• Korean Journal of Environment and Ecology
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• v.22 no.2
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• pp.173-183
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• 2008

This research was aimed at looking into the vegetation structure of Abies holophylla forest distributed between Iljumun of Woljeong Temple and Keumgang bridge in Odaesan National Park. It was found that existed a total of 977 tree of Abies holophylla which are more than 20cm in DBH within the target site, and in 2006 when the survey was made, the number of fallen trees and poor growth trees was about 96, accounting for 9.8% of all. The age of Abies holophylla ranged from 41 years to 135 years($11\sim82cm$ in DBH). The number of Abies holophylla over 100cm in DBH was 8 and the largest Abies holophylla was 175cm in DBH and 31m in height. Its density was 5.9 individuals per $400m^2$. As a result of the analysis of the plant community structure using the TWINSP AN classification, Abies holophylla was divided into four community types. Firstly, Pinus densiflora-Abies holophylla community was predicted to vary into Abies holophylla community. In case of other three other communities, Abies holophylla communities were predicted to compete with deciduous broadleaf trees, such as Tilia amurensis and Acer pictum subsp. mono. Abies holophylla forest adjacent to Woljeong Temple of Odaesan National Park has a high value as sustainable resources for culture, landscape and tourism. Thus, it is necessary to clarify the reason for the incidence of poor growth trees and fallen trees among all trees of Abies holophylla and take counter-measures against it for the preservation and management of Abies holophylla forest. In addition, a more aggressive managrment like getting rid of the deciduous broadleaf trees, such as Tilia amurensis and Acer pictum subsp. mono, which appear mostly on understory layer or shrub layer within Abies holophylla, and continuous management is also needed for the young trees of Abies holophylla which are feared to be pressurized outside from their neighboring trees because their initial growth after germination is very slow.

• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.230-251
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• 2017

According to the survey on higher fungi from 2009 to 2011 and also in 2015 in Byeonsanbando National Park, a total of 2 division, 6 class, 18 orders, 61 families, 157 genera and 323 species were observed. In case of Agaricales, there were 23 families, 67 genera and 153 species; Boletales, there were 6 families, 27 genera and 45 species; Russulales, there were 3 family, 4 genera and 40 species; Polyporales, there were 6 family, 21 genera, 28 species. Thus, most of them belonged to the following 4 orders: Agaricales, Russulales, Boletales and Polyporales. Dominant species belonged to Boletaceae (37 species), Russulaceae (36 species), Agaricaceae (28 species) and Amamtaceae (25 species). For the habitat environment, the ectomycorrhizal mushrooms were 40.2% (poisonous mushrooms, 46 species; edible & medicinal mushrooms, 51 species; unknown edible & poisonous mushrooms, 26 species), litter decomposing and wood rotting fungi 35.3%(poisonous mushrooms, 10 species; edible & medicinal mushrooms, 52 species; unknown edible & poisonous mushrooms, 46species), grounding Fungi 22.3%(poisonous mushrooms, 8 species; edible & medicinal mushrooms, 31 species; unknown edible & poisonous mushrooms, 29 species). Monthly, most of poisonous mushrooms, edible & medicinal mushrooms and unknown edible & poisonous mushrooms were found in July and August. In terms of altitude, the most species were observed at 1~99m and the populations dropped by a significant level at an altitude of 200m or higher. It seemed that the most diversified poisonous mushrooms, edible & medicinal mushrooms and unknown edible & poisonous mushrooms occurred at climate conditions with a mean air temperature at $24.0{\sim}25.9^{\circ}C$, the highest air temperature at $28.0{\sim}29.9^{\circ}C$, the lowest air temperature at $20.0{\sim}21.9^{\circ}C$, a relative humidity at 77.0~79.9% and a rainfall of 300.0~499.9mm.

• Journal of Bio-Environment Control
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• v.12 no.1
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• pp.45-53
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• 2003

