• Environmental Analysis Health and Toxicology
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• v.23 no.2
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• pp.67-77
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• 2008

It has been observed that the linear relationship between the logarithm of bioconcentration factor (log BCF) of highly hydrophobic chemicals and their log $K_{ow}$ breaks when log $K_{ow}$ becomes greater than 6.0. Consequently, super hydrophobic chemicals were not thought to cause baseline toxicity as a single compound. Researchers often call this phenomenon as "hydrophobicity cutoff" meaning that bioconcentration or corresponding baseline toxicity has a certain cutoff at high log $K_{ow}$ value of hydrophobic organic pollutants. The underlying assumption is that the increased molecular size with increasing hydrophobicity prohibits highly hydrophobic compounds from crossing biological membranes. However, there are debates among scientists about mechanisms and at which log $K_{ow}$ this phenomenon occurs. This paper reviews three hypotheses to explain observed "cutoff": steric effects, kinetic or physiological limitations, and chemical activity cutoff. Although the critical molecular size that makes biological membranes not permeable to hydrophobic organic chemicals is uncertain, size effects in combination with kinetic limitation would explain observed non-linearity between log BCF and log $K_{ow}$. Chemical activity of hydrophobic chemicals generally decreases with increasing melting point at their aqueous solubility. Thus, there may be a chemical activity cutoff of baseline toxicity if there is a critical chemical activity over which baseline effects can be observed.

• Convergence Security Journal
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• v.15 no.7
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• pp.85-96
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• 2015

In IT system, logs are an indicator of the previous key events. Therefore, when a security problem occurs in the system, logs are used to find evidence and solution to the problem. So, it is important to ensure the integrity of the stored logs. Existing schemes have been proposed to detect tampering of the stored logs after the key has been exp osed. Existing schemes are designed separately in terms of log transmission and storage. We propose a new log sys tem for integrating log transmission with storage. In addition, we prove the security requirements of the proposed sc heme and computational efficiency with existing schemes.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.139.1-139.1
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• 2012

Wilson and Bappu (1957) found a significant relationship (WBR) between the absolute magnitude ($M_v$) and the width of the Ca II K emission line (W) for late type stars. In this study, we revisit the WBR to claim that WBR can be an excellent indicator of stellar surface gravity. We analyze 95 high-resolution spectra of G, K and M type stars obtained with UVES and BOES. WBR found in this work is $M_v$=34.22-18.34logW. In addition, stellar atmospheric parameters ($T_{eff}$, logg, [Fe/H], ${\xi}_{tur}$) are determined with the MOOG code and the Kurucz ATLAS9 model grids for G and K type stars. For M type stars, the method of Belle et al. (1999) is used to derive effective temperature which shows good agreement with other methods. Using the derived $T_{eff}$ and the measured logW,we find the relationship between logg and [logW, logT]; ${\log}g-_{fit}=-25.051-5.527{\log}W+10.254{\log}T_{eff}$. This relation can be applied to estimate the surface gravity of M type stars, which is difficult to be determined by other methods.

• Journal of Korea Multimedia Society
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• v.18 no.1
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• pp.42-51
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• 2015

In this paper, we analyze the quality status of Health and Welfare division's standardized log and asses the characteristics of the institutions' logs analysis to establish the criteria to minimize hazards and control the quality of log's institutional details to limit extraction. As a result, extraction condition's proposed development direction to adequately assess and control health and welfare abuses privacy control target log. This improvement over the status and quality of information shared with relation to institutional work of the log quality characteristics is made possible. In addition, quality control and inspection standards were prepared in accordance with the institutional log characteristics. Future research will include performing continuous analysis and improvement activities on the quality of logs with integrated control of sharing personal information and distributing information about logs' quality to proactively target organ. Therefore, we expect that correcting proactive personal information misuse and leakage is possible to achieve.

