• Journal of Digital Convergence
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• v.15 no.12
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• pp.313-321
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• 2017

Traffic accidents in the country have steadily increased. Although IOT technologies have been applied so as to prevent the primary accident, practical solutions to prevent the secondary accident have not been suggested. A general guideline is simply recommended. In this paper, utilizing existing communication technology, we implement a proposed model and its simulation to prevent the secondary accident. When it is possible for a driver to secure visibility, the secondary accident can be prevented; In areas like tunnel, mountain terrain, and curve road with heavy traffic, where the driver has difficulty in securing the visibility, the secondary accident rates after the primary accident have been increasing. Therefore, we implement an accident prevention system that determines the primary accident utilizing sensor technology and prevents the secondary accident communicating through V2V or V2I. After the simulation, we found that the proposed model and the existing model made no difference with regard to the secondary accident rates when the visibility of the driver is secured; With the application of the proposed model, however, the accident rates decreased for 3-7 percent even though the visibility and communication were not secured.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.4
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• pp.24-38
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• 2017

The awareness and demand for technological elements in the field of cloud computing and their application models have increased. Cloud-based service information systems are being expanded for use in many applications. Advancements in information technology are directly related to spatial information. PaaS is an important platform for implementing a substantial cloud ecosystem to develop geo-based application services. For this reason, it is necessary to analyze the PaaS cloud technology prior to the development of SaaS. The PaaS cloud supports sharing of related extensions, database operations and management, and application development and deployment. The development of geo-spatial information systems or services based on PaaS in ranging the domestic and overseas range is in the initial stages of both research and application. In this study, state-of-the-art cloud computing is reviewed and a conceptual design for geo-based applications is presented. The proposed model is based on container methods, which are the core elements of PaaS cloud technology based on open source. It is thought that these technologies contribute to the applicability and scalability of the geo-spatial information industry that addresses cloud computing. It is expected that the results of this study will provide a technological base for practical service implementation and experimentation for geo-based applications.

• Journal of the Korean Chemical Society
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• v.44 no.6
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• pp.600-610
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• 2000

The purpose of this study was to design the new teaching strategy based on the particulate model facilitating the reflective thinking (RE-PM) in the learning of the particulate nature of matter, and to investigate the effect of the new teaching strategy in compare with the traditional teaching strategy (TS-PM) after treating with new teaching strategy on preliminary teachers of elementary school. The problems of traditional teaching strategy are as follows: 1) Most of students didn't think the particulate model connected with practical material. 2) Most of students have a tendency of the rote memory on learning of the traditional particulate model. 3) The ratio of changing the view of continuous matter into the view of particulate nature of matter was very low, after learning the particulate model using of the traditional teaching strategy. The new teaching strategy facilitating the reflective thinking was more effective on the understanding of particulate nature of matter and the driving of motivation than the traditional teaching strategy in the learning of the particulate nature of matter.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.3
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• pp.269-275
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• 2020

In this study, flexural tests of precast concrete panels according to the thickness of cross-sectional and the with or not of reinforcement were carried out in order to develop and assess of a lightweight precast concrete panel using ultra high performance concrete. For the test, four panels were fabricated, and consisted of one normal concrete panel and three ultra high performance concrete panels. As a test result, it was found that the plain precast panel using ultra high performance concrete had a lower flexural performance than the reinforced normal concrete panel, regardless of the cross-sectional size. The flexural performance of the hollow-sectional precast panel applying ultra high performance concrete, is improved by 150% compared to that of the reinforced normal concrete panel. That is, through additional performance verification and optimization of the cross-sectional design of the panel, the ultra high performance concrete precast panel can be made lighter. Also, the practical use of lightweight precast panels with ultra high performance concrete can be available through evaluation on shear, joint connection and anchoring, etc.

• Journal of The Korean Association For Science Education
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• v.33 no.2
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• pp.284-309
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• 2013

This study aims to explore how to characterize high school science inquiry. For this research, data were collected from fifteen science classes (18 hours), through observation and videotaping, interviews with a few students and their teacher, and documents such as lesson plan or activity sheet in 13 Science Core High Schools. All the data were transcribed and analyzed. Analyses of these transcripts were proceeded in three steps: first, classroom cases showing active interactions between teacher-students and among students were selected; second, according to cognitive process of inquiry (Chinn & Malhotra, 2002), each segment was analyzed and interpreted; lastly, distinctive cases were determined to show essential features of school science inquiry. Based on the analyses, we characterize high school science inquiry in terms of features of variables controlling-device improvement, design studies, evidence-explanation transformation, and reasoning to formulate explanations from evidence. Teachers' role and educational support were discussed as well as the practical characters or features of school science inquiry.

