Tree Analysis Approach Research Articles

Reliability and criticality analysis of a large-scale solar photovoltaic system using fuzzy-fault tree analysis approach

Over time, solar Photovoltaic (PV) systems experience a decline in performance and reliability due to various environmental factors. Fault Tree Analysis (FTA) can be used to assess the reliability of these systems and identify faults and failure modes that can significantly impact the entire PV system’s performance. However, in practice, obtaining accurate failure probability values for the components of a solar PV system is challenging since systems operate in an ever-changing environment, resulting in a scarcity of data for statistical estimation. This paper proposes a fuzzy theory-based FTA approach to obtain the failure probabilities of the faults more accurately. The Fuzzy-FTA methodology converts experts’ subjective opinions expressed in linguistic terms into a Failure Possibility Score (FPS), which is then converted into a failure probability value. The results of the proposed approach are compared to those obtained through the conventional FTA to assess its effectiveness, applicability, feasibility, and efficiency. Soiling, dust accumulation, inadequate system maintenance, bad system configuration, bird dropping, delamination, improper installation, shading, grounding, and discoloration are the most critical faults and impact on the performance and reliability of solar PV systems.

Decision Tree Analysis Approaches to Classify Sensors Data in a Water Pumping Station

Decision Tree Analysis Approaches to Classify Sensors Data in a Water Pumping Station

Quantitive HAZOP and D-S evidence theory-fault tree analysis approach to predict fire and explosion risk in inert gas system on-board tanker ship

Tanker ships carry volatile cargo, presenting inherent risks of fire and explosion. Inert gas systems (IGS) are pivotal in mitigating risks by displacing oxygen in cargo tanks. However, failure of IGS components may lead to fatal consequences such as loss of life and marine pollution. This paper prompts a systematic approach integrating Quantitative Hazard and Operability (HAZOP) analysis under D-S (Dempster–Shafer) evidence theory and Fault Tree Analysis (FTA) to predict and quantify the fire and explosion risk associated with IGS malfunction on tanker ships. The methodology systematically evaluates failure probabilities, and consequences using HAZOP to identify critical scenarios. D-S evidence theory is employed to address uncertainties and incorporate expert knowledge into the analysis. FTA is applied to model fault propagation and assesses the likelihood of fire and explosion events based on the identified failure scenarios. A case study is presented to demonstrate the application of the proposed methodology, illustrating effectiveness in identifying high-risk scenarios and providing insights for enhancing operational safety minimising the risk of IGS on tanker ships. The findings show that the risk of fire and explosion in the inert gas system due to the high concentration of oxygen entering the tank was found to be 2.86E-01. Besides its robust theoretical background, the findings of the paper provide the utmost contribution to ship crew, ship inspectors, HSEQ managers and safety professionals for proactive risk mitigation strategies, contributing to the advancement of safety management practices in the maritime industry.

Analisis Pelarangan Operasional Tiktok Shop Dalam Langkah Pengambilan Keputusan Melalui Perspektif Problem Tree Analysis

The controversial TikTok Shop case has become a hot topic of discussion lately. The violation committed by the TikTok company is combining online buying and selling platforms with social media platforms. Legally in Indonesia, this is considered illegal and has a negative impact on the sustainability of domestic MSMEs and causes various other problems. The government revised the old Permendag, namely No. 50 of 2020, which did not clearly emphasize the legal PMSE system in Indonesia, which also discussed the social commerce system. The issue of TikTok violating PMSE is an interesting thing to study regarding the relationship between the government's decision to issue a policy to stop TikTok Shop and its driving factors. Researchers use descriptive research methods with a qualitative approach. Literature study and documentation are data collection techniques used in this study. The data analysis technique used is the Problem Tree Analysis approach. While the focus of his research is on PMSE violations by TikTok Companies in Indonesia. From this research, it was found that there is an unclear legal and regulatory umbrella from government regulations regarding PMSE itself. And there are also various consequences caused by TikTok Shop violations that have fatal consequences on the country's economy and domestic MSMEs. For this reason, legal clarity must be paid more attention to by the government so that when there is increasingly rapid technological development as well as increasingly complex systems do not create problems due to technology gaps.

