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Genetic resources in agroecosystems
Published in Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz, Agroecology, 2023
Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz
As each problem presents itself, crop breeders screen the genetic variability of a crop until they find a resistant genotype. This resistance is often provided by a single gene. The gene-transfer and back-crossing techniques described above are employed to incorporate the gene into a specific crop pedigree. The result is sometimes called vertical resistance. It has two weaknesses. First, the resistance will continue to function only as long as the limiting factor does not change. Unfortunately, in the case of pests, diseases, and weeds, the limiting factor is never static for very long because of continual natural selection. So, the problem organism eventually develops “resistance to the resistance,” and an outbreak or epidemic occurs. This dynamic is the basis of the well-known crop breeders’ treadmill. Second, in the process of breeding for vertical resistance, genes providing partial resistance to the wider spectrum of pathogens are lost.
Modelling and analysis of skin pigmentation
Published in Ahmad Fadzil Mohamad Hani, Dileep Kumar, Optical Imaging for Biomedical and Clinical Applications, 2017
Ahmad Fadzil Mohamad Hani, Hermawan Nugroho, Norashikin Shamsudin, Suraiya H. Hussein
Crossover operation consists of swapping one randomly selected parameter between two randomly chosen parents to generate two offspring. It exchanges genetic information between parents and combines two parents to breed two children. The exchange of genetic information supposes that the children contain relevant information from their parents. The crossover operation is an important technique to increase the fitness of the population. Generally, the procedure of crossing are synthesised using four steps: selecting two individuals from the population by the crossing operator (single or multipoint crossing); selecting a random gene from the chromosome; interchanging the gene information between the two parents and generating two children. The crossing procedure interchanges the gene of two parents in one or several points. This operation can be applied to different types of coding (real-value and binary) for only involving a gene swapping.
Introduction to Biometry
Published in Ling Guan, Yifeng He, Sun-Yuan Kung, Multimedia Image and Video Processing, 2012
Carmelo Velardo, Jean-Luc Dugelay, Lionel Daniel, Antitza Dantcheva, Nesli Erdogmus, Neslihan Kose, Rui Min, Xuran Zhao
Since the beginning of biometry’s history the discriminative power of some traits (e.g., fingerprints) was used for the identification and tracking of criminals. Recently, after the attacks of September 11, 2001, a urge of security promoted the use of biometry as a tool that could ease the prevention of such events [3]. International organizations started gathering information about all passengers crossing international borders by using biometrics. Thus, biometric authentication started being used in many airports and train stations. Biometric traits are mainly used to perform identification in order to allow/deny access to restricted areas, to index a set of pictures by person, or to enable decrypting data in biometric-enabled devices. Thus, biometry is now employed in many technologies not always related to security.
A review of chewing detection for automated dietary monitoring
Published in Journal of the Chinese Institute of Engineers, 2022
Yanxin Wei, Khairun Nisa’ Minhad, Nur Asmiza Selamat, Sawal Hamid Md Ali, Mohammad Arif Sobhan Bhuiyan, Kelvin Jian Aun Ooi, Siti Balqis Samdin
Signal segmentation is one of the fundamental problems of digital signal processing in various information, prediction and control systems. Sazonov et al. divided chewing signals into decision epochs, which are non-overlapping windows of fixed duration in a chewing signal. A decision epoch is defined as food intake detection time resolution; a shorter one leads to a higher temporal resolution and a shorter time to determine food intake (Sazonov and Fontana 2012). Feature extraction is used to transform high-dimensional feature information into a low-dimensional feature by mapping or to transform and compress feature information. Farooq et al. divided all detected signals into non-overlapping epochs for feature computation and chose the appropriate epoch size to detect short snacking episodes. Moreover, Farooq and Sazonov (2016b) computed the set of 68 times and frequency features for each epoch. The feature set includes time and frequency domain features. Time domain features are related to time statistics of epoch data and crossing characteristics. Frequency domain features are based on the spectrum’s peak frequency and standard deviation.
Description of quasidegenerate electronic states exhibiting avoided crossing
Published in Molecular Physics, 2018
In the case of avoided curve crossings, the relative contributions of the different reference coefficients tend to vary strongly with variations in the molecular geometry. Moreover, avoided crossing problems typically display very large differences in reference configuration mixing coefficients between the reference wave function and the final correlated wave function. The location of the avoided crossing region significantly depends on the level at which the dynamic correlation is captured. Consequently, an inappropriate treatment of the electronic correlation changes the relative energy of a state with respect to the other and consequently amends the corresponding wave functions. Moreover, near the avoided crossing, it is a nontrivial task to converge the working equation even at the MR mean-field level due to unexpected root-flipping problems. Therefore, in our experience, it is difficult to keep track of the proper state to optimise. The orbitals required to describe the two energy curves involved are quite different specially around the avoided crossing region. Needless to say, the study of coupling between the electronic states due to avoided crossing requires a detailed knowledge of the PECs within chemical accuracy. The appearance of avoided crossing is also often experienced for various kinds of adsorbates on metal surfaces when the interaction occurs through an ionic bond formation. Note that the curve crossing is at the heart of oxidation-reduction procedure at metal surfaces and is pertinent to the realm of electro-chemistry and corrosion science. This aspect acted precisely as the catalyst to execute the present work.
A dynamic optimization method for adaptive signal control in a connected vehicle environment
Published in Journal of Intelligent Transportation Systems, 2020
Zhihong Yao, Yangsheng Jiang, Bin Zhao, Xiaoling Luo, Bo Peng
The common crossover rules include one-cut-point and multi-point crossovers. The gene in the signal timing plan is short, and thus, adopting a multi-point crossover will decrease the stability of the solution. Accordingly, the one-cut-point crossover is used in this study. In the crossover operation, a one-cut-point is first randomly selected, and then the last several genes after the crossing point are exchanged. For example, if the crossing point is at the second gene, then the two chromosomes and after the crossover will be and