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• To understand the working principle of support vector machine (SVM).
• To comprehend the rules for identification of correct hyperplane.
• To understand the concept of support vectors, maximized margin, positive and negative hyperplanes.
• To apply an SVM classifier for a linear and non-linear dataset.
• To understand the process of mapping data points to higher dimensional space.
• To comprehend the working principle of the SVM Kernel.
• To highlight the applications of SVM.
10.1 Support Vector Machines
Support vector machines (SVMs) are supervised machine learning (ML) models used to solve regression and classification problems. However, it is widely used for solving classification problems. The main goal of SVM is to segregate the n-dimensional space into labels or classes by defining a decision boundary or hyperplanes. In this chapter, we shall explore SVM for solving classification problems.
10.1.1 SVM Working Principle
SVM Working Principle | Parteek Bhatia, https://youtu.be/UhzBKrIKPyE
To understand the working principle of the SVM classifier, we will take a standard ML problem where we want a machine to distinguish between a peach and an apple based on their size and color.
Let us suppose the size of the fruit is represented on the X-axis and the color of the fruit is on the Y-axis. The distribution of the dataset of apple and peach is shown in Figure 10.1.
To classify it, we must provide the machine with some sample stock of fruits and label each of the fruits in the stock as an “apple” or “peach”. For example, we have a labeled dataset of some 100 fruits with corresponding labels, i.e., “apple” or “peach”. When this data is fed into a machine, it will analyze these fruits and train itself. Once the training is completed, if some new fruit comes into the stock, the machine will classify whether it is an “apple” or a “peach”.
Most of the traditional ML algorithms would learn by observing the perfect apples and perfect peaches in the stock, i.e., they will train themselves by observing the ideal apples of stock (apples which are very much like apples in terms of their size and color) and the perfect peaches of stock (peaches which are very much like peaches in terms of their size and color). These standard samples are likely to be found in the heart of stock. The heart of the stock is shown in Figure 10.2.
After careful study of this chapter, students should be able to do the following:
LO1: Identify stress concentration in machine members.
LO2: Explain stress concentration from the theory of elasticity approach.
LO3: Calculate stress concentration due to a circular hole in a plate.
LO4: Analyze stress concentration due to an elliptical hole in a plate.
LO5: Evaluate notch sensitivity.
LO6: Create designs for reducing stress concentration.
9.1 INTRODUCTION [LO1]
Stresses given by relatively simple equations in the strength of materials for structures or machine members are based on the assumed continuity of the elastic medium. However, the presence of discontinuity destroys the assumed regularity of stress distribution in a member and a sudden increase in stresses occurs in the neighborhood of the discontinuity. In developing machines, it is impossible to avoid abrupt changes in cross-sections, holes, notches, shoulders, etc. Abrupt changes in cross-section also occur at the roots of gear teeth and threads of bolts. Some examples are shown in Figure 9.1.
Any such discontinuity acts as a stress raiser. Ideally, discontinuity in materials such as non-metallic inclusions in metals, casting defects, residual stresses from welding may also act as stress raisers. In this chapter, however, we shall consider only the geometric discontinuity that arises from design considerations of structures or machine parts.
Many theoretical methods and experimental techniques have been developed to determine stress concentrations in different structural and mechanical systems. In order to understand the concept, we shall begin with a plate with a centrally located hole. The plate is subjected to uniformly distributed tensile loading at the ends, as shown in Figure 9.2.
This chapter develops a modal structuralist understanding of our experience of time, of causes, and of the robust particularity present in our visual experience of ordinary environmental objects.
• To define machine learning (ML) and discuss its applications.
• To learn the differences between traditional programming and ML.
• To understand the importance of labeled and unlabeled data and its various usage for ML.
• To understand the working principle of supervised, unsupervised, and reinforcement learnings.
• To understand the key terms like data science, data mining, artificial intelligence, and deep learning.
1.1 Introduction
In today’s data-driven world, information flows through the digital landscape like an untapped river of potential. Within this vast data stream lies the key to unlocking a new era of discovery and innovation. Machine learning (ML), a revolutionary field, acts as the gateway to this wealth of opportunities. With its ability to uncover patterns, make predictive insights, and adapt to evolving information, ML has transformed industries, redefined technology, and opened the door to limitless possibilities. This book is your gateway to the fascinating realm of ML—a journey that empowers you to harness the power of data, enabling you to build intelligent systems, make informed decisions, and explore the boundless possibilities of the digital age.
