Monday, January 27, 2020
Partitioning Methods to Improve Obsolescence Forecasting
Partitioning Methods to Improve Obsolescence Forecasting Amol Kulkarni Abstract Clustering is an unsupervised classification of observations or data items into groups or clusters. The problem of clustering has been addressed by many researchers in various disciplines, which serves to reflect its usefulness as one of the steps in exploratory data analysis. This paper presents an overview of partitioning methods, with a goal of providing useful advice and references to identifying the optimal number of cluster and provide a basic introduction to cluster validation techniques. The aim of clustering methods carried out in this paper is to present useful information which would aid in forecasting obsolescence. INRODUCTION There have been more inventions recorded in the past thirty years than all the rest of recorded humanity, and this pace hastens every month. As a result, the product life cycle has been decreasing rapidly, and the life cycle of products no longer fit together with the life cycle of their components. This issue is termed as obsolescence, wherein a component can no longer be obtained from its original manufacturer. Obsolescence can be broadly categorized into Planned and Unplanned obsolescence. Planned obsolescence can be considered as a business strategy, in which the obsolescence of a product is built into it from its conception. As Philip Kotler termed it Much so-called planned obsolescence is the working of the competitive and technological forces in a free society-forces that lead to ever-improving goods and services. On the other hand, unplanned obsolescence causes more harm to a burgeoning industry than good. This issue is more prevalent in the electronics industry; the procurem ent life-cycles for electronic components are significantly shorter than the manufacturing and support life-cycle. Therefore, it is highly important to implement and operate an active management of obsolescence to mitigate and avoid extreme costs [1]. One such product that has been plagued by threat of obsolescence is the digital camera. Ever-since the invention of smartphones there has been a huge dip in the digital camera sales, as can be seen from Figure 1. The decreasing price, the exponential rate at which the pixels and the resolution of the smart-phones improved can be termed as few of the factors that cannibalized the digital camera market. Figure 1 Worldwide Sales of Digital Cameras (2011-2016) [2] and Worldwide sale of cellphones on the right (2007-2016) [3] CLUSTERING Humans naturally use clustering to understand the world around them. The ability to group sets of objects based on similarities are fundamental to learning. Researchers have sought to capture these natural learning methods mathematically and this has birthed the clustering research. To help us solve problems at-least approximately as our brain, mathematically precise notation of clustering is important [4]. Clustering is a useful technique to explore natural groupings within multivariate data for a structure of natural groupings, also for feature extraction and summarizing. Clustering is also useful in identifying outliers, forming hypotheses concerning relationships. Clustering can be thought of as partitioning a given space into K groups i.e., à °Ã ââ¬Ëââ¬Å": à °Ã ââ¬Ëâ⬠¹ à ¢Ã¢â¬ ââ¬â¢ {1, à ¢Ã¢â ¬Ã ¦, K}. One method of carrying out this partitioning is to optimize some internal clustering criteria such as the distance between each observation within a c luster etc. While clustering plays an important role in data analysis and serves as a preprocessing step for a multitude of learning task, our primary interest lies in the ability of clusters to gain more information from the data to improve prediction accuracy. As clustering, can be thought of separating classes, it should help in classification task. The aim of clustering is to find useful groups of objects, usefulness being defined by the goals of the data analysis. Most clustering algorithms require us to know the number of clusters beforehand. However, there is no intuitive way of identifying the optimal number of clusters. Identifying optimal clustering is dependent on the methods used for measuring similarities, and the parameters used for partitioning, in general identifying the optimal number of clusters. Determining number of clusters is often an ad hoc decision based on prior knowledge, assumptions, and practical experience is very subjective. This paper performs k-means and k-medoids clustering to gain information from the data structure that could play an important role in predicting obsolescence. It also tries to address the issue of assessing cluster tendency, which is a first and foremost step while carrying out unsupervised machine learning process. Optimization of internal and external clustering criteria will be carried out to identify the optimal number of cluster. Cluster Validation will be carried out to identify the most suitable clustering algorithm. DATA CLEANING Missing value in a dataset is a common occurrence in real world problems. It is important to know how to handle missing data to reduce bias and to produce powerful models. Sometimes ignoring the missing data, biases the answers and potentially leads to incorrect conclusion. Rubin in [7] differentiated between three types of missing values