Laptop Research Articles

Musculoskeletal disorders and functional characteristics of the neck and shoulder: Comparison between office workers using a laptop or desktop computer.

Using a laptop for work is gaining rapid popularity, but there is little evidence of how it influences musculoskeletal disorders (MSDs) and functional characteristics of the neck and shoulder area. This study aimed to compare the prevalence of upper body MSDs and functional characteristics of the neck between office workers using a laptop or desktop computer. A total of 110 office workers with a mean age of 41±10 years participated. 45 office workers (73% female) used a laptop and 65 office workers (86% female) used desktop computers. The prevalence of MSDs was recorded using the Nordic Musculoskeletal Questionnaire. Active range of motion (AROM), maximal voluntary isometric contraction (MVC) force, joint position error (JPE), and pain-pressure threshold (PPT) of the neck and shoulder area were measured. Laptop users experienced significantly more MSDs in the right shoulder area on the day of participation (p < 0.001, OR = 4.47), during the previous 7 days (p < 0.01, OR = 3.74), and at 6 months (p < 0.01, OR = 3.57). Laptop users also experienced significantly more MSDs in the left shoulder during the previous 7 days (p < 0.05, OR = 2.44). There were no statistically significant differences in any of the functional characteristics of the neck and shoulder area between the groups. Using the laptop computer for office work may pose a higher risk of developing MSDs in the right shoulder area, but might not have long-term effects on the functional characteristics of the neck and shoulder area.

Exploring the Didactics of Learning in Technology-Rich Environments for Teacher Educators amidst Covid-19 Pandemic in Uganda

This study was conducted on Teacher Educators in National Teachers’ Colleges found in the Northern (West-Nile) and South-Eastern Uganda. It focused on didactical questions to help teacher educators explore what it is that creates technology-rich environments to trainees. It was also anchored on a wide range of literature review. It adopted a phenomenological design with a qualitative approach of using interviews and Focus Group Discussions. Three specific objectives were used, namely to: (i). Assess how teacher educators implement technology-enhanced learning (ii). Establish the availability of Technology-enhanced learning tools used (iii). Identify challenges of Technology-enhanced learning in NTCs in Uganda. Participants were Sixty-four (64) in the study. Data was collected and analysed qualitatively using verbatim statements backed with direct quotations of participants. The findings of the study revealed that majority were short of ICT skills to conduct online teaching. The commonest tools were mobile phones because majority could access them as compared to Desktop and Laptop computers. In addition, blending of content and pedagogy was highly challenging, there was inadequate prior knowledge and skills in using ICT applications, coupled with network and unreliable power supply. Institution-based training through CPDs and peer mentorship are recommended in addition to the paradigm shift from teacher-centredness to learner-centredness

Grade 9 teachers’ experience of digital technologies in the classroom

The use of digital technologies in the classroom has escalated, especially during the COVID-19 pandemic. Although technology and teacher development centres are available for teachers to use, they are often not optimally utilised. This study used explorative qualitative case study methodologies to understand Grade 9 teachers’ use of digital technologies as they integrate it into their lessons and classrooms. Seven teachers were purposely selected to be sources of data collection. Framed by the Technological Pedagogical and Content Knowledge (TPACK) framework, data was generated using semi-structured interviews to explore the Grade 9 teachers’ experiences and views on the integration of digital technology post the outbreak of the COVID-19 pandemic. To analyse the data, a thematic analysis was conducted. Although the findings show limited digital technology integration, some teachers are found to be using videos, projectors, and laptop computers in their classrooms. Inadequate infrastructure and lack of support contribute and impact teachers’ experience of integrating digital technology in the Grade 9 classroom.

