• Journal of the Korean Geosynthetics Society
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• v.21 no.1
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• pp.49-56
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• 2022

In this study, finite element numerical analysis was performed considering various influence factors(cavity shape and size, pavement thickness and size of traffic load) in order to analyze the impact factors in the underground of the road where the cavity occurred and to evaluate the stability of the ground. In order to verify the reliability of the numerical analysis method applied in this study and the results it was compared and analyzed with the results of previous studies and field measurements. The correlation between the influence factors was analyzed through the distribution of vertical displacement obtained from the numerical analysis results, the distribution of surface settlement and surface settlement, the distribution of the stress ratio, and the distribution of the safety factor. As a result, it was confirmed that as the size of the cavity and traffic load increased and the thickness of the pavement decreased, the vertical displacement and surface settlement at the top of the cavity increased. Also, the shape of the cavity was square, the stability of the ground was significantly reduced compared to the case of a circular cavity. Through these results, it was possible to confirm the overall stability of the lower ground of the road where the cavity was generated.

• Journal of Venture Innovation
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• v.2 no.2
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• pp.95-115
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• 2019

In the context of today's business environment, not only is the nation or company's credit rating considered very important in our recent society, but it is also becoming important in international transactions. Likewise, at this point of time when the importance and reliability of credit evaluation are becoming important at home and abroad, this study analyzes financial ratios related to corporate profitability, safety, activity, financial growth, and profit growth to study the impact of financial indicators on enterprise value and corporate taxes on credit evaluation. To proceed with this, the financial ratio of 465 companies of KOSPI securities listed in 2017 was calculated and the impact of enterprise value and corporate taxes on credit evaluation was analyzed. Especially, this further study tried to derive a reliable and consistent conclusion by analyzing the financial data of KOSPI securities listed companies for eight years from 2011, which is the first year of K-IFRS introduction, to 2018. Research has shown that the significance levels among variables that show the profitability, safety, activity, financial growth, and profit growth of each financial ratio were significant at the 99% level, except for the profit growth. Validation of the research hypothesis found that while the profitability of KOSPI-listed companies significantly affects corporate value and income tax, indicators such as safety ratio and growth ratio do not significantly affect corporate value and income tax. Activity ratio resulted in significant effects on the value of enterprise value but not significant impacts on income taxes. In addition, it was found that the enterprise value has a significant effect on the company's credit and corporate income taxes, and that corporate income taxes also have a significant effect on the corporate credit evaluation, and this also shows that there is a mediating function of corporate tax. And as a result of further study, when looking at the financial ratio for eight years from 2011 to 2018, it was found that two variables, KARA and LTAX, are significant at a 1% significant level to KISC, whereas LEVE variables is not significant to KISC. The limitation of this study is that credit rating score and financial score cannot be said to be reliable indicators that investors in the capital market can normally obtain, compared to ranking criteria for corporate bonds or corporate bills directly related to capital procurement costs of enterprise. Above all, it is necessary to develop credit rating score and financial score reflecting financial indicators such as business cash flow or net assets market value and non-financial indicators such as industry growth potential or production efficiency.

• The Journal of the Korea Contents Association
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• v.17 no.10
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• pp.343-359
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• 2017

This study aims to analyze the government accounting system of South Korea on the institutional complex and institutional congruence of new institutional theory and suggests policy reform for the system. I researched the literatures on the national and local accounting system and compiled research materials from the Ministry of Strategy and Finance, the Ministry of Interior and Safety, the Board of Audit and Inspection, and Government Accounting and Finance Statistics Center websites. Analysis showed that the government accounting system consists of various elements in institutional complex and the congruence level of national and local accounting system of South Korea is low in production, disclosure, and application of information. The suggestions of this study include: introducing accounting position recruitment, adopting government audit system, and improving cooperation between national accounting organizations and local accounting organizations for reliable information production; disclosing real time information and revealing information linking national and local accounting for transparent information disclosure; educating information user, providing accurate cost and available financial analysis indicators, introducing chief financial officer, and expanding range of consolidated national financial statements for information application.

• Journal of Korean Society of Transportation
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• v.30 no.3
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• pp.43-55
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• 2012

Bicycle is an environment-friendly transport mode contributing to a more sustainable transportation systems. To innovatively increase the use of bicycle as a significant transport mode, bicycle-friendly roadway environment should be provided. This study proposes a method to evaluate cycling environment based on the analysis of data collected from an specially equipped probe bicycle. The inertial measurement unit(IMU) consisting of a gyro sensor, accelerometer, and a global positioning systems(GPS) receiver was installed on the probe bicycle. Cycling stability index(CSI) and bicycle speed data were used as inputs of the proposed evaluation framework adopting the Fault Tree Analysis, which is a well-known technique for the risk analysis. The outcomes of this study will serve as an intelligent assesment tool for cycling environment.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.293-293
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• 2021

