• Journal of the Institute of Electronics Engineers of Korea TC
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• 제37권3호
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• pp.9-17
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• 2000

In this paper we implement computer simulation system of 4FSK signal MODEM using Quadrature detector and analyze overall tranceiver system. We follow the FLEX wireless paging system standards and construct premodulation filter and data frame. We propose an efficient open loop symbol timing recovery algorithm which takes advantage of 128 bit length preamble pattern and also propose a 32 bit UW pattern which Is based on the optimal UW detection method, and excellent aperiodic autocorrelation characteristic. The BER simulation in the fading channel as well as AWGN is performed with BCH coding and Interleaving to the Quadrature detector system and it is shown that a high coding fain occurs in the fading channel rather than AWGN channel.

• Journal of Microbiology and Biotechnology
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• 제33권12호
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• pp.1576-1586
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• 2023

Vaccination is the most effective method for preventing the spread of the influenza virus. Cell-based influenza vaccines have been developed to overcome the disadvantages of egg-based vaccines and their production efficiency has been previously discussed. In this study, we investigated whether treatment with forskolin (FSK), an adenylyl cyclase activator, affected the output of a cell-based influenza vaccine. We found that FSK increased the propagation of three influenza virus subtypes (A/H1N1/California/4/09, A/H3N2/Mississippi/1/85, and B/Shandong/7/97) in Madin-Darby canine kidney (MDCK) cells. Interestingly, FSK suppressed the growth of MDCK cells. This effect could be a result of protein kinase A (PKA)-Src axis activation, which downregulates extracellular signal-regulated kinase (ERK)1/2 activity and delays cell cycle progression from G1 to S. This delay in cell growth might benefit the binding and entry of the influenza virus in the early stages of viral replication. In contrast, FSK dramatically upregulated ERK1/2 activity via the cAMP-PKA-Raf-1 axis at a late stage of viral replication. Thus, increased ERK1/2 activity might contribute to increased viral ribonucleoprotein export and influenza virus propagation. The increase in viral titer induced by FSK could be explained by the action of cAMP in assisting the entry and binding of the influenza virus. Therefore, FSK addition to cell culture systems could help increase the production efficiency of cell-based vaccines against the influenza virus.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제19권10호
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• pp.1925-1934
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• 1994

In this paper, it was studied the method of performance improvement of trellis encoded 4-ray continuous phase FSK with nonconstant frequency space when permitted complexity. It was used the nonconstant mapper in order to produce nonconstant frequency, fixed maximum symbol values 3, -3 for comparision in similar bandwidth, changed symbol values 1, -1 from 0.5 to 3.0 as symmetry. Free Euclidean distance evaluation of all encoder/nonconstant mapper combinations, which is the parameter of performance of error probability, was performed with the trellis-based algorithm, we analyzed the characteristics of those.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제7권5호
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• pp.879-886
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• 2003

Agile frequency synthesizers are the common device used for commandable, wide-band frequency hopping in frequency-hopped (FH) communications. In this paper, synthesizer phase transient effect and its compensation methods in an FH/FSK(Frequency Hopped Frequency Shift Keying) system are studied. Models for these analysis are developed and resulting performance degradations are computed. The basic PLL is difficult to implement for fast frequency hopping in narrowband radio communication systems. To solve this problem, digital frequency synthesizer/CPM (Continuous Phase Modulation)modulator is proposed. And it's performance is analyzed theoretically. The analysis show that fast frequency hopping is possible in frequency hopping system that use digital frequency synthesizer/CPM modulator.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• 제24권5호
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• pp.583-587
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• 2015

In this study, a half-duplex mutual communication device via human skin was developed. Frequency-shift keying (FSK) digital modulation and demodulation control were used to transmit and receive data. Data communication through the human body is an effective communication technique and has high-grade security characteristics. In addition, making contact is a natural instinct of humans. Transmitting data through the human body is currently a highly conspicuous technology, because recently a lot of commercial sensors for humans have been developed. A body area network (BAN) can be easily constructed by this communication method on human skin. In this study, a half-duplex FSK mutual communication device was developed using a commercial FSK modulator and demodulator. A special control switching circuit and communication sequence were developed for mutual communication through human skin.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제10권3호
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• pp.579-585
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• 2006

