• Convergence Security Journal
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• v.24 no.1
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• pp.51-57
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• 2024

Although industrial control systems (ICSs) recently keep evolving with the introduction of Industrial IoT converging information technology (IT) and operational technology (OT), it also leads to a variety of threats and vulnerabilities, which was not experienced in the past ICS with no connection to the external network. Since various control command messages are sent to field devices of the ICS for the purpose of monitoring and controlling the operational processes, it is required to guarantee the message integrity as well as control center authentication. In case of the conventional message integrity codes and signature schemes based on symmetric keys and public keys, respectively, they are not suitable considering the asymmetry between the control center and field devices. Especially, compromised node attacks can be mounted against the symmetric-key-based schemes. In this paper, we propose message authentication scheme based on double hash chains constructed from cryptographic hash function without introducing other primitives, and then propose extension scheme using Merkle tree for multiple uses of the double hash chains. It is shown that the proposed scheme is much more efficient in computational complexity than other conventional schemes.

• Convergence Security Journal
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• v.4 no.2
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• pp.35-41
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• 2004

Proxy signature scheme based on delegation of warrant is studied in these days. Proxy signature Is a signature scheme that the original signer delegates his signing warrant to the proxy signer, and the proxy signer creates a signature on behalf of the original signer. For using this scheme, the security for protecting from the forgeability or misuse is necessary. There are several security requirements for using the proxy signature schemes. In this paper we suggest the proxy-register protocol scheme that original signer registers to the verifier about the proxy related information. In our scheme, verifier verifies the signature that original signer creates about the proxy information and sets the warrant of proxy signer, validity period for proxy signature and some limitation. Finally, we will show the advantages of our suggestion by comparing with the previous proxy signature schemes.

• Journal of the Korean Society for Library and Information Science
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• v.7
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• pp.3-67
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• 1980

Because of the changes made in the modes of cataloguing and classification in its long history, the present catalogue of the National Central Library has become complicated and provides an inadequate guide to its collection. There can be no doubt that this is a serious deficiency in a closed access library since materials housed in the library are virtually inaccessible to unskilled readers. The whole breakdown of the efficiency of the catalogue is emminent and will ultimately create the most serious problems for the library. The main purpose of this survey is: (a) to identify problem areas created by the frequent changes in the cataloguing and classifying principles in the library and (b) to grope a rational direction for the future development. Analysing the various classification schemes and cataloguing rules adopted in processing materials (mainly books) in the library, the following conclusions have been made. A. The library adopted five different clasification schemes in different periods, of which KDCP was used for the most part of its collection. KDCP is recommended to use for the future colletion. A classification development office is recommended to be established within the library, of which the main function is to revise the KDCP in collaboration with the appropriate committee of the Korean Library Association. B. The present practice in the library is to apply three different cataloguing rules and two different author notation tables to the Oriental, classical, and Western collections. Efforts should be made to find out an efficient system so that this variety is simplified. An alphabetical index should be added to the classified catalogue, and improvements are required in the Japanese collection. C. The technical services division is inadequately staffed. The staff should be sufficiently numerous and specially qualified. D. The present financial support for the technical services of the library is inadequate. Sufficient financial provision should be made to ensure the effective work. E. A feasibility study should be carried out to develop a computer processing system for providing machine-readable catalogue records on magnetic tape for use by the library community in Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.4
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• pp.497-507
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• 1993

Four truncation selection schemes (SSs) were framed to predict and compare the age structures and genetic responses under the influence of various factor employing the scheme-specific algorithms. Two paths of selection, sires (bulls' sires) and dams (bulls' dams) to breed young bulls were considered. Among variable factors, four levels (0.3, 0.5, 0.7, 0.9) of precision of evaluation, five levels (0.0, 0.05, 0.10, 0.15, 0.20 genetic standard deviation) of genetic differences among age classes and 4 levels of proportions selected (for bulls' sire, 0.05, 0.10, 0.125, 0.25, and for bulls' dams 0.02, 0.04, 0.05, and 0.10) contemplated on both paths of selection. The number of age classes for bulls' dams and bulls' sires were 4 or 8 and 2 or 4, respectively. The stayability across age classes for bulls' dams was assumed to be 0.80 or 0.60. The candidates for selection for bulls' sires were equally distributed (0.5 or 0.25) across the age classes. The SS1 (selection on same proportions as candidates' distribution) revealed longest generation lengths and lowest yearly genetic responses. The average ages were youngest and yearly genetic responses were highest in SS4 (selection at each age-specific truncation point with the same average genetic superiority of selected parents across the ages) and followed by SS3 (selection at each agespecific truncation point with same predicted genetic values) and SS2 (selection at common truncation point on phenotypic values) in a population with overlapping generations. The results revealed the importance of choosing suitable selection scheme to acquire maximum yearly genetic responses especially when the genetic differences among age classes are large and the precision of evaluation is relatively low.

• Journal of Labour Economics
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• v.26 no.3
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• pp.115-147
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• 2003

This paper scrutinizes the robustness of the profit-sharing findings first employing an original panel data on the Employee Welfare Fund over the period from 1992 to 2000. In examining the effects of profit-sharing schemes on labor productivity, it controls for simultaneity among profit-sharing, production factors, and productivity using both the two-stage least squares procedure and the lagged variable method. The empirical results show that an increase in firm's contribution to the Employee Welfare Fund is associated with capital-embodied and disembodied productivity enhancement, which is both statistically and economically highly significant. The empirical results are in contrast with predictions of both agency and transaction cost theories, and they imply that more tax benefits and financial incentives for expansion of the Employee Welfare Fund should be required to get productivity gains.