in the dataset: Missing completely at random (MCAR): when cases with missing values can be thought of as a random sample of all the cases; MCAR occurs rarely in practice. Missing at random (MAR): when conditioned on all the data we have, any remaining missing value is completely random; that is, it does not depend on some missing variables. So, missing values can be modelled using the observed data. Then, we can use specialized missing data analysis methods on the available data to correct for the effects of missing values. Missing not at random (MNAR): when data is neither MCAR nor MAR. This is difficult to handle because it will require strong assumptions about the patterns of missing data. While in practice the use of complete case methods which drops the observations containing missing values is quite common, this method has the disadvantage that it is inefficient and potentially leads to bias. Initial approach was to visually explore each individual variable with the help of VIM. However, upon learning the limitations of filling in missing values through exploratory data analysis, this approach was abandoned in favor of multiple imputations. Joint Modelling (JM) and Fully Conditional Specification (FCS) are the two emerging general methods in imputing multivariate data. If multivariate distribution of the missing data is a reasonable assumption, then Joint Modelling which imputes data based on Markov Chain Monte Carlo techniques would be the best method. FCS specifies the multivariate imputation model on a variable-by-variable basis by a set of conditional densities, one for each incomplete variable. Starting from an initial imputation, FCS draws imputations by iterating over the conditional densities. A low number of iterations is often sufficient. FCS is attractive as an alternative to JM in cases where no suitable multivariate distribution can be found [8]. The Multiple imputations approach involves filling in missing values multiple times, creating multiple complete datasets. Because multiple imputations involve creating multiple predictions for each missing value, the analysis of data imputed multiple times take into account the uncertainty in the imputations and yield accurate standard errors. Multiple imputation techniques have been utilized to impute missing values in the dataset, primarily because it preserves the relation in the data and it also preserves uncertainty about these relations. This method is by no means perfect, it has its own complexities. The only complexity was having variables of different types (binary, unordered and continuous), thereby making the application of models, which assumed multivariate normal distribution- theoretically inappropriate. There are several complexities that surface listed in [8]. In order to address this issue It is convenient to specify imputation model separately for each column in th e data. This is called as chained equations wherein the specification occurs at a variable level, which is well understood by the user. The first task is to identify the variables to be included in the imputation process. This generally includes all the variables that will be used in the subsequent analysis irrespective of the presence of missing data, as well as variables that may be predictive of the missing data. There are three specific issues that often come up when selecting variables: (1) creating an imputation model that is more general than the analysis model, (2) imputing variables at the item level vs. the summary level, and (3) imputing variables that reflect raw scores vs. standardized scores. To help make a decision on these aspects, the distribution of the variables may help guide the decision. For example, if the raw scores of a continuous measure are more normally distributed than the corresponding standardized scores then using the raw scores in the imputation model, will likely better meet the assumptions of the linear regressions being used in the imputation process. The following image shows the missing values in the data-frame containing the information regarding digital camera. Figure 2 Missing Variables We can see that Effective Pixels has missing values for all its observations. After cross verifying it with the source website, the web scrapper was rewriting to correctly capture this variable from the website. The date variable was converted from a numeric to a date and this enabled the identification of errors in the observation for USB in the dataset. Two cameras that were released in 1994 1995 were shown to have USB 2.0, after searching online, it was found out that USB 2.0 was released in the year 2005 and USB 1.0 was released in the year 1996. As, most of the cameras before 1997 used PC-serial port a new level was introduced to the USB variable to indicate this. DATA DESCRIPTION The dataset containing the specification of the digital cameras was acquired using rvest -package [5] in R from the url provided in [6]. The structure of the data set is as shown in Appendix A. The data-frame contains 2199 observation and 55 variables. Appendix B contains the descriptive statistics of the quantitative variables in the data-frame. Figure 4 The Distribution of Body-Type in the dataset Observation: Most of the compact, Large SLR and ultracompact cameras are discontinued. Figure 5 Plot showing the status of Digital Cameras from 1994-2017 Observation: Most of the cameras