View factors for circular air ducts in attics: fast and accurate approximations

Attic energy modeling is a topic of interest as current whole building energy models have a difficult time predicting the thermal performance of attics. Recent developments in attic energy modeling has allowed, for the first time, many different attic shapes to be analyzed. This allows analysis of roofs beyond standard gable, shed, flat, and saltbox type roofs. With this generalization of attic geometries, the calculation of view factors becomes a potential issue for these diffusely emitting nonconvex polygon shaped attics. The presence of air ducts further complicate calculation of view factors and radiation heat transfer in attics. Currently there are two methods to produce these view factors, 1) solving the double integral that defines the view factor or 2) simple calculations based on engineering assumptions to allow for the view factors to be easily calculated. The first approach can be computationally intensive as air ducts and complex geometry can drastically increase the number of surfaces to be calculated in the integral equation, and can be tedious to set up. On the other hand, the second (very fast) approach is built upon assumptions in ASHRAE RP-717. Very limited analysis has been documented on the validity of these assumptions. Furthermore, with current advances in the ability to model different attic geometries these assumptions may no longer be valid. This work focuses on updating the view factor assumptions to provide a fast and accurate method for calculating view factors in attics containing circular air ducts under more generalized conditions. The assumptions are updated by first systematically evaluating the old assumptions to determine whether a modification is needed, followed by designing and testing an alternative approach when needed. In all cases, extensive evaluation and comparison of proposed alternative approach with the older assumptions and double integral calculations are performed. Finally, a comparison between approach in RP-717 and the new rules developed in this thesis is reported. We envision that these updated assumptions can easily be included in whole building or attic specific energy modeling software to better capture the thermal effects of radiation heat transfer between air ducts and attic surfaces

Key factors affecting small bamboo enterprises upgrading in North Vietnam: Case studies from Chuong My, Hanoi and Thanh Hoa province

The bamboo sector significantly contributes to environmental protection, employment opportunities, and poverty reduction in rural and mountainous areas. This assertion holds true for Vietnam. Bamboo processing enterprises play increasingly important roles in value chain upgrading, despite growing overexploitation and mismanagement. This significantly affects small bamboo enterprises (SBEs) upgrading. In effect, SBEs are constrained by several factors, including the application of outdated technology, the lack of product innovation, limited capital, unstable labour resources, and poor market access. In addition, these enterprises do not only face stiff competition from large scales enterprise, but they are also confronted with international competitors (e.g. bamboo and rattan manufacturers from China). As current policies are yet to address these issues, SBEs remain exposed to shocks that may cause them to disappear. The consequences may include rising unemployment and poverty levels within rural communities in Vietnam. In the face of multi-faceted structural deterrents to the survival of SBEs, a few SBEs in the study region have grown successfully, and have established themselves in international markets over the last years. The conditions under which such SBEs thrived remain relatively less understood. Furthermore, a comprehensive analysis of the key determining factors for the upgrading of SBEs is lacking. To address this gap, this thesis presents evidence of both successful and unsuccessful cases of SBEs upgrading in Vietnam.Der Bambussektor trägt wesentlich zum Umweltschutz, zu Beschäftigungsmöglichkeiten und zur Armutsbekämpfung in ländlichen und bergigen Gebieten bei. Dies trifft auch auf Vietnam zu. Bambus verarbeitende Unternehmen spielen eine zunehmend wichtige Rolle in der Wertschöpfungskette, trotz des wachsenden Raubbaus und Missmanagements. Dies hat erhebliche Auswirkungen auf die Entwicklung kleiner Bambusbetriebe (small bamboo enterprises - SBEs). Tatsächlich werden SBEs durch mehrere Faktoren eingeschränkt, darunter die Anwendung veralteter Technologie, der Mangel an Produktinnovationen, begrenztes Kapital, instabile Arbeitsressourcen und schlechter Marktzugang. Darüber hinaus stehen diese Unternehmen nicht nur im harten Wettbewerb mit nationalen Unternehmen, sondern auch mit internationalen Marktteilnehmern (z.B. Bambus- und Rattanverarbeiter aus China). Da die derzeitige Politik sich diesen Problemen noch nicht gewidmet hat, sind die SBEs weiterhin Schocks ausgesetzt, die zu ihrem Verschwinden führen können. Die Folgen können steigende Arbeitslosigkeit und Armut in den ländlichen Gemeinden Vietnams sein. Trotz der vielschichtigen strukturellen Hindernisse für das Überleben von SBEs sind einige wenige von ihnen in der Studienregion erfolgreich gewachsen und haben sich in den letzten Jahren auf internationalen Märkten etabliert. Die Bedingungen, unter denen solche SBEs gediehen sind, sind noch wenig bekannt. Zudem fehlt bislang eine umfassende Analyse der wichtigsten Einflussfaktoren für die Weiterentwicklung von SBEs. Um diese Wissenslücke zu schließen, werden in dieser Arbeit sowohl erfolgreiche als auch erfolglose Fälle von SBEs in Vietnam vorgestellt

