Risk Analysis Commons^™

Component Maintenance Strategies And Risk Analysis For Random Shock Effects Considering Maintenance Costs, Chao Zhang, Yadong Zhang, Hongyan Dui, Shaoping Wang, Mileta Tomovic

Engineering Technology Faculty Publications

Maintenance can improve a system’s reliability in a long operation period or when a component has failed. The reliability modeling method that uses the stochastic process degradation model to describe the system degradation process has been widely used. However, the existing reliability models established using stochastic processes only consider the internal degradation process, and do not fully consider the impact of external random shocks on their reliability modeling. Furthermore, the existing theory of importance does not consider the actual factors of maintenance cost. In this paper, based on the reliability modeling of random processes, the degradation rate under the influence …

Heavy Metal Distribution Pattern And Potential Ecological Risk In Roadside Soils As A Function Of Highway Traffic, Wassamon Thongaiod

Chulalongkorn University Theses and Dissertations (Chula ETD)

Roadside soil contamination by heavy metals due to traffic pollution presents a significant environmental concern. Assessing concentration levels and evaluating ecological risks are crucial steps toward understanding and mitigating this issue. This study focuses on soil properties and the presence of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), and zinc (Zn) along two high-traffic highways in Thailand. The empirical geological background was determined by sampling the parent materials. Out of 40 roadside soil surface samples collected, the average levels of Cu, Pb, and Zn surpass background concentrations. Significant differences in heavy metal concentrations between the two highways …

Corporate Governance And Risk-Taking: A Statistical Approach, Steven L. Schwarcz

Faculty Scholarship

Because prudent corporate governance often requires managers to take risks based on statistically expected outcomes, corporate failures that have a small but finite chance of occurring cannot always be prevented. This Article makes three related claims about risk-taking in corporate governance.

This Article’s first claim is that managers should not automatically be presumed to be at fault for corporate failures that result from risk-taking decisions based on statistical methodologies that reasonably justify the decisions ex ante. Conceptually, the business judgment rule should protect corporate managers for engaging in a reasonable decision-making process, including one that is statistically based. Jurisdictionally, however, …

The Rhetorical Art Of Risk Assessment: Lessons From Risk Management In Rural And Tribal Communities, John L. Velat

Dissertations, Master's Theses and Master's Reports

Risk assessment, mitigation, and communication rely on data from multiple sources to form a complete understanding of hazards and how to manage them. Experts can use these data to make informed decisions about the nature and extent of risks and inform the public to protect health, the environment, and economic welfare. However, in an effort to objectively make decisions, technical experts and policymakers increasingly rely on quantitative data as the most important determiner of risk, which can alienate the public, limit risk understanding, and delay or miss obvious signals of impending catastrophe. I examine several cases based on my experiences …

Ground Risk Model For Uavs, Andrew V. Shelley

International Journal of Aviation, Aeronautics, and Aerospace

This paper develops an alternative to the ground risk model provided by JARUS SORA. Key inconsistencies in the SORA ground risk model are identified, specifically ground risk continuing to increase when there is no further increase in fatality probability.

Population density is a critical component of UAS ground risk. Definitions of population density adopted by various regulatory jurisdictions are reviewed. A categorisation of population density is developed based on official statistics categories for New Zealand. This categorisation is more granular than that provided by SORA, enabling a more nuanced assessment of risk.

A ground risk model is then developed using …

Trihalomethane Formation Potentials From Effluent Of Different Wastewater Treatment Sources And Health Risk Assessment, Kangsadal Phlaengsattra

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to investigate the levels of THMs and THM formation potentials (THMFP) in treated wastewater originating from different sources i.e., domestic, food-processing industry and hospital, and to evaluate the maximum potential carcinogenic risk through dermal exposure. The samples from each source were collected three times between June and August 2023. Dissolved organic carbon (DOC), ultraviolet absorbance at 254 nm (UV254), and specific ultraviolet absorbance (SUVA) were evaluated from the samples prior to and after disinfection with chlorine over 7 days. The results found that the concentration of DOC was highest in hospital effluent, with an average value of …

Exploring Information Leakage In Historical Stock Market Data, Edison Hua

Dissertations and Theses

Information leakage is a major concern for traders who want to execute large orders without affecting the market price. In this paper, we explore the sources and effects of information leakage in historical stock market data using various methods and metrics. We first define information leakage as a pattern caused by a trader that would otherwise not occur without the trader’s activity. Using historical data, the direct impact of a potential large trade cannot be measured, but we consider a minimal impact large trade to be one that minimizes changes to the established trading data. We then analyze how information …

Health Risk And Ecological Risk Assessment From Microplastic Contamination In Sea Salt : Case Study In Ban Laem Salt Field, Phetchaburi, Thailand, Kusuman Promdontree

Chulalongkorn University Theses and Dissertations (Chula ETD)

