• Title/Summary/Keyword: spectral measures

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Application of the SASW Method to the Evaluation of Grouting Performance for a Soft Ground of a Tunnel (터널 원지반의 그라우팅 보강 평가를 위한 SASW 기법의 적용)

  • 조미라;강태호
    • Journal of the Korean Geotechnical Society
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    • v.19 no.6
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    • pp.273-283
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    • 2003
  • Fissured rock and soft ground always suggest, problems in the construction of the underground space. The stress release of the weak underground material by opening the underground space with a soft ground, fissures and joints can lead to the failure of the opening. Grouting of the weak rock and the soft ground, which is a process of injecting some bonding agents into the soft ground, is one of the measures to reinforce the soft ground and to prohibit the failure of the underground construction due to the stress release. The proper installation of the grouting is essential to ensuring the safety of the tunneling operation, so that the evaluation of the grouting performance is very significant. The general procedure of evaluating the grouting is coring the grouted section and measuring the compression strength of the core. However, sometimes when the grouted section is at the crown of the tunnel and the grouting is installed at a wide section, the coring is not good enough. This study is oriented to propose a new and a non-destructive procedure of evaluating the grouting performance. The proposed method is based on the wave propagation of elastic waves, and evaluates the shear stiffness of the ground and investigates the anomalies such as voids and cracks. The SASW ( Spectral-Analysis-of-Surface-Waves) method is one of the candidate s to make the inspection of the pouting performance, and is adopted in this study. The practical grouting activity was monitored by SASW method, and the proposed method was applied to the inspection of the grouting performance to check the verification of the proposed method.

A Study on Standard Ocean Lighted Buoy Type System for Real-time Ocean Meteorological Observation (실시간 해양관측을 위한 표준형 등부표용 시스템 연구)

  • Park, Sanghyun;Park, Yongpal;Bae, Dongjin;Kim, Jinsul;Park, Jongsu
    • Journal of Digital Contents Society
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    • v.19 no.9
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    • pp.1739-1749
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    • 2018
  • We propose a marine observation system using existing light buoys to observe various marine information of marine locations. Our proposed ocean observation system is composed of the existing standard light buoy type and can be easily connected to the light buoy. The proposed marine observation system measures the mean wave height, maximum wave height, mean wave height and water temperature measured in the ocean. Besides, it can measure the air pressure, temperature, wind speed and wind speed in real time. In order to measure important peaks in marine observations, 2200 peak data are collected for 10 minutes, and the collected data are subjected to spectral analysis to extract significant wave and wave period data. The developed system removes the noise by using the filter because the marine observation system attaches to the light buoy. We compare and analyze the measurement data of the existing proven floating marine observation system and the standard equivalent system developed. Also, it is proved that the data of the standard type backbone ocean observation system developed through the comparative experiment is similar to that of the existing ocean observation system.

Evaluation of Autonomic Function in Patients with Head-Hyperhidrosis by Power Spectral Analysis of Heart Rate Variability (심박변이도 측정을 통한 두한증(頭汗證) 환자의 자율신경계 기능 평가)

  • Lee, Kun-Young;Hwang, Joon-Ho;Lee, Sung-Hun;Jeong, Seung-Yeon;Rhee, Hyung-Koo;Jung, Sung-Ki;Jung, Hee-Jae
    • The Journal of Internal Korean Medicine
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    • v.27 no.4
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    • pp.822-826
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    • 2006
  • Objectives : Essential hyperhidrosis is a socially and occupationally disabling disorder. There are many suggestions that hyperhidrosis is associated with the autonomic nervous system, especiallythe sympathetic system. This study was designed to investigate the autonomic nerve system in patients with essential hyperhidrosis and healthy controls by the frequency domain analysis of heart rate variability (HRV). Methods : 17 head-hyperhidrosis patients in the ambulatory care were investigated. All were inspected at the first medical examination. using the PSA of HRV. HRV was measured for minutes after 5 minutes bed rest. We checked the frequency domain analysis of HRV (i.e. TP, VLF, LF, HF) which were transformed into natural logarithm of patients against the standard measures of the HRV components. Then we compared the values of patients with means of normal Korean subjects. Results : The values of natural logarithmic measure of HRV (LnTP, LnHF, LnLF, LnVLF) of patients With head-hyperhidrosis we examined were $6.85{\pm}1.61$, $4.93{\pm}$2.00, $5.40{\pm}1.83$, and $6.13{\pm}1.37$, respectively. None of these values were higher than means of normal subjects. Conclusions : This study suggests that the function of the autonomic nervous system does not increase in patients with head-hyperhidrosis.

