• Journal of the Korean Geosynthetics Society
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• v.17 no.3
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• pp.9-18
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• 2018

The soil parameters important for the design of the soft ground are the compression index ($C_c$), the consolidation settlement and consolidation speed at the field. Compression index is obtained by laboratory consolidation test. In the laboratory consolidation test, sample disturbance always occurs. In order to correct the disturbance phenomena, the method of calculating the compression index proposed by Schmertmann (1955) is generally used. However, recent developments in sampling technology and Korean soil conditions are different from those proposed by Schmertmann. So it needs to be verified. In this study, each consolidation curve's cross void ratio is evaluated by doing consolidation test varying disturbance on high-plastic clay (CH), low-plastic clay (CL) and low-plastic silt (ML). The test results were $0.521e_0$ for low-plastic silt, $0.404e_0$ for low-plastic clay, and $0.458e_0$ for the high-plastic clay. This results were different from those of Schmertmann's suggested value of $0.42e_0$. Therefor we proposed a correction formula using the plastic index according to soil type. However, since the results of this study are limited test results, further studies on various korean soil are needed to suggest the compression index correction method according to the degree of plasticity index of soil.

• Journal of Biomedical Engineering Research
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• v.43 no.1
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• pp.27-34
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• 2022

Drunk driving defines a driver as unable to drive a vehicle safely due to drinking. To crack down on drunk driving, alcohol concentration evaluates through breathing and crack down on drinking using S-shaped courses. A method for assessing drunk driving without using BAC or BrAC is measurement via biosignal. Depending on the individual specificity of drinking, alcohol evaluation studies through various biosignals need to be conducted. In this study, we measure biosignals that are related to alcohol concentration, predict BrAC through SVM, and verify the effectiveness of the S-shaped course. Participants were 8 men who have a driving license. Subjects conducted a d2 test and a scenario evaluation of driving an S-shaped course when they attained BrAC's certain criteria. We utilized SVR to predict BrAC via biosignals. Statistical analysis used a one-way Anova test. Depending on the amount of drinking, there was a tendency to increase pupil size, HR, normLF, skin conductivity, body temperature, SE, and speed, while normHF tended to decrease. There was no apparent change in the respiratory rate and TN-E. The result of the D2 test tended to increase from 0.03% and decrease from 0.08%. Measured biosignals have enabled BrAC predictions using SVR models to obtain high Figs in primary and secondary cross-validations. In this study, we were able to predict BrAC through changes in biosignals and SVMs depending on alcohol concentration and verified the effectiveness of the S-shaped course drinking control method.

• Journal of the Korean Geotechnical Society
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• v.38 no.10
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• pp.49-60
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• 2022

Underground urbanization appears to be a promising solution in response to the shortage of construction sites in the above-ground space. In this context, an accurate evaluation of a construction site ensures the long-term performance of geosystems. This study characterizes potential sites for complex plants built in underground space using geophysical methods (i.e., seismic refraction exploration and electrical resistivity survey) and in situ tests (i.e., standard penetration tests (SPTs) and downhole tests). SPTs are conducted in nine boreholes BH-1-BH-9 to estimate the groundwater level and vertical distribution of geological structures. The seismic refraction method enables us to obtain the elastic wave velocity and thickness of each soil layer for each cross-sectional area. An electrical resistivity survey conducted using the dipole array method provides the electrical resistivity profiles of the cross-sectional area. Data obtained using geophysical techniques are used to assess the classification of the soil layer and bedrock, particularly the fracture zone. This study suggests that geotechnical information using in situ tests and geophysical methods are useful references to design an underground complex plant construction.

• The Research Journal of the Costume Culture
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• v.26 no.5
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• pp.727-743
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• 2018

In this study, we used the 3D simulation program to create bodice patterns for adolescents boy students and analyze the fitting and air gap through 3D simulation. The purpose of this study was to select the bodice pattern method that best suited the body shapes of the adolescents male students. The subjects of this study were the French E pattern, Japanese N pattern, and Korean industrial L and J patterns. The applied size was the sixth Korean human body size survey data of 2010 Korea. The age range of the subjects was 13-18 years. DC Suite Program Ver. 5.1 was used, and SPSS 23.0 program was used for data analysis. As a result of comparing the shapes of the bodice patterns in the 3D simulation program, the E pattern had two waist darts on the front and one shoulder dart and one waist dart on the back, and the J and L patterns only had one dart on the back. The N pattern had no darts on either the front or back. As a result of examining the appearance evaluation of the pattern, air gap, color distribution, and clothing cross-section, the E pattern was evaluated as the closest to the body, and the N pattern was evaluated as the pattern with the largest allowance. The J pattern was evaluated as the best fit for body shape of the male adolescents. However, it is necessary to develop a pattern system by adding extra ease in setting the center front length.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.4924-4931
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• 2011