The object of this study was to develop the control technology of daily integral photosynthetic photon flux (PPF) by the artificial lighting and shading screen in greenhouse. The shading time needed to get the target PPF by using two types of shading screens having shading ratio of 55% and 85% was analyzed. The results showed the shading ratio of screen to be installed in greenhouse should be different depending on the amount of target PPF to be controlled. The PPF control experiment by using the 55% shading screen in July and August showed that the maximum difference between measured and calculated value was about 5 mol$.$ $m^{-2}$ $.$ $d^{-1}$ in no shading condition. This difference is satisfactory result because the daily integral PPF is quite different depending on the weather condition. The simulation result about PPF distribution pattern shortened the time needed to find the proper arrangement of artificial lightings in greenhouse. But the further study was required to find the supplemental lighting arrangement to be able to provide the exactly uniform distribution of target light intensity. The supplemental irradiation time needed to acquire the target daily integral PPF for different supplemental light intensities, weather conditions, and months was analyzed. The result showed that the supplemental light intensity should be decided depending on the amount of target PPF to be controlled. The result of PPF control experiment conducted by using 55% shading screen and 300 $\mu$mol$.$ $m^{-2}$ $.$ $s^{-1}$ supplemental light intensity from the end of May to the beginning of June showed that the maximum difference between target and measured value was about 3 mol$.$ $d^{-1}$ $.$ $m^{-2}$ . If we consider that the difference of the daily integral PPF depending on weather condition was the maximum 30 mol$.$ $m^{-2}$ $.$ $d^{-l}$, the control effect was acceptable. Although the result of this study was the PPF control technology to grow lettuce, the data and control method obtained could be employed for other crop production.n.

• Journal of Bio-Environment Control
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• v.18 no.2
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• pp.148-152
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• 2009

Numerous studies have presented evidence that global atmospheric carbon dioxide ($CO_{2}$ ) concentration and temperature is increasing every year. Both of the $CO_{2}$ and temperature are important components for photosynthesis activity of plants and thusgrowth and yield. However, little information is available in terms of the reaction of vegetable plants to increased $CO_{2}$ concentration and temperature, and also the reaction to a complex condition of both increased $CO_{2}$ concentration and temperature. The aim of this research was therefore to investigate changes in growth, photosynthetic activity and ultra-cellular structure of leaf tissue of Chinese cabbage. Plants were grown under either of elevated $CO_{2}$ concentration (elevated $CO_{2}$, 2-fold higher than atmospheric $CO_{2}$ ) or elevated temperature (elevated temp, 4$^{\circ}C$ higher than atmospheric temperature), under both of elevated $CO_{2}$ concentration and elevated temperature (elevated temp+$CO_{2}$), and under atmospheric $CO_{2}$ concentration and temperature (control). The treatment of 'elevated temp' negatively affected leaf area, fresh weight, chlorophyll and starch content. However, when the treatment of 'elevated temp' was applied coincidently with the treatment of 'elevated $CO_{2}$', growth and photosynthetic performance of plants were as good as those in the treatment of 'elevated $CO_{2}$', Microscopic study resulted that the highest starch content and density of cells were observed in the leaf tissue grown at the treatment of 'elevated $CO_{2}$', whereas the lowest ones were observed in the leaf tissue grown at the treatment of 'elevated temp'. These results suggest that when Chinese cabbage grows under a high-temperature condition, supplement of $CO_{2}$ would improve the growth and yield. In our knowledge, it is the first time to determine the effect of a complex relationship between the increased $CO_{2}$ concentration and temperature on the growth of Chinese cabbage.

• Progress in Medical Physics
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• v.7 no.1
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• pp.65-77
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• 1996

Using the 2-D and 3-D Hoffman brain phantom, 3-D Jaszczak phantom and Single Photon Emission Computed Tomography, the effects of data acquisition parameter, attenuation, noise, scatter and reconstruction algorithm on image quantitation as well as image quality were studied. For the data acquisition parameters, the images were acquired by changing the increment angle of rotation and the radius. The less increment angle of rotation resulted in superior image quality. Smaller radius from the center of rotation gave better image quality, since the resolution degraded as increasing the distance from detector to object increased. Using the flood data in Jaszczak phantom, the optimal attenuation coefficients were derived as 0.12cm$\^$-1/ for all collimators. Consequently, the all images were corrected for attenuation using the derived attenuation coefficients. It showed concave line profile without attenuation correction and flat line profile with attenuation correction in flood data obtained with jaszczak phantom. And the attenuation correction improved both image qulity and image quantitation. To study the effects of noise, the images were acquired for 1min, 2min, 5min, 10min, and 20min. The 20min image showed much better noise characteristics than 1min image indicating that increasing the counting time reduces the noise characteristics which follow the Poisson distribution. The images were also acquired using dual-energy windows, one for main photopeak and another one for scatter peak. The images were then compared with and without scatter correction. Scatter correction improved image quality so that the cold sphere and bar pattern in Jaszczak phantom were clearly visualized. Scatter correction was also applied to 3-D Hoffman brain phantom and resulted in better image quality. In conclusion, the SPECT images were significantly affected by the factors of data acquisition parameter, attenuation, noise, scatter, and reconstruction algorithm and these factors must be optimized or corrected to obtain the useful SPECT data in clinical applications.

