• Journal of Construction Engineering and Project Management
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• v.8 no.2
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• pp.17-33
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• 2018

This study investigates the stability of professionals' cost variability factor-rankings across different levels of cost-variability and response scenarios. Descriptive statistics are used to examine the stability of factor-ranking for 20 cost variability factors and a Multinomial Logistic (MNL) regression model was implemented to examine the stability of cost variability factors across three cost variability levels. The finding on the descriptive statistics indicated that professionals' factors-rankings are stable only for external factors. The MNL regression results on factor-stability suggested that 8 out of the 20 evaluated factors were unstable determinant of lower cost variability levels. These factors are "risk associated with the project", "personal bias and poor professionalism of the estimators", "limited time available to complete the project", "lack of skills and experience by estimator" "geographical location of projects", "incomplete & rush designs for estimate", "unforeseen or unexpected site constraints", "high class bidders for the contractors". Similarly lack of experience and large size projects were observed to be unstable as well. These observations suggest that professionals' view on pre-tender cost variability factor-ranking yields unstable factor rankings hence should not be relied upon as the only mechanisms to mitigate cost related risks in construction projects.

• Korean Journal of Environment and Ecology
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• v.29 no.2
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• pp.236-249
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• 2015

The master plan of forest land management proposes forest watershed management that considers regional characteristics in order to overcome the problem of uniform forest land management. In order to manage the forest watersheds in Gyeonggi-do, this study classified 1,823 forest watersheds in Gyeonggi-do and attempted to understand their characteristics. It conducted a factor analysis and cluster analysis from the perspective of conservation value and development pressure using forest land indicators. In terms of conservation value, three factors were drawn: the topography factor, vegetation factor and public service factor, while in terms of development pressure, three factors were drawn: the easiness of development factor, economic benefits factor and development activity factor. Using these factors, forest watersheds were divided into three clusters in terms of conservation value while they were divided into three clusters in terms of development pressure. Using the results of the cluster analysis from a conservation-development perspective, the forest watersheds were classified into nine different types, and the characteristics were identified by each type. It is judged that the factors and clusters drawn as a result of the research accurately reflect the present conditions of Gyeonggi-do, and the nine types of forest watersheds have clear characteristics according to each type, which are judged to be utilized in forest management in the future.

• Journal of Environmental Science International
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• v.30 no.10
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• pp.779-787
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• 2021

This study analyzes structural landscape changes over a time-series for a small and medium-sized city, Gangneung-Si, based on area and distribution patterns, and according to the type of land cover. Among the types of land cover, the area ratio of urbanized areas increased by 2.02% in the late 2010s as compared to the late 1980s, while there was a decrease of 2.69% in farmland and 0.69% in grassland areas. On analyzing the changes in land cover use by applying the Fragstats program, it was confirmed that landscape changes in urban and management areas were relatively severe according to the Landscape Shape Index, Largest Patch Index, and Aggregation Index. A pattern of concentrated expansion was also found around certain areas. In particular, from the analysis, it was established that the proportion of urbanized area had considerably increased and that the extent of farmland damage to management areas, including planned management areas, was large. Additionally, the Total Core Area generally indicated a reduction in the core areas of farmland and forest within urban and management areas. A medium-sized city showed significant changes besides large cities in terms of landscape structure. The developmental pressure on management areas, in particular, was quite high.

• Korean Journal of Environment and Ecology
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• v.17 no.1
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• pp.56-70
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• 2003

Reviewing the trend of land use in urban cultivated land, the large part of land has been changed into the high-profit cultivated land of green houses or the developing areas. So, its percent of cultivated land in land use comparing to the other types of cultivated land would get far higher. Therefore, this study aims to identify the characteristics of landscape ecological pattern in the cultivated land of green houses and to find its alternatives for management, which would be a basis of regional planning and management in terms of space and time. The cultivated land of green houses, whose its area reaches 19.3ha, in Seoul are mainly dispersed on the south eastern part of Seoul and its area is larger than the other types of cultivated lands. According to the result of shape index analysis, its perimeters were very simple. Also, Analyzing the first three major neighboring land use to the cultivated land of green houses, the most frequent biotope types of neighboring land use to the cultivated land of green houses were that transportation facility represented 60%, forest, 43%, the other types of cultivated land, 36%, and residential area, 33%. The cause why the percent of transportation facility was higher in the neigh-boring land use types was assumed for the production and distribution of crops. On the basis of the result of landscape ecological pattern analysis, the cultivated land would be managed and contributed to enhance biodiversity and urban environment preservation.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.608-616
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• 2013

