DOCSLIB.ORG

Energy-Aware Topology Control and Data Delivery in Wireless Sensor Networks

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Energy-Aware Topology Control and Data Delivery in Wireless Sensor Networks Energy-Aware Topology Control and Data Delivery in Wireless Sensor Networks A Thesis Presented to The Academic Faculty by Seung-Jong Park In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy • I N S T A I T I U G T R E O • E O G F • • E T H E T C • H F S S P R O G R ES E R V I C E N O A N D O • L L O A G E Y S • • 1 8 8 5 School of Electrical and Computer Engineering Georgia Institute of Technology July 2004 Energy-Aware Topology Control and Data Delivery in Wireless Sensor Networks Approved by: Raghupathy Sivakumar, Advisor Jennifer E. Michaels John A. Copeland Samit Soni Henry L. Owen Date Approved: 7 July 2004 To my companion for life: Young-Jin Juhn. iii ACKNOWLEDGEMENTS I first would like to express my sincere gratitude to my thesis advisor, Dr. Raghupathy Sivakumar. He has always advised me on not only the direction of research but also the way of campus life. I will miss the days and nights having brainstorming which enables me to finish my thesis. I also would like to thank to the members of dissertation committee, Dr. John Copeland, Dr. Henry Owen, Dr. Jennifer Michaels, and Dr. Samit Soni, who have also given many constructive comments during the proposal and final dissertation process. For the helpful discussion about simulation and the thesis, I would like to give special appreciation to Dr. George Riley and Dr. Chuanyi Ji. Thanks are also due to fellow graduate students at GNAN research group. Above all, I would like to express my gratitude in writing to my family, Young-Jin, Katie, and Jason, for their loving support and sacrifice. iv TABLE OF CONTENTS DEDICATION ......................................... iii ACKNOWLEDGEMENTS .................................. iv LIST OF FIGURES ...................................... ix SUMMARY .......................................... xii CHAPTER I INTRODUCTION ............................. 1 CHAPTER II WIRELESS SENSOR NETWORKS ................... 5 2.1 Applications . 5 2.1.1 Data Collecting Applications . 5 2.1.2 Event Monitoring Applications . 6 2.1.3 Object Tracking Applications . 7 2.1.4 Hybrid Applications . 8 2.2 Challenges in Wireless Sensor Networks . 8 2.3 Research in Protocol Layers . 10 2.3.1 Research in Application Layer . 10 2.3.2 Research in Transport Layer . 12 2.3.3 Research in Network Layer . 13 2.3.4 Research in Data Link Layer . 15 2.3.5 Research in Physical Layer . 16 2.3.6 Research in Inter-Layer Planes . 17 CHAPTER III ATC: ADAPTIVE TOPOLOGY CONTROL ............... 18 3.1 Problem Definition . 18 3.2 Motivation . 19 3.2.1 Terminology and Models . 19 3.2.2 Preliminary Observations . 22 3.3 Related Works . 25 3.4 Theoretical Analysis . 26 3.4.1 Per-flow Throughput . 26 3.4.2 Spatial-Reuse Factor and Hop-Count . 27 v 3.4.3 Mini-channel Utilization . 28 3.4.4 Summary of Motivation for Adaptive Topology Control . 30 3.5 Design Goals and Key Ideas . 31 3.5.1 Goals . 31 3.5.2 Key Ideas . 32 3.6 ATC Protocol . 36 3.6.1 Basic Algorithm . 36 3.6.2 ATC-CP . 38 3.6.3 ATC-IP . 39 3.6.4 ATC-MS . 41 3.7 Convergence Analysis of ATC Schemes . 42 3.7.1 Problem Formulation . 43 3.7.2 Analysis . 43 3.8 Performance Evaluation . 45 3.8.1 Evaluation Environments . 45 3.8.2 Evaluation Results . 46 3.9 Summary . 57 CHAPTER IV GARUDA-DN: RELIABLE DOWNSTREAM DATA DELIVERY ... 58 4.1 Problem Definition . 58 4.2 Motivation . 60 4.2.1 Assumptions . 60 4.2.2 Observations . 61 4.3 Related Works . 63 4.4 Design Preliminaries and Challenges . 65 4.4.1 Preliminary Design Choices . 66 4.4.2 Challenges . 70 4.5 Theoretical Approaches . 