released before 2007 have been discontinued however, we can see that few cameras announced between the period of 1996-2006 are still in production. Fewer new cameras have been announced after the year 2012, this can be evidenced due to the decreasing number of camera sales presented in Figure 5. Figure 6 Distribution of different Cameras (1994-2017) Observation: Between the period of 1996 2012 the digital camera market was dominated by the compact cameras. After 2012, fewer new compact cameras have been announced or are still in production. Same can be said about the fate of ultracompact cameras. In the year 2017, only SLR style mirrorless cameras have been announced, signaling the death of point and shoot cameras. Figure 7 Plot showing the Change in the Total Resolution and Effective Pixels of Digital Camera over the Years Observation: Total resolution has seen an improvement over the years. The presence of outliers can be seen in the top-left corner of the plot. Although the effective pixel is around 10, the total resolution is far higher than any of the cameras announced between the period 1996-2001. These could be the cameras that are still in production as evidenced from Figure 7. ASSESSING CLUSTER TENDENCY A primary issue with unsupervised machine learning is the fact if carried out blindly, clustering methods will divide the data into clusters, because that is what they are supposed to do. Therefore, before choosing a clustering approach, it is important to decide whether the dataset contains meaningful clusters. If the data does contain meaningful clusters, then the number of clusters is also an issue that needs to be looked at. This process is called assessing clustering tendency (feasibility of cluster analysis). To carry out a feasibility study of cluster analysis Hopkins statistic will be used to assess the clustering tendency of the dataset. Hopkins statistic assess the clustering tendency based on the probability that a given data follows a uniform distribution (tests for spatial randomness). If the value of the statistic is close to zero this implies that the data does not follow uniform distribution and thus we can reject the null hypothesis. Hopkins statistic is calculated using the following formula: Where xi is the distance between two neighboring points in a given, dataset and yi represents the distance between two neighboring points of a simulated dataset following uniform distribution. If the value of H is 0.5, this implies that and are close to one another and thus the given data follows a uniform distribution. The next step in the unsupervised learning method is to identify the optimal number of clusters. The Hopkins statistic for the digital camera dataset was found to be 0.00715041. Since Hopkins statistic was quite low, we can conclude that the dataset is highly clusterable. A visual assessment of the clustering tendency was also carried out and the result can be seen in Figure 8. Figure 8 Dissimilarity Matrix of the dataset DETERMINING OPTIMAL NUMBER OF CLUSTERS One simple solution to identify the optimal number of cluster is to perform hierarchical clustering and determine the number of clusters based on the dendogram generated. However, we will utilize the following methods to identify the optimal number of clusters: An optimization criterion such as within sum of squares or Average Silhouette width Comparing evidence against null hypothesis. (Gap Statistic) SUM OF SQUARES The basic idea behind partitioning methods like k-means clustering algorithms, is to define clusters such that the total within cluster sum of squares is minimized. Where Ck is the kth cluster and W(Ck) is the variation within the cluster. Our aim is to minimize the total within cluster sum of squares as it measures the compactness of the clusters. In this approach, we generally perform clustering method, by varying the number of clusters (k). For each k we compute the total within sum of squares. We then plot the total within sum of squares against the k-value, the location of bend or knee in the plot is considered as an appropriate value of the cluster. AVERAGE SILHOUETTE WIDTH Average silhouette is a measure of the quality of clustering, in that it determines the how well an object lies within its cluster. The metric can range from -1 to 1, where higher values are better. Average silhouette method computes the average silhouette of observations for different number of clusters. The optimal number of clusters is the one that maximizes the average silhouette over a range of possible values for different number of clusters [9]. Average silhouette functions similar to within sum of squares method. We carry out the clustering algorithm by varying the number of clusters, then we calculate average silhouette of observation for each cluster. We then plot the average silhouette against different number of clusters. The location with the highest value of average silhouette width is considered as the optimum number of cluster. GAP STATISTIC This method compares the total within sum of squares for different number of cluster with their expected values while assuming that the data follows a distribution with no obvious clustering. The reference dataset is generated using Monte Carlo simulations of the sampling process. For each variable (xi) in the dataset we compute its range [min(xi), max(xj)] and generate n values uniformly from