• Journal of Convergence for Information Technology
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• v.12 no.1
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• pp.7-14
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• 2022

Unlike general maps, the underground geospatial Information is a system made to view underground information in a 3D shape. This system is managed by a tile maps to lighten the data. But there are various underground structures in the basement, and the structures are made of 3D data, so the data size is large. Therefore, when a client mobile program requests a tile map, the service server fetches the requested tile map from the DB server and transmits ti to the client, but there is a transmission delay time problem. In this paper, we design the tile cache method to improve the request response speed for the tile map data provided to the client in the mobile underground geospatial information system. We propose a method in which a service server predicts and prefetchs the next tile map while the client is viewing tile map, and stores the prefetching data in the memory of client mobile terminal. Then, the transmission delay time problem can be solved.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.6
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• pp.88-95
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• 2011

An embedded mobile device mostly has lower computation power than a general purpose computer because of its relatively lower system specifications. Consequently, conventional face tracking and face detection methods, requiring complex algorithms for higher recognition rates, are unsuitable in a mobile environment aiming for real time detection. On the other hand, by applying a real-time tracking and detecting algorithm, we would be able to provide a two-way interactive multimedia service between an user and a mobile device thus providing a far better quality of service in comparison to a one-way service. Therefore it is necessary to develop a real-time face and eye tracking technique optimized to a mobile environment. For this reason, in this paper, we proposes a method of tracking horizontal face position of a user on a T-DMB device for enhancing the quality of 3D DMB content. The proposed method uses the orientation of edges to estimate the left and right boundary of the face, and by the color edge information, the horizontal position and size of face is determined finally to decide the horizontal face. The sobel gradient vector is projected vertically and candidates of face boundaries are selected, and we proposed a smoothing method and a peak-detection method for the precise decision. Because general face detection algorithms use multi-scale feature vectors, the detection time is too long on a mobile environment. However the proposed algorithm which uses the single-scale detection method can detect the face more faster than conventional face detection methods.

• The KIPS Transactions:PartD
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• v.12D no.3 s.99
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• pp.455-460
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• 2005

An improvement of a mobile game content production and a service technology are bringing an explosive increase of a mobile game market. Currently serviced mobile games are using a WAP method and a download method. Because of technical problems, we couldn't develop the mobile game content which sequentially linked WAP->download and download->WAP. In this study, we design and develop the mobile game content which sequentially linked WAP->download and download->WAP. In the proposed method, we can linked the stage and the ranking information as sharing a data on real time that it is impossible in the previous mobile game content.

• The KIPS Transactions:PartA
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• v.14A no.5
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• pp.279-286
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• 2007

The need of contents adaptation in ubiquitous environments is growing to support multiple target platforms for 3D graphics contents. Since 3D graphics deal with a large data set md a high performance, a service adaptation for context changing is required to manipulate graphics contents with a more complicated method in multiple devices such as desktops, laptops, PDAs, mobile phones, etc. In this paper, we suggest a new notion of service adaptation middleware based on service rendering algorithm, which provides a flexible and customized service for user-centric 3D graphics contents. The service adaptation middleware consists of Service Adaptation(SA) for analyzing environments and Service Rendering(SR) for reconfiguring customized services by processing customized data. These adaptation services are able to intelligently and dynamically support the same computer graphics contents with good quality, when user environments are changed.

• Korean Management Science Review
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• v.26 no.3
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• pp.101-115
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• 2009

In this paper, we propose a technology mining framework for mobile communication industry. We develop a two phase approach of new technology identification and service enhancement. The new technology identification process consists of R&D issues analysis, technology theme design, and emerging technology sampling. On the other hand, existing service enhancement process has technology landscaping, keyword based search, and technological growth analysis. By implementing these two phase frameworks, we develop a technology portfolio for mobile communication industry.

