Figure P10.45 shows a feedback triple utilizing MOSFETs. All three MOSFETs are biased and sized to operate at mA/V. You may neglect their s (except for the calculation of as indicated below).(a) Considering the feedback amplifier as a transconductance amplifier with output current , find the value of that results in a closed-loop transconductance of approximately 100 mA/V. (b) Sketch the A circuit and find the value of (c) Find and Compare to the value of you designed for. What is the percentage difference? What resistance can you change to make exactly 100 mA/V, and in which direction (increase or decrease)? (d) Assuming that k find the output resistance . Since the current sampled by the feedback network is exactly equal to the output current, you can use the feedback formula. (e) If the voltage is taken as the output, in which case the amplifier becomes seriesshunt feedback, what is the value of the closed-loop voltage gain ? Assume that has the original value you selected in (a). Note that in this case should be considered part of the amplifier and not the feedback network. The feedback analysis will reveal that changes somewhat, which may be puzzling given that the feedback loop did not change. The change is due to the different approximation used. (f) What is the closed-loop output resistance of the voltage amplifier in (e) above?
Intro to Psychology Study Guide for Exam #2 Developmental Psychology 1) Nature vs. Nurture 2) Continuity vs. Stages (need to develop certain stages before others but continuous) 3) Change vs. Stability (temperament, potential IQ, eye color) Stability – Nature Stages – Nature Cognitive development – development of how you think, learning through experience Piaget noticed young children were all making the same errors, errors in the way they think as they develop Teratogens – “monster makers”, can cause birth defects Habituate – get used to, so don’t habituate them to silence when its time to sleep! Rooting reflex – trying to find nipple Sucking reflex – will suck really hard Crying – cry when they are hungry for survival Piaget’s Stages of Cognitive Development Sensorimotor Birth to about 2 years Experience the world through the senses Looking, touching, sucking Object permanence & stranger anxiety Preoperational 2 to 7 years Represent things with language & images but lack logic Pretend play, egocentrism, language development, theory of mind Concrete operational 7 to 11 years Have trouble with abstract concepts (analogies & metaphors) but can think logically and solve arithmetic problems Logical thought, conversation, mathematical transformations, reversibility Formal operational 11 to Adulthood Can explore concrete & abstract concepts Abstract reasoning, potential for mature moral reasoning Schema – folders, how we categorize things, children don’t encounter things as much so they assimilate things together Accommodation – new schema with new formation Harlow Wire Mother/Cloth Mother Food over warmth/security NO! Attachment – more towards who provided comfort and safety than who provided food Monkeys were never able to recover because of their isolation 3 Main Types of Attachment 1) Secure 2) Ambivalent 3) Avoidant Caregiver in room with child, how does the child interact with them How does the child react when the caregiver leaves And how does the child react when the caregiver returns 1) Secure Attachment Caregiver is secure base, checking back with them while exploring Child is upset when the caregiver leaves Child is soothed when the caregiver returns 2) Ambivalent Attachment Child is wanting to play with the caregiver Child is devastated when the caregiver leaves Child cannot be comforted when the caregiver returns 3) Avoidant Attachment Child avoids caregiver Child is startled when they leave Child avoids caregiver when they return Not just the mother’s behavior to the child but the temperament of the child also factors into the child’s attachment. Parenting Styles 1) Authoritarian – strict, no reasons given, harsh consequences, high control, “because I said so” 2) Authoritative – firm but flexible, give and take, realistic and consistent, communication is key 3) Permissive – lets them do whatever they want, warm and nurturing, trying to be their friend 4) Neglectful – not there for the child Repercussions for Early Puberty For females – jealously, bullies, sexual harassment, more likely to engage in sex earlier, substance and alcohol abuse For males – sexual activity earlier, substance and alcohol abuse, more popular and confident Trust vs. Mistrust 1 18 months Trying to develop trust in people Attachment style is developing Autonomy vs. Shame/Doubt 1 – 3 years old Walking Potty training Independence Failures – shame and doubt Initiative vs. Guilt 35 years old Learning to dress selves Explore surroundings Pretend play Sense of purpose and control Industry vs. Inferiority 6 – 11 years old School focus Finding something that you excel at Need to feel that they can excel Identity vs. Identity/Role Confusion Who are you Your identity Trying different roles Confused about your role and how you fit in the world Psychological Moratorium Period proposed by Erikson linked to Identity vs. Identity Confusion Society gives permission to teen/adolescents so that they could experiment with different roles so they could sample them before going out in the world Chance to try different hats More likely to be more comfortable with their identity Intimacy vs. Isolation Young adulthood Not necessarily sexual relationships Developing intimate relationships, close friendships If they are not able to feel that then they may have