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(101 - 120 of 392)
Pages
- Title
- SPECTRUM SHARING USING CYCLOSTATIONARY SIGNATURES FOR PUBLIC SAFETY PROVISION
- Creator
- Iyer, Swapna
- Date
- 2011-11-21, 2011-12
- Description
-
With the growth in wireless technology, and the ever increasing use of the available spectrum by radio systems, Spectrum Access and Sharing is...
Show moreWith the growth in wireless technology, and the ever increasing use of the available spectrum by radio systems, Spectrum Access and Sharing is highly desired in order to completely utilize the available band of frequencies and thus improve the overall Spectrum E ciency. Cognitive Radio can be used as a technology to improve the spectrum utilization in case of Public Safety Systems. With FCC reserving a 10 MHz band of dedicated spectrum allocated in the 700 MHz band for Broadband Communications, the need to use this band e ciently is necessary. In this thesis, we propose a method by which the available spectrum can be shared among multiple cognitive users in the presence of a high priority cognitive user. We use a Cyclostationary Signature to improve the detection method by other cognitive users. By using this signature we can achieve faster and reliable detection which in turn will improve the Spectrum Utilization.
M.S. in Electrical Engineering, December 2011
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- Title
- IMAGE PROCESSING ALGORITHMS FOR PROSTATE CANCER LOCALIZATION WITH MULTISPECTRAL MAGNETIC RESONANCE IMAGING
- Creator
- Xin, Liu
- Date
- 2011-11, 2011-12
- Description
-
In this thesis, we develop a series of image processing algorithms to localize prostate cancer with multispectral magnetic resonance (MR)...
Show moreIn this thesis, we develop a series of image processing algorithms to localize prostate cancer with multispectral magnetic resonance (MR) images to guide biopsy, surgery and minimally invasive therapy. Besides, we develop a new method to for evaluation of image classification algorithms considering correlation between neighboring pixels. Prostate cancer is one of the most prevalent cancer types and one of the leading causes of cancer death among men in the United States. High-resolution MRI has shown higher accuracy than trans-rectal ultrasound (TRUS) to ascertain the presence of prostate cancer. In this work, three different types of MR techniques are employed to provide both morphological and functional information about the benign and malignant tissues of the prostate. These are T2-weighted (T2w) MRI, diffusionweighted imaging MRI (DWI) and dynamic contrasted enhanced MRI (DCE MRI). In the first chapter of this thesis, we briefly describe the fundamentals of different MR techniques, and the multispectral MR dataset used in our experiment. Then, we focus on two tasks of the prostate cancer localization problem: prostate gland extraction and prostate tumor localization. For each topic, we review the previous studies available in the literature, and present our methods with their advantages. Finally, the new image evaluation method considering correlation between pixels is presented. Our prostate segmentation method is fully unsupervised and extracts the prostate gland from DWI MRI in 3D by fusing the active contour model and shape prior information. For tumor localization, we develop an unsupervised approach which is based on fuzzy Markov random field (fuzzy MRF) model, a new scheme based on relative intensity values which can be combined with supervised segmentation classifiers to mimic the cancer localization procedures performed by human readers and a new feature named location map which incorporates the spatial inforx mation of the tumors to remove the need for manual peripheral zone extraction. The proposed image evaluation algorithm is based on receiver operating characteristics (ROC) analysis and it considers the correlation between neighboring pixels. This method could replace the conventional ROC analysis and offers a more accurate evaluation of the test image. Our algorithms are tested on 20 patients’ multispectral MR images, and the qualitative as well as quantitative experimental results demonstrate the efficacy of our segmentation methods and show that the proposed segmentation methods outperform the currently available used approaches. The evaluation method has been tested on computer simulated images and shows very promising results. The summary and future work is also described at the end of the thesis.
Ph.D. in Electrical Engineering, December 2011
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- Title
- SOFT ERROR TOLERANT LATCH CIRCUIT DESIGN FOR DEEPLY SCALED CMOS TECHNOLOGY
- Creator
- Nan, Haiqing
- Date
- 2012-01-25, 2012-05
- Description
-
As CMOS technology keeps scaling down, circuit designers face variety of challenges. Due to the scaling of supply voltage and node capacitance...
