250 research outputs found
Social and contextual taxonomy of cybercrime: Socioeconomic theory of Nigerian cybercriminals
No full textAbstractThis article aims to establish the particularities of cybercrime in Nigeria and whether these suggest problems with prevailing taxonomies of cybercrime. Nigeria is representative of the Sub-Saharan region, and an exemplary cultural context to illustrate the importance of incorporating social and contextual factors into cybercrime classifications. This paper anchors upon a basic principle of categorisation alongside motivational theories, to offer a tripartite conceptual framework for grouping cybercrime nexus. It argues that cybercrimes are motivated by three possible factors: socioeconomic, psychosocial and geopolitical. Whilst this contribution challenges the statistics relied on to inform the prevalence of cybercrime perpetrators across nations, it provides new ways of making sense of the voluminous variances of cybercrime. Concomitantly, it enables a clearer conceptualisation of cybercrime in Nigeria and elsewhere, because jurisdictional cultures and nuances apply online as they do offline
sj-pdf-2-cpc-10.1177_10556656241244976 - Supplemental material for Barriers in Cleft Service Access in Sub-Saharan Africa: A Thematic Analysis of Practical Needs of Rural Families
No full textSupplemental material, sj-pdf-2-cpc-10.1177_10556656241244976 for Barriers in Cleft Service Access in Sub-Saharan Africa: A Thematic Analysis of Practical Needs of Rural Families by Abdurrazaq Olanrewaju Taiwo, Uta Lehmann, Vera Scott, Isah Shafi’u, Suleman Gusau Lawal, Usamatu Abdulmajid, Ramat Oyebummi Braimah, Adebayo Aremu Ibikunle, Abdullahi Bello Abubakar, Bala Mujtaba, Mike Eghosa Ogbeide, Suwaiba Labbo-Jadadi, Olufemi Ibrahim Adigun and Bruno Oludare Ile-Ogedengbe in The Cleft Palate Craniofacial Journal</p
sj-docx-1-cpc-10.1177_10556656241244976 - Supplemental material for Barriers in Cleft Service Access in Sub-Saharan Africa: A Thematic Analysis of Practical Needs of Rural Families
No full textSupplemental material, sj-docx-1-cpc-10.1177_10556656241244976 for Barriers in Cleft Service Access in Sub-Saharan Africa: A Thematic Analysis of Practical Needs of Rural Families by Abdurrazaq Olanrewaju Taiwo, Uta Lehmann, Vera Scott, Isah Shafi’u, Suleman Gusau Lawal, Usamatu Abdulmajid, Ramat Oyebummi Braimah, Adebayo Aremu Ibikunle, Abdullahi Bello Abubakar, Bala Mujtaba, Mike Eghosa Ogbeide, Suwaiba Labbo-Jadadi, Olufemi Ibrahim Adigun and Bruno Oludare Ile-Ogedengbe in The Cleft Palate Craniofacial Journal</p
Comparative study of various hydrogen production methods for vehicles.
No full textHydrogen as an energy carrier is a promising candidate to store green energy and it has a
potential to solve various critical energy challenges. Although, hydrogen is a clean
energy carrier, the possible negative impacts during its production cannot be disregarded.
Therefore life cycle analyses for various scenarios have been investigated in this study.
In this thesis, a comparative environmental assessment is presented for different
hydrogen production methods. The methods are categorized on the basis of various
energy sources such as renewables and fossil fuel. For the fossil fuel based hydrogen
production, steam methane reforming (SMR) of natural gas is studied. Renewable based
hydrogen production includes electrolysis using sodium chlorine cycle. Electrolytic
hydrogen production is also compared using different cells such as membrane cell,
diaphragm cell and mercury cell. Wind and solar based electricity is also used in
electrolytic hydrogen production. Furthermore, vehicle cycle is studied on the basis of
available literature to compare the hydrogen vehicle with gasoline vehicle.
