A Deep Feature Reliability-Based Framework for Offline Handwritten Signature Verification

/0 Comments/in /by

Offline handwritten signature verification is widely employed as a biometric authentication technique in financial, legal, and administrative applications. However, accurately distinguishing genuine signatures from skilled forgeries remains a challenging task because of natural intra-writer variations and the inconsistent discriminative capability of deep feature representations. This paper presents a Deep Feature Reliability-Based Framework for Offline Handwritten Signature Verification that enhances verification performance by identifying and utilizing stable writer-specific deep features. Initially, signature images are preprocessed and represented using 2048-dimensional deep features extracted from a pre-trained ResNet50 network. A feature reliability estimation scheme is then introduced to evaluate the statistical consistency of individual feature dimensions across genuine signatures of each writer. Based on the estimated reliability scores, the most reliable features are selected and incorporated into a weighted cosine similarity measure for signature verification. The proposed framework is evaluated on the CEDAR offline handwritten signature dataset using three training–testing splits of 25–75, 50–50, and 75–25. Experimental results demonstrate that the proposed method achieves its best performance with the 75–25 split, obtaining an accuracy of 77.61%, precision of 83.77%, recall of 68.48%, and an F1-score of 75.33%. The findings indicate that incorporating feature reliability into the verification process improves the robustness of deep feature representations and provides an effective framework for offline handwritten signature verification.

Linking Empirical Nickel Laterite Leaching Responses to Preliminary Economic Performance: Trade-Offs among Ni-Co Extraction, Acid Dosage, Fe Dissolution, and Residence Time

/0 Comments/in /by

This revised manuscript develops a transparent metallurgical-economic screening framework for atmospheric sulfuric acid leaching of a ferruginous nickel laterite ore. The objective is not to prove a universal kinetic mechanism or a final project-level feasibility estimate, but to evaluate how experimentally observed extraction responses translate into preliminary economic ranking under clearly stated assumptions. Duplicate leaching tests were performed at 95-100 °C using sulfuric acid dosages of 700-1000 kg H2SO4/t ore and residence times of 30-420 min. The tables report average values used for mass-balance and screening calculations; individual duplicate results are not shown in the main text, and formal significance claims are therefore avoided. Nickel and iron responses were modeled empirically as functions of acid dosage and residence time, while cobalt was included as a revenue component in selected base-case scenarios. The results show that the highest observed Ni extraction, 74.1% at 360 min and 1000 kg H2SO4/t ore, also produced the highest Fe dissolution, 65.8%, and a low Ni/Fe selectivity indicator. Under the base-case economic assumptions, the most attractive evaluated scenario was 420 min and 700 kg H2SO4/t ore, because the lower acid-addition cost and Fe penalty offset the lower Ni and Co extraction. Sensitivity analysis confirmed that this ranking is assumption-dependent and should be interpreted as a feasibility-screening result rather than a global economic optimum. Non-monotonic extraction behavior between 360 and 420 min is discussed cautiously as a possible combination of experimental dispersion, sampling effects, and secondary Ni retention associated with Fe(III) hydrolysis and sulfate-bearing phases. The revised framework provides a practical route for converting duplicated laboratory leaching tests into auditable, assumption-sensitive screening inputs for early-stage nickel laterite project evaluation.

Development and Validation of a Rubric-Based Mobile Scoring Application for Folk Dance Performance Assessment

