Similarity Metrics for Closed Loop Dynamic Systems

To what extent and in what ways can two closed-loop dynamic systems be said to be "similar?" This question arises in a wide range of dynamic systems modeling and control system design applications. For example, bounds on error models are fundamental to the controller optimization with modern control design methods. Metrics such as the structured singular value are direct measures of the degree to which properties such as stability or performance are maintained in the presence of specified uncertainties or variations in the plant model. Similarly, controls-related areas such as system identification, model reduction, and experimental model validation employ measures of similarity between multiple realizations of a dynamic system. Each area has its tools and approaches, with each tool more or less suited for one application or the other. Similarity in the context of closed-loop model validation via flight test is subtly different from error measures in the typical controls oriented application. Whereas similarity in a robust control context relates to plant variation and the attendant affect on stability and performance, in this context similarity metrics are sought that assess the relevance of a dynamic system test for the purpose of validating the stability and performance of a "similar" dynamic system. Similarity in the context of system identification is much more relevant than are robust control analogies in that errors between one dynamic system (the test article) and another (the nominal "design" model) are sought for the purpose of bounding the validity of a model for control design and analysis. Yet system identification typically involves open-loop plant models which are independent of the control system (with the exception of limited developments in closed-loop system identification which is nonetheless focused on obtaining open-loop plant models from closed-loop data). Moreover the objectives of system identification are not the same as a flight test and hence system identification error metrics are not directly relevant. In applications such as launch vehicles where the open loop plant is unstable it is similarity of the closed-loop system dynamics of a flight test that are relevant

Separating snow, clean and debris covered ice in the Upper Indus Basin, Hindukush-Karakoram-Himalayas, using Landsat images between 1998 and 2002

NOTICE: this is the author’s version of a work that was accepted for publication in the Journal of Hydrology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in the Journal of Hydrology Volume 521, February 2015, Pages 46–64. http://dx.doi.org/10.1016/j.jhydrol.2014.11.048The full text of this version of the article is embargoed for 24 months from the date of publication to meet the publisher's requirementsThe Hindukush Karakoram Himalayan mountains contain some of the largest glaciers of the world, and supply melt water from perennial snow and glaciers to the Upper Indus Basin (UIB) upstream of Tarbela dam, which constitutes greater than 80% of the annual flows, and caters to the needs of millions of people in the Indus Basin. It is therefore important to study the response of perennial snow and glaciers in the UIB under changing climatic conditions, using improved hydrological modeling, glacier mass balance, and observations of glacier responses. However, the available glacier inventories and datasets only provide total perennial-snow and glacier cover areas, despite the fact that snow, clean ice and debris covered ice have different melt rates and densities. This distinction is vital for improved hydrological modeling and mass balance studies. This study, therefore, presents a separated perennial snow and glacier inventory (perennial snow-cover on steep slopes, perennial snow-covered ice, clean and debris covered ice) based on a semi-automated method that combines Landsat images and surface slope information in a supervised maximum likelihood classification to map distinct glacier zones, followed by manual post processing. The accuracy of the presented inventory falls well within the accuracy limits of available snow and glacier inventory products. For the entire UIB, estimates of perennial and/or seasonal snow on steep slopes, snow-covered ice, clean and debris covered ice zones are 7238 ± 724, 5226 ± 522, 4695 ± 469 and 2126 ± 212 km^2 respectively. Thus total snow and glacier cover is 19,285 ± 1928 km^2, out of which 12,075 ± 1207 km^2 is glacier cover (excluding steep slope snow-cover). Equilibrium Line Altitude (ELA) estimates based on the Snow Line Elevation (SLE) in various watersheds range between 4800 and 5500 m, while the Accumulation Area Ratio (AAR) ranges between 7% and 80%. 0 °C isotherms during peak ablation months (July and August) range between ~ 5500 and 6200 m in various watersheds. These outputs can be used as input to hydrological models, to estimate spatially-variable degree day factors for hydrological modeling, to separate glacier and snow-melt contributions in river flows, and to study glacier mass balance, and glacier responses to changing climate

Role of Values and Environmental Concerns for the Sustainable Purchasing Behavior: Evidence From Pakistan

Sustainable purchasing is an attempt to purchase greener, healthier, and more economical items from greener, more sustainable organizations. It is based on the idea that each and every buy has shrouded human wellbeing through natural and social effects and that it is possible to decrease unfavourable effects by purchasing better items. The motive of the present study was to identify the role of values and environmental concerns for sustainable purchasing behaviour of buyers in the Pakistani green market. With the help of reliable and valid Likert type self-administered questionnaires, data was collected from the sample of the people who claim to live green lifestyles and purchase green products. Results of Smart PLS path model confirm that values and environmental concerns have an influence on sustainable purchasing behaviour in the Pakistani green market. This study provides a greater insight to improve purchaser behaviour in the green market of Pakistan and will help to increase the trust of buyers towards the green market

Effect of Two Different Rodenticides on Serum Biochemistry of House Rats (Rattus rattus)

