• Title/Summary/Keyword: Selecting Construction Methods

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Optimum design of steel space truss towers under seismic effect using Jaya algorithm

  • Artar, Musa;Daloglu, Ayse T.
    • Structural Engineering and Mechanics
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    • v.71 no.1
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    • pp.1-12
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    • 2019
  • This study investigates optimum designs of steel space truss towers under seismic loading by using Jaya optimization algorithm. Turkish Earthquake Code (2007) specifications are applied on optimum designs of steel space truss towers under the seismic loading for different local site classes depending on different soil groups. The proposed novel algorithm does not have any algorithm-specific control parameters and depends only a simple revision equation. Therefore, it provides a practical solution for structural optimization problems. Optimum solutions of the different steel truss examples are carried out by selecting suitable W sections taken from American Institute of Steel Construction (AISC). In order to obtain optimum solutions, a computer program is coded in MATLAB in corporated with SAP2000-OAPI (Open Application Programming Interface). The stress and displacement constraints are applied on the design problems according to AISC-ASD (Allowable Stress Design) specifications. Firstly, a benchmark truss problem is examined to see the efficiency of Jaya optimization algorithm. Then, two different multi-element truss towers previously solved with other methods without seismic loading in literature are designed by the proposed algorithm. The first space tower is a 582-member space truss with the height of 80 m and the second space tower is a 942-member space truss of about 95 m height. The minimum optimum designs obtained with this novel algorithm for the case without seismic loading are lighter than the ones previously attained in the literature studies. The results obtained in the study show that Jaya algorithm is a practical and robust optimization method for structural optimization problems. Moreover, incorporation of the seismic loading causes significant increase in the minimum design weight.

A Study on the Polarity of Apartment Price News Using Big Data Analysis Method (빅데이터 분석기법을 활용한 아파트 가격 관련 뉴스 기사의 극성 분석)

  • Cho, Sang-Yeon;Hong, Eun-Pyo
    • Journal of Digital Convergence
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    • v.17 no.9
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    • pp.47-54
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    • 2019
  • This study confirms the polarity of news articles on apartment prices using Opinion Mining which has widely been used for a big data analysis. The analyses were carried out utilizing internet news articles posted on the Naver for two years: 2012 and 2018. We proposed a sentiment analysis model and modeled a topic-oriented sentiment dictionary construction methods. As a result of analyzing the proposed sentiment analysis model, it was confirmed that there was a difference according to the tendency of the media companies in selecting social issues at the time of rising apartment prices. At the same time, we were able to find more affirmative articles in the media companies which share similar sentiment with the government in charge. In this paper, we proposed a sentiment analysis model that can be used in real estate field and analyzed the polarity of unformatted data related to real estate. In order to integrate them into various fields in the future, it is necessary to build the sentiment dictionaries by themes, as well as to collect various unformatted data over extended periods.

Development of a Virtual Reality-Based Physics Experiment Training Simulator Centered on Motion of Projectile (포물선 운동을 중심으로 한 가상현실 기반 물리 실험 교육 시뮬레이터 개발)

  • Kim, Yeon Jeong;Yun, Sei Hee;Shin, Byoung-Seok
    • KIPS Transactions on Software and Data Engineering
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    • v.10 no.1
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    • pp.19-28
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    • 2021
  • Recently, in the field of education, various attempts have been made to apply virtual reality technology to an educational field and use it as an educational medium. Accordingly, in the science subject area, it is necessary to simulate science experiments that can make various and active experiments out of various limitations such as space and situation by using virtual reality environment construction technology. In this study, after selecting a physics course from a science subject, an experimental simulation using a parabolic motion formula, one of physical phenomena, is implemented in a virtual space, and then used in actual physics education based on the learning standards of the STEAM theory. Prove this is possible. Through this, it was confirmed that a specific educational model using virtual reality space can be designed, and it shows that education can be conducted with more effective educational methods in various subjects of education through the combination of traditional educational model and modern technology. Regarding the results of the research, it suggests the possibility of future research plans and practical use in the educational field.

