• Journal of Satellite, Information and Communications
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• v.12 no.1
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• pp.1-5
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• 2017

In this paper, multiuser detector (MUD) based on radial basis function (RBF) is proposed and simulated for a multicode direct sequence/code division multiple access (DS/CDMA) system in a multipath fading channel. The performance of RBF-based MUD is compared with that of many suboptimal multiuser detectors in terms of bit error probability. From the simulation results, it is confirmed that the RBF-based MUD outperforms decorrelating detector, and achieves near-optimum performance under various environments. The results in this paper can be applied to design of MUD for a multicode DS/CDMA system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.3
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• pp.582-590
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• 1994

This paper introduce a highly verstile and simple data transmission system designed for commercial power distribution lines. The system operates on the DSSS principle but utilizes two independent carrier frequencies each represents polarity of DS MODEM outiputs. At the receiving terminal, outputs of two envelope detectors are directly applied to separate DS correlators before the two components are compared. The recovered signals which represents data and line noise are then compared at comparator. With the noise power greatly rudused at the correlator, the error rate of the data observed at comparator desplays great improvement comparing to the conventional FSK-DS system in which the detector output are compared before the correlator stage. Despite its simplest structure, the prototype MODEM transmitts 2400 bps with the error rate 10 , about 10dB improved compared to conventional FSK system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.12 s.91
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• pp.1199-1206
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• 2004

In this paper, we analyzed the orthogonal MC DS-CDMA system and no-overlapping MC DS-CDMA System, which were divided by the normalized spacing between adjacent subcarrier over Nakagami-m fading channels. In order to reduce the number of selective paths occurring in the MC system, the Hybrid SCMRC technique was applied, which was compared with the case when the MRC technique was used. As a result of simulations, it was found that the Hybrid SC/MRC method could be replaced by the MRC method and if the number of subcarriers was increased when the given bandwidth was fixed, the interval between subcarriers increased and bigger bandwidths were required. an, the number or subcarriers should be selected in consideration or given bandwidth.

• BMB Reports
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• v.42 no.1
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• pp.6-15
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• 2009

The most common genetic disorder Down syndrome (DS) displays various developmental defects including mental retardation, learning and memory deficit, the early onset of Alzheimer's disease (AD), congenital heart disease, and craniofacial abnormalities. Those characteristics result from the extra-genes located in the specific region called 'Down syndrome critical region (DSCR)' in human chromosome 21. In this review, we summarized the recent findings of the DYRK1A and RCAN1 genes, which are located on DSCR and thought to be closely associated with the typical features of DS patients, and their implication to the pathogenesis of neural defects in DS. DYRK1A phosphorylates several transcriptional factors, such as CREB and NFAT, endocytic complex proteins, and AD-linked gene products. Meanwhile, RCAN1 is an endogenous inhibitor of calcineurin A, and its unbalanced activity is thought to cause major neuronal and/or non-neuronal malfunction in DS and AD. Interestingly, they both contribute to the learning and memory deficit, altered synaptic plasticity, impaired cell cycle regulation, and AD-like neuropathology in DS. By understanding their biochemical, functional and physiological roles, we hope to get important molecular basis of DS pathology, which would consequently lead to the basis to develop the possible therapeutic tools for the neural defects in DS.

• The Korean Journal of Physiology
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• v.19 no.2
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• pp.155-160
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• 1985

Dantrolene sodium(DS) is a long acting skeletal muscle relaxant which has been successfully used to control muscle spasticity in patients with various neurological disorders. However, its use is associated with hepatotoxicity. Tissue sulfhydryl group has many important roles for cellular integration and glutathione serves as a substrate for the detoxification metabolism. The purpose of this study were to investigate the effect of DS on tissue sulfhydrl group and glutathione content. Foully albino rats were divided into two groups ; saline treated (control) and DS treated groups. DS dissolved in saline was administered orally. All rats were sacrificed after 7. 14. 21 and 28 days of DS ana saline treatment by dacapitation ana liver was removed for the enzyme preparation. Total and nonprotein sulfhydryl were measured by the method of Sedlak and Lindsay (1968). Total glutathione content was assayed according to the method described by Tietze (1969) and glutathione reductase was assayed according to the method of Racker (1955), The results obtained are summarized as follows : DS administration significantly depressed the total, protein and nonprotein sulfhydryl content in liver. There were significant reduction of both total glutathione content and glutathione reductase activity in liver. On the basis of the above results it may be speculated that the toxicity of DS are well correlated with tissue sulfhydryl content and glutathione reductase activity.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.3
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• pp.446-450
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• 2001

