• Korean Journal of Ecology and Environment
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• v.51 no.3
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• pp.205-211
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• 2018

In this study, we estimated the applicability of length-weight relationship-based biomass calculations by comparison of body length of genus Polyarthra collected from different habitats. Through the comparison, we also tested availability of representative species-specific biomass value of Polyarthra which is often used without length measurement. Polyarthra samples were collected from rivers (Han River and Nakdong River) and reservoir (Paldang Reservoir), and the body length was measured for statistical comparison among habitats and biomass calculations using different equations suggested previously. According to the results, the body length of Polyarthra spp. was significantly different among sampling sites, and the necessity of body length measurement for rotifer species in each situation has been suggested rather than using the representative biomass values which is fixed without considering time and space. Comparison of suggested biomass calculations based on our measured Polyarthra body length, the equation suggested by McCauley showed more reasonable range of biomass values than that suggested by EPA. In addition, in order to calculate more accurate biomass, it is necessary to measure the body length of rotifers, at least more than 44 individuals to reduce error probability to less than 5% with 99% probability. However, since direct measurement of rotifers biomass is limited, it is considered that further analyses are required for more precise application of rotifer biomass of which has high variability due to complex morphologies and species-specific cyclomorphosis often induced by biotic and abiotic factors in the habitats.

• Korean Journal of Ecology and Environment
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• v.56 no.2
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• pp.161-171
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• 2023

The medium-large cladoceran species Simocephalus spp. predominantly occur in habitats with developed aquatic vegetation. Accordingly, due to Simocephalus' high contribution to zooplankton community biomass in the lake's littoral zone and wetland habitats, estimating their biomass is important to understand the matter cycling based on biological interactions within the aquatic food web. In this study, we reviewed the length-weight regression equations used previously to estimate Simocephalus biomass, directly measured S. serrulatus' body specification (length, width and area) and their biomass(dry weight) using instruments such as a microscopic digital camera and a microscale, and performed regression analysis between each other. When S. serrulatus biomass was estimated using the equation (Kawabata and Urabe, 1998) presented in 『Biomonitoring Survey and Assessment Manual』, Korea, errors between estimates and measures were relatively large compared to the S. serrulatus species-specific biomass estimate equation developed by Lemke and Benke (2003). In addition, both equations showed not only increasing trends in error (estimate-measure) with increasing S. serrulatus' body length, but also in error variance among similar-sized individuals. The results of regression analysis with dry weight by body specifications indicated that the most appropriate equation for estimating the biomass of S. serrulatus was derived from the width-dry weight exponential regression equation (R²=0.9555). The review and development study of such species-specific biomass estimation equations for zooplankton can be used as a tool to understand their role and function in aquatic ecosystem food webs.

• Journal of Biomedical Engineering Research
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• v.20 no.2
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• pp.199-204
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• 1999

As the correct measuring of the light dosimetry in biological tissues give the important affection to the effect of PDT treatment we used Monte Carlo simulation to measure the light dosimetry on this study. The parameters using in experiments are the optical properties of the real biological tissue, and we used Henyey-Greenstein phase function among the phase functions. As we results, we displayed the result the change of Fluence rate and the difference against the previous theory was at least 0.35%. Biological tissues using in experiment were Human tissue, pig tissue, rat liver tissue and rabbit muscle tissue. The most of biological tissue have big scattering coefficient in visible wavelength which influences penetration depth. The penetration depth of human tissue in visible region is 1.5~2cm. We showed that it is possible to measure fluence rate and penetration depth within the biological tissues by Monte Carlo simulation very well.

