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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of The Korean Society of Civil Engineers
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Journal DOI :
Korean Society of Civil Engeneers
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Volume & Issues
Volume 34, Issue 6 - Dec 2014
Volume 34, Issue 5 - Oct 2014
Volume 34, Issue 4 - Aug 2014
Volume 34, Issue 3 - Jun 2014
Volume 34, Issue 2 - Apr 2014
Volume 34, Issue 1 - Feb 2014
Selecting the target year
Structural Performance Evaluation of Floating PV Power Generation Structure System
Choi, Jin Woo ; Seo, Su Hong ; Joo, Hyung Joong ; Yoon, Soon Jong ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1353~1362
DOI : 10.12652/Ksce.2014.34.5.1353
In recent years, numerous environmental problems associated with the excessive use of fossil fuel are taking place. For an alternative energy resource, the importance of renewable energy and the demands of facilities to generate renewable energy are continuously rising. To satisfy such demands, a large number of photovoltaic energy generation structures are constructed and planned with large scale. However, because these facility zones are mostly constructed on land, some troubles are occurred such as rising of construction cost due to the cost of land use, environmental devastation, etc. To solve such problems, the floating type photovoltaic energy generation system using FRP members have been developed in Korea. FRP members are recently available in civil engineering applications due to many advantages such as high strength, corrosion resistance, light weight, etc. and they are suitable to fabricate the floating structures because of their material properties. In this study, the analytical and experimental investigations to evaluate the structural performance of floating PV generation structure and SMC FRP vertical member which is used to fabricate the structure were conducted. The static and dynamic performances of floating PV generation structure are evaluated through the FE analysis and the experiment, respectively. Moreover, the structural safety evaluation and buckling analysis of SMC FRP vertical compression member are also conducted by the FE analysis, and the structural behavior of SMC FRP member under compression and pullout is investigated by the experiments. From this study, it was found that the structural system composed of pultruded FRP and SMC FRP members are safe enough to resist externally applied loads.
Strength Evaluation on Sectional Members of Prefabricated Precast Concrete Arch with Reinforced Joint
Joo, Sanghoon ; Chung, Chulhun ; Bae, Jaehyun ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1363~1372
DOI : 10.12652/Ksce.2014.34.5.1363
In the previous study, the structural performance of proposed precast concrete arch with reinforced joint was evaluated by structural experiment. In this paper, finite element analysis considering both material and contact nonlinearity was carried out on the specimens of the previous study. Based on the result of analysis and experiment, friction coefficient between concrete blocks was determined. To evaluate the strength of sectional member, elastic analysis was carried out on the arch using linear elastic analysis program. The section force was compared with the nominal strength of arch section. It was concluded that the maximum load of all the specimens exceed the nominal strength of arch section. Those results of the strength evaluation were similar to the results of structural experiments. Therefore, it is concluded that the elastic analysis and ultimate strength model can effectively evaluate the strength for the proposed precast concrete arch composed of concrete blocks and reinforced joint in design.
Development of the Hydraulic Performance Graph Model and its Application
Seo, Yongwon ; Seo, Il Won ; Shin, Jaehyun ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1373~1382
DOI : 10.12652/Ksce.2014.34.5.1373
This paper presents a hydraulic performance graph model in which the flow carrying capacity of a channel system was determined by accounting the interacting backwater effect among channel reaches and incoming lateral flow. The method utilizes hydraulic performance graphs (HPGs), and the method is applied to a natural channel Nakdong River to examine its applicability. This research shows that estimation results using HPG are close to records from the stage station and the results from a widely-accepted model, HEC-RAS. Assuming that a water level gage site is ungaged, water level estimations by HPGs compared with observation show that with a flood event, the HPGs underestimate in the water level ascension phase, but in the recession phase they overestimate results. The accuracy of estimation with HPGs was greatly improved by considering the time difference of flooding between the observation and estimation locations.