Block-based state-expanded network models for multi-activity shift scheduling

This paper presents new mixed-integer linear programming formulations for multi-activity shift scheduling problems (MASSP). In these formulations, the rules governing shift feasibility are encoded in block-based state-expanded networks in which nodes are associated with states and arcs represent assignments of blocks of work or break periods inducing state transitions. A key advantage of these formulations is that for the anonymous MASSP in which all employees are considered as equal only a single network with integer flow variables is needed as long as the network encodes all shift composition rules. A challenging aspect is that the networks can become very large, yielding huge models that are hard to solve for large problem instances. To address this challenge, this paper proposes two exact modeling techniques that substantially reduce the size of the model instances: First, it introduces a set of aggregate side constraints enforcing that an integer flow solution can be decomposed into paths representing feasible shifts. Second, it proposes to decouple the shift composition from the assignment of concrete activities to blocks of work periods, thereby removing a large amount of symmetry from the original model. In a computational study with two MASSP instance sets from the literature dealing with shift scheduling problems, we demonstrate the effectiveness of these techniques for reducing the both size of the model instances and the solution time: We are able to solve all instances, including more than 70 previously open instances, to optimality–the vast majority of them in less than 30 min on a notebook computer.

OpenDroneMap: Multi-Platform Performance Analysis

This paper analyzes the performance of the open-source OpenDroneMap image processing software (ODM) across multiple platforms. We tested desktop and laptop computers as well as high-performance cloud computing and supercomputers. Multiple machine configurations (CPU cores and memory) were used. We used eBee S.O.D.A. drone image datasets from Namibia and northern Finland. For testing, we used the OpenDroneMap command line tool with default settings and the fast orthophoto option, which produced a good quality orthomosaic. We also used the “rerun-all option” to ensure that all jobs started from the same point. Our results show that ODM processing time is dependent upon the number of images, a high number of which can lead to high memory demands, with low memory leading to an excessively long processing time. Adding additional CPU cores is beneficial to ODM up to a certain limit. A 20-core machine seems optimal for a dataset of about 1000 images, although 10 cores will result only in slightly longer processing times. We did not find any indication of improvement when processing larger datasets using 40-core machines. For 1000 images, 64 GB memory seems to be sufficient, but for larger datasets of about 8000 images, higher memory of up to 256 GB is required for efficient processing. ODM can use GPU acceleration, at least in some processing stages, reducing processing time. In comparison to commercial software, ODM seems to be slower, but the created orthomosaics are of equal quality.

Joint Gramian inversion of gravity, magnetic and gravity gradient tensor data for the modelling of Mesoproterozoic iron oxide deposits, southeast Missouri, USA

SUMMARY Within the iron metallogenic province of southeast Missouri, USA, there are several mines that contain not only economic iron resources, magnetite and/or hematite, but also contain rare earth elements, copper and gold. An area including three major deposits, Pea Ridge, Bourbon and Kratz Spring, was selected for detailed modelling for the upper crustal magnetic susceptibility and density structures. For the study area, ground gravity and high-resolution airborne magnetic and gravity gradiometry data sets are available. An efficient and novel joint inversion algorithm for the simultaneous inversion of these multiple data sets is presented. The Gramian coupling constraint is used to correlate the reconstructed density and magnetic susceptibility models. The implementation relies on the structures of the sensitivity matrices and an efficient minimization algorithm to achieve significant reductions in the memory requirements and computational costs. Consequently, it is feasible to use a laptop computer for the inversion of multiple data sets, each containing thousands of data points, for the recovery of models on the study area, each including approximately one million model parameters. This is the first time that these multiple data sets have been simultaneously inverted for this area. The L1-norm stabilizer is used to provide compact and focused images of the ore deposits. For contrast, independent inversions of each data set are also discussed. In general, our results provide new insights about the concealed ore deposits in the Mesoproterozoic basement rocks of southeast Missouri. Both short- and long-wavelength anomalies exist in the recovered models; these provide a high-resolution image of the subsurface. The geometry and physical properties of the known deposits are determined very well. Additionally, some unknown concealed deposits are revealed; these could be economically valuable and should be considered in future geophysical and geological investigations.

Improved image processing for 3D virtual object construction from serial sections reveals tissue patterns in root tips of Zea mays.

