CS 412: Introduction to Data Mining Course Syllabus Course Description This course is an introductory course on data mining. It introduces the basic concepts, principles, methods, implementation techniques, and applications of data mining, with a focus on two major data mining functions: (1) pattern discovery and (2) cluster analysis.In this schedule page, you will find the list of assignments you will have to complete this semester: L#: These are the PrairieLearn Lecture Assignments including the pre-recorded lectures and short questions testing concepts introduced in the videos. These PL assessments will also include links to lecture notes, slides and annotations from the ...Quizzes will be available from Wednesday until Saturday (this is what we call the Quiz Period) for students in sections M and N. Students in section ZJ1 will take the quiz during class time (Thursdays 8pm CT) at the CBTF in China. The policies of the CBTF are the policies of this course, and academic integrity infractions related to the CBTF ...Induced (or operator) matrix norms are associated with a specific vector norm ‖ ⋅ ‖ and are defined as: ‖ A ‖ := max ‖ x ‖ = 1 ‖ A x ‖. An induced matrix norm is a particular type of a general matrix norm. Induced matrix norms tell us the maximum amplification of the norm of any vector when multiplied by the matrix.There are two sections of CS 357: Section N: In-person, TR 12:30pm - 1:45pm CT, CIF 0035. Section M: Online, TR 12:30pm - 1:45pm CT (no assigned classroom) ALL students will have to complete the SAME assessments via PrairieLearn: homework, quizzes, group activities, machine problems. CS 357 is a flipped course, thus all course content will be ...Office hours. Office hours will start from week 2 . Most office hours will be offered in-person at the Siebel basement (tutoring rooms). We also provide virtual office hours, marked with (*) in the table below. Each course staff will be using their own virtual conference meeting for office hours. You can find their links by clicking on their ...Gaussian Elimination — Hand Calculations. The elimination phase transforms the matrix and right hand side to an equivalent system. x1 + 3x2 = 5 2x1 + 4x2 = 6. ! x1 + 3x2 = 5 -2x2 = -4. The two systems have the same solution. The right hand system is upper triangular. Solve the second equation for x2. -4. x2 = = 2.This subreddit is for anyone/anything related to UIUC. Students, Alumni, Faculty, and Townies are all welcome. Given the lack of a regional subreddit, it also covers most things in the Champaign-Urbana area. This subreddit is not sponsored or endorsed by the University of Illinois or any other on-campus group.123-867-5309 123 College St. Champaign, IL 61820. Computer Science, BS-MCS. for the joint degree of Bachelor of Science in Computer Scienceand Master of Computer Science in Computer Science. The five-year B.S.-M.C.S. program in Computer Science combines two degrees: a B.S. in Computer Science with an M.C.S. in Computer Science.2020-02-19 Peter Sentz [email protected]: Add section on role of constants, change Big-Oh's to "mathcal" 2020-01-26 Wanjun Jiang [email protected]: add scientific notations, digits and figures; 2018-01-31 Aming Ni [email protected]: changed three graphs; 2018-01-16 Yu Meng [email protected]: minor fixes throughoutCS 357 Alumni; Corporate; People; My.CS; University of Illinois at Urbana-Champaign ... My.CS; University of Illinois at Urbana-Champaign. The Grainger Technical of Engineering. Computer Science. Search. Menu. Hunt. About. About. Rankings & Statistics; Contact Ours & Office Locations; Our Project ... B.S. in Mathematics & Computer Science; B.S ...Schedule. L#: These are the PrairieLearn Pre-Lecture Assignments including the pre-recorded lectures and short questions testing concepts introduced in the videos. These PL assessments will also include links to lecture notes, slides and annotations from the lectures. You will have pre-lecture assignments opening every Tuesday and Thursday.CS 357 Fall 2021. Syllabus; Schedule; Support; Collaborate; Quizzes; Resources; Resources; This site was for the Fall 2021 semester and is not maintained. For the ...Sorry for this stupid question, I'm not quite familiar with the credit system :) [CS 357]: Numerical Methods I -- 3 hours -- Offered in Spring 2021 -- Recent Average GPA: 3.16. [CS 450]: Numerical Analysis -- 3 or 4 hours -- Offered in Spring 2021 -- Recent Average GPA: 3.16. A great question for an advisor.Schedule. L#: These are the PrairieLearn Pre-Lecture Assignments including the pre-recorded lectures and short questions testing concepts introduced in the videos. These PL