• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.1
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• pp.81-87
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• 2013

In this paper, we propose a music search algorithm for automotive infotainment system. The proposed method extracts fingerprints using the high peaks based on log-spectrum of the music signal, and the extracted music fingerprints store in cloud server applying a hash value. In the cloud server, the most similar music is retrieved by comparing the user's query music with the fingerprints stored in hash table of cloud server. To evaluate the performance of the proposed music search algorithm, we measure an accuracy of the retrieved results according to various length of the query music and measure a retrieval time according to the number of stored music database in hash table.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.111-116
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• 2018

This paper introduces the concept of a random universal hash function to amplify security in a quantum key distribution system. It seems to provide security amplification using the relationship between quantum error correction and security. In addition, the approach in terms of security amplification shows that phase error correction offers better security. We explain how the universal hash function enhances security using the BB84 protocol, which is a typical example of QKD(Quantum Key Distribution). Finally, we show that the BB84 protocol using random privacy amplification is safe at higher key rates than Mayers' performance at the same error rate.

• The Journal of Information Systems
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• v.27 no.2
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• pp.77-94
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• 2018

Purpose As the amount of data became enormous, it became a time when more efforts were needed to find the necessary information. Curation is a new term similarly to the museum curator, which is a service that helps people to collect, share, and value the contents of the Internet. In SNS, hash tag is used for emotional vocabulary to be transmitted between users by using (#) tag. Design/methodology/approach As the amount of data became enormous, it became a time when more efforts were needed to find the necessary information. Curation is a new term similarly to the museum curator, which is a service that helps people to collect, share, and value the contents of the Internet. In SNS, hash tag is used for emotional vocabulary to be transmitted between users by using (#) tag. Findings This study base on seven emotional sets such as 'Happy', 'Angry', 'Sad', 'Bad', 'Fearful', 'Surprised', 'Disgusted' to construct 327 emotional seeds and utilize the autofill function of web browser to collect 1.5 million emotional words from emotional seeds. The emotional dictionary of this study is considered to be meaningful as a tool to make emotional judgment from unstructured data.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.390-395
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• 2009

The robustness of audio fingerprinting system in a noisy environment is a principal challenge in the area of content-based audio retrieval. The selected feature for the audio fingerprints must be robust in a noisy environment and the computational complexity of the searching algorithm must be low enough to be executed in real-time. The audio fingerprint proposed by Philips uses expanded hash table lookup to compensate errors introduced by noise. The expanded hash table lookup increases the searching complexity by a factor of 33 times the degree of expansion defined by the hamming distance. We propose a new method to improve noise robustness of audio fingerprinting in noise environment using predominant pitch which reduces the bit error of created hash values. The sub-fingerprint of our approach method is computed in each time frames of audio. The time frame is transformed into the frequency domain using FFT. The obtained audio spectrum is divided into 33 critical bands. Finally, the 32-bit hash value is computed by difference of each bands of energy. And only store bits near predominant pitch. Predominant pitches are extracted in each time frames of audio. The extraction process consists of harmonic enhancement, harmonic summation and selecting a band among critical bands.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.9
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• pp.2388-2404
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• 2012

Cryptographic hash functions are widely used in many information security applications like digital signatures, message authentication codes (MACs), and other forms of authentication. In response to recent advances in cryptanalysis of commonly used hash algorithms, National Institute of Standards and Technology (NIST) announced a publicly open competition for selection of new standard Secure Hash Algorithm called SHA-3. One important aspect of this competition is evaluation of hardware performances of the candidates. In this work we present efficient hardware implementations of SHA-3 finalists: JH, Keccak and Skein. We propose high speed architectures using Look-Up Table (LUT) resources on FPGAs, to minimize chip area and to reduce critical path lengths. This approach allows us to design data paths of SHA-3 finalists with minimum resources and higher clock frequencies. We implemented and investigated the performance of these candidates on modern and latest FPGA devices from Xilinx. This work serves as performance investigation of leading SHA-3 finalists on most up-to-date FPGAs.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.1
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• pp.27-34
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• 2018

Various messages generated in vehicles are transmitted based on the wireless telecommunication which is a core technology of vehicle to everything (V2X). However, the hackers attack them upon penetration to the system and network to cause the generation of users' inconveniences for vehicular communication. Moreover, huge damage could be occurred in terms of physical and materialistic areas if the users in the vehicles were attacked in the communication environment. Therefore, this study was to design the safe communication protocol using hash tree technique in the V2X environments. Using hash tree technique, processes of issuing certificate and registration and communication protocol were designed, and safety analysis was performed on the attacking technique which is occurred in the existing vehicles. Approximately 62% of decrease in the capacity analysis was found upon comparative analysis of telecommunication processes with the system to issue the certificate which is used in the existing vehicles.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.9
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• pp.41-48
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• 2004

In this work, a domain-wise hash structure is developed for efficient data handling, and by using the developed domain-wise hash structure, an automatic triangular mesh generation algorithm is proposed. To generate the optimal nodal points and triangles efficiently, the advancing layer method and Delaunay triangulation method are utilized. To investigate the performance of the proposed algorithm, benchmarking tests are carried out for various models including convex, concave and complicated shapes through the developed object oriented C++ mesh generation code.

• Journal of IKEEE
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• v.14 no.4
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• pp.339-345
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• 2010

So far, many researches have been done to index high-dimensional feature values for fast content-based image retrieval. Still, many existing indexing schemes are suffering from performance degradation due to the curse of dimensionality problem. As an alternative, heuristic algorithms have been proposed to calculate the result with 'high probability' at the cost of accuracy. In this paper, we propose a new extendible hash-based indexing scheme for high-dimensional feature values. Our indexing scheme provides several advantages compared to the traditional high-dimensional index structures in terms of search performance and accuracy preservation. Through extensive experiments, we show that our proposed indexing scheme achieves outstanding performance.

• The Journal of the Acoustical Society of Korea
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• v.34 no.2
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• pp.157-162
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• 2015

In this paper, we propose an audio fingerprinting using robust hash based on the MCLT (Modulated Complex Lapped Transform) peak-pair. In existing methods, the robust audio fingerprinting is not generated if various distortions occurred; time-scaling, pith-shifting and equalization. To solve this problem, we used the spectrum of the MCLT, an adaptive thresholding method for detection of prominent peaks and the novel hash function in the audio fingerprinting. Experimental results show that the proposed method is highly robust in various distorted environments and achieves better identification rates compared to other methods.

• Journal of Information Technology Services
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• v.16 no.1
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• pp.73-82
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• 2017

Recently in-memory data stream processing has been actively applied to various subjects such as query processing, OLAP, data mining, i.e., frequent item sets, association rules, clustering. However, finding regular periodic patterns of events in an infinite data stream gets less attention. Most researches about finding periods use autocorrelation functions to find certain changes in periodic patterns, not period itself. And they usually find periodic patterns in time-series databases, not in data streams. Literally a period means the length or era of time that some phenomenon recur in a certain time interval. However in real applications a data set indeed evolves with tiny differences as time elapses. This kind of a period is called as a pseudo-period. This paper proposes a new scheme called FPMH (Finding Periods using Multiple Hash functions) algorithm to find such a set of pseudo-periods over a data stream based on multiple hash functions. According to the type of pseudo period, this paper categorizes FPMH into three, FPMH-E, FPMH-PC, FPMH-PP. To maximize the performance of the algorithm in the data stream environment and to keep most recent periodic patterns in memory, we applied decay mechanism to FPMH algorithms. FPMH algorithm minimizes the usage of memory as well as processing time with acceptable accuracy.