Search results for: Hamming code
1400 Simulation of Hamming Coding and Decoding for Microcontroller Radiation Hardening
Authors: Rehab I. Abdul Rahman, Mazhar B. Tayel
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This paper presents a method of hardening the 8051 microcontroller, that able to assure reliable operation in the presence of bit flips caused by radiation. Aiming at avoiding such faults in the 8051 microcontroller, Hamming code protection was used in its SRAM memory and registers. A VHDL code and its simulation have been used for this hamming code protection.Keywords: radiation, hardening, bitflip, hamming
Procedia PDF Downloads 4991399 Error Detection and Correction for Onboard Satellite Computers Using Hamming Code
Authors: Rafsan Al Mamun, Md. Motaharul Islam, Rabana Tajrin, Nabiha Noor, Shafinaz Qader
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In an attempt to enrich the lives of billions of people by providing proper information, security and a way of communicating with others, the need for efficient and improved satellites is constantly growing. Thus, there is an increasing demand for better error detection and correction (EDAC) schemes, which are capable of protecting the data onboard the satellites. The paper is aimed towards detecting and correcting such errors using a special algorithm called the Hamming Code, which uses the concept of parity and parity bits to prevent single-bit errors onboard a satellite in Low Earth Orbit. This paper focuses on the study of Low Earth Orbit satellites and the process of generating the Hamming Code matrix to be used for EDAC using computer programs. The most effective version of Hamming Code generated was the Hamming (16, 11, 4) version using MATLAB, and the paper compares this particular scheme with other EDAC mechanisms, including other versions of Hamming Codes and Cyclic Redundancy Check (CRC), and the limitations of this scheme. This particular version of the Hamming Code guarantees single-bit error corrections as well as double-bit error detections. Furthermore, this version of Hamming Code has proved to be fast with a checking time of 5.669 nanoseconds, that has a relatively higher code rate and lower bit overhead compared to the other versions and can detect a greater percentage of errors per length of code than other EDAC schemes with similar capabilities. In conclusion, with the proper implementation of the system, it is quite possible to ensure a relatively uncorrupted satellite storage system.Keywords: bit-flips, Hamming code, low earth orbit, parity bits, satellite, single error upset
Procedia PDF Downloads 1301398 Features of Testing of the Neuronetwork Converter Biometrics-Code with Correlation Communications between Bits of the Output Code
Authors: B. S. Akhmetov, A. I. Ivanov, T. S. Kartbayev, A. Y. Malygin, K. Mukapil, S. D. Tolybayev
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The article examines the testing of the neural network converter of biometrics code. Determined the main reasons that prevented the use adopted in the works of foreign researchers classical a Binomial Law when describing distribution of measures of Hamming "Alien" codes-responses.Keywords: biometrics, testing, neural network, converter of biometrics-code, Hamming's measure
Procedia PDF Downloads 11381397 Characterization of Onboard Reliable Error Correction Code FORSDRAM Controller
Authors: N. Pitcheswara Rao
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In the process of conveying the information there may be a chance of signal being corrupted which leads to the erroneous bits in the message. The message may consist of single, double and multiple bit errors. In high-reliability applications, memory can sustain multiple soft errors due to single or multiple event upsets caused by environmental factors. The traditional hamming code with SEC-DED capability cannot be address these types of errors. It is possible to use powerful non-binary BCH code such as Reed-Solomon code to address multiple errors. However, it could take at least a couple dozen cycles of latency to complete first correction and run at a relatively slow speed. In order to overcome this drawback i.e., to increase speed and latency we are using reed-Muller code.Keywords: SEC-DED, BCH code, Reed-Solomon code, Reed-Muller code
Procedia PDF Downloads 4281396 Characterization of Onboard Reliable Error Correction Code for SDRAM Controller
Authors: Pitcheswara Rao Nelapati
