Dipole mode photonic crystal point defect laser on InGaAsP/InP

In this paper, we focus on the dipole mode of the two-dimensional (2D) photonic crystal (PC) single point defect cavity (SPDC) lasers and we report the fabrication and characterization of 2D PC SPDC lasers with the structure of adjusted innermost air holes. The photonic band and cavity Q factors are simulated by means of plane wave expansion (PWE) and finite-difference time-domain (FDTD), respectively. In order to improve the optical confinement of the SPDC, the diameter of the innermost holes was adjusted. Different lasing performances are observed experimentally. The experimental results agree with the theoretical prediction very well. (c) 2006 Elsevier B.V. All rights reserved.

Public-public partnerships (PUPs) in water

Water operators need to be efficient, accountable, honest public institutions providing a universal service. Many water services however lack the institutional strength, the human resources, the technical expertise and equipment, or the financial or managerial capacity to provide these services. They need support to develop these capacities. The vast majority of water operators in the world are in the public sector – 90% of all major cities are served by such bodies. This means that the largest pool of experience and expertise, and the great majority of examples of good practice and sound institutions, are to be found in existing public sector water operators. Because they are public sector, however, they do not have any natural commercial incentive to provide international support. Their incentive stems from solidarity, not profit. Since 1990, however, the policies of donors and development banks have focussed on the private companies and their incentives. The vast resources of the public sector have been overlooked, even blocked by pro-private policies. Out of sight of these global policy-makers, however, a growing number of public sector water companies have been engaged, in a great variety of ways, in helping others develop the capacity to be effective and accountable public services. These supportive arrangements are now called 'public-public partnerships' (PUPs). A public-public partnership (PUP) is simply a collaboration between two or more public authorities or organisations, based on solidarity, to improve the capacity and effectiveness of one partner in providing public water or sanitation services. They have been described as: “a peer relationship forged around common values and objectives, which exclude profit-seeking”.1 Neither partner expects a commercial profit, directly or indirectly. This makes PUPs very different from the public–private partnerships (PPPs) which have been promoted by the international financial institutions (IFIs) like the World Bank. The problems of PPPs have been examined in a number of reports. A great advantage of PUPs is that they avoid the risks of such partnerships: transaction costs, contract failure, renegotiation, the complexities of regulation, commercial opportunism, monopoly pricing, commercial secrecy, currency risk, and lack of public legitimacy.2 PUPs are not merely an abstract concept. The list in the annexe to this paper includes over 130 PUPs in around 70 countries. This means that far more countries have hosted PUPs than host PPPs in water – according to a report from PPIAF in December 2008, there are only 44 countries with private participation in water. These PUPs cover a period of over 20 years, and been used in all regions of the world. The earliest date to the 1980s, when the Yokohama Waterworks Bureau first started partnerships to help train staff in other Asian countries. Many of the PUP projects have been initiated in the last few years, a result of the growing recognition of PUPs as a tool for achieving improvements in public water management. This paper attempts to provide an overview of the typical objectives of PUPs; the different forms of PUPs and partners involved; a series of case studies of actual PUPs; and an examination of the recent WOPs initiative. It then offers recommendations for future development of PUPs.

2.4 GHz high-efficiency power-combining Class-E amplifier with transmission-line harmonic traps

Experimental assessments of the modified power-combining Class-E amplifier are described. The technique used to combine the output of individual power amplifiers (PAs) into an unbalanced load without the need for bulky transformers permits the use of small RF chokes useful for the deployment in the EER transmitter. The modified output load network of the PA results in excellent 50 dBc and 46 dBc second and third-harmonic suppressions, dispensing the need for additional lossy filtering block. Operating from a 3.2 V dc supply voltage, the PA exhibits 64% drain efficiency at 24 dBm output power. Over a wide bandwidth of 350 MHz, drain efficiency of better than 60% at output power higher than 22 dBm were achieved. © 2010 IEICE Institute of Electronics Informati.

Design technique for mm-wave IC realization of the load network of switched-mode class-EF power amplifier

Analysis and synthesis of the new Class-EF power amplifier (PA) are presented in this paper. The proposed circuit offers means to alleviate some of the major issues faced by existing Class-EF and Class-EF PAs, such as (1) substantial power losses due to parasitic resistance of the large inductor in the Class-EF load network, (2) unpredictable behaviour of practical lumped inductors and capacitors at harmonic frequencies, and (3) deviation from ideal Class-EF operation mode due to detrimental effects of device output inductance at high frequencies. The transmission-line load network of the Class-EF PA topology elaborated in this paper simultaneously satisfies the Class-EF optimum impedance requirements at fundamental frequency, second, and third harmonics as well as simultaneously providing matching to the circuit optimum load resistance for any prescribed system load resistance. Furthermore, an elegant solution using an open and short-circuit stub arrangement is suggested to overcome the problem encountered in the mm-wave IC realizations of the Class-EF PA load network due to lossy quarter-wave line. © 2010 IEICE Institute of Electronics Informati.

Statistical Tests for Joint Analysis of Performance Measures

Recently there has been an increasing interest in the development of new methods using Pareto optimality to deal with multi-objective criteria (for example, accuracy and architectural complexity). Once one has learned a model based on their devised method, the problem is then how to compare it with the state of art. In machine learning, algorithms are typically evaluated by comparing their performance on different data sets by means of statistical tests. Unfortunately, the standard tests used for this purpose are not able to jointly consider performance measures. The aim of this paper is to resolve this issue by developing statistical procedures that are able to account for multiple competing measures at the same time. In particular, we develop two tests: a frequentist procedure based on the generalized likelihood-ratio test and a Bayesian procedure based on a multinomial-Dirichlet conjugate model. We further extend them by discovering conditional independences among measures to reduce the number of parameter of such models, as usually the number of studied cases is very reduced in such comparisons. Real data from a comparison among general purpose classifiers is used to show a practical application of our tests.