Show moreAs CMOS technology keeps scaling down, circuit designers face variety of challenges. Due to the scaling of supply voltage and node capacitance, digital circuits are more aware of noise and variations, which cause reliability issues such as soft error. Traditionally the soft error aware VLSI design is limited to applications which require high reliability and operated in high radiation environment such as avionics applications, medical equipments, space industry and military applications. However, with CMOS technology scales down to nanometer region, the VLSI circuits can also be affected by soft errors at ground level which features low radiation energy. In this thesis, totally 5 soft error tolerant latch designs are proposed including HLR-1, HLR-2, HLR-CG1, HLR-CG2, and HLR-CG3. All the proposed designs protect internal nodes as well as output node for soft error regardless the radiation energy. The proposed HLR-1 and HLR-2 latch circuits tolerate soft error for non-CG systems. Since the proposed HLR-1 and HLR-2 designs take advantages of floating node to tolerate soft error, these two designs cannot be applied with clock gating techniques and the minimum clock frequency of these two designs should be greater than 16MHz in order to maintain correct logic at the floating node. The power consumption and circuit delay between the proposed HLR-1 and HLR-2 designs are very close. The proposed HLR-1 design achieves a small amount of benefits in terms of power and delay compared with the proposed HLR-2 design. But the proposed HLR-2 circuit reduces area 3.5% compared to the proposed HLR-1 circuit. The proposed HLR-CG1, HLR-CG2 and HLR-CG3 latch designs fully tolerate soft error regardless of radiation energy for both CG and non-CG systems. Due to the auto correction mechanism embedded in the proposed HLR-CG1, HLR-CG2 and HLRCG3 designs, any soft error at any location will be automatically corrected without generating any floating nodes. The proposed HLR-CG3 features the smallest power consumption and delay but it has the largest area overhead compared to HLR-CG1 and HLR-CG2 circuits. The proposed HLR-CG1 design features the smallest area compared with HLRCG2 and HLR-CG3 designs. The design cost of HLR-CG2 design is between the proposed HLR-CG1 and HLR-CG3 designs. All the proposed designs achieve faster speed and smaller PDP compared to previous hardening techniques. Compared to the proposed HLR-1 design, previous designs increases power 3.77% on average, delay 272.74% on average, PDP 300.29% on average and decreases area 7.09% on average. Compared to the proposed HLR-2 design, previous designs increases power 3.77% on average, delay 272.40% on average, PDP 299.89% on average and decreases area 3.93% on average. Compared to the proposed HLR-CG1 design, previous designs increases area 19.65% on average, delay 213.14% on average, PDP 203.78% on average and decreases power 5.82% on average. Compared to the proposed HLR-CG2 design, previous designs increase area 6.49% on average, delay 193.28% on average, PDP 223.45% on average and power 6.51% on average. Compared to the proposed HLR-CG3 design, previous designs increases delay 272.18% on average, PDP 314.38% on average, power 8.01% on average and area 2.93% on average.
Ph.D. in Electrical and Computer Engineering, May 2012
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- Title
- NUMERICAL OBSERVER FOR MOTION QUALITY ASSESSMENT
- Creator
- Massanes, Francesc
- Date
- 2011-04-25, 2011-05
- Description
-
The objective of this work is to develop mathematical models (using machine learning regression) that can mimic human ability to perceive...
Show moreThe objective of this work is to develop mathematical models (using machine learning regression) that can mimic human ability to perceive motion of a small object in an image sequence or a video. The motivation for this work comes from the diagnostic cardiac imaging where a small deformation of a cardiac wall motion represents a signi cant diagnostic marker. First a brief overview of the state of the art in image and video quality assessment is given. This overview also points out a need for a new task based quality metrics which can better quantify, subjective, image sequence quality under various degradations, like blur and noise. Next a study is designed to measure human observers motion perception under various degradation models. Later, the results from this study are analyzed to detect which image sequence features are the most relevant for motion perception and the development of a mathematical model aiming to emulate humans. The chosen features are based on so called visual attention and estimated object motion. Since the computation requirement to calculate visual attention and estimated object motion are considerable we also present a fast parallel implementations based on graphical processing units using NVIDIA Compute Uni ed Device Architecture. The preliminary results indicate that proposed machine learning regression models with the use of the visual attention and estimated object motion can accurately predict human motion perception.
