• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.412-419
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• 2009

Large quantity of extra soils discharged from excavation site in Songdo area can be treated by hardening agents and utilized in surface stabilized layer overlying thick reclaimed soft soil deposit. Though surface layer stabilization method using cement or lime for very soft soils has been studied in recent years, but studies on moderately soft clayey silt has not been tried. The purpose of this research is to investigate optimum mixing condition for stabilizing Songdo marine soil with low plasiticity. The optimum mixing conditions of hardening agents with Songdo soil such as kind of agents, mixing ratio, initial water content and curing time are investigated by uniaxial compression test and laboratory vane test. The results indicate that strength increases with high mixing ratio and long curing time, while decreases drastically under certain water content before mixing. Finally, optimum mixing condition considering economic efficiency and workability with test results was proposed.

• Journal of the Korean Geotechnical Society
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• v.28 no.6
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• pp.39-52
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• 2012

Magnetic sensing system and automated monitoring system based on digital hall sensor for ground settlement are developed to change traditional method for monitoring surface settlement and underground settlement by manual type and to overcome technical limits of existing automated settlement monitoring system. It's possible to monitor surface settlement and underground settlement with multi-points at the same time in a single hole with NX size. It was possible to verify technical confidence and stability by several case studies of soft ground improvement project.

• Journal of the Korean institute of surface engineering
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• v.29 no.5
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• pp.393-398
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• 1996

Soft magnetic properties and microstructural evolution of FeTaNC films were investigated, and compared with FeTaN and FeTaC films. Effects of substrate species (glass vs. $CaTiO_3$) on the magnetic properties were also investigated. Co-addition of N and C significantly enhance the grain refinments and magnetism, compared with N or C addition only. Good soft magnetic characteristics of coercivity of 0.17 Oe, permeability of 4000 (5MHz), and saturation flux density of 17 kG can be obtained in the FeTaNC in the relatively wide process windows. While these values appears to be similar to those of FeTaN on glass substrate, most distinctive difference between FeTaNC and FeTaN(or C) is in the effects of substrate. Whereas FeTaNC films show good magnetic characteristics for both glass and $CaTiO_3$ substrates, FeTaN(or C) films show significant degradation on the $CaTiO_3$ substrate.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.3
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• pp.238-242
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• 2005

In this paper, a surface permanent magnet motor made of the Soft Magnetic Composites (SMC) is analysed using the 3-D finite element method. By comparing with the motor made of the silicon steel sheets, the usefulness of the SMC for the eddy current loss is clarified quantitatively.

• Applied Chemistry for Engineering
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• v.16 no.4
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• pp.527-532
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• 2005

Ionic polymer metal composites (IPMC) are soft polymeric smart materials having large displacement at low voltage in air and water. The polymeric electrolyte actuator consists of a thin and porous membrane and metal electrodes plated on both faces, in impregnation electro-plating method. The response and actuation of actuator are governed. Among many factors governing the activation and response of IPMC actuator, the surface electrode plays an important role. In this study, the well-designed modification of electrode surface was carried out in order to improve the chemical stability well as electromechanical characteristics of the IPMC actuator. We employed Ion Beam Assisted Deposition (IBAD) method to prepare the topologically homogeneous thin surface electrode. After roughing the surface of Nafion membrane in order to get a larger surface area, the IPMC was prepared by impregnation for electro-plating and re- coating on the surface through traditional chemical deposition, followed by an additional surface treatment with high conductive metals with IBAD. It was observed that our IPMC specimen shows the enhanced surface electrical properties as well as the improved actuation and response characteristics under applied electric field.

• Journal of Dental Anesthesia and Pain Medicine
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• v.21 no.1
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• pp.71-80
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• 2021

