• Proceedings of the Korean Society of Crop Science Conference
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• 2003.10a
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• pp.216-217
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• 2003

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.17-20
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• 2005

In this work, we compared several feature selection methods in the field of spam mail filtering. The proposed fuzzy inference method outperforms information gain and chi squared test methods as a feature selection method in terms of error rate. In the case of junk mails, since the mail body has little text information, it provides insufficient hints to distinguish spam mails from legitimate ones. To address this problem, we follow hyperlinks contained in the email body, fetch contents of a remote web page, and extract hints from both original email body and fetched web pages. A two-phase approach is applied to filter spam mails in which definite hint is used first, and then less definite textual information is used. In our experiment, the proposed two-phase method achieved an improvement of recall by 32.4% on the average over the $1^{st}$ phase or the $2^{nd}$ phase only works.

• Journal of the Korean Operations Research and Management Science Society
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• v.14 no.1
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• pp.88-96
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• 1989

General measure in the reliability is the k-terminal reliability, which is the probability that the specified vertices are connected by the working edges. To compute the k-terminal reliability components are usually assumed to be statistically independent. In this study the modeling and analysis of the k-terminal reliability are investigated when dependency among components is considered. As the size of the network increases, the number of the joint probability parameter to represent the dependency among components is increasing exponentially. To avoid such a difficulty the structured-event-based-reliability model (SERM) is presented. This model uses the combination of the network topology (physical representation) and reliability block diagram (logical representation). This enables us to represent the dependency among components in a network form. Computational algorithms for the k-terminal reliability in SERM are based on the factoring algorithm Two features of the ractoring algorithm are the reliability preserving reduction and the privoting edge selection strategy. The pivoting edge selction strategy is modified by two different ways to tackle the replicated edges occuring in SERM. Two algorithms are presented according to each modified pivoting strategy and illustrated by numerical example.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1032-1034
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• 1999

The design of an $H{\infty}$ controller for a TCSC to enhance the damping of an inter-area oscillation in a Power system is presented. The paper describes a comprehensive and systematic way of applying the $H{\infty}$ control design algorithm in power systems. Eigen sensitivity analysis to selction a TCSC location is described. Time simulation and eigenvalue analysis show that the proposed TCSC $H{\infty}$ controller can suppress the inter-area oscillations efficiently with robustness.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.412-417
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• 2007

The energy efficiency and environment-friendly aspect of the railway system would be superior to other on-land transportation systems. In a preliminary feasibility study stage, the energy efficiency and problems related with environment are usually not considered. Selection of optimal railway line is taken into consideration include of the purpose of railway, geographical features and facility of management. The railway Alignment which could be reasons of environmental problems are focused and studied in this paper. This study performed opinions of specialists, checking of industrial environment, analysis of bid guideline to select the optimal line and executed AHP method to make quality model and choose weight factors. The investment for railway systems could be encouraged by the considering of main environmental elements evaluated with the modified noise and vibration standard for environment-friendly railway construction.

• Archives of Pharmacal Research
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• v.5 no.2
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• pp.71-77
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• 1982

Improvements in the analytical methodology used in the gas chromatographic/mass spectral analysis of phenolic compounds from cigarette smoke are described. For the direct analysis of crude samples, pyridine extraction and the glass capillary column GC was used for the separation of phenolics as trimethylsilyl derivativatives. The separations of cigarette smoke on Carbowax 20M and SE-54 wall coated open tubular columns are given. Improved methodology for the routine quantitation of the identified components using the computer-controlled multiple ion selection technique of MS presented. Considerations pertaining to routine analyses of a multitude of complex smoke samples are also discussed.

