• Journal of the Korea Concrete Institute
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• v.26 no.5
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• pp.607-614
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• 2014

The purpose of this dissertation was to investigate the effect of mineral admixtures, such as fly ash, blast furnace slag powder, meta kaolin and silica fume, on the basic properties and durability of crushed sand shotcrete, selecting a series of shotcrete mixtures with a variable admixture. Compressive strength increased as the content of mineral admixtures increased, specially it was the most effective when using meta kaolin both at sample specimen and core after shotcreting. Rapid chloride ion permeability test and sulfuric acid resistance test showed that both durability increased as the substitute rate of mineral admixture increased. In air void analysis with image analysis, the targeted the spacing factor and specific surface were not satisfied because air-entrained agent was not used.

• The Journal of Korean Association of Computer Education
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• v.4 no.2
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• pp.145-154
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• 2001

As it is shown that the Ministry of Education has asked teacher to use ICT (Information and Communication Technology) at least 10% of class time in core subjects of the 7th national curriculum, the ICT using education is being facilitated. In this point of view, current information subject curriculum can be criticized due to the lack of series and redundancy, less connectivity with ICT utilization in other subjects, limitation of training students to adapt rapidly changing world environment. Therefore, we analyze the England's ICT curriculum and derive the concrete objects for competence of students according to their ability, systematic connection with other subjects, class teaching methods based on activities. We insist on that information subject curriculum should focus on the development of learners' concrete competencies rather than learning of tools' functions.

• Journal of Korean Academy of Nursing Administration
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• v.1 no.1
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• pp.112-131
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• 1995

The purpose of this study is to know experiences and process of patients' healing relation with nurses. This study had been conducted from July to September in 1994. The subjects were 7 patients who had hospitalized within 10 days at general surgery unit in C university hospital. The data were collected through in-depth interview and observation on the basis of Grounded Theory. In-depth interview were performed 3-6 times for each patient and taken 10-15 minutes at once. The result were as follows : (1) The main concepts are worry to operation, worry to hospital environment, worry to their children, worry to nurses, general appraisal, appraisal of appearance, appraisal of attitude, appraisal of nurses' response, appraisal of nurses' help, interest to patients, appraisal of explanation, appraisal of direct nursing, appraisal of nursing role, appraisal of nursing fairness, empathy, feeling of jung, discontent exposure, content, rapport. (Jung is a unique feeling that appeared in only korean culture) (2) The main categories are worry, general appraisal, concrete appraisal, empathy, and rapport. (3) These process is worry, appraisal, empathy, and rapport in the order. (4) The core category is the need of relation formation. The hospitalized patients have had need of relation formation with nurses. In order to satisfy this need, patients in the early of hospitalization had the worries to nurses, hospital environment, their children and themselves. The more patients have information about themselves, the more they have worries. In addition to, patients have general appraisal through the first impression or feeling to nurses. A time goes by, general appraisal has changed concrete appraisal. High educated group (above bachelor degree) have expressed concretely and variousely their needs. The patients who have empathy to nurses are content with nurses and form rapport to be shown frankly thier discontents. Therefore, patients' healing relation formation is the process of being filled up the need of relation formaton with Nurses. As mentioned above, researcher suggests that nurses need study nursing strategies to make earlier the last phase of the healing relation formation, rapport.

• Journal of the Korean Operations Research and Management Science Society
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• v.37 no.1
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• pp.61-71
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• 2012

Other-regarding preferences (such as trust, reciprocity and altruism) between companies, between consumers and retailers, and between employers and employees are integral elements in determining economic performance. Social trust which is a core element of social capital, especially, is known to reduce transaction costs, help solve collective action problems, and contribute to economic, social, and political development. Therefore, social trust has been given a great deal of attention across an array of academic disciplines for its role in promoting cooperation among individuals and groups, and for its positive influence on economic performance. Most studies describe Korea as a low-trust society than Japan or China. To identify the causes of social trust, this paper focuses on differences of social values (perception on competition and wealth accumulation) in 4 countries (Japan, China, Korea, and United States). Based on World Values Survey data, this paper analyzes effects of the social values on social trust. Social trust was measured by degree to which a respondent thinks that most people can be trusted. Perception on competition was measured by the degree to which a respondent thinks that competition is harmful, and perception on wealth accumulation was done by the degree to which a respondent thinks that wealth can grow so there is enough for everyone. The results showed that social trust was affected by perception on competition and wealth accumulation. A respondent showed higher level of social trust when he (or she) perceived positively competition and wealth accumulation. For enhancing social trust in a country, it is not easy to reduce income inequality and corruption which were reported as causes of social trust by previous studies. Compared to them, social values can be changed more easily by various concrete measures like education and mass-media. Differently from previous studies this paper stresses the concrete measures to enhance social trust in a country.

