Hasil untuk "Technology"

Dylan Yaga, P. Mell, N. Roby et al.

Blockchains are tamper evident and tamper resistant digital ledgers implemented in a distributed fashion (i.e., without a central repository) and usually without a central authority (i.e., a bank, company, or government). At their basic level, they enable a community of users to record transactions in a shared ledger within that community, such that under normal operation of the blockchain network no transaction can be changed once published. This document provides a high-level technical overview of blockchain technology. The purpose is to help readers understand how blockchain technology works.

Bing Wu, Xiaohui Chen

A. Manthiram

Lithium ion batteries as a power source are dominating in portable electronics, penetrating the electric vehicle market, and on the verge of entering the utility market for grid-energy storage. Depending on the application, trade-offs among the various performance parameters—energy, power, cycle life, cost, safety, and environmental impact—are often needed, which are linked to severe materials chemistry challenges. The current lithium ion battery technology is based on insertion-reaction electrodes and organic liquid electrolytes. With an aim to increase the energy density or optimize the other performance parameters, new electrode materials based on both insertion reaction and dominantly conversion reaction along with solid electrolytes and lithium metal anode are being intensively pursued. This article presents an outlook on lithium ion technology by providing first the current status and then the progress and challenges with the ongoing approaches. In light of the formidable challenges with some of the approaches, the article finally points out practically viable near-term strategies.

D. Yeo, T. Murthy

Coronavirus disease 2019 (COVID-19) is a newly emerging human infectious disease that causes severe respiratory distress. The COVID-19 reproductive number is highly infectious, spreading to ≥2.2, yet no drugs or vaccines are available. SARS-CoV-2—the virus causing COVID-19— has been found to be more similar to SARS-CoV than MERS-CoV (Middle East respiratory syndrome coronavirus). Like SARS-CoV, SARS-CoV-2 uses angiotensin-converting enzyme 2 (ACE2) for efficient cell entry. SARS-CoV-2 uses its spike (S) protein to bind with the ACE2 for efficient cellular entry. Currently, real-time reverse transcription (RT) PCR is the chief method to detect SARS-CoV-2. RT-PCR requires the extraction of viral RNA, taking at least 3–4 h to process. It has several limitations, including the requirement for RNA preparation that could affect diagnostic accuracy. Field-effect transistor (FET) biosensing can sensitively and instantaneously measure minute quantities of analytes. Graphene-based FET biosensors can detect changes on their surface, allowing ultrasensitive and low-noise detection, making it attractive for sensitive antibody-based diagnosis. The authors develop a FET biosensor by functionalizing graphene with anti-S antibodies. Prior to functionalizing, the anti-S antibody enabled detection of SARS-CoV-2 using an enzyme-linked immunosorbent assay (ELISA), but not the MERS-CoV S protein or bovine serum albumin (BSA), up to a detection limit (LOD) of 4 ng/mL. Successful immobilization of antibodies resulted in a decrease in the currentvoltage slope characteristics. Further characterization suggests that FET biosensing provides reliable detection signal characteristics for their target analytes. The FET biosensor was ultrasensitive, able to detect as low as 1 fg/mL of SARS-CoV-2 S protein in saline solution, which was substantially lower than detection using an ELISA format. Removal of the antibody and MERS-CoV S proteins generated negligible signal—demonstrating the specificity of the FET biosensor. The authors then propagated SARSCoV-2 in culture, demonstrating an LOD of 16 PFU/mL with 4 logs of linear signal response. Finally, the authors compared samples from infected and uninfected individuals in diluted samples containing as few as 242 copies/mL. Further optimization would be necessary to reduce signal noise. Thus, the FET biosensor is suitable for SARS-CoV-2 detection over a large dynamic range without sample processing. Such biosensing technologies show sufficient specificity and sensitivity and could be adapted to identify emerging infectious disease threats. (Seo, G.; et al. ACS Nano 2020, 14, 5135–5142.)

M. Brongersma, N. Halas, P. Nordlander

Melissa Bond, Katja Buntins, S. Bedenlier et al.

