Servomechanism

In control engineering, a servomechanism, usually shortened to servo, is an automatic device that uses error-sensing negative feedback to correct the action of a mechanism. In displacement-controlled applications, it usually includes a built-in encoder or other position feedback mechanism to ensure the output is achieving the desired effect. The term correctly applies only to systems where the feedback or error-correction signals help control mechanical position, speed, attitude or any other measurable variables. For example, an automotive power window control is not a servomechanism, as there is no automatic feedback that controls position—the operator does this by observation. By contrast a car's cruise control uses closed-loop feedback, which classifies it as a servomechanism. Applications Position control A common type of servo provides position control. Commonly, servos are electric, hydraulic, or pneumatic. They operate on the principle of negative feedbac

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HMM-Based Error Correction Mechanism for Five-Key Chording Keyboards

Pierre Dillenbourg, Bixio Rimoldi, Adrian Dan Tarniceriu

As different text input devices lead to different typing error patterns, considering the device characteristics when designing an error correction mechanism can lead to significantly improved results. In this paper, we propose and evaluate a spelling correction algorithm based on Hidden Markov Models. It is designed for a five-key chording keyboard and uses the probabilities that one character is typed for another, named confusion probabilities. For the used evaluation text, the proposed algorithm reduces the error rate from 10.11% to 1.27%. In comparison, MsWord and iSpell reduce the error rate to 4.75% and 6.69%, respectively.

2015

MAP-Based Error Correction Mechanism for Five-Key Chording Keyboards

Pierre Dillenbourg, Bixio Rimoldi, Adrian Dan Tarniceriu

Because of different designs, different text input devices have different error patterns. If we consider these aspects when designing an error correction mechanism, we can obtain significantly lower error rates. In this paper, we propose and evaluate a spelling algorithm specifically designed for a five-key chording keyboard. It is based on the maximum a posteriori probability (MAP) criterion, taking into account a dictionary model and the probability that one character is typed for another. These probabilities are determined experimentally. For the considered evaluation text, the proposed method reduced the error rate from 10.11% to 2.17%. As comparison, MsWord and iSpell reduced the error rate to 5.15% and 6.69%, respectively.

2015

A Study of Forward Error Correction Schemes for Reliable Transport in Underwater Sensor Networks

Florent Frédéric Garcin, Bin Liu

Underwater communications is a very challenging topic due to its singular channel characteristics. Most protocols used in terrestrial wireless communications can not be directly applied in the underwater world. A high bit error rate and low propagation delay make the design of reliable transport protocols especially awkward. In this paper, we first propose four schemes that combine forward error correction mechanisms at the bit and/or packet level to increase the reliability in a non-cooperative scenario. The broadcast property of the underwater environment allows us to extend them to a cooperative setting. Based on our analyses, we introduce ADELIN: an adaptive reliable transport protocol for underwater sensor networks. We suggest an architecture for implementation and compare our protocol to other schemes. We show that it succeeds in a better probability and energy tradeoff for both single- and multi-hop communications.

IEEE2008

Control theory

Control theory is a field of control engineering and applied mathematics that deals with the control of dynamical systems in engineered processes and machines. The objective is to develop a model or a

Feedback

Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to feed back into itself. The noti

Servomotor

A servomotor (or servo motor) is a rotary actuator or linear actuator that allows for precise control of angular or linear position, velocity, and acceleration. It consists of a suitable motor coup

EE-208: Microcontrollers and digital systems

Microcontrôleurs et conception de systèmes numériques couvre le fonctionnement interne d'un microcontrôleur, des notions de base d'architecture de processeur et de système informatique ainsi que les interfaces de microcontrôleurs, et protocoles de communication série.

ME-410: Mechanical product design and development

Study and explore design principles of the different mechatronic components and systems. We will cover in-depth especially on meso-scale actuators, sensors and body construction methods.

CH-319: Experimental biochemistry and biophysics

A semester long experiment where you plan and construct a fluorescent sensor protein starting from DNA bricks. The protein will be expressed in and purified from bacteria, and characterized by biochemical and spectroscopic methods. Your report will be in the style of a scientific paper.