Doppler sodar observations of the winds and structure in the lower atmosphere over Fairbanks, Alaska

Thesis (M.S.) University of Alaska Fairbanks, 2007Fairbanks, Alaska (64°49ʹ N, 147°52ʹ W) experiences strong temperature inversions which when combined with the low wind speeds prevailing during the winter cause serious air pollution problems. The SODAR (Sound Detection And Ranging) or acoustic sounder is a very useful instrument for studying the lower atmosphere as it can continuously and reliably measure the vertical profiles of wind speed and direction,vertical motions, turbulence and the thermal structure in the lower part of the troposphere. A Doppler sodar was operated from December 2005 to April 2006 at the National Weather Service site in Fairbanks. The wind observations from the sodar indicate that the majority of the winds during the winter months were from the North, Northeast or the East, which is in good agreement with the radiosonde measurements and the long term trends in the wind patterns over Fairbanks area. Case studies were carried out using the sodar data depicting drainage winds, low-level jets, formation and breakup of inversions and estimation of the mixing layer height.1. Introduction -- 1.1. Climatic features in Fairbanks during winter -- 1.1.1. Temperature inversions -- 1.1.2. Valley winds and drainage winds -- 1.1.3. Urban heat island -- 1.1.4. Air pollution and ice fog -- 1.2. SODAR and its applications -- 1.2.1 Acoustic sounder observations at Fairbanks in the past -- 2. Theory and instrumentation 2.1. Estimation of Ct² -- 2.1.1. Scattering theory -- 2.1.2. Sodar equation -- 2.2. Wind speed and direction -- 2.3. Sodar installation and data acquisition -- 2..4. Sodar dataset and additional sources of data -- 2.5. Algorithm to detect strong layers of temperature inversion -- 3. Results and discussion -- 3.1. Results from the inversion detection algorithm -- 3.1.1. Diurnal variations in inversion characteristics -- 3.1.2. Effect of cloud cover on inversion characteristics -- 3.2. Wind observations from sodar data -- 3.3. Case studies from sodar observations -- 3.3.1. Drainage winds overflowing the stable layer of air beneath -- 3.3.2. Nocturnal jet associated with a temperature inversion -- 3.3.3. Destruction of an inversion due to forced mixing and increasing cloud cover -- 3.3.4. Estimation of the mixing layer height from the backscatter intensity -- 4. Conclusions and future work -- References

A Note on Gauss-Bonnet Black Holes at Criticality

With in the extended thermodynamics, we give a comparative study of critical heat engines for Gauss-Bonnet and charged black holes in AdS in five dimensions, in the limit of large Gauss-Bonnet parameter $\alpha$ and charge $q$, respectively. We show that the approach of efficiency of heat engines to Carnot limit in Gauss-Bonnet black holes is higher(lower) than charged black holes when corresponding parameters are small(large).Comment: 14 pages, 17 figure

Towards a Finite-NN Hologram

We suggest that holographic tensor models related to SYK are viable candidates for exactly (ie., non-perturbatively in $N$) solvable holographic theories. The reason is that in these theories, the Hilbert space is a spinor representation, and the Hamiltonian (at least in some classes) can be arranged to commute with the Clifford level. This makes the theory solvable level by level. We demonstrate this for the specific case of the uncolored $O(n)^3$ tensor model with arbitrary even $n$, and reduce the question of determining the spectrum and eigenstates to an algebraic equation relating Young tableaux. Solving this reduced problem is conceptually trivial and amounts to matching the representations on either side, as we demonstrate explicitly at low levels. At high levels, representations become bigger, but should still be tractable. None of our arguments require any supersymmetry.Comment: 16 page

An inventory planning problem for time-varying linear demand and parabolic holding cost with salvage value

In this manuscript, a model is proposed for the inventory planning problem with items which deteriorate linearly with respect to time. The concept of salvage value for deteriorated items is considered and incorporated in this model. The solution procedure of proposed optimization model is illustrated by a couple of numerical examples. A convexity check of the average total cost function is performed by plotting a two dimensional graph. The sensitivity test of the proposed model is performed to study the effect of changing the least as well as the most sensitive parameters in the proposed optimization model. Some graphical representations are constructed to discuss the outcomes and results so obtained for a choice of various parameters</p

DESIGN PROCESS MODELING: TOWARDS AN ONTOLOGY OF ENGINEERING DESIGN ACTIVITIES

An ontology of engineering design activities, called the Design Activity Ontology (DAO), is developed in this research. The DAO models 82 information flows and 25 design activities. These activities cover phases of the design process from conceptual phase through detail design phase. The ontology provides a formalized and structured vocabulary of design activities for consistency and exchange of design process models. The DAO enables design processes to be modeled, analyzed and optimized. The DAO is constructed using information flows identified in current design literature, commonly accepted engineering design textbooks, and an existing activity ontology. Specifically, the DAO is an extension and refinement of the ontology proposed by Sim and Duffy. The DAO addresses several shortcomings of the Sim and Duffy ontology including: (1) lack of computational representation, (2) inability to construct process models from defined design activities, (3) redundant and semantically equivalent information flows, (4) complex information flows, and (5) inconsistent classification. These shortcomings are identified through Design Structure Matrix (DSM) modeling and analysis, and certain protocols for the analysis of the individual information flows. A total of 112 information flows and 26 activities from the Sim and Duffy ontology are reduced to 82 and 25 respectively. The DAO is implemented in the ProtŽgŽ using the Web Ontology Language (OWL) and Description Logic (DL). The implemented DAO is analyzed using DL\u27s subsumption property through the Fact++ reasoner. Finally, the DAO is exercised through two demonstration examples: (1) the design of a trash truck and (2) the design of an automotive tail light installation fixture. Results from the example support the completeness of the ontology; ability to formulate design processes; and identify \u27dead-end\u27 information flows, information flows required in design but not generated and critical information flows

Climate Change - A threat to National Security of India- Understanding and identifying the key threats to Indian National Security emanating from Climate Change

Question of survival and security are the fundamental questions before any individual, community, group or state. This has always been the question of debate, discussion and writing in all the fields of knowledge. Apart of intellectual exercise, question or survival and security leads to conflicts and wars among individuals, groups and state. Perception of threat has been changing from time to time, but state ( be it in the form of city state, nation state or some other form) was always the key actor in security. Some time it protected its people from external threat and sometime it created threat to its own people. Over the period of time, on the basis of time – space and ideology, ideas of threat are manifested in different forms. National security is about protecting the boundary from external actors. But what should be done when the external actor is not one state or two states? How to recognize the enemy? How to solve the threat in absence of clear enemy? These questions become relevant when we discuss climate change? There is no one single actor which can be made responsible for the climate change. Climate change is a problem which will impact all the actors in international actors. It has the capacity to pose a threat to national security of a nation. This paper is a humble attempt to understand these big questions in the light of climate change and Indian national security. We will deal with the question of threat India have and its capacity to deal with these threat. Paper is been divided into 5 sections. First section of the paper will deal with question of security in International Relations theory. Key aspects of security and its relations with human security and national security will be explored. Second part of the paper will deal with the question of climate change and global warming. What are the causes of global warming and climate change and what can be the impact of climate change on world security and how it impact national security? In this section, we will also discuss the measures taken for solving the environmental and climate change. Third section of the paper deals with impact of climate change on Indian National security. Traditional and nontraditional aspects of security will be explored in connection with climate change. Fourth section will try to look into the measures India has taken to reduce the impact of climate change on its National Security, at domestic level as well as on international level. Fifth section will find the problems in Indian strategy and end with few suggestions for a better mechanism to deal with climate change and its impact on national security