Crises of Representation, Representations of Crisis: Historical Consciousness in Contemporary Latin American Art and Literature

The late 1970s and the 1980s were crucial years for the emergence of a new form of historical consciousness in Latin American art and literature, especially concerned with questions of collective memory and identity. The aim of this article is twofold. The first aim is to map the main strands in the debate surrounding the relationships between history, art, and literature in this period, focusing on the current discussions on the epistemological crises that led to the rise of this new historical consciousness. The second aim is to address the question of Latin American specificity. I will take into consideration several theoretical contributions in order to outline a standpoint that not only considers Latin American specificity but also its contribution to think the articulation of art, history and politics

Alternative Solutions to Traditional Problems: Contextualizing the Kitchener John School Diversion Program

This thesis is an exploratory study of the Kitchener John School Diversion Program. As a primarily community-based initiative, this program has been developed in response to a particular social problem, street prostitution. The primary focus of the program is to address the problem by targeting the clients of prostitutes. Using a contextual constructionist framework, eight qualitative, semi-structured interviews and three participant observation sessions were conducted to explore and understand how the John School works within the context of its objectives and mandate. Four research questions have been developed to achieve this and focus on (1) how program objectives are implemented within the operation of the diversion program, (2) how stakeholders problematize prostitution and its social actors, (3) what the social conditions and characteristics related to the social construction of prostitution are, as perceived by the social actors, and finally, (4) how the diversion program addresses the problem of prostitution. Through analysis of the data collected, key findings emerge that help to contextualize the diversion program within a broader understanding of its mandates and operations. Specifically, four objectives are identified as the primary goals of the school, being knowledge dissemination, accountability, diversion and change. There are notable discrepancies, however, in terms of how program staff interpret these objectives within the context of their program lectures and materials. Additionally, while strong themes and typifications emerge with respect to how prostitution and its social actors are problematized by the program staff, these themes and typifications have a tendency to conflict with one another when presented to the participants. For example, where prostitution is understood to be a social problem with a number of victims and perpetrators, the participants are frequently typified simultaneously as both victim and villain. In light of these discrepancies, however, it appears that the intended objectives and the actual operation of the diversion program both work towards the same, ultimate goal: change

Modeling a NOx Storage and Reduction Catalyst

Lean burn engines are more fuel efficient than standard stoichiometric-burn engines but at the same time, the conventional three-way catalyst is not effective in reducing the NOx in oxygen-rich exhaust. One of the recent advancements in exhaust after treatment technologies for lean burn engines is the NOx storage and reduction (NSR) methodology. In this mechanism, NOx is stored on the storage component of a NSR catalyst during normal engine operation. However, before the catalyst reaches its saturation capacity, an excess of fuel is injected to the engine for a very short period resulting in reductant rich exhaust and during this period, NOx is released and subsequently reduced to N2, therefore, restoring the storage capacity of the catalyst. The operation is cyclic in nature, with the engine operating between an oxygen rich feed for long periods and a fuel rich feed for relatively shorter periods. To implement this technology in the most efficient way, a detailed understanding of the NSR chemistry under different operating conditions is required. For the past few years, several authors have studied the NSR systems using both experimental and modeling techniques. However, most of the models proposed in the literature were calibrated against the steady cyclic operation where the NOx profiles are similar for each cycle. In real life situations, the engine operation changes with different driving conditions, occurring due to sudden acceleration, roads in hilly areas, non-uniform braking, etc., which results in operation with a number of different transient cycle-to-cycle regimes depending upon the frequency with which the engine operation is altered. Due to such varying conditions, it is very important to investigate the significance of transients observed between the two different steady cycle-to-cycle operations for the optimization and control purposes. Also, the models in the literature are specific to the catalyst used in the study and therefore, their adaptation to other NSR catalysts is not straightforward. Therefore, one of the main motivations behind this research work is to develop a general approach to explain the storage dynamics. Moreover, the existing models have not studied the regeneration mechanisms, which is very important to explain the cyclic data in complete operation including both transients and steady state cycles. In this study, a pseudo one-dimensional model of a commercial NOx storage/release (NSR) catalyst is presented. The NOx storage is considered to be mass transfer limited, where as the storage proceeds, the barium carbonate particle is converted into the nitrate and for further storage, the NOx has to diffuse through this growing nitrate layer and a after certain depth, this penetration becomes nearly impossible. To explain the transient nature of the cyclic NOx profile, it is hypothesized that when incomplete regeneration occurs, only part of the nitrate is converted back to carbonate. Therefore, the nitrate layer increases in thickness with each cycle, thus making further storage increasingly more difficult. The shrinking core concept with incomplete storage in the lean phase followed by incomplete regeneration of the nitrate layer during the regeneration phase accounts for a net drop in storage capacity of the catalyst in each cycle, which continues decreasing until the amount of sites regenerated equal the amount used in NOx storage. The number of unknown parameters used for fitting were reduced by parameter sensitivity analysis and then fitted against a NOx profile at the reactor exit. The overall amount of NOx that can be stored in the lean phase of the cycle depends on the extent of regeneration that can be achieved during the previous rich phase, which in turn depends directly on the concentration of reductants in the feed. Therefore, there is a trade-off between the amount of fuel used and the NOx emissions. The proposed model can be potentially used to improve this trade-off by using model-based optimization techniques