Dam-Break and Transcritical Flow Simulation of 1D Shallow Water Equations with Discontinuous Galerkin Finite Element Method
Yun, Kwang Hee ; Lee, Haegyun ; Lee, Namjoo ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1383~1393
DOI : 10.12652/Ksce.2014.34.5.1383
Recently, with rapid improvement in computer hardware and theoretical development in the field of computational fluid dynamics, high-order accurate schemes also have been applied in the realm of computational hydraulics. In this study, numerical solutions of 1D shallow water equations are presented with TVD Runge-Kutta discontinuous Galerkin (RKDG) finite element method. The transcritical flows such as dam-break flows due to instant dam failure and transcritical flow with bottom elevation change were studied. As a formulation of approximate Riemann solver, the local Lax-Friedrichs (LLF), Roe, HLL flux schemes were employed and MUSCL slope limiter was used to eliminate unnecessary numerical oscillations. The developed model was applied to 1D dam break and transcritical flow. The results were compared to the exact solutions and experimental data.
Development of River Recreation Index Model by Synthesis of Water Quality Parameters
Seo, Il Won ; Choi, Soo Yeon ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1395~1408
DOI : 10.12652/Ksce.2014.34.5.1395
In this research, a River Recreation Index Model (RRIM) was developed to provide sufficient information on the water quality of rivers to the public in order to secure safety of publics. River Recreation Index (RRI) is an integrated water quality information for recreation activities in rivers and expressed as the point from 0 to 100. The proposed RRIM consisted of two sub models: Fecal Coliform Model (FCM) and Water Quality Index Model (WQIM). FCM predicted Fecal Coliform Grade (FCG) using a logistic regression and WQIM synthesized water quality parameters of, DO, pH, turbidity and chlorophyll a into Water Quality Index (WQI). FCG and WQI were integrated into RRI by the integrating algorithm. The proposed model was applied to upstream of Gangjeong Weir in Nakdong River, and compared with Real Time Water Quality Index (RTWQI) which is the existing water quality information system for recreation use. The results show that calculated RRI reflected change of integrated water quality parameters well. Especially chlorophyll a showed Pearson correlation coefficient -0.85 with RRI. Also, RRIM produced more conservative index than RTWQI because RRI was calculated considering uncertainty of water quality criteria. Further, RRI showed especially low values when fecal coliform was predicted as low grade.
Sensitivity Analysis of Hydrogeologic Parameters by Groundwater Table Fluctuation Model in Jeju Island
Kim, Nam Won ; Kim, Youn Jung ; Chung, Il-Moon ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1409~1420
DOI : 10.12652/Ksce.2014.34.5.1409
In this work, we have carried out a sensitivity analysis of hydrogeologic parameters such as reaction factor and drainable pore space in groundwater table fluctuation model and have found characteristics of parameter distribution according to the altitude. We found that drainable pore space which is hydrogeologic parameter of aquifer didn't show any trend with altitude while reaction factor which is groundwater flow characteristic showed clear trend with altitude. To find a sensitivity of parameters, we compared RMSE of estimated groundwater recharges by using the mean value and linear relationship of parameters. As results, the linear equation derived for entire watersheds could be applied to estimate parameters for ungauged watershed. Furthermore, the features of parameter distribution can be used to predict hydrogeologic parameter in ungauged watersheds and it is expected that those features could be used for a basic data for groundwater modeling.
Assessment and Improvement of Snow Load Codes and Standards in Korea
Yu, Insang ; Kim, Hayong ; Necesito, Imee V. ; Jeong, Sangman ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1421~1433
DOI : 10.12652/Ksce.2014.34.5.1421
In this study, appropriate probability distribution and parameter estimation method were selected to perform snowfall frequency analysis. Generalized Extreme Value (GEV) and Probability Weighted Moment Method (PWMM) appeared to be the best fit for snowfall frequency analysis in Korea. Snowfall frequency analysis applying GEV and PWMM were performed for 69 stations in Korea. Peak snowfall corresponding to recurrence intervals were estimated based on frequency analysis while snow loads were calculated using the estimated peak snowfall and specific weight of snow. Design snow load map was developed using 100-year recurrence interval snow load of 69 stations through Kriging of ArcGIS. The 2009 Korean Building Code and Commentary for design snow load was assessed by comparing the design snow loads which calculated in this study. As reflected in the results, most regions are required to increase the design snow loads. Thus, design snow loads and the map were developed from based on the results. The developed design snow load map is expected to be useful in the design of building structures against heavy snow loading throughout Korea most especially in ungaged areas.
