• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.10
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• pp.1065-1074
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• 2008

T-DMB(Terrestrial Digital Multimedia Broadcasting) system, is based on the Eureka-147 standard, provides various multimedia data services. However T-DMB system needs upgrades for more various services and better services. Therefore, we proposed advanced T-DMB system using unequal error protection system and hierarchical modulation in this paper while maintaing backward compatibility. And we simulated various bit split methods and double binary turbo code of DVB-RCS standard as method of LP data stream for additional service of advanced T-DMB. As the simulation results, double binary turbo code of proposed advanced T-DMB system have each coding gain of over 2 dB compared to conventional T-DMB.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.72-79
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• 2015

Electricity can be generated when the natural gas passes through a turbo-expander pressure reduction system at natural gas pressure reduction stations. Efficiency of the turbo-expander depends on the ratio of the natural gas flow rates to the design flow rate of the turbo-expander. Therefore, the optimal conditions for the operation of the pressure reduction system can be determined by controlling the natural gas flow rates. In this study, we have calculated the electric energy generation depending on the natural gas flow rates at the two low-pressure reduction stations when the pressure of the natural gas is reduced from 17.5 bar to 8.5 bar and have found the optimal conditions for the turbo-expander pressure reduction system through the comparison with the calculation results. The turbo-expander generates the electric power efficiently for the high natural gas flow rates which variations are slight. The determined design flow rate of the turbo-expander has the highest coverage of the natural gas flow rates. The electricity generation is calculated as much as 9 MW(B station) and 12 MW(D station) at each pressure reduction station.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.1135-1138
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• 2011

안드로이드 시장이 급성장함에 따라 안드로이드 기반 어플리케이션에 대한 수요가 많아지고 있다. 그로 인해 3D 그래픽적 기능을 요구하는 어플리케이션에 대한 요구도 늘어났다. 그러나 안드로이드 단말기에서는 3D 처리능력이 데스크 탑과 비교하여 성능과 서비스에 한계가 있다. 그렇기 때문에 VNC(Virtual Network Computing)를 사용하여 고성능의 그래픽을 요구하는 프로그램을 실행할 수 있게 된다. VNC 란 클라이언트에서 데스크 탑으로 접속하여 원격으로 제어하고 그 결과를 그래픽으로 확인하는 프로그램이다. 그러나 기존의 Android VNC 는 해상도가 낮고, 이미지 전송 속도가 느리기 때문에 3D 렌더링 이미지 처리가 불가능했다. 또한 Android VNC 는 인터페이스가 불편하여 입력 오류가 많아 사용이 불편했다는 단점 등이 지적되어 왔다. 본 논문에서는 이를 개선하기 위한 Android Turbo VNC 를 제안한다. Android Turbo VNC는 libjpeg-turbo 코덱을 적용하여 3D 이미지 부분에서 기존의 Android VNC 에 비하여 약 80~120%의 이미지 개선과 이미지 압축률을 4 배정도 높여 CAD 와 같은 고성능의 그래픽을 요구하는 프로그램의 사용을 가능하게 한다. 그리고 Android Turbo VNC 에서는 기존 Android VNC 의 불편한 UI 를 개선하였다. 클라우드 서버에서는 CAD, Document, Game, Video, General 총 5 가지의 프로그램을 서비스하여 그에 맞는 테마 별 UI 를 제공한다. libjpeg-turbo 코덱의 적용을 통해 Android-Turbo VNC 는 수십 장의 설계 도면을 굳이 들고 다니지 않더라도 하나의 테블릿 PC 안에서 보는 것이 가능하게 된다. 테마별 UI 중 CAD 테마는 3D CAD 를 사용하는 산업현장에서 적극적으로 활용될 것으로 기대된다.