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Precise Estimation of Nonlinear Parameter in Pulse-Like Ultrasonic Signal (펄스형 초음파 신호에서 비선형 파라미터의 정밀 추정)

  • Ha, Job;Jhang, Kyung-Young;Sasaki, Kimio;Tanaka, Hiroaki
    • Journal of the Korean Society for Nondestructive Testing
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    • v.26 no.2
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    • pp.77-83
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    • 2006
  • Ultrasonic nonlinearity has been considered as a solution for the detection of microcracks or interfacial delamination in a layered structure. The distinguished phenomenon in nonlinear ultrasonics is the generation of higher-order harmonic waves during the propagation. Therefore, in order to quantify the nonlinearity, the conventional method measures a parameter defined as the amplitude ratio of a second-order harmonic component and a fundamental frequency component included in the propagated ultrasonic wave signal. However, its application In field inspection is not easy at the present stage because no standard methodology has yet been made to accurately estimate this parameter. Thus, the aim of this paper is to propose an advanced signal processing technique for the precise estimation of a nonlinear ultrasonic parameter, which is based on power spectral and bispectral analysis. The method of estimating power spectrum and bispectrum of the pulse-like ultrasonic wave signal used in the commercial SAM (scanning acoustic microscopy) equipment is especially considered in this study The usefulness of the proposed method Is confirmed by experiments for a Newton ring with a continuous air gap between two glasses and a real semiconductor sample with local delaminations. The results show that the nonlinear parameter obtained tv the proposed method had a good correlation with the delamination.

Simultaneous Analysis Method for Polar and Non-polar Ginsenosides in Cultivated Wild Ginseng by Reversed-phase HPLC-CAD (HPLC-CAD에 의한 산양삼의 극성 및 비극성 ginsenoside 동시 분석)

  • Ok, Seon;Kang, Jae Seon;Kim, Kang Min
    • Journal of Life Science
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    • v.26 no.2
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    • pp.247-252
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    • 2016
  • Cultivated wild ginseng is a widely used dietary supplement and medicinal herb. The aim of this study was to optimize the ginseng using high performance liquid chromatography (HPLC)- charged aerosol detection (CAD) for ginsenoside analysis. CAD measures the physical property of an analyte and responds to almost all non-volatile species, independent of their nature, spectral properties, or particle size. It has become widely employed in pharmaceutical analysis. The cultivated wild ginseng extracts were analyzed for compositions of ginsenosides Rb1, Rd, Rg1, Rf, Re, and Rh1. The optimal analysis condition was set up from an experiment using a gradient. Ten grams of cultivated wild ginseng were extracted with 95% EtOH 100 ml for 24 hr at 80℃. The contents of the 6six major ginsenosides in the cultivated wild ginseng extract were Rb1 (5.48±0.12 mg/g), Rd (5.33±0.14 mg/g), Rg1 (12.80± 0.05 mg/g), Rf (19.08±0.68 mg/g), Re (19.87±0.05 mg/g), and Rh1 (16.47±0.16 mg/g), respectively. HPLC showed that the protopanaxatriol group (Rg1, Rf, Re, Rh1) had more content than the protopanaxadiol group (Rb1, Rd) in cultivated wild ginseng extract. In summary, the ginsenosides were identified with HPLC-CAD analysis, and their presence and quantity imply the importance of quality control, as well as the pharmacological activity of the ginseng root.

Advances, Limitations, and Future Applications of Aerospace and Geospatial Technologies for Apple IPM (사과 IPM을 위한 항공 및 지리정보 기술의 진보, 제한 및 미래 응용)

  • Park, Yong-Lak;Cho, Jum Rae;Choi, Kyung-Hee;Kim, Hyun Ran;Kim, Ji Won;Kim, Se Jin;Lee, Dong-Hyuk;Park, Chang-Gyu;Cho, Young Sik
    • Korean journal of applied entomology
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    • v.60 no.1
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    • pp.135-143
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    • 2021
  • Aerospace and geospatial technologies have become more accessible by researchers and agricultural practitioners, and these technologies can play a pivotal role in transforming current pest management practices in agriculture and forestry. During the past 20 years, technologies including satellites, manned and unmanned aircraft, spectral sensors, information systems, and autonomous field equipment, have been used to detect pests and apply control measures site-specifically. Despite the availability of aerospace and geospatial technologies, along with big-data-driven artificial intelligence, applications of such technologies to apple IPM have not been realized yet. Using a case study conducted at the Korea Apple Research Institute, this article discusses the advances and limitations of current aerospace and geospatial technologies that can be used for improving apple IPM.

