• Journal of Korean Tunnelling and Underground Space Association
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• v.6 no.3
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• pp.213-225
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• 2004

The number of tunnels are in fact increasing as a part of linear improvement project of general national highway and road enlargement and pavement project. Recently, collapses of portal slope are also occurring considerably, due to local raining from severe rain storm and abnormal weather. Accordingly, it was risen a necessity to efficiently respond to tunnel portal slope damage and maintenance in Korea and oversea nations. This paper is a basic proposal to execute a survey on the current status and state of the tunnel portal slopes that were already installed and are now being operated along general national highways, and also to execute state evaluation for the purpose of managing those effectively. As a research method, domestic tunnels were analyzed in accordance with geometrical shape such as access type, portal form, and tunnel type, etc. via field survey to analyze the types of tunnel portal slopes along national highways. State evaluation classification sheet is presented to divide classes for the danger state of the surveyed portal slopes, and then the related grades are divided. It is mainly aimed at classifying the tunnel portal slope along national highways with using this state evaluation, to use it as basic data so that continuous maintenance can be executed in the future in accordance with danger classes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.98-104
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• 2018

The assessment of the light trespass in terms of light pollution is difficult due to the complexity of light environments. As a result, the light pollution research has examined the influences of light pollution using simulation program such as RELUX. However, there still exists a differences between the real measurement value and the simulation value for the light trespass. In this paper, we analyzed the light trespass using the RELUX simulation program, and compared results with real measurement values. In this study, the regions (Seoul, Incheon, etc.) were investigated regarding the light trespass for outdoor lighting. The survey of vertical illuminance was analyzed measuring point (more than 2 point) out the window that was expected to light trespass for the higher anticipated to illumination. The illuminational predicted values for the RELUX program were compared with maximum one. As a result of this study, the illuminational errors between the measurement values and predicted values for the simulation were examined from -0.97 lx to 0.65 lx except 2.08 lx and -7.70 lx. The light trespass was analyzed the higher by how much the located close to the height, length, width of the outdoor lighting for the window. For measuring predicted values using RELUX, it was not sufficiently considered in the simulation conditions because of environmental factors and investigator error etc. Limitations of this study include the limited number of measurements, and greater field data is required in future studies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.513-522
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• 2017

Rapid urbanization is being portrayed around the world au causing difficulty to manage public hygiene and maintain public order. Common problems often detected in urban areas including traffic congestion and the deterioration of the ecological environment are also being exacerbated. Despite all the effort being made by the government and local governments to manage urban facilities, urban residents are subjected to various levels of difficulty, due to the number of facilities to be managed exceeding the number of management personnel and the lack of an adequate management system. The aim of this study is to propose a management method using smart phones to improve the maintenance efficiency of urban facilities. First, the one-stop maintenance of urban facilities, including facilities information management, maintenance management and history management, is made possible by using smart phones to collect and transfer pictures and the locations of the urban facilities. Second, maintenance management is based on the location and picture information of the subject, not the location of the smart phones, which enables a prompt understanding of and actions to be taken for the facility. This method is especially effective as the smart phone application sends the facility status information directly to the maintenance personnel. Third, all of the information and figures relating to the facilities is managed using a database, resulting in the easy utilization of the history management and data. Fourth, all of the urban residents have access to this information via smart phone applications and, therefore, expanding the role of the facility maintenance personnel is made possible without any additional investment in infrastructure. Lastly, the location-based information enables the management of roads, trees and trails.

• Journal of Navigation and Port Research
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• v.40 no.4
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• pp.213-222
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• 2016

Recently, as cases of organizations' information disclosure occur continuously, it is urgent to manage security of information and establish measures to enhance security of information by an organization itself. Especially, members of an organization should be prepared with measures for information security, and an organization should do its efforts to raise its members' awareness toward information security. I set a research model to verify what effects an organization's fulfillment of regulations to secure information brings to performance of information security and selected members from maritime and port organizations and financial and insurance institutes as sample. Results of the analysis to identify factors affecting information security performance among members of maritime and port organizations are as follows. Firstly, I found that the factors affecting information security awareness are information security attitude and information security standards. Secondly, the factor giving influence on information security policy of an organization was found to be information security standards. In contrast, information security punishments and information security training were verified not to give influence on compliance of information security policy. Thirdly, information security awareness was identified to give significant influence on compliance of information security policy, information security competence and information security behavior. Fourthly, compliance of information security policy was verified to be those factors that give influence on information security competence and information security behavior. Lastly, information security competence and information security behavior were found to be such factors that give influence on information security performance.

• Korean Journal of Remote Sensing
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• v.33 no.2
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• pp.231-242
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• 2017

Monitoring of facilities such as roads, dams and bridges is important for their long-term sustainable usage. It has usually suffered with safety and cost problems, which makes more frequent monitoring difficult. As an efficient and economicalsolution to these problems, one may consider the use of smartphone to capture the status of the facilities. To derive quantitative analysis results with the smartphone images for facility monitoring, one should first rectify the images in a way as automatic and economical as possible. In thisstudy, we propose such a rectification method, which rectifiessmartphone images acquired from arbitrary locations based on reference images.In the proposed method, we determine the camera extrinsic parameters of each smartphone images using the reference imagesrather than ground control points, and project the image to the target surface of the facility based on the determined camera parameters. The method were applied to test data acquired from a small dam toward water-area facility monitoring. The experimental results showed that the camera extrinsic parameters were determined with the accuracy of 5 cm and $0.28^{\circ}$ in the position and attitude. The accuracy of the distance measured from the rectified image was evaluated to 10 cm. With the rectified images, one can accurately determine the location and length of the target objects required for facility monitoring.

