On the Benefits of Abstraction in Concurrent Haskell

Heutzutage haben selbst durchschnittliche Computersysteme mehrere unabhängige Recheneinheiten (Kerne). Wird ein rechenintensives Problem in mehrere Teilberechnungen unterteilt, können diese parallel und damit schneller verarbeitet werden. Obwohl die Entwicklung paralleler Programme mittels Abstraktionen vereinfacht werden kann, ist es selbst für Experten anspruchsvoll, effiziente und korrekte Programme zu schreiben. Während traditionelle Programmiersprachen auf einem eher geringen Abstraktionsniveau arbeiten, bieten funktionale Programmiersprachen wie z.B. Haskell, Möglichkeiten zur fortgeschrittenen Abstrahierung. Das Ziel der vorliegenden Dissertation war es, zu untersuchen, wie gut verschiedene Arten der Abstraktion das Programmieren mit Concurrent Haskell unterstützen. Concurrent Haskell ist eine Bibliothek für Haskell, die parallele Programmierung auf Systemen mit gemeinsamem Speicher ermöglicht. Im Mittelpunkt der Dissertation standen zwei Forschungsfragen. Erstens wurden verschiedene Synchronisierungsansätze verglichen, die sich in ihrem Abstraktionsgrad unterscheiden. Zweitens wurde untersucht, wie Abstraktionen verwendet werden können, um die Komplexität der Parallelisierung vor dem Entwickler zu verbergen. Bei dem Vergleich der Synchronisierungsansätze wurden Locks, Compare-and-Swap Operationen und Software Transactional Memory berücksichtigt. Die Ansätze wurden zunächst bezüglich ihrer Eignung für die Synchronisation einer Prioritätenwarteschlange auf Basis von Skiplists untersucht. Anschließend wurden verschiedene Varianten des Taskpool Entwurfsmusters implementiert (globale Taskpools sowie private Taskpools mit und ohne Taskdiebstahl). Zusätzlich wurde für das Entwurfsmuster eine Abstraktionsschicht entwickelt, welche eine einfache Formulierung von Taskpool-basierten Algorithmen erlaubt. Für die Untersuchung der Frage, ob Haskells Abstraktionsmethoden die Komplexität paralleler Programmierung verbergen können, wurden zunächst stencil-basierte Algorithmen betrachtet. Es wurde eine Bibliothek entwickelt, die eine deklarative Beschreibung von stencil-basierten Algorithmen sowie ihre parallele Ausführung erlaubt. Mit Hilfe dieses deklarativen Interfaces wurde die parallele Implementation vollständig vor dem Anwender verborgen. Anschließend wurde eine eingebettete domänenspezifische Sprache (EDSL) für Knoten-basierte Graphalgorithmen sowie eine entsprechende Ausführungsplattform entwickelt. Die Plattform erlaubt die automatische parallele Verarbeitung dieser Algorithmen. Verschiedene Beispiele zeigten, dass die EDSL eine knappe und dennoch verständliche Formulierung von Graphalgorithmen ermöglicht.

Characteristics, socioeconomic benefits and household livelihoods of beef buffalo and beef cattle farming in Northeast Thailand

Since the Thai economy experiences rapid growth, agricultural systems, i.e. crop-livestock systems, are changing rapidly. On account of these changes, buffalo and cattle production has to be re-examined in terms of performance characteristics and roles of livestock for farm households in order to initiate suitable development programmes. Therefore, this study aimed to investigate the present characteristics of beef buffalo and beef cattle farms in Northeast Thailand. Using a semi-structured questionnaire, 121 randomly selected beef buffalo and beef cattle farms were interviewed in Nakhon Ratchasima province between October 2007 and May 2008. Both buffaloes and cattle were mostly integrated in mixed crop-livestock systems with medium to large farm sizes (7.9 ha), whereof less than half of the area was used for livestock. Family members were mainly responsible for the different activities of livestock farming and salaried labourers were only found on large-scale farms. The dominant roles of livestock were income generation to build up wealth or savings, the coverage of expected and unexpected expenses and earning of regular and additional income. Another important issue was the improvement of the social status, which increased with herd size. In order to improve farmers’ livelihoods and develop sustainable farming systems in Northeast Thailand the changing economic circumstances of cattle and especially buffalo production should receive more attention of researchers, governmental institutions and stakeholders.

