• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.380-391
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• 1993

The experimental study was made to propose the treatment method of wastewater in the high-density fish culture system. The BOD to COD ratios of effluents were almost same to 0.65 in the eel-farm, but were various in the farm rearing together with tilapia etc. A BOD rate curve of the eel-farm effluent could be described mathematically by the equation, $BODu=14.1(1-10^{-0.222t})+30.9(1-10^{-0.035(t-8)})$. Nitrification in Biological Fluidized Bed(BFB) system to treat the fish-farm wastewater could be reduce ammonium level up to $65{\sim}79\%$ when ammonium loading rates were between 0.014 and 0.075g $NH_4/g$ BVS-day. Nitrification efficiency was decreased by organic matters in the wastewater when ammonium loading was low(0.014 g $NH_4/g$ BVS-day). T-N removal ratios were decreased to increase loading in denitrification process, because of low C/N ratio. Based on much higher biological mass concentrations, BFB system takes many advantages of a practical viewpoint, such as stability of treatment efficiency and reduction of necessary site area for the facility, as compared with conventional treatment systems.

• Current Research on Agriculture and Life Sciences
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• v.8
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• pp.129-138
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• 1990

This study investigated the relationship between the cutflow of rural population and agricultural policy by using time series method. For the analytical tools, decomposition time series methods and regression technique were employed in computing seasonal fluctuation and cyclical fluctuation of population migration. Also, this study predicted farmhouse, rural population till the 2000's by means of the mathematical methods. The analytical forms employed in forecasting farmhouse, rural population were Exponential curve, Gompertz curve and Transcendental form. The major findings of this study were identified as follows: 1) Rural population and farmhouse population began to decrease from 1965 and hastily went down since 1975. Rural population which accounted for 36.4 percent, 35.6 percent of national population respectively in 1960 diminished about two times: 17.5 percent, 17.1 percent respectively. 2) The rapid decreasing of the rural population was caused because of the outflow of rural people to the urban regions. Of course, that was also caused from the natural decreases but the main reason was heavily affected more the former than the latter. In the outflowing course shaped from rural to the urban regions, rural people concentrated on such metropolis as Seoul, Pusan, Keanggi. But these trends were diminishing slowly. On the other hand, compared with that of the 1970's the migration to Keanggi was still increasing in the 1980's. That is, people altered the way of migration from the migration to Seoul, Pusan to the migration to the out-skirts of Seoul. 3) The seasonal fluctuation index of population migration has gone down since the June which the request of agricultural labor force increases and has turned to be greatly wanted in the March as result of decomposition time series method. As result of cyclical analysis, the cyclical patterns of migration have greatly 7 cycle. 4) As result of forecasting the rural and farmhouse population, rural and farmhouse population in the 2000 will be about 9,655(thousand/people) and 4,429(thousand/people) respectively. Thus, it is important to analyze the probloms that rural and farmhouse population will decrease or increase by the degree. But fairly defining the agricultural into a industry that supply the food, this problem - how much our nation need the rural and farmhouse population - is greatly significant too. Therefore, the basic problems of the agricultural including the outflows of rural people are the earning differentials between rural and urban regions. And we should regard the problems of the gap of relative incomes between rural and urban regions as the main task of the agricultural policy and treat the agricultural policy in the viewpoint of developing economic equilibrium than efficiency by using actively the natural resources of the rural regions.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.1159-1166
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• 2009