• Progress in Medical Physics
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• v.15 no.4
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• pp.202-209
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• 2004

Flat panel based digital radiography (DR) systems have recently become useful and important in the field of diagnostic radiology. For DRs with amorphous silicon photosensors, CsI(TI) is normally used as the scintillator, which produces visible light corresponding to the absorbed radiation energy. The visible light photons are converted into electric signal in the amorphous silicon photodiodes which constitute a two dimensional array. In order to produce good quality images, detailed behaviors of DR detectors to radiation must be studied. The relationship between air exposure and the DR outputs has been investigated in many studies. But this relationship was investigated under the condition of the fixed tube voltage. In this study, we investigated the relationship between the DR outputs and X-ray in terms of the absorbed energy in the detector rather than the air exposure using SPEC-l8, an X-ray energy spectrum model. Measured exposure was compared with calculated exposure for obtaining the inherent filtration that is a important input variable of SPEC-l8. The absorbed energy in the detector was calculated using algorithm of calculating the absorbed energy in the material and pixel values of real images under various conditions was obtained. The characteristic curve was obtained using the relationship of two parameter and the results were verified using phantoms made of water and aluminum. The pixel values of the phantom image were estimated and compared with the characteristic curve under various conditions. It was found that the relationship between the DR outputs and the absorbed energy in the detector was almost linear. In a experiment using the phantoms, the estimated pixel values agreed with the characteristic curve, although the effect of scattered photons introduced some errors. However, effect of a scattered X-ray must be studied because it was not included in the calculation algorithm. The result of this study can provide useful information about a pre-processing of digital radiography.

• Progress in Medical Physics
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• v.24 no.4
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• pp.278-283
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• 2013

Breast cancer is the leading cause of cancer death in women worldwide and the number of women breast cancer patient was increased continuously. Most of breast cancer patient has suffered from unnecessary radiation exposure to heart, lung. Low radiation dose to the heart could lead to the worsening of preexisting cardiovascular lesions caused by radiation induced pneumonitis. Also, several statistical reports demonstrated that left-sided breast cancer patient showed higher mortality than right-sided breast cancer patient because of heart disease. In radiation therapy, Deep Inspiration Breath Hold (DIBH) technique which the patient takes a deep inspiration and holds during treatment and could move the heart away from the chest wall and lung, has showed to lead to reduction in cardiac volume and to minimize the unnecessary radiation exposure to heart during treatment. In this study, we investigated the displacement of heart using DIBH CT data compared to free-breathing (FB) CT data and radiation exposure to heart. Treatment planning was performed on the computed tomography (CT) datasets of 10 patients who had received lumpectomy treatments. Heart, lung and both breasts were outlined. The prescribed dose was 50 Gy divided into 28 fractions. The dose distributions in all the plans were required to fulfill the International Commission on Radiation Units and Measurement specifications that include 100% coverage of the CTV with ${\geq}95%$ of the prescribed dose and that the volume inside the CTV receiving >107% of the prescribed dose should be minimized. Scar boost irradiation was not performed in this study. Displacement of heart was measured by calculating the distance between center of heart and left breast. For the evaluation of radiation dose to heart, minimum, maximum and mean dose to heart were calculated. The present study demonstrates that cardiac dose during left-sided breast radiotherapy can be reduced by applying DIBH breathing control technique.

• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.14-30
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• 1998

