• Journal of Broadcast Engineering
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• v.19 no.5
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• pp.687-698
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• 2014

ATSC is currently working on standardization of hybrid 3DTV broadcasting service in heterogenous network environment after completion of service-compatible 3DTV broadcasting service standard based on broadcasting channel. This paper proposes a convergence 3D video broadcasting method on broadcasting and IP network while guaranteeing a Full-HD 3D quality without degrading the image quality of legacy DTV. Specifically, this paper describes transmission of the 3D additional video using the ISO/IEC 23009-1 DASH, robust synchronization method under heterogenous network environments and system target decoder model for hybrid 3DTV receiver. Based on experimental results, we confirm that proposed technologies can be used as a core technology in the hybrid 3DTV standardization and a reference model for a development of hybrid 3DTV encoder and receiver.

• Journal of the Korea Safety Management & Science
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• v.15 no.3
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• pp.7-17
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• 2013

The recent trend in modern systems development can be characterized by the increasing complexity in terms of both the functionality and HW/SW scale that seems to be accelerated by the growing user requirements and the rapid advancement of technology. Among the issues of complexity, the one related to systems safety has attracted great deal of attention lately in the development of the products ranging from mass-transportation systems to defence weapon systems. As such, the incorporation of safety requirements in systems development is becoming more important. Note, however, that since such safety-critical systems are usually complex to develop, a lot of organizations and thus, engineers should participate in the development. In general, there seems to be a variety of differences in both the breadth and depth of the technical background they own. To address the problems, at first this paper presents an effective design process for safety-critical systems, which is intended to meet both the systems design and safety requirements. The result is then advanced to obtain the models utilizing the systems modeling language (SysML) that is a de facto industry standard. The use of SysML can facilitate the construction of the integrated process and also foster active communication among many participants of diverse technical backgrounds. As a case study, the model-based development of high-speed trains is discussed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.4
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• pp.139-145
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• 2016

On the ICT healing platform designed to issue early disease alerts, TOS connected between the provider of personal health-related data and the service provider and relayed personalized health data. In the previous study, TOS proposed how to monitor the retrieval and management of document/measurement resources by taking mobile devices into account. Recently the healthcare field, however, defined the standard items needed for communication and data exchanges with a mobile device through HL7 FHIR. This study designed a data grid model between TOS and FHIR to provide personal health resources relayed through TOS in FHIR bundle search sets. The proposed design was organized as follows: first, it stated similarities between the method of TOS resource request and that of FHIR observation request. Then, it designed an eventbus module to process a retrieval request for FHIR service based on the imdb and cluster technologies. The proposed design can be used to expand the old service terminals of ICT healing platform to mobile health devices capable of using FHIR resources.

• Journal of dental hygiene science
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• v.19 no.4
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• pp.238-244
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• 2019

Background: Recently, three-dimensional (3D) printing has been hailed as a disruptive technology in dentistry. Among 3D printers, a digital light processing (DLP) 3D printer has certain advantages, such as high precision and relatively low cost. Therefore, the latest trend in resin crown manufacturing is the use of DLP 3D printers. However, studies on the internal fitness of such resin crowns are insufficient. The recently introduced 3D evaluation method makes it possible to visually evaluate the error of the desired area. The purpose of this study is to evaluate the internal fitness of resin crowns fabricated a by DLP 3D printer using the 3D evaluation method. Methods: The working model was chosen as the maxillary molar implant model. A total of 20 resin crowns were manufactured by dividing these into two groups. One group was manufactured by subtractive manufacturing system (PMMA), while the other group was manufactured by additive manufacturing system, which uses a DLP 3D printer. Resin crowns data were measured using a 3D evaluation program. Internal fitness was calculated by root mean square (RMS). The RMS was calculated using the Geomagic Verify software, and the mean and standard deviation (SD) were measured. For statistical analysis, IBM SPSS Statistics for Windows ver. 22.0 (IBM Corp., USA) was used. Then, independent t-test was performed between the two groups. Results: The mean±SD of the RMS were 41.51±1.51 and 43.09±2.32 for PMMA and DLP, respectively. There was no statistically significant difference between PMMA and DLP. Conclusion: Evaluation of internal fitness of the resin crown made using a DLP 3D printer and subtractive manufacturing system showed no statistically significant differences, and clinically acceptable results were obtained.

• Journal of Broadcast Engineering
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• v.22 no.5
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• pp.541-547
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• 2017

The Joint Exploration Model (JEM), which is a reference SW codec of the Joint Video Exploration Team (JVET) exploring the future video standard technology, provides a recursive Quadtree plus Binary Tree (QTBT) block structure. QTBT can achieve enhanced coding efficiency by adding new block structures at the expense of largely increased computational complexity. In this paper, we propose a fast decision algorithm of QTBT block partitioning depth that uses the rate-distortion (RD) cost of the upper and current depth to reduce the complexity of the JEM encoder. Experimental results showed that the computational complexity of JEM 5.0 can be reduced up to 21.6% and 11.0% with BD-rate increase of 0.7% and 1.2% in AI (All Intra) and RA (Random Access), respectively.

