• Journal of Korean Society for Atmospheric Environment
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• v.22 no.6
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• pp.808-820
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• 2006

In regard to indoor air quality patterns, the government introduced various polices that were about managing and monitoring quality of indoor air as a major assignment, and also executed 'Indoor Air Quality Management Act' which was presented in the May, 2004. However, among the multi-usage facilities controlled by the Act, the school was not included yet. This study goal was to investigate PM 10 pollution patterns of the high school classrooms using a pattern recognition method based on cluster analysis and disjoint principal component analysis, and further to survey levels of inorganic elements in May, June, and September, 2004. A hierarchical clustering method was examined to obtain possible objects in pseudo homogeneous sample classes by transformation raw data and by applying various distance. Following the analysis, the disjoint principal component analysis was used to define homogeneous sample class after deleting outliers. Then three homogeneous Patterns were obtained as follows: the first class had been separated and objects in the class were considered to be sampled under semi-open condition. This class had high concentration of Ca, Fe, Mg, K, Al, and Na which are related with a soil and a chalk compounds. The second class was obtained in which objects were sampled while working air-conditioners and was identified low concentration of PM 10 and elements. Objects in the last class were assigned during rainy day. A chalk, soil element and various types of anthropogenic sources including combustions and industrial influenced the third class. This methodology was thought to be helpful enough to classify indoor air quality patterns and indoor environmental categories when controlling an indoor air quality.

• Nuclear Engineering and Technology
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• v.48 no.5
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• pp.1184-1191
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• 2016

This paper introduces the development of a transient monitoring system to detect the early stage of a transient, to identify the type of the transient scenario, and to inform an operator with the remaining time to turbine trip when there is no operator's relevant control. This study focused on the transients originating from a secondary system in nuclear power plants (NPPs), because the secondary system was recognized to be a more dominant factor to make unplanned turbine-generator trips which can ultimately result in reactor trips. In order to make the proposed methodology practical forward, all the transient scenarios registered in a simulator of a 1,000 MWe pressurized water reactor were archived in the transient pattern database. The transient patterns show plant behavior until turbine-generator trip when there is no operator's intervention. Meanwhile, the operating data periodically captured from a plant computer is compared with an individual transient pattern in the database and a highly matched section among the transient patterns enables isolation of the type of transient and prediction of the expected remaining time to trip. The transient pattern database consists of hundreds of variables, so it is difficult to speedily compare patterns and to draw a conclusion in a timely manner. The transient pattern database and the operating data are, therefore, converted into a smaller dimension using the principal component analysis (PCA). This paper describes the process of constructing the transient pattern database, dealing with principal components, and optimizing similarity measures.

• Food Science and Preservation
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• v.8 no.4
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• pp.412-418
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• 2001

This study was carried out to set up alcohol fermentation condition for uncooked brown rice. Response surface methodology(RSM) was applied to optimize and monitor of the alcohol fermentation condition with uncooked brown rice. The optimal yeast strain for fermentation of uncooked brown rice was S. cerevisiae GRJ. The polynomial equation for alcohol contents, brix pH and total acditiy showed 0.8828, 0.8409, 0.9431 and 0.9280 of R$^2$, respectively. Optimum range of uncooked alcohol fermentation for maximum alcohol contents were 0.34%(w/w) of enzyme concentration and 350%(w/w) of added water content, respectively. Predicted values at optimum alcohol fermentation condition agreed with experimental values.

• Journal of Digital Convergence
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• v.15 no.9
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• pp.463-470
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• 2017

The aim of this research is to examine patterns of design governance used by Northern European countries to respond to social crises and understand design governance as a tool for sophistication of social services and social integration. Design governance as applied in Sitra of Finland, MindLab of Denmark and the Gulliver project of Germany encourages using design methodology for analyzing and solving problems related to social phenomena based on involvement of the private, public, industrial, and academic groups. Especially, the citizens are actively involved in developing problem-solving ideas and designing new policy with other governance members, rather than simply providing information or one-time participation. In the cases discussed in this study, design governance reduce unnecessary administrative and financial consumption and inconvenience caused by complicated rules, based on field-oriented approach, regional characteristics, pluralism, and respect for diversity. Therefore, future design policy paradigm will need to evolve into concept of policy design and pluralistic monitoring centered on design governance based on participation of private sector to lead policy development, from the current system in which only few officials decide policy.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.3
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• pp.645-653
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• 2016

Ransomware was first created in 1999, but its existence become widely known in Korean by 2015. As information and communication technology have developed, the storage capacity of computer has enlarged, it accordingly is getting more important to effectively manage these information, rather than the information itself. In such situation, the ransomware break into other people's computer and encrypt an files without a user's permission. So, it adversely affect the user. In this paper, we monitor an access of a specific process to the file. And on the basis of this monitoring information, we detect whether the abnormal approach happened. Through the detection result, we block the permission about access to the file for a specific process. Using this method, we propose a blocking technique for the ransomeware's abnormal approach and encryption to the files.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.3
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• pp.287-294
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• 2008

