• Journal of the Korea Concrete Institute
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• v.28 no.3
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• pp.267-278
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• 2016

In this study, the ultimate strength of 335 simply supported reinforced concrete beams with shear span-to-effective depth ratio of less than 3 was evaluated by the ACI 318-14's strut-tie model approach implemented with the indeterminate strut-tie models and load distribution ratios of the companion paper. The ultimate strength of the beams was also estimated by using the experimental shear strength models, the theoretical shear strength models, and the current strut-tie model design codes. The validity of the proposed strut-tie models and load distribution ratios was examined by comparing the strength analysis results classified according to the prime design variables of the shear span-to-effective depth ratio, flexural reinforcement ratio, and compressive strength of concrete.

• Korean Journal of Construction Engineering and Management
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• v.14 no.5
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• pp.131-143
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• 2013

There is the difference of criteria to apply guidelines among the project participants and to depend on the purpose of utilizing BIM models, although modeling criteria are basically provided through BIM guidelines. Therefore, it is quite important to check compliance with guidelines to raise quality of the BIM model. But Quality Checking (QC) items and method for BIM model modeled in accordance with guidelines is not provided. This study suggested QC items and Rule Specifications(RS) for automatic QC. First of all, QC items were derived by analyzing domestic BIM guidelines and a process for structuring natural language is conducted by utilizing flowchart and pseudocode. So, by combining them, RS was suggested. Finally, RS-based case study was conducted by implementing automatic QC process with solibri model checker$^{TM}$. This study will contribute to the improvement of design quality and completeness of BIM model including huge data of 3 dimension. Furthermore, it is necessary to develop BIM guidelines according to the use case and to provide detailed process and standard for QC of BIM model.

• Land and Housing Review
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• v.14 no.1
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• pp.135-144
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• 2023

LH Corporation uses the construction waste disposal fee standard, of which the model was developed a long time ago. Therefore, this model is problematic because it needs to reflect waste treatment facilities' technological development and environmental conditions. In this study, the estimated manpower and costs required for the process operation of waste treatment facilities were analyzed, followed by the proposed estimation criteria. This improved standard model can be used as a cost calculation standard for the recycling and treatment of construction waste in public institutions. The study also suggests that an increase in waste treatment costs is needed.

• Journal of Korean Society of Steel Construction
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• v.28 no.3
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• pp.195-202
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• 2016

In this study, it is carried out to analyze the international design standards such as Eurocode 8, API 650, NZSEE and etc for the seismic design of steel liquid storage tanks. From the comparison and analysis, the data for the required parameters and factors are provided for the establishment of Korean seismic design standard for steel liquid storage tanks. The simplified mechanical models have been presented for the seismic design of steel liquid storage tanks in all design standards and the parameters of mechanical models in design standards have similar values. Although the models for the seismic design of steel liquid storage tanks are similar in design standards, design approaches are given differently in accordance with the design methods, allowable stress design or limit state design. Therefore it is not easy to compare seismic forces presented in design standards directly. After comparison of design standards, it is concluded that establishment of Korean design standard for the seismic design of steel liquid storage tanks is necessary.

• Proceedings of the KSRS Conference
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• 2008.03a
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• pp.207-212
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• 2008

연구에서는 SPOT-3 인공위성 영상으로부터 얻어진 영상 스테레오 스트립과 GCP(Ground Control Point)자료를 이용하여 다양한 GCP배치에 따른 궤도기반 센서모델의 정확성에 대해 분석하였다. 실험에 사용된 기준점자료는 춘천지역에서부터 나주지역에 이르기 까지 약 420km 길이의 지역에 대해 GPS측량을 통해 획득하였다. 궤도기반 센서모델에 적용된 미지수는 위성의 위치와 속도, 자세를 표현하는 방정식의 계수를 미지수로 선택하여 일곱 가지 방식으로 조합하였다. 실험은 우선 모델점의 위치를 일곱 가지 경우로 결정하고 각 경우에 대해 일정한 개수의 모델점을 선택하였다. 그리고 각 경우의 모델점의 위치에 대해 궤도기반 센서모델의 미지수 조합 모델을 각 각 다르게 적용해 본 후 그 결과를 시각적, 수치적으로 분석해 보았다. 실험 결과 모델점의 위치에 관계 없이 궤도기반 모델에 적용할 수 있는 높은 정확도를 나타내는 미지수 조합모델을 찾아낼 수가 있었고, 여러 가지 모델점의 위치를 궤도기반 센서모델에 적용해 본 결과 지리적, 시간적, 경제적 효율성을 갖는 최적의 미지수 조합을 찾을 수가 있었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.124-124
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• 2016