the range min to max. The total within cluster variation for both the observed data and the reference data is computed for different number of clusters. The gap statistic for a given number of cluster is defined as follows: denotes the expectation under a sample of size n from the reference distribution. is defined via bootstrapping and computing the average . The gap statistic measures the deviation of the observed Wk value from its expected value under the null hypothesis. The estimate of the optimal number of clusters will be a value that maximizes Gapn(k). This implies that the clustering structure is far away from the uniform distribution of points. The standard deviation (sdk) of is also computed in order to define the standard error sk as follows: Finally, we choose the smallest value of the number of cluster such that the gap statistic is within one standard deviation of the gap at k+1 Gap(k)à ¢Ã¢â¬ °Ã ¥Gap(k+1) sk+1 The above method and its explanation are borrowed from [10]. DATA PRE-PROCESSING The issue with K-means clustering is that it cannot handle categorical variables. As the K-means algorithm defines a cost function that computes Euclidean distance between two numeric values. However, it is not possible to define such distance between categorical values. Hence, the need to treat categorical data as numeric. While it is not improper to deal with variables in this manner, however categorical variables lose their meaning once they are treated as numeric. To be able to perform clustering efficiently, Gower distance will be used for clustering. The concept of Gower distance is that for each variable a distance metric that works well for that particular type of variable is used. It is scaled between 0 and 1 and then a linear combination of weights is calculated to create the final distance matrix. PARTITIONING METHODS K-MEANS K-means clustering is the simplest and the most commonly used partitioning method for splitting a dataset into a set of k clusters. In this method, we first choose K initial centroids. Each point is then assigned to the closest centroid, and each collection of points is assigned to a centroid in the cluster. The centroid of each cluster is updated based on the additional points assigned to the cluster. We repeat his until the centroids find a steady state. Figure 9 Plot Showing total sum of square and Average Silhouette width for different number of clusters We can see from Figure 9, that the optimal number of clusters suggested by the optimization criteria is 3 clusters using WSS method and 2 clusters using Average Silhouette width method. Considering the dependent variable is factor with two levels, having two clusters does make sense. The disadvantage of optimization criterion to identify the optimal clusters is that, it is sometimes ambiguous. A more sophisticated method is the gap statistic method. Figure 10 Gap Statistic for different number of clusters From Figure 10, we can see that the Gap statistic is high for 2 clusters. Hence, we carry out k-means clustering with 2 clusters on a majority basis. Figure 11 Visualizing K-means Clustering Method The data separates into two relatively distinct clusters, with the red category in the left region, while the region on the right contains the blue category. There is a limited overlap at the interface between the classes. To visualize K-means it is necessary to bring the number of dimensions down to two. The graph produced by fviz_cluster: Factoextra Ver: 1.0 [11] is not a selection of any two dimensions. The plot shows the projection of the entire data onto the first two principle components. These are the dimensions which show the most variation in the data. The 52.8% indicates that the first principle component accounts for 52.8% variation in the data, whereas the second principle component accounts for 23.9% variation in the data. Together both the dimensions account for 76.7% of the variation. The polygon in red and blue represent the cluster means. PARTITIONING AROUND MEDOIDS K means clustering is highly sensitive to outliers, this would affect the assignment of observations to their respective clusters. Partitioning around medoids also known as K-medoids clustering are much more robust compared to k-means. K-medoids is based on the search of medoids among the observation of the dataset. These medoids represent the structure of the data. Much like K-means, after finding the medoids for each of the K- clusters, each observation is assigned to the nearest medoid. The aim is to find K-medoids such that it minimizes the sum of dissimilarities of the observations within the cluster. Figure 12 Plot Showing total sum of square and Average Silhouette width for different number of clusters We can see from Figure 12, that the optimal number of clusters suggested by the optimization criteria is 3 clusters using WSS method and 2 clusters using Average Silhouette width method. Considering the dependent variable is factor with two levels, having two clusters does make sense. The disadvantage of optimization criterion to identify the optimal clusters is that, it is sometimes ambiguous. A more sophisticated method is the gap statistic method. Figure 13 Gap Statistic for different number of clusters From Figure 13, we can see that the Gap statistic is high for 2 clusters. Hence, we carry out partitioning around medoids clustering with 2 clusters on a