Conventional Differential Method Research Articles

Evaluating 3-D positioning infrastructure quality and utilization: The potential improvement with multi-GNSS methods

This article evaluates the quality of the national 3-D positioning infrastructure using multi-criteria decision making (MCDM) to simulate the potential application of multi-GNSS method. The MCDM evaluation used coverage and availability of Indonesia Continuous Operating Reference System (INACORS) services, distribution of survey pillars, and accuracy of height determination using the Indonesian Geoid Model (INAGEOID). The term multi-GNSS method refers to the utilization of PPP method as a complement to the conventional differential GNSS method for the production of mapping control points. The results of this evaluation were complemented by a questionnaire analysis on the utilization of positioning infrastructure by respondents from various professional backgrounds. The MCDM evaluation results showed that Java had nearly 100% good or excellent 3-D positioning infrastructure quality. Other regions in Indonesia still had significant areas of average, fair, or even poor quality. The questionnaire results showed that many users have faced some problems in areas with fair or poor infrastructure quality. The application of multi-GNSS method can contribute to reduce up to half of the area with fair and poor positioning infrastructure quality.

The Differentiated Creative Search (DCS): Leveraging differentiated knowledge-acquisition and creative realism to address complex optimization problems

This article introduces differentiated creative search (DCS), a groundbreaking optimization algorithm that revolutionizes traditional decision-making systems in complex environments. In contrast to conventional differential evolution methods, DCS integrates a unique knowledge-acquisition process with a creative realism paradigm, thereby transforming optimization strategies. The primary aim of DCS is to enhance decision-making efficacy by employing a newly proposed dual-strategy approach that balances divergent and convergent thinking within a team-based framework. High-performing members apply divergent thinking via the DCS/Xrand/Linnik(α,σ) strategy, which incorporates existing knowledge and Linnik flights. Conversely, the remaining team harnesses convergent thinking through the DCS/Xbest/Current-to-2rand strategy, which combines insights from both the team leader and fellow members. This division of labor, coupled with a strategy tailored to the performance levels of team members, allows for a dynamic and effective decision-making process. The methodology of DCS involves iterative cycles of divergent and convergent thinking, supported by a differentiated knowledge-acquisition process and retrospective assessments. The algorithm's novelty lies in its differentiated knowledge-acquisition, adjusted based on individual team member performance, fostering an environment of continuous learning and adaptation. The paper's contributions are demonstrated through rigorous testing of DCS on various benchmark functions, including CEC2017, classical, and sensor selection problems, as well as real-world applications such as car side impact design, gear train design, and FM sound wave parameter estimation. The results showcase the promising performance of DCS compared to that of existing algorithms, attributable to its innovative approach to problem solving and decision making in complex scenarios. The results and impact section highlights that DCS considerably outperforms traditional optimization algorithms, offering a robust and versatile tool for complex decision-making systems. Its impact is particularly notable in scenarios requiring a balance between innovative solutions and practical decision-making, making DCS a valuable asset in strategic planning and execution across various industries.

Real-time numerical differentiation of sampled data using adaptive input and state estimation

Real-time numerical differentiation plays a crucial role in many digital control algorithms, such as PID control, which requires numerical differentiation to implement derivative action. This paper proposes an algorithm for estimating the numerical derivative of a signal from noisy sampled data measurements. The method uses adaptive input estimation with adaptive state estimation (AIE/ASE), and thus it requires only minimal prior information about the signal and noise statistics. Furthermore, since the estimates of the derivative at step k provided by AIE/ASE depend only on data available up to step k, AIE/ASE is thus implementable in real time. The accuracy of AIE/ASE is compared numerically to several conventional numerical differentiation methods. Finally, AIE/ASE is applied to simulated vehicle position data, generated in the CarSim simulator software.