The use of cone-beam computed tomography(CBCT) has been proposed for guiding the delivery of radiation therapy. A kilovoltage imaging system capable of radiography, fluoroscopy, and cone-beam computed tomography(CT) has been integrated with a medical linear accelerator. A standard clinical linear accelerator, operating in arc therapy mode, and an amorphous-silicon (a-Si) with an on-board electronic portal imager can be used to treat palliative patient and verify the patient's position prior to treatment. On-board CBCT images are used to generate patient geometric models to assist patient setup. The image data can also, potentially, be used for dose reconstruction in combination with the fluence maps from treatment plan. In this study, the accuracy of Hounsfield Units of CBCT images as well as the accuracy of dose calculations based on CBCT images of a phantom and compared the results with those of using CT simulator images. Phantom and patient studies were carried out to evaluate the achievable accuracy in using CBCT and CT stimulator for dose calculation. Relative electron density as a function of HU was obtained for both planning CT stimulator and CBCT using a Catphan-600 (The Phantom Laboratory, USA) calibration phantom. A clinical treatment planning system was employed for CT stimulator and CBCT based dose calculations and subsequent comparisons. The dosimetric consequence as the result of HU variation in CBCT was evaluated by comparing MU/cCy. The differences were about 2.7% (3-4MU/100cGy) in phantom and 2.5% (1-3MU/100cGy) in patients. The difference in HU values in Catphan was small. However, the magnitude of scatter and artifacts in CBCT images are affected by limitation of detector's FOV and patient's involuntary motions. CBCT images included scatters and artifacts due to In addition to guide the patient setup process, CBCT data acquired prior to the treatment be used to recalculate or verify the treatment plan based on the patient anatomy of the treatment area. And the CBCT has potential to become a very useful tool for on-line ART.)

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.2
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• pp.113-124
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• 2005

Purpose : The using of endo-rectal balloon has proposed as optimal method that minimized the motion of prostate and the dose of rectum wall volume for treated prostate cancer patients, so we make the customized rectal balloon device. In this study, we analyzed the efficiency of the Self-customized rectal balloon in the aspects of its reproducibility. Materials and Methods : In 5 patients, for treatment planning, each patient was acquired CT slice images in state of with and without rectal balloon. Also they had CT scanning samely repeated third times in during radiation treatment (IMRT). In each case, we analyzed the deviation of rectal ballon position and verified the isodose distribution of rectum wall at closed prostate. Results : Using the rectal balloon, we minimized the planning target volume (PTV) by decreased the internal motion of prostate and overcome the dose limit of radiation therapy in prostate cancer by increased the gap between the rectum wall and high dose region. Conclusion : The using of rectal balloon, although, was reluctant to treat by patients. View a point of immobilization of prostate internal motion and dose escalation of GTV (gross tumor volume), its using consider large efficients for treated prostate cancer patients.

• Korean Chemical Engineering Research
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• v.48 no.3
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• pp.391-396
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• 2010

In this research the characteristics of ammonia removal from malodorous waste-air were investigated under various operating condition of biofiilter packed with equal volume of rubber media and compost for the efficient removal of ammonia, representative source of malodor frequently generated at compost manufacturing factory and publicly owned facilities. Then the optimum conditions were constructed to treat waste-air containing ammonia with biofilter. Biofilter was run for 30 days(experimental frequency of 2 times/day makes 60 experimental times.) with the ammonia loading from $2.18g-N/m^3/h$ to $70g-N/m^3/h$ at $30^{\circ}C$. The ammonia removal efficiency reached almost 100% for I through IV stage of run to degrade up to the ammonia loading of $17g-N/m^3/h$. However the removal efficiency dropped to 80% when ammonia loading increased to $35g-N/m^3/h$, which makes the elimination capacity of ammonia $28g-N/m^3/h$ for V stage of run. However, the removal efficiency remained 80% and the maximum elimination capacity reached $55g-N/m^3/h$ when ammonia loading was doubled $70g-N/m^3/h$ for VI stage of run. Thus the maximum elimination capacity exceeded $1,200g-N/m^3/day$(i.e., $50g-N/m^3/h$) of the experiment of biofilter packed with rock wool inoculated with night soil sludge by Kim et al.. However, the critical loading did not exceed $810g-N/m^3/day$ (i.e., $33.75g-N/m^3/h$) of the biofilter experiment by Kim et al.. The reason to exceed the maximum elimination capacity of Kim et al. may be attributed to that the rubber media used as biofilter packing material provide the better environment for the fixation of nitrifying and denitrification bacteria to its surface coated with coconut based-activated carbon powder and well-developed inner-pores, respectively.

