• Journal of the Korean GEO-environmental Society
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• v.12 no.10
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• pp.39-49
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• 2011

Recently PBD method, one of acceleration of consolidation methods is used in the soft ground to shorten consolidation time for fast settlement during construction. It is economical and easy to work. Discharge capacity of PBD is sensitive in proportion to thickness of soft ground layer, and drainage of PBD declines due to disturbance effect in surrounding ground by mandrel used for vertical drainage setting and setting machines and type. Also, deviation of discharge capacity is large according to ground condition, construction condition and soil properties. In addition, when embankment loading is not conducted instantly after PBD setting due to rain or lack of embankment material supply, it causes leaving period problems. But cause and analysis of those problems for discharge capacity is lack. So, in this test, ground improvement and discharge capacity is investigated by implementing composite discharge capacity test for analysis of an effect factor of PBD discharge capacity with leaving period. After fixing the vertical drain on a cylindrical cylinder, put churned sample into the cylinder. Then leave 0day, 30day, 60day and 90day. And then, load following the loading step of 30, 70 and 120kPa using a pressure device. As a result, the longer leaving period, discharge capacity is reduced. It is caused by a decrease of discharge area caused by creep transformation moisture absorption of PBD filter after long leaving period.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.3
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• pp.177-183
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• 2004

The discharge of waste nutrient solution from greenhouse to natural ecosystem leads to the accumulation of excess nutrients that results in contamination or eutrophication. There is a need to recycle the waste nutrient solution in order to prevent the environmental hazards. The amount and kind of nutrients in waste nutrient solution might be enough to grow photosynthetic microorganisms. Hence in the present study, we examined the growth and mass cultivation of cyanobacteria in the waste nutrient solution with an objective of removing N and P and concomitantly, its mass cultivation. Four photosynthetic filamentous cyanobacteria (Anabaena HA101, HA701 and Nostoc HN601, HN701) isolated from composts and soils of the Chungnam province were used as culture strains. Among the isolates, Nostoc HN601 performed faster growth rate and higher N and P uptake in the BG-II ($NO_3{^-}$) medium when compared to those of other cyanobacterial strains. Finally, the selected isolate was tested under optimum conditions (airflow at the rate of $1L\;min^{-1}$. in 15 L reactor, initial pH 8) in waste nutrient solution from tomato hydroponic in green house condition. Results showed to remove 100% phosphate from the waste nutrient solution in the tomato hydroponics recorded over a period of 7 days. The growth rate of Nostoc HN601 was $16mg\;Chl-a\;L^{-1}$ in the waste nutrient solution from tomato hydroponics with optimum condition, whereas growth rate of Nostoc HN601 was only $9.8mg\;Chl-a\;L^{-1}$ in BG-11 media. Nitrogen fixing capacity of Nostoc HN601 was $20.9nmol\;C_2H_4\;mg^{-1}\;Chl-a\;h^{-1}$ in N-free BG-11. The total nitrogen and total phosphate concentration of Nostoc HN601 were 63.3 mg N gram dry weight $(GDW)^{-1}$ and $19.1mg\;P\;GDW^{-1}$ respectively. Collectively, cyanobacterial mass production using waste nutrient solution under green house condition might be suitable for recycling and cleaning of waste nutrient solution from hydroponic culture system. Biomass of cyanobacteria, cultivated in waste nutrient solution, could be used as biofertilizer.

• The Korean Journal of Emergency Medical Services
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• v.11 no.3
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• pp.163-174
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• 2007

