• Environmental Engineering Research
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• v.14 no.4
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• pp.226-236
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• 2009

The performance of phytoremediation has proven effective in the removal of nutrients and metals from aqueous systems. However, little information is available regarding the behavior of pesticides and their removal pathways in aquatic environments involving plant-uptake. A detailed understanding of the kinetics of pesticide removal by plants and information on compound/plant partition coefficients can lead to an effective design of the phytoremediation process for anthropogenic pesticide reduction. It was determined that the reduction rates of four organophosphorus (OP) and two organochlorine (OC) pesticides (diazinon, fenitrothion, malathion, parathion, dieldrin, hexachlorobenzene [HCB]) could be simulated by first-order reaction kinetics. The magnitude of k was dependent on the pesticide species and found within the range of 0.409 - 0.580 $d^{-1}$. Analytical results obtained by mass balances suggested that differential chemical stability, including diversity of molecular structure, half-lives, and water solubility, would greatly influence the removal mechanisms and pathways of OPs and OCs in a phytoreactor (PR). In the case of OP pesticides, plant accumulation was an important pathway for the removal of fenitrothion and parathion from water, while pesticide sorption in suspended matter (SM) was an important pathway for removal of dieldrin and HCB. The magnitude of the pesticide migration factor (${\Large M}_p^{pesticide}$) is a good indication of determining the tendency of pesticide movement from below- to above-ground biomass. The uncertainties related to the different phenomena involved in the laboratory phyto-experiment are also discussed.

• Journal of Korean Society of Transportation
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• v.30 no.3
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• pp.107-118
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• 2012

The purpose of the study is to analyze the travel characteristics of freight trucks in metropolitan areas, focusing on activity generation, destination choice, and trip chaining behaviors. The results showed that the number of service companies at departure areas has a primary influence on the activity generation pattern and destination choice behavior of trucks in metropolitan areas. The number of trips within a trip chain is largest, in case where the prevailing industry in destination areas is wholesale or retail and the shipment item is food or beverage. These results imply that for the reasonable estimation of truck travel demand both the trip chaining behaviors and the industrial compositions in departure and destination areas should be separately considered for each type of commodity.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.1
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• pp.23-28
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• 2010

Reliable dynamic analysis is essential in order to properly maintain structures so that structural hazards may be minimized. The finite element method (FEM) is proven to be an affective approximate method of structural analysis if proper element types and meshes are chosen. When the method is applied to dynamics analyzed in time domain, the meshes may need to be modified at each time step. As many meshes need to be generated, adaptive mesh generation schemes have become an important part in complex time domain dynamic finite element analyses of structures. In this paper, an adaptive mesh generation scheme for dynamic finite element analyses of structures is described. The concept of representative strain value is used for error estimates and the refinements of meshes use combinations of the h-method (node movement) and the r-method (element division). The validity of the scheme is shown through a cantilever beam example under a concentrated load with varying values. The example shows reasonable accuracy and efficient computing time. Furthermore, the study shows the potential for the scheme's effective use in complex structural dynamic problems such as those under seismic or erratic wind loads.

• Korean Journal of Childcare and Education
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• v.9 no.2
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• pp.263-283
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• 2013

This study analyzed picture book "Who Pooped on my Head?" by using semiotic theories and considered involved meaning of the text. Because characteristics of children's development and picture book should be in harmony, it is necessary to understand the text in-depth. As a result of analysis, the text helps psychological stability and contains the meaning and value that guides children into social value or norm. Analyzing the text by using Greimas' Semiotic square, the meaning that following bowel movement standard is socially established behavior was involved. It seems that giving up instinct and accepting standard are process to extend thought. In conclusion, this study confirmed that the meaning and value that support cognitive and emotional development was contained in the picture book, "Who Pooped on my Head?".

• Korean Journal of Environment and Ecology
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• v.12 no.2
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• pp.156-162
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• 1998

The disposition of ecotourism was surveyed form October 5 to 22 in 1996. 600 persons were participated from 5 big cities including Seoul in Korea. Of those individuals, 48% were males, 52% were females, 50％ of respondents reported that they had gone as far as college, and 38% were 20 years of age. Most percentage of respondents (72%) were not satisfied from their leisure behavior in their daily life, 60% of respondents had a chance to visit outdoor recreation areas per month. The most respondents(75%) didn't hear the concept of ecotourism, but they recognized necessity of the ecotourism development. There was a tendency in the sample for high disposition of ecotourism subjects to be more likely to intend to interest in environmental problems, and participate to environment movement. They were very interested in ecotourism. The differences existed in ecotourists' dispositions of ecotourism, according to their scio-economic characteristics. The potentional ecotourists' intentions of visiting eco-park had strong relationships with the disposition of ecotourism.