72 4.5.1 Ideal Solution: Minimum Set Cover Problem . 73 4.5.2 Reduction to Minimum Dominating Set Problem . 74 4.5.3 Performance Ratio between MDS and MSC . 75 4.6 GARUDA-DN Design . 77 vi 4.6.1 Loss Recovery Servers: Core . 78 4.6.2 Loss Recovery Process . 79 4.6.3 Multiple Reliability Semantics . 81 4.6.4 Reliable Single/First Packet Delivery . 82 4.7 GARUDA-DN Framework . 84 4.7.1 Single/First Packet Delivery . 84 4.7.2 Instantaneous Core Construction . 87 4.7.3 Two-Phase Loss Recovery . 92 4.8 Supporting Other Reliability Semantics . 95 4.8.1 Reliable Delivery within a Sub-Region . 96 4.8.2 Reliable Delivery to Cover Sensing Field . 97 4.8.3 Reliable Delivery to Probabilistic Subset . 97 4.9 Performance Evaluation . 98 4.9.1 Simulation Environment . 98 4.9.2 Metrics . 99 4.9.3 Evaluation of Single Packet Delivery . 100 4.9.4 Evaluation of Multiple Packet Delivery . 102 4.9.5 Microscopic Analysis . 105 4.9.6 Evaluation of GARUDA-DN Variants . 107 4.9.7 Summary of Evaluation . 108 4.10 Summary . 111 CHAPTER V GARUDA-UP: ENERGY-EFFICIENT UPSTREAM DATA AGGREGA- TION ........................................... 112 5.1 Problem Definition . 112 5.2 Motivation and Idealized Models . 115 5.2.1 Correlation of Data . 115 5.2.2 Problem Statement . 116 5.2.3 Optimal Solutions for Different Correlation Factors . 118 5.3 Related Works . 121 5.3.1 Default Aggregation in WSNs . 121 5.3.2 Intelligent Aggregation in WSNs . 122 vii 5.3.3 Graph Theory Techniques . 123 5.4 Design Goals and Key Idea . 123 5.4.1 Problem Scopes and Goals . 123 5.4.2 Key Ideas . 125 5.5 GARUDA-UP Design . 127 5.5.1 Overview . 127 5.5.2 Construction of the Core Set . 128 5.5.3 Aggregation at a Core Node . 128 5.5.4 Aggregation among Core Nodes . 128 5.5.5 Synchronization . 129 5.5.6 Message Complexity . 129 5.6 GARUDA-UP Framework . 130 5.6.1 Core Construction . 130 5.6.2 Stage 1: Original Data Transmission . 131 5.6.3 Stage 2: Aggregated Data Transmission . 133 5.6.4 Other Considerations . 134 5.7 Performance Evaluation . 135 5.7.1 Simulation Environments . 135 5.7.2 Different Node Densities . 139 5.7.3 Different Source Densities . 139 5.7.4 Number of Core Nodes . ..
Load more

Recommended publications
  • Defensive Responsibilities
    DEFENSIVE RESPONSIBILITIES http://www.baseballpositive.com/ "Baseball is a Game of Movement". This is a foreign concept for most youth baseball and softball players. If we could dig into the brain of ballplayers ages 5-12 right next to the idea of 'Baseball' we would find the phrase 'a game where you stand around a lot and don't do anything' (and we wonder why participation is dwindling). When the game is played properly each player on defense is moving (sprinting) the moment the ball comes off the bat. We can do a better job of teaching kids how to play the game. This section is dedicated to helping coaches teach kids their defensive responsibilities on each play regardless of where the ball is hit or where the runners are. Before digging in, let's add something to the old coaching comment, "Be sure you know what to do if the ball is hit to you". But the ball is hit to one player; what about the other eight? The must also teach our players, "Know what you are going to do when the ball is NOT hit to you". The first part of this section outlines in clear and simple terms, the 'Rules for Defensive Movement'. These rules form the foundation for the drills and concepts in the rest of this section. Some of the plays found here are not consistent with player responsibilities on the larger 80' or 90' diamonds. The game on the smaller diamond is slower and the players are not as strong. These facts combined with the shorter distance between the players and the bases makes this game quite different than the one played on the large diamond.