Development of Empirical Fragility Function for High-speed Railway System Using 2004 Niigata Earthquake Case History (2004 니가타 지진 사례 분석을 통한 고속철도 시스템의 지진 취약도 곡선 개발)

  • Yang, Seunghoon;Kwak, Dongyoup
    • Journal of the Korean Geotechnical Society
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    • v.35 no.11
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    • pp.111-119
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    • 2019
  • The high-speed railway system is mainly composed of tunnel, bridge, and viaduct to meet the straightness needed for keeping the high speed up to 400 km/s. Seismic fragility for the high-speed railway infrastructure can be assessed as two ways: one way is studying each element of infrastructure analytically or numerically, but it requires lots of research efforts due to wide range of railway system. On the other hand, empirical method can be used to access the fragility of an entire system efficiently, which requires case history data. In this study, we collect the 2004 MW 6.6 Niigata earthquake case history data to develop empirical seismic fragility function for a railway system. Five types of intensity measures (IMs) and damage levels are assigned to all segments of target system for which the unit length is 200 m. From statistical analysis, probability of exceedance for a certain damage level (DL) is calculated as a function of IM. For those probability data points, log-normal CDF is fitted using MLE method, which forms fragility function for each damage level of exceedance. Evaluating fragility functions calculated, we observe that T=3.0 spectral acceleration (SAT3.0) is superior to other IMs, which has lower standard deviation of log-normal CDF and low error of the fit. This indicates that long-period ground motion has more impacts on railway infrastructure system such as tunnel and bridge. It is observed that when SAT3.0 = 0.1 g, P(DL>1) = 2%, and SAT3.0 = 0.2 g, P(DL>1) = 23.9%.

Brief Introduction of Research Progresses in Control and Biocontrol of Clubroot Disease in China