Generation of a stably transfected mouse embryonic stem cell line for inducible differentiation to excitatory neurons

In vitro differentiation of stem cells into various cell lineages is valuable in developmental studies and an important source of cells for modelling physiology and pathology, particularly for complex tissues such as the brain. Conventional protocols for in vitro neuronal differentiation often suffer from complicated procedures, high variability and low reproducibility. Over the last decade, the identification of cell fate-determining transcription factors has provided new tools for cellular studies in neuroscience and enabled rapid differentiation driven by ectopic transcription factor expression. As a proneural transcription factor, Neurogenin 2 (Ngn2) expression alone is sufficient to trigger rapid and robust neurogenesis from pluripotent cells. Here, we established a stable cell line, by piggyBac (PB) transposition, that conditionally expresses Ngn2 for generation of excitatory neurons from mouse embryonic stem cells (ESCs) using an all-in-one PB construct. Our results indicate that Ngn2-induced excitatory neurons have mature and functional characteristics consistent with previous studies using conventional differentiation methods. This approach provides an all-in-one PB construct for rapid and high copy number gene delivery of dox-inducible transcription factors to induce differentiation. This approach is a valuable in vitro cell model for disease modeling, drug screening and cell therapy.

Частота инверсий в хромосомах Т-лимфоцитов у облученных жителей Южного Урала

It is well-known that ionizing radiation is among factors increasing the rate of chromosomal rearrangements. The inversion rate was poorly understood due to difficulty of inversion identification by the conventional differential staining method. A comprehensive study of chromatin and its complex rearrangements has become possible with the use of the high-tech molecular genetic method, fluorescence in situ hybridization (FISH). The study was aimed to assess frequency of inversions involving the chromosome telomeric regions in 36 residents of the South Urals, almost all of them were affected by combined chronic exposure. The calculated individualized cumulative external and internal doses were 0.0001–4.7 Gy. Inversions were identified by fluorescence staining of the chromosome telomeric region. It was found that chromatid inversions were more abundant than chromosomal variants (9 : 0.3 per 100 cells (p < 0.001). No relationship between the studied parameters and the absorbed dose, sex and age at the time of the examination was revealed.

Development of an integrin αv-based universal marker, capable of both prediction and direction of stem cell fate.

Integrin-mediated focal adhesion (FA) and subsequent cytoskeletal reorganization influence cell morphology, migration, and ultimately cell fate. Previous studies have used various patterned surfaces with defined macroscopic cell shapes or nanoscopic FA distributions to explore how different substrates affect the fate of human bone marrow mesenchymal stem cells (BMSCs). However, there is currently no straightforward relationship between BMSC cell fates induced by patterned surfaces and FA distribution substrates. In this study, we conducted single-cell image analysis of integrin αv-mediated FA and cell morphological features of BMSCs during biochemically induced differentiation. This enabled the identification of distinct FA features that can discriminate between osteogenic and adipogenic differentiation, demonstrating that integrin αv-mediated focal adhesion (FA) can be used as a non-invasive biomarker for real time observation. Based on these results, we developed an organized microscale fibronectin (FN) patterned surface where the fate of BMSC could be precisely manipulated by these FA features. Notably, even in the absence of any biochemical inducers, such as those contained in the differentiation medium, BMSCs cultured on these FN patterned surfaces exhibited upregulation of differentiation markers comparable to BMSCs cultured using conventional differentiation methods. Therefore, the present study reveals the application of these FA features as universal markers not only for predicting differentiation status, but also for regulating cell fate by precisely controlling the FA features with a new cell culture platform. STATEMENT OF SIGNIFICANCE: Although the effects of material physiochemical properties on cell morphology and subsequent cell fate decisions have been extensively studied, a simple yet intuitive correlation between cellular features and differentiation remains unavailable. We present a single cell image-based strategy for predicting and directing stem cell fate. By using a specific integrin isoform, integrin αv, we identified distinct geometric features that can be used as a universal marker for discriminating between osteogenic and adipogenic differentiation in real-time. From these data, new cell culture platform capable of regulating cell fate by precisely controlling FA features and cell area can be developed.

On the Analysis of Tactile Sensation Based on Time Measurement: An Experimental Case Study on the Interaction Between Skin and Lotion.

This paper presents a novel experimental case study in which tactile sensation is analyzed as 4-dimensional subjective data consisting of stimulus, participant, evaluation term, and temporal components, using a temporal measurement approach. Specifically, the skin and lotion interaction was evaluated using the Temporal Check-All-That-Apply (TCATA) method. Two practical analysis examples were conducted to experimentally demonstrate the potential use cases of time-series subjective tactile data. In the first example, stimulus classification accuracy was compared between different sampling periods, including the whole and late periods, with the latter being akin to the conventional Semantic Differential (SD) method condition. The results indicate that the whole and early periods exhibit higher accuracy compared to the latest period, implying that temporal measurements may capture more stimulus characteristics than the conventional approach. In the second example, cluster analysis based on the time-series subjective data was conducted. The results revealed that the participants were classified into two distinct clusters, with the trends of time-series changes being significantly different between the clusters.

