• 한국정보통신설비학회:학술대회논문집
• /
• 2008.08a
• /
• pp.398-402
• /
• 2008

Cyclic prefix (CP) is one of the most important technique to OFDM system and is reducing inter-symbol interference (ISI) effects in high speed wireless mobile communication system. At the time varying channel condition, however, fixed CP length is not only increasing power consumption but also reducing data transmission rate. So in this paper, we propose the system that has adaptive CP length for high speed data transmission system. We don't control CP length of every symbol but adjust symbol interval depending on channel condition to CP reconstruction.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1920-1921
• /
• 2007

본 논문에서는 나선주사 영상에서 발생하는 off-resonance 현상에 의한 영상의 번짐을 보정하는 새로운 알고리즘을 제안하였다. 공간상에서의 inhomogeneity와 chemical-shift 현상으로 생기는 off-resonance 효과는 공간의 자장의 세기에 비례한다. 현재 사용되고 있는 보정 방법에서의 절차를 간소화 하고 보다 효과적인 보정 알고리즘을 적용함으로써 보다 나은 Spiral scan 영상을 얻고자 하였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2001.04a
• /
• pp.371-374
• /
• 2001

본 논문에서는 셀룰라 오토마타(Cellular Automata : CA)를 이용한 다항식 모듈라 멱승 알고리즘을 제안한다. 또한 이를 이용하여 공개키 암호 알고리즘인 EiGamal 알고리즘을 구현한다. 기존의 모듈라 멱승 알고리즘은 대부분 선형 귀환 시프트 레지스트(Linear Feedback Shift Register : LFSR)를 이용하여 구현하였다. 그러나 LFSR을 이용한 구조는 기저가 자주 변경되는 연산에 대하여 구현하기에 곤란한 단점을 가지고 있다. 본 논문에서 제안된 알고리즘은 CA의 병렬성과 높은 적응성을 이용함으로써 기저가 자주 변경되는 멱승 연산 알고리즘에 쉽게 적용할 수 있는 장점이 있다.

• Proceedings of the Korea Institute of Convergence Signal Processing
• /
• 2000.08a
• /
• pp.253-256
• /
• 2000

In this paper, we propose the lossless image compression algorithm using the integer wavelet transform. Recently, the S＋P transform is widely used and computed with only integer addition and bit-shift operations, but not proper to remove the correlation of smooth images. then we compare the Harr wavelet of the S＋P transform with various integer coefficient filter banks and apply 9/7 ICFB to the wavelet transform. In addition, we propose a entropy-coding method that exploits the multiresolution structure and the feedback of the prediction error, and can efficiently compress the transformed image for progressive transmission. Simulation results are compared to the compression ratio using the S+P transform with different types of images.

• Transactions of The Korea Fluid Power Systems Society
• /
• v.6 no.3
• /
• pp.23-31
• /
• 2009

Counter shaft transmission is a popular automatic transmission power train in construction vehicles such as wheel loader and forklift. The gear train layout of counter shaft transmission is a very basic and important development stage because it affects the most of components design including hydraulic system and shift control algorithm, etc. This paper presents a design methodology for the gear train layout from the analysis of power flow path and clutch hook-up of the existing counter shaft transmission that is adopted in commercialized construction vehicles. Also, independent constraints for the meshed gear ratios are derived in order to realize forward 4-speed and reverse 3-speed gear ratio. The layout design principle proposed here was applied to the new original counter shaft transmission that is underdevelopment.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2012.11a
• /
• pp.552-555
• /
• 2012

The main goal of this paper is to develop a robust visual tracking algorithm with particle filtering. Visual Tracking with particle filter technique is not easy task due to cluttered environment, illumination changes. To deal with these problems, we develop an efficient observation model for target tracking with particle filter. We develop a robust phase correlation combined with motion information based observation model for particle filter framework. Phase correlation provides straight-forward estimation of rigid translational motion between two images, which is based on the well-known Fourier shift property. Phase correlation has the advantage that it is not affected by any intensity or contrast differences between two images. On the other hand, motion cue is also very well known technique and widely used due to its simplicity. Therefore, we apply the phase correlation integrated with motion information in particle filter framework for robust tracking. In experimental results, we show that tracking with multiple cues based model provides more reliable performance than single cue.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2004.05a
• /
• pp.731-734
• /
• 2004

본 논문은 입력영상의 화질 향상을 위하여 기존의 스트레칭 알고리즘을 이용하여 개선된 콘트라스트 알고리즘을 제안하였다. 입력영상의 픽셀(pixel)을 DR(Difference Range)의 범위에 따라 정해진 가중치를 적용하여 새로운 픽셀을 출력한다. 특별한 사용자 정의(User Define)없이 실시간적으로 화질을 개선할 수 있는 장점이 있다. 또한, 하드웨어 적인 측면에서 곱셈 과 나눗셈 연산을 배럴쉬프트(Barrel Shift)를 이용하여 하드웨어 복잡도를 감소 시켰다. 제안한 방식의 알고리즘의 검증을 위하여 C를 이용한 시각적 검증과 하드웨어 측면에서의 검증을 VHDL을 이용한 컴퓨터 시뮬레이션을 통해 확인하였다.

