1,723,171 research outputs found
Mediapipe based Preprocessed VGGFace2 Dataset
No full textVGGFace2 Dataset and Face Mesh PreprocessingIntroductionThe VGGFace2 dataset is a large-scale face recognition dataset containing over 3.31 million images of 9,131 identities, with an average of 362 images per identity. The dataset is designed to include extensive variations in pose, age, illumination, ethnicity, and profession, making it one of the most diverse and challenging face recognition datasets available. For more details, please refer to the original publication:VGGFace2: A dataset for recognizing faces across pose and age - DOI: 10.48550/arXiv.1710.08092
Preprocessing Using MediaPipe 3D Face MeshOn this dataset, we applied the MediaPipe-based 3D face mesh algorithm to accurately detect faces while removing all background elements, including hair. Our preprocessing strictly retained facial landmarks, ensuring that only the essential facial features were preserved. This approach significantly enhanced the accuracy and generalization of our model, as the model was trained exclusively on landmark-based facial data.
Training and PerformanceThe preprocessed data was utilized to train Xception model, which resulted in remarkably accurate outcomes due to the strictly landmark-based facial representation. The model demonstrated robust performance including explainable-AI, proving that eliminating unnecessary background elements contributed positively to its efficiency and reliability.
CitationIf you use this dataset or the preprocessed version in your work, please cite both of the following:
VGGFace2 Dataset:
@article{Cao2018VGGFace2, title={VGGFace2: A dataset for recognizing faces across pose and age}, author={Cao, Qiong and Shen, Li and Xie, Weidi and Parkhi, Omkar M and Zisserman, Andrew}, journal={arXiv preprint arXiv:1710.08092}, year={2018}}
DOI: [10.48550/arXiv.1710.08092](https://doi.org/10.48550/arXiv.1710.08092) Preprocessed Dataset using MediaPipe:@dataset{Shah2025_MediaPipe_FaceMesh, title={MediaPipe-based 3D Face Mesh Preprocessed VGGFace2 Dataset}, author={Shah, Syed Taimoor Hussain and Shah, Syed Adil Hussain and Zamir, Ammara and Qayyum, Kainat and Shah, Syed Baqir Hussain and Fatima, Syeda Maryam and Deriu, Marco Agostino}, year={2025}, doi={10.5281/zenodo.15078557}} DOI: [10.5281/zenodo.15078557](https://doi.org/10.5281/zenodo.15078557)
ContactFor any questions or further details, please feel free to contact us.Syed Taimoor Hussain ShahPolitoBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, ItalyEmail: [email protected]: 0000-0002-6010-677
EMPIRICAL CHARACTERIZATION OF SOFTWARE QUALITY
Full text linkThe research topic focuses on the characterization of software quality considering the main software elements such as people, process and product. Many attributes (size, language, testing techniques etc.) probably could have an effect on the quality of software. In this thesis we aim to understand the impact of attributes of three P’s (people, product, process) on the quality of software by empirical means. Software quality can be interpreted in many ways, such as customer satisfaction, stability and defects etc. In this thesis we adopt ‘defect density’ as a quality measure. Therefore the research focus on the empirical evidences of the impact of attributes of the three P’s on the software defect density. For this reason empirical research methods (systematic literature reviews, case studies, and interviews) are utilized to collect empirical evidence. Each of this research method helps to extract the empirical evidences of the object under study and for data analysis statistical methods are used. Considering the product attributes, we have studied the size, language, development mode, age, complexity, module structure, module dependency, and module quality and their impact on project quality. Considering the process attributes, we have studied the process maturity and structure, and their impact on the project quality. Considering the people attributes, we have studied the experience and capability, and their impact on the project quality. Moreover, in the process category, we have studied the impact of one testing approach called ‘exploratory testing’ and its impact on the quality of software. Exploratory testing is a widely used software-testing practice and means simultaneous learning, test design, and test execution. We have analyzed the exploratory testing weaknesses, and proposed a hybrid testing approach in an attempt to improve the quality.
Concerning the product attributes, we found that there exist a significant difference of quality between open and close source projects, java and C projects, and large and small projects. Very small and defect free modules have impact on the software quality. Different complexity metrics have different impact on the software quality considering the size. Product complexity as defined in Table 53 has partial impact on the software quality. However software age and module dependencies are not factor to characterize the software quality.
Concerning the people attributes, we found that platform experience, application experience and language and tool experience have significant impact on the software quality. Regarding the capability we found that programmer capability has partial impact on the software quality where as analyst capability has no impact on the software quality.
