• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.295-298
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• 2003

In this paper, a novel maximum a posterion (MAP) estimation for the channel decoding of H.264 codes in the presence of transmission error is presented. Arithmetic codes with a forbidden symbol and trellis search techniques are employed in order to estimate the best transmitted. And, there has been growing interest of communication, the research about transmission of exact data is increasing. Unlike the case of voice transmission, noise has a fatal effect on the image transmission. The reason is that video coding standards have used the variable length coding. So, only one bit error affects the all video data compressed before resynchronization. For reasons of that, channel needs the channel codec, which is robust to channel error. But, usual channel decoder corrects the error only by channel error probability. So, designing source codec and channel codec, Instead of separating them, it is tried to combine them jointly. And many researches used the information of source redundancy In received data. But, these methods do not match to the video coding standards, because video ceding standards use not only one symbol but also many symbols in same data sequence. In this thesis, We try to design combined source-channel codec that is compatible with video coding standards. This MAP decoder is proposed by adding semantic structure and semantic constraint of video coding standards to the method using redundancy of the MAP decoders proposed previously. Then, We get the better performance than usual channel coder's.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.6
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• pp.1323-1329
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• 2014

In this paper, we analyzed efficient decoding scheme with FTN (Faster than Nyquist) method that is transmission method faster than Nyquist theory and increase the throughput. we proposed viterbi equalizer model to minimize ISI (Inter-Symbol Interference) when FTN signal is transmitted. the proposed model utilized interference as branch information. In this paper, to decode FTN singal, we used turbo equalization algorithms that iteratively exchange probabilistic information between soft Viterbi equalizer (BCJR method) and LDPC decoder. By changing the trellis diagram in order to maximize Euclidean distance, we confirmed that performance was improved compared to conventional methods as increasing throughput of FTN signal.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.470-473
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• 2018

Using High-order Modulation in wideband system is sensitive to change of wireless channel environment as well as changes in ripple characteristics that can occur when baseband signals pass through RF equipment. Therefore, it is necessary to design and RF tuning that minimizes ripple characteristics change, which is difficult to implement systematically and takes a long time. In this paper, we analyze the fixed ripple characteristics of the baseband signal distored through the RF transmitting and receiving equipment. And the function of compensating the compensation filter by the modem receiver is implemented in 256 TCM. Also, it is confirmed that SNR and received sensitivity are improved by applying a digital compensation filter in a channel with poor RF equipment ripple characteristics.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.3A
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• pp.188-195
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• 2002

The M-algorithm for decoding convolutional codes can significantly reduce the complexity of the Viterbi algorithm by tracking a fixed number of survivor paths in each level of the decoding trellis. It is an easily-implementable algorithm suited for real-time processing of high-speed data. The algorithm, however, generates a sequence of catastrophic errors when the correct path is not included in the set of survivor paths. In this paper, the performance of the M-algorithm obtained from using various decoding complexity levels, frame lengths, and code constraint lengths is presented. The performance gain is quantified when the algorithm is used in conjunction with codes of increased constraint length. In particular, it is demonstrated the gain from the increased code free distance overcompensates the loss from the correct path being excluded from the survivors, when the frame length is short to moderate. Using 64 survivor paths, the signal-to-noise ratio gain obtained by increasing the constraint length from K=7 to K=9, 11, 15 is respectively 0.6, 0.75, and 08dB, when the frame of length L=100 has the frame error rate of 0.01%.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1531-1538
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• 2015

In this paper, we proposed receiver structure based on an iterative turbo equalization to cope with phase difference between two sensors in MIMO underwater communication channel. In a space-time coded system, it is often assumed that there are no phase errors among the multiple transmitter and receiver chains. In this paper, we have studied the effect of the phase errors between different transmit sensors and different propagation paths in the environment of MIMO underwater communication system, and have shown through BER performance by computer simulations that the bit-error-rate performance can be severely degraded. A decision-directed estimation and compensation algorithm has been proposed to minimize their effects on the system performance. In this paper, we investigate the phase differences and their effects on multiple-input and multiple-output systems, and propose a compensation algorithm for underwater channel model to minimize their effects.