ML has emerged as the dominant approach for solving problems in the modern world, and its wide-ranging applications have made it an integral part of our lives. Right from search engines to social networking sites, everything is powered by ML algorithms. Your favorite search engine uses ML algorithms to get you the appropriate search results. Smart home assistants like Alexa and Siri use ML to serve us better. The influence of ML in our day-to-day activities is so much that we cannot even realize it. Online shopping sites like Amazon, Flipkart, and Myntra use ML to recommend products. Facebook is using ML to display our feed. Netflix and YouTube are using ML to recommend videos based on our interests.
Data is growing exponentially with the Internet and smartphones, and ML has just made this data more usable and meaningful. Social media, entertainment, travel, mining, medicine, bioinformatics, or any field you could name uses ML in some form.
To understand the role of ML in the modern world, let us first discuss the applications of ML.
After careful study of this chapter, students should be able to do the following:
LO1: Identify the difference between engineering mechanics and the theory of elasticity approach.
LO2: Explain yielding and brittle fracture.
LO3: Describe the stress–strain behavior of common engineering materials.
LO4: Compare hardness, ductility, malleability, toughness, and creep.
LO5: Explain different hardness measurement techniques.
1.1 INTRODUCTION [LO1]
Mechanics is one of the oldest physical sciences, dating back to the times of Aristotle and Archimedes. The subject deals with force, displacement, and motion. The concepts of mechanics have been used to solve many mechanical and structural engineering problems through the ages. Because of its intriguing nature, many great scientists including Sir Isaac Newton and Albert Einstein delved into it for solving intricate problems in their own fields.
Engineering mechanics and mechanics of materials developed over centuries with a few experiment-based postulates and assumptions, particularly to solve engineering problems in designing machines and structural parts. Problems are many and varied. However, in most cases, the requirement is to ensure sufficient strength, stiffness, and stability of the components, and eventually those of the whole machine or structure. In order to do this, we first analyze the forces and stresses at different points in a member, and then select materials of known strength and deformation behavior, to withstand the stress distribution with tolerable deformation and stability limits. The methodology has now developed to the extent of coding that takes into account the whole field stress, strain, deformation behaviors, and material characteristics to predict the probability of failure of a component at the weakest point. Inputs from the theory of elasticity and plasticity, mathematical and computational techniques, material science, and many other branches of science are needed to develop such sophisticated coding.
The theory of elasticity too developed but as an applied mathematics topic, and engineers took very little notice of it until recently, when critical analyses of components in high-speed machinery, vehicles, aerospace technology, and many other applications became necessary. The types of problems considered in both the elementary strength of material and the theory of elasticity are similar, but the approaches are different. The strength of the materials approach is generally simple. Here the emphasis is on finding practical solutions to a problem with simplifying assumptions.
In a small, rectangular dimly lit room, Khatun Shaikh, a female qazi (Islamic judge) in a women's sharia court, lent a patient ear to women who approached her with complaints of marital discord and violence. The sharia court is an alternative dispute resolution forum run by members of the Bharatiya Muslim Mahila Andolan (Indian Muslim Women's Movement, henceforth BMMA), a social movement led by Muslim women aimed at achieving equality and justice in the adjudication of Muslim family law in India. These alternative forums were frequented by women from poor neighbourhoods in Mumbai who did not have the wherewithal to access the formal justice system. As cases of marriage, divorce, maintenance and domestic violence were discussed and debated in these forums, quarrels broke out between the spouses and their relatives. Allegations of abuse and counter-allegations flew thick and fast. In the midst of these heated exchanges between spouses, Shaikh often emphasised the importance of raham (compassion) as an everyday, lived ethical ideal that both the spouses ought to practice. While the disputes revolved around women claiming specific rights during and after the breakdown of their marriage, Shaikh insisted on how both men and women needed to be compassionate. According to Shaikh, one could display compassion in moments of crisis in the marriage by avoiding the use of harsh words, refraining from overt displays of anger and addressing each other respectfully. This practice of compassion thus entailed using the body in specific ways while claiming one's rights. Shaikh construed compassion as a lived ideal that resonated with the teachings of the Quran and the life of the Prophet. The pursuit of this ideal was closely tethered to the realisation of equality (barabari) and justice (insaf) in the domain of the family.
The sharia court emerged as a space of self-making for both the activists of the BMMA and the women visiting the court. Women spoke their mind. They spoke about the violence and injustice in the family. Interactions between activists, lawyers and the women who visited these forums helped in creating a supportive community space for women who faced injustice in their marital homes. On some days, the court room also doubled as a space where activists of the BMMA conducted training sessions on Muslim family law, the Quran and the Constitution for women of the neighbourhood.
After careful study of this chapter, students should be able to do the following:
LO1: Describe constitutive equations.
LO2: Relate the elastic constants.
LO3: Recognize boundary value problems.