• Journal of the Korean GEO-environmental Society
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• v.9 no.7
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• pp.13-23
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• 2008

In this study, the centrifuge tests and numerical analyses were performed to investigate the lateral flow behavior and stability of abutment when high filling was applied on the soft ground improved by SCP. The centrifuge model tests and numerical analyses were fulfilled in the case of the back of abutment filled by EPS (case 1) and soil (case 2), and the potentiometer was installed on the abutment and fill to measure the vertical and horizontal displacement at the top of abutment. As a result of the centrifugal tests, the horizontal displacement of abutment in the case 1 was 1.4cm that is almost coincide with the results of numerical and satisfy the allowable standard. On the other hand, the horizontal displacement of abutment in the case 2 was 12 cm that is 18% greater than that of numerical analysis and exceed the allowable standard. As a result of analysis, the maximum horizontal displacement of pile was 1.26 cm in case 1 that satisfies the criterion of allowable horizontal displacement (1.5 cm). In contrast, the maximum horizontal displacement of pile was 1.005 m in case 2 that greatly exceeds the allowable horizontal displacement.

• Journal of the Korean Geotechnical Society
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• v.15 no.5
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• pp.157-170
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• 1999

A new design technique is presented to stabilize cut slopes in cohesive soils by use of piles. The design method can consider systematically factors such as the gradient and height of slope, the number and position of pile's rows, the interval and stiffness of piles, etc. The design method is established on the basis of the stability analysis of slope with rows of piles. The basic concept applied in the stability analysis is that the soil across the open space between piles can be retained by the arching action of the soil, when a row of piles is installed in soil undergoing lateral movement such as landslides. To obtain the whole stability of slope containing piles, two kinds of analyses for the pile-stability and the slope- stability must be performed simultaneously. An instrumentation system has been installed at a cut slope in cohesive soil, which has been designed according to the presented design process. The behavior of both the piles and the soil across the open space between piles is observed precisely. The result of instrumentation shows that the cut slope has been stabilized by the contribution of stabilizing effect of piles on the slope stability in cohesive soil.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.397-406
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• 2003

Several sensor systems are used to estimate the reinforcing effect of stabilizing pile in slopes, and to find a failure surface in slopes effectively. FBG(Fiber Brags Crating) sensor, V/W(Vibrating Wire) sensor and inclinometer have shown a great potentiality to serve real time health monitoring of the reinforcing structures. Field tests and test results have shown great solutions for sensor systems of Smart Structures. The purpose of this research is to seek for the relationships among the slope movement and the reinforcing effect of stabilizing pile, and the strain distribution of stabilizing pile in a active zone by analyzing the data from the in-situ measurement so that the possible failure surface should be well defined based on the relationships. The field test results have shown that the data by FBG sensor are well coincided with those of V/W sensor and inclinometer, and the reinforcing effect of the stabilizing pile is good enough.

• Korean Journal of Health Education and Promotion
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• v.27 no.3
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• pp.85-96
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• 2010

Objectives: Television is the most influencing mass media. It has taken an important part in our daily life as the information source. Transmitted informations are the important sources for building one's conscience, value and behavior for all age groups from young children to aged. Methods: In this paper, all land-based TV programs for young children has been monitored by quantity and quality from July 1st 2008 'till December 31st. General programs for young children have been monitored by its theme, type, contents delivery method, proportion of diet and health information in the program, and appropriateness. For the analysis, SPSS was used. Results: Young children's program 2,771 programs and 47,169 minutes during the period were monitored. From programs for young children about 'general' and 'cooking', there were 48programs(30.6%) that has contents about dishes, 47programs(29.9%) about food and nutrition, 34programs(21.7%) about life habits. From the programs, diet and health has been delivered by 'practical exercise(38.9%)', by 'cartoon & puppet show(31.2%)', followed by 'explanation from experts(15.3%)', 'song & movement(8.9%)', and 'simple introduction(4.4%)'. From programs for young children about 'general' and 'cooking', there were 157programs that has contents about ideas and delivery method being considered, 'appropriate(45.7%)' for giving positive and 'inappropriate(54.3%)' for its negative influence to young children, the need of improvement was suggested. Conclusion: Considering the importance of infancy in one's lifetime, not only specific field but each program for young children itself should be monitored by experts of each field. A plan on how to deliver accurate content effectively to young children should be searched in various ways.

• Convergence Security Journal
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• v.14 no.7
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• pp.53-58
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• 2014

MANET can quickly build a network because it is configured with only the mobile node and it is very popular today due to its various application range. However, MANET should solve vulnerable security problem that dynamic topology, limited resources of each nodes, and wireless communication by the frequent movement of nodes have. In this paper, we propose a domain-based distributed cooperative intrusion detection techniques that can perform accurate intrusion detection by reducing overhead. In the proposed intrusion detection techniques, the local detection and global detection is performed after network is divided into certain size. The local detection performs on all the nodes to detect abnormal behavior of the nodes and the global detection performs signature-based attack detection on gateway node. Signature DB managed by the gateway node accomplishes periodic update by configuring neighboring gateway node and honeynet and maintains the reliability of nodes in the domain by the trust management module. The excellent performance is confirmed through comparative experiments of a multi-layer cluster technique and proposed technique in order to confirm intrusion detection performance of the proposed technique.