Concerning process attributes we found that there is no difference of quality between the project developed under CMMI and those that are not developed under CMMI. Regarding the CMMI levels there is difference of software quality particularly between CMMI level 1 and CMMI level 3. Comparing different process types we found that hybrid projects are of better quality than waterfall projects. Process maturity defined by (SEI-CMM) has partial impact on the software quality. Concerning exploratory testing, we found that exploratory testing weaknesses induce the testing technical debt therefore a process is defined in conjunction with the scripted testing in an attempt to reduce the associated technical debt of exploratory testing.
The findings are useful for both researchers and practitioners to evaluate their project
Reconfigurable Intelligent Surfaces for Enhanced Localisation Advancing Performance with KAN-Based Deep Learning Models
Full text link, ; Shah, Syed Tariq; Ullah, Insaf; Mahboob, Tahira; Abdellatif, Ahmed Gamal; Elaziz, Mohamed Abd; Almogren, Ahmad; Shawky, Mahmoud A
Synthesis of transition metal nitrides and silicon based ternary nitrides
No full textSolution phase ammonolysis and sol-gel techniques that produce polymeric metal-amide precursors are of growing interest in the synthesis of nitride materials, which result from the thermal decomposition of the polymer. They can be used to control composition and to produce a large number of useful morphologies such as nanoparticles, films, monoliths, aerogels, and materials with large surface area such as foams. The synthesis of nitride materials using ammonolysis of metal amides and chlorides has so far largely focused on producing powders for applications such as catalysis, or thin films by chemical vapour deposition and related techniques.In this thesis, formation of tantalum and molybdenum nitride nanoparticles and metal-silicon nitride based nanocomposites have been synthesised using non-oxide precursors by solution phase ammonolysis and sol-gel methods respectively. For tantalum nitride nanoparticles Ta(NMe2)5 in THF was ammonolysed with ammonia at - 78 °C and the polymeric precursor was pyrolysed at various temperatures under ammonia. Amorphous TaN was obtained at 700 °C and below, while Ta3N5 was obtained at 800 °C under ammonia and also by re-annealing the amorphous samples at 800 °C under nitrogen. Molybdenum nitride powders were obtained by solution phase ammonolysis of MoCl5 or Mo(NMe2)4 and further annealing the polymeric precursors on different temperatures. The chloride precursor resulted in hexagonal MoNx at 500 °C, or rock salt MoNx at 700-1000 °C and mixture of both at 600 °C. The amide precursor resulted phase pure hexagonal MoNx at 600 °C and rock salt mixed with hexagonal at 1000 °C. Samples produced at 600 °C consisted mainly of nanotubes. Some decomposition to molybdenum metal was found in MoN obtained at 1000 °C from either precursor source.Co-ammonolysis of Ta(NMe2)5 or Mo(NMe2)4 with Si(NHMe)4 was carried out using sol-gel technique. Polymeric metal-silicon amide precursors were annealed at 600 or 1000 °C. The Ta/Si precursor produced amorphous nanocomposites and no phase segregation was observed even after high temperature annealing. With molybdenum the products were nanocomposites of molybdenum nitride particles, including nanotubes, supported on a silicon nitride amorphous matrix
Inorganic-organic hybrid thermoelectric materials for energy harvesting applications
No full textOrganic-inorganic hybrid thermoelectric composites have emerged as promising candidates for flexible thermoelectric devices due to their low cost, solution processability, and ease of large-scale fabrication. Nevertheless, hybrid composite materials have been scarcely used primarily due to the unavailability of robust, high-performance materials. Therefore, it is essential to develop new materials with attributes such as elevated carrier mobility, electrical conductivity, Seebeck coefficients, and low thermal conductivity.This dissertation primarily describes to develop organic-inorganic hybrid thermoelectric composites, predominantly composed of tellurium nanowires (TeNWs) and the conducting polymer poly(3-hexylthiophene-2,5-diyl) (P3HT), thereby improving thermoelectric (TE) performance by manipulating charge transport at the interfaces between nanowires and P3HT. Various strategies such as oxidation control, doping, surface modification, extending the dimensions of nanowires, and utilizing high molecular weight polymers are presented in this dissertation to enhancing TE performance of these hybrid composites. Aqueous solution chemical (ASS) method was developed to synthesize TeNWs. TeNWs and tellurium oxide (TeO2) nanowires were combined with P3HT to fabricate two hybrid composite systems, and dispersions were drop-casted on quartz substrates. Hybrid films were doped in FeCl3-acetonitrile solution to investigate the doping