• Korean Chemical Engineering Research
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• v.52 no.4
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• pp.503-515
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• 2014

A lot of existing wastewater treatment plants (WWTPs) are rebuilt or retrofitted for advanced wastewater treatment processes to cope with reinforced effluent criteria of nitrogen and phosphorous. Moreover, how to treat the wasted sludge from WWTPs has been also issued since the discharge of the wasted sludge into ocean is impossible from 2011 due to the London Convention 97 protocol. These trend changes of WWTPs get a motivation to assess environmental and economic impacts from the construction stage to the waste stage in WWTPs. Therefore, this study focuses on evaluation of environmental and economic impacts of the advanced wastewater treatment processes and waste sludge treatment process by using life cycle assessment. Four advanced wastewater treatment processes of Anaerobic/Anoxic/Oxic ($A_2O$), 5 stages-Bamard Denitrification Phosphate (Bardenpho), Virginia Initiative Plant (VIP), and Modified University of Cape Town (MUCT) are chosen to compare the conventional activated sludge (CAS) and three waste sludge treatment methods of land fill, incineration, and composting are used. To evaluate environmental and economic impacts of each advanced wastewater treatment processes, life cycle assessment (LCA) and life cycle cost (LCC) are conducted based on International organization for standardization (ISO) guidelines. The results clearly represent that the $A_2O$ process with composting shows 52% reduction in the environmental impact than the CAS process with landfill. On the other hand, the MUCT process with composting is able to save 62% of the life cycle cost comparing with the CAS process with landfill. This result suggested the qualitative and quantitative criteria for evaluating eco-environmental and economic technologies of advanced treatment processes and also sludge treatment method, where their main influence factors on environmental and economic impacts are analyzed, respectively. The proposed method could be useful for selecting the most efficient and eco-friendly wastewater treatment process and sludge treatment method when retrofitting the existing WWTPs to advanced treatments.

• Resources Recycling
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• v.18 no.5
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• pp.52-62
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• 2009

This research was carried out to formulate environmentally friendly wood preservatives with okara and to investigate the effects of the acid concentration used for the hydrolysis of okara and salt type on the decay resistance of the preservatives. Okara-based preservatives were formulated with okara hydrolyzates, which were prepared with 0, 1%, and 2% sulfuric acid at $25^{\circ}C$ for 1 hr, and salts such as copper chloride and/or sodium borate. The preservatives were treated into wood blocks by vacuum-pressure method, and then the treated wood blocks were leached in $70^{\circ}C$ hot water for 72 hrs. The fungal treatments of the leached wood blocks were conducted by brown-rot fungus, Tyromyces palustris, and white-rot fungus, Trametes versicolor, to examine the decay resistance of the preservatives. As the acid concentration used for hydrolysis of okara increased, the treat-ability and decay resistance of the preservatives were improved, which the leachability was decreased. Wood blocks treated with the okara/copper or okara/copper/borax, showed very good decay resistance against T. palustris and T. versicolor. However, wood blocks treated with the okara/borax and okara-free preservative solutions, were observed the fungal decay by T. palustris. The optimal conditions for the preparation of okara-based wood preservatives were formulated with okara hydrolyzed with 1% sulfuric acid, copper chloride and borax.

• Sijohaknonchong
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• v.26
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• pp.25-54
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• 2007

This paper examines the literatherapy effects of Korea's oldest form of literature, Sijo, and its role in the future of literatherapy. Since literature is the expression of human emotions, and therapy is related to medicine, the two seem to have little in common, but they share the function of resolving conflicts. The effectiveness of literatherapy has only recently become a matter of discussion. However, literatherapy is greatly involved with the utility value of literature, and should be taken seriously. This research focused on the literatherapy function of the 16th-17th century Gangho-Sijo. Gangho-Sijo was created by literary men from the Sarim-school, who were removed from their posts in the government due to a massacre(Sawha) and rianly(Dangjaing), and spent most of their time away from politics. Their Sijo were mostly about life in retreat, and their mental state at that time. In relation to literatherapy, the mentality and attitudes of these scholars can be divided into three stages. The first is anxiety and depression, the second tranquility and harmony. and the third serenity. At the final stage, the scholars are liberated from worldly desires. Each of these phases hold the effect of literatherapy. The first stage can relate to 'theory of purgation', ISO-Prinsip, which is based on 'like cures like' which means to treat something with its own kind Fight fire with fire. The second step involves 'theory of purification', and by balancing his emotions, the scholar can achieve mental stability. In the final stage, literatherapy is acquired when the scholar expresses his emotions in a clarification(theory of clarification). At this phase, literatherapy finally has an effect, while the phase itself functions as literatherapy as well. The study of literatherapy is still at its early stages, thus has many limitations. However, literatherapy has bright prospects, and it is my hope that this report will be used as a reference for its further research.