• Bulletin of the Korean Chemical Society
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• v.18 no.11
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• pp.1158-1161
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• 1997

The potentiometric methods have been used to determined the protonation constants (logKiH) for the synthesized 1,7,13-trioxa-4,10,16-triazacyclooctadecane-N,N',N''-tri(methylacetic acid) [N3O3-tri(methylacetic acid)] and the stability constants (logKML) of the complexes of divalent and trivalent metal ions with the ligand N3O3-tri(methylacetic acid). The protonation constants of N3O3-tri(methylacetic acid) were 9.70 for logK1H, 9.18 for logK2H, 7.27 for logK3H, 3.38 for logK4H, and 2.94 for logK5H. The stability constants for the complexes of divalent metal ions with N3O3-tri(methylacetic acid) were 10.39 for Co2+, 10.68 for Ni2+, 13.45 for Cu2+, and 13.00 for Zn2+. The order of the stability constants for the complexes of the divalent metal ions with N3O3-tri(methylacetic acid) was Co2+ < Ni2+ < Zn2+ < Cu2+. The stability constants for the complexes of trivalent metal ions with N3O3-tri(methylacetic acid) were 16.20 for Ce3+, 16.40 for Eu3+, 16.27 for Gd3+, and 15.80 for Yb3+. The results obtained in this study were compared to those obtained for similar ligands, 1,7-dioxa-4,10,13-triazacyclopentadecane-N,N',N"-tri(methylacetic acid) and 1,7,13-trioxa-4,10,16-triazacyclooctadecane-N,N',N"-triacetic acid, which have been previously reported.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.4
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• pp.19-27
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• 2014

Software reliability in the software development process is an important issue. Software process improvement helps in finishing with reliable software product. Infinite failure NHPP software reliability models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, proposes the reliability model with log type mean value function (Musa-Okumoto and log power model), which made out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on mean square error (MSE) and coefficient of determination($R^2$), for the sake of efficient model, was employed. Analysis of failure using real data set for the sake of proposing log type mean value function was employed. This analysis of failure data compared with log type mean value function. In order to insurance for the reliability of data, Laplace trend test was employed. In this study, the log type model is also efficient in terms of reliability because it (the coefficient of determination is 70% or more) in the field of the conventional model can be used as an alternative could be confirmed. From this paper, software developers have to consider the growth model by prior knowledge of the software to identify failure modes which can be able to help.

• Communications for Statistical Applications and Methods
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• v.31 no.3
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• pp.349-363
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• 2024

Compositional data refers to data where the sum of the values of the components is a constant, hence the sample space is defined as a simplex making it impossible to apply statistical methods developed in the usual Euclidean vector space. A natural approach to overcome this restriction is to consider an appropriate transformation which moves the sample space onto the Euclidean space, and log-ratio typed transformations, such as the additive log-ratio (ALR), the centered log-ratio (CLR) and the isometric log-ratio (ILR) transformations, have been mostly conducted. However, in scenarios with sparsity, where certain components take on exact zero values, these log-ratio type transformations may not be effective. In this work, we mainly suggest an alternative transformation, that is the square-root transformation which moves the original sample space onto the directional space. We compare the square-root transformation with the log-ratio typed transformation by the simulation study and the real data example. In the real data example, we applied both types of transformations to the USG% data obtained from NBA, and used a density based clustering method, DBSCAN (density-based spatial clustering of applications with noise), to show the result.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1867-1872
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• 2010

