• Land and Housing Review
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• v.12 no.3
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• pp.87-96
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• 2021

Korea has begun to use the Helical pile prevalent in Europe. Korea hasn't still set up the standard design criteria on Helical pile due to the lack of relevant researches. In this regard, this study carried out static and dynamic load tests on Helical pile and then performed reliability analysis including the previous research data. The results present that Road bridge design standard design criteia for pre-boring pile with regard to Modified Davisson method showed good reliability and consistency because Resistance bias factor of this design criteria approached '1.0' and Design C.O.V. showed 'low' level.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.35-45
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• 2005

The speed enforcement camera has been regarded as one of the most important safety countermeasures. Drivers decelerate in front of the speed enforcement camera and gain speed up after passing the camera. So there is a strong need to develop the method how to place the camera to overcome this problem. This study applied the concept of design consistency to the installation of the camera, so speed difference along the road sections should be controlled within the predetermined boundary. Specially, this study also regarded camera as the one of the elements of the road alignments which can change the speed of drivers abruptly, and suggested the way to put this concept into the selection of the placement of the camera.

• Journal of Digital Policy
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• v.2 no.4
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• pp.1-10
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• 2023

This study conducted preliminary study to identify effective ways to use ChatGPT in traffic policing by analyzing ChatGPT's responses to the driver's license test and the road traffic accident appraiser test. I collected ChatGPT responses for the driver's license test item pool and the road traffic accident appraiser test using the OpenAI API with Python code for 30 iterative experiments, and analyzed the percentage of correct answers by test, year, section, and consistency. First, the average correct answer rate for the driver's license test and the for road traffic accident appraisers test was 44.60% and 35.45%, respectively, which was lower than the pass criteria, and the correct answer rate after 2022 was lower than the average correct answer rate. Second, the percentage of correct answers by section ranged from 29.69% to 56.80%, showing a significant difference. Third, it consistently produced the same response more than 95% of the time when the answer was correct. To effectively utilize ChatGPT, it is necessary to have user expertise, evaluation data and analysis methods, design a quality traffic law corpus and periodic learning.

• International Journal of Highway Engineering
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• v.10 no.1
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• pp.1-9
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• 2008

Five bases for of highways are sight distance, vehicle stability, driver comfort, drainage and aesthetics. Among these bases, the sight distance is the most critical one in the highway alignment design. It is certain that highways and drivers' observation actions are 3-dimensional in nature. But, the highway alignment design and the sight distance analysis have been performed on 2-dimensional planes because of various constraints and complexity of calculating 3-dimensional sight distance. The purpose of this study is to derive a model for determining exact available sight distance in 3-D combined horizontal and vertical alignments. Application of the model is illustrated using numerical examples. The proposed model should be useful in quantifying the criteria for 3-D highway alignments.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.2
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• pp.65-73
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• 2014

An overall responding security-centered framework is necessary required for infringement accidents, failures, and cyber threats. On the other hand, the correspondence structures of existing administrative, technical, physical security have weakness in a system responding to complex attacks because each step is performed independently. This study will recognize all internal and external users as a potentially threatening element. To perform connectivity analysis regarding an action, an intelligent convergence security framework and road map is suggested. A suggested convergence security framework was constructed to be independent of an automatic framework, such as the conventional single solution for the priority defense system of APT of the latest attack type, which makes continuous reputational attacks to achieve its goals. This study suggested the next generation convergence security framework to have preemptive responses, possibly against an APT attack, consisting of the following five hierarchical layers: domain security, domain connection, action visibility, action control, and convergence correspondence. In the domain, the connection layer suggests a security instruction and direction in the domains of administrative, physical and technical security. The domain security layer has consistency of status information among the security domain. A visibility layer of an intelligent attack action consists of data gathering, comparison and decision cycle. The action control layer is a layer that controls the visibility action. Finally, the convergence corresponding layer suggests a corresponding system of before and after an APT attack. The administrative security domain had a security design based on organization, rule, process, and paper information. The physical security domain is designed to separate into a control layer and facility according to the threats of the control impossible and control possible. Each domain action executes visible and control steps, and is designed to have flexibility regarding security environmental changes. In this study, the framework to address an APT attack and load map will be used as an infrastructure corresponding to the next generation security.

• International Journal of Highway Engineering
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• v.17 no.3
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• pp.49-58
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• 2015