• Journal of Advanced Navigation Technology
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• v.8 no.2
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• pp.190-196
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• 2004

The development of a new hardware structure which can implement the viterbi algorithm efficiently is required for applications such as a software radio because the viterbi algorithm, which is an error correction code function for the second and the third generation of mobile communication, needs a lot of arithmetic operations. The length of K in the viterbi algorithm different from each standard, for examples, K=7 in case of IS-95 standard and GSM standard, and K=9 in case of WCDMA and CDMA2000. In this paper, we propose a new hardware structure of an adaptive viterbi decoder which can decode the constraint length in K=3~9 and the data rate in 1/2 ~ 1/3. Prototyping results targeted to Altera Cyclon EPIC20F400C8, shows that the proposed hardware structure needs maximum 19,276 logic elements and power dissipation of 222.6 mW.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.58-58
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• 2020

다양한 품종이 개발되어 재배되고 있는 다래(Actinidia arguta (Siebold & Zucc.) Planch. ex Miq.)의 재배유형이 T덕형과 평덕형으로 나누어지고, 덕 형태 및 품종에 따라 다래의 생육 양상에 차이가 있음에도 불구하고 결과모지 길이를 15cm 길이의 단일한 형태로 전정해 왔다. 본 연구에서는 T덕형을 활용한 다래 재배에서 품종별로 수확량을 증대하면서 과실 품질을 향상시킬 수 있는 적정한 결과모지 길이를 결정하고자 하였다. 이를 위해 국립산림과학원에서 개발한 '새한', '대성' '칠보' 및 '오텀센스' 등 4품종을 대상으로 하여 결과모지 길이가 15, 30 및 50cm가 되도록 전정하였다. 동일한 방법으로 재배한 후 수확기인 9월에 수확량 및 열매 특성을 조사하였다. 그 결과 품종과 가지수, 결과지의 수와 미결실지 수, 열매 무게, 총 수확량 에서 유의한 차이가 있었고, 전정 길이에 따라서는 총 착과 수, 열매 무게 및 총 수확량에서 차이가 있었다. 모든 품종에서 결과모지 길이가 길어질수록 총 수확량은 증가하였으며, 총 수확량은 품종에 따라 2~7배까지 증가하는 경향을 보였다. 결과모지 전정은 '새한', '대성' 및 '오텀센스'는 50cm 전정에서 칠보는 30cm 전정에서 생산량 및 품질특성이 우수하였다.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.4
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• pp.1-21
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• 2013

This study has researched the characteristics and elements of the chuibyong, a sort of trellis in the Joseon Dynasty through the old pictorial data. The results were as follows; First, as a result of the analysis for the 25 pictorial data in the Joseon Dynasty, the chuibyongs have usually functioned as screening the facility to protect the private life and dividing the spaces of the site, but it was internally regarded as the props which symbolized the dignity and elegance of high class. Especially, not only the faunas such as crane and deer, and the floras such as Pinus densiflora, Musa basjoo, bamboo species and Paulownia coreana, but also various garden elements including oddly shaped stone, pond and pavilion were shown in the surrounding area of the chuibyong, and they were considered as a series of combination that was needed in the ideal garden for the literati. Secondly, the chuibyong was recognized as the ideological object which was typical of the literati culture in the story derived from an ancient event of China. Such image has been reflected intactly in the garden culture, and the chuibyong has been used(considered) as the important scenery of the season to imitate and reenact the Chinese Classical Garden in the narrative painting. Thirdly, in terms of the shape and function, the chuibyong in the paintings in the Joseon Dynasty basically had the function of the shielding and spatial division. Fourthly, the height of the chuibyung was similar to the one of fence which exceeds the person's height or Youngbyek(影壁) which is installed in the front and the rear of the main gate in China, and the various shape's chuibyung was properly set up in many spaces. Lastly, the making of the chuibyong in Joseon Dynasty was related to the trend of the writer's culture which was popular nationally in Ming dynasty rather than the particular functions or the location conditions. Especially, the symbol expression of the chuibyong showed on 'Elegant Gathering in the Western Garden' which was brought from China was recreated in the mansion of the upper class in Hanyang city as the center, and the primary mode for the expression of the wealth and writer's spirit through the chuibyong was transformed into the high-quality's garden element which could be created in the royal palace or the mansion of the upper class. Also, the use of the chuibyung was changed by spreading into the residential style for common people after the mid-nineteenth century, and it means that the chuibyung was developed into Korean styles.

