• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1839-1844
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• 2015

The low-density parity-check(LDPC) code has been adopted in many communication standards due to its error correcting performance, and the quasi-cyclic LDPC(QC-LDPC) is widely used because of implementation easiness. In the QC-LDPC decoder, a cyclic-shifter is required to rotate data in various sizes. This kind of cyclic-shifters are called multi-size circular shifter(MSCS), and this paper proposes a low-complexity structure for MSCS. In the conventional serially-placed two barrel-rotators, the unnecessary multiplexers are revealed and removed, leading to low-complexity. The experimental results show that the area is reduced by about 12%.

• Tunnel and Underground Space
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• v.14 no.3
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• pp.229-240
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• 2004

Coastal aquifers may serve as major sources fur freshwater. In many coastal aquifers, intrusion of seawater has become one of the major constraints imposed on groundwater utilization. The management of groundwater in coastal acquifers means making decision as to the pumping rate and the spatial distribution of wells. Several numerical techniques for flow and solute transport simulation can provide the means to achieve this goal. As a basic study to predict the intrusion of seawater in coastal phreatic aquifers, the coupled flow and solute transport analysis was conducted by use of the 3-D finite element code, SWICHA. In order to understand how the location and the shape of freshwater-seawater transition zone were affected by the boundary conditions and hydrogeologic variables, parametric study was carried out.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.266-269
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• 2012

화재 시뮬레이션을 이용하면, 건축물에서 화재가 발생하는 경우 건물에 설치된 감지 시스템 및 자동식 소화설비 등의 작동 여부에 따라 건물 내부의 온도 변화, 산소 및 일산화탄소 농도 변화, 연기유동 현상 등 화재 안전에 관련된 요소를 확인, 분석이 가능하기 때문에 건물의 화재 안전성을 검증하는데 활용할 수 있고 방재시스템 설계 조건을 변경하여 반복 시뮬레이션을 실시함으로써 보다 효율성이 높은 방재 시스템을 설계 및 채택할 수 있다. 또한 화재 시뮬레이션 결과를 감안하여 유사시 효과적으로 대응할 수 있도록 방재계획을 수립할 수 있고, 건축물의 구조, 내장재 및 수용품에 대한 설계, 배치 등에 사용할 수 있으며, 화재사고조사 및 원인 규명에도 활용할 수 있는 등 화재 시뮬레이션의 활용분야는 광범위하다. 최근 국내에도 화재로 인한 인적/물적 피해와 화재 안전 설계에 대한 관심증가로 화재 모델에 대한 많은 연구가 이루어지고 있다. 그러나 대부분의 연구가 시뮬레이션을 이용한 결과 분석에 치중되어있고 화재 시뮬레이션에 관한 특성 연구 및 개발은 거의 이루어지지 않고 있다. 본 자료는 국내에서 화재 시뮬레이션 코드로 많이 알려지지 않았으며, 유럽에서 개발된 SOFIE(Simulation of Fire in enclosures)에 대해서 기초적인 연구를 수행하였으며, SOFIE에 대한 특정 문제나 평가 부분은 다루지 아니하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.1
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• pp.9-17
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• 2001

GPS is an efficient system in surveying and car navigation. but it is difficult to catch minimum number of satellite when it is hindered by obstacle such as city area. GLONASS system doesn't have perfect constellation yet, but it has many similarities with GPS system in principle of point positioning and signal system. so, it is expected to be much efficient when it is used with GPS system. For the purpose of this, the coordinates of GPS and GLONASS system, the quality of time and frequency was investigated, and the algorithm of point positioning was made. also, the efficiency of GPS/GLONASS combination was presented by analysing the precision of 3D point positioning using C/A code and Yuma satellite orbit information.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10C
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• pp.983-991
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• 2009

While H.264/AVC is in wide use for multimedia applications such as DMB and IPTV service, we have limited usage cases for embedded real-time applications due to its high computational demand. The paper provides judicious guide line for optimization method selection, by presenting the detailed experiments data through the development process of a real time H.264 software encoder on embedded DSP. The experimental analysis includes an intensive profiling analysis, fast algorithm application, optimal memory assignment, and intrinsic-based instruction selection. We have realized a real-time software that encodes CIF resolution videos 15 fps on TMS320DM64x processors.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.1_2
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• pp.27-40
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• 2004