자연유량이란 인위적 행위에 의한 하천의 유량 변화가 없는 개발되지 않은 상태의 하천유량을 말하며, 실제 유량을 측정하거나 관측자료를 활용한 장기유출모형을 통해 산정할 수 있다. 미계측 유역에 대한 강우-유출 모형 구축시, 무엇보다 실제 미계측유역에 적용시 나타날 수 있는 문제점을 최소화할 수 있는 방향으로 모형 개발이 이루어지는 것이 필요하다. 강우-유출 모형 매개변수의 수가 많아질수록 과적합(over-fitting)의 발생 소지가 증가하게 되며, 지역화 모형 구축시 불확실성을 더욱 가중시키게 된다. 이러한 이유로, 모형의 검정보다는 검증에 초점이 맞춰져 있어야 하며, 더불어 사용되는 강우-유출 모형의 매개변수가 적어야 한다. 본 연구에서는 대표 강우-유출모형의 선정시 여러 평가 기준 중 예측의 정확성 측면에서 통계적 지표를 통해 모형의 수행능력에 중점을 두었으며, 적은 개수의 매개변수를 갖음에도 불구하고 상대적 우수한 모의결과를 제공하는 GR4J(Ge'nie Rural a 4 parame tres Journalier)모형을 최적 유출모형으로 선정하여 댐 상류유역에 대한 자연유량 재현성능을 평가하였다. 최종적으로 강우-유출모형의 최적매개변수와 유역특성인자 사이의 상호연관성을 고려해 매개변수를 지역화하기 위하여, 본 연구에서는 두 가지 이상의 변량에 대한 상관성을 효과적으로 재현하는데 효과적이며, 자유로운 주변확률분포 선택과 결합확률분포의 추정이 용이한 장점이 있는 Copula 함수를 활용하였다. 제시된 방법론에 대한 적합성을 평가하기 위해 교차검증 관점에서 지역화된 매개변수의 적합성을 검토하였으며, 본 연구에서 도출된 결과는 유역특성에 따른 미계측유역의 자연유량 산정시 지역 매개변수를 강우-유출모형에 활용함으로써 신뢰성 있는 자연유량 산정 결과를 제공할 수 있을 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.43-43
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• 2020

보령댐은 충남 서부지역 8개 시·군에 생활용수와 공업용수를 공급하고 있는 중요한 수원으로 최근 우리나라에서 발생한 연속적인 가뭄으로 2015년에는 저수율이 7.5 %까지 감소하여 제한급수가 시행되었다. 본 연구에서는 가뭄으로 인한 물 공급 부족에 취약함을 보인 보령댐 유역(297.4 ㎢)을 대상으로 SWAT(Soil and Water Assessment Tool) 모델과 RCP(Representative Concentration Pathways) 시나리오를 활용하여 극한 기후변화 사상이 반영된 보령댐의 내한능력을 평가하였다. SWAT 모형을 활용하여 보령댐의 물수지를 모의하기 위하여 보령댐의 실측 유출량, 저수량, 방류량으로 보령댐 유입량과 저수량을 보정(2002~2004) 및 검정(2005~2007)하였으며, 실측 저수량을 기반으로 미래 댐 운영을 모의하였다. 검·보정 결과, 댐 유입량과 저수량의 PBIAS(%)는 -0.04, -0.09, NSE(Nash and Sutcliffe Efficiency)는 0.52, 0.96, RMSE(Root Mean Square Error)는 1.80 mm/day, 0.67 × 10⁶㎥로 분석되어 신뢰성 있는 모의 결과를 보였다. 보정된 SWAT 모형으로 가뭄 사상이 반영된 기후변화를 모의하기 위하여 APCC의 26개 CMIP5 GCM 시나리오를 SPI (Standardized Precipitation Index)와 연속 이론(Runs theory)으로 분석하여 6개의 극한 가뭄 시나리오 (RCP 4.5, 8.5 CMCC-CM, INM-CM4, IPSL-CM5A-MR)를 선정하였으며, 선정된 시나리오를 모형에 적용하여 가뭄 사상을 반영한 보령댐의 미래 내한능력을 평가하였다. 내한능력평가 및 분석 기간은 Historical(1980~1999; 1990s), Present(2000~2019; 2010s), 그리고 미래 기간 (2020~2039; 2030s, 2040~2059; 2050s, 2060~2079; 2070s, 2080~2099; 2090s)으로 나누었으며, 취약성(Reliability), 회복성(Resilience), 위험성(Vulnerability), 세 가지 지표로 내한능력 평가를 수행하였다. 평가 결과, 미래 취약성은 2050s IPSL-CM5A-MR 시나리오에서 0.803까지 감소하였으며, 회복성과 위험성은 2070s IPSL-CM5A-MR 시나리오에서 0.003, 3,567.6 × 10⁶㎥까지 감소하였다.

