• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.9
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• pp.3-10
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• 2014

The synchronization signal in Long Term Evolution (LTE) systems contains the primary synchronization signal (PSS) and the secondary synchronization signal (SSS), and the overall synchronization performance is dominated by PSS detection. In this paper, we propose a PSS detection scheme employing three partial correlation based PSS detectors with different partial correlation lengths, in which calculated partial correlation values are reused in order to reduce computational complexity. A coherent selection scheme using tentative frequency offsets is also proposed to select one reliable result from outputs of partial correlation based PSS detectors. It is shown through computer simulation that the proposed scheme can have a robust detection performance in wide range of frequency offsets.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.3
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• pp.412-421
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• 2022

All 5G NR devices must first perform the cell search and synchronization process to communicate with the base station. In this process, PSS detection is one of the most important and difficult problems in 5G NR communication because PSS detection must first be successful in order to extract essential information from the following signals. Among the various PSS detection methods, this paper describes a cross-correlation-based detection method, and the implementation methods of the tap delay line hardware with parallelization are introduced and compared in terms of complexity and detection speed. In addition, the interface required for system configuration including the PSS detector and control software for efficient and flexible operation are also explained. In this paper, the resource usages of Xilinx's UltraScale+ FPGA are compared for various PSS detector structures and analyzed according to various parallelization levels.

• Journal of Broadcast Engineering
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• v.25 no.6
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• pp.870-881
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• 2020

This paper presents cell ID (cell identity) detection schemes using PSS/SSS (primary synchronization signal/secondary synchronization signal) for 5G NR (new radio) system and evaluates the detection performance. In this paper, we consider two cell ID detection schemes, i.e. two-stage detection and joint detection schemes. The two-stage detection scheme consists of two stages which estimate a channel gain between a transmitter and receiver and detect the PSS and SSS sequences. The joint detection scheme jointly detects the PSS and SSS sequences. In addition, this paper presents coherent and non-coherent combining schemes. The coherent scheme calculates the correlation value for the total length of the given PSS and SSS sequences, and the non-coherent combining scheme calculates the correlation within each group by dividing the total length of the sequence into several groups and then combines them non-coherently. For the detection schemes considered in this paper, the detection error rates of PSS, SSS and overall cell ID are evaluated and compared through computer simulations. The simulation results show that the joint detection scheme outperforms the two-stage detection scheme for both coherent and non-coherent combining schemes, but the two-stage detection scheme can greatly reduce the computational complexity compared to the joint detection scheme. In addition, the non-coherent combining detection scheme shows better performance under the additive white Gaussian noise (AWGN), fixed, and mobile environments.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.127.2-127.2
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• 2013

오늘날 유기고분자기반 태양전지는 다른 태양전지와 비교될 정도로 낮은 광변환효율로 인해 효율향 상을 위한 많은 연구들이 진행되어 왔다. 그중 패터닝을 통한 광포집률과 charge carrier 수집효율이 증가되었다는 많은 보고들이 있었다. 따라서 우리는 200~1,400 nm polystyrene bead를 합성하여 air-liquid interfacial 방법을 이용해 2차원 육방조밀구조를 갖는 template를 형성하고 Nanosphere lithography (NSL)를 이용하여 대면적으로 균일한 poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS)를 패턴화하였다. 균일한 패턴형성을 측정하기위해 Field Emission Scanning Electron Microscopy (FE-SEM), image를 얻었으며, Atomic Force Microscopy (AFM)를 통해 형성된 패턴의 낙차 높이를 얻었고, Near IR-UV-Vis을 통해 bead size 변화에따라 얻어진 PEDOT:PSS 패턴의 반사율을 측 정하였다.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2291-2296
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• 2013

An efficient carbon monoxide (CO) sensor was developed based on poly(3,4-ethylenedioxy)thiophenepoly(styrenesulfonate) (PEDOT:PSS) modified with a new pyrimidine-fused heterocyclic compound, bis(2-hydroxyphenyl)dihydropyrido[2,3-d:6,5-d]dipyrimidine-tetraone (B2HDDT). B2HDDT remains stable in the polymer matrix through interactions with functional groups of the polymer. It created prominent sites that captured CO gas, and the experimental parameters, including the amount of doped B2HDDT in the PEDOT:PSS film, were optimized. The sensor probe was also examined to verify its reliability for detecting CO in the presence of atmospheric gases in a discriminating manner. NMR, AFM, and FT-IR spectra were obtained to evaluate the structure and morphology of the B2HDDT-doped PEDOT:PSS (PEDOT:PSS/B2HDDT) film. The content of 35 vol % B2HDDT (7.0 mM) in PEDOT:PSS provided the largest response factor (${\Delta}R/R_o$) for the CO gas. The sensor response was reproducible, with a relative standard deviation < 5% (n = 5). The detection limit was determined to be $0.44{\pm}0.05$ vol %.

