Conference Session

Electrical ET Curriculum

Collection

2006 Annual Conference & Exposition

Authors

Jeffrey Richardson, Purdue University; John Denton, Purdue University; James Jacob, Purdue University

Tagged Divisions

Engineering Technology

2006-871: THREADING TOPICS AND CREATING COURSE LINKAGE AMONGCOURSES AND CURRICULAR AREASJeffrey Richardson, Purdue University Jeffrey J. Richardson is an Assistant Professor for the Electrical and Computer Engineering Technology Department at Purdue University where he teaches introductory and advanced embedded microcontroller courses. At Purdue, he is active in Project Lead the Way, recruitment and retention of students, applied research and has written several conference papers related to teaching embedded microcontroller systems.John Denton, Purdue University John P. Denton is an Associate Professor for the Electrical and Computer Engineering Technology Department at Purdue

Conference Session

Promoting Scientific and Technological Literacy

Collection

2006 Annual Conference & Exposition

Authors

Scott Douglas, Southern Methodist University

Tagged Divisions

K-12 & Pre-College Engineering

typical high school teaching schedule and its relation to other school events such as assemblies and state testing requirements affected the development, as did non- obvious ones such as the number of available electrical outlets in a laboratory or classroom. 2) Laboratory technology was chosen and developed based on a number of factors, including ease of teacher training, relevance to the chosen classroom subject material, and design flexibility. The Hyperception Visual Application Builder design environment, part of the suite of graphical design and programming tools offered by National Instruments, gives both teachers and students the ability to simulate and implement complex signal processing

Conference Session

Capstone Design I

Collection

2006 Annual Conference & Exposition

Authors

Mark W. Steiner, Rensselaer Polytechnic Institute; Richard Smith, Rensselaer Polytechnic Institute

Tagged Divisions

Design in Engineering Education

Multidisciplinary Design Experiences into the Capstone ExperienceAbstractAs educators we must ask ourselves whether we are truly meeting the needs of today’syoung people to become engineers. Are we showing students what it means to be anengineer and how engineers help people and contribute to society? Are our youngengineers prepared to successfully integrate knowledge from diverse areas of thesciences, mathematics, arts and humanities, and social sciences, to solve the complexmultidisciplinary problems that the world is facing? The mission of Rensselaer’s O.T.Swanson Multidisciplinary Design Laboratory (MDL) is to provide clinical real-worldexperiences for students that build confidence and teaches them to integrate disciplinespecific

Conference Session

Emerging Trends in Engineering Education Poster Session

Collection

2006 Annual Conference & Exposition

Authors

Dennis Robbins, Borough of Manhattan Community College/CUNY; Mahmoud Ardebili, Borough of Manhattan Community College/CUNY

for learning thermal physics and preparing them tounderstand engineering thermodynamics. In this study traditional instruction or standardcourses in physics refers to methods of teaching which do not rely on principles of“scientific teaching” and are characterized by their heavy dependence on lectures,textbook reading and laboratories that are often referred to as “cookbook” exercises10. • What understanding do engineering students have of heat and temperature? Do they have a functional understanding of the concepts of heat transfer and temperature? Does a course in engineering thermodynamics improve students’ fundamental conceptions thermal physics? • After traditional instruction in physics do engineering majors

Conference Session

Thermodynamics and Fluid Mechanics Instruction

Collection

2006 Annual Conference & Exposition

Authors

John Cimbala, Pennsylvania State University; Laura L. Pauley; Sarah Zappe; Meng-Fen Hsieh, Pennsylvania State University

Tagged Divisions

Mechanical Engineering

2006-1357: EXPERIENTIAL LEARNING IN A FLUID FLOW CLASS VIATAKE-HOME EXPERIMENTSJohn Cimbala, Pennsylvania State University JOHN M. CIMBALA is Professor of Mechanical Engineering at Penn State University, University Park. Dr. Cimbala teaches courses in the thermal sciences and conducts research in experimental and computational fluid mechanics and heat transfer. He received his Ph.D. from Caltech in 1984, and has been at Penn State since then. He is co-author of two books – Indoor Air Quality Engineering, Marcel-Dekker, 2003 and Fluid Mechanics: Fundamentals and Applications, McGraw-Hill, 2006. He may be contacted at jmc6@psu.edu.Laura Pauley, Pennsylvania State University LAURA L. PAULEY is

