There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

计量经济分析 = Econometric analysis

This chapter discusses leading problems linked to energy that the world is now confronting and to propose some ideas concerning possible solutions. Oil deserves special attention among all energy sources. Since the beginning of 1981, it has merely been continuing and enhancing the downward movement in consumption and prices caused by excessive rises, especially for light crudes such as those from Africa, and the slowing down of worldwide economic growth. Densely-populated oil-producing countries need to produce to live, to pay for their food and their equipment. If the economic growth of the industrialized countries were to be 4%, even if investment in the rational use of energy were pushed to the limit and the development of nonpetroleum energy sources were also pursued actively, it would be extremely difficult to prevent a sharp rise in prices. It is evident that it is absolutely necessary to pursue actively the development of coal, natural gas, and nuclear power if a physical shortage of energy is not to block economic growth.

World energy outlook

Introduction to stochastic programming

This paper investigates the problem of fault location based on transient current signals measured at few transmission line ends in a large transmission net- work. Current traveling waves (CTW) are utilized to locate faults on transmission system since current trans- formers (CTs) can reproduce the current transient with sufficient accuracy in their secondary circuits. The num- ber of traveling wave recorders (TWR) is usually less than the number of buses; hence there is a need for an economi- cal method to find the fault from these recording units. The signals are analyzed using digital wavelet transform (DWT) and the optimum mother wavelet and optimum details level were selected according to their energy con- tent using MATLAB Wavelet toolbox. The shortest path between the best-selected TWRs is calculated. The fault can then be calculated using the double-end method. Trav- eling wave speeds were calculated at each DWT details level. Results show that traveling waves have different speeds at different frequency bands. Several test cases were investigated from ATP/EMTP simulation and measurements from the Finnish 400 kV Transmission System. Results show a practical solution to the existing fault location system and proposals for optimal location of recording units are suggested.

Multi-end traveling wave fault location based on current traveling waves

Optimal capacity planning of substation transformers by demand response combined with network automation

Dynamic Thermal State Forecasting of Distribution Network Components

https://research.aalto.fi/files/34828375/ELEC_Tukia_etal_Modeling_the_Aggregated_AppEne_251_113356_final.pdf

Matti Lehtonen

Papers

Multi-end traveling wave fault location based on current traveling waves

Optimal capacity planning of substation transformers by demand response combined with network automation

Dynamic Thermal State Forecasting of Distribution Network Components

Modeling the aggregated power consumption of elevators – the New York city case study

Modified V-I droop based adaptive vector control scheme for demand side management in a stand-alone microgrid