Question Patients arrive randomly at an eye care clinic for eye exam. Suppose that there is only one optometrist. The time required for the exam varies from patient to patient. Arrival rates have been found to follow the Poisson distribution (i.e., exponentially distributed inter-arrival times), and the service times follow the exponential distribution. The average arrival rate is 10 patients per hour, and the average service rate is 16 patients per hour. On arrival, a patient needs to stay in the waiting room until the optometrist becomes available. Once the optometrist is available, the next patient goes to the examination room for the eye exam. How many patients, on the average, will be in the examination room? Note: Keep two decimal places for your answer.

Discuss FIVE (5) functions, according to Fayol, that the managers fulfil at Nucor steel , giving an example for each.

5.12. Consider the AIRLINE relational database schema shown in Figure 5.8, which describes a database for airline flight information. Each FLIGHT is identified by a Flight_number, and consists of one or more FLIGHT_LEGs with Leg_numbers 1, 2, 3, and so on. Each FLIGHT_LEG has scheduled arrival and departure times, airports, and one or more LEG_INSTANCEs— one for each Date on which the flight travels. FAREs are kept for each FLIGHT. For each FLIGHT_LEG instance, SEAT_RESERVATIONs are kept, as are the AIRPLANE used on the leg and the actual arrival and departure times and airports. An AIRPLANE is identified by an Airplane_id and is of a particular AIRPLANE_TYPE. CAN_LAND relates AIRPLANE_TYPEs to the AIRPORTs at which they can land. An AIRPORT is identified by an Airport_code. Consider an update for the AIRLINE database to enter a reservation on a particular flight or flight leg on a given date. a. Give the operations for this update. b. What types of constraints would you expect to check? c. Which of these constraints are key, entity integrity, and referential integrity constraints, and which are not? d. Specify all the referential integrity constraints that hold on the schema shown in Figure 5.8. 172 Chapter 5 The Relational Data Model and Relational Database Constraints AIRPORT Airport_code Name City State FLIGHT Flight_number Airline Weekdays FLIGHT_LEG Flight_number Leg_number Departure_airport_code Scheduled_departure_time Arrival_airport_code Scheduled_arrival_time LEG_INSTANCE Flight_number Leg_number Date Number_of_available_seats Airplane_id Departure_time Arrival_airport_code Arrival_time Departure_airport_code FARE Flight_number Fare_code Amount Restrictions AIRPLANE_TYPE Airplane_type_name Max_seats Company CAN_LAND Airplane_type_name Airport_code AIRPLANE Airplane_id Total_number_of_seats Airplane_type SEAT_RESERVATION Flight_number Leg_number Date Seat_number Customer_name Customer_phone Figure 5.8 The AIRLINE relational database schema.

Determine undamped natural frequency 0, and damping ratio 5 of the below closed-loop system, R(s) Gls) C(s) 4 G(S) = H(S) = 5 + 1 H(s)

A researcher is interested in the proteins that E-cadherin binds to. She expresses full-length E-cadherin as well some truncated constructs of the protein in a mouse cell line that does not express any other cadherins. The scheme of constructs is shown in figure A, (E represents the extracellular domain, TM the transmembrane domain and C the cytoplasmic domain). She labels the cells with 35S methionine for 16 hours, homogenizes them in detergent, and an antibody raised against the extracellular domain of the cadherin E-cadherin to pull-down (co-immunoprecipitate) E-cadherin and any associated proteins. She then analyses the immune precipitates by electrophoresis by SDS-PAGE, followed by autoradiography to make the labelled proteins visible. In lane 1 of figure B, the antibody precipitates three major proteins in cells transfected with a plasmid expressing the full-length intact cadherin. These proteins are not precipitated from untreated control cells. H₂N A 553aa B kd 200 - 97- 67- 45- 24 aa www. um m M Full-length E 31 aa 70 aa 105 aa E-Cad 437 E-Cad 48 TM C COOH 151 aa E-Cad 431 E-Cad 470 E-Cad 105 control 1 2 3 4 5 6 7 37 aa b. Which segment of cadherin is responsible for binding to other proteins? (2 marks) Full-length E-Cad 437 E-Cad 48 E-Cad 431 E-Cad 470 E-Cad A105 a. Which protein bands in the autoradiograph (Figure B) correspond to cadherin and which correspond to proteins that bind to cadherin? Explain your answer. (2 marks)

Determine undamped natural frequency \( \omega_{n} \) and damping ratio \( \zeta \) of the below closed-loop system, \[ G(s)=\frac{4}{s} \quad H(s)=s^{2}+1 \]

database Consider the relation CLASS(Course#, Univ_Section#, Instructor_name, Semester, Building_code, Room#, Time_period, Weekdays, Credit_hours). This represents classes taught in a university, with unique Univ_section#s. Identify what you think should be various candidate keys, and write in your own words the conditions or assumptions under which each candidate key would be valid.