majority basis. Figure 14 Plot visualizing PAM clustering method The data separates into two relatively distinct clusters, with the red category in the lower region, while the upper region contains the blue category. There is a limited overlap at the interface between the classes. fviz_cluster: Factoextra Ver: 1.0 [11] transforms the initial set of variables into a new set of variables through principal component analysis. This dimensionality reduction algorithm operates on the 72 variables and outputs the two new variables that represent the projection of the original dataset. CLUSTER VALIDATION The next step in cluster analysis is to find the goodness of fit and to avoid finding patterns in noise and to compare clustering algorithms, cluster validation is carried out. The following cluster validation measures to compare K-means and PAM clustering will be used: Connectivity: Indicates the extent to which the observations are placed in the same cluster as their nearest neighbors in the data space. It has a value ranging from 0 to à ¢Ãâ Ã
¾ and should be minimized Dunn: It is the ratio of shortest distance between two clusters to the largest intra-cluster distance. It has a value ranging from 0 to à ¢Ãâ Ã
¾ and should be maximized. Average Silhouette width The results of internal validation measures are presented in the table below. K-means for two cluster has performed better for each statistic. Figure 15 Plot Comparing Connectivity and Dunn Index for K-means and PAM for different number of clusters à à à Figure 16 Plot Comparing Average Silhouette width of K-means and PAM Clustering Algorithm Validation Measures Number of Clusters 2 3 4 5 6 kmeans Connectivity 139.9575 292.5563 406.5429 514.3913 605.5373 Dunn 0.0661 0.0246 0.0223 0.0244 0.0291 Silhouette 0.4369 0.3174 0.2814 0.2679 0.2447 pam Connectivity 156.1004 333.754 474.4298 520.3913 635.3687 Dunn 0.0275 0.0397 0.022 0.028 0.0246 Silhouette 0.4271 0.3035 0.2757 0.2661 0.2325 Table 1 Presenting the values of different validation measures for K-means and PAM Validation Measures Score Method Clusters Connectivity 139.9575 kmeans 2 Dunn 0.0661 kmeans 2 Silhouette 0.4369 kmeans 2 Table 2 Optimal Scores for the Validation Measures CONCLUSION In this research work, partitioning methods like K-means and Partitioning around medoids were developed. The performances of these two approaches have been observed on the basis of their Connectivity, Dunn index and Average Silhouette width. The results indicate that K-means clustering algorithm with K = 2 performs better than partitioning around medoids with two clusters. The findings of this paper will be very useful to predict obsolescence with higher accuracy. FUTURE WORK Advanced clustering algorithms such as Model based clustering and Density based clustering can be carried out to find the multivariate data structure as most of the variables are categorical. [1] Bjoern Bartels, Ulrich Ermel, Peter Sandborn and Michael G. Pecht (2012). Strategies to the Prediction, Mitigation and Management of Product Obsolescence. [2] Source Figure 1: https://www.statista.com/statistics/269927/sales-of-analog-and-digital-cameras-worldwide-since-2002/ [3] Source, Figure 1: https://www.statista.com/statistics/263437/global-smartphone-sales-to-end-users-since-2007/ [4] S. Still, and W. Bialek, How many Clusters? An Information Theoretic Perspective, Neural Computation, 2004. [5] Wickham, Hadley, rvest: Easily Harvest (Scrape) Web Pages. https://cran.r-project.org/web/packages/rvest/rvest.pdf, Ver. 0.3.2 [6] https://www.dpreview.com [7] Rubin, D.B., Inference and missing data. Biometrika, 1976. [8] Multivariate Imputation by Chained Equations Stef van Buuren, Karin Groothuis . [9] Learning the k in k-means Greg Hamerly, Charles Elkan [10] Robert Tibshirani, Guenther Walther and Trevor Hast
Sunday, January 19, 2020
Assess the usefulness of social action theories in the study of society Essay
Social action theories are known as micro theories which take a bottom-up approach to studying society; they look at how individuals within society interact with each other. There are many forms of social action theories, the main ones being symbolic interactionism, phenomenology and ethnomethodology. They are all based on the work of Max Weber, a sociologist, who acknowledged that structural factors can shape our behaviour but individuals do have reasons for their actions. He used this to explain why people behave in the way in which they do within society. Weber saw four types of actions which are commonly committed within society; rational, this includes logical plans which are used to achieve goals, traditional-customary behaviour, this is behaviour which is traditional and has always been done; he also saw affectual actions, this includes an emotion associated with an action and value-rational actions, this is behaviour which is seen as logical by an individual. Weberââ¬â¢s discovery of these actions can therefore be seen as useful in the study of society. Weber discovered these actions by using his concept of verstehan, a deeper understanding. However, some sociologists have criticised him as they argue that verstehan cannot be accomplished as it is not possible to see thing in the way that others see them, leaving sociologists to question whether Weberââ¬â¢s social action theory is useful in the study of society. Social action theories have also been referred