• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.1
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• pp.61-71
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• 2010

The attributes related to the health condition of RC deck slabs are analyzed to help us identify and rate the safety level of the bridges in this study. According to the related reports the state assessment for the outward aspects of bridges is the important and critical part for rating the overall structural safety. In this respect, the careful identification for the various state attributes make the field inspection and structural diagnosis very effective. This study analyzes the influence of the state attributes on evaluation classes and the relationship of them by the inductive reasoning, which raise the understanding and performance for evaluation work, and support the logical approach for the state assessment. ID3 algorithm applied to the case set which is constructed from the field reports indicates the main attributes and the precedence governing the assessment, and derives the decision hierarchy for the state assessment.

• The Journal of the Korea Contents Association
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• v.19 no.8
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• pp.399-411
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• 2019

TV Broadcasting is an undeniable cultural medium. TV Broadcasting Station needs a long-term perspective that suits cultural media and an aggressive cultural and artistic program development strategy that matches rapidly changing culture and technology. Of course, production staff should be composed of experts in the field as well as cultural artists. This paper is researching the promotion strategy of TV Arts programs by substituting the three keywords - the U.S., the public broadcasting station(TV) and Arts programs. And through case studies and analyses of PBS TV's "Art in the 21st Century" series, the way the public TV broadcasting station shares cultural arts with viewers is extracted. It raises the question of how the U.S. TV public broadcaster's cultural and artistic programs are different from South KOREA's. Through the above research, let's find a clue to the future direction of how the new media, now represented as Korea's blacklist, should recognize, foster, educate and strategize Fine Arts.

• Journal of the Society of Disaster Information
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• v.18 no.2
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• pp.306-313
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• 2022

Purpose: The purpose of this study is suggested to improve upon current existing methods of ammonia chemical accident prevention and damage reduction. Method: Ammonia is one of the most common toxic substances that causes frequent chemical accidents. And it was selected as leakage materials according to statistics on chemical accident. Based on actual cases of chemical accidents, CARIS modeling was used to compare the damage impact range of Ammonia and HCl and Cl. Also, find out problems with the current systems. Result: As a result of find out the range of accident influence that spreads to the surroundings when an ammonia chemical accident, it was longer than the range of influence of hydrochloric acid and shorter than that of chlorine. In addition, it was found that when chemical accident by ammonia, hydrochloric acid, or chlorine, there are apartments and schools, which can have an effect. Conclusion: It is decided that it is necessary to determine whether or not chemical accident prevention management plans and statistical investigations are submitted for workplaces dealing with ammonia, and detailed guidelines and reviews are necessary. In addition, it is judged that it is necessary to establish a DB for ammonia handling plants, and it is considered that information sharing and joint inspection among related organizations should be pursued.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.67-74
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• 2021

Domestically, technical condition evaluation for breakwaters has been conducted through safety checks and safety diagnosis. If necessary, maintenance for the facility is conducted. However, in recent years, the need for infrastructure management has been increasing from a life-cycle-cost perspective. For these reasons, the "Sustainable Infrastructure Management Basic Act" was enacted. Previously, only the technical part of the breakwaters was evaluated. However, based on the act, comprehensive management of breakwaters will be possible through performance improvement by adding economic and political evaluations. In this study, evaluation factors and evaluation methods were developed for a breakwater rehabilitation project. The purpose of this study is to present a development direction, items, and methods for the evaluation of breakwater performance improvement to be applied in future practice. This study reviews the concept of maintenance and performance improvement, the literature related to performance improvement, and the project type for the common standard of performance improvement. Evaluation items and evaluation methods for breakwater rehabilitation are suggested to be reviewed by experts. The methodology suggested in this study could be used for preventive maintenance and to reduce accidents.

• Journal of Service Research and Studies
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• v.13 no.3
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• pp.105-126
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• 2023

The domestic used car market continues to grow along with the used car online platform service. The used car online platform service discloses vehicle specifications, accident history, inspection history, and detailed options to service consumers. Most of the preceding studies were predictions of used car prices using vehicle specifications and some options for vehicles. As a result of the study, it was confirmed that there was a nonlinear relationship between used car prices and some specification variables. Accordingly, the researchers tried to solve the nonlinear problem by executing a Machine Learning model. In common, the Regression based Machine Learning model had the advantage of knowing the actual influence and direction of variables, but there was a disadvantage of low Cost Function figures compared to the Decision Tree based Machine Learning model. This study attempted to predict used car prices of six domestic brands by utilizing both vehicle specifications and vehicle options. Through this, we tried to collect the advantages of the two types of Machine Learning models. To this end, we sequentially conducted a regression based Machine Learning model and a decision tree based Machine Learning model. As a result of the analysis, the practical influence and direction of each brand variable, and the best tree based Machine Learning model were selected. The implications of this study are as follows. It will help buyers and sellers who use used car online platform services to predict approximate used car prices. And it is hoped that it will help solve the problem caused by information inequality among users of the used car online platform service.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.305-305
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• 2023