• Korean Journal of Animal Reproduction
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• v.27 no.2
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• pp.97-102
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• 2003

This study was carried out to find out PSS(Porcine Stress Syndrome) with the PSE(Pale, Soft, Exudative) in different piglets. These experiments were accomplished with the aid of PCR-RFLP(Polymerase Chain Reaction-Restriction Fragment Length Polymorphism). The samples were collected and examined from umbilical cord blood of piglets of Yorkshire, Landrace and Crossbred. And then, the PCR products were digested by restriction enzyme, Hha I. The results obtained were as follows; The PCR products of the blood genomic DNA of ryanodine receptor gene were length of 1 .8kb in umbilical cord blood. Normal type(NN), heterozygous type(Nn) and recessively homozygous type(nn, PSS) as a result of digestion of restriction enzyme, Hha 1, were 90.0%, 10.0% and 0.0% in Yorkshire piglets, 76.2%, 19.0% and 4.8% in Landrace, 69.1%, 23.8% and 7.1% in crossbred, respectively. As already showing the above results, the blood from piglets umbilical cord can be availably used for the determination of genotypes of PSS because of easiness of blood collection without stress in live piglets.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.1C
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• pp.113-122
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• 2010

In this paper, we propose a CP (Cyclic Prefix) detection based SSS (Secondary Synchronization Signal) detection method for initial cell search in 3GPP LTE (3rd Generation Partnership Project Long Term Evolution) FDD/TDD (Frequency Division Duplex/Time Division Duplex) dual mode downlink receiver. In general, a blind coherent SSS detection method which can detect SSS without CP detection is applied. However, coherent detection method caused performance degradation by channel compensation error at high speed environment because it uses estimated CFR (Channel Frequency Response) at PSS (Primary Synchronization Signal), and it can be more serious problem in TDD mode due to increased distance between PSS and SSS. Also blind detectionhas the drawback of high computational complexity. Therefore, we proposed a CP type pre-decision structure with non-coherent SSS detection which has stable operation in high speed channel environments for 3GPP LTE TDD mode as well as FDD mode, and can reduce computational complexity by applying CP detection before SSS detection. Simulation results show that the proposed method has stable operation for 3GPP LTE TDD/FDD dual mode downlink receiver in various channel environments.

• ETRI Journal
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• v.38 no.1
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• pp.30-40
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• 2016

Co-channel interference between macro-femtocell networks is an unresolved problem, due to the frequency reuse phenomenon. To mitigate such interference, a secondary femtocell must acquire channel-state knowledge about a co-channel macrocell user and accordingly condition the maximum transmit power of femtocell user. This paper proposes a pilot-based spectrum sensing (PSS) algorithm for overlaid femtocell networks to sense the presence of a macrocell user over a channel of interest. The PSS algorithm senses the pilot tones in the received signal through the power level and the correlation metric comparisons between the received signal and the local reference pilots. On ensuring the existence of a co-channel macrocell user, the maximum transmit power of the corresponding femtocell user is optimized so as to avoid interference. Time and frequency offsets are carefully handled in our proposal. Simulation results show that the PSS algorithm outperforms existing sensing techniques, even at poor received signal quality. It requires less sensing time and provides better detection probability over existing techniques.

• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.2
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• pp.49-59
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• 1993

A new signal processing technique is applied to four-cylinder spark and compression ignition engines for the diagnosis of power faults inside the cylinders. This technique utilizes two-sided directional power spectra(예S) of complex vibration signals measured from engine blocks as the patterns for engine cylinder power faults. The dPSs feature that they give not only the frequency contents but also the directivity of the engine block motion. For the automatic detection/diagnosis of cylinder power faults, pattern recognition method using multi-layer neural networks is employed. Experimental results show that the sucess rate for diagnosis of cylinder power faults using dPSs is higher than that using the conventional one-sided power spectra. The proposed technique is also tested to check the robustness to the sensor position and the engine rotational speed.

• Smart Structures and Systems
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• v.32 no.2
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• pp.111-121
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• 2023

This study proposes an automated assembly performance evaluation method for prefabricated steel structures (PSSs) using machine learning methods. Assembly component images were segmented using a modified version of the receptive field pyramid. By factorizing channel modulation and the receptive field exploration layers of the convolution pyramid, highly accurate segmentation results were obtained. After completing segmentation, the positions of the bolt holes were calculated using various image processing techniques, such as fuzzy-based edge detection, Hough's line detection, and image perspective transformation. By calculating the distance ratio between bolt holes, the assembly performance of the PSS was estimated using the k-nearest neighbors (kNN) algorithm. The effectiveness of the proposed framework was validated using a 3D PSS printing model and a field test. The results indicated that this approach could recognize assembly components with an intersection over union (IoU) of 95% and evaluate assembly performance with an error of less than 5%.