Microplastics are ubiquitous in all terrestrial and aquatic environments. In this research, microplastic contamination in sea salt produced from traditional and plastic salt fields was studied. Including seawater used as a raw material for producing sea salt in Ban Leam salt fields, Phetchaburi, Thailand. Random samples were collected 3 replicates per point, for a total of 42 samples. 5M NaCl solution was used to separate the density and digest the organic substances using 0.05 M Fe (II) and 30% H2O2. The shape and color of the microplastics were characterized using a 30x magnification microscope. The amount, size, and polymer type …

Evaluation Of Recreational Surface Water Quality According To Water Quality Index And Quantitative Microbial Risk Assessment Of Noroviruses And Sars-Cov-2, Parichart Soisoongnern

Chulalongkorn University Theses and Dissertations (Chula ETD)

Outbreak of waterborne virus are the major concern worldwide. The Water Quality Index (WQI) is a tool used to assess water quality for related activities. However, its suitability for assessing risks associated with waterborne pathogens remains questionable. This study aims to identify potential limitations and gaps in the WQI, especially in the context of risks from waterborne pathogens. The WQI of Maha Sawat Canal (MSC), Thailand was evaluated during both wet and dry seasons. The results were then integrated with the quantitative microbial risk assessment (QMRA) methodology for norovirus GI (NoV GI) and SARS-CoV-2. The results have shown that NoV …

Correlation Between Virus Reduction And Trihalomethanes Risk After Chlorine Disinfection, Waraporn Khantong

Chulalongkorn University Theses and Dissertations (Chula ETD)

While wastewater disinfection is essential to mitigate the threats from waterborne pathogens, there arises a potential risk from disinfection byproducts. Striking a balance between achieving microbial reduction and managing the occurrence of disinfection byproducts is crucial for maintaining both microbial and chemical risks at acceptable levels. The cancer risk assessment was based on THMs through of oral ingestions, inhalation absorptions, and dermal absorptions exposure. This study aims to investigate the relationship between virus reduction and THMs formation, and to assess their respective cancer risk levels post-chlorination, and determined treatment process was used to decreased cancer risk post-chlorination. Effluent wastewater was …

Risk Assessment Of Leached Heavy Metals From End-Of-Life Thin Film Solar Photovoltaics, Pornnapat Ruengrit

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study investigated the risk of heavy metal leaching from end-of-life thin film solar photovoltaic (PV) panels, commonly disposed of in landfills, potentially contaminating groundwater. Various heavy metals including Al, Ag, Cd, Cu, Cr, Fe, Ga, In, Mo, Ni, Pb, Se, Te, As, Mn, and Zn were studied for leaching using standard methods such as TCLP and SPLP. The research compared the efficacy of these methods and examined the announcement of the Ministry of Industry regarding the disposal of waste or unused materials, B.E. 2023. Aging processes were applied to thin film PV samples including a-Si, CIGS, and CdTe. The …

Correlation Between Meteorological Conditions, Pm2.5, And Covid-19 Mortality In Thailand, Viranphat Singrakphon

Chulalongkorn University Theses and Dissertations (Chula ETD)

The appearance of a new strain of coronavirus led to a worldwide health crisis, affecting public health and economies globally, including Thailand since 2019. Previous research had suggested possible links between environmental factors and the surge in COVID-19 cases, but these connections remained uncertain. This study examined the ratios of indoor to outdoor (I/O) environments and investigated potential associations between fine particulate matter (PM2.5), meteorological conditions, and the Case Fatality Rate (CFR%) of COVID-19 in Bangkok and its surrounding metropolitan area from January to December 2021. Through Spearman’s Rank correlation analysis, the findings indicated a positive correlation between CFR% and …

Effects Of Tidal Variations On Nutrient Dynamics In The Chao Phraya River Estuarine Ecosystem, Korawee Khongmanont

Chulalongkorn University Theses and Dissertations (Chula ETD)

The Chao Phraya River estuary is a coastal ecosystem that is very important for both ecological and economic services. Moreover, it is a very complex and constantly changing ecosystem due to pollution loading from human activities through the river freshwater runoff. On the other hand, the Chao Phraya River estuary is also polluted by the influence of tidal currents of the inner Gulf of Thailand. One of the most important and persistent problems in this ecosystem is eutrophication and its effects. Therefore, the present study is aimed to improve “how freshwater runoff and tidal phenomena are affecting nutrient dynamics in …

Fecal Microbiome In Lead-Exposed Industrial Workers, Chatchawan Praditwongsin

Chulalongkorn University Theses and Dissertations (Chula ETD)