This study was conducted to compared the serum biochemical parameters of the Rattus rattus as influenced by feeding two different rodenticides i.e., brodifacoum and food energy inhibitor (cellulose). The experiment was conducted on total 42 rats which were divided equally into 3 groups. One group was fed brodifacoum while the other was fed cellulose. The third group served as a control. Both the groups were fed with the calculated amount of brodifacoum and cellulose for 14 days. At the end of experiment, rats of all the three groups were killed and blood was collected to obtain serum. Significantly low feed intake was recorded in food energy inhibitor fed group. Serum was analyzed for glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), Triiodothyronine (T3) and Thyroxine (T4). It was observed that serum glucose and T3 were significantly low (p<0.05) in brodifacom fed group while ALT and T4 were significantly high (p<0.05) in brodifacom fed rats. The biochemical comparison of these rodenticides provides useful information regarding the controlling strategy of Rattus rattus

Particulate pollution in urban residential built environments during winter and summer seasons in Lahore, Pakistan

Indoor air pollution in urban residential areas of developing countries is of growing public health concern. The seasonal variation in mass concentration of PM1, PM2.5 and PM10was investigated in a residential built environment in Lahore, Pakistan by two DustTrak aerosol monitor (model 8520, TSI Inc.) during the winter and summer season. The measurements were carried out in the kitchen and living room simultaneously.The 24-hr meanconcentrationsfor PM1, PM2.5 and PM10in the kitchen and living room during the winter season were 157μg/m3 (±54), 733 μg/m3(±243), 409 μg/m3(±177) and 135μg/m3 (±39), 240 μg/m3 (±87), 300 μg/m3 (±115), respectively.During the summer the 24-hr mass concentration, for the same size fraction, in the kitchen and living room fell to 37μg/m3 (±4), 74μg/m3 (±11), 100 μg/m3 (±22) and31μg/m3 (±4), 71 μg/m3 (±19), 190 μg/m3 (±21), respectively. Apart from a higher concentration in winter than summer, a vast variation in 24hr and hourly mean concentration was also observed in the latter than in the former.Moreover background concentrations (hourly minimum) were also higher in winter than summer. These clearly highlight the impact of ventilation on indoor particulate matter as the sampling spaces (kitchen and living room) were more ventilated in summer than winter. The higher concentrationof the coarse size fraction in the living room than in the kitchen during summer time also shows the contribution from outdoor sources. These findings highlightthe impact of location, use and management of a residential built environment on exposure to indoor air pollutants

Quantitatively evaluating the effect of social barriers: a case-control study of family members' opposition and women's intention to use contraception in Pakistan.

BACKGROUND: Uptake of family planning services in Pakistan has remained slow over the past decade despite a rapid increase in availability and awareness, indicating that social barriers may be preventing uptake. Social barriers such as opposition by family members have largely been studied qualitatively; there is a lack of quantitative evidence about the effect of different family members' opposition on women's intention to use contraceptives. The objective of this study was to quantitatively evaluate the effect of family members' opposition to family planning on intention to use contraception amongst poor women in Pakistan who have physical access to family planning services. METHODS: An unmatched case control study (nested within a larger cohort study) was conducted in two public hospitals in Karachi, Pakistan. Univariable and multivariable logistic regression analyses were conducted to compare risk factors between women that were not intending to use any contraceptive methods in the future (cases) and women that were planning to use contraceptive methods (controls). RESULTS: 248 cases and 496 controls were included in the study. Negative contraceptive intent was associated with no knowledge of contraception (AOR = 3.79 [2.43-5.90]; p < 0.001), husband's opposition (AOR = 21.87 [13.21-36.21]; p < 0.001) and mother-in-law's opposition (AOR = 4.06 [1.77-9.30]; p < 0.001). CONCLUSIONS: This study is the first to quantitatively assess the effect of opposition by different family members on women's contraceptive intent in Pakistan. Our results indicate that of all family members, husband's opposition has the strongest effect on women's intention to use contraception, even when the women have knowledge of and physical access to family planning services

Entamoeba species associated with chronic diarrhoea in Pakistan

We determined the prevalence of Entamoeba (E.) histolytica, E. dispar and E. moshkovskii in patients with chronic diarrhoea associated with abdominal pain or discomfort mimicking irritable bowel syndrome. Stool samples were collected from 161 patients with chronic diarrhoea and from 157 healthy controls. Stool microscopy with modified trichrome stain, culture and polymerase chain reaction (PCR) for Entamoeba spp. differentiation was performed. Microscopy demonstrated Entamoeba cysts in 44% (57/129) of patients with diarrhoea compared to 29% (44/151) of controls (P=0·009). In patients with diarrhoea, PCR for E. histolytica was positive in 9% (11/129) (P=0·008), E. dispar in 19% (24/129) (P=0·117) and E. moshkovskii in 19% (24/129) (P\u3c0·001). E. histolytica and E. moshkovskii were significantly associated with diarrhoea while E. dispar was found equally in both groups

Monetary Policy and Financial Asset Prices: Empirical Evidence From Pakistan

Monetary transmission mechanism assumed to be significantly influenced by the effect of policy decisions on financial markets. However, various previous studies have come up with different outcomes. The purpose of this study is to examine the impact of monetary policy on different asset classes (shares and bonds) in Pakistan. This study using stock price and bond yield as dependent variable and discount rate, money supply, inflation, and exchange rate are independent variables. Data of all variables have collected from 2010 to 2016, and Vector Autoregressive (VAR) technique has applied. The empirical results indicate that there is an impact of monetary policy components on both stock and bond market as an increase in policy rate causes decline in stocks prices and bonds yields. The findings of this study will help the potential investors in making long-term (in general) and short-term (in particular) investment strategies concerning monetary policy.DOI: 10.15408/sjie.v7i2.709