Increasing Information Density Research Articles

Investigation of a hyperspectral Scanning Laser Optical Tomography setup for label-free cell identification

The development of non-destructive, tomographic imaging systems is a current topic of research in biomedical technologies. One of these technologies is Scanning Laser Optical Tomography (SLOT), which features a highly modular setup with various contrast mechanisms. Extending this technology with new acquisition mechanisms allows us to investigate untreated and non-stained biological samples, leaving their natural biological physiology intact. To enhance the development of SLOT, we aimed to extend the density of information with a significant increase of acquisition channels. This should allow us to investigate samples with unknown emission spectra and even allow for label-fee cell identification. We developed and integrated a hyperspectral module into an existing SLOT system. The adaptations allow for the acquisition of three-dimensional datasets containing a highly increased information density. For validation, artificial test objects were made from fluorescent acrylic and acquired with the new hyperspectral setup. In addition, measurements were made on two different human cell spheroids with an unknown spectra, to test the possibilities of label-free cell identification. The validation measurements of the artificial test target show the expected results. Furthermore, the measurements of the biological cell spheroids show small variations in their tomographic spectrum that allow for label-free cell type differentiation. The results of the biological sample demonstrate the potential of label-free cell identification of the newly developed setup.

Concatenated Bragg grating fiber-optic sensors for simultaneous measurement of curvature, temperature, and axial pressure

Abstract. This paper presents the development and evaluation of four sensors based on multiple fiber Bragg grating (FBG) constellations embedded in a silicon dioxide single-mode fiber (SMF) for simultaneous measurement of pressure, temperature, and bending curvature. We applied dimension and material variations – including core, cladding, and coating dimensions; coating material; and the number and arrangement of the FBGs – to optimize the reflected signal response and increase information density. A bootstrap-aggregated ensemble of decision trees was used to evaluate the sensor signal. The results show that adjusting the cladding-to-coating ratio led to significant improvements in pressure and bending prediction performance. Additionally, two combined FBGs were fabricated to form a fiber Bragg grating Fabry–Pérot interferometer, which enabled the detection of curvature with a root-mean-square error (RMSE) of 0.0034 L mm−1 (R2=1), axial pressure with an RMSE of 0.0564 bar (R2=0.99), and temperature with an RMSE of 0.0265 °C (R2=1). At the time of writing, there is no commercially available instrument that can perform these measurements simultaneously.

Growth of multiferroic γ-BaFe2O4 thin films by Pulsed Electron Deposition technique

Multiferroic materials have attracted significant attention due to their potential to revolutionize logic and memory devices by reducing energy consumption or increasing information density. Barium monoferrite (γ-BaFe2O4 or BaFeO) is a promising lead- and bismuth-free multiferroic material with a stuffed tridymite-like structure, exhibiting both ferroelectricity and antiferromagnetism at room temperature. BaFeO thin films with engineered grain orientation, composition, elastic strain, and magnetic interlayer couplings could open new avenues for novel devices. However, synthesizing the stoichiometric "1–2–4" phase in the BaO-Fe2O3 system remains a challenge. This study focuses on the deposition of pure and crystalline γ-BaFe2O4 thin films using the Pulsed Electron Deposition (PED) method. An analysis of the plasma plume revealed that two main mechanisms govern the dynamics of BaFeO deposition: a congruent ablation process occurring far from thermodynamic equilibrium and an incongruent low-energy evaporation process. The regions of the film with maximized ablative/evaporative ratios are free from the secondary Ba2Fe2O5 phase, suggesting that the thermal evaporative contribution is the primary factor responsible for the out-of-stoichiometry composition. The influence of the substrate type on the structural properties of BaFeO films was also evaluated. It was confirmed that (h00)-oriented BaFeO tends to grow on amorphous quartz and polycrystalline Pt-coated quartz in the 700–800°C temperature range. Conversely, the growth on SiO2/Si leads to the preferential grain orientation along the (0k0) and (0kl) directions by increasing the temperature. These findings demonstrate the potential of PED for producing high-quality γ-BaFe2O4 polycrystalline thin films. A fully heteroepitaxial (h00)-BaFeO/(111)-MgO system was even achieved by depositing on a single-crystal MgO substrate. This unprecedented result paves the way for utilizing such thin films in multiferroic applications, where phase purity, structural orientation, and defect-free structures can be exploited to enhance the magnetoelectric properties of the device.