Previously we described methods for generating three-dimensional (3D) virtual reconstructions of plant tissues from transverse thin sections. Here, we report the applicability of longitudinal sections and improved image-processing steps that are simpler to perform and utilize free applications. In order to obtain improved digital images and a virtual 3D object (cuboid), GIMP 2.10 and ImageJ 2.3.0 running on a laptop computer were used. Sectional views of the cuboid and 3D visualization were realized with use of the plug-ins "Volume Viewer" and "3D Viewer" in ImageJ. A 3D object was constructed and sectional views along several cutting planes were generated. The 3D object consisted of selected tissues inside the cuboid that were extracted and visualized from the original section data, and an animated video of the 3D construct was also produced. Virtual cuboids can be constructed by stacking longitudinal images along the transverse depth direction or stacking transverse images vertically along the organ axis, with both generating similar 3D objects. Which to use depends on the purpose of the investigation: if the vertical cell structures need close examination, the former method may be better, but for more general spatial evaluations or for evaluation of organs over longer tissue distances than can be accommodated with longitudinal sectioning, the latter method should be chosen.

Single MCMC chain parallelisation on decision trees

AbstractDecision trees (DT) are highly famous in machine learning and usually acquire state-of-the-art performance. Despite that, well-known variants like CART, ID3, random forest, and boosted trees miss a probabilistic version that encodes prior assumptions about tree structures and shares statistical strength between node parameters. Existing work on Bayesian DT depends on Markov Chain Monte Carlo (MCMC), which can be computationally slow, especially on high dimensional data and expensive proposals. In this study, we propose a method to parallelise a single MCMC DT chain on an average laptop or personal computer that enables us to reduce its run-time through multi-core processing while the results are statistically identical to conventional sequential implementation. We also calculate the theoretical and practical reduction in run time, which can be obtained utilising our method on multi-processor architectures. Experiments showed that we could achieve 18 times faster running time provided that the serial and the parallel implementation are statistically identical.

Motion Artifact Suppression Method for the Clinical Application of Otoscopic Spectral-Domain Optical Coherence Tomography

A compact OCT device and a method for image reconstruction are described. The proposed algorithm contains a novel procedure for motion artifact suppression based on a correction of the phase of the original interferometric signal due to the mutual correlation of adjacent A-scans. This procedure corrects distortions caused by unwanted displacements of the probe relative to the object in real time at a speed of up to 3 mm/s and an image acquisition rate of 20 B-scans per second. All processing is performed in real time using only the CPU, allowing the device to be controlled from a consumer-grade laptop or compact PC without the need for a discrete GPU. Due to its compact size, the device can be used in the conditions of an ENT examination room or operating room and can be freely moved to another room without the help of additional personnel, if necessary.

Assessing embodied carbon emissions of communication user devices by combining approaches

The use of information and communication technologies are increasing in society. Carbon emissions can be found throughout the entire life cycle of access networks, data centers and communication user devices. The focus of this study is the embodied carbon emissions of user devices associated with accessing networks, hence tablets, smartphones and feature phones, laptop and desktop PCs, PC displays and customer premises equipment (CPEs). The purpose is to investigate the embodied carbon emissions by applying different approaches: i) the commonly used approach where estimated product carbon emissions are scaled up by shipments, ii) allocation of the electronic sector companies’ reported data combined with materials data for the products, and iii) the upstream carbon emissions reported by user device vendors (final manufacturers). Despite its sensitivity to allocation the second approach is considered to give the most reasonable overall result of about 180 million tonnes carbon dioxide equivalents (CO2e) related to chosen user device types and shipments in 2020. Underreporting of scope 3 in the data sources of the vendors, and sensitivity to specific product data sets with very high display values are two major concerns of the other approaches. Representative embodied emissions for user devices are derived for 2020: 50 kg CO2e for a smartphone, 20 kg CO2e for a feature phone, 100 kg CO2e for a tablet, 200 kg CO2e for a laptop, 350 kg CO2e for a desktop PC, 100 kg CO2e for a PC display and 30 kg CO2e for a CPE.