A Study on Environmental Impact Assessment Guidelines for Marine Environments in Harbor Construction Projects (항만건설사업의 해양환경 환경영향평가 가이드라인 개발 연구)

  • Maeng, Junho;Kim, Taeyun;Lee, Haemi
    • Journal of Environmental Impact Assessment
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    • v.31 no.3
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    • pp.141-160
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    • 2022
  • The harbor construction projects can lead to various marine environmental problems including habitat degradation and loss, marine water pollution, change of flow patterns, erosion, scour, sedimentation, and so on. The EIA is a measure to prevent various environmental problems in advance from examining and minimizing the environmental impacts before the proposed developments are implemented. In addition, institutions reviewing EIA reports have made efforts to conduct scientific and standardized EIA by applying EIA guidelines for each project. This study aims to create a EIA guideline focusing on the harbor construction projects. Based on the review comments of the harbor construction EIA reports for the past 13 years (2009-2021) and the EIA guidelines of different types of projects, we identified the marine environmental problems and provided the appropriate guideline. This guideline summarizes and presents the contents which must be reviewed in the baseline condition survey, impact assessment, mitigation, and post-environmental impact investigation in the fields of marine fauna and flora, marine physics, and marine water and sediment quality. In the case of a baseline condition survey of marine fauna and flora, a method for selecting survey points considering the characteristics of sea area and project was presented. When estimating the impact of marine fauna and flora, we presented methods for predicting the impact on them due to the spread of suspended sediments and the damage to benthic habitats due to dredging and reclamation. In consideration of the characteristics of the sea area, we divided the survey items of the marine physics into essential items and supplementary items. In predicting the impact of marine physics, various methods for major issues such as seawater circulation, suspended sediment and bottom sediment transport, water temperature and salinity diffusion, seawater exchange, wave transformation, harbor tranquility, and shoreline change were presented. The research results will contribute to protect the marine environment by inducing more systematic and scientific surveys, impact assessments, and mitigation in the EIA process.

Selecting Aquifer Artificial Recharge Methods Based on Characteristics of the Target Aquifer (주입대상 대수층의 특성을 고려한 인공함양 방법 선정 연구)

  • Lee, Yeoung-Dong;Shin, Dong-Min;Kim, Byeong-Jun;Kim, Gyoo-Bum
    • The Journal of Engineering Geology
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    • v.29 no.4
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    • pp.483-494
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    • 2019
  • This study aimed to determine the extent of artificial aquifer recharge and to evaluate appropriate recharge techniques based on field investigations and comparative analysis of each recharge method. Characteristics of the aquifer determine the target aquifer and the recharge method for artificial groundwater recharge. Electrical conductivity surveys, drilling, permeability tests, and grain-size analysis indicate that the hydraulic conductivity of weathered soil and weathered rock is higher than that of upper unconsolidated soil. Pumping tests indicate that the groundwater level was stable at a depth of 12 m until 9 hours of pumping, but after that it dropped again, indicating anisotropic aquifer characteristics. Three types of artificial recharge method were reviewed, including recharge wells, ditches, and ponds, and a combination of two methods is proposed: a recharge well system directly injecting into weathered soil and rock sections with good permeability, and an injection ditch that can increase the recharge effect by line-type injection in the upstream area. The extent of groundwater recharge by the selected methods will be evaluated through on-site tests and if their applicability is verified, they will contribute to securing water in areas of water shortage.

A study on the methods of identifying and verifying the causes of defects on rock bolt stressmeter and rod extensometer (터널계측용 록볼트축력계와 지중변위계의 불량원인 파악과 검증방법에 대한 연구)

  • Kim, Yeong-Bae;Noh, Won-Seok;Lee, Seong-Won;Jeon, Hunmin;Lee, Kang-Il
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.24 no.5
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    • pp.411-429
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    • 2022
  • Instrumentations are essential in NATM tunnels, however measuring instruments are installed and applied without performance verification procedures due to insufficient research on methods, procedures, regulations, etc. to verify the reliability of the measuring instruments. In this study, domestic and foreign regulations relating to the verification and calibration of instruments were investigated and necessities for accreditation standards were proposed. In order to identify the causes of the defects, an external inspection was performed on rock bolt stressmeter and rod extensometer, which are measuring instruments with relatively complex structures. For verifying the performance of these instruments, verification devices were developed that can load step-by-step and the causes of defects were identified in measuring instruments of nine domestic manufacturers. Through the performance test, a number of measuring instruments were found to be defective. It was important to test the performance of the instruments in the state of a finished product and accordingly performance inspection methods and procedures were proposed. The results of this study are expected to help preparing related regulations for verifying instrument performance and selecting instruments in the field.

