• Title/Summary/Keyword: Multi-modulation

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Matricellular proteins in immunometabolism and tissue homeostasis

  • Kyoungjun Eun;Ah Young Kim;Seungjin Ryu
    • BMB Reports
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    • v.57 no.9
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    • pp.400-416
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    • 2024
  • Matricellular proteins are integral non-structural components of the extracellular matrix. They serve as essential modulators of immunometabolism and tissue homeostasis, playing critical roles in physiological and pathological conditions. These extracellular matrix proteins including thrombospondins, osteopontin, tenascins, the secreted protein acidic and rich in cysteine (SPARC) family, the Cyr61, CTGF, NOV (CCN) family, and fibulins have multi-faceted functions in regulating immune cell functions, metabolic pathways, and tissue homeostasis. They are involved in immune-metabolic regulation and influence processes such as insulin signaling, adipogenesis, lipid metabolism, and immune cell function, playing significant roles in metabolic disorders such as obesity and diabetes. Furthermore, their modulation of tissue homeostasis processes including cellular adhesion, differentiation, migration, repair, and regeneration is instrumental for maintaining tissue integrity and function. The importance of these proteins in maintaining physiological equilibrium is underscored by the fact that alterations in their expression or function often coincide with disease manifestation. This review contributes to our growing understanding of these proteins, their mechanisms, and their potential therapeutic applications.

Nonlinear Synthetic Aperture Radar using FMCW signal (FMCW 신호를 활용한 비선형 합성개구레이다)

  • Won-Ryeol Lee;Sun K. Hong
    • Journal of IKEEE
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    • v.28 no.3
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    • pp.465-468
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    • 2024
  • In this paper, we propose a synthetic aperture radar based on FMCW using a nonlinear radar platform. we construct a nonlinear radar platform with different transmit and receive frequencies using FMCW signals. The platform moves along a 1.5 m path to acquire second harmonics signals, implementing a nonlinear SAR (synthetic aperture radar). Multiple nonlinear targets were placed in an indoor multipath environment with linear objects to detect weak second harmonics. After undergoing the SAR focusing precess, a 2D hamming window was applied to enhance the focusing performance.

Performance Analysis of Multiple-Antenna Receiver in Cloud Transmission System for Building Single Frequency Networks (단일주파수방송망 구축을 위한 클라우드 전송 시스템에서의 다중 안테나 수신 성능 분석)

  • Gwak, Gye Seok;Kim, Jaekil;Ahn, Jae Min
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.8
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    • pp.474-480
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    • 2014
  • In this paper, we propose a study for the next generation terrestrial broadcasting technology based on SFN(Single Frequency Networks), which applies multiple receiving antenna to improve receiving performance of cloud transmission system. By applying multiple receiving antenna, the received broadcast signals at the boundary of different SFN broadcasting area could be modelled by distributed MIMO system. Due to the interference cancellation effect of the MIMO detector, the proposed scheme could suppress the adjacent area interference more efficiently compared to the single receiving antenna case. Simulation results show that receiving performance can be improved dramatically in overlapping area of SFN by applying multiple antenna receivers in cloud transmission system.

Design and Demonstration of All-Optical XOR, AND, OR Gate in Single Format by Using Semiconductor Optical Amplifiers (반도체 광증폭기를 이용한 다기능 전광 논리 소자의 설계 및 측정)

  • Son, Chang-Wan;Yoon, Tae-Hoon;Kim, Sang-Hun;Jhon, Young-Min;Byun, Yung-Tae;Lee, Seok;Woo, Deok-Ha;Kim, Sun-Ho
    • Korean Journal of Optics and Photonics
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    • v.17 no.6
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    • pp.564-568
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    • 2006
  • Using the cross-gain modulation (XGM) characteristics of semiconductor optical amplifiers (SOAs), multi-functional all-optical logic gates, including XOR, AND, and OR gates are successfully simulated and demonstrated at 10Gbit/s. A VPI component maker^TM simulation tool is used for the simulation of multi-functional all-optical logic gates and the10 Cbit/s input signal is made by a mode-locked fiber ring laser. A multi-quantum well (MQW) SOA is used for the simulation and demonstration of the all-optical logic system. Our suggested system is composed of three MQW SOAs, SOA-1 and SOA-2 for XOR logic operation and SOA-2 and SOA-3 for AND logic operation. By the addition of two output signals XOR and AND, all-optical OR logic can be obtained.

A 4-Channel Multi-Rate VCSEL Driver with Automatic Power, Magnitude Calibration using High-Speed Time-Interleaved Flash-SAR ADC in 0.13 ㎛ CMOS

  • Cho, Sunghun;Lee, DongSoo;Lee, Juri;Park, Hyung-Gu;Pu, YoungGun;Yoo, Sang-Sun;Hwang, Keum Cheol;Yang, Youngoo;Park, Cheon-Seok;Lee, Kang-Yoon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.3
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    • pp.274-286
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    • 2016
  • This paper presents a 4-channel multi-rate vertical-cavity surface-emitting laser (VCSEL) driver. In order to keep the output power constant with respect to the process, voltage, temperature (PVT) variations, this research proposes automatic power and magnitude. For the fast settling time, the high-speed 10-bit time-interleaved Flash-successive approximation analog to digital converter (Flash-SAR ADC) is proposed and shared for automatic power and magnitude calibration to reduce the die area and power consumption. This chip is fabricated using $0.13-{\mu}m$ CMOS technology and the die area is $4.2mm^2$. The power consumption is 117.84 mW per channel from a 3.3 V supply voltage at 10 Gbps. The measured resolution of bias /modulation current for APC/AMC is 0.015 mA.

