• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.2
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• pp.175-180
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• 2018

In this paper, a feature extraction and object recognition algorithm using only morphological operations is proposed. The morphological operations used in feature extraction are erosion and dilation, opening and closing combining erosion and dilation, and morphological edge and skeleton detection operation. In the process of recognizing an object based on features, a pooling operation is applied to reduce the dimension. Among various structuring elements, $3{\times}3$ rhombus, $3{\times}3$ square, and $5{\times}5$ circle are arbitrarily selected in morphological operation process. It has confirmed that the proposed algorithm can be applied in object recognition fields through experiments using Internet images.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.7
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• pp.743-751
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• 1999

공개키 암호 시스템에서 모듈러 지수 연산은 주된 연산으로, 이 연산은 내부적으로 모듈러 곱셈을 반복적으로 수행함으로써 계산된다. 본 논문에서는 GF(2m)상에서 수행할 수 있는 Montgomery 알고리즘을 분석하여 right-to-left 방식의 모듈러 지수 연산에서 공통으로 계산 가능한 부분을 이용하여 모듈러 제곱과 모듈러 곱셈을 동시에 수행하는 선형 시스톨릭 어레이를 설계한다. 본 논문에서 설계한 시스톨릭 어레이는 기존의 곱셈기보다 모듈러 지수 연산시 약 0.67배 처리속도 향상을 가진다. 그리고, VLSI 칩과 같은 하드웨어로 구현함으로써 IC 카드에 이용될 수 있다.Abstract One of the main operations for the public key cryptographic system is the modular exponentiation, it is computed by performing the repetitive modular multiplications. In this paper, we analyze Montgomery's algorithm and design a linear systolic array to perform modular multiplication and modular squaring simultaneously. It is done by using common-multiplicand modular multiplication in the right-to-left modular exponentiation over GF(2m). The systolic array presented in this paper improves about 0.67 times than existing multipliers for performing the modular exponentiation. It could be designed on VLSI hardware and used in IC cards.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.1
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• pp.1-9
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• 2021

This paper proposes to automate the process of predicting crypto-operations from the power signal generated in RSA decoding process by frequency analysis and K-means algorithm. RSA decoding process is divided into square and multiply operation, and if we can predict the type of operations over time, we will know the RSA key value. After converting the power signal generated in the process of decoding into two-dimensional frequency signal, this paper used K-means algorithm to classify the frequency vector according to the type of operation. these classified frequency vector were used to predict the types of operations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.123-130
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• 2016

In this paper, a high-performance arithmetic unit which can efficiently accelerate a number of algorithms for multimedia application was designed. The 3-stage pipelined arithmetic unit can execute 38 operations for complex and fixed-point data by using efficient configuration for four 16-bit by 16-bit multipliers, new sign extension method for carry-save data, and correction constant scheme to eliminate sign-extension in compression operation of multiple partial multiplication results. The arithmetic unit has about 300-MHz operating frequency and about 37,000 gates on 45nm CMOS technology and its estimated performance is 300 MCOPS(Million Complex Operations Per Second). Because the arithmetic unit has high processing rate and supports a number of operations dedicated to various applications, it can be efficiently applicable to multimedia processors.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3A
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• pp.217-225
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• 2005

This paper presents specialized DSP instructions and their architecture for the Viterbi algorithm used in various wireless communication standards. The proposed architecture can significantly reduce the Trace Back (TB) latency. The proposed instructions perform the Add Compare Select (ACS) and TB operations in parallel and the architecture has special hardware, called the Offset Calculation Unit (OCU), which automatically calculates data addresses for the trellis butterfly computations. Logic synthesis has been Performed using the Samsung SEC 0.18 μm standard cell library. OCU consists of 1,460 gates and the maximum delay of OCU is about 5.75 ns. The BER performance of the ACS-TB parallel method increases about 0.00022dB at 6dB Eb/No compared with the typical TB method, which is negligible. When the constraint length K is 5, the proposed DSP architecture can reduce the decoding cycles about 17% compared with the Carmel DSP and about 45% compared with 7MS320c15x.