• Journal of Soil and Groundwater Environment
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• v.13 no.4
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• pp.30-39
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• 2008

The uranium removal efficiency of rhizofiltration was investigated in lab scale experiment. Three plants such as sunflower (Helianthus annuus L.), bean (Phaseolus vulgaris var.), and Indian mustard (Brassica juncea (L.) Czern.) were cultivated in artificially contaminated solution by uranium at 30 ${\mu}g$/L and 80 ${\mu}g$/L for 72 hours. The removal efficiencies of three cultivars were calculated from the ICP/MS analysis of uranium mass in solution and the plant. For Helianthus annuus L., more than 80% of initial uranium were removed from the solution and the uranium concentration of residual solution maintained lower than 10 ${\mu}g$/L. For Phaseolus vulgaris var. and Brassica juncea (L.) Czern., their uranium removal efficiencies ranged from 60 to 80%. Even the uranium concentration of solution was higher than 500 ${\mu}g$/L, these cultivars removed more than 70% of initial uranium by rhizofiltration, suggesting that the rhizofiltration has a great capability to remove uranium in the contaminated groundwater. The removal efficiency of rhizofiltration by using Brassica juncea (L.) Czern decreased from 83% to 42% with the increase of pH in solution. From the results of the analysis for the uranium accumulation in plants, 99% of uranium transferred into the plant from solution were accumulated in the root and only 1% of uranium existed in the shoot part (including leaves), suggesting that the cost and the time to treat massive grown plants after the rhizofiltration could be dramatically cut down because only their root parts needs to be treated. Finally, the genuine groundwater having high uranium concentration (81.4 ${\mu}g$/L), sampled from Daejoun area, was used in the experiment. The uranium removal efficiency of Helianthus annuus L. for the real groundwater was higher than 95%, investigating that the rhizofiltration is the very useful method to remediate uranium contaminated groundwater.

• Radiation Oncology Journal
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• v.17 no.4
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• pp.321-328
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• 1999

Purpose : Total body irradiation (TBI) or whole body irradiation is used to acquire immune suppression, to treat malignant lymphoma and leukemia, and as an conditioning regimen for bone marrow transplantation. For these purposes, many methods were developed to obtain homogenous dose distribution. The objective of this study was to analyze and confirm the accuracy and the homogeneity of the treatment setup, the parallel opposed lateral technique, currently used in Seoul National University Hospital. Materials and Metheods : Surface dose data, measured with a thermoluminescent dosimeter, of 8 patients among 10 patients, who were given total body irradiation with the parallel opposed lateral technique between September 1996 to August 1998, at Seoul National University Hospital were analyzed. Surface doses were measured at the head, neck, axilla, thigh, and ankle level. Surface and midline doses were measured with similar set-up and technique in the Humanoid phantom. Results : Measured surface doses relative to prescribed dose for the head, neck, axilla, thight, and ankle leve were $91.3{\pm}7.8,{\;}98.3{\pm}7.5,{\;}95.1{\pm}6.3,{\;}98.3{\pm}5.5$, and $95.3{\pm} 6.3\%$, respectively. The midline doses of the head, neck, axilla, thigh, and ankle level estimated from the surface-to-midline ratios in the Humanoid Phantom were $103.4{\pm}9.0,{\;}107.8{\pm}10.5,{\;}91.1{\pm}6.1,{\pm} 93.8{\pm}4.5,{\;}and{\;}104.5{\pm}9.3\%$, respectively. Measured surface doses and estimated midline doses ranged from $-8.9\%$ to $+7.8\%$. Midline doses at the neck and the axilia level deviated more than $5\%$ from the prescribed doses. The difference of the estimated midline doses at the neck and the axilla level and the actual doses were attributed to the thickness differences between the Humanoid phantom and the patients. Conclusion Distribution of the midline doses as well as the suface doses were measured to be within $-8.7\~{\pm}7.8\%$ range. Actual dose distribution in the patient is expected to be better than the measured dose range mainly attributed to thickness difference between the patient and the Humanoid phantom.