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C Programming
Published in Paul W. Ross, The Handbook of Software for Engineers and Scientists, 2018
Many programmers place the main() function first in the file and place other function definitions later in the file. This can potentially lead to a problem. Remember that a general principle of C is that identifiers should be declared before they are used. That principle holds for the name of functions also. However, if the main() function calls a user-defined function whose definition comes later in the file, this principle is violated. C allows this violation, but makes some assumptions about such a function. It assumes that it returns an int, and that the types of the actual parameters are the correct types of formal parameters. These assumptions may be incorrect, and may lead to some run-time errors in the program. The ANSI standard provides a solution to this potential problem: function prototypes. A function prototype is a declaration of the return type, function name, and parameter type with no function body. If a function prototype is placed at the beginning of a file, then the full function definition can be placed at the end of the file after some of the function calls. The compiler will have the necessary information to correctly translate function calls. Figure 13.38 gives function prototypes for some of the function examples given above.
Recognizing mixed urban functions from human activities using representation learning methods
Published in International Journal of Digital Earth, 2023
Junjie Hu, Yong Gao, Xuechen Wang, Yu Liu
We assumed that the locations contained similar urban functions if they had similar human activities. Thus, the areas with comparable functions tended to aggregate in the vector space. Such patterns can be detected by clustering algorithms. We applied FCM clustering method (Bezdek, Ehrlich, and Full 1984) to the aggregated vectors to infer the proportions of mixed urban functions. FCM is an unsupervised soft clustering method that calculates the membership value of cluster prototypes for each sample, given the cluster number as a hyper parameter. We regarded each cluster prototype as an urban function, assuming that the proximity in vector space denoted the similarity of mixed urban functions. Accordingly, the membership value of a cluster was regarded as the proportion of the corresponding urban functions, as it indicates the likelihood of the area belonging to that function prototype. The sum of the membership values for each place was normalized to 1 so that the membership values were equivalent to the proportions of mixed urban functions.
Design and implementation of second-order microwave integrator
Published in International Journal of Electronics, 2020
Mridul Gupta, Dharmendra Kumar Upadhyay
A new methodology based on digital signal processing techniques was developed by Chang and Hsue (2001) to obtain microwave filters from a digital transfer function prototype which fulfils the design specifications. Chain scattering matrices of equal electrical-length transmission line elements were derived in domain for formulating the desired network transfer function. To implement the filters at microwave range, impedance values of the network line elements were obtained using the coefficients of their prototype digital filter through an optimization process. Based on this approach, a first-order microwave integrator was implemented by Hsue et al. (2006) using open- circuited shunt-stubs and serial transmission lines. Afterwards, Upadhyay and Singh (2013) realized microwave integrators with different time-constants using only single open-circuited shunt stub. Thus, it is identified that an open-circuited shunt stub produces the characteristic/behaviour of a low pass filter or an integrator circuit. Further, serial transmission line sections are cascaded with this open stub to achieve magnitude response of an ideal second-order integrator viz. , where is a scaling constant.
Improving breast cancer classification by dimensional reduction on mammograms
Published in Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization, 2018
Mohammad Kazem Ebrahimpour, Hamid Mirvaziri, Vahid Sattari-Naeini
where W(u, v) are the wavelet coefficients, f(x, y) is original image, u and v are the transmission and scaling parameters, respectively. The transmission defines the time shift and the displacement of window and it includes time information of the transformation. Scale parameter defines the time scale and inversely relate to frequency i.e. s = 1/f · ψ is window function, commonly called the mother wavelet. The term of mother also is used in order to transfer and scale versions that all obtained from a primary function. In fact, mother wavelet is a template function (prototype) to produce other versions.