level. A significant improvement was observed in the power factor (65 μW/m·K²) of the oxidation-controlled P3HT-TeNWs hybrid composites compared to TeO2NW-P3HT (PF ~ 15 μW/mK²) at room temperature with an optimum doping of 0.06M and 0.03M, respectively (Chapter 3). We then modified the surface of TeNWs with sulfide linkers and encapsulated the synthesized S2--TeNWs in P3HT to fabricate hybrid composite materials. Intriguingly, the S2--TeNWs-P3HT hybrid composites demonstrated improved TE performance, with an electrical conductivity (σ) of 35 S/cm, a Seebeck coefficient (S) of 150 μV/K, resulting a PF of about 78 μW/m-K² at room temperature (Chapter 4). Finally, we scaled up ASS process to synthesize long TeNWs (~ 13 μm) and embedded them into P3HT with varying molecular weights (50-70 kDa and 80-143 kDa) to create hybrid composite systems (Chapter 5). The hybrid composite Te-P3HT (80-143 kDa) exhibited a significant improvement in PF of 303 ± 38 μW/mK², with σ of 91 S/cm, S of 183 μV/K, and a thermal conductivity (к) of 0.25 W/m-K, leading to a ZT value of 0.36 ± 0.06 with an optimum doping of 0.02M FeCl3. Theoretical modelling has confirmed the strong templating of P3HT on the TeNWs surface. This templating enhances the charge carrier concentration, leading to increased σ. Whilst the charge transport induces de-doping at interface, resulting in high S. Both σ and S collectively contributes to improve power factors of composite hybrid materials
Synthesis, characterisation and charge storage behaviour of some transition metal nitrides
No full textThe application of nanostructured materials with ordered morphologies and properties to electrochemical capacitors (ECs) is being studied in order to provide enhanced energy density without comprising their inherent high power density and excellent cyclability. In this study we have synthesised some metal nitrides through various routes using non-oxide precursor sources and studied their structure, composition and morphology. As synthesised materials were made in to electrodes and their capacitances were measured using cyclic voltammetry.Manganese nitrides were obtained in a solvothermal synthesis by reacting MnCl2 and LiNH2. Nanotubes at 350 °C or spherical shape particles were seen at higher temperatures. Capacitances were seen to drop with scan number when run for longer periods at higher scan rates. Molybdenum nitride samples were obtained by solution phase ammonolysis of MoCl5 or Mo(NMe2)4 to obtain the polymers. Annealing the choloroimide polymer yielded hexagonal MoN at 500 °C, rock salt Mo2N at 700 °C and above and a mix of both the phases at 600 °C. Imide derivatives yielded distorted cubic up to 800 °C and a mix of hexagonal and rock salt at high temperature. Nanotubes were obtained from imide derivatives up to 900 °C, while spherical particles above this temperature and for chloroimide derivatives at any temperature. CVs obtained for chloroimide derivatives show to double layer supercapacitors dominating over redox reaction, while imide derivatives were found to be redox in nature. Chloroimide samples show high capacities up to 247 F g-1 at 2 mV s-1 and long cycling lifetime for both the derivatives through 1000 cycles.Vanadium nitride samples were obtained by solution phase ammonolysis of V(NMe2)4. Annealing the polymer at various temperatures under NH3 produced VN with standard rock salt structure at 500-1000 °C while distorted rock salt in the samples obtained at lower temperature. Particles were found to be spherical in shape. Highest capacitance of 128 F g-1 was seen for the sample obtained at 600 °C at lower 2 mV s-1. Capacitance was found to be stable through 1000 scans only when a short potential window was used. TiN samples were produced by obtaining a precursor from solution phase ammonolysis of Ti(NMe2)4 and annealing the precursor under ammonia or through sol-gel route using long chain amines as the templating agents. PXD patterns showed rock salt TiN with broad peaks at 500 °C or highly crystalline at 800 °C. TEM images suggested particles to be spherical in shape. A fairly high surface area of 319 m2 g-1 was observed for the sample obtained from annealing the HDA/PrNH2 polymer at 500 °C. Cyclic voltammograms showed poor charge storage and most of the samples tend to oxidise rapidly in aqueous KOH. VN/C samples were obtained carrying an overnight reaction of V(NMe2)4 with NH3 in a hydrothermal bomb at various temperature. PXD reviled rock salt VN, some distortion was in the structure was found in the sample obtained at lower temperature. TEM images show vanadium nitride nano particles with carbon nanotubes. Specific capacitances were observed to be decreased with scan number through 100 cycles in 1 M KOH
ARCHITECTED MATERIALS FOR FUNCTIONAL PROPERTIES
