Nursing Informatics FACT Sheet Essay Example | Topics and Well Written Essays - 500 words

Nursing Informatics FACT Sheet - Essay Example rmation required does not pertain only to technical knowledge, scientific development, quality control, clinical and administrative documentation, but also extends to the domains of human materials and resources and their availability for the delivery of the required nursing care (Marin, 2005). Information technology began to be used for processing the vast amount of information as a part of nursing care. Nursing informatics evolved from a nice-to-have accessory to nursing to the current status of an essential part of the nursing profession (Simpson, 2007). The two main catalysts in the development of nursing informatics have been the federal initiatives that have encouraged the use of electronic health records (EHRs) and the evidence that suggests clinical information systems improve processes that lead to better patient outcomes (An emerging giant: Nursing informatics). Safety is expedited by nursing informatics through continuous monitoring, seamless transition at points of transition between care settings, when the probability of mistakes are at the highest and appropriate information-sharing in clinical decision making. Nursing informatics addresses equity issues by facilitating access, like discharge information in the language of the patient and furthermore nursing informatics is blind to race, gender, age, economic status and physical appearance. The incompatibility of databases of institutions is a barrier to nursing informatics, and has virtually remained so because of the fear of legal repercussions or proprietary information falling into the hands of competitors. The fear of the nursing professionals that nursing informatics may lead to the nursing becoming a mere implementation of a set of standardized protocols and cause the profession becoming reductionistic (McBride, 2005). Information technology has transformed human development in many dramatic ways. Nursing informatics making use of information technology offers to lift nursing care of

Existing Home Automaton Systems Controlled via the internet Essay

Existing Home Automaton Systems Controlled via the internet - Essay Example The internet technology plays an important part in such automation, as these homes are also called ‘smart homes’ or ‘e-homes’. The innovative technology and software available currently for home automation systems ensures the safe and secure life, while providing mobile and email alerts about the happenings at home to the specific user who may be away to far-off locations. The ‘know and control kit’ as shown in the picture above puts the mobile phone in control of almost all gadgets in the home. Accordingly, it monitors the lighting devices, temperature of different systems such A/C or heating arrangements, locks and other safety devices, among others. The email notifications and mobile alerts provide reports regarding the function of each device. Although various manufactures supply such kits, the ‘Smart Things’ kit comprises of two multi-sensors, 2 sensors responsible for detecting the presence of anyone in the home, 2 additional motion sensors, Ethernet cable with power cord and the necessary outlet plug. The kit comes with all required batteries. The Ethernet cable ensures connection of the system kit to internet. As and when the kit detects some kind of motion by people, cars or pets, it sends an alert to the owner. It also sends early warnings on the detection of any leakage, presence of carbon monoxide or smoke in the home. There are no installation hassles or any kindly of monthly contract fees attached to this kit. While the user has complete control over the gadgets working at home, there is no remedy in the event of any accident or hazard that occurs due to malfunction of any device. The system cannot help much in such cases except sending immediate email or mobile alerts. The following image represents a ’Belk in’ Net Cam, which has Wife connectivity along with a camera that can

The Sublime and Architectural Theory Essay Example for Free

The Sublime and Architectural Theory Essay As Michael K. Hayes comments in Architecture Theory since 1968, a typology to emerge in the mid eighteenth century was a return of architecture to its natural origins, an example of the primitive shelter. This return and respect of nature was interestingly enough occurring across art, literature and landscape design simultaneously and internationally. It was as if people were warily eyeing the beginnings of the Industrial Revolution and entered into a love-hate tolerance of the machine age with the concepts of nature playing a reassuring role throughout these social and industrial evolutions. In reference to nature, the sublime countered many perceptions of the tamed environment through poetry, painting, national parks and urban design. The term sublime was first used to describe nature by British writers taking the Grand Tour of the Swiss Alps in the 17th and 18th centuries. The sublime was meant as an aesthetic quality in nature that was both beautiful and terrible, horrible and harmonious, appreciating the unexpected and dangerous forms found in nature that had been avoided in literature and art through the concepts of a more tamed and friendly environment. German philosopher Immanuel Kant reflects on the concept of boundaries between beauty and the sublime in his Critique of Judgment written in 1790. Distinguishing between the differences of beauty versus the sublime, beauty is connected with the form of the object, respecting the objects boundaries whereas the sublime is found in a formless object, boundless, unfamiliar and unexpected. The Romantic Period revealed a shift from the picturesque paintings of a controlled and safe landscape to paintings depicting the grotesque and beautiful as found in works such as Frederic Edwin Churchs Cotopaxi , oil on canvas 1826, an opposition to the classical ideals of perfection. The concept of sublime evolved through the machine age with a sense of self-forgetfulness, an awe-inspired feeling of well-being and security when faced with an object or place of superiority. It is a realization of unavoidable suffering that is to be accepted and that the difficulties in life will never be completely resolved. The terrible, beautiful and inescapable sublime resonated with the social instability found in the Modernist period. These two movements faced suffering brought about by the consequences of the Industrial Revolution. Inescapably crowded cities meant survival was dependent on the proximity to work. Leisure was a little afforded luxury. As John Mitchell much later on discusses in his book What Is to be Done about Illness and Health (1984), the attributes of a healthy life is a clean and safe environment, time for rest and recreation, a reasonable living standard, freedom from chronic worries, hope for the future, an adequate level of self-confidence and autonomy, and finally to have a worthwhile and fulfilling job. These well-being concepts were absent for many low and middle class families working in factories during the machine age and were threatened by social injustices of modern times. Throughout difficult times experienced in the Romantic period up through present day, the order and at times chaos of nature remained a constant influence in the perceptions of design and life. It would seem our societies distanced themselves from primitive nature through perfect geometry of the Classical movement, imitated nature through the rusticity of the hut and embraced the sublime during the Romantic period. It was as if a return to the most basic and natural state gave a sense of control over the uncontrollable, the forest/city was to be tamed, brought into rational order by means of the gardeners art; the ideal city of the late eighteenth century was thereby imaged on the garden The acknowledgment and connection of the roles of nature throughout our design history offered an outlying and abstract zeitgeist: a continuing spirit of admiration, reverence and fearful respect of our natural surroundings as they are impacted by our industrial and socially changing cities.