Analysis of Coherent Structure of Turbulent Flows in the Rectangular Open-Channel Using LES
Ban, Chaewoong ; Choi, Sung-Uk ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1435~1442
DOI : 10.12652/Ksce.2014.34.5.1435
This study presented numerical simulations of smooth-bed flows in the rectangular open-channel using the source code by OpenFOAM. For the analysis of the turbulent flow, Large Eddy Simulations were carried out and the dynamic sub-grid scale model proposed by Germano et al. (1991) is used to model the residual stress term. In order to analyze the coherent structure, the uw quadrant method proposed by Lu and Willmarth (1973) is used and the contribution rate and the fraction time of the instantaneous Reynolds stress are obtained in the Reynolds stress. The results by the present study are analyzed and compared with data from previous laboratory studies and direct numerical simulations. It is found that the contribution rate of the ejection events is larger than that of sweep events over the buffer layer in the open-channel flow over the smooth bed, however, the frequency of the sweep event is higher than that of the ejection events.
Impact Assessment of Spatial Resolution of Radar Rainfall and a Distributed Hydrologic Model on Parameter Estimation
Noh, Seong Jin ; Choi, Shin Woo ; Choi, Yun Seok ; Kim, Kyung Tak ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1443~1454
DOI : 10.12652/Ksce.2014.34.5.1443
In this study, we assess impact of spatial resolution of radar rainfall and a distributed hydrologic model on parameter estimation and rainfall-runoff response. Radar data measured by S-band polarimetric radar located at Mt. Bisl in the year of 2012 are used for the comparative study. As different rainfall estimates such as R-KDP, R-Z, and R-ZDR show good agreement with ground rainfall, R-KDP are applied for rainfall-runoff modeling due to relatively high accuracy in terms of catchment averaged and gauging point rainfall. GRM (grid based rainfall-runoff model) is implemented for flood simulations at the Geumho River catchment with spatial resolutions of 200m, 500m, and 1000m. Automatic calibration is performed by PEST (model independent parameter estimation tool) to find suitable parameters for each spatial resolution. For 200m resolution, multipliers of overlandflow and soil hydraulic conductivity are estimated within stable ranges, while high variations are found from results for 500m and 1000m resolution. No tendency is found in the estimated initial soil moisture. When parameters estimated for different spatial resolution are applied for other resolutions, 200m resolution model shows higher sensitivity compared to 1000m resolution model.
Outlier Detection and Replacement for Vertical Wind Speed in the Measurement of Actual Evapotranspiration
Park, Chun Gun ; Rim, Chang-Soo ; Lim, Kwang-Suop ; Chae, Hyo-Sok ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1455~1461
DOI : 10.12652/Ksce.2014.34.5.1455
In this study, using flux data measured in Deokgokje reservoir watershed near Deokyu mountain in May, June, and July 2011, statistical analysis was conducted for outlier detection and replacement for vertical wind speed in the measurement of evapotranspiration based on eddy covariance method. To statistically analyze the outliers of vertical wind speed, the outlier detection method based on interquartile range (IQR) in boxplot was employed and the detected outliers were deleted or replaced with mean. The comparison was conducted for the measured evapotranspiration before and after the outlier replacement. The study results showed that there is a difference between evapotranspiration before outlier replacement and evapotranspiration after outlier replacement, especially during the rainy day. Therefore, based on the study results, the outliers should be deleted or replaced in the measurement of evapotranspiration.
