• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.8
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• pp.1435-1442
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• 2006

The ideal method of safety evaluation is to verify results of execution against all possible operations within operating system, but it is impossible. However, the formal method can theoretically prove the safety on actual logic of operating system. Therefore we explain the contents of the art of the safety verification of security kernel, and make a comparative study of various standardized formal verification tools. And then we assigned PVS(Prototype Verification system) of SRI(Stanford Research Institute) to verify the safety of a modified BLP(Bell & LaPadula) model, the core access control model of multi-lavel based security kernel. Finally, we describe formal specification of the revised BLP model using the PVS, and evaluate the safety of the model by inspecting the specification of the PVS.

• Journal of KIISE:Software and Applications
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• v.31 no.6
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• pp.792-798
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• 2004

In this paper, we will introduce a new corner detector for the wafer die position recognition. The die position recognition procedure is necessary for WSCSP(Wafer Scale Chip Scale Packaging) technology, decide the accuracy of post-procedure. We present a hierarchical gray level corner detection method for the recognition of the die position from a wafer image. The new corner detector divides the corner region into many homocentric circles, and calculates the comer response and the angle of direction about each circle to get an accurate toner point. The new corner detector has a hierarchical structure so it can detect comer point more quickly than general gray level corner detector.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.1
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• pp.111-119
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• 1994

In this paper we propose a reversible image coding methods with progressive build-up function by bit-plane of multi-lavel image. Firstly, the differencial conversion is applied to reduce the entropy of source images. Then the bit-plane sequences of converted images are coded by means of the newly designed VFRL(Variable to Fixed Run-Llength) code and the RDHC(Run-length Dynamic Huffman Coding). We aim to the simple construction to reduce the complexity. The computer simulated results show that the proposed methods are very effective to the multi-level digital images. For "GIRL" and "COUPLE" of 1EEE monochromatic standard images, the compressibility are superior to the results obtained by the well-known universal codes.own universal codes.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.181-184
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• 2000

Proteins in friable and compact calli of Viola patrinii DC. were analysed. The protein contents in friable calli were lower than those in compact calli. In suspension culture, it increased to the maximum after 3 weeks culture from inoculation and decreased after 4 weeks culture. Several strong lavel signals were detected with the SDS-PAGE analysis. The polypeptides of 28, 31 and 35 KD were observed from the friable cell culture, from the compact cell culture strong band of 30 KD was determined, indicating that these polypeptides may be the major protein occurring during their cultures. Changes in amino acid contents during culture of the viola suspension cells were investigated the amino acid contents were greatest between two and three weeks culture of the viola suspension cells.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.6
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• pp.1556-1571
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• 1993

Nitrogen oxides ($NO_x$) are air pollutants which are generated from the combustion of fossil fuels. Stage combustion is an effective method to reduce $NO_x$ emissions. The effects of $NO_x$ reduction by stage combustion in a pilot scale combustor(6.6kW) have been investigated using propane gas flames laden with NH$_{3}$ as Fuel-N. The results in this study are follows; (1) $NO_x$ emissions are dependent on the reducing environment of fuel-rich zone regardless of total air ratio. The maximum $NO_x$ reduction is at the stoichiometric ratio of 0.8 to 0.9 in the reducing zone. (2) $NO_x$ reduction is maximum when burnout air is injected at the point where the oxygen in reducing zone is almost consumed. (3) $NO_x$ reduction is dependent upon the temperature of reducing zone with best effect above 950.deg. C in the reducing zone. (4) The fuel stage combustion is more effective to reduce $NO_x$ formation in the wide range of stoichiometric ratio than two stage combustion. (5) The results of this study could be utilized mainly in a design strategy for low $NO_x$ emission from the combustion of high fuel-nitrogen in energy sources ratio than as an indication of the absolute levels of $NO_x$ which can be achieved by stage combustion techniques in large scale facilities.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.368-372
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• 1998

A field assay was conducted to study whether the by-product of Autoclaved Lightweight Concrete(ALC) could be used as a silicate fertilizer for Korean Zoysiagrass. ALC application rates (0, 2.0, 4.0, 6.0 and $8.0Mg\;ha^{-1}$) were investigated for their effects on growth status, mineral nutrient concentrations, yield of fresh and dry matter of lawn grass and soil properties after experiments. The number of stolon and length of stolon at 180 day after Zoysiagrass transplanting were increased in the treatemnt of $2.0{\sim}6.0Mg\;ha^{-1}$ of ALC application, but those of $8.0Mg\;ha^{-1}$ of ALC plot were deceased with excess of ALC. The fresh weight and dry matter at harvesting time of lawn grass treated with $6.0Mg\;ha^{-1}$ of ALC was heavier than those of other ALC plots. There were statistically significant between the number of stolon and length of stolon remarkably. Mineral nutrient contents such as Si and Ca in Zoysiagrass were increased by higher ALC application, while T-N, available P and K were no difference with application lavel of ALC. Soil pH and Si contents in soil after experiment were increased by ALC application remarkably.