Digital technology has become a central aspect of higher education, inherently affecting all aspects of the student experience. It has also been linked to an increase in behavioural, affective and cognitive student engagement, the facilitation of which is a central concern of educators. In order to delineate the complex nexus of technology and student engagement, this article systematically maps research from 243 studies published between 2007 and 2016. Research within the corpus was predominantly undertaken within the United States and the United Kingdom, with only limited research undertaken in the Global South, and largely focused on the fields of Arts & Humanities, Education, and Natural Sciences, Mathematics & Statistics. Studies most often used quantitative methods, followed by mixed methods, with little qualitative research methods employed. Few studies provided a definition of student engagement, and less than half were guided by a theoretical framework. The courses investigated used blended learning and text-based tools (e.g. discussion forums) most often, with undergraduate students as the primary target group. Stemming from the use of educational technology, behavioural engagement was by far the most often identified dimension, followed by affective and cognitive engagement. This mapping article provides the grounds for further exploration into discipline-specific use of technology to foster student engagement.

S. A. Kamal, Muhammad Imtiaz Shafiq, Muhammad Imtiaz Shafiq et al.

Abstract Background Developing countries around the globe are striving continuously to provide free access to health care services. Telemedicine services represent a significantly increasing form of an adequate health care delivery mechanism in developing countries. Research objective This research study was aimed at investigating the factors influencing the acceptance of telemedicine services among the rural population of Pakistan. Technology Acceptance Model (TAM) was used as a theoretical framework for this research, with the inclusion of several other antecedents. Research method A face-to-face survey method was used to collect research data from 275 participants. The data were analyzed using Partial Least Squares (PLS) method. Results The findings suggest that usage intention of telemedicine services is a function of perceived ease of use, technological anxiety, social influence, perceived ease of usefulness, trust, facilitating conditions, perceived risk, and resistance to technology. Conclusions This research study confirms the applicability of TAM with the inclusion of additional variables to model the adoption of telemedicine services in developing countries. The study offers valuable information for policymakers and health service providers for understanding the facilitators and inhibitors influencing the large scale implementation of telemedicine services. The research findings regarding factors including perceived risk, trust, facilitating conditions and resistance to change can aid in the design and adequate provision of telemedicine services in developing countries.

Peggy A. Ertmer, Anne T. Ottenbreit-Leftwich, Olgun Sadik et al.

Flávio Cunha, James J. Heckman, Susanne M. Schennach

This paper formulates and estimates multistage production functions for child cognitive and noncognitive skills. Output is determined by parental environments and investments at different stages of childhood. We estimate the elasticity of substitution between investments in one period and stocks of skills in that period to assess the benefits of early investment in children compared to later remediation. We establish nonparametric identification of a general class of nonlinear factor models. A by-product of our approach is a framework for evaluating childhood interventions that does not rely on arbitrarily scaled test scores as outputs and recognizes the differential effects of skills in different tasks. Using the estimated technology, we determine optimal targeting of interventions to children with different parental and personal birth endowments. Substitutability decreases in later stages of the life cycle for the production of cognitive skills. It increases in later stages of the life cycle for the production of noncognitive skills. This finding has important implications for the design of policies that target the disadvantaged. For some configurations of disadvantage and outcomes, it is optimal to invest relatively more in the later stages of childhood.

J. Lehmann, S. Joseph

W. Orlikowski, S. Scott

K. Hew, T. Brush

R. Bagozzi

E. Nainar, Khekiye Aye, Reenamol T.X et al.

M. Katz, C. Shapiro

Kiam Heong Ang, G. Chong, Yun Li

J. Gaĺı

Gabriel M. Rebeiz

W. Vielstich, A. Lamm, H. Gasteiger

Demet Bağıran Özşeker, Hülya Kurgun, Özen Kırant Yozcu

The goal of the present paper is to identify the effects of service employees’ technology readiness on technology acceptance in TAV Airports Holding, Izmir Adnan Menderes Airport. In our study we combined the technology readiness index (TRI) and the Technology Acceptance Model (TAM) into one model. Specifically, we measured the relation between TRIs personality trait dimensions – optimism, innovativeness, discomfort, and insecurity – and the cognitive dimensions of TAM. Also, the demographics of the employees were examined to determine the effect of demographics on the technology readiness and technology acceptance level. TRI (Parasuraman & Colby, 2015) and TAM (Davis, 1989) were adapted to measure employees’ propensity to embrace and use cutting-edge high technologies. The data were collected from 300 employees of a multisite tourism service provider. Analysis revealed that personality traits had the expected impact on user perceptions. The results of the study showed that personal optimism and innovativeness (motivators) positively influenced perceived usefulness and perceived ease of use, but discomfort and insecurity (inhibitors) in a negative relationship with them. Surprisingly, while insecurity had no impact on perceived usefulness, discomfort had no impact on perceived ease of use.