Development of a 3-D Coupled Hydro-Morphodynamic Model between Numerical Wave Tank and Morphodynamic Model under Wave-Current Interaction
Lee, Woo-Dong ; Hur, Dong-Soo ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1463~1476
DOI : 10.12652/Ksce.2014.34.5.1463
In order to understand hydrodynamic and morphodynamic characteristics under wave-current interactions in an estuary, a coupled model for two-way analysis between existing 3-d numerical wave tank and newly-developed 3-d morphodynamic model has been suggested. Comparing to existing experimental results it is revealed that computed results of the newly-suggested model are in good agreement with each laboratory test result for wave height distribution, vertical flow profile and topographical change around ocean floor pipeline in wave-current coexisting field. Also the numerical result for suspended sediment concentration is verified in comparison with experimental result in solitary wave field. Finally, it is shown that the 3-D coupled Hydro-Morphodynamic model suggested in this study is applicable to morphological change under wave-current interaction in an estuary.
An Experimental Study on Filtration Efficiency of Sand Filter Layers to TSS and COD in Non-point Source Pollutant
Ahn, Jaeyoon ; Lee, Dongseop ; Han, Shinin ; Choi, Hangseok ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1477~1488
DOI : 10.12652/Ksce.2014.34.5.1477
Prevalent construction of impermeable pavements in urban areas causes diverse water-related environmental issues, such as lowering ground water levels and shortage of water supply for the living. In order to resolve such problems, a rainwater reservoir can be an effective and useful solution. The rainwater reservoir facilitates the hydrologic cycle in urban areas by temporarily retaining precipitation-runoff within a shallow subsurface layer for later use in a dry season. However, in order to use the stored water of precipitation-runoff, non-point source pollutants mostly retained in initial rainfall should be removed before being stored in the reservoir. Therefore, the purification system to filter out the non-point source pollutants is essential for the rainwater reservoir. The conventional soil filtration technology is well known to be able to capture non-point source pollutants in a economical and efficient way. This study adopted a sand filter layer (SFL) as a non-point source pollutant removal system in the rainwater reservoir, and conducted a series of lab-scale chamber tests and field tests to evaluate the pollutant removal efficiency and applicability of SFL. During the laboratory chamber experiments, three types of SFL with the different grain size characteristics were compared in the chamber with a dimension of
. To evaluate performance of the reservoir systems, the concentration of the polluted water in terms of TSS (Total Suspended Solids) and COD (Chemical Oxygen Demand) were measured and compared. In addition, a reduction in hydraulic conductivity of SFL due to pollutant clogging was indirectly estimated. The optimum SFL selected through the laboratory chamber experiments was verified on the in-situ rainwater reservoir for field applicability.
Partial Safety Factor of Offshore Wind Turbine Pile Foundation in West-South Mainland Sea
Yoon, Gil Lim ; Kim, Sun Bin ; Kwon, O Soon ; Yoo, Moo Sung ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1489~1504
DOI : 10.12652/Ksce.2014.34.5.1489
This paper is aimed to suggest a site specific partial safety factor of offshore wind turbine (OWT) pile foundation design for the offshore wind turbine complex at a West-South mainland sea in Korea. International offshore wind design standards such as IEC, GL, DNV, API, ISO and EUROCODE were compared with each partial safety factor and resistance factor. Soil uncertainty analysis using a large number of soil data sampled was carried out, and their results were adapted to estimate partial safety factor of OWT pile foundation through reliability analyses. The representative partial safety factor has been estimated as 1.3. When a proposed partial factor is willing to use to other sites, it is recommended that further studies on code calibration are required to validate their accuracy using more site characterization data.
Study on the Direct Tensile Test for Cemented Soils Using a Built-In Cylinder
Park, Sung-Sik ; Lee, Jun-Woo ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1505~1516
DOI : 10.12652/Ksce.2014.34.5.1505
In this study, a cylinder embedded within cemented soils was used to cause directly tensile failure of cemented soils. An existing dumbbell type direct tensile test and a split tensile test that is most general indirect tensile test were also carried out to verify the developed built-in cylinder tensile test. Testing specimens with two different sand/cement ratios (1:1 and 3:1) and two curing periods (7 and 28 days) were prepared and tested. Total 10 specimens were prepared for each case and their average value was evaluated. Unconfined compression tests were also carried out and the ratio of compressive strength and tensile strength was evaluated. The tensile strength determined by built-in cylinder tensile test was slightly higher than that by dumbbell type direct tensile test. The dumbbell type test has often failed in joint part of specimen and showed some difficulty to prepare a specimen. Among three tensile testing methods, the standard deviation of tensile strength by split tensile test was highest. It was shown that the split tensile test is applicable to concrete or rock with elastic failure but not for cemented soils having lower strength.