This research performed to evaluate a production processes reporting by the HACCP system of green vegetable juice products, containing lactic acid bacteria, stage of processing raw materials agricultural products and production facilities of general bacteria and pathogenic micro organism. General bacteria are found from four samples of storage of agricultural products at process stage and water was detected 8.67~14.67 CFU/ml. However, all samples were detected less than 105 CFU/ml as a legal standards after the process of UV sterilization. For the outcome of experiment of E.coli, E.coli O157:H7, B.cereus, L.moonocytogenes, Salmonella spp, Staph.aureus as the food poisoning bacterial, E.coli was detected until UV pre-step process in storage process and B.cereus was detected partly till 1st washing. Since all bacterial, Yeast and Mold are detected in main materials, pre-control method is a necessary to establish for decreasing with a number of initial bacteria of main materials and it is considered to establish the effective ways of washing and sterilization such as production facilities for cross contamination prevention of bacteria and Sthaphylococcus. Based on above results, the process of UV sterilization should be managed with CCP as an important process to reduce or eliminate the general and food poisoning bacterial of green vegetable juice products, including lactic acid bacteria. Therefore, it is considered to need an exhaustive HACCP plan such as control manual of UV sterilization, solution method, verification, education and training and record management.

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.3
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• pp.26-31
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• 2015

The domestic and foreign specifications presented the effective width based on flange length to width ratio only. The existing paper on the effective width grasped of the effect of span, load type and cross-section properties, but localized steel bridges. Recently, The studies are going on in progress for the application of fiber reinforced composite material in construction field. Therefore, it is required to optimum design that have a good grasp the deformation characteristic of the displacements and stresses distribution and predict variation of the effective width for serviceability loading. This research addresses the effective width of all composite material box girder bridges using the finite element method. The characteristics of the effective width of composite structures may vary according to several causes, e.g., change of fibers, aspect, etc. Parametric studies were conducted to determine the effective width on the stress elastic analysis of all composite materials box bridges, with interesting observations. The various results through numerical analysis will present an important document for construct all composite material bridges.

• Journal of the Korean Electrochemical Society
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• v.11 no.1
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• pp.16-21
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• 2008

The key component of a direct methanol fuel cell (DMFC) is the membrane electrode assembly (MEA), which comprises a polymer electrolyte membrane and catalyst layers (anode and cathode electrode). Generally the catalyst layer is coated on the porous electrode supporter (e.g. carbon paper or cloth) using various coating methods such as brushing, decal transfer, spray coating and screen printing methods. However, these methods were disadvantageous in terms of the uniformity of catalyst layer thickness, catalyst loss, and coating time. In this work, we used bar-coating method which can prepare the catalyst layer with uniform thickness for MEA of DMFC. The surface and cross-section morphologies of the catalyst layers were observed by SEM. The performances and resistance of the MEAs were investigated through a single cell evaluation and impedance analyzer.

• Environmental Analysis Health and Toxicology
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• v.29
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• pp.12.1-12.8
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• 2014

Objectives Cohort studies of associations between air pollution and health have used exposure prediction approaches to estimate individual-level concentrations. A common prediction method used in Korean cohort studies is ordinary kriging. In this study, performance of ordinary kriging models for long-term particulate matter less than or equal to $10{\mu}m$ in diameter ($PM_{10}$) concentrations in seven major Korean cities was investigated with a focus on spatial prediction ability. Methods We obtained hourly $PM_{10}$ data for 2010 at 226 urban-ambient monitoring sites in South Korea and computed annual average $PM_{10}$ concentrations at each site. Given the annual averages, we developed ordinary kriging prediction models for each of the seven major cities and for the entire country by using an exponential covariance reference model and a maximum likelihood estimation method. For model evaluation, cross-validation was performed and mean square error and R-squared ($R^2$) statistics were computed. Results Mean annual average $PM_{10}$ concentrations in the seven major cities ranged between 45.5 and $66.0{\mu}g/m^3$ (standard deviation=2.40 and $9.51{\mu}g/m^3$, respectively). Cross-validated $R^2$ values in Seoul and Busan were 0.31 and 0.23, respectively, whereas the other five cities had $R^2$ values of zero. The national model produced a higher cross-validated $R^2$ (0.36) than those for the city-specific models. Conclusions In general, the ordinary kriging models performed poorly for the seven major cities and the entire country of South Korea, but the model performance was better in the national model. To improve model performance, future studies should examine different prediction approaches that incorporate $PM_{10}$ source characteristics.