Deposits in Thermal Power Plant Condensers

Deposits in Thermal Power Plant Condensers Abstract: Unexpected fouling in condensers has always been one of the main operational concerns in thermal power plants. This paper describes an approach to predict fouling deposits in thermal power plant condensers by means of support vector machines (SVMs). The periodic fouling formation process and residual fouling phenomenon are analyzed. To improve the generalization performance of SVMs, an improved differential evolution algorithm is introduced to optimize the SVMs parameters. The prediction model based on optimized SVMs is used in a case study of 300MW thermal power station. The experiment result shows that the proposed approach has more accurate prediction results and better dynamic self-adaptive ability to the condenser operating conditions change than asymptotic model and T-S fuzzy model. Keywords: Fouling prediction; Condensers; Support vector machines; Differential evolution 1. Introduction Condenser is one of key equipments in thermal power plant thermodynamic cycle, and its thermal performance directly impacts the economic and safe operation of the overall plant [1]. Fouling of steam condenser tubes is one of the most important factors affecting their thermal performance, which reduces effectiveness and heat transfer capability with time [2, 3]. It is found that the maximum decrease in effectiveness due to fouling is about 55 and 78% for the evaporative coolers and condensers, respectively [2]. As a consequence, the formation of fouling in condenser of thermal power plants has special economic significance [4-6]. Furthermore, it represents the concerns of modem society in respect of conservation of limited resources, for the environment and the natural world, and for the improvement of industrial working conditions [6, 7]. The fouling of heat exchangers is a wide ranging topic coveting many aspects of technology, the designing and operating of condenser must contemplate and estimate the fouling resistance to the heat transfer. The knowledge of the progression and mechanisms of formation of fouling will allow a design of * Manuscript an appropriate fouling mitigation strategy such as optimal cleaning schedule to be made. The most common used models for fouling estimation are the thermal resistance method and heat transfer coefficient method [6-10]. However, the residual fouling of periodic fouling deposition process and the dynamic changes of heat exchanger operating condition are not considered in these models. Consequently, the estimation error of those methods is very large. Artificial Neural Networks (ANNs) are capable of efficiently dealing with many industrial problems that cannot be handled with the same accuracy by other techniques. To eliminate most of the difficulties of traditional methods, ANNs are used to estimate and control the fouling of heat exchanger in recent years. Prieto et al [11] presented a model that uses non-fully connected feedforward artificial neural networks for the forecasting of a seawater-refrigerated power plant condenser performance. Radhakrishnan et al [12] developed a neural network based fouling model using historical plant operating data. Teruela et al [13] described a systematic approach to predict ash deposits in coal-fired boilers by means of artificial neural networks. To minimize the boiler energy and efficiency losses, Romeo and Gareta illustrated a hybrid system that combines neural networks and fuzzy logic expert systems to control boiler fouling and optimize boiler performance in [14]. Fan and Wang proposed diagonal recurrent neural network [15] and multiple RBF neural network [16] based models for measuring fouling in thermal power plant condenser. Although the technique of ANNs is able to estimate the fouling evolution of heat exchanger with satisfaction, there are some problems. The selection of structures and types of ANNs dependents on experience greatly, and the training of ANNs are based on empirical risk minimization (ERM) principle [18], which aims at minimizing the training errors. ANNs therefore face some disadvantages such as over-fitting, local optimal and bad generalization ability. Support vector machines (SVMs) are a new machine learning method deriving from statistical learning theory [18, 19]. Since later 1990s, SVMs are becoming more and more popular and have been successfully applied to many areas such as handwritten digit recognition, speaker identification, function approximation, chaotic time series forecasting, nonlinear control and so on [20-24]. Established on the theory of structural risk minimization (SRM) [19] principle, compared with ANNs, SVMs have some distinct advantages such as globally optimal, small sample-size, good generalization ability and resistant to the over-fitting problem [18-20]. In this paper, the use of SVMs model is developed for the predicting of a thermal power plant condenser. The prediction model was used in a case study of 300MW thermal power station. The experiment result shows that the prediction model based on SVMs is more precise than thermal resistance model and other methods, such as T-S fuzzy model [17]. Moreover, to improve the generalization performance of SVMs, an improved differential evolution algorithm is introduced to optimize the parameters of SVMs. 2. Periodic fouling process in condenser The accumulation of unwanted deposits on the surfaces of heat exchangers is usually referred to as fouling. In thermal power station condensers, fouling is mainly formed inside the condenser tubes, reducing heat transfer between the hot fluid (steam that condenses in the external surface of the tubes) and the cold water flowing through the tubes. The presence of the fouling represents a resistance to the transfer of heat and therefore reduces the efficiency of the condenser. In order to maintain or restore efficiency it is often necessary to clean condensers. The Taprogge system has found wide application in the power industry for the maintenance of condenser efficiency, which is one of on-line cleaning systems [6]. When the fouling accumulation in condensers reached a threshold, the sponge rubber balls cleaning system is activated, slightly oversized sponge rubber balls continuously passed through the tubes of the condenser by the water flow, and the fouling in the condenser is reduced or eliminated. The progresses of fouling accumulating and cleaning continue alternatively with time. Therefore, the fouling evolution in power plant condensers is periodic. However, the sponge rubber ball system is only effective of preventing the accumulation of waterborne mud, biofilm formation, scale and corrosion product deposition [6]. As for some of inorganic materials strongly attached on the inside surface of tubes, e.g. calcium