Microbe and quality changes of vacuum-packaged ready-to-eat lettuce were analyzed. While the vacuumpackaged lettuce after chlorine sanitizer were stored at $5^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$ for 7 days, viable numbers of total aerobic bacteria (TAB), coliform, E. coli, food-borne pathogens and lactic acids bacteria (LAB) were counted with gas production and sensory evaluation. Before the storage, only TAB of 2 log CFU/g and coliform of 1 log CFU/g were detected and LAB was not detected. TAB, coliform and LAB increased by 1 log CFU/g at $5^{\circ}C$ for 7 days without any detection of the pathogens. Sensory evaluations for off-flavour and crispness dropped to half the best value at 5 day storage. TAB and coliform increased by 3 log CFU/g and 2 log CFU/g, respectively, but LAB grew very actively by 4 log CFU/g under anaerobic environment and only B. cereus were detected after enrichment of the lettuce at $15^{\circ}C$ for 3 days. The evaluations for off-flavour and crispness were half the best value for 3 days. However, TAB and coliform increased by 3 log CFU/g, 1 log CFU/g, and 4 log CFU/g, respectively only at 1 day storage under $25^{\circ}C$. Also B. cereus were detected after enrichment and the sensory evaluation were half the best value within 1 day storage. Therefore, preservation at the lowest temperature possible is required for growth inhibition of the bacteria contaminated in the lettuce. Interestingly, LAB among them grew most actively under the anaerobic condition and the adulteration of lettuce might be closely related with the growth of LAB.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.224-230
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• 2006

Microbial contamination levels and legal preservative appropriation in child foods sampled from the neighborhood of elementary schools were investigated. Contamination levels of total aerobic bacteria in seasoned dried fish slices, bread and snacks, sausages, sugar products and dumplings were $1.70\~6.91,\;1.40\~6.66$, 4.50, $3.48\~5.88$, and $4.79\~4.82\;log_{10}$ CFU/g, respectively. Coliforms in four kinds of foods except for dumplings were $2.30\~6.60,\;4.22\~~5.98$, 2.00, and $2.78\;log_{10}$ CFU/g, respectively. Yeasts and molds in those foods were $0.10\~4.23,\;1.66\~4.91,\;1.46\~1.91,\;1.56\~4.26$, and $1.12\~1.84\;log_{10}$ CFU/g, respectively. S. aureus was isolated in $18\%$ of seasoned dried fish slices ($1.00\~2.84\;log_{10}$ CFU/g), $33\%$ of bread and snacks ($1.70\~1.79\;log_{10}$ CFU/g), $50\%$ of sausages ($3.28\;log_{10}$ CFU/g), $22\%$ of sugar products ($2.16\~2.88\;log_{10}$ CFU/g), and $100\%$ of dumplings $(1.18\~3.31\;log_{10}\;CFU/g)$ B. cereus was isolated in $21\%$ of seasoned dried fish slices $(0.70\~2.48\;log_{10}\;CFU/g)$, $50\%$ of bread and snacks $(0.70\;log_{10}\;CFU/g)$, and $11\%$ of sugar products $(0.30\;log_{10}\;CFU/g)$. Both E. coli and Salmonella spp. were not isolated in all samples. Preservative was only labeled on four products among 15 products but preservative on 13 products including 4 products haying an indication of preservative were not detected. Moreover, $0.30\%$ of sorbic acid was detected in one of Squid products . The results of this study indicated that the hygienic level of child foods in Gyeonggi and Incheon was very poor and need to be improved.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.420-426
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• 2012

The purpose of this study was to identify control points through microbiological hazard analysis in the manufacturing processes of starch noodles. Samples were collected from the ingredients, manufacturing processes, equipment and environment. Microbiological hazard assessments were performed using aerobic plate counts (APC), Enterobacteriaceae (EB), E. coli and five pathogens including B. cereus, E. coli O157:H7, L. monocytogenes, Salmonella spp., and S. aureus. The APC levels in raw materials were from 2.12 to 3.83 log CFU/g. The contamination levels after kneading were 4.31 log CFU/g for APCs and 2.88 log CFU/g for EB counts. APCs decreased to 1.63 log CFU/g and EB were not detected after gelatinization, but their levels slightly increased upon cooling, cutting, ripening, freezing, thawing, and separating. The reuse of cooling and coating water would be a critical source of microbial increase after cooling. After drying, APCs and EB counts decreased to 5.05 log CFU/g and 2.74 log CFU/g, respectively, and the levels were maintained to final products. These results suggest that the cooling process is a critical control point for microbiological safety, and the cooling water should be treated and controlled to prevent cross contamination by pre-requisite program.