• Title/Summary/Keyword: Attenuation relationship

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A Study on the Status and Prediction of Arterial Road Noise in Seoul, Korea (서울시 간선도로의 소음도 현황 및 예측식에 관한 고찰)

  • Park, Joon-Cheol;Kim, Yoon-Shin;Hong, Seung-Cheol;Choi, Joon-Gyu
    • Journal of Environmental Health Sciences
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    • v.34 no.5
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    • pp.395-402
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    • 2008
  • Road traffic noise causes considerable disturbance and annoyance in exposed inhabitants. Particularly, arterial road noise is a significant environmental problem in many urban areas in which higher traffic volume and higher car speed occur. Arterial road noise became the target of this investigation in Seoul, South Korea. Noise levels were measured at four points that were based on distance from roadside at the same measurement site and under the conditions as reported by the National Institute of Environmental Research (NIER) in 1999. The average noise levels ($L_{eq,1h}$) of the arterial road was 80.3 dBA at 5 m, 77.4 dBA at 10 m, 73.7 dBA at 20 m, 70.9 dBA at 30 m. A comparison between 1999 and 2008's measurement values has shown that in 2008 noise level is up by about 1.5 dBA, traffic volume has increased by about 15.7%, while car speed has decrease by about 8%. The relationship between 2008' measured values and predicted values using the NIER Equation is low under 10 m from the roadside. The influence range of arterial noise is calculated at 26 m for road noise limits in daytime. In relation to the comparison between traffic volume and noise level, the equivalence in traffic volume (Light car+10xHeavy car) is higher than other variables.

Nutritional Status and Bone Mineral Density of Elderly Women in Asan

  • Kim Ji Sun;Kwon Young Suk;Shin Yoon Jeong;Kim Min Kyung;Kim Hee Seon
    • Journal of Community Nutrition
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    • v.7 no.1
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    • pp.49-57
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    • 2005
  • Nutrition factors play an important role in the pathogenesis of osteoporosis. The purpose of this study is to investigate the relationship between nutritional status and bone mineral density of elderly women. Three hundred thirty five elderly women (over 65 years) in Asan were divided into three age groups (group 1, less than 70 y ; group 2, from 70 to 75 y ; group 3, 75 y or more). Total alkaline phosphatase and serum calcium (Ca) were analyzed using spectrophotometric procedure. Data for food and nutrient intakes were obtained by a 24-hour recall method. Bone density was measured by broadband ultrasound attenuation (BUA) using QUS-2. Age differences were tested with the X 2 test for categorical variables and with ANOVA and Tukey's test for continuous variables. Correlation was conducted to test the association between bone density and nutrient intake. The subjects in age groups 1,2 and 3 were $36.7\%$, $32.8\%$ and $30.4\%$, respectively. Height and body weight of the subjects were significantly decreased with age. Average bone density of the subjects in group 3 was lower than the other age groups. Osteoporosis determined by t-score is $17.9\%$ for group 1, $24.5\%$ for group 2 and $55.9\%$ for group 3 (p < 0.001). The serum Ca level of the subjects in group 2 was significantly lower than that of group 1 although mean values in all age groups are within the normal range. Dietary Ca intake, nutrient adequacy ratio (NAR) and index of nutrient quality (INQ) were decreased with age. Bone density was negatively correlated with age (p < 0.001), while body mass index (p < 0.01) was positively related with bone density. Although partial correlation did not reveal the significant correlation of BMD and dietary calcium after controlling for age, since calcium intake was very poor compared to sodium and phosphorous intakes, recommendation of more calcium intake for elderly women especially those over 75 years must be continuously emphasized.

Effects of Central GABA and Glutamate on Blood Pressure and Single Unit Spikes in the RVLM of Rats

  • Park, Jae-Sik;Lee, Zee-Ihn;Jang, Jae-Hee;Ahn, Dong-Kuk
    • The Korean Journal of Physiology and Pharmacology
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    • v.6 no.3
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    • pp.149-154
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    • 2002
  • The blood pressure (BP) is regulated by the nervous system and humoral factors, such as renin- angiotensin system, vasopressin and others. In the present study, we examined the central effects of glutamate and GABA on the cardiovascular regulation by injection of these substances into the lateral ventricle and also investigated the relationship between these central effects and the action of angiotensin II (Ang). Male Sprague Dawley rats, $350{\sim}400$ g, were anesthetized with urethane and instrumented with an arterial catheter for direct measurement of BP and heart rate (HR), and an guide cannula in the lateral ventricle for drug injection. A glass microelectode was inserted into the rostral ventrolateral medulla (RVLM) for recording single unit spikes. Barosensitive neurons were identified by changes of single unit spikes in RVLM following intravenous injection of nitroprusside and phenylephrine. The effects of GABA and glutamate injected into the lateral ventricle were studied in single neuronal activity of the RVLM in addition to changes in BP and heart rate, and compared the results before and after treatment with intravenous losartan, nonpeptide Ang II-type 1 receptor antagonist (1 mg/100 g BW). Intracerebroventricular administration of GABA decreased systolic blood pressure (SBP) and HR, but increased the firing rates in the RVLM. However, intracerebroventricular glutamate injection produced effects opposite to GABA. After pretreatment of intravenous losartan, the central effects of GABA on BP and firing rate in the RVLM were significantly attenuated and that of glutamate showed a tendency of attenuation. These results suggested that central GABA and glutamate regulated BP and firing rates in RVLM were inversely related to BP change. The central effects of GABA or glutamate on the autonomic nervous function were modulated by humoral factor, Ang II, by maintaining BP.

