Texas A&M University-Kingsville: AKM Digital Repository
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1689 research outputs found
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Calculation of nonlinear optical susceptibilities in Silicon quantum dots: an Ab-initio study
No full textUsing Time Independent Density Functional Theory (TIDFT) implemented in SIESTA® the 2nd order and 3rd order nonlinear optical susceptibilities of small Silicon Quantum Dots (SiQDs) have been calculated. It is observed that symmetry breaking in the Quantum Dot (QD) structure due to surface termination enhances the second order susceptibility, χ(2) up to 0.06375 pm/V, contributing towards a strong Second Harmonic Generation (SHG) in SiQDs. Diagonal components for χ(2) tensor are 0.002397, 0.038705 and 0.008885pm/V, for xxx, yyy and zzz, respectively. The 3rd order susceptibility, χ(3), is within the range of (8.0-9.6)×10−22 m2/V2 which is close to the reported experimental values of bulk Silicon. This study suggests possibilities of enhancing SHG in SiQDs through symmetry breaking via strain and surface termination. This also supports for the suitability of the Density Functional Theory (DFT) -based method for predicting nonlinear optical susceptibilities of nano-structures in a fast and less-computationally intensive way
Development of an engineering origami inspired active sweeping wing
No full textThis thesis introduces an alternative approach to the current mechanical sweeping wing concept. The primary focus is to develop a wing structure which can carry and direct aerodynamic loads in an extended, partially swept, and a fully swept configuration. This work replaces mechanical parts with flexible hinges and continuous compliant hinges to improve the current mechanical sweeping wing structure. Utilizing engineering origami and compliant mechanism concepts on a sweeping wing; a dynamic wing structure was designed with target goals of reducing drag while maintain high lift, strength, and maneuvering capabilities with the help of fence structures. Mathematical models were developed and applied for rectangular and tapered wing structures using Excel. The verified models can be used to create various configurations, given the number of wing segments, segment sweep angle, and desired wingspan. Using the formulations, 3D models with compliant hinges with flexible and rigid sections were successfully 3D printed and evaluated. This work shows great promise in bringing science, art, and biology together to solve challenging problems.
Key Words: Engineering Origami, Compliant Mechanisms, Flexible Composite
The effects of mortality salience on the ego identity statuses
No full textTerror Management theory asserts that mortality salience causes paralyzing existential anxiety, and that an individual’s cultural worldviews will be bolstered to mitigate this effect. Ego identity status theory places individuals in one of four identity statuses based on their levels of exploration and commitment to domains of identity. Given that cultural worldviews and domains of identity share similar characteristics, this research examined if the induction of mortality salience would cause participants to bolster their domains of identity in a way that causes them to transition to a different identity status. An individual’s initial identity status, level of self-esteem, race, gender, age, and income were also evaluated to determine if any of these would affect rates of transitioning. However, only a small sample of potential participants completed the survey, so insufficient data were available to support the hypotheses. Future recommendations for research are discussed based on the results that were available
Human hand gesture enabled assistive cyber-human interaction design
No full textIn the advent of technology, human-computer assistive interfacing is becoming a reality. This is also applicable for persons with an artificial hand (prosthetic arm), who have an alternative use of keyboard and mouse in their computing and media interaction tasks through the advance of assistive interfacing. In this case, using human gesture as a direct tool to communicate with computers makes life easier. A surface Electromyography (sEMG) study uncovers human muscle activity that is calibrated by hand gestures can be used to trigger different applications. The objective of this study is to analyze a wearable Human-Computer Interface (HCI) and apply it to interface with computers so that humans with prosthetic arms can use the technology in computing. The technology tool used in this study is called Myo armband (introduced by Thalmic labs) which recognizes gestures from different hand postures through surface Electromyography (sEMG – the measure of the muscle activity from the skin surface.) A small pilot study is performed to collect sEMG data, identify patterns, and to interface with the computer.
