Data Science Project

I have subscription of ineuron (tech neuron). Anyone interested please let me know. It is paid.

Date: 07-12-2022 Company name: Wipro Role: Data scientist Topic: knn , imputation, n gram, data mining 1. What is the difference between data mining and data profiling. Data mining Process: It generally involves analyzing data to find relations that were not previously discovered. In this case, the emphasis is on finding unusual records, detecting dependencies, and analyzing clusters. Data Profiling Process: It generally involves analyzing that data's individual attributes. In this case, the emphasis is on providing useful information on data attributes such as data type, frequency, etc. 2. Explain the KNN imputation method. A KNN (K-nearest neighbor) model is usually considered one of the most common techniques for imputation. It allows a point in multidimensional space to be matched with its closest k neighbors. By using the distance function, two attribute values are compared. Using this approach, the closest attribute values to the missing values are used to impute these missing values.  3. Explain Hierarchical clustering. This algorithm group objects into clusters based on similarities, and it is also called hierarchical cluster analysis. When hierarchical clustering is performed, we obtain a set of clusters that differ from each other. This clustering technique can be divided into two types: Agglomerative Clustering (which uses bottom-up strategy to decompose clusters) Divisive Clustering (which uses a top-down strategy to decompose clusters) 4. Explain N-gram N-gram, known as the probabilistic language model, is defined as a connected sequence of n items in a given text or speech.  It is basically composed of adjacent words or letters of length n that were present in the source text. In simple words, it is a way to predict the next item in a sequence, as in (n-1).

Date: 30-11-2022 Company name: TCS Role: Data Analyst Topic : data cleaning, data wrangling, cte in sql 1. Define the term 'Data Wrangling. Data Wrangling is the process wherein raw data is cleaned, structured, and enriched into a desired usable format for better decision making. It involves discovering, structuring, cleaning, enriching, validating, and analyzing data. This process can turn and map out large amounts of data extracted from various sources into a more useful format. 2. What are the best methods for data cleaning? Create a data cleaning plan by understanding where the common errors take place and keep all the communications open. Before working with the data, identify and remove the duplicates. This will lead to an easy and effective data analysis process.Focus on the accuracy of the data. Set cross-field validation, maintain the value types of data, and provide mandatory constraints.Normalize the data at the entry point so that it is less chaotic. You will be able to ensure that all information is standardized, leading to fewer errors on entry. 3. Explain 4 steps to use CTE in sql. All CTE starts with "with" clause. After with you need to define CTE name and the field names. For instance in the below code snippet I have 3 fields Count,Column and Id. The name of CTE is "MyTemp". Once you have defined CTE we need to specify the SQL which will give the result for the CTE. Finally you can use the CTE in your SQL query.

Company name: IKEA Role: Data Analyst Topic: powerbi, cte, data manipulation 1. What are the various types of refresh options provided in Power BI? Package refresh - This synchronizes your Power BI Desktop or Excel file between the Power BI service and OneDrive, or SharePoint Online. Model or data refresh - This refreshes the dataset within the Power BI service with data from the original data source. Tile refresh - This updates the cache for tile visuals every 15 minutes on the dashboard once data changes. Visual container refresh - This refreshes the visible container and updates the cached report visuals within a report once the data changes. 2. Explain some date manipulation functions in SQL. Getdate: As its name suggests, the getdate function gives us today’s date. Dateadd: The dateadd function is used for adding a time or date interval to a date.Datediff: The datediff function is used for calculating the difference between two dates based on a given interval. Datename: The datename function can be used for extracting the parts of a date.  Year, month, day: The year, month, and day functions allow for decomposing a date. 3. What is CTE in SQL? A CTE (Common Table Expression) is a one-time result set that only exists for the duration of the query. It allows us to refer to data within a single SELECT, INSERT, UPDATE, DELETE, CREATE VIEW, or MERGE statement's execution scope. It is temporary because its result cannot be stored anywhere and will be lost as soon as a query's execution is completed.

Date: 26-11-2022 Company name: Hitachi Role: SQL Developer Topic :SQL vs MySQL, pattern match, cross join, stored procedure 1. What is the difference between SQL and MySQL? SQL is a standard language for retrieving and manipulating structured databases. On the contrary, MySQL is a relational database management system, like SQL Server, Oracle or IBM DB2, that is used to manage SQL databases. 2. What is a Cross-Join? Cross join can be defined as a cartesian product of the two tables included in the join. The table after join contains the same number of rows as in the cross-product of the number of rows in the two tables. If a WHERE clause is used in cross join then the query will work like an INNER JOIN. 3. What is a Stored Procedure? A stored procedure is a subroutine available to applications that access a relational database management system (RDBMS). Such procedures are stored in the database data dictionary. The sole disadvantage of stored procedure is that it can be executed nowhere except in the database and occupies more memory in the database server. 4. What is Pattern Matching in SQL? SQL pattern matching provides for pattern search in data if you have no clue as to what that word should be. This kind of SQL query uses wildcards to match a string pattern, rather than writing the exact word. The LIKE operator is used in conjunction with SQL Wildcards to fetch the required information.