Monitoring and spatio-temporal analysis of UHI effect for Mansa district of Punjab, India

  • Kaur, Rajveer;Pandey, Puneeta
    • Advances in environmental research
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    • v.9 no.1
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    • pp.19-39
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    • 2020
  • Urban heat island (UHI) is one of the most important climatic implications of urbanization and thus a matter of key concern for environmentalists of the world in the twenty-first century. The relationship between climate and urbanization has been better understood with the introduction of thermal remote sensing. So, this study is an attempt to understand the influence of urbanization on local temperature for a small developing city. The study focuses on the investigation of intensity of atmospheric and surface urban heat island for a small urbanizing district of Punjab, India. Landsat 8 OLI/TIRS satellite data and field observations were used to examine the spatial pattern of surface and atmospheric UHI effect respectively, for the month of April, 2018. The satellite data has been used to cover the larger geographical area while field observations were taken for simultaneous and daily temperature measurements for different land use types. The significant influence of land use/land cover (LULC) patterns on UHI effect was analyzed using normalized built-up and vegetation indices (NDBI, NDVI) that were derived from remote sensing satellite data. The statistical analysis carried out for land surface temperature (LST) and LULC indicators displayed negative correlation for LST and NDVI while NDBI and LST exhibited positive correlation depicting attenuation in UHI effect by abundant vegetation. The comparison of remote sensing and in-situ observations were also carried out in the study. The research concluded in finding both nocturnal and daytime UHI effect based on diurnal air temperature observations. The study recommends the urgent need to explore and impose effective UHI mitigation measures for the sustainable urban growth.

Estimation of probabilistic hazard for Bingol province, Turkey

  • Balun, Bilal;Nemutlu, Omer Faruk;Benli, Ahmet;Sari, Ali
    • Earthquakes and Structures
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    • v.18 no.2
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    • pp.223-231
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    • 2020
  • Due to the fact that Bingöl province is at the intersection of the North Anatolian Fault and the Eastern Anatolian Fault, the seismicity of the region is important. In this study, probabilistic seismic hazard analyzes (PSHA) were conducted to cover the boundaries of Bingöl province. It occurred since 1900, the seismicity of the region was obtained statistically by considering the earthquake records with a magnitude greater than 4 and the Gutenberg-Richter correlation. In the study, magnitude-frequency relationship, seismic hazard and repetition periods were obtained for certain time periods (10, 20, 30, 40, 50, 75 and 100 years). Once a project area determined in this study, which may affect the peak ground acceleration according to various attenuation relationships are calculated and using the Turkey Earthquake Hazard Map, average acceleration value for Bingöl province were determined. As a result of the probabilistic seismic hazard analysis, the project earthquakes with a probability of exceeding 50 years indicate that the magnitude of the project earthquake is 7.4 and that the province is in a risky area in terms of seismicity. The repetition periods of earthquakes of 6.0, 6.5, 7.0 and 7.5 are 42, 105, 266 and 670 years respectively. Within the province of Bingöl; the probability of exceeding 50 years is 2%, 10% and 50%, while the peak ground acceleration values are 1.03 g, 0.58 g and 0.24 g. As a result, probabilistic seismic hazard analysis shows that the seismicity of the region is high and the importance of considering the earthquake effect during construction is emphasized for this region.

Relationship between the Distribution of Space doses in X-ray Rooms and the "Inverse Square Law of Distance" (X선 촬영실 내 공간선량의 분포와 거리 역자승 법칙과의 관련성)

  • Choi, Seong-Kwan
    • The Journal of the Korea Contents Association
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    • v.13 no.8
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    • pp.301-307
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    • 2013
  • In the present study, space doses generated during X-ray radiography of hand, head, and abdomen, etc. were examined and whether the intensity of space doses of scattering rays is attenuated by the "inverse square law of distance" was figured out. First, the space doses of X-ray with small amounts of generated scattering rays such as hand radiography were mostly attenuated by the "inverse square law of distance" and were not detected at all at a distance of 2m. Second, the space doses of X-ray with large amounts of generated scattering rays such as head or abdomen radiography attenuated in higher rates than the rates under the "inverse square law of distance" at distances ranging from 30cm to 1m from the center of the irradiation field and were attenuated by the "inverse square law of distance" at distances ranging from 1m to 2m. Therefore, in X-ray rooms, the subject should be at least 2m away from the center of the irradiation field in the case of hand radiography and X-ray exposure prevention actions using protective devices are required in the entire spaces of the X-ray rooms in the case of head or abdomen radiography.