assessments will also include links to lecture notes, slides and annotations from the lectures. You will have pre-lecture assignments opening every Tuesday and Thursday.CS 357 Fall 2021. Syllabus; Schedule; Support; Collaborate; Quizzes; Resources; Resources; This site was for the Fall 2021 semester and is not maintained. For the latest content, please visit the course website for this semester. Learning resources. Online …https://mfsilva.web.illinois.edu [email protected] Research Area: Computers and Education •Started teaching at UIUC Sp2012 ... •Teaching CS 357 since Sp2018.2020-04-28 Mariana Silva [email protected]: moved rounding content to a separate page; 2020-01-26 Wanjun Jiang [email protected]: add normalized fp numbers, and some examples; 2018-01-14 Erin Carrier [email protected]: removes demo links; 2017-12-13 Adam Stewart [email protected]: fix incorrect formula under number systems and basesWe can achieve this by carrying out PCA algorithm with the following steps: Shift the data set A so that it has zero mean: A = A − A. mean(). Compute SVD for the original data set: A = UΣVT. Note that the variance of the data set are determined by the singular values of A, i.e. σ1,..., σn. Note that the columns of V represents the ...https://mfsilva.web.illinois.edu [email protected] Research Area: Computers and Education •Started teaching at UIUC Sp2012 •Taught 10 different courses •Teaching CS …Schedule. L#: These are the PrairieLearn Pre-Lecture Assignments including the pre-recorded lectures and short questions testing concepts introduced in the videos. These PL assessments will also include links to lecture notes, slides and annotations from the lectures. You will have pre-lecture assignments opening every Tuesday and Thursday.how would CS225, CS222, STAT 410, STAT 425, CS 357, and a gen ed be in one sem? title^. Taking these four classes together would save me a lot of stress for upper level CS classes like 340, 374, 421. Also, I'm pretty sure 410 and 425 need to be taken together for CS+stats so its really hard to move these two as a package to other semesters ...CS 357. Fundamentals of numerical methods; floating-point computation, systems of linear equations, approximation of functions and integrals, the single nonlinear equation, and …2017-11-25 Adam Stewart [email protected]: fixes missing partial in Hessian matrix; 2017-11-20 Kaushik Kulkarni [email protected]: fixes table formatting; 2017-11-20 Nate Bowman [email protected]: adds review questions; 2017-11-20 Erin Carrier [email protected]: removes Gauss-Newton/LM, minor rewording and small changes throughoutCS 412: Introduction to Data Mining Course Syllabus Course Description This course is an introductory course on data mining. It introduces the basic concepts, principles, methods, implementation techniques, and applications of data mining, with a focus on two major data mining functions: (1) pattern discovery and (2) cluster analysis.Schedule. L#: These are the PrairieLearn Pre-Lecture Assignments including the pre-recorded lectures and short questions testing concepts introduced in the videos. These PL assessments will also include links to lecture notes, slides and annotations from the lectures. You will have pre-lecture assignments opening every Tuesday and Thursday.CS 357. Numerical methods play an increasingly important role in a wide variety of engineering and physical sciences. In past decades, to test the efficiency of a new aircraft design, an expensive physical prototype had to be built and flown; now, an aerospace engineer can perform this test with an accurate simulation on her laptop.Course format: online vs in-person. We will have two sections of CS 357 in the Fall 2021 semester: Section M: Online, TR 12:30pm - 1:45pm. Section N: In-person, TR 12:30pm - 1:45pm, Location pending. Students registered in either section will have to complete the SAME assessments via PrairieLearn: homework, quizzes, group activities, machine ...CS 423: Operating System Design Fall 2022. Instructor Tianyin Xu [email protected] 4108 Siebel Center Lectures Tue/Thu 14:00-15:15pm ... The University of Illinois at Urbana-Champaign Student Code should also be considered as a part of this syllabus. Students should pay particular attention to Article 1, Part 4: Academic Integrity. ...Learn about the course content, grading policies, and group activities of CS 357, a flipped course on data structures and algorithms. Choose from three sections: M (in-person), N (online), or ZJ1 (online).CS 450 Rant. Midterm 2 was just ridiculous. Ending up guessing like ~12 out of all 22 questions. I understand the material is hard, but