LO4: Explain St. Venant's principle.
LO5: Describe the principle of superposition.
LO6: Illustrate the uniqueness theorem.
LO7: Develop stress function approach.
4.1 CONSTITUTIVE EQUATIONS [LO1]
So far, we have discussed the strain and stress analysis in detail. In this chapter, we shall link the stress and strain by considering the material properties in order to completely describe the elastic, plastic, elasto-plastic, visco-elastic, or other such deformation characteristics of solids. These are known as constitutive equations, or in simpler terms the stress–strain relations. There are endless varieties of materials and loading conditions, and therefore development of a general form of constitutive equation may be challenging. Here we mainly consider linear elastic solids along with their mechanical properties and deformation behavior.
Fundamental relation between stress and strain was first given by Robert Hooke in 1676 in the most simplified manner as, “Force varies as the stretch”. This implies a load–deflection relation that was later interpreted as a stress–strain relation. Following this, we can write P = kδ, where P is the force, δ is the stretch or elongation, and k is the spring constant. This can also be written for linear elastic materials as σ = E∈, where σ is the stress, ∈ is the strain, and E is the modulus of elasticity. For nonlinear elasticity, we may write in a simplistic manner σ = E∈n, where n ≠ 1.
Hooke's Law based on this fundamental relation is given as the stress–strain relation, and in its most general form, stresses are functions of all the strain components as shown in equation (4.1.1).
This chapter explores the question of whether the epistemology of the secret of international law and the necessities it puts in place can be resisted. No definite answer to that question is sought here and only tentative reflections on the possibility of resisting the epistemology of the secret are provided in the following paragraphs. This chapter proceeds as follows. This chapter starts by elaborating on why it matters to spare no effort to resist the epistemology of the secret and rein in its consequences. The chapter then recalls that a mere termination or discontinuation of the epistemology of the secret, of its necessities, and of all the literary, hermeneutical, critical, economic, and ideological attitudes it entails is an impossibility. Resistance, it is subsequently argued, can only take the form of an act of obnubilation, a notion whose concrete implications for international legal thought and practice are subsequently spelled out.
• To understand the concept of artificial neural network (ANN).
• To comprehend the working of the human brain as an inspiration for the development of neural network.
• To understand the mapping of human brain neurons to an ANN.
• To understand the working of ANN with case studies.
• To understand the role of weights in building ANN.
• To perform forward and backward propagation to train the neural networks.
• To understand different activation functions like threshold function, sigmoid function, rectifier linear unit function, and hyperbolic tangent function.
• To find the optimized value of weights for minimizing the cost function by using the gradient descent approach and stochastic gradient descent algorithm.
• To understand the concept of the mini-batch method.
16.1 Introduction to Artificial Neural Network
Neural networks and deep learning are the buzzwords in modern-day computer science. And, if you think that these are the latest entrants in this field, you probably have a misconception. Neural networks have been around for quite some time, and they have only started picking up now, putting up a huge positive impact on computer science.
Artificial neural network (ANN) was invented in the 1960s and 1970s. It became a part of common tech talks, and people started thinking that this machine learning (ML) technique would solve all the complex problems that were challenging the researchers during that time. But sooner, the hopes and expectations died off over the next decade.
The decline could not be attributed to some loopholes in neural networks, but the major reason for the decline was the “technology” itself. The technology back then was not up to the right standard to facilitate neural networks as they needed a lot of data for training and huge computation resources for building the model. During that time, both data and computing power were scarce. Hence, the resulting neural network remained only on paper rather than taking centerstage of the machine to solve some real-world problems.
Later on, at the beginning of the 21st century, we saw a lot of improvements in storage techniques resulting in reduced cost per gigabyte of storage. Humanity witnessed a huge rise in big data due to the Internet boom and smartphones.
I have been frustrated for five years now. I just want chutkara [riddance] from my husband. Nothing else.
When will this issue [triple talaq] be resolved? When will this issue be resolved? For how long will poor helpless women keep approaching us with issues of talaq? Will we keep running such adalat [women shariat adalats] forever? At some point, this must become the law. At some point, people like us [Muslim women] need to be involved in law-making.
