• Magazine of the Korean Society of Agricultural Engineers
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• 제35권2호
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• pp.43-56
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• 1993

The laboratory tests are performed on how the liquefaction potential of the sea dike structures on the saturated sand or silty sand seabed could be affected due to earthquake before and after construction results are given as follows ; 1. Earthquake damages to sea dike structures consist of lateral deformation, settlement, minor abnormality of the structures and differential settlement of embankments, etc. It is known that severe disasters due to this type of damages are not much documented. Because of its high relative cost of the preventive measures against this type of damages, the designing engineer has much freedom for the play of judgement and ingenuity in the selection of the construction methods, that is, by comparing the cost of the preventive design cost at a design stage to reconstruction cost after minor failure. 2. The factors controlling the liquefaction potential of the hydraulic fill structure are magnitude of earthquake(max. surface velocity), N-value(relative density), gradation, consistency(plastic limit), classification of soil(G & vs), ground water level, compaction method, volumetric shear stress and strain, effective confining stress, and primary consolidation. 3. The probability of liquefaction can be evaluated by the simple method based on SPT and CPT test results or the precise method based on laboratory test results. For sandy or silty sand seabed of the concerned area of this study, it is said that evaluation of liquefaction potential can be done by the one-dimensional analysis using some geotechnical parameters of soil such as Ip, Υt' gradation, N-value, OCR and classification of soils. 4. Based on above mentioned analysis, safety factor of liquefaction potential on the sea bed at the given site is Fs =0.84 when M = 5.23 or amax= 0.12g. With sea dike structures H = 42.5m and 35.5m on the same site Fs= 3.M~2.08 and Fs = 1.74~1.31 are obtained, respectively. local liquefaction can be expected at the toe of the sea dike constructed with hydraulic fill because of lack of constrained effective stress of the area.

• KCID journal
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• 제18권2호
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• pp.142-160
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• 2011

This study was performed to apply the preventive management technique that is known for more economic and preventive for disaster than corrective technique to Repair & Improvement(R&I) Project policy of irrigational facilities. The appropriate periods of R&I Project had been driven to 40yrs, 24yrs, 27yrs, and 29yrs for reservoir, Pumping and drainage pumping station, Diversion weir and Irrigation & drainage canal respectively. The cost of R&I Project for 10 years had been estimated as 616.9 billion won per year including the 85 billion won for the project of 'Disaster prevention and Function continuity'. After the period of 'Improvement all at once', about 30yrs, 421.8 billion won was requested for 'Function continuity'.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.1185-1192
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• 2001

This paper reviews available techniques for monitoring corrosion of steel in concrete. The need for early detection and diagnosis of corrosion related deterioration in reinforced structures is widely acknowledged. This is particularly important in reinforced concrete structures on account of the economic and social significance of the problem. The current generally used on-site procedure for corrosion monitoring of reinforced structures employs a method of half-cell surface potential measurements. While the technique has provided a useful means of delineating areas of high or low corrosion risk, there are difficulties in its use and interpretation when assessing rates of deterioration. Electrochemical techniques are by far the most suitable for corrosion monitoring purpose and meet most of the requirements. The aim of this paper is to describe the electric resistance sensor(ER sensor) and electrochemical techniques employed to monitor and estimate corrosion rates of reinforcement. Early detection and diagnosis of corrosion hazards allows preventive measures to be taken, hence the typically expensive repair of severely deteriorated structures can be avoided.

• Journal of Ginseng Research
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• 제47권6호
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• pp.694-705
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• 2023

Panax ginseng Meyer is a traditional Chinese medicine that is widely used as tonic in Asia. The main pharmacologically active components of ginseng are the dammarane-type ginsenosides, which have been shown to have anti-cancer, anti-inflammatory, immunoregulatory, neuroprotective, and metabolic regulatory activities. Moreover, some of ginsenosides (eg, Rh2 and Rg3) have been developed into nutraceuticals. However, the utilization of ginsenosides in clinic is restrictive due to poor permeability in cells and low bioavailability in human body. Obviously, the dammarane skeleton and glycosyls of ginsenosides are responsible for these limitations. Therefore, improving the oral bioavailability of ginsenosides has become a pressing issue. Here, based on the structures of ginsenosides, we summarized the understanding of the factors affecting the oral bioavailability of ginsenosides, introduced the methods to enhance the oral bioavailability and proposed the future perspectives on improving the oral bioavailability of ginsenosides.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 한국정보기술응용학회 2002년도 추계공동학술대회 정보환경 변화에 따른 신정보기술 패러다임
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• pp.199-204
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• 2002

Reliability Centered Maintenance(RCM) was initially developed for the commercial aviation industry in the late 1960s and now is equally applicable to a variety of equipment other than aircraft. RCM is a method for establishing a preventive maintenance program which will efficiently and effectively allow the achivement of the required safety and availability levels of equipment and structures. RCM provides for the use of a decision logic tree to identify applicable and effective preventive maintenance requirements for equipment and structures. The end result of working through the decision logic is a judgement as to the necessity of performing a maintenance task. In this paper, we provide guiding principles based on IEC 60300-3-11 for RCM analysis methods and operational method of structure and equipment.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 한국산업정보학회 2002년도 추계공동학술대회
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• pp.199-204
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• 2002