it's completely unreasonable to offer a midterm 1 w/ an 85 average and then an impossible midterm 2. I had a 100 in midterm 1 and am expecting a 50 for midterm 2. In many similar classes (namely cs 357 or math ...Computing and Data Science. This new school will provide an even greater depth of resources to our top-5 ranked computer science program and a planned new building, made possible through a generous $50 million gift from Illinois alumnus Thomas M. Siebel. Pending approval by the University of Illinois Board of Trustees and Illinois Board of ...Eigenvalues and Eigenvectors. An eigenvalue of an n × n matrix A is a real or complex scalar λ such that Ax = λx for some nonzero vector x ∈ Rn. This equation is called the eigenvalue equation and any such vector x is called an eigenvector of A corresponding to λ. The eigenvalue equation can be rearranged to (A − λI)x = 0 and because x ...There are two sections of CS 357: Section N: In-person, TR 12:30pm - 1:45pm CT, CIF 0035. Section M: Online, TR 12:30pm - 1:45pm CT (no assigned classroom) ALL students will have to complete the SAME assessments via PrairieLearn: homework, quizzes, group activities, machine problems. CS 357 is a flipped course, thus all course content will be ...Quizzes. Throughout the semester, you will take 6 quizzes (50-minute) that will have a mixture of short questions and short coding questions (similar to the questions that appear in your HW, L, GA and practice assessments). Students will take all quizzes at CBTF. You will need to register for your own quiz using PrairieTest, which will take ...Computing and Data Science. This new school will provide an even greater depth of resources to our top-5 ranked computer science program and a planned new building, made possible through a generous $50 million gift from Illinois alumnus Thomas M. Siebel. Pending approval by the University of Illinois Board of Trustees and Illinois Board of ...CS 357 (MATH 357) - Numerical Methods I; MATH 299 - Computational Tools Linear Alg ... Illinois Computer Science in Chicago 200 South Wacker Drive, 7th Floor Chicago ...CS 357 isn't too much coding. You have a few short and straightforward problems on each homework assignment and the occasional MP which is basically just another homework assignment. Reply Poge_ B.S. Eng. Phys, M.S. EE Alum • ... University of Illinois.Course format: online vs in-person. We will have two sections of CS 357 in the Fall 2021 semester: Students registered in either section will have to complete the SAME …Quizzes. Throughout the semester, you will take 6 quizzes (50-minute) that will have a mixture of short questions and short coding questions (similar to the questions that appear in your HW, L, GA and practice assessments). Students will alternate taking the quizzes at CBTF or online via PrairieTest with Zoom proctoring.The condition number of a square nonsingular matrix A is defined by cond ( A) = κ ( A) = ‖ A ‖ ‖ A − 1 ‖ which is also the condition number associated with solving the linear system A x = b. A matrix with a large condition number is said to be ill-conditioned. The condition number can be measured with any p -norm, so to be precise we ...Office hours. Office hours will start from week 2 . Most office hours will be offered in-person at the Siebel basement (tutoring rooms). We also provide virtual office hours, marked with (*) in the table below. Each course staff will be using their own virtual conference meeting for office hours. You can find their links by clicking on their ...Course Information: Same as MATH 357. Credit is not given for CS 357 if credit for CS 450 has been earned. (Counts for advanced hours in LAS). Prerequisite: One of CS 101, CS 105 or CS 125; MATH 241; one of MATH 225, MATH 415, MATH 416 or ASRM 406. ... Illinois Computer Science in Chicago 200 South Wacker Drive, 7th Floor Chicago, IL 60606 ...CS 357. Numerical methods play an increasingly important role in a wide variety of engineering and physical sciences. In past decades, to test the efficiency of a new aircraft design, an expensive physical prototype had to be built and flown; now, an aerospace engineer can perform this test with an accurate simulation on her laptop. ...Languages. Jupyter Notebook 100.0%. Workspace for CS357. Contribute to rese1f/UIUC-CS357-22SP development by creating an account on GitHub.These quizzes will follow the CS honors code and UIUC Academic Integrity policies. You will be expected to comply with the Student Code, and the course policies provided below. ... CS 357 online quiz policies: Do not: Have someone else in the room with you. If this is impossible, let your proctor know at the beginning of the exam and refrain ...CS 124. CS 128. CS 225. CS 374. CS 233. CS 241. CS 421. CS 100. CS 173. CS 222. MATH 220 or 221. MATH 231. MATH 241. MATH 257,. 