758 research outputs found
Crypto Embedded System for Electronic Document
In this paper, a development of low-cost RSA-based Crypto Embedded System targeted for electronic document security is presented. The RSA algorithm is implemented in a re-configurable hardware, in this case Field Programmable Gate
Array (FPGA). The 32-bit soft cores of AlteraÂ’s Nios RISC processor is used as the basic building blocks of the proposed complete embedded solutions. AlteraÂ’s SOPC Builder is used to facilitate the development of crypto embedded system, particularly in hardware/software integration stage. The use of Cryptographic Application Programming Interface (CAPI) to bridge the application and the hardware, and the associated communication layer in the embedded system is also discussed. The result obtained shows that the crypto embedded system provides a suitable compromise between the constraints of speed, space and required security level based on the specific demands of targeted applications
Machine learning approach for credit score analysis : a case study of predicting mortgage loan defaults
Dissertation submitted in partial fulfilment of the requirements for the degree of Statistics and Information Management specialized in Risk Analysis and ManagementTo effectively manage credit score analysis, financial institutions instigated techniques and models that are mainly designed for the purpose of improving the process assessing creditworthiness during the credit evaluation process. The foremost objective is to discriminate their clients – borrowers – to fall either in the non-defaulter group, that is more likely to pay their financial obligations, or the defaulter one which has a higher probability of failing to pay their debts. In this paper, we devote to use machine learning models in the prediction of mortgage defaults. This study employs various single classification machine learning methodologies including Logistic Regression, Classification and Regression Trees, Random Forest, K-Nearest Neighbors, and Support Vector Machine. To further improve the predictive power, a meta-algorithm ensemble approach – stacking – will be introduced to combine the outputs – probabilities – of the afore mentioned methods. The sample for this study is solely based on the publicly provided dataset by Freddie Mac. By modelling this approach, we achieve an improvement in the model predictability performance. We then compare the performance of each model, and the meta-learner, by plotting the ROC Curve and computing the AUC rate. This study is an extension of various preceding studies that used different techniques to further enhance the model predictivity. Finally, our results are compared with work from different authors.Para gerir com eficácia a análise de risco de crédito, as instituições financeiras desenvolveram técnicas e modelos que foram projetados principalmente para melhorar o processo de avaliação da qualidade de crédito durante o processo de avaliação de crédito. O objetivo final é classifica os seus clientes - tomadores de empréstimos - entre aqueles que tem maior probabilidade de pagar suas obrigações financeiras, e os potenciais incumpridores que têm maior probabilidade de entrar em default. Neste artigo, nos dedicamos a usar modelos de aprendizado de máquina na previsão de defaults de hipoteca. Este estudo emprega várias metodologias de aprendizado de máquina de classificação única, incluindo Regressão Logística, Classification and Regression Trees, Random Forest, K-Nearest Neighbors, and Support Vector Machine. Para melhorar ainda mais o poder preditivo, a abordagem do conjunto de meta-algoritmos - stacking - será introduzida para combinar as saídas - probabilidades - dos métodos acima mencionados. A amostra deste estudo é baseada exclusivamente no conjunto de dados fornecido publicamente pela Freddie Mac. Ao modelar essa abordagem, alcançamos uma melhoria no desempenho do modelo de previsibilidade. Em seguida, comparamos o desempenho de cada modelo e o meta-aprendiz, plotando a Curva ROC e calculando a taxa de AUC. Este estudo é uma extensão de vários estudos anteriores que usaram diferentes técnicas para melhorar ainda mais o modelo preditivo. Finalmente, nossos resultados são comparados com trabalhos de diferentes autores
Seismic Behavior Prediction Of Concentrically Braced Steel Frames