Performance of spectrum-overlapped BPSK DS/SFH-SSMA communication system is considered in MAI and MTI channel. SSMA system is studied that the frequency spectrums of DS spread signals are overlapped. The increase of overlapping makes ACI and processing gain larger simultaneously. Therefore, BER performance can be optimized by controlling the amount of overlapping. BER equation are derived far the overlapping BPSK DS/SFH-SSMA communication system in multitone interference channel. From the numerical analyses and the simulation results, it can be concluded that the BER performance is considerably improved in optimized overlapping system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12C
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• pp.1208-1213
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• 2005

Recently, ultra wideband(UWB) is emerging as a solution for the IEEE 802.15.3a(TG3a) standard because of its potential to enable high-speed data transmission with low power consumption. One of the submitted systems as s PHY proposal is M-ary biorthogonal keying direct sequence ultra wideband(M-BOK DS-UWB). In this paper, adaptive multiple antenna transmission scheme for achieving high capacity and reliability in M-BOK DS-UWB is proposed. This proposed system can overcome the limitations of STBC and V-BLAST, such as bit error rate performance and throughput.

• Journal of fish pathology
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• v.23 no.3
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• pp.273-280
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• 2010

To determine whether rock bream Oplegnathus fasciatus can be protected from rock bream iridovirus (RBIV) infection by intramuscular injection of long double-stranded RNAs (dsRNAs), we compared protective effect of virus-specific dsRNAs corresponding to major capsid protein (MCP), ORF 084, ORF 086 genes, and virus non-specific green fluorescent protein (GFP) gene. Furthermore, to determine whether the non-specific type I interferon (IFN) response was associated with protective effect, we estimated the activation of type I IFN response in fish using expression level of IFN inducible Mx gene as a marker. As a result, mortality of fish injected with dsRNAs and challenged with RBIV was delayed for a few days when comparing with PBS injected control group. However, virus-specific dsRNA injected groups exhibited no significant differences in survival period when compared to the GFP dsRNA injected group. Semi-quantitative analysis indicated that the degree of antiviral response via type I IFN response is supposedly equal among dsRNA injected fish. These results suggest that type I IFN response rather than sequence-specific RNA interference might involve in the lengthened survival period of fish injected with virus-specific dsRNAs.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.634-636
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• 2021

In this study, we studied the macro-modeling of an feedback field-effect transistor (FBFET) using SPICE simulation. The previously presented macro-model of the FBFET is consisting of two circuits. one is charge integration circuit, and the other is current generation circuit. The previous current generation circuit has problem that can't predict performance accurately of the circuits, due to implementing only I_DS-V_GS characteristics. To solve this problem, we presents a model that can implement not only I_DS-V_GS characteristics but alos I_DS-V_DS characteristics by adding the diode in the current generation circuit.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.837-842
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• 2010

The physicochemical properties of coarse semolina (CS), medium semolina (MS) and fine semolina (FS) were investigated to research method applied in noodles processing of Korean wheat semolina. Large particle (>250 ${\mu}m$) was over 75% in all semolinas, except for FS, and the particle distribution of MS and durum semolina (DS) was similar. Crude protein and crude ash were the highest in DS followed by CS>MS>FS. Crude lipid of DS was the lowest among samples and CS, MS and FS were not significantly different. L value was high in semolina with small particle distribution and starch damage was the lowest in DS followed by FS>MS. Amylose content was high in DS (29.80%) and FS (29.08%) with small particle distribution. Water binding capacity was the highest in DS, and FS showed the highest water binding capacity among Korean wheat samples. Solubility and swelling power were noticeably high in FS with low starch damage and small particle distribution. In scanning electron microscope (SEM), FS and MS showed distribution of separated fine particles of flours. From these results, the physicochemical properties of semolina showed many differences by grinding methods. FS should be applied in noodles processing through additional examination about characteristic of noodle making.