• Journal of Internet Computing and Services
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• v.24 no.5
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• pp.107-120
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• 2023

The public bicycle of Seoul, Ttareungyi, was launched at October 2015 to reduce traffic and carbon emissions in downtown Seoul and now, 2023 Oct, the cumulative number of user is upto 4 million and the number of bike is about 43,000 with about 2700 stations. However, super growth of Ttareungyi has caused the several problems, especially demand/supply mismatch, and thus the Seoul citizen has been complained about out of stock. In this point, this study conducted a real time demand forecasting model to prevent stock out bike at stations. To develop the model, the research team gathered the rental·return transaction data of 20,000 bikes in whole 1600 stations for 2019 year and then analyzed bike usage, user behavior, bike stations, and so on. The forecasting model using machine learning is developed to predict the amount of rental/return on each bike station every hour through daily learning with the recent 90 days data with the weather information. The model is validated with MAE and RMSE of bike stations, and tested as a prototype service on the Seoul Bike Management System(Mobile App) for the relocation team of Seoul City.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.363-369
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• 2008

Change is inevitable and is a reality of construction projects. Change adjustment includes the cost associated with materials, labor, etc. However, the actions of a contractor can cause a loss of productivity and furthermore can result in disruption of the whole project because of a cumulative or ripple effect. Because of its complicated nature, it becomes a complex issue to determine the cumulative impact (ripple effect) caused by single or multiple change orders. Furthermore, owners and contractors do not always agree on the adjusted contract price for the cumulative impact of the changes. What is needed is a reliable method to identify and quantify the loss of productivity caused by cumulative impact of change orders. This study survey the change orders data in domestic area for public construction and analyze to quantify change order impact. This study developed concepts of "%CO", "%Delta", "%T" to capture change order effect on project and search the relationships between them. Finally, this study find strong relationship between change order and loss.

• Journal of Korean Society of Archives and Records Management
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• v.9 no.1
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• pp.175-196
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• 2009

The government and public institutions are conducting public-opinion surveys as means of drawing the scientific policy decisions throughout the country's whole sectors ; society, culture, welfare, education, etc. The Government Survey Data have been under management by each governmental department, but the improper ways of data collection and management have led to omissions and losses of some data. Also there are limitations on the statistic usage and access to the data due to the fact that the data are managed dispersedly in the form of printed materials. Accordingly, to make the survey data available for the long-term preservation and usage, this study suggests collection policy, standard of evaluation, metadata, the procedure and method of converting materials, preservation format.

• Journal of Korean Society of Archives and Records Management
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• v.21 no.1
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• pp.41-56
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• 2021

This study aims to analyze the court ruling on "Inter-Korean Summit Meeting Minutes Deletion," identify how the established requirements, concept, and scope for the records prescribed in the Public Records Management Act are applied in actual cases, and summarize the future tasks. It analyzes the "approval theory" as the point of establishment for records by the ruling means and how the meaning of approval is determined, and examines the difference between the e-jiwon System and the On-Nara System to understand the meaning of ruling clearly. Moreover, it analyzes how the "Invalidity of Public Documents Crime" in Article 141 in the Criminal Act influences record management. Based on such comprehensive case analyses, the study proposes what tasks the administrative agencies such as the National Archives of Korea and the Ministry of the Interior and Safety should perform.

• Korean Journal of Construction Engineering and Management
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• v.2 no.2 s.6
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• pp.90-97
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• 2001

The paper considers non-deterministic methods of analysing the risk exposure in a cost estimate. The method(referred to as the 'Monte Carlo simulation' method) interprets cost data indirectly, to generate a probability distribution for total costs from the deficient elemental experience cost distribution. The Monte Carlo method is popular method for incorporating uncertainty relative to parameter values in risk assessment modelling. Non-deterministic methods, they are here presented as possibly effective foundation on which to risk management in cost estimating. The objectives of this research is to develop a computerized algorithms to forecast the probabilistic total construction cost and the elemental work cost at the planning stage.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.305-305
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• 2020