하천에서의 분변성대장균은 분변성 오염 정도를 나타내는 지표로서, 이 농도가 높을수록 오염된 하천수와의 접촉을 통한 호흡기, 소화기 및 피부 관련 질병의 발발 확률이 높다고 알려져 있다. 따라서 하천에서의 수영, 수상스키 등과 같은 입수형 친수활동을 할 때, 분변성대장균 농도가 농도 기준 이하인지를 확인하고 이러한 정보를 친수활동에 이용할 필요가 있다. 그러나 분변성대장균의 경우, 현재 자동수질측정망에서 측정되고 있는 다른 수질인자들과는 달리 실시간 측정이 불가능하다고 알려져 있다. 분변성대장균을 측정하는데 있어 최소 18시간 이상이 필요하며, 이러한 분변성대장균 측정 방식은 하천 이용자들이 안전한 친수활동을 영위하는데 있어 적절한 수질 정보를 제공하지 못한다. 그러므로 분변성대장균을 예측하는 모델을 개발하고, 이를 이용하여 실시간 분변성대장균 정보를 생성하여 하천 이용자들에게 제공할 필요가 있다. 본 연구에서는 친수활동이 활발하게 이루어지는 곳 중 하나인 북한강의 대성리 지점에 대해 데이터 기반 모델을 이용하여 분변성대장균을 예측하였다. 데이터 기반 모델은 물리 기반 모델에서 필요한 지형데이터나 비점오염원 등의 초기 오염물의 양에 대한 데이터를 필요로 하지 않고, 대신 독립변수로 사용되는 기상 및 수질데이터를 필요로 한다. 이러한 기상 및 수질데이터는 기존 기상관측소, 수질관측소에서 매일 자동으로 측정되기 때문에 데이터 기반 모델은 물리 기반 모델에 비해 입력데이터를 구성하기가 쉽다는 장점을 지닌다. 이러한 데이터 기반 모델 중 분류 모델은 회귀 모델과 달리 분변성대장균 농도가 일정 수질기준 이상을 넘는지를 바로 예측할 수 있다. 본 연구에서는 분류 모델 중 높은 예측력을 가진다고 알려진 랜덤포레스트(random forest) 기법을 이용하여 분변성대장균 예측 모델을 개발하였다. 분변성대장균 예측 모델은 주어진 기상 및 수질 조건에 대해 분변성대장균이 200 CFU/100ml가 넘는지를 예측하였다. 예측된 분변성대장균이 기준을 넘는 경우를 2등급, 넘지 않는 경우를 1등급으로 명명하였다. 모델을 개발하기 위하여 북한강 대성리 인근 측정소에서 2010년부터 2015년까지 측정된 기상 및 수질데이터를 수집하였다. 수집한 데이터를 훈련 및 검증데이터로 샘플링하였으며, 이 때 샘플링한 데이터가 기존 데이터가 가지고 있던 등급별 비율을 유지하기 위하여 층화샘플링을 하였다. 본 연구에서는 샘플링에 의한 불확실성을 줄이기 위하여 랜덤하게 50번 샘플링된 각각의 훈련데이터에 대해 모델을 개발하였다. 50개의 모델의 검증 결과를 종합한 결과, 전체 예측률은 0.139로 나타났다.

• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.891-898
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• 2022

Purpose: There is not much time left for mandatory BIM implementation for all sectors and stages of the construction industry. Therefore, it is necessary to find a way to secure technology to substantially improve the productivity of BIM work. In the research, we proposed a method to automatically verify related construction standards for major objects produced by BIM modeling procedures so that engineers can verify construction standards in the BIM-based design process. Method: We defined a modeling work procedure for BIM-based road design work and prepared a method for constructing related design standards in a database. In addition, a process map for developing a BIM-based design basis review automation system was also presented. Result: A BIM-based design standard review automation module was developed using Civil3D and Dynamo. And it was confirmed by the test application that it is possible to quickly judge whether the BIM object manufactured in the design process conforms to the construction design standard. Conclusion: BIM-based design standard review automation technology can improve the productivity of BIM model production work and secure the quality of the BIM model.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.6_2
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• pp.613-623
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• 2007

The main purpose of this study is to investigate the coordinate transformation based on two different systems between local geodetic datum(tokyo datum) and international geocentric datum(new Korea geodetic datum). For this purpose, three methods were used to determine seven parameters as follows: Bursa-Wolf model, Molodensky-Badekas model, and Veis model. Also, we adopted multiple regression equation method to convert from Tokyo datum to KTRF. We used 935 control points as a common points and applied gross error analysis for detecting the outlier among those control points. The coordinate transformation was carried out using similarity transformation applied the obtained seven parameters and the precision of transformed coordinate was evaluated about 9,917 third or forth order control points. From these results, it was found that Bursa-Wolf model and Molodensky-Badekas model are more suitable than other for the determination of transformation parameters in Korea. And, transforming accuracy using MRE is lower than other similarity transformation model.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.2
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• pp.137-145
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• 2005

In this paper, we investigate the accuracy of various sensor models developed for linear pushbroom satellite images. We define the accuracy of a sensor model in two aspects: the accuracy of bundle adjustments and the accuracy of estimating exterior orientation parameters. The first accuracy has been analyzed and reported frequently whereas the second accuracy has somewhat been neglected. We argue that the second accuracy is as important as the first one. The second accuracy describes a model's ability to predict satellite orbit and attitude, which has many direct and indirect applications. Analysis was carried out on the traditional collinearity-based sensor models and orbit-based sensor models. Collinearity-based models were originally developed for aerial photos and modified for linear pushbroom-type satellite images. Orbit-based models have been used within satellite communities for satellite control and orbit determination. Models were tested with two Kompsat-1 EOC scenes and GPS-driven control points. Test results showed that orbit-based models produced better estimation of exterior orientation parameters while maintained comparable accuracy on bundle adjustments.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.4
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• pp.60-70
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• 1999

In this paper, model reference adaptive fuzzy controller (MRAFC) was proposed in order to overcome the difficulty of extracting rules and defects of the adaptation performance in the FLC. MRAFC comprised inner feedback loop consisting of the FLC and plant, and outer loop consisting of an adaptation mechanism which was designed for tuning a control rule of the FLC. A reference-model was used for design criteria of a fuzzy controller which characterizes and quantizes the control performance required in the overall control system. Tuning control rules of FLC is performed by the adaptation mechanism. The performance of proposed algorithm was verified through experiment for the DC servo motor.