415, or 416. Group I. CS 357.Lecture 8 Banded, LU, Cholesky, SVD T. Gambill Department of Computer Science University of Illinois at Urbana-Champaign February 16, 2010 T. Gambill (UIUC) CS 357 February 16, 2010 1 / 54Course Information: Same as MATH 357. Credit is not given for CS 357 if credit for CS 450 has been earned. (Counts for advanced hours in LAS). Prerequisite. A 100-level computer science course; MATH 225 or MATH 415; MATH 241. Learning Objectives. Analyze the sources of errors in mathematical operations on the computerThe due dates are indicated in the lecture schedule (the schedule may be subjected to changes during the semester). Each MP is due at 8pm on the due date. If you don’t complete the MP by the recommended deadline, you can still complete it by the last day of classes for 96% credit.CS 357. Numerical methods play an increasingly important role in a wide variety of engineering and physical sciences. In past decades, to test the efficiency of a new aircraft design, an expensive physical prototype had to be built and flown; now, an aerospace engineer can perform this test with an accurate simulation on her laptop.is a non-linear least-squares problem.. Review Questions. See this review link; ChangeLog. 2022-04-09 Arnav Shah [email protected]: add few comments from slides asked in homework; 2020-08-08 Jerry Yang [email protected]: adds formal proof link for solving least-squares using SVD; 2020-04-26 Mariana Silva [email protected]: improved text overall; removed theory of the nonlinear least ...CS 357 Alumni; Corporate; People; My.CS; University of Illinois at Urbana-Champaign. The Grainger College of Engineering. Computer Science. Search. Menu. Search. About. Ready to apply? Your path to CS at Illinois begins here. Start Here. About. CS CARES Committee; Values & Code of Conduct ...The exam will follow the CS honors code and UIUC Academic Integrity policies. The final exam is scheduled using the Non-Combined UIUC schedule : Students registered in the M section (TTh 9:30-9:45pm): Friday, Dec 18, 1:30-4:30 p.m.Computing and Data Science. This new school will provide an even greater depth of resources to our top-5 ranked computer science program and a planned new building, made possible through a generous $50 million gift from Illinois alumnus Thomas M. Siebel. Pending approval by the University of Illinois Board of Trustees and Illinois Board of ...Kdog0073. •. I had 242, 357, old 473, 427, and 465 in one semester. It was a tough semester, but it was more doable than the majority of CS majors made it out to be. 357 and 242 are not bad at all and I would actually expect them to be relief classes when compared to ones like 241, 374, and 421. 357 was pretty easy.CS 357 - FALL 2023 Syllabus; Schedule; Support; Lectures; Quizzes; Resources; Resources; References. Computing Resources. This page contains links to helpful resources for learning Python and Numpy+Scipy+Matplotlib, including links to documentation, books, and tutorials. The material below was not created by course staff and are not required ...Siebel School of. Computing and Data Science. This new school will provide an even greater depth of resources to our top-5 ranked computer science program and a planned new building, made possible through a generous $50 million gift from Illinois alumnus Thomas M. Siebel. Pending approval by the University of Illinois Board of Trustees and ...Explore a Computer Science + Bioengineering, Bachelor of Science (BS) degree at the nation's #5 best computer science program at the University of Illinois Urbana-Champaign, Grainger College of Engineering. ... CS 357 may be substituted. ... Illinois Computer Science in Chicago 200 South Wacker Drive, 7th Floor Chicago, IL 60606. About Cookies ...Lecture 8 Banded, LU, Cholesky, SVD T. Gambill Department of Computer Science University of Illinois at Urbana-Champaign February 16, 2010 T. Gambill (UIUC) CS 357 February 16, 2010 1 / 54A new reversible USB plug is likely to hit the market next year. A new reversible USB plug is likely to hit the market next year. The next generation of USBs is currently being dev...Quizzes. Throughout the semester, you will take 6 quizzes (50-minute) that will have a mixture of short questions and short coding questions (similar to the questions that appear in your HW, L, GA and practice assessments). Students will take all quizzes at CBTF. You will need to register for your own quiz using PrairieTest, which will take ...Jacob (*2) , Arnav. 