to as interactionism as they aim to explain day-to-day interactions between individuals within society. G. H Mead came up with the idea of interactionism and argued that the self is ââ¬Ëa social construction arising out of social experienceââ¬â¢. This is because, according to Mead, social situations are what influence the way in we act and behave. He claims that we develop a sense of self as a child and this allows us to see ourselves in the way in which other people see us; we act and behave in certain ways depending on the circumstances which we are in. Mead also claimed that we have a number of different selves which we turn into when we are in certain situations; i. e. we may have one self for the work place and another self for home life. Mead concluded that society is like a stage, in which we are all ââ¬Ëactorsââ¬â¢. Meadââ¬â¢s theory if interactionism is useful in the study of society as it explains why people behave in different ways in certain situations. Mead argues that the social context of a situation is what influences our behaviour, humans use symbols, in the form of language and facial expressions, to communicate, he also argued that humans and animals differ as reasons behind humansââ¬â¢ actions are thought through and not instinctive, unlike those of animalsââ¬â¢. However, it has been argued that not all action is meaningful, as Weberââ¬â¢s category of traditional action suggests that much action is performed unconsciously and may have little meaning. Therefore, meadââ¬â¢s idea of interactionism cannot be seen as an appropriate theory to use when studying society. Blumer, a sociologist, who elaborated on Meadââ¬â¢s concept of the self ââ¬â ââ¬ËIââ¬â¢ and ââ¬Ëmeââ¬â¢ ââ¬â stated that there were three principles about actions and behaviours within social situations. He argued that our actions are the result of situations and events and they have reasons. The reasons behind our actions are negotiable and changeable, so theyââ¬â¢re not fixed. Our interpretation of a situation is what gives it meaning. Blumerââ¬â¢s three principles can therefore be used in the study of society. However, it has been argued that his principles cannot explain the consistent patterns which we see in peopleââ¬â¢s behaviours. This therefore leaves many sociologists to question whether Blumerââ¬â¢s principles can be used to study society. Labelling theory has also been used to apply the interactionist theory to society; the theory, like Mead, emphasises the importance of symbols and situations in which they are used. The main interactionist concepts are the definition of the situation ââ¬â if we believe in something then it could affect the way in which we behave. The looking glass ââ¬âself ââ¬â this was created by Cooley who argues that we see ourselves in a way in which we think others see us. These concepts have been useful in explaining why people act in certain ways in certain situations; therefore, the labelling theory is effective in the study of society. Overall, in conclusion, there are many different social action theories which can be used in the study of society, however, not all of them can be applied to all individuals.
Saturday, January 11, 2020
Network Server Administration
Course number CIS 332, Network Server Administration, lists as its main topics: installing and configuring servers, network protocols, resource and end user management, security, Active Directory, and the variety of server roles which can be implemented. My experience and certification as a Microsoft Certified System Administrator (MCSA) as well as a Microsoft Certified System Engineer (MCSE) demonstrates that I have a thorough grounding in both the theory and practice of the topics covered in this course and should receive credit for it. Installing and configuring servers was the subject of Installing, Configuring and Administering Microsoft Windows 2000 Server, which I took in 2001 in preparation for my initial Microsoft Certified Professional certification. This exam covered such topics as installing Microsoft Windows 2000 Server using both an attended installation and an unattended installation; server upgrades from Windows NT (the previous version) and troubleshooting and repairing failed installations. This exam also covered installing and configuring hardware devices and user management. Network protocols were discussed during the training for the exam Implementing and Administering a Microsoft Windows 2000 Network Infrastructure, which I also took in 2001. This exam covered installing, configuring, troubleshooting and administering such protocols as DNS and DHCP, TCP/IP, NWLink, and IPSec. The training covered such aspects of network protocols as remote access policies and network routing. Security was one of the topics of this exam, as well. Network security using IPSec and encryption and authentication protocols was discussed along with the network implementation details. Resource and end user management was one of the main topics of the Managing and Maintaining a Windows Server 2003 Environment exam, which also updated my knowledge of security, networking and utilities. The exam covered such topics as user creation and modification, user and group management, Terminal Services management and implementing security and software update services. Security was covered in a number of exams, including Implementing and Administering a Microsoft