An improved probability-based discrete particle swarm optimization algorithm for solving the product portfolio planning problem

Product Portfolio Planning (PPP) is one of the most critical decisions for companies to gain an edge in the competitive market. It seeks for the optimal combination of products and attribute levels offered for customers in the target market, which is a NP-hard combinatorial optimization problem. In this paper, a Probability-based Discrete Particle Swarm Optimization (PDPSO) algorithm is proposed to solve the PPP problem. In PDPSO, the particle is encoded as discrete values, which can be straightforwardly used to represent the product portfolio with discrete attributes. PDPSO adopts a probability-based mechanism to update particles. Specifically, a probability vector is used to decide the probability of three search behaviors, i.e., learning from the personal best position, global best position, or random search. In experiments, the search performance of PDPSO has been compared with that of a Genetic Algorithm (GA) and a Simulated Annealing (SA) algorithm on generated PPP problem cases with different sizes. The results indicate that PDPSO obtains significantly better optimization results than GA and SA in most cases and obtains desirable/near-optimal solutions on various PPP problem cases. A case study of notebook computer portfolio planning is also presented to illustrate the efficiency and effectiveness of PDPSO.

Chebyshev-series solutions for nonlinear systems with hypersonic gliding trajectory example

In order to design a drag-based predictor-corrector entry guidance in the future, new analytical formulae, expressed as finite-term Chebyshev series, are developed for fast predicting a three-dimensional (3D) Hypersonic Gliding Trajectory (HGT) by proposing a Newton-like method to solve a highly nonlinear entry dynamics model. Specifically, first, a new reduced-order dynamics model is developed by properly simplifying the original dynamics model such that the drag acceleration (AD) and the ratio of the horizontal component of the lift to the drag (LDz), which are important for governing the 3D trajectory, emerge as key parameters of the dynamical equations. Then, AD and LDz are planned as polynomials of speed. However, the simplified model is still not easy to solve due to its high nonlinearity. To deal with the difficulty, a Newton-like method is proposed to transform the simplified model into Linear Differential Recurrence Equations (LDREs). By evaluating the LDREs repeatedly, a sequence of approximations of the 3D HGT can be generated, the limit of which is the trajectory specified by that simplified model. In fact, due to the fast convergence speed of the Newton-like method, the LDREs need be solved only twice to achieve high accuracy. By using Chebyshev series to approximate some complex terms appearing in the LDREs, the LDREs become analytically solvable. As a result, the approximate analytical solutions to the 3D HGT are obtained. Simulation results show that the analytical solutions need to consume less than 1 ms of time on a laptop computer and have errors of less than 4 percentage. The computational efficiency is fundamental for onboard predictor-corrector guidance.

63‐1: Integrated ultra‐thin direct‐lit LCD backlight using glass components

In this paper we present the results of development of a backlight in which a single glass plate serves as both a light guide and a core of the printed circuit delivering current to the mini‐LED light sources. The backlight integrates a patterned glass diffuser (PGD) and a glass printed circuit board (GCB). The integrated backlight has the advantages of exceptional thinness, reduced component count and weight, very low thermal expansion, fixed registration, and improved heat dissipation, making it uniquely suitable for portable displays such as those in tablet or laptop computers. An early prototype had a total thickness of 2.5 mm and demonstrated luminance uniformity better than 98.5%. In the future versions, we project that the thickness can be further reduced to 1.5 mm, while keeping all the advantages of direct‐lit backlights including high luminance and local dimming capability.

P‐18: Development of Oxide UHD Panel LCD with High Mobility for Notebook PC

We have developed a new oxide BCE technology with high mobility of more than 46 cm2/Vs and used it in a 13.3‐inch 144Hz oxide UHD LCD panel for a Notebook PC. Because of the low carrier concentration of the new oxide materials, the high mobility characteristics can be ensured by using single‐layer materials, and the homogeneity of the prepared short‐channel TFTs is also perfect. They also have reliability PBTS/NBTIS enough to use the application. These results indicate that a variety of backplanes are possible to be made in a single factory of Oxide.

