• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.3
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• pp.92-99
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• 2021

In the case of precise safety inspection and precise safety diagnosis of a building, a condition evaluation must be conducted to determine the safety grade. Since 2004, an evaluation method using fuzzy theory has been introduced for quantitative condition evaluation,and the relationship and importance of reinforced concrete members using fuzzy theory have been applied. Generally, fuzzy theory is a method used to deal with ambiguous expressions with unclear correlations, but at the time of development, it seems that it was developed by applying fuzzy theory as an alternative in a situation where inspection and diagnosis result data were insufficient. Therefore, it is necessary to verify the relationship and importance of evaluation items derived based on the current fuzzy theory using actual inspection and diagnosis result data.In this study, the correlation between the evaluation items was derived by using the results of 19 precision safety inspections and 9 precision safety inspections and the performance score function formula, and using this, a reasonable durability score calculation formula of the member was presented.

• Journal of Wetlands Research
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• v.23 no.1
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• pp.74-84
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• 2021

Active stormwater management is essential to minimize the impact of urban development and improve the hydrological cycle system. In recent years, the Low Impact Development (LID) technique for urban stormwater management is attracting attention as a reasonable alternative. The Storm Water Management Model (SWMM) is actively used in urban hydrological cycle improvement projects as it provides simulation functions for various GI (Green Infra) facilities through its LID module. However, in order to simulate GI facilities using SWMM, there are many difficulties in setting up complex watersheds and deploying GI facilities. In this study, a model that can evaluate the performance of GI facilities is proposed while implementing the core hydrological process of GI facilities. Since the proposed model operates based on hydrological routing, it can not only reflect the infiltration, storage, and evapotranspiration of GI facilities, but also quantitatively evaluate the effect of improving urban hydrological cycle by GI facilities. The applicability of the proposed model was verified by comparing the results of the proposed model with the results of SWMM. In addition, a discussion of errors occurring in the SWMM's permeable pavement system simulation is included.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.1
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• pp.13-20
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• 2022

Aircraft weight is an important factor affecting performance and fuel efficiency. In the conceptual design stage of the aircraft, the process of balancing cost and weight is performed using empirical formulas such as fuel consumption cost per weight in estimating element weight. In addition, when an airline operates an aircraft, it promotes fuel efficiency improvement, fuel saving and carbon reduction through weight management activities. The relationship between changes in aircraft weight and changes in fuel consumption is called the cost of weight, and the cost of weight is used to evaluate the effect of adding or reducing weight to an aircraft on fuel consumption. In this study, the problems of the existing cost of weight calculation method are identified, and a new cost of weight calculation method is introduced to solve the problem. Using Breguet's Range Formula and actual flight data of the A350-900 aircraft, two weight costs are calculated based on take-off weight and landing weight. In conclusion, it was suggested that it is reasonable to use the cost of weight based on the take-off weight and the landing weight for other purposes. In particular, the cost of weight based on the landing weight can be used as an empirical formula for estimating element weight and optimizing cost and weight in the conceptual design stage of similar aircraft.

• Journal of Environmental Impact Assessment
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• v.31 no.3
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• pp.129-140
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• 2022

Environmental impact assessment on development projects is a process in which various stakeholders derive consultations by reflecting project characteristics and regional environmental status, and implementation of consultations is a prerequisite for securing sustainability of the local environment. The business plan can be changed to respond to changes in social and environmental conditions. And the business plan for which the environmental impact assessment consultation has been completed, it can be changed as a systematically prepared procedure (called Consultations on Amendment). As a result of investigating and analyzing the current status and major changes in the development project, Consultations on Amendment in industrial complexes were the most common, and the environmental impact is increasing accordingly. As the results of the analysis of operational status and the case studies, the main causes of Consultations on Amendment in industrial complex can be summarized into three categories: (1) formal demand forecasting for tenant industries, (2) excessive omission and simplification of administrative procedures under the Special Act, and (3) the use of an expedient change consultation system to facilitate environmental impact assessment consultation and shorten the period. This study proposes the following three measures to prevent the deterioration of the environmental impact assessment function due to frequent consultations on industrial complex changes; (1) Ensuring residents' participation procedures for Consultations on Amendment that changes important matters, (2) Reasonable revision of the "Simplification of Industrial Complex Procedures Act" to enhance the feasibility of industrial complex development plans and locations, (3) Development of evaluation criteria and methods for verification of real demand for objective demand management for industrial complexes, and (4) Preparation of a review guideline for Consultations on Amendment.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.230-237
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• 2023

