The Temperature Sensitivity Analysis of Power System Load Demand with Neural Networks Chih-Hung Chen* Chao-Shun Chen** Institute of Electrical Engineering National Sun Yat-Sen University Kaohsiung, Taiwan, R.O.C. ABSTRACT The analysis of customer load characteristic plays the fundamental role of power system operation. Based on the load survey study, the load pattern of each customer class is derived to achieve more effective load forecast for system planning to reduce the risk of system capacity shortage. For the load survey study, a stratified sampling method has been used to select the proper size of customers for meter installation to collect the customer power consumption. By the way, the customer load patterns derived can represent the load behavior of whole customer population. The standardized daily load pattern of each customer class has been solved with the mean per-unit method of customer load. According to the total power consumption by all customers within the same class and considering the corresponding daily load pattern, the daily load profile of the customer class is then determined. The standard daily load pattern of each customer class and total power consumption within the territory of service districts of Taipower system are integrated to construct Taipower system daily load profile. The temperature sensitivity analysis of customer power consumption is performed for each customer class by applying neural networks. The proposed method has been used to investigate the change of power consumption due to temperature rise for each district and Taipower system. For the districts with high ratio of the air conditioner loading, the increase of power consumption is in proportion to the temperature. It is concluded that the research of temperature sensitivity on power consumption can support power system operation and better capacity planning of power system in the future. *Author **Advisor

Abstract This thesis presents that the closed-loop sensitivity function shaping combined with -synthesis applies to design the controller with structured uncertainties. The sensitivity function shaping is directly based on the indices of the closed-loop performances. The closed-loop frequency response and the robust stability for the system could approach the designed performances by adjusting weighting functions. Since the robust performance of the closed-loop systems bases on the index of the open-loop function in the loop shaping, it may not accomplish the requirement of the designer. The loop shaping can¡¦t be applied to design controllers for the system with structured uncertainties. Therefore, using the closed-loop sensitivity function shaping to design controller will contain the system with structured uncertainties and satisfy the closed-loop performance.

This paper is to investigate the impact of temperature sensitivity to the load profiles of power system by artificial neural networks (ANN). The load survey study is performed to derive the typical load patterns of the residential, commercial, and industrial customers respectively. By executing the training process of customer power consumption and temperature, the ANN model is created to derive the temperature sensitivity of power consumption for each customer class, which is then used to solve the impact of temperature rise to system power profiles. According to the system load composition and temperature sensitivity of power consumption by each customer class, the hourly increase of system power loading due to 1¢J temperature rise is solved. To study the temperature effect to the system reliability, the ¡§IEEE Reliability Test System¡¨ is selected as test system for power system reliability analysis. Based on the temperature sensitivity of power consumption for each customer class and load composition of each load bus. The power demand is updated with the temperature rise. The temperature sensitivity of commercial customers is very significant because of the high air conditioner loading. When the system load composition is most composed of commercial customers, the power demand are due to temperature rise will have very critical impact to system reliability. On the other hand, the tempearture rise will have less impact of reliability analysis for the system which serves high percentage of industrial customers. It is concluded that the research of temperature sensitivity on power consumption can provide important information for system reliability analysis. Better substation planning and system capacity expansion can be obtained to meet system reliability criterion by taking into account the temperature effect to system loading.

Spectral properties of global surface temperature and uncertainties of global climate sensitivity are explored in this work through the medium of Energy Balance Climate Models (EBCMs) and observational surface temperature data. In part I, a complete series of 2D time-dependent non-orthogonal eigenmodes of global surface temperature are analytically derived and their geographic patterns are presented. The amplitudes of these modes have temporal characteristics and present exponentially decaying patterns. Theoretically, if the energy balance model is forced by white noise forcing in time, the autocorrelation functions of the mode amplitudes should present the same exponentially decaying patterns. When observed surface temperature data are projected onto these theoretical modes, the autocorrelation time scales of the mode amplitudes exhibit similar exponential decaying patterns. These modes are believed to be useful for surface temperature studies and model intercomparison. In part II, an objective means of deriving the probability density function (PDF) of global climate sensitivity is investigated. The method constrains the PDF by its fit to the present climate in terms of surface temperature. We found that a wide range of parameter combinations, which corresponds to a broad range of the sensitivity, shows equally good fits to the present climate. It means that the uncertainties in global climate sensitivity are very difficult to eliminate if climate models are tuned to fit observations of surface temperature alone. The origin of the skewness of the PDF is found in very simple terms.

