20 ppb with a power consumption of only 4.6 mW. At the same time, the response and recovery times of the sensor were 6 and 19 s, respectively, toward 3 v/v% hydrogen. After testing over a 100-day period, Ra fluctuated only 0.0026%, indicating that the hydrogen sensor had good long-term stability for low-concentration detection. More results also showed that the sensor has good repeatability, selectivity, and humidity resistance. With the wide measurement range (20 ppb to 3 v/v%), the sensor has the potential to meet hydrogen detection requirements in multiple scenarios.

Modification of the method for determining the flow coefficient K of an Iris damper with a flowmeter with consideration for its applicability in a wider measurement range

In industrial practice, among many types of measuring devices, a significant group comprises instruments for measuring velocity as well as single-phase and two-phase flow rates. Due to numerous measurement challenges, manufacturers of such equipment strive to obtain highly accurate measurement results while keeping the devices simple in structure and operation. Several measurement methods meet these criteria. One proposed measurement device based on pressure difference measurement is the commercial Iris damper with a flowmeter. The authors of a notable study conducted research on this flowmeter under atypical flow conditions. Additionally, they modified the method of determining the correction coefficient K for this type of flowmeter, which represents a novelty in their work. The obtained measurement results indicate the possibility of applying this measurement device in a significantly wider range of flow rates than specified by the manufacturer. The investigated Iris flowmeter can be a suitable instrument for measuring gas flow rates up to 600 l/s, while simultaneously exhibiting a measurement uncertainty of 0.5% of the measured value.

High temperature resistant thin film thermocouple prepared based on inkjet printing

Thin film thermocouples (TFTCs) are known for their wide temperature measurement range and high precision, showing significant potential in aerospace and steel metallurgy applications. The lack of effective manufacturing techniques has been a major barrier to their mass production. Inkjet printing, a high-quality thin film additive manufacturing process operating outside vacuum environments, offers a viable solution for large-scale practical applications of TFTCs. We successfully fabricated ITO/In2O3 high-temperature thin film thermocouples on ceramic substrates using inkjet printing technology. We developed a printable ink with excellent fluid characteristics, suitable for constructing the sensitive layer of the thermocouples. The fabricated sensors exhibited outstanding high-temperature stability and reliability, with a maximum measurement temperature exceeding 800 °C, surpassing the upper limits reported in other inkjet-printed temperature sensors. Continuous operation at 800 °C for 8 hours resulted in a low drift rate of 1.53 °C/h. The sensors demonstrated 98.55% high repeatability and 98.7%FS high accuracy across a wide temperature range, with a maximum Seebeck coefficient reaching 111 μV/°C, superior to most other high-temperature thin film sensors reported in literature. These findings show great potential in enhancing the safety of aerospace engineering equipment and ensuring the quality of products in the steel metallurgy industry.

Vacuum Filtration-Coated Silver Electrodes Coupled with Stacked Conductive Multi-Walled Carbon Nanotubes/Mulberry Paper Sensing Layers for a Highly Sensitive and Wide-Range Flexible Pressure Sensor.

Flexible pressure sensors based on paper have attracted considerable attention owing to their good performance, low cost, and environmental friendliness. However, effectively expanding the detection range of paper-based sensors with high sensitivities is still a challenge. Herein, we present a paper-based resistive pressure sensor with a sandwich structure consisting of two electrodes and three sensing layers. The silver nanowires were dispersed deposited on a filter paper substrate using the vacuum filtration coating method to prepare the electrode. And the sensing layer was fabricated by coating carbon nanotubes onto a mulberry paper substrate. Waterborne polyurethane was introduced in the process of preparing the sensing layers to enhance the strength of the interface between the carbon nanotubes and the mulberry paper substrate. Therefore, the designed sensor exhibits a good sensing performance by virtue of the rational structure design and proper material selection. Specifically, the rough surfaces of the sensing layers, porous conductive network of silver nanowires on the electrodes, and the multilayer stacked structure of the sensor collaboratively increase the change in the surface contact area under a pressure load, which improves the sensitivity and extends the sensing range simultaneously. Consequently, the designed sensor exhibits a high sensitivity (up to 6.26 kPa-1), wide measurement range (1000 kPa), low detection limit (~1 Pa), and excellent stability (1000 cycles). All these advantages guarantee that the sensor has potential for applications in smart wearable devices and the Internet of Things.