• Proceedings of the Korea Information Assurance Society Conference
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• 2004.05a
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• pp.91-96
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• 2004

Proxy signature scheme based on delegation of warrant is studied in these days. Proxy signature is a signature scheme that the original signer delegates his signing warrant to the proxy signer, and the proxy signer creates a signature on behalf of the original signer. For using this scheme, the security for protecting from the forgeability or misuse is necessary, There are several security requirements for using the proxy signature schemes. In this paper we suggest the proxy-register protocol scheme that original signer registers to the verifier about the proxy related information. In our scheme, verifier verifies the signature that original signer creates about the proxy information and sets the warrant of proxy signer, validity period for proxy signature and some limitation. Finally, we will show the advantages of our suggestion by comparing with the previous proxy signature schemes.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.11
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• pp.1559-1571
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• 2008

A rule was developed to constrain the annual rate of inbreeding to a predefined value in a population with different lifetimes between sires and dams, and to maximize the selection response over generations. This rule considers that the animals in a population should be divided into sex-age classes based on the theory of gene flow, and restricts the increase of average inbreeding coefficient for new offspring by limiting the increase of the mean additive genetic relationship for parents selected. The optimization problem of this rule was formulated as a quadratic programming problem. Inputs for the rule were the BLUP estimated breeding values, the additive genetic relationship matrix of all animals, and the long-term contributions of sex-age classes. Outputs were optimal number and contributions of selected animals. In addition, this rule was combined with the optimization of emphasis given to QTL, and further increased the genetic gain over the planning horizon. Stochastic simulations of closed nucleus schemes for pigs were used to investigate the potential advantages obtained from this rule by combining the standard QTL selection, optimal QTL selection and conventional BLUP selection. Results showed that the predefined rates of inbreeding were actually achieved by this rule in three selection strategies. The rule obtained up to 9.23% extra genetic gain over truncation selection at the same rates of inbreeding. The combination of the extended rule and the optimization of emphasis given to QTL allowed substantial increases in selection response at a fixed annual rate of inbreeding, and solved substantially the conflict between short-term and long-term selection response in QTL-assisted selection schemes.

• Water for future
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• v.28 no.4
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• pp.125-136
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• 1995

ELM, a characteristic line based method, was applied to advection-dispersion equation, and the results obtained were compared with those of Eulerian schemes(Stone-Brian and QUICKEST). The calculation methods consisted of Lagrangian interpolation scheme and cubic spline interpolation scheme for the advection calculation, and the Crank-Nicholson scheme for the dispersion calculation. The results of numerical methods were as follows: (1) for Gaussian hill: ELM, using Lagrangian interpolation scheme, gave the most accurate computational result, ELM, using cubic spline interpolation scheme, and QUICKEST scheme gave numerical damping for Peclet number 50. Stone-Brian scheme gave phase shift introduced in the numerical solution for Peclet number 10 and 50. (2) for advanced front: All schemes gave accurate computational results for Peclet number 1 and 4. ELM, Lagrangian interpolation scheme, and Stone,Brian scheme gave dissipation error and ELM, using cubic spline interpolation scheme, and QUICKEST scheme gave numerical oscillation for Peclet number 50.

• International Journal of Contents
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• v.11 no.2
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• pp.31-36
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• 2015

Recent years have seen a significant increase in demand for multimedia data over wireless sensor networks for monitoring applications that utilize sensor nodes to collect multimedia data, including sound and video. However, the multimedia streams generate a very large amount of data. When data transmission schemes for traditional wireless sensor networks are applied in wireless multimedia sensor networks, the network lifetime significantly decreases due to the excessive energy consumption of specific nodes. In this paper, we propose a data compression scheme that implements the Chinese remainder theorem to a wireless multimedia sensor network. The proposed scheme uses the Chinese Remainder Theorem (CRT) to compress and split multimedia data, and it then transmits the bit-pattern packets of the remainder to the base station. As a result, the amount of multimedia data that is transmitted is reduced. The superiority of our proposed scheme is demonstrated by comparing its performance to that of an existing scheme. The results of our experiment indicate that our proposed scheme significantly increased the compression ratio and reduced the compression operation in comparison to those of existing compression schemes.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.3
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• pp.57-66
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• 2011

The current trend of the handover authentication delay time is gradually increased according to the interworking between 3G cellular network and WLANs. Therefore, authentication mechanism minimized in delay is required to perform the seamless handover and support the inter-subnet and inter-domain handover. In this paper, we propose a novel pre-authentication scheme based on the fast channel switching which directly performs the authentication with the next access point in advance. In addition, the proposed scheme is efficient in the inter-domain handover and can be easily implemented in current WLANs since it just modifies the client side of user. To analysis and evaluate our scheme, we compare the packet loss ratio and the delay time with the two standard 802.11 authentication schemes. The analytical results show that our scheme is approximate 10 times more effective than the standard schemes in packet loss and the delay time is minimized down to 0.16 msec.