Lead exposure in industrial environments poses serious health risks. While its detrimental effects on human health are well-known, the connection between lead exposure and alterations in the fecal microbial community remains largely unexplored, highlighting a critical gap in our understanding of its wider health implications. This study explores the fecal microbiota of workers in a lead-utilizing factory, comparing individuals with blood lead levels (BLLs) above and below 3.06 µg/dL, and between those exposed to lead and those not exposed. The results demonstrate a strong correlation between lead exposure and BLLs, especially at levels below 3.06 µg/dL, with significant changes noted …

Application Of Big Data Technology, Text Classification, And Azure Machine Learning For Financial Risk Management Using Data Science Methodology, Oluwaseyi A. Ijogun

College of Graduate Studies: Theses & Dissertations

Data science plays a crucial role in enabling organizations to optimize data-driven opportunities within financial risk management. It involves identifying, assessing, and mitigating risks, ultimately safeguarding investments, reducing uncertainty, ensuring regulatory compliance, enhancing decision-making, and fostering long-term sustainability. This thesis explores three facets of Data Science projects: enhancing customer understanding, fraud prevention, and predictive analysis, with the goal of improving existing tools and enabling more informed decision-making. The first project examined leveraged big data technologies, such as Hadoop and Spark, to enhance financial risk management by accurately predicting loan defaulters and their repayment likelihood. In the second project, we investigated …

Improving The Health And Safety Of Manufacturing Workers By Detecting And Addressing Personal Protective Equipment (Ppe) Violations In Real-Time With The Use Of Automated Ppe Detection Technology, Joseph Olufemi Fasinu

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Centers for Disease Control and Prevention (CDC) emphasized that Personal Protective Equipment (PPE) can significantly reduce the risk of occupational injuries and illnesses. However, improper use, failure to use, and other PPE-related violations can still result in injuries and fatalities. Eye and face protection violation has been one of the top 10 most frequently violated OSHA standards in fiscal years 2018, 2019, 2020, 2021 and 2022 consecutively. A common practice among safety professionals to ensure PPE compliance has been to physically inspect or monitor PPE usage among workers, which has been found to be unsustainable on a continuous real-time …

Structural Risk-Based Underwater Inspection (Rbui) As A Cost Reduction Of Field’S End Of Production Life, Ivan Fitrian Putra, Johny Wahyuadi Soedarsono, Mirza Mahendra, Yuki Haidir, Faisal Dwiyana Purnawarman, Iwan Sukirna, Widi Hernowo

Journal of Materials Exploration and Findings

Mubadala Petroleum operates offshore platforms in a southern Makassar Straits that needs to be periodically inspected. The cost for the inspection is massive due to the high cost of mobilization and demobilization of vessels including crew and equipment. In response of a new approach to reduce cost, a Risk-Based Underwater Inspection (RBUI) methodology is developed. This RBUI purpose is to reduce the inspection interval of the offshore platform, from every 2 years to a longer period^[1]. There are existing RBUI methodologies, which are already developed and implemented in other companies^[5]. Purpose of this paper is to …

Risk Management Of Carbon Steel Piping In Sweet Environment Multiphase Fluid Production, Triadhi Panthun Tiggor, Rini Riastuti

Journal of Materials Exploration and Findings

As well reserved depleted and limited, it is necessary to lower the capital expenditure so that lifting SZ reservoir be more profitable. This article first contextualizes the effort done to increase the hydrocarbon lifting in a mature field. Despite the importance to sustain the production, and massive studies done to quantify the associate risk, no structured methodology proposed to manage the risk in respect to optimize the production expenditure by selection of carbon steel as alternative for corrosion resistance material piping. Hence, this article proposed a framework to support the decision-making process to operate in safely manner. Real case study …

Dynamic Rbi With Central Difference Method Approach In Calculation Of Uniform Corrosion Rate: A Casestudy On Gas Pipelines, M.Riefqi Dwi Alviansyah, Fernanda Hartoyo, Zahra Nadia Nurullia, Ari Kurniawan

Journal of Materials Exploration and Findings

The oil and gas industry generally uses a piping system to drain fluids. Even though the pipes used have been well designed, the use of pipes as a means of fluid transportation still provides the possibility of failure that can occur at any time, one of which is due to uniform corrosion. The use of standard Risk Based Inspection (RBI) according to the API RBI 581 document has been widely used to anticipate potential failures to pipe components. The use of standard RBI can reduce the risk of failure significantly. Because the standard RBI considers the component risk value to …

Cloud Container Security’ Next Move, Vishakha Sadhwani

Dissertations and Theses

In the last few years, it is apparent to cybersecurity experts everywhere that the proverbial container tech genie is out of the bottle, and has been widely embraced across multiple organizations. To achieve the flexibility of building and deploying applications anywhere and everywhere, cloud native environments have gained great momentum and made the development lifecycle simpler than ever. However, container environments brings with them a range of cybersecurity issues that includes images, containers, hosts, runtimes, registries, and orchestration platforms, which needs the necessity to focus on investing in securing your container stack.

According to this report[1], released by cloud-native …