• Journal of the Korean Geotechnical Society
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• v.15 no.3
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• pp.161-176
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• 1999

A powerful numerical method that can be used for modeling rock-structure interaction is the Discontinuous Deformation Analysis (D D A) method developed by Shi in 1988. In this method, rock masses are treated as systems of finite and deformable blocks. Large rock mass deformations and block movements are allowed. Although various extensions of the D D A method have been proposed in the literature, the method is not capable of modeling water-block interaction, sequential loading or unloading and rock reinforcement; three features that are needed when modeling surface or underground excavation in fractured rock. This paper presents three new extensions to the D D A method. The extensions consist of hydro-mechanical coupling between rock blocks and steady water flow in fractures, sequential loading or unloading, and rock reinforcement by rockbolts, shotcrete or concrete lining. Examples of application of the D D A method with the new extensions are presented. Simulations of the underground excavation of the \ulcornerUnju Tunnel\ulcorner in Korea were carried out to evaluate the influence of fracture flow, excavation sequence and reinforcement on the tunnel stability. The results of the present study indicate that fracture flow and improper selection of excavation sequence could have a destabilizing effect on the tunnel stability. On the other hand, reinforcement by rockbolts and shotcrete can stabilize the tunnel. It is found that, in general, the D D A program with the three new extensions can now be used as a practical tool in the design of underground structures. In particular, phases of construction (excavation, reinforcement) can now be simulated more realistically.

• The KIPS Transactions:PartD
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• v.14D no.2
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• pp.265-272
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• 2007

In this paper, we implement an automated composition system of web services using hybrid techniques that merge the benefit of BPEL techniques, with the advantage of OWL-S, BPEL techniques have practical capabilities that fulfil the needs of the business environment such as fault handling and transaction management. However, the main shortcoming of these techniques is the static composition approach, where the service selection and flow management are done a priori and manually. In contrast, OWL-S techniques use ontologies to provide a mechanism to describe the web services functionality in machine-understandable form, making it possible to discover, and integrate web services automatically. This allows for the dynamic integration of compatible web services, possibly discovered at run time, into the composition schema. However, the development of these approaches is still in its infancy and has been largely detached from the BPEL composition effort. In this work, we describe the design of the SemanticBPEL architecture that is a hybrid system of BPEL4WS and OWL-S, and propose algorithms for web service search and integration. In particular, the SemanticBPEL has been implemented based on the open source tools. The proposed system is compared with existing BPEL systems by functional analysis. These comparisions show that our system outperforms existing systems.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.8
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• pp.543-554
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• 2013

Model-Driven Development(MDD) helps developers verify requirements and design issues of a software system in the early stage of development process by taking advantage of a software model which is the most highly abstracted form of a software system. In practice, however, many software systems have been developed through a code-centric method that builds a software system bottom-up rather than top-down. So, without support of appropriate tools, it is not easy to introduce MDD to real development process. Although there are many researches about extracting a model from code to help developers introduce MDD to code-centrically developed system, most of them only extracted base-level models. However, using concept of abstract component one can continuously extract higher level model from base-level model. In this paper we propose a practical method for automatic extraction of base level abstract component from source code, which is the first stage of continuous extraction process of abstract component, and validate the method by implementing an extraction tool based on the method. Target code chosen is the source code of TinyOS, an operating system for wireless sensor networks. The tool is applied to the source code of TinyOS, written in nesC language.

• Spatial Information Research
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• v.9 no.2
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• pp.239-261
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• 2001

A large suite of official statistical data sets has been compiled for geographical units under the national directives, and it is the quantitative regional analysis procedures that could add values to them. This paper reports our attempts at prototyping a statistical GIS which is capable of serving over the Web a variety of regional analysis routines as well as value-added statistics and maps. A pilot database of some major statistical data was ingested for the city of Seoul. The baseline subset of regional analysis methods of practical usage was selected and accommodated into the business logic of the target system, which ranges from descriptive statistics, regional structure/inequality measures, spatial ANOVA, spatial (auto) correlation to regression and residual analysis. The leading-edge information technologies including the application server were adopted in the system design and implementation so that the database, analysis modules and analytic mapping components may cooperate seamlessly behind the Web front-end. The prototyped system supports tables, maps, and files of downloadable format for input and output of the analyses. One of the most salient features of out proposed system is that both the database and analysis modules are extensible via the bi-directional interface for end users; The system provides users with operators and parsers for algebraic formulae such that the stored statistical variables may be transformed and combined into the newly-derived set of variables. This functionality eventually leads to on-the-fly fabrication of user-defined regional analysis algorithms. The stored dataset may also be temporarily augmented by user-uploaded dataset; The extension of this form, in essence, results in a virtual database which awaits for users commands as usual. An initial evaluation of the proposed system confirms that the issues involving the usage and dissemination of information can be addressed with success.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.791-800
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• 2013

Needs for developing a better way of cost estimating process for public construction projects have been widely recognized. Those needs are mainly from the early phases of the project through the construction life cycle due to the its importance to the control process. In contrast to the traditional estimating method based on unit-price references, this research utilized this following process. The first step is analyzing the real cost data from actual cost activities (2000~2010) about the statement of P.S.C(Prestressed Concrete) Box Girder Bridge. The collected data was broken into four categories based on technical construction methods such as I.L.M(Incremental Launching Method), M.S.S(Movable Scaffolding System), F.S.M(Full Staging Method), and F.C.M(Free Cantilever Method). The second, actual design documents including the actual cost estimating documents, drawings and specifications were carefully reviewed to cluster the cost itemized statement from four categories. It was also attempted to seek the proper breakdown of standard works that are responsible for more than 95 percentage in each categories in terms of its cost. The third, this research comes up the index for standard unit materials and unit price of standard work and develops the approximate estimating model applying for the specification(length and breadth of bridges) per square area that the user takes as well as suggests the practical application plan within the original time alloted.