ANALISIS PELAYANAN BPJS DI INDONESIA DALAM MENINGKATKAN KESEJAHTERAAN MASYARAKAT DENGAN PENDEKATAN PROBLEM TREE ANALYSIS

This research aims to identify problems in BPJS services in Indonesia in improving community welfare using a problem tree analysis approach. The problem tree analysis method is used in this research to identify the root of problems in BPJS services, to provide a clearer picture, more appropriate solutions, good treatment priorities, as well as a structured evaluation and improvement process for BPJS services in the future. The research results revealed several main problems in BPJS services, such as low service quality, lack of service management, employee discriminatory behavior, and limited facilities and infrastructure. These problems violate the principles of good governance, such as the supremacy of law, effectiveness, efficiency, equality, accountability, and transparency. This condition makes it difficult for people to access quality and timely health services and can have a serious impact on people's health and welfare. This research suggests the need to increase supervision, optimize coordination, train employees, distribute facilities and infrastructure, and implement a reward and punishment system to improve the quality of BPJS services. With planned improvement efforts, it is hoped that BPJS Health services can provide optimal benefits for the health and welfare of the Indonesian people as a whole. Keywords: Service, BPJS, Good Governance, Problem Tree Analysis

VFT and AHP Approach to Selecting the Best Option in Decision-Making at PLN: A Case Study in the Cawang-Gandul Project

PLN EIC is one of PLN’s business units and is responsible for the development of electrical infrastructure in the working area of DKI Jakarta, Banten Province, and its surroundings. One of the national strategic projects included in the PLN is the 500 kV Cawang Baru II/Cililitan-Gandul transmission line project, with a COD target of 2026. The delay in the completion of this project and the non-fulfillment of stakeholders’ expectations will certainly have a broad impact on the operation of the electricity system, the impact on PLN’s financial performance, the social impact, the environmental impact, as well as the direct impact on the performance and image of PLN EIC. This research aims to assist management in making decisions related to the best transmission line design for the Cawang-Gandul project so that project completion can be on time and in accordance with stakeholder expectations. In this research, several methodological approaches were used to gain a broader and more complete understanding. The Problem Tree Analysis approach, combined with brainstorming and structured interview techniques, was used to explore business issues. Two complementary approaches, namely Value-Focused Thinking (VFT) and the Stakeholder Analysis method, are used to formulate stakeholder expectations and will become guidelines for formulating alternative strategies. Using a structured interview technique, 4 alternative strategies were formulated in the form of the transmission line design, namely (1) Compact Lattice Tower, (2) Underground Cable, (3) Combine Design (Compact Lattice Tower + Underground Cable), and (4) Steel Pole Tower. The next methodological approach uses the Analytic Hierarchy Process (AHP) to determine the best transmission line design, which is then analyzed using AHP Super Decision software. The results of this research show that the Underground Cable design is the best design alternative that can be implemented in the Cawang-Gandul project with several advantages, namely minimal social conflict, easy implementation, and a relatively faster work process. The final stage of research is to make an implementation plan.

Risk assessment of inter-basin water transfer plans through integration of Fault Tree Analysis and Bayesian Network modelling approaches

Inter-basin water transfer projects are a common method used to balance water resources and meet regional demand, particularly in the drinking water supply sector. The potential failure risk associated with inter-basin water transfer projects was examined using Fault Tree Analysis (FTA) and Fuzzy Fault Tree Analysis (FFTA) methodologies in this study. Additionally, the conversion of Fault Tree models into Bayesian Network (BN) and Fuzzy Bayesian Network (FBN) models was explored. Ten basic events were identified as factors that could affect the success of inter-basin water transfer plans, including socio-political, environmental, water resource, economic, and technical criteria. Fault Tree and Fuzzy Fault Tree models were utilized to conduct a risk analysis, which was then converted into crisp and fuzzy FTA-BN through an integrated approach. This approach was applied to evaluate inter-basin water transfer scenarios from the Great Karun basin to the Central Iran Plateau. The superior scenario among eight water transfer scenarios was found to be water transfer from the Behesht-Abad Basin to Isfahan province and from the Khersan Basin to Kerman and Yazd provinces, with a failure risk of 0.649 and 0.601 respectively, based on the crisp and fuzzy integrated models. Basic events were ranked based on their contribution to the occurrence of the top event using two FIM and BI indices in the Fault Tree model and two indices of MI and SI in the Bayesian Network. Furthermore, after considering the correlation between basic events and risk factors, the risk obtained by crisp and fuzzy integrated models was found to increase to 0.811 and 0.789 respectively. The results of this study demonstrate that an integrated approach can assist decision-makers and stakeholders in evaluating inter-basin water transfer projects.