and magnesium salts, can not be effectively reduced by this technique. As a result, at the end of every sponge rubber ball cleaning period, there still exist a lot of residual fouling in the condensers, and the residual fouling will be accumulated continuously with the time. Where, the fouling can be cleaned by the Taprogge system is called soft fouling, and those can not be cleaned residual fouling is called hard fouling. When the residual fouling accumulated to some degree, the cleaning techniques that can eliminate them, such as chemistry cleaning method, should be used. Generally, the foul degree of heat exchanger is expressed as fouling thermal resistance, defined as the difference between rates of deposition and removal [6]. In this paper, the corresponding fouling thermal resistance of soft fouling and hard fouling expressed as Rfs and Rfh, respectively. Then, the condenser fouling thermal resistance Rf in any time is the sum of soft fouling thermal resistance and hard fouling thermal resistance, expressed as Eq. (1). ( ) ( ) ( ) ( ) ( ) ( ) 0 0 0 R t R t R t R t R t t R t t f fs fh f fs fh ? ? ? ? ? ? ? (1) where ( ) 0 R t f is the initial fouling. Fig. 1 periodic fouling evolution in power plant condensers Fig. 1 demonstrates the periodic evolution process of fouling in power plant condensers. In fact, the evolution process of fouling in a condenser is very complex, which is related to a great number of variables, such as condenser pressure, cooling water hardness, the velocity of the circulating water and the corresponding inlet and outlet temperatures, the non-condensing gases present in the condenser, and so on. The Rfs(t) and Rfh(t) expressed a very complex physical and chemical process, their accurate mathematic models are very hard to be obtained. Hence, measurement and prediction of fouling development is a very difficult task. Since the fouling evolution process is a very complex nonlinear dynamic system, the traditional techniques based on mathematic analysis, i.e. asymptotic fouling model, are not efficient to describe it [11]. SVMs, as a small sample method to deal with the highly nonlinear classification and regression problems based on statistic learning theory, is expected to be able to reproduce the nonlinear behavior of the system. 3. SVMs regression and parameters 3.1 SVMs regression SVMs are a group of supervised learning methods that can be applied to classification or regression. SVMs represent an extension to nonlinear models of the generalized portrait algorithm developed by Vladimir Vapnik [18]. The SVMs algorithm is based on the statistical learning theory and the Vapnik-Chervonenkis (VC) dimension introduced by Vladimir Vapnik and Alexey Chervonenkis [19]. Here, the SVMs regression is applied to forecast the fouling in power plant condensers. Let the given training data sets represented as ?( , ), ( , ), , ( , )? 1 1 2 2 n n D ? x y x y ? ? ? x y , where d i x ? R is an input vector, y R i ? is its corresponding desired output, and n is the number of training data. In SVMs, the original input space is mapped into a high dimensional space called feature space by a nonlinear mapping x ? g(x) . Let f (x) be the SVM outputs corresponding to input vector x. In the feature space, a linear function is constructed: f (x) ? wT g(x) ? b (2) where w is a coefficient vector, b is a threshold. The learning of SVMs can be obtained by minimization of the empirical risk on the training data. Where, ? -intensive loss function is used to minimize the empirical risk. The loss function is defined as L? (x, y, f ) ? y ? f (x) ? max(0, y ? f (x) ) e (3) where ? is a positive parameter to allow approximation errors smaller than ? , the empirical risk is ? n i emp i i L x y f n R w 1 ( , , ) 1 ( ) ? (4) Besides using ? -intensive loss, SVMs tries to reduce model complexity by minimizing 2 w , which can be described by slack variables. Introduce variables i ? and i , then SVMs regression is obtained as the following optimization problem: min ? ? ? ? n i i i w C 1 2 ( ? ) 2 1 ? ? (5) s.t. i i i y ? f (x ) ? ? , i i i f (x ) ? y ? ? , i ? , i ? 0 where C is a positive constant to be regulated. By using the Lagrange multiplier method [18], the minimization of (5) becomes the problem of maximizing the following dual optimization problem max ( ? )( ? ) ( , ) 2 1 ( ? ) ( ? ) 1 1 , 1 j j i j n i j i i n i i i i i n i i ? y ? ? ? ? ? ? ? ? ? K x x ? ? ? (6) s.t. ( ? ) 0 1 ? ? ? ? n i i i ? ? ,C = i , i ? =0 where i and i ? are Lagrange multipliers, and kernel ( , ) i j K x x is a symmetric function which is equivalent to the dot product in the feature space. The kernel ( , ) i j K x x is defined as the following. ( , ) ( ) ( ) j T i j i K x x ? g x g x (7) There are some kernels, i.e. polynomial kernel K(x, y) ? (x ? y ? 1) d and hyperbolic tangent kernel ( , ) tanh( ( ) ) 1 2 K x y ? c x ? y ? c can be used. Where the Gaussian function is used as the kernel. ) 2 ( , ) exp( 2 2 ? x y K x y ? ? ? (8) Replacing i i i ? ? ? ? ? ? and relation 0 ? ? ? ? i , then the optimization of (6) is rewritten as max ( , ) 2 1 1 1 , 1 j i j n i j i n i i i n i i ? y ? ? ? ? ? K X X ? ? ? ? ? (9) s.t. 0 1 ? ? ? n i i ? ,C ? i ? ? ? C The learning results for training data set D can be derived from equation (9). Note that only some of coefficients i ? are not zeros and the corresponding vectors x are called support vectors (SV). That is, only those vectors whose corresponding coefficients i i are not zero are SV. Then the regression function is expressed as equation (10). f x K x x b i j p i i i ? ? ? ( ) ( ? ) ( , ) 1 ? ? (10) It should be noted that p is the numbers of SV, and the constant b is expressed as ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? p i i i i i p i i i i i b y K x x y K x x 1 1 min ( ? ) ( , ) max ( ? ) ( , ) 2 1 ? ? ? ? (11) 3.2 SVM parameters The quality of SVMs models strongly depends on a proper setting of parameters and SVMs approximation performance is sensitive to parameters [25, 26]. Parameters to be regulated include hyper-parameters C, ? and kernel parameter? , if the Gaussian kernel is used [25]. The values of C, ? and ? are relate to the actual object model and there are not fixed for different data set. So the problem of parameter selection is complicated. The values of parameter C, ? and ? affect model complexity in a different way. The parameter C determines the trade-off between model complexity and the tolerance degree of deviations larger than ? . The parameter? controls the width of the ? -insensitive zone and can affect the numbers of SV in optimization problem. The kernel parameter? determines the kernel width and relates to the input range of the training data set. Here, parameters selection is regarded as compound optimization problem and an improved differential evolution algorithm is proposed to select suitable parameters value. 