• Title/Summary/Keyword: frequency of occurrence

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Reduced wavelet component energy-based approach for damage detection of jacket type offshore platform

  • Shahverdi, Sajad;Lotfollahi-Yaghin, Mohammad Ali;Asgarian, Behrouz
    • Smart Structures and Systems
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    • v.11 no.6
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    • pp.589-604
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    • 2013
  • Identification of damage has become an evolving area of research over the last few decades with increasing the need of online health monitoring of the large structures. The visual damage detection can be impractical, expensive and ineffective in case of large structures, e.g., offshore platforms, offshore pipelines, multi-storied buildings and bridges. Damage in a system causes a change in the dynamic properties of the system. The structural damage is typically a local phenomenon, which tends to be captured by higher frequency signals. Most of vibration-based damage detection methods require modal properties that are obtained from measured signals through the system identification techniques. However, the modal properties such as natural frequencies and mode shapes are not such good sensitive indication of structural damage. Identification of damaged jacket type offshore platform members, based on wavelet packet transform is presented in this paper. The jacket platform is excited by simple wave load. Response of actual jacket needs to be measured. Dynamic signals are measured by finite element analysis result. It is assumed that this is actual response of the platform measured in the field. The dynamic signals first decomposed into wavelet packet components. Then eliminating some of the component signals (eliminate approximation component of wavelet packet decomposition), component energies of remained signal (detail components) are calculated and used for damage assessment. This method is called Detail Signal Energy Rate Index (DSERI). The results show that reduced wavelet packet component energies are good candidate indices which are sensitive to structural damage. These component energies can be used for damage assessment including identifying damage occurrence and are applicable for finding damages' location.

A Study on the Vessel Structure of Fagaceae Species in Korea (II) -Micromorphology of Vessel Wall Sculpture- (한국산(韓國産) 참나무과(科) 수종(樹種) 도관구조(道管構造)에 관(關)한 연구(硏究)(II) -도관벽(導管壁)의 수식구조(修飾構造)-)

  • Lee, Sung Jae;Lee, Wan Yang
    • Journal of Forest and Environmental Science
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    • v.8 no.1
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    • pp.51-66
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    • 1992
  • This study was carried out to investigate the micromorphology of vessel wall sculpture such as shape of perforation plate, perforation rim, steepness of perforation plate, occurrence of vestured pit, warty layer and ray-vessel pitting on 13 species of Fagaceae in Korea. The results were summarized as follows ; 1. In the species examined, all sample species except Fagus crenata var. multinervis have simple perforation plate. But Fagus crenata var. multinervis has simple and scalariform perforation plate (it was called to combination perforation plate) in a tree stem. 2. The shapes of perforation rim could be classified into five types; Type A without tail, Type B with small tail on both sides, Type C with long tail on both sides, Type D with tail only one side and Type E with the very short interval between perforations. Among five types, Type Band C have higer frequency of distribution than the others. 3. The steepness of perforation plate measured was about 20 degree on pore zone and 43 degree on outside parts of pore zone. 4. Species with vestured pit were Q. aliena, Q, dentata, Q. variabilis, Fagus crenata var. multinervis, Castanopsis cuspidata var sieboldii, Q. acuta, Q. stenophylla, and Q. glauca. But the extent of vesturing was very slight and vestured pits were observed mainly in ray-vessel pit of some vessel elements. 5. Species with warty layer on the inner surface wall of all vessel elements were Q. acuta, Q. stenophylla, Q. glauca, Fagus crenata var. multinervis and species with warty layer of some vessel elements were Q. aliena, Q, dentata, Q. variabilis, Castanopsis cuspidata var. sieboldii. 6. Species with palisade ray-vessel pit were Q. acuta, Q. stenophylla, Q. glauca, Castanea crenata, Castanea bungeana, Q. aliena, Q. serrata, Q. mongolica, and species with scalariform ray-vessel pit was Fagus crenata var. multinervis and species with oval ray-vessel pit were Q, dentata, Castanopsis cuspidata var sieboldii.

