• 동위원소뉴스
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• no.11 s.107
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• pp.1-1
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• 2005

• Journal of information and communication convergence engineering
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• v.9 no.6
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• pp.652-656
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• 2011

In this paper, a transmitter-based multipath processing and inter-channel interference (ICI) cancellation scheme for a ultra-wideband (UWB) spatial multiplexing (SM) multiple input multiple output (MIMO) system is presented. It consists of taps delayed lines and zero-forcing (ZF) filters in the transmitter and correlators in the receiver. For a UWB SM MIMO system with N transmit antennas, M receive antennas, and Q resolvable multipath components, the BER performance of a linear transmit ZF scheme is analyzed in a log-normal fading channel and also compared with that of a receiver-based ICI rejection approach. It is found that when M ${\leq}$ N, the transmit ZF processing approach outperforms the ZF receiver while making the mobile units low-cost and low-power.

• International Journal of Computer Science & Network Security
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• v.23 no.7
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• pp.1-8
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• 2023

An Orthogonal Frequency Division Multiplexing (OFDM) based wireless communication system has drawn wide attention for its high transmission rate and high spectrum efficiency in not only radio but also Underwater Acoustic (UWA) applications. Because of the narrow sub-carrier spacing of OFDM, orthogonality between sub-carriers is easily affected by Doppler effect caused by the movement of transmitter or receiver. Previously, Doppler compensation signal processing algorithm for Desired propagation path was proposed. However, other Doppler shifts caused by delayed Undesired signal arriving from different directions cannot be perfectly compensated. Then Receiver Bit Error Rate (BER) is degraded by Inter-Carrier-Interference (ICI) caused in the case of Multi-path Doppler channel. To mitigate the ICI effect, a modified Delay and Doppler Profiler (mDDP), which estimates not only attenuation, relative delay and Doppler shift but also sampling clock shift of each multi-path component, is proposed. Based on the outputs of mDDP, an ICI canceling multi-tap equalizer is also proposed. Computer simulated performances of one-tap equalizer with the conventional Time domain linear interpolated Channel Transfer Function (CTF) estimator, multi-tap equalizer based on mDDP are compared. According to the simulation results, BER improvement has been observed. Especially, in the condition of 16QAM modulation, transmitting vessel speed of 6m/s, two-path multipath channel with direct path and ocean surface reflection path; more than one order of magnitude BER reduction has been observed at CNR=30dB.

• Journal of the Korean Chemical Society
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• v.9 no.4
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• pp.161-168
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• 1965

The effect of solvents on the stabilities of the $C_6H_6{\cdot}I_2$ complex and the $C_6H_6{\cdot}ICl$ complex has been investigated through ultraviolet spectrophotometric measurements. The equilibrium constants obtained at room temperature for the formation of $C_6H_6{\cdot}I_2$ complex are 0.090, 0.216 and 0.328$ lmole^{-1}$ in chloroform, cyclohexane and n-hexane, respectively. The corresponding equilibrium constants at room temperature for $C_6H_6{\cdot}ICl$ complex are 0.125, 0.676 and 0.689 $lmole^{-1}.$ These results indicate that the stabilities of the two complexes increase with decreasing dielectric constants of the solvents used, the increase in stability being more rapid in the $C_6H_6{\cdot}ICl$ complex than in the $C_6H_6{\cdot}I_2$ complex. This may support the conclusion that the dative ionic structures, $C_6H_6^+{\cdots}I_2^-$ and/or ($C_6H_6I)^+{\cdots}Cl^-,$ play important roles on the reasonance stabilization of both the $C_6H_6{\cdot}I_2$ complex and the $C_6H_6{\cdot}ICl$ complex, the roles being more important in the latter complex than in the former complex.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.6
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• pp.635-641
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• 2010