• Economic and Environmental Geology
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• v.55 no.1
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• pp.77-95
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• 2022

The Gonamsan gabbroic complex in the Pocheon area, northwestern region of South Korea consists of a variety types of gabbroic rocks and associated Fe-Ti oxide deposits caused by magmatic differentiation. Post-magmatic intrusions (i.e., gabbroic pegmatite and pyroxene-apatite-zircon rocks) partly intruded into the gabbroic rocks. The gabbroic pegmatite occurs in monzodiorite and oxide gabbro of the complex, intimately and spatially associated with high-grade lenticular Fe-Ti oxide mineralization. The pegmatite can be subdivided into plagioclase-amphibole and pyroxene-olivine pegmatite, in which the contact surface is sharp. The plagioclase-amphibole pegmatite comprises plagioclase and amphibole, with lesser amount of pyroxene, ilmenite, sphene, apatite, and biotite. The pegmatite shows plagioclase-amphibole intergranular texture, in which the open space formed by large plagioclase laths (An_2-26Ab_72-98Or_0-2) are infilled by amphibole. The pyroxene-olivine pegmatite is dark gray to black in color and also contains magnetite, ilmenite, spinel, apatite, and calcite as a minor component. The pyroxene (En_35-36Fs_8-9Wo₅₅) and olivine (Fo_84-85Fa_15-16) partly show a poikilitic texture defined by smaller euhedral olivine enclosed by coarser clinopyroxene. Fe-Ti oxide minerals consist mainly of magnetite and ilmenite that are found interstitially to earlier formed silicates. Subsequently, they are encompassed by reaction rim (almost of amphibole and biotite) along the boundary with surrounding silicate minerals. Under the microscope, magnetite contains a lot of oxyexsolved ilmenite (trellis type) and spinel, and thereby is weakly enriched in magnetite-compatible elements such as Ti, Al, Mg, and V. The structure and textures at the contact zone as well as mineralogical disequilibrium between gabbroic pegmatite and the host gabbroic rocks suggest that the pegmatite may form as a result of accumulation from Fe-rich melt (or liquid) that occurred somewhere rather than in situ form from the host gabbroic rock during the magmatic differentiation. Consequently, the preliminary study suggests that further study on the post-magmatic activities can not only help us improve our understanding on magmatic fractionation but also provide critical information on Fe-Ti oxide mineralization in gabbroic rocks resulting from the magmatic differentiation.

• The KIPS Transactions:PartC
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• v.11C no.1
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• pp.141-148
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• 2004

Recently, the demand of broadband communications such as high-speed internet, HDTV, 3D-HDTV and ATM backbone network has been increased drastically. For transmitting the broad-bandwidth data using wireless network, it is needed to use ka-band frequency. However, the use of this ka-band frequency is seriously affected to the received data performance by rain fading and atmospheric propagation loss at the Ka-band satellite communication link. So, we need adaptive MODEM to endure the degraded performance by channel environment. In this paper, we will present the structure and design of the 155Mbps adaptive Modem adaptively compensated against channel environment. In order to compensate the rain attenuation over the ka-band wireless channel link, the adaptive coding schemes with variable coding rates and the multiple modulation schemes such as trellis coded 8-PSK, QPSK, and BPSK are adopted. And the blind demodulation scheme is proposed to demodulate without Information of modulation mode at the multi-mode demodulator, and the fast phase ambiguity resolving scheme is proposed. The design and simulation results of adaptive Modem by SPW model are provided. This 155Mbps adaptive MODEM was designed and implemented by single ASIC chip with the $0.25\mu{m}$ CMOS standard cell technology and 950 thousand gates.