• Journal of Ocean Engineering and Technology
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• v.12 no.3 s.29
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• pp.86-95
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• 1998

CAD/CAM program developers have made substantial progress in enabling engineers to design, analyze, visualize, visualize, and simulate the performance of structures and systems. Many researchers, however, agree that there is still a way to go before the existing commercial computer software can be used in ship structural analysis to their full potential as solvers which can identify opportunities to reduce man-hours and cut costs. CAD systems used for these works in ship yards are general-purposed and not custom-tailored for ship structures, which force end-users to do tiresome and routine works. The new preprocessor "MeshGen" announced in this study can load several ship types and user-friendly generate their FE meshes employing the object-oriented approach based on the parametric and top-down design. Also "MeshGen" reduces dramatically the time required to prepare CAD models under window-based environments on desktop personal computers and makes it much easier and faster for end-users to change topology and material properties.

• Geomechanics and Engineering
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• v.33 no.2
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• pp.203-209
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• 2023

One major advantage of ground penetrating radar (GPR) over other field test methods is its ability to obtain subsurface images of roads in an efficient and non-intrusive manner. Not only can the strata of pavement structure be retrieved from the GPR scan images, but also various irregularities, such as cracks and internal cavities. This article introduces a deep learning-based approach, focusing on detecting subsurface cracks by recognizing their distinctive hyperbolic signatures in the GPR scan images. Given the limited road sections that contain target features, two data augmentation methods, i.e., feature insertion and generation, are implemented, resulting in 9,174 GPR scan images. One of the most popular real-time object detection models, You Only Learn One Representation (YOLOR), is trained for detecting the target features for two types of subsurface cracks: bottom cracks and full cracks from the GPR scan images. The former represents partial cracks initiated from the bottom of the asphalt layer or base layers, while the latter includes extended cracks that penetrate these layers. Our experiments show the test average precisions of 0.769, 0.803 and 0.735 for all cracks, bottom cracks, and full cracks, respectively. This demonstrates the practicality of deep learning-based methods in detecting subsurface cracks from GPR scan images.

• Journal of Internet Computing and Services
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• v.5 no.4
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• pp.77-94
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• 2004

Recently, the needs of index structure which manages moving objects efficiently have been increased because of the rapid development of location-based techniques. Existing index structures frequently need updates because moving objects change continuatively their positions. That caused entire performance loss of the index structures. In this paper, we propose a new index structure called the TPKDB-tree that is a spatio-temporal index structure based on KDB-tree. Our technique optimizes update costs and reduces a search time for moving objects and reduces unnecessary updates by expressing moving objects as linear functions. Thus, the TPKDB-tree efficiently supports the searches of future positions of moving objects by considering the changes of moving objects included in the node as time-parameter. To maximize space utilization, we propose the new update and split methods. Finally, we perform various experiments to show that our approach outperforms others.

• The KIPS Transactions:PartB
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• v.9B no.6
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• pp.817-826
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• 2002

In Korean dialogue honorification phenomenon may occur, an honorific pronoun may be used, and a subject or an object may be completely omitted when it can be recovered based on context. This paper proposes that in order to process Korean dialogue in which such distinct linguistic phenomena occur and to construct its representation structure we mark and use the following information explicitly, not implicitly : information about dialogue participants, information about the speech act of an utterance, information about the relative order of social status for the people involved in dialogue, and information flow among utterances of dialogue. In addition, this paper presents a method of marking and using such situational information and an appropriate representation structure of Korean dialogue. In this paper we set up Korean dialogue representation structure by modifying and extending DRT (Discourse Representation Theory) and SDRT (Segmented Discourse Representation Theory). Futhermore, this paper shows how to process Korean dialogue computationally and construct its representation structure by using Prolog programming language, and then applies such representation structure to spontaneous Korean dialogue to know its validity.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.1
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• pp.81-89
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• 2015

This study takes shear wall of reinforced concrete structure as study object, and the purpose of this study is to suggest structure BIM based on automatic reinforcing bar placement system applying set-based design through the most optimum reinforcing bar placement group that was selected by applying AHP (analytical hierarchy process) method from design step. For this, the most optimum reinforcing bar placement group was selected by pairwise comparison analysis on complex standard of multiple alternatives. And shear wall automatic reinforcing bar placement system has been developed, which can automatically generate members and arrange reinforcing bar by structure design algorithm and using open API (application programming interface) provided by a BIM software vendor. As a result, the most optimum reinforcing bar placement group of the highest weight, ALT1, was selected and was generated using Tekla Structure program.