    [Show full text]
  • Xvi: 3-Man Mechanics Standard Operating Procedures
    XVI: 3-MAN MECHANICS STANDARD OPERATING PROCEDURES – 3-MAN CREWS ABBREVIATIONS: The plate umpire will be referred to as U1, the first-base umpire as U2, and the third-base umpire will be referred to as U3. It is assumed that in all play situations, U1 will start out behind the plate. There are four basic positions for the base umpires: positions A, B, C and D. These positions are described as follows, and will remain unchanged, regardless of the number of outs: Position A — Both feet in foul territory, approximately 10 feet behind the first baseman. Position B — At the infield cutout near second base, first-base side of the infield, feet parallel to the pitcher's plate, able to move to cover a pickoff attempt at second base. Position C — Halfway between the mound and second base, third-base side of the infield, feet parallel to the pitcher's plate, able to move to cover a pickoff attempt or attempted steal at either second base or third base. Position D — Both feet in foul territory, approximately 10 feet behind the third baseman. If covering a base with runners on, Positions A and D are modified somewhat in that the umpire on the baseline will move up closer to the base, still in foul territory, in order to get an angle on the pickoff attempt and line up the pitcher's foot crossing over the back edge of the pitcher's plate. GENERAL DUTIES AND RESPONSIBILITIES: U1: 1. Call balls and strikes. 2. Rule fair/foul on any batted ball that is played on or comes to rest in front of the front edge of the base down the first-base line with U2 in Position A and down the third-base line with U3 in position D.
    [Show full text]
  • Traveling Skills & Drills
    HUDSON BOOSTER CLUB Hudson Boosters TRAVELING TEAM SKILLS LIST COMPETITIVE TEAM SKILLS 1 COMPETITIVE TEAM SKILLS AND CONCEPTS The skills and concepts listed are the minimum skills that a person coming out of each program should possess. This list is not meant to limit the amount of skills that can be taught and demonstrated, rather, it is meant to provide a base of instruction for coaches. TEACHING SKILLS When you introduce a new skill, you should practice the IDEA method. I – Introduce the skill. Explain what you’re trying to accomplish D – Demonstrate the skill. E – Explain the mechanics of the skill. A – Activate the drill that reinforces the skill. HITTING SKILLS Stance / Swing Hitting the Pitch Bunting BASE RUNNING SKILLS Base running rules Proper running techniques Leading off base Sliding FIELDING SKILLS General Information Set Position Fielding Catching Throwing Infield Skills Infield Positions Outfield Skills Catcher Position PITCHING SKILLS Throwing Wind up and Delivery Pitching from the Set (stretch) position Fielding after the throw COMPETITIVE TEAM SKILLS 2 HITTING SKILLS Stance: Proper bat size Stand so that bat can reach the far side of Home plate Feet apart at a comfortable distance Swing Eyes on the ball Step towards the pitcher on the swing, drive with back leg. Keep both hands on the bat during the follow-through Level swing Hitting the Pitch Inside pitch - Pull the ball down the line Middle pitch - Hit straight away Outside pitch - Drive to opposite field Bunt (Sacrifice) Move upper hand towards end of bat Square to the pitcher during wind-up Know where to bunt on any situation BASE RUNNING SKILLS Base running rules LISTEN TO THE COACH After hitting the ball: Locate ball half way to 1st base Overrun 1st base on a hit to the infield "Flaring out" on a base hit half way to 1st base Rounding the base on a base hit Touching the inside of the bases when going extra bases On base: Taking a primary and secondary lead Primary lead is before ball is pitched.
    [Show full text]
  • Youth Baseball Rules 8U, 10U, 12U Revised 3/24/2021 A
    Youth Baseball Rules 8U, 10U, 12U Revised 3/24/2021 A. Ground Rules 1. Line up cards should always be exchanged before pregame during ground rules meeting. 2. The Home Team is the “official” scorebook for the game. Coaches are encouraged to check in every half inning to ensure accuracy of score, and pitch counts. 3. Only the Head Coach, a maximum of 2 assistant coaches and players on the roster are permitted in the dugout. In 8U only, an additional parent may be in the dugout controlling the team if the coach is needed to pitch. 4. The defensive players presently in the game, the batter, and two base coaches (1st and 3rd base) are the only personnel permitted on the field. In 8U, the coach pitcher/machine operator is allowed. All other coaches and players must remain in the dugout. The only exception would be in 8U where a coach is using the pitching machine. 5. Equipment must be kept in the dugout and off the field of play. PENALTY: For violation of Rules C3 – C4, obstruction or interference may be called against the offending team, and the umpire may impose appropriate penalties. 6. A ball thrown out of play is an immediate dead ball. The results of the play are the following: A. If it is the first throw by an infielder, the result will be two (2) bases from the runner’s position at the time of the pitch. B. If it is on any other throw (i.e. – 2nd or 3rd throw or a throw from the outfield), the result will be two bases from the base runners position at the time of release.