4. Improved Differential Evolution Differential evolution (DE) algorithm is a simple but powerful population-based stochastic search technique for solving global optimization problems [27]. DE has three operations: mutation, crossover and selection. The crucial idea behind DE is a scheme for generating trial vectors. Mutation and crossover are used to generate trial vectors, and selection then determines which of the vectors will survive into the next generation. The original DE algorithm is described in the following briefly. 4.1 Basic differential evolution Let S ? Rn be the search space of the problem under consideration. Then, the DE algorithm utilizes NP, n-dimensional vectors X x x xt S i NP in t i t i t i ( , , , ) , 1,2, , 1 2 ? ? ? ? ? as a population for each generation of the algorithm. t denotes one generation. The initial population is generated randomly and should cover the whole parameter space. In each population, two operators, namely mutation and crossover, are applied on each individual to yield a trial vector for each target vector. Then, a selection phase takes place to determine the trial vector enters the population of the next generation or not. For each target individual t i X , a mutant vector { 1 , , 1} 1 ?1 ? ? t ? n t t i V v ? v is determined by the following equation. ( ) 1 2 3 1 t r t r t r t i V ? ? X ? F ? X ? X (12) Where F ? 0 is a real parameter, called mutation constant, which controls the amplification of the difference vector ( ) 2 3 t r t r X ? X to avoid search stagnation. According to Storn and Price [27], the F is set in (0, 2]. 1 r , 2 r , 3 r are indexes, randomly selected from the set {1,2,, NP} . Note that indexes must be different from each other and from the running index i so that NP must be a least four. Following the mutation phase, the crossover (recombination) operator is applied on the population. For each mutant vector t ?1 i V , a trial vector { 1 , , 1} 1 ?1 ? ? t ? n t t i U u ? u is generated, using the following scheme. ? ? ? ? ? ? ? ? , ( ) ( ) 1 , ( ) ( ) 1 x rand j CR and j randn i v rand j CR or j randn i u t ij t t ij ij (13) Where j=1, 2, ?, n. rand( j) is the jth evaluation of a uniform random number generator within [0, 1]. CR is a crossover probability constant in the range [0, 1], which has to be determined previously by the user. randn(i) ? (1,2,,n) is a randomly chosen index which ensures that t ?1 i U gets at least one element from t ?1 i V . Otherwise, no new parent vector would be produced and the population would not alter. To decide whether the trial vector t ?1 i U should be a member of the population comprising the next generation, it is compared to the corresponding target vector t i X , and the greedy selection strategy is adopted in DE. The selection operator is as following. ? ? ? ? ? ? , otherwise 1 , ( 1 ) ( ) 1 t i t i t i t t i i X U f U f X X . (14) 4.2 Modification of Mutation From the mutation Eq. (12) we can see that in the original DE three vectors are chosen at random for mutation and the base vector is then chosen at random within the three, which has an exploratory effect but it slows down the convergence of DE. In order to accelerate the convergence speed, a modified mutation scheme is adopted. The randomly selected three vectors for mutation are sorted by ascending in terms of the fitness function value. The tournament best vector is t tb x , the better vector is t tm x and the worst vector is t tw x . For speeding up convergence, the base vector in the mutation equation should select t tb x , and the direction of difference vector should direct to t tm x , that is to choose ( t ) tw t tm x ? x as the difference vector. Then the new modified mutation strategy is as following Eq. (15). 1 ( t ) tw t tm t tb t i v ? ? x ? F ? x ? x . (15) After such modification, this process explores the region around each t tb x in the direction of ( t ) tw t tm x ? x for each mutated point. The mutation operator is not random search any more, but a determinate search. However, the vectors for mutation are selected randomly in the population space, so in the whole evolutionary process it is still a random search, which can ensure the global optimization performance of the algorithm [28]. 5 Optimization procedures of IDE for SVMs 5.1 Objective function The objective of SVMs parameters optimization is to minimize deviations between the outputs of training data and the outputs of SVMs. Where, the mean square error (MSE) is used as the performance criterion. 2 1 1 ( ( , ))2 1 ? ? ? ? ? ? ? ? K k k k y f x w K Obj (16) Where K is the number of training data, k y is the output of the kth training data, and f (x ,w) k is the output of SVMs correspond to input k x . Then the objective of the IDE is to search optimal parameter C, ? and ? to minimize Obj: min F(C,? ,? ) ? minObj (17) Generally, the search range of these parameters is C? [1, 1000], ? ? (0, 1], ? ? (0, 0.5]. For special problem, the search range is changeable. 5.2 Optimization procedures The searching procedures of the improved differential evolution (IDE) for optimization of SVMs parameters are shown as below. Step1: Input the training data and test data, select the Gaussian kernel function. Step2: Specify the number of population NP, the difference vector scale factor F, the crossover probability constant CR, and the maximum number of generations T. Initialize randomly the individuals, i.e. C, ? and ? , of the population and the trial vector in the given searching space. Set the current generation t=0. Step3: Use each individual as the control parameters of SVMs, train the SVMs using training data. Step4: Calculate the fitness value of each individual in the population using the objective function given by equation (17). Step5: Compare each individual?s fitness value and get the best fitness and best individual. Step6: Generate a mutant vector according to equation (15) for each individual. Step7: According to equation (13), do the crossover operation and yield a trial vector. Step8: Execute the selection operation in terms of equation (14) and generate a new population. Step9: t=t+1, return to Step3 until to the maximum number of generations. 