The OSGi service platform has several characteristics as in the followings. First, the service is deployed in the form of self-installable component called service bundle. Second, the service is dynamic according to its life-cycle and has interactions with other services. Third, the system resources of a home gateway are restricted. Due to these characteristics of a home gateway, there are a lot of rooms for malicious services can be Installed, and further, the nature of service can be changed. It is possible for those service bundles to influence badly on service gateways and users. However, there is no service bundle authentication mechanism considering those characteristics for the home gateway In this paper, we propose a service bundle authentication mechanism considering those characteristics for the home gateway environment. We design the mechanism for sharing a key which transports a service bundle safely in bootstrapping step that recognize and initialize equipments. And we propose the service bundle authentication mechanism based on MAC that use a shared secret created in bootstrapping step. Also we verify the safety of key sharing mechanism and service bundle authentication mechanism using a BAN Logic. This service bundle authentication mechanism Is more efficient than PKI-based service bundle authentication mechanism or RSH protocol in the service platform which has restricted resources such as storage spaces and operations.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.982-990
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• 2019

The interest of researchers and governments in exploiting tidal energy resources is increasing. Jangjuk strait is a place with high tidal energy density potential and is therefore appropriate for the constructing of a tidal turbine farm. In this study, a numerical approach is presented to evaluate the current flow and power potential in Jangjuk strait with an ADCIRC model. Then, the tidal field characteristics are utilized as input parameters for tidal resource calculation with an in-house program. The 1 MW scale tidal energy converter devices are employed and arranged in 4 layouts to investigate the annual energy yield as well as flow deficit due to the wake ef ect at the surveyed area. The best-performed array generates an annual energy yield up to 12.96 GWh/year (without considering the wake effect); this value is reduced by 0.16 GWh/year when accounting for the energy loss caused by the flow deficit. Moreover, by altering the turbine yaw angle during the flood and ebb tides, the impacts of this factor on the energy extraction are analyzed. This indicates that the turbine array attains the maximum tidal power when the turbine yaw angle is at 346° and 164° (clockwise, to the North) for the spring and neap tide in turns.

• Journal of the Korea Computer Graphics Society
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• v.19 no.4
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• pp.1-11
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• 2013

In this paper, we represented the HTML5 webpage in 3D space for the 3D stereoscopic display by using CSS3 stylesheet; browser-based declarative contents, and proposed CSS Stereo 3DTV Profile. First, we suggested various webpage separation methods for reconstructing webpages in the 3D space effectively. Next, we suggested 3D view volume setting method by using extended CSS3 modules. And then, pre-processor converts sample contents which is written extended CSS stylesheet into the present CSS stylesheet for displaying in the webkit based browser. For the resulting stereoscopic images, we developed a rendering engine emulator which is implemented in JavaScript for simple display in the web browser, which produced dual images from virtual left and right-eyed cameras. And we have checked the sample contents displayed on the 3DTV.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.11
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• pp.247-249
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• 2020

In the era of the 4th industrial revolution, the demand for convergence between ICT technologies is increasing in various fields. Accordingly, a new term that combines data, network, and artificial intelligence technology, DNA (Data, Network, AI) is in use. and has recently become a hot topic. DNA has various potential technology to be able to develop intelligent application in the real world. Therefore, this paper introduces the reviewed papers on the service image placement mechanism based on the logical fog network, the mobility support scheme based on machine learning for Industrial wireless sensor network, the prediction of the following BCI performance by means of spectral EEG characteristics, the warning classification method based on artificial neural network using topics of source code and natural language processing model for data visualization interaction with chatbot, related on DNA technology.

• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.355-364
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• 2005

Ubiquitous environment can be supported by various service on networked appliance, sensors and devices. In home network and telematics, open service gateway is widely used for ubiquitous environment and Present environment for service installation, deployment and execution. Service gateway is a middle layer which is located between service and various devices in ubiquitous environment and offers a unique opportunity for pervasive computing as a potential framework for achieving interoperability between various sensors, home appliances. and networked devices. In ubiquitous environments, these services must support the mobility among service gateway because users and devices has a mobility characteristic. However the OSGi framework supports only a remote installation of a bundle, which is a unit that installs and deploys services. This paper develops a system that can manage bundles for supporting this dynamic bundle's mobility between service gateway. This system we are proposing implements a bundle form which can perform in an OSGi framework as well as manage the mobile services. As a result, mobility in a ubiquitous computing environment will be supported more efficiently.