7-8pm. Jacob (*2) , Victor. (*1) Linjia in-person location: Grainger Library Room 409. (*2) Jacob in-person location: Siebel Terrace weather permitting, else Siebel Basement. The office hours table may be updated during the semester. Please check here often for the most updated information.University of Illinois at Urbana-Champaign. The Grainger College of Engineering. Computer Science. Search. Menu. Search. About. About. Facts & Rankings; Contact Us & Office Locations ... Same as MATH 357. Credit is not given for CS 357 if credit for CS 450 has been earned. (Counts for advanced hours in LAS). Prerequisite: A 100-level …Discover the best homework help resource for CS at University of Illinois at Urbana-Champaign. Find CS study guides, notes, and practice tests for UIUC. AI Homework Help. Expert Help. Study Resources. ... CS 357 219 Documents; 22 Q&As; CS 361 452 Documents; 27 Q&As; CS 371M 1 Document; CS 373 130 Documents; 5 Q&As; CS 374 698 Documents; 67 Q&As ...Familiarity with introductory numerical methods (e.g., CS 357 or TAM 470) and the basics of machine learning and neural networks (e.g., CS 446). Theory and practice of Scientific Machine Learning (SciML), which leverages machine learning tools for scientific computing. ... Illinois Computer Science in Chicago 200 South Wacker Drive, 7th Floor ...What is the definition of an eigenvalue/eigenvector pair? If \(\mathbf{v}\) is an eigenvector of \(\mathbf{A}\), what can we say about \(c\mathbf{v}\) for any nonzero ...Course Information: Same as MATH 357. Credit is not given for CS 357 if credit for CS 450 has been earned. (Counts for advanced hours in LAS). Prerequisite. A 100-level computer science course; MATH 225 or MATH 415; MATH 241. Learning Objectives. Analyze the sources of errors in mathematical operations on the computerIf you mess up on an mp there's barely any partial credit. Also, the actual lecture content of the class is going to be more challenging. There's also a lot of extra credit. Basically, the coding part of the class is easier, but the conceptual and learning part (lectures, exams) is harder. 233 is more comparable workload wise to 128.In this schedule page, you will find the list of assignments you will have to complete this semester: L#: These are the PrairieLearn Lecture Assignments including the pre-recorded lectures and short questions testing concepts introduced in the videos. These PL assessments will also include links to lecture notes, slides and annotations from the ...Computing and Data Science. This new school will provide an even greater depth of resources to our top-5 ranked computer science program and a planned new building, made possible through a generous $50 million gift from Illinois alumnus Thomas M. Siebel. Pending approval by the University of Illinois Board of Trustees and Illinois Board of ...Please see the Computer Science advisor in 1210 Siebel Center, as well as the Animal Sciences Undergraduate Curriculum Coordinator, Dr. David Miller, 116 Animal Sciences Lab. Animal Sciences Animal Sciences Website Animal Sciences Laboratory 1207 West Gregory Drive Urbana, IL 61801 217-333-3131 Email: [email protected] subreddit is not sponsored or endorsed by the University of Illinois or any other on-campus group. ... I never used any textbook in CS 357. I personally don't believe either is necessary. Reply reply Top 2% Rank by size . More posts you may like r/learnmath. r/learnmath. Post all of your math-learning resources here. ...Eric Shaffer (UIUC) CS 357 January 15, 2013 18 / 30. Course Info Book: Numerical Methods: Design, Analysis, and Computer Implementation of Algorithms by Anne Greenbaum and Timothy P. Chartier Eric Shaffer (UIUC) CS 357 January 15, 2013 19 / 30. FAQ Q: What will the grading curve be?CS 357. Fundamentals of numerical methods; floating-point computation, systems of linear equations, approximation of functions and integrals, the single nonlinear equation, and the numerical solution of ordinary differential equations; programming exercises and use of high quality mathematical library routines. Material Schedule.Computer Science. Thomas M. Siebel Center for Computer Science. 