• Journal of Korean Society of Transportation
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• v.31 no.4
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• pp.47-57
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• 2013

This study aims at analyzing transportation equity between geographical areas of Gyonggi Province, by taking both the transportation infrastructure and travel behavior into account. Indicators of transportation infrastructure include the indices of road infrastructure, transit infrastructure and regional characteristics. Travel behavior concerns information from bus card data on a survey day. The hot-spot analysis conducted included spatial cluster analysis and global/local regression analyses. The analysis results identified geographical areas of four different classes of transportation equity, from the area with high level infrastructure surrounded by the areas with high level infrastructure (HH) to the area with low level surrounded by the areas with low level (LL). The area of HH type showed big numbers of passengers, trips and transfers, whereas the area of LL type shows big figures of internal trip frequency, travel time, travel distance, travel speed and transit fare. Global regression analysis showed that number of passengers, number of transfers, number of internal trips and mean travel speed are important to the level of transportation infrastructure. GWR with these four significant variables significantly improved the AICs and ANOVA results, which implies that the infrastructure is likely explained by travel characteristics differently between geographical areas in Gyonggi Province.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.891-901
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• 2016

By comparing test blasting data experimented in three layered-structure polymorphic grounds to a geological profile, influence of blast vibration with respect to uncontrollable ground characteristics was analyzed. Inefficient blast have been performed without sufficient verifications or confirmations because insufficiencies with regard to experiments and data of blasting engineering on the layered structures to be irregularly repeated clinker layer consisted of volcanic clastic zones. It is difficult to quantify N values of clinkers within test blasting region because they have diverse ranges, or coverages. An absolute value of attenuation coefficient N in a field, estimated by blasting vibration predictive equation (SRSD), are lesser than criteria of a design instruction, meaning that vibrations caused by blast can spread far away, and the vibrational characteristics of blasting test No.1, indicating relatively small values, inferred by the geological profile, pressures of gas by the explosion may be lost into a widely distributed clinker layers by penetrating holes resulted from blast into vicinity of clinker layers located in bottom of soft rock layers at the moment of blast. As a result, amounts of spalling rocks are decreased by almost half. Also, ranges of primary frequencies in the fields are identified as similar to those of natural frequency of typical structures.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.8
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• pp.26-33
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• 2017

Vehicle communication can facilitate efficient coordination among vehicles on the road and enable future vehicular applications such as vehicle safety enhancement, infotainment, or even autonomous driving. In the $3^{rd}$ Generation Partnership Project (3GPP), many studies focus on long term evolution (LTE)-based vehicle communication. Because vehicle speed is high enough to cause severe channel distortion in vehicle-to-vehicle (V2V) environments. We can utilize channel estimation methods to approach a reliable vehicle communication systems. Conventional channel estimation schemes can be categorized as least-squares (LS), decision-directed channel estimation (DDCE), spectral temporal averaging (STA), and smoothing methods. In this study, we propose a smart channel estimation scheme in LTE-based V2V environments. The channel estimation scheme, based on an LTE uplink system, uses a demodulation reference signal (DMRS) as the pilot symbol. Unlike conventional channel estimation schemes, we propose an adaptive smoothing channel estimation scheme (ASCE) using quadratic smoothing (QS) of the pilot symbols, which estimates a channel with greater accuracy and adaptively estimates channels in data symbols. In simulation results, the proposed ASCE scheme shows improved overall performance in terms of the normalized mean square error (NMSE) and bit error rate (BER) relative to conventional schemes.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.77-87
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• 2018

Traffic Density is the most important of the three primary macroscopic traffic stream parameters, because it is most directly related to traffic demand(Traffic Engineering, 2004). It is defined as the number of existing vehicles within a given distance at a certain time. However, due to weather, road conditions, and cost issues, collecting density directly on the field is difficult. This makes studies of density less actively than those of traffic volume or velocity. For these reasons, there is insufficient attempts on divers collecting methods or researches on the accuracy of measured values. In this paper, we used the 'Density Measuring System' based on the synthesise technology of several camera images as a method to measure density. The collected density value by the 'Density Mesuring System' is selected as the true value based on the density define, and this value was compared with the density calculated by the traditional measurement methods. As a result of the comparison, the density value using the fundamental equation method is the closest to the true value as RMSE shows 1.8 to 2.5. In addition, we investigated some issues that can be overlooked easily such as the collecting interval to be considered on collecting density directly by calculating the moment density and the average density. Despite the actual traffic situation of the experiment site is LOS B, it is difficult to judge the real traffic situation because the moment density values per second are observed max 16.0 (veh/km) to min 2.0 (veh/km). However, the average density measured for 15 minutes at 30-second intervals was 8.3-7.9 (veh/km) and it indicates precisely LOS B.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.110-123
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• 2019

Traffic data is the most basic element necessary for transportation planning and traffic system operation. Recently, a method of estimating traffic flow characteristics using distance to a leading vehicle measured by an ADAS camera has been attempted. This study investigated the feasibility of the ADAS vehicle reflecting the distance error of image-based vehicle identification technology as a means to estimate the traffic flow through the normalized root mean square error (NRMSE) based on the number of lanes, traffic demand, penetration rate of probe vehicle, and time-space estimation area by employing the microscopic simulation model, VISSIM. As a result, the estimate of low density traffic flow (i.e., LOS A, LOS B) is unreliable due to the limitation of the maximum identification distance of ADAS camera. Although the reliability of the estimates can be improved if multiple lanes, high traffic demands, and high penetration rates are implemented, artificially raising the penetration rates is unrealistic. Their reliability can be improved by extending the time dimension of the estimation area as well, but the most influential one is the driving behavior of the ADAS vehicle. In conclusion, although it is not possible to accurately estimate the traffic flow with the ADAS camera, its applicability will be expanded by improving its performance and functions.