Windows 2000 Network Infrastructure, Installing, Configuring and Administering Microsoft Windows 2000 Server and Designing Security forà a Windows 2000 Network. All aspects of network security were covered in the various training sessions for these exams, including topics such as analysis of network security requirements in relation to organizational realities and requirements, design and implementation of such specifics as authentication policies, public-key infrastructures and encryption techniques, physical security, and design and implementation of security audit and assurance strategies. Also included were security considerations for all auxiliary services, such as DNS, Terminal Services, SNMP, Remote Installation Services and others. Implementation of Active Directory and knowledge of varied server roles was provided by the exam Designing a Microsoft Windows 2000 Directory Services Infrastructure. The training for this exam encompassed the design and implementation of an Active Directory forest and domain structure as well as planning a DNS strategy for client and server naming. This training also included design and implementation of a number of different server types, such as file and print servers, databases, proxy servers, Web servers, desktop management servers, applications servers and dial-in management servers. Further knowledge of Active Directory and auxiliary services was provided in the training for Implementing and Administering a Microsoft Windows 2000 Directory Services Infrastructure. This training included such topics as installing, configuring and troubleshooting Active Directory and DNS, implementing Change and Configuration Management, and managing all the components of Active Directory, including moving, publishing and locating Active Directory Objects, controlling access, delegating administrative privileges for objects, performing backup and restore and maintaining security for the Active Directory server via Group Policy and the Security Configuration and Analysis tool. The topics covered in CIS 332, Network Server Administration, have been completely encompassed by my previous experience, training and certification with Microsoft Windows Server 2000, as well as updated knowledge gained byà training for Microsoft Windows Server 2003. I have been constantly increasing my skills and knowledge in this area for the past six years, using both training and work experience to gain certifications which prove that I have a complete grasp of all aspects of the subject matter included in this course. Installing and configuring servers and network protocols, troubleshooting failed installations or configurations, resource and end user management, security design and management, design and implementation of Active Directory services and implementing and administering a wide variety of network server roles are all major aspects of my training and certification experience. I feel I am fully qualified for the information covered in CIS 332, and should be granted credit for this course.
Thursday, January 2, 2020
Youth Crime - 1946 Words
Sociological theories of youth crime This essay will discuss the understanding of the sociological and psychological factors of youth crime. It will be agreeing and disagreeing in the above statement Youth crime is also known as juvenile delinquency, juvenile delinquency refers to criminal acts performed by juveniles. Most legal systems prescribe specific procedures for dealing with juveniles, such as juvenile detention centres. There are a multitude of different theories on the cause of crime, most if not all of which can be applied to the cause of youth crime. Youth crime is aspect of crime which receives great attention from the news media and politicians. Crime committed by young people has risen since the mid- twentieth century,â⬠¦show more contentâ⬠¦Preventing youth crime before it happens is the first and best way to protect society. The Youth Justice Strategy identifies prevention as one of its key objectives. This new approach to youth crime also acknowledges that the law is only one part of the solution à ¾ some of the most effective responses to crime lie outside the criminal justice system. Crime and disorder remains an important concern for our communities. We know this from our own experiences and our knowledge is backed by the 2000 Crime Survey, where just over 8 in 10 people identified crime as a serious problem. And although disorder may not involve criminal behaviour, the Scottish Household Survey has consistently reported that around 30% of respondents think groups of young people hanging around to be a problem in their area. Over half of families living in council flats identified this as a problem. Long-lasting strategies that address the causes of youth crime must involve a variety of individuals, organizations and governments in such areas as crime prevention, child welfare, mental health, education, social services and employment. The Strategy supports the involvement of a broad range of organizations that work with children. Families, communities and victims will also be more involved in addressing youth crime under the governments new strategy.Show MoreRelatedThe Crime Of Youth Crime Essay2505 Words à |à 11 PagesYouth crime has vastly changed compared to how it was seen 10 years ago, and will likely be much different 10 years from today. Over the