This article explores the use of grounded theory to generate conceptualizations of emergent social patterns in research data. The naming of patterns and their abstraction across time, place and people, are discussed. ...
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An implementation of coding and encryption for data in a low Earth orbit satellite channel is presented. A system of block coding and block cipher is designed to improve the noise performance and for data security, re...
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ISBN:
(纸本)7505336355
An implementation of coding and encryption for data in a low Earth orbit satellite channel is presented. A system of block coding and block cipher is designed to improve the noise performance and for data security, respectively. The Reed-Muller code is adopted as the coding scheme and an improved algorithm based on the Reed algorithm is used as decoding algorithm. A supercipher system combined with a block cipher and a stream cipher is put forward to compensate the shortage of total encryption keys brought about by the short block length of the block cipher. For a system with a bit rate as high as 10/sup 6/ b/s, an EPROM array is used and one search process could implement both the coding and encryption.
A novel data compression scheme of light field is presented. Different from the prior codecs, we perform image predicting and data coding in a set of subbands not directly in original images. In our approach, firstly ...
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ISBN:
(纸本)0780385543
A novel data compression scheme of light field is presented. Different from the prior codecs, we perform image predicting and data coding in a set of subbands not directly in original images. In our approach, firstly the original images are decomposed into subbands using wavelet packet transform, and the corresponding wavelet packet bases are divided into two parts: the predictable bases and the unpredictable bases by some criterions. In coding, a propagating algorithm and a rhombuses structure is used, and the subbands corresponding to the basis in predictable and unpredictable bases are added sequently by relative energy until the reconstructing images meet the pre-established reconstruction quality. Experiments for two standard light fields verify the efficiency of our approach.
Tato práce se zabývá kódováním dat a datovými formáty, které lze použít pro výměnu informací a je možné je použít pro serializaci a deserializaci ...
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Tato práce se zabývá kódováním dat a datovými formáty, které lze použít pro výměnu informací a je možné je použít pro serializaci a deserializaci dat. V rámci přenosu dat je podrobněji vysvětlen serializační a deserializační proces převodu datových struktur, objektů do sekvence bitů, kde později může být uložen ve vyrovnávací paměti, nebo přenesen počítačovou sítí. Jsou důkladně popsány nejznámější datové formáty XML a JSON. Práce hodnotí jednotlivé formáty a porovnává je z hlediska rychlosti počítačového zpracování, paměťové náročnosti a způsobu provedení jednotlivých formátů. Navržení a aplikace vlastního datového formátu pro přenos a ukládání dat.
With the rapid development of information storage and networking technologies, quintillion bytes of data are generated every day from social networks, business transactions, sensors, and many other domains. The increa...
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With the rapid development of information storage and networking technologies, quintillion bytes of data are generated every day from social networks, business transactions, sensors, and many other domains. The increasing data volumes impose significant challenges to traditional data analysis tools in storing, processing, and analyzing these extremely large-scale data. For decades, hashing has been one of the most effective tools commonly used to compress data for fast access and analysis, as well as information integrity verification. Hashing techniques have also evolved from simple randomization approaches to advanced adaptive methods considering locality, structure, label information, and data security, for effective hashing. This survey reviews and categorizes existing hashing techniques as a taxonomy, in order to provide a comprehensive view of mainstream hashing techniques for different types of data and applications. The taxonomy also studies the uniqueness of each method and therefore can serve as technique references in understanding the niche of different hashing mechanisms for future development.
This note reports on a project to develop a codebook and data set for the analysis of bilateral civilian nuclear power agreements. It briefly provides a rationale for treaty coding projects of this kind, a description...
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This note reports on a project to develop a codebook and data set for the analysis of bilateral civilian nuclear power agreements. It briefly provides a rationale for treaty coding projects of this kind, a description of the codebook and of the data set to be used with it, and a general discussion of some of the problems encountered in the development of the codebook.
The Bettman-Park (BP) verbal-protocol coding scheme was developed to examine consumer choice behavior. The BP scheme is made up of 5 categories with 70 codes: 1. processes of attribute comparison (21 codes), 2. proces...
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The Bettman-Park (BP) verbal-protocol coding scheme was developed to examine consumer choice behavior. The BP scheme is made up of 5 categories with 70 codes: 1. processes of attribute comparison (21 codes), 2. processes within brand (11 codes), 3. prior knowledge usage (24 codes), 4. statements of processing plans or needs (5 codes), and 5. general statements (9 codes). Biehal and Chakravarti (1982) used the BP scheme to examine consumer recall processes, as well as choice processes. The protocol was divided into short phrases relating to tasks. Biehal and Chakravarti have suggested possible solutions to traditional coding problems: 1. Pay attention to overall context of protocol segments. 2. Recognize contingencies and processing transitions. 3. Develop additional prior knowledge codes. 4. Use response times to determine when processing occurs.
The Behavioral Correlates of War data set, which has been recently released for public use, is described and its potential uses are explored. The data set consists of coded descriptions of the actions of states engage...
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The Behavioral Correlates of War data set, which has been recently released for public use, is described and its potential uses are explored. The data set consists of coded descriptions of the actions of states engaged in a sample of thirty-eight interstate crises occurring between 1816 and 1975. The article begins by briefly comparing the BCOW data to extant events data collections, and then turns to detailed descriptions of the structure and content of the typology and coding scheme. The final section of the article discusses statistical techniques employed in analyzing the data, and reports on the most salient findings to date.
Non-uniquely-decodable (non-UD) codes can be defined as the codes that cannot be uniquely decoded without additional disambiguation information. These are mainly the class of non-prefix-free codes, where a code-word c...
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Non-uniquely-decodable (non-UD) codes can be defined as the codes that cannot be uniquely decoded without additional disambiguation information. These are mainly the class of non-prefix-free codes, where a code-word can be a prefix of other(s), and thus, the code-word boundary information is essential for correct decoding. Due to their inherent unique decodability problem, such non-UD codes have not received much attention except a few studies, in which using compressed data structures to represent the disambiguation information efficiently had been previously proposed. It had been shown before that the compression ratio can get quite close to Huffman/Arithmetic codes with an additional capability of providing direct access in compressed data, which is a missing feature in the regular Huffman codes. In this study we investigate non-UD codes in another dimension addressing the privacy of the high-entropy data. We particularly focus on such massive volumes, where typical examples are encoded video or similar multimedia files. Representation of such a volume with non-UD coding creates two elements as the disambiguation information and the payload, where decoding the original data from these elements becomes hard when one of them is missing. We make use of this observation for privacy concerns. and study the space consumption as well as the hardness of that decoding. We conclude that non-uniquely-decodable codes can be an alternative to selective encryption schemes that aim to secure only part of the data when data is huge. We provide a freely available software implementation of the proposed scheme as well.
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