Due to the COVID-19 pandemic and climate change, shortages of essential commodities and resources continue to occur globally. To address this problem, trade volume demand suddenly increased, driving up the freight rate of container ships sharply. The size of container vessels progressively increased from 1,500 TEU (twenty-foot equivalent unit) in the 1960s to 24,400 TEU in 2021. As the improvement of container loading capacity is closely related to the enlargement of the lashing bridge structure, it is necessary to design a structure effective for good container securing and safe under the various external loads that occur during voyage. Major classification societies have recently issued structural-analysis-based guidelines to evaluate the structural safety of lashing bridges, but their acceptance criteria and evaluation methods are different, causing confusion among engineers during design. In this study, the strength change characteristics are summarized by variations in the main variables (modeling range, opening consideration, mesh size) likely to affect the results. Based on this result, the authors propose a reasonable structural-analysis-based evaluation that is expected to serve as a reference in the next revision of classification standards.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.7
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• pp.929-943
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• 2018

Together with the increase of public housing complex, the issues of community following residential environment under contemporary society has become an important issue and the collapse of traditional community has long been emerged as an important social issue. In order to facilitate communities within the public housing complex, various discussions have been continued, and for addressing such an issue under this study, the public housing complexes n Seoul, the capital region and other major cities have been surveyed and analyzed to draw following conclusion as the design-type study to propose a model of community facilities. It displays that there is certain limitation with respect to the diversity of programs when comparing the community facility standard defined under the public housing related laws and regulations. This is attributable to the fact that it is a limitation to satisfy the level of satisfaction for residents that expect the improvement in quality of leisure life, and the facility standard that is standardized around the physical facility environment has certain limitations to enhance the level of satisfaction for residents when the demand has been on the rise with respect to quality. For this fact, the approach in consideration of diversity for the facility standard has to be made in advance. As the utility of external space for the public housing is increased, it is reasonable to consider the plan to secure environment through the architectural factors, and it has the strength in enhancing the utility of internal and external space of the community facilities.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6B
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• pp.579-587
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• 2010

The mid-range streamflow forecast was performed using NWP(Numerical Weather Prediction) provided by KMA. The NWP consists of RDAPS for 48-hour forecast and GDAPS for 240-hour forecast. To enhance the accuracy of the NWP, QPM to downscale the original NWP and Quantile Mapping to adjust the systematic biases were applied to the original NWP output. The applicability of the suggested streamflow prediction system which was verified in Geum River basin. In the system, the streamflow simulation was computed through the long-term continuous SSARR model with the rainfall prediction input transform to the format required by SSARR. The RQPM of the 2-day rainfall prediction results for the period of Jan. 1~Jun. 20, 2006, showed reasonable predictability that the total RQPM precipitation amounts to 89.7% of the observed precipitation. The streamflow forecast associated with 2-day RQPM followed the observed hydrograph pattern with high accuracy even though there occurred missing forecast and false alarm in some rainfall events. However, predictability decrease in downstream station, e.g. Gyuam was found because of the difficulties in parameter calibration of rainfall-runoff model for controlled streamflow and reliability deduction of rating curve at gauge station with large cross section area. The 10-day precipitation prediction using GQPM shows significantly underestimation for the peak and total amounts, which affects streamflow prediction clearly. The improvement of GDAPS forecast using post-processing seems to have limitation and there needs efforts of stabilization or reform for the original NWP.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.5
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• pp.261-269
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• 2023