An ad hoc network is formed by a group of self-configuring nodes, typically deployed in two or three dimensional spaces, and communicating with each other through wireless or some other media. The distinct characteristics of ad hoc networks include the lack of pre-designed infrastructure, the natural correlation between the network topology and geometry, and limited communication and computation resources. These characteristics introduce new challenges and opportunities for de- signing ad hoc network applications. This dissertation studies various optimization problems in ad hoc network information retrieval and transmission. Information stored in ad hoc networks is naturally associated with its location. To effectively retrieve such information, we study two fundamental problems, range search and object locating, from a distance sensitive point of view, where the retrieval cost depends on the distance between the user and the target information. We develop a general framework that is applicable to both problems for optimizing the storage overhead while maintaining the distance sensitive retrieval requirement. In addition, we derive a lowerbound result for the object locating problem which shows that logarithmic storage overhead is asymptotically optimal to achieve linear retrieval cost for growth bounded networks. Bandwidth is a scarce resource for wireless ad hoc networks, and its proper utilization is crucial to effective information transmission. To avoid conflict of wireless transmissions, links need to be carefully scheduled to satisfy various constraints. In this part of the study, we first consider an optimization problem of end-to-end on- demand bandwidth allocation with the single transceiver constraint. We study its complexity and present a 2-approximation algorithm. We then discuss how to estimate the end-to-end throughput under a widely adopted model for radio signal interference. A method based on identifying certain clique patterns is proposed and shown to have good practical performance.

Due to the difficulty of reinforcement in power network and the interconnection of more distributed generators, fault current level has become a serious problem in transmission and distribution system operations. The utilization of fault current limiters (FCLs) in power system provides an effective way to suppress the fault currents. In this thesis the sensitivity of impedance matrix due to changes in the branch parameters is derived and used to choose the candidates for FCL installation in a complex power system. The proposed method also considers the effect on power system transient stability due to the installation of FCL. The Extended Equal Area Criterion (EEAC) is used to simplify the multi-machine transient stability problem to a simple equivalent modal and to simplify the transient stability evaluation. A fuzzy logic approach considering impedance of FCL, transient stability and voltage sag effects is used to choose good FCL installation locations in loop transmission systems.

Thesis (Ph.D.)--University of Delaware, 2009. / Principal faculty advisor: Mary Dozier, Dept. of Psychology. Includes bibliographical references.

The aim of this study was to determine whether there was an association between a failed test of cough reflex sensitivity and history of chest infection in a general population of rest home residents. One hundred rest home residents from four different levels of care (rest home, hospital, dementia and psycho-geriatric) were recruited and their cough reflex assessed using a solution of 0.6 Mol/L citric acid nebulised and presented via a facemask.Participant’s records were then checked to see if there were any documented episodes of chest infection in the 6 month period prior to cough reflex testing.The results showed that out of 100 participants, 4 failed the cough reflex test. Of the 4 that failed the test, 3 had no documented episodes of chest infections recorded in the 6 month period prior to cough reflex testing. Data was not available for one participant who was deceased by the time of collection of the second data set. As such, there was no direct association demonstrated between a failed cough reflex test and development of chest infection or aspiration pneumonia. The results of the study are unexpected in two ways. Firstly, the relatively low number of participants who failed the cough reflex test is surprising as 72% of the participants for whom a full data set was obtained had neurological conditions that are known predisposing factors for reduced cough reflex sensitivity. Secondly, the finding of no association between a failed cough reflex test and history of recorded chest infection is not consistent with other studies. There is however an established body of research that indicates the causes of aspiration pneumonia are multifactorial and not solely dependent upon aspiration. The characteristics of participants and the implications of the findings are described. The potential use of cough reflex testing as a tool to screen against the risks of silent aspiration in relation to assessment of oro-pharyngeal dysphagia in this frail, elderly population is discussed.

