• 한국지반신소재학회논문집
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• 제4권3호
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• pp.45-52
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• 2005

대부분의 항만구조물은 초연약 지반상에 축조되고 있으며 도로나 건물부지에는 지반개량이 필요하다. 이 논문에서는 여러 사례연구를 통하여 표층처리후의 복토사례에 대하여 몇가지 고려사항을 언급하였다. 또한, 모래나 산토를 이용한 복토공법에 대하여 강도적용이 고려되었다. 국내 복토공법 토목섬유 인장강도는 15t/m, 복토두께는 1.6~3.1m, 점토지반의 표층강도는 $0.2{\sim}1.2t/m^2$이 대표적이다. 표층처리공 시공시 발생되는 지반교란, 점토유출, 장비전도 등의 사고를 최소화하기 위한 연구가 필요하다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.612-615
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• 1996

In the continuous casting process, molten metal contacts the mold wall and the molten metal surface is subject to the mold oscillation. The mold oscillation results in the oscillation marks on the surface of solidified steel, which has undesirable effects on the quality of slabs. In order to reduce the oscillation marks by achieving soft contact of molten metal with the mold surface, alternating magnetic field is applied to the surface of molten metal. However, if the magnetic field strength becomes too strong, the melt flow induced by the magnetic field. causes the instability of the molten metal surface, which has also the bad influence on the slab quality. Therefore, it is very important to choose the optimal position of the inductor coil and the optimal level of electric power to minimize the surface defects. In the present work, as a first step toward the optimization problem of the process, numerical studies are performed to investigate the effects of coil position and the electric power level on the meniscus shape and the flow field. As numerical tools, the boundary integral equation method(BIEM) is used for the magnetic field analysis and the finite difference method (FDM) with orthogonal grid generation is used for the flow analysis.

• The Journal of Advanced Prosthodontics
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• 제3권1호
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• pp.16-19
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• 2011

PURPOSE. Purpose of this study was to evaluate effect of two surface treatments, sandblasting and monomer treatment, on tensile bond strength between two long term resilient liners and poly (methyl methacrylate) denture base resin. MATERIALS AND METHODS. Two resilient liners Super-Soft and Molloplast-B were selected. Sixty acrylic resin (Trevalon) specimens with cross sectional area of $10{\times}10$ mm were prepared and divided into two groups of 30 specimens each. Each group was surface