Balancing Economic Development with Environmental Conservation: Challenges Facing the North and South

This paper critically explores how development policies tend to ignore pressing environmental concerns. In the first section development in the North and South and the Bhopal disaster will be juxtaposed to show how development without environmental governance can be deadly. The article then turns to the way in which the Sri Lankan government’s Moragahakanda Development Project strives for economic development without concern for the environment. It will be contended in this article that governments and big companies in the North and South have tended to carelessly use scarce resources for development.

Integrated Livelihoods and Landscape Approach for Smallholders in Northern Thailand

This paper examines the strategies and techniques researched and implemented by the International Union for Conservation of Nature (IUCN) in villages in the vicinity of Doi Mae Salong in Chiang Rai Province, Thailand. The strategies revolve around the paradigm linking poverty alleviation, conservation and landscape restoration. IUCN and its partners specifically researched and implemented schemes directed toward diversification of the household economy through alternative and sustainable intensified agriculture techniques based on balancing conservation and livelihood objectives. The projects aimed to reduce poverty and build the resilience of smallholders through decentralised governance arrangements including land use planning schemes and stakeholder negotiation. Considering the agro-ecological system on a catchment-wide scale enhances the conceptual understanding of each component, collectively forming a landscape matrix with requisite benefits for biodiversity, smallholder livelihoods and ecosystem services. In particular, the role of enhancing ecosystem services and functions in building socio-ecological resilience to vulnerabilities such as climate and economic variability is paramount in the process.

Changes of traditional farming systems and their effects on land degradation and socio-economic conditions in the Inle Lake region, Myanmar

