Clandestinity and militant culture in Latin America, 1960s to the early 1980s: epistemological and historical reflections and an agenda for research

Clandestinity was a central aspect of the life and organisation of the militancies of the diverse cultures of the Cold War Latin America left. Yet the topic is scarcely considered central in testimonies or historical analyses of the period. In this article I approach both clandestinity as culture and the culture of clandestinity as lived experiences, ways of organising and modi operandi among militant organisations and individuals of the period. To do this, I resort to diverse types of literature, ranging from academic analyses to personal testimonies, including fictionalised accounts. I then elaborate on the possible historical, methodological and epistemological reasons why clandestinity has not been explored in the majority of the academic or testimonial corpuses presently available, stressing the possibility, as a hypothesis, that we may still be facing silence – a main tenet of clandestinity – as political doctrine. I also briefly discuss oral history as a main tool to access knowledge of clandestinity and question whether clandestinity may be an object of the historical record

A Historical Account and Technical Reassessment of the Broyden-based Input Space Mapping Optimization Algorithm

The Broyden-based input space mapping (SM) algorithm, better known as the aggressive space mapping (ASM) algorithm, is revisited in this article. The most fundamental SM-based optimization methods developed until now, in which ASM is framed, are overviewed. More than two decades of ASM evolution are briefly accounted, evidencing its popularity in both academia and industry. The two main characteristics that explain its popularity are emphasized: 1) simplicity, and 2) efficiency (when it works, it works extremely well). The fundamentals behind the Broyden-based input SM algorithm are illustrated, accentuating key steps for its successful implementation, as well as typical scenarios where it may fail. Finally, some future directions regarding ASM are ventured

Advancing Robot Autonomy for Long-Horizon Tasks

Autonomous robots have real-world applications in diverse fields, such as mobile manipulation and environmental exploration, and many such tasks benefit from a hands-off approach in terms of human user involvement over a long task horizon. However, the level of autonomy achievable by a deployment is limited in part by the problem definition or task specification required by the system. Task specifications often require technical, low-level information that is unintuitive to describe and may result in generic solutions, burdening the user technically both before and after task completion. In this thesis, we aim to advance task specification abstraction toward the goal of increasing robot autonomy in real-world scenarios. We do so by tackling problems that address several different angles of this goal. First, we develop a way for the automatic discovery of optimal transition points between subtasks in the context of constrained mobile manipulation, removing the need for the human to hand-specify these in the task specification. We further propose a way to automatically describe constraints on robot motion by using demonstrated data as opposed to manually-defined constraints. Then, within the context of environmental exploration, we propose a flexible task specification framework, requiring just a set of quantiles of interest from the user that allows the robot to directly suggest locations in the environment for the user to study. We next systematically study the effect of including a robot team in the task specification and show that multirobot teams have the ability to improve performance under certain specification conditions, including enabling inter-robot communication. Finally, we propose methods for a communication protocol that autonomously selects useful but limited information to share with the other robots.Comment: PhD dissertation. 160 page

Willingness-to-Pay for Attribute Level and Variability: The Case of Mexican Millers’ Demand for Hard Red Winter Wheat

In-person interviews were carried out with Mexican millers who were administered a conjoint-type survey designed to incorporate uncertainty in attribute levels. Two methods were used to model millers’ risk preferences: a modified mean-variance approach and an explicit expected utility approach. Controlling for variability, Mexican millers are willing to pay premiums for increases in quality factors such as test weight, protein content, falling number, and dough strength/extensibility. We find millers are not particularly sensitive to changes in the variability of quality characteristics. Out-of-sample forecasts suggest the mean-variance model provides an accurate depiction of actual Mexican imports.mean-variance, Mexican wheat market, moment generating function, preference elicitation, wheat quality, Agribusiness, Farm Management, Food Consumption/Nutrition/Food Safety, International Relations/Trade, Marketing, Production Economics, Risk and Uncertainty, C35, C42, Q13,

Promoting and Empowering the RF and Microwave Community in Costa Rica

This article describes a recent and very fruitful IEEE MTT-S initiative in Latin America focusing on Costa Rica. Envisaged by the Membership and Geographical Activities (MGA) Committee of the MTT-S Administrative Committee (AdCom), this initiative, which was implemented by the end of 2022, aimed at developing MTT-S membership, volunteer base, and increased engagement in MTT-S activities in Region 9 of IEEE, especially focusing on Costa Rica. The delegation consisting of the MTT-S MGA Chair, Goutam Chattopadhyay, and the MTT-S Region 9 Coordinator, José Rayas-Sánchez, visited San Jose, Costa Rica. The 2022 MTT-S President, Rashaunda Henderson, was to accompany the delegation but had to drop out at the last moment due to some unavoidable circumstances. The delegation carried MTT-S President’s message to the microwave community in Costa Rica. This article presents the rationale and goals of the MTT-S delegation, the planning for the initiative, the agenda and activities, and the outcomes achieved. Several months after its implementation, the results obtained indicate that the initiative was very successful, confirming it as an effective strategy to promote RF and microwave-related technical activities and revitalize communities in similar emerging regions of the world.ITESO, A.C

