• Journal of the Korean Geotechnical Society
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• v.20 no.1
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• pp.101-108
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• 2004

For the last 30 years, the use of EPS as a lightweight filling material has grown significantly throughout the world. The fields of applying EPS block have also increased. The most representative example in geotechnical applications is using EPS block as a compressible inclusion that causes the reduction of static earth pressure on earth-retaining wall, bridge abutment and pipes. EPS blocks have a good workability by its lightweight characteristic and a uniform engineering property with the change of its density. Also EPS blocks have best material property as a compressible inclusion. This paper analyzes that the compressible inclusion function of EPS causes the reduction of static earth pressure on retaining wall and concrete box culvert. A series of in-situ tests were conducted to evaluate the reduction of static earth pressure using EPS inclusion. Based on in-situ test, it is found that the magnitude of static earth pressure was reduced to about 20% for the retaining wall and about 45∼53% for the box culvert compared with theoretical active earth pressure.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.5
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• pp.154-161
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• 2004

A new column type electric power steering system (EPS-TT) is proposed in this study. The remarkable features of EPS-TT are its opto-isolated torque sensor and assist torque control methodology. EPS-TT uses a uni-directional motor and two clutches. Full order and simplified models for EPS-TT are developed to evaluate the EPS-TT. A full car model is also used to investigate the vehicle responses. A PID control logic is designed to control the torque of the assist motor. Various sinusoidal inputs are applied to the system and the resulting performances are analyzed. The results prove that the performances achieved by the EPS-TT are improved compared to those of a conventional EPS-TT across the frequency domain. In addition, it is inexpensive and easy to control the motor. The results of the full order steering system model are similar to those simplified model, but the vehicle responses are slightly different.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.4 no.2
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• pp.18-23
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• 1998

Weight loss of cucumber packed with corrugated paperboard box after 7 days storage at 20oC was 4.9%, and those of 20LD, 40LD film and EPS box were 0.8, 0.7, and 0.8%. Total ascorbic acid content of EPS was 15% higher than that of control. Hardness of EPS was also similar trend. Chlorophil content of cucumber packed with EPS box was 21% higher than that of control. Decay of control was 1-2 pieces per box, but the others was not found. Overall appearence of LD, EPS was better than that of control.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.152-153
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• 2013

Based on the Fire Service Act of mandatory provision, new buildings are strictly forced to use fire protection materials. Flame resistant EPS is one of those materials. Unlike conventional EPS that can be fused to make EPS ingot and be recycled for various purposes, flame resistant EPS waste cannot be recycled due to the presence of protective coating that is applied to increase the fire protection properties of EPS. A suitable alternative that can process large amount of flame resistant EPS wastes needs to be developed, and one of the possible alternative is to use them as construction materials. In this research, experiments were designed to observe whether the flame resistant EPS wastes can be utilized as partial replacements of fine aggregates in cement mortar. The replacement ratio of waste EPS was varied, and its effect on compressive strength and absorption capacity was investigated. According to the experimental results, both compressive strength and absorption capacity met the Korean Standard specification for cement bricks and blocks, indicating that flame resistant EPS wastes can be used for construction purposes.

• Korean Journal of Microbiology
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• v.49 no.3
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• pp.297-300
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• 2013

EPS producing bacteria were enumerated in ginseng root system (rhizosphere soil, rhizoplane, inside of root). EPS producing bacterial density of rhizosphere soil, rhizoplane and inside of root were distributed $9.0{\times}10^6$ CFU/g, $7.0{\times}10^6$ CFU/g, and $1.4{\times}10^3$ CFU/g, respectively. Phylogenetic analysis of the 24 EPS producing isolates based on the 16S rRNA gene sequences, EPS producing isolates from rhizosphere soil (RS) belong to genus Arthrobacter (6 strains) and Rhizobium (1 strain). EPS producing bacteria from rhizoplane (RP) were Arthrobacter (6 strains), Rhodococcus (1 strain) and Pseudomonas (1 strain). EPS producing bacteria from inside of root (IR) were categorized into Rhzobium (6 strains), Bacillus (1 strain), Rhodococcus (1 strain), and Pseudomonas (1 strain). Phylogenetic analysis indicated that Arthrobacter may be a member of representative EPS producing bacteria from ginseng rhizosphere soil and rhizoplane, and Rhizobium is typical EPS producing isolates from inside of ginseng root. The yield of EPS was 10.0 and 4.9 g/L by Rhizobium sp. 1NP2 (KACC 17637) and Arthrobacter sp. 5MP1 (KACC 17636). The purified EPS were analyzed by Bio-LC and glucose, galactose, mannose and glucosamine were detected. The major EPS sugar of these strains was glucose (72.7-84.9%).