Detection for Abnormal Commutation Process State of Converter Based on Temporal and Amplitude Characteristics of AC Current

Commutation failure (CF) increases the current flowing through the converter and endangers the converter. To protect the converter, CF protection is used in high voltage direct current systems. The core of CF protection is accurate CF detection. Owing to the nonlinear characteristics of converter and the rapid control, the conventional differential current method used to detect CF faces challenges. This paper proposes a method to detect CF directly by tracking commutation process. The study indicates that the characteristics of commutation process differ significantly between normal operation and CF. By extracting these characteristics, commutation process can be tracked, and CF can be detected. For improving reliability, the proposed method depends on the relative relationship between AC current and DC current, reducing the influence of current fluctuation. Temporal and amplitude characteristics are both extracted to judge commutation process state and detect CF. The performance of the proposed scheme is validated using an actual engineering model and recorded engineering data. The results indicate that the proposed method can effectively detect CF under different scenarios.

Abstract 12398: CD151 Expression Reflects Different Features in Cardiac Subtype Specification From Human Pluripotent Stem Cells

Introduction: In conventional cardiac differentiation methods, a heterogeneous cardiac population is generated from human induced pluripotent stem cells (hiPSCs). Purifying ventricular- or atrial cardiomyocytes (VCMs or ACMs, respectably) is valuable for drug discovery for region-specific heart diseases. Previously, we have identified a novel marker, CD151, which can separate advanced specified subtypes; CD151 high VCMs in ventricular inducing condition (VIC) and CD151 low ACMs in atrial inducing condition (AIC). Although CD151 is known as a cell adhesion molecule, the function in cardiac subtype specification is unclear. In this study, we addressed the mechanisms of how CD151 distinguishes cardiomyocyte subtypes in cardiac differentiation from hiPSCs. Methods: We performed RNA sequencing in VIC- and AIC- CD151 high/low CMs. Pathway analysis using differential expression genes between CD151 high/low CMs was conducted to identify prominent pathways in subtype specification. Results: In VIC, mitosis-related genes were enriched in CD151 high VCMs. To clarify whether those genes affect cell proliferation or multi-nucleation, we performed the flow cytometric analysis of CD151 high/low VCMs with KI-67 proliferation marker and Hoechst staining. Although the percentage of KI67-positive cells was almost the same, binucleated cells were significantly more in CD151 high VCMs than in CD151 low VCMs. In AIC, transcriptome analysis suggested that Notch signaling was activated in CD151 high ACMs. To reveal that Notch signaling inhibits atrial specification, we analyzed ACMs treated with LY411575, a Notch signaling inhibitor. LY411575 induced atrial marker gene expression and increased the number of cells showing action potentials of ACMs. CD151 low ACMs after LY411575 treatment contained ACMs with the highest efficiency. Conclusion: Our results demonstrate that the CD151 expression indicates mitotic activity in VCMs. CD151 high VCMs are more advanced specified VCMs with binucleation without cell proliferation. On the other hand, in ACMs, CD151 works as an indicator of Notch signaling, which suppresses atrial specification. Our study provides a novel approach to generating and purifying hiPSCs-ACMs by Notch inhibition and CD151 separation.

Entropy Production Evaluation within a Prototype Pump-Turbine Operated in Pump Mode for a Wide Range of Flow Conditions

