• KSBB Journal
• /
• v.26 no.5
• /
• pp.365-373
• /
• 2011

Effective Microorganisms (EM), a fermented medium developed by Professor Higa at the University of the Ryukyus, is a mixed culture containing dozens of microorganisms which are beneficial to nature including people, animals, plants and many microbial species in environment. EM is known to contain more than 80 kinds of anaerobic or aerobic microbes including photosynthetic bacteria, lactic acid bacteria, yeast, actinomycetes, fungi and so on, with yeast, lactic acid bacteria and photosynthetic bacteria as the main species of EM. Antioxidant effect generated by the concert of complex coexistence and coprosperity among these microbes is considered to be the main source of EM benefits. Currently, EM is earning an increasing attention with applications in agriculture, forestry, animal husbandry, fisheries, environment and medicine among others. At the same time, however, a quantitative interpretation of EM system based on a mixed culture model needs efforts from biochemical engineers for efficient production and further promotion of EM. In this paper, we describe the functions of major microbes in EM and current researches and applications of EM in agriculture, forestry, animal husbandry, fisheries, environment and medicine.

• Journal of electromagnetic engineering and science
• /
• v.6 no.4
• /
• pp.229-234
• /
• 2006

This paper presents an advanced method of simulation for EM(electromagnetic) environment that affects on mobile receivers. A new calibration algorithm in the process of simulation is introduced. With a proposed calibration method, the time required for simulation is reduced and this makes it possible to simulate a near-real time EM environment in a shielded anechoic chamber. EM environment data acquisition and logging techniques with GPS for simulation were developed.

• Journal of information and communication convergence engineering
• /
• v.13 no.1
• /
• pp.36-41
• /
• 2015

With the rapidly increasing and widespread use of electronic and controlling equipment, the control of the electromagnetic (EM) wave environment becomes an important social issue. To solve the electromagnetic compatibility (EMC, both electromagnetic interface and electromagnetic susceptibility) problems, in this paper, we introduce the countermeasure techniques focused on EM wave absorbers for EMC problems in our laboratory at the Korea Maritime and Ocean University. The current technologies related to EM wave absorbers to solve EMC problems will first be described. The prospects of and a design for EM wave absorbers including a smart absorber with a heat radiating function will then be suggested.

• Journal of the Korean housing association
• /
• v.20 no.3
• /
• pp.105-112
• /
• 2009

The purpose of this study is to investigate a top floor, indoor, thermal environment by comparison between the indoor air temperature and the rooftop surface temperature, and between the indoor air temperature and the outdoor air temperature using an experimental model. The model experiment was conducted with 4 cases,: no-rainfall, 1 em-height, 10 em-height and 20em-height of rainfall on the rooftop. According to the results of the height of stored rainfall, the average air temperature difference between the indoor and outdoor air with 1, 10 and 20 em-height of rainfall on the rooftop was $4.0^{\circ}C$, rooftop $1.2^{\circ}C$ and rooftop $1.0^{\circ}C$, respectively. The upper 10 em-height of rainfall on the rooftop acted to decrease the indoor air temperature on the top floor.

• Geophysics and Geophysical Exploration
• /
• v.14 no.2
• /
• pp.152-157
• /
• 2011

The small-loop electromagnetic (EM) method is one of the rapid and non-destructive geophysical methods and has been used widely for many geophysical investigations, particularly for shallow engineering and environmental surveys. Especially in the shallow marine environment, the small-loop EM technique is very effective because of rapid and convenient data acquisition, large signal and low noise level. However, the method has been rarely applied in the very conductive marine environment since it's penetration or investigation depth might be considered too low. In this study, we demonstrated that the small-loop EM method can be effectively applied in the extremely conductive marine environment through the analysis of 1D small-loop EM data. Furthermore, we confirmed that the resistivity distribution under the sea bottom can be quantitatively predicted from the 1D inversion results of synthetic and field data.

• Journal of Navigation and Port Research
• /
• v.34 no.7
• /
• pp.539-542
• /
• 2010

In this paper, we designed and fabricated the Electro-Magnetic (EM) wave absorber for wireless LAN by using Amorphous and CPE. The material constants and the absorption properties were measured for the samples containing 50 %, 60 %, and 70 % weight fraction of Amorphous. Moreover, the EM wave absorption abilities were simulated for the EM absorbers in different thicknesses by adopting the measured permittivity and permeability, and then the EM wave absorber was fabricated based on the simulated design values. As a result, the EM wave absorber with the composition ratio in Amorphous : CPE = 60 : 40 wt.% with the thickness of 4 mm has the absorption ability more than 35 dB at 2.4 GHz. Thus, it is expected the wireless LAN environment can be improved by using the developed absorber.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.4
• /
• pp.565-574
• /
• 2011