Exploring the Impact of Climate Variables on Livestock Anthrax Outbreaks: A Machine Learning Approach

Anthrax, a globally significant disease, poses substantial threats to both livestock and human populations. Timely identification of anthrax outbreaks is paramount to mitigate its impact on animal health, human health, and public safety. This study aims to construct a predictive model for livestock anthrax disease occurrence. By leveraging the potential of advanced Machine-Learning techniques, we projected the likelihood of anthrax outbreaks across India, through incorporating a diverse set of meteorological, and remote sensing parameters. The ultimate goal is to establish a spatial risk map that can serve as an early warning system, aiding in the anticipation and management of future anthrax outbreaks in India's livestock population. Our analysis revealed elevated risk zones for anthrax outbreaks in the southern and north-eastern regions of India, contrasting with medium to low-risk areas in the central parts. Notably, Enhanced Vegetation Index (EVI), Normalized Difference Vegetation Index (NDVI), rainfall, soil moisture, and wind speed emerged as pivotal variables driving the model's predictive accuracy. Among the employed models, the random forest, adaptive boosting, and classification tree analysis approaches showcased superior performance in livestock anthrax risk assessment. The risk map was generated using significant variables by exploiting best fitted models. These findings hold profound implications for policymakers, guiding the targeted deployment of control strategies against anthrax outbreaks. The dynamic risk maps generated through this study enhance public awareness, equipping decision-makers with vital insights for informed action. By spotlighting risk management endeavours, these maps further enhance governance and risk mitigation efforts.

Alzheimer’s disease susceptibility in African American elders: a classification and regression tree (CART) analysis approach

Alzheimer's disease (AD) is increasingly prevalent, especially among African American older adults. Despite its widespread nature, accurate and timely diagnosis of AD remains challenging. Addressing the research gap in sociodemographic and cardiovascular risk factor research associated with AD in African American older adults, this study aimed to identify and analyze distinct subgroups within this population that are particularly vulnerable to AD, thereby contributing to the development of targeted interventions and healthcare strategies. This study employs a rigorous methodology utilizing classification and regression tree (CART) analysis to examine data from the 2017 Uniform Data Set (UDS). This approach enables a nuanced analysis of AD susceptibility among African American older adults. The CART analysis revealed significant associations between the studied sociodemographic and cardiovascular risk factors and AD susceptibility among African American older adults. The results indicate the presence of specific subgroups with increased vulnerability to AD, shaped by varying levels of education [relative importance (RI): 100%], antidepressant usage (RI: 83.1%), BMI (RI: 71.2%), use of antipsychotic agents (RI: 35.5%), and age of smoking cessation (RI: 21.5%). These findings underscore the importance of culturally specific research and interventions for addressing AD among African Americans. This study's findings, revealing significant associations between sociodemographic and cardiovascular risk factors and AD susceptibility among African American older adults, underscore the necessity of developing healthcare policies and interventions specifically tailored to address these risks.

Risk profiles for smoke behavior in COVID-19: a classification and regression tree analysis approach

BackgroundCOVID-19 pandemic emerged worldwide at the end of 2019, causing a severe global public health threat, and smoking is closely related to COVID-19. Previous studies have reported changes in smoking behavior and influencing factors during the COVID-19 period, but none of them explored the main influencing factor and high-risk populations for smoking behavior during this period.MethodsWe conducted a nationwide survey and obtained 21,916 valid data. Logistic regression was used to examine the relationships between each potential influencing factor (sociodemographic characteristics, perceived social support, depression, anxiety, and self-efficacy) and smoking outcomes. Then, variables related to smoking behavior were included based on the results of the multiple logistic regression, and the classification and regression tree (CART) method was used to determine the high-risk population for increased smoking behavior during COVID-19 and the most profound influencing factors on smoking increase. Finally, we used accuracy to evaluated the performance of the tree.ResultsThe strongest predictor of smoking behavior during the COVID-19 period is acceptance degree of passive smoking. The subgroup with a high acceptation degree of passive smoking, have no smokers smoked around, and a length of smoking of ≥ 30 years is identified as the highest smoking risk (34%). The accuracy of classification and regression tree is 87%.ConclusionThe main influencing factor is acceptance degree of passive smoking. More knowledge about the harm of secondhand smoke should be promoted. For high-risk population who smoke, the “mask protection” effect during the COVID-19 pandemic should be fully utilized to encourage smoking cessation.