Analysis of the Affecting Factors on the Bike-sharing Demand focused on Daejeon City
Do, Myungsik ; Noh, Yun Seung ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1517~1524
DOI : 10.12652/Ksce.2014.34.5.1517
In recent years, the interest of environmental-friendly transportation modes has been growing. This is because of social and environmental problems such as increasing gas price and climate change. In Europe, bike-sharing service, one of the environmental-friendly transportation modes, has been already operated. Bike-sharing service named "Tashu" has been operated in Daejeon city since 2009. This study is a fundamental research to increase utilization efficiency of bike-sharing service and to decide optimal locations of bike stations. In addition this study examines characteristics of bike usage and analyzes factors affecting to demands using multiple regression model. Based on the result of examining of characteristics of bike usage, the rate of bike usage is higher compared with installation rate of public bike stations near parks in Daejeon. In addition demands of bike usage in weekend is higher than in weekday. It reveals that the main purpose of bike usage could be recreational activities. The return rate at the same location with rental station is comparatively high. Moreover, bike usage pattern is biased in specific areas (Dunsan and Yuseong) because bike-sharing stations are not equally located. As a result of multiple regression model, the factors affecting to demands are number of passengers in buses, length of bike lanes, parks, distance to waterfront, and rate of young people. A statistical significance of factors (r-square) is 0.748, which has strong relationship.
Developing a Transit Assignment Model Considering Waiting Time Variation and Line Capacity
Kim, Jin Howan ; Kim, Dong Sun ; Kim, Ji Hyun ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1525~1534
DOI : 10.12652/Ksce.2014.34.5.1525
In recent years, the passengers are likely to decide their route on impulse due to the development of the integrated public transport system, and real-time information system. Especially, public transport fare integration in Seoul Metropolitan area, 2004 makes them not to have resistance about changing the modes or routes and their route choice is most effected by the degree of congestion. Assignment model have limitations to describe route changes by congestion. In this study, the concept of a link cost function used in road assignment and Effective frequency is introduced to describe the passengers' behavior when the capacity of public transport is over and the waiting time variation. Two situations, new transit line operation and accident, are set up to validate the model, as a result of the transit assignment by this model, the traffic on networks is not over the capacity. It is expected that this study will be of help to reflect the various behaviors in transit assignments.
A Study on Improving the Reliability of DSRC Traffic Information Considering Traffic and Road Characteristics - Focusing on Busan Urban Expressway -
Jeong, Yeon Tak ; Jung, Hun Young ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1535~1545
DOI : 10.12652/Ksce.2014.34.5.1535
This study aims at improving the Reliability of DSRC Traffic information considering Traffic and Road Characteristics. First of all, this study analyzed the characteristics of DSRC data on urban expressway and problems of outlier data occurrence. After then, this study produced reliable traffic information by using an optimal method of the Outlier-Filtering. After Outlier-Filtering, this study performed accuracy evaluation and appropriateness check for the number of samples per confidence level. As a result, it showed that the MAPE was between 2.2% and 9.7% and RSME was between 2.2 and 7.5 which are very similar figures to the actual average traffic speed. Also, The samples of both Am peak and Pm peak periods were analyzed to be appropriate at the confidence level of 95%, and 90% within the allowable error range of 5kph.