6 Case study 6.1 Fouling prediction scheme The formation and development of fouling in condensers is influenced not only by cooling water hardness and turbidity but also by working conditions of condensers, such as velocity of the cooling water and the corresponding inlet and outlet temperatures, the saturation temperature of steam under entrance pressure of condenser, the non-condensing gases present in the condenser, and so on. According to the previous analysis of periodic fouling process of power plant condensers, the fouling can be classified as soft fouling and hard fouling. Therefore, two SVMs models are developed to forecast thermal resistance of soft and hard fouling, respectively. Then, the whole prediction fouling thermal resistance ( f R? ) in condenser is the sum of output of soft fouling prediction model ( fs R? ) and output of hard fouling prediction model ( fh R? ). Generally, the evolution of soft fouling is determined by the velocity (v), turbidity (d), inlet (Ti) and outlet temperatures (To) of cooling water, saturation temperature of steam under entrance pressure of condenser (Ts), and prediction time range (Tp) (the running time in a sponge rubber ball cleaning period). Therefore, these variables are chosen as inputs of the soft fouling thermal resistance predictive model. As for hard fouling of the class of calcium and magnesium salts, it is related to the residual fouling at the beginning and the end of previous sponge rubber ball cleaning period (corresponding thermal resistance is Rfb,n-1, Rfe,n-1, respectively), hardness of cooling water (s), saturation temperature of steam under entrance pressure of condenser (Ts), and the accumulating running time of condenser (Ta). Hence, those variables are chosen as the inputs of hard fouling thermal resistance prediction model. The soft and hard fouling prediction model based on SVMs illustrated in Fig. 2 and Fig. 3, respectively. ( , ) 1 K x x ( , ) 2 K x x ( , ) p?1 K x x ( , ) p K x x 1 1 2 2 1 1 ? ? ? ? p p ? ? p p ( , ) 1 K x x ( , ) 2 K x x ( , ) p?1 K x x ( , ) p K x x S b Ts 1 1 2 2 1 1 ? ? ? ? p p ? ? p p Ta Rfh Rfb,n-1 R fe,n-1 ? ^ Fig. 2 Soft fouling prediction model Fig. 3 Hard fouling prediction model The parameters of the two prediction models are optimized by the IDE algorithm. Fig. 4 illustrates the fouling prediction model using SVMs optimized by IDE. ? Fig. 4 fouling prediction model based on SVMs optimized by IDE 6.2 Experiment results In this section, experiments on N-3500-2 condenser (300MW) in Xiangtan thermal power plant are carried out to prove the effectiveness of the proposed approach. The cooling water of this plant is river water that pumped from the Xiangjiang river. The Taprogge systems are installed in the plant to on-line clean the condensers. At present, the condenser is cleaned every two days using the Taprogge system, and every cleaning time is about 6 hours. Obviously, the fitted cleaning period is not optimal, because the fouling accumulating process is dynamic changing with the operating conditions changing. The experiment system consists of sensors for operating condition parameters measuring, data acquisition system, PC-type computer, etc. A set of 1362 real-time running data in different operating conditions in 84 cleaning periods is collected to train and optimize the SVMs model for fouling prediction, another set of 300 data is chosen for model verification. The proposed IDE is used to optimize the SVMs parameters. The control parameters of IDE are the following. The number of population is 30, the crossover probability constant CR is 0.5, the mutation factor F is 0.5, and the maximum number of generations is 100. The selection of above parameters is based on the literature [27] and [28]. After application of IDE, the optimal SVMs parameters of soft fouling prediction model are C=848, ? =0.513, ? =0.0117, the optimal SVMs parameters of hard fouling prediction model are C=509, ? =0.732, ? =0.0075. The velocity, turbidity, and inlet temperature of cooling water is different in summer and winter, the evolution of fouling in condensers is also different in the two seasons. In the experiments, four sponge rubber ball cleaning periods in different seasons are investigated. Among them, three periods, i.e. the first, 18th and 40th period, are in summer, and the other period is in winter. The hardness and turbidity of cooling water is 56mg/L and 17mg/L in summer, and is 56mg/L and 29mg/L in winter. To demonstrate the effectiveness of the proposed approach, the comparison between the SVMs model, T-S fuzzy logic model [17] and asymptotic model is considered. The asymptotic model is obtained by probability analysis method, and the corresponding expression is the following [17]. ( ) ? 41.3?[1? ?(t ?1.204) /14.57 ] f R t e (17) Table 1 and Table 2 show the fouling thermal resistance prediction results of the above three models in the first and the 18th cleaning periods, respectively. From the Table 1 and Table 2, we can see that compared with tradition asymptotic model and T-S fuzzy logic model, the SVMs based prediction model has higher prediction precision. Fig. 5 and Fig. 6 show the predicted fouling thermal resistance evolution based on the optimized SVMs model and asymptotic model. Fig.6 clearly shows that the asymptotic model is not able to forecast the fouling evolution process at the beginning stage of the 18th cleaning period, the reason is that the residual fouling in the periodic fouling formation process is not considered in the asymptotic models. Table 1 fouling thermal resistance prediction results in the first cleaning period Running time Tpa (hour) Operating conditions Measuring values Rf (K.m2/kW) Prediction values (K.m2/kW) Relative error v(m/s) Ti(?) Ts(?) SVMs model T-S model Asymptotic model SVMs model T-S model Asymptotic model 0 2.0 19.1 33.2 0.0258 0.0260 0.0258 0.62 0 5 2.0 18.5 33.3 0.0995 0.0992 0.1018 0.0947 0.26 2.31 4.82 10 2.0 15.6 31.9 0.2028 0.2037 0.2007 0.1872 0.45 1.04 7.69 15 2.0 14.3 31.6 0.2501 0.2494 0.2411 0.2528 0.27 3.6 1.08 20 2.0 15.5 33.5 0.2865 0.2864 0.2830 0.2993 0.03 1.22 4.48 25 2.0 15.5 34.0 0.3174 0.3172 0.3123 0.3323 0.06 1.61 4.69 30 2.0 16.1 34.8 0.3420 0.3393 0.3321 0.3558 0.79 2.89 4.04 35 2.0 14.4 34.6 0.3567 0.3562 0.3497 0.3724 0.14 1.96 4.40 40 2.0 14.2 34.9 0.3722 0.3736 0.3600 0.3842 0.37 3.28 3.22 Table 2 fouling thermal resistance prediction results of the 18th cleaning period Running time Ta (hour) Operating conditions Measuring values Rf (K.m2/kW) Prediction values (K.m2/kW) Relative error v(m/s) Ti(?) Ts(?) SVMs model T-S model Asymptotic model SVMs model T-S model Asymptotic model 632 2.0 14.0 29.8 0.0774 0.0791 0.074 2.26 0 637 2.0 14.2 30.9 0.1772 0.1773 0.1850 0.0947 0.06 4.40 46.56 642 2.0 12.5 30.4 0.2474 0.2479 0.2438 0.1872 0.21 1.46 24.33 647 2.0 11.9 30.4 0.2898 0.2908 0.2955 0.2528 0.36 1.97 12.77 652 2.0 10.6 30.1 0.3230 0.3222 0.3354 0.2993 0.25 3.84 7.34 657 2.0 11.4 31.5 0.3447 0.3437 0.3525 0.3323 0.28 2.26 3.60 662 2.0 10.2 31.2 0.3655 0.3652 0.3648 0.3558 0.08 0.19 2.65 667 2.0 10.7 32.0 0.3831 0.3815 0.3767 0.3724 0.42 1.67 2.79 672 2.0 11.8 33.5 0.3985 0.3978 0.3912 0.3842 0.18 1.83 3.59 To eliminate the influence of residual fouling and improve the prediction precision, an improved asymptotic models are i

Fishing and Relaxing at the Lake Essay -- Descriptive Essay, Descriptiv