Concentrically braced steel frames (CBFs) are efficient and commonly used steel systems for resisting seismic loads through a complete truss action. In strong earthquake events, multi-storey concentrically braced steel frames (CBFs) are prone to form a storey-collapse mechanism after buckling and yielding of the braces in a storey. This thesis evaluates the seismic performance of steel concentrically braced frames (CBFs) in Abu Dhabi, UAE. The aim of this study is to assess the overall lateral capacity of multi-storey buildings and the associated sequence of formation of plastic hinges using inelastic pushover analysis technique. The time history analysis approach is employed to assess the local and global seismic performance of braced frame structures under various earthquake records representing the potential seismic loading scenarios. In addition, the adequacy of using inelastic pushover analysis as a simplified means to examine the seismic integrity of braced frame structures and to predict the sequence of development of plastic hinges within the system is evaluated. This study shows that under the expected level of Abu Dhabi’s seismicity the designed concentrically braced steel frames (CBFs) perform in an excellent manner by suffering of repairable damages with no life safety threatening. This study puts a step forward in the effort of spreading the knowledge of using the concentrically braced steel frames as lateral force resisting system in Abu Dhabi for mid and high rise buildings
Traumatic obturator dislocation of the hip joint: a case report and review of the literature
We describe a case of traumatic obturator hip dislocation in an adult. Closed reduction was done under general anesthesia. Post-reduction radiographs showed concentric and congruent reduction of the right hip. Traction was applied for three weeks followed by progressive mobilization and loading. Follow up for two years after the injury showed that the patient achieved a full recovery without any evidence of hip pain or a decreased range of motion. There were no signs of osteonecrosis of the femoral head.Keywords: Hip dislocation, obturator, closed reduction, osteonecrosi
Readiness of Malaysian public sector employees in moving towards accrual accounting for improve accountability: The case of Ministry of Education (MOE)
In recent years, there has been increasing number of debates between adoptions of cash accounting versus accrual accounting in government accounting in the Malaysian public sector.This issue arises due to the government needs to determine either to stay on cash accounting or move to accrual accounting.The objective of the study is to determine the readiness of Malaysian public sector employees in the Ministry of Education (MOE) for the implementation of accrual accounting, major concerns together with challenges in moving towards accrual accounting.Finding from this study shows that accounting employees are ready for the implementation of accrual accounting and are willing to move to accrual accounting
Variations of Weeds Seeds of Species Belonging to Poaceae on the Basis of Germination, Production and Morphological Characteristics
Aims: Seed characters are very helpful for identification of a large number of species or genera. In many cases, morphological characteristics, germination and production of seeds, can be used to distinguish species and varieties.
Methodology: Study it thoroughly in the laboratory where researchers often observe it by naked eyes, in addition to the reliance on references and researches concerning describing seeds to make the study effective and successful it must be conducted carefully with continual vigilance because of the smallness of some seeds so we use magnifying glass, the optical microscope and pocket lamp to see the different external parts of seeds. Germination of seeds was carried out in laboratory under different temperature (5°C, 10°C, 15°C, 20°C, 25°C, 30°C). Production of abundant small seeds is a common adaptation that ensures a high probability of dispersal and re-infestation. Eight characteristics were used to identify eight species of seeds which belong to Poaceae family. The morphological characteristics in which the study was based on are: shape, color, size (length, breadth), solidity, brightness, surface, appendages, weight per 100 seeds. Considerable differences were noticed between the various species of weeds seeds.
Results: The seeds of the family have great variation in their seed mass and size, considered one of the important factors affecting germination percentage and production rate. Germination percentages ranged from 80% to 100%, depending on the species and temperature. The highest germination percentages were reached at alternating temperatures (05°C/30°C). Studies on seed production potential in Bromus sterilis, Bromus rubens, Bromus lanceolatus and Bromus madritensis showed that each plant produces an average of 3700±637, 5000±592, 3000±380 and 4500±426 seeds respectively. Lolium rigidum produces 950±304 seeds /plant whereas Lolium multiflorum produces 900±258 seeds/Plant. One isolated Avena sterilis plant can produce over 235±14 seeds. Thus Avena alba produced 64±15 seeds per plant. Each weeds species shows morphological characteristics different from the plant or other species, these morphological characteristics are not restricted to the external form of the plant only but it can be on level of different other parts of plant like fruit and seed.