Efficient design approaches to model CNTFET-based Ternary Schmitt Trigger circuits

Digital computation using radix three offers the benefit of increased information density with less power consumption due to reduced interconnect complexity. Hence this brief presents two architectures for ternary Schmitt trigger designs that are implemented by combining shifting literals, ternary inverters and decoder equivalents using carbon nanotube technology. In the first proposed design, Schmitt trigger hysteresis curves are realized using shifting literals i.e. successor and predecessor cells. The second proposed design employs ternary inverters and a decoder equivalent of intermediate logic level for the implementation. The experimental analysis involves the simulations that are conducted using HSPICE and the standard Stanford CNTFET model. Simulation results confirm that the proposed ternary Schmitt trigger designs outperform in terms of power consumption and power delay product(PDP), showcasing the power reduction average of 75% and PDP reduction average of 79% respectively in comparison to recent counterparts. Moreover, Monte Carlo simulations are conducted to verify the robust operation of proposed designs and lesser deviations are observed in performance parameters towards process variations.

Memristor-Based CMOS Hybrid Circuit Design and Analysis

Electronic memory with ever-increasing storage capacity is always in high demand. Every year, a computer transforms into a smaller, faster, and more reliable device. Memristor is a passive aspect recently developed that is gaining popularity. The non-volatile and small area features of this element are very essential. A Memristor's ability to fabricate around CMOS architectures is a step forward in VLSI design enhancement. When developing a fast multilevel switching device, increasing information density in the same silicon area is a desirable feature. In this design and analysis, a unique memristor-based CMOS inverter is presented. A unique inverter with a nonvolatile output and good performance. This characteristic makes it useful for a substitute inverter as well as an SRAM memory cell that supports input negation for special uses. Memristor-based CMOS design is an emerging concept that targets efficient memory computing systems. Simulations were performed in cadence using a memristor model extracted to analyze and compare power consumption. The analyses of non-volatility, the voltage produced, and the read/write period were performed with cadence virtuoso 130 nm CMOS technology using a power supply voltage of 1.9 V while consuming 35.67 µW, and the delay is 9.235 ps. The comparison with a pure CMOS implementation is promising in terms of power, area and delay significant improvement. Further, the Monte Carlo simulation results using 2000 samples confirmed the total power and delay of the proposed design.

Putting manufacturing on the offensive

The path for elevating the role of manufacturing in the company strategy in the last few decades has been rather clear: Improve the basic production capabilities—typically quality, reliability, lead times, and cost efficiency of production processes. Leading Japanese companies, like Toyota, showed the way. But as many have heeded the advice and followed suit, this approach has become essentially a defensive strategy; you must do it not to fall behind. Has manufacturing lost its potential to create capabilities on which a company's strategy can rest? Our answer is absolutely not. In fact, unlike before, manufacturing has multiple paths for creating a competitive advantage and these paths require development of new and often nontraditional capabilities. We identify five sets of new capabilities, and since it is hard to excel in all of them, we provide a framework for choosing the right mix depending on the company's business strategy. The framework focuses on the implications of two recent trends: increasing information density embedded in products and increasing connectedness of manufacturing processes. We suggest specific mixes of the five groups of capabilities that can support and accelerate a company's strategy to exploit these trends. We use examples from three multinationals to illustrate the process. These new opportunities change the traditional role of manufacturing executives. Their focus will need to shift exceedingly to collaborating and interfacing with colleagues in other functions as well as managing relationships beyond the boundaries of the company.