In light of recent social concerns related to issues such as water supply pipe deterioration leading to problems like leaks and degraded water quality, the significance of maintenance efforts to enhance water source quality and ensure a stable water supply has grown substantially. In this study, scan statistic was applied to analyze water quality complaints and water leakage accidents from 2015 to 2021 to present a reasonable method to identify areas requiring improvement in water management. SaTScan, a spatio-temporal statistical analysis program, and ArcGIS were used for spatial information analysis, and clusters with high relative risk (RR) were determined using the maximum log-likelihood ratio, relative risk, and Monte Carlo hypothesis test for I city, the target area. Specifically, in the case of water quality complaints, the analysis results were compared by distinguishing cases occurring before and after the onset of "red water." The period between 2015 and 2019 revealed that preceding the occurrence of red water, the leak cluster at location L2 posed a significantly higher risk (RR: 2.45) than other regions. As for water quality complaints, cluster C2 exhibited a notably elevated RR (RR: 2.21) and appeared concentrated in areas D and S, respectively. On the other hand, post-red water incidents of water quality complaints were predominantly concentrated in area S. The analysis found that the locations of complaint clusters were similar to those of red water incidents. Of these, cluster C7 exhibited a substantial RR of 4.58, signifying more than a twofold increase compared to pre-incident levels. A kernel density map analysis was performed using GIS to identify priority areas for waterworks management based on the central location of clusters and complaint cluster RR data.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.2 no.2
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• pp.93-120
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• 2007

To promote the commercialization of high technology based start-up company, it is essential to activate technology trading for the Innovative Small & Medium companies which eager to acquire technology competitiveness through technology trading and facilitate financial system which provide Small & Medium companies with technology commercialization money. This study focus on enhancing credibility of technology valuation solutions through the improvement of the existing technology valuation solutions. The existing technology valuation solutions in practice have deficiency in reasonable valuation because of subjective technology factor's calculation. And the commercialization risk of high technology based start-up companies cannot be fully reflected in the existing valuation solutions. The high risk of technology commercialization acts as a hurdle in the facilitation of providing money for the start-up companies. The improved new model will have more acceptable objectivity and reasonably reflect the commercialization risk of start-up companies. The new model has two distinctive features compared to existing solutions. The new model newly adopts commercialization success factor which reflects the risk of high technology based start-up company. And the new model excludes technology factor which is controversial among interested parties. The exclusion of technology factor will improve the objectivity of technology valuation and the adoption of commercialization success factor will solicit investor and capitalist who concern the high risk of technology based start-up companies. In conclusion, the improved new model is expected to activate technology trading and facilitate the money market through which high technology based start-up companies raise commercialization money.

• Environmental and Resource Economics Review
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• v.14 no.2
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• pp.519-547
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• 2005

The aim of this study is to analysis how economic welfare lost happens within the present korea seasonal and time period electricity pricing system and find out reasonable electricity price system acceptable during the transitional period of korea electricity industry restructuring To analyze economic welfare lost in the electricity industry, in advance seasonal and time periodic 9 demand curves(summer, spring ＆fall, winter/peak-load time, middle-load time, low-load time) and one market supply curve are made and then using these demand and supply curve, seasonal and time periodic market equilibrium prices is calculated. Finally, comparing these market equilibrium prices with present regulated classified seasonal and time periodic prices, the whole economic welfare lost in the electricity industry is calculated. The result of this study shows that in 2002, the total economic welfare lost in electricity industry is 137,770 million Won and under present price system, the worst welfare lost is happening seasonally in spring ＆ fall, time periodically in the middle-load time. Specifically analyzing the characteristics of welfare lost, especially on the industry customers and service customers which are applied in seasonal and time periodic pricing, for the industry customers, the welfare lost calculated in this class occupies 51% of the total welfare lost in the whole electricity industry and the worst welfare lost is happening seasonally in spring ＆ fall, time periodically in the middle-load time. For service customers, the welfare lost calculated in this class occupies 13% of the total welfare lost in the whole electricity industry and the worst welfare lost is happening seasonally in summer, time periodically in the peak time Finally, this study was made based on the year of 2002 and KEPCO has practiced two times of rate change until now. The result of rate change was positively analyzed in the direction of economic welfare improvement(welfare improvement achieved by 16.3% compared to 2002 result).