Purpose : This study analyzes prehospital care report of emergency service at prehospital stage, examines characteristics of activities of 119 paramedics and its users and aims to provide help for improving emergency system in future. Methods : Data collected were 119 prehospital care report and hospital records with 7,160 patients to emergency room by 119 ambulance from Jan. 1 to Dec. 31, 2006 and percentage and frequency of the data were obtained. Results : 1) Use of emergency room by 119 ambulance was increased in summer and autumn such as August(9.1%), September(11.2%) and October(13.5%) and it was more frequently used on Monday(17.3%), Saturday(17.2%) and Friday(16.1%) by telephone(98.6%). 2) Using emergency room was most in over sixties(51.8%), men(64.2%), community residents (78.3%), by report of family(50.3%) and at '09:01~12:00'(16.5%). 3) Symptoms of emergency room users included headache, chest pain, stomachache, lumbago and others as 40.6% and places where patients were found were at home(60.1%) due to chronic internal diseases at 49.2%. 4) Most of non-emergency patients(80.2%) arriving at hospital had normal pupil condition (88.4%) and clear consciousness(71.2%) and most of them left hospital after having first-aid treatment. 5) Physiological symptom tests evaluated by paramedics at prehospital stage included blood pressure(56.6%), pulse(22.9%), breathing(13.0%) and temperature(9.2%), and there was no SPo2 case. 6) Classification of severity by paramedics showed difference as emergency patients(18.0%) by paramedics and those(24.9%) by hospital. 7) First-aid treatments by paramedics at prehospital stage were promoting comfort(28.9%), hemostasis(7.7%), fixing cervical vertebrae(4.0%) and ensuring vein route(3.1%). 8) Selectors of medical agency were patients or guardians(86.2%) and emergency medical technicians(73.6%). Conclusion : To sum up the above research, it was found that percentage of using 119 ambulance by non-emergency patients was higher and paramedics performed basic first-aid treatment rather than professional first-aid treatment due to several conditions such as legal problems, range of allowance, etc. Therefore, it is considered that method to reduce frequency of ambulance by non-emergency patients and approaches to alleviate limitations of allowance of paramdeics to make them perform effective first-aid treatment at prehospital stage should be sought in the dimension of individual, organization and government.

• Korean Journal of Agricultural Science
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• v.41 no.4
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• pp.473-480
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• 2014

Upon setting up a dedicated plastic greenhouse for tomato cultivation developed by the Rural Development Administration on the Gyehwa reclaimed land, this study was aimed at analyzing the problems can be occurred in the installation of plastic greenhouse on reclaimed lands as well as finding out solutions for improvement. A relatively cheaper wooden pile was used in the installation in order to supplement the soft ground conditions. Based on the results of ground investigation of the installation site, both the allowable bearing capacity and pulling resistance of the wooden pile with a diameter of 150 mm and a length of 10 m were computed and came out to be 30.645 kN. It was determined that the values were enough to withstand the maximum compressive force (17.206 kN) and the pullout force (20.435 kN) that are generally applied to the greenhouse footing. There are three problems aroused in the process of greenhouse installation, and the corresponding countermeasures are as follow. First, due to the slightly bent shape of the wooden pile, there were phenomenon such as deviation, torsion, and fracture when driving the pile. This could be prevented by the use of the backhoe (0.2) rotating tongs, which are holding the pile, to drive the pile while pushing to the direction of the driving and fixing it until 5 m below ground and applying a soft vibrating pressure until the first 2 m. Second, there exists a concrete independent footing between the column of the greenhouse and the wooden pile driven to the underground water level. Since it is difficult to accurately drive the pile on this independent footing, the problem of footing baseplate used to fix the column being off the independent footing was occurred. In order to handle with this matter, the diameter of the independent footing was changed from 200 mm to 300 mm. Last, after films were covered in the condition that the reinforcing frame and bracing are not installed, there was a phenomenon of columns being pushed away by the strong wind to the maximum of $11m{\cdot}s^{-1}$. It is encouraged to avoid constructions in winter, and the film covering jobs always to be done after the frame construction is completely over. The height of the independent footing was measured for 9 months after the completion of the greenhouse installation, and it was found to be within the margin of error meaning that there was no subsidence. The extent to the framework distortion and the value of inclinometers as well showed not much alteration. In other words, the wooden pile was designed to have a sufficient bearing capacity.

• Journal of the Korean Institute of Navigation
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• v.19 no.3
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• pp.35-65
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• 1995