years, types of crimes committed by youth have changed, and the overall seriousness of crimes has reduced over time as well (Carrington, 2013). These changes in crime statistics can vastly change how police agencies respond and react to youth crime, and can often be misconstrued to make public feel a state of moral panic. Yout h are also becoming increasingly involvedRead MoreThe Nature Of Youth Crime877 Words à |à 4 PagesWhat is the nature of youth crime in Australia? Youth crime is the crime committed by juvenile offenders. It is the common issue in Australia. The age group between 14-19 years old is the popular group of youth crime. (News 2013) Different age groups commit different types of crimes. (The youth court 2009) Also, there are many kinds of crime and crime method in the society, such as, drug offences, robbery, burglary, assault and violent offenses. The group of people who crime together that is calledRead MoreYouth Unemployment and Crime2379 Words à |à 10 PagesThe causes and consequences of youth unemployment in Australia has been of particular concern within both government and private sectors for many years. According to the Australian Bureau of Statistics (ABS), 10.9% of the total 15-24 age population was unemployed in September, 1995. This figure climbed to 15.3% in September, 2003. This evidence gives cause to the growing concern surrounding the increase in youth unemployment. For sizeable numbers of youth, its not going to get any easier to findRead MorePreventing Youth Crime1810 Words à |à 8 PagesOutline and evaluate strategies used by criminal agencies to control youth crime. An estimate number of 10 to 17 yr olds in UK in 1999 was 2704392 males and 2561681 females. These young people represent of the general population and are also often the group who elicit the most concern and discussion within local communities and the media. There is a big interest in the consistent crimes in this age group, resulted in a lot of research being made. Therefore this essay will be establishing researchRead MoreYouth Crime Essay3259 Words à |à 14 Pagesï » ¿ Youth Gang Involvement MET CJ/631ââ¬âYouth Crime Problems Boston University Dr. Frank Carney April 20, 2013 Abstract Within the United States, youth involvement in gangs has become a serious problem for the future safety and security of the United States. The following thesis explores the growing problem of youth involvement in gangs and attempts to understand the growing trend by exploring historical facts and figures, policies and programs. Within the lastRead MoreYouth in Crime Essay876 Words à |à 4 Pagespeople are criminals; but when living in an area that is known for high crime rates, and viewed solemnly on their skin color to determine whether they are criminals, its not easy for them to live each day fearing for their life and being harassed by the police. Even though people can at times determine if someone is affiliated with a gang, or if they are not good news meaning they appear to be someone involved in crimes, the media plans a major part in these determination of people. AccordingRead MoreYouth Crime vs Youth Organized Sports2647 Words à |à 11 Pagesidea of a possible correlation between youth organized sports and youth crime rates. Sports are able to teach youth discipline, honesty, character building and social skills. Since there are not many variables in the data being researched most data will be taken from case studies and examples. Although there are a lot of variables regarding youth crime it would take too much time and effort to try and pinpoint all the different factors affecting youth crime (socio-economic, cultural influences etcRead MoreCrime and Youth Care Facility1116 Words à |à 5 Pageschildren in conflict with the law, majority of who are guilty of petty crimes such as petty theft, vagrancy and sniffing g lue. Prior to the Juvenile Justice and Welfare Act of 2006, children in conflict with the law were thrown into the same prison cells as hardened criminals. Studies show that most of them were first-time offenders, while eight percent committed crimes against property. These children are then doomed to a life of crime, rending them victims of a judicial system that inadvertently breedsRead MoreYouth And Crime By John Muncie2703 Words à |à 11 PagesCritically discuss the assertion that ââ¬Å"young people are propelled into crime through circumstances beyond their controlâ⬠(Muncie, 2005, p.116). In his 2005 book Youth and Crime, John Muncie stated that ââ¬Å"young people are propelled into crime through circumstances beyond their controlâ⬠. While this may be true in part, there have been many studies written since which differ significantly. Conversely, there are also studies that are at least in part, if not wholly in line with his findings. WhetherRead MoreThe Role Of Migrant Youth And Crime1861 Words à |à 8 PagesTitle: Assignment 1 - Essay Student Name: James Patrick Ryan Student Id: 17832377 Unit: (400684) Juvenile Crime and Justice Word Count: 1569 Question: Discuss the mediaââ¬â¢s contribution to a racialized construction of the relationship between migrant youth and crime. Begin this discussion by describing the term racialisation. Ã¢â¬Æ' The effect of labelling potential offenders and the causal relationship between label and offence is an enduring question for criminal sociologists (Cunneen 1995). The
Subscribe to:
Comments (Atom)