Studying The Effect of Tourism Revitalization Program : Sustainable Upgrading Slums Settlements of Malang, Indonesia

Consequent of urban poverty is lack of affordable housing in urban areas. It leads to the increasing slum settlements of urban inhabitants living in deprived urban areas. Typically, slum settlements were distress and discomfort aspect on social, economic and environmental. However, policy efforts slum revitalization in Indonesia is observed to have a economic effect on the residents, where revitalization slum area of Tridi subdistrict in Malang become site tourism. Therefore, the purpose of this study is to investigate influence of revitalization slum program refer to Sustainable Development Goals (SDGs) index on development community, community behavior on environmental and ecosystem-based sustainability. This study uses a qualitative fault tree analysis (FTA) approach in sequence. Data were obtained through observation, surveys, and documentation. The results indicate a considerable built environment discomfort was due to lack of social spaces and poor design of the slum revitalization landscape. This study offers the concept of improvement strategy for slum shall not orientate to merely for beautification but also considering to improve the sustainability of the slum wellbeing.

Assessment of human error contribution to container loss risk under fault tree analysis and interval type-2 fuzzy logic-based SLIM approach

Human is a key element of the safety of life on board ships and a significant contributing factor to most of the accidents and incidents in the maritime industry. At this point, risk analysis plays a critical role in ensuring operational safety and maritime transportation sustainability. This paper aims to systematically evaluate how human errors (HEs) contribute to operational risks. Based on this, Fault Tree Analysis (FTA) is combined under an Interval Type-2 Fuzzy Logic environment with Success Likelihood Index Method (SLIM). Whilst the FTA evaluates the criticality of the operational activities, the Interval Type-2 Fuzzy Sets (IT2FS) deals with vagueness and subjectivity in using experts’ judgements, and the SLIM estimates the probabilities for the human error-related basic events. Since container losses can lead to severe damage and catastrophic events in a container terminal, loading operation was investigated as a case study. Safety culture, experience, and fatigue were observed as highly effective factors in crew performance. The obtained results also indicate that this hybrid approach can effectively be applied to determine the operational vulnerabilities in high-risk industries. The paper intends to improve safety control levels and lower losses in the future of maritime container transport besides emphasising the potential consequences of failures and crucial human errors in the operational process.

Identification Methodology for Chemical Warehouses Dealing with Flammable Substances Capable of Causing Firewater Pollution

Major accidents involving flammable substances can lead to significant environmental damage. The operators of chemical warehouses—in order to prevent and mitigate harmful environmental impacts—based on fire prevention strategies should apply “firewater pollution prevention” (FPP) measures. The identification of affected warehouses already in operation is an important law enforcement task. Therefore, the authors—based on the assessment of firewater run-off scenarios—propose a simple and easy-to-use dangerous establishment identification procedure and methodology based on event tree analysis and indexing preliminary risk analysis approaches. Two independent expert groups validated—in the case of 10 facilities—the index components of the approach. The testing of the applicability of the approach took place in parallel with the analyses of the Hungarian operator’s practice. The research results—covering the inspection of 24 facilities—can assist the operators in the effective and unified implementation of FPP measures. In the case of 14 facilities, it was necessary to introduce FPP measures, which highlight the need to improve the law enforcement compliance of identified operators. The investigation results can also contribute to increases in the fire and environmental safety performance of chemical warehouses, which ensures a higher level of environmental protection and people’s health near chemical warehouses.

