• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.141-150
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• 2010

In this paper, performance of a turbo-coded OFDM system is analyzed and simulated in a power line communication channel. Since the power line communication system typically operates in a hostile environment, turbo code has been employed to enhance reliability of transmitted data. The performance is evaluated in terms of bit error probability. As turbo decoding algorithms, MAP (maximum a posteriori), Max-Log-MAP, and SOVA (soft decision viterbi output) algorithms are chosen and their performances are compared. From simulation results, it is demonstrated that Max-Log-MAP algorithm is promising in terms of performance and complexity. It is shown that performance is improved 3dB by increasing the number of iterations, 2 to 8, and interleaver length of a turbo encoder, 100 to 5000. The results in this paper can be applied to OFDM-based high-speed power line communication systems.

• Journal of the Korea Society of Computer and Information
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• v.13 no.7
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• pp.127-138
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• 2008

Configuration and data management system for weapon system research and development processes should assist concurrent engineering and collaboration activities for various documents, drawings, part informations and product structure informations. In this thesis we defined the system architecture using the CBD methodology and implemented the component based system development process. Most of the configuration and data management systems consist of three layered system architecture which use the general MVC models. In this thesis we defined four layered system architecture based on EJB structure under J2EE environments. Through the four layered system architecture, we break down the general model layer into two detailed business layers and the ordinary control layer into two system dependent layers. With these four layers, we proposed the methodology that detailed the characteristics of the components. Through the CBD approach and the component based development process, we can get the representation model and implement the actual system of the configuration and data management system for weapon system R&D.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.355-361
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• 2018

Mining is important as a national key industry that supplies energy and raw materials that are the basis for industrial development. On the other hand, mine development is necessarily accompanied by mineralization, for example, ground subsidence, heavy metal pollution, and water pollution. The mine hazard has a large range of damage, and it takes much time and cost to recover. In addition, there is a need for systematic mining management in order to prevent damages from occurring continuously. In this study, the present status of domestic mining industry and geospatial information construction technology for mining management were investigated. 95% of the mines surveyed were nonmetallic, and limestone mines accounted for 67%, and the constructed mine spatial information is not constructed with 3D geospatial information due to 2D current status, section, and geological map. Considering the results of the survey and analysis of 3D laser scanner and characteristics of Korean mine, handheld scanner is considered to be the most suitable method for constructing mine geospatial information. In addition, the data acquired through the 3D laser scanner can effectively visualize the object, and it can contribute to the systematic management of mining because it can be used for various purposes such as generation of drawings and calculation of volume.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.3
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• pp.93-103
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• 2014

Regarding to the cadastral information and building information as a spatial information, studies on linking between cadastral records and building information, or integration methodology on 2D based building map and land information were proposed. Cadastral information has grown its values by cadastral resurvey project and cadastral confirmation survey. There is a tendency of BIM in the design stage which is not just simple 3D dataset and BIM is spreading in public and private sectors. However, studies on the linkage between building information and cadastral information is relatively weak comparing to the BIM spreading. One of the main features that have been improved in IFC4 is the interoperability with GIS. In this regards, the researcher propose several revision methods to link cadastral information to building information. Cadastral information needs to improve the quality of the dataset's such as unifying the different coordinate systems and preparing continuous cadastral map. For buildings, standardization of BIM in the public and private sectors is urgent task. IFC4 and upcoming IFC5 are international standards which need to be considered and BIM reverse engineering for the existing buildings is necessary for the public utilization in the near future.

• Korean Journal of Construction Engineering and Management
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• v.15 no.4
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• pp.128-138
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• 2014

Development of infrastructure component libraries is a critical requirement for the accelerated adoption of BIM in the civil engineering sector. Libraries reduce the time for BIM model creation, allows accurate quantity take offs, and shared use of standard models in a project. However, such libraries are currently in very short supply in the domestic infrastructure domain. This research introduces library components for retaining walls and box culverts generated from 2D standard drawings made publicly available by MOLIT. Commercial BIM software was used to create the concrete geometry and rebar, and dimensional/volumetric parameters were defined to maximize the reuse and generality of the libraries. Use of the these libraries in a project context demonstrates that they allow accurate and quick quantity take offs, and easier management of geometric information through the use of a single library as to numerous 2D drawings. It also demonstrates the easy modification of the geometries of the components if and when they need to changed. However, the application also showed that some of the rebar components (stirrups and length wise rebars) do not get properly updated when concrete geometries are changed, demonstrating the limits of current software applications. The research provides evidence of the many advantages of using BIM libraries in the civil engineering, thus providing the incentive for further development of standard libraries and promoting the use of BIM in infrastructure projects.

