• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.383-389
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• 2011

The purpose of this paper is to analyze the blind spot for public transportation by level of service(LOS) in public transportation supply service. For the purpose, we proposed indices of service coverage area, service frequency and hours of service and analysis method for them. Service coverage area analysis is to decide station location and network design for the maximum beneficiary area. Moreover, we can use the service frequency is for the maximum service frequency decision and hours of service is for the minimum operation hours. The results of this study are applied to the plan of minimum supply service, minimum service frequency and minimum operation hours for city and national public transportation plan.

• Journal of Digital Convergence
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• v.6 no.3
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• pp.23-34
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• 2008

Progressing of Web2.0 and social digitalization are lead to changing citizens participation and citizen centric service of civic service. To meet this trends that is online collaboration and sharing, citizen's service that provides our government, also need to changing web2.0 style. This paper argues that government could now grasp the opportunities that are emerging in terms of web2.0 Current policy and action is not yet adequate to grasp these opportunities. So this study focused on strategies of civil services based on web2.0 using NCIA(National Computerization Integrated Agency) cases. For the purpose, we analyze former researches related with civil service. And then, we propose web2.0 adaptation strategies for NCIA.

• Computers and Concrete
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• v.10 no.6
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• pp.587-607
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• 2012

The purpose of this research is to propose a design technique of concrete mix proportions satisfying service life through genetic algorithm (GA) and neural network (NN). For this, thirty mix proportions and the related diffusion coefficients in high performance concrete are analyzed and fitness function for diffusion coefficient is obtained considering mix components like w/b (water to binder ratio), cement content, mineral admixture (slag, flay ash and silica fume) content, sand and coarse aggregate content. Through averaging the results of 10 times GA simulations, relative errors to the previous data decrease lower than 5.0% and the simulated mix proportions are verified with the experimental results. Assuming the durability design parameters, intended diffusion coefficient for intended service life is derived and mix proportions satisfying the service life are obtained. Among the mix proportions, the most optimized case which satisfies required concrete strength and the lowest cost is selected through GA algorithm. The proposed technique would be improved with the enhancement of comprehensive data set including wider the range of diffusion coefficients.

• Journal of the Korean Society of Safety
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• v.24 no.5
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• pp.48-56
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• 2009

This paper presents the procedure for the optimal design of a PSC-I girder bridge considering life cycle cost (LCC). The load carrying capacity curves for the concrete deck, PSC-I girder and $\pi$-type pier were derived and used for the estimate of service lives. Total life cycle cost for the service life was calculated as sum of initial cost, damage cost, maintenance cost, repair and rehabilitation cost, user cost, and disposal cost. The advanced First Order Second Moment method was used to estimate the damage cost. The optimization method was applied to the design of PSC-I girder bridge. The objective function was set to the annual cost, which is defined by dividing the total life cycle cost by the service life, and constraints were formulated on the basis of Korean Standards. The optimal design was performed for various service lives and the effects of design factors were investigated.

• Fire Science and Engineering
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• v.20 no.4 s.64
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• pp.42-57
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• 2006

This study suggests improvement plans : safety check system security through combination in stages, unification of fire inspection, enterprising security of prevention work, enforcement of certificate of qualification for safety, activation of civil partner-ship of fire disaster prevention through contrast prevention work of administrative service with civil mind and an in-depth analysis : dispersed and duplicated management current safety check service, improper commission collection, immorality diffusion of involved, potential irregularities causes, deficit of professionalism security.

• Geomechanics and Engineering
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• v.18 no.4
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• pp.373-389
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• 2019

It is important to study the problem of durability for tunnel structures. As a main influence on the durability of tunnel structures, carbonation-induced corrosion is studied. For the complicated environment of tunnel structures, based on the data samples from real engineering examples, the intelligent method (genetic programming) is used to construct the service life prediction model of tunnel structures. Based on the model, the prediction of service life for tunnel structures in carbonation environments is studied. Using the data samples from some tunnel engineering examples in China under carbonation environment, the proposed method is verified. In addition, the performance of the proposed prediction model is compared with that of the artificial neural network method. Finally, the effect of two main controlling parameters, the population size and sample size, on the performance of the prediction model by genetic programming is analyzed in detail.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2007.11a
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• pp.289-297
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• 2007

• Smart Structures and Systems
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• v.6 no.5_6
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• pp.423-438
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• 2010

Wireless smart sensors enable new approaches to improve structural health monitoring (SHM) practices through the use of distributed data processing. Such an approach is scalable to the large number of sensor nodes required for high-fidelity modal analysis and damage detection. While much of the technology associated with smart sensors has been available for nearly a decade, there have been limited numbers of fulls-cale implementations due to the lack of critical hardware and software elements. This research develops a flexible wireless smart sensor framework for full-scale, autonomous SHM that integrates the necessary software and hardware while addressing key implementation requirements. The Imote2 smart sensor platform is employed, providing the computation and communication resources that support demanding sensor network applications such as SHM of civil infrastructure. A multi-metric Imote2 sensor board with onboard signal processing specifically designed for SHM applications has been designed and validated. The framework software is based on a service-oriented architecture that is modular, reusable and extensible, thus allowing engineers to more readily realize the potential of smart sensor technology. Flexible network management software combines a sleep/wake cycle for enhanced power efficiency with threshold detection for triggering network wide operations such as synchronized sensing or decentralized modal analysis. The framework developed in this research has been validated on a full-scale a cable-stayed bridge in South Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2481-2486
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• 2013

It requires a lot of time and effort for general users who do not have enough understanding of GPS to properly processing GPS data. However, the GPS data processing field heavily relies on foreign-produced software and there is almost no development of user-oriented technology. Therefore, in this study, it was attempted to build an expert service that enables non-experts to use high-precision GPS data processing. As a result, an expert service that can maximize user convenience simply by entering the minimum required information for GPS data processing was developed, and the expert service was verified by relative positioning processing of the observation data of satellite control point provided by National Geographic Information Institute and observation data obtained by GPS survey. The expert service significantly reduces the effort and time for processing GPS data, which will contribute to precise positioning and other various studies.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.10b
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• pp.1-18
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• 2001

Recently advanced composite materials have been successfully used in the civil infrastructure application due to its many advantages such as light weight, high strength, corrosion resistance. Demand for longer service life, increased durability and reduced maintenance have prompted such developments. In this article, characteristics of composite materials, fabrication process, case studies for various field and future of advanced composite materials for civil infrastructures is presented.