• Journal of the Economic Geographical Society of Korea
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• v.15 no.2
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• pp.332-342
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• 2012

The current research aims at classifying the bus stops as transfer center in order to establish the rational bus transfer systems. Existing research typically identifies characteristics of demands for bus stops and land use surrounding the bus stops and classifies and profiles the bus stops. A common problem with this type of research is that the results with cross-sectional characteristics of land use and bus stop usage do not capture the details of trip chain, the fundamental characteristics of the trips with transfer. This paper therefore examines bus stop classifications with such variables as transport mode chains, intermediate stop chains and timing chains. The analysis on the data collected on Monday 20 April 2009 for passengers of Gyeong-gi bus results in a clear classification among bus stops in terms of such trip chain variables. The research would provide useful information for the decision support of transfer stops location choice and infrastructure design.

• Education of Primary School Mathematics
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• v.14 no.3
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• pp.277-291
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• 2011

It is necessary for the teacher to understand why teach mathematics in order to implement the visions and expectations of the national mathematics curriculum in her actual classroom. This study conducted a survey of examining how elementary school teachers might understand the purpose of teaching mathematics. The results of this study showed that teachers' conceptions of the purpose of teaching mathematics were related mainly to the development of logical thinking, practical use of mathematics in everyday life, and a tool for studying other subjects or disciplines. However, teachers did not perceive much other purposes of mathematics education such as understanding the world, appreciating aesthetic value of mathematics, and developing communicative ability as well as sociality. Whereas teachers did not think of the significance of mathematics as an intellectual field when asked to write down how they would explain students why they had to learn mathematics, they tended to strongly agree it in the Likert-scale responses. Teachers' conceptions were not different according to their gender but teachers with less than five years' teaching experience were relatively negative than others with more experience. Given these results, this study provided issues and implications of teachers' conceptions of the purpose of teaching mathematics.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.10
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• pp.691-697
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• 2014

Though the upper stream basin area of Gwanpyung-Cheon in Daejeon, Korea is protected as Green Belt Zone, the stream is under constant environmental pressure due to current agricultural practices and infrastructure development in its basin area. To develop appropriate integrated water resources management plan for the stream, it is necessary to consider not only water quality problems but also water quantity aspect. In this study, Storm Water Management Model (SWMM) was calibrated and validated with sets of field measurements to predict for future water flow and water quality conditions for any rainfall event. While flow modeling results showed good agreement by showing correlation coefficient is greater than 0.9, water quality modeling results showed relatively less accurate levels of agreements with correlation coefficient between 0.67 and 0.87. Hypothetical basin development scenarios were developed to compare effect on stream water quality and quantity when Low Impact Development (LID) technologies are applied in the basin. The results of this study can be used effectively in decision making processes of urban development Gwanpyung-Cheon area by comparing basin management alternatives such as LID methods.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.2
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• pp.10-20
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• 2013

To evaluate the safety of a beam structure, strains are measured as an indicator of structural states. However, unless strain sensors are installed exactly on where maximum or other representative strains occur, the techniques by which rational assessment through measured strains is accomplished are required. Thus, this study suggests a process to estimate strain distribution on the steel beam from discrete strains measured by sensors. In the presented technique, the targeted beam is regarded to be subjected to unknown loads so that applicability is enhanced. Final strain distribution is given as form of a function after regression analysis. To verify the performance of estimation, a bending test for steel beam on which distributed and concentrated loads simultaneously act is conducted. From the comparison between estimated and directly measured strains in the test, the curve of strain distribution and the strain at arbitrary location could be predicted within maximum relative error 3.32% and maximum absolute error of $2.32{\mu}{\varepsilon}$, respectively. Thus reliable and practical monitoring is expected to apply effectively for the steel beam structure.

• Journal of Radiation Protection and Research
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• v.29 no.2
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• pp.73-90
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• 2004

The Reg. Guide 1.109 model was reviewed against its applicability to calculating radionuclide concentrations in agricultural products for operating nuclear facilities and an improved method was proposed. The model was so modified that the radionuclides deposited since the start of operation could be considered in assessing the root uptake. Translocation factors were introduced in the equation for calculating the concentrations in edible parts due to direct plant deposition. Values specific to Korea were set up for the input parameters of the modified model. The concentrations of $^{54}Mn,\;^{60}Co,\;^{90}Sr\;and\;^{137}Cs$ in rice seeds, Chinese cabbage and radish root were calculated for various hypothetical deposition histories using the Reg. Guide 1.109 model and the modified model with parameter values in the guide and those specific to Korea put in alternately. Through comparisons among the results, it could be expected that the use of the modified model with the input of parameter values specific to Korea would result In a more resonable and realistic assessment.