Robust Algorithms for Optimization of Chemical Processes in the Presence of Model-Plant Mismatch

Process models are always associated with uncertainty, due to either inaccurate model structure or inaccurate identification. If left unaccounted for, these uncertainties can significantly affect the model-based decision-making. This thesis addresses the problem of model-based optimization in the presence of uncertainties, especially due to model structure error. The optimal solution from standard optimization techniques is often associated with a certain degree of uncertainty and if the model-plant mismatch is very significant, this solution may have a significant bias with respect to the actual process optimum. Accordingly, in this thesis, we developed new strategies to reduce (1) the variability in the optimal solution and (2) the bias between the predicted and the true process optima. Robust optimization is a well-established methodology where the variability in optimization objective is considered explicitly in the cost function, leading to a solution that is robust to model uncertainties. However, the reported robust formulations have few limitations especially in the context of nonlinear models. The standard technique to quantify the effect of model uncertainties is based on the linearization of underlying model that may not be valid if the noise in measurements is quite high. To address this limitation, uncertainty descriptions based on the Bayes’ Theorem are implemented in this work. Since for nonlinear models the resulting Bayesian uncertainty may have a non-standard form with no analytical solution, the propagation of this uncertainty onto the optimum may become computationally challenging using conventional Monte Carlo techniques. To this end, an approach based on Polynomial Chaos expansions is developed. It is shown in a simulated case study that this approach resulted in drastic reductions in the computational time when compared to a standard Monte Carlo sampling technique. The key advantage of PC expansions is that they provide analytical expressions for statistical moments even if the uncertainty in variables is non-standard. These expansions were also used to speed up the calculation of likelihood function within the Bayesian framework. Here, a methodology based on Multi-Resolution analysis is proposed to formulate the PC based approximated model with higher accuracy over the parameter space that is most likely based on the given measurements. For the second objective, i.e. reducing the bias between the predicted and true process optima, an iterative optimization algorithm is developed which progressively corrects the model for structural error as the algorithm proceeds towards the true process optimum. The standard technique is to calibrate the model at some initial operating conditions and, then, use this model to search for an optimal solution. Since the identification and optimization objectives are solved independently, when there is a mismatch between the process and the model, the parameter estimates cannot satisfy these two objectives simultaneously. To this end, in the proposed methodology, corrections are added to the model in such a way that the updated parameter estimates reduce the conflict between the identification and optimization objectives. Unlike the standard estimation technique that minimizes only the prediction error at a given set of operating conditions, the proposed algorithm also includes the differences between the predicted and measured gradients of the optimization objective and/or constraints in the estimation. In the initial version of the algorithm, the proposed correction is based on the linearization of model outputs. Then, in the second part, the correction is extended by using a quadratic approximation of the model, which, for the given case study, resulted in much faster convergence as compared to the earlier version. Finally, the methodologies mentioned above were combined to formulate a robust iterative optimization strategy that converges to the true process optimum with minimum variability in the search path. One of the major findings of this thesis is that the robust optimal solutions based on the Bayesian parametric uncertainty are much less conservative than their counterparts based on normally distributed parameters

L'impact des politiques d'ajustement dans l'agriculture égyptienne

Compte tenu des spécificités de l'agriculture égyptienne et des prévisions à moyen terme, les politiques d'ajustement structurel peuvent-elles atteindre les objectifs qui leur ont été fixés? Peuvent-elles accroître les superficies cultivées et les rendements, l'investissement et la production, en rétablissant les incitations par les prix et en valorisant les avantages comparatifs du pays ? Nous allons tenter de montrer dans cette étude que de telles politiques menacent au contraire de ralenti..

Kontribusi Kemampuan Koneksi, Kemampuan Representasi, Dan Disposisi Matematis Terhadap Prestasi Belajar Matematika Siswa SMA Swasta Di Kabupaten Manggarai

