Highly Efficient Quasi 2D Blue Perovskite Electroluminescence Leveraging a Dual Ligand Composition

Perovskite light-emitting diodes (PeLEDs) are advancing because of their superior external quantum efficiencies (EQEs) and color purity. Still, additional work is needed for blue PeLEDs to achieve the same benchmarks as the other visible colors. This study demonstrates an extremely efficient blue PeLED with a 488 nm peak emission, a maximum luminance of 8600 cd m⁻², and a maximum EQE of 12.2% by incorporating the double-sided ethane-1,2-diammonium bromide (EDBr₂) ligand salt along with the long-chain ligand methylphenylammonium chloride (MeCl). The EDBr₂ successfully improves the interaction between 2D perovskite layers by reducing the weak van der Waals interaction and creating a Dion–Jacobson (DJ) structure. Whereas the pristine sample (without EDBr₂) is inhibited by small stacking number (n) 2D phases with nonradiative recombination regions that diminish the PeLED performance, adding EDBr₂ successfully enables better energy transfer from small n phases to larger n phases. As evidenced by photoluminescence (PL), scanning electron microscopy (SEM), and atomic force microscopy (AFM) characterization, EDBr₂ improves the morphology by reduction of pinholes and passivation of defects, subsequently improving the efficiencies and operational lifetimes of quasi-2D blue PeLEDs.     

GENs: generative encoding networks

Machine Learning - Mapping data from and/or onto a known family of distributions has become an important topic in machine learning and data analysis. Deep generative models (e.g., generative...     

Entrepreneurial acquisitions,open innovation and UK high growth SMEs

This paper examines the dynamics of entrepreneurial acquisitions undertaken by UK high growth small and medium enterprises (SMEs). While entrepreneurial acquisitions are increasingly deployed by SMEs, little is known about their antecedents, motivational drivers and organisational outcomes. Drawing on detailed case study evidence from Scotland, the key factor found to be driving these acquisitions was the desire to augment and exploit technological complementarities between the acquiring and acquired firms. Acquisition can therefore be conceptualised as an advanced stage of the outside-in ‘open innovation’ strategies proactively used within these innovative SMEs. Firms executing this strategy typically have an acute propensity for risk, a desire for close customer engagement, effective business models and strong external orientation. The work suggests that greater attention should be paid within M&A theory to the dynamics of these types of smaller scale entrepreneurial acquisitions.     

Detecting Periods of Significant Increased Communication Levels for Subgroups of Targeted Individuals

This paper investigates detecting significant increases in communication patterns and levels between small groups of individuals within a moderate‐size targeted group. Potential applications range from trying to establish emerging thought leaders within an organisation to the detection of the planning stages of a crime. The scan statistic is a popular choice for monitoring and detecting spatio‐temporal outbreaks, but it is difficult to apply to large‐scale target groups because of the computational effort required. When monitoring communication levels between thousands of people, the number of combinations of people whose communication may have increased is very high, and to scan through all of these to find which combinations have increased communications significantly is an enormous task. A successful surveillance plan will have early communication outbreak detection properties and good diagnostic capabilities for identifying individuals contributing to this outbreak. This paper proposes a new computationally feasible approach for detecting communication outbreaks based on exponentially weighted moving average smoothed communication counts between individuals within the network. We apply a cumulative sum of ordered signal‐to‐noise (SN) ratios for communication counts to flag significant departures from their respective median values. This plan is demonstrated to be efficient at detecting changes in communication levels for a small part of the network and diagnosing who is involved in the outbreak. Copyright © 2015 John Wiley & Sons, Ltd.     

Comparison of three-dimensional surface scanning techniques for capturing the external ear

Congenital facial anomalies, such as microtia (malformation of the external ear), lead to significant psychosocial effects starting from early childhood. Three-dimensional (3D) scanning and advanced manufacturing are being investigated as a cheaper and more personalised method of fabricating reconstructive treatments for patients compared to traditional approaches. To date, most case studies have used expensive 3D scanners, yet, there is potential for low-cost devices to provide comparable results. This study aimed to investigate these different approaches. Both ears of 16 adult participants were scanned with three devices: Artec Spider (Artec Group), Intel^® RealSense? (Intel), and the Apple iPhone^® 7 (Apple Inc.) combined with photogrammetry using 90, 60 and 30 photographs. The scanning time, processing time, accuracy, completeness, resolution and repeatability of each technique were assessed using the Artec Spider as a reference scanner. Our results show that the iPhone had the longest processing time however, this decreased nine-fold when reducing the number of photos from 90 to 30. There was no significant difference in the accuracy, completeness or repeatability of the iPhone scans with 90 photographs (1.4?±?0.6?mm, 79.9%, 1.0?±?0.1?mm), 60 photographs (1.2?±?0.2, 79.3%, 0.9?±?0.2?mm) or 30 photographs (1.2?±?0.3?mm, 74.3%, 1.0?±?0.2?mm). The Intel RealSesne performed significantly worse in each parameter (1.8?±?03?mm; 46.6%, 1.4?±?0.5). Additionally, the RealSense had significantly lower resolution with not enough detail captured for the application. These results demonstrate that the ear can be accurately 3D scanned using iPhone photographs. We would recommend capturing between 30 and 60 photographs of the ear to create a scan that is accurate but without the downfall of long processing time. Using these methods we aim to provide a more comfortable setting for the patient and a lower-cost and more personalised ear prosthesis.     