The development of Korean shipping industry is maybe defined into three development stages-industry fixing stage, industry coordinating stage, industry development stage-. The development of shipping industry has been depended on the geovernment/authority role such as shipping policy, system, law, rules and regulations. In 1983, Korean shipping industry reorganization and coordination by shipping authority have made our shipping industry on the stable condition together with each company's efforts. Today's world economic environment such WTO/UR negotiation results get this government role limited. According to the being reduced government role, each company's competitive advantage power becomes more important. Besides, korean shipping industry is exposed into the entire and bitter world competition. In order to win and prevent the world shipping competition, it is necessary to look out the competitive advantage power of Korean shipping industry. The first purpose of this study is the situation analysis for competitive advantage power of Korean shipping industry. The second is to compare with our shipping policies with foreign ones concerned with ship, cargo, crew, tax and others. But in order to compare with foreign shipping, this study need their shipping statistics data, this study has some limit of the foreign data. This study has been carried on the basis of the following items. 1. Shipping environment, 2. Ships and ship acquirement(shipbuilding/purchasing), 3. Oceangoing cargo and ship's stowage rate, 4. Human factor in shipping-crew, 5. The incomes and costs in finacial statements. We have some conclusions as following through the this study. First, Korean shipping industry environment-competitive disadvantage situation- has changed rapidly due to the shipping market opening, free market entering of foreign shipping. Second, Korean shipping is disadvantageous due to the high tax rate and financing conditions in connection with ship acquirement. In order to improve the competitive advantage power, the shipping tax system and ship financing conditions should be reviewed to profitable for owners. Third, but both world and Korean oceangoing cargoes quantity have been increased annualy, Korean ship's cargo stowage rate is being decreased. This is serious situation but Korean shipping take well use of foreign vessel with hire. It is recommended to take use of owner's vessel and hired ones in the long range view, considering the world shipping management. But the number of crew has been decreased by 2, 000~3, 000 annualy, it is desirable that the long sea-experienced crew have been increased. Almost of owners usauly complain the crew cost is the main obstacles to competitive advantage power. Human factor is the most important firm's asset. All owners should pay attention to this though, and invest the proper budget to training, education, welfare as much as possible. In the long run this effects could be feedback to owners. Fifth, We must improve the financial statements structure, that is, the first step is to increase income, the second is to decrease cost, the third is to increase income on the same cost, the fourth is to decrease cost on the same income. It is essential to find out what the urgent investment is and what unnecessary cost is. At last, in order to competite world shipping race, each shipping firm must try for himself to retain the power. The government/authority is no longer dependable. I believe that each firm's power will be the industry's power, the industry's power will be the nations's power.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1869-1879
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• 2000

A series of experiments were conducted for modeling the fate and effect of the coupled oxidation reduction reaction of ethanol and propionate recognized as important intermediates in anaerobic degradation metabolism. Anaerobic kinetics for conversion of propionate and the interaction with ethanol were investigated using the model of specific substrate priority utilization effect. Seed cultures for the experiment were obtained from an anaerobically enriched steady-state propionate master culture reactor (HPr-MCR), ethanol-propionate master culture reactor (EtPr-MCR) and glucose master culture reactor (Glu-MCR). Experiments were consisted of four phases. Phase I, II and III were conducted by fixing the propionate organic loading as 1.0 g COD/L with increasing ethanol loading of 0, 100, 200, 400 and 1,000 mg/L, to find metabolic interaction of ethanol and propionate degradation by each enriched anaerobic culture. In phase IV, different mixing ratios of Glu-MCR and HPr-MCR cultures with fixed propionate organic loading, 1.0 g COD/L, were applied to observe the propionate degradation metabolic behavior. In the results of this study, different pathways of propionate and ethanol conversion were found using a modified competitive inhibition kinetic model. Increase of $K_{s2}$ value reflected the formation of acetate followed by ethanol degradation. In addition. $K_3$ value was increased slightly as the reactions of acetate formation and degradation were occurred in acetoclastic methanogenesis.

• Journal of Aerospace System Engineering
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• v.12 no.4
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• pp.49-56
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• 2018

In this paper, the performance analysis and the experiment of the brake system using the small piezoelectric-hydraulic pump were performed. Initially, the 3-D modeling of the brake load components was performed for the construction of the brake system. Subsequently, modeling using the commercial program AMESim was performed. A floating caliper model was used as a load for modeling the brake system. Through the AMESim simulation, load pressure, check valve displacement and flow rate under no load state were calculated, and performance analysis and changes in dynamic characteristics were confirmed by adding brake load. A jig for use in fixing the brake load during performance test was manufactured. The flow rate was assessed under no load condition and load pressure formation experiments were performed and compared with simulation results. Experimental results revealed the maximum load pressure as about 73bar at 130Hz and the maximum flow rate as about 203cc/min at 145Hz, which satisfied the requirement of small- and medium-sized UAV braking system. In addition, simulation results revealed that the load pressure and discharge flow rate were within 6% and 5%, respectively. Apparently, the modeling is expected to be effective for brake performance analysis.

