• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.428-436
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• 1995

The studies were conducted to escape for laber concentration during rice harvest and barley sowing through the scattering sowing before rice harvest(SS) compared to the drilling on high ridge(DS) of barley from 1990 to 1994. There were longer in plant height and more in tiller number under the SS than those under the DS of barley while cold-injured leaves of barley were inversely affected by two different sowing methods. The barley growth was more vigorous in the DS. There was similar at heading and maturing date. The grain yield of barley was lower in the SS by 20.6% which was resulted from the reduction of spike number per m$^2$ and number of grain per spike. There was not significant at growth and yield for sowing date before rice harvest. The variation of successive years on growth, yield and its components were higher in the SS than those in the DS.

• Clinical and Experimental Pediatrics
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• v.50 no.12
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• pp.1180-1187
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• 2007

Systemic lupus erythematosus (SLE) is an episodic, multi-system, autoimmune disease characterized by widespread inflammation of blood vessels and connective tissues and by the presence of antinuclear antibodies (ANAs), especially antibodies to native (double-stranded) DNA (dsDNA). Its clinical manifestations are extremely variable, and its natural history is unpredictable. Untreated, SLE is often progressive and has a significant fatality rate. The most widely used criteria for the classification of SLE are those of the American College of Rheumatology (ACR), which were revised in 1982 and modified in 1997. The presence of four criteria have been diagnosed as a SLE. Rashes are common at onset and during active disease. The oral mucosa is the site of ulceration with SLE. Arthralgia and arthritis affect most children and these symptoms are short in duration and can be migratory. Lupus nephritis may be more frequent and of greater severity in children than in adults. The initial manifestation of nephritis is microscopic hematuria, followed by proteinuria. The most common neuropsychiatric symptoms are depression, psychosis(hallucination and paranoia) and headache. CNS disease is a major cause of morbidity and mortality. Pericarditis is the most common cardiac manifestation. Libman-Sacks endocarditis is less common in children. The most frequently described pleuropulmonary manifestations are pleural effusions, pleuritis, pneunonitis and pulmonary hemorrhage. During the active phase ESR, CRP, gamma globulin, ferritin and anti-dsDNA are elevated. Antibodies to dsDNA occur in children with active nephritis. Antibodies to the extractable nuclear antigens (Sm, Ro/SS-A, La/SS-B) are strongly associated with SLE. Specific treatment should be individualized and based on the severity of the disease. Sepsis has replaced renal failure as the most common cause of death.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.4
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• pp.761-770
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• 1997

Narrowband signals can be treated like a single tone interference at the receiver which demodulates wideband signals spectrum overlaid at the same frequency band. In this paper, the single tone interference is effectively suppressed by the use of a multicarrier DPSK direct-sequence(DS) spread spectrum(SS) with maximal-ratio(MR) combining instead of notch filter, which is hard to implement. A noncoherent DPSK system is considered because it is more realizable and does not require any complicate phase tracking, compared with a single carrier system subject to a constraint system bandwidth, and their performance comparisons are validated through simulation. We also propose a suboptimal-ratio(SR) combining which yields uniform and tight low bound on the performance of the MR combining, and then system parameters re optimized by theoretically evaluating the low bound, since an exact analysis appears intractable.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.587-587
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• 2006

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.11
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• pp.28-36
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• 1998

In the CDMA mobile communication system with asynchronous mode among base stations, the initial PN code acquisition method using a matched filter can be considered for the rapid PN code synchronization acquisition in the handoff region. In the model of the noncoherent QPSK/DS-SS under the Rayleigh fading channel, the mean acquisttion time of the matched filter is analyzed to have a shortened time in proportion to the length of matched filter to be compared with the serial correlation method. In this paper to improve the HW complexity of the conventional matched device which enables the repeated correlation process, is designed and its function is verified through the FPGAsimulation using Altera MaxPlus Ⅱ.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.6B
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• pp.1015-1023
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• 1999

We propose nonlinear processing schemes for robust acquisition of direct-sequence spread spectrum (DS/SS) signals in wideband pulse jamming. To mitigate the interference effect due to impulse-like wideband jamming signals, the received signal is preprocessed by using the median filter, a simple order statistic filter Since only parts of the PN sequence are used for rapid acquisition, it is indispensable for analytic design of an acquisition scheme to have an appropriate model of the partial PN signal. The partial correlation of the median filtered PN signal is approximated by a two-piecewise linear model using an approximate upper bound. The acquisition performance of the proposed schemes is compared to that of other schemes. Finally, the analytic design is verified by computer simulation.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.11
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• pp.1329-1334
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• 1988

A new method was developed for growing oxidation film by thermal reaction of $NH_3$ and $O_2$. The growth rate increased with the increase of partial pressure of $NH_3$. Optical transparency of the growth film was 12% at the wave number 1100 $cm^{-1}$ compared with 17% by thermal dry oxidation method, and the quality was much better. In C-V characteristic curve, $Q_{OX}$ was almost equal to $Q_{SS}$ and no hysteresis phenomena was observed. n-MOS transistors fabricated with this new method showed $I_D$-$V_{DS}$ characteristics better than thermal dry oxidation method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.2
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• pp.417-426
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• 2000

In this paper, CE-CPSK(Constant Envelope Continuous Phase Shift Keying) modulated DS/SS(Direct Sequence Spread Spectrum) transceiver with 908 MHz carrier frequency and 1.5 MHz PN clock rate is proposed. To overcome the effect of nun-linear power amplifier, CE-CPSK modulation method which has the constant envelope and continuous phase characteristics is proposed. To analyze the DS/SS receiver performance with respect to code tracking loop, multipath fading channel is characterized as a two-ray Rayleigh fading channel. To compensate the demerit of analog delay locked loop, digital delay locked loop is employed for code tracking loop. Simulation and experimental examination has been carried out in AWGN(Additive White Gaussian Noise) and Rayleigh fading channel environment in order to prove validity of the proposed method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.9A
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• pp.2141-2152
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• 1998

In this paper, we design and implement an indoor wireless modem using small signal of ISM band regulation, which can tranceive reliable data streams. We use direct sequence spead spectrum (DS-SS) signaling with synchronous BPSK and QPSK modulation, convolutional coding with viterbi decoding. The radio frequency module uses frequency devision duplexing in 900 MHz band, and the digital module is implemented with FPGAs for the purpose fo ASIC design. The perfomrance of our own acquistion and tracking circuit consisting digital matched filter and decision logic is proved by experiments, and the possibility of file transfer at indoor environment with the entrie system that the modem is connected the PC through RS-232C port is verified.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7A
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• pp.635-640
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• 2002

We investigate optimal and suboptimal decision rules for parallel code acquisition in chip asynchronous direct-sequence spread-spectrum systems. The conventional decision rule for parallel acquisition is to choose the largest correlator output of a receiver. However, such a scheme is optimum only for chip synchronous models. In this paper, an optimal decision rule is derived based on the maximum-likehood criterion for chip asynchronous models. A simpler suboptimal decision rule is also discussed. The performance of the optimum and suboptimum decision rules is compared to that of the conventional decision rule. Numerical results show that, for chip asynchronous models, both the optimal and suboptimal decision rules outperform the conventional decision rule.