Los jóvenes de Cali : mensajeros, entreras, coperas y gamines 1960-1970

Este trabajo aborda el estudio de las juventudes como articuladas a un espacio y un tiempo determinados, es decir, históricamente definidas por la sociedad. Particularmente detiene su mirada en aquellas múltiples juventudes vinculadas a un empleo en la ciudad de Cali durante la década del sesenta. Se hace un seguimiento a la manera en que la oferta laboral define quiénes son los jóvenes de ese momento, en qué sectores económicos participarían y bajo qué condiciones. En el texto se les concibe a éstos como una construcción social que responde a unos intereses particulares. A partir de allí se examinan las características y problemáticas de mensajeros, entreras, coperas y gamines, quienes constituyeron la mayoría de los jóvenes trabajadores para el período estudiado. La base factual del análisis fue uno de los periódicos de la ciudad, El País; en sus páginas se buscó aquella información atinente a anuncios clasificados, columnas de opinión, registros de noticias y sección judicial. Especialmente interesante resultó el acercamiento a los primeros, su contenido fue fundamental en el desarrollo de la investigación. Con todo se considera, este ejercicio como un punto de partida para la realización de otros análisis de este tipo, desde perspectivas políticas, sociales o culturales.MaestríaMAGISTER EN HISTORI

Bandwidth Allocation Mechanism based on Users' Web Usage Patterns for Campus Networks

Managing the bandwidth in campus networks becomes a challenge in recent years. The limited bandwidth resource and continuous growth of users make the IT managers think on the strategies concerning bandwidth allocation. This paper introduces a mechanism for allocating bandwidth based on the users’ web usage patterns. The main purpose is to set a higher bandwidth to the users who are inclined to browsing educational websites compared to those who are not. In attaining this proposed technique, some stages need to be done. These are the preprocessing of the weblogs, class labeling of the dataset, computation of the feature subspaces, training for the development of the ANN for LDA/GSVD algorithm, visualization, and bandwidth allocation. The proposed method was applied to real weblogs from university’s proxy servers. The results indicate that the proposed method is useful in classifying those users who used the internet in an educational way and those who are not. Thus, the developed ANN for LDA/GSVD algorithm outperformed the existing algorithm up to 50% which indicates that this approach is efficient. Further, based on the results, few users browsed educational contents. Through this mechanism, users will be encouraged to use the internet for educational purposes. Moreover, IT managers can make better plans to optimize the distribution of bandwidth

Las condiciones de replicabilidad del texto científico como condiciones hermenéuticas para el historiador de la ciencia

Treinta años atrás Charles Percy Snow, y como hace doscientos cincuenta Denis Diderot y Jean LeRond D'Alembert, señaló la existencia de dos subculturas en la sociedad, la científica y la humanística, cuyos miembros permanecen ajenos los unos de los otros. El daño que este mutuo apartheid les infiere como hombres de letras, pues ambos lo son pese a sus diferencias, es evidente cuando los humanistas, sin indagar la naturaleza de la literatura científica, interpretan, juzgan o rememoran la obra de sus autores

Implementation of Modified AES as Image Encryption Scheme

Since images have bigger size than text, a faster encryption algorithm is needed to provide higher security in digital images. The paper presents a modified AES algorithm that address the requirement in image encryption. The modified algorithm used bit permutation in replacement of MixColumns to reduce the computational requirement of the algorithm in encrypting images. Results of the study show that the modified algorithm exhibited faster encryption and decryption time in images. The modified algorithm also achieved a good result in the key sensitivity analysis, histogram analysis, information entropy, the correlation coefficient of adjacent pixels, Number of Pixel Change Rate and Unified Average Change Intensity making the modified algorithm resistant to statistical and differential attack

An Improved Overlapping Clustering Algorithm to Detect Outlier

MCOKE algorithm in identifying data objects to multi cluster is known for its simplicity and effectiveness. Its drawback is the use of maxdist as a global threshold in assigning objects to one or more cluster while it is sensitive to outliers. Having outliers in the datasets can significantly affect the effectiveness of maxdist as regards to overlapping clustering. In this paper, the outlier detection is incorporated in MCOKE algorithm so that it can detect and remove outliers that can participate in the calculation of assigning objects to one or more clusters. The improved MCOKE algorithm provides better identification of overlapping clustering results. The performance was evaluated via F1 score performance criterion. Evaluation results revealed that the outlier detection demonstrated higher accuracy rate in identifying abnormal data (outliers) when applied to real datasets

QR Code Integrity Verification Based on Modified SHA-1 Algorithm

The modified SHA-1 algorithm was applied in the data integrity verification process of certificates with QR code technology. This paper identified the requirements needed in the certificate verification that uses the modified SHA-1. The application was tested using legitimate and fraudulent certificates. Based on the results, the application successfully generated QR codes, printed certificates, and verified certificates with 100% accuracy. During the trial run of the app, four test cases were seen which involves correct names and QR codes, and three other possible test cases of faking certificates such as modification of the name, regeneration of QR codes using valid hash and a fake name, and modification of the QR code. Although these cases exist, the app successfully verified all thirty certificates correctly. Also, it is noticed that during the scanning, the smartphone camera should be in focus to capture the QR code clearly

A New Approach in Expanding the Hash Size of MD5

The enhanced MD5 algorithm has been developed by expanding its hash value up to 1280 bits from the original size of 128 bit using XOR and AND operators. Findings revealed that the hash value of the modified algorithm was not cracked or hacked during the experiment and testing using powerful bruteforce, dictionary, cracking tools and rainbow table such as CrackingStation, Hash Cracker, Cain and Abel and Rainbow Crack which are available online thus improved its security level compared to the original MD5. Furthermore, the proposed method could output a hash value with 1280 bits with only 10.9 ms additional execution time from MD5. Keywords: MD5 algorithm, hashing, client-server communication, modified MD5, hacking, bruteforce, rainbow table