M.S. in Electrical Engineering, May 2011
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- Title
- Thermostatic control of electric heating appliances
- Creator
- Prochazka, R. V
- Date
- 2009, 1917
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/thermostaticcont00proc
Thesis (B.S.)--Armour Institute of Technology, 1917 Bibliography: leaves 26-27 B.S. in...
Show morehttp://www.archive.org/details/thermostaticcont00proc
Thesis (B.S.)--Armour Institute of Technology, 1917 Bibliography: leaves 26-27 B.S. in Electrical Engineering, 1917
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- Title
- Test of a potassium chlorate signal cell
- Creator
- Reid, John S., Jr
- Date
- 2009, 1911
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/testofpotassiumc00reid
Thesis (B.S.)--Armour Institute of Technology
- Title
- DEVELOPMENT OF A VERSATILE WIRELESS NETWORKING TESTBED AND ITS APPLICATIONS
- Creator
- Paladugu, Ravi Kiran
- Date
- 2011-07-26, 2011-07
- Description
-
Wireless networks have been an essential part of communication and a very hot research interest in the last century. It is a truly...
Show moreWireless networks have been an essential part of communication and a very hot research interest in the last century. It is a truly revolutionary paradigm shift, enabling multimedia communications between people and devices from any location. Wireless networking is becoming increasingly ubiquitous, there has been a major development in communication hardware and protocol stack for better quality of service, increased throughput, reduced latency, reduced energy consumption, security, etc. As wireless networks continue to develop, usage has grown day-by-day and it becomes a critical part of home, business and industrial infrastructure. To meet all these increasing demands, growing wireless networks and standards researchers are providing new networking technologies. However, these technologies must be tested before they can be released for mainstream use. As academic research in wireless networking relies heavily on simulation, the accuracy depends on the fidelity of the models used in simulation. Even the well-known simulators used in academic research, like ns-3 and qualnet, fails to provide accurate behavior of the signal propagation and wireless channels. Without high confidence in the accuracy of wireless network simulation tools, it is difficult to make concrete progress in cross-layer protocol optimization research. In this thesis, we built a versatile wireless networking testbed, which can support variety of applications. This testbed supports Multi-Radio Multi-Channel (MRMC) wireless mesh networks and can implement various multi radio routing protocols. We have made several modifications to the wireless interface device drivers to improve the performance of multichannel protocols. Furthermore, we will discuss the details of our testbed and its implementation.
M.S. in Electrical and Computer Engineering, July 2011
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- Title
- MICROCALCIFICATION DETECTION WITH DEEP BELIEF NETWORK
- Creator
- Liu, Lu
- Date
- 2012-04-24, 2012-05
- Description
-
In this thesis, deep belief net (DBN) is applied for detection of microcalcification (MC) clusters in digital mammograms. DBN is a relatively...
Show moreIn this thesis, deep belief net (DBN) is applied for detection of microcalcification (MC) clusters in digital mammograms. DBN is a relatively new type of neural network in machine learning which can learn complex structures from data by using a deep architecture. Based on a database of 200 clinical mammograms, a 3-level unsupervised network followed by a supervised back-propagation fine-tuning classifier is trained and tested. For each location in the image, the classifier is applied to decide whether there is an MC, and subsequently all the detected MCs are grouped into clusters. Free-response receiver operating characteristic (FROC) curves are used to evaluate the performance. The performance of DBN is compared to a well-known support vector machine (SVM) detector. Experimental results show that DBN can outperform SVM. In particular, DBN can achieve a detection rate of 83% at the cost of only one false positive cluster per image. These promising results show that DBN can be adopted in the study of object detection in medical image.