    [Show full text]
  • Shetland Division (4-, 5-, & 6-Year-Olds)
    Meadows Place PONY Baseball Ground Rules Shetland Division (4-, 5-, & 6-year-olds) Managers are required to have a copy of the rules in their possession for each game. PONY Baseball rules (https://www.pony.org/Default.aspx?tabid=1026027) and MLB rules shall apply unless otherwise specified. Objectives . Shetland Division focuses on instruction of beginning players. Managers and coaches will teach players to properly swing a bat, catch, throw and run the bases. Players are encouraged to experience different positions throughout the season. Sportsmanship . Unsportsmanlike behavior will not be tolerated. Umpires will maintain control and have the authority to eject or remove players, coaches, or fans from the facility. Umpires should not be approached after the game under any circumstances. Any manager, coach, player, or fan demonstrating unsportsmanlike behavior may be ejected from the game and may be suspended for additional games. Razzing, heckling, chanting, or making disparaging remarks or noises directed at opponents in any manner is prohibited. Shakers or noise makers are not allowed. For the safety of all players and to maintain integrity of the game, organized cheering or chanting is not allowed while the batter is preparing to hit the ball. Like all rules, enforcement is subject to umpire judgment. Foul and abusive language will not be tolerated under any circumstances. Cursing or throwing equipment is grounds for an automatic ejection. There is a zero-tolerance policy for making threats or taking physical action. Any occurrence will be immediately reported to the Board and the proper authorities. Declared League Age . As part of the League registration, each player MUST declare a league age (determined by their age on May 1) for the up coming season.
    [Show full text]
  • Catching Thrown Balls a Fielder May Receive a Ball When Covering a Base Or Not Covering a Base
    144 Coaching Youth Softball Backstop (continued) attempts to block each pitch. Catcher scores one point for each success- ful block. Throwing out runners—The fielder plays shortstop. A runner on first tries to steal second as the pitcher pitches. The catcher throws to the shortstop covering second, who tries to tag the runner out (see figure 8.57b). Do this play three times. The catcher scores one point for each throw to second that arrives in time to get the runner out (the point is scored even if the shortstop drops the ball at second or misses the tag). Blocking the plate—The runner is on third base. The catcher (or you) throws a ground ball to the fielder, who is playing shortstop (see figure 8.57c). The runner breaks for home and tries to score. The catcher blocks the plate and attempts to tag out the runner. Do this play three times, scoring one point for each successful tag. Fielding a bunt and throwing to first base—A runner is at home and the fielder is at first base (see figure 8.57d). Roll a bunt down the first- or third-base line; the runner heads for first base as the ball leaves your hand. The catcher, starting from a crouched position, springs up as the ball is rolled and the runner takes off for first. The catcher at- tempts to throw the runner out. Do this play three times, scoring a point for the catcher for each out at first (if the ball arrives in time to get the runner out, score the point for the catcher even if the fielder at first base drops the ball).
    [Show full text]
  • Physical Education and Sport for the Secondary School Student. INSTITUTION American Alliance,For Health, Physical Education, Recreation and Dance, Reston, VA
    DOCUMENT RESUME ED 231 783 sp 022 615 AUTHOR Dougherty, Neil J., IV, Ed. TITLE - Physical Education and Sport for the Secondary School Student. INSTITUTION American Alliance,for Health, Physical Education, ReCreation and Dance, Reston, VA. National Association for Sport and Physical Education. REPORT NO ISBN-0-88314-249-X PUB DATE 83 NOTE 413p. AVAILABLE FROMAmerican Alliance for Healthe Physical Education, Recreation and Dance, P. 0. Box 704, Waldorf, MD 20601 ($11.95). PUB, TYPE Reports -.Descriptive (141) EDRS PRICE MF61 Plus Postage. PC Not Available from EDRS. DESCRIPTORS *Athletics;,Dance Education; Exercise; Leisure Time; 'Lifetime Sports; Motor Development; *Outdoor Activities; Physical Education; *Physical Fitness; *Recreational Activities; Recreational Facilities; Secondary Education ABSTRACT This book provides an overview of sports and -information on skills and technique acquisition, safety, scoring, rules and etiquette, strategy, equipment, and related terminology. The emphasis is on individual and dual sports for which facilities are widely available and body contact is limited or unnecessary. Chapters are included on:(1) Health Fitness (Russell R. Pate); (2) Motor,Skill Development and Evaluation (Jerry R. Thomas and Jack K. Nelson); (3) Archery (Ruth E. Rowe and Julia Heagey Bowers); (4) Badminton (Arne L. Olson); (5) Basketball (Gene Doane); (6) Bowling (Norman_E.___Showers); (7) Dance in ducation (Dennis.Fallon); (8) Field Hockey (Barbara J. Berf-and-B-arbara-J7-Reimann): 1-9) Cced-Flag- Football (Maryann Domitrovitz); (10) Golf (DeDe Owens); (11) Tumbling (Diane Bonanno and Kathleen Feigley); (12) Jogging (Russell R. Pate); (13) Orienteering (Arthur Hugglestone and Joe Howard); (14) Self-defense (Kenneth G. Tillman); (15) Racquetball/Handball (John P.