feelings of isolation Alone time is ok But not having those bonds and feelings of sharing and caring can lead to isolation Importance of parents decreases while the importance of peers increases Parents influence Religious views Education and career paths Selfdiscipline Responsibility Cooperation Style of interacting with authority Peers influence Cultural choices Recreations Good and bad habits Choices in clothes, music, etc. Emerging Adulthood 1925 years old In between stage where you’re technically an adult but still dependent You want to be independent but you can’t afford to move out Parents also want you to be able to live on your own too Compromise, work it out Show them you’re an adult, be considerate, ask them for advice, contribute to the home in lots of different ways (doesn’t have to be financially) Potential Life Span Human body we think has the capacity to live 122 years Aging Body Women outnumber men 5 to 1 Men tend to do more dangerous things Young boys are more reckless than young girls Jobs – armed service, construction jobs, jobs with high mortality rates Decline in visual acuteness Decline in quality of hearing Slower reaction time and processing speed 6570 year olds experience an increase in car accidents Immune System Decreases as we age You don’t get small stuff because you already have antibodies Brain Shrinks and deteriorates, 5% lighter by the age of 80 Frontal lobe atrophy Inhibition and selfcontrol lost – they can be super blunt Generativity vs. Stagnation Middle adulthood, 35 50/65 years old Pass down money, ideas, energy Family or jobs Looking towards the next generation through biological children or through your own work Leaving your legacy, showing you can be useful Stagnation – not really accomplishing or moving forward Ego Integrity vs. Despair 65+ years Life review Good or “coulda/woulda/shoulda” Midlife Change is common It’s if you can’t handle the change that it becomes a Midlife crisis (but that is less common) Erikson’s levels build up on each other, but you can go back and work on others Do you get happier or sadder as you age Depends on your personality, how you lived your life More of what you were in life Work out kinks – most tend to be happier Better sense of self but experience more loss so it evens out KüblerRoss – Stages of Greif Denial Anger * Bargaining Depression * Acceptance (not all can accept) * major ones that most experience Not necessarily experienced in this order Not all necessarily experience all of them Easier to go through process with prior warning Grief natural process, be kind to them and to yourself, no set time or formula Day After Christmas spike Will to make it through the last family holiday Cross Sectional studies Info on all sorts of things Benefit – differences between different age groups, getting it all today and quickly, less expensive But they are all raised in different generations so they all experienced different impacts Longitudinal studies 1 group of people and seeing how they change over time You see how they change over time and age No changes in cohort But it takes a long time and its expensive Sequential Design studies Start with Cross sectional study and then add a cohort every couple of years, add another group Some people die, move, drop from the study Constantly adding people in Classical Conditioning reflexive, psychological, not a lot of control if you’re aware of it then it doesn’t have as much power US – Unconditioned Stimulus (naturally happens) UR – Unconditioned Response (naturally happens) NS – Neutral Stimulus CS – Conditioned Stimulus CR – Conditioned Response US – UR (naturally occurring stimulant and response) NS – US – UR (add in neutral stimulant, but it has to be first to associate bell with food) CS – X – CR (neutral stimulant becomes conditioned stimulant, can exclude the unconditioned stimulant, and get a conditioned response) Extinction If you use the CS to get the CR but you exclude the US, after a while it goes away Important to the treatment of phobias Spontaneous Recovery Learned again suddenly Reemergence of a previously learned condition response after a delay Generalization Drool to more stimuli All different kinds of bells, lights, sounds Discrimination Drool to less stimuli Only a certain bell Much more narrower range Operant Conditioning – level of choice involved, choice in behavior Positive Reinforcement Add a positive stimulus Treats Strengthen a behavior Negative Reinforcement Take away a negative stimulus Stop annoying beeping by putting on seatbelt Strengthen a behavior Positive Punishment Adding a negative stimulus Spanking Weakens a behavior Negative Punishment Taking away a positive stimulus Taking away cell phone Weaken a behavior Shaping – process of getting someone or something to do what you want Punishment > Reinforcement in the case of avoiding dangers and in natural settings Immediate and certain more effective than severe punishments Discriminating Will do trained behavior when you’re around but do whatever they want when you’re gone Happens a lot when using negative punishment Attitude of fear and hatred Schedules of Reinforcement 1.) Interval – time based Fixed – every so often (getting paid on Friday) Variable – after an unpredictable amount of time 2.) Ratio – behavior/instances Fixed – after every so many behaviors Ratio – after an unpredictable amount of behaviors (a pat on the back at work) Fixed ratio – high rate of response Variable ratio – high consistent responders even without a reward, slot machines! They resist extinction Interval – slow rates of responding Fixed interval – checking clock at the end of class