When people discuss Naples and describe the sights, they usually just mention the beach, Fifth Avenue, and the swamp. To the people who live here and experience the unseen places, there is much more. There is one place I particularly like. That is Horseshoe Lake and it is a lake where some of the greatest fishing experiences occur that include catching large fish and relaxing with a friend. There is an indescribable felling that occurs at Horseshoe Lake. It is a feeling of mild comfort and much needed relaxation mixed with exhilaration. The comfort comes from the light breeze, which quickly comes and goes while you are fishing. It is this breeze that allows your fishing line to float one way or another, thus doing the luring for you. The tall oak trees provide shade that prevents you f... Fishing and Relaxing at the Lake Essay -- Descriptive Essay, Descriptiv When people discuss Naples and describe the sights, they usually just mention the beach, Fifth Avenue, and the swamp. To the people who live here and experience the unseen places, there is much more. There is one place I particularly like. That is Horseshoe Lake and it is a lake where some of the greatest fishing experiences occur that include catching large fish and relaxing with a friend. There is an indescribable felling that occurs at Horseshoe Lake. It is a feeling of mild comfort and much needed relaxation mixed with exhilaration. The comfort comes from the light breeze, which quickly comes and goes while you are fishing. It is this breeze that allows your fishing line to float one way or another, thus doing the luring for you. The tall oak trees provide shade that prevents you f...

Virginia Woolf :: essays research papers

My Thought on Virginia Woolf There are many authors who have the ability to be one of the greatest writers of all time, but to my knowledge of books I believe the majority I read are excellent. Virginia Woolf to many, is a prominent writer. I wish I could say the same as well. I can not judge her writing for I have just began to study such remarkable essayists. I can state this, her ability to capture ones mind is unprecedented. She does it so well, it is almost natural. It is clear in all her writings she has the readers attention in full, while she explains facts in great detail. Even though she had a traumatic childhood, having manic-depressive illness, she is a brilliant writer. In her essay, Thoughts on Peace in an Air Raid, she says, "We are both prisoners tonight—he boxed up in his machine with a gun handy; we lying in the dark with a gas-mask handy. If we were free we should be out in the open, dancing, at the play, or sitting at the window talking together." She was told they were free, but they were still locked in their houses occupied with fear, every hour the thought of death progressing in their head. This is an example of great imagery she uses in explaining an event. In the same essay she has many more examples of imagery, more than can be expressed. I am beginning to believe she is as remarkable as people say. The more and more I read her writing, the more I began to believe this. She grabs my attention faster and more intensely than any other essayist. Many people believe her writing style is hard to comprehend, which I can understand why. This allows her examples of imagery to go far beyond other great essayists. Her vocabulary is exceedingly more advanced and at a higher pace than of my own. It gives me the opportunity to learn such vocabulary and to use in oral communication. This paper has given me the chance to learn more about

‘I Spy’ by Graham Green Essay

1. Setting We can say exactly that all the described events take place in England, particularly, they happen in the Eastern part of England. The father of the Charlie Stowe, of the main character, was supposed to be in Norwich that night we know about it directly from the text (â€Å"Tonight he said he would be in Norwich†¦Ã¢â‚¬ ). Norwich is the regional administrative center and country town of Norfolk. Besides, one sentence tells us that place isn’t far from water (â€Å"the wind blew from the sea, and Charlie Stowe could hear†¦the beating of the waves†) and now we can say precisely that it is just by the North Sea that washes the shores of England. The events happen at night in the house where the family of Charlie Stowe lives, particularly, at the tobacconist’s shop that was kept by his father. It is said in second paragraph of the text. It was time of the World War I. The following clues help us to understand it: â€Å"enemy airships†, â€Å"Zeppelin†, which was a type of airship pioneered in Germany in the beginning of XX century and used widely to bombard England during the period of the World War I, such features of fashion of that time as â€Å"bowler hats† and â€Å"belted mackintoshes†, brands of cigarettes that Charlie’s father was selling (Gold Flake, Players, Woodbines were wide-spread that time). Moreover, in the text â€Å"Huns† were mentioned. It is an Offensive slang used as a disparaging term for a German, especially, a German soldier in World War I. 2. Plot Charlie Stowe, the main character, gets mocked by his schoolmates at the County school, because he has never tried a cigarette at his 12 in his life. One night he decides to have a smoke and sneaks to the tobacconist’s shop run by his father whom he doesn’t love. His mother is sleeping and his father isn’t supposed to be at home. But when Charlie finds himself at the shop he hears footfalls in the street. It is his father and two strangers. They have a brief chat and then leave the shop. Charlie goes upstairs, he is  very frightened but the attitude to his father changed. We can observe the structure of the text. The expositions of the story include the description of that night and Charlie’s family. The climax happens when his father and two strangers have a talk, particularly, on the phrase â€Å"Well†¦there’s nothing to be done about it, and I may as well have my smokes†. It was said by Charlie’s father and it is the most important moment of the story, because here we see strong likeness between the father and the boy: during boy’s attempt to â€Å"commit† a crime (to smoke a cigarette) he tries to encourage himself with â€Å"grown-up† and childish exhortations and what is interesting Charlie uses the same words to encourage himself in the forth paragraph and his father saying the phrase above also tries to encourage himself. Maybe he committed a crime being a spy because two strangers seem to be policemen or secret-service agents and the father tells them that â€Å"The wife will sell out†, talking about his tobacco business. Also unusual behavior says to us this fact: his voice has an unfamiliar to Charlie note and he holds his stiff collar. It indicates that he is very nervous and also his voice is â€Å"dry as a biscuit†. When Mr. Stowe wants to get his coat one of the strangers would like to go with him not letting him be alone. It seems that Charlie’s father is arrested. We can do this guess-work and find one more likeness between Charlie and his father: committing a crime. The resolution happens when the father and two strangers leave the shop, frightened Charlie goes upstairs and understands how much he loves his father. 