• Korean Journal of Clinical Laboratory Science
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• v.36 no.1
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• pp.13-18
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• 2004

This study was designed to establish working range for reoportable range in own laboratory in order to cover the upper and lower limits of the range in test method. We experimented ten times during 10 days for setting of reportable range with between run for method evaluation. It is generally assumed that the analytical method produces a linear response and that the test results between those upper and lower limits are then reportable. CLIA recommends that laboratories verify the reportable range of all moderate and high complexity tests. The Clinical Laboratory Improvement Amendments(CLIA) and Laboratory Accreditation Program of the Korean Society for Laboratory Medicine states reportable range is only required for "modified" moderately complex tests. Linearity requirements have been eliminated from the CLIA regulations and from others accreditation agencies, many inspectors continue to feel that linearity studies are a part of good lab practice and should be encouraged. It is important to assess the useful reportable range of a laboratory method, i.e., the lowest and highest test results that are reliable and can be reported. Manufacturers make claims for the reportable range of their methods by stating the upper and lower limits of the range. Instrument manufacturers state an operating range and a reportable range. The commercial linearity material can be used to verify this range, if it adequately covers the stated linear interval. CLIA requirements for quality control, must demonstrate that, prior to reporting patient test results, it can obtain the performance specifications for accuracy, precision, and reportable range of patient test results, comparable to those established by the manufacturer. If applicable, the laboratory must also verify the reportable range of patient test results. The reportable range of patient test results is the range of test result values over which the laboratory can establish or verify the accuracy of the instrument, kit or test system measurement response. We need to define the usable reportable range of the method so that the experiments can be properly planned and valid data can be collected. The reportable range is usually defined as the range where the analytical response of the method is linear with respect to the concentration of the analyte being measured. In conclusion, experimental results on reportable range using concentrated control sample and zero calibrators covering from highest to lowest range were salicylate $8.8{\mu}g/dL$, phenytoin $0.67{\mu}g/dL$, phenobarbital $1.53{\mu}g/dL$, primidone $0.16{\mu}g/dL$, theophylline $0.2{\mu}g/dL$, vancomycine $1.3{\mu}g/dL$, valproic acid $3.2{\mu}g/dL$, digitoxin 0.17ng/dL, carbamazepine $0.36{\mu}g/dL$ and acetaminophen $0.7{\mu}g/dL$ at minimum level and salicylate $969.9{\mu}g/dL$, phenytoin $38.1{\mu}g/dL$, phenobarbital $60.4{\mu}g/dL$, primidone $24.57{\mu}g/dL$, theophylline $39.2{\mu}g/dL$, vancomycine $83.65{\mu}g/dL$, valproic acid $147.96{\mu}g/dL$, digitoxin 5.04ng/dL, carbamazepine $19.76{\mu}g/dL$, acetaminophen $300.92{\mu}g/dL$ at maximum level.

• Journal of the Ergonomics Society of Korea
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• v.36 no.1
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• pp.37-52
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• 2017

Objective: The present study developed a user-centered 3D virtual liver surgery planning (VLSP) system called Dr. Liver to provide preoperative information for safe and rational surgery. Background: Preoperative 3D VLSP is needed for patients' safety in liver surgery. Existing systems either do not provide functions specialized for liver surgery planning or do not provide functions for cross-check of the accuracy of analysis results. Method: Use scenarios of Dr. Liver were developed through literature review, benchmarking, and interviews with surgeons. User interfaces of Dr. Liver with various user-friendly features (e.g., context-sensitive hotkey menu and 3D view navigation box) was designed. Novel image processing algorithms (e.g., hybrid semi-automatic algorithm for liver extraction and customized region growing algorithm for vessel extraction) were developed for accurate and efficient liver surgery planning. Usability problems of a preliminary version of Dr. Liver were identified by surgeons and system developers and then design changes were made to resolve the identified usability problems. Results: A usability testing showed that the revised version of Dr. Liver achieved a high level of satisfaction ($6.1{\pm}0.8$ out of 7) and an acceptable time efficiency ($26.7{\pm}0.9 min$) in liver surgery planning. Conclusion: Involvement of usability testing in system development process from the beginning is useful to identify potential usability problems to improve for shortening system development period and cost. Application: The development and evaluation process of Dr. Liver in this study can be referred in designing a user-centered system.