coding

The decision-making process is critical to the success of any construction project, construction personnel make decisions related to their duties every day and justify these decisions. Wrong decisions can disrupt the project in terms of time, quality, cost and relationships and can even impose exorbitant costs. On the other hand, design, engineering and construction include complex decisions with high uncertainty, so special attention should be paid to this part. The main goal of this research is to determine the dominant model of the decision-making process of experts in construction projects. In the first step, decision-making models will be identified through library studies, and then their decision-making processes will be determined by attending construction workshops and interviewing experts in the field of construction. In the next step, by communicating between the decision-making processes of experts and decision-making models, the most used model is determined through coding؛ In this research, based on the conducted research, the 3 dominant models used in the decision-making process of expert project managers are: the contingency model, the multi-criteria decision-making model, and the classic model.

The need for high-speed data transfer on the one hand and the limited resources available, especially the lack of frequency spectrum on the other hand, are the most important challenges facing G4-standard telecommunications networks, such as WiMAX, LTE and TD-SCDMA. Methods have been devised to improve spectral efficiency (SE). One of these methods is adaptive modulation and coding (AMC) in which the sender selects its modulation and coding scheme (MCS) based on channel conditions and with respect to the error probability limit of a certain set. In this paper, the performance of two AMC methods with the same modulation and coding design, one with the Moore state machine method and the other with the first-order finite state Markov chain method, is simulated and the optimal state is extracted. In each of these two methods, each state is represented by a pair of regular modulation and coding rates. The designs are QPSK, 16QAM and 64QAM modulations and block codes with rates of 1.2, 2.3 and 3.4. In Moore -adaptive method, the modulation and coding scheme is adapted based on the average attenuation coefficient of the channel, and in Markov-adaptive method, it is done based on the signal-to-noise ratio (SNR) of the average channel. The simulation results show that the spectral efficiency of the Moore method is better in the signal-to-noise ratio from 9 to 13.35 dB to 31.6% and in the signal-to-noise ratio of 13.35 to 18.6 dB is 7.9% better than the spectral efficiency of the Markov-adaptive method. Also, the spectral efficiency of Markov method in signal-to-noise ratio from 18.6 to 22 decibels is 52.1% better than the spectral efficiency of Moore-adaptive method.

Technology development is one of the ways to develop countries and one of the categories of knowledge-based economy. It is one of the major topics in incubators. The dominant view of incubators is more related to the business growth and at a higher level, it is the acceleration of business for a permanent presence in the market. Fewer research can be found addressing incubators in technology development. This research identified the challenges of technology development of university incubators. This survey was applicable, and in terms of controlling variables, indirect, random and descriptive in matter exploration of library and filed in data collection, and in terms of nature, descriptive. In terms of data type, it was a qualitative type of exploration and in terms of how to collect data was field research and library research. Books, publications, internet resources, and valid databases using library studies, documentary studies, interviews and field research were used for collecting data. The result of this section was to identify the dimensions of the challenges of technology development in the university incubators. In this research, a semi-structured interview with experts is presented to identify the issues. Qualitative data analyzing has been done using (Atlas-ti®) software. All interviews are recorded, transcript-ed to word software and assigned in Atlas-ti® software. The result of coding and categorizing, including 4 categories and 16 main codes, states technology development challenges related to networking contexts.

Coding theory is one of the most interesting and applied branches of mathematics that has been widely used in Wireless networking, include mobile networks, wireless local area networks, wireless sensor networks and satellite communication networks. In this paper, our goal is to provide some new codes by using t- Pell number sequences and Hadamard product. In order to achieve this goal, we first study the properties of matrix of t- Pell number sequences and their Hadamard product of these matrices. Then, using the obtained results, we present some coding and decoding algorithms. Finally, we study the blocking algorithm on the matrix of the t- Pell number sequences and their Hadamard product.