수문조사기기 검정은 강수량, 수위, 유량 등과 같은 수문자료를 관측하는 수문조사기기가 대상지역의 수문상황을 정확하게 관측하는지를 검사하는 일련의 과정으로 「수자원의 조사 계획 및 관리에 관한 법률」 제12조에 법적 기반을 두고 있다. 검정 대상은 강수량, 수위, 유속, 유사량, 토양수분량, 증발산량, 증발량 측정기기 총 7종이며, 환경부장관으로부터 한강홍수통제소가 검정업무를 위임받고, 한국건설기술연구원과 한국수자원조사기술원이 위탁받아 운영중에 있다. 최근에는 증발산량, 토양수분량 및 유량 측정기기기 등이 첨단화되어 기존 검정 방식에 대한보완 및 신설에 대한 요구가 증가하고 있다. 특히, 유량 측정시 기존에 사용하였던 회전식 유속계는 ADCP(Acoustic Doppler Current Profiler) 유량측정기기로 대체되어 활용률이 2013년 24%에서2021년 67%로 약 2.8배 급격히 증가하였다. 하지만 수문조사기기 검정 관련 고시 내 ADCP에 대한검사방법 및 허용오차 등의 규정이 부재하여 수문조사기기의 검정 공백이 발생하는 등의 문제가 존재하고 있다. 이에 본 연구에서는 ADCP 운영 및 기술 현황, 현행 법령, 국외 사례 등을 검토하여 ADCP 유량측정기기의 검사방법 및 허용오차에 대한 방안을 제시하고자 한다. ADCP 검사방법은 총 5단계로 외관검사, 자가진단 검사, 온도센서 검사, 수심측정 검사, 유량비교측정 검사에 따라 검정을 실시한다. 첫 번째 외관검사시에는 기기 외관과 센서 등 물리적 손상을 점검하고, 두 번째 자가진단 검사에서는 센서 변환 매트릭스 값, 수신부 센서 테스트, RAM/ROM 테스트, 통신 테스트 등에 관한 정상값 산출 여부를 확인한다. 세 번째 온도센서 검사에서는 검증용 온도센서를 이용한 값과 ADCP에 부착된 온도센서 값과 차이를 확인하고 ±2℃초과시 재검사 또는 적절한 조치를 취한 후 다음 단계의 검사를 진행한다. 네 번째 수심측정 검사에서는 수조 내 수심 측정을 확인하여 실제 수심과의 오차를 확인하고 ±1% 초과시 재검사 또는 적절한 조치 후 다음 검사를 실시한다. 유량비교 측정검사에서는 각 기기 간의 평균유량의 상대오차를 평가하는 것으로 ±5%미만에는 합격, ±5이상 ±10%미만에서는 재검사, ±10%이상에서는 공장수리를 권고하도록 하고, 1~5 단계의 검사를 통과한 기기를 대상으로 인증서를 발급하도록 한다. 유량비교 측정검사시에는 매년 ADCP를 사용하는 일반기업 및 공공기관 등이 모여 ADCP의 성능을 상호간 비교하는 'ADCP 기술협력 워크숍'을 확장하여 실시할 수 있다. 각 검사 단계의 허용오차는 USGS 또는 제조사 기준과 2022년 ADCP 기술협력 워크숍 성능검사 분석 결과를 토대로 하였다. 본 ADCP 검정 방안은 향후 ADCP 모델별로 단계별 시범 검토를 통해 세부사항에 대한 제시가 필요하며, 온도센서 검사, 수심측정 검사, 유량 비교측정검사에 대한 허용오차에 대한 타당성에대한 검증 및 검토가 이루어져야 할 것으로 사료된다.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.3
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• pp.19-31
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• 2022