Eye Diagram Optimization based on Design of Experiments (DoE) to Accelerate Industrial Testing of High Speed Links

Higher data rates in high speed input/output (HSIO) links demand more equalization (EQ) complexity, leading to an ever larger number of possible combinations of EQ settings. Finding the optimal set of EQ parameters through exhaustive methods is prohibitive given the time-to-market requirements. This paper presents a methodology to design a statistically sufficient set of experiments for optimizing the receiver eye diagram of a HSIO link while greatly reducing the overall testing time. Our methodology is illustrated by a 5-Gbps HSIO link comprised of a Tx, a channel (including packages, vias, PCB traces, connectors and a crosstalk aggressor) and an Rx

An Objective Function Formulation for Circuit Parameter Extraction Based on the Kullback-Leibler Distance

Numerical circuit parameter extraction is widely used for modeling many kinds of high-frequency structures. In particular, parameter extraction can be used to find the optimal parameter values of an equivalent circuit model to match as close as possible a given target response. This paper presents a novel objective function formulation for parameter extraction based on the Kullback-Leibler distance. A rigorous graphical and numerical comparison of the proposed new formulation against classical l-th norm formulations is included. One- and two-dimensional synthetic examples are used to illustrate the advantages of the proposed Kullback-Leibler distance formulation. Our results indicate that the proposed new formulation yields similar or better-behaved parameter extraction objective functions than those obtained from l-th norm formulations.ITESO, A.C

An Early History of Optimization Technology for Automated Design of Microwave Circuits

This paper outlines the early history of optimization technology for the design of microwave circuits—a personal journey filled with aspirations, academic contributions, and commercial innovations. Microwave engineers have evolved from being consumers of mathematical optimization algorithms to originators of exciting concepts and technologies that have spread far beyond the boundaries of microwaves. From the early days of simple direct search algorithms based on heuristic methods through gradient-based electromagnetic optimization to space mapping technology we arrive at today’s surrogate methodologies. Our path finally connects to today’s multi-physics, system-level, and measurement-based optimization challenges exploiting confined and feature-based surrogates, cognition-driven space mapping, Bayesian approaches, and more. Our story recognizes visionaries such as William J. Getsinger of the 1960s and Robert Pucel of the 1980s, and highlights a seminal decades-long collaboration with mathematician Kaj Madsen. We address not only academic contributions that provide proof of concept, but also indicate early formative milestones in the development of commercially competitive software specifically featuring optimization technology.ITESO, A.C

Towards signal-power integrity analysis by efficient power delivery network lumped models obtained from parameter extraction

The combined signal integrity (SI) and power integrity (PI) design process is getting more relevant and complex as a result of the continuous computing system performance growth. This complexity drives longer design cycle times using traditional tools and methods. In this paper, a low computational cost optimization method based on a parameter extraction (PE) technique is proposed to develop accurate and fast power delivery network (PDN) lumped models. Once this model is available, it is used in the simulation process during the SI and PI analysis, making the whole design process much more efficient. Our proposed methodology is applied to a classical dual data rate (DDR) memory sub-system problem, saving 99.8% of the analysis time with only 1.2% of the computational resources typically used in current industrial practices.ITESO, A.C

Nutritional value of forage species from the Central Highlands Region of Mexico at different stages of maturity

This paper has two objectives, the first is to determine the chemical composition, gas production parameters and the gas release kinetics, at different stages of maturity, of three grasses and a legume commonly found in long established pastures in Mexico central highland plateau. The second is to combine the gas release kinetics analysis and the GP fitted to a mathematical model in order to improve the biological understanding of the fermentation kinetics obtained from the GP technique. Representative samples of Pennisetum clandestinum (kikuyu grass), Sporobolus indicus (mouse tail), Eleocharis dombeyana (reed), Trifolium amabile (Aztec clover) plus a composite sample were collected in the growing season (July, September and November 2003) and analysed using an in vitro gas production (GP) technique. The accumulated GP was fitted to the model described in PALMER et al. (2005). Significant differences (P<0.001) were observed among species and periods for chemical composition, organic matter and neutral detergent fibre digestibility. Significant differences (P<0.05) were observed regarding fermentation parameters and gas release kinetic, with T. amabile and P. clandestinum being the species with the highest fermentability, whereas S. indicus and E. dombeyana were poorly fermented. P. clandestinum and T. amabile showed higher nutritive value than S. indicus and E. dombeyana. Composite samples were influenced by the chemical and fermentation characteristics of all species. It was concluded that the use of gas release kinetics analysis was useful for differentiating the fermentation kinetic of the soluble and insoluble fraction in the grasses and legume. Therefore by performing both approaches, the gas release kinetics analysis and the GP fitted to a mathematical model, gave a better description of the fermentation kinetic of grasses and the legume was achieved when only one approach had been used