Plants paly a very important role in creating and maintaining the biological balance which is vital for the life of each living creature including humans. Due to the great importance of vegetation cover in terms of habitat, energy production and other important characteristics on the planet, the recognition and monitoring of various plant species has always been a concern for ecologists and decision makers from the economic points of view. This will be possible on a large scale with remote sensing technology and the use of satellite images containing vegetation and their classification. Different techniques of classification are deployed where in some of them, use have been made of reflectance curves and their derivatives. In some other methods, some coding system applied on reflectance curves and their derivatives are used as a fast method.  In this work, a method named CBOSE is presented in which, a coding approach on reflectance and its derivatives is applied. The CBOSE method is coding based on extreme points of the reflectance spectrum and combines from one to several bits to distinguish between plant species with relatively high spectral similarity. This coding method, after necessary pre-processing such as water vapor correction and continuum removal analysis, on AVIRIS hyperspectral images of Indian pine region containing various species such as wheat, barley, alfalfa, grass, tree, soybean and corn were also applied in three stages of germination, medium growth and full growth. Then, the features with the highest separability between the classes were extracted and the classification was done on the properties derived from the codes by selecting the training samples. The classification output of CBOSE was compared with the result of classification by classifiers Support Vector Machine (SVM), Maximum likelihood (ML), Spectral Angle Mesure (SAM), and Hamming similarity criteria and with those of field data. Also the methodology of CBOSE was evaluated and compared with those of coding methods such as Spectral analysis manager (SPAM), Spectral feature-based binary coding (SFBC), Spectral derivative feature coding (SDFC), and Spectral feature probabilistic coding) SFPC). The results show that the CBOSE methods on the average performs respectively 20, 16, 11 and 7 percent better compared to the afore-mentioned methods. Also, in order to evaluate the effects of using derivatives in the coding process, all aforementioned procedures were repeated without using derivatives in the coding processes. It showed that on the average, deployment of reflectance derivative would 8% enhances the accuracy in classification.

Due to the explosive increment of data in recent application, available data storage cannot respond to this volume of data, for this reason molecular memory have been suggested in recent research. DNA is molecular data storage that can store a large amount of data in a limited space with high endurance. Storing data in low volumes can be provided using appropriate mapping. In this paper, a new method for mapping digital data to DNA have been proposed with the aim of simple coding, omitting the decoding faults, increasing the speed of coding and storing digital data and sign-digit with sufficient compression. Studies show that the proposed method can guarantee long-term retrieval of information from DNA compared to previous methods. It also uses less compression to store digital data as compared to the previous methods.

Through the passage of time, computer technology has been considered as a pivotal element in human life. Because of this point, it is more evident that information security gained a prominent position. Cryptography is utilized to secure information in a way that information became impenetrable under attack. In this paper, a new method of encryption is introduced according to the theoretical channel coding method and modular calculations. In this method, with the help of science of numerical theory and modular calculations, a method is used to generate dynamic permutation boxes and dynamic subsituation boxes. Then, with the help of information theory and coding, random errors are added to the text. Generated random errors should be detected and corrected at decryption time using decoding methods. The production of an independent cryptographic method with the pattern of intentional error use, along with the use of a shortcut key (256 bits), has the advantage of this method over the pattern-matching methods.This method can perform an encryption algorithm in which the performance of algorithm for a fixed text and a fixed encryption key, produce a differentiated encrypted text, with Hamming distance nearly 50%, in comparison to the previous performances.

