Hermann Henrich Steffen was born in 1801 in Kalldorf, Lippe-Detmold, Germany. He married Marie-Elisabeth Schwarze in 1827. They had eight children. Hermann died in 1846. Marie-Elisabeth and the children emigrated in 1856 and settled in Freeport, Stephenson County, Illinois. Descendants and relatives lived in Illinois, Iowa, North Dakota and elsewhere.

According to the great mathematician Paul Erdös, God maintains perfect mathematical proofs in The Book. This book presents the authors candidates for such "perfect proofs," those which contain brilliant ideas, clever connections, and wonderful observations, bringing new insight and surprising perspectives to problems from number theory, geometry, analysis, combinatorics, and graph theory. As a result, this book will be fun reading for anyone with an interest in mathematics.

William Gemmill (1722-1789) and his wife, Jannett, immigrated in 1745 from Scotland to York County, Pennsylvania. He served in both the French and Indian War and the Revolutionary War. Two of his brothers immigrated later. Descendants and relatives lived in Pennsylvania, Ohio, Illinois, Iowa, Kansas, Washington and elsewhere. Other Gemmill family members immigrated from Scotland to Canada, settling in Ontario, Manitoba and elsewhere. Includes notes on ancestry in Scotland and Denmark.

Designed for the freshman/sophomore Calculus I-II-III sequence, the eighth edition continues to evolve to fulfill the needs of a changing market by providing flexible solutions to teaching and learning needs of all kinds. The new edition retains the strengths of earlier editions such as Anton's trademark clarity of exposition, sound mathematics, excellent exercises and examples, and appropriate level. Anton also incorporates new ideas that have withstood the objective scrutiny of many skilled and thoughtful instructors and their students.

The idea of the ICMI Study 13 is outlined as follows: Education in any social environment is influenced in many ways by the traditions of these environments. This study brings together leading experts to research and report on mathematics education in a global context. Mathematics education faces a split phenomenon of difference and correspondence. A study attempting a comparison between mathematics education in different traditions will be helpful to understanding this phenomenon.

The Proceedings of the ICM publishes the talks, by invited speakers, at the conference organized by the International Mathematical Union every 4 years. It covers several areas of Mathematics and it includes the Fields Medal and Nevanlinna, Gauss and Leelavati Prizes and the Chern Medal laudatios.

A rigorous introduction to optimal control theory, with an emphasis on applications in economics. This book bridges optimal control theory and economics, discussing ordinary differential equations, optimal control, game theory, and mechanism design in one volume. Technically rigorous and largely self-contained, it provides an introduction to the use of optimal control theory for deterministic continuous-time systems in economics. The theory of ordinary differential equations (ODEs) is the backbone of the theory developed in the book, and chapter 2 offers a detailed review of basic concepts in the theory of ODEs, including the solution of systems of linear ODEs, state-space analysis, potential functions, and stability analysis. Following this, the book covers the main results of optimal control theory, in particular necessary and sufficient optimality conditions; game theory, with an emphasis on differential games; and the application of control-theoretic concepts to the design of economic mechanisms. Appendixes provide a mathematical review and full solutions to all end-of-chapter problems. The material is presented at three levels: single-person decision making; games, in which a group of decision makers interact strategically; and mechanism design, which is concerned with a designer's creation of an environment in which players interact to maximize the designer's objective. The book focuses on applications; the problems are an integral part of the text. It is intended for use as a textbook or reference for graduate students, teachers, and researchers interested in applications of control theory beyond its classical use in economic growth. The book will also appeal to readers interested in a modeling approach to certain practical problems involving dynamic continuous-time models.

This study focuses on the cultural-historical environment of the 88,900-acre (35,560-ha) Valles Caldera National Preserve (VCNP) over the past four centuries of Spanish, Mexican, and U.S. governance. It includes a review and synthesis of available published and unpublished historical, ethnohistorical, and ethnographic literature about the human occupation of the area now contained within the VCNP. Documents include historical maps, texts, letters, diaries, business records, photographs, land and mineral patents, and court testimony.