The investigation uses life cycle assessment (LCA), which is an analytical tool to
identify and quantify environmentally critical phases during the life cycle of a system or a
product and/or to evaluate and decrease the overall environmental impact of the system or
product. The LCA results of the hydrogen production processes indicate that SMR of
natural gas has the highest environmental impacts in terms of abiotic depletion, global
warming potential, and in other impact categories. The abiotic depletion for SMR is
found to be 0.131 kg Sb eq. which is the highest among all methods. The second highest
abiotic depletion value comes under electrolysis using mercury cell which is 0.00786 kg
Sb eq. However, thermodynamic results suggested that SMR is the efficient method of
hydrogen production because the amount of hydrogen energy produced as output in the
system is larger than any other method. The energy efficiency of the system in this
method is about 76.8% and the exergy efficiency is about 72.4%. In terms of vehicle
cycle comparison, it is found that the gasoline vehicle appears to be the largest
contributor in energy consumption and GHGs emissions. The energy consumption of
gasoline vehicle is three times higher than hydrogen vehicle. Moreover, GHGs emissions
of the hydrogen vehicle are 8% of the gasoline vehicle.University of Ontario Institute of Technolog
Improved image quality using monolithic scintillator detectors with dual-sided readout in a whole-body TOF-PET ring: A simulation study
No full textWe have recently built and characterized the performance of a monolithic scintillator detector based on a 32 mm × 32 mm × 22 mm LYSO:Ce crystal read out by digital silicon photomultiplier (dSiPM) arrays coupled to the crystal front and back surfaces in a dual-sided readout (DSR) configuration. The detector spatial resolution appeared to be markedly better than that of a detector consisting of the same crystal with conventional back-sided readout (BSR). Here, we aim to evaluate the influence of this difference in the detector spatial response on the quality of reconstructed images, so as to quantify the potential benefit of the DSR approach for high-resolution, whole-body time-of-flight (TOF) positron emission tomography (PET) applications. We perform Monte Carlo simulations of clinical PET systems based on BSR and DSR detectors, using the results of our detector characterization experiments to model the detector spatial responses. We subsequently quantify the improvement in image quality obtained with DSR compared to BSR, using clinically relevant metrics such as the contrast recovery coefficient (CRC) and the area under the localized receiver operating characteristic curve (ALROC). Finally, we compare the results with simulated rings of pixelated detectors with DOI capability. Our results show that the DSR detector produces significantly higher CRC and increased ALROC values than the BSR detector. The comparison with pixelated systems indicates that one would need to choose a crystal size of 3.2 mm with three DOI layers to match the performance of the BSR detector, while a pixel size of 1.3 mm with three DOI layers would be required to get on par with the DSR detector.RST/Applied Radiation & Isotope
Measurement of the residence time distribution of FCC catalyst in rotary kilns
No full textContinuous rotary kilns are among the most widely used solid handling equipment for industrial applications such as drying, incineration, mixing, pre-heating, humidification, calcining, and gas-solid reactions. Longer residence times prove beneficial in ensuring that all particles have been treated sufficiently, but this can lead to large material and energy costs. As a result, efficient calcination will require shorter residence time and lower axial dispersion. The purpose of this research is to contribute towards a better understanding of these mass transfer mechanisms in rotary kilns, using industrially relevant equipment and operating conditions directed towards large-scale catalyst manufacturing. In this work, the residence time distribution and axial dispersion coefficient for a free flowing fluid cracking catalyst (FCC) powder is measured in pilot-scale kilns using a tracer study developed by Danckwerts (1952). The tracer study was used to determine residence time distributions for different sets of operating parameters, which were successfully matched to the Taylor fit of the axial dispersion model and the Sullivan prediction for mean residence time. It was found that the mean residence time and axial dispersion coefficient varied inversely with rotary speed of the kiln. The bed depths corresponding to respective flow regimes in such a calcination system were not previously reported. The predictive models showed accuracy for the system considered, even at fill levels <1% which was not the case in previously reported studies with cohesive powders.M.S.Includes bibliographical referencesby Sahil Suleman Navodi
A new framework for defect detection using hybird machine learning techniques
No full textIn this study, some logs obtained with the Firewall Device are classified using multiclass
support vector machine (SVM) classifier optimized by grid search algorithm. The presented
method was compared with various data mining techniques. In addition, these learning
algorithms were compared using four measures: Accuracy, Precision, Recall, and Fmeasure.
In this paper, we propose the use of an automatic ICA-SVM to solve the defect problem in
the computer network. It is the first automatic ICA to be used to reduce the size of input
data. Then, the output of the ICA is connected to classifiers. SVM categorizes the attributes
into three attacks (normal and abnormal). The proposed system showed results with an
accuracy of 99.21% compared to some studies
A Scalable Architecture for Harvest-Based Digital Libraries - The ODU/Southampton Experiments
No full textThis paper discusses the requirements of current and emerging applications based on the Open Archives Initiative (OAI) and emphasizes the need for a common infrastructure to support them. Inspired by HTTP proxy, cache, gateway and web service concepts, a design for a scalable and reliable infrastructure that aims at satisfying these requirements is presented. Moreover it is shown how various applications can exploit the services included in the proposed infrastructure. The paper concludes by discussing the current status of several prototype implementations
Optimalisasi Program Sekolah Siaga Bencana: Upaya Perlindungan Komprehensif terhadap Ancaman Bencana Tanah Longsor di Sekolah Dasar 47 Dumbo Raya
No full textBencana memiliki dampak yang besar pada masyarakat, terutama pada kelompok rentan seperti lanjut usia, anak-anak, perempuan, dan penyandang disabilitas, yang rentan karena keterbatasan fisik, mental, dan sosial. Program kesiapsiagaan bencana seperti Sekolah Siaga Bencana (SSB) dapat menjadi solusi untuk mengurangi dampak bencana terhadap kelompok rentan, khususnya anak-anak di lingkungan sekolah. Melalui SSB, siswa dilatih untuk memiliki pengetahuan, keterampilan, dan sikap yang tepat dalam menghadapi situasi bencana. Pelatihan ini bertujuan untuk meningkatkan pemahaman masyarakat tentang bahaya tanah longsor dan kesiapsiagaan dalam menghadapi bencana melalui program SSB. Metode pelatihan mencakup ceramah dan praktik simulasi evakuasi, dengan peserta utamanya adalah siswa dari Sekolah Dasar No. 47 Dumbo Raya. Pemilihan kelompok rentan didasarkan pada karakteristik sosial dan ekonomi masyarakat setempat. Hasil dari pelatihan menunjukkan peningkatan pemahaman masyarakat terhadap bencana tanah longsor dan kesiapsiagaan dalam menghadapi bencana setelah mengikuti program ini. Selain itu, pelatihan ini juga berhasil meningkatkan kemampuan siswa dan kelompok rentan untuk melakukan evakuasi dengan aman dan efektif. Program SSB perlu terus disosialisasikan dan didukung oleh pihak-pihak terkait untuk memastikan kesiapsiagaan optimal dalam menghadapi bencana tanah longsor dan upaya mitigasi di Kota Gorontalo
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