• Tunnel and Underground Space
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• v.33 no.6
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• pp.483-494
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• 2023

Measurement of the physical properties of rocks or minerals is an important factor in determining the distribution of the underground medium as well as mineral resource investigations. Resistivity and induced polarization, which are widely used in Korea, are methods for measuring electrical properties, which are representative properties of obtaining subsurface information. In order to precisely analyze the exploration data obtained from various sites, it is important to accurately measure the material properties. Electrical properties of rock is measured using two-electrode or four-electrode method. Compared to the four-electrode method, the two-electrode method is generally used because it is very easy to contact the sample and the electrode, but there is a problem in that the impedance of the electrode and the sample is measured together. In this study, the time-domain the induced polarization effects were measured using the 2-electrode method and the 4-electrode method for artificial samples mixed with graphite and cement having induced polarization characteristics, and the results were compared. Although the 4-electrode method has difficulties in installing potential electrodes, it was confirmed that it is effective in measuring electrical properties because it can reduce the problem caused by the impedance of potential electrodes compared to the 2-electrode method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5247-5253
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• 2012

The purpose of this study was to apply in the HACCP(Hazard Analysis Critical control) system of liquefied coffee and sikhe. The establishment of Critical limit during sterilization processing was measured by sterilization temperature and sterilization time for 30 days from April 1~30, 2012, and it was conducted at P company in Jincheon (Chungcheongbuk-do), korea. As a result, microbial(coliform, bacillus cereus, Clostridium perfringens and yeast & mold) of sikhe and liquefied coffee were detected before sterilization. In contrat, all microbial was not detected to Sikhe(238mL Can, 500mL and 300mL PP, 1.8L PP) after sterilization ($15{\pm}1$, $35{\pm}1$ and $45{\pm}1$ mins at $121{\pm}1^{\circ}C$, respectively) and Liquefied coffee was not detected after sterilization($121{\pm}1^{\circ}C$, $20{\pm}1$ mins). The sterilizer condition for deciding the most temperature and time were $121{\pm}1^{\circ}C$, $20{\pm}1$ mins. In conclusion, the sterilization process would be a great alternative to prevention, decreasing and removing of harmful microorganism, such as general bacteria, coliform and pathogenic bacteria etc. Therefore, the critical limit of sterilization temperature and time for quality control and biosafety was established at $121{\pm}1^{\circ}C$, $20{\pm}1$ mins. And it suggests that HACCP plan is necessary for monitoring method, monitoring cycle, solving method, education, training and record management during sterilization processing.

• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.307-317
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• 1999

The purpose of this study is to utilize conventional procedures for evaluation of liquefaction potential and to compare the results obtained by modified detailed method based on Korean earthquake magnitude (M=6.5). Liquefaction potential is assessed by comparing liquefaction strength of soil and cyclic shear stress generated in the soil layers during earthquakes. The cyclic shear stress is computed from the earthquake response analysis, and liquefaction strength of soil is evaluated by using results from cyclic triaxial tests. The cyclic triaxial tests are performed on many different conditions of sample ; relative densities(50%, 60%, and 70%), initial effective confining pressures (70kPa, 100kPa, and 150kPa), and fine contents(10%, 20%, and 30%). From the result of comparing the conventional procedure with the modified detailed method, it is found that the modified detailed method tends to evaluate larger safety factor against liquefaction in the weak sand site$(FS \leq1.5)$. Therefore in this case, it is suggested that liquefaction potential should be evaluated by using the modified detailed method based on cyclic triaxial tests. It is also found that in modified detailed method based on earthquake magnitude 6.5, critical depth where liquefaction can be generated is around 15m from the ground surface.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.1
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• pp.263-271
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• 2012

The purpose of this study is to investigate the relationship between entrepreneurial factors and entrepreneurial intention on student. This study is designed to examine the effect of entrepreneurial factors on entrepreneurial intention. Data for the study was compiled through surveys on 300 students who study in engineering school of H university. Empirical results of the hypothesis testing are summarized as follows: The results indicate that both two variable groups have positively influenced the entrepreneurial factors was highly related to entrepreneurial intention. The factors entrepreneurship are background, individual and situational factor. This all factors influence on entrepreneurial intention. The entrepreneurial factors had a positively influence on will power of entrepreneur. The entrepreneurial factors had a positively influence on performance of entrepreneur.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.273-281
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• 2012

The purpose of this study was to examine about correlation among dental hygienists' work environment, recognition on preventive education of musculoskeletal disease, the work-related musculoskeletal disease, and the work characteristics. The aim is to suggest a management plan for reducing symptom of musculoskeletal disease. The self-administered questionnaire was surveyed and collected from August 1-12 of 2011 targeting 210 dental hygienists Seoul, Gyeonggi, Daegu, Pohang. Except 5 people whose responses are not clear and who suffered accident, the analysis was made on 205 people. The collected data was analyzed by using SPSS WIN 15.0 program. As a result, dental hygienists, the average was the highest with 3.07 in 'between shoulder and neck(right side).' Seeing the pain frequency by body region, the average was the highest with 1.47 in 'ankle/calf(left side).' Seeing the appearance of having trouble in work ability related to pain experience of musculoskeletal disease by body region, the average was indicated to be the highest with 1.84 in 'knee(right side).Therefore, the agencies have to pay more attentions and efforts to ensure safety of musculoskeletal disorders in dental hygienist.