Conference Session

Computers in Education Poster Session

Collection

2006 Annual Conference & Exposition

Authors

Lisa Jones, Southwest Tennessee Community College; James M. Northern, Southwest Tennessee Community College

Tagged Divisions

Computers in Education

College James M. Northern, P.E., is currently Program Coordinator of Electrical Engineering Technology at Southwest Tennessee Community College. He graduated from Memphis State University with a B.S. in Electrical Engineering in 1970. He also has a B.S. in Psychology and a M.S. in Technical Education from Memphis State University. Mr. Northern worked as an engineer and senior engineer at Allan & Hoshall for 8 years in the area of rural power system analysis and has been teaching at Southwest for 25 years in the areas of instrumentation and electrical engineering technology. Page 11.1417.1

Conference Session

Emerging Trends in Engineering Education Poster Session

Collection

2006 Annual Conference & Exposition

Authors

Kevin McLaughlin, University of Connecticut

these teachersinfluence their students’ interest in engineering and then ultimately resulting in majoringin engineering is not clear. To aid in the direct encouragement of promoting engineeringto students and eliminating the uncertainty of how science and math teachers inspirethese students to enter engineering we bring the math and science teachers to the UConncampus for a week long residential summer workshop. They work along side engineeringfaculty in their research laboratories to get a clear idea of what engineering disciplinesexist and their potential. The teachers, in addition to strengthening their math and sciencebackgrounds, then serve as spokespersons for engineering in their respective classroomsby being able to discuss engineering

Conference Session

Emerging Trends in Engineering Education Poster Session

Collection

2006 Annual Conference & Exposition

Authors

Leo McAfee, University of Michigan; Khalil Najafi, University of Michigan; Yogesh Gianchandani, University of Michigan; Kensall D. Wise, University of Michigan; Michel M. Maharbiz, University of Michigan; Dean Aslam, Michigan State University; Paul Bergstrom, Michigan Technological University; Craig Friedrich, Michigan Technological University

2006-2332: MEMS AND MICROSYSTEMS COURSES WITH NATIONAL ANDINTERNATIONAL DISSEMINATIONLeo McAfee, University of Michigan Leo C. McAfee received the BS in electrical engineering from Prairie View A&M University, Prairie View, TX, in 1966, and the MSE and PhD degrees from the University of Michigan, Ann Arbor, MI, in 1967 and 1970, respectively. He joined the University of Michigan in 1971 and is currently an associate professor. He has had summer and leave positions at General Motors Research Laboratories, IBM T.J. Watson Research Center, AT&T Bell Laboratories, and Telecom Analysis Systems. He has held leadership positions for curriculum and degree program development, as well as

Conference Session

Building Communities for Engineering Education Research

Collection

2006 Annual Conference & Exposition

Authors

Heidi Diefes-Dux, Purdue University; Robin Adams, Purdue University; Monica Cox, Purdue University; Deborah Follman, Purdue University

Tagged Divisions

Educational Research and Methods

. Then new teams, inwhich each team member had expertise regarding a different learning activity, were formed andcharged to rank the five activities from least- to best-aligned with formal cooperative learningprinciples. In a separate learning activity, student teams postulated the values and philosophy ofan engineering instructor who incorporates cooperative learning in his/her classes.Student teaching and research philosophies and their elevator speeches went through at least oneiteration cycle, with students receiving feedback from classmates, the course instructors, and, inthe case of the teaching philosophies, peers from the Laboratory for User-Centered EngineeringEducation (LUCEE8) at the University of Washington (LUCEE is devoted to

Conference Session

Installing & Assessing Technology Literacy Courses

Collection

2006 Annual Conference & Exposition

Authors

John Krupczak, Hope College; Greg Pearson, National Academy of Engineering; David Ollis, North Carolina State University

Tagged Divisions

Technological Literacy Constituent Committee

on the results of surveysof student interests. Topics covered include the automobile, basic electrical appliances,telecommunications, medical imaging, and computers, Laboratories involve activities such asdisassembling a car engine, and building a simple electronic music keyboard. Enrollment isabout 48 students each semester. The lecture portion of the course is taught in a singlesection. There are two laboratory sections of 24 students each. Each laboratory section isrun by one faculty member assisted by undergraduate teaching assistants.Case Study Design A total of 139 students participated during the 2003-2004 academic year: 47 studentsin the Fall 2003 semester, 54 in the Spring 2004 semester, and 38 in the May Term (four-week