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In the process of conveying the information there may be a chance of signal being corrupted which leads to the erroneous bits in the message. The message may consist of single, double and multiple bit errors. In high-reliability applications, memory can sustain multiple soft errors due to single or multiple event upsets caused by environmental factors. The traditional hamming code with SEC-DED capability cannot be address these types of errors. It is possible to use powerful non-binary BCH code such as Reed-Solomon code to address multiple errors. However, it could take at least a couple dozen cycles of latency to complete first correction and run at a relatively slow speed. In order to overcome this drawback i.e., to increase speed and latency we are using reed-Muller code.Keywords: SEC-DED, BCH code, Reed-Solomon code, Reed-Muller code
Procedia PDF Downloads 4291395 GPU Based High Speed Error Protection for Watermarked Medical Image Transmission
Authors: Md Shohidul Islam, Jongmyon Kim, Ui-pil Chong
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Medical image is an integral part of e-health care and e-diagnosis system. Medical image watermarking is widely used to protect patients’ information from malicious alteration and manipulation. The watermarked medical images are transmitted over the internet among patients, primary and referred physicians. The images are highly prone to corruption in the wireless transmission medium due to various noises, deflection, and refractions. Distortion in the received images leads to faulty watermark detection and inappropriate disease diagnosis. To address the issue, this paper utilizes error correction code (ECC) with (8, 4) Hamming code in an existing watermarking system. In addition, we implement the high complex ECC on a graphics processing units (GPU) to accelerate and support real-time requirement. Experimental results show that GPU achieves considerable speedup over the sequential CPU implementation, while maintaining 100% ECC efficiency.Keywords: medical image watermarking, e-health system, error correction, Hamming code, GPU
Procedia PDF Downloads 2901394 Zero Cross-Correlation Codes Based on Balanced Incomplete Block Design: Performance Analysis and Applications
Authors: Garadi Ahmed, Boubakar S. Bouazza
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The Zero Cross-Correlation (C, w) code is a family of binary sequences of length C and constant Hamming-weight, the cross correlation between any two sequences equal zero. In this paper, we evaluate the performance of ZCC code based on Balanced Incomplete Block Design (BIBD) for Spectral Amplitude Coding Optical Code Division Multiple Access (SAC-OCDMA) system using direct detection. The BER obtained is better than 10-9 for five simultaneous users.Keywords: spectral amplitude coding-optical code-division-multiple-access (SAC-OCDMA), phase induced intensity noise (PIIN), balanced incomplete block design (BIBD), zero cross-correlation (ZCC)
Procedia PDF Downloads 3661393 Step Height Calibration Using Hamming Window: Band-Pass Filter
Authors: Dahi Ghareab Abdelsalam Ibrahim
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Calibration of step heights with high accuracy is needed for many applications in the industry. In general, step height consists of three bands: pass band, transition band (roll-off), and stop band. Abdelsalam used a convolution of the transfer functions of both Chebyshev type 2 and elliptic filters with WFF of the Fresnel transform in the frequency domain for producing a steeper roll-off with the removal of ripples in the pass band- and stop-bands. In this paper, we used a new method based on the Hamming window: band-pass filter for calibration of step heights in terms of perfect adjustment of pass-band, roll-off, and stop-band. The method is applied to calibrate a nominal step height of 40 cm. The step height is measured first by asynchronous dual-wavelength phase-shift interferometry. The measured step height is then calibrated by the simulation of the Hamming window: band-pass filter. The spectrum of the simulated band-pass filter is simulated at N = 881 and f0 = 0.24. We can conclude that the proposed method can calibrate any step height by adjusting only two factors which are N and f0.Keywords: optical metrology, step heights, hamming window, band-pass filter
Procedia PDF Downloads 831392 Code-Switching and Code Mixing among Ogba-English Bilingual Conversations
Authors: Ben-Fred Ohia
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Code-switching and code-mixing are linguistic behaviours that arise in a bilingual situation. They limit speakers in a conversation to decide which code they should use to utter particular phrases or words in the course of carrying out their utterance. Every human society is characterized by the existence of diverse linguistic varieties. The speakers of these varieties at some points have various degrees of contact with the non-speakers of their variety, which one of the outcomes of the linguistic contact is code-switching or code-mixing. The work discusses the nature of code-switching and code-mixing in Ogba-English bilinguals’ speeches. It provides a detailed explanation of the concept of code-switching and code-mixing and explains the typology of code-switching and code-mixing and their manifestation in Ogba-English bilingual speakers’ speeches. The findings reveal that code-switching and code-mixing are functionally motivated and being triggered by various conversational contexts.Keywords: bilinguals, code-mixing, code-switching, Ogba