The Perception Scale for the 7E Model-Based Augmented Reality Enriched Computer Course (7EMAGBAÖ): Validity and Reliability Study

Education, teaching, and learning topics, known to have gained an international dimension with technological developments, are still seen as the most discussed themes and subject to change. It is clear that in the 21st century, the increasing information density, the means of transfer, and the technological adaptation skills of the teacher and the learner are at the forefront, and more efforts are required to develop them. The integration of technologies in education and training is related to the necessity of preparing learners in the most suitable way for future work and lifelong learning within the information society. For this reason, for the COVID-19 pandemic process and thereafter, starting with known education models makes it necessary to enable the development of education, teaching, and learning under better conditions and situations by blending them with technological developments. Everyone has understood the ever-changing and developing universal digital world much better during this pandemic. The 7E model of the Constructivist Learning Theory (CLT), known as the student-centered model based on distance education, has been mandatory for the entire education community during the first global pandemic of the digital age. Augmented Reality (AR) is another web-based technological development that can work in harmony with the 7E model. In the 7E model, the teaching of the lessons was at the forefront since the learners learn by doing, experiencing, and applying, directly participating in the lesson, and sharing opinions. For the present study, a scale was developed to determine the perceptions of the learners about the 7E model-based AR-enriched computer lesson. Validity and reliability studies were also conducted on the data obtained from the developed scale. The scale, which was prepared using a five-point Likert scale, was applied to 400 students who fit the profile of the sample group. A statistical analysis of the results concluded that 26 low-factor loading items should be removed from the questionnaire, and the final version of the 28-item scale was a six-factor structure. The statistical analysis concluded that the scale was suitable for all criteria in terms of validity and reliability. Considering the values revealed in the study, it was concluded that the overall scale (α = 0.932) was highly reliable.

Investigation of Multiple-valued Logic Technologies for Beyond-binary Era

Computing technologies are currently based on the binary logic/number system, which is dependent on the simple on and off switching mechanism of the prevailing transistors. With the exponential increase of data processing and storage needs, there is a strong push to move to a higher radix logic/number system that can eradicate or lessen many limitations of the binary system. Anticipated saturation of Moore’s law and the necessity to increase information density and processing speed in the future micro and nanoelectronic circuits and systems provide a strong background and motivation for the beyond-binary logic system. In this review article, different technologies for Multiple-valued-Logic (MVL) devices and the associated prospects and constraints are discussed. The feasibility of the MVL system in real-world applications rests on resolving two major challenges: (i) development of an efficient mathematical approach to implement the MVL logic using available technologies, and (ii) availability of effective synthesis techniques. This review of different technologies for the MVL system is intended to perform a comprehensive investigation of various MVL technologies and a comparative analysis of the feasible approaches to implement MVL devices, especially ternary logic.

Optical Multilevel Spin Bit Device Using Chiral Quantum Dots.

The technological advancement of data storage is reliant upon the continuous development of faster and denser memory with low power consumption. Recent progress in flash memory has focused on increasing the number of bits per cell to increase information density. In this work an optical multilevel spin bit, based on the chiral induced spin selectivity (CISS) effect, is developed using nanometer sized chiral quantum dots. A double quantum dot architecture is adsorbed on the active area of a Ni based Hall sensor and a nine-state readout is achieved.

Visception: An interactive visual framework for nested visualization design

Nesting is the embedding of charts into the marks of another chart. Related to principles such as Tufte’s rule of utilizing micro/macro readings, nested visualizations have been employed to increase information density, providing compact representations of multi-dimensional and multi-typed data entities. Visual authoring tools are becoming increasingly prevalent, as they make visualization technology accessible to non-expert users such as data journalists, but existing frameworks provide no or only very limited functionality related to the creation of nested visualizations. In this paper, we present an interactive visual approach for the flexible generation of nested multilayer visualizations. Based on a hierarchical representation of nesting relationships coupled with a highly customizable mechanism for specifying data mappings, we contribute a flexible framework that enables defining and editing data-driven multi-level visualizations. As a demonstration of the viability of our framework, we contribute a visual builder for exploring, customizing and switching between different designs, along with example visualizations to demonstrate the range of expression. The resulting system allows for the generation of complex nested charts with a high degree of flexibility and fluidity using a drag and drop interface.