No full textQuesta tesi analizza l'influenza della morfologia dei nanomateriali e dell'ingegneria interfacciale sulla dinamica del trasferimento di carica in sistemi eterostrutturati. Lo studio inizia con una valutazione sistematica di nanoparticelle di TiO2 e di array di nanotubi di TiO2 (TNTAs), rivelando che i TNTAs in fase anatase con un'altezza ottimizzata di 8 μm mostrano un'attività superiore nella reazione di evoluzione dell'idrogeno (HER), grazie a percorsi di trasporto di carica migliorati e a proprietà elettroniche favorevoli. Successivamente, è stato esplorato il ruolo della chimica superficiale nel controllo del trasferimento di carica interfacciale utilizzando nanocristalli di perovskite CsPbBr3 (PNCs) con lunghezze di catena dei leganti controllate. I leganti a catena corta hanno facilitato un trasferimento elettronico più efficiente verso le nanostrutture di TiO2, con gli array di nanotubi che hanno superato le pellicole di nanoparticelle nelle configurazioni allo stato solido. Le perovskiti drogati con Mn hanno ulteriormente evidenziato il comportamento di quenching dipendente dalla morfologia del TiO2, sebbene approfondimenti più dettagliati sulla dinamica dei portatori di carica richiedano tecniche spettroscopiche avanzate. Infine, i quantum dots core–shell CdTe/CdSe sono stati interfaccati con morfologie di TiO2, rivelando comportamenti contrastanti tra le fasi in soluzione e in film sottile. In soluzione, le nanoparticelle di TiO2 hanno promosso un quenching più marcato, mentre nei film sottili, i TNTAs hanno consentito un'estrazione di carica più efficiente e un trasporto direzionale, portando a una degradazione fotocatalitica efficace del colorante Rhodamine B in soluzione acquosa. Complessivamente, questo lavoro dimostra che l'ottimizzazione della morfologia, della fase e della chimica superficiale dei nanomateriali è fondamentale per migliorare i processi di trasferimento di carica e l'attività fotocatalitica. Le conoscenze acquisite offrono una strada per la progettazione di nanostrutture ibride ad alte prestazioni per la generazione fotocatalitica di idrogeno e per applicazioni optoelettroniche correlate.This thesis investigates the influence of nanomaterial morphology and interfacial engineering on charge transfer dynamics in a heterostructure system. The study begins with a systematic evaluation of TiO2 nanoparticles and nanotube arrays (TNTAs), revealing that anatase-phase TNTAs with an optimized height of 8 μm exhibit superior hydrogen evolution reaction (HER) activity, driven by enhanced charge transport pathways and suitable morphology. Subsequently, the role of surface chemistry in governing interfacial charge transfer was explored using CsPbBr3 perovskite nanocrystals (PNCs) with controlled ligand chain lengths. Short-chain ligands facilitated more effective electron transfer to TiO2 nanostructures, with nanotube arrays outperforming nanoparticle films in solid-state configurations. Mn-doped perovskites further highlighted the morphology-dependent quenching behaviour of TiO2, though deeper insights into charge carrier dynamics require advanced spectroscopic techniques. Finally, CdTe/CdSe core–shell quantum dots were interfaced with TiO2 morphologies, revealing contrasting behaviours between solution and thin-film phases. In solution, TiO2 nanoparticles promoted stronger quenching, while in thin films, TNTAs enabled more efficient charge extraction and directional transport leading to efficient photocatalytic degradation of aqueous Rhodamine B dye. Collectively, this work demonstrates that fine-tuning nanomaterial morphology, phase, and surface chemistry is critical to optimizing charge transfer processes and photocatalytic activity. The insights gained may provide a pathway for designing high-performance, hybrid nanostructures for photocatalysis and other optoelectronic applications
ORYANTALİSTLERİN HADİS ARAŞTIRMALARINDA KULLANDIKLARI METOT VE KAYNAKLARIN DEĞERLENDİRİLMESİ
Full text linkÇalışmamızın konusu “Oryantalistlerin Hadis Araştırmalarında Kullandıkları Metot ve Kaynakların Değerlendirilmesi’’dir. Konu kapsamlı olduğundan bütün oryantalistlerin metot ve kaynaklarına değil, hadis alanında mühim araştırmaları olan bazı oryantalistlere ağırlık verilmiştir. Çalışmamız önsöz, giriş, üç bölüm ve sonuçtan oluşmaktadır. Birinci bölümde oryantalizm, oryantalistler, Batı’nın Kitâb-ı Mukaddes tenkit sisteminin oryantalistlere etkisi, oryantalistlerin sınıfları ve onların hadislere dair ana iddiaları incelenmiştir. İkinci bölümde oryantalistlerin hadis araştırmalarına dair ortaya koydukları teori, kural, delil, teknik ve yaklaşımdan oluşan metotlar değerlendirilmiştir. Üçüncü bölümde ise oryantalistlerin hadis araştırmalarındaki metotları ve kaynak kullanımlarındaki sorunlar ele alınmıştır. Sonuç kısmında bu çalışmada ulaştığımız netice ve tavsiyeler zikredilmiştir. Her bölümün sonunda kısa bir değerlendirme yapılmıştır. Çalışmamızda literatür taraması, tahkik, tespit, analiz, tenkit ve değerlendirme gibi beşerî bilimlerin temel metotları kullanılmıştır
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