• Geomechanics and Engineering
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• v.23 no.5
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• pp.419-429
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• 2020

To investigate the effect of spatial variability on hydraulic properties of unsaturated soils, a numerical model is set up which can simulate seepage process in an unsaturated heterogeneous soil. The unsaturated heterogeneous soil is composed of matrix sand embedded with a small proportion of clay for simulating the heterogeneity. Soil-water characteristic curve and unsaturated hydraulic conductivity curve of the unsaturated soil are expressed by Van Genuchten model. Hydraulic parameters of the matrix sand are considered as random fields. Different autocorrelation lengths (ACLs) of hydraulic parameter of the matrix sand and different proportions of clay are assumed to investigate the influence of spatial variability on the equivalent hydraulic properties of the heterogeneous soil. Four model sizes are used in the numerical experiments to investigate the influence of scale effects and to determine the sizes of representative volume element (RVE) in the numerical simulations. Through a number of Monte Carlo simulations of unsaturated seepage analysis, the means and the coefficients of variations (COVs) of the equivalent hydraulic parameters of the heterogeneous soil are calculated. Simulations show that the ACL and model size has little influence on the means of the equivalent hydraulic parameters, but they have a large influence on the COVs of the equivalent hydraulic parameters. The size of an RVE is mainly affected by the ACL and the proportion of heterogeneity. The influence of spatial variability on the hydraulic parameters of the heterogeneous unsaturated soil can be used as a guidance for geotechnical reliability analysis and design related to unsaturated soils.

• Geomechanics and Engineering
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• v.31 no.5
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• pp.505-518
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• 2022

This study introduces soil resistance multipliers at locations encompassed by the zone of influence of the helix plate to consider the added lateral resistance provided to the helical pile. The zone of influence of a helix plate is a function of its diameter and serves as a boundary condition for the modified soil resistance springs. The concept is based on implementing p-multipliers as a reduction factor for piles in group action. The application of modified p-y springs in the analysis of helical piles allows for better characterization and understanding of the lateral behavior of helical piles, which will help further the development of design methods. To execute the proposed method, a finite difference program, HPCap (Helical Pile Capacity), was developed by the authors using Matlab. The program computes the deflection, shear force, bending moment, and soil resistance of the helical pile and allows the user to freely input the value of the zone of influence and Ω (a coefficient that affects the value of the p-multiplier). Results from ten full-scale lateral load tests on helical piles embedded at depths of 3.0 m with varying shaft diameters, shaft thicknesses, and helix configurations were analyzed to determine the zone of influence and the magnitude of the p-multipliers. The analysis determined that the value of the p-multipliers is influenced by the ratio between the pile embedment length and the shaft diameter (D_p), the effective helix diameter (D_h-D_p), and the zone of influence. Furthermore, the zone of influence is recommended to be 1.75 times the helix diameter (D_h). Using the numerical analysis method presented in this study, the predicted deflections of the various helical pile cases showed good agreement with the observed field test results.

• Journal of Distribution Science
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• v.3 no.1
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• pp.23-42
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• 2005

The service offer expectation and the desire of customers to a large-sized rate influence store also increase as a result of such environmental change. the counter where research of a book was upgraded from differentiation pursuit by competition between business condition in business condition in the case of the domestic rate influence store which has put the focus on service strengthening The work shrine which cannot reach here the competition predominance in the domestic market it will be hard coming to secure, when environmental change of inside large-sized rate influence store industry is taken into consideration The research which tried to receive customer service failure recovery carried out actual proof analysis in the influence to which fair nature lateness of a customer attains to the re-purchase intention to this store of customer satisfaction and future by service recovery process for an object in the customer who held service failure recovery experience in the domestic large-sized rate influence store.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.7-13
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• 2018

The strength of concrete is affected significantly not only by the internal influence factors of cement, water, sand, aggregate, and admixture, but also by the external influence factors of concrete placement delay and curing temperature. The objective of this research was to predict the concrete strength considering both the internal and external influence factors when concrete is placed at the construction site. In this study, a concrete strength test was conducted on the 24 combinations of internal and external influence factors, and a neural network model was constructed using the test data. This neural network model can predict the concrete strength considering the external influence factors of the concrete placement delay and curing temperature when concrete is placed at the construction site. Contractors can use the concrete strength prediction neural network model to make concrete more robust to external influence factors during concrete placement at a construction site.

• Hwankyungkyoyuk
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• v.17 no.1
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• pp.101-111
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• 2004

The selection rates of Environmental subject have been increasing since the environmental subject was made. Although the quantitative growth, environmental subject is not acknowledged yet in many schools in Korea. Most of environmental teachers teach two subjects; main subject on their own major and environmental subject. In this respect, this qualitative case study aims to show the influence of teachers' charge on environmental class or environmental subject. In the case study, Teacher 'A' takes charge one subject; Environmet, and teacher 'B' takes charge two subjects; Social Study and Environment. Teacher 'A' took some current issues such as SARS(Severe Acute Respiratory Syndrome) and Saemangum project, and uses various instructional methods and instruments. On the other hand, teacher 'B' might not choose the current issues, or usually gives up various instructional methods and instruments because of lack of time. Although they have those differences on the instruction, the teachers 'A' and 'B' both agreed to the importance of Environmental Education as well as they did their best to prepare for class on environmental subject. As a result, all these outcomes show teachers need to be responsible for single subject on environment as teachers' interests seriously affect to environmental subject and class.

