Personal mobility (PM) is one of the key issues in realizing personal communications service (PCS) in emerging thirdgeneration mobile communication networks such as International Mobile Telecommunication 2000 (IMT-2000). It can be realized through universal personal telecommunication (UPT) service. Two PM management schemes are proposed to manage PM information related to UPT users for incoming...

Water management and utilization is an ongoing problem in developing countries with semi-arid to arid climates such as Afghanistan. The lack of effective irrigation systems are oftentimes the most limiting factor for maximizing agricultural productivity in these countries. In Afghanistan, the most widely used irrigation methods are basin/border for cereal crops and furrow for vegetables and gra...

I ncreasing production efficiency is becoming a major theme for producers in order to maintain or increase their economic return in an increasingly competitive global market. In the case of irrigated agriculture, producers must also address increasing public concern about water conservation, water quality, and environmental protection. Two irrigation management issues require attention in order...

Timely irrigation of cotton has been shown to increase yields, but almost every year producers and researchers observe poor plant development even with irrigation under some condition. Adequate moisture must be present when the cotton crop needs it, but saturated soil conditions deprive the roots of necessary oxygen. Current recommendations lack detail concerning irrigation management. Use of t...

Appropriate benchmarks for water productivity (WP), defined here as the amount of grain yield produced per unit of water supply, are needed to help identify and diagnose inefficiencies in crop production and water management in irrigated systems. Such analysis is lacking for maize in the Western U.S. Corn Belt where irrigated production represents 58% of total maize output. The objective of thi...

Spatial variability in crop production occurs as a result of spatial and temporal variations in soil structure and fertility; soil physical, chemical and hydraulic properties; irrigation applications; pests and diseases; and plant genetics. It is argued that this variability can be managed and the efficiency of irrigation water use increased by spatially variable application of irrigation water...

Quantifying the local crop response to irrigation is important for establishing adequate irrigation management strategies. This study evaluated the effect of irrigation applied with subsurface drip irrigation on field corn (Zea mays L.) evapotranspiration (ETc), yield, water use efficiencies (WUE = yield/ETc, and IWUE = yield/irrigation), and dry matter production in the semiarid climate of wes...