• The Korean Journal of Ecology
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• v.28 no.3
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• pp.163-168
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• 2005

This study was carried out to estimate above-ground biomass and inorganic nutrient distribution for a Camellia japonica stand located Mt. Cheon-gwan, Jeonnam province. Regression analysis of biomass for stem, current twig, branch and foliage versus diameter at breast height(DBH) was used to calculate regression equations of the form of logY = a + blogD(Y: component biomass, D: DBH). Total above-ground biomass for a Camellia japonica stand was 115.2 ton/ha(47.9 for main stem, 1.4 for current twig, 53.4 for live and dead branch, 5.6 for current foliage and 6.9 for ${\geq}1$-yr-old foliage). Component biomass was non-linearly correlated with DBH, and the difference in biomass between ${\geq}1$-yr-old and current foliage increased in proportion to DBH. Current foliage and live branch showed higher N, P and K concentrations compared to ${\geq}1$-yr-old foliage and dead branch, respectively. However, Ca concentration of current foliage and live branch was lower than that of ${\geq}1$-yr-old foliage and dead branch, respectively. Total above-ground inorganic nutrient contents(kg/ha) were distributed as follows; K: 366.4. N: 442.7, Ca: 433.3, Mg: 118.4, P: 50.5 and Na: 25.3. The proportions of inorganic nutrient content for live branch were generally the highest in all the inorganic nutrients.

• Korean Journal of Veterinary Service
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• v.32 no.2
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• pp.165-169
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• 2009

Suppuratives bronchopneumonia was found in a 3-month old domestic muskrat (Ondatra zibethicus). Dead muskrat showed hemorrhagic nasal discharge, severe hemorrhage and consolidation were observed in the lungs in necropsy. Histologically, severe polymorphic neutrophils and alveolar macrophages were infiltrated in the bronchus, bronchioles, alveoli. P. multocida and B. bronchiseptica were identified from the lungs, Klebsiella was isolated from the cecum. We demonstrated those organisms by biochemical test and confirmed P. multocida capsular type A by means of polymerase chain reaction (PCR).

• Journal of Forest and Environmental Science
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• v.34 no.6
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• pp.419-428
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• 2018

Spatial point-patterns analyses were conducted to provide insight into the ecological process behind competition and mortality in two lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands, one in the Lower Foothills, and the other in the Upper Foothills natural subregions in the boreal forest of Alberta, Canada. Spatial statistical tests were applied to live and dead trees and included Clark-Evans nearest neighbor statistic (R), nearest neighbor distribution function (G(r)), and a variant of Ripley's K function (L(r)). In both lodgepole pine plots, the results indicated that there was significant regularity in the spatial point-pattern of the surviving trees which indicates that competition has been a key driver of mortality and forest dynamics in these plots. Dead trees generally showed a clumping pattern in higher density patches. There were also significant bivariate relationships between live and dead trees, but the relationships differed by natural subregion. In the Lower Foothills plot there was significant attraction between live and dead tees which suggests mainly one-sided competition for light. In contrast, in the Upper Foothills plot, there was significant repulsion between live and dead trees which suggests two-sided competition for soil nutrients and soil moisture.

• Journal of Power Electronics
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• v.16 no.6
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• pp.2129-2138
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• 2016

The full-bridge inverter, widely used for single-phase photovoltaic grid-connected applications, presents a leakage current issue. Therefore, an AC bypass branch is introduced to overcome this challenge. Nevertheless, existing modulation strategies entail drawbacks that should be addressed. One is the zero-crossing distortion (ZCD) of the AC current caused by neglecting the AC filter inductor voltage. Another is that the system cannot deliver reactive power because the AC bypass branch switches at the power frequency. To address these problems, this work proposes an optimized hybrid modulation strategy. To reduce ZCD, the phase angle of the inverter output voltage reference is shifted, thereby compensating for the neglected leading angle. To generate the reactive power, the interval of the negative power output is calculated using the power factor. In addition, the freewheeling switch is kept on when power is flowing into the grid and commutates at a high frequency when power is fed back to the DC side. In this manner, the dead-time insertion in the high-frequency switching area is minimized. Finally, the performances of the proposed modulation strategy and traditional strategies are compared on a universal prototype inverter. Experimental results validate the theoretical analysis.