Fostering human-elephant co-existence: a classification tree analysis approach

ABSTRACT Subsistence farmers in elephant rangelands suffer food insecurity, economic losses and emotional stress from crop damage by elephants, resulting in reduced local support toward elephant conservation. To foster human-elephant co-existence in a dynamic social-ecological system, we explored the validity of Classification Tree (CT) analysis application to identify human-elephant hotspots in an effort to target approaches to reduce human-elephant conflicts. The CT analysis revealed that the most important factors affecting occurrence of crop damage were crop types, field sizes and distance to nearest road and river. From CT generated thresholds, we propose establishment of multi-criteria-based risk zones, as an alternative approach, to quickly identify and prioritize future human-elephant conflict (HEC) hotspots for improved agrarian livelihood and elephant conservation outcomes. We also explained the limitations of CT models. This study contributes to the existing theory and body of work on elephant habitat use at the human-elephant interface.

STRIDE threat model-based framework for assessing the vulnerabilities of modern vehicles

Modern automobiles are becoming increasingly sophisticated with enhanced features. Modern car systems have hundreds of millions of lines of code, which increase the attack surface. To address this concern, this paper proposes a new cybersecurity analysis framework that complies with the ISO/SAE 21434:2021 standard. The framework uses the Spoofing, Tampering, Repudiation, Information disclosure, Denial of service, and Elevation of privileges (STRIDE) threat model, the Attack Tree Analysis (ATA) approach, and the Common Vulnerability Scoring System (CVSS) as a key score exploitation matrix to rate identified potential threats. To evaluate, the framework was applied, to real-life scenarios, to examine the possible cyber threats in Advanced Driver-Assistance Systems (ADAS). To assess, a tool was implemented to automate threat impact ratings, according to safety, operational, financial, privacy, and legislative metrics. It also automates attack feasibility ratings considering attack vectors, complexity, authentication, and risk level identification based on a five-by-five risk matrix. As a result, 199 potential threats were identified and addressed in, four targeted, ADAS-related use cases. For the Lane-Keeping safety-critical use case, as an example, five security requirements were elicited as countermeasures. These results show that ADAS in modern vehicles are vulnerable to cyberattacks.

Analisis Keselamatan dan Kesehatan Kerja (K3) Dengan Metode Fault Tree Analysis (FTA) Pada PT. Surya Karya Setiabudi

The problems that exist at PT. Surya Karya Setiabudi is employee negligence which can result in work accidents. The number of workplace mishaps that occurred at the company in 2021 was 26 cases.The goal of this research is to identify the value of K3 statistics and find out the sources of work failures that exist in the company. The Fault Tree Analysis (FTA) approach was utilized in this investigation to determine what elements cause work failure.The results of calculating the statistical value of K3 Frequency Rate obtained 553.3/1 million operating hours, Severity Rate 1,404/1 million operating hours, and the safe T-score is 0. The FTA analysis results suggest that there is a lack of safety induction is the main cause of the human factor that can cause accidents such as not being careful when working such as being in a hurry when doing work, when welding the distance between the face and the object is less than 50 cm, not using PPE such as employees forgetting to wear welding goggles, forgetting to wear gloves, lack of awareness of employees work safety and lack of awareness of employees about the importance of PPE, not being serious at work such as being too tired so employees feel bored or bringing external problems while working so they don't focus. Another factor that causes employees not to use PPE is the lack of PPE monitoring from K3 staff.Factors causing accidents in companies are mostly caused by humans. From the FTA analysis, it can be seen that the lack of safety induction is the main cause of the human factor.

Economic evaluation of tele-resuscitation intervention on emergency department pediatric visits in the Niagara Region, Canada a pilot study.

The use of telemedicine in critical care is emerging, however, there is a paucity of information surrounding the costs relative to health gains in the pediatric population. This study aimed to estimate the cost-effectiveness of a pediatric tele-resuscitation (Peds-TECH) intervention compared to the usual care in five community hospital emergency departments (EDs). Using a decision tree analysis approach with secondary retrospective data from a 3-year time period, this cost-effectiveness analysis was completed. A mixed methods quasi-experimental design was embedded in the economic evaluation of Peds-TECH intervention. Patients aged <18 years triaged as Canadian Triage and Acuity Scale 1 or 2 at EDs were eligible to receive the intervention. Qualitative interviews were conducted with parents/caregivers to explore the out-of-pocket (OOP) expenses. Patient-level health resource utilization was extracted from Niagara Health databases. The Peds-TECH budget calculated one-time technology and operational costs per patient. Base-case analyses determined the incremental cost per year of life lost (YLL) averted, and additional sensitivity analysis confirmed the robustness of the results. Odds ratio for mortality among cases was 0.498 (95% CI: 0.173, 1.43). The average cost of a patient receiving the Peds-TECH intervention was $2,032.73 compared to $317.45 in usual care. In total, 54 patients received the Peds-TECH intervention. Fewer children died in the intervention group resulting in 4.71 YLL. The probabilistic analysis revealed an incremental cost-effectiveness ratio of $64.61 per YLL averted. Peds-TECH appears to be a cost-effective intervention for resuscitating infants/children in hospital emergency departments.