M.S. in Electrical Engineering, May 2012
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- Title
- DEVELOPMENT AND ANALYSIS OF A SECURE AND EFFICIENT VEHICULAR AD HOC NETWORK
- Creator
- Hao, Yong
- Date
- 2012-07-06, 2012-07
- Description
-
Vehicular ad hoc networks (VANETs) enable vehicles to communicate with each other by equipping every vehicle with an on board unit (OBU). Many...
Show moreVehicular ad hoc networks (VANETs) enable vehicles to communicate with each other by equipping every vehicle with an on board unit (OBU). Many interesting and promising functionalities can be achieved in the VANETs, such as safety related application and data downloading application. In this thesis, we focus on the security and privacy provision as well as efficiency improvement of above two applications in the VANETs. In the safety related application, each vehicle periodically broadcasts messages including its current position, direction and velocity (which can be generated by a global positioning system (GPS) device) to inform its geographic data to its neighbors. Privacy is an important issue in VANETs. Meanwhile, some important security functionalities such as message authentication, integrity and non-repudiation should be integrated into the VANETs. In this thesis, we propose a distributed key management protocol based on group signature to provide security and privacy for vehicles. Distributed key management is expected to facilitate the revocation of malicious vehicles, verification efficiency, maintenance of the system and heterogeneous security policies, compared with the centralized key management assumed by the existing group signature schemes. In our framework, each road side unit (RSU) acts as the key distributor for the group, where a new issue incurred is that the semi-trust RSUs may be compromised. Therefore, we develop security protocols which are able to detect compromised RSUs and their malicious accomplices. Moreover, we address the issue of large computation overhead due to the group signature implementation. A practical cooperative message authentication protocol (CMAP) is thus proposed to alleviate the verification burden for vehicles. In the CMAP, on average, each vehicle just needs to verify a very small amount of received geographic messages. Compared with the existing probabilistic verification protocol, CMAP can save at least 40 % computation resource for vehicles. In the data downloading application, we propose a secure cooperative data downx loading framework for payment services in VANETs. In our framework, vehicles download data when they pass by an RSU and then share the data after they travel out of the RSU’s coverage. A fundamental issue of our framework is how vehicles share data with each other. Thus, we develop an application layer data sharing protocol (DSP) in which vehicles share their downloaded data one by one in sequence according to their positions. A better performance can be achieved by the proposed protocol because it is able to avoid medium access control (MAC) layer collisions and the hidden terminal effect. Analytical models are derived to quantitatively evaluate the impact of the distance between RSUs on the amount of data that vehicles can download in a drive through. The simulation results show that our protocol can download 87.4% more data for vehicles than the existing scheme “VC-MAC” when the distance between two consecutive RSUs reaches 10 kilometers. Moreover, we also address security and privacy issues in the process of data downloading and sharing. Both applicants’ exclusive access to the applied data and vehicles’ privacy are ensured by our framework. Compared with the communication overhead in the intuitive method, the communication overhead in our framework will be reduced to 50%. We also propose a security protocol to detect sybil attacks in privacy preserved VANETs. In the above two applications, vehicles’ location information is utilized to facilitate the efficiency. However, if malicious vehicles launch the sybil attack by forging several fake entities and claim they are at some certain positions. The overall performance of the applications will be compromised greatly. So, we propose a security protocol to detect sybil attacks by examining the rationality of vehicles’ positions. The attack detection utilizes the characteristics of communication. No extra hardware and little communication and computation overhead will be introduced to vehicles. Moreover, a smart attacker scenario in which a malicious vehicle may adjust its communication range to avoid detection and the malicious vehicles’ collusion scenario are also considered.
Ph.D. in Computer Engineering, July 2012
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- Title
- 3D RECONSTRUCTION FROM MULTIPLE IMAGES USING SINGLE MOVING CAMERA
- Creator
- Zhou, Zhen
- Date
- 2015, 2015-05
- Description
-
A new technique to reconstruct an object or environment in 3D using a single moving camera was developed. The technique requires only one...