Economic Feasibility of An Extra Stop Need at Kimpo Metro Station of AREX Express Trains
Kim, Dong-Hwan ; Lim, Kwangkyun ; Kim, Sigon ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1547~1552
DOI : 10.12652/Ksce.2014.34.5.1547
AREX (Incheon Airport Railway Express) operates trains between Seoul and Incheon Airport. One type of trains stops on every 10 stations, and another only on the two end-stations which called an Express train. The passengers traveled on express trains are very small since there are only two stops, Seoul and Incheon Airport Stations. The passengers of express trains will be more attracted if the express train stops on the intermediate stops (Gimpo station) since Line #9 and Line #5 are connected to from Gangnam. An on-board survey was conducted to predict the potential demand in case the express train stops at the Gimpo station. Further the costs required to improve platforms of the station were estimated to figure out the economic feasibility against the demand increases. It analyzed 938 increases for the case of intermediate stopping on the same travel time condition and 1,299 increases for the case of extra stop with decreased travel time. The study concluded the latter case appears desirable in the stance of long-term while both cases are economically feasible.
An Analysis on the Correlation between Types of Urban Railway Stations and Users' Travel Patterns
Kim, Hwang Bae ; Oh, Dong Kyu ; Lee, Sang Hwa ; Jin, Sang Kyu ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1553~1558
DOI : 10.12652/Ksce.2014.34.5.1553
The travel demand, peak hour ratio and forms of platform of urban railway stations are very different each other, also the users' behavior is. So the types of urban railway stations have to be classified according to these characteristics. However, the current methods of classification are arbitrary on the purpose of each studies and the legal standards are very simple; categorized by normal station vs. whistle station, types of trains, forms of platforms and shapes of architecture. This study clarifies the standards for classifying the types of urban railway stations, results the complete enumeration survey on all the urban railway stations in Seoul Metropolitan Area and makes the database based on the surveyed data, purposing on helping for making strategies and researching. On this study, utilizing the database which is established for this study, the correlation between the physical and geographical characteristics and users' travel patterns of urban railway stations is clarified by the statistical analysis. In the future, the statistical results will be helpful for making strategies and researching.
The Cost Structure of the Lines of Urban Railway
Kim, Soo Hyun ; Jung, Hun Young ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1559~1569
DOI : 10.12652/Ksce.2014.34.5.1559
The purpose of this study is to estimate the degree of cost inefficiency for the urban railway lines of a metropolitan city operated by public institutions in Korea and identify the causes of this inefficiency. To this end, we assume that the urban railway lines produce the output of train-km by putting three production factors of labor, electric power and maintenance and set the variable cost function model with the translog function to make a stochastic cost frontier analysis. Based on estimated result, we conclude that the cost savings for 6 years of all lines are about 6,672 hundred million won and top five lines with high inefficiency are Busan Line1, Daegu Line1, Daejeon Line1, Gwangju Line1, and Daegu Line2. The causes of inefficiency are attributable to labor and maintenance factors. The results of this study can be useful in case of finding the priorities of measures and specific plans for reducing labor and maintenance costs in the urban railway operation.
A Study on Clarifying Relationship between the Traffic Culture Index and Traffic Accidents Using Structural Equation Model
Park, Woongwon ; Joo, Sungkab ; Lim, Joonbeom ; Lee, Soobeom ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1571~1579
DOI : 10.12652/Ksce.2014.34.5.1571
93% of road traffic accidents result from drivers' fault and Korea has the largest number of deaths from traffic accidents among the OECD members. For this reason, the country is measuring Traffic Culture Index (TCI) in each city, gun and gu annually to improve traffic safety policies and promote safety consciousness, but the influencing relation between TCI and actual traffic accidents is only based on the assumptions and no verification has been carried out, yet. Therefore, this study aims to verify if in reality, TCI represents the traffic culture level and has an influencing relation with traffic accidents and to suggest an improvement plan of research on the present state of TCI, based on the result. For this purpose, bases on data of the report about the present state of TCI from 2010 to 2012, and the influencing relation between the number of traffic accidents and the number of deaths from traffic accidents was analyzed through structural equation model. For influencing relation analysis through structural equation, research 1 to analyze the relation among TCI in each city, gun and gu, the number of traffic accidents and the number of deaths, and research 2 to analyze the influencing relation of the increase in TCI, the number of traffic accidents and the number of deaths were carried out. When verifying the influencing relation with traffic accidents through structural equation, the goodness of fit of the model was low in research 1 and as TCI increased, the number of accidents and deaths decreased in research 2 and thus the effect of TCI was verified.
