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

Overhead distribution lines are prone to lightning overvoltages due to their configurations and characteristics. Metal Oxide Varistor (MOVs) arresters for many years have proven to be more advantageous than others arresters in lightning surge protection; therefore it is worthwhile to continually assess the behavior and performance of these arresters to different kind of overvoltages caused by lightning strokes for power system applications. This paper presents the performance of MOV arresters to multiple lightning strokes nearby a substation transformer. All simulations were performed with Alternative Transients Program/ Electromagnetic Transients Program (ATP/EMTP Program). Key-words: Lightning strokes, surge arrester, ATPDraw, Transient Overvoltages.

Performance of surge arrester to multiple lightning strokes on nearby distribution transformer

A Review of the Effects of Electric Vehicle Charging on Distribution Network Operation and Power Quality

Effects of harmonics on trasformers loss of life

Signal Processing Considerations in Traveling Waves Fault Locators

Induced voltages on overhead distribution lines owing to lightning return strokes cause insulators flashovers and consequently, line outages. Basically, shield wires and surge arresters form the lightning protection system for overhead lines to improve the performance of distribution systems against return strokes. The effectiveness of the lightning protection system depends essentially on the grounding system on which shield wire and surge arrester are installed. This article presents a numerical approach to consider the transient models at the points of discontinuity where the lightning protection system exists on multiconductor overhead line. The finite-difference time-domain method is applied to Agrawal coupling model to solve numerically the electromagnetic wave propagation along the line, whereas the Newton–Raphson method is exclusively used for the points of discontinuity. The results obtained considering the transient model as well as a dc model are compared to clarify the influence of the line discontinuity model on the propagating electromagnetic waves. The computational stability of the proposed method is confirmed for different cases of lightning waveforms, distances between points of discontinuity, and stroke locations with line discontinuities.

Matti Lehtonen

Papers

Performance of surge arrester to multiple lightning strokes on nearby distribution transformer

A Review of the Effects of Electric Vehicle Charging on Distribution Network Operation and Power Quality

Effects of harmonics on trasformers loss of life

Signal Processing Considerations in Traveling Waves Fault Locators

Protection Against Lightning-Induced Voltages: Transient Model for Points of Discontinuity on Multiconductor Overhead Line