• ETRI Journal
• /
• v.30 no.4
• /
• pp.597-599
• /
• 2008

This letter presents the design of a small and low-profile RFID tag antenna in the UHF band that can be mounted on metallic objects. The designed tag antenna, which uses a ceramic material as a substrate, consists of a radiating patch and a microstrip line with two shorting pins for a proximity-coupled feeding structure. Using this structure, impedance matching can be simply obtained between the antenna and tag chip without a matching network. The fractional impedance bandwidth for $S_{11}$ <3 dB and radiation efficiency are about 1.4% and 56% at 911 MHz, respectively. The read range is approximately from 5 m to 6 m when the tag antenna is mounted on a metallic surface.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.36 no.1
• /
• pp.1-7
• /
• 2023

An artificial intelligence (AI) method based on image deep learning is proposed to predict the entire displacement shape of a structure using the feature of partial displacements. The performance of the method was investigated through a structural test of a steel frame. An image-to-image regression (I2IR) training method was developed based on the U-Net layer for image recognition. In the I2IR method, the U-Net is modified to generate images of entire displacement shapes when images of partial displacement shapes of structures are input to the AI network. Furthermore, the training of displacements combined with the location feature was developed so that nodal displacement values with corresponding nodal coordinates could be used in AI training. The proposed training methods can consider correlations between nodal displacements in 3D space, and the accuracy of displacement predictions is improved compared with artificial neural network training methods. Displacements of the steel frame were predicted during the structural tests using the proposed methods and compared with 3D scanning data of displacement shapes. The results show that the proposed AI prediction properly follows the measured displacements using 3D scanning.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2004.03b
• /
• pp.946-951
• /
• 2004

ITIS is applied to the several tunnel construction sites in Korea. Tunnel construction properties which are acquired from these sites are transferred to information management server(SQL 2000 server)by client application program in real time. Access permission to DB server depends on the user's roles. Some functions which cannot be embodied in SQL Server are serviced through XML and GMS server is used for spatial data based on GIS part. This system is supposed to give engineers the advantages which are not only easy handling of the program and computerized documentation on every information during construction but also analyzing the acquired data in order to predict the structure of ground and rock mass to be excavated later and show the guideline of construction. Neung-Dong tunnel and Mu-Gua express way tunnel are now under construction and with this system they have 3D visualized map of the geology and tunnel geometry and accumulate database of construction information such as tunnel face mapping results, special notes and pictures of construction and 3D monitoring data, all matters on the stability of rock bolts and shotcrete, and so on. Ground settlement prediction program included in ITIS, based on the artificial neural network(ANN) and supported by GIS technology is applying to the subway tunnel. This prediction tool can make it possible to visualize the ground settlement according to the excavation procedures by contouring the calculated result on 3D GIS map and to assess the damage of buildings in the vicinity of construction site caused by ground settlement.

• Journal of KIISE:Software and Applications
• /
• v.36 no.6
• /
• pp.479-490
• /
• 2009

A number of temporal abstraction approaches have been suggested so far to handle the high computational complexity of Markov decision problems (MDPs). Although the structure of temporal abstraction can significantly affect the efficiency of solving the MDP, to our knowledge none of current temporal abstraction approaches explicitly consider the relationship between topology and efficiency. In this paper, we first show that a topological measurement from complex network literature, mean geodesic distance, can reflect the efficiency of solving MDP. Based on this, we build an incremental method to systematically build temporal abstractions using a network model that guarantees a small mean geodesic distance. We test our algorithm on a realistic 3D game environment, and experimental results show that our model has subpolynomial growth of mean geodesic distance according to problem size, which enables efficient solving of resulting MDP.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.5C
• /
• pp.618-626
• /
• 2004

In this paper, we describe a robot endeffector recognition system based on a Modular Neural Networks (MNN). The proposed recognition system can be used for vision system which track a given object using a sequence of images from a camera unit. The main objective to achieve with the designed MNN is to precisely recognize the given robot endeffector and to minimize the processing time. Since the robot endeffector can be viewed in many different shapes in 3- D space, a MNN structure, which contains a set of feedforwared neural networks, can be more attractive in recognizing the given object. Each single neural network learns the endeffector with a cluster of training patterns. The training MNN patterns for a neural network share the similar characteristics so that they can be easily trained. The trained UM is les s sensitive to noise and it shows the better performance in recognizing the endeffector. The recognition rate of MNN is enhanced by 14％ over the single neural network. A vision system with the MNN can precisely recognize the endeffector and place it at the center of a display for a remote operator.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.27 no.9
• /
• pp.775-782
• /
• 2016

In this paper, we propose a dual-band GPS antenna using a single-layer coupled-feed structure for improvement of isolation and design complexity. The proposed antenna consists of a central feed patch and outer dual loops, and the loops are electromagnetically fed by the feed patch to induce currents. This feeding network can improve the isolation between antenna elements arranged in small arrays because the magnetic field strength near the antenna is minimized by confining the fields around the dual loops. The isolation characteristics of the proposed antenna are compared with those of the conventional multi-layer patch antenna, and the average field strength and the isolation are improved by 3 dB and 2 dB, respectively, which verifies that the antenna is suitable for small CRPA arrays.

