• Title/Summary/Keyword: density index

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A Feasibility Study on the Damage Detection of Infinite Beams Using the Structural Intensity Measurement Technique (진동 인텐시티 계측 방법을 이용한 무한보의 손상감지에 관한 기초 연구)

  • Huh, Young-Cheol;Lee, Jong-Won;Kim, Jae-Kwan;Kil, Hyun-Gwon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.54-58
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    • 2008
  • The structural intensities have been applied to understand a source point and the path of vibrational energy flows in interested structures by many researchers. In this paper, a feasibility study was carried out to investigate the characteristics of a damaged beam with a inflicted open crack using the structural intensities. The damaged beam was taken as a continuous system with equivalent bending stiffness and the flexural vibrations were only considered in numerical simulation and experiments. A four(4)-transducer array was used to measure the flexural vibrations of the beam and the structural intensities were estimated by means of cross spectral density method. As a result, the magnitude changes of the structural intensities could be observed in the vicinity of the damage location and a damage index was newly proposed to identify the damage zone. It has been confirmed that the measurement of the structural intensities was simple and effective method to find out the damage zone.

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Vegetation Structure and Ecological Restoration of Disturbed Forest due to Artificial Plant (인공식재에 의해 교란된 산림의 식생구조 및 생태적 복원기법)

  • Bae, Byung-Ho;Yoon, Yong-Han;Kim, Jeong-Ho
    • Journal of Environmental Science International
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    • v.20 no.6
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    • pp.701-710
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    • 2011
  • The purpose of this study is to investigate the vegetation structure and ecological restoration of disturbed forest due to artificial plant. To this end, 12 plots were set up and surveyed. The result analyzed considering mean importance percentage(M.I.P) showed that the types were divided into three groups which are artificial planted forest type(three plots), natural forest-artificial planted forest type(four plots), natural forest type(five plots). Dominant proportion of artificial planted species were as follows: artificial planted forest type was over 60%, natural forest-artificial planted forest types were 14~49%. The range of Shannon's index of all associations was from 0.7131 to 0.7771(natural forest-artificial planted forest > natural forest > artificial planted forest). Also we suggested restoration method of vegetation for ecological value as follow: Control of density considering step and Remove of Pinus koraiensis seedlings of understory layer and shurb layer.

Triglycerides and C-peptide are Increased in BMI over than $23kg/m^2$ Diabetic Patients (BMI $23kg/m^2$ 이상의 비만 당뇨병 환자에서 중성지방과 식후 2시간 C-peptide 증가)

  • Kim, Hee-Seung;Song, Min-Soon
    • Journal of Korean Biological Nursing Science
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    • v.5 no.1
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    • pp.5-12
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    • 2003
  • The purpose of this study to compare of clinical profile between obese and nonobese type 2 diabetic patients. The subjects were consist of 111 obese (50 male, 61 female) and 159 non obese (79 male, 80 female) type 2 diabetic patients underwent fasting blood glucose, 2-hour postprandial blood glucose, $HbA_1c$, total cholesterol, triglyceride, high density lipoprotein, microalbuminuria, fasting C-peptide and 2-hour postprandial C-peptide were measured. Diabetes was diagnosed according to the American Diabetes Association (ADA) criteria. Obesity was defined as body mass index (BMI, kilograms per meters squared) ${\geq}23$. Data analyses were t-test, chisquare test in SAS program. The results were as follows : 1) Triglycerides and 2-hour postprandial C-peptide were significant higher in obese than non-obese patients. 2) Systolic blood pressure, Diastolic blood pressure, fasting blood sugar, 2-hour postprandial blood glucose, $HbA_1c$, total cholesterol, high-density lipoprotein, microalbuminuria and fasting C-peptide were no difference between obese and non-obese groups. These data indicate that obesity is a risk factor for the development of coronary heart disease (CHD) in diabetic patients. Therefore, weight reductions have beneficial effects on insulin action and glycemic control in obese type 2 diabetic patients.