Competition of strategy between China and India in the Indian Ocean nowadays

In recent years, the Indian Ocean Region has become central to the strategies of major global powers due to a series of geoeconomic and geopolitical factors. While China increased its influence in this region by opening up connections within the framework of the BRI, offering loans, and constructing infrastructures, India, with its "neighborhood first" policy, also preserved its traditional sphere of influence. Due to the rising strategic competition by powers, Indian Ocean Region was at the crossroads of great power competition, especially the strategic competition between China and India. The article was based on a comparative approach and simultaneously compared India and China's influence in each field in the Indian Ocean region. The analysis showed that competition between China and India in the context of the two countries still has many tensions, leading to each country's efforts to strengthen military control over the Indian Ocean region. However, this competition tends to serve as a balance between the two countries, motivating them to develop regional power rather than allowing a single dominant state to become a hegemon

Automatic Crack Detection in Built Infrastructure Using Unmanned Aerial Vehicles

This paper addresses the problem of crack detection which is essential for health monitoring of built infrastructure. Our approach includes two stages, data collection using unmanned aerial vehicles (UAVs) and crack detection using histogram analysis. For the data collection, a 3D model of the structure is first created by using laser scanners. Based on the model, geometric properties are extracted to generate way points necessary for navigating the UAV to take images of the structure. Then, our next step is to stick together those obtained images from the overlapped field of view. The resulting image is then clustered by histogram analysis and peak detection. Potential cracks are finally identified by using locally adaptive thresholds. The whole process is automatically carried out so that the inspection time is significantly improved while safety hazards can be minimised. A prototypical system has been developed for evaluation and experimental results are included.Comment: In proceeding of The 34th International Symposium on Automation and Robotics in Construction (ISARC), pp. 823-829, Taipei, Taiwan, 201

Developing graduate knowledge and skills for the world of work: The case of the translation curriculum in Vietnam

National and global challenges have given rise to the need to prepare Vietnamese graduates for effective adaptation to the increasingly changing professional field, their community, their society and the globalised world. The tertiary education curriculum thus needs to take into account the employment market, socio-cultural demands and students’ individual needs in order to develop highly educated populations for the world of work and for the current knowledge economy. Based on a case study of the translation curriculum in a B.A. (Bachelors of Arts) language program, this paper addresses the mismatch between the demands of the translation employment market and the curriculum within the context of Vietnamese tertiary education. It raises a number of important issues related to the tensions between the centralised curriculum, learner-centred education, the actual demands of the employment market as well as the issue of capacity building in response to the socialist-oriented market economy and the changing workplace context in Vietnam. Implications are drawn not only for the translation curriculum, but also for the reform of the Vietnamese tertiary education curriculum as a whole, in order to enhance graduate employability

The debates and the long-awaited reform

Trung Tran, Phuong-Thao T. Trinh, Thu-Trang Vuong, Hiep-Hung Pham (2019). Chapter 1. The debates and the long-awaited reform. In Quan-Hoang Vuong, Trung Tran (Eds.), The Vietnamese Social Sciences at a Fork in the Road (pp. 17–32). Warsaw, Poland: De Gruyter / Sciendo. DOI:10.2478/9783110686081-006 Online ISBN: 9783110686081 © 2019 De Gruyter / Sciend

Effects of sorghum grain processing upon swine performance and preference during the growing finishing period

Call number: LD2668 .T4 1963 N34Master of Scienc