Optimization-based Dielectric Metasurfaces for Angle-Selective Multifunctional Beam Deflection

Synthesization of multiple functionalities over a flat metasurface platform offers a promising approach to achieving integrated photonic devices with minimized footprint. Metasurfaces capable of diverse wavefront shaping according to wavelengths and polarizations have been demonstrated. Here we propose a class of angle-selective metasurfaces, over which beams are reflected following different and independent phase gradients in the light of the beam direction. Such powerful feature is achieved by leveraging the local phase modulation and the non-local lattice diffraction via inverse scattered field and geometry optimization in a monolayer dielectric grating, whereas most of the previous designs utilize the local phase modulation only and operate optimally for a specific angle. Beam combiner/splitter and independent multibeam deflections with up to 4 incident angles are numerically demonstrated respectively at the wavelength of 700 nm. The deflection efficiency is around 45% due to the material loss and the compromise of multi-angle responses. Flexibility of the approach is further validated by additional designs of angle-switchable metagratings as splitter/reflector and transparent/opaque mirror. The proposed designs hold great potential for increasing information density of compact optical components from the degree of freedom of angle.

Deep learning of brain lesion patterns and user-defined clinical and MRI features for predicting conversion to multiple sclerosis from clinically isolated syndrome

Multiple sclerosis (MS) is a neurological disease with an early course that is characterised by attacks of clinical worsening, separated by variable periods of remission. The ability to predict the risk of attacks in a given time frame can be used to identify patients who are likely to benefit from more proactive treatment. We aim to determine whether deep learning can extract latent MS lesion features that, when combined with user-defined radiological and clinical measurements, can predict conversion to MS (defined with criteria that include new T2 lesions, new T1 gadolinium enhancing lesions and/or new clinical relapse) in patients with early MS symptoms (clinically isolated syndrome), a prodromal stage of MS, more accurately than imaging biomarkers that have been used in clinical studies to evaluate overall disease state, such as lesion volume and brain volume. More specifically, we use convolutional neural networks to extract latent MS lesion patterns that are associated with conversion to definite MS (based on the McDonald 2005 criteria) using lesion masks segmented from baseline MR images. The main challenges are that lesion masks are generally sparse and the number of training samples is small relative to the dimensionality of the images. To cope with sparse voxel data, we propose utilising the Euclidean distance transform (EDT) for increasing information density by populating each voxel with a value indicating distance to the closest lesion boundary. To reduce the risk of overfitting resulting from high image dimensionality, we use a synergistic combination of downsampling, unsupervised pretraining and regularisation during training. A detailed analysis of the impact of EDT and unsupervised pretraining is presented. In contrast to our previous work, which only used automatically learned image features for prediction, we incorporate three user-defined magnetic resonance imaging (MRI) measurements and eight user-defined clinical measurements into the prediction model. In total, the baseline user-defined measurements consist of 11 features. Using the baseline MRI scans and all available measurements from 140 subjects in a sevenfold cross-validation procedure, we demonstrate that our model can achieve an average accuracy rate of 75.0% (SD = 11.3%) in predicting disease activity that is indicative of radiological or clinical conversion to definite MS within two years, which is higher than the 65.0% (SD = 14.6%) that is attained with lesion volume alone. More significantly, our model also outperformed a random forest using all available user-defined measurements (67.9%, ), thereby demonstrating the potential benefit of automatic extraction of latent lesion features by deep learning.

Implementing Multilayer Neural Network Behavior Using Polychronous Wavefront Computation

Polychronous Wavefront Computation (PWC) is an abstraction of spiking neural networks that provides a potentially practical model for implementing neuromorphic computing systems. While it's has been shown to exhibit some basic computational capabilities, its use in complex neuro-computational models remains to be explored. The paper presents a model and approach for configuring PWC transponders to implement multilayer neural network behavior to provide a basis for more complex applications of the technology. The model uses a set of input transponders representing pattern features to stimulate hidden layer transponders that combine features and trigger output layer transponders to identify patterns. The input layer transponder geometry is selected to create wavefront intersections for all relevant feature combinations. Hidden layer transponders are positioned by solving the intersection of the circles equations defined by sets of input transponders. Output layer transponders are defined to collect complete sets of features for recognition based on the hidden layer transponder geometry. The approach uses the intersections of three wavefronts to maximize transponder selectivity and increase information density. The concept is experimentally demonstrated and analyzed with a 7-segment display digit recognition application which provides a simple but representative example of more complex pattern recognition problems.