Procedia PDF Downloads 1811391 A Rapid Code Acquisition Scheme in OOC-Based CDMA Systems
Authors: Keunhong Chae, Seokho Yoon
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We propose a code acquisition scheme called improved multiple-shift (IMS) for optical code division multiple access systems, where the optical orthogonal code is used instead of the pseudo noise code. Although the IMS algorithm has a similar process to that of the conventional MS algorithm, it has a better code acquisition performance than the conventional MS algorithm. We analyze the code acquisition performance of the IMS algorithm and compare the code acquisition performances of the MS and the IMS algorithms in single-user and multi-user environments.Keywords: code acquisition, optical CDMA, optical orthogonal code, serial algorithm
Procedia PDF Downloads 5401390 Usage of Channel Coding Techniques for Peak-to-Average Power Ratio Reduction in Visible Light Communications Systems
Authors: P. L. D. N. M. de Silva, S. G. Edirisinghe, R. Weerasuriya
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High peak-to-average power ratio (PAPR) is a concern of orthogonal frequency division multiplexing (OFDM) based visible light communication (VLC) systems. Discrete Fourier Transform spread (DFT-s) OFDM is an alternative single carrier modulation scheme which would address this concern. Employing channel coding techniques is another mechanism to reduce the PAPR. Previous research has been conducted to study the impact of these techniques separately. However, to the best of the knowledge of the authors, no study has been done so far to identify the improvement which can be harnessed by hybridizing these two techniques for VLC systems. Therefore, this is a novel study area under this research. In addition, channel coding techniques such as Polar codes and Turbo codes have been tested in the VLC domain. However, other efficient techniques such as Hamming coding and Convolutional coding have not been studied too. Therefore, the authors present the impact of the hybrid of DFT-s OFDM and Channel coding (Hamming coding and Convolutional coding) on PAPR in VLC systems using Matlab simulations.Keywords: convolutional coding, discrete Fourier transform spread orthogonal frequency division multiplexing, hamming coding, peak-to-average power ratio, visible light communications
Procedia PDF Downloads 1541389 A Resistant-Based Comparative Study between Iranian Concrete Design Code and Some Worldwide Ones
Authors: Seyed Sadegh Naseralavi, Najmeh Bemani
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The design in most counties should be inevitably carried out by their native code such as Iran. Since the Iranian concrete code does not exist in structural design software, most engineers in this country analyze the structures using commercial software but design the structural members manually. This point motivated us to make a communication between Iranian code and some other well-known ones to create facility for the engineers. Finally, this paper proposes the so-called interpretation charts which help specify the position of Iranian code in comparison of some worldwide ones.Keywords: beam, concrete code, strength, interpretation charts
Procedia PDF Downloads 5261388 Iris Feature Extraction and Recognition Based on Two-Dimensional Gabor Wavelength Transform
Authors: Bamidele Samson Alobalorun, Ifedotun Roseline Idowu
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Biometrics technologies apply the human body parts for their unique and reliable identification based on physiological traits. The iris recognition system is a biometric–based method for identification. The human iris has some discriminating characteristics which provide efficiency to the method. In order to achieve this efficiency, there is a need for feature extraction of the distinct features from the human iris in order to generate accurate authentication of persons. In this study, an approach for an iris recognition system using 2D Gabor for feature extraction is applied to iris templates. The 2D Gabor filter formulated the patterns that were used for training and equally sent to the hamming distance matching technique for recognition. A comparison of results is presented using two iris image subjects of different matching indices of 1,2,3,4,5 filter based on the CASIA iris image database. By comparing the two subject results, the actual computational time of the developed models, which is measured in terms of training and average testing time in processing the hamming distance classifier, is found with best recognition accuracy of 96.11% after capturing the iris localization or segmentation using the Daughman’s Integro-differential, the normalization is confined to the Daugman’s rubber sheet model.Keywords: Daugman rubber sheet, feature extraction, Hamming distance, iris recognition system, 2D Gabor wavelet transform
