266 research outputs found
THE FOUNDER FACTOR: FOUNDER PROFILES IN PREDICTING STARTUP SUCCESS WITH MACHINE LEARNING
Get PDFVenture capital (VC) investment decisions are often susceptible to subjective human judgment, potentially leading to cognitive biases and inconsistent outcomes. Advances in artificial intelligence (AI), specifically machine learning (ML) and natural language processing (NLP), promise improvements in the accuracy and fairness of startup evaluations. This research investigates whether incorporating founder attributes derived from LinkedIn profiles into predictive models enhances the accuracy of early-stage venture success predictions. Employing NLP methods, including transformer-based embedding techniques and sentiment analysis, this study integrates structured financial metrics and textual founder characteristics to holistically assess startup potential. Empirical results demonstrated that under the proposed framework in this study, adding founder-specific data did not significantly improve predictive accuracy across modeling techniques, highlighting challenges such as feature dimensionality, data quality, and collinearity. These findings do not clearly support or refute traditional VC assumptions about founder importance in predictive analytics. Future research should explore dimensionality reduction methods, and improved feature balancing and data sourcing to improve predictive accuracy. The dataset constructed in this study offers a potential for additional exploration and methodological developments in startup success prediction.Bachelor of Scienc
Home Cooking, Food Consumption and Food Production among the Unemployed and Retired Households
Get PDFUtilizing the 1996 Canadian Food Expenditure survey matched with Canadian Nutrient File, we separate actual food consumption from observed expenditure and test the Permanent Income/Life Cycle Hypothesis on the true consumption data. We find that the lower food expenditure during periods of unemployment or retirement (previously reported in the literature), does not translate into poorer nutrition. Household calorie intake and major nutrient intake seem to be unaffected by changes in employment status. We find evidence that unemployed or retired households substitute food purchased from restaurants for food purchased for at home consumption. Further, with the 1998 Time Use Survey we find that individuals who are not employed devote more time for food preparation. Finally we present limited evidence that unemployed and retired households substitute precooked meals for meals made from primary ingredients.Food Production, Nutrition, Consumption Smoothing
Flame synthesis of tungsten-doped titanium dioxide nanoparticles
No full textMetal-doped titanium dioxide nanoparticles can be employed in various applications, including dye-sensitized solar cells and gas sensors. Metal-doping is able to enhance the performance of titanium dioxide as photocatalysts by the dispersion of metal ions into the TiO2 matrix. In this work, tungsten-doped titanium dioxide nanoparticles are synthesized by a multiple diffusion flames burner using TTIP as the precursor (for titania) and tungsten mesh as the metal source (for doping). This novel method of using a metal mesh as precursor for doping is especially advantageous for low-vapor-pressure precursors and the entire nanoparticle synthesis process to be gas-phase based. The effect of varying the tungsten loading rate is studied for synthesizing doped titanium dioxide with different tungsten amount. The results show that high loading rate of tungsten can trigger homogenous nucleation of WO3 prior to reaching the TTIP precursor loaded region, thereby leaving less tungsten ions to be doped into TiO2, when compared to the relatively lower tungsten loading rate configuration. Heat treatment at 973 K in an Ar atmosphere moves some of the tungsten out of the TiO2 structure, thus making a new WOx-TiO2 solid solution, while tungsten ions are reduced to lower oxidation states. Moreover the annealing process also increases the unit cell volume of W-doped TiO2, making the value closer to that of the un-doped TiO2. XRD, SEM, TEM, and XPS results are to prove the theory presented. UV Vis results show tungsten doping and heat treatment improve the absorbing ability of titanium dioxide in the visible light wavelength range significantly.M.S.Includes bibliographical referencesby Yuqian Zhan
