• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.489-496
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• 2003

Korea Gas Corporation has recently constructed a LNG pilot tank with 1, 000㎥ capacity in Incheon, Korea. The main objective of this pilot tank construction is to accumulate field data under different operating conditions for the future use in design procedure, construction, and maintenance. As the part of the project, a field dynamic test, so-called modal test, is performed to obtain the dynamic characteristics of the pilot tank. This paper describes the instrumentation and measurement Process used in the testing. From the measured Frequency Response Functions (FRFs), resonant frequencies and corresponding mode shapes of the tank are extracted and provided. Also, these results are compared to those calculated from a finite element model. The change of dynamic characteristics of the pilot tank due to the effect of internal fluid and the possible structural deterioration will be investigated in near future.

• Proceedings of the Korean Geotechical Society Conference
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• 1994.09a
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• pp.199-208
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• 1994

This paper presents an evaluation of new drill and blast method with two different drilling directions for pilot tunnel enlargement using numerical experiment and field test. To evaluate the effieiency of new tunnel enlargement method, field tests were performed and compared with conventional drill and blast method. Also, three dimensional transient dynamic analysis was made to investigate the effect of the ground vibration when blasting was performed at same position using the equivalent single hole charge.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.6
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• pp.989-994
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• 2011

Nitrate contamination of groundwater is a common problem throughout intensive agriculture areas (non-point source pollution). Current processes (e.g. ion exchange and membrane separation) for nitrate removal have various disadvantages. The objective of this study was to evaluate electrochemical method such as electroreduction using bipolar ZVI packed bed electrolytic cell to remove nitrate from groundwater at field pilot. In addition ammonia stripping tower continuously removed up to 77.0% of ammonia. Bipolar ZVI packed bed electrolytic cell also removed E.coli. In the field pilot experiment for groundwater in 'I' city (average nitrate 30~35 mg N/L, pH 6.4), maximum 99.9% removal of nitrate was achieved in the applied 600 V.

• Journal of the military operations research society of Korea
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• v.24 no.1
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• pp.41-57
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• 1998

Since the aircraft has a property of moving in the three-dimensional space, it may cause personally and financially critical damage in the case of an accident. Among the causes of aircraft accident, human factor has occupied about 70% of all accidents. Specially, fatigue among human's problems has been studied earlier than any other factor. Fatigue has been the cause of 75% of accidents that are related to human factor. So many studies have been conducted. But the direction of these studies mainly attach importance to the sleep loss and circadian rhythm. Limitation for flight time of ICAO is 8 hours per day, civil airlines in domestic line also adopt the limitation. But this rule is not based on human's performance but compromise between labor and management. The long-haul flight brings about a mental block to pilot. This mental block decreases performance of pilot and loses a lot of important information. So this may cause many accidents. This paper is to offer optimal flight time according to the amount of fatigue due to increasing flight time. The optimal flight time is searched through the field experiment. The experiment has adopted two methods. One is to examine pilot's objective fatigue accumulation rate through the critical fusion frequency, and another is to investigate pilot's subjective fatigue feeling through the fatigue subjective symptoms investigation table.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.600-606
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• 2007

Livestock wastewater containing concentrated organic matters and nutrients has been known as one of the major pollutants. It is difficult to apply the conventional activated sludge process to treat livestock wastewater because of high Non-biodegradable (NBD) matter and ammonia. The objectives of this study are to remove NBD matters including aromatic compounds and ammonia in livestock wastewater using Coagulation-Fenton oxidation-Zeolite (CFZ) processes and ascertain applicable feasibility in the field through pilot plant experiment. NBD matters and color remained in the treated water were removed over 92% by Fenton oxidation as the second treatment process. Ammonia was removed by over 99.5% in the zeolite ion exchange process as the last treatment method. From $UV_{254}$, $E_2/E_3$ ratio and GC/MS analyses of treated water at each process, the aromatic compound was converted to aliphatic and aromaticity was decreased. In pilot scale test, organics and ammonia removal efficiencies were not much different from the result of lab-scale test at various operation conditions. Furthermore, reaction time and dosage of Fenton reagent in pilot scale experiment reduced by 40 min and 50% rather than in lab-scale test. $BOD_5$, $COD_{Mn}$, SS, T-N and T-P of treated water in the pilot-scale experiment also met the effluent standards.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.2
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• pp.125-131
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• 1993

