• The Journal of Korean Association of Computer Education
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• v.18 no.6
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• pp.23-31
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• 2015

The main aim in software education is to improve problem-solving ability based on computational thinking with the healthy information ethics. For this purpose, many institutions have attempted various educational programs such as Educational Programming Language, Physical Computing, and Robot education. However, it is possible to obscure the essence of computer education for computational thinking if the computer education focuses on using certain special education programming language and products. Therefore, this paper suggests a method of algorithm education using RAPTOR which is a visual programming development environment and is based on flowcharts. In order to verify the effectiveness of the algorithms education using the RAPTOR, 16 high-school students were applied to an educational program for twelve hours on five steps and then we obtained positive results.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.1
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• pp.65-70
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• 2013

In this paper, we propose the construction of Raptor code using LDGM code instead of LDPC code as precode. To see their merits, the simulations are done. The results show that the performance in case of using LDGM code is worse than that of using LDPC code as precode, and the complexity of encoding LDGM code is lower than that of LDPC.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.5
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• pp.53-64
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• 2021

SpaceX has lowered rocket launch cost innovatively and put first stage reuse to the practical use with Falcon 9. Now the company is developing Starship system that is fully reusable with the heaviest payload in the world. So the system can lower the cost much more and fulfull more diverse mission. For the system the company have developed Raptor engine which is a full-flow staged combustion cycle one with methane fuel. And for the full reusability the company is manufacturing and testing the system prototypes with the barely used technologies such as stainless steel tank, belly flop and retropropulsion during descent. In this study the specification, missions and design features of the system are investigated. Also the development processes of Raptor engine and initial 13 Starship prototypes, which have been manufactured very rapidly, are presented.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.767-770
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• 1998

This paper introduces an instruction fetch unit which is designed for RAPTOR, an on-chip multiprocessor. In order to reduce control hazards, the proposed fetch unit supports a hybrid branch prediction scheme which consists of a static scheme and the 2bC branch prediction scheme. The fetch unit also utilizes the branch folding technique with two instruction buffers to avoid the branch penalty caused by imspredictions. Instructions are predecoded in the fetch unit to achieve extra performance gain.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.763-766
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• 1998

This paper describes the microarchitecture of the integer processor unit of RAPTOR which is an on-chip multiprocessor. The integer processor unit implements the 64-bit SPARC-V9 architecture and supports by hardware out-of-order instruction execution. The unit is designed to be handy so that multiple copies of the unit cn be integrated with cache memories into a single chip. The design was proceeded in a top-down manner. The hardware description and its verfication were performed using Verilog-HDL.

• Journal of Korea Multimedia Society
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• v.17 no.8
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• pp.961-967
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• 2014

Raptor codes are a class of rateless codes originally designed for binary erasure channels. This paper presents a compact set of mathematical expressions for iterative soft decoding of raptor codes. In addition, an early termination scheme is employed, and it is embedded in a single algorithm with the formula. In the proposed algorithm, the performance is enhanced by adopting iterative decoding, both in each inner and outer code and in the concatenated code itself between the inner and outer codes. At the same time, the complexity is reduced by applying an efficient early termination scheme. Simulation results show that our proposed method can achieve better performance with reduced decoding complexity compared to the conventional schemes.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2008.11a
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• pp.157-160
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• 2008

본 논문에서는 Raptor 코드를 이용하여 계층화 비디오를 적응적으로 전송하는 방법을 보여 준다. 클라이언트는 정보를 수신 할 뿐만 아니라 수신한 정보를 다른 클라이언트와 교환함으로서 서버 의존도를 줄여 손실 상황에 대한 강인함을 지니게 된다. Raptor code의 특징을 이용하여 peer-to-peer 환경에서 효율적인 비디오 전송이 가능하다. 이러한 방법을 이용하여 실시간 UCC 비디오와 같은 콘텐츠를 자원이 제한적인 환경에서도 효율적으로 전송 할 수 있는 방법을 보인다.

• Journal of Veterinary Clinics
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• v.35 no.6
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• pp.266-268
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• 2018

A wild Falco tinnunculus, which is a small raptor, was rescued and presented due to immobilization. On physical examination, a left ulnar fracture was detected, which was reduced with an intramedullary (IM) pin and soft bandaging. Passive range of motion (PROM) exercises were then conducted to prevent complications such as ankylosis. The raptor was released into the wild four weeks postoperatively. We suggest that IM pinning with bandaging and appropriate PROM exercises may effectively treat ulnar fractures in small raptors.

• KIISE Transactions on Computing Practices
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• v.23 no.2
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• pp.134-139
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• 2017

The existing screen mirroring systems are vulnerable to packet loss and inefficient for mobile devices with limited energy capacity. To overcome these problems, we propose a packet loss robust and energy efficient screen mirroring system for mobile device. The proposed system employs systematic Raptor codes for a forward error correction method to mitigate the video quality degradation that is caused by packet loss over wireless networks. For the mobile device energy saving, the proposed system shapes the screen mirroring traffic and adjusts the Raptor encoding parameters. In this paper, the proposed system is fully implemented on single board computers and is examined in a real Wi-Fi Direct network.

• Journal of Communications and Networks
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• v.15 no.2
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• pp.198-206
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• 2013

Recent advances in forward error correction (FEC) coding techniques were focused on addressing the challenges of multicast and broadcast delivery. However, FEC approaches can also be used for unicast content delivery in order to solve transmission control protocol issues found in wireless networks. In this paper, we exploit the error resilient properties of Raptor codes by proposing Raptor-based content delivery protocol (RCDP) - a novel solution for reliable and bidirectional unicast communication in lossy links that can improve content delivery in situations where the wireless network is the bottleneck. RCDP has been designed, validated, optimized, and its performance has been analyzed in terms of throughput and resource efficiency. Experimental results show that RCDP is a highly efficient solution for environments characterized by high delays and packet losses making it very suitable for intelligent transport system oriented applications since it achieves significant performance improvements when compared to traditional transport layer protocols.