Inside the pump-turbine, energy is irreversibly lost due to turbulent pulsations in the high Reynolds number zone and actions of viscous forces close to the wall. The conventional differential pressure method cannot obtain specific details of the hydraulic loss within the machine’s flow passages; on the other hand, the entropy production method can provide accurate information on the location of irreversible losses and the spatial distribution of energy dissipation. Therefore, based on the entropy production theory, this study investigates the composition and distribution of hydraulic losses under different flow conditions for a prototype pump-turbine in pump mode. Study results indicated that total hydraulic losses significantly decreased, then slowly increased with an increase in flow rate. The entropy production rate caused by turbulence dissipation (EPTD), direct dissipation (EPDD), and wall shear stress (EPWS) displayed the same variation patterns as that of total hydraulic losses, with EPTD and EPDD being the most dominating. The location of hydraulic loss within the pump-turbine’s flow domain strongly depended on flow conditions. High hydraulic losses primarily occurred in the guide vanes (GV) and draft tube under low flow rates. Under high flow conditions, however, high hydraulic losses were mostly concentrated in the stay vanes (SV), spiral casing, and GV. Hydraulic losses at low flow rates were primarily caused by flow separation within the GV flow channels, vortices in the vaneless region, and inlet flow impacts on the runner blade’s leading edge. On the other hand, large vortices within the GV and SV flow channels, GV wake flow, and unsteady flow at the spiral casing were the main contributors to hydraulic loss under high flow conditions. EPDD was mainly caused by strain rate, so it was closer to the main vortex regions, whereas EPTD was affected by turbulence intensity and had a wider distribution range in the unsteady flow.

Image Edge Detection Methods in Perimeter Security Systems Using Distributed Fiber Optical Sensing.

This paper aims to evaluate detection algorithms for perimeter security systems based on phase-sensitive optical time-domain reflectometry (-OTDR). Our own designed and developed sensor system was used for the measurement. The main application of the system is in the area the perimeter fencing intrusion detection. The system is unique thanks to the developed motherboard, which contains a field-programmable gate array (FPGA) that takes care of signal processing. This allows the entire system to be integrated into a 1U rack chassis. A polygon containing two different fence types and also cable laid underground in a plastic tube was used for testing. Edge detection algorithms using the Sobel and Prewitt operators are considered for post-processing. The comparison is made based on the signal-to-noise ratio (SNR) values calculated for each event. Results of algorithms based on edge detection methods are compared with the conventional differential method commonly used in -OTDR systems.

Adaptive Local Mean Decomposition and Multiscale-Fuzzy Entropy-Based Algorithms for the Detection of DC Series Arc Faults in PV Systems

DC series arc fault detection is essential for improving the productivity of photovoltaic (PV) stations. The DC series arc fault also poses severe fire hazards to the solar equipment and surrounding building. DC series arc faults must be detected early to provide reliable and safe power delivery while preventing fire hazards. However, it is challenging to detect DC series arc faults using conventional overcurrent and current differential methods because these faults produce only minor current variations. Furthermore, it is hard to define their characteristics for detection due to the randomness of DC arc faults and other arc-like transients. This paper focuses on investigating a novel method to extract arc characteristics for reliably detecting DC series arc faults in PV systems. This methodology first uses an adaptive local mean decomposition (ALMD) algorithm to decompose the current samples into production functions (PFs) representing information from different frequency bands, then selects the PFs that best characterize the arc fault, and then calculates its multiscale fuzzy entropies (MFEs). Eventually, MFE values are inputted to the trained SVM algorithm to identify the series arc fault accurately. Furthermore, the proposed technique is compared to the logistic regression algorithm and naive Bayes algorithm in terms of several metrics assessing algorithms’ validity for detecting arc faults in PV systems. Arc fault data acquired from a PV arc-generating experiment platform are utilized to authenticate the effectiveness and feasibility of the proposed method. The experimental results indicated that the proposed technique could efficiently classify the arc fault data and normal data and detect the DC series arc faults in less than 1 ms with an accuracy rate of 98.75%.

Development and validation of a novel method “SpermX™” for high throughput differential extraction processing of sexual assault kits (SAKs) for DNA analysis

The Sperm X method uses a nanotechnology derived polymer membrane that functions as a separation medium to effectively trap sperm cells while enabling efficient flow through of the digested epithelial cell DNA. This specialized membrane enabled development of a method that could significantly increase a forensic laboratory’s ability to obtain male sperm fraction DNA profiles. The SpermX device provides a rapid, reproducible procedure that is easy to implement in a single-tube format as well as high-throughput truly automated hands-free workflows.Validation studies, performed using the manual SpermX method, include sensitivity, stability, precision (reproducibility and repeatability), mixtures, and a method comparison to the traditional differential extraction. Sensitivity and method comparison studies demonstrated a wide range of sperm cells, from a high of over 2.78 million cells (9158 ng) to a low of 25 cells (83 pg), can be trapped by the SpermX membrane. Stability studies on various substrates (i.e., carpet, cotton, denim, polyester, and silk) and degraded semen gave the expected male DNA profiles. Data from the same operator and a different operator were consistent with low variance. Mixtures, with ratios ranging from approximately 10:1–18182:1, created to simulate real casework type samples including buccal/semen, vaginal epithelial/semen, and post coital swabs at different time intervals, were tested. A comparison of the SpermX method to the conventional differential extraction method resulted in comparable probative male profile allelic data and associated statistical probabilities. For low level sperm samples, down to 25 sperm cells (83 pg), the SpermX method outperformed the conventional differential extraction with more genotypic information and associated probabilities.