Show moreA new technique to reconstruct an object or environment in 3D using a single moving camera was developed. The technique requires only one camera moving through the environment. Once a set of images or a video is captured, a point cloud and the camera path of the environment or the object can be generated. The camera has to be calibrated in advance. The procedure of 3D reconstruction consists of the SIFT feature matching algorithm, the Epipolar geometry reconstruction, fundamental matrix algebra, points cloud triangulation, and the estimation of the camera motion. The algorithm explored in this thesis is only based on visual information captured by a single moving RGB-camera.
M.S. in Electrical Engineering, May 2015
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- Title
- MOBILE ANDROID SENSOR SYSTEM FOR REAL-TIME PATIENT MONITORING AND HEALTHCARE APPLICATION
- Creator
- Yi, Won-jae
- Date
- 2012-04-25, 2012-05
- Description
-
A system using Android devices that collects, displays sensor data on the screen and streams to the central server in real-time is presented...
Show moreA system using Android devices that collects, displays sensor data on the screen and streams to the central server in real-time is presented in this research. Common Android devices, such as smartphones and tablets, are considered for this system to demonstrate its flexibility and compatibility of the application on any Android device. Bluetooth and wireless Internet connections are used for data transmission among the devices. Also, using Near Field Communication (NFC) technology on the smartphone, the system constructs a more efficient and convenient mechanism to achieve an automatic Bluetooth connection and an automatic application execution. This system is beneficial on Body Sensor Network (BSN) establishments for medical healthcare applications by adding wireless technology. Various types of sensors can be adapted to monitor a patient’s status in real-time. For demonstration purposes, an accelerometer, a temperature sensor and vital signs signal sensor data, including electrocardiography (ECG), blood pressure, electroencephalography (EEG) and respiration, are used to perform the experiment to provide fundamentals of remote patient diagnosis. Raw sensor data is interpreted to either graphical or text notations to be presented on the Android device and the central server. Furthermore, a Java-based central server application is introduced to demonstrate communication with the Android system for data storage and analysis through Internet connections. This system is capable of data transmission in real-time without exploiting system resources for data collection and interpretation. This system is also can be further extended for additional sensors, such as a sweatiness sensor, an electromyography (EMG) sensor, a glucose sensor and more for enhanced patient status diagnosis.
M.S. in Computer Engineering, May 2012
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- Title
- AN ANALYTICAL APPROACH TO REAL-TIME MISBEHAVIOR DETECTION IN IEEE 802.11 WIRELESS NETWORKS
- Creator
- Chen, Ying
- Date
- 2011-07, 2011-07
- Description
-
It is easy for the malicious nodes to take advantage of CSMA/CA based wireless protocols to gain unfair larger share of the network throughput...
Show moreIt is easy for the malicious nodes to take advantage of CSMA/CA based wireless protocols to gain unfair larger share of the network throughput because of the distributed nature of the IEEE 802.11 distributed coordination function (DCF). The backoff misbehavior will happen when one node deliberately chooses smaller backoff parameters. This paper adopts a promising non-parametric cumulative sum test (CUSUM) based scheme to quickly find abrupt changes in a process without prior knowledge of the statistics of the change occurrences. According to a Markov chain based analytical model, we can systematically study the real-time misbehavior detection results from CUSUM based method, thus quantitatively computer the system configuration parameters for guaranteed performance in terms of average false positive rate, average detection delay, and missed detection ratio.
M.S. in Computer Engineering, July 2011
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- Title
- OPERATION AND PLANNING OF COORDINATED NATURAL GAS AND ELECTRICITY INFRASTRUCTURES
- Creator
- Zhang, Xiaping
- Date
- 2015, 2015-07
- Description
-
Natural gas is becoming rapidly the optimal choice for fueling new generating units in electric power system driven by abundant natural gas...