• Archives of design research
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• no.18
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• pp.25-34
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• 1996

Industrial design development methods and processes have changed in accordance with Industrial Information Age. These days, problems are created by existing methods and evaluation of design value , all problems concerned with time and finances sitaution have been made a subject of discussion. Development of design processes have been changed by the development of problem recognition and solving tools, and dpsign tpchnulugy havp hppn replaced by computer technology,Thus. software design processes linking thoughtware to hardware are used in the solution of design problems with many parts. In this study, 3D Modeling samples are presented, 3D Modeling can realise ' Ideas' to '3Dimentional Virtual Ohjects'. These effect and value are anle to decisively influence the process of design problem conference-ebealuation-solution.Proxesses of actual modeling and rendering are made as follows. By compusition of simple 20 drawings and shaping them into 30 objects, 30 solid models can be made. To prssent effectivley, we can make a sample model by varying camera views,light sourses,materials and colours etc. This sample is evaluated by various cumposition, methods and PERT(Program Evaluation and Review Technique). This cuncrete sample (tentative plan)is changed within the CAD SYSTEM by design evaluation, and then converted to flowchart of mass productive conception through refined data. So, that tentative plan can be conformed to design desire actuillly, to the utmost degree. Finally, this design process can be proposed as il new method in cuntrast with current methods. The aim of this study is to suggest effective evaluation methods of design outcome among many evaluating elements.

• Spatial Information Research
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• v.8 no.2
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• pp.317-328
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• 2000

It is a well-known fact that groundwater is difficult to be recovered, once it is polluted. Since its damage may continue for a long time, its management is very much necessary. For groundwater pollution managemet, current groundwater quality should be analyzed and its diffusion should be estimated. Such analysis and estimation are greatly enhanced by a GIS. In order to build the GIS, groundwater information management system, various database related to groundwater should be constructed. The system can be utilized to analyze groundwater quality and to help administrative processes of groundwater management. In this study, we analyze No3N diffusion in the groundwater under the study area, a part of Jung-Gu area, by using groundwater analysis subsystem and create the 1/5,000 scale map for the diffusion prediction of groundwater pollution. Although Seoul Metropolitan Government has constructed the 1/25,000 scale hydrogeology map of Seoul area through basic groundwater survey in 1996, the survey data are not sufficient for local groundwater pollution management. The large scaled map constructed in this study is expected to be utilized for the management. The GIS softwares, Arc/Info and Arc/View, are used. MODFLOW and MT3D programs are extensively used to analyze groundwater pollution.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.130-144
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• 2023

Recently, various positioning technologies are being researched based on signal-based positioning and image-based positioning to obtain accurate indoor location information. Among these, various studies are being conducted on image positioning technology that determines the location of a mobile terminal using images acquired through cameras and sensor data collected as needed. For video-based positioning, a method of determining indoor location is used by matching mobile terminal photos with virtual landmark images, and for this purpose, it is necessary to build indoor spatial information about various landmarks such as billboards, vending machines, and ATM machines. In order to construct indoor spatial information on various landmarks, a panoramic image in the form of a road view and accurate 3D survey results were obtained through c 13 buildings of the Electronics and Telecommunications Research Institute(ETRI). When comparing the 3D total station final result and the terrestrial lidar panoramic image coordinates, the coordinates and distance performance were obtained within about 0.10m, confirming that accurate landmark construction for use in indoor positioning was possible. By utilizing these terrestrial lidar achievements to perform 3D landmark modeling necessary for image positioning, it was possible to more quickly model landmark information that could not be constructed only through 3D modeling using existing as-built drawings.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.61-71
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• 2015