A Tale of Two Rivers
No full textThe thesis starts with the launch of two national projects in the source of yellow river, which is on top of Tibet Plateau, the most fragile and delicate ecosystem on the earth, is endangering the region. The sky river project, an external imposition that aims to turn the region into a huge landscape machine and the Nation Park plan, an internal separation that denials the indigenous relationship with their land. My project serves as the negotiation process that gradually brings the land back to its people, respecting their traditional knowledge and engaging local cultures towards a autonomous national reserve of their own through the building of a resilient ecosystem, dynamically maintaining of its unity and actively sustaining its vibrancy that can deal with the future hydrological cycle in multi-scale.It weaves a tale of an ambitious national environmental initiative in a century where the clarion call for sustainability rings louder than ever. It explores the intimate entanglements of indigenous communities with their ancestral lands, and grapples with the question of how they can harmoniously align with the nation’s aspirations. This narrative unfolds against the backdrop of a world in dire need of sustainable practices, as it bears witness to the profound bonds that tie indigenous peoples to their territories and deliberates on the means to synchronize these ties with the pulsating rhythm of the nation’s dreams.Architecture, Urbanism and Building Sciences | Transitional Territorie
Leveraging Database Honeypots to Gather Threat Intelligence
No full textIn the digital age, the proliferation of personal data within databases has made them prime targets for cyberattacks. As the volume of data increases, so does the frequency and sophistication of these attacks. This thesis investigates database security threats by deploying open source database honeypots to gather threat intelligence. We utilized five different honeypots at various interaction levels, deploying a total of 275 low-interaction, 50 medium-interaction, and 8 high-interaction honeypots over 20 to 23 days to collect a wide range of adversarial data. Through this deployment, we gathered 37, 618, 111 log entries from 8, 786 IPs.Our analysis of these logs indicate that databases exposed to the internet are most likely to be dis-covered within an hour of deployment due to pervasive internet scanning. Additionally, we found that adversaries exhibit preferences for attacking certain database management systems, engage in irregular attack frequencies marked by short bursts, utilize diverse tools, and exploit both cloud service providers and infected machines. The findings also provide a high-level overview and analysis of observed attacks, including remote code execution, worms, botnets, data theft, and cryptojacking.Computer Scienc
Stabilization of nonlinear systems via the center manifold approach
No full textAbstract This paper considers the problem of the stabilization of affine nonlinear control systems. First, we assume that the systems under investigation are of the generalized Byrnes-Isidori normal form. A new way to approximate the center manifold is proposed, which can reduce the error degree of the center manifold approximation. A new matrix product, called the semi-tensor product, is introduced to obtain the approximation of the center manifold. Then the Lyapunov function with homogeneous derivative (LFHD) is used to design a stable center manifold by state feedback control. Finally, the method is applied to general affine nonlinear control systems. c 2008 Elsevier B.V. All rights reserved. Keywords: Stabilization; Center manifold; Byrnes-Isidori normal form; Semi-tensor product Preliminary The center manifold theory emerged in the sixties of the last century, and soon became a powerful tool for the investigation of the stability of dynamic systems Consider an affine nonlinear systeṁ where f (x) and g i (x) are smooth vector fields on R n with f (0) = 0. The normal form of an affine nonlinear control system was proposed in ( Theorem 1.1 ([9]). For system (1.1) and (1.2), if (1) the essential point relative degree vector is (ρ 1 , . . . , ρ m ); (2) the corresponding essential point decoupling matrix is nonsingu-0167-6911/$ -see front matter
