Sharif Digital Repository

Cardiovascular disease is one of the leading causes of death and mortality. among these diseases, heart muscle inability, especially acute decompensated heart failure is very common. There are several methods to diagnose and monitor this disease, but a method that is accurate, non-invasive, portable and easy to access and easy to measure without multiple visits to the clinic; Priority for use. Early detection and continuous monitoring of fluid status by measuring the bio-impedance (Bio-Z) measurement of thoracic magnitude or phase is critical in reducing the mortality of chronic heart failure (CHF) patients. In this dissertation, for monitoring chronic heart failure, bio-impedance chips with... 

Accurate housing price prediction has long been a strategic issue in economic market analysis and urban decision-making. Due to the structural complexity of the housing market—characterized by hidden variables, incomplete data, and nonlinear relationships among influencing factors—traditional models often fail to provide sufficient accuracy. This study aims to design and evaluate a hierarchical machine learning framework to improve housing price prediction under the non-ideal data conditions of Iran’s market. In the first stage, latent or incomplete macroeconomic variables such as daily exchange rate and gold price were estimated using intermediate models, including the SARIMA algorithm. The... 

The location problem is one of the main topics at the strategic level. This problem is investigated along with many areas such as network design and path covering problems. Routing between source and destination nodes is done in such a way that maximizes traffic coverage and reduces costs as much as possible. Routing problems are considered in goods distribution areas and urban transit systems. Goods distribution from set of cross-docks can help to reduce costs and improve resource efficiency. So, this topic is considered in this research and a suitable model is proposed. Defining and developing of the road and rail transportation networks are main topics in urban traffic management which... 

High Swirl Combustors can provide stable flames in wide range of operating conditions. Double swirl combustors, as one of the newest designs in this field, have particular effects on improving the efficiency of combustion chambers in terms of flame stability, mixing process quality and reducing combustion pollutants. In this study, a double swirl gas turbine combustor, SGTMC, which is redesigned version of a German combustor (GTMC), has been investigated. According to experimental section of this study, lean stability limits, UHCs, CO and NOx has been measured and analyzed. Results show that this burner can provide a stable flame even in very low equivalence ratios. Also in some specific... 

We explain a new trust region algorithm for solving unconstrained optimization problems where the redius update is computed using the model information at the current iterate rather than at the preceding one, recently proposed by Bastin, Malmedy, Mouffe, Toint and Tomanos. Then we discuss a modification mixing the concepts of nonmonotone trust region, line search and internal doubling. We use line search to finds a point that satisfies the Wolfe conditions. After that, we explain a new trust region algorithm for solving unconstrained optimization problems where simultaneously satisfies the quasi-Newton condition at each iteration and maintains a positive-definite approximation to the Hessian... 

The pharmaceutical industry, as one of the most vital pillars of the healthcare system, plays a key role in improving quality of life. Rising global demand, coupled with threats such as natural disasters, pandemics, and shortages of raw materials, has highlighted the necessity of redesigning pharmaceutical supply chains with a resilience-oriented approach. This study proposes a multi-objective mathematical model for designing a pharmaceutical supply chain network that enhances system efficiency by minimizing costs, unmet demand, and delivery time. The model also accounts for drug perishability and defines disposal centers for the safe elimination of expired medicines. To address demand... 

In the contemporary era where organizations face increasing competition in the global market, human resources analytics has emerged as a crucial strategic tool. Human resources data analysis enables organizations to make more effective workforce management decisions through a systematic and data-driven approach. The primary challenge addressed in this research is the complexity of optimal human resource allocation across various job positions. This challenge stems from multiple variables involved in the process, including candidate competencies, organizational requirements, and labor market conditions. The high volume of applicants and job positions in today’s labor market has further... 

In recent years, the popularity and applications of Non-Fungible Tokens (NFTs) have increased dramatically. For this reason, especially in the current decade, many researches have been conducted in different fields about the use of these tokens at the global level. One of the important and vital topics in the field of non-exchangeable tokens is the issues related to price prediction and the factors affecting their prices, which are mainly investigated using data analysis approaches. In this research, the factors affecting the price of non-exchangeable tokens of Bored Ape Yacht Club (BAYC) have been studied. These factors include traits, transaction data, rarity scores, transaction volume,... 

Today, demand function forecasting is one of the fundamental and critical challenges in organizational decision-making at both strategic and operational levels. Key decisions that significantly impact the success or failure of organizations -such as pricing, production planning, resource allocation, and market development- are directly influenced by the accuracy of demand forecasting. Since the demand function is typically affected by multiple factors including price, quality, economic conditions, social factors, and other variables shaping customer behavior, precise estimation requires employing diverse and accurate methods. Various approaches have been proposed in the literature for demand... 

Implementation of various incentive-based demand response strategies has great potential to decrease peak load growth and customer electricity bill cost. Using advanced metering and automatic demand management makes it possible to optimize energy consumption, to reduce grid loss, and to release generation capacities for the sake of providing sustainable electricity supply, and reducing electricity bills for the customers. With these objectives, this thesis examines the previously suggested load scheduling programs in both residential and industrial sectors, and proposes new practical strategies for load management. This thesis has mainly focuses on three subdivisions of load management... 

The main purpose of this thesis is to analyze the total productive maintenance based on computerized maintenance management system. At first, a detailed study on total productive maintenance is performed and then the requirements of this maintenance strategy are specified. Also, a computerized maintenance management system is defined which can help total productive maintenance to reach to its requirements. Finally, a conceptual model and entity-relationship model for computerized maintenance management system data base has been created  

In this thesis, DC transmission of offshore wind farms is studied thoroughly. Various system configurations that are introduced in the literatures are discussed and their control scheme for normal conditions and grid faults are studied. Then, the HVDC transmission based on voltage source converter, located between a local offshore ac grid and the onshore ac system is investigated as the most practical choice. The HVDC linke circuit elements are calculated and the control strategies of the offshore and onshore converters are introduced. DFIGs are considered to be the best choice for the offshore wind turbine generators. Then, the system is simulated and the frequency of the offshore grid is... 

The main aim of this thesis is to develop the technical knowledge of designing and making active ingredients of domestically produced drugs, decreasing the costs, independency in producing these products, and checking outflow of currency. It also aims to reduce the financial challenges of patients who have to pay huge amounts for such drugs. Conducting research in the field of reverse engineering and using its definition, and attempt in made to get knowledge into the stages of product development process, to determine the technical standards associated with each stage, to recognize how knowledge is shared during this process, and to present some methods of establishing the infrastructure... 

Increase in growing concerns over environmental pollution and depletion of fossil fuel resources motivate the need for cleaner energy technologies and stimulate research in facilitating renewable energy systems. In recent years, photovoltaic systems have attracted great attention since they remove the need for energy storage systems and intermediate processess for energy conversion. However, high capital cost, low efficiency and low energy density per area of these systems, as compared with other technologies hinder its industrial use. To surmount these bottlenecks and improve technical performance of PV systems, it is crucial to optimize configuration of convertor connection and to improve...