The effect of viscoplastic deformation of the energetic material HMX on the mechanical, thermal, and ignition response of a two-phase (HMX and Estane) polymer bonded explosive (PBX) is analyzed. Specific attention is given to the high strain rate response of the material during the first passage of the stress wave when impacted by a constant velocity piston. PBX microstructures are subjected to impact loading from a constant velocity piston traveling at a rate of 50 to 200 m/s using a 2D cohesive finite element (CFEM) framework. The initial focus is to fully quantify the effect that viscoplastic HMX has on the behavior of a PBX composite, a thorough thermo-mechanical analysis is performed. The thermal response of the PBX specimens having viscoplastic HMX is characterized by a significant reduction in average heating, peak temperature rise, and the number or amount of material experiencing localized heating (hotspots). This reduction in heating is found to be accomplished through the mechanism of greatly reducing the density of fracture in the PBX. The second focus of this work is to evaluate the ignition sensitivity of these materials to determine the effect, if any, of the viscoplastic HMX. Viscoplastic HMX is shown to increase the minimum load duration, mean load duration, and range of critical load durations required for ignition. A 3D crystal plasticity framework is employed to quantify the potential heterogeneities in the stress and temperature field resulting from the inherent crystalline anisotropy of the HMX grains. It is found that in a densely packed HMX, the heterogeneities due to material anisotropy can contribute to increased stress gradients and localized temperature rise. Finally, the 2D framework is used to study a hypothetical composite containing HMX grains suspended in an aluminum matrix. This investigation focuses not on the feasibility of producing such a composite, but on determining whether such an arrangement would be advantageous from a mechanical and ignition sensitivity standpoint. Results indicate that this hypothetical composite would be considerably less sensitive than a similar PBX.

The primary purpose of this study was to assess Spanish-speaking patients’ satisfaction with their clinical pharmacists’ communication skills and demonstration of cultural sensitivity and to determine their association with Spanish-speaking patients’ socio-demographic, clinical, and communication factors, as well as pharmacists’ Spanish proficiency, cultural rapport, knowledge of complementary and alternative medicines, and race/ethnicity. A self-administered survey was designed to assess the study objectives, and a convenience sample of 93 adult (≥18 years) Spanish speakers with limited English proficiency was obtained from five CommUnityCare Health Centers in Austin, Texas. Satisfaction with communication skills and satisfaction with cultural sensitivity were measured as a 6-item construct and a 4-item construct, respectively, where Spanish-speaking patients rated their satisfaction using a 4-point Likert scale (1=extremely dissatisfied, 2=dissatisfied, 3=satisfied, 4=extremely satisfied). The participants’ mean age was 52.0±14.3 years, where respondents primarily were female (65.9%), utilized publicly-funded insurance (100%), received less than a high school education (86.9%), and reported a “fair” health status (64.8%). Spanish-speaking participants reported overall satisfaction with their clinical pharmacists’ communication skills (3.6±0.5) and demonstration of cultural sensitivity (3.6±0.5). Study participants also indicated items within the cultural rapport subscale were generally important characteristics to Spanish speakers (3.5±0.5). The cultural rapport subscale instructed participants to rate the importance of pharmacists’ specific characteristics (i.e., speaks Spanish, is Latino, provides written information in Spanish, is respectful, is kind, is friendly, and understandings the importance of family opinion in healthcare decisions) on a 4-point Likert scale, where 1=not at all important, 2=somewhat important, 3=important, 4=very important. Multiple linear regression analyses showed that cultural rapport was the only significant predictor of Spanish speakers’ satisfaction with their clinical pharmacists’ communication skills (p<0.01) and demonstration of cultural sensitivity (p<0.001). The results of this study may be instrumental in understanding the communication-related and cultural sensitivity-related needs of Spanish speakers in relation to pharmacists’ cultural rapport and may help initiate future initiatives and interventions involving pharmacists and Spanish-speaking patients with limited English proficiency. / text