Currently, the role of public accelerators in the domestic accelerator market is gradually expanding. Accordingly, in order to establish relevant policies properly, it is necessary to check the effect and validity of public accelerators' investment. However, there is no quantitative research conducted on domestic accelerators, using their financial data, as domestic accelerators have a short history and quantitative data on them are not disclosed. Therefore, this study conducted an empirical analysis with financial data of the startups that received equity investments from public accelerators to confirm the effect of public accelerators'investment in startups. A regression analysis was conducted with financial data from 112 startups that acquired investments from public accelerators in the period of 2016~2020. And the findings are as follows: First, it was found that the initial investment of public accelerators had an effect on the growth and profitability of startups. Specifically, it was confirmed that the initial investment of public accelerators had a positive (+) effect on sales growth rates and total asset growth rates, which are growth indicators. Second, it was found that the joint investment of public accelerators had a significant positive (+) effect on profit margin, an indicator of profitability, rather than on growth. Therefore, it is deemed that it will be a great force for growth if investment in the early-stage startups that showed significant investment results in this study is continuously expanded in combination with support projects, which are a strength of public accelerators. Since this study has confirmed the investment effect of public accelerators, it is deemed necessary to actively promote policies that direct public accelerators' projects toward improving the performance of startups through joint investment with the private sector and supplementing private accelerators' deficiencies.

• Journal of Service Research and Studies
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• v.14 no.1
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• pp.27-43
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• 2024

The market share of online platform services in the used car market continues to expand. And The used car online platform service provides service users with specifications of vehicles, accident history, inspection details, detailed options, and prices of used cars. SUV vehicle type's share in the domestic automobile market will be more than 50% in 2023, Sales of Hybrid vehicle type are doubled compared to last year. And these vehicle types are also gaining popularity in the used car market. Prior research has proposed a used car price prediction model by executing a Machine Learning model for all vehicles or vehicles by brand. On the other hand, the popularity of SUV and Hybrid vehicles in the domestic market continues to rise, but It was difficult to find a study that proposed a used car price prediction model for these vehicle type. This study selects a used car price prediction model by vehicle type using vehicle specifications and options for Sedans, SUV, and Hybrid vehicles produced by domestic brands. Accordingly, after selecting feature through the Lasso regression model, which is a feature selection, the ensemble model was sequentially executed with the same sampling, and the best model by vehicle type was selected. As a result, the best model for all models was selected as the CBR model, and the contribution and direction of the features were confirmed by visualizing Tree SHAP Value for the best model for each model. The implications of this study are expected to propose a used car price prediction model by vehicle type to sales officials using online platform services, confirm the attribution and direction of features, and help solve problems caused by asymmetry fo information between them.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.1
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• pp.47-56
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• 2010

At present, 265 national food waste recycling facilities have been operated by public facilities 95 and private facilities 160. it has continuously installed a food waste treatment facility from 1997. The government set up and implemented guidelines and inspection standards for the installation and operation of the facilities. However, unclear detailed examination items, designs and process standards for the installation procedures of the facilities are causing problems due to the unskilled operation management system, decrease in efficiency and defects of a facility. This study conducted mail and site surveys on 95 public food waste recycling facilities that it suggest the ways to operate facilities which minimize problems. At the result of investigation, a pre-treatment facility was not installed 2 systems(2 inputting facilities) and hopper covers and food was overloaded. also the transportation amount was excessive. In case of a main treatment facility, the secondary environmental pollution was caused by inexperienced operation and the efficiency of the facility was reduced due to excessive input of food. also the operation management standards of the facilities were inappropriate. The odor and food waste leachate treatment facility is investigated as problems that are unskilled operation, lack of regular inspection and inappropriate capacity of the treatment facility. Based on the problems found through the investigation, it suggested some ways of efficient operation. this study might contribute to minimize mistakes and defects and improve the efficiency of install and operation course of food waste recycling facilities through finding.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.5
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• pp.112-124
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• 2021

This study was conducted to examine and analyze local governments, park status, project characteristics, and the implementation in detail for private park special projects across the country as a means of responding to the sunsetting of urban parks. As a result of the analysis, first, the private park special project, was found to be mainly implemented in cities with a population of more than 100,000, so there was a limit to the application on military installations or in local small cities. Therefore, rather than applying the special system collectively, it was judged that institutional flexibility, considering the characteristics and size of local government, was needed. Second, the current special projects by the park creation donation collection method shows monotonous development centered on apartment houses, so it is necessary to diversify the development by introducing a park preservation method that purchases and donates park sites. Third, it was found that the area standard needs to be eased to less than 50,000m² to include parks with high utilization and good accessibility in urban areas of large cities, as the type and area of parks are limited. Fourth, most special projects are mountain parks, which are feared to damage the natural terrain and skyline, so separate ordinances should be established and applied, and development approaches should be made to allow nature and parks to coexist with the setting of detailed building guidelines for each type of facility. The guidelines should include, first, after the nationwide private park special projects are completed, standards for appropriate returns for similar projects should be established, institutional standards such as the recovery of excess profits should be established, and environmental reviews should be conducted. Second, it was found that local governments should institutionalize the composition of private consultations to promote the efficient management of projects through a cooperative system, and third, a roadmap for maintenance after the donation of special parks should be established.