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Body Composition, Blood Pressure, Blood Lipids, and Glucose according to Obesity Degree by Body Fat Percentage in Female University Students (여대생의 체지방률분류 비만도에 따른 체성분, 혈압, 혈중지질 및 혈당)

  • Jang, Eun Hee;Park, Young Rye
    • Journal of Korean Biological Nursing Science
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    • v.14 no.4
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    • pp.231-238
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    • 2012
  • Purpose: The purpose of this study was to investigate body composition, blood pressure, blood lipids, and glucose according to obesity degree by body fat percentage in female university students. Methods: A total of 231 subjects were participated between July and December 2010. The anthropometric measures and blood analyzer were used. Data were analyzed using descriptive statistics, ANOVA, and Pearson's correlation coefficient with SPSS 18.0. Results: Percentage of body fat (PBF)-defined obesity had higher prevalence than body mass index (BMI)-defined obesity. Weight, BMI, PBF, fat mass, Waist to hip ratio (WHR), Systolic blood pressure (SBP), Diastolic blood pressure (DBP) in obesity group were higher than normal group and Soft lean mass and Low density lipoprotein (LDL) in obesity group were lower than normal group. There were significant correlations between PFB, SBP, DBP, Triglyceride (TC), High density lipoprotein (HDL), and LDL. Conclusion: In conclusion, when screening for obesity in female university students, body fat should be considered. It is needed to develop obesity management program according to obesity degree and to identify the effectiveness.

Approximate Analytical Expression of the Laser Wavelength Distribution Incurred by the Grating Period Fluctuation in QWS-DFB Lasers (QWS-DFB 레이저에서 회절격자 주기의 랜덤 변이에 따른 주모드 파장 분포의 해석적 근사식)

  • Ha, Seon-Yong;Kim, Sang-Bae;Na, Sang-Sin
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.38 no.9
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    • pp.616-623
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    • 2001
  • Effects of the grating period fluctuation on the wavelength distribution have been studied by an effective index transfer matrix method in quarter wavelength shifted (QWS) DFB lasers. The wavelength distribution is expressed by a probability density that is an analytical function of the correlation coefficient and normalized standard deviation of the grating period fluctuation. The probability density function of wavelength distribution is shown to be nearly Gaussian, and its standard deviation increases with normalized standard deviation of the grating period fluctuation, and decreases with the negative correlation between adjacent half-periods.

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Quality Changes of Salted Baechu with Packaging Methods during Long Term Storage (포장방법을 달리한 절임배추의 장기저장중 품질변화)

  • Han, Eung-Soo;Seok, Moon-Sik;Park, Ji-Hyun
    • Korean Journal of Food Science and Technology
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    • v.30 no.6
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    • pp.1307-1311
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    • 1998
  • Optimal packaging methods for the long term storage of salted winter baechu were investigated. Salted baechu was packaged individually in 20 ㎏ unit weight in LDPE (low density polyethylene), HDPE (high density polyethylene), PVC-box and then stored at $0^{\circ}C$ for 8 weeks. During storage, quality index of salted baechu were measured in terms of salinity, pH, reducing sugar content, total cell counts and lactic acid bacterial counts. Salted baechu deteriorated rapidly in PVC-box, and slowly in HDPE but sustained for 8 weeks in LDPE. In all treatment, salted baechu was maintained better at submerged parts in exudate, but deteriorated at emerged parts.

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ENVIRONMENT DEPENDENCE OF DISK MORPHOLOGY OF SPIRAL GALAXIES

  • Ann, Hong Bae
    • Journal of The Korean Astronomical Society
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    • v.47 no.1
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    • pp.1-13
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    • 2014
  • We analyze the dependence of disk morphology (arm class, Hubble type, bar type) of nearby spiral galaxies on the galaxy environment by using local background density (${\Sigma}_n$), projected distance ($r_p$), and tidal index (T I) as measures of the environment. There is a strong dependence of arm class and Hubble type on the galaxy environment, while the bar type exhibits a weak dependence with a high frequency of SB galaxies in high density regions. Grand design fractions and early-type fractions increase with increasing ${\Sigma}_n$, $1/r_p$, and T I, while fractions of flocculent spirals and late-type spirals decrease. Multiple-arm and intermediate-type spirals exhibit nearly constant fractions with weak trends similar to grand design and early-type spirals. While bar types show only a marginal dependence on ${\Sigma}_n$, they show a fairly clear dependence on $r_p$ with a high frequency of SB galaxies at small $r_p$. The arm class also exhibits a stronger correlation with $r_p$ than ${\Sigma}_n$ and T I, whereas the Hubble type exhibits similar correlations with ${\Sigma}_n$ and $r_p$. This suggests that the arm class is mostly affected by the nearest neighbor while the Hubble type is affected by the local densities contributed by neighboring galaxies as well as the nearest neighbor.

