02088nas a2200265   450000500170000000800410001703500150005810000370007310000220011024500810013226000520021330000160026549000270028150001520030850200580046052009640051865000170148270000310149970000410153070000460157170000480161771000330166581000590169885600650175720260818145356.0011298s1985    th      r     000| 0eng d  a.b10399197  all Number:   AIT Thesis no.EV-850 aKreeta Sroikeeree10aLeast cost design of drainage systems with three-dimensional state variables  aBangkok :bAsian Institute of Technology,c1985  a51, (39) p.1 aThesis ;vno. EV-85-15  aA thesis submitted in partial fulfillment of requirements for the degree of Master of Engineering, School of Environment, Resources and Development  aThesis (M.Eng.) - Asian Institute of Technology, 1985  aDrainage systems can be efficiently designed for minimum cost by  Dynamic Programing. Present models generally use a one-dimensional  state variable with the pipe level as parameter. Although the  theoretical need for at least a two-dimensional state variable is  recognised, more dimensional state variables are still considered as  impracticable due to computational requirements. In this study one-,  two-, and three-dimensional models were developed. The parameters  are the pipe elevation, the pipe diameter, and the time of flow as  in the Rational Method. The model has been implemented on a IBM  personal computer. Three test examples show the operationability of  the developed program. It has been found for the test examples that  introducing the time of flow into the state variable reduces the  least cost between 0 and 7.2%. Depending on topography, introducing  the diameter in some certain cases reduces the least cost more than  17% {u2022}   0aFlocculation1 aOrth, H.M.,eChairperson  1 aLohani, B.N.,eExamination Committee1 aHuynh, Ngoc Phien,eExamination Committee0 aChongrak Polprasert,eExamination Committee2 aUS-ASEAN,eScholarship Donor2 aAsian Institute of Technology.tThesis ;vno. EV-85-15  3Full-Textuhttp://203.159.5.9/ait-thesis/detail.php?q=B20014