Openness of Information-Communications Systems: The Rescue Tool for Preserving Information Age Heritage

Introduction From the first days of human history, people wanted to store information in order to establish collective memory for future generations. The history of information storage started in pre-historic time--the first stage achieved by writing or putting art on stones and walls. The process of information storage development is continuously increasing information density and the need for more and more sophisticated tools to gather and read information from various media. Hence, the electrical storage techniques of the late 19th century discarded old media formats in favor of an electrical recording. At the same time, these techniques also introduced a crucially new dimension of storage medium--the interface, as the way to represent and control the signal bearing data. It changed how media function. Media properties were no longer dependent solely on the data stored inside but also on the tools that provided interfaces to these data. The move to digital data and digital media software in twentieth century extended this principle further. Since almost all data were encoded in digital form, they could be accessed only by programmed interface. Consequently, digital media properties are now defined by the computer programs instead of being contained in the actual content. The relations between electro-magnetic techniques developed in the second half of the nineteenth century and digital media developed 100 years later highlights some interesting points. While preceding reproduction technologies retained the original form of media, the new discarded it and an electrical signal became the base for any kind of data recording. In other words, these technologies introduced coding as a way to store and transmit media (Manovich, 2013). Further, the way we form memories in the information age is under the interaction with external information repositories, making possibilities for a new era in which we will store less information inside our brains. Information sources interlinked through communications networks as well as human activities becoming increasingly reliant on communication have become the foundation of the information age. As Edwards, Edwards, Wahl, and Myers (2012) pointed out, we are currently in the communication age where all members of a society are connected through the Internet, not just to it. These new information technologies have decreased the need for brain power, particularly with respect to that area of the brain used to memorize stuff for a short time span. Individual memory, however, shapes the personality. Moreover, the sum of individual memories shapes the collective memory. Hence, memory becomes an important part of culture (Carr, 2011). In the years since its start in 1992, UNESCO's Memory of the World Program has supported dozens of preservation projects intended to preserve original documents from human history. The program is designed to maintain a register of important collections from the earliest history to modern times, all of which urgently require preservation. Our entire heritage needs to be preserved in a form that will enable its consumption by future generations. And, unless an intensive international effort is made to digitize our information heritage, the knowledge we have today will fade away. Sooner or later, all old magnetic records will not be playable, even as old replay machines are disappearing. In fact, even where we have preserved collections of documents, we will not have the tools to access them. Ironically, we have found old paper to be more stable than paper from the modern times, much of which gradually loses its readability as time passes. Solutions that involve digitization of the paper texts need to incorporate their context. This digital content is in a form such that storage of individual media or interconnected hypermedia is executed through a variety of technologies. Hence, a uniform communications system is prerequisite for fully operable open systems where Information-Communication systems provide a huge set of information that can be accessed as the information commons by anyone, anywhere, and any time. …

Thermodynamic Aspects of DNA Nanoconstruct Stability and Design

In the present study, we use the fluorescent DNA base analog tC° to investigate the thermal stability of a small DNA hexagon and the thermodynamic factors that govern the formation of such a structure. The DNA molecule is becoming increasingly popular as a material for bottom-up construction of nanostructures; however, relatively little attention has been given to the thermodynamics of such biomacromolecule-based constructs. With the goal of increasing information density and structural complexity, the size of the nanoarchitectures decreases and, more importantly, the fine structure is becoming more detailed. In this process the thermal stability and formation of unwanted byproducts will become critical features to consider in the design and assembly of such structures. Using tC° as a fluorescent probe in fluorescence monitored DNA melting allows for individually observing the denaturing of each of the six 10-mer sides in the pseudohexagonal multicomponent system. Experimental results demonstrate that the ring-opening of the cyclized hexamer is virtually exclusive to one side and that the stability of this side is increased as a result of the cyclization. Moreover, a theoretical model describing the formation and melting of the nanostructure is presented. The results show that the cyclized structure is thermodynamically favored over linear polymeric structures under the conditions and concentrations used for the self-assembly.