2019년 10월에 발생한 태풍 미탁은 강원도 삼척시 근덕면 궁촌리 기준 시간당 최대 129mm/hr, 누적강수량 488.5mm를 기록하며 폭우와 강풍, 홍수, 토석류 및 산사태로 사망 13명, 실종 2명, 이재민 910세대 1,442명의 인명피해와 공공시설 1,835건, 사유시설 3,700건 등의 재산 피해가 발생하였다. 한편 Hyper KANAKO 모형은 일본에서 개발된 토석류 수치 모델로 오픈소스인 QGIS와 연동되어 도구의 형태로 사용할 수 있어 사용자에게 편리함을 제공하고 토석류 해석 시 침식 및 퇴적작용의 해석이 가능하다. 1차원의 지형(계류)과 2차원의 지형(퇴적부)의 지반설정과 사방댐의 종류(Closed, Slit, Landslide) 및 개수, 위치, 높이 등을 쉽게 조절할 수 있다는 장점이 있다. 또한, DEM을 기반으로 변환 프로그램을 사용하여 구축한 자료인 LP(Laser Profiler) 데이터를 바탕으로 3차원의 지형을 볼 수 있어 2차원의 지형보다 사용자의 직관적인 해석이 가능하다. 본 연구에서는 QGIS와 Hyper KANAKO를 이용하여 태풍 미탁으로 토석류 피해가 발생한 강원도 삼척시 신남지역을 대상으로 DEM과 LP 데이터를 구축하고 수치모델링을 실시하여 현장조사 결과와 비교분석 하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.906-909
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• 2015

ITSM(IT Service Management)은 2000년대 중반 이후 기업 및 공공기관에 본격적으로 적용되기 시작하였다. ITSM의 한 부분으로 IT 조직에서는 외주업체와 SLA(Service Level Agreement)을 체결하여 정보시스템 서비스의 품질을 적정수준으로 관리토록 노력하고 있다. 그러나 SAL를 적용하는 서비스 측정항목을 선택하는데 있어 측정이 비교적 용이한 서버 운영시간, 서버 성능, 서비스 가동률 등 서버운영에 주로 초점이 맞춰져 왔다. 응용시스템에 대한 서비스 요청 적기 처리율, 변경요청 적기 처리율 등에 대해서는 고객과 외주업체의 협의요소 증가, 데이터 관리 및 정확성 부족 등으로 SLA 항목에서 제외되어 왔다. 본 논문에서는 응용시스템의 유지보수 관련 SLA 적용에 초점을 맞춰 서비스데스크 구축방안을 제시하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1350-1353
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• 2010

최근, 스마트폰 등 무선랜 이용가능 단말기의 출시와 저렴한 무선 AP(Access Point) 보급 확대로 무선랜 이용이 급속히 확대되고 있다. 그동안 국내 무선인터넷 환경은 이동통신사가 구축한 고비용 폐쇄적 3G 네트워크의 데이터 통신 위주로 이루어졌으며, 무선랜 이용은 일부 기업환경 및 호텔/식당 등의 고객용 무선랜, 개인용 무선랜 등으로 한정되어 사용되었다. 하지만 '10년 스마트폰의 폭발적인 확산으로 무선랜을 통해 빠르고 저렴하게 무선 인터넷을 사용할 수 있게 됨에 따라 가정, 공공시설 등에서 무선랜 구축/활용이 매우 증가하고 있다. 논문은 무선랜에 대한 물리적, 기술적, 관리적 보안위협을 살펴보고 구축, 관리, 이용 주체별 대응방안을 제시한다.

• Korean Journal of Construction Engineering and Management
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• v.18 no.6
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• pp.13-25
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• 2017

Apartments are a major type of residence and their number has continuously increased. Apartments have multiple meanings in that for public they are not only for residence purpose but for investment, a major commodity for construction firms and a critical policy measure of public well-fare for the government. Therefore, it is critical to understand and analyze trends in apartments demand for pro-active actions. The objective of the study is to analyze and identify key trends in apartments demand based on big data drawn from articles of major daily newspapers. The study identifies 17 major trends from seven themes including development, trade, sale in lots, location requirements, policy, residential environment, and investment and profit. The research methods in the study can be usefully applied to further studies for various issues in relation to the construction industry.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.513-516
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• 2008

The risk in the constructions projects is extremely diverse because there are too many indefinite factors. Therefore, Performance Measurement Baseline(PMB) is needed regularly during the construction process. However, nowdays, the PMB in the constructions projects is for contractors' PMB and Performance Management(PM). Clients have a lot of difficulties to control and manage the projects. Therefore, this paper classifies schedule and cost data of the public apartments houses which is a actual cases into types and then conducts regression analysis and deduces a regression. In addition to this paper establishes the Work Breakdown Structure(WBS) and suggests the PMB for the clients through using that.