ANALISIS FAKTOR PENYEBAB KETERLAMBATAN PENYELESAIAN PADA PROYEK PEMBANGUNAN APARTEMEN URBAN SIGNATURE CIRACAS

The delay in completion of construction that has exceeded the work time target according to the initial agreement is very powerful on the construction project itself. Delays in the project occur due to problems that arise in terms of materials, labor, costs, equipment, environment, and others. In this research, an analysis was carried out on what factors were the cause of the delay in the completion of the superstructure and the rating of the value of the reliability function of each work. The Fault Tree Analysis (FTA) approach would be employed, which is a method that makes use of fault tree analysis in the form of a graphic model based on the outcomes of conducted interviews. In the graphic model, there were several event symbols and logic gate symbols to connect the event symbols. On the graphic model, the simplest cut set was acquired using Boolean algebra and the Method of Obtain Cut Set (MOCUS). Based on the results of the analysis, there were 33 basic events or jobs that experienced delays, including changes in rebar supply by the Owner, limited human resources, a lot of repair work, evaluation of the project schedule, SILO SIO PH licensing, late payments, delays in material delivery, and others. Typical structural work and ladder structures, the Boolean algebra law can be applied because it has a repeating code. Meanwhile, on the roof of the engine room, the law of algebra cannot be applied since the work does not have a repeating code. The reliability function is calculated in the analysis that follows. When all three variables are accurate, the system operates as intended.

Reliability and Criticality Analysis of a Large-Scale Solar Photovoltaic System Using Fault Tree Analysis Approach

Solar Photovoltaic (PV) systems typically convert solar irradiance into electricity, thereby helping to reduce the need for fossil fuels and the amount of greenhouse gases released. They provide a reliable and continuous renewable source of energy. However, PV systems are continuously exposed to diverse and changing environmental conditions, such as temperature, humidity, dust, and rain. Exposure to such conditions creates electrical and visible faults in the PV systems. These faults may reduce the PV system’s performance, reliability, and lifetime. In this regard, this paper aims to propose a framework/methodology for reliability modeling and assessment of large-scale grid-connected PV systems using a Fault Tree Analysis (FTA) approach. Specifically, an exhaustive literature survey is carried out to acquire the failure rates of different components/faults existing on the DC side of the PV system. Then, the Fussel-Vesely (F-V) importance measure is employed to identify critical faults and their criticality ranking. Results showed that solder bond failure, broken cell, broken interconnect (finger interruption), rack structure, grounding/lightning protection system, delamination, discoloration, and partial shading are the most critical faults which severely degrade the performance of the PV systems. The recommendations and scope for further study are provided to optimize operations and maintenance costs.

Where Failures May Occur in Automated Driving: A Fault Tree Analysis Approach

There will be circumstances where partial or conditionally automated vehicles fail to drive safely and require human interventions. Within the human factors community, the taxonomies surrounding control transitions have primarily focused on characterizing the stages and sequences of the transition between the automated driving system (ADS) and the human driver. Recognizing the variance in operational design domains (ODDs) across vehicles equipped with ADS and how variable the takeover situations may be, we describe a simple taxonomy of takeover situations to aid the identification and discussions of takeover scenarios in future takeover studies. By considering the ODD structure and the human information processing stages, we constructed a fault tree analysis (FTA) aimed to identify potential failure sources that would prevent successful control transitions. The FTA was applied in analyzing two real-world accidents involving ADS failures, illustrating how this approach can help identify areas for improvements in the system, interface, or training design to support drivers in level 2 and level 3 automated driving.