3. Elements of plot This short story abounds with conflicts. At the beginning we know that Charlie has never tried a cigarette in his life and gets mocked by boys at school. It is the first conflict: the boy versus schoolmates, his peers, and it can be considered as the conflict of a man and society. The second one happens between Charlie and his father which he doesn’t like at the beginning. That’s why we can call Charlie protagonist, and his father – antagonist. We see the third direct conflict between Charlie’s father and two men. The mystery is hidden in their talk. And finally there is the forth conflict – the inner conflict of the boy who at his 12 wants to be an adult trying to have a smoke against the fear and prohibition and maybe commit the hardest crime of his age. 4. The theme/message The main idea of the story is a generation gap, the relations of Fathers and Sons. It is still relevant nowdays, parents should pay attention to the way of upbringing of their children. Lie, mistakes, carelessness and insufficiency of attention of parents would reflect on the behavior and personality of their children. The other idea is found in the conflict of Charlie and his peers. Sometimes to be respected in society we try to do what it dictates us. Children are exposed to the society influence easier, because they haven’t enough experience in life and their world outlook isn’t finally formed. The minor idea of this story is to show how our attitude can be wrong judging people around us, even our closest people, our relatives, and it may happen that it would be too late to say the warmest words to the dearest people and even living with our family we cannot notice the likeness or common things that connect us. We should be more attentive, more sensitive and sympathe tic and keep in mind that our children would somehow look like us. 5. Narration The type of narration is entrusted narrative. The story is told from the point of view of Charlie who uses the 3d person. It is an omniscient point of view. 6. Fiction elements/Structure The author entrusts the main character telling us the story. That’s why we can consider this story as an interior monologue. In the text we also encounter with protagonist’s inner dialog and the dialog between the antagonist and two strangers. It is a kind of blend of dialogs and monologue speech. It makes us imagine more vivid the situation and keeps us in tension. On the whole the structure of the text is chronological. Only the second paragraph is a little bit detached telling about Charlie’s family and his conflicts with boys from County school and his father. The story starts at the beginning and moves through time. 7. Style: level of complexity The structure of the text is very complex. There are a lot of commas, semi-colons and conjunctions. Also inclusion of the dialogs tells us about it. Equally with conjunctions such stylistic device as asyndeton is used many times in the text. Abrupt changes from long sentences to short ones and vice versa create a very strong effect of tension and suspense for they serve to arrange a nervous, ragged rhythm of the utterances. Also very short sentences produce a very strong emphatic impact. In the text we can notice loose, periodic and balanced sentences, it also says to us about very sophisticated structure of the text. We can encounter with apokoinu constructions â€Å"light burning†, â€Å"chin cupped in his hands†, â€Å"made him grab†, â€Å"sound of several men walking rapidly†, â€Å"†¦quick steps going away†, â€Å"†¦don’t’ let me be caught†. Apokoinu constructions are mostly used in the entrusted narrative. We ca n find also a lot of attachments, particularly, in dialogs (In speech of Charlie’s father), in the 5th paragraph (â€Å"†¦belted mackintoshes. They were strangers.†) The story abounds with literary words as it should be with the fiction. The author chose very colored words such as â€Å"banks of cloud†, â€Å"thin haze†, â€Å"stale smoke†, â€Å"boisterous†, â€Å"spasmodically†, â€Å"wraith†, â€Å"despair†, â€Å"lurked†, â€Å"held his breath†, â€Å"dare not to move†, â€Å"cowered† and etc. Dialogs are very colloquial, a lot of phrasal verbs are used (â€Å"sell out†, â€Å"to be off†, â€Å"put off†). What is very interesting in the text you can find some proverbs. Firstly, in the inner dialog of the boy (â€Å"May as well be hung for a sheep†, but it isn’t full, we can consider it as ellipsis) and secondly in the speech of Charlie’s father, not finished as well (â€Å"while there’s life†¦Ã¢â‚¬ , the continuation is â€Å"†¦there is hope†) and â€Å"a stitch in time† (also isn’t fin ished (continuation: â€Å"†¦saves nine†)), and wrenched proverb â€Å"Never do today what you can put off till tomorrow†. The latter is said with a touch of sarcasm. The usage of proverbs also is a common characteristic of the boy and his father. Elipsises reflect the natural omissions characterizing oral colloquial speech and the main function is to achieve the authenticity and plausibility of fictious dialog. When Charlie wants to encourage himself he says â€Å"Cowardy, cowardy custard†. It is a very interesting expression and is a taunt used by schoolchildren in the UK equivalent to â€Å"scaredy cat† in the U.S. By the way it is one more clue in support of the story happens in England. It means one who is excessively fearful. The word â€Å"Cowardy† is made with the help of diminutive  suffix –y, it underlines additional emotional coloring. The descriptions in the story are very detailed, author uses a lot of epithets (â€Å"boisterous†, â€Å"wraith†, â€Å"stale†, â€Å"noisy† and etc.). Figurative language is traced through the whole story. We can find metaphors such as â€Å"a searchlight†¦probing the dark deep spaces†¦Ã¢â‚¬  (we can also call it personification), â€Å"surprise and awe kept him†¦awake†, â€Å"the tobacconist’s shop†¦drew him on†, personification â€Å"†¦familiar photograph had stepped from the frame to reproach him with neglect†, similis such as â€Å"dry as biscuit†, â€Å"but his father’s affection and dislike were as indefinite as his movements†, disguised simili can be find in the mentioned phrase â€Å"Cowardy, cowardy custard†, periphrasis â€Å"the packets were piled twelve deep below† instead of â€Å"there were 12 packets of cigarettes† which conveys a purely individual perception of the described object, onomatopoeia â€Å"when they cracked† if we talk about stairs and emphasizes the reigning tension. Talking again about the phrase â€Å"Cowardy, cowardy custard† author from Charlie’s point of view describes it as childish exhortation. We can notice one more morphological device, suffix –ish. It deepens the coloring of the utterance expressing some contempt. In the second and in the last paragraphs we can find antithesises: the first one in the description of Charlie’s father who is opposed to his mother and the second one â€Å"†¦while his mother was boisterous and kindly, his father was very like himself doing things in the dark which frightened him’. Through this device we can understand the real attitude of Charlie to his parents. In the last antithesis there is also a comparison of the boy and his father. In the text we can also find â€Å"don’t you† constructions, the first of which was used to emphasize sarcasm of one of the strangers (â€Å"Don’t you want to speak to your wife?