At many locations in Myanmar, ongoing changes in land use have negative environmental impacts and threaten natural ecosystems at local, regional and national scales. In particular, the watershed area of Inle Lake in eastern Myanmar is strongly affected by the environmental effects of deforestation and soil erosion caused by agricultural intensification and expansion of agricultural land, which are exacerbated by the increasing population pressure and the growing number of tourists. This thesis, therefore, focuses on land use changes in traditional farming systems and their effects on socio-economic and biophysical factors to improve our understanding of sustainable natural resource management of this wetland ecosystem. The main objectives of this research were to: (1) assess the noticeable land transformations in space and time, (2) identify the typical farming systems as well as the divergent livelihood strategies, and finally, (3) estimate soil erosion risk in the different agro-ecological zones surrounding the Inle Lake watershed area. GIS and remote sensing techniques allowed to identify the dynamic land use and land cover changes (LUCC) during the past 40 years based on historical Corona images (1968) and Landsat images (1989, 2000 and 2009). In this study, 12 land cover classes were identified and a supervised classification was used for the Landsat datasets, whereas a visual interpretation approach was conducted for the Corona images. Within the past 40 years, the main landscape transformation processes were deforestation (- 49%), urbanization (+ 203%), agricultural expansion (+ 34%) with a notably increase of floating gardens (+ 390%), land abandonment (+ 167%), and marshlands losses in wetland area (- 83%) and water bodies (- 16%). The main driving forces of LUCC appeared to be high population growth, urbanization and settlements, a lack of sustainable land use and environmental management policies, wide-spread rural poverty, an open market economy and changes in market prices and access. To identify the diverse livelihood strategies in the Inle Lake watershed area and the diversity of income generating activities, household surveys were conducted (total: 301 households) using a stratified random sampling design in three different agro-ecological zones: floating gardens (FG), lowland cultivation (LL) and upland cultivation (UP). A cluster and discriminant analysis revealed that livelihood strategies and socio-economic situations of local communities differed significantly in the different zones. For all three zones, different livelihood strategies were identified which differed mainly in the amount of on-farm and off-farm income, and the level of income diversification. The gross margin for each household from agricultural production in the floating garden, lowland and upland cultivation was US$ 2108, 892 and 619 ha-1 respectively. Among the typical farming systems in these zones, tomato (Lycopersicon esculentum L.) plantation in the floating gardens yielded the highest net benefits, but caused negative environmental impacts given the overuse of inorganic fertilizers and pesticides. The Revised Universal Soil Loss Equation (RUSLE) and spatial analysis within GIS were applied to estimate soil erosion risk in the different agricultural zones and for the main cropping systems of the study region. The results revealed that the average soil losses in year 1989, 2000 and 2009 amounted to 20, 10 and 26 t ha-1, respectively and barren land along the steep slopes had the highest soil erosion risk with 85% of the total soil losses in the study area. Yearly fluctuations were mainly caused by changes in the amount of annual precipitation and the dynamics of LUCC such as deforestation and agriculture extension with inappropriate land use and unsustainable cropping systems. Among the typical cropping systems, upland rainfed rice (Oryza sativa L.) cultivation had the highest rate of soil erosion (20 t ha-1yr-1) followed by sebesten (Cordia dichotoma) and turmeric (Curcuma longa) plantation in the UP zone. This study indicated that the hotspot region of soil erosion risk were upland mountain areas, especially in the western part of the Inle lake. Soil conservation practices are thus urgently needed to control soil erosion and lake sedimentation and to conserve the wetland ecosystem. Most farmers have not yet implemented soil conservation measures to reduce soil erosion impacts such as land degradation, sedimentation and water pollution in Inle Lake, which is partly due to the low economic development and poverty in the region. Key challenges of agriculture in the hilly landscapes can be summarized as follows: fostering the sustainable land use of farming systems for the maintenance of ecosystem services and functions while improving the social and economic well-being of the population, integrated natural resources management policies and increasing the diversification of income opportunities to reduce pressure on forest and natural resources.

Benefits of Implementing Lean Practices and the Impact of the Lean Aerospace Initiative in the Defense Aerospace Industry and Government Agencies

In the 1980’s, many United States industrial organizations started developing new production processes to improve quality, reduce cost, and better respond to customer needs and the pressures of global competition. This new paradigm was coined Lean Production (or simply “Lean”) in the book The Machine That Changed The World published in 1990 by researchers from MIT’s International Motor Vehicle Program. In 1993, a consortium of US defense aerospace firms and the USAF Aeronautical Systems Center, together with the AFRL Materials and Manufacturing Directorate, started the Lean Aircraft Initiative (LAI) at MIT. With expansion in 1998 to include government space products, the program was renamed the Lean Aerospace Initiative. LAI’s vision is to “Significantly reduce the cost and cycle time for military aerospace products throughout the entire value chain while continuing to improve product performance.” By late 1998, 23 industry and 13 government organizations with paying memberships, along with MIT and the UAW were participating in the LAI.

The Benefits of Re-Evaluating Real-Time Fulfillment Decisions

At the time of a customer order, the e-tailer assigns the order to one or more of its order fulfillment centers, and/or to drop shippers, so as to minimize procurement and transportation costs, based on the available current information. However this assignment is necessarily myopic as it cannot account for all future events, such as subsequent customer orders or inventory replenishments. We examine the potential benefits from periodically re-evaluating these real-time order-assignment decisions. We construct near-optimal heuristics for the re-assignment for a large set of customer orders with the objective to minimize the total number of shipments. We investigate how best to implement these heuristics for a rolling horizon, and discuss the effect of demand correlation, customer order size, and the number of customer orders on the nature of the heuristics. Finally, we present potential saving opportunities by testing the heuristics on sets of order data from a major e-tailer.