Femtosecond modification of electron localization and transfer of angular momentum in nickel

The rapidly increasing information density required of modern magnetic data storage devices raises the question of the fundamental limits in bit size and writing speed. At present, the magnetization reversal of a bit can occur as quickly as 200 ps (ref. 1). A fundamental limit has been explored by using intense magnetic-field pulses of 2 ps duration leading to a non-deterministic magnetization reversal. For this process, dissipation of spin angular momentum to other degrees of freedom on an ultrafast timescale is crucial. An even faster regime down to 100 fs or below might be reached by non-thermal control of magnetization with femtosecond laser radiation. Here, we show that an efficient novel channel for angular momentum dissipation to the lattice can be opened by femtosecond laser excitation of a ferromagnet. For the first time, the quenching of spin angular momentum and its transfer to the lattice with a time constant of 120+/-70 fs is determined unambiguously with X-ray magnetic circular dichroism. We report the first femtosecond time-resolved X-ray absorption spectroscopy data over an entire absorption edge, which are consistent with an unexpected increase in valence-electron localization during the first 120+/-50 fs, possibly providing the driving force behind femtosecond spin-lattice relaxation.

Sequential photobleaching of fluorochromes for polychromatic slide‐based cytometry

Slide-based cytometry is a key technology for polychromatic cytomic investigations. Here we exploit the relocalization and merge feature of Laser Scanning Cytometry for distinguishing fluorochromes of comparable emission spectra but different photostabilities. Blood specimens were stained with the fluorochrome pairs: FITC/ALEXA488, PE/ALEXA532, or APC/ALEXA633. Bleaching was performed by repeated laser excitation. Since ALEXA dyes are photostable as compared to the conventional fluorochromes FITC, PE, and APC, a differentiation within one fluorochrome pair is possible. The sequential photobleaching method results in an increased information density on a single cell level and represents an important component to perform polychromatic cytometry.

Simulation of Magnetic Induction Mapping in the TEM

The design of modern magnetic storage devices with their rapidly increasing information density ne-cessitates a full characterization of the underlying microstructure of the device materials. Lorentz microscopy has for several decades been the main vehicle for micro-magnetic observations. The pri-mary limitation of the Lorentz modes is perhaps the attainable magnification. To avoid saturation, the sample must be placed in a low-field or preferably field-free region in the column, and this invariably means that the microscope can only be operated at low magnifications. Both Fresnel and Foucault images are rather sensitive to the exact experimental conditions which renders quantitative observa-tions quite difficult, if not impossible. Inelastic scattering further limits the usefulness of Lorentz observations to very thin foils.We have recently reported1 a novel Lorentz microscopy setup, combining a Gatan Imaging Filter (GIF) and a JEOL 4000EX top-entry high resolution TEM, operated at 400 kV with the main objective lens switched off.

Magneto-optical Kerr spectroscopy in Pt-Ni multilayers

The magnetic multilayers consisting of ultrathin 3d-transition metal and Pt or Pd layers are considered for the magneto-optical storage media with increased information density. This paper reports on the magneto-optical polar Kerr rotation and ellipticity spectra in Pt-Ni multilayers at photon energies from 1.5 to 5.2 eV prepared by evaporation onto glass substrates. The thickness of individual Pt layers was kept constant at 2 nm in all samples studied while that of Ni layers varied between 0.9 and 3.9 nm. The prominent feature of the Kerr rotation spectra is a broad negative peak the amplitude of which increases with the individual Ni-layer thickness. The multilayer spectra show less structure than that of pure Ni. Nevertheless the trends in multilayer spectra when the thickness of individual Ni layers changes can be reasonably simulated using the electromagnetic wave theory and permittivity spectra in bulk (or thick film) Ni and Pt.

Optically read disks with increased information density

A method is described which allows an increase of information density on optically read disks by a reduction of the track spacing by a factor of 2. The cross talk between neighboring tracks is maintained at an acceptable level by modulating from track to track the depth of the relief pattern on the disk. By an appropriate readout method (a compromise between differential and integral detection), the signals from neighboring tracks are suppressed. The layout of such a disk and the possible geometries of the relief pattern are indicated.