Procedia PDF Downloads 651387 Code-Switching in Facebook Chatting Among Maldivian Teenagers
Authors: Aaidha Hammad
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This study examines the phenomenon of code switching among teenagers in the Maldives while they carry out conversations through Facebook in the form of “Facebook Chatting”. The current study aims at evaluating the frequency of code-switching and it investigates between what languages code-switching occurs. Besides the study identifies the types of words that are often codeswitched and the triggers for code switching. The methodology used in this study is mixed method of qualitative and quantitative approach. In this regard, the chat log of a group conversation between 10 teenagers was collected and analyzed. A questionnaire was also administered through online to 24 different teenagers from different corners of the Maldives. The age of teenagers ranged between 16 and 19 years. The findings of the current study revealed that while Maldivian teenagers chat in Facebook they very often code switch and these switches are most commonly between Dhivehi and English, but some other languages are also used to some extent. It also identified the different types of words that are being often code switched among the teenagers. Most importantly it explored different reasons behind code switching among the Maldivian teenagers in Facebook chatting.Keywords: code-switching, Facebook, Facebook chatting Maldivian teenagers
Procedia PDF Downloads 2451386 Development of Fem Code for 2-D Elasticity Problems Using Quadrilateral and Triangular Elements
Authors: Muhammad Umar Kiani, Waseem Sakawat
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This study presents the development of FEM code using Quadrilateral 4-Node (Q4) and Triangular 3-Node (T3) elements. Code is formulated using MATLAB language. Instead of using both elements in the same code, two separate codes are written. Quadrilateral element is difficult to handle directly, that is why natural coordinates (eta, ksi) are used. Due to this, Q4 code includes numerical integration (Gauss quadrature). In this case, complete numerical integration is performed using 2 points. On the other hand, T3 element can be modeled directly, by using direct stiffness approach. Axially loaded element, cantilever (special constraints) and Patch test cases were analyzed using both codes and the results were verified by using Ansys.Keywords: FEM code, MATLAB, numerical integration, ANSYS
Procedia PDF Downloads 4191385 Code Switching: A Case Study Of Lebanon
Authors: Wassim Bekai
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Code switching, as its name states, is altering between two or more languages in one sentence. The speaker tends to use code switching in his/her speech for better clarification of his/her message to the receiver. It is commonly used in sociocultural countries such as Lebanon because of the various cultures that have come across its lands through history, considering Lebanon is geographically located in the heart of the world, and hence between many cultures and languages. In addition, Lebanon was occupied by Turkish authorities for about 400 years, and later on by the French mandate, where both of these countries forced their languages in official papers and in the Lebanese educational system. In this paper, the importance of code switching in the Lebanese workplace will be examined, stressing the efficiency and amount of the production resulting from code switching in the workplace (factories, universities among other places) in addition to exploring the social, education, religious and cultural factors behind this phenomenon in Lebanon.Keywords: code switching, Lebanon, cultural, factors
Procedia PDF Downloads 2871384 Optical Multicast over OBS Networks: An Approach Based on Code-Words and Tunable Decoders
Authors: Maha Sliti, Walid Abdallah, Noureddine Boudriga
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In the frame of this work, we present an optical multicasting approach based on optical code-words. Our approach associates, in the edge node, an optical code-word to a group multicast address. In the core node, a set of tunable decoders are used to send a traffic data to multiple destinations based on the received code-word. The use of code-words, which correspond to the combination of an input port and a set of output ports, allows the implementation of an optical switching matrix. At the reception of a burst, it will be delayed in an optical memory. And, the received optical code-word is split to a set of tunable optical decoders. When it matches a configured code-word, the delayed burst is switched to a set of output ports.Keywords: optical multicast, optical burst switching networks, optical code-words, tunable decoder, virtual optical memory