Electrostatic Precipitator has been widely used to get high efficiency which is required for collection of fine particles. In order to provide collection efficiency and size distribution data for a pilot electrostatic precipitator, a pilot study has been conducted on fly ash from pulverized coal burning apparatus. The aims of this study are to investigate characteristics of electric charge, to measure collection efficiency varied with the applied voltage, to get an optimum current and current density. Optimum current density was obtained to 0.7mA/$cm^2$ at the average electric field strength 2.33kV/cm in this experiment. Maximum particle collection efficiency was indicated 99.21% at the applied voltage 7kV. Finally, particle size distribution is also compared with photographic results. Both coarse and fine particles at the range of 0.5$\sim$2$\mu$m and 3$\sim$10 SEM $\mu$m were clearly removed by increasing applied voltage.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.130-133
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• 2006

It is well-known that the resources for tide and tidal current energy are abundant in Korea. The south coast in Korea is recognized as one of the most appropriate places in the world for developing tidal current energy. The target site for harnessing tidal current energy is the Uldolmok, where the strongest tidal current in Korea occurs. In order to commercialize and industrialize the tidal current power generation, the construction of pilot tidal current power plant of 1MW has been started in April 2006, and is expected to be completed by May 2007. Extensive works including field investigation, field experiment for evaluating the efficiency of helical turbine and numerical analysis have been performed. This paper present the several design parameters for constructing the Uldolmok pilot tidal current power plant.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.3
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• pp.383-390
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• 2011

In this study, a process combined biofiltration with sulfur-utilizing autotrophic denitrification and membrane separation was proposed to examine the efficiency of nitrogen removal. As an experimental device, hollow-fiber module was installed in the center of reactor to generate the flux forward sulfur layer in the cylinder packed with granular sulfur. In addition, a simple module was installed in activated sludge aeration tank which inside and outside of sulfur-using denitrification module was covered with microfilter and the module was considered as an alternative of clarifier. The experiment for developing new MBR process was carried out for three years totally. As the results of first two-year experiment, successful nitrogen removal performance was revealed with lab-scale test and pliot scale plant using artificial wastewater and actual plating wastewater. In this year, pilot scale test using actual domestic wastewater was performed to prove field applicability. As the results, high-rate nitrogen removal performance was confirmed with about 0.19 kg ${NO_3}^--N/m^3$ day of rate. Also significant fouling and pressure increase were not found during the experiment. And, the production ratio of sulfate and the consumption ratio of alkalinity showed a slightly higher value about 311 mg ${SO_4}^{2-}/L$ and 369 mg $CaCO_3$/L, respectively. In conclusion, the developed MBR process can be utilized as an alternative for retrofiting existing wastewater plants as well as new construction of advanced sewage wastewater treatment plants, with cost-effective merit.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.695-701
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• 2020

This study aimed to monitor a pilot-scale vertical flow reactor (VFR) system being operated in long-term for water quality control of pH-neutral mine drainage containing Fe, Mn and As, discharged in D mine site. The treatment systems of VFR and zero manganese reactor (ZMR) consisted of sand/limestone, and steel slag/limestone, respectively. The systems were operated during about six months in order to evaluate their long-term treatment efficiency It was observed that both pH and alkalinity of mine drainage were remarkably increased and more than 98% of Fe, As and Mn ions was continuously removed during the tested period of time. In conclusion, the field results of this work demonstrated that the vertical flow reactor system can effectively treat mine drainage contaminated by Fe, As and Mn.

• Journal of the Korean Society of Earth Science Education
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• v.4 no.3
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• pp.258-266
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• 2011

This study was carried out to P University of Education 111 students who participated in science materials study course 1 in spring semester 2011. Students have taken the course pre-service teachers of elementary school classes to target elementary school earth science field, they selected one of the sections to create a class and the students have fulfilled 15-minute classes in respectively from the first week of May 2011 to until end of that course. In this class, colleagues evaluated the classes and we used evaluated scores to determine level of instructional motivation strategy. The obtained results from this study are as follows; First, motivational strategies used by preliminary elementary school teacher were questions, presentation of pictures and photographs, storytelling, presentation of contradictory concepts and phenomena, pilot experiments Second, among preliminary elementary teachers' motivational strategies for teaching in the field of the earth storytelling, presenting contradictory phenomena and concepts, pilot experiment, presentation of contradictory concepts, questions got higher scores in the order. Third, storytelling received the highest scores by the evaluators. So we can consider storytelling as a good strategy for the next class. In particular, storytelling used by animism were more effective. Fourth, preliminary elementary school teachers used life knowledges and dairy experiences as instructional motivation.