In general a store like it's still exist and it is necessary for developing a strategy and management. The strategy is meant by increasing the quality of marketing , management, service and others including the application of information... more
In general a store like it's still exist and it is necessary for developing a strategy and management. The strategy is meant by increasing the quality of marketing , management, service and others including the application of information teknology in it. Based on observation and interviews, information system affects many aspects, including aspects of the sale is still conventional system usually only use the book to back up sales data and a written memorandum clerk. Officers cashier often make mistakes when many consumers come together. Thus the problems created for compulterized information system sales that will make more efficient and accurate sales data. With the sale information system can assist the cashier in the process of seling data management more efficient and accurate. 1. PENDAHULUAN a. Latar Belakang Kasir adalah tempat melakukan transaksi / pembayaran yang menjadi akhir dari sebuah transaksi jual beli antar konsumen dan produsen sehingga menghasilkan kepuasan pada masing masing pihak Kasir juga dapat di artikan sebagai pintu pertama dan terakhir di setiap transaksi yang terjadi di toko. Jika mempunyai pramuniaga yang sopan, melayani konsumen dengan tulus, ternyata setelah konsumen melakukan pembayaran kasirnya kurang ramah, kurang sopan sehingga menyebabkan kebanyakan dari pengunjung tidak mau kembali lagi ke toko anda lagi. Lain halnya jika anda mempunyai pramuniaga yang kurang cakap cenderung kurang sopan kepada konsumen tapi di imbangi dengan
Abstractó LDPC convolutional codes have been shown to be capable of achieving the same capacity-approaching performance as LDPC block codes with iterative message-passing decoding. However, traditional means of comparing block and... more
Abstractó LDPC convolutional codes have been shown to be capable of achieving the same capacity-approaching performance as LDPC block codes with iterative message-passing decoding. However, traditional means of comparing block and convolu- tional codes tied to the implementation complexity of trellis- based decoding are irrelevant for message-passing decoders. In this paper, we undertake a comparison of LDPC block and convolutional
In this chapter, we discuss a number of codes for error control. Only block codes are treated here. Discussion on convolutional codes will be deferred until next chapter. After reviewing some information theoretic foundations of coding in... more
In this chapter, we discuss a number of codes for error control. Only block codes are treated here. Discussion on convolutional codes will be deferred until next chapter. After reviewing some information theoretic foundations of coding in the first section, linear block codes are treated in Section 3.2. The concepts of parity-check and generator matrices to represent linear block codes are discussed. Several examples of block codes are given, including the important class of Hamming codes. Principles behind syndrome decoding and decoding using a standard array are treated in Section 3.3. Section 3.4 provides some useful bounds on coding and introduces the concept of coding gain. Section 3.5 discusses the principles behind cyclic codes. Some important decoding techniques for these codes are treated in Section 3.6. These include the Meggitt and error-trapping decoders. After introducing some algebra in Section 3.7, in the next three sections that follow, we treat the most important and practical of all cyclic codes, the Bose-Chaudhuri-Hocquenghem (BCH) codes and Reed-Solomon codes. The treatment includes the MasseyBerlekamp algorithm for decoding these codes. In Section 3.11, we turn to coding for burst error control, which has been successfully applied to storage media such as magnetic tapes and compact disc. Automatic-repeat-request (ARQ) schemes find wide applicability in computer networks and these schemes are treated in the last section.
Poset and block metrics were introduced in recent years as alternative metrics to study error correcting codes. Poset-block codes were introduced in 2008, encompassing both poset and block metrics. In this paper, we study a family of such... more
Poset and block metrics were introduced in recent years as alternative metrics to study error correcting codes. Poset-block codes were introduced in 2008, encompassing both poset and block metrics. In this paper, we study a family of such metrics, the Niederreiter-Rosenbloom-Tsfasman block metrics. In this context, we classify the classes of equivalent codes, describe canonical representatives of each class and develop much of the classical theory of error correcting codes for Niederreiter-Rosenbloom-Tsfasman block codes, including determination of packing radius and classification of MDS and perfect codes, determination of covering radius and characterization of quasi-perfect codes, and the description of an algorithm for syndrome decoding.