In this work, Support Vector Machine (SVM) is used as a machine learning algorithm to classify hand gestures on extracted feature, dimensionality reduced time-series sEMG data. Moreover, a graphical tool is developed to demonstrate the assistive interface for simulating iv animated car movements and hand gesture paint applications in the Python Pygame module. These applications demonstrate how wearable devices such as Myo Armband can play a vital role in assisting trans-radial amputees while interfacing with human computer interfaces using hand gesture recognition
A communication system architecture for smart homes based on Internet of Things
No full textThe Internet of Things is making a new world, the place where individuals and organizations can avail themselves of various services to make sophisticated choices about what they need or need to do. This new world of Internet of things (IoT) brings key changes in the detection of our surrounding conditions and makes numerous realistic changes using various gadgets thereby ensuring better accommodation, wellbeing and security, while enhancing liveliness, ability and comfort. The IoT will add another source of making one’s life more comfortable. IoT gadgets can be classified into three categories: (1) wearables, (2) smart home gadgets, and (3) M2M gadgets. In this research work, use of IoT in establishing a communication network for smart homes has been discussed. In the network, every household gadget, including light controllers, movement sensors, indoor regulators and many others are included. It assumes that the smart home has a Wi-Fi connection to the Internet. Regardless of the considerable number of developments, the IoT needs to be extended further. It can be made more secure and precise in the field of protection and security. In this research work, communication system aspect of a smart home has been explored. Communication between the sensors and controllers and their respective base stations has been explored. Various communication system architectures and their underlying protocols proposed by previous investigators has been analysed to determine their strengths and weaknesses. On the basis of this analysis, a new or modified communication system architecture has been proposed. The strength and weakness of this communication system architecture, in the context of some typical smart home configurations, have been discussed
A cooperative game-theoretic model for residential energy management in smart grid
No full textIn this study, a bi-directional demand side management between multiple residential users and utility companies is modeled based on cooperative game theory. In residential users’ game model, strategy of each residential user is to collaboratively schedule his/her household appliances by minimize all users’ billing cost and in utility companies’ game model, strategy of each utility companies is to cooperatively select appropriate proportion of total energy to provide to residential users by minimizing companies’ total energy cost. The utility companies provide both thermal and solar source of energy. We also consider that residential users can sell energy back to the grid with plug-in electric vehicles (PHEVs). An iterative algorithm is formulated to solve game models. The advantage of the double cooperative-game model is analyzed by comparing the model results to solutions of model without Energy Consumption Scheduling (ECS) in residential users; non-game-theoretic utility company game model; residential game model without PHEVs discharging and utility companies providing only traditional energies, respectively
The application of sanctions in the Italo-Ethiopian conflict
No full textThis study was undertaken with the idea of arriving at some conclusion as to the effectiveness of economic sanctions. No study of the diplomacy of the conflict, other than that directly connected with the application of sanctions was made, nor was any study made of the actual war itself.
The effectiveness of sanctions was well-demonstrated in one way; that is, in the curtailment of trade, Sanctions as a weapon for international peace, however, is another matter. In a world torn by armed conflict at the present time in China and Spain, in a world apparently dominated by the desire of many nations to become strong military empires, those who desire peace should be making every effort to arrive at some plan to insure world peace. Italy, since the Ethiopian conquest, has continued to increase her arms, until at the present time she has nine million men under arms, according to Winston Churchhill. Germany has annexed Austria and is endeavoring to interfere in Czechoslovakian affairs with the intention of annexing her also. Russia and Japan, as a result of recent border incidents, are threatening war. The situation between the United States and Mexico over the confiscation of lands, while in no way carrying a threat of war in the immediate future, could grow into a serious situation. For the anti-militaristic Anglo-Saxon people of the world the situation is alarming, and as a result they are casting about for some means of promoting international peace.
The writer seriously hopes that those who read the succeeding pages will carefully study the various questions arising and will try to reach some definite conclusion that will help fight for world peace
The elementary principalship of Corpus Christi schools
No full textPurpose: Since there has never been a detailed study made of the duties of the elementary principals of Corpus Christi, the purpose of this thesis is to present, as accurately as it can be done, a picture of the eight elementary principals in their daily professional work. This research is limited to presenting an accurate picture of what is now being done. No evaluation is undertaken. Such an evaluative study in the light of educational philosophy might grow out of this type of study
The port of Corpus Christi
No full textIt is the purpose of this study to determine the process through which the port of Corpus Christi has become an economic asset to Southwest Texas because of its geographic situation and through an analysis of the resources of its rate advantage territory. The study will also involve the factor of future development of the area after sufficient grounds have been found upon which to base such prediction.
Any affirmation relative to the question involved will of necessity attempt to answer clearly such inquiries as the effect of the port on agricultural production, on live stock endeavor, on population trends, on the location of industries, on the development of natural resources; and it should also offer proof that its establishment and the enlargement of its facilities is a sound business venture
Synthesizing constant force compliant mechanisms using prebuckled beams
No full textA constant force compliant mechanism generates an output force that keeps invariant in a large range of input displacement. Because of the constant force feature and the merits of compliant mechanisms, they are utilized in many applications. A problem in the current constant force compliant mechanisms is their preloading range that is a certain starting range of the input displacement. In the preloading displacement, the output force of a constant force compliant mechanism does not have the desired value. It goes up from zero value. The preloading displacement often occupies one quarter or more of the entire input displacement range, which weakens the performance of constant force compliant mechanisms. The preloading issue is eradicated in this research by using prebuckled beams as components for constructing constant force compliant mechanisms. It is difficult to synthesize constant force compliant mechanisms that are composed of prebuckled beams because of the intertwined force, buckling and deflection characteristics. In this research, the undeformed beams are represented by spline curves and controlled by its interpolation points. The synthesis of constant force compliant mechanisms is systemized as optimizing the design parameters of the composed prebuckled beams. Fully compliant constant force compliant mechanisms are synthesized without preloading. The synthesis solutions are validated by experimental results