Wearable computers as a virtual environment interface for people with visual impairment

People who are totally blind or who have vevere visual impairments (e.g. less than 20/200 acuity, central macular scotomas, or advanced diabetic retinopathy) see the environment in a fashion that may be completely foreign to those who operate in a very visual fashion. For this population, the visual complexity of the environment is not a concern. What is of concern are salient features found within the environment that relate to their ability to navigate successfully in, and/or interact with, the environment as needed. Toward the purpose of representing these salient features in comprehensive form, investigators at the Atlanta Veterans Affairs Research and Development Center are employing wearable computer technology to develop a virtual environment interface. The long-range goal is to create a simplistic virtual representation of the environment that includes only features related to the current navigational task and/or interactive needs of the person. In a completed study, the use of digital infrared transmitters as beacons representing salient features of the environment was explored. The purpose of a current study now in progress is to evaluate and compare various user interface structures that were suggested by subjects during the preliminary study. The problem of interest in the current study is street-crossing; however, the results of this research should be applicable to many other problems, including identifying and locating building entrances, and identifying, locating and interacting with electronic devices such as information kiosks, automated teller machines, and self-serve point-of-sale terminals. The long-range result desired is a wearable computer with which one can easily identify and interact with a wide variety of devices in the environment via one familiar, easy-to-use interface.     

Comparison of paper-and-pencil versus Web administration of the Youth Risk Behavior Survey (YRBS): Participation,data quality,and perceived privacy and anonymity

The Youth Risk Behavior Surveillance System (YRBSS) monitors priority health-risk behaviors among US high school students. To better understand the ramifications of changing the YRBSS from paper-and-pencil to Web administration, in 2008 the Centers for Disease Control and Prevention conducted a study comparing these two modes of administration. Eighty-five schools in 15 states agreed to participate in the study. Within each participating school, four classrooms of students in grades 9 or 10 were randomly assigned to complete the Youth Risk Behavior Survey questionnaire in one of four conditions (in-class paper-and-pencil, in-class Web without programmed skip patterns, in-class Web with programmed skip patterns, and “on your own” Web without programmed skip patterns). Findings included less missing data for the paper-and-pencil condition (1.5% vs. 5.3%, 4.4%, 6.4%; p < .001), less perceived privacy and anonymity among respondents for the in-class Web conditions, and a lower response rate for the “on your own” Web condition than for in-class administration by either mode (28.0% vs. 91.2%, 90.1%, 91.4%; p < .001). Although Web administration might be useful for some surveys, these findings do not favor the use of a Web survey for the YRBSS.     

Linear-Time Recognition of Helly Circular-Arc Models and Graphs

A circular-arc model ℳ is a circle C together with a collection A\mathcal{A} of arcs of C. If A\mathcal{A} satisfies the Helly Property then ℳ is a Helly circular-arc model. A (Helly) circular-arc graph is the intersection graph of a (Helly) circular-arc model. Circular-arc graphs and their subclasses have been the object of a great deal of attention in the literature. Linear-time recognition algorithms have been described both for the general class and for some of its subclasses. However, for Helly circular-arc graphs, the best recognition algorithm is that by Gavril, whose complexity is O(n ³). In this article, we describe different characterizations for Helly circular-arc graphs, including a characterization by forbidden induced subgraphs for the class. The characterizations lead to a linear-time recognition algorithm for recognizing graphs of this class. The algorithm also produces certificates for a negative answer, by exhibiting a forbidden subgraph of it, within this same bound.     

Introducing the IA-64 architecture

Microprocessors continue on the relentless path to provide more performance. Every new innovation in computing-distributed computing on the Internet, data mining, Java programming, and multimedia data streams-requires more cycles and computing power. Even traditional applications such as databases and numerically intensive codes present increasing problem sizes that drive demand for higher performance. Design innovations, compiler technology, manufacturing process improvements, and integrated circuit advances have been driving exponential performance increases in microprocessors. To continue this growth in the future, Hewlett Packard and Intel architects examined barriers in contemporary designs and found that instruction-level parallelism (ILP) can be exploited for further performance increases. This article examines the motivation, operation, and benefits of the major features of IA-64. Intel's IA-64 manual provides a complete specification of the IA-64 architecture