• Journal of KIISE
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• v.41 no.11
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• pp.935-942
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• 2014

Today, it is very important issue to high quality of software issue on huge scale of code and time-to-market. In the industrial fields still developers focuses on Code based development. Therefore we try to consider two points of views 1) improving the general developer the bad development habit, and 2) maintenance without design, documentation and code visualization. To solve these problems, we need to make the code visualization of code. In this paper, we suggest how to visualize the inner structure of code, and also how to proceed improvement of quality with constructing the Tool-Chain for visualizing Java code's inner structure. For our practical case, we applied Object Code with NIPA's SW Visualization, and then reduced code complexity through quantitatively analyzing and visualizing code based on setting the basic module unit, the class of object oriented code.

• Journal of Broadcast Engineering
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• v.21 no.6
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• pp.944-956
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• 2016

In this paper, we propose a new hardware architecture to generate computer-generated holograms based on the block based calculation method and implement a VLSI (very large scaled integrated circuit) in ASIC (application specific integrated circuit) environment. The proposed hardware has a structure that can produce a part of a hologram in the unit of a block in parallel. After calculating a block of a hologram by using an object point, the calculation is repeated to all object points and intermediate results from them are accumulated to produce a final block of a hologram. Through this structure, we can make various size of holograms with the optimized memory access in real-time operation. The proposed hardware was implemented in the Hynix 0.18um CMOS technology of Magna chip Inc. and has 876,608 gate counts. It can generate complex holograms unlike the previous researches and stably operate in the clock frequency of 200MHz.

• Journal of Cadastre & Land InformatiX
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• v.44 no.2
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• pp.91-101
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• 2014

This study tried to create 3D object with LOD3 level for Korean traditional house which is atypical structure, upload to spatial information open platform and confirm the possibility for creating 3D-map. And this study tried to create 3D model for Korean traditional house based on BIM, performed 3D modeling for interior spatial information of Korean traditional house and confirm the development possibility of 3D modeling and visualization method of Korean traditional house. Also this study present the possibility of LOD4 level visualization for spatial information of Korean traditional house which is atypical structure, but 3D object with LOD4 level can't be uploaded to Spatial Information Open Platform currently, cause by data volume limitation of spatial information open platform.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.3
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• pp.81-89
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• 2021

Under natural conditions, Apple detection has the problems of occlusion and small object detection difficulties. This paper proposes an improved model based on SSD. The SSD backbone network VGG16 is replaced with the ResNet50 network model, and the receptive field structure RFB structure is introduced. The RFB model amplifies the feature information of small objects and improves the detection accuracy of small objects. Combined with the attention mechanism (SE) to filter out the information that needs to be retained, the semantic information of the detection objectis enhanced. An improved SSD algorithm is trained on the VOC2007 data set. Compared with SSD, the improved algorithm has increased the accuracy of occlusion and small object detection by 3.4% and 3.9%. The algorithm has improved the false detection rate and missed detection rate. The improved algorithm proposed in this paper has higher efficiency.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.2
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• pp.46-64
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• 2003

The vector shaped object is generally very long (hundreds or thousands of kilometers) and very narrow (10-100 meters). Image mapping techniques and tools for these objects should be totally different from the traditional area-based targets. Acknowledging these unique characteristics of the vector shaped object, a motion picture mapping system has been developed by combining internet GIS technology with airborne video. In particular, integration between airborne video and digital maps took advantage of each component, and enabled the landscape structure to be visualized, interacted with and deployed all on the Web. The motion picture maps provided a completely new means for disseminating information for area-wide landscape in a visual and interactive manner to the general public while digital map with location information revealed successfully the major parameters that influence an area-wide spatial structure in the study area. The remote video approach breaks down the usual concept of image mapping in a conventional cartography. As a result, the research findings have established the new concept of 'internet airborne video mapping for vector shaped object', proposed as an initial aim of this paper. It would playa crucial role in improving the quality of public information service if the mapping system is operationally introduced into the Government since the highly user-friendly moving picture provides a completely new means for disseminating spatia) information for vector shaped object.