Background: The options for stabilization appliance therapy for masticatory muscle pain include soft occlusal and hard stabilization appliances. A previous study suggested that hard stabilization appliance therapy was effective for patients with local myalgia who developed long facets on their occlusal appliances. The objective of this study was to identify patients in whom a soft occlusal appliance should be used to treat masticatory muscle pain by analyzing the type of muscle pain present and patient factors that influenced the effectiveness of this treatment. Methods: The study included 42 patients diagnosed with local myalgia or myofascial pain according to the Diagnostic Criteria for Temporomandibular Disorders Diagnostic Decision Tree. The analysis of patient factors included variables believed to be associated with temporomandibular disorders. First, a temporary screening appliance was used for 2 weeks to assess each patient for bruxism during sleep. Soft appliance therapy was then started. For each patient, the effectiveness of the appliance was evaluated according to the intensity of tenderness during muscle palpation and the treatment satisfaction score at one month after starting treatment. Results: Data from 37 of the 42 patients were available for analysis. Twenty-five patients reported satisfaction with the appliance. In logistic regression analysis, the odds ratio for reduction of facet length was 1.998. Nineteen patients showed at least a 30% improvement in the visual analog scale score. The odds ratio for local myalgia was 18.148. Conclusion: Soft appliance therapy may be used in patients with local myalgia. Moreover, patients who develop short facets on the appliance surface are likely to be satisfied with soft appliance therapy. Soft appliance therapy may be appropriate for patients with local myalgia who develop short facets on their occlusal appliance.

• Geomechanics and Engineering
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• v.34 no.2
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• pp.139-154
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• 2023

Red-bed soft rock is a common stratum and it is necessary to evaluate the mechanical properties and bearing capacity of red-bed soft rock mass affected by different environmental effects. This paper presents a complete procedure for evaluating the bearing capacity of red-bed soft rock by means of geophysical exploration and in-situ rock mechanics tests. Firstly, the thickness of surface loosened rock mass of red-bed soft rock was determined using geophysical prospecting method. Then, three environmental effects, including natural weathering effect, dry-wet cycling effect and concrete sealing effect, were considered. After each effect lasted for three months, in-situ rock mass mechanical tests were conducted. The test results show that the mechanical properties of rock mass considering the sealing effect of concrete were maintained. After considering the natural weathering effect, the mechanical parameters decrease to a certain extent. After considering the effect of dry-wet cycling, the decreases of mechanical parameters are the most significant. The test results confirm that the red-bed soft rock dam foundation rock mass will be significantly affected by various environmental effects. Therefore, combined with the mechanical test results, some useful implementations are proposed for the construction of a red-bed soft rock dam foundation.

• Journal of the Korean Home Economics Association
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• v.11 no.4
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• pp.363-373
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• 1973

The Sewability was tested with the seam strength and Puckering Grade by a general sewing machine according to some properties of simulated Leather, yarn tensile strength needle and stitches. The main results tested are as follows ; 1. The thick and uncomfortable leather is unable to be sewed by a general sewing machine, but the thin and soft one is able to. 2. The interval between stitches depends on type of leather used, and the variance in accordance with type of leather varies much more in the case of narrower interval. 3. When the sewability of leather-surface is not so good, is desirable to pour oil on the surface for the purpose of better efficiency. 4. The seam strength is directly proportional to interval of stitch and tensile strength of yarn and leather used, and needle No. 14 is more effective than No.1l. 5. The more the soft and thin leather is, the lower the Puckering Grade becomes. Type of yarn and interval of stitches do not seem to effect the Puckering Grade.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1256-1263
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• 2010

Suction Drain Method is soft ground improvement technique, in which a vacuum pressure can be directly applied to the Vertical Drain Board to promote consolidation and strengthening the soft ground. This method does not require a surcharge load, different to embankment or Preloading Method. In this study, ground improvement efficiency of suction drain method was estimated when duplex loading pressure with vacuum and pressure. During suction drain method process, surface settlement and pore pressure were monitored, and cone resistance test as well as water content were also measured after the completion of Suction Drain Method treatment.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.408-415
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• 2001

Hardening agent has been the traditional material for surface soil stabilization of soft ground. The aim of this study if to determine optimal mixture ratio of hardening agent in accordance with the required design specifications. Hardening agent consists of fly ash, gypsum, slag and cement for the ettringite hydrates and if effective for early stabilization of unconsolidated soil. The raw ground material is the clay that is widely found here and there in Korea. In this study, preliminary tests were performed to get optimal mixture ratio of stabilizer ingredient and marine clay in Jinhae was used to get physical and chemical properties. Laboratory tests of 50 stabilized soils were performed to get optimal mixture ratio for 16-stabilizer materials of 6 types, and mixture ratio of stabilizer ingredient and marine clay was determined.