  • He, Yueqiu;Wu, Yixin;He, Pengfei;Li, Xinyu
    • 한국균학회소식:학술대회논문집
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    • 2015.05a
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    • pp.45-46
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    • 2015
  • Clubroot disease of crucifers has occurred since 1957. It has spread to the whole China, especially in the southwest and nourtheast where it causes 30-80% loss in some fields. The disease has being expanded in the recent years as seeds are imported and the floating seedling system practices. For its effective control, the Ministry of Agriculture of China set up a program in 2010 and a research team led by Dr. Yueqiu HE, Yunnan Agricultural University. The team includes 20 main reseachers of 11 universities and 5 institutions. After 5 years, the team has made a lot of progresses in disease occurrence regulation, resources collection, resistance identification and breeding, biological agent exploration, formulation, chemicals evaluation, and control strategy. About 1200 collections of local and commercial crucifers were identified in the field and by artificiall inoculation in the laboratories, 10 resistant cultivars were breeded including 7 Chinese cabbages and 3 cabbages. More than 800 antagostic strains were isolated including bacteria, stretomyces and fungi. Around 100 chemicals were evaluated in the field and greenhouse based on its control effect, among them, 6 showed high control effect, especially fluazinam and cyazofamid could control about 80% the disease. However, fluzinam has negative effect on soil microbes. Clubroot disease could not be controlled by bioagents and chemicals once when the pathogen Plasmodiophora brassicae infected its hosts and set up the parasitic relationship. We found the earlier the pathogent infected its host, the severer the disease was. Therefore, early control was the most effective. For Chinese cabbage, all controlling measures should be taken in the early 30 days because the new infection could not cause severe symptom after 30 days of seeding. For example, a biocontrol agent, Bacillus subtilis Strain XF-1 could control the disease 70%-85% averagely when it mixed with seedling substrate and was drenching 3 times after transplanting, i.e. immediately, 7 days, 14 days. XF-1 has been deeply researched in control mechanisms, its genome, and development and application of biocontrol formulate. It could produce antagonistic protein, enzyme, antibiotics and IAA, which promoted rhizogenesis and growth. Its The genome was sequenced by Illumina/Solexa Genome Analyzer to assembled into 20 scaffolds then the gaps between scaffolds were filled by long fragment PCR amplification to obtain complet genmone with 4,061,186 bp in size. The whole genome was found to have 43.8% GC, 108 tandem repeats with an average of 2.65 copies and 84 transposons. The CDSs were predicted as 3,853 in which 112 CDSs were predicted to secondary metabolite biosynthesis, transport and catabolism. Among those, five NRPS/PKS giant gene clusters being responsible for the biosynthesis of polyketide (pksABCDEFHJLMNRS in size 72.9 kb), surfactin(srfABCD, 26.148 kb, bacilysin(bacABCDE 5.903 kb), bacillibactin(dhbABCEF, 11.774 kb) and fengycin(ppsABCDE, 37.799 kb) have high homolgous to fuction confirmed biosynthesis gene in other strain. Moreover, there are many of key regulatory genes for secondary metabolites from XF-1, such as comABPQKX Z, degQ, sfp, yczE, degU, ycxABCD and ywfG. were also predicted. Therefore, XF-1 has potential of biosynthesis for secondary metabolites surfactin, fengycin, bacillibactin, bacilysin and Bacillaene. Thirty two compounds were detected from cell extracts of XF-1 by MALDI-TOF-MS, including one Macrolactin (m/z 441.06), two fusaricidin (m/z 850.493 and 968.515), one circulocin (m/z 852.509), nine surfactin (m/z 1044.656~1102.652), five iturin (m/z 1096.631~1150.57) and forty fengycin (m/z 1449.79~1543.805). The top three compositions types (contening 56.67% of total extract) are surfactin, iturin and fengycin, in which the most abundant is the surfactin type composition 30.37% of total extract and in second place is the fengycin with 23.28% content with rich diversity of chemical structure, and the smallest one is the iturin with 3.02% content. Moreover, the same main compositions were detected in Bacillus sp.355 which is also a good effects biocontol bacterial for controlling the clubroot of crucifer. Wherefore those compounds surfactin, iturin and fengycin maybe the main active compositions of XF-1 against P. brassicae. Twenty one fengycin type compounds were evaluate by LC-ESI-MS/MS with antifungal activities, including fengycin A $C_{16{\sim}C19}$, fengycin B $C_{14{\sim}C17}$, fengycin C $C_{15{\sim}C18}$, fengycin D $C_{15{\sim}C18}$ and fengycin S $C_{15{\sim}C18}$. Furthermore, one novel compound was identified as Dehydroxyfengycin $C_{17}$ according its MS, 1D and 2D NMR spectral data, which molecular weight is 1488.8480 Da and formula $C_{75}H_{116}N_{12}O_{19}$. The fengycin type compounds (FTCPs $250{\mu}g/mL$) were used to treat the resting spores of P. brassicae ($10^7/mL$) by detecting leakage of the cytoplasm components and cell destruction. After 12 h treatment, the absorbencies at 260 nm (A260) and at 280 nm (A280) increased gradually to approaching the maximum of absorbance, accompanying the collapse of P. brassicae resting spores, and nearly no complete cells were observed at 24 h treatment. The results suggested that the cells could be lyzed by the FTCPs of XF-1, and the diversity of FTCPs was mainly attributed to a mechanism of clubroot disease biocontrol. In the five selected medium MOLP, PSA, LB, Landy and LD, the most suitable for growth of strain medium is MOLP, and the least for strains longevity is the Landy sucrose medium. However, the lipopeptide highest yield is in Landy sucrose medium. The lipopeptides in five medium were analyzed with HPLC, and the results showed that lipopeptides component were same, while their contents from B. subtilis XF-1 fermented in five medium were different. We found that it is the lipopeptides content but ingredients of XF-1 could be impacted by medium and lacking of nutrition seems promoting lipopeptides secretion from XF-1. The volatile components with inhibition fungal Cylindrocarpon spp. activity which were collect in sealed vesel were detected with metheds of HS-SPME-GC-MS in eight biocontrol Bacillus species and four positive mutant strains of XF-1 mutagenized with chemical mutagens, respectively. They have same main volatile components including pyrazine, aldehydes, oxazolidinone and sulfide which are composed of 91.62% in XF-1, in which, the most abundant is the pyrazine type composition with 47.03%, and in second place is the aldehydes with 23.84%, and the third place is oxazolidinone with 15.68%, and the smallest ones is the sulfide with 5.07%.

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