The deliberate and unintentional attacks of the enemy in order to destroy and damag the country’s communications infrastructure as an undeniable fact, underscores the importance of the structuralist defense approach. In this regard, the balancing of the defense and offense budgets to prevent any increase in the index of service expectations was studied.To do so ,Increasing the security of the country’s most important infrastructures from the passive defense approach was investigated , and a comprehensive defense-based algorithm to increase the power and reduce vulnerability against attackers’s deliberate attacking was provided. Furthermore, Extensive pressure control system has been selected as a case study, and considering the risk of attacks, a comprehensive defense algorithm has been undertaken.In order to increase the security of the extensive pressure control system, two methods of hardware and software were proposed, which can reduce the risk of vulnerability to a great extent and ultimately provide the system security.The use of shielding using different materials as a hardware method for coping with field attacks has been investigated and its desirable results have been provided by FEKO software. Morover, in this study, the information coding as a proposed software method, guarantees the security of information transmition. In this paper, while presenting a constructed algorithm to meet the requirements of passive defense in the vital infrastructures of the country, we have reviewed practical solutions to increase the security of information transmission that can be used to deal with cyber-field attacks.

Multi-path propagation is one of the most important limiting factors for sending high bit rate information. It is possible to send high bit rates at frequencies in the GHz range, which is the biggest problem in this multi-channel propagation frequency band. OFDM technique is very resistant and efficient in dealing with the adverse effects of multipath propagation by dividing the sent symbols between several sub-carriers and sending them simultaneously. With the increasing growth of high-capacity systems, the applications of this technique are increasing day by day. The OFDM system along with CDMA is proposed for next-generation mobile networks. Channel coding plays a very important role in improving OFDM efficiency. Due to the special structure of OFDM, the use of channel coding in it has special features compared to single-carrier systems that increase the efficiency of the system. Hence, this system is also called coded OFDM or COFDM. In this paper, while studying the OFDM technique, the effect of the channel coding range on the efficiency of the OFDM system is investigated.

Compression can be done by lossy or lossless methods. The lossy methods have been used widely than the lossless compression. Although, many methods for image compression have been proposed yet, the methods using intelligent skipping proper to the visual models has not been considered in the literature. Image inpainting refers to the application of sophisticated algorithms to replace lost or corrupted parts of the data so that visual difference cannot be inferred from the reconstructed image. In this paper, first we review some of the image inpainting algorithms and some of the image compression techniques using the inpainting algorithms, we propose a new inpainting based image compression algorithm that can improve the compression rate considerably. Simulation results show that our proposed method has reasonable visual quality in comparison with the other proposed image compression algorithms.

In this paper, aiming at maximizing the system throughput link selection strategies for buffer-aided two-hop relaying and overlay cognitive radio systems which employ discrete-rate adaptive modulation and coding (AMC), have been proposed. At first, a simple tree-node relaying scenario is considered in which the intermediate node (relay) equipped with a buffer and AMC, facilitates data communication between a source (also equipped with AMC) and a destination node in a two-hop communications system. For this scenario we formulate the optimal link selection problem as an integer programming problem and subsequently propose a genetic-based approximate solution using relaxation techniques. We then extend the simple buffer-aided relaying model to an overlay cognitive radio scenario comprising a pair of primary source-destination nodes and a pair of secondary (cognitive) source-destination nodes. In this model, the cognitive source node equipped with a buffer, acts as a relay to facilitate data transmission in the primary system and by this way it finds some opportunities to transmit its data to the cognitive destination node. Hence we optimize the cognitive link throughput by proposing a genetic-based link selection strategy which satisfies a target predefined average rate for the primary system. Numerical and simulation results are provided to evaluate the performance of the proposed link selection strategies.

In this article, polar codes that have recently been presented by Arikan, to integrate channel coding and encryption is used. Polar coded bits are divided into two categories. The first batch are the bits that virtual high-capacity channels of the passage that briefly bits of high-capacity are called and the information on it. The second group are bits that are virtual channels with capacity for short passes that "constant bits" are called. In the first proposal of fixed bits as we use encryption key, and on all bits of the plan (data bits and fixed bits) are key. In fact, the plan proposed 8-bit Arikan, we use the 8 key. Then, the proposed method is that it can be applied to the number of key bits can be reduced. The encryption system is effective and desirable that, in addition to the high complexity and lack of correlation between bits, the least it used to be key.