OFDM with Quadrature amplitude modulation (QAM) technique can be used for high speed optical applications. As the order of modulation increases, the bit error rate (BER) increases. Forward Error correction (FEC) coding like LDPC coding is... more
OFDM with Quadrature amplitude modulation (QAM) technique can be used for high speed optical applications. As the order of modulation increases, the bit error rate (BER) increases. Forward Error correction (FEC) coding like LDPC coding is generally used to Improve BER performance. LDPC provides large minimum distance and also the power efficiency of the LDPC code increases significantly with the code length. Here we have given a theoretical review on the design of encoder and decoder for the Block codes followed by the fundamentals of various modified Block codes. Finally using a long Irregular LDPC code, it is shown that LDPC coded OFDM provides very low bit error rate compared to OFDM without coding case with a gain in transmitter power and thus making the link power efficient.
In many applications encryption/decryption of compressed images or videos is desired to be transparent to the compression decoder to maintain the file format, file size and content-relevant functionalities. We propose in this paper a... more
In many applications encryption/decryption of compressed images or videos is desired to be transparent to the compression decoder to maintain the file format, file size and content-relevant functionalities. We propose in this paper a transparent encryption mechanism for JPEG-encoded image files to meet the requirements of format-compliance and file-size preservation. The algorithm is based on a special cross-block varied-length codes (VLC) shuffling method perceptually enhanced by a reversible histogram spreading processing, which tends to smoothly re-distribute VLCs among spatial blocks in a reversible way. The algorithm performs visually better than existing shuffling based schemes against content leakage attacks such as DC value removal.
The 1999 AUVFest was held near Gulfport, Mississippi in a shallow-water area with depths between 3 and 8 meters. The acoustic channel was characterized by multipath spanning up to 20 msec and high noise levels from snapping shrimp.... more
The 1999 AUVFest was held near Gulfport, Mississippi in a shallow-water area with depths between 3 and 8 meters. The acoustic channel was characterized by multipath spanning up to 20 msec and high noise levels from snapping shrimp. Acoustic communication testing was performed with the REMUS AUV transmitting both known test data and realtime status information. In addition, a series of ship-to-ship tests were performed in order to characterize stationary performance at ranges of one to five kilometers. Data rates of 60-5000 bits per second were transmitted and, despite the very shallow water conditions, the communication link was reliable at ranges up to 5 km at all data rates
This paper presents a Trellis Coded Modulation (TCM) scheme that is built from Linear Block Codes (LBC). These codes are referred to as Trellis Coded Block Codes (TCBC), and unlike conventional TCM, can be used for both discrete as well... more
This paper presents a Trellis Coded Modulation (TCM) scheme that is built from Linear Block Codes (LBC). These codes are referred to as Trellis Coded Block Codes (TCBC), and unlike conventional TCM, can be used for both discrete as well as continuous channels. This has been made possible by utilizing a new algebraic structure discovered by the authors. This structure allows one to partition any linear block code into sub-codes with a constant distance between the code words. As in the conventional TCM scheme, the proposed code-set partitioning is used to increase the minimum distance between code words. Another feature of TCBC is that implementations with and without bandwidth expansion are possible. Simulation results are provided to demonstrate the coding gain obtainable in binary symmetric channel (BSC) and additive white Gaussian noise (AWGN) channel. I. INTRODUCTION
OFDM with Quadrature amplitude modulation (QAM) technique can be used for high speed optical applications. As the order of modulation increases, the bit error rate (BER) increases. Forward Error correction (FEC) coding like LDPC coding is... more
OFDM with Quadrature amplitude modulation (QAM) technique can be used for high speed optical applications. As the order of modulation increases, the bit error rate (BER) increases. Forward Error correction (FEC) coding like LDPC coding is generally used to Improve BER performance. LDPC provides large minimum distance and also the power efficiency of the LDPC code increases significantly with the code length. Here we have given a theoretical review on the design of encoder and decoder for the Block codes followed by the fundamentals of various modified Block codes. Finally using a long Irregular LDPC code, it is shown that LDPC coded OFDM provides very low bit error rate compared to OFDM without coding case with a gain in transmitter power and thus making the link power efficient.