Procedia PDF Downloads 6071383 Quick Response(QR) Code for Vehicle Registration and Identification
Authors: S. Malarvizhi, S. Sadiq Basha, M. Santhosh Kumar, K. Saravanan, R. Sasikumar, R. Satheesh
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This is a web based application which provides authorization for the vehicle identification and registration. It also provides mutual authentication between the police and users in order to avoid misusage. The QR code generation in this application overcomes the difficulty in the manual registration of the vehicle documents. This generated QR code is placed in the number plates of the vehicles. The QR code is scanned using the QR Reader installed in the smart devices. The police officials can check the vehicle details and file cases on accidents, theft and traffic rules violations using QR code. In addition to vehicle insurance payments and renewals, the renewal alert is sent to the vehicle owner about payment deadline. The non-permitted vehicles can be blocked in the next check-post by sending the alert messages.Keywords: QR code, QR reader, registration, authentication, idenfication
Procedia PDF Downloads 4941382 PUF-Based Lightweight Iot Secure Authentication Chip Design
Authors: Wenxuan Li, Lei Li, Jin Li, Yuanhang He
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This paper designed a secure chip for IoT communication security integrated with the PUF-based firmware protection scheme. Then, the Xilinx Kintex-7 and STM-32 were used for the prototype verification. Firmware protection worked well on FPGA and embedded platforms. For the ASIC implementation of the PUF module, contact PUF is chosen. The post-processing method and its improvement are analyzed with emphasis. This paper proposed a more efficient post-processing method for contact PUF named SXOR, which has practical value for realizing lightweight security modules in IoT devices. The analysis was carried out under the hypothesis that the contact holes are independent and combine the existing data in the open literature. The post-processing effects of SXOR and XOR are basically the same under the condition that the proposed post-processing circuit occupies only 50.6% of the area of XOR. The average Hamming weight of the PUF output bit sequence obtained by the proposed post-processing method is 0.499735, and the average Hamming weight obtained by the XOR-based post-processing method is 0.499999.Keywords: PUF, IoT, authentication, secure communication, encryption, XOR
Procedia PDF Downloads 1411381 Analyzing the Impact of Code Commenting on Software Quality
Authors: Thulya Premathilake, Tharushi Perera, Hansi Thathsarani, Tharushi Nethmini, Dilshan De Silva, Piyumika Samarasekara
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One of the most efficient ways to assist developers in grasping the source code is to make use of comments, which can be found throughout the code. When working in fields such as software development, having comments in your code that are of good quality is a fundamental requirement. Tackling software problems while making use of programs that have already been built. It is essential for the intention of the source code to be made crystal apparent in the comments that are added to the code. This assists programmers in better comprehending the programs they are working on and enables them to complete software maintenance jobs in a more timely manner. In spite of the fact that comments and documentation are meant to improve readability and maintainability, the vast majority of programmers place the majority of their focus on the actual code that is being written. This study provides a complete and comprehensive overview of the previous research that has been conducted on the topic of code comments. The study focuses on four main topics, including automated comment production, comment consistency, comment classification, and comment quality rating. One is able to get the knowledge that is more complete for use in following inquiries if they conduct an analysis of the proper approaches that were used in this study issue.Keywords: code commenting, source code, software quality, quality assurance
Procedia PDF Downloads 851380 Lowering Error Floors by Concatenation of Low-Density Parity-Check and Array Code
Authors: Cinna Soltanpur, Mohammad Ghamari, Behzad Momahed Heravi, Fatemeh Zare