In this study, we analysis an optical receivers using the optical preamplifier in a spectrum-sliced WDM systems. The average numbers of photons/bit, for an $10^{-9}$ error probability, counts using the OOK and FSK transmission. As a result, the theoretical sensitivity for PIN receiver and optical preamplifier receiver are approximately $9.2\times10^4\;and\;7.2\times10^2$ in the m=20, respectively. Also, the average numbers of photons/bit, for and given error probability, theoretical receiver sensitivity for Gaussian method and k-square method are approximately $9\times10^2\;and\;2.16\times10^2$ in the m=40, respectively. And the average numbers of photons/bit, for an given error probability, theoretical receiver sensitivity, OOK and FSK transmission are approximately $1.9\times10^2\;and\;3.1\times10^2$ in the m=20, respectively.

• Journal of the Institute of Electronics Engineers of Korea TC
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• 제45권2호
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• pp.83-91
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• 2008

To design the light control system using the PLC(Power Line Communication) with the ballasts of MH(Metal Halide) lamps, we analyzed the noise effect on the power line by the electronic ballast. For the power line characteristics are changed by the loads, the ballast have to be designed to be suitable to the PLC. Therefore, this paper proposed the optimal ballast and designed two kinds of PLM(Power Line Modem) which one is ASK type and the other is FSK type. Two type of PLM have used the manchester codes or DS/SS code. Experimental results have shown that the FSK type modem by the DS/SS coding technique have the best characteristics.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제6권8호
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• pp.1251-1258
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• 2002

The weather FAX machine is the one of necessary of safety navigation for ship. which is the machine which make the weather image by the receiving radio signal which is modulated using FSK method and transmitted on air by coast station. after Coast station scan the weather image and broadcast the image with black dot to 1500Hz and white dot to 2300Hz using FSK modulation. This paper implement weather fax machine using only general IBM-PC by software. By using IBM-PC we can make some good functions like print, edit, save etc. The modulated signal from SSB go into RS232C port via photo coupler not to give damage to PC. by using Timer Interrupt and RS232C serial interrupt, we can measure signal frequency and remake weather image. This paper use only IBM-PC with general SSB receiver which is widely spread on the ship. so this is very economic and possible to implement mutifunctions.

• Journal of the Institute of Electronics Engineers of Korea TC
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• 제43권1호
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• pp.25-32
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• 2006

We propose a new M-ary state-transition FSK modulator technique for enhancing demodulator's symbol timing recovery which can be applied to acoustic MODEM. In the previous technique, the demodulator's symbol timing performance can degrade when the sequences of same symbols are transmitted. This proposed method, because the transmission symbol changes in every single symbol period, increases the synchronization performance dramatically and has a simple MODEM and frame structure. On the one hand, we improve modulation-derived synchronization(MDS) which is M-ary FSK's symbol timing recovery scheme, then analyze it. Finally the proposed method is analyzed from the viewpoint of frequency efficiency, which proves this method is appropriate for acoustic MODEM.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제25권2호
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• pp.245-250
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• 2014

This paper introduces the inverse synthetic aperture radar(ISAR) imaging technique for rear view target of an automobile, which uses both linear frequency modulation-frequency shift keying(LFM-FSK) waveform and monopulse tracking. LFM-FSK waveform consists of two sequential stepped frequency waveforms with some frequency offset, and thus, can be used to generate ISAR images of rear view target of an automobile. However, ISAR images can often be blurred due to non-uniform change rate of relative aspect angle between radar and target. In order to address this problem, one-dimensional(1-D) Lagrange interpolation technique in conjunction with angle information obtained from the monopulse tracking is applied to generate uniform data across the radar's aspect angle. Simulation results show that the proposed method can provide focused ISAR images.