A Sludge Collector Selection Model by Life Cycle Cost Analysis (LCC분석에 의한 슬러지수집기 선정 모델)

  • Lee, Seung-Hoon;Woo, Yu-Mi;Lee, Sung-Rak;Koo, Kyo-Jin;Hyun, Chang-Taek;Hong, Tae-Hoon
    • Korean Journal of Construction Engineering and Management
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    • v.7 no.6
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    • pp.175-184
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    • 2006
  • This study focused on developing Life Cycle Cost(LCC) analysis model for selecting sludge collectors in wastewater treatment system and applying the model to a case study. Cost items are examined through literature review and historical data of a facility. Analysis period, discount rate, energy cost escalation ratio are assumed to reasonable level. Monetary evaluation is performed using historical data and estimations from vendors. Sensitive analysis is executed using Monte Carlo Simulation for assumed factors. Interviews with operators, vendors, constructors, managers are conducted to define factors which indicates ease of maintenance, ease of delivery, technical performance, efficiency, environmental friendship. Factors are representing technical and social factors. Results from LCC analysis and qualitative analysis are evaluate together with Weighted Matrix Evaluation Methods for optimum alternative of sludge collectors.

Modification of the Fixed Coefficient Method for the Parameter Estimation of Storage Function Method (저류함수법의 매개변수 추정을 위한 상수고정법의 개선)

  • Chung, Gunhui;Park, Hee-Seong
    • Journal of Korea Water Resources Association
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    • v.46 no.1
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    • pp.73-85
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    • 2013
  • The researches on the parameter estimation for storage function method have been conducted for a long time using different methods. However, the determination of the optimal parameters takes a long time and there is a controversy that the proposed optimal parameters do not likely represent the physical characteristics of watershed. In this study, the characteristics of the continuity and storage function equation was analyzed and sensitivities were evaluated. As the result, the only optimal solution is suggested among several local optimums. It is also shown that the lag time is able to be determined using the direct runoff starting time of the watershed. From the sensitivity analysis, it is also proved that the determination of the lag time is very important and the only optimal solution could be found easily after selecting the lag time. Therefore, unlike the traditional optimization method, the proposed method does not take a long time to find the optimal solution which is depending on the characteristics of the rainfall events. The fixed coefficient method which is a method to estimate the optimal parameters of storage function method has been modified using the proposed method. Therefore, the practical efficiency to apply storage function method could be enhanced by applying the proposed method. While the traditional method takes care only the error of the runoff hydrograph, it is very important that the proposed method considers the characteristics of the watershed.

Development of Traffic Accident Prediction Models Considering Variations of the Future Volume in Urban Areas (신설 도시부 도로의 장래 교통량 변화를 반영한 교통사고 예측모형 개발)

  • Lee, Soo-Beom;Hong, Da-Hee
    • Journal of Korean Society of Transportation
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    • v.23 no.3 s.81
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    • pp.125-136
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    • 2005
  • The current traffic accident reduction procedure in economic feasibility study does not consider the characteristics of road and V/C ratio. For solving this problem, this paper suggests methods to be able to evaluate safety of each road in construction and improvement through developing accident Prediction model in reflecting V/C ratio Per road types and traffic characters. In this paper as primary process, model is made by tke object of urban roads. Most of all, factor effecting on accident relying on road types is selected. At this point, selecting criteria chooses data obtained from road planning procedure, traffic volume, existence or non-existence of median barrier, and the number of crossing point, of connecting road. and of traffic signals. As a result of analyzing between each factor and accident. all appear to have relatives at a significant level of statistics. In this research, models are classified as 4-categorized classes according to roads and V/C ratio and each of models draws accident predicting model through Poisson regression along with verifying real situation data. The results of verifying models come out relatively satisfactory estimation against real traffic data. In this paper, traffic accident prediction is possible caused by road's physical characters by developing accident predicting model per road types resulted in V/C ratio and this result is inferred to be used on predicting accident cost when road construction and improvement are performed. Because data using this paper are limited in only province of Jeollabuk-Do, this paper has a limitation of revealing standards of all regions (nation).