Direct Conversion to Achieve Glial Cell Fates: Oligodendrocytes and Schwann Cells.

Glia have been known for its pivotal roles in physiological and pathological conditions in the nervous system. To study glial biology, multiple approaches have been applied to utilize glial cells for research, including stem cell-based technologies. Human glial cells differentiated from pluripotent stem cells are now available, allowing us to study the structural and functional roles of glia in the nervous system, although the efficiency is still low. Direct conversion is an advanced strategy governing fate conversion of diverse cell types directly into the desired lineage. This novel strategy stands as a promising approach for preliminary research and regenerative medicine. Direct conversion employs genetic and environmental cues to change cell fate to that with the required functional cell properties while retaining maturity-related molecular features. As an alternative method, it is now possible to obtain a variety of mature cell populations that could not be obtained using conventional differentiation methods. This review summarizes current achievements in obtaining glia, particularly oligodendrocytes and Schwann cells.

Neuro-fuzzy based estimation of rotor flux for Electric Vehicle operating under partial loading

The primary objective of this work is to optimize the induction motor rotor flux so that maximum efficiency is attained in the facets of parameter and load variations. The conventional approaches based on loss model are sensitive to modelling accuracy and parameter variations. The problem is further aggravated due to nonlinear motor parameters in different speed regions. Therefore, this work introduces an adaptive neuro-fuzzy inference system-based rotor flux estimator for electric vehicle. The proposed estimator is an amalgamation of fuzzy inference system and artificial neural network, in which fuzzy inference system is designed using artificial neural network. The training data for neuro-fuzzy estimator is generated offline by acquiring rotor flux for different values of torque. The conventional fuzzy logic and differential calculation methods are also developed for comparative analysis. The efficacy of developed system is established by analyzing it under varying load conditions. It is revealed from the results that suggested methodology provides an improved efficiency i.e. 94.51% in comparison to 82.68% for constant flux operation.

Moyal equation—Wigner distribution functions for anharmonic oscillators

We investigate the structure of Wigner distribution functions of energy eigenstates of quartic and sextic anharmonic oscillators. The corresponding Moyal equations are shown to be solvable, revealing new properties of Schrödinger eigenfunctions of these oscillators. In particular, they provide alternative approaches to their determination and corresponding eigenenergies, away from the conventional differential equation method, which usually relies on the not so widely known bi- and tri-confluent Heun functions.

An Efficient Method for the Differentiation of Human iPSC-Derived Endoderm toward Enterocytes and Hepatocytes.

The endoderm, differentiated from human induced pluripotent stem cells (iPSCs), can differentiate into the small intestine and liver, which are vital for drug absorption and metabolism. The development of human iPSC-derived enterocytes (HiEnts) and hepatocytes (HiHeps) has been reported. However, pharmacokinetic function-deficiency of these cells remains to be elucidated. Here, we aimed to develop an efficient differentiation method to induce endoderm formation from human iPSCs. Cells treated with activin A for 168 h expressed higher levels of endodermal genes than those treated for 72 h. Using activin A (days 0–7), CHIR99021 and PI−103 (days 0–2), and FGF2 (days 3–7), the hiPSC-derived endoderm (HiEnd) showed 97.97% CD−117 and CD−184 double-positive cells. Moreover, HiEnts derived from the human iPSC line Windy had similar or higher expression of small intestine-specific genes than adult human small intestine. Activities of the drug transporter P-glycoprotein and drug-metabolizing enzyme cytochrome P450 (CYP) 3A4/5 were confirmed. Additionally, Windy-derived HiHeps expressed higher levels of hepatocyte- and pharmacokinetics-related genes and proteins and showed higher CYP3A4/5 activity than those derived through the conventional differentiation method. Thus, using this novel method, the differentiated HiEnts and HiHeps with pharmacokinetic functions could be used for drug development.