Economic Analysis of Two-Layer Quiet Asphalt Pavement Considering Noise Cost Benefits
Kang, Haet Vit ; Park, Ki Sun ; Kim, Nak Seok ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1581~1587
DOI : 10.12652/Ksce.2014.34.5.1581
Two-lalyered quiet asphalt pavements are well known for their noise reduction capabilities compared to the conventional ones. This study was conducted to analyze the economic effects on two-layered quiet asphalt pavement rather than on one-layered. Noise prediction was performed on the data surveyed from the two-layered quiet asphalt pavement. In addition, the economic analysis was executed considering cost benefits using the noise prediction result. The permeability test was also investigated to evaluate the clogging recovery of two-layered quiet asphalt pavement. Analysis results revealed that the construction cost of two-layered quiet asphalt pavements was cheaper than that of the conventional soundproof walls. The two-layered quiet asphalt pavement with simulated clogging conditions was satisfied the permeability requirements of the permeable asphalt pavements. The permeability test results showed that the permeable time was recorded as 6.77 seconds for one cycle of cleaning job with 400 mL of water.
Development of a Greenhouse Gas Monitoring System for Construction Projects
Kim, Tae Yeong ; Park, Hee-Sung ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1589~1597
DOI : 10.12652/Ksce.2014.34.5.1589
For several decades, economic growth has achieved in the aspect of productivity and effectiveness not environmental friendly. As a result, global warming is a major agenda to solve. Therefore, global effort to sustainable development has been adopted like UNFCCC and Kyoto protocol that aimed to reduce greenhouse gas. However, the construction industry has only focused on applying techniques for using less energy sources not monitoring sustainable construction and development. Therefore, this study developed a tool for monitoring greenhouse gas emissions in construction industry. The proposed system evaluates and estimates BAU (Business as usual) for each phase of a construction project. For this purpose, analyzed the greenhouse gas emission factors coincide to life cycle of a construction project. The scope of monitoring is determined according to data availability and emission factor. Then, the system framework is developed and the calculation logic is proposed the system features provide comparison between the emission estimates for eco-friendly design and the actual emission of construction and operation phases. The system would be utilized as a tool for supporting to green construction realization and green construction performance evaluation.
Interaction Analysis between Construction Business Indicators and Business Performance Indicators of Civil Specialty Contractors
Kim, Nam-Sik ; Lee, Dong Wook ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1599~1608
DOI : 10.12652/Ksce.2014.34.5.1599
This study is to suggest specialty contractors with countermeasures to construction orders falling off, one of the construction business indicators for the construction industry, by analyzing the impact of dwindling construction orders to business performance indicators of specialty contractors as well as identifying inter-relationships between those performance indicators. For specialty contractors of civil construction, it is analyzed that their current ratio is significantly affecting obtention of construction orders, which in turn greatly affecting the ratio of owner's equity. It seems that the amount of construction orders has a direct relationship with the corporate stability. Therefore, this type of specialty contractors are determined to be able to obtain more orders for construction by improving current ratio.
A Multi-agent based Cooperation System for an Intelligent Earthwork
Kim, Sung-Keun ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1609~1623
DOI : 10.12652/Ksce.2014.34.5.1609
A number of studies have been conducted recently regarding the development of automation systems for the construction sector. Much of this attention has focused on earthwork because it is highly dependent on construction machines and is regarded as being basic for the construction of buildings and civil works. For example, technologies are being developed in order to enable earthwork planning based on construction site models that are constructed by automatic systems and to enable construction equipment to perform the work based on the plan and the environment. There are many problems that need to be solved in order to enable the use of automatic earthwork systems in construction sites. For example, technologies are needed for enabling collaborations between similar and different kinds of construction equipment. This study aims to develop a construction system that imitates collaborative systems and decision-making methods that are used by humans. The proposed system relies on the multi-agent concept from the field of artificial intelligence. In order to develop a multi-agent-based system, configurations and functions are proposed for the agents and a framework for collaboration and arbitration between agents is presented. Furthermore, methods are introduced for preventing duplicate work and minimizing interference effects during the collaboration process. Methods are also presented for performing advance planning for the excavators and compactors that are involved in the construction. The current study suggests a theoretical framework and evaluates the results using virtual simulations. However, in the future, an empirical study will be conducted in order to apply these concepts to actual construction sites through the development of a physical system.