• Journal of the Korean GEO-environmental Society
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• v.15 no.2
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• pp.5-15
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• 2014

Target reliability index in the limit state design indicated the safety margin and it is important to determine the partial factor. To determine the target reliability index which is needed in the limit state design, the six design and construction case histories of gravel compaction piles (GCP) were investigated. The limit state functions were defined by bulging failure for the major failure mode of GCP. The reliability analysis were performed using the first order reliability method (FORM) and the reliability index was calculated for each ultimate bearing capacity formulation. The reliability index of GCP tended to be penportional to the safety factor of allowable stress design and average value was ${\beta}$=2.30. Reliability level that was assessed by reliability analysis and target reliability index for existing structure foundations were compared and analyzed. As a result, The GCP was required a relatively low level of safety compared with deep and shallow foundations and the currd t reliability level were similar to the target reliability in the reinforced earth retaining-wall and soil-nailing. Therefore the target reliability index of GCP suggested as ${\beta}_T$=2.33 by various literatures together with the computed reliability level in this study.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.890-898
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• 2022

Dispersion of suspended sediment, caused by coastal and marine development, is a key item in assessing marine environmental impact as it adversely affects marine life by increasing the level of turbidity and decreasing the amount of sunlight in seawater. However, its estimation has not been reliable because of the absence of a standard for the data measurement and divergent approaches to the impact assessment. In this study, we examined the estimation models from 58 Marine Environmental Impact Statements (MEISs, 2012-2014) to identify the gaps in the assessment and devise ways of improving the estimation. We developed four index items-grid system; unit load, particle size, and settling velocit-to evaluate their reliability in the estimation. The mean reliability score of each index was overall low-25 for grid system, 60 for unit load, 34 for particle size, and 17 for settling velocity. To ensure high reliability, it is important to develop a standard guideline that defines precise measurement of suspended sediment for unit load and settling velocity by particle size, followed by a grid system with compatible size for modelling. This can improve the estimation and thus underlie coherent impact assessment of suspended sediment dispersion on marine environment.

• Analytical Science and Technology
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• v.24 no.6
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• pp.503-509
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• 2011

Specific surface area is becoming a very important factor when newly developed advanced nano-materials are evaluated. But there have been many differences in results when measuring specific surface areas, depending on the measuring equipments and analysis method. To verify the reliability of the specific surface area measurement device supplied within the country, Round Robin Test (RRT) has been done at 21 affiliated research institutes. As a result, it was found that several institute had problems in measuring of gas adsorption amount in measuring equipment, and this proved the need for certified reference material (CRM). Furthermore, it was also found that the results from BET analysis is easily swayed by the analyst's subjectivism, and the calculated results may differ up to 16% in case of CRM I depending on the selection range of BET analysis. So this showed that a standard guideline for BET constant C value and fitting correlation coefficient R is needed, to properly select range in BET analysis. The experience in RRT, distribution of CRM, and standardized procedure would result in improved reliability in industrial processes, and thus, would contribute to the quality management, the productivity improvement, the safety evaluation, and the new material development.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.4
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• pp.113-123
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• 2018

The purpose of this research is to develop evaluation indicators forperformance improvement of horticultural therapy garden. In order to achieve a therapeutic purpose, the gardening activity held by the trained horticultural therapist. Moreover, horticultural therapy is 'a medical model' for the treatment and basic premise of the research was set, as horticultural therapy garden is characterized area to support activities of patients and horticultural therapist functionally and efficiently. For this study, three times of Delphi and AHP techniques were proceeded to export panels who were recruited by purposive sampling. Through these techniques, it was possible to deduct the evaluation indicator which maximizes the performance of the horticultural therapy garden. The evaluation items were prioritized by typing and stratification of the indicator. The results and discussions were stated as followings. Firstly, a questionnaire of experts was conducted to horticultural therapists and civil servants who were in charge of horticultural therapy. As results(horticultural therapists: 87.8%, civil servants: 75.2%), It is possible to conclude that both positions have the high recognition and agreed on the necessity of horticultural therapy. Secondly, Delphi investigation was conducted three times in order to develop the evaluation indicator for performance evaluation. After Delphi analysis, total 34 of evaluation elements to improve the performance of the horticultural therapy garden by reliability and validity analysis results. Thirdly, AHP analysis of each evaluation indicator was conducted on the relative importance and weighting. Moreover, the results showed 'interaction between nature and human' as the most important element, and in order of 'plan of the program', 'social interaction', 'sustainable environmental', and 'universal design rule', respectively. On the other hand, the exports from the university and research institute evaluated the importance of 'interaction between nature and human', while horticultural therapists chose 'plan of the program' as the most important element. Fourthly, the total weight was used to develop weight applied evaluation indicator for the performance evaluation of the horticultural therapy garden. The weight applying to evaluation index is generally calculated multiply the evaluation scores and the total weight using AHP analysis. Finally, 'the evaluation indicator and evaluation score sheet for performance improvement of the horticultural therapy garden' was finally stated based on the relative order of priority between evaluation indicators and analyzing the weight. If it was deducted the improvement points for the efficiency of already established horticultural therapy garden using the 'weight applied evaluation sheet', it is possible to expand it by judging the importance with the decision of the priority because the item importance decided by experts was reflected. Moreover, in the condition of new garden establishment, it is expected to be helpful in suggesting ways for performance improvement and in setting the guidelines by understanding the major indicators of performance improvement in horticultural therapy activity.