Empirical evaluations of transformers
No full textThe transformer architecture of neural networks immediately took over the machine learning world upon the release of the paper "Attention is All You Need" by a team at Google Brain in 2017. But, perhaps more importantly, the Summer and Fall 2022 releases of generative networks such as ChatGPT, Midjourney, and DALL-E 2 saw the technology make an immediate impact on millions of people unrelated to the academic circles that had been talking about transformers for several years, shaking up creative industries and introducing the technology to many people with widely varying understandings of how it works. Thus, we set out to evaluate temporal sequence models such as transformers; first, on a deeply technical level, investigating the role of one of transformers' unique contributions, positional encoding, on the overall training time and efficacy of the system. We then evaluated the system empirically in a broader sense as a tool that a common person would use, in order to quantitatively identify shortcomings and misconceptions on what the systems are and are not able to accomplish. Finally, we looked at another more established temporal sequence model in the form of reinforcement learning in order to understand hierarchical representation of such models and discuss the utility of hierarchical models of transformers in the future.M.S.Includes bibliographical reference
SCRAPYARDS UNITED: Nesting local scrap metal cycles in a national network - ZH2050
No full textSteel is a widely used and very circular material, it can be recycled endlessly but that consumes a lot of energy, therefore, it is one of the most polluting industries in the world. Only 2% of this pollution is caused by production, the other 98% is caused by transportation during the production and recycling process. Half of the pollution caused by transport is by export en import of scrap metal from and to the port of Rotterdam to Asian and African countries, this also creates geo-dependency on non-EU countries for essential materials. We will use research through design approach, quantitative (LISA data and Openstreetmap data) and qualitative methods such as research on the steel cycle, scrapyard activities, stakeholders, and social and spatial environment. The main objective is to reduce the logistic effort by closing loops more locally by creating a network of bigger and smaller hubs and reinstalling makers- and manufacturing industries around the hubs in a symbiotic relationship. Hereby we aim to move metal recycling higher up in the R-ladder of circularity. Different socio-spatial, techno-economic and governmental strategies should make scrapyards more attractive and interesting locations and intertwine them more into the urban tissue. Hereford, they should attract makers- and manufacturing industries around the scrapyards to form a symbiosis in the use of metal and scrap metal. Simultaneously, this increases dutch manufacturing and increases the local economy and decreases geo-dependency. The end of the report provides a set of strategies that can be applied to scrapyards throughout the country to improve the locations and the network between them. This project can form a precedent, both for other bigger industrial or port cities in Europe, as well as for different material flows.AR2U086 R&D Studio – Spatial Strategies for the Global MetropolisArchitecture, Urbanism and Building Sciences | Urbanis
Biocide resistance in Methicillin-susceptible and -resistant Staphylococcus aureus
No full textM.Phil.金黃葡萄球菌是一種重要致病菌。耐甲氧西林金葡菌（MRSA）業已成為一種難以清除的致病菌。質粒關聯和染色質關聯多重耐藥（MDR）外排泵基因能幫助瞭解對有機物消毒劑（包括苯紮氯銨（BAC）、西曲溴銨、氯己定和三氯生等）的抗性。過往研究提出部分金葡菌分型有高於其他分型的MDR基因分佈，同時這些分型有對消毒劑較高抗性。然而在亞洲地區類似研究直到目前為止還未有，所以香港地區是否存在含有較高MDR基因分佈的分型以及對消毒劑抗性的效能是本研究的主要研究方向。本研究的主要目標包括研究以下四方面：1.香港MRSA及MSSA分型分佈特徵；2.MDR外排泵基因（qacA/B、smr、norB、norC、mdeA、mepA、sdrM、sepA及lmrS）在香港金葡菌中的分佈特徵；3.MSSA與MRSA對常用抗生素及消毒劑（包括苯唑西林、頭孢西丁、氯己定、BAC、西曲溴銨、丫啶黃、乙醇、次氯酸鈉和三氯生等）的MIC（最小抑菌濃度）與MBC（最小殺菌濃度）並找出規律特徵；4.使用氯己定和BAC消毒過的表面對金葡菌之影響。本研究使用2014至2015年間來自的121株MSSA及469株MRSA病人樣品（包括356株血液樣品、155株傷口樣本和79株組織樣本）。香港主流MRSA分型為ST45（血液樣品n=82（34.9%）、傷口樣本n=37（23.9%）、組織樣本n=18（22.8%））及ST22（血液樣品n=73（31.1%）、傷口樣本n=52（33.5%）、組織樣本n=34（43.0%））。主流MSSA分型則為ST6（n=36（29.8%））。