Low Level Light Intensity Measurement from Repetitive Signals†

Background noise is a limiting factor in many cases where photo-electric measurement of light intensities is made. In the present case this problem is dealt with and the effect of noise reduced by special electronic circuit techniques for the study of temporal variations of light emission from microsecond transient discharges. The electronic circuits are dealt with in some detail, and examples are given of the uses to which the apparatus can be put.     

The near field of an antenna surrounded by a dielectric with two teeth

The near field of an antenna surrounded by a dielectric with two teeth is studied when the ambient medium is dissipative. We use the continuity of radial power flux and the boundary conditions at each interface, but not near the discontinuity, to express this field.     

面向802.11b/g应用的RF功放性能优化新一代RF功放积极应对WiFi的性能挑战

随着商业和家庭应用市场范围的不断扩大,802．11无线局域网(WLAN)的市场(业界称之为WiFi)出现了快速增长的局面。根据Strategy Analytics公布的数据,WLAN芯片的市场有望在2004年达到7．57亿美元,器件出货量年度增长32％。     

MODELING AND MEASURING PRODUCTION PROCESSES FOR A MULTI‐SPECIES FISHERY: ALTERNATIVE TECHNICAL EFFICIENCY ESTIMATES FOR THE NORTHERN SPAIN HAKE FISHERY

ABSTRACT. The economic performance of fisheries is difficult to measure, due to the importance of (multi‐species) biological dynamics, property rights and regulatory issues affecting fishermen's behavior and efficiency. However, an understanding of performance patterns is essential for enhancing the economic and biological viability of fisheries. In this paper we estimate and evaluate alternative primal stochastic approaches to modeling and measuring technical efficiency for the Northern Spain hake fishery. We then compare the resulting efficiency measures to identify variations in their potential interpretation, and application to policy guidance. We find that multi‐output models are more theoretically and empirically justifiable than aggregate output production function models, and provide additional policy‐relevant insights, but that relative production and efficiency estimates are not sub‐stantively affected by model specification.     

The FeH radical: rotational assignment of the a6A Δ(ν = 2) and b6II (ν = 1) levels

A dispersed fluorescence study of the FeH radical at near ambient (～450 K) temperature has identified the g⁶Φ-a ⁶δ (0, 2) and g⁶Φ-b⁶II (0, 1) bands in the orange region of the spectrum. The corresponding bands with upper state e⁶II are located at about 640nm in the red. High resolution measurements in LIF have enabled the assignment of around 275 lines to these four transitions. Analysis of these bands has provided a second vibrational interval for the a⁶δ state and a first vibrational interval for the b⁶II state as 1536cm^?1 and 1542cm^?1, respectively. Term values have also been measured for a set of levels with a tentative assignment to c⁴Φ_9/2 (ν = 1).     

MEASURING PRODUCTIVITY AND ITS COMPONENTS FOR FISHERIES: THE CASE OF THE ALASKAN POLLOCK FISHERY, 1994–2003

Abstract Traditional productivity measures have been much less prevalent in fisheries economics than other measures of economic and biological performance. It has been increasingly recognized, however, that modeling and measuring fisheries' production relationships is central to understanding and ultimately correcting the repercussions of externalities and poorly designed regulations. We use a transformation function production model to estimate productivity and its components for catcher–processors in the Bering Sea and Aleutian Islands pollock fishery, before and after the introduction of a cooperative system that grants exclusive harvesting privileges and allows quota exchange. We also recognize the roles of externalities from pollock harvesting by incorporating data on climate, bycatch, and fish biomass. We find that productivity has been increasing over time, that many productive contributions and interactions of climate, bycatch, and fishing strategies are statistically significant, and that regulatory changes have had both direct and indirect impacts on catch patterns and productivity.