• The Transactions of the Korea Information Processing Society
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• v.3 no.1
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• pp.144-152
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• 1996

Recently, as the demands for radio spectrum are growing and the number of cell sites is increasing rapidly, the spectrum engineering plays an important role in estimating frequency sharing and reuse. The radio propagation analysis is essential in the basic technology of radio network design such as deciding the service area and selecting the position of the base station. But, domestic propagation environment in which mountainous region is occupying over 70% of our terrain does not allow us to apply foreign studies which are deduced in highly different environments. Therefore, we need to have our propagation analysis system derived from our own terrain condition. In this paper, we propose the propagation prediction model which issuitable toour propagation environment, and also usinghis model, we implement thesimulator based on GIS(Geographic Information System)which can be applied to both spectrum engineering and radio propagation analysis. We showed that this simulator can well be applied to frequency assignment, propagation network design as well as other radio services. Considering the results of our analysis, we could guarantee the standard deviation of error between the measured data and predicted results as 5 to 7 dB.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.5
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• pp.645-652
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• 2010

The aim of this investigation was study on the non-evaporation diesel spray characteristics injected through a common-rail diesel injector under various ambient pressure. The diesel spray was investigated with observation of macroscopic characteristics such as spray tip penetration and spray cone angle by the shadowgraph and the image processing method. The numerical study was conducted using a computational fluid dynamics code, AVL-FIRE. The breakup models used were WAVE model and standard $k-{\varepsilon}$ turbulence model was applied. The numerical study used input data which spray cone angle and fuel injection rate was achieved by Zeuch's method. Comparison with experimental result such as spray tip penetration was good agreement. Distribution of droplet diameter were conducted on four planes where the axial distances were 5, 15, 39 and 49mm respectively downstream from the orifice exit.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.1102-1109
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• 1993

This paper describes the research and development of Walking Tractors and Tillage Implements for Phase I (1991-1992) . The project consists of : (1) the study and need for the development of the walking tractors for Thailand and other Southeast Asian countries ; (2) the comparison in the use of the walking tractors and their transmission systems that are made in Thailand and aborad : and (3) the design of future walking tractors for Asian farmers in developing countries. The design of the walking tractors is concentrated to provide the ease to farmers, especially the elderly and female which will play an important role in the future agriculture of Thailand due to the lack of manpower. In addition , the design of the walking tractors is also aiming for small-scale farmers, the majority that have limited land capital. The walking tractors consist of several components but the most important one is the " Transmission System" . Thus, the research is concentrated in the devel pment an design of the a new transmission system. The new machine , currently developed, is named after the Chulalongkron University as " Chular Walking Tractor " , model SPJS -60. The tractor uses a 6-7 horsepower diesel engine with three forward gears and one reverse gear. The tractor also uses the latest gearing technology so called planetary gearing system with steering clutches system that never been used in any earlier model. The advantages of the planetary gearing system are : (1) the final drive gear can be small, and can be designed to provide higher strength with less wearing resistance, (2) the system eliminates a shaft which is used in other systems, thus reduces the weight and the manufacturing cost . Furthermore, the Chular Walking Tractor has an additional power take off shaft that can be used or linked with other standard agricultural implements.

• Journal of radiological science and technology
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• v.39 no.2
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• pp.257-262
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• 2016

This study aimed to suggest a novel method of modeling a hearing aid ear shell based on Digital Imaging and Communication in Medicine (DICOM) in the hearing aid ear shell manufacturing method using a 3D printer. In the experiment, a 3D external auditory meatus was extracted by using the critical values in the DICOM volume images, and the modeling surface structures were compared in standard type STL (STereoLithography) files which could be recognized by a 3D printer. In this 3D modeling method, a conventional ear model was prepared, and the gaps between adjacent isograms produced by a 3D scanner were filled with 3D surface fragments to express the modeling structure. In this study, the same type of triangular surface structures were prepared by using the DICOM images. The result showed that the modeling surface structure based on the DICOM images provide the same environment that the conventional 3D printers may recognize, eventually enabling to print out the hearing aid ear shell shape.

• International Commerce and Information Review
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• v.6 no.3
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• pp.63-79
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• 2004

Peer-to-peer(P2P) has potential strength and possible factors which enable it to develop toward a new business by supplementing the limitation of the existing central server-type network. In various business sectors, various attempts have already been made to apply P2P. The computing power which was possible to be formed through peer-to-peer networking will become a powerful tools for expanding toward new business area depending the utilization methods by sector. Although the technology-centric P2P concept is a major interest now, its development direction will head toward service-centric P2P concept for satisfying desires of end-users(individual peers) for reliable contents and improving their purchasing convenience. But the solution requisites should be solved for the efficient application of P2P to business such as the establishment of and supplement for the industrial standard and legal system for P2P, the enhancement of peers recognition of P2P. Presently e-commerce using P2P is being implemented by a few enterprises locally by means of B2C. But if many enterprises enter this type of e-commerce, and the standardization of peer programmes, goods and documents is made, it will be able to be extended to B2B. Also it seems that it can be utilized in international transactions as well as in domestic transactions. So there is much room for the application of P2P to be extended further. Also there has been presented the necessity for related industries to support their work with theories and for academic studies to be made actively to set the direction of its development. It is hoped that multi-angled and in-depth studies on the utilization of P2P and various attempts to application of it to business be made on the basis of this study. For the development of P2P, continuous study and attempts are needed. The field of P2Ps application is very large and it will become a powerful tool, depending upon its application methods.