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Occurrence of Rhizoctonia Blight of Zoysiagrasses in Golf Courses in Korea (국내 골프장 한국잔디의 라이족토니아마름병 발생)

  • 심규열;김진원;김희규
    • Korean Journal Plant Pathology
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    • v.10 no.1
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    • pp.54-60
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    • 1994
  • Incidence of Rhizoctonia blight ranged from 22.2% to 100% in the golf courses at six geographical locations in Korea from 1989 to 1993. Rhizoctonia blight occurred more severly in southern area than in northern area. Fifty seven isolates of Rhizoctonia solani obtained from diseased parts of zoysiagrasses were grouped to AG2-2 by anastomosis test. Pathogenicity testes revealed that this pathogen was strongly pathogenic to Korean lawngrasses(Zoysia japonica, Z. matrella, Z. tenuifolia), but not pathogenic to creeping bentgrass(Agrostis palustris), bermuldagrass(Cynodon dactylon), Kentucky bluegrass(Poa pratensis), perennial ryegrass(Lolium prenne), and creeping red fescue(Festuca rubra subsp. rubra L.). The isolation frequency of R. solani AG2-2 fro sheaths of the infected plants was the highest by 91.67%, and that from stolons and roots was 11.13% and 5.63% respectively. The pathogen was not isolated from the leaves. Population density of R. solani in the lawn of large circular patch was highest on surface soils down to 1 cm deep with the value of 4.9$\times$104 (CFU/g soil), but below 1 cm population density decreased sharply down to 0.8~9.8$\times$103 (CFU/g soil). Horizontal distribution of propagules in turfgrass soil was higher in the margin than in center of patch, where the number of propagules was similar to these of healthy looking soils close to the margin of diseased patch. The meteorological factors influencing the outbreak of the disease were temperature, the number of rainy days and precipitation. Optimum temperature for disease development of Rhizoctonia blight in field was 20~22$^{\circ}C$, and that for hyphal growth of R. solani AG2-2 in vitro was 25~3$0^{\circ}C$. In Pusan area, Rhizoctonia blight first occurred in late April and rapidly developed in late June. The disease slightly decreased during July to August and developed again in late September in 1993. The monthly disease progress in Pusan area was similar to that in Kyeonggi province.

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Cloning of Notl-linked DNA Detected by Restriction Landmark Genomic Scanning of Human Genome

  • Kim Jeong-Hwan;Lee Kyung-Tae;Kim Hyung-Chul;Yang Jin-Ok;Hahn Yoon-Soo;Kim Sang-Soo;Kim Seon-Young;Yoo Hyang-Sook;Kim Yong-Sung
    • Genomics & Informatics
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    • v.4 no.1
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    • pp.1-10
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    • 2006
  • Epigenetic alterations are common features of human solid tumors, though global DNA methylation has been difficult to assess. Restriction Landmark Genomic Scanning (RLGS) is one of technology to examine epigenetic alterations at several thousand Notl sites of promoter regions in tumor genome. To assess sequence information for Notl sequences in RLGS gel, we cloned 1,161 unique Notl-linked clones, compromising about 60% of the spots in the soluble region of RLGS profile, and performed BLAT searches on the UCSC genome server, May 2004 Freeze. 1,023 (88%) unique sequences were matched to the CpG islands of human genome showing a large bias of RLGS toward identifying potential genes or CpG islands. The cloned Notl-loci had a high frequency (71%) of occurrence within CpG islands near the 5' ends of known genes rather than within CpG islands near the 3' ends or intragenic regions, making RLGS a potent tool for the identification of gene-associated methylation events. By mixing RLGS gels with all Notl-linked clones, we addressed 151 Notl sequences onto a standard RLGS gel and compared them with previous reports from several types of tumors. We hope our sequence information will be useful to identify novel epigenetic targets in any types of tumor genome.

Spatial and Temporal Patterns on Wildlife Road-kills on Highway in Korea (우리나라 고속도로에서 야생동물 로드킬에 관한 시공간 추이 분석)