• Journal of the Korean Wood Science and Technology
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• v.39 no.2
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• pp.140-147
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• 2011

The strength properties of wooden retaining wall which was made with pitch pine were evaluated. Wooden retaining wall was made with diameter 90 mm of pitch pine round posts treated with CUAZ-2 (Copper Azole). The length of the front stretcher of the retaining wall was 3,000 mm. The distance between the headers (the notched member) is 1,000 mm in center and is 900 mm in side. There were connections every 2,000 mm because actually the length of stretcher is limited in the retaining wall. The strength test was carried out according to connection type because the section between stretchers can act as a defect. A result of the strength test according to connection type confirms that connection does not act as defect because the strength of retaining wall in single stretcher is similar to that in the section between stretchers. The strength test of the wooden retaining wall was carried out in 5 types according to the condition of the base section. When the upper soil pressure was 9.8 kN/$m^2$, the maximum load of the retaining wall fixing the front foundation shows higher values than those of others. But the total deformation is lower in the retaining wall not to fix a base section than in that to fix a base section. It is thought that the retaining wall not to fix a base section shows low value because the deformation is distributed throughout the retaining wall and it is confirmed that the soil pressure affects supporting the structure because the deformation of the retaining wall under low pressure is 3~4 fold higher than those of others. The failure mode of the retaining wall is the overturning type because the high section is deformed. Mostly, the failure mode is the separation of the header in the notched section.

• Journal of Embryo Transfer
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• v.28 no.1
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• pp.31-39
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• 2013

Alpha-tocopherol as an antioxidant acts in preservation of chilled semen by preserving cell membrane damage from lipid peroxidation. Optimum concentrations of ${\alpha}$-tocopherol in egg yolk-citrate (EYC) extender need to be studied in crossbred bull's semen. Different concentrations of ${\alpha}$-tocopherol viz. 0, 1, 2, 4 and 6mg per ml of extender were used. Semen was collected once a week from four bulls used to regular collection, aged 4 to 7 years, weighing 320 to 450 kg, and with body condition score 4 to 4.5 and scrotal circumference 23 to 32 cm. Semen was evaluated routinely and sperm morphology was viewed under light microscope at ${\times}1,000$ magnification after fixing with buffered formal saline. Over 90% had normal head, acrosome, mid-piece and tail. Semen was diluted with egg-yolk-citrate extender to produce $15{\times}10^6$ spermatozoa/ml and 0, 1, 2, 4 and 6 mg/ml ${\alpha}$-tocopherol were added. The semens amples were kept at $8^{\circ}C$. Sperm motility and viability were examined daily up to 5 days under light microscopy at ${\times}200$ magnification. Sperm viability was acceptable (${\geq}40%$) up to the $4^{th}$ day with all concentrations of ${\alpha}$-tocopherol and up to the $5^{th}$ day with 2 mg/ml ${\alpha}$-tocopherol. Sperm motility was acceptable (${\geq}40%$) up to the $3^{rd}$ day irrespective of ${\alpha}$-tocopherol concentration, and up to the $4^{th}$ day with 2 mg/ml ${\alpha}$-tocopherol. It is suggested that the lifespan of chilled semen may be extended up to 4 days by adding 2mg/ml ${\alpha}$-tocopherol.

• Land and Housing Review
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• v.3 no.4
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• pp.357-367
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• 2012

The efficient business scheme were suggested with the consideration of the local development condition at Ulaanbaatar. Major findings of the study were presented as follows. First, high level of education and the underground resources are presented as the merits of Mongolia. On the other side, the defects are limited domestic demands of 2.6 millions of population and the insufficiency of the infrastructure. The improvement of the infrastructures like roads, water & sewage, electric power, and heating is urgent while the development pressure of Ulaanbaatar is expected to be high due to the continuous inflow of population. Secondly, the Mongolian land system consists of the right of ownership, lease and use, therefore there are some differences among the right of land. Thirdly, definite business scheme to sell land in lots and to sell buildings in lots are suggested which are actual methods to participate in the development project in Ulaanbaatar. Moreover, enhancing the possibility to sell the lands, fixing the proper sale price to secure the profit, finding the proper buyer for the profitable lands, investing of quota and guaranteeing of granting the principal and interest by the Mongolian government, etc. are presented as consideration when participate in projects.