This research aimed at investigating: 1) the contribution of mathematical connection ability toward mathematics achievement through mathematical disposition, 2) the contribution of mathematical representation ability toward mathematics achievement through mathematical disposition, 3) the contribution of mathematical connection and representation mathematical ability toward mathematical disposition simultaneously, and 4) the contribution of the connection ability, representation ability and mathematical disposition toward students\u27 mathematics achievement simultaneously. The research applied ex post facto design. The population of this research was second year students\u27 of science program of private senior high schools in Manggarai regency in the academic year 2012/2013. The total members of sample was 230 which chosen using cluster sampling technique. The data of the connection and representation mathematical abilities were gathered using essay test. The data of mathematical disposition were collected by questionnaire. The data of students\u27 mathematics achievement were collected by using students\u27 first semester score. The data were analyzed using Path Analysis. The result indicated that: 1) the contribution of mathematical connection ability toward students\u27 mathematics achievement through mathematical disposition is 19,36%, 2) the contribution of mathematical representation ability toward students\u27 mathematics achievement through mathematical disposition is 14,12%, 3) the contribution of mathematical connection and representation ability toward mathematical disposition is 83,7%, and 4) the contribution of connection ability, representation ability, and mathematical disposition toward students\u27 mathematics achievement is 81,3%. Based on these research findings, it was concluded that connection ability, representation ability, and mathematical dispositions contribute significantly to mathematics achievement of grade XI science students of Manggarai directly or indirectly. keyword : Key words: contribution, connection ability, representation ability, disposition mathematical, and mathematics achievemen

Respon Mahasiswa Terhadap Penyelesaian Soal Koneksi Matematis Melalui Taksonomi Fink

Student response is an important aspect of learning because it helps educators understand student development. One of the frameworks used to analyze student responses to cognitive, affective, and metacognitive aspects is the Fink taxonomy. This study aims to find patterns of student response rates in solving mathematical connection through Fink's taxonomy. This research method is qualitative. The data collected were data on the ability of mathematical connections to measure student responses to cognitive and metacognitive aspects taken using test instruments as well as data on social and caring dimensions to measure student responses to affective aspects that were taken using questionnaires. The results of this study are student responses at the basic knowledge level of 18.42%, application of 12.79%, integration of 12.22%, social dimensions 23.28%, caring aspects of 22.34%, and metacognitive 10.95. % and student response results at the level of basic knowledge of 18.94%, application of 13.16%, integration of 11.23%, social dimensions 23.87%, caring aspects of 22.78%, and metacognitive of 10.02%. Student responses to cognitive, affective, and metacognitive aspects provide an overview for educators to pay attention to students' abilities and attitudes in building knowledge independently on a subject matter

Pembelajaran Matematika Berbantuan Spreadsheet pada Materi Grafik Fungsi

Dalam pembelajaran matematika, perangkat komputer berupa spreadsheet dapat berperan sebagai alat bantu belajar siswa serta sumber belajar bagi guru agar pembelajaran menjadi lebih optimal. Spreadsheet telah meluncurkan berbagai fitur yang dapat dimanfaatkan sebagai media dinamis yang dapat mensimulasikan konsep matematika selain operasi aljabar, yakni visualisasi grafik fungsi kuadrat. Melalui penelitian pengembangan, peneliti terdorong untuk mengimplementasikan pembelajaran matematika yang terintegrasi media spreadsheet demi tercapainya pemahaman tentang grafik fungsi secara optimal. Penelitian ini adalah penelitian pengembangan/Research and Development (R&D). Pembuatan media pembelajaran mengacu pada model pengembangan Plomp. Subjek penelitian ini siswa kelas X SMA. Selain itu, terdapat dua subjek lain yaitu validator dan guru. Hasil penelitian ini menunjukan bahwa media pembelajaran matematika berbantuan spreadsheet memenuhi kriteria valid, praktis, dan efektif

Konstruksi Tes High Order Thinking Skills (HOTS) bagi Guru-Guru Matematika SMP di Manggarai Timur

Kegiatan pelatihan ini dilatarbelakangi oleh pentingnya pengembangan soal HOTS dalam seiap proses evaluasi pembelajaran. Pengembangan tentang HOTS saat ini menjadi pusat perhatian pendidikan dan pada bagian tertentu, kurikulum untuk matematika sekolah menengah telah bergeser pada pengembangan berpikir HOTS. Kegiatan ini dilakukan kepada guru-guru matematika SMP di kabupaten Manggarai Timur. Tujuannya adalah agar mereka dapat memahami apa itu HOTS serta bagaimana menyusun soal HOTS. Metode pelaksanaan program adalah melakukan pelatihan berupa pengenalan HOTS, cara menyusun soal HOTS, dan menelaah soal-soal yang dihasilkan oleh para guru. Kegiatan ini dilakukan dengan melibatkan lima dosen yang berasal dari program studi pendidikan matematika STKIP Santu Paulus. Hasil dari penelaan soal menunjukkan bahwa semua peserta memahami apa itu HOTS dan berhasil menyusun soal HOTS sesuai dengan prosesur penyusunan soal HOTS. Selain itu, berdasarkan hasil wawancara semua peserta menyatakan menyukai kegiatan pelatihan yang dibawakan oleh tim. Salah satu rekomendasi dan komitmen bersama dari kepala sekolah dan para guru setelah kegiatan ini adalah mewajibkan menyusun soal HOTS pada setiap proses evaluasi pembelajaran