  • Lee, Gyoungju;Tak, Jong-Hoon;Pak, Son-Il
    • Journal of Veterinary Clinics
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    • v.31 no.4
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    • pp.282-287
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    • 2014
  • The negative impacts of roads on wildlife mortality have been well documented, and one of the most significant impact is wildlife-vehicle collisions (WVCs) in most countries throughout the world. While road impacts on wildlife are a truly global concern with a large socio-economic cost, few researches in Korea have been quantified road-kill occurrence on highways or identified extensively seasonal and geographic patterns of this phenomenon. Therefore, we analyzed highway mortality of wild mammals in Korea using database from five years of nation-wide data on WVCs, and estimated road-kill density by standardizing on per km and per $10^3$ vehicle basis. During 2008 through 2012, a total of 10,940 wildlifes were reported killed on highways, with an average of 2,188 cases per year. There were 2,376 road-kills in 2012, and this equates to 0.01 road-kills per km per week or one road-kill every 88.5 km per week. For time of day, road-kills occurred more frequently in the early morning (05:00-08:00, 38.3%), and day of week did not have a significant influence in any individual year. The road-kill was highest in the spring (March- May, 33.0%) and least in the winter (December-February, 16.1%), and the most frequently killed native species were of Korean water deer (79.7%), raccoon dog (12.7%), Korean hare (3.1%), and leopard cat (1.2%). The overall standardized kill-rate (number/10 km/1,000 vehicles/month) in 2012 was 0.057 with highest on Dangjinyeongdeok highway (0.476), followed by Yeongdong (0.274), Sooncheonwanju (0.233), Iksanpohang (0.187), and Joongang (0.150). This study highlights that the frequency of WVCs are prevalent throughout the highways in Korea. Further work is needed to determine whether such a level of mortality is sustainable from an ecological point of view.

Association of PNPLA3 Polymorphism with Hepatocellular Carcinoma Development and Prognosis in Viral and Non-Viral Chronic Liver Diseases

  • Khlaiphuengsin, Apichaya;Kiatbumrung, Rattanaporn;Payungporn, Sunchai;Pinjaroen, Nutcha;Tangkijvanich, Pisit
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8377-8382
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    • 2016
  • Background: The aim of this study was to evaluate any association between a single nucleotide polymorphism (SNP) in the patatin-like phospholipase domain containing 3 (PNPLA3) (rs738409, C>G) and the development and prognosis in patients with hepatocellular carcinoma (HCC). Materials and Methods: Two hundred heathy controls and 388 HCC cases were included: 211 with HBV, 98 patients with HCV, 29 with alcoholic steatohepatitis (ASH) and 52 with non-alcoholic steatohepatitis (NASH). The SNP was determined by real-time PCR based on TaqMan assays. Results: The prevalence of rs738409 genotypes CC, CG and GG in controls was 91 (45.5%), 88 (44.0%), and 21 (10.5%), respectively, while the corresponding genotypes in all patients with HCC was 158 (40.7%), 178 (45.9%), and 52 (13.4%). The GG genotype had significantly higher distribution in patients with ASH/NASH-related HCC compared with controls (OR=2.34, 95% CI=1.16-4.71, P=0.018), and viral-related HCC cases (OR=2.15, 95% CI=1.13-4.08, P=0.020). However, the frequency of the GG genotype was similar between controls and patients with viral-related HCC. At initial diagnosis, HBV-related HCC were larger and at more advanced BCLC stage than the other HCC groups. There were no significant differences between the GG and non-GG groups regarding clinical characteristics, tumor stage and overall survival. Conclusions: These data suggest an influence of the PNPLA3 polymorphism on the occurrence of HCC in patients with ASH/NASH but not among those with chronic viral hepatitis. However, the polymorphism was not associated with the prognosis of HCC.

Physiological and Ecological Studies of the Vegetation on Ore Deposits -2. Incidence of Lime-chlorosis in the Vegetation of Korea- (금속광체상에 나타나는 식물에 관한 생리생태학적 연구 -2. 석회암지대의 백화현상-)

  • Chang, Nam Kee;Chang Soo Mok
    • The Korean Journal of Ecology
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    • v.4 no.1_2
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    • pp.25-32
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    • 1981
  • During the period of 1975∼77, a survey and an investigation were carried out to estimate the frequency of lime-chlorosis in the natural vegetation in Korea and the relationships between plants and calcareous soils. The symptoms of lime-chlorosis were observed in flowering plants in the calcareous areas of Weonju (I, II), Yeongweol(I, II), Jecheon, Danyang and Samcheok. Although the species found to be lime-chlorotic on at least one occasion numbered 60, the total quantity of lime-chlorotic foliage observed was small. Severe lime-chlorosis of Capsicuym annuum in agricultural fields was found out at Danyang. However, some of the species which were of widespread occurrence in affected areas showed no lime-chlorosis. The comparison of the inorganic components in calcareous soils in lime-chlorotic and normal leaves showed that the essential mineral nutrients substantially less soluble in water in alkaline than in acid conditions and calcifuges planted on calcareous soils often show visual signs resembling those of P or Fe deficiency.