Adipose tissue-derived stem cells: a comparative review on isolation, culture, and differentiation methods.

Adipose tissue-derived stem cells (ADSCs) are an available source of mesenchymal stem cells with the appropriate capacity to in vitro survive, propagate, and differentiate into cells from three lineages of ectoderm, mesoderm, and endoderm. The biological features of ADSCs depend on the donor physiology and health status, isolation procedure, culture conditions, and differentiation protocols used. Adipose tissue samples are provided by surgery and lipoaspiration-based methods and subjected to various mechanical and chemical digestion techniques to finally generate a heterogeneous mixture named stromal vascular fraction (SVF). ADSCs are purified through varied cell populations that exist within SVF and cultured under standard conditions to give rise to a highly rich resource of stem cells directly applied in the clinic or differentiated into a wide range of cells. The development and optimization of conventional isolation, expansion, and differentiation methods seem noteworthy to preserve the desirable biological functions of ADSCs in pre-clinical and clinical investigations.

Pharmacokinetic functions of human induced pluripotent stem cell-derived small intestinal epithelial cells

To develop a novel intestinal drug absorption system using intestinal epithelial cells derived from human induced pluripotent stem (iPS) cells, the cells must possess sufficient pharmacokinetic functions. However, the CYP3A4/5 activities of human iPS cell-derived small intestinal epithelial cells prepared using conventional differentiation methods is low. Further, studies of the CYP3A4/5 activities of human iPS-derived and primary small intestinal cells are not available. To fill this gap in our knowledge, here we used forskolin to develop a new differentiation protocol that activates adenosine monophosphate signaling. mRNA expressions of human iPS cell-derived small intestinal epithelial cells, such as small intestine markers, drug-metabolizing enzymes, and drug transporters, were comparable to or greater than those of the adult small intestine. The activities of CYP3A4/5 in the differentiated cells were equal to those of human primary small intestinal cells. The differentiated cells had P-glycoprotein and PEPT1 activities equivalent to those of Caco-2 cells. Differentiated cells were superior to Caco-2 cells for predicting the membrane permeability of drugs that were absorbed through a paracellular pathway and via drug transporters. In summary, here we produced human iPS cell-derived small intestinal epithelial cells with CYP3A4/5 activities equivalent to those of human primary small intestinal cells.

Monitoring Vehicles on Highway by Dual-Channel φ-OTDR

As a fully distributed sensor, the phase-sensitive optical time domain reflectometer (φ-OTDR) has attracted remarkable attention in real-time vibration detection. We present a dual-channel φ-OTDR (DC-φ-OTDR), formed by two single-channel φ-OTDRs (SC-φ-OTDR), to monitor running vehicles on a highway. In the double-channel system, an improved algorithm (will be referred to as the CDM&V) is proposed to alleviate the strong dependence of vibration detection on the differential step as in the widely used conventional differential method (CDM). The DC-φ-OTDR is first tested over campus road before applying it to locate moving vehicles on the highway. For comparison purposes, both the DC-φ-OTDR and SC-φ-OTDR are used to monitor the vehicles with respective signal processing methods of the CDM and CDM&V. The experimental results at campus show that the dual-path scheme can undoubtedly reduce vibration misjudgment relative to the single one due to the very small possibility of false measurements occurred simultaneously at the same location in both channels. In signal demodulation, the CDM&V greatly relaxes the constraints on the differencing interval for identifying the vehicle-caused vibration. With a step size of 5 or lower, the CDM fails to locate the running vehicle at z=~8.5 km, but the CDM&V successfully demonstrates the feasible capability of locating the vibration. With an increase in the differential interval, both the CDM and CDM&V are able to detect the vibration signal, but with the latter showing a much better noise suppression performance and hence a larger SNR. Importantly, in comparison with the SC-φ-OTDR system, the DC-φ-OTDR exhibits a considerable enhanced SNR for the detection signal regardless of which processing algorithm (i.e., CDM, CDM&V) is used. The vehicle locations positioned by the DC-φ-OTDR are confirmed by the monitoring cameras.