Factors related to Osteopenia in Community People (일 지역주민의 골감소증 영향요인)

  • Kim, Sung Hey;Lee, Young Hee
    • Journal of Korean Public Health Nursing
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    • v.29 no.2
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    • pp.177-189
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    • 2015
  • Purpose: The purpose of this study was to investigate bone mineral density (BMD) and risk factors related to osteopenia in community people. Methods: The subjects consisted of 145 community people. The variables of osteoporosis knowledge and preventive health promoting behavior were measured using questionnaires. BMD and BMI (body mass index) were measured. Dietary nutrients intake related to osteoporosis was measured using 24hours recall. Data analysis was performed using the SPSS 18.0 program, using mean, standard deviation, ${\chi}^2-test$, t-test, and logistic regression. Results: Eighty six people (59.3%) had an osteopenia. According to normal group and osteopenia group, there was significant difference in gender (${\chi}^2=6.72$, p=.010) and smoking (${\chi}^2=5.18$, p=.023). Predictors of osteopenia group were male (OR=2.65, CI=1.03-8.98), BMI(OR=0.86, CI=0.72-0.96). Conclusion: Health care providers must consider factors that affect osteopenia such as gender, BMI. These results suggest the need to instruct nursing activities and interventions which are beneficial for prevention of osteoporosis.

Vegetation Management Units and Its Landscape Structures of Mt. Cheolma, in Incheon City, Korea

  • Cho, Hyun-Je;Cho, Je-Hyung
    • 한국생태학회:학술대회논문집
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    • 2002.08a
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    • pp.71-77
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    • 2002
  • For landscape ecological management of the isolated forestlands in Incheon city located in the western tip of South Korea, the forest vegetation of Mt. Cheolma was classified phytosciologically and mapped out its spatial distribution at a scale of 1:5,000. Characteristics of forest landscape structures were discussed in terms of the number and size of patches obtained by analyzing vegetation map. Units to manage the forest vegetation were categorized into eighteen communities, seventeen groups, and sixteen subgroups. Landscape elements were classified into five types: secondary vegetation, introduced vegetation for forestry (IVF), introduced vegetation for agriculture (IVA), and other elements. Two hundred and ninety-three forest landscape patches covers 443.3ha of which IVF accounted for 316.8ha(71.5%), the largest portion, secondary vegetation for f01.2ha(22.8%), IVA for 6.2ha(1.4%), and others for 19.1ha(4.3%). The ratio of natural forest elements of 31.9% showed that this area was mainly comprised of artificially introduced vegetation, such as Robinia pseudoacacia plantation and Pinus rigida plantation. Forest landscape patches have a mean area of 4.5ha, a density of 66.1/100ha, and a diversity index of 0.87. It was estimated that differentiation of patches recognized in community level would be related to human interference and those in subordinate level to natural processes.

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Change the Properties of Amorphous Carbon Hardmask Film Prepared with the Variation of Process Parameters in Plasma Enhanced Chemical Vapor Depostion Systems

  • Kim, Seok Hwan;Yeo, Sanghak;Yang, Jaeyoung;Park, Keunoh;Hur, Gieung;Lee, Jaeho;Lee, Jaichan
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.381.2-381.2
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    • 2014
  • In this study the amorphous carbon films were deposited by PECVD at the substrate temperature range of 250 to $600^{\circ}C$, and the process conditions of higher and lower precursor flow rate, respectively. The temperature was a main parameter to control the density and mirco-structures of carbon films, and their's properties depended with the process temperatrue are changed by controlling precursor flow rate. The precursor feeding rate affect on the plasma ion density and a deposition reactivity. This change of film properties was obtained the instrinsic stress, FT-IR & Raman analysis, refractive index (RI) and ext. coef. (k) measured by ellipsometer. In the process conditions of lower and higher flow rate of precursor it had a different intrinsic stress as a function of the substrate temperature.

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