• Clean Technology
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• v.3 no.2
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• pp.36-46
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• 1997

CFC and organic chlorine solvents has been used in the fine machinery and electronics industries for a long time since they have various excellent properties as cleaning agents. However, it is inevitable that alternative cleaning agents should be used since CFC and organic chlorine solvents were identified as ozone-depleting chemicals. There are various alternative cleaning agents. Among them, aqueous/semi-aqueous cleaning agents are environmentally friendly and promising in the long term. And their use and developement are on the increase in advanced countries, but few in our countries. In this paper, the charactistics and major components aqueous/semi-aqueous cleaning agents are analyzed and compared. And various cleaning equipments for aqueous/semi-aqueous cleaning agents such as immersion cleaner, ultronsonic cleaners, power spray cleaner, and vibration or rotational cleaners are compared and evaluated. Finally, important consideration points for selction of a cleaning system are analyzed and suggested in this paper.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.487-493
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• 1995

This study was carried out to select useful chemicals to control pathogens inciting soybean-sprout rot. Pathogen strains were isolated from decaying soybean seedlings. The isolated strains were identified as Pseudomonas spp. (Pse. strains) through microbiological test, however, no rot-inciting fungus was isolated. Eight food additives were tested with different concentrations in controlling pathogens and harmfulness. Five chemicals(over 5% cone.) including sodium hypochlorite apparently inhibited the growth of Pse. strains on media plate, however, sodium hypochlorite was discarded due to its severe germination inhibition. Propionic acid and acetic acid inhibited the growth of Pse. strains more effectively than calcium propionate and sodium propionate relatively. As no harmful effect on seed germination and no growth retard of soybean sprouts were observed by those chemicals with lower concentration(0.5∼1.0%), these chemicals were considered to be applicable to sprout rot control judged by the effectiveness and permissible concentration as food additives.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.2
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• pp.83-92
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• 1976

The relationships between various nitrogen efficiencies among 57 rice cultivars grouped into three developmental categories were investigated by simple correlation with (12kg/10a) and without nitrogen fertilizer under the field condition. The relationship showed similar in a group or among all varieties of three groups. Yield among varieties showed highly significant correlation with Fe (fertilization efficiency: yield increment/nitrogen applied), E (nitrogen efficiency for yield), Ef(efficiency of nitrogen derived from fertilizer) and Eu (fertilizer use efficiency: nitrogen derived from fertilizer divided by total nitrogen applied). The E was correlated significantly and positively with harvest index (HI), percent translocation (T) of nitrogen to ear and negatively with nitrogen uptake amount (N), nitrogen concentration in grain (GN%) and in straw (SN%). The E depends almost on Ef and only inTongil group partly on Es (efficiency of nitrogen derived from soil). The Ef contributes to Fe more than Eu does (Fe = $Ef{\cdot}Eu$). It appears that Ef and Eu increased from the old group to the recommended local varieties, but only EF and Es increased markedly when rice was developed from recommended local group to Tongil line ($indica{\times}japonica$ hybrid selction). The fact that E and Fe depend more on Ef among rice varieties is very good contrast to the result that E and Fe depend more on Es and Eu respectively among soils in the previous investigatigation. The Ef appears as the most important parameter for rice varietal selection under fertilizer application system.

• Culinary science and hospitality research
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• v.21 no.2
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• pp.243-253
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• 2015

This study examined the factors that affect the relationship between customer consumption propensity, customer bakery selction and customer behavioral intention. A total of 300 questionnaires were distributed to the consumers, of which 27 were deemed suitable for analysis after the removal of 28 unusable responses. In order to perform statistical analyses required in the study, SPSS 18.0 Statistical Program was employed for frequency analysis, factor analysis, and reliability analysis. The results of exploratory factor analysis showed that three factors regarding customer consumption propensity were extracted from all measurements with a KMO of 0.778 and a total cumulative variance of 62.121%. With regard to bakery selection attributes, three factors were extracted with a total cumulative variance of 65.69% and a KMO score of 0.776. One factor for behavioral intention was extracted that accounted for a total cumulative variance of 69.82% and a KMO score of 0.803. All factors were significant to 0.000 and the correlation between variables was significant. Thus, based on the results, the main research hypothesis that identifies the relationships between bakery selection attributes and behavioral intention was partially adopted.