Assessment of Low Impact Development (LID) Integrated in Local Comprehensive Plans for Improving Urban Water Cycle
Kang, Jung-Eun ; Hyun, Kyoung-Hak ; Park, Jong-Bin ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1625~1638
DOI : 10.12652/Ksce.2014.34.5.1625
Recently, Low Impact Development (LID) has been emphasized as a critical strategy for improving urban water cycle and adapting to climate change. LID is needed to be incorporated in urban planning and development process for effective implementation in the real world. However, little research has examined the relationship between urban planning and LID in Korea. This study addresses this critical gap by 1) examining whether current urban planning institutional system considers LID or not and 2) assessing the extent to which local comprehensive plans integrate LID in seven large cities. Study results show that a few planning guidelines declaratively mention the need of LID but they don't include specific LID strategies. In addition, we found that 7 local comprehensive plans in the sample received a mean score of 11.71, which represents 19.52% of the total possible points and there are wide variations among cities. These findings indicate that there is still considerable room for improvement of local governments on LID. We propose the revision of planning guideline by incorporating LID principles and non-structural and structural LID technologies.
Comparison of Image Matching Method for Automatic Matching of High Resolution SAR Imagery
Baek, Sang Ho ; Hong, Seung Hwan ; Yoo, Su Hong ; Sohn, Hong Gyoo ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1639~1644
DOI : 10.12652/Ksce.2014.34.5.1639
SAR satellite can acquire clear imagery regardless of weather and the images are widely used for land management, natural hazard monitoring and many other applications. Automatic image matching technique is necessary for management of a huge amount of SAR data. Nevertheless, it is difficult to assure the accuracy of image matching due to the difference of image-capturing attitude and time. In this paper, we compared performances of MI method, FMT method and SIFT method by applying arbitrary displacement and rotation to TerraSAR-X images and changing resolution of the images. As a result, when the features having specific intensity were distributed well in SAR imagery, MI method could assure 0~2 pixels accuracy even if the images were captured in different geometry. But the accuracy of FMT method was significantly poor for the images having different spatial resolutions and the error was represented by tens or hundreds pixels. Moreover, the ratio of corresponding matching points for SIFT method was only 0~17% and it was difficult for SIFT method to apply to SAR images captured in different geometry.
The Development of a Multi-sensor Payload for a Micro UAV and Generation of Ortho-images
Han, Seung Hee ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 5, 2014, Pages 1645~1653
DOI : 10.12652/Ksce.2014.34.5.1645
In general, RGB, NIR, and thermal images are used for obtaining geospatial data. Such multiband images are collected via devices mounted on satellites or manned flights, but do not always meet users' expectations, due to issues associated with temporal resolution, costs, spatial resolution, and effects of clouds. We believe high-resolution, multiband images can be obtained at desired time points and intervals, by developing a payload suitable for a low-altitude, auto-piloted UAV. To achieve this, this study first established a low-cost, high-resolution multiband image collection system through developing a sensor and a payload, and collected geo-referencing data, as well as RGB, NIR and thermal images by using the system. We were able to obtain a 0.181m horizontal deviation and 0.203m vertical deviation, after analyzing the positional accuracy of points based on ortho mosaic images using the collected RGB images. Since this meets the required level of spatial accuracy that allows production of maps at a scale of 1:1,000~5,000 and also remote sensing over small areas, we successfully validated that the payload was highly utilizable.