A study on the Measurement of Soil Water Concentration by Time Domain Reflectometry (TDR(Time Domain Reflectometry)을 이용한 토양수농도 측정에 관한 연구)

  • Park, Jae-Hyeon
    • Journal of Korea Water Resources Association
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    • v.31 no.2
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    • pp.123-132
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    • 1998
  • Monitoring solute transport has been known to be difficult especially for the unsaturated soil. The object of this study is to investigate the TDR application to monitoring solute concentration in the vadose zone. The TDR calibration test was conducted for soil samples with various water contents and concentrations. The voltage attenuation of electromagnetic wave of TDR was used to estimate the bulk electrical conductivity of a soil. The relationship between the bulk soil electrical conductivity and the solute concentration was assumed to be linear at a constant volumetric soil water content. In this study four proposed relationships were compared using data obtained from KCI solution at three different concentrations. Relationships given by Topp, Daltaon, Yanuka showed the linearity between the bulk soil electrical conductivity and the solute concentration, which were more pronounced than Zegelin's. The three relationships were found to be useful to measure the solute concentration in the vadose zone. In addition, TDR method was proven to be a viable technique in monitoring solute transport through unsaturated soils in transient flow condition.

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Estimation of Fracture Toughness Degradation of High Temperature Materials by Nonlinear Acoustic Effects (비선형 음향효과에 의한 고온 재료의 파괴인성 열화도 평가)

  • Jeong, Hyun-Jo;Nahm, Seung-Hoon;Jhang, Kyung-Young;Nam, Young-Hyun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.20 no.5
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    • pp.424-430
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    • 2000
  • In order to develop an ultrasonic evaluation method for properties degradation of high temperature materials, a number of Cr-Mo-V steel samples were heat-treated and their damage mechanism was examined. Ultrasonic parameters such as velocity, attenuation, and more recently developed nonlinear acoustic parameter were measured. The nonlinear acoustic parameter was found to be most sensitive to material degradation mainly attributed to the precipitation of impurities in grain boundaries. When compared to the electrical resistivity results, the nonlinear parameters showed similar behavior. There existed a relatively good correlation between the nonlinear parameter and the fracture appearance transition temperature (FATT) obtained by Charpy V-notch impact test. Based on the relationship between the FATT and the fracture toughness ($K_{IC}$), correlation between the nonlinear parameter and $K_{IC}$ was established.

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Hourly Rainfall Surface Prediction with Meteorological Radar Data (기상레이더 자료를 이용한 시우량곡면 예측)

  • 정재성;이재형
    • Water for future
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    • v.29 no.3
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    • pp.187-195
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    • 1996
  • In this study, a methodology for the hourly prediction of rainfall surfaces was applied to the Pyungchang river basin at the upstream of South Han river with meteorological radar and ground rainfall data. The methods for the exclusion of abnormal echoes, and suppression of ground clutter, and the augmentation of attenuation effects associated with rainfall phenomena were reviewed, and the relationship between radar reflectivity (Z) and rainfall rate (R) was analyzed. The transformation of augmented radar reflectivities into the rdar rainfall surfaces was carried out, and afterward they were synthesized with the ground rainfall data generating the hourly rainfall surfaces. For the prediction of hourly rainfall surface, the moving factors of rainfall field estimated by the cross correlation coefficient method and the temporal variation of radar rainfall intensities were considered. The synthesized hourly rainfall surfaces were used to predict the hourly rainfall surfaces up to 3 hours in advance and subsequently the results were compared with the measured and the synthesized. It seems that the prediction method need to be verified with more data and be complemented further to consider the physical characteristics of rainfall field and the topography of the basin.

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Rainfall Estimation by X-band Marine Radar (X밴드 선박용 레이더를 이용한 강우 추정)

  • Kim, Kwang-Ho;Kwon, Byung-Hyuk;Kim, Min-Seong;Kim, Park-Sa;Yoon, Hong-Joo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.4
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    • pp.695-704
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    • 2018
  • The rainfall cases were identified by rainfall estimation techniques which were developed by using X - band marine radar. A digital signal converter was used to convert the signal received from the marine radar into digital reflectivity information. The ground clutter signal was removed and the errors caused by beam attenuation and beam volume changes were corrected. The reflectivity showed a linear relationship with the rain gauge rainfall. Quantitative rainfall was estimated by converting the radar signal into an cartesian coordinate system. When the rainfall was recorded more than $5mm\;hr^{-1}$ at three automatic weather stations, the rain cell distribution on the marine radar was consistent with that of the weather radar operated by Korea meteorological Adminstration.