Empirical Method

Surface radiation data were collected at seven sites in the Riviera Valley in southern Switzerland during the special observing period of the Mesoscale Alpine Programme's Riviera project from August until October 1999. During the daytime on selected 'valley wind' days, strong site contrasts occurred with respect to solar and downward long-wave radiation fluxes. Site-to-site differences of incoming global radiation were caused by the different orientations of valley surfaces relative to the direct solar beam component and by shading from surrounding topography. Diurnal cycles of albedo, determined from horizontal and slope-parallel measurements of reflected and incoming global radiation at three eastern side-wall sites, show that reflection of the direct radiation component from the inclined surfaces is predominantly anisotropic diffuse radiation. Downward longwave radiation decreases with elevation in the valley because the higher sites have an increased angular exposure to the radiating sky (i.e. sky view factor). Contrasts between the valley-floor and ridge-top sites are largest on valley wind days but also occur on overcast days. Finally,strong site-to-site variations of the net all-wave radiation occur during daytime due to variations in the received direct beam component of incoming global radiation. During night-time, net outgoing all-wave radiation increases with elevation, again because sky view fraction increases with elevation. On valley wind days, significant contrasts are found in mean diurnal cycles and daily sums of available radiation energy between south-west and north-east facing slopes. When the direct beam component is absent, inter-site contrasts in radiation components are reduced, especially short-wave radiation components. A simple semi-empirical method is described to estimate the net all-wave radiation in a slope-parallel frame of reference from measurements with horizontally exposed net radiometers. This method employs the theoretical ratio of short-wave radiation on a slope to the horizontal equivalent. The method is tested successfully at one site where simultaneous measurements were made with inclined and horizontal sensors.

Conventional benchmarking measures focus mainly on water produced whilst ignoring water produced but not reaching consumers, unaccounted for water (UFW). Benchmarking must credit utilities for a reduction in UFW and improvements in service delivery. This study measures the performance of 20 urban water utilities using data from an Asian Development Bank survey of Indian water utilities in 2005. It applies directional distance function as an analytical tool for measuring performance of water utilities. The results reveal that at the mean level, Indian water utilities have the potential of increasing water delivery levels and reducing UFW by 20%. About half of that can be realized by changing the scale of operation. Metering of the water delivered and the length of the distribution network are major determinants of performance of water utilities.

The belief that laws of nature are contingent played an important role in the emergence of the empirical method of modern physics. During the scientific revolution, this belief was based on the idea of voluntary creation. Taking up Peter Mittelstaedt’s work on laws of nature, this article explores several alternative answers which do not overtly make use of metaphysics: some laws are laws of mathematics; macroscopic laws can emerge from the interplay of numerous subsystems without any specific microscopic nomic structures (John Wheeler’s “law without law”); laws are the preconditions of scientific experience (Kant); laws are theoretical abstractions which only apply in very limited circumstances (Nancy Cartwright). Whereas Cartwright’s approach is in tension with modern scientific methodology, the first three strategies count as illuminating, though partial answers. It is important for the empirical method of modern physics that these three strategies, even when taken together, do not provide a complete explanation of the order of nature. Thus the question of why laws are valid is still relevant. In the concluding section, I argue that the traditional answer, based on voluntary creation, provides the right balance of contingency and coherence which is in harmony with modern scientific method.

To what extent are firms kept out of a market by patents covering related technologies? Do patents held by potential entrants make it easier to enter markets? We estimate the empirical relationship between market entry and patents for 27 narrowly defined categories of software products during the period 1990-2004. Controlling for demand, market structure, average patent quality, and other factors,

This exploratory case study provides empirical support for three critical assumptions of empowerment theory. Many empowerment theorists have argued that empowerment takes on multiple forms across people, is contextually embedded, and shifts over time (Rappaport, 1984; Zimmerman, 1990, 1995). To better understand the implications of these assumptions for empowerment theory and the research and intervention methods we employ, the empowerment experiences of 49 employees within a large human service delivery organization were explored. A method well suited to investigate empowerment's assumptions of multiplicity and dynamism—a constructivist approach to inquiry—was employed. Content analyses of interview and observational data revealed that the process of empowerment may be more complex than originally conceived. Not only did multiple meanings and desires for empowerment emerge across employees and between employees and leaders, but several shifting ecologies impacted the employees' lives, causing the employees' empowerment experiences to fluctuate. Empowerment emerged as a dynamic, highly individualistic, contextually layered process. Multiple forms, contexts, and dynamics that influenced employee empowerment are described. Implications of these findings for empowerment research and intervention are discussed.