在樣品中MDR染色體編碼外排泵基因被廣泛檢出。其中，qacA在ST45樣品中有異常高的檢出率。PCR結果顯示88.1%qacA（100.0%MSSA及86.5%MRSA）陽性株皆為ST45。這一發現或許與ST45在香港的主流地位有聯繫。相對其他分型，ST45菌株檢出對吖啶黃（MIC及MBC：p<0.001對MSSA及MRSA）、西曲溴銨（MIC：p<0.001對MRSA；MBC：p=0.007對MRSA）及氯己定（MIC：p<0.001對MSSA；MBC：p=0.001對MRSA）有抗性的株系比例較高（有可能受高qacA檢出率影響），並且對抗生素頭孢西丁和苯唑西林的耐藥性較低。MRSA的ST22菌株檢出對頭孢西丁（p<0.001）和苯唑西林（p<0.001）的耐藥性較其他分型高。含qacA基因菌株在同等濃度氯己定處理的已消毒表面上有更低的被殺菌數，在已消毒表面更快恢復。總之，MRSA分型在香港的分佈與在別的地區/國家以及與MSSA分型分佈不同。作為香港第一流行的MRSA分型，ST45與其他分型相比有異常高的qacA基因檢出率及對部分消毒劑的抗性檢出比例。經常較高濃度的消毒劑使用能減少它的生長擴散。研究對此進行的分析將有助於通過消毒劑及抗生素控制香港的MRSA的演化和傳播。Staphylococcus aureus is an important bacterial pathogen of public concern. Methicillin-resistant S. aureus (MRSA), in particular, has become one of the more difficult pathogens to be eliminated. Plasmid-encoded and chromosomally-encoded multidrug-resistant (MDR) efflux pump genes in S. aureus, relating to resistance to disinfectants, including benzalkonium chloride (BAC), cetrimide, chlorhexidine, and triclosan, were under study. Previous studies showed that certain MRSA sequence types (STs) have a higher possibility in containing MDR efflux pump genes and have resistance towards certain disinfectants, but such studies are yet to be done in Asia. Thus, the aim of this study is to evaluate the distribution of MDR efflux pump genes in prevalent types of S. aureus and their effects on disinfection.The major objectives of this thesis included determination of: 1. the distribution of S. aureus STs by rapid multiplex PCR strategy and spa typing; 2.the distribution of MDR efflux pump genes (qacA, smr, norB, norC, lmrS, mdeA, mepA, sdrM, and sepA) in S. aureus by PCR; 3. the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of oxacillin, cefoxitin, and disinfectants (such as chlorhexidine, BAC, cetrimide, acriflavine, ethanol, NaOCl, and triclosan) towards S. aureus; and 4. the microbiocidal effect (ME) of chlorhexidine and BAC against S. aureus by surface test of disinfection.MRSA (n=469) and MSSA (n=121) from blood (n=356), wound (n=155), and tissue (n=79) were tested in this study. The predominant MRSA ST types in Hong Kong were ST45 (blood n=82 (34.9%), wound n=37 (23.9%), tissue n=18 (22.8%) and ST22 (blood n=73 (31.1%), wound n=52 (33.5%), tissue n=34 (43.0%). The predominant MSSA ST type from blood isolates was ST6 (n=36, 29.8%).MDR efflux pump genes were widely distributed in S. aureus strains. Plasmid-encoded qacA gene existed in 4.1% of MSSA and 15.7% of MRSA isolates. Particularly, 88.1% of qacA gene (100.0% MSSA and 86.5% MRSA isolates) was detected in ST45 isolates, suggesting a relation to the predominance of ST45 in Hong Kong.The susceptibility test result of acriflavine towards S. aureus ST45 was four-times higher than other ST types (p<0.001 for MSSA and MRSA by MIC and MBC) and two-times higher for CTAB (p<0.001 for MRSA by MIC and p=0.011 for MRSA by MBC), cetrimide (p<0.001 for MRSA by MIC and p=0.007 for MRSA by MBC) and chlorhexidine (p<0.001 for MSSA by MIC and p=0.001 for MRSA by MBC), which may due to higher distribution of qacA. However, MIC and MBC of ST45 towards cefoxitin and oxacillin were relatively lower than other STs. Meanwhile, MRSA ST22 had significantly higher MIC and MBC to cefoxitin (p<0.001 for both) and oxacillin (p<0.001 for both). Further study by surface tests of disinfectants showed that isolates containing qacA gene survived better and recovered sooner against chlorhexidine than those without qacA.In summary, ST45 remained the predominant MRSA ST in Hong Kong, which may be attributed by the significantly higher distribution of qacA genes in this ST and leading to higher resistances against a number of organic disinfectants. Since qacA positive MRSA survives better after disinfection, frequent disinfection on surfaces as opposed to using high concentrations of disinfectants with reduced frequency is more appropriate to minimize the growth and spread of these persistent survivors. The analysis revealed insights to the selection of disinfectants and antibiotics that might affect the epidemiology of MRSA in Hong Kong.Wu, Yuqian.Thesis M.Phil. Chinese University of Hong Kong 2017.Includes bibliographical references (leaves 120-150).Abstracts also in Chinese.Title from PDF title page (viewed on 24, October, 2019).Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only
- …
