• Journal of Environmental Science International
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• v.19 no.11
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• pp.1391-1396
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• 2010

Three biphenyl-degrading microorganisms were isolated from polluted soil samples in Sasang-gu, Busan. Among them, isolate DS-94 showing the strong degrading activity was selected. The morphological, physiological, and biochemical characteristics of DS-94 were investigated by API 20NE and other tests. This bacterium was identified as the genus Pseudomonas by 16S rDNA sequencing and designated as Pseudomonas sp. DS-94. The optimum temperature and pH for the growth of Pseudomonas sp. DS-94 were $25^{\circ}C$ and pH 7.0, respectively. This isolate could utilize biphenyl as sole source of carbon and energy. Biphenyl-degrading efficiency of this isolate was measured by HPLC analysis. As a result of biological biphenyl-degradation at high biphenyl concentration (500 mg/L), biphenyl-removal efficiency by this isolate was 73.5% for 7 days.

• Speech Sciences
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• v.15 no.3
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• pp.79-94
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• 2008

The purpose of this study was to compare phonological awareness ability of students with Down Syndrome(DS) and typically developing children(TD). TD and DS were equal the reading abilities(reading recognition). The subject were 10 DS and 10 TD, and were examined by test of phonological awareness. The test of phonological awareness was composed according to phonological units(word, syllable, phoneme) and task types(deletion, discrimination, blending). The results obtained in this study were as follows: The total score of phonological awareness ability of DS were significantly lower than TD. And the score of phonological awareness ability according to phonological units and task types were significantly lower than TD. But both DS and TD performed better on phonological deletion and blending task than discrimination. TD and DS represented different correlation between task types and phonological units. This means that TD performed better on all types of tasks and phonological units than DS.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.1
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• pp.9-15
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• 1997

In this paper, the performance of a hybrid direct-sequence/slow-frequency-hoped (DS/SFH) spread-spectrum (SS) system with noncoherent DPSK modulation is considered. Th ebit error probability is derived ovef a rayleigh fading channel in the presence of multiple tone jamming. Numerical evaluations are presented for some combinations of system parameters. The performance of a hybrid DS/SFH SS system is shown to be inferior to that of a pure DS SS system at low jamming-to-signal power ratio (JSR). At high JSR, the performance of a pure DS SS system is shown to be the same as the worst case peformance of a hybrid DS/SFH SS system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.390-396
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• 2009

MC-DS-CDMA is technique where a single data symbol is transmitted at multiple subcarriers which are orthogonal to each other. With this technique, frequency diversity can be achieved. The performance of PSAM MC-DS-CDMA system with the application of STBC antenna diversity is analyzed. The BER performance of this system over multipath fading environment is evaluated, considering the channel estimation ernr, carrier frequency offset, and the nonlinear high power amplifier.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.12
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• pp.3196-3204
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• 1996

We analyze the capacity of the imperfect power controlled DS/CDMA system with the Nakagami faded AMPS interferers by means of the analytical approach. Unlike the theoretical aassumption, the power control of the DS/CDMA system is not perfect. Therefore in this analysis we consider various parameters which cause the capacityreduction of the DS/CDMA system, the imperfect power control, the Nakagami fading index, he processing gain, and the number of AMPS interferers. The analytical results are compared with the Prasad's results which are considered only the imperfect power control of the DS/CDMA system. It is shown that the DS/CDMA capacity is decreased according to the increase of the deviation of the imperfect power control, to icrease the number pf the analog interfering users, and to decrease the processing gain.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.11
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• pp.10-18
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• 1996

In this paper, performance of a hybrid direct-sequency/slow-frequency-hopped (DS/SFH) spread-spectrum (SS) system with coherent BPSK modulation is analyzed. The bit error probability is derived over a frequency=-selective rician fading channel in the presence of multiple tone jamming. The fading channel is modeled as the wide-sense stationary uncorrelated scattering (WSSUS) model. Numerical evaluations are presented for some combinations of system parameters. The performance of a hybrid DS/SFH SS system is shown to be inferior to that of a ure DS SS system at low jamming-to-signal power ratio (JSR). At high JSR, the performance of a pure DS SS system is shown to be the smae as the worst case performance of a hybrid DS/SFH SS system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.686-690
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• 2003