• Journal of the Korea Institute of Building Construction
• /
• v.18 no.3
• /
• pp.305-312
• /
• 2018

This study is about the development of a non-sintered binder (NSB) which does not require a sintering process by using the industrial by-products Phosphogypsum (PG), Waste Lime (WL) and Granulated Blast Furnace Slag (GBFS). In this report, through SEM analysis of the NSB paste hardening body, micropore analysis of paste using the mercury press-in method and microstructure observation were executed to consider the influence of the formation of the pore structure and the distribution of pore volume on strength, and the following conclusions were reached. 1) Pore structure of NSB paste of early age is influenced by hydrate generation amount by GBFS and activator. 2) Through observing the internal microstructure of NSB binder paste, it was found that the strength expression at early age due to hydration reaction was achieved with a large amount of ettringite serving as the frame with C-S-H gel generated at the same time. It was confirmed that C-S-H gel wrapped around ettringite, and as time passed, the amount generated continually increased, and C-S-H gel tightly filled the pores of hardened paste, forming a dense network-type web structure. 3) For NSB-type cement, the degree of formation of gel pores below $10{\mu}m$ had a greater influence on strength improvement than simple pore reduction by charging capillary pores, and the pore size that had the greatest effect on strength was micropores with diameter below $10{\mu}m$.

• Ocean and Polar Research
• /
• v.34 no.3
• /
• pp.349-364
• /
• 2012

This study focuses on systematic structure of factors, which affect commercialization of ocean science and technology (OST), applying both grounded theory methodology (GTM) and semantic network analysis methodology (SNAM) by using in-depth interviews with 8 specialists previously experienced in the same field. This study further focuses on clarification of the distinctiveness and universality of commercialization factors on OST by comparatively analyzing on the commercialization factors of general sciences and technologies. Using SNAM, it was determined that commercialization success required connected support system, government support, technology marketing, technology power and characteristics of commercialized entities, which were identified as dominant factors. GTM presented an outcome that connected support systems among participants in commercialization and found that research institute strategies are significant factors in the core phenomenon of commercialization, while technology marketing, technology power and market-oriented technology are important conditions. In addition, the factors of technology, market, connection of participants and government support of commercialized entities are shown as equally important factors for commercialization of ocean science and technology. Secondly, SNAM results indicate that ocean science characteristics depend on a network of government support, research institute strategy, organization and manpower, capital power, and technology marketing, as these ocean science characteristics have been identified as significant factors in the GTM study. It has been determined that technology, market and government support should be connected in order for commercialization of ocean science and technology (OST). Moreover, commercialization methods, applied to the marketing of commercialization of ocean science and technology is differentiated from others since commercialization success is more relevant to these factors.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.11-12
• /
• 2011

In electromagnetic coupled resonance(ECR) WPT system, the main key for wireless power transmission is the design method of the ECR coils. The ECR coils is classified to the helical coil(3D) type and the spiral coil(2D) type as a coil structure. The pattern of the spiral coil type has been studied in favor of commercialization. In this paper, the design characteristics of the helical coil and the spiral coil is considered using a Vector Network Analyzer. It is analyzed according to the distance of coupling coefficient between the ECR coils. Also, It is analyzed for the relationships such as the maximum transmission efficiency and the resonant frequency depending on the distance between the coils.

• 한국IT서비스학회:학술대회논문집
• /
• 2006.05a
• /
• pp.233-240
• /
• 2006

This paper measures and compares the traffic of a series of Massively Multiplayer On-line Role Playing Games(MMORPG). The target games are 'Lineage' and 'Lineage II' developed by NCsoft, which are ones of the world's largest MMORPGs in terms of the number of concurrent users. We collected about 1 tera bytes of packets of 'Lineage II' for four days including a weekend. These packets are analyzed and compared with those of 'Lineage.' Packet size, packet inter-arrival time, and bandwidth usage are compared. The traffic of the two games shows much difference because original 'Lineage' is a kind of 2-D based MMORPG, while 'Lineage II' is 3-D based. By comparing the characteristics of the traffic of these games, we can anticipate future needs of network and game structure.