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Low-density parity-check (LDPC) codes have been shown to deliver capacity approaching performance; however, problematic graphical structures (e.g. trapping sets) in the Tanner graph of some LDPC codes can cause high error floors in bit-error-ratio (BER) performance under conventional sum-product algorithm (SPA). This paper presents a serial concatenation scheme to avoid the trapping sets and to lower the error floors of LDPC code. The outer code in the proposed concatenation is the LDPC, and the inner code is a high rate array code. This approach applies an interactive hybrid process between the BCJR decoding for the array code and the SPA for the LDPC code together with bit-pinning and bit-flipping techniques. Margulis code of size (2640, 1320) has been used for the simulation and it has been shown that the proposed concatenation and decoding scheme can considerably improve the error floor performance with minimal rate loss.Keywords: concatenated coding, low–density parity–check codes, array code, error floors
Procedia PDF Downloads 3561379 UNIX Source Code Leak: Evaluation and Feasible Solutions
Authors: Gu Dongxing, Li Yuxuan, Nong Tengxiao, Burra Venkata Durga Kumar
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Since computers are widely used in business models, more and more companies choose to store important information in computers to improve productivity. However, this information can be compromised in many cases, such as when it is stored locally on the company's computers or when it is transferred between servers and clients. Of these important information leaks, source code leaks are probably the most costly. Because the source code often represents the core technology of the company, especially for the Internet companies, source code leakage may even lead to the company's core products lose market competitiveness, and then lead to the bankruptcy of the company. In recent years, such as Microsoft, AMD and other large companies have occurred source code leakage events, suffered a huge loss. This reveals to us the importance and necessity of preventing source code leakage. This paper aims to find ways to prevent source code leakage based on the direction of operating system, and based on the fact that most companies use Linux or Linux-like system to realize the interconnection between server and client, to discuss how to reduce the possibility of source code leakage during data transmission.Keywords: data transmission, Linux, source code, operating system
Procedia PDF Downloads 2701378 Code Refactoring Using Slice-Based Cohesion Metrics and AOP
Authors: Jagannath Singh, Durga Prasad Mohapatra
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Software refactoring is very essential for maintaining the software quality. It is an usual practice that we first design the software and then go for coding. But after coding is completed, if the requirement changes slightly or our expected output is not achieved, then we change the codes. For each small code change, we cannot change the design. In course of time, due to these small changes made to the code, the software design decays. Software refactoring is used to restructure the code in order to improve the design and quality of the software. In this paper, we propose an approach for performing code refactoring. We use slice-based cohesion metrics to identify the target methods which requires refactoring. After identifying the target methods, we use program slicing to divide the target method into two parts. Finally, we have used the concepts of Aspects to adjust the code structure so that the external behaviour of the original module does not change.Keywords: software refactoring, program slicing, AOP, cohesion metrics, code restructure, AspectJ
Procedia PDF Downloads 5131377 Maximum Distance Separable b-Symbol Repeated-Root γ-Constacylic Codes over a Finite Chain Ring of Length 2
Authors: Jamal Laaouine, Mohammed Elhassani Charkani
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Let p be a prime and let b be an integer. MDS b-symbol codes are a direct generalization of MDS codes. The γ-constacyclic codes of length pˢ over the finite commutative chain ring Fₚm [u]/ < u² > had been classified into four distinct types, where is a nonzero element of the field Fₚm. Let C₃ be a code of Type 3. In this paper, we obtain the b-symbol distance db(C₃) of the code C₃. Using this result, necessary and sufficient conditions under which C₃ is an MDS b-symbol code are given.Keywords: constacyclic code, repeated-root code, maximum distance separable, MDS codes, b-symbol distance, finite chain rings
Procedia PDF Downloads 1371376 The Development, Validation, and Evaluation of the Code Blue Simulation Module in Improving the Code Blue Response Time among Nurses
Authors: Siti Rajaah Binti Sayed Sultan