Groundwater inflow assessment is essential for the design of tunnel drainage systems, as well as for assessment of the environmental impact of the associated drainage. Analytical and empirical methods used in current engineering practice do not adequately account for the effect of the jointed-rock-mass anisotropy and heterogeneity. The impact of geo-structural anisotropy of fractured rocks on tunnel inflows is addressed and the limitations of analytical solutions assuming isotropic hydraulic conductivity are discussed. In particular, the study develops an empirical correction to the analytical formula frequently used to predict groundwater tunnel inflow. In order to obtain this, a discrete network flow modelling study was carried out. Numerical simulation results provided a dataset useful for the calibration of some empirical coefficient to correct the well-known Goodman’s equation. This correction accounts for geo-structural parameters of the rock masses such as joint orientation, aperture, spacing and persistence. The obtained empirical equation was then applied to a medium-depth open tunnel in Bergamo District, northern Italy. The results, compared with the monitoring data, showed that the traditional analytical equations give the highest overestimation where the hydraulic conductivity shows great anisotropy. On the other hand, the empirical relation allows a better estimation of the tunnel inflow. L’évaluation du flux de nappe est essentiel pour la conception des systèmes de galerie drainante et pour l’évaluation de l’impact environnemental du drainage proprement dit. Des méthodes analytiques et empiriques utilisées actuellement par l’ingénierie ne prennent pas suffisamment en compte l’anisotropie et l’hétérogénéité de la roche. L’impact de l’anisotropie structurale des roches fracturées sur les flux de drainage est considéré et les restrictions aux solutions analytiques supposant une conductivité hydraulique isotrope sont discutées. En particulier, l’étude apporte une correction empirique à la formulation analytique fréquemment utilisée pour prédire un flux de drainage de nappe. Dans ce but, on a modélisé le flux par réseau discret. Des résultats de simulation fournissent une base de données utile pour le calage de coefficients corrigeant l’équation bien connue de Goodman. Cette correction porte sur les paramètres géo-structuraux des masses rocheuses, tels l’orientation, l’ouverture, l’espacement et la continuité de fissuration. L’équation empirique obtenue a été appliquée à un drain libre, de profondeur moyenne, dans le district de Bergame, Italie du Nord. Les résultats, comparés avec les données enregistrées, montrent que les équations analytiques traditionnelles surestiment la conductivité hydraulique en milieu plus anisotrope. D’autre part, la relation empirique fournit une meilleure estimation du flux drainé. La evaluación del flujo de ingreso de agua subterránea es esencial para el diseño de un sistema de túneles de drenaje, así como para la evaluación del impacto ambiental asociado al drenaje. Los métodos analíticos y empíricos usados en las prácticas de ingeniería actuales no contabilizan adecuadamente el efecto de la anisotropía y heterogeneidad de las masas de rocas diaclasadas. Se considera el impacto de la anisotropía geoestructural de rocas fracturadas sobre el flujo de ingreso a un túnel y se discuten las limitaciones de las soluciones analíticas asumiendo la isotropía de la conectividad hidráulica. En particular, el estudio desarrolla una corrección empírica a la fórmula analítica frecuentemente usada para predecir el flujo de agua subterránea de ingreso a un túnel. Para obtener esto, se llevó a cabo un estudio de modelación del flujo de una red discreta. Las simulaciones numéricas resultantes proveen un set de datos útiles en la calibración de algún coeficiente empírico para corregir la bien conocida, ecuación de Goodman’s. Esta corrección contabiliza parámetros geoestructurales de masas de rocas, tales como la profundidad media de un tunel abierto en el distrito de Bergamo, en el norte de Italia. Los resultados, comparados con los datos de monitoreo, mostraron que las ecuaciones analíticas tradicionales dan una sobreestimación más alta cuando la conductividad hidráulica muestra una gran anisotropía. Por otro lado, la relación empírica permite una mejor estimación del flujo de ingreso al túnel. 