• 신재생에너지
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• 제18권4호
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• pp.70-78
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• 2022

To respond to global warming, there is an increasing interest in eco-friendly alternative energy sources. Therefore, unused forest biomass that has been neglected due to a lack of marketability is attracting attention. With the introduction of the "unused forest biomass certification system" in 2019, ways of determining quantity of unused forest biomass have steadily increased. However, there have been reported cases whereby unused forest biomass weighed more than the amount of harvested trees. It was found that it was possible that forest resources that can be used as round wood were mixed with unused forest biomass. In this context, this study aimed to estimate the amount of mixed round wood in the unused forest biomass supply. The relative expression of growing stock/ha versus the amount of final clearing/ha collected was modeled (y=1.490x-94.341, R²=0.861). As a result, it was found that round wood was mixed into the unused forest biomass, contributing to the disparity observed between the weighted forest biomass and the amount of trees harvested. In conclusion, proper declaration and certification procedures should be carried out for the use of forest resources and promoting unused forest biomass usage.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권4호
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• pp.351-356
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• 2006

This study developed an artificial neural network (ANN) to estimate the growth of microorganisms during a fermentation process. The ANN relies solely on the cumulative consumption of alkali and the buffer capacity, which were measured on-line from the on/off control signal and pH values through automatic pH control. The two input variables were monitored on-line from a series of different batch cultivations and used to train the ANN to estimate biomass. The ANN was refined by optimizing the network structure and by adopting various algorithms for its training. The software estimator successfully generated growth profiles that showed good agreement with the measured biomass of separate batch cultures carried out between at 25 and $35^{\circ}C$.

• Journal of Ecology and Environment
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• 제29권5호
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• pp.485-488
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• 2006

Allometric equations for biomass measurement of the shrub species, Lindera obtusiloba, were developed. The allometric equations between $(BD)^2H$ and dry weight of leaves ($W_I$), stems and branches ($W_{sb}$), roots ($W_r$) and total weight ($W_t$) of the Lindera obtusiloba were as follows: $W_I=0.7318\;(BD^2H)^{0.6108},\;W_{sb}=0.6067(BD^2H)^{0.8355},\;W_r=0.4524(BD^2H)^{0.7608},\;W_t=1.672 (BD^2H)^{0.7664}$. The $R^2s$ between $(BD)^2H\;and\;W_I,\;W_{sb},\;W_r\;and\;W_t$ of the Lindera obtusiloba were 0.9251, 0.9571, 0.9353 and 0.9546, respectively. Root weight of this Lindera obtusiloba was about 38% of the aboveground biomass.

• 상하수도학회지
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• 제18권2호
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• pp.113-120
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• 2004

The biodegradability of organics has become essential for the design and modeling of a biological nutrient removal process. Respirometry for the batch test just with wastewater has been conducted to estimate active biomass and readily biodegradable organics in municipal wastewater simultaneously. Municipal wastewater contains significant active biomass, which is estimated about 17% of COD. Compared to the batch test seeded with sludge, the batch test just with wastewater represents a little higher readily biodegradable organics. This might be due to the different environment of the logarithmic growth of active biomass. The nitrate uptake rate test has been also performed for the estimation of the readily biodegradable organics. The nitrate uptake rate test results in a little higher readily biodegradable organics compared to the batch test seeded with sludge and similar organics compared to the batch test just with wastewater. This might be caused by the different sludge of a sequencing batch reactor process. Taking the result of the previous research into account, the readily biodegradable, slowly biodegradable, active biomass, soluble inert, and particulate inert organics are estimated about 11%, 49%, 17%, 11%, and 12% of COD, respectively.

• 임산에너지
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• 제21권1호
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• pp.25-31
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• 2002

경상북도 포항 지역에서 생육하는 평균 수령 37년생 상수리나무 천연림 생태계의 지상부 현존생물량 및 연순생산량을 분석하기 위해 2001년 8월에 총 10주의 표본목을 선정 벌목하였다. 수식 Wt=aD/sup b/ 를 사용하여 추정한 지상부 총 현존생물량은 115.47ton/ha으로 나타났다. 부위별 구성비는 수간목부 63.9%, 생지부 19.8%, 수피 14.0%, 그리고 잎 1.2%의 순으로 높았다. 총 연순생산량은 7.89ton/ha이었으며, 부위별 구성비는 현존생물량의 경우와는 다르게 수간목부, 수피, 생지부, 그리고 잎의 순 이었다.

• 수산해양기술연구
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• 제48권2호
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• pp.128-136
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• 2012

Hybrid surveys using hydroacoustic and fish sampling gears such as trammel net, trap were conducted to investigate total biomass, distribution and dominant fish species of the demersal fishes in the marine ranching area (MRA) of Jeju. Four surveys were carried out in June, August, October and November using 38kHz quantitative echo sounder. Catch data using trammel net and trap were used to calculate biomass and to examine dominant fish species. Fish schools were mainly detected in the waters of 20 meters below and around Chagwido waters. By the result of fishing experiments, fish species living in MRA of Jeju were about 40 species, dominant fish species of a detectable fish such as Family Sparidae and Family Monacanthidae etc. were identified 59.4~68.8% of total biomass. Based on the hydroacoustic data, fish length-weight function and target strength information, mean density of the demersal fish estimated were as follows; 0.88g/$m^2$ on June, 1.12g/$m^2$ on August, 1.35g/$m^2$ on October and 1.18g/$m^2$ on November. An estimated average biomass in MRA of Jeju was founded 20.5 tons in 2007, 20.6 tons in 2008, 23.0 tons in 2009, 25.9 tons in 2010. The results showed that biomass of MRA is getting increased slowly. Therefore the hybrid survey method using hydroacoustic and fish sampling gears is assured an effective biomass survey in the waters of mixed species.

• 농업과학연구
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• 제49권2호
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• pp.317-330
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• 2022

Recently, the policy regarding climate change in Korea and overseas has been to promote the utilization of forest biomass to achieve net zero emissions. In addition, with the implementation of the unused forest biomass system in 2018, the size of the Korean market for manufacturing wood pellets and wood chips using unused forest biomass is rapidly expanding. Therefore, it is necessary to estimate the total amount of unused forest biomass that can be used as an energy source and to identify the capacity that can be continuously produced annually. In this study, we estimated the actual forest area that can be produced of logging residue and the potential amount of unused forest biomass resources based on GT (green ton). Using a forest functions classification map (1 : 25,000), 5th digital forest type map (1 : 25,000), and digital elevation model (DEM), the forest area with a slope of 30° or less and mountain ridges of 70% or less was estimated based on production forest and IV age class or more. The total forest area where unused forest biomass can be produced was estimated to be 1,453,047 ha. Based on GT, the total amount of unused forest biomass potential resources in Korea was estimated to be 117,741,436 tons. By forest type, coniferous forests were estimated to be 48,513,580 tons (41.2%), broad-leaved forests 27,419,391 tons (23.3%), and mixed forests 41,808,465 tons (35.5%). Data from this research analysis can be used as basic data to estimate commercial use of unused forest biomass.

• 한국산림과학회지
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• 제101권1호
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• pp.138-147
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• 2012

본 연구는 맹종죽 임분의 현존량을 추정하기 위하여 적절한 줄기 절단부위를 파악하고, 죽령에 따른 지상부 및 지하부의 각 기관별 현존량을 비교분석하였다. 5개 죽령급 별 총 9개의 조사구(각 0.04 ha)에서 표준죽에 대한 상대수고에 의한 결정간별 건중비를 군집분석한 0~55% 구간)과 제 6~8 결정간(수고의 55~100% 구간)으로 두 개의 큰 집단으로 구분되었다. 일반적인 임목에서 매 2m 단위의 결정간을 각각 측정하는 조사 방법에 비하여 대나무의 경우 수고의 55~70% 구간을 기준으로 상단부와 하단부의 2개 결정간에 대한 각 1 kg 시료의 현존량을 조사하는 것이 더욱 효율적이라고 분석되었다. 결정계수가 가장 높은 맹종죽의 생체량 추정식은 $W=aD+bD^2$ 이었으며, 각 수령별 지상부 추정치를 합산한 총량과 수령별 구분 없이 추정한 총량 간에 유의적인 차이가 없었다. 맹종죽의 지상부 바이오메스는 총 57.77 ton/ha로서 줄기 40.47 ton/ha, 가지 9.29 ton/ha, 잎 8.01 ton/ha으로서 줄기부위가 가장 높게 나타났다. 지하부의 생체량은 53.35 ton/ha으로 나타났다.

• 한국수산과학회지
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• 제36권5호
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• pp.541-548
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• 2003

Species identification in hydroacoustic survey is one of the key requirements to estimate biomass of organism and to understand the structure of zooplankton community. Feasibility of species identification using two frequencies (38 and 120 kHz) was investigated on the basis of mean volume backscattering strength difference (MVBS). Virtual echogram technique was applied to two frequencies data sets that obtained from surveys in the Antarctic Ocean and Yellow Sea. Virtual echogram method using MVBS revealed the possibility of species identification, which species identification relying on visual scrutiny of single frequency acoustic data resulted in significant errors in biomass estimation. Through noise cancellation using MVBS, much of the acoustic noise caused by acoustic instruments could be removed in new virtual echogram, and the biomass estimation and data quality was improved.

• 한국산림과학회지
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• 제99권5호
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• pp.673-681
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• 2010

This study examined the biomass data estimated from different allometric models and calculated the mean aboveground biomass, mean belowground biomass and root/shoot ratio values according to the forest types and age classes. These mean values and the forest inventories in 2009 were used to estimate the aboveground and total biomass carbon storage in different forest types (coniferous, deciduous and mixed forests). The aboveground and total biomass carbon storage for all forest types in Korea were 350.201 Tg C and 436.724 Tg C. Over the past 36 years, plantations by reforestation programs have accounted for more than 70% of the observed carbon storage. The carbon storage in Korean forest biomass was 436.724 Tg C, of which 175.154 Tg C for coniferous forests, 126.772 Tg C for deciduous forests and 134.518 Tg C for mixed forests, comprising approximately 1/20 of the total carbon storage of the East Asian countries. The total carbon storage for the whole forest sector in Korea was 1213.122 Tg C, of which 436.724 Tg C is stored in forest biomass if using the ratio of carbon storage in different pools examined from the United States. Such large carbon storage in Korean forests is due mainly to active plantations growth and management practices.