• The Journal of Engineering Geology
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• v.26 no.3
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• pp.413-422
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• 2016

With the rapidly increasing population density and development of infrastructure, the loss of life and property damage caused by landslides has increased gradually in urban area. Especially, Because Busan has high percentage of mountainous terrain among the metropolitan in Korea, it is unavoidable to develop mountainous region excessively. The objective of this evaluation is to study on landslide hazard possibility for Mt. Hwangryeong in Busan Metropolitan City using the infinite slope model considering the groundwater level. All data related to creating the thematic maps was carried out using ArcGIS 10.0. The results show that FS (Factor of Safety) for landslide is inversely proportional to groundwater level change as expected. Most area indicates stable state in dry condition, and unstable area increase due to high pore water pressure when the groundwater level rise. However, several places in high lineament density area where landslide has been previously occurred, are more stable than other places according to the analysis. This inconsistency between real situation and analysis results indicates that additional analytical method would be necessary to solve the problem. Therefore, we suggest that development of new infiltration theory for unsaturated zone would be helpful to evaluate groundwater level distribution as time goes by.

• Science of Emotion and Sensibility
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• v.21 no.1
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• pp.3-16
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• 2018

The emergence of the fourth industrial revolution is rapidly changing the conventional society and the industry, eroding the boundaries among the technology, culture, and finance. In the mobility industry, as the engineering-based industry converges with the information technology, the mobile space is changing from mobility or safety-centric space into space where the passengers can consume infotainment or contents services. The contents evaluation of the future mobility is conducted in terms of usability or technology acceptance aspect, but according to the trend analysis, the mobility industries, such as vehicle OEMs, it is necessary to evaluate the emotional or sensibility factors for the development of their future mobile space design. Herein, this research study evaluates which sensibility factor should be evaluated in priority to develop the contents interaction in the future mobile space. Thus, using Patrick Jordan's Four Pleasure Model, the priority evaluation has been conducted among 116 Korean drivers. As a result of the statistical analysis and AHP (Analytic Hierarchy Process), it has been found that first, it is necessary to evaluate psychological, ideological, social and physical sensibility in the respective order, and second, it is necessary to evaluate based on the contents user type.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.4
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• pp.144-152
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• 2016

This paper focuses on the experimental study for investigating the performance for lap splice of hooked or headed reinforcement in beam with different depths. In the experiment, seven specimens, with its variables as the lap length of headed or hooked bar, the existence of stirrups, etc., was manufactured. Bending test was conducted. Lap strengths by test were compared with the theoretical model based on KCI2012. The result showed that the cracks at failure mode occurred along the axial direction to a headed bar. The initial stiffness and the stiffness after initial crack were similar for all specimens. For HS series specimens without stirrups, a 25% increase in lap length was increased 11.8~18.1% maximum strengths. For HH series specimens without stirrups, a increase in lap length did not affect the maximum strengths because of the pryout failure of headed bar. For HS series specimens, the theoretical lap strengths based on KCI2012 considering the B grade lap and the reduction factor for stirrup were evaluated. They are smaller than the test strengths and can ensure the safety in terms of strength capacity. For HH series specimens, the stirrups in the lap zone are needed to prevent the pryout behaviour of headed bar.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.372-381
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• 2019

In this study, the National Disaster Management System (NDMS) was analyzed to evaluate the disaster impact assessment standards for steep slopes. Problems in the assessment methods and systems were discovered, which could be reasons for poor reliability. The disaster-risk evaluation index needs improvement to evaluate various types of retaining walls, such as concrete/reinforced soil walls and reinforcing stone masonry. Additionally, using the same score for overturning, bulging, and efflorescence could be reasons for poor reliability, and different weighting factors are needed. Assessment methods are needed to subdivide the social influence evaluation index while considering environmental conditions of steep slopes, such as railroads and reservoirs. For the evaluation of steep slopes, standards for start and end points of steep slopes should be created for effective management, and disaster impact assessment needs to be performed after redevelopment from an advanced index for protection and reinforcement. These problems were derived from a current evaluation system, so a disaster impact assessment is necessary to supplement the results of this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4018-4024
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• 2012

The purpose of this study was to application in the HACCP(Hazard Analysis Critical control) system of fried kimchi soup. The establishment of Critical limit during sterilization processing was measured by sterilization temperature, sterilization time, sensory test, storage test and pH change in storage for 30 days (May 1~30, 2012). Before sterilization, general bacteria, coliform and thermophile bacteria were detected to be $6.00{\times}10^5\;CFU/m{\ell}$, $7.50{\times}10^2\;CFU/m{\ell}$ and $2.75{\times}10^2\;CFU/m{\ell}$, respectively. In contrast, all microbial was not detected after sterilization($90{\pm}5^{\circ}C$, $22{\pm}5$ mins). The sensory test was decided as the most delicious kimchi according to $90{\pm}5^{\circ}C$, $22{\pm}5min$. In conclusion, the sterilization process of fried kimchi soup would be a great alternative to prevention, decreasing and removing of harmful microorganism, such as general bacteria, coliform and thermoduric bacteria etc. Therefore, the critical limit of sterilization temperature and time for quality control and biosafety was established at $90{\pm}5^{\circ}C$, $22{\pm}5$ mins. And it suggested that HACCP plan was necessary for monitoring method, monitoring cycle, problem solving method, education, training and record management during sterilization processing.