Group Mentoring: A Study of Mentoring Groups in Three Programs

In an effort to provide more youth with mentors, mentoring programs are implementing several promising new approaches. This report describes the strengths and challenges of group mentoring-an approach that is gaining popularity. Findings suggest that group mentoring is reaching youth and volunteers who are unlikely to participate in traditional one-on-one mentoring, and that the approach may provide youth with important benefits, especially the development of social skills. On the other hand, mentoring groups vary widely in their size, structure and focus, and in the extent to which they foster strong mentoring relationships and benefits for youth. Implications for the mentoring field and for future research are discussed

Does Efficient Irrigation Technology Lead to Reduced Groundwater Extraction?: Empirical Evidence

Policies that encourage the use of more efficiency irrigation technology are often viewed as effective, politically feasible methods to reduce the consumptive use of water for agricultural production. Despite their widespread use, these policies have not been subject to empirical evaluation. In this article, we evaluate the effect on groundwater extraction of a widespread conversion from traditional center pivot irrigation systems to higher efficiency dropped-nozzle center pivot systems that has occurred in western Kansas. State and national cost-share programs subsidized the conversion. We find that the programs have not had the intended effect; the shift to more efficient irrigation technology has not decreased the amount of water applied to a given crop, and has actually increased groundwater extraction through changing cropping patterns.irrigation efficiency, groundwater management, irrigation technology, Environmental Economics and Policy, Land Economics/Use,

The Method of Combinatorial Telescoping

We present a method for proving q-series identities by combinatorial telescoping, in the sense that one can transform a bijection or a classification of combinatorial objects into a telescoping relation. We shall illustrate this method by giving a combinatorial proof of Watson's identity which implies the Rogers-Ramanujan identities.Comment: 11 pages, 5 figures; to appear in J. Combin. Theory Ser.

Implementasi Algoritma Pelatihan Levenberg Marquardt Dan Regularisasi Bayes Untuk Prediksi Curah Hujan

Algoritma Levenberg Marquardt digunakan untuk pelatihan feedforward neural network karena keefektifan dan kecepatan konvergensinya. Levenberg Marquardt merupakan metode optimasi nonlinier yang digunakan pada saat koreksi error backpropagation untuk menemukan bobot yang disesuaikan. Salah satu cara untuk meningkatkan performa generalisasi jaringan syaraf tiruan adalah regularisasi. Tehnik regularisasi yang sering digunakan adalah regularisasi bayes. Penelitian ini dilakukan untuk mengetahui bagaimana kinerja jaringan syaraf tiruan dengan metode pelatihan Levenberg Marquardt dengan penambahan regularisasi untuk prediksi data time series serta membandingkan dengan algoritma Levenberg Marquardt tanpa regularisasi. Data yang digunakan dalam penelitian ini adalah data bulanan curah hujan, suhu rata-rata, kelembaban udara, tekanan udara di atas stasiun pengamatan dan kecepatan angin rata-rata di stasiun pengamatan Pangsuma Putussibau Kalimantan Barat dari tahun 2008-2009. Pelatihan data dilakukan pada jaringan syaraf pada satu hidden layer dengan tiga buah neuron dan satu buah neuron pada output layer. Arsitektur jaringan ditentukan dengan cara coba-coba dan melihat MSE pelatihan terbaik yang dihasilkan. Dalam kasus ini hasil penelitian menunjukan bahwa algoritma Levenberg Marquardt dengan regularisasi menjadi lebih baik