† and another one is an inve rsion â€Å"Don’t you worry to much†. Mr. Stowe used it to produce sarcasm as well. Talking about dialogs we can underline its colloquialism also by repetition â€Å"Yes, yes†. 8. Tone/mood The tone of the story is very tense, serious, suspenseful and sometimes in characters’ words sarcasm slips. Tension and fear are seen in the description of boy’s actions â€Å"sat in despair†, â€Å"cowered in darkness†, â€Å"held his breath†, â€Å"clutched his nightshirt tight and prayed†. In some phrases of the one stranger we can find sympathy. Also we feel sympathy both to the boy  who is mocked at school and his father who seems to be arrested. In the detailed description of Charlie’s father we can notice that the boy is offended by him (â€Å"†¦left even punishment to his mother†). The mood of the story is hopeless and tense. We feel it throughout the story, the setting â€Å"helps† us to feel it deeply as well. But in the end we feel a kind of relief for a moment when the boy understands he loves his father. We say â€Å"for a moment† because we will never know if the father and the boy ever meet ag ain. 9. Types of characters a) Charlie 12 years old kid, brave enough to do what is prohibited (to have a smoke). But is under impact of his schoolmates who mock at him, it is a common phenomenon of children of his age. He is smart, we can say it reading how he encourages himself with the proverb. Maybe it tells us that he is well-read. The peculiarity of children of the World War I time was that they were elder mentally, more clever than the children of the peace time. The severe environment made them like that. Charlie tries to prove his maturity, to go against the fear. He is very cautious and skillful. But one thing he forgets is matches. He was so rash in his desire that make him forget a very important thing without what he can’t fulfill his wish. Though Charlie loves his mother very much, we can’t say he is mother’s darling. He wants to be with his father, share problems and feelings with him, but he sees that his father isn’t interested in him. That makes him frustrated. Charlie is a dynamic type of character, because he has a very strong position against his father and the attitude to him changes in the end. And he understands himself differently than at the beginning. b) Mr. Stowe From the very beginning we know that Charlie doesn’t love his father. He describes him as â€Å"unreal to him, a wraith, pale, thin and indefinite, who noticed him only spasmodically and left even punishment to his mother.† â€Å"Tonight he had said he would be in Norwich, and yet you never knew† – this tells us that he lies to his family. He is afraid of revealing his crime. It is seen in the phrase told one of the strangers: â€Å"if you wouldn’t mind being quite, gentlemen. I don’t want to wake up the family.†., The same we can see  in his answer on the stranger’s question â€Å"Don’t you want to speak to your wife?† – â€Å"Not me†¦Ã¢â‚¬ . But at the same time Mr. Stowe is very polite with strangers (â€Å"if you wouldn’t mind†¦Ã¢â‚¬ , â€Å"Mind if†¦Ã¢â‚¬ ). It also emphasizes his deceitfulness. Mr. Stowe is fond of what he is doing – running the tobacconist’s shop (â€Å"It’s a good little business†¦for those that like it†). We can notice how carefully he behaves with the packets of cigarettes (â€Å"†¦he lifted a pile of Gold Flake and Players from a shelf and caressed the packets with the tips of his fingers.†). He couldn’t be the closest person to his own kid, but he is good at business. c) Mr. Stowe Charlie opposes his father to his mother at the beginning of the story describing that her presence is â€Å"boisterous† and her charity is â€Å"noisy†. She filled the world for him, â€Å"†¦from her speech he judged her the friend of everyone, from the rector’s wife to the â€Å"Dear Queen†, except the â€Å"Huns†Ã¢â‚¬ ¦Ã¢â‚¬ . â€Å"For his mother he felt a passionate demonstrative love†¦Ã¢â‚¬ . The word â€Å"demonstrative† underlines the ostentation of his love opposing more strong his father to her. It seems that Charlie is very angry with his father at the beginning. Her kindness and boisterous presence are mentioned in the end of the story again, but now the boy doesn’t feel her presence, it is evident in the last sentence â€Å"He was alone in the house with his mother†¦Ã¢â‚¬ . He wants to say the warmest words not to her, but to his father. At the end Mr. Stowe becomes the dearest person to the Charlie. d) Two strangers These two strangers seem to be secret-service agents as it was mentioned above. Their appearance (â€Å"bowler hats and mackintoshes†) and phrase â€Å"†¦we are on duty† hint at that. One of them is polite enough thanking for the offered cigarette â€Å"Thank you all the time†, â€Å"one of us’ll come with you, if you don’t mind, – said the stranger gently†. The other one is trying to be sarcastic. 10. Methods of characterization Direct 11. Symbolism We can compare growing of a child with the stairs. Every footstep is a phase or life period. We can observe the dynamics of Charlie’s life, his growing, throughout the story, though it is a very little period of time. But the changes are evident. And we can imagine the stairs as a symbolic element. Moreover, we can find symbolism in night characterizing Charlie’s fears and hesitation and uncertainty. 12. Stylistic devices A lot of stylistic devices were mentioned above. But in this part of the analysis I want to discuss the title of the story â€Å"I Spy†. It sounds like a kids’ game â€Å"Eye Spy†, where the player-spy silently selects an object that is visible to all the players and does not reveal his or her choice. The same with Charlie: he wants to share his feelings, emotions and problems with the father, but doesn’t do it. His father isn’t interested in him, he is indefinite and the boy feels it. â€Å"I Spy† and â€Å"Eye Spy† is a stylistic device called pun, based on the play of words that sound similar.