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Managing the code blue event is stressful for nurses, the patient, and the patient's families. The rapid response from the first and second responders in the code blue event will improve patient outcomes and prevent tissue hypoxia that leads to brain injury and other organ failures. Providing 1 minute for the cardiac massage and 2 minutes for defibrillation will significantly improve patient outcomes. As we know, the American Heart Association came out with guidelines for managing cardiac arrest patients. The hospital must provide competent staff to manage this situation. It can be achieved when the staff is well equipped with the skill, attitude, and knowledge to manage this situation with well-planned strategies, i.e., clear guidelines for managing the code blue event, competent staff, and functional equipment. The code blue simulation (CBS) was chosen in the training program for code blue management because it can mimic real scenarios. Having the code blue simulation module will allow the staff to appreciate what they will face during the code blue event, especially since it rarely happens in that area. This CBS module training will help the staff familiarize themselves with the activities that happened during actual events and be able to operate the equipment accordingly. Being challenged and independent in managing the code blue in the early phase gives the patient a better outcome. The CBS module will help the assessor and the hospital management team with the proper tools and guidelines for managing the code blue drill accordingly. As we know, prompt action will benefit the patient and their family. It also indirectly increases the confidence and job satisfaction among the nurses, increasing the standard of care, reducing the complication and hospital burden, and enhancing cost-effective care.Keywords: code blue simulation module, development of code blue simulation module, code blue response time, code blue drill, cardiorespiratory arrest, managing code blue
Procedia PDF Downloads 661375 A Characterization of Skew Cyclic Code with Complementary Dual
Authors: Eusebio Jr. Lina, Ederlina Nocon
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Cyclic codes are a fundamental subclass of linear codes that enjoy a very interesting algebraic structure. The class of skew cyclic codes (or θ-cyclic codes) is a generalization of the notion of cyclic codes. This a very large class of linear codes which can be used to systematically search for codes with good properties. A linear code with complementary dual (LCD code) is a linear code C satisfying C ∩ C^⊥ = {0}. This subclass of linear codes provides an optimum linear coding solution for a two-user binary adder channel and plays an important role in countermeasures to passive and active side-channel analyses on embedded cryptosystems. This paper aims to identify LCD codes from the class of skew cyclic codes. Let F_q be a finite field of order q, and θ be an automorphism of F_q. Some conditions for a skew cyclic code to be LCD were given. To this end, the properties of a noncommutative skew polynomial ring F_q[x, θ] of automorphism type were revisited, and the algebraic structure of skew cyclic code using its skew polynomial representation was examined. Using the result that skew cyclic codes are left ideals of the ring F_q[x, θ]/〈x^n-1〉, a characterization of a skew cyclic LCD code of length n was derived. A necessary condition for a skew cyclic code to be LCD was also given.Keywords: LCD cyclic codes, skew cyclic LCD codes, skew cyclic complementary dual codes, theta-cyclic codes with complementary duals
Procedia PDF Downloads 3451374 Performance Analysis and Comparison of Various 1-D and 2-D Prime Codes for OCDMA Systems
Authors: Gurjit Kaur, Shashank Johri, Arpit Mehrotra
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In this paper we have analyzed and compared the performance of various coding schemes. The basic ID prime sequence codes are unique in only dimension i.e. time slots whereas 2D coding techniques are not unique by their time slots but with their wavelengths also. In this research we have evaluated and compared the performance of 1D and 2D coding techniques constructed using prime sequence coding pattern for OCDMA system on a single platform. Results shows that 1D Extended Prime Code (EPC) can support more number of active users compared to other codes but at the expense of larger code length which further increases the complexity of the code. Modified Prime Code (MPC) supports lesser number of active users at λc=2 but it has a lesser code length as compared to 1D prime code. Analysis shows that 2D prime code supports lesser number of active users than 1D codes but they are having large code family and are the most secure codes compared to other codes. The performance of all these codes is analyzed on basis of number of active users supported at a Bit Error Rate (BER) of 10-9.Keywords: CDMA, OCDMA, BER, OOC, PC, EPC, MPC, 2-D PC/PC, λc, λa
Procedia PDF Downloads 5101373 The Effect of the 2015 Revision to the Corporate Governance Code on Japanese Listed Firms
Authors: Tomotaka Yanagida