201 North Goodwin Avenue MC 258. Urbana, IL 61801. Phone: Fax: Email: The Grainger College of Engineering. CS 401.Pending approval by the University of Illinois Board of Trustees and Illinois Board of Higher Education. Explore a Mathematics & Computer Science, Bachelor of Science in Liberal Arts and Sciences (BSLAS) degree at the nation's #5 best computer science program at the University of Illinois Urbana-Champaign.Transferring to Computer Science programs in The Grainger College of Engineering. First-year students admitted to the following computer science majors in The Grainger College of Engineering at the University of Illinois in the fall of 2022 and thereafter are direct admit only and closed to on-campus transfer (ICT/IDT): B.S. Computer ScienceCS 357. Fundamentals of numerical methods; floating-point computation, systems of linear equations, approximation of functions and integrals, the single nonlinear equation, and the numerical solution of ordinary differential equations; programming exercises and use of high quality mathematical library routines. Material Schedule.CS 357. Numerical methods play an increasingly important role in a wide variety of engineering and physical sciences. In past decades, to test the efficiency of a new aircraft design, an expensive physical prototype had to be built and flown; now, an aerospace engineer can perform this test with an accurate simulation on her laptop.For each one of the topics below, you have a collection of PrairieLearn assignments to support your learning: lectures, homework, machine problems group activities. Since we provide a variety of learning resources, we do not require a textbook for the course. However, in case you need extra reading material, we suggest "Numerical Mathematics ...Course format: online and in-person. There are two sections of CS 357: Students registered in either section will have to complete the SAME assessments via PrairieLearn: homework, quizzes, group activities, machine problems. All lecture content will be delivered via pre-recorded videos.If you prefer to take the quiz in the classroom (CIF 0035), (for example, you may have other classes before or after CS 357 and want a quiet place on campus), ... These quizzes will follow the CS honors code and UIUC Academic Integrity policies. You will be expected to comply with the Student Code, and the course policies provided below.Wednesdays 12:30-1:30pm, Siebel 2213. This is not the "traditional" office hours. This is just a time when I will be at my office to connect with students. We can talk about anything you want: career goals, projects, research, hobbies, big-picture conversations about course content, other courses and programs, weather, food, etc.Yeah idk why the avg gpa is that low, maybe the class has changed a lot. In spring 2020, the class was really easy in the sense that exams were mostly a non factor in your grade. MPs were worth 60% of your grade with a max of 6% extra credit making each MT 10% and final 20%. With the cutoffs they had for this sem 88% being an A, you could a get ...Criteria for 1-D Local Minima. In the case of 1-D optimization, we can tell if a point x ∗ ∈ S is a local minimum by considering the values of the derivatives. Specifically, (Second-order) Sufficient condition: f ′ ( x ∗) = 0 and f ″ ( x ∗) > 0. Example: Consider the function f ( x) = x 3 − 6 x 2 + 9 x − 6 The first and second ...Incomplete grade(s) in a prerequisite course must be resolved before prerequisite overrides are granted. Exceptions may be made for cases where a passing final course grade is certain at the time of the request. Undergraduate Academic Advising. 4th Floor Grainger Library — East Wing. 1301 W. Springfield Ave.what are the differences between the online section of CS 357 and the in person one? : r/UIUC. r/UIUC. r/UIUC. • 1 hr. ago. Professional-Fly4273.We will have two sections of CS 357 in the Fall 2021 semester: Section M: Online, TR 12, In this schedule page, you will find the list of assignm, CS 357. Fundamentals of numerical methods; floating-poi, other CS courses Regarding current CS course start of semester end of semester °2.0 °1.5 °1.0 °0.5 0.0 , University of Illinois at Urbana-Champaign. The Grain, Group Activity Grade 2) Participation (2% of the grade): Manager: Create groups assessment, record roles, keep team , Go to UIUC r/UIUC • by WhybroSciencebro. View community ranking In the Top 5% of largest communiti, University of Illinois at Urbana-Champaign. The Grainger Colleg, We would like to show you a description here but the, CS 357 - Spring 2021 CS 357 - Spring 2021. Show Details. Hi, This subreddit is for anyone/anything related to UIUC. Students, Alu, If you enjoy courses like CS 225, you'd probably like CS 241. , Lang Son Travel Guide 2023, 15 places to experience i, CS 357 Alumni; Corporate; People; My.CS; Universit, Lecture 12 Interpolation/Splines T. Gambill Departme, Siebel School of. Computing and Data Science. This , T. Gambill (UIUC) CS 357 February 14, 2012 5 / 40. Basic Roo, This new school will provide an even greater depth of resources t.