Conference Session

Trends in Energy Conversion and Conservation

Collection

2006 Annual Conference & Exposition

Authors

Giri Venkataramanan, University of Wisconsin-Madison; Annette Muetze, University of Wisconsin-Madison

Tagged Divisions

Energy Conversion and Conservation

evident that in the absence of a laboratory – real-world experience thelearning cycle is plainly incomplete.The ‘cone’ of learning shown in Fig. 1 illustrates the effectiveness of various domains ofexperience from a pedagogic point of view11. The activities at the bottom of the cone are said toprovide learning opportunities with higher motivational and retention levels compared to thosethat are at the top. The limited effectiveness of the ‘top heavy’ classical teaching styles withthree weekly lectures supplemented with textbook reading may be readily observed from thefigure. Course activities that are authentic, with an emphasis on real-world inspired and student-directed laboratory projects provide the best learning opportunity possible within

Conference Session

Emerging Trends in Engineering Education Poster Session

Collection

2006 Annual Conference & Exposition

Authors

Mysore Narayanan, Miami University

an effective and efficient learninggroup of students.In a paper he presented at the 2004 ASME Heat Transfer/Fluids Engineering SummerConference at Westin Charlotte & Convention Center, Charlotte, North Carolina (July11-15, 2004) the author raised five questions : 1. What should be counted as appropriate goals in an undergraduate engineering course that has a significant laboratory component ? 2. Are the teaching practices utilized by the instructor in this course providing reasonably acceptable paths toward accomplishing the specified learning goals ? 3. What do students actually accomplish in the course and the laboratory exercises and how does the instructor’s teaching methodologies

Conference Session

Curricula of the Past, Present, and Future

Collection

2006 Annual Conference & Exposition

Authors

Cristina Pomales-Garcia, University of Michigan; Yili Liu, University of Michigan; Virginia Soto, University of Michigan

Tagged Divisions

Educational Research and Methods

Arthur F. Thurnau Professor and Associate Professor of Industrial and Operations Engineering at the University of Michigan. His Ph.D. is in Engineering and Cognitive Psychology from the University of Illinois. His research and teaching interests include cognitive modeling, cognitive ergonomics, cognitive psychology, engineering aesthetics, human factors, and human-computer interactionVirginia Soto, University of Michigan Virginia Soto Pinto is an undergraduate student in the department of Industrial and Operations Engineering at the University of Michigan. Page 11.610.1© American

Conference Session

Programs for High School Students

Collection

2006 Annual Conference & Exposition

Authors

June Marshall, St. Joseph's College; John Marshall, University of Southern Maine

Tagged Divisions

K-12 & Pre-College Engineering

information), relays (to control output loads),electric motors and motor starters (switches heavy loads), and solenoid directional controlvalves (widely used, controls fluids).After the PLC overview, we proceeded to the programming software. The best methodfor teaching the software is via lab activities that require the students to develop ladderlogic programs designed to control a process. The six laboratory activities that weutilized are the: Industrial start cycle with an automated stop function; Conveyor systemwith indicating lights; Timing six sequential outputs; Automated palletized materialhandling system; Computerized parking garage; and the Vehicle intersection traffic lightcontroller.Laboratory Activity One - Industrial start cycle with an

Conference Session

Mechanical ET Curriculum

Collection

2006 Annual Conference & Exposition

Authors

Ronald Earley, Miami University

Tagged Divisions

Engineering Technology

analyses of mechanism configurations.Typically, students are more energized and motivated to learn and retain concepts when coursescontain computer laboratory experiences. A new course in mechanisms analysis was designedby the author and included within the curriculum of a newly created baccalaureate program inmechanical engineering technology at Miami University. The program was officially approvedin the spring of 2003 and course offerings were begun in the fall of the same year. Hence thedata confirming and/or refuting the above premise is limited.While many mechanisms courses currently being taught within the curriculums of mechanicalengineering technology programs make use of computer enhanced project assignments, theauthor believes that this