• Journal of Korean Society of Forest Science
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• v.95 no.6
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• pp.663-671
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• 2006

This study was performed for exploring the spatial distribution pattern of Pinus densiflora and Quercus spp. in Korea. Firstly, the spatial distribution map of Pinus densiflora and Quercus spp. was prepared in grid of $100m{\times}100m$ at national level, using digital forest type map and actual vegetation map. And thematic maps for topography, climate, and soil were also prepared in the raster form of $100m{\times}100m$. Through GIS based spatial analysis of the digital distribution map of Pinus densiflora and Quercus spp. and thematic maps, the spatial characteristics of Pinus densiflora and Quercus spp. distribution was explored in relation to the environmental factors such as topography, climate, and soil. And the occurrence frequency models of Pinus densiflora and Quercus spp. were derived. Pinus densiflora occurs more often than Quercus spp. at low elevation, low slope gradient, and high temperature areas. In addition, Pinus densiflora is mainly distributed at shallow and well-drained loamy soil from igneous rocks. In contrast, Quercus spp. is more common at shallow and well-drained loamy soil from metamorphic rocks. As a result, the prediction model for the spatial distribution of Pinus densiflora and Quercus spp. by topographical variables has proven successful with high statistical significance. The result of this study can contribute to rational management of Pinus densiflora and Quercus spp. stand in Korea, considering environmental factors such as topography, climate, and soil.

• Journal of Korean Society of Forest Science
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• v.85 no.1
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• pp.15-23
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• 1996

Preparing the era of forest resources management requires studies on forest fire. This study attempted to develop forest fire occurrence model using meteorological characteristics for the practical purposes of forecasting forest fire danger rate. To accomplish this goal, the relationships between forest fire occurrence and meteorological characteristics are estimated. In the process, the forest fire occurrence pattern of the study region(Taegu-Kyungpook) is categorized by employing qualification IV method. The study region was divided into three areas such as, Taegu, Andong and Pohang area. The meteorological variables emerged as affective to forest fire occurrence are relative humidity, longitude of sunshine, and duration of precipitation. To estimate the probability of forest fire danger, forest fire occurrence of three areas are regressed on the time series data of affective meteorological variables using logistic and probit model. The effectiveness of the models estimated are tested and showed acceptable degree of goodness. Those models developed would be helpful to increase the efficiency of forest fire management such as detection of forest fire occurrence and effective disposition of forest fire fight equipments.

• Korean Journal of Construction Engineering and Management
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• v.17 no.4
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• pp.3-11
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• 2016

Recently, overseas plant orders of domestic enterprises are steadily increased, and the amount of orders in the first half of 2014 were 93% increased compared to the previous year. In addition, now which is the third quarter of 2015, overseas plant orders are already over 249.8 billion dollars so the interests of plant industry research has been increased. In the life cycle of the plant project, CM before the construction stage is to complement the uncertainties that are inherent in the early stages of the project, and from the viewpoint of supporting the rational decision-making, the importance of its role is on the rise. Among them, excavating and investing participation plan in the planning stage is an important work that has a large impact force to influence the success and failure of future project. However, the work has become a problem with frequent consultations due to decision-making, continuous modification, and inefficient repetitive tasks. Therefore, it is needed that work process should be changed to effectively accommodate. The purpose of this paper is to derive the major work items for excavating and investing participation plan in the planning stage of the plant project, and establish a standardized work process through the Delphi analysis. The result of this study is expected to be utilized for EPC companies in ensuring the technical competitiveness in planning on overseas markets, and improve the efficiency of work.

• Korean Journal of Construction Engineering and Management
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• v.14 no.2
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• pp.171-183
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• 2013

Domestric Construction & Engineering market has been long in recession due to the global economic crisis. Domestic construction industries consequently looks at overseas construction markets where relatively more construction projects are constantly required. In order to provide meaningful information for Korean engineering companies to keep the pace with the changes in the construction industry, various construction related date and statistics are analyzed. In addition, previous research from the related organizations and construction engineering companies are closely reviewed. Investigation of preliminary data and research have been conducted to draw remedies for their overseas expansion. Moreover, it is attempted to classify foreign markets as the Asia, Africa and etc. (Europe, North America/the Pacific and Latin America) to provide the list of first target countries and its regional market information focusing on their bidding system. This study had tried to show comparative analysis of different bidding procedures between Korea and the selected countries to suggest measures of improvements for the domestic bidding system. Finally, this study suggested policy recommendations to meet the requirement of bid qualification to advance the global market that was suggested with validated clustering bidding data.

• Korean Journal of Construction Engineering and Management
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• v.17 no.5
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• pp.108-119
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• 2016

Since the introduction of the converted accident rate in Pre-Qualification(PQ) process in 1992, the safety evaluation system has contributed to a reduction of construction accidents and development of the safety management system in public construction projects. As the comprehensive evaluation method the government plans to introduce includes the indicators 'accident rate' and 'death rate per 10,000 workers', the influences on the safety evaluation in the bidding process would be broader in public sector construction projects. However, the current safety evaluation system is operated by different estimating standards in the bidding process. At this point, a study of improvement on the safety evaluation index is required to review its current conditions and to propose its efficient operating method. Therefore, the purpose of this study is to analyze problems of the current safety evaluation system through the questionnaire survey on the qualified workers in construction safety management and to propose an improvement plan for the problems noticed. Our results suggest the standards of the unified process for the safety evaluation index, the size of construction firms needed for accident rate estimation, and the improvement plan for unreported accidents. The proposed improvement plan enables the reasonable estimation and efficient operation of the safety evaluation index, and further, it would contribute to reducing construction accidents through the activation of voluntary safety management by construction firms.