The objective of this study was to suggest contingent valuation method, simple random sampling method, systematic sampling method, maximum practice area method, and overlay practice area method as the estimation methods for forest management area to estimate carbon dioxide sink by forest management as stated in Article 3.4 of the Kyoto Protocol. A case study for Chungcheongbuk-do was performed using maximum practice area method which was thought of as the most rational method within MRV(Measurable, reportable and verifiable). The forest management ratio was defined as forest management area over the total forest area. Based on the definition of forest management activity, forest area was divided into practice forest land and non-practice forest land. The area of forest mangement for practices was based on the 'National Forest Management Information System' and the history of practices from the 'Proposals on Private Management Information Database'. The area of forest management for non-practices was based on the public used forest land from 'Categorial map of forest land'. It was shown that the forest management area of Chuncheongbuk-do was 115,566 ha for practice forest land, and 131,008 ha for non-practice forest land. The forest managent ratio was 49.7% of the total forest area of 495,806 ha. This study made possible to the estimation of the forest management ratio under Kyoto Protocol, and had an advantage in searching for a practical method of forest management plan in which the forest management ratio could be enhanced.

• Journal of Environmental Science International
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• v.29 no.12
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• pp.1249-1260
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• 2020

Non-point source pollutants have characteristics the render them difficult to manage owing to the uncertainty of flow paths. As agricultural non-point sources account for more than 57% of non-point source pollutants, the necessity for management is increasing. This study examines the possibility of utilizing land cover maps to suggest a more appropriate method of setting management priority for agricultural non-point sources in the Daecheong Lake area and draws implications by comparing the results derived using the cadastral map, as mentioned in the TMDL Basic Policy. To define the prioritized areas for management, the pollution load was calculated for each subbasin using the formula from the TMDL technical guidelines. As a result, the difference in the average pollution load between the land cover map and cadastral map ranged from 11.6% to 21% among the subbasins. In almost all subbasins, there were differences in the ranking of management priorities depending on the land information that was used. In addition, it was found that it was reasonable to use the level 3 land cover map to calculate the load generated by the land system for examining the implementation goals and methods of each data and comparing them with satellite images.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.329-334
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• 2003

The aim of this study is propriety review for underground facility surveying on development area of land for housing and efficient management. Because of integration information administration system construction of the nation and development of information technology, construction of Urban information system(UIS) to manage systematically city space is increasingly necessary We manage systematically attribute information for each lot in the development area of land lot housing that it Is connected with NGIS in order to drive gradual computerization of underground facilities and arrange the base of facility management. Review arrangement methods on development area of land for housing makes it to check safety accident of urban and to leading base of urban information. Thus, this study draw the most suitable way through analysis of driving methods and expectation effect from above facts.

• The Journal of Fisheries Business Administration
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• v.47 no.4
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• pp.1-13
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• 2016

Fish mortality is the most important success factor in aquaculture management. To analyze the effect of mortality considering biological and economic condition is a important problem in land-based aquaculture. This study is aimed to analyze the effect of mortality for duration of cultivation in land-based aquaculture. This study builds the mathematical model that finds the value of decision variable to minimize cost that sums up the water pool usage cost, sorting cost, fingerling cost and feeding cost under critical standing corp constraint. The proposed mathematical model involves many aspects, both biological and economical: (1) number of fingerlings (2) timing and number of batch splitting event, based on (3) fish growth rate, (4) mortality, and (5) several farming expense. Numerical simulation model presented here in. The objective of numerical simulation is to provide for decision makers to analyse and comprehend the proposed model. When extensive biological and cost data become available, the proposed model can be widely applied to yield more accurate results.

• Journal of Forest and Environmental Science
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• v.32 no.2
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• pp.182-188
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• 2016

In this study 'forest design in waterside unused land' of 'waterside area' in the specificity that multilateral, including landscape, recreation, social and environmental aspects in the space, taking into account by multiple factors :Raise 'practicality' than a functional management and police to hang out with, each element is usually way to improve the beauty. There is currently carried out waterside green area creation, which is artificial plantation and open spaces only emphasizing 'landscape' with lacking multi-function purpose, as a 'forest design in waterside unused land' strategy but it should be lowered by performance in this strategy. And the study suggested a strategy which prepared cultural and social infrastructure to be able to attract different fund and build local character as an alternative demand plan considered environmental character as a top priority.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.1
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• pp.93-101
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• 2002

By the rapid development of computer technology and the more efficient use of land-related information, Land-related Information System has been developed by the central and local government respectively. The problems of the storage, maintenance and exchange of land-related data will be anticipated. The purpose of this study is to meet the demands of governments and prevent the duplicate investment for the information system. The data sharing and standardization should be achieved for the more efficient land management. The theme of UN's sustainable land management and the future vision of cadastre according to Cadastre 2014 are thoroughly reviewed. The advanced foreign cases of LIS development are studied, too. Linkage among land-related data, the improvement of organizational institution and the training for GIS specialists are suggested as the strategies for the more efficient land-related information system development.