/in /by

Folk dance performance assessment in Philippine Physical Education is still largely conducted through paper-based rubric scoring, a process that is time-consuming, prone to computation error, and difficult to aggregate across multiple judges. This study developed and validated a rubric-based mobile scoring application for Android intended for Physical Education teachers and competition judges scoring Philippine folk dance performances. The application was built using the ADDIE framework across all five phases: Analysis, Design, Development, Implementation, and Evaluation. It digitizes a five-criterion rubric covering rhythm and timing, technique and execution, expression and artistry, costume and presentation, and synchronization, with automatic weighted score computation, live ranking, and PDF or CSV export. The design was validated by a panel of nine experts drawn from Physical Education master teachers, mobile application developers, and members of the PSHS-CRC Engineering and Research Academic Unit, using a five-domain instrument covering functionality, usability, content and rubric accuracy, visual design, and overall acceptability. The panel rated the application 4.61 out of 5.00 (Highly Acceptable), with a content validity index (S-CVI/Ave) of 0.96. A usability pilot with 20 Physical Education teachers produced a mean System Usability Scale score of 84.6, corresponding to an adjective rating of Excellent and grade A. A reliability comparison scored 30 folk dance performances using both the paper rubric and the application with the same five judges; app-computed and manual totals showed a Pearson correlation of r = 0.994 (p < .001) and a two-way mixed, absolute-agreement intraclass correlation coefficient of ICC = 0.991 (95% CI 0.982 to 0.996), indicating near-perfect agreement. A paired-samples t-test found no significant difference between the two methods (t(29) = 1.42, p = .166), while the application reduced mean scoring-and-tally time per performance from 4.7 minutes to 1.3 minutes. The validated application is a complete, reusable, and empirically supported tool that resolves the multi-judge, low-connectivity constraints of live folk dance scoring, and it is now suitable for institutional adoption at PSHS-CRC with continued monitoring.

Development of A Guided Inquiry Model Mathematics Learning Tool to Improve Students’ Analytical Skills in Social Arithmetic

/in /by

This study aims to develop a guided inquiry model of mathematics learning tools to improve students’ analytic abilities in social arithmetic material. The study used the Research and Development (R&D) method with a 4D model that includes the define, design, develop, and disseminate stages. The developed tools consist of a user manual, teaching modules, LKPD, and test packages. The trial subjects were 28 seventh-grade students of SMP Negeri 14 Jember. Data were obtained through validation sheets, observations of learning implementation, observations of analyticity behavior, student response questionnaires, and pretest and posttest tests. The results showed that the learning tools met the valid criteria with an average validity score of 3.72–3.85, practical with an average implementation score of 3.33, and effective based on classical completeness of 82.14%, a high category of N-Gain increase, good category of analyticity behavior, and positive student responses of 89.7%.​

Developing Van Hiele-Based Project Learning Tools through Plastic Waste Paving Block Design on Similarity Materials

/in /by

This study aimed to develop Project Based Learning (PjBL) instructional tools through plastic-waste paving block design based on Van Hiele theory that are valid and practical for learning similarity topics. The study employed a Research and Development (R&D) approach using the 4D model developed by Thiagarajan, consisting of the define, design, develop, and disseminate stages. The participants were seventh-grade students of SMP Science Quran Al Irsyad Al Islamiyyah Jember in the 2025/2026 academic year, consisting of an experimental class and a control class. Data were collected using validation sheets, observation sheets, student response questionnaires, and readability instruments. The results indicated that the developed instructional tools met the validity criteria, with validity scores of 3.76 for the teaching module, 3.67 for the student worksheet, and 3.72 for the user guide. The practicality criteria were also achieved, as indicated by a learning implementation score of 3.5 (high category), student activity of 90% (very good category), and student responses of 92% (very positive category). These findings indicate that Project Based Learning instructional tools integrating Van Hiele theory and plastic waste paving block design are valid and practical for supporting geometry learning on similarity topics through authentic project activities involving plastic-waste paving block design.

Analog Vs Digital Signals: A Comparative Analysis of Their Roles in Modern Electronics

/in /by

Modern electronic and communication systems rely fundamentally on signal processing techniques, where information is represented in either analog or digital form. This study provides a structured comparison between these two signal categories, focusing on their operational behavior, performance characteristics, and practical relevance in contemporary technology.

Analog signals describe physical quantities in a continuously varying manner, offering high fidelity representation of natural phenomena. However, their susceptibility to noise and distortion limits their efficiency in complex systems. Conversely, digital signals represent information in discrete levels, typically binary form, which enhances stability, accuracy, and compatibility with computational systems.

The paper discusses the strengths and limitations of both signal types and highlights their combined use in modern hybrid electronic architectures.