Logistics Network Design with Differentiated Delivery Lead-Time: Benefits and Insights

Most logistics network design models assume exogenous customer demand that is independent of the service time or level. This paper examines the benefits of segmenting demand according to lead-time sensitivity of customers. To capture lead-time sensitivity in the network design model, we use a facility grouping method to ensure that the different demand classes are satisfied on time. In addition, we perform a series of computational experiments to develop a set of managerial insights for the network design decision making process.

Inside the competences evaluation, the stress tolerance of students. An empirical study based on conservation of resources theory

Competence development is considered a preventive strategy of burnout. At an organizational context some competences could be linked as precursors or consequences. In self-assessment of competence development, students perceive stress tolerance as a priority competence to ameliorate. Moreover employers and recruitment consultants agree that this is a new authentic challenge for organizations. The main reasons of this result are debated, this study should consider the importance of competence development from a holistic point of view. In addition it considers the exploration of the relationship between stress tolerance and competence development, according to Conservation Resources (COR) theory (Hobfoll 1988, 1989, 1998, 2004) where the resource loss is considered the principal component in the stress process

Towards a knowledge economy

This paper provides a preliminary formulation of a new currency based on knowledge. Through a literature review of alternative currencies, various properties and benefits are selected that we hope will enable such a currency to be created. Nowadays not only money but also knowledge is necessary to do business. For instance, knowledge about markets and consumers is highly valuable but difficult to achieve, and even more difficult to store, transport or trade. The basic premise of this proposal is a knowledge measurement pattern that is formulated as a new alternative social currency. Therefore, it is an additional means of contributing to the worldwide evolution of a knowledge society. It is intended as a currency to facilitate the conservation and storage of knowledge, and its organization and categorization, but mainly its exploitation and transference

Efecto del flujo del dializado sobre la ganancia interdialítica en hemodiálisis crónica (Estudio FLUGAIN)

Objetivos: Determinar si existe diferencia en la ganancia interdialítica entre los pacientes al ser tratados con flujo de dializado (Qd) de 400 mL/min y 500 mL/min. Diseño: Se realizó un estudio de intervención, cruzado, aleatorizado, doble ciego en pacientes con enfermedad renal crónica en hemodiálisis para determinar diferencias en la ganancia de peso interdialítica entre los pacientes tratados con flujo de dializado (Qd) de 400 ml/min y 500 ml/min. Pacientes: Se analizaron datos de 46 pacientes en hemodiálisis crónica con Qd de 400 ml/min y 45 con Qd de 500 ml/min. Análisis: La prueba de hipótesis para evaluar diferencias en la ganancia interdialítica y las otras variables entre los grupos se realizó mediante la prueba T para muestras pareadas. Para el análisis de correlación se calculó el coeficiente de Pearson. Resultados: No hubo diferencia significativa en ganancia interdialítica usando Qd de 400 ml/min vs 500 ml/min (2.37 ± 0.7 vs 2.41 ± 0.6, p=0.41) ni en Kt/V (1.57 ± 0.25 vs 1.59 ± 0.23, p = 0.45), potasio (4.9 ± 1.1 vs 5.1 ± 1.0, p=0.45), fosforo (4.5 ± 1.2 vs 4.4 ± 1.2, p=0.56) o hemoglobina (11.3 ± 1.8 vs 11.3 ± 1.6, p=0.96). Conclusiones: En pacientes con peso ≤ 65 Kg el uso de Qd de 400 ml/min no se asocia con menor ganancia interdialítica de peso. No hay diferencia en la eficiencia de diálisis lo que sugiere que es una intervención segura a corto plazo.

ALPS Workshop 5 p3 Benefits of feedback Table

Graphic

Benefits of Linked & Open Data

Presentation to ARMA2013 (Association of Research Managers and Administrators)