Conclusion: The study showed that the seeds morphological characteristics can be helpful in identification of species. The ability to produce seeds with big capacity of germination is, most probably, a mechanism by which species of Poaceae as other weed species adapts to new environmental situations and ensures its survival by facilitating the dispersal of its seeds in time and space
Biochemical profile, antioxidant effect and antifungal activity of Saudi Ziziphus spina-christi L. for vaginal lotion formulation
Ziziphus spina-christi L. extract from the northern region of Saudi Arabia, was investigated to determine its chemical composition and to evaluate its antioxidant and antifungal properties. Fresh leaves were extracted using Soxhlet apparatus and the yield was 8% w/w. Results of the qualitative study showed that this extract is rich in chemical compounds belonging to several classes (saponins, phenols, tannins). GC-MS analysis detected 38 chemical compounds with different concentrations representing 99.71 % of the total extract. However, Z. spina-christi leaves extract is mainly composed of Octadecanoic acid, 2-hydroxy-1-(hydroxymethyl)ethylester (18.80%). The extract has free radical scavenging activity at different concentrations and the best result was obtained with IC50 of 148.33 µg/ml. C. albicans and other Candida species caused vulvovaginal candidiasis, which is a high-risk occurrence in hospitalized patients. In vitro antifungal activity was investigated by the agar well diffusion test to measure and compare diameter of zones of inhibition (in mm) against Candida albicans, Candida glabrata and Candida tropicalis. Ethanolic extract of Z. spina-christi demonstrated a substantial inhibitory impact on several Candida species, especially against C. glabrata which has the highest inhibitory effect (90%). Therefore, Saudi Z. spina-christi leaves extract is a source of natural antioxidants and it can be used as well antifungal pharmaceutical product
Femtosecond Pulsed Laser Deposition of Indium on Si (100)
Deposition of indium on Si(100) substrates is performed under ultrahigh vacuum with an amplified Ti:sapphire laser (130 fs) at wavelength of 800 nm and laser fluence of 0.5 J/cm2. Indium films are grown at room temperature and at higher substrate temperatures with a deposition rate of similar to 0.05 ML/pulse. Reflection high-energy electron diffraction (RHEED) is used during the deposition to study the growth dynamics and the surface structure of the grown films. The morphology of the grown films is examined by ex situ atomic force microscopy (AFM). At room temperature indium is found to form epitaxial two-dimensional layers on the Si(100)-(2x1) surface followed by three-dimensional islands. AFM images show different indium island morphologies such as hexagonal and elongated shapes. At substrate temperatures of 400-420 °C, RHEED intensity oscillations are observed during film growth indicating that the indium film grows in the layer-by-layer mode
Understanding multilevel barriers to childhood vaccination uptake among Internally Displaced Populations (IDPs) in Mogadishu, Somalia: a qualitative study
BACKGROUND:
Disparities in vaccination coverage exist in Somalia with Internally Displaced Persons (IDPs) being among the groups with the lowest coverage. We implemented an adapted Participatory Learning and Action (PLA) intervention, which focused on routine vaccinations among displaced populations living in Mogadishu IDP camps. The intervention was successful in improving maternal knowledge and vaccination coverage but unsuccessful in improving timely vaccination. We conducted a qualitative study to understand this result and analyze the multi-level barriers to routine childhood immunization uptake.
METHOD:
In this qualitative study we used observation data from 40 PLA group discussions with female caregivers and purposively sampled nine vaccination service providers and six policy makers for interview. We also reviewed national-level vaccine policy documents and assessed the quality of health facilities in the study area. We used the socioecological framework to structure our analysis and analyzed the data in NVivo.
RESULTS:
The barriers to childhood vaccination among IDPs at the individual level were fear due to lack of knowledge, mistrust of vaccines, concerns about side effects and misinformation; opportunity costs; and costs of transportation. At the interpersonal level, family members played an important role as did the extent of decision-making autonomy. Community factors such as cultural practices, gender roles, and household evictions influenced vaccination. Organizational issues at health facilities such as waiting times, vaccine stock-outs, distance to the facility, language differences, and hesitancy of health workers to open multi-dose vials affected vaccination. At the policy level, confusion about the eligible age for routine vaccination and age restrictions for catch-up vaccination and certain antigens such as BCG were important barriers.
CONCLUSION:
Complex and interrelated factors affect childhood vaccination uptake among IDPs in Somalia. Interventions that address multiple barriers simultaneously will have the greatest impact given the complex nature of vulnerabilities in this population. There is a need to strengthen the health system and connect it with existing community structures to increase demand for services. Our research highlights the importance of formative research before implementing interventions. Further research on the integration of health service strengthening with PLA to improve childhood vaccination among IDPs is recommended.
TRIAL REGISTRATION NUMBER:
ISRCTN-83,172,390. Date of registration: 03/08/2021
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