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The Prevalence of Post-traumatic Stress Disorder Among Emergency Room Workers and Factors Contributing to Its Occurrence (응급실 근무자의 외상 후 스트레스장애 유병률 및 발생 기여 요인)

  • Ko, Dong-Ryul;Kim, Gun-Bae;Lee, Ji-Hwan
    • Quality Improvement in Health Care
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    • v.27 no.1
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    • pp.10-19
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    • 2021
  • Purpose: This study was designed to investigate that the prevalence of Post-traumatic stress disorder (PTSD) and occupational environmental factors that contribute to the developing of PTSD in workers who worked in emergency room in Korea. Methods: This study is a multicenter cross-sectional study that was conducted in three emergency rooms. Data was collected by self-response method through questionnaire. The Impact Event Scale-Revised was used to screen the high-risk group of PTSD. Univariate and multivariate regression analysis was used to identify the factors associated with the developing of high-risk group of PTSD. Results: Total 211 subjects responded to the questionnaire. Of these, 170 subjects experienced psychological trauma event (PTE) in the working environment. And 60 subjects classified as high risk group of PTSD, so a prevalence of high risk group for PTSD was 28.4%. Factors related to the high risk group of PTSD were the frequency of psychological trauma events experienced over the past 1 year and the high score of QIDS-SR16. Conclusion: The prevalence of high risk group for PTSD among emergency room workers in Korea is very high. This may adversely affect the safety of patients, so early screening and intervention are necessary.

Prescriptive analysis of liquid gastric digestive solutions (액상형 건위소화제의 방제학적 분석)

  • Hong Seok Lee;Min Ju Kim;Ye Bin Shin;Soo Myeong Kim;Sung Jong Shin;Kyung Hwan Jegal
    • Herbal Formula Science
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    • v.32 no.3
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    • pp.277-296
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    • 2024
  • Objective : Dyspepsia is one of the most common ailments among Koreans, leading to a continuously expanding market for liquid digestive solutions. These products are popular due to their convenience and low risk of side effects. However, there is a lack of research on the basic prescription composition of these ingredients and their precise indications according to Korean Medicine. Methods : Drugs were selected from the Korea Pharmaceutical Information Service website (http://www.health.kr), focusing on oral and liquid products classified under the Ministry of Food and Drug Safety's category of stomach and digestive aids (category 233). Frequency analysis was conducted to determine the occurrence and combinations of herbal ingredients within each product. Additionally, the four properties and five flavors of each product were calculated using their herbal ingredient composition ratios, and Pearson correlation coefficients were employed to verify the linear relationships between the composition ratios of the ingredients. Results : A comparative analysis of 33 liquid digestive medicines revealed that Zingiberis Rhizoma was the most frequently used herb. The most common dual-herb combination was Zingiberis Rhizoma and Citri Unshius Pericarpium, and the most prevalent tri-herb combination was Zingiberis Rhizoma, Citri Unshius Pericarpium, and Cinnamomi Cortex. Pearson correlation coefficient analysis showed a strong positive correlation between the composition ratios of Zingiberis Rhizoma and Cinnamomi Cortex. The analysis of four properties and five flavors indicated that products with warm and bitter flavors were the most common. Conclusions : The most frequently used herbal combination in liquid digestive solutions was Zingiberis Rhizoma, Citri Unshius Pericarpium, and Cinnamomi Cortex. This composition is suitable for treating dyspepsia caused by cold-dampness in the digestive system.

An Analysis on the Effect of the University in Area Development (대학이 지역발전에 미치는 영향 -천안시를 중심으로-)

  • Park, Jong-Gwan
    • The Journal of the Korea Contents Association
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    • v.11 no.6
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    • pp.360-371
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    • 2011
  • This study dealt with the effect of the university in area development to Cheonan city. This study ran parallel literature investigation and actual proof investigation. Questionnaires 394 enforce frequency analysis in SPSS 15.0 versions. University positive effect on local community is smooth supply of human capital in local community, increase of regional income, improvement of area image by expanded education opportunities, supply of various university facilities in local communities etc. Contradictory effect is expansion of gap for areas that young persons in local community taken to education of good quality leave other local community, occurrence of conflict by collision of new culture and culture of area characteristic. Role of university for area development is role of help consultation, symbolic role, educational role etc. But the weighed role is leading role which university leads area development. Finally, the prompting methods of university for local community development .must accomplish interchange of operational mode with high quality human resources activating removal of manpower between arithmetic.