Show moreNatural gas is becoming rapidly the optimal choice for fueling new generating units in electric power system driven by abundant natural gas supplies and environmental regulations that are expected to cause coal-fired generation retirements. The growing reliance on natural gas as a dominant fuel for electricity generation throughout North America has brought the interaction between the natural gas and power grids into sharp focus. The primary concern and motivation of this research is to address the emerging interdependency issues faced by the electric power and natural gas industry. This thesis provides a comprehensive analysis of the interactions between the two systems regarding the short-term operation and long-term infrastructure planning. Natural gas and renewable energy appear complementary in many respects regarding fuel price and availability, environmental impact, resource distribution and dispatchability. In addition, demand response has also held the promise of making a significant contribution to enhance system operations by providing incentives to customers for a more flat load profile. We investigated the coordination between natural gas-fired generation and prevailing nontraditional resources including renewable energy, demand response so as to provide economical options for optimizing the short-term scheduling with the intense natural gas delivery constraints. As the amount and dispatch of gas-fired generation increases, the long-term interdependency issue is whether there is adequate pipeline capacity to provide sufficient gas to natural gas-fired generation during the entire planning horizon while it is widely used outside the power sector. This thesis developed a co-optimization planning model by incorporating the natural gas transportation system into the multi-year resource and transmission system planning problem.This consideration would provide a more comprehensive decision for the investment and accurate assessment for system adequacy and reliability. With the growing reliance on natural gas and widespread utilization of highly efficient combined heat and power (CHP), it is also questionable that whether the independent design of infrastructures can meet potential challenges of future energy supply. To address this issue, this thesis proposed an optimization framework for a sustainable multiple energy system expansion planning based on an energy hub model while considering the energy efficiency, emission and reliability performance. In addition, we introduced the probabilistic reliability evaluation and flow network analysis into the multiple energy system design in order to obtain an optimal and reliable network topology.
Ph.D. in Electrical and Computer Engineering, July 2015
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- Title
- DEVELOPMENT OF A PROGRAMMABLE WIRELESS NETWORK TEST BED OVER ANDROID SMARTPHONE
- Creator
- Zhou, Chenyang
- Date
- 2016, 2016-05
- Description
-
As wireless applications are increasingly prevalent in recent years, smartphones, the link between wireless world and common life, become more...
Show moreAs wireless applications are increasingly prevalent in recent years, smartphones, the link between wireless world and common life, become more and more indispensable. Subsequently, smartphone applets become more and more complicated, protocols like 3G,LTE,4G have also been improved to satisfy people’s increasing requirement. This leads to an exponentially increase in energy consumption. However, the power of smartphone battery is limited, and thus how to improve energy efficiency and extend the life-time of smartphone battery becomes a critical issue. In wireless local area networks (WLANs), switching to low-power sleep mode to save energy is common. Power-Saving mode (PSM) was one of the standard algorithm in order to save energy. This feature allows devices to switch the WiFi on and off several times a second. However, research papers have shown that PSM is not really efficient in practice, and in many cases (e.g. multiple stations), can actually degrade performance. This sleep-scheduling algorithm, derived from GreenCall Algorithm is demonstrated to have lower packets loss rate while achieving higher energy efficiency than that of the existing GreenCall Algorithm.
M.S. in Electrical Engineering, May 2016
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- Title
- Transmission of Niagara Falls power to Chicago.
- Creator
- Roller, L. H.
- Date
- 2009, 1912
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/transmissionofni00roll
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaves. 52-53
- Title
- CABLE MODELING AND FAULTSTUDY FOR THE lIT PERFECT POWER SYSTEM
- Creator
- Gupta, Abhinav
- Date
- 2011-05-02, 2011-05
- Description
-
IIT has taken part in the smart grid initiative by converting the existing radial distribution network into a looped network to increase the...
Show moreIIT has taken part in the smart grid initiative by converting the existing radial distribution network into a looped network to increase the reliability of the system as part of the ’Perfect Power’ project. A total of 7 loops have been planned with the help of fast fault clearing relays (’Vista Switches’). As part of the project, the cable is modeled using the various impedance calculators and was also done using the PSCADrsoftware. With the obtained impedance values from the impedance calculators, the cables were analyzed under various outage/contingency cases. They include base case power flows of the old IIT distribution network as well as the Loop 3 of the perfect power project implemented and open circuit analysis and short circuit analysis of the Loop 3 alone. Also, with the help of the fault current values from the short circuit study we can analysis the relay settings and operations and review the later for the newly installed relays. And finally, the cable fault classifier was designed using the Artificial Neural Network (ANN) method in MATLABrand PSCADrsoftware. Here we model the cable using the impedance calculated and collect the voltage and current samples from the two ends of the cable which is given as input to the ANN classifier and the same is tested for accuracy.