• Korean Journal of Veterinary Service
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• v.26 no.2
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• pp.135-144
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• 2003

Fowl typhoid is a septicemic disease of turkeys and chickens. The antigen is Salmonella(S) gallinarum, which cross-reacts with S pullorum because of common antigen. The organism is maintained in the ovary of carrier birds and transmitted vertically in the york. It is also transmitted horizontally through feces and broken eggs. The symptoms are weakness, drowsiness, wing drooping, hyperexcitability, paresis and diarrhea. In the many cases, the birds are found dead in the morning before any symptoms have been noticed. this experiment was carried out to investigate the characteristics of S gallanarum and scrutinized about the control systems. 1. Fowl typhoid was came about in the winter than the other seasons. The average of mortality was 46.3%. And it was came about not only adult poultry but also chicks. 2. S gallinarum was isolated from liver and spleen in infected chickens. Total isolated strains were 60. 3. The organisms were all extinct at 60$^{\circ}C$, 30mins. 4. A survival rate was higher in underground water than a secondary distilled water. It was detected in underground water until 30 days. 5. When being exposed to the solar light, it became extinct almost within 24 hours. 6. It was survived in a refrigerator until 12 months. 7. It was extinct among 5 mins in 0.1% phenol and 2% formalin. 8. When the cultured organism fluid was inoculated in SD-rat abdominal cavity, rat died within 24 hours. 9. Pullorum-typhoid related program must disciplines in order to destroy the fowl typhoid, and breeding system must be converted to cage system.

• Korean Journal of Veterinary Research
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• v.48 no.2
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• pp.139-143
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• 2008

We report here two cases of Rhodococcus (R.) equi-causing pneumonia of Throughbred foals in Gyeonggi-do in 2006. R. equi was isolated from the lung lesions of the dead foals, and from the feces and soils on the farms where the clinical cases of R. equi infection occurred. The isolates were characterized by biochemical properties, polymerase chain reaction for vapA gene and antimicrobial susceptibility. In drug susceptibility test, erythromycin, gentamycin, vancomycin, and rifampin were found to be the most susceptible for all isolates. These results suggest that R. equi pneumonia may be endemic in the horse-breeding farms in inland Korea and the farm environment may be widely contaminated with virulent R. equi.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2007.11a
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• pp.468-473
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• 2007

• Membrane and Water Treatment
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• v.7 no.4
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• pp.297-311
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• 2016

Modeling and simulation of air humidification by hollow fiber membrane contactors are investigated in the current study. A computational fluid dynamic model was developed by solving the k-epsilon turbulence 2D Navier-Stokes equations as well as mass conservation equations for steady-state conditions in membrane contactors. Finite element method is used for the study of the air humidification under different operating conditions, with a focus on the humidity density, total mass transfer flux and velocity field. There has been good agreement between simulation results and experimental data obtained from literature. It is found that the enhancement of air stream decreases the outlet humidity from 0.392 to 0.340 (module 1) and from 0.467 to 0.337 (module 2). The results also indicated that there has been an increase in air velocity in the narrow space of shell side compared with air velocity wide space of shell side. Also, irregular arrangement has lower dead zones than regular arrangement which leads to higher water flux.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.443-452
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• 1996

A study has been made to estimate biomass and NPP based on equation form of $Wt=aD^bH^c$ for Quercus variabilis and Quercus mongolica natural stands(Mean age; 67, 62yrs old) in Chungju. Equation form of $Wt=aD^bH^c$ was more adequate than $Wt=a(D^2H)^b$ and $Wt=aD^b$ for the estimation of the biomass and NPP. Individual biomass was compared using a paired t-test by tree component which showed no significant differences. Total aboveground biomass of Quercus mongolica was 130.6 t/ha and that of Quercus variabilis was 137.4 t/ha. Biomass of Q. mongolica was composed of foliage 5.1 t/ha(3.9%), dead branch 3.5 t/ha(2.7%), live branch 29.7 t/ha(23.0%), bolebark 16.2 t/ha(12.5%), and bolewood 74.9 t/ha(58.0%), and that of Q. variabilis was composed of foliage 3.8 t/ha(2.9%), dead branch 2.9 t/ha(2.2%), live branch 24.3 t/ha(18.4%), bolebark 20.4 t/ha(15.5%), and bolewood 80.4 t/ha(61.0%). Net primary production was 10.0 t/ha/yr in the Q. mongolica stand and 8.6 t/ha/yr in the Q. variabilis stand, respectively. Net primary production of Quercus forest in Chungju was very close to the mean NPP of the broadleaved forest of temperate zone.

• Structural Monitoring and Maintenance
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• v.4 no.1
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• pp.17-31
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• 2017

Since extensometers are used to determine the absolute deformation of foundation and abutments and all results are obtained in reference to the base rod, the accuracy of these results has been constantly a subject of debate. In this regard, locating and installing extensometers outside the range of effect zone is also another challenge. The main purpose of this paper is to investigate and modify extensometers results based on the mentioned issues. For this aim, the concrete RCC Zhaveh dam in Iran was selected as the case study. To study the results of extensometers installed in this dam, first, the 3DEC_DP 5.00 software was applied for numerical modeling. Parameters such as discontinuities, dead load and piezometric pressure in the interface of concrete and rock were considered. Next, using the results obtained from 6 extensometers in foundation and abutments and 4 clinometers in dam body, the numerical model was calibrated through back analysis method. The results indicate that the base rod is moved and is not recommended being used as the base point. In other words, because installation of base anchor outside the range of effect zone is not possible due to the operational and economic considerations, the obtained results are not accurate enough. The results indicate a considerable 2-3 mm displacement of the base rod (location of the base anchor) in reference to the real zero point location, which must be added to the base rod results.