Arch dam point cloud segmentation based on deep feature learning and normal vector data optimization

Separating the dam body, spillway, and other structures from the point cloud in the dam area is an important step in dam deformation monitoring. Manual segmentation is time consuming and inaccurate. This study proposes a point cloud segmentation neural network model based on normal vector optimization suitable for dam environment: (1) This model utilizes the voxel uniform sampling method of equal length cubes to solve the problem of uneven point cloud density caused by wide range and long-distance measurement during point cloud measurement in dam areas. (2) Designed block input and combined output modules in the model, achieving efficient input of large volume point cloud and eliminating the impact of interpolation points offset during seq2seq model decoding process. (3) In response to the diverse characteristics of point cloud normal vectors presented by vegetation, rock mass, and complex dam structures in the dam area, this paper proposes an adaptive radius plane fitting vector estimation method based on eigenvalue method to improve the accuracy of segmentation. The experiment on the prototype arch dam shows that the proposed normal estimation method improves the classification accuracy of PointNet + + from 96.26 to 98.27%. Compared with the other three normal estimation methods (2-jets, Hough CNN, iterative PCA), the overall accuracy is improved by 0.82%, 1.22%, and 0.22%, and the joint average intersection is improved by 0.0293, 0.0325, and 0.0104. The prototype arch dam experiment shows that our proposed method has a segmentation accuracy of 98.27%. Compared with 2-jets, Hough CNN, and iterative PCA, the overall accuracy has been improved by 0.82%, 1.22%, and 0.22%. This study provides a high-precision segmentation scheme for applications such as deformation detection of dam components based on point clouds.

Degradable Multilayer Fabric Sensor with Wide Detection Range and High Linearity.

Integration of multiple superior features into a single flexible pressure sensor would result in devices with greater versatility and utility. To apply the device to a variety of scenarios and solve the problem of accumulation of e-waste in the environment, it is highly desirable to combine degradability and wide-range linearity characteristics in a single device. Herein, we reported a degradable multilayer fabric (DMF) consisting of an ellipsoidal carbon nanotube (ECNT) and polyvinylpyrrolidone/cellulose acetate electrospun fibers (PEF). The alternative layer-by-layer stacking of the ECNT and PEF notably accelerates the sensitivity toward pressure. The optimized device demonstrated a sensitivity of 3.38 kPa-1 over a wide measurement range from 0.1 to 500 kPa, as well as great mechanical stability over 2000 cycles. A good degradation performance was confirmed by both Fourier transform infrared (FTIR) characterization and decomposition experiments in sodium hydroxide solution. The fabricated sensor is capable of precepting a variety of physiological scenarios including subtle arterial pulse, dancing training, walking postures, and accidental falls. This work throws light onto the fundamental understanding of the mechanical interfacial coupling in piezoresistive materials and provides possibilities for the design and development of on-demand wearable electronics.

“Between formulas and freestyle” – a qualitative analysis of peer tutor preparation and its impact on peer relations

BackgroundPeer tutorials are widely used in medical and health professions education. Some evidence suggests that peer tutorials can have positive effects for student peer tutors and tutees alike. To promote these positive effects, peer tutors are often prepared for their tasks. However, detailed information about this preparation is missing in the literature. The present study thus examines from the tutors’ perspective how peer tutor preparation is conducted, both in interprofessional and uniprofessional contexts, and how this preparation affects peer relations.MethodsA qualitative design was used for the study. For data gathering, three online focus group discussions were conducted with student peer tutors from uniprofessional and interprofessional settings who had a background in health professions. Data were analysed inductively via thematic analysis.ResultsA total of 19 individuals participated in three focus group discussions (n = 6/n = 6/n = 7). From the participants’ perspective, preparation measures were heterogenous. Of a wide range of different measures, some were perceived as more helpful, others as less helpful. In analysing the data, three relevant themes came up which were dereived from the peer tutors’ perspective: roles, eye level, and (self-)trust. All three themes were found to be closely related and appeared to have a direct influence on peer relations. This influence on the learning/teaching process was either positive or negative depending on the respondents’ experiences.ConclusionFrom the peer tutors’ perspective, the preparation they received affected their relationships with their peers in a variety of ways, influenced by the context and the peer tutors’ needs. This finding should be taken into account when planning and implementing future preparatory activities. In addition, further pedagogical considerations and discussions about preparatory activities for peer tutors and their potential impact on social and cognitive congruence are needed.