Conference Session

Environmental Engineering Curricula

Collection

2006 Annual Conference & Exposition

Authors

Alexa Rihana-Abdallah, University of Detroit Mercy

Tagged Divisions

Environmental Engineering

2006-2544: BRIDGING THE GAP BETWEEN ENVIRONMENTAL ENGINEERING,CHEMISTRY, AND BIOLOGYAlexa Rihana-Abdallah, University of Detroit Mercy The Author has written a number of articles published in the ASEE Annual Conference proceedings over the years. The Author teaches at the University of Detroit Mercy in the Department of Civil and Environmental Engineering. Page 11.285.1© American Society for Engineering Education, 2006 Bridging the Gap between Environmental Engineering, Chemistry, and BiologyAbstractRecognizing the intellectual merit of interdisciplinary studies to

Conference Session

Best Zone Paper Competition

Collection

2006 Annual Conference & Exposition

Authors

Nathan Klingbeil, Wright State University; Richard Mercer, Wright State University; Kuldip Rattan, Wright State University; Michael Raymer, Wright State University; David Reynolds, Wright State University

Tagged Divisions

Council of Sections

ASEE North Central Section Outstanding Teaching Award (2004), and both the CECS Excellence in Service (2004) and Excellence in Teaching (2002) awards at Wright State University.Richard Mercer, Wright State University RICHARD E. MERCER is an Associate Professor in the Department of Mathematics and Statistics at Wright State University. He received his Ph.D. in Mathematics from the University of Washington in 1980. Professor Mercer is active in curriculum reform, and has led an NSF supported effort to integrate Mathematica laboratory sessions into the freshman calculus sequence at Wright State University.Kuldip Rattan, Wright State University KULDIP S. RATTAN is a Professor in the

Conference Session

Women & New Faculty Development

Collection

2006 Annual Conference & Exposition

Authors

Elizabeth DeBartolo, Rochester Institute of Technology; Cory Hoffman, Rochester Institute of Technology; Melissa Zaczek, Rochester Institute of Technology

Tagged Divisions

New Engineering Educators

years both grading for the Materials Science course and teaching laboratories.Melissa Zaczek, Rochester Institute of Technology MELISSA A. ZACZEK is a student at Rochester Institute of Technology completing her BS and ME in Mechanical Engineering. Her Masters focus is project management with a concentration in business. Her undergraduate focus is bioengineering with an American Politics minor. Page 11.1160.1© American Society for Engineering Education, 2006 Student-Faculty PartnershipsAbstractOne of the biggest challenges facing new engineering faculty members is finding good

Conference Session

Curriculum Development and Applications

Collection

2006 Annual Conference & Exposition

Authors

La Verne Abe Harris, Arizona State University; Richard Newman, Arizona State University

Tagged Divisions

Engineering Design Graphics

University at thePolytechnic campus. ASU’s Department of Technology Management has been offering a totallyonline Master of Science Degree in Technology from Environmental Technology Management(ETM) for the past three years. January 2006 a totally online Master of Science Degree inTechnology from Graphic Information Technology was introduced.27 Other EngineeringTechnology programs are offering individual courses such as Circuits Laboratory and someintroductory AC/DC circuits with a reasonable success.Virtual laboratoriesOne dilemma in higher education is the expense of building and maintaining realistic appliedresearch and teaching laboratory facilities for institutions offering degree programs in electronicsystems technology. Even in states with

Conference Session

Reforming the Industrial Engineering Curriculum

Collection

2006 Annual Conference & Exposition

Authors

Ana Ferreras, University of Central Florida; Lesia Crumpton-Young, University of Central Florida; Sandra Furterer, University of Central Florida; Luis Rabelo, University of Central Florida; Kent Williams, University of Central Florida; Pamela McCauley-Bell, University of Central Florida; Edward Hampton, University of Central Florida

Tagged Divisions

Industrial Engineering

, Engineering Leadership, and Ergonomics.Lesia Crumpton-Young, University of Central Florida Dr. Crumpton-Young is an accomplished academician who has excelled in the areas of teaching, research, and service to the engineering community. Currently, Dr. Crumpton-Young is PI of the NSF Engineering Education sponsored grant for Departmental Reform. Dr. Crumpton-Young’s research record includes hundreds of technical publications and presentations. Her research endeavors have received external support from NSF, ONR, NASA, DOE and private industries, such as UPS, IBM, Caterpillar, Intel, LA-Z-Boy, Lockheed Martin, Garan Manufacturing, and Southwest Airlines. She was also an NSF CAREER award