Accessing News in the Digital Era: The Case of Sarawak, Malaysia

news via mobile devices and digital platforms such as search engines and social media. The study examined whether such trends were escalating in the contexts where a large number of people continued to access news from traditional media sources such as TV, news, and print. A survey of 512 respondents living in Sarawak, Malaysia was conducted (33.8% rural, 10% suburban, and 56.2% urban). The results showed that the mobile gadgets most commonly used to access news are smartphones (49%) and 29.5% of respondents used both smartphones and laptop computers to read the news. The streaming device most frequently used to get news was Chromecast with Google TV. A majority of the respondents read online newspapers but they mostly read free news. Only 21.7% subscribed to online news portals. A comparison showed that online newspaper was gaining popularity over printed newspapers, and the use of live news streaming, news video, and podcast was on the rise. The study revealed that 19.3% did not use any gadgets to read the news, and they relied on traditional forms such as TV, printed newspapers, and radio. The most popular TV news channels for the Sarawakians were TV3 Media Prima and the newly established TV Sarawak. Among pay TV, Astro was popular. The study showed the appeal of mainstream news outlets to satisfy the news needs of Sarawakian viewers for updates on daily news, local news, and breaking news in the digital era.

Compact and portable quantum sensor module using diamond NV centers

We developed a compact and portable measuring instrument using diamond NV centers that operates on the USB 3.0 power supply of a laptop computer. Its portability is achieved by the low power consumption of the optics, realized by the diamond corner cube that enhanced the current of the photodiode to 2.1 times higher than that of the planar diamond, and that of the microwave source, reduced by 20 dB, which was realized by a microwave resonator using a λ/4 open stub that strongly magnetically drives the NV center. These results contribute to the social implementation of diamond sensors.

Validity, Reliability, and Measurement Error of the Remote Fugl-Meyer Assessment by Videoconferencing: Tele-FMA.

The objective of this study was to investigate the validity, reliability, and measurement error of the Fugl-Meyer Assessment (FMA) when it was administered remotely by videoconferencing (Tele-FMA) and to describe barriers to remote administration of the FMA. Forty-five participants who had strokes and had a smartphone or laptop computer with a camera and internet access were included. An in-person assessment was compared to a remote assessment in 11 participants, and 34 participants completed only the remote assessment. Rater 1 remotely administered, recorded, and scored the items of the FMA, after which the recording was forwarded to be scored by Rater 2. At least 7days later, rater 1 rated the videorecording of the remote assessment a second time for the evaluation of intrarater reliability. In-person assessment was completed by rater 1 at the participant's home. Criterion validity was analyzed using the Bland-Altman limits of agreement, and convergent validity was analyzed using Spearman correlation coefficient. The intrarater and interrater reliability was analyzed using the intraclass correlation coefficient, and individual items were analyzed using the weighted kappa. The standard error of measurement (SEM) and minimal detectable change (MDC) were calculated to evaluate the measurement error. Bland-Altman plots showed adequate agreement of in-person FMA and tele-FMA. A moderate positive correlation was found between Tele-FMA lower extremity (LE) scores and step test results, and a strong positive correlation was found between Tele-FMA-upper extremity (UE) and Stroke Impact Scale hand function domain. Significant and excellent (0.96 ≤ ICC ≤ 0.99) interrater and intrarater reliabilities of the Tele-FMA, Tele-FMA-UE, and tele-FMA-LE were found. Regarding the individual items, most showed excellent reliability (weighted kappa >0.70). The SEM for both reliabilities was small (≤3.1 points). The MDC95 for both the Tele-FMA and Tele-FMA-UE was 2.5 points, whereas it was 1.3 points for the Tele-FMA-LE. Tele-FMA has excellent intrarater and interrater reliability and should be considered as a valid measurement. The FMA is widely used in clinical practice. However, the measurement properties of the remote version applied by videoconferencing were unknown. This study's results demonstrate the validity and reliability of the Tele-FMA for assessing poststroke motor impairment remotely via videoconferencing. The Tele-FMA may be used to implement telerehabilitation in clinical practice.