    [Show full text]
  • D.O.L.L.S. Second Grade Level Rules Revised April 2021
    D.O.L.L.S. Second Grade Level Rules Revised April 2021 Emphasis of this league is on developing basic softball skills - batting, fielding ground balls and fly balls, throwing, catching, pitching, rounding bases, defensive positions, and making cut-offs. USA softball rules apply for this age group for all aspects of the game not addressed by the below rules. 1. All girls are required to play all defensive positions during the season. At every game, all girls are required to play 1 complete inning in the infield and 1 complete inning in the outfield. No player may play the outfield a 2nd inning until all players on the roster have played outfield for 1 inning. Similarly, all players must rotate sitting out, no player may sit out 2 innings in a row. Every player must sit out once before any player sits out twice. Equal playing time, best as can be maintained, is required for all players each game. 2. Outfielders are required to play in the outfield; they may not cover a base. Covering bases is the job of the infielders. A runner shall be declared safe if the out is the result of an outfielder covering a base. 3. Maximum of 10 defensive players per inning will be allowed. The infield will play the regular 6, and the outfield may play 4 defensive players. 4. A continuous batting order is mandatory. “Continuous” batting order means that all players present are placed in the batting order, regardless of which players are playing in the field any given inning.
    [Show full text]
  • 2020 UCCRL Competitive T-Ball Rules
    2020 UCCRL Competitive T-ball Rules 1. Up to 10 players on the field at a time. 2. Teams may use a catcher but is not required. If team has a catcher, they must be in full catcher’s gear. And not standing behind the plate. (Catcher should be in foul territory in safe position while each batter hits). Coach is required to check with the catcher before placing the ball on tee before every swing. 3. Teams my play up to 4 outfielders. 4. There will be a 6’ arch in front of home plate from foul line to foul line. A batted ball must pass the 6’ arch to be considered a live ball. 5. The pitcher must stay on the pitching rubber (chalked line) 30’ from the back of home plate until the ball is put in play. 6. The pitching rubber (chalked line) will be in the center of a 5’ circle. 7. Bases will be at 45’ 8. There should be hash marks at 23’ in between bases. 9. If a base runner is not past the hash mark before a defensive player enters the pitching circle (with control of the baseball) the baserunner must return to previous base. Once defensive player enters the circle with the baseball the play is considered dead. 10. A base runner can only advance one base on a throwing error. If the runner makes the attempt to advance the defense can get the player out. If the runner advances safely more than one base the runner must return to the previous base.