Structural Breaks and Crime Dynamics in Guyana: A Longitudinal Analysis of Serious Crimes, 1990-2025

/in /by

Crime and violence remain persistent structural challenges in Guyana, with important implications for governance, public safety, and socioeconomic development. This study examines long-term serious crime dynamics in Guyana from 1990 to 2025 using a quantitative longitudinal design. The analysis integrates descriptive statistics, trend regression, structural break analysis (Bai–Perron), and category-level decomposition to assess overall crime trends, differences across offence types, and the relative contribution of each crime category to aggregate crime patterns. Data were obtained from the Guyana Bureau of Statistics and include major offence categories such as murder, manslaughter, rape, wounding, burglary, larceny, arson, and other offences. The results indicate that total serious crime does not follow a statistically significant linear trend over time, but instead exhibits pronounced temporal fluctuations and distinct structural shifts around 1994, 2012, and 2017. Property-related offences dominate the crime structure, accounting for 86.92% of total recorded crime, compared with 11.66% for violent crime and 1.41% for other offences. Burglary and larceny emerge as the primary drivers of aggregate crime variation, while violent offences such as murder and manslaughter remain comparatively stable over time. Structural break analysis further reveals that different crime categories experience shifts at different points in time, reflecting heterogeneous underlying dynamics. Overall, the findings show that changes in total crime are largely driven by property-related offences rather than uniform changes across all crime types, highlighting the importance of category-specific analysis in understanding long-term crime patterns in Guyana.

A Scenario-Based Electro-Physical Assessment of Urban Surface Heat Transfer and Electrical Cooling Demand in Smart Urban Environments

/in /by

Urban overheating is an electro-physical problem because surface heat accumulation changes outdoor temperature conditions and increases the electrical energy required for cooling. This study develops a scenario-based electro-physical assessment model for analysing the relationship between urban surface heat transfer, surface material properties, green infrastructure and electrical cooling demand. The model links physical parameters such as albedo, emissivity, thermal mass, vegetation coverage and urban–rural temperature difference with engineering indicators such as cooling energy demand, energy-efficiency improvement and CO₂ emissions related to electricity use. The case-study application uses Sofia Municipality as a spatial reference environment. Real spatial and land-use indicators are combined with scenario-based calculations in order to compare a baseline urban condition with an optimized scenario. The results are interpreted as early-stage engineering estimates rather than direct measurements of Urban Heat Island reduction or electricity consumption. The contribution of the paper is an integrated framework that connects heat-transfer processes with electrical energy performance in smart urban environments.

Tamarind Juice Assisted Benign Synthesis Of 2,3-Dihydro-1h-Perimidine Derivatives

/in /by

A green and efficient way to make 2,3-dihydro-1H-perimidine derivatives is through a one pot reaction of 1,8-diaminonaphthalene with different aromatic aldehydes using tamarind (Tamarindus indica L.) juice. The reactions were carried out in mild conditions, giving us the desired products in good or excellent yields with short reaction times. Tamarind juice was inexpensive, and easily available, and it was a metal-free and eco-friendly catalyst. The protocol is easy to follow, easy to separate products, low amount of catalyst, and does not include hazardous chemicals and chromatographic purification. This green way shows that tamarind juice is a good green catalyst for biologically important perimidine derivatives.

From Poetry to Opera: Pushkin And Tchaikovsky’s Eugene Onegin in A Holistic Accordance

/in /by

The present article examines Tchaikovsky’s Eugene Onegin to demonstrate how a holistic approach can deepen the performance of opera; the approach integrates the composer’s dramaturgical strategies, the literary source, and critical scholarship into a unified interpretive framework. The discussion focuses on Onegin’s rejection aria and establishes that Belinsky’s characterisation of Onegin as an “involuntary egoist” reshapes the performer’s vocal and dramatic choices. By tracking how contextual understanding directly informs decisions of vocal colour, articulation, and phrasing, the article illustrates the practical necessity of a holistic approach in which interpretation and technical execution are inseparable.