Time-varying channel characteristics in OFDM systems over doubly selective channels cause inter-carrier interferences(ICI) in the frequency domain. Time domain windowing gives rise to restriction on the bandwidth of the frequency domain channel matrix and makes it possible to approximate the OFDM system as a simplified linear input-output model. When successive interference cancellation based on linear MMSE estimation is employed for channel equalization in OFDM systems, symbol detection ordering produces considerable effects on overall system performances. In this paper, we show the reduction of the residual ICI by time domain windowing and the resultant performance improvements, and investigate the effects of SINR- and CSEP-based symbol detection ordering on the performance of successive interference cancellation.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.6
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• pp.1353-1362
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• 2012

Many studies have demonstrated that articles from international collaborations are more cited than articles from domestic collaborations. However, difference between the citation impact of international and domestic co-authored papers is supposed to be widened due to the collaboration strategy adopted by individual institute. In short, each institute will show the significantly different citation impact between international and domestic co-authored papers. In this paper, we applied the index of Incremental Ciation Impact(ICI) to identify the different value of citation impact between international and domestic co-authored papers for research institutes of KRCF, results of which will be understood under the strategy of international research collaboration.

• Journal of Yeungnam Medical Science
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• v.39 no.1
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• pp.62-66
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• 2022

Immune checkpoint inhibitor (ICI)-associated adrenal insufficiency is rare but may become a serious adverse event in patients treated with ICIs. The present case report documents two cases of adrenal insufficiency developed during chemotherapy plus tislelizumab (百泽安, Baize'an; BeiGene Ltd.) therapy in patients with advanced gastric cancer. Adrenal insufficiency developed after 6 and 13 cycles of treatment and was well controlled with hydrocortisone. The patients also developed hypothyroidism, which was managed with levothyroxine. Two patients showed a partial response, and one patient out of two achieved a near-complete response, sustaining over 11 months. Increased awareness of ICI-related adrenal insufficiency is crucial for early detection and prompt management of patients treated with ICIs.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.6
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• pp.78-85
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• 2009

In time-varying multipath fading channels, orthogonal frequency division multiple access (OFDMA) uplink systems suffer severe performance degradation caused by inter-channel interference (ICI). In this paper, we propose a hybrid interference cancellation (HIC) for suppressing the degradation effect of ICI. The proposed HIC can achieve both exact interference cancellation and low detection complexity through efficient combination of parallel detection and serial cancellation. Simulation results show that, as the effect of Doppler increases, the proposed HIC achieves bit error rate (BER) performance enhancement in compared with severe performance degradation of conventional OFDMA receivers. In addition, both the computational complexity and total detection time are reduced.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.6
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• pp.1914-1925
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• 2014

Inter-symbol interference (ISI) problem is inevitable when the guard interval (GI) is shorter than the delay spread (DS) for an orthogonal frequency division multiplexing (OFDM) system. Iterative techniques have been proposed to overcome such a problem. However, most of existing algorithms are not efficient for an OFDM system with a small GI working under the channel with a large DS. Especially in the case of the DS spans a longer time than the half of the OFDM symbol duration. On the other hand, conventional algorithms, which can reduce the effects of the severe ISI, often employ several impractical assumptions to support the conclusions. In this paper, we present a robust decision feedback equalizer (DFE) for the OFDM system to overcome the severe ISI problem. The proposed DFE removes the ISI in a same manner as the residual inter-symbol interference cancellation (RISIC) algorithm. However, the inter-carrier interference (ICI) is reduced via cyclicity removal instead of the cyclicity restoration used in the conventional algorithms. The link-level simulation (LLS) results indicate that our proposed DFE scheme can dramatically improve the BER performance when the DS spans longer than the half of ODFM symbol duration.

• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.20-24
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• 1998

Poly(ethylene 2,6-naphthalate) (PEN) has been known since 1948, when its synthesis was first reported by ICI. Co. In spite of its long history. application of PEN is limited as compared with poly(ethylene terephthalate) (PET). because PEN monomer is very expensive, and PEN exhibits relatively high melt viscosity that is not easy for fiber spinning and injection molding.(omitted)