地下水涌水估算对于隧道排水系统以及评价排水的环境影响至为重要。当前工程实践中使用的解析解和经验方法不能充分考虑节理岩体的各向异性和非均质性。本文讨论了裂隙岩体地质结构的各向异性对隧道涌水的影响及假定渗透系数各项同性时的解析解的局限性。特别是, 该研究提出了一个与常用的预测地下水隧道涌水的解析公式相关的经验校正。为此, 进行了离散网络流动模拟。数值模拟结果为校正用于修正著名的Goodman方程的某些经验系数提供了一套有用的数据。这种校正考虑了岩体的地质结构参数, 如节理的方向、开度、间距和连通性。然后, 将得到的经验方程应用于意大利北部贝加莫区某中等深度的开放隧道。与监测数据相比较, 得到的结果表明, 在渗透系数各项异性显著时, 传统的解析方程将给出隧道涌水的最大的高估值。而该经验关系能够给出隧道涌水的更好的估计值。 La previsione delle venute d’acqua in galleria è essenziale sia in fase di progettazione dei sistemi di drenaggio sia per la valutazione dell’impatto ambientale derivante dal drenaggio stesso. I metodi analitici comunemente impiegati nella pratica ingegneristica non tengono conto in maniera adeguata del’anisotropia e dell’eterogeneità tipica degli ammassi rocciosi fessurati. Nel presente studio si valuta l’effetto dell’anisotropia geologico-strutturale delle rocce fessurate sull’entità delle venute d’acqua in galleria, analizzando i limiti delle tradizionali formulazioni analitiche che ipotizzano una conducibilità idraulica isotropa, proponendo una correzione empirica alle formule analitiche più diffusamente utilizzate nella previsione delle venute d’acqua in galleria. A questo scopo, si è condotto uno studio modellistico tramite l’impiego di un codice numerico che simula il flusso dell’acqua in un reticolo fessurativo. I risultati ottenuti dalla modellazione hanno fornito un campione di dati sufficiente per la calibrazione di alcuni coefficienti empirici, in grado di correggere le stime fornite dalla ben nota equazione di Goodman, in funzione di alcuni parametri geologico-strutturali tipici degli ammassi rocciosi fessurati, quali l’orientazione, l’apertura, la spaziatura e la persistenza dei giunti. L’equazione empirica messa a punto è stata poi applicata allo studio di una galleria di media profondità, non impermeabilizzata, ubicata nella Provincia di Bergamo (Lombardia, Nord Italia). I risultati così ottenuti, confrontati coi dati di monitoraggio, hanno evidenziato come le tradizionali formule analitiche forniscano una notevole sovrastima delle portate drenate dalla galleria, soprattutto nei tratti caratterizzati da una maggiore anisotropia della conducibilità idraulica; al contrario, la relazione empirica proposta consente una miglior stima delle portate in ingresso alla galleria. A avaliação do afluxo de água subterrânea é essencial para o planeamento dos sistemas de drenagem em túneis, assim como para a avaliação do impacte ambiental da drenagem associada. Os métodos analíticos e empíricos utilizados na prática corrente da engenharia não têm suficientemente em conta o efeito da anisotropia e da heterogeneidade das massas rochosas fracturadas. O impacte das anisotropias geo-estruturais das rochas fracturadas no afluxo de água em túneis é estudado e as limitações das soluções analíticas que assumem a isotropia da conductividade hidráulica é discutida. Em particular, o estudo desenvolve uma correcção empírica da fórmula analítica frequentemente usada para prever o afluxo de água subterrânea em túneis. A fim de obter isso, foi realizado o estudo de um modelo de fluxo discreto. Os resultados da simulação numérica forneceram um conjunto de dados úteis para a calibração de alguns coeficientes empíricos, para corrigir a bem conhecida equação de Goodman. Esta correcção teve em consideração parâmetros geo-estruturais das massas rochosas, tais como a orientação das diaclases, a sua abertura, espaçamento e persistência. A equação empírica obtida foi então aplicada a um túnel de média profundidade aberto no Distrito de Bergamo, no norte de Itália. Os resultados, comparados com os dados de monitorização, mostraram que as equações analíticas tradicionais dão a máxima sobrestimação onde a conductividade hidráulica tem grande anisotropia. Por outro lado, a relação empírica permite uma melhor avaliação do afluxo de água no túnel.