• Steel and Composite Structures
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• v.20 no.2
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• pp.379-397
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• 2016

Due to creep and shrinkage of the concrete core, concrete-filled steel tubular (CFST) arches continue to deform in the long-term under sustained loads. This paper presents analytical investigations of the effects of geometric nonlinearity on the long-term in-plane structural performance and stability of three-pinned CFST circular arches under a sustained uniform radial load. Non-linear long-term analysis is conducted and compared with its linear counterpart. It is found that the linear analysis predicts long-term increases of deformations of the CFST arches, but does not predict any long-term changes of the internal actions. However, non-linear analysis predicts not only more significant long-term increases of deformations, but also significant long-term increases of internal actions under the same sustained load. As a result, a three-pinned CFST arch satisfying the serviceability limit state predicted by the linear analysis may violate the serviceability requirement when its geometric nonlinearity is considered. It is also shown that the geometric nonlinearity greatly reduces the long-term in-plane stability of three-pinned CFST arches under the sustained load. A three-pinned CFST arch satisfying the stability limit state predicted by linear analysis in the long-term may lose its stability because of its geometric nonlinearity. Hence, non-linear analysis is needed for correctly predicting the long-term structural behaviour and stability of three-pinned CFST arches under the sustained load. The non-linear long-term behaviour and stability of three-pinned CFST arches are compared with those of two-pinned counterparts. The linear and non-linear analyses for the long-term behaviour and stability are validated by the finite element method.

• Journal of the Korean Geotechnical Society
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• v.20 no.1
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• pp.5-12
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• 2004

The purpose of this paper is to make an understanding of fundamental mechanism of shear behaviour between rock and concrete interfaces in the pile socketed into granite. The interface of pile socketed in rock can be modeled in laboratory tests by resolving the axi-symmetric pile situation into the two dimensional situation under CNS(constant normal stiffness) direct shear condition. In this paper, the granite core samples were used to simulate the interface condition of piles socketed in granite in our country. The samples were prepared in the laboratory to simulate field condition, roughness(angle and height), stress boundary condition, and then tested by CNS direct shear tests. This paper describes shearing behaviour of socket piles into domestic granite through the analysis of CNS test results. It was found out that the peak shear strength increases with the angle of asperity and CNS value, and also the dilation increases with the angle of asperity but decreases with the CNS value.

• Journal of the Korean Institute of Gas
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• v.21 no.3
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• pp.39-45
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• 2017

The LNG storage tank as core facility of LNG industry is mainly composed of the inner tank of nikel 9% steel and the outer tank of prestressed concrete. To respond proactively increased risk of structure performance deterioration due to fatigue of the inner tank and durability reduction of the outer tank, life evaluation program for LNG storage tank is needed. In this study, life evaluation program for LNG storage tank was developed to assess fatigue of the inner tank and durability(carbonation and chloride attack) of the outer tank. By defining the main three scenarios in the inner tank, the fatigue life analysis is conducted from structural analysis and Miner's damage rule. Carbonation progress of the outer tank is predicted according to thickness of cover concrete by using carbon dioxide contents and data of penetration depth. To consider a variety of input conditions and a reliability in results of chloride attack, the evaluation of choride attack for the outer tank is constructed through Life-365 program of open source.

• International Journal of Highway Engineering
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• v.9 no.3
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• pp.51-62
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• 2007

Recently various low-noise-pavement methods have been developed. Since tire/pavement noise is the major source of traffic noise at high speed condition, the core-technology of low-noise pavement is to produce the road surface texture that can reduce tire/pavement noise. The difficulties in the development of the low-noise pavements are high costs and time to construct test roads, since vehicles have to travel on the test roads to evaluate the noise from a particular condition of pavement surface. Tire/Pavement Noise Simulator were developed to overcome those difficulties and the reliability of developed Tire/Pavement Noise Simulator are investigated based on the simulating and measuring the noise of tire-tined concrete pavement and tire-non tined concrete pavement.

• Earthquakes and Structures
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• v.16 no.3
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• pp.295-310
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• 2019

This study attempts to develop new simplified approximate formulas to predict the fundamental natural periods of vibration (T) for bearing wall systems engaged with special reinforced concrete shear walls (RCSW) under seismic loads. Commonly, seismic codes suggested empirical formulas established by regression analysis of measured T for buildings during earthquake motions. These formulas depend on structure type, building height, number, height and length of SW, and ratio of SW area to base area of structure. In this study, a parametric investigation is performed for T of 110 selected models of bearing RCSW systems with varying structural height, configuration of horizontal plans including building width, number and width of bays, presence of middle corridors and core SWs. For this purpose, a 3D non-linear response time history (TH) analysis is implemented using ETABS v16.2.1. New formulas to estimate T are anticipated and compared with those obtained from formulas of IBC 2012 and ASCE/SEI 7-10. Moreover, the study examines responses of an arbitrarily two selected test model of 60 m and 80 m in height with presence of SWs having middle corridors. It is observed that the performance of the tested buildings is different through arising of considerable errors when using codes' formulas for estimating T. Accordingly, using the present proposed formulas exhibits more reasonable and safer design compared to codes' formulas. The results showed that equitable enhancement is promising to improve T formulas approaching enhanced and accurate estimation of T with reliable analysis, design, and evaluation of bearing RCSW systems.

• Journal of Convergence for Information Technology
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• v.9 no.10
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• pp.87-93
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• 2019

Microcapsules were prepared by using a mixture of linseed oil and a small amount of fluorescent fluid as a core material. Self-healing protective coatings were prepared by applying coating formulations containing varying amounts of microcapsules on mortar surface. After scratch or crack was generated in the coating, when the damaged region was exposed to ultraviolet light (${\lambda}=365nm$), it was observed that fluorescence emission area increased with increasing microcapsule loading. In the cases of the self-healing coatings having 20wt% or more microcapsule loading, the damaged region was almost filled with the healing agent. In water sorptivity test, the self-healing coating having 20wt% or more microcapsule loading showed a healing efficiency of about 85%. The fluorescence emission from the damaged region was easily observed at a distance of 3 m. The self-healing protective coating is expected to be useful to confirm its self-healing function with the eye.