• Journal of IKEEE
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• v.25 no.2
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• pp.261-266
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• 2021

This paper suggests design methodology for thermal infrared data correction algorithms considering environmental temperature variations. First, a thermal infrared measurement model is suggested by a parameter-dependent first-order input-output equation using the relationship between infrared measurement data and model environmental parameters. In order to compensate the influence of environmental temperatures on infrared data, a compensation function is identified. Through experiments, the proposed algorithm is shown to reduce the influence of environmental temperatures on the infrared data effectively.

• Culinary science and hospitality research
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• v.20 no.5
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• pp.1-10
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• 2014

The employment rate has become the standard for university values. This raises the need to investigate the antecedents of university students' career exploration. Focused on the hospitality majored students, this study aims to investigate both individual and relational factors that influence their career exploration behaviors. Differentiation of self has been chosen as the individual and the relational antecedents based on Bowen's theory. It was investigated whether each dimension(I-position, emotional reactivity, fusion with others, and emotional cutoff) explains the amount of self-exploration and the amount of environmental exploration. The university students majoring in hospitality were surveyed and a total of 269 cases out of 300 cases were analyzed employing descriptive statistics and multi-variate analysis of variance, and structural equation modeling(SEM). The study found that I-position positively influenced self-exploration and environmental exploration. Emotional reactivity made an influence on environmental exploration, while it failed to explain self-exploration. Fusion with others and emotional cutoff also significantly influenced environmental exploration, however, it didn't make any significant influence on self-exploration. This study implies that the college of hospitality majors needs to understand that differentiation of self forms through family relationship and needs to provide the students the programs of how to understand themselves and what to do for their career exploration.

• Journal of The Korean Association For Science Education
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• v.32 no.8
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• pp.1378-1389
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• 2012

Environmental education is usually taught across the curriculum in most of the countries. This teaching approach has been a challenge for teachers to implement it especially in the Malaysian curriculum context. Thus, science teachers require effectual Pedagogical Content Knowledge of Environmental Education (PCK-EE). The purpose of this study was to explore the influence of teaching option and teaching experience on science teachers' PCK-EE. Five components of PCK-EE were investigated in this study, which were: a) knowledge of curriculum, b) knowledge of content, c) knowledge of student, d) knowledge of teaching strategies, and e) knowledge of evaluation. 347 secondary science teachers from the state of Selangor have participated in this survey study. The questionnaire used had 60 items. The findings revealed teaching option has a significant influence on science teachers' knowledge of content (p=0.000); knowledge of student (p=0.000) and knowledge of teaching strategies (p=0.016). In the case of teaching experience, it was found that there is a low correlation on knowledge of content (r=0.174) and knowledge of evaluation (r=0.170) only. Implication of this study leads to the suggestion in enhancing teachers' service training to improve their PCK-EE and subsequently their ability in teaching environmental education across curriculum.

• Journal of Environmental Impact Assessment
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• v.2 no.1
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• pp.57-63
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• 1993

An analysis for particle settling effects via of plume centerline tilted exponentially under the influence of panicle settling velocity is carried out for particle of $30{\mu}m$ diameter with $1g/cm^3$ density and 0.02m/s settling velocity corresponding to its particle characteristic according to various wind speeds, atmospheric stabilities. Characteristic analysis of surface concentration distribution simulated by Lagrangian model also are carried out under the influence of plume centerline tilted exponentially at 10m stack height emitted 200 particles per second. This study reveals that plume centerline at the nearby source is sharply tilted exponentially under the condition of stable, weakly wind speed, therefore the lower concentration at the nearby source, the higher concentration at the downwind distance far away from source than actual one is brought out, if not apply the effect of plume centerline tilted exponentially to diffusion Model.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.283-288
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• 2018

Since the crack self-healing materials are activated according to the exposure environmental conditions from the time of crack occurrence, it is very important to clarify the relationship between the healing performance and the exposure environmental conditions of the crack surface. In this paper, the influence of the exposure environmental conditions on the crack healing performance of self-healing repair mortar was investigated through the water permeability test. The influence of temperature and humidity on the crack width of cracked specimens was evaluated. As a result of measuring the change of the crack width, the effect of curing temperature was negligible but it was confirmed that crack-closing occurred due to the change of dry-wet condition. The healing materials produced on the crack surface of the specimens was identified as calcite minerals. Since the minerals with high density are precipitated under the influence of gravity, the healing performance is somewhat different according to the direction of the crack surface, and the healing performance was significantly improved in the wet exposure condition than the air exposure condition.