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The Corporate Governance Code, revised in 2015, requires firms listed within the first and second sections of Japan’s Tokyo stock exchange to select two or more independent outside directors (the Corporate Governance Code4-8). Therefore, Japanese listed firms must do this or explain the reason why they are not able to do so. This study investigates how the Corporate Governance Code affects Japanese listed firms. We find that the Corporate Governance Code increases the ratio of outside directors by nearly 8.8% for a sample of Japanese firms comprising nearly 4,200 firm-year observations from 2014 to 2015 using a difference-in-differences approach. This implies that they felt it would have been difficult to explain why it was not appropriate to have an outside director at the annual shareholders' meeting. Moreover, this suggests that they appoint outside directors as defined by the Corporate Governance Code, but maintain board size. This situation shows that compliance in Japan may simply be 'window dressing,' that is, more form than substance.Keywords: board structure, comply or explain, corporate governance code, soft law
Procedia PDF Downloads 1731372 A Sociolinguistic Investigation of Code-Switching Practices of ESL Students Outside EFL Classrooms
Authors: Shehroz Mukhtar, Maqsood Ahmed, Abdullah Mukhtar, Choudhry Shahid, Waqar Javaid
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Code switching is a common phenomenon, generally observed in multilingual communities across the globe. A critical look at code switching literature reveals that mostly code switching has been studied in classroom in learning and teaching context while code switching outside classroom in settings such as café, hostel and so on have been the least explored areas. Current research investigated the reasons for code switching in the interactive practices of students and their perceptions regarding the same outside the classroom settings. This paper is the study of the common practice that prevails in the Universities of Sialkot that bilinguals mix two languages when they speak in different class room situations. In Pakistani classrooms where Multilingual are in abundance i.e. they can speak two or more than two languages at the same time, the code switching or language combination is very common. The teachers of Sialkot switch from one language to another consciously or unconsciously while teaching English in the class rooms. This phenomenon has not been explored in the Sialkot’s teaching context. In Sialkot private educational institutes does not encourage code-switching whereas the public or government institutes use it frequently. The crux of this research is to investigate and identify the importance of code switching by taking its users in consideration. Survey research method and survey questionnaire will be used to get exact data from teachers and students. We will try to highlight the functions and importance of code switching in foreign language classrooms of Sialkot and will explore why this trend is emerging in Sialkot.Keywords: code switching, bilingual context, L1, L2
Procedia PDF Downloads 651371 Code Embedding for Software Vulnerability Discovery Based on Semantic Information
Authors: Joseph Gear, Yue Xu, Ernest Foo, Praveen Gauravaran, Zahra Jadidi, Leonie Simpson
Abstract:
Deep learning methods have been seeing an increasing application to the long-standing security research goal of automatic vulnerability detection for source code. Attention, however, must still be paid to the task of producing vector representations for source code (code embeddings) as input for these deep learning models. Graphical representations of code, most predominantly Abstract Syntax Trees and Code Property Graphs, have received some use in this task of late; however, for very large graphs representing very large code snip- pets, learning becomes prohibitively computationally expensive. This expense may be reduced by intelligently pruning this input to only vulnerability-relevant information; however, little research in this area has been performed. Additionally, most existing work comprehends code based solely on the structure of the graph at the expense of the information contained by the node in the graph. This paper proposes Semantic-enhanced Code Embedding for Vulnerability Discovery (SCEVD), a deep learning model which uses semantic-based feature selection for its vulnerability classification model. It uses information from the nodes as well as the structure of the code graph in order to select features which are most indicative of the presence or absence of vulnerabilities. This model is implemented and experimentally tested using the SARD Juliet vulnerability test suite to determine its efficacy. It is able to improve on existing code graph feature selection methods, as demonstrated by its improved ability to discover vulnerabilities.Keywords: code representation, deep learning, source code semantics, vulnerability discovery
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