직접 확산 부호 분할 다원 접속 (Direct Sequence Code Division Multiple Access : DS-CDMA) 시스템과 시분할 다원 접속 (Time Division Multiple Access : TDMA) 시스템을 동일 주파수 대역에서 중첩되어 전송할 때 DS-CDMA 신호에서의 TDMA 신호의 협대역 간섭이 문제된다. 본 논문에서는 DS-CDMA 신호의 협대역 간섭(narrowband interference : NI)를 제거하는 방법으로서 노치필터를 이용해서 협대역 간섭파 제거법을 제안하고, 간섭제거기(CCI canceller)를 이용해서 다중접속간섭을 제거하여 DS-CDMA 신호의 성능을 개선한다. 본 논문은 잡음, 다중접속 간섭 및 협대역 간섭환경에서 DS-CDMA 신호와 TDMA 신호의 주파수 공용 시스템에 적용할 때의 성능을 분석하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.4
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• pp.817-823
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• 2010

MC-DS-CDMA is technique where a single data symbol is transmitted at multiple subcarriers which are orthogonal to each other. With this technique, frequency diversity can be achieved. The performance of PSAM MC-DS-CDMA system with the application of MRRC antenna diversity is analyzed. The BER performance of this system over multipath fading environment is evaluated, considering the channel estimation error, carrier frequency offset, and the nonlinear high power amplifier.

• Molecules and Cells
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• v.45 no.1
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• pp.33-40
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• 2022

The various DNA-protein interactions associated with the expression of genetic information involve double-stranded DNA (dsDNA) bending. Due to the importance of the formation of the dsDNA bending structure, dsDNA bending properties have long been investigated in the biophysics field. Conventionally, DNA bendability is characterized by innate averaging data from bulk experiments. The advent of single-molecule methods, such as atomic force microscopy, optical and magnetic tweezers, tethered particle motion, and single-molecule fluorescence resonance energy transfer measurement, has provided valuable tools to investigate not only the static structures but also the dynamic properties of bent dsDNA. Here, we reviewed the single-molecule methods that have been used for investigating dsDNA bendability and new findings related to dsDNA bending. Single-molecule approaches are promising tools for revealing the unknown properties of dsDNA related to its bending, particularly in cells.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.4
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• pp.539-549
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• 1999

In this paper, the bit error rare (BER) performance of DS/CDMA DQPSK communication system in the presence of multi access interference, impulsive noise and Nakagami fading is investigated. The DS/CDMA DQPSK communication system adopts Maximum Ratio Combining (MRC) diversity reception and error correcting BCH code technique to enhance system performance. Using the derived error probability equation, the error rate performance of DS/CDMA DQPSK communication system has been evaluated and shown in figures to discuss as a function of impulsive index(A), Gaussian noise to impulsive noise power ratio($\Gamma$'), multi access interference(Κ), Nakagami fading parameter(m), the number of diversity branch (Ｌ), the number of error correction symbol (t), PN code sequence length(N) and $E_b/N_0$. The error performance of DS/CDMA-MDPSK signals improve by adopting MRC diversity and BCH(15,7) coding technique in the environment of impulsive noise plus Nagakami fading. From the results, we known that proposed system is affected by multi access interference, impulsive noise and Nakagami fading in radio communication system environment. Also, BER performance of DS/CDMA DQPSK communication system cam be improved increasing either the power of desired signal or the value of Gaussian noise to impulsive noise power ratio. And BCH(15,7) code technique is more effective to restrain the affection of multi access, interference, impulsive noise and Nakagami fading in DS/CDMA DQPSK communication system than MRC diversity reception technique.