Using the METHONTOLOGY Approach to a Graduation Screen Ontology Development: An Experiential Investigation of the METHONTOLOGY Framework

  • Park, Jin-Soo;Sung, Ki-Moon;Moon, Se-Won
    • Asia pacific journal of information systems
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    • v.20 no.2
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    • pp.125-155
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    • 2010
  • Ontologies have been adopted in various business and scientific communities as a key component of the Semantic Web. Despite the increasing importance of ontologies, ontology developers still perceive construction tasks as a challenge. A clearly defined and well-structured methodology can reduce the time required to develop an ontology and increase the probability of success of a project. However, no reliable knowledge-engineering methodology for ontology development currently exists; every methodology has been tailored toward the development of a particular ontology. In this study, we developed a Graduation Screen Ontology (GSO). The graduation screen domain was chosen for the several reasons. First, the graduation screen process is a complicated task requiring a complex reasoning process. Second, GSO may be reused for other universities because the graduation screen process is similar for most universities. Finally, GSO can be built within a given period because the size of the selected domain is reasonable. No standard ontology development methodology exists; thus, one of the existing ontology development methodologies had to be chosen. The most important considerations for selecting the ontology development methodology of GSO included whether it can be applied to a new domain; whether it covers a broader set of development tasks; and whether it gives sufficient explanation of each development task. We evaluated various ontology development methodologies based on the evaluation framework proposed by G$\acute{o}$mez-P$\acute{e}$rez et al. We concluded that METHONTOLOGY was the most applicable to the building of GSO for this study. METHONTOLOGY was derived from the experience of developing Chemical Ontology at the Polytechnic University of Madrid by Fern$\acute{a}$ndez-L$\acute{o}$pez et al. and is regarded as the most mature ontology development methodology. METHONTOLOGY describes a very detailed approach for building an ontology under a centralized development environment at the conceptual level. This methodology consists of three broad processes, with each process containing specific sub-processes: management (scheduling, control, and quality assurance); development (specification, conceptualization, formalization, implementation, and maintenance); and support process (knowledge acquisition, evaluation, documentation, configuration management, and integration). An ontology development language and ontology development tool for GSO construction also had to be selected. We adopted OWL-DL as the ontology development language. OWL was selected because of its computational quality of consistency in checking and classification, which is crucial in developing coherent and useful ontological models for very complex domains. In addition, Protege-OWL was chosen for an ontology development tool because it is supported by METHONTOLOGY and is widely used because of its platform-independent characteristics. Based on the GSO development experience of the researchers, some issues relating to the METHONTOLOGY, OWL-DL, and Prot$\acute{e}$g$\acute{e}$-OWL were identified. We focused on presenting drawbacks of METHONTOLOGY and discussing how each weakness could be addressed. First, METHONTOLOGY insists that domain experts who do not have ontology construction experience can easily build ontologies. However, it is still difficult for these domain experts to develop a sophisticated ontology, especially if they have insufficient background knowledge related to the ontology. Second, METHONTOLOGY does not include a development stage called the "feasibility study." This pre-development stage helps developers ensure not only that a planned ontology is necessary and sufficiently valuable to begin an ontology building project, but also to determine whether the project will be successful. Third, METHONTOLOGY excludes an explanation on the use and integration of existing ontologies. If an additional stage for considering reuse is introduced, developers might share benefits of reuse. Fourth, METHONTOLOGY fails to address the importance of collaboration. This methodology needs to explain the allocation of specific tasks to different developer groups, and how to combine these tasks once specific given jobs are completed. Fifth, METHONTOLOGY fails to suggest the methods and techniques applied in the conceptualization stage sufficiently. Introducing methods of concept extraction from multiple informal sources or methods of identifying relations may enhance the quality of ontologies. Sixth, METHONTOLOGY does not provide an evaluation process to confirm whether WebODE perfectly transforms a conceptual ontology into a formal ontology. It also does not guarantee whether the outcomes of the conceptualization stage are completely reflected in the implementation stage. Seventh, METHONTOLOGY needs to add criteria for user evaluation of the actual use of the constructed ontology under user environments. Eighth, although METHONTOLOGY allows continual knowledge acquisition while working on the ontology development process, consistent updates can be difficult for developers. Ninth, METHONTOLOGY demands that developers complete various documents during the conceptualization stage; thus, it can be considered a heavy methodology. Adopting an agile methodology will result in reinforcing active communication among developers and reducing the burden of documentation completion. Finally, this study concludes with contributions and practical implications. No previous research has addressed issues related to METHONTOLOGY from empirical experiences; this study is an initial attempt. In addition, several lessons learned from the development experience are discussed. This study also affords some insights for ontology methodology researchers who want to design a more advanced ontology development methodology.