This study proposes a novel method for in service evaluation of tension force of a prestressed 7-wire strand which is frequently employed for retrofitting bridge superstructure. The smart strand is made by replacing the straight king wire of the strand with an instrumented steel tube in which the FBG sensor is embedded. Since the strain of the smart strand can easily be measured using the sensor, it is possible to monitor tension force of the strand during the service. For the sake of demonstrating effectiveness of the proposed strand, we came up with a 7.0m long prototype with 2 FBG sensors, and it is applied as an external tendon to a 6.4m long and 0.6 high RC T-shaped beam. A loading-unloading test has been carried out, and estimated tension forces using the smart strand are compared with measured forces by load cell. The comparison showed that the proposed smart tendon is useful and accurate for monitering tension force of the prestressed tendon.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.3
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• pp.100-107
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• 2015

Recently as the manufacturers want competitiveness in dynamically changing environment, they are trying a lot of efforts to be efficient with their production systems, which may be achieved by diminishing unplanned operation stops. The operation stops and maintenance cost are known to be significantly decreased by adopting proper maintenance strategy. Therefore, the manufacturers were more getting interested in scheduling of exact maintenance scheduling to keep smooth operation and prevent unexpected stops. In this paper, we proposedan integrated maintenance approach in injection molding manufacturing line. It consists of predictive and preventive maintenance approach. The predictive maintenance uses the statistical process control technique with the real-time data and the preventive maintenance is based on the checking period of machine components or equipment. For the predictive maintenance approach, firstly, we identified components or equipment that are required maintenance, and then machine parameters that are related with the identified components or equipment. Second, we performed regression analysis to select the machine parameters that affect the quality of the manufactured products and are significant to the quality of the products. By this analysis, we can exclude the insignificant parameters from monitoring parameters and focus on the significant parameters. Third, we developed the statistical prediction models for the selected machine parameters. Current models include regression, exponential smoothing and so on. We used these models to decide abnormal patternand to schedule maintenance. Finally, for other components or equipment which is not covered by predictive approach, we adoptedpreventive maintenance approach. To show feasibility we developed an integrated maintenance support system in LabView Watchdog Agent and SQL Server environment and validated our proposed methodology with experimental data.

• Food Science and Preservation
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• v.15 no.3
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• pp.396-404
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• 2008

This study investigated the functional properties of lateral roots of red ginseng following roasting treatment The ten different conditions, based on the central composite design for roasting parameters, were pre-established according to roasting temperature($140{\sim}240^{\circ}C$) and time($5{\sim}25\;min$). The functional characteristics were monitored using response surface methodology, whereby polynomial equations and correlation coefficients were investigated between roasting conditions. The functional properties of the samples were affected more by roasting time than temperature. The optimal roasting condition ranges for maximizing the functional qualities of lateral roots of red ginseng were predicted to be a roasting temperature of $194.5-210.9^{\circ}C$, and a roasting time of 13.8-20.0 min.

• Food Science and Preservation
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• v.10 no.3
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• pp.308-313
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• 2003

In the present study, we investigated the optimum recipe of the pumpkin drink using old pumpkin extract. Response surface methodology (RSM) was applied to optimize and monitor the drink recipe with pumpkin extract. The polynomial equation for color, flavor, taste, mouth feel, overall palatability, pH, brix and viscometer showed 0.7682, 0.9046, 0.9364, 0.9110, 0.8456, 0.9264, 0.7135 and 0.9906 of R$^2$, respectively and flavor, taste, mouth feel, overall palatability, pH and viscometer showed 5～10％ of significance level. The optimum ranges of recipe on organoleptic properties of pumpkin pouch drink were estimated on 86.5～87.5％ of the old pumpkin extract, 0.36～0.42％ of xanthan gum and 9％ of vinegar.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.117-124
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• 2000

Considering the thermal unstableness of ginseng components, microwave-assisted extraction(MAE) was performed under the atmospheric pressure condition. The monitoring of extraction characteristics and the optimization of extraction conditions were made by response surface methodology. The extraction efficiency of soluble ginseng components was high at lower ethanol concentration and at higher microwave power, while crude saponin content was easily extracted at higher ethanol concentration. Estimated conditions for the maximized extraction of soluble components including crude saponin, total phenolics and electron donating ability were $54{\sim}60%$ in ethanol concentration, $41{\sim}90$ W in microwave power, and within 4 min in extraction time. Predicted values at the optimum condition(60% ethanol, 80 W microwave power and 4 min extraction time) were in good agreement with observed values.