On 22 August 2017, the majority judgments of the Supreme Court of India pronounced oral, unilateral divorce, known in popular parlance as triple talaq, un-Islamic and hence illegal. A few months following the Supreme Court judgment, the right-wing BJP government proposed a legislation to criminalise the practice of triple talaq. While the fight to declare triple talaq unconstitutional had united most Muslim women's groups, the move to criminalise the practice saw a wide chasm between multiple voices seeking to represent Muslim women and a Muslim community. Across the country, a public sphere of fierce debate about law reform was shaped by competing voices that sought to speak for the Muslim community. However, this debate did not fundamentally challenge the idea of a homogenous Muslim community whose identity rests on a state-defined conception of Muslim personal law based on a gendered division of labour in the heterosexual family. Against the backdrop of this fierce debate, women navigating the legal domain of the women's shariat adalat in Mumbai – a space which is also a part of the BMMA's struggle for gender justice in community spaces – continually challenged the narrative of a homogeneous Muslim community founded on a Muslim family. The logic of the shariat adalat was based on a recognition of the violence and fragility of the family and the fluidity of gendered roles in the family. It provided women with a space of comfort where they could openly talk about the violence of the family and fight for a divorce at points of crisis in the heterosexual family. In that sense, the alternative dispute resolution forums were semi-public spaces situated in between the public sphere of debate on law reform and the home. These spaces provided a supportive environment where women could talk about the violence at home.
• To implement the k-means clustering algorithm in Python.
• To determining the ideal number of clusters by implementing its code.
• To understand how to visualize clusters using plots.
• To create the dendrogram and find the optimal number of clusters for agglomerative hierarchical clustering.
• To compare results of k-means clustering with agglomerative hierarchical clustering.
• To implement clustering through various case studies.
13.1 Implementation of k-means Clustering and Hierarchical Clustering
In the previous chapter, we discussed various clustering algorithms. We learned that clustering algorithms are broadly classified into partitioning methods, hierarchical methods, and density-based methods. The k-means clustering algorithm follows partitioning method; agglomerative and divisive algorithms follow the hierarchical method, while DBSCAN is based on density-based clustering methods.
In this chapter, we will implement each of these algorithms by considering various case studies by following a step-by-step approach. You are advised to perform all these steps on your own on the mentioned databases stated in this chapter.
The k-means algorithm is considered a partitioning method and an unsupervised machine learning (ML) algorithm used to identify clusters of data items in a dataset. It is one of the most prominent ML algorithms, and its implementation in Python is quite straightforward. This chapter will consider three case studies, i.e., customers shopping in the mall dataset, the U.S. arrests dataset, and a popular Iris dataset. We will understand the significance of k-means clustering techniques to implement it in Python through these case studies. Along with the clustering of data items, we will also discuss the ways to find out the optimal number of clusters. To compare the results of the k-means algorithm, we will also implement hierarchical clustering for these problems.
We will kick-start the implementation of the k-means algorithm in Spyder IDE using the following steps.
Step 1: Importing the libraries and the dataset—The dataset for the respective case study would be downloaded, and then the required libraries would be imported.
Step 2: Finding the optimal number of clusters—We will find the optimal number of clusters by the elbow method for the given dataset.
Step 3: Fitting k-means to the dataset—A k-means model will be prepared by training the model over the acquired dataset.
Step 4: Visualizing the clusters—The clusters formed by the k-means model would then be visualized in the form of scatter plots.
A small room at the end of a courtyard housed the sharia adalat of the Indian Muslim Women's Movement (BMMA) in Mumbai. A group of men and women waited inside the room as the female judge (qazi) presided over cases. The female qazi usually sat in one corner of the rectangular room surrounded by some other activists of the BMMA as she heard cases of divorce, marriage and maintenance. Though this was an alternative dispute resolution forum meant to adjudicate Muslim personal law, the cases often included instances of criminal violations such as domestic violence. On the days when the shariat adalat was not hearing cases, this space hosted meetings with human rights organisations that trained women in approaching the police in instances of domestic violence. Stacks of leaflets and pamphlets provided by this human rights organisation lay in one corner of the sharia adalat. These resource materials provided details of how women citizens could access the police, how an FIR might be filed in a police station, and so on. These materials circulated within and beyond the shariat court. Activists of the BMMA distributed these materials to women who frequented the sharia court. They also distributed these materials in neighbourhoods in Mumbai where they conducted workshops on issues of gender equality and Muslim law with women. Some activists of the BMMA were also part of other activist networks. They frequented the meetings with senior police officials organised and facilitated by the members of the MCMT. In these meetings, activists exchanged pleasantries with police officials even as they recounted the difficulties that they faced in approaching the police. These events were held once a month in an auditorium where several activist groups and non-governmental organisations would assemble.
During the hearings of the cases, state laws were often invoked rhetorically by the qazi to convince men to pay post-divorce maintenance to their wives. The coercion of the state and state law remained an imminent threat, under the shadow of which marriage, divorce and maintenance claims were adjudicated by the female qazi. Deliberations on criminalising a certain form of oral, unilateral divorce by the right-wing BJP government found their way to the sharia adalat.