The development of satisfactory alternatives for supplying the nutrients needed by crops could decrease the problems associated with conventional NPK chemical fertilizers. In this study, the effects of bacterial and fungal effective microorganisms (EM) on the growth of Chinese cabbage (Brassica rapa) were evaluated. This investigation was carried out parrallel with conventional NPK chemical fertilizer and a commercial sold microbial fertilizer to compare between each of their effect. Sterile water and molasses were served as controls. Azotobacter chroococcum effect also was studied either alone or in combination with the effective microorganisms on the growth parameters. In contrast to the bacterial EM, the fungal EM alone without A. chroococcum had a more stimulating effect than fungal EM combined with A. chroococcum. Results showed that seedling inoculation significantly enhanced B. rapa growth. Shoot dry and fresh weight, and leaf length and width significantly were increased by both bacterial and fungal inoculation. The results indicated that the NPK chemical fertilizer deteriorates the microflora inhabiting the soil, while the effective microorganisms either fungal or bacterial ones increased the microbial density significantly. This study implies that both of fungal and bacterial EM are effective for the improvement of the Chinese cabbage growth and enhance the microorganisms in soil. The results showed antagonism occurred between A. chroococcum and each of Penicillium sp and Trichoderma sp in both agar and plant assays. The data were statistically analyzed by ANOVA and Dunnett test.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2007.06a
• /
• pp.245-250
• /
• 2007

The small loop EM method is a fast and convenient geophysical tool which can give shallow subsurface resistivity distribution. It can be a useful alternative of resistivity method in conductive environment. We applied the multi-frequency small loop EM method for the investigation of a soft ground landfill site which was constructed on a tideland since the resistivity of the survey area is extremely low. 3D resistivity distribution was obtained by merging 1D inversion results and shallow subsurface structure can be interpreted. By comparing the result with the drilling log and measured soil resistivity sampled at 16 drill holes, we can get lot of information such as groundwater level, thickness of landfill, salinity distribution, depth to the basement and etc.

• Korean Journal of Organic Agriculture
• /
• v.15 no.2
• /
• pp.207-218
• /
• 2007

Coming with the well-being era, consumer's demand for safe agricultural products is increasing. So, it is urgent to develop an environment-friendly rice production system. Accordingly, this study was conducted to develop an environment-friendly rice production system by using Amo known as EM(effective microorganisms) and also known as being effective in environment-friendly rice production with several other environment-friendly agricultural materials. The highest number of tillers per hill was obtained from level 2 of EM treatment (48.8 tillers per hill), while the lowest was obtained from the control plot (41.0 tillers per hill). Leaf area per hill at heading stage was the highest in level 3 of EM treatment $(3228.5cm^2)$, while control was the lowest leaf area $(2264.7cm^2)$, which is 70.2% compared to the level 3 of EM treatment. The highest effective tillers was obtained from the control (63.7%), while the lowest effective tillers was obtained from the level 3 of EM treatment (55.4%), which were treated with higher amounts of environment-friendly agricultural materials. Level 3 of EM treatment showed the highest number of panicles per hill (20.9), while the control showed the lowest number of panicles per hill (19.3). In the spikelets per panicle, level 2 of EM treatment showed the highest number of spikelets (85.2), while the control showed the lowest number of spikelets (81.9) and there was a statistically significant difference among the three levels and control. The highest grain filling ratio was obtained from the control (85.0%), while level 3 of EM treatment was the lowest grain filling ratio and there were no great difference between treatment levels. Regarding the 1000 grain weight, the control showed the highest 1000 grain weight (21.7g), which is heavier by about 1g compared to treatment levels. Level 2 of EM treatment showed the highest rough rice yield per 10a, while level 3 of EM treatment was the lowest and they also showed a statistically significant difference among treatment levels.

• Journal of Advanced Navigation Technology
• /
• v.24 no.3
• /
• pp.198-204
• /
• 2020

This paper designs a electromagnetic-log (EM-Log) aided navigation filter for maritime environment without global navigation satellite system (GNSS). When navigation is performed for a long time, Inertial navigation system (INS)'s error gradually diverges. Therefore, an integrated navigation method is used to solve this problem. EM-Log sensor measures the velocity of the vehicle. However, since the measured velocity from EM-Log contains the speed of the sea current, the aided navigation filter is required to estimate the sea current. This paper proposes a single model filter and interacting multiple (IMM) model filter methods to estimate the sea current and analyzes the influence of the sea current model on the filter. The performance of the designed aided navigation filter is verified using a simulation and the improvement rate of the filter compared to the pure navigation is analyzed. The performance of single model filter is improved when the sea current model is correct. However, when the sea current model is incorrect, the performance decreases. On the other hands, IMM model filter methods show the stable performance compared to the single model.