• Journal of Magnetics
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• v.21 no.3
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• pp.421-424
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• 2016

The purpose of this study is to evaluate an effectiveness of switching turbo direction to improve motion artifacts of small bowels and aorta. From June to October 2015, 60 patients suspected of having Crohn's disease were enrolled. The MR Enterography scans were performed using same protocol other than the turbo direction: with the Z phase encoding (group A) and with Y phase encoding (group B). Qualitative analysis of each group was performed to evaluate the effectiveness of switching turbo direction from Z to Y. As a result, the 5-point Likert scale for paired observers were $2.33{\pm}0.88$ for group A and $3.80{\pm}0.85$ for group B on dynamic contrast enhanced coronal images. In conclusion, group B is proved to be superior to group A and can lessen the motion artifacts derived from phase shifts.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.4
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• pp.40-46
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• 2006

The performance of iterative multiuser detector and turbo decoder is presented to provide high quality multimedia services in WCDMA (wideband code division multiple access) system in this paper. Especially the relationship between the local iteration of turbo decoder and the global iteration of multiuser detector including the turbo decoder is analyzed. As a result, three local iterations and three global iterations are considered to be sufficient to provide satisfactory error performance with resonable complexity. The interference cancellation capability of global iteration is improved when the number of users is increased.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.6
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• pp.1184-1189
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• 2001

In this paper was analyzed the performance of turbo code using semi-random interleaver which proposed a reference numbers 11. Which was analyzed comparison the performance of between the current mobile communication system had been used the viterbe decoding algorithm of convolutional code and turbo codes when fixed constraint length. The result was defined that the performance of turbo code rose a $E_{b/}$ $N_{o}$=4.7[㏈] than convolutional code, when convolutional code and turbo code was fixed by BER = 10$^{-4}$ and constraint length K 5.5.5.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.975-981
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• 2012

In this paper, we considered the received signal of the wideband CDMA systems using turbo code in the multipath channel environments, and analyze the performance of the system. This study is to analyze the performance for the variable system bandwidth according to the number of branches of rake receiver by passing the received signal through a rake receiver with a turbo code in Rayleigh fading channel environments. For the design of receiver in wideband CDMA systems, we presented the efficient parameters for the number of iterative decoding and the number of branches of rake receiver.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.3
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• pp.34-38
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• 2018

Recently, the turbo charger has become an important part because it yields little displacement and high power while downsizing the engine's fuel ratio for environmental purposes. In this study, flow analysis was conducted to form the basis of data regarding the best efficiency. The axial displacement was changed from none to 25 mm by controlling the configuration of the turbo charger and the flow analyses were compared with each other. The maximum rate of the outlet of model 1 was 46.36 m/s and the maximum pressure of model 4 was 0.761946 Pa. The maximum flow rate of model 4 was 0.000187650 kg/s. This study's result should aid in the effective design of a turbo charger with high performance.

• ETRI Journal
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• v.27 no.2
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• pp.223-226
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• 2005

This paper presents the application of a turbo coding technique combined with a bandwidth efficient method known as trellis-coded modulation. A transformation applied to the incoming I-channel and Q-channel symbols allows the use of an off-the-shelf binary/quadrature phase shift keying (B/QPSK) turbo decoder without any modifications. A conventional turbo decoder then operates on transformed symbols to estimate the coded bits. The uncoded bits are decoded based on the estimated coded bits and locations of the received symbols.

• Progress in Superconductivity and Cryogenics
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• v.17 no.3
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• pp.41-46
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• 2015

Recently, the development of the HTS power cable is actively promoted. As the length of HTS power cable increases, there have been many efforts to develop large capacity cryocooler. Among the various cryocooler, the Brayton refrigerator is the most competitive for HTS power cable. The Brayton refrigerator is composed of recuperative heat exchangers, a compressor, and a cryogenic turbo expander. In these components, the cryogenic turbo expander is a part to decrease the temperature and it is the most significant component that is closely related with overall system efficiency. It rotates with high speed using a high-pressure helium or neon gas at cryogenic temperature. This paper describes the design of a 10 kW class Brayton refrigeration cycle and the cryogenic turbo expander. Flow and structural analysis are performed for the rotating impeller and nozzle to verify the efficiency and the design performance.