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.793-798
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• 2003

The purpose of this study is to investigate the setting properties of polystyrene mortars using waste expanded polystyrene(EPS) solution-based binders. The binders for polystyrene mortars are made by mixing crosslinking agent with waste EPS solutions which prepared by dissolving EPS in styrene. Polystyrene mortars are prepared with various EPS concentrations of EPS solutions and crosslinking agent contents, subjected to a dry curing, and tested for working life, peak exotherm temperature and 10h-length change. From the test results, the working lives of polystyrene mortars are shortened with raising EPS concentration of EPS solution and crosslinking agent content. Low-shrinkage or non-shrinkage of polystyrene mortars should be accomplished by adjusting EPS concentration of EPS solution and crosslinking agent content.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.6
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• pp.566-571
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• 2010

EPS (Electric Power Steering) is important device for improving vehicle's dynamics and static performances. This paper deals with simulator design for C-EPS (Colum type-EPS), development assist and returnability control algorithm. First, C-EPS system model was simply designed because EPS system is complex control system that has many unknown variables. These parameters were simplified through assumptions. Second, C-EPS simulator was designed for development of control algorithm. This simulator has SAS (Steering Angle Sensor), dual torque sensor, dual load cell for measuring rack force, dual linear actuator for generating tire force and Data Acquisition System. Using this simulator, control methods ware tested. Third, control algorithm was designed for torque assist and returnability. Assist torque map and returnability torque map were found by lots of simulation test. These torque maps were tuned for EPS actuator control. The simulation result was compared with non-EPS system result. In this research, the C-EPS simulator was designed for development of control algorithm about torque assistant and returnability. Using this simulator, control algorithm was improved.

• IMMUNE NETWORK
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• v.10 no.6
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• pp.230-238
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• 2010

Background: The MK1 strain, a novel bacterial isolate from soft-rotten tissue of the Neungee mushroom, produces copious amounts of exopolysaccharide (EPS) in a dextrose minimal medium. This study examined the molecular characteristics and immunomodulatory activity of MK1 EPS. Methods: The EPS in the culture supernatant was purified by cold ethanol precipitation, and characterized by SDS- PAGE/silver staining and Bio-HPLC. The immunomodulatory activities of the EPS were examined using the mouse monocytic cell line, RAW 264.7 cells. Results: The molecular weights of the purified EPS were rather heterogeneous, ranging from 10.6 to 55 kDa. The EPS was composed of glucose, rhamnose, mannose, galactose, and glucosamine at an approximate molar ratio of 1.00 : 0.8 : 0.71 : 0.29 : 0.21. EPS activated the RAW cells to produce cytokines, such as TNF-${\alpha}$ and IL-$1{\beta}$, and nitric oxide (NO). EPS also induced the expression of co-stimulatory molecules, such as B7-1, B7-2 and ICAM-1, and increased the phagocytic activity. The macrophage-activating activity of EPS was not due to endotoxin contamination because the treatment of EPS with polymyin B did not reduce the macrophage-activating activity. Conclusion: The EPS produced from the MK1 strain exerts macrophage-activating activity.

• Geotechnical Engineering
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• v.12 no.6
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• pp.185-198
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• 1996

EPS is increasingly used as a filling material in soft ground. The beneficial effects of the use of EPS derive from minimizing the stress increment, which, in turn, increases the bearing capacity and reduces the settlement. EPS can also be used as a backfill material for retaining walls and abutments to reduce the horizontal earth pressure. However, there is no rational application for the selection of the EPS fill which is essential to the selection of the filling configuration and the settlement calculation. In this paper, therefore, the nonlinear numerical model developed from the results of triaxial compression tests is applied to the construction of EPS and verified through the comparison between the prediction and in-situ measurements.

• Composites Research
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• v.23 no.3
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• pp.64-68
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• 2010

Expanded polystyrene(EPS) foams are often used in packaging to protect electrical appliances from impact loads. The energy absorbing performances of the EPS foams depend on several parameters such as density, microstructure and strain rate. Thus, the effects of the parameters on the strength of the EPS foams need to be investigated for an optimized packaging design by FEM. In this study, various EPS foams which have different densities were quasi-statically and dynamically loaded in order to obtain the stress-strain curves. EPS foams of various densities from 18.5 to 37.0kg/m3 were considered in the experiments. A drop-mass type apparatus was developed for the intermediate strain rate tests up to several hundreds/second. It was found from the experimental results that the strength of the EPS foams increase about 170% as the strain rate increases from 0.06/s to 60/s. Experimental results also showed that the strain rate sensitivity increases as the strain increases.