• ETRI Journal
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• v.19 no.4
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• pp.389-401
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• 1997

In this paper, we consider the relationship between nonlinearity and correlation immunity of Boolean functions. In particular, we discuss the nonlinearity of correlation immune functions suggested by P. Camion et al. For the analysis of such functions, we present a simple method of generating the same set of functions, which makes it possible to construct correlation immune functions with controllable correlation immunity and nonlinearity. Also, we find a bound for the correlation immunity of functions having maximal nonlinearity.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.4
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• pp.89-95
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• 2007

There are various methods constructing correlation immune functions such as Siegenthaler's, Camion et al's and Seberry et al's. In particular, Soberry et al's is a method which directly constructs balanced correlation immune functions of any order using the theory of Hadamard matrices. In this paper, we have studied Seberry et al's method for constructing a correlation immune function on a higher dimensional space by combining known correlation immune functions on a lower dimensional space. Futhermore, we calculated the nonlinearity of functions which are constructed by combining of several correlation immune functions. That is, we have shown that the direct sum of two correlation immune functions and a combination of four correlation immune functions have higher nonlinearity in comparison with each functions. This functions in stream cipher are safe against correlation attacks.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.9 no.1
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• pp.127-134
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• 1999

Boolean functions have an important role for designing block ciphers and hash functions. In this paper, we propose a method for designing optimum correlation immune functions. We also analyze their cryptographic properties - balancedness, nonlinearity, correlation value to the set of linear functions, correlation immunity, propagation characteristic, and algebraic degree. Such functions are special type of Semi-bent functions [2,5]

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.7
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• pp.1433-1440
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• 2015

In this paper, we propose an unambiguous correlation function to improve tracking performance for binary offset carrier (BOC) signals. Specifically, we divide a BOC sub-carrier into multiple rectangular pulses, and analyze that the BOC autocorrelation function is made up of the sum of several partial correlation functions. Then, we obtain two sub-correlation functions by combining two partial correlation functions and propose a novel unambiguous correlation function with no side-peak which can be regulated its width based on the combination of the sub-correlation functions and partial correlation functions. From numerical results, it is confirmed that the proposed correlation function provides a tracking performance improvement over the conventional correlation functions in terms of the tracking error standard deviation.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.6 no.3
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• pp.11-22
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• 1996

In this paper, we consider the relationship between the nonlinearity and correlation immunity of functions suggested in [1], [3]. For the analysis of such functions, we present a simple method of generating the same set of functions, which makes us possible to construct correlation immune functions with controllable correlation immunity and nonlinearity.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.7 no.2
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• pp.3-10
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• 1997

Correlation immune functions can be used not only as filter functions or nonlinear combiners in stream ciphers but also as a primitive logic in block cipher. In this paper, we suggest a construction method of correlation immune functions. Using this method, we find lower and upper bound of the cardinality of the correlation immune functions. This result improves Mitchell's result and Yang-Guo's result.

• PNF and Movement
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• v.12 no.4
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• pp.217-224
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• 2014

Purpose: The purpose of this study is to analyze the hand functions of elderly persons according to their cognitive status and age. Methods: A total of 65 persons voluntarily participated in the study. The subjects were divided into three groups: impairment cognitive group, normal cognitive group, adult group (persons in their twenties). Assessment of cognitive status was performed using a mini-mental state examination for Koreans (MMSE-K). Hand function was assessed using the Purdue pegboard test. The collected data were analyzed using a one-way ANOVA and Pearsonn Acorrelation. Results: There were significant differences in hand functions in the three groups. Post-hoc test results showed significant differences between each group. There were statistically significant differences in the correlation among hand functions, cognitive status, and age. The findings of this study suggest that hand functions have a positive correlation with cognitive status. However, a negative correlation was found between hand function and age. Conclusion: According to the study's results, hand functions are correlated with age and cognitive functions in elderly persons. This study suggests that hand rehabilitation with cognitive intervention increases hand functions in elderly persons.

• The Korean Journal of Applied Statistics
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• v.5 no.2
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• pp.113-121
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• 1992

Statistical interpolation which uses past experience about the behaviour of the atmosphere(correlation function) to interpolate the observations irregularly distributed in space and time to regular grids is discussed. Correlation functions are computed in the Far East Asian region during the winter periods of December 1977 to February 1980. Results show from the computation of correlation functions that there exists a large difference in the autocorrelation functions by slowly decreasing geopotential height and temperature, and rapidly decreasing wind and mixing ratio with increasing data-correlation functions between geopotential height and wind are well corresponed to persistence of wintertime synoptic features.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.3
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• pp.296-302
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• 2013

The binary offset carrier (BOC) modulation has attracted much attention as a new physical layer implementation for satellite communication and global navigation satellite systems. In this paper, we propose a new correlation function for sine-phased BOC signals. Specifically, we separate a sub-carrier pulse into several rectangular pulses, and then, generate a number of partial correlation functions. Finally we combine the partial correlation functions to yield an unambiguous correlation function with no side-peak. From numerical results, it is demonstrated that the proposed correlation function provides a significant tracking performance improvement over the conventional correlation functions.

• The Pure and Applied Mathematics
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• v.22 no.3
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• pp.299-313
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• 2015

In this paper, we show the effectiveness of copulas by comparing the correlation of market data of year 2010 with those of years 2006-2009 and investigate copula functions as pricing methods of digital and rainbow options through real market data. We propose an accurate method of pricing rainbow options by using the correlation coefficients obtained from the copula functions depending on strike prices between assetes instead of simple traditional correlation coefficients.