PURPOSES : The use of environmentally friendly construction methods has been recently encouraged to reduce fuel consumption and the effects of global warming. For this purpose, the roller compacted concrete pavement (RCCP) construction method has been developed. RCCP is more environmentally friendly and economically efficient than general concrete by reducing the amount of CO2 generated through the application of a smaller amount of cement. RCCP has a number of advantages such as an easy construction method, low cost, high structural hydration performance, and aggregate interlocking. However, mix design standards and construction guidelines of RCCP are required for domestic application. In addition, a study on aggregate selection, which has an effect on the characteristics of RCCP, is necessary owing to a limited number of researches. Thus, the aggregate effect on the performance of RCCP in securing the required strength and workability was evaluated in consideration of domestic construction. METHODS : Sand and coarse aggregates of both 19mm and 13mm in maximum size were used in this study. Four types of aggregate gradations (s/a = 30%, 58%, and 70% for the sand and coarse aggregate of 19mm in maximum size, and s/a = 50% for a combination of the three types of aggregates) were set up to investigate the effects of the PCA band on the RCC characteristics. The conditions of s/a = 30% and 70% were evaluated to check the gradation effect outside of the recommended band. The conditions of s/a = 58% and 50% were used because they are the optimum combination of the two and three types of aggregates, respectively. RCCP gradation band was suggested gradation with a proper construction method of RCCP by synthetically comparing and analyzing the correlation of optimum water content, maximum dry density, and strength of requirements through its consistency and compaction test. RESULTS : The lower and upper limit lines are insufficient to secure a relatively strong development and workability compared to an aggregate gradation in the RCCP gradation band region. On the other hand, the line in the RCCP gradation band and the 0.45 power curve in the RCCP gradation band region were satisfactory, ensuring the required strength and workability. CONCLUSIONS : The suitable aggregate gradation on RCCP process should meet the RCCP gradation band area; however, fine particles passing through a #60 sieve do not need to be within the recommended gradation band because the influence of this region on such fine particles is small.

• The Journal of Engineering Geology
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• v.21 no.3
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• pp.239-246
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• 2011

Upon encountering weathering soil at a construction site, it may be necessary to change the design and construction plans for geotechnical structures. When weathering soil is exposed to air, the weathering process proceeds rapidly, resulting in significant damage to geotechnical structures, particle defects, and an increase in moisture sensitivity. The management of weathering-soil compaction is challenging. Because the engineering properties of weathering-soils vary regionally, it is important to report the result of research into the regional characteristics of such soils. At two locations of granite gneiss in the Gansung area of Gangwon-do, geological studies were performed at 22 and 8 sites, respectively. At each site, test samples were collected for analysis by XRD and to measure particle size, consistency, and compaction. To evaluate the suitability of the material for road subgrade, we examined the interrelationship between CBR value and the uniformity coefficient, the 200 sieve passing ratio and the aggregate ${\geq}$ 2 mm) content. We found that for the weathered granite soil, aggregate sized > 2 mm has a significant effect on the CBR value. In addition, the mixing of aggregate sized > 2 mm with sub-quality soil improves the soil condition.

• Korean Journal of Construction Engineering and Management
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• v.10 no.1
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• pp.114-125
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• 2009

In this study, a design value analysis technique that considered stochastic LCC and stochastic performance evaluation was proposed, and by introducing the concept of reliability analysis, a decision making that secured reliability was supported. The results of this study, which was carried out according to the above objectives and methods, are summarized as follows: 1) The design value analysis procedures and value state function, improved in order to carry out a reliable analysis when evaluating alternate proposals that were extracted after the function definition was complete, were formalized, and in order to secure consistency and efficiency for value evaluation procedures, an evaluation index scheme was proposed; 2) Database collection and analysis were done for a bridge's LCC analysis. As for the collection scope of data, literature of previous research done on a bridge's LCC analysis was used as the basis for analysis, and for securing reliability regarding analysis results and dealing with uncertainty of collected data, the MCS technique was applied; 3) Weights and evaluation ranks for performance evaluation of each of the alternate proposals, as well as LCC analysis model, analysis period, discount rate, user expense, safety inspection and safety diagnosis expense conditions for LCC analysis were proposed. Lastly, a feasibility study was done and conclusion was made about "OO grand bridge and connecting road construction work execution design" project centered on value analysis execution case.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.203-211
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• 2014

Tunnel reduces travel time as and it is essential facilities for the eco-friendly road construction. In recent years, It has been accelerating the tunnel construction to provide a higher level of traffic service but a driver driving in the narrow and dark tunnel takes characteristically psychological anxiety and the restriction of the sight. Moreover, A driver passing through more than 1,000m long tunnel, as to pass inside the monotonous form of the tunnel for a long time can cause drowsiness and increase the driver load. This driver load can degrade road-holding of the inside of the long tunnel highly and pose a high risk of accidents. Accordingly, In this study is to present the proper length of the Tunnel, considering the characteristics of traffic accident. For this, this study is that the long tunnel that affects traffic safety traffic safety variables are selected and classified. Traffic safety variables are classified in detail as a variable of the traffic accident and velocity one, the applicable variables the number of the traffic accident, the ratio of the traffic accident, driving velocity, the individual vehicle velocity etc. Traffic safety variables are categorized as more than a pole length of the tunnel in order to examine its impact on correlation analysis. The results indicate significant results in traffic accidents in accordance with traffic accidents, traffic safety, selects the variable was Variable depending on the length of the tunnel traffic safety point of significantly increasing the possibility of an accident can be seen as a high point. And the point of the Distribution of selected variables in order to create a traffic safety was a significant increase in traffic safety variables was set at critical intervals. Before reaching the critical point and the corresponding length of the long tunnel was set at the proper length. In this study, the optimum length of the proposed long tunnel through the long tunnel that occur in the future to contribute to reducing traffic accidents would be able to be determined.