Conference Session

Materials Science and Engineering of 2020

Collection

2006 Annual Conference & Exposition

Authors

Barry Dupen, Indiana University Purdue University-Fort Wayne (ET)

Tagged Divisions

Materials

, NIST internalreport NIST-IR 6118.Figure 1: This supplemental handout from my first Figure 2: A typical first year homework assignmentyear of teaching is printed as a half-sheet. handout printed as a half-sheet has plenty of space for wordy problem statements, as well as reminders about upcoming exams and laboratory experiments.Second Year of Teaching In my second year of teaching, I transformed two Materials courses, a Fluid Power course,and an Instrumentation and Controls course from chalkboard to PowerPoint (PP). Initially

Conference Session

ECE Pedagogy and Assessment

Collection

2006 Annual Conference & Exposition

Authors

Jason Coutermarsh, Rensselaer Polytechnic Institute; Kenneth Connor, Rensselaer Polytechnic Institute; Don Millard, Rensselaer Polytechnic Institute

Tagged Divisions

Electrical and Computer

and software (developed by Rensselaer) which, when connected to the PC via aUSB port, provides similar functionality to an oscilloscope (with a full 50KHzbandwidth), 2 function generators, a multimeter and bipolar power supplies (for less thanthe cost of a typical textbook – approximately $80). With the advent of this mobileinstrumentation studio PC-based laboratory, many instrumentation-based course offeringscan now be held in normal classrooms rather than in specially outfitted facilities. Inaddition, students are asked to perform hands-on experiments outside of the classroomanywhere/anytime, thus facilitating new opportunities for them to “tinker,” to gainvaluable insight through practical experience and to rekindle the passion for

Conference Session

Energy Curriculum Advancements

Collection

2006 Annual Conference & Exposition

Authors

Stephen Williams, Milwaukee School of Engineering

Tagged Divisions

Energy Conversion and Conservation

2006-1124: BRUSHLESS DC MOTOR PROJECT IN AN INTRODUCTION TOELECTRICAL ENGINEERING COURSEStephen Williams, Milwaukee School of Engineering Dr. Stephen Williams is Associate Professor of Electrical Engineering and Computer Science at the Milwaukee School of Engineering (MSOE). He received the Ph.D. degree from the University of Missouri in 1990 and has 20 years of experience across the corporate, government, and university sectors. He is a registered Professional Engineer in Wisconsin. He teaches courses in control systems, electronic design, and electromechanics. Page 11.291.1© American Society for

Conference Session

ECE Poster Session

Collection

2006 Annual Conference & Exposition

Authors

Yakov Cherner, ATeL, LLC; Amin Karim, DeVry University; Ahmed Khan, DeVry University-Addison; Victor Rubanchik, Don State Technical University (DSTU), Rostov-on-Don, Russia

Tagged Divisions

Electrical and Computer

2006-2119: INTEGRATION OF INTERACTIVE SIMULATIONS AND VIRTUALEXPERIMENTS IN TELECOMMUNICATIONS COURSES FOR ONSITE, ONLINEAND HYBRID DELIVERYYakov Cherner, ATeL, LLC Dr. Yakov E. Cherner, a Founder and President of ATEL, LLC, combines 20+ years of research and teaching practice with extensive experience in writing curricula and developing educational software. He is the author of an innovative concept of multi-layered simulation-based conceptual teaching of science and technology. This instructional approach uses real-world objects, processes and learning situations that are familiar to students as the context for virtual science and technology investigations. To facilitate this methodology for

Conference Session

Faculty Development Toolkit

Collection

2006 Annual Conference & Exposition

Authors

William Jordan, Baylor University; Bill Elmore, Mississippi State University; Walter Bradley, Baylor University

Tagged Divisions

New Engineering Educators

in the state of Louisiana.Bill Elmore, Mississippi State University BILL ELMORE, Ph.D., P.E., is Associate Professor and Hunter Henry Chair, Mississippi State University. His teaching areas include the integrated freshman engineering and courses throughout the chemical engineering curriculum including unit operations laboratories and reactor design. His current research activities include engineering educational reform, enzyme-based catalytic reactions in micro-scale reactor systems, and bioengineering applied to renewable fuels and chemicals.Walter Bradley, Baylor University WALTER BRADLEY is a Distinguished Professor of Mechanical Engineering at Baylor University. He has a B.S