Reliability Centered Maintenance(RCM) was initially developed for the commercial aviation industry in the late 1960s and now is equally applicable to a variety of equipment other than aircraft. RCM is a method for establishing a preventive maintenance program which will efficiently and effectively allow the achivement of the required safety and availability levels of equipment and structures. RCM provides for the use of a decision logic tree to identify applicable and effective preventive maintenance requirements for equipment and structures. The end result of working through the decision logic is a judgement as to the necessity of performing a maintenance task. In this paper, we provide guiding principles based on IEC 60300-3-11 for RCM analysis methods and operational method of structure and equipment.

• Advances in concrete construction
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• 제1권1호
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• pp.45-63
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• 2013

Upon completion of new concrete structures, the achieved construction quality always shows a high scatter and variability, and in severe environments, any weaknesses and deficiencies will soon be revealed whatever durability specifications and materials have been applied. To a certain extent, a probability approach to the durability design can take the high scatter and variability into account. However, numerical solutions alone are not sufficient to ensure the durability and service life of concrete structures in severe environments. In the present paper, the basis for a probability-based durability design is briefly outlined and discussed. As a result, some performance-based durability requirements are specified which are used for quality control and quality assurance during concrete construction. The final documentation of achieved construction quality and compliance with the specified durability are key to any rational approach to more controlled and increased durability. As part of the durability design, a service manual for future condition assessment and preventive maintenance of the structure is also produced. It is such a service manual which helps provide the ultimate basis for achieving a more controlled durability and service life of the given concrete structure in the given environment.

• Preventive Nutrition and Food Science
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• 제1권2호
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• pp.168-173
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• 1996

The effect of methanol soluble fraction(MSF) of kimchi on the proliferating and differentiating activity of normal rat mammary epithelial cells or organoids in culture were studied. Reconstituted basement membrane, Matrigel, supported the growth and development several different multicellular structures from mammary organoids. The five type colonies of multicellular structures, stellate, ductal, webbed, squamous, and lobulo-ductal colonies, were observed in Matrigel culture. In methanol extract groups, webbed colonies were more and squamous colonies were less than control group. and the lobulo-ductal colonies which is known that it formed in well differentiated mammary epoithelial cells were developed more in MSF treated group than control group. These results showed that methanol extract of kimchi affected on the proliferation and differentiation of normal rat mammary epithelial cells cultured in serum free medium condition.

• Journal of Preventive Medicine and Public Health
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• 제57권2호
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• pp.167-175
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• 2024

Objectives: Rural housewives are integral to household management and family care, yet their sedentary lifestyles present significant health risks. This study used the transtheoretical model (TTM) to investigate strategies that encourage and maintain regular exercise habits among rural housewives. Methods: A semi-experimental study was conducted in 2021 with 114 housewives aged 30 to 59 who attended rural health centers in Gorgan, Iran. Participants were randomly assigned to 1 of 2 groups. Data collection involved a validated questionnaire that gathered demographic information and constructs of the TTM. The intervention group participated in a comprehensive educational program, which included four 60-minute sessions. Data were collected again 6 months post-intervention and analyzed using descriptive and inferential statistics in SPSS version 21. Results: The study encompassed women with an average age of 39.75±6.05 years, the majority of whom had educational levels below a diploma, and over 90% were married. We observed strong correlations between the processes of change, self-efficacy, and decisional balance. At the outset, there were no significant differences in demographics or model structures between the 2 groups. However, 6 months post-intervention, the intervention group exhibited statistically significant differences in the mean scores of model structures, stages of change, and body mass index (p<0.05). Conclusions: This study highlights the importance of physical activity training for rural housewives. The findings suggest that the educational intervention, which utilized the TTM, significantly impacted the participants' model structures and their stages of change.

• Smart Structures and Systems
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• 제22권2호
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• pp.151-159
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• 2018

Maintenance activities are regarded as a key part of the repairable deteriorating system because they maintain the equipment in good condition. In practice, many maintenance policies are used in engineering fields to reduce unexpected failures and slow down the deterioration of the system. However, in traditional maintenance policies, maintenance activities have often been assumed to be performed at the same time interval, which may result in higher operational costs and more system failures. Thus, this study presents two non-periodic preventive maintenance (PM) policies for repairable deteriorating systems, employing the failure rate of the system as a conditional variable. In the proposed PM models, the failure rate of the system was restored via the failure rate reduction factors after imperfect PM activities. Operational costs were also considered, which increased along with the operating time of the system and the frequency of PM activities to reflect the deterioration process of the system. A numerical example was provided to illustrate the proposed PM policy. The results showed that PM activities performed at a low failure rate threshold slowed down the degradation of the system and thus extended the system lifetime. Moreover, when the operational cost was considered in the proposed maintenance scheme, the system replacement was more cost-effective than frequent PM activities in the severely degraded system.