• Journal of Korea Spatial Information System Society
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• v.9 no.3
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• pp.1-16
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• 2007

A spatial data warehouse is a system to support decision making using a spatial data cube. A spatial data cube is composed of a dimension table and a fact table. For decision support using this spatial data cube, the concept hierarchy of spatial dimension and the summarized information of spatial fact should be provided. In the previous researches, however, spatial summarized information is deficient. In this paper, the spatial aggregation for spatial summarized information in a spatial data warehouse is proposed. The proposed spatial aggregation is separated of both the numerical aggregation and the object aggregation. The numerical aggregation is the operation to return a numerical data as a result of spatial analysis and the object aggregation returns the result represented to object. We provide the extended struct of spatial data for spatial aggregation and so our proposed method is efficient.

• Journal of KIISE:Databases
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• v.29 no.6
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• pp.429-440
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• 2002

Temporal databases manage time-evolving data. They provide built-in supports for efficient recording and querying of temporal data. The temporal aggregate in temporal databases is an extension of the conventional aggregate to include time concept on the domain and range of aggregation. This paper focuses on multidimensional temporal aggregation. In a multidimensional temporal aggregate, we use one or more general attributes as well as a time attribute on the range of aggregation, thus it is a useful operation for historical data warehouse, Call Data Records(CDR), etc. In this paper, we propose a structure for multidimensional temporal aggregation, called PTA-tree, and an aggregate processing method based on the PTA-tree. Through analyses and performance experiments, we also compare the PTA-tree with the simple extension of SB-tree that was proposed for temporal aggregation.

• Journal of KIISE:Software and Applications
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• v.28 no.11
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• pp.833-841
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• 2001

Abstract In this work, we analyze the Levy mutation operations based on the Levy probability distribution in the evolutionary programming via the mean square displacement and the distinctness. The Levy probability distribution is characterized by an infinite second moment and has been widely studied in conjunction with the fractals. The Levy mutation operators not only generate small varied offspring, but are more likely to generate large varied offspring than the conventional mutation operators. Based on this fact, we prove mathematically, via the mean square displacement and the distinctness, that the Levy mutation operations can explore and exploit a search space more effectively. As a result, one can get better performance with the Levy mutation than the conventional Gaussian mutation for the multi-valued functional optimization problems.

• Journal of KIISE:Software and Applications
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• v.27 no.7
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• pp.691-701
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• 2000

Software documents consists of a number of objects and relationships between them, and structure of documents can be changed frequently. In this paper, we propose a version storage and consistency management model for fine-grained software objects based on operations applied to edit software objects. An object has an interface and can be updated only through operations defined in its interface. Operations applied to objects are recorded in the operation history, which is used to retrieve versions of a document and manage consistency between documents. Because versions of an object are stored and retrieved using the operation delta, it is not needed to compare versions of a document to extract delta and it is easy to identify the changes between versions in order to propagate the changes. Consistencies between documents are managed using dependencies between objects and kinds of the operations applied to the objects. Therefore unnecessary version propagation can be avoided. This paper presents a formal model of version retrieval and consistency management at the fine-grained level based on operations applied to the objects.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.1
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• pp.162-171
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• 2017

Low frequency noise components causes the baseline drift in the ECG signals. In this paper, a morphological operation and smoothing spline technique are used for ECG signal processing in order to accomplish baseline correction. Removing the baseline drift from ECG signal using morphology operation, the feature of original signal may be distorted. To resolve this distortion problem, we applied a smoothing spline operation after morphology operation. In order to compare with existing morphology operation method for baseline correction, we apply proposed method to ECG data in MIT/BIH database. Compared to other existing method, our proposed method achieved low data distortion on the original signal.