Showing papers by "Istanbul Technical University published in 1977"
TL;DR: In this article, a general methodology for determining various run-sum properties of a given hydrologic process, based on the random sum of random variables, has been developed, and application of the method to some independent and dependent processes has been given.
87 citations
TL;DR: This paper presents a quantitative planning model to determine the optimal characteristics number, size and locations of a regional health facility system which consists of a medical center, intermediate and local hospitals, and health centers.
Abstract: This paper presents a quantitative planning model to determine the optimal characteristics number, size and locations of a regional health facility system. The system consists of a medical center, intermediate and local hospitals, and health centers. The quantitative model is based on the minimization of the total cost sum of the transportation and facility costs to the society. The optimal characteristics of the system are obtained using a heuristic method which includes both interactions of sublevel hospitals and environmental conditions as well. A numerical example is given to illustrate the computational procedure.
55 citations
TL;DR: Tin-induced temper embrittlement of 3.5 pct Ni, 1.7 pct Cr and 0.4 pct C was studied by means of notched-bar testing, scanning electron fractography, and Auger electron spectroscopy of isothermally aged specimens as mentioned in this paper.
Abstract: Tin-induced temper embrittlement of 3.5 pct Ni, 1.7 pct Cr steels containing 0.2 and 0.4 pct C was studied by means of notched-bar testing, scanning electron fractography, and Auger electron spectroscopy of isothermally aged specimens. The ductile-brittle transition temperature varied linearly with Sn concentration on grain boundaries at a rate which increased with hardness of the steel. The rate of approach to the steady state level of embrittlement was faster in the higher C steel. The grain boundary concentrations of Ni and Sn bear a unique relationship in a manner analogous to the behavior found previously in Sb-doped steels. The potency of Sn as an embrittling element is somewhat less than that of Sb, but considerably greater than that of P.
42 citations
TL;DR: Optimum control of a linear large scale dynamic system is formulated as a game problem using individual subsystem quadratic cost functions and an overall Nash solution strategy using parametric series solution based on @e-coupling.
32 citations
23 citations
TL;DR: In this article, a numerical method of solution is given for the differential equation describing the discrete settling in two-dimensional uniform and turbulent open-channel flow, and the stability condition of the finite difference equations is derived by applying linear stability analysis.
Abstract: A numerical method of solution is given for the differential equation describing the discrete settling in two-dimensional uniform and turbulent open-channel flow. Stability condition of the finite difference equations is derived by applying linear stability analysis. By neglecting the effect of longitudinal turbulent diffusion, settling efficiency is generally expressed in terms of two independent variables. Further, it is assumed that turbulence is isotropic and solid particles behave like a fluid mass. Three sets of solutions are obtained for uniform, logarithmic, and parabolic velocity distributions in vertical direction. However, the results of the last two are graphically given herein. In the case of uniform velocity distribution, results of numerical solution is compared with Camp's solutions and high accuracy is obtained. The effect of turbulence and velocity distribution is shown. Solutions obtained for the logarithmic velocity distribution which was experimentally verified are suggested for practical applications. /ASCE/
21 citations
9 citations
TL;DR: In this article, the strength and drift characteristics of unbraced multistory steel frames subjected to combined loads are studied with emphasis on P-Δ effect, and four designs are made for each frame: three stress-controlled designs and one drift controlled design, and the results show that even though the strength of the structures is reduced by P − Δ effect, all stress designs can achieve a wind load factor equal to or greater than 1.40 under proportional loads, 2.06 under nonproportional loads with gravity load maintained at working value.
Abstract: The strength and drift characteristics of unbraced multistory steel frames subjected to combined loads are studied with emphasis on P-Δ effect. Seven frames having dimensions and loads typical of those found in apartment and office structures were selected. Four designs are made for each frame: three stress-controlled designs and one drift controlled design. The frames are then analyzed for their response under proportioned and nonproportioned loads. Results show that even though the strength of the structures is reduced by P-Δ effect, all stress designs can achieve a wind load factor equal to or greater than 1.40 under proportional loads, 2.06 under nonproportional loads with gravity load maintained at working value. The stress design having columns proportioned to satisfy AISC provisions does not show significant increase in strength when compared with the design neglecting instability effect. The drift designs have large wind load-carrying capacity, ranging from 1.45 to 4.0, depending on the amount of gravity load.
7 citations
3 citations
TL;DR: In this article, the free flexural vibration of an elastic circular thin plate with an initial imperfection is investigated and a numerical analysis is made with particular reference to this analogy and the results are given in various figures which represent the vibratory motion and the period of vibration versus the initial amplitude of the plate or of the particle of mass.
3 citations
Abstract: The stability of tall, rigidly-jointed, unbraced, steel frames under pure gravity loads is ensured when proportioned by the current allowable-stress concept provided they meet certain specified constraints. These requirements, in fact, govern the individual story stiffnesses and the maximum axial stresses in the columns. A study on seven building frames confirms that for a class of inherently stiff frames, all instability effects may be ignored in design without affecting structural safety under gravity loads.
TL;DR: In this article, the analysis and control of interconnected systems which have a multi-time scale property, are presented, and two basic assumptions are made: (1) there are inherent distinct time scales in the system; (2) prior insight and knowledge about the system to identify the multi time scale behavior are available.
TL;DR: In this article, the relationship of various definitions of retention times in biological filters is investigated and equations expressing flow times as a function of surface tension, grain size, porosity, temperature and some other hydraulic quantities have been given.