• Journal of Korean Society of Forest Science
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• v.90 no.3
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• pp.338-345
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• 2001

This study was conducted to elucidate the relationship between the root structure and the crown structure of Norway spruce(Picea abies [L.] Karst), and thereafter to obtain the regression equation for the estimation of relative root and needle biomass using the tree height and diameter at breast height(DBH) without measurement of root and needle biomass. The study site was Barbis stands of Harz region located in central part of Germany. Five dominant and three co-dominant trees of 30 to 40 year-old Norway spruce were selected and tree height, diameter at breast height, clear bole length, weight of total needle and branch, cross section and sapwood area at breast height for biomass of above ground part and also the length of root, the number of root, the weight of root, the cross section area of root etc. by dividing the horizontal and vertical roots for below ground part of tree were measured. The significantly correlation was shown between the biomass of most of variables of above ground parts and those of below ground parts. For the diameter of breast height to the weight of total root, regression equation was Y = 3.56X - 45.94 and decision coefficient was 0.96 showing highly correlation. The weight of total branches and needles, and the tree height etc. of above ground parts showed highly positive relationship with below ground biomass. The results obtained from this study can be used to the estimating of biomass of below ground using variables of above ground such as DBH in the 30 to 40 year-old Norway spruce stands.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.378.1-378.1
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• 2016

나노바이오연구분야에서 ToF-SIMS를 이용하여 lipid와 metabolite같은 저 분자의 생체물질을 측정하는데 널리 이용되어 왔다. 최근에는 고 분자량의 생체물질을 측정하기 위해서 C60, water cluster, argon cluster등의 다양한 종류의 클러스터 이온빔들이 개발되어 왔다. [1,2] 하지만 tissue샘플을 클러스터 이온빔을 이용하여 분석한 결과에서도 m/z 1500이상의 고분자를 측정한 결과는 거의 없다. 바이오샘플의 charging을 상쇄하기위해 low energy electron beam (~20 eV)을 사용하는데, low energy electron beam이 샘플에 damage를 주기 때문이다. [3] 본 연구에서는 electron fluence (electrons/cm2)가 증가함에 따라 PC(16:0/18:1(9Z)와 Ganglioside GM1의 intensity가 감소함을 알았고, low energy electron beam에 의해 생체 물질이 damage를 받을 수 있음을 확인하였다. 따라서 tissue 샘플을 SUS기판에 샘플링하고 Ar-GCIB를 이용하면 charging없이 tissue imaging을 성공적으로 수행할 수 있고, m/z 2000이상의 고 분자량의 생체물질을 측정할 수 있음을 확인하였다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.1 no.1
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• pp.107-114
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• 1998

Purpose: The purpose of our study is to provide useful information for me-asurement methods of childhood obesity and to provide clinical significance of bioelectrical impedance analysis. Methods: We measured height, weight, waist to hip ratio, skinfold thickness and bioelectrical impedance from 206 elementary students in Kwangju from May to July 1997. Results: In males; 1) There were statistically high correlations between tri-ceps skinfold thickness and body mass index (BMI), percentage of body fat (%BF), weight, Rohler index (RI), total fat weight (TFW), waist to hip (W/H) ratio, height, lean body mass (LBM) (all, p<0.001). 2) There were statistically high correlations between subscapular skinfold thickness and BMI, RI, weig-ht, %BF, TBW (all, p<0.001). 3) There were statistically high correlations between %BF and BMI, triceps skinfold thickness, RI, TFW, subscapular skinfold thickness, weight (all, p<0.001). In females; 4) There were statistically high correlations between triceps skinfold thickness and BMI, weight, LBM, height, %BF (all, p<0.001). 5) There were statistically significant correlations between subscapular skinfold thickness and BMI, weight, LBM, RI, height. 6) There were statistically high correlations between percentage of body fat and BMI, RI, triceps skinfold thickness. The percentage of body fat according to the bioelectrical impedance analysis highly correlated with that calculated by skinfold thickness in males (r＝0.57, p<0.01) and in females (r＝0.30, p<0.01). Conclusion: The results of our study suggests that bioelectrical impedance analysis is a useful method of estimating body fat in the childhood obesity.