Purpose : 3D Printers are used to create three-dimensional models based on blueprints. Based on this characteristic, it is feasible to develop a bolus that can minimize the air gap between skin and bolus in radiotherapy. This study aims to compare and analyze air gap and target dose at the branded 1 cm bolus with the developed customized bolus using 3D printers. Materials and Methods : RANDO phantom with a protruded tumor was used to procure images using CT simulator. CT DICOM file was transferred into the STL file, equivalent to 3D printers. Using this, customized bolus molding box (maintaining the 1 cm width) was created by processing 3D printers, and paraffin was melted to develop the customized bolus. The air gap of customized bolus and the branded 1 cm bolus was checked, and the differences in air gap was used to compare $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$ and $V_{95%}$ in treatment plan through Eclipse. Results : Customized bolus production period took about 3 days. The total volume of air gap was average $3.9cm^3$ at the customized bolus. And it was average $29.6cm^3$ at the branded 1 cm bolus. The customized bolus developed by the 3D printer was more useful in minimizing the air gap than the branded 1 cm bolus. In the 6 MV photon, at the customized bolus, $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of GTV were 102.8%, 88.1%, 99.1%, 95.0%, 94.4% and the $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of branded 1cm bolus were 101.4%, 92.0%, 98.2%, 95.2%, 95.7%, respectively. In the proton, at the customized bolus, $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of GTV were 104.1%, 84.0%, 101.2%, 95.1%, 99.8% and the $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of branded 1cm bolus were 104.8%, 87.9%, 101.5%, 94.9%, 99.9%, respectively. Thus, in treatment plan, there was no significant difference between the customized bolus and 1 cm bolus. However, the normal tissue nearby the GTV showed relatively lower radiation dose. Conclusion : The customized bolus developed by 3D printers was effective in minimizing the air gap, especially when it is used against the treatment area with irregular surface. However, the air gap between branded bolus and skin was not enough to cause a change in target dose. On the other hand, in the chest wall could confirm that dose decrease for small the air gap. Customized bolus production period took about 3 days and the development cost was quite expensive. Therefore, the commercialization of customized bolus developed by 3D printers requires low-cost 3D printer materials, adequate for the use of bolus.

• 대한공업교육학회지
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• v.40 no.2
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• pp.155-174
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• 2015

The purposes of this study were to analyze the property of educational needs of teachers for educational contents of invention and intellectual property in secondary vocational education and provide fundamental data for the development of job training programs so as to develop the capabilities of teachers, the base for effective education of invention intellectual property in secondary vocational education. To achieve them, educational needs for the educational contents of invention intellectual property and the priority of the educational needs in secondary vocational education based on the recognition of the teachers were analyzed and suggested. Concrete results of this study can be suggested as follows. First, the average of educational needs of the teachers for the educational contents of invention intellectual property in secondary vocational education was 5.02. There were 23 items of the educational contents whose educational needs were higher than the average of the whole items and for those items and the average of each item, there were F4(The average of patent applications) 6.72, F5(Modification and supplementation of specification sheets) 6.46, F2(Writing of patent floor plans) 6.39, F3(Writing of patent specification sheets and abstraction) 6.31, A5(Invention method and activity) 6.27, E6(Invention design project) 6.15, H3(Invention commercialization) 5.97, F1(Patent information and application) 5.90, E5(Design obligation) 5.78, E3(Designing process of inventional design) 5.77, A4(Invention and problem solving) 5.57, G2(Patent investigation and classification) 5.47, C2(Thinking method of inventional problem solution) 5.45, E4(Production of inventional design product) 5.45, B5(Inventional patent project) 5.42, A2(Creativity development) 5.26, C4(Inventional problem solving project) 5.26, H4(Invention marketing) 5.26, H2(Analysis on invention commercialization) 5.20, D4(Invention and management) 5.16, C3(Problem solving activity) 5.14, E2(Inventional design devise and expression) 5.11, B3(Actuality of inventional method) 5.08 in order. Second, for the priority of educational needs of the teachers for the educational contents of invention intellectual property in secondary vocational education, there were 13 items of the educational contents for the first rank, 10 for the second rank and 17 for the third rank. The items of the educational contents for the first rank were A4(invention and problem solving), A5(inventional method and activity), B5(Invention patent project), C2(Thinking method of inventional problem solution), C4(Inventional problem solving project), E3(Inventional design process), E4(Production of inventional design product), E5(Design obligation), E6(Invention design project), F1(Patent information and application), F2(Writing of patent floor plan), F3(Writing of patent specification sheet and abstract), and H3(Invention commercialization. The items of the educational contents for the second rank were A2(Creativity development), B3(Actuality of inventional method), C3(Problem solving activity), D4(Invention and management), E2(Invention design devise and expression), F4(Range of patent demand), F5(Modification and supplementation of specification sheet), G2(Patent investigation and classification), H2(Analysis on invention commercialization), and H4(Invention marketing). The items for the third rank were the educational contents except the ones of the first rank and the second rank.