• Journal of IKEEE
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• v.16 no.3
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• pp.159-166
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• 2012

In this paper, we designed and implemented the MIMO (Multiple-Input Multiple-Output) antenna for the mobile handset that could be used for multiple services. Simulation results were obtained using SEMCAD X by SPEAG based on the FDTD (Finite Difference Time Domain) Method which showed that S11 values were less than -6 dB (VSWR < 3) for LTE (Long Term Evolution) 700/2300/2500, K-PCS (Korea-Personal Communication Service : 1,750 ~ 1,870 MHz), US-PCS (US-Personal Communication Service : 1,850 ~ 1,990 MHz), Wibro (2,300 ~ 2,390 MHz), Bluetooth (2,400 ~ 2,483 MHz), and US-WiMAX (US-World interoperability for Microwave Access: 2,400 ~ 2,590 MHz) frequency bands. Measured results of the fabricated antenna also showed that it could be used for LTE 700/2300/2500, K-PCS, US-PCS, Wibro, Bluetooth, and US-WiMAX. services.

• The Journal of the Korea Contents Association
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• v.18 no.1
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• pp.250-257
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• 2018

Today, the integration of the rapid development of ICT and the smart devices moves our lives quickly into an online community environment through not only quick and easy information search but also various social media. Accordingly, individual activities in the smart media environment are pouring out vast quantities of data in many fields, accumulating a tremendous amount of data. The everyday data of individuals is reproducing different values from the previous ones, while suggesting new customized services that utilize them in various fields. Recently, big data utilization has attracted a great attention in the field of healthcare. Especially, development of healthcare service linked with mobile is expected to bring a new paradigm in this field. In this study, creation of a 3D avatar character model as a means to transfer information to individuals more efficiently is proposed in the development of mobile customized service for health promotion and growth prediction of children and adolescents, at the same time, an effective visual expression method to have a sense of immersion and unity is searched.

• International Journal of Advanced Culture Technology
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• v.9 no.4
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• pp.295-301
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• 2021

Digital media technology is gradually developing with the development of convergence quaternary industrial technology and mobile devices. The combination of deep learning and augmented reality can provide more convenient and lively services through the interaction of 3D virtual images with the real world. We combine deep learning-based pose prediction with augmented reality technology. We predict the eight vertices of the bounding box of the object in the image. Using the predicted eight vertices(x,y), eight vertices(x,y,z) of 3D mesh, and the intrinsic parameter of the smartphone camera, we compute the external parameters of the camera through the PnP algorithm. We calculate the distance to the object and the degree of rotation of the object using the external parameter and apply to AR content. Our method provides services in a web environment, making it highly accessible to users and easy to maintain the system. As we provide augmented reality services using consumers' smartphone cameras, we can apply them to various business fields.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.5
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• pp.568-575
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• 2011

In this paper, we propose a small broadband antenna for mobile device. The proposed antenna consists of a printed rectangular monopole antenna and a parastic element connected to ground using narrow meander line and it is designed on a FR-4 substrate that has a thickness of 0.8 mm and a dielectric constant of 4.4. The FR-4 substrate's size is 50 mm${\times}$90 mm comparable to the real mobile device. The fabricated antenna's size is 12.5 mm${\times}$10.5 mm${\times}$0.8 mm and the measurement shows -10 dB return loss bandwidth of 2,200~6,000 MHz and gains of 2.86~4.01 dBi. Accordingly, the proposed antenna can support mobile device for WiBro(2,300~2,380 MHz), WLAN(IEEE 802.11b/g/n: 2,400~2,480 MHz, IEEE 802.11a: 5,150~5,825 MHz), and mobile WiMAX(IEEE 802.16e : 2,500~2,690 MHz, 3,400~3,600 MHz) service bands.

• Journal of the Korea Society of Computer and Information
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• v.22 no.4
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• pp.67-74
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• 2017

The objective of this paper is to design broadband microstrip patch antenna for mobile communication service. The enhanced features were confirmed and proved by comparing the proposed antenna with the antennae that have been reported in the relevant literatures. The experimental results show that the impedance bandwidth(VSWR ${\leq}2$) of 19.6%(fo=1,920MHz) and the peak gain of 5.53dBi(at 1,900MHz) were obtained by the mobile communication service frequency band. The proposed antenna had the impedance bandwidth of about 3.1% larger than that of the reported microstrip antenna.