• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
• /
• pp.412-419
• /
• 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.

• 한국지반공학회논문집
• /
• 제28권6호
• /
• pp.39-52
• /
• 2012

연약지반 계측에 있어, 원거리 측량에 의한 지표침하 측정 및 수동 방식의 층별침하 측정 방식을 탈피하고 기존 자동 침하 계측기술의 한계를 극복하고자, 디지털 홀센서를 이용한 자력감지 시스템 및 원위치 지반침하 자동 계측시스템을 개발하였다. 본 연구를 통한 개발 시스템은 지표침하와 다수 층별침하를 NX 규격의 단일 시추공내에서 동시에 측정할 수 있다. 개발 시스템의 실제 연약지반 개량현장 적용 및 기존 수동계측 결과와의 비교, 분석을 통해 그 기술검증 및 안정성을 확인할 수 있었다.

• 한국표면공학회지
• /
• 제29권5호
• /
• pp.393-398
• /
• 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
• /
• 제5B권3호
• /
• pp.238-242
• /
• 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.

• 공업화학
• /
• 제16권4호
• /
• pp.527-532
• /
• 2005

이온성고분자-금속복합체(Ionic Polymer Metal Composites, IPMC)는 전기활성 고분자이며, 낮은 구동전압에서도 큰 변위를 나타내는 유연한 스마트 소재(soft smart material)이다. 이온성고분자-금속복합체의 표면전극 제조는 일반적으로 화학적 환원방법(무전해 전기도금)에 의해 제조되고 있지만, 이러한 방법에서는 그 재료가 다공성 고분자 막으로 표면이 균일한 전극을 제조하기에 어려움이 있다. 본 연구에서는 전극의 표면 저항을 감소시켜 응답속도를 증가시킴과 동시에 낮은 전압에서 큰 변위를 낼 수 있는 IPMC 제조방법을 고안하여 수행하였다. 화학적 환원방법으로 이온고분자-금속 복합체를 형성시킨 후, 이온빔보조증착법(Ion Beam Assisted Deposition)으로 균질한 표면 전극 층을 형성시켜 화학적 특성을 개선하여 전기적 자극에 의한 구동반응 속도를 향상시킬 수 있는 구동체 제조방법을 제안하였다.

• Journal of Dental Anesthesia and Pain Medicine
• /
• 제21권1호
• /
• pp.71-80
• /
• 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
• /
• 제34권2호
• /
• pp.139-154
• /
• 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.

• 대한가정학회지
• /
• 제11권4호
• /
• pp.363-373
• /
• 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.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2010년도 춘계 학술발표회
• /
• pp.1256-1263
• /
• 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.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2001년도 춘계학술대회 논문집
• /
• pp.408-415
• /
• 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.