M.S. in Electrical Engineering, May 2011
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- Title
- A test of a 2,500 KVA turbo-generator
- Creator
- Grabendike, C. A.
- Date
- 2009, 1921
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/testof2500kvatur00grab
Thesis (B.S.)--Armour Institute of Technology
- Title
- TWO-LAYERED DEPTH ESTIMATION USING SEMI-GLOBAL MATCHING WITH MUTUAL INFORMATION
- Creator
- Zhang, Chen
- Date
- 2014, 2014-07
- Description
-
Depth estimation plays an important role in three-dimensional computer vision area. Its recent development focuses on real-time application....
Show moreDepth estimation plays an important role in three-dimensional computer vision area. Its recent development focuses on real-time application. To be able to provide depth map for real-time applications like pedestrian detection and intelligent vehicles, three challenges must be overcome: 1. Real-time processing speed; 2. Insensitive to brightness change; 3. Clear boundaries and smooth surface. The thesis first describes the major steps of depth estimation, then many commonly used methods are reviewed. From them and other related real-time method, we found that the iteration based semi-global matching with mutual information has much potential to be improved. Based on that, the thesis proposed a method with two layers to provide depth map for pedestrian detection. The low resolution layer’s task is to produce a coarse depth map as quick as possible, then it helps to produce accurate mutual information distribution without iterations. The Full-resolution layer applies semi-global matching with two optional simplification schemes to speed up. The proposed method is implemented on both CPU and GPU. Experimental results and evaluation shows that it has great insensitivity to brightness changes and achieves real-time processing speed while maintaining a comparable performance with state-of-the-art real-time depth estimation methods.
M.S. in Electrical Engineering, May 2014
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- Title
- Tests of a mechanical rectifier
- Creator
- Smith, Bernard M, Wolfson, William
- Date
- 2009, 1916
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/testsofmechanica00smit
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaf 50
- Title
- DESIGN OF VANET COOPERATIVE MESSAGE AUTHENTICATION PROTOCOL AND PERFORMANCE EVALUATION WITH PRACTICAL SIMULATION
- Creator
- Han, Tingting
- Date
- 2012-07-24, 2012-07
- Description
-
In the near future, vehicular ad hoc networks (VANETs) are expected to be more widely deployed, where vehicles would be equipped with on-board...
Show moreIn the near future, vehicular ad hoc networks (VANETs) are expected to be more widely deployed, where vehicles would be equipped with on-board devices that permit wireless networking between vehicles on the road, and between vehicles and in- frastructure. To ensure security and privacy, digital signature and veri cation schemes have been extenstively developed. The group signature implemented in VANETs causes large computation overhead, While the On Board Units installed on vehicles have limited CPU computing capacity. To address this issue, a practical cooperative message authentication protocol (CMAP) is designed and simulated in this work. In the protocol, vehicles share their veri cation results with each other in a cooperative way so that each vehicle just needs to verify a small number of messages. Compared with other work considering 1-D highway road scenario, 2-D city road scenario is built with the tra c simulator VanetMobiSim. Our CMAP simulation is based on the basic Periodic BroadCast (PBC) platform available in newer versions of ns-2 system. The protocol design and all detailed procedures of CMAP algorithms are implemented in the network simulator ns-2 with C++ programming. The simulation also evaluates the performance of CMAP with metrics including missed detection ratio, CPU load, under conditions of di erent vehicle densities and di erent numbers of veri ers. The performance of our CMAP with n-nearest veri er selction method is compared with previously reported probabilistic veri cation method, and shows the advantage.
M.S. in Electrical Engineering, July 2012
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