Manganese is an essential element in the body. It is mainly deposited in the liver and to a lesser degree in the basal ganglia of the brain and eliminated through the bile duct. Rapid turnover of managanese in the body makes it difficult to evaluate the manganese exposure in workers, esecially in those with irregular or intermittent exposure, like welders. Therefore, conventional biomarkers, including blood and urine manganese can provide only a limited information about the long-tern or cumulative exposure to manganese. Introduction of magnetic resonance imaging (MRI) made a progress in the assessment of manganese exposure in the medical conditions related to manganese accumulation, e. g. hepatic failure and long-term total parenteral nutrition. Manganese shortens spin-lattice(T1) relaxation time on MRI due to its paramagnetic property, resulting in high signal intensity (HSI) on T1-weighted image(T1W1) of MRI. Manganese deposition in the brain, therefore, can be visualizedas an HSI in the globus pallidus, the substantia nigra, the putamen and the pituitary. clinical and epidemiologic studies regarding the MRI findings in the cases of occupational and non-occupational manganese exposure were reviewed. relationships between HSI on T1W1 of MRI and age, gender, occupational manganese exposure, and neurological dysfunction were analysed. Relationships betwen biological exposure indices and HSI on MRE werealso reviewed. Literatures were reviewed to establish the relationships between HSI, Manganese deposition in the brain, pathologic findings, and neurological dysfunction. HSI on T1W1 of MRI reflects regional manganese deposition in the brain. This relationship enables an estimation of regional manganese deposition in the brain by analysing MR signal intensity. Manganese deposition in the brain can induce a neuronal loss in the basal ganglia but functional abnormality is supposed to be related to the cumulative exposure of manganese in the brain, use of brain MRI for the assessment of exposure in a group of workers seems to be hardly rationalized, while ti can be a useful adjunct for the evaluation of manganese exposure int he cases with suspected manganese-related health problems.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.1
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• pp.89-96
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• 1999

Some of the information concerning sexual function in the male diabetes has been focused upon the problems of endocrine or semen parameters. However, the characteristics of acrosome reaction and spermatozoa concentration at the epididymis and vas deferens have scarcely been studied, and the causes of the infertility has not been critically identified. So, we designed to inspect the spermatozoa concentration and the characteristics of acrosome reaction at epididymis and vas deferens of diabetic Wistar rat induced by streptozotocin (STZ, 70 mg/kg, ip). Experimental animal was sacrificed at 3 days and 14 days after the STZ injection. In the diabetes-induced rat, the levels of insulin and glucose had a pattern of inverse proportion. The spermatozoa concentrations in caput and corpus epididymis were significantly decreased in all diabetic condition. In cauda epididymis, however, there was significant decrease in sperm concentration at 14 days onward. In diabetic rat, the spontaneous reaction rate of spermatozoa of cauda and vas deferens were significantly higher than the control group. The ARIC (acrosome reaction to ionophore challenge) value of caudal sperm was 28.7 at control, 22.1 at 3 days, and 8.3 at 14 days. In the present study the spermatozoa concentration was decreased and the spontaneous reaction rate was increased by diabetes. In ARIC-test, it is revealed that the fertility of spermatozoa of 14 days group was lower than control or 3 days group. Diabetes mellitus may be provoke the decreased fertilization rate and subsequent infertility and subsequent infertility.

• Korean journal of applied entomology
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• v.3
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• pp.31-39
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• 1964

The authors studied on the bionomics of the Florida wax scale, Ceroplastes floridensis Comstock and bionomics of two kind of parasites which attack on this Florida wax scale in 1963 to 1964. 1. Ceroplastes floridensis Comstock was heavily infested on the persimmon tree planted in the southern part of Korea, specially at the center of Taegu city. Parasitic ratio of important parasite of Ceroplastes floridensis Comstock, Microterys clauseni was $66.67\%$ and appeared low parasited ratio at the center of the city. 2. The developed eggs of the Ceroplastes floridensis Comstock was appear며 from mid-May to early July. The peak of it was late-May to early June. Average stored eggs inside of a body is 2030. $2030.77\pm0.49.$. 3. The hatching period of the Ceroplastes floridensis Comstock begins from early June to early July. Mid-June was the peak period of it. Pupation period of the male was August 14 to September 7 and adult was emerged on August 20 to September 8. Mean longevity for adult male was 3 days in August but 4 days in September. 4. On the differences of the body- length parasited on the three host plants, persimmon, platanus, and trifoliate orange, the body length parasited on the persimmon was the largest, medium on platanus and the smallest on the trifoliate orange. 5. Microterys clauseni H. Compere parasite on tile Ceroplastes floridensis Comstock with 5 generations in a year. Hibernate in the body of the host as tan·at stage. The first adult appears in middle April. Fifteen days was required for one generation in $21^{\circ}$. The authors observed on the form ovary, female with 6 ovarioles, and mean number of eggs per female was $47.19\pm0.55$. 6. On the parasited individuals of the Microterys clauseni H. Compere a larva was the most numerous and was found 2 individuals or 4 individuals parasite on the one Ceroplastes floridensis Comstock. 7. Coccophagus app. parasited on the only male body of the Ceroplastes floridensis Comstock. The parasitic ratio was $14.831\%$ on persimmon tree in Taegu city.