    [Show full text]
  • Baseball Positive 2015
    Baseball Positive Fall Instructional Ball 2015 Coaches Manual —— For Personal Use Only —— Table of Contents Day 1 ………………………………………….…….…...4 Day 2 ……………………………………………..…….10 Day 3 …………………………………………………...15 Day 4 …………………………………………………...21 Day 5 …………………………………………………...26 Day 6 …………………………………………………...29 Day 7 …………………………………………………...36 Day 8 …………………………………………………...40 Day 9 …………………………………………………...43 Day 10 ………………………………………………….47 Batting Drills Sheet …………………………………………………………..…………..……..…...20 Drill Diagrams —> Base Running Touch Point on a Base …………………………………………………….…………..30 Turns & Touches ……………………………………………………………..…………..31 Running Through First Base …………………………………….…………………..32 —> Defensive Positional Responsibilities Infield Base Coverage …………………………………………………….....………….6-7 OF Backing-up …………………………………………………………………….……..….9 Middle Infield Movement - balls hit to the outfield ……………….…….11 Pitchers Backing-up ……………………………………………………………….…….12 Pitchers Covering a Corner Base …………………………………….…………….13 Receiving Throws at a Base …………………………………………………...…….14 Pitchers Covering a Corner Base - three different plays/drills …..….18 —> Fielding Underhand Toss / Throwing on the Run - Shuttle ………………..…………5,13 Underhand Toss - phase 2 ……………………………………………………..…...17 20’ Ground Balls ……………………………………………………………………….....22 Fly Ball Drills ……………………………………………………………….……………....27 1-6 Play (“Turn Glove Side”) ……………………………………………...………..44 5-1 Play …………………………………………………………………………………..…..48 1-3 Play …………………………………………………………………………………..…..49 —> Team Drills Ambush (Rundown) ………………………………………………………...…………..34
    [Show full text]
  • 10U 2018 Study Guide Coach Sarah Johnson DEFENSE
    10U 2018 Study Guide Coach Sarah Johnson DEFENSE: Ready Position and Communication: All players are responsible to be in ready position and communicate on EVERY play. Knowing your responsibilities on each pitch is the greatest part of being READY. Each player has 3 responsibilities on EVERY PITCH: 1. Understand where to go if the ball is hit to you. If the ball is not hit to you THEN your additional responsibilities become 2. Cover a base for a possible play or to keep runners from advancing and/or 3. Position yourself to cover a possible overthrow. You will have one of the 3 responsibilities on each play regardless of your position – “Ball, Base, Back‐up”. Fielding the Bunt: The bunt will be covered by 3rd base and 1st base along with the catcher and pitcher. Second base will be responsible for fielding the throw to first on the bunt at all times. Right field will work to back up the throws to first. Short stop will cover 2nd base if NOBODY is on base. If there are one or more baserunners on base at the time of the bunt, short stop will cover 3rd base. Centerfield will cover 2nd base if short stop is covering 3rd base. If short stop is covering 2nd base, centerfield will back up 2nd base. Left field is responsible for backing up 3rd base. Defending the Steal: Shortstop will cover the throw to 2nd on all steals. Center field will back up the throws. 2nd base should be the lead communicator on the steal yelling, “she’s going” but should not become involved with the throw down.
    [Show full text]
  • Base Running Drills
    Base Running Drills V3.0 February 2018 © Copyright Palo Alto Girls Softball 2016-18. All Rights Reserved. 1 Author/Person to Blame: Tom Kemp Drills 1. Simple March Drill (younger ages) 2. Time to 1st Drill (all ages) 3. Time to 2nd Drill (all ages) 4. Lead of at 1st Drill (all ages) 5. Triplet Sprint (all ages) 6. 5 Cone Drill (all ages) 7. Relay Game (all ages) 8. Beat Me if You Can Game (8U and 10U) 9. What to Do at 1st Drill (all ages) 10. Wait Wait Go Drills (older ages) 11. Tag Up and Run Home Drill (older ages) 12. Overthrow at 1st Drill (older ages) 13. Retreating Back to Bag Drill (older ages) 14. Stretching a Single to a Double Drill (older ages) 15. Hands Up Sliding Drill (older ages) 2 But First, a Few Important Notes • Safety First! Whenever there is a live ball being used in a drill, the runners must be wearing a helmet • Read the Fundamentals of Base Running document to acquaint yourself with proper technique 3 Appropriate for: 1. Simple March Drill Younger Ages • Have runners walk from home to 1st and march while pumping their arms • Pause when knee is at top to ensure proper form (opposite knee, opposite arm) • https://www.youtube.com/watch?v=Wr67-XvIC_c (:25 to :50) 4 Appropriate for: 2. Time to 1st Base Drill All Ages • Use your mobile phone’s stopwatch (usually with the clock app) as a way to time the players running to 1st base • Have them line up near home, with one girl at a time at home • Coach lines up near 1st, yells go, hit starts button • When runner at home base hears go, they take a practice/pretend swing (with no bat), and then runs to 1st as fast as they can • When they touch 1st base, the coach hits the stop button on phone’s stopwatch app and tells the girl their time • See https://www.youtube.com/watch?v=EqcDG9_oni0 (0:20 to 1:00) for tips you can give • Have them run multiple times and have each girl try to beat in subsequent attempts their 1st time running in the drill 5 Appropriate for: 3.
    [Show full text]