가구 내 미디어 기기 구매와 폐기 분석: 집단 의사결정의 개인화에 대하여

Personalization is one of the keywords that has been gaining more attention in recent years. As times change, individual targeted media devices and media content are produced, which has led to a change in the composition of media devices in households. Now that personalization is accelerating, this study focuses on TVs, desktop computers, laptops, and tablet PCs to see what changes are made in determining the purchase and disposal of media devices at the household level. This study analyzed the household"s purchase and disposal of media devices using the intrahousehold utility model. As a result, the decisions of households to purchase the media purchasing device in all devices were personalized compared to the decisions to increase the amount of possession by purchasing. We also confirmed that over time, most of the device"s purchase and disposal decisions are becoming personalized, and this trend is most pronounced in laptop and tablet PC disposal decisions. In addition, 3,200 households of three-person households were analyzed on what changes would occur in the decision process within the household when one household member was separated from the three-person household in a situation where the number of single-person households is increasing. As the average number of household members decreases and the number of single-person households increases, TV and tablet PC holdings are expected to increase, and desktop PCs and laptops are expected to decrease.

Experimental and numerical investigation of flattened and bent miniature heat pipes with two heat sources for laptop computers

In this study, the combined effects of bending and flattening heat pipes with two heat sources on thermal resistance were numerically and experimentally studied. A composite wick of grooves and fibers was used in the heat pipe to prevent wick damage from the deformation of the heat pipe. The heat pipes were bent up to 90° and flattened to three final thicknesses of 2.5, 3.0 and 4.0 mm. Two discrete heat sources were supplied to the heat pipe, with a total heat load of 40 W. It was observed that not only damage to the composite wick was prevented but also the thermal performance of the heat pipe was slightly enhanced, particularly when a higher heat load was placed farther from the condenser. Bending the 3 mm final thickness heat pipe from 0° to 90° led to a 40.8% reduction in thermal resistance when supplying evaporator section 1 (located farthest from the condenser) at 30 W and a 25% reduction for another case when supplying 10 W at evaporator section 1. The mathematical models, generally used in previous studies, predicted the thermal resistance unsatisfactorily with a relative root mean square error of up to 70.74% compared with the experimental results. In this study, a novel mathematical model was developed to include the existence of liquid receding in the wick, a new concept of the contact factor at the heating surface, and the extension of an absorbable length in the fibrous wick. The proposed model provided a much better agreement with a relative root-mean-square error as low as 23.68%. Thus, the proposed mathematical model can provide better predictions of the thermal performance of the groove–fiber wick heat pipe.

Reactive Message Passing for Scalable Bayesian Inference

We introduce reactive message passing (RMP) as a framework for executing schedule-free, scalable, and, potentially, more robust message passing-based inference in a factor graph representation of a probabilistic model. RMP is based on the reactive programming style, which only describes how nodes in a factor graph react to changes in connected nodes. We recognize reactive programming as the suitable programming abstraction for message passing-based methods that improve robustness, scalability, and execution time of the inference procedure and are useful for all future implementations of message passing methods. We also present our own implementation ReactiveMP.jl, which is a Julia package for realizing RMP through minimization of a constrained Bethe free energy. By user-defined specification of local form and factorization constraints on the variational posterior distribution, ReactiveMP.jl executes hybrid message passing algorithms including belief propagation, variational message passing, expectation propagation, and expectation maximization update rules. Experimental results demonstrate the great performance of our RMP implementation compared to other Julia packages for Bayesian inference across a range of probabilistic models. In particular, we show that the RMP framework is capable of performing Bayesian inference for large-scale probabilistic state-space models with hundreds of thousands of random variables on a standard laptop computer.