• Journal of the Korean Society for Precision Engineering
• /
• v.10 no.1
• /
• pp.77-88
• /
• 1993

In this paper, we propose a stereo vision system to solve correspondence problem with large disparity and sudden change in environment which result from small distance between camera and working objects. First of all, a specific feature is divided by predfined elementary feature. And then these are combined to obtain coded data for solving correspondence problem. We use Neural Network to extract elementary features from specific feature and to have adaptability to noise and some change of the shape. Fourier transformation and Log-polar mapping are used for obtaining appropriate Neural Network input data which has a shift, scale, and rotation invariability. Finally, we use associative memory to obtain coded data of the specific feature from the combination of elementary features. In spite of specific feature with some variation in shapes, we could obtain satisfactory 3-dimensional data from corresponded codes.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2022.06a
• /
• pp.186-189
• /
• 2022

스마트팜 피노믹스 시스템은 재배하는 식물의 성장조건에 맞게 생육 환경을 일정하게 유지하고 관리하는 장치이지만, 그럼에도 불구하고 식물의 질병은 여러 가지 이유로 발생할 수 있다. 본 논문에서는 스마트팜 피노믹스 시스템에서 Mean Shift Segmentation 을 통한 식물의 질병을 자동으로 검출하는 식물 질병 검출 알고리즘을 제안한다. 식물의 질병 정도가 임의의 임계값을 넘을 경우, 해당 식물을 질병의 정도가 심한 식물로 판별하고, 적절한 수확시기를 결정하여 더 나은 상품성을 가진 식물을 재배할 수 있는 방법을 제시한다. 또한 식물의 질병이 급격하게 심해지는 기간을 확인하여 인간의 개입 없이 완전히 자동화된 시스템으로 더욱 세심하고 효율적인 식물 재배를 가능하게 함을 제시한다. 본 논문에서는 아이스버그(양상추)에 대한 재배 환경을 구축하여 생장 기간에 아이스버그에 발생하는 질병인 팁번 현상을 검출하는 실험을 진행하였다. 본 논문에서 제안한 방법은 다른 종류의 다양한 식물에서도 질병 검출이 가능하며, 스마트팜 피노믹스 시스템에서 질병 검출의 자동화를 위한 한 가지 방법으로 활용될 수 있을 것으로 기대된다.

• Nuclear Engineering and Technology
• /
• v.55 no.10
• /
• pp.3913-3923
• /
• 2023

Todays, medium energy resolution detectors are preferably used in radioisotope identification devices(RID) in nuclear and radioactive material categorization. However, there is still a need to develop or enhance « automated identifiers » for the useful RID algorithms. To decide whether any material is SNM or NORM, a key parameter is the better energy resolution of the detector. Although masking, shielding and gain shift/stabilization and other affecting parameters on site are also important for successful operations, the suitability of the RID algorithm is also a critical point to enhance the identification reliability while extracting the features from the spectral analysis. In this study, a RID algorithm based on Bayesian statistical method has been modified for medium energy resolution detectors and applied to the uranium gamma-ray spectra taken by a LaBr3:Ce detector. The present Bayesian RID algorithm covers up to 2000 keV energy range. It uses the peak centroids, the peak areas from the measured gamma-ray spectra. The extraction features are derived from the peak-based Bayesian classifiers to estimate a posterior probability for each isotope in the ANSI library. The program operations were tested under a MATLAB platform. The present peak based Bayesian RID algorithm was validated by using single isotopes(²⁴¹Am, ⁵⁷Co, ¹³⁷Cs, ⁵⁴Mn, ⁶⁰Co), and then applied to five standard nuclear materials(0.32-4.51% at.²³⁵U), as well as natural U- and Th-ores. The ID performance of the RID algorithm was quantified in terms of F-score for each isotope. The posterior probability is calculated to be 54.5-74.4% for ²³⁸U and 4.7-10.5% for ²³⁵U in EC-NRM171 uranium materials. For the case of the more complex gamma-ray spectra from CRMs, the total scoring (ST) method was preferred for its ID performance evaluation. It was shown that the present peak based Bayesian RID algorithm can be applied to identify ²³⁵U and ²³⁸U isotopes in LEU or natural U-Th samples if a medium energy resolution detector is was in the measurements.