Performance Enhancement by Scaling Soft Bit Information of APSK (APSK 변조 방식에 대한 연판정 출력의 스케일링을 통한 성능 개선)

  • Zhang, Meixiang;Kim, Sooyoung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38C no.10
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    • pp.858-866
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    • 2013
  • In the DVB-S2, which is the technical specification of the second generation digital video broadcasting via satellite, APSK modulation scheme along with LDPC coding schemes are defined. APSK is a multi-lelvel PSK modulation scheme and decoding of LDPC coded signal requires soft decision information. Therefore, the APSK demodulator at the receiver should have capability of estimating soft information. In this paper, we introduce a method to estimate soft information by using simple distance estimation, and show that this method overestimates the soft information. Subsequently, this overestimated soft information leads to performance degradation. In order to overcome this problem, we propose a scaling method to improve the performance at the receiver In addition, we show that the proposed scaling scheme enables us to estimate the soft information with linear order complexity and produce the performance close to the maximum likelihood detection.

Performance Comparison of OFDM Based on Fourier Transform and Wavelet OFDM Based on Wavelet Transform (웨이블릿 변환 기반의 Wavelet-OFDM 시스템과 푸리에 변환 기반의 OFDM 시스템의 성능 비교)

  • Lee, Jungu;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.3
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    • pp.184-191
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    • 2018
  • Orthogonal frequency division multiplexing(OFDM) is a multicarrier modulation(MCM) system that enables high-speed communications using multiple carriers and has advantages of power and spectral efficiency. Therefore, this study aims to complement the existing shortcomings and to design an efficient MCM system. The proposed system uses the inverse discrete wavelet transform(IDWT) operation instead of the inverse fast Fourier transform(IFFT) operation. The bit error rate(BER), spectral efficiency, and peak-to-average power ratio(PAPR) performance were compared with the conventional OFDM system through the OFDM system design based on wavelet transform. Our results showed that the conventional OFDM and Wavelet-OFDM exhibited the same BER performance, and that the Wavelet-OFDM using the discrete Meyer wavelet had the same spectral efficiency as the conventional OFDM. In addition, all systems of Wavelet-OFDM based on various wavelets confirm a PAPR performance lower than that of conventional OFDM.

Computer Generated Hologram for Beam Control of LCOS based Wavelength Selective Switch (LCOS기반의 파장선택스위치 빔제어용 컴퓨터 생성 홀로그램)

  • Lee, Yong-Min;Han, Chang Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.6
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    • pp.744-749
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    • 2016
  • This paper presents the design of a computer-generated hologram for beam control of an LCOS-based wavelength selective switch, which is the core technology for next-generation ROADM. By introducing a computer-generated hologram instead of general grating patterns to control the LCOS device, we contribute to building a more efficient wavelength selective switch. With the use of phase modulation properties of LCOS devices, we designed the hologram for five-port output and a 40-channel wavelength selective switch. We applied a multi-level phase modulation technique with the Gerchberg-Saxton algorithm to produce the hologram, which is easily scalable to any different type of wavelength selective switch. With an experimental setup, we verified the usability of the hologram designed for five-port output. We also suggest a hologram design technique for beam control of a 40-channel wavelength selective switch.

A Study on the Optimization of the Transmission Method for COMS Satellite Control Signal (통신해양기상위성의 위성 관제 신호 전송 방식의 최적화 연구)

  • Kim, Yeong-Wan;Yang, U-Jin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.11
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    • pp.47-53
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    • 2006
  • The power losses due to modulation index for multi-modulation scheme were analyzed under various transmission mode of satellite control and the necessary satellite link margin for transmission mode were proposed in this paper On the basis of the analyses for interference between the transmission signals and threshold of satellite control signal receiver, the optimal subcarrier signals were proposed for satellite range measurement methods, respectively. The subcarrier signal of 12 kHz or 14 kHz is proper for telecommand using the ESA method, and 16 kHz for telecommand signal using the GSTDN method. On the other hand, the telemetry subcarrier of 65.536 kHz is a proper in the viewpoint of receiver threshold value.

A Study on Calculation of Protection Ratio for Interference Analysis in Fixed Radio Relay Networks (고정 무선중계 망의 간섭 분석을 위한 보호비 계산에 대한 연구)

  • Suh Kyoung-Whoan;Lee Joohwan
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.1 s.343
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    • pp.133-142
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    • 2006
  • This paper suggests an efficient method of protection ratio(PR) calculation and shows some results of point-to-point radio relay system for frequency coordination. The proposed PR can be expressed as a function of C/N of modulation scheme, noise-to-interference ratio(N/I), multiple interference allowance, fade margins of multi-Path and rain attenuation and net filter discrimination. And PR calculation is performed in view of fade margin, modulation scheme, distance, and interference for actual point-to-point radio relay frequency. According to results for 6.2 GHz, 64-QAM and 60 km at BER 10-6, fade margin and co-channel Protection ratio reveal 41.1dB and 74.9 dB, respectively The merit of presented method provides a systematic and easy calculation by means of PR correction factor related with various parameters and can apply the same concept to frequency coordination of millimeter wave radio relay system.