From today be attentive in group.

Sorry guys, I was busy busy these days because I was traveling to Bengaluru.

Stress Detection Project using Machine Learning Python https://www.nomidl.com/projects/stress-detection-project-using-machine-learning/

Date: 29-10-2022 Role: Data Analyst Company – MorningStar Topic: Python, SQL, PowerBI 1. Is indentation required in python? Indentation is necessary for Python. It specifies a block of code. All code within loops, classes, functions, etc is specified within an indented block. It is usually done using four space characters. If your code is not indented necessarily, it will not execute accurately and will throw errors as well. 2. What are Entities and Relationships? Entity: An entity can be a real-world object that can be easily identifiable. For example, in a college database, students, professors, workers, departments, and projects can be referred to as entities. Relationships: Relations or links between entities that have something to do with each other. For example – The employee’s table in a company’s database can be associated with the salary table in the same database. 3.  What is a stored procedure? Stored Procedure is a function consists of many SQL statements to access the database system. Several SQL statements are consolidated into a stored procedure and execute them whenever and wherever required. 4.  What is Auto Increment? Auto increment keyword allows the user to create a unique number to be generated when a new record is inserted into the table. AUTO INCREMENT keyword can be used in Oracle and IDENTITY keyword can be used in SQL SERVER. Mostly this keyword can be used whenever PRIMARY KEY is used. 5.  Which operator is used in query for pattern matching? LIKE operator is used for pattern matching, and it can be used as -. 1.   % – Matches zero or more characters. 2.   _(Underscore) – Matching exactly one character.

Date: 12-11-2022 Company name: DataZymes Role: Database Developer Topic: E-R model, Attribute, Relation, database transaction, atomicity 1. What do you understand about the E-R model? Answer: E-R model is an Entity-Relationship model which defines the conceptual view of the database. The E-R model basically shows the real-world entities and their association/relations. Entities here represent the set of attributes in the database. 2. Explain the terms ‘Attribute’ and ‘Relations’ Answer: Attribute is described as the properties or characteristics of an entity. For Example, Employee ID, Employee Name, Age, etc., can be attributes of the entity Employee. Relation is a two-dimensional table containing a number of rows and columns where every row represents a record of the relation. Here, rows are also known as ‘Tuples’ and columns are known as ‘Attributes’. 3. What is the Database transaction? Answer: Sequence of operation performed which changes the consistent state of the database to another is known as the database transaction. After the completion of the transaction, either the successful completion is reflected in the system or the transaction fails and no change is reflected. 4. What do you understand about ‘Atomicity’ and ‘Aggregation’? Answer: Atomicity is the condition where either all the actions of the transaction are performed or none. This means, when there is an incomplete transaction, the database management system itself will undo the effects done by the incomplete transaction. Aggregation is the concept of expressing the relationship with the collection of entities and their relationships.

Date: 11-11-2022 Company name: Walmart role: Data Scientist Topic: pooling, relative cell excel, where vs having,  moving average 1.What are the different types of Pooling? Explain their characteristics. Max pooling: Once we obtain the feature map of the input, we will apply a filter of determined shapes across the feature map to get the maximum value from that portion of the feature map. It is also known as subsampling because from the entire portion of the feature map covered by filter or kernel we are sampling one single maximum value. Average pooling: Computes the average value of the feature map covered by kernel or filter, and takes the floor value of the result. Sum pooling: Computes the sum of all elements in that window. 2. What is a Moving Average Process in Time series? In time-series analysis, moving-average process, is a common approach for modeling univariate time series. The moving-average model specifies that the output variable depends linearly on the current and various past values of a stochastic term. 3. What is the difference between SQL having vs where? The WHERE clause specifies the criteria which individual records must meet to be selected by a query. It can be used without the GROUP by clause. The HAVING clause cannot be used without the GROUP BY clause . The WHERE clause selects rows before grouping. The HAVING clause selects rows after grouping. The WHERE clause cannot contain aggregate functions. The HAVING clause can contain aggregate functions 4. What is Relative cell referencing in excel? In Relative referencing, there is a change when copying a formula from one cell to another cell with respect to the destination. cells’ address Meanwhile, there is no change in Absolute cell referencing when a formula is copied, irrespective of the cell’s destination. This type of referencing is there by default. Relative cell referencing doesn’t require a dollar sign in the formula.

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