• Journal of Biomedical Engineering Research
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• v.22 no.1
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• pp.41-47
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• 2001

본 연구는 한 대의 칼라 카메라와 광학장치를 이용하여 인체의 운동량을 측정하는 시스템에 관한 것이다. 광학을 이용하여 인체의 운동량을 측정하기 위해서는 일반적으로 두 대 이상의 카메라로부터 획득된 영상으로 측정물체에 대한 좌표를 구하는 입체화상법을 사용한다. 제시한 시스템은 서로 다른 색의 칼라필터와 거울을 통과한 두 개의 광경로를 빔스플리터로 중첩시켜서 한 대의 칼라카메라로 영상을 획득하여 분석하는 것으로, 한 대의 칼라카메라가 두 대의 단색 가상카메라 역할을 하는 것이다. 단색 가상카메라는 적색, 녹색과 청색의 세 가지로 본 실험에서는 적색의 밝기가 가장 낮아서 녹색과 청색 가상카메라를 사용하였다. 광학장치를 이용하여 칼라카메라로 획득된 적색, 녹색과 청색별로 8bit인 24bit 디지털영상에서 녹색과 청색 영상은 각각 녹색과 청색의 가상카메라로 획득한 영상이다. 이 영상들을 이진화하여 측정물체를 배경으로부터 분리하고, 이진영상에서 일정한 면적을 지닌 영역의 중심을 측정물체가 영상면에 투영된 좌표로 본다. 녹색과 청색 영상에서 동일한 측정물체에 대한 영상선을 구하고 이들의 교차점을 측정물체의 공간좌표로 하였다. 이 시스템을 이용하여 직립 및 신전자세에서 척추의 형상을 측정하였으며 향후 시스템의 추가적인 개발과 적응분야에 대하여도 살펴보았다.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.27-34
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• 2013

Most of existing biomedical signal measurement devices measure and evaluate biomedical signal only in a single device. Also, even if the device is multi-functional, those biomedical signals can be measured by selection of the user. In this paper, we implemented wristband-style biomedical signal measurement device for u-healthcare system to solve the problem above. Implemented device uses 4 infrared sensors to measure the pulse, 2 electrodes to measure the skin conductivity, and 3-axis accelerometer to measure momentum. Also, we propose a communication packet frame for transmitting biomedical signal data to PC or mobile device, using Zigbee. Studies show that our device has the error rate of less than twice for pulse measurement, 85.6%, 84.7% reliability for momentum measurement, and the skin conductivity has changed according to the user's physical status.

• Korean Journal of Microbiology
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• v.38 no.2
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• pp.119-126
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• 2002

ATP concentrations far estimating total microbial biomass in the sediment were measured in three different marine sedimentary environments. ATP concentrations were highest in the surface sediment and decreased with increasing sediment depth and distance from the land. The results indicated that the benthic microbial biomass is primarily controlled by nutrient inputs from the overlying water column. Because of the longer residence time and adsorption to the sediment, the variations in organic carbon (OC) contents with sites and depths were not as distinct as that of ATP, and the correlation between OC and ATP was not significant in the coastal sediments. No significant correlation between OC and ATP in the coastal sediments also suggested that microbial biomass in the labile organic-enriched coastal sediment is suppressed by the grazing of higher trophic level such as meiofauna. Overall regional and vertical distribution of ATP indicated that h\`w can be a relevant tool for measuring total microbial biomass in various marine sedimentary environments.

• Journal of Korean Society of Forest Science
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• v.100 no.1
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• pp.42-51
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• 2011

This study was conducted to analyze correlation of above- and below-ground biomass and to drive regression equation suitable for estimating standing tree biomass between natural and planted stands of Pinus densiflora for. erecta of one age-class in Gangwon province, Republic of Korea. Total 40 trees, 10 from the naturally regenerated and 10 from the planted stands in each of two studied sites, were uprooted to measure height, diameter at root color (DRC), and the dry weights of stem, branches, and needles. The length, weight, and volume of the main and horizontal roots were also measured. Most of the above-ground traits except height were highly correlated with most of the other above-ground traits and the below-ground traits except the length of roots (p < 0.05). Especially, the DRC, which is measured easily on the standing tree, was highly correlated with most of the traits in all studied stands (p < 0.01). Thus, the DRC would be the most desirable trait to estimate not only above-ground biomass but also below-ground biomass. However, height was not a good variable to estimate standing tree biomass of Pinus densiflora for. erecta of one age-class in Gangwon province because it was not correlated with most of other traits. Regression equations derived from the current study could be used effectively as a basic data for estimating above-ground and below-ground biomass using DRC.