Conference Session

Promoting Scientific and Technological Literacy

Collection

2006 Annual Conference & Exposition

Authors

Suzanne Soled, University of Cincinnati; Patricia McNerney, University of Cincinnati; Laura Koehl, University of Cincinnati; Kelly Obarski, University of Cincinnati; Anant Kukreti, University of Cincinnati

Tagged Divisions

K-12 & Pre-College Engineering

, inquiry based activities into the secondary school science and mathematics curriculum that enhance and reinforce basic concepts already taught in the secondary curriculum. • Motivate secondary school students, through real-world experiments, observations, and measurements, to study problems that affect their daily lives. • Use these activities at various grade levels from different classes and schools, via peer teaching, collaborations, and the Internet, as they focus on common themes and learning tasks. • Include computers, up-to-date sampling probes, and laboratory equipment in activities so students gain experience with current technology. • Incorporate computer-based self-paced learning

Conference Session

Curricula of the Past, Present, and Future

Collection

2006 Annual Conference & Exposition

Authors

Thomas Litzinger, Pennsylvania State University; Robert Pangborn, Pennsylvania State University; David Wormley, Pennsylvania State University

Tagged Divisions

Educational Research and Methods

2006-375: 15 YEARS OF ENGINEERING EDUCATION REFORM: LESSONSLEARNED AND FUTURE CHALLENGESThomas Litzinger, Pennsylvania State University Thomas A. Litzinger is currently Director of the Leonhard Center for the Enhancement of Engineering Education and a Professor of Mechanical Engineering at Penn State, where he has been on the faculty since 1985. His work in engineering education involves curricular reform, teaching and learning innovations, faculty development, and assessment. He teaches and conducts research in the areas of combustion and thermal sciences. He can be contacted at TAL2@psu.edu.Robert Pangborn, Pennsylvania State University Rob Pangborn is Professor of Engineering Mechanics and

Conference Session

Evaluation and Assessment of IE Programs

Collection

2006 Annual Conference & Exposition

Authors

R. Radharamanan, Mercer University

Tagged Divisions

Industrial Engineering

teaching, as well as methods of testing: • In the year 2001, the course title has been changed to “Manufacturing Processes”. A new text book has been adopted to reflect the changes in the course description by removing the management aspects in manufacturing such as forecasting, inventory control, aggregate planning, sequencing and scheduling, and project management, and by adding welding and joining processes, introduction to geometric dimensioning and tolerancing, metrology and testing, and process automation. • In the year 2002, the integrated laboratory assignments have been enhanced by acquiring a coordinate measuring machine (Brown & Sharp) and incorporating a design, fabrication, and

Conference Session

Emerging Trends in Engineering Education Poster Session

Collection

2006 Annual Conference & Exposition

Authors

Melinda Seevers, Boise State University; Pat Pyke, Boise State University; William Knowlton, Boise State University; Cheryl Schrader, Boise State University; John Gardner, Boise State University

and Engineering where he is the Coordinator for Graduate Studies and holds a joint appointment. His research activities include device and simple circuit reliability physics, materials characterization, nanofabrication of materials and devices, biomaterials, and molecular electronic devices. He is actively involved in integrating teaching and research has received several teaching and research awards.Pat Pyke, Boise State University Patricia Pyke is the Director of Special Programs for the College of Engineering at Boise State University. She oversees projects in freshman curriculum development, retention, math support, mentoring, and women’s programs. She earned a B.S.E. degree in

Conference Session

New trends in ECE education

Collection

2006 Annual Conference & Exposition

Authors

Douglas Jacobson, Iowa State University; Thomas Daniels, Iowa State University

Tagged Divisions

Electrical and Computer

presentations from the faculty members that teach the courses. Thefaculty created power point presentations that were included in a notebook that was given toevery participant. We also included in the notebook a course syllabus and copies of labsexperiments for each course.The workshop schedule for the 2005 workshop is shown below. The focus of the 2005workshop is lab exercises for computer security courses. The first morning starts withintroductions and a survey from the participants gathering information about their programs.The remainder of the day focuses on eight of our security courses and the laboratory exercises.Intermixed with the course presentations are discussions of the high school computer securitysummer camp and the cyber defense