• Journal of Ecology and Environment
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• v.42 no.4
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• pp.155-162
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• 2018

Background: In ecosystem carbon cycle studies, distinguishing between $CO_2$ emitted by roots and by microbes remains very difficult because it is mixed before being released into the atmosphere. Currently, no method for quantifying root and microbial respiration is effective. Therefore, this study investigated the relationship between soil respiration and underground root biomass at varying distances from the tree and tested possibilities for measuring root and microbial respiration. Methods: Soil respiration was measured by the closed chamber method, in which acrylic collars were placed at regular intervals from the tree base. Measurements were made irregularly during one season, including high temperatures in summer and low temperatures in autumn; the soil's temperature and moisture content were also collected. After measurements, roots of each plot were collected, and their dry matter biomass measured to analyze relationships between root biomass and soil respiration. Results: Apart from root biomass, which affects soil's temperature and moisture, no other factors affecting soil respiration showed significant differences between measuring points. At each point, soil respiration showed clear seasonal variations and high exponential correlation with increasing soil temperatures. The root biomass decreased exponentially with increasing distance from the tree. The rate of soil respiration was also highly correlated exponentially with root biomass. Based on these results, the average rate of root respiration in the soil was estimated to be 34.4% (26.6~43.1%). Conclusions: In this study, attempts were made to differentiate the root respiration rate by analyzing the distribution of root biomass and resulting changes in soil respiration. As distance from the tree increased, root biomass and soil respiration values were shown to strongly decrease exponentially. Root biomass increased logarithmically with increases in soil respiration. In addition, soil respiration and underground root biomass were logarithmically related; the calculated root-breathing rate was around 44%. This study method is applicable for determining root and microbial respiration in forest ecosystem carbon cycle research. However, more data should be collected on the distribution of root biomass and the correlated soil respiration.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.55-70
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• 1995

Periapical lesions develop as a result of immunopathologic response to irritants from infected root canal systems. Removal of these irritants from the root canal system and sealing the root canal space may induce he31ing of the periapical lesions. 83 periapical lesions diagnosed as periapical abscess, periapical granuloma, chronic nonspecific inflammation, fibrosis and periapical Cyst were evaluated for the distribution of immunoglobulin containing cells. The influence of the state of root canal treatment on the distribution of immunoglobulin containing cells has evaluated. All lesions were divided into a group with no treatment, a group with canal enlargement, a group filled with gutta percha, and a group filled with Vitapex(calcium hydroxide). The distribution of immunoglobulin-containing cells according to the presence of pain and fistula was also evaluated. The following results were obtained. 1. Statistically significant difference in the distribution of immunoglobulin-containing cells among periapical abscess, periapical granuloma, chronic nonspecific inflammation/fibrosis and periapical cyst were found.(Kruskal-Wallis analysis, P<0.05) The number of immunoglobulin-containing cells in fibrosis was remarkably lower than that of periapical abscess, granuloma and cyst. 2. IgM and IgA containing cells were predominantly observed in periapical abscesses and periapical cysts, respectively. 3. All periapical lesions showed a large number of IgG containing cells followed by IgM, IgA and IgE containing cells. 4. There was a decrease in all Ig-containing cells in the group with canal filling compared to groups without treatment or with enlargement. That is, there is a decrease in Ig-containing cells as treatment progresses. 5. No significant correlation existed between the presence of pain and fistula and the distribution of immunoglobulin containing cells in periapical lesions.(t-test) Results appear to support that immune response are actively involved in the development and progress in periapical lesions. The fact that distribution of immunoglobulins differ according to the state of endodontic treatment suggests that root canal treatment may alter the humoral immune response of the periapical lesions.

• The Journal of the Acoustical Society of Korea
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• v.21 no.3
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• pp.304-309
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• 2002

We propose the computation reduction method of real root method that is mainly used in the CELP (Code Excited Linear Prediction) vocoder. The real root method is that if polynomial equations have the real roots, we are able to find those and transform them into LSP. However, this method takes much time to compute, because the root searching is processed sequentially in frequency region. In this paper, to reduce the computation time of real root, we compare the real root method with two methods. In first method, we use the mal scale of searching frequency region that is linear below 1 kHz and logarithmic above. In second method, The searching frequency region and searching interval are ordered by each coefficient's distribution. In order to compare real root method with proposed methods, we measured the following two. First, we compared the position of transformed LSP (Line Spectrum Pairs) parameters in the proposed methods with these of real root method. Second, we measured how long computation time is reduced. The experimental results of both methods that the searching time was reduced by about 47% in average without the change of LSP parameters.

• Journal of Forest and Environmental Science
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• v.10 no.1
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• pp.8-24
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• 1994

Because of the underground existence of roots, a few studies have been reported on root system. The developmental information of roots should be understood for the studies of specific tree traits and the influence of such traits on the soil surface fixation. In order to clarify the specific character of pine forest in Kangwon Province, the investigation on the form and distribution of root system of pine trees were carried out for 5 trees in the Campus Forest, Kangwon National Univ.. Root form was very well in flat root. As soil depth was approximatly 50cm, fine roots were very sparsly distributed(+), roots of 0.2cm in diameter were most common and roots > 0.2cm were very rare, also thickness thined. 60~70% all the roots were developed at the depth of 0~30cm, where big roots were below 0.9cm in diameter and fine roots were higly sparse(+).

• Journal of Advanced Marine Engineering and Technology
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• v.17 no.3
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• pp.80-87
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• 1993

The various configuration of thin-shaped bevel gears are used usually for such as main reduction gear of the hovercraft. But the reasonable and concise guide to thedesign of the se bevel gears is not yet obtained, since the tooth of bevel gear has complex form. The purpose of these investigation is to be establish the design guide and to propose the desirable configuration form for thin-shaped straight bevel gear. In this report, the desirable configuration is examined experimentally by clearing up the effect of web and rim thickness, rim support condition upon the load distribution and root stress distribution along the tooth trace. The results are summarized as follows. (1) The crowning of tooth trace exerts a significant effect on the root stress distribution of thin-shaped bevel gear. (2) As the desirable configuration of the thin-shaped bevel gear, it is to be recommended that the rim is supported at the heel side of tooth trace. (3) But, as special type, it is desirable that the rim is supported at the toe side.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.5
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• pp.1-9
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• 1995

The purpose of this study is to develop a computer simulation program for analyzing load transmission characteristics of a helical gear system in design stage. In this analysis, the rotational delay, load distribution, root stress, and contact area are investigated. That is, the influence function of deflection is obtained by finite element analysis and the influence function of approach and gear tooth error are considered. Load distribution, rotational delay, and contact area are calculated by solving load-deflection equation which includes these influence functions and tooth error, and the influence function of the bending moment is obtained by finite element analysis. The root stress is calculated by the load distribution and the influence function of the bending moment. The results of the simulation are cross-checked through a specially designed experimental set-up.

• Journal of Ginseng Research
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• v.17 no.3
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• pp.219-223
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• 1993

Assessment of root weight grade system for the numeral definition in Korea ginseng was tried by investigation of 13 boxes of the 15-root-grade of 4-year-old white ginseng as a model. In this case satisfaction to theoretical value was 58% in root weight and 50% in root number. The coefficient of variation (CV) was high (35%) for individual root weight in package. The CV of tap root weight 1 among package is low (7.1%) even though there was no significant correlation between tap root weight : and lateral root weight among roots. The mean percentage of tap root to root weight in each package ranged 61 to 74% with CV range of 16.5 to 33.2%. The CV was not much different between 1st and 2nd lateral root weight and the means was above 60%. Strict practice of numeral definition of root weight grade system will be prerequisite for chemical standardization of Korea ginseng.

• Korean Journal of Medicinal Crop Science
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• v.7 no.3
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• pp.177-184
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• 1999

This study was carried out to find growth characters and distribution of above and underground in natural crossed population of Paeonia lactiflora Pallas. Sprouting time was 1 April to 15 April, and distribution of stem length ranged from 21 to 80cm, and 3 to 18 in stem number. Distribution of root length ranged from 12 to 59cm, root number per plant was 73 to 4, root yield per plant was highly varied by 37 to 882g, and larger root above 750g was occupied by 7.1%. Paeoniflorin content was 1.9 to 10.29% and plants containing higher paeoniflorin was 14.3%. Root length and yield had highly positive correlation. Root diameter and stem length was also positively correlated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.20-25
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• 1999

This experiment was conducted to elucidate the relation-ship between vertical distribution of rice roots and yield traits under field conditions. Eight IRRI's new plant type rices (NPTRs) were tested in a volcanic ash soil paddy field under dense (IO 10 cm) and common (20 20 cm) planting densities. These lines were evaluated to have more spikelet numbers per panicle (SNP), lower filled grain rate (FGR), and lower rough grain weight per hill (RGWH). In dense planting, rough grain weight per stem (RGWS) was increased due to heavier culm and leaf dry weight (CLDW), and both RGWS and CLDW were related with the percentage of root distribution (%RWI) in the 10~30 cm soil layer, while in common planting, RGWS was not closely related with CLDW. SNP was highly related with root dry weight (RDW) in the 0~10cm soil layer. FGR was mainly affected by ROW in the 10~30 cm soil layer under both planting densities. RGWS was positively correlated with top dry weight (TDW) and harvest index (HI), and TDW was positively correlated with RWI under common planting or %RWI under dense planting, and HI was positively correlated with RWI in the 10~30 cm soil layer only under dense planting. RGWS was closely related with root weight index by dry weight (RWI) in the 10~30 cm soil layer and %RWI in the 0~30 cm or 10~30 cm soil layer under dense planting, and with only RWI in the 10~30 cm soil layer under common planting. But RGWH showed the close positive relationship with RDW and RWI in the 10~30 cm soil layer under dense planting, while under common planting, it showed the close positive relationship with RWI and %RWI in the 10~30 cm soil layer or %RWI in the 0~30 cm soil layer. The deeper root system in rice, especially under dense planting, is important for high yield of NPTRs focusing on the increment of top mass production and harvest index.

• Journal of the Korean Statistical Society
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• v.36 no.4
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• pp.447-456
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• 2007

On the basis of marginal likelihood of the residual vector which is free of nuisance mean parameters, we propose new Lagrange Multiplier seasonal unit root tests in seasonal autoregressive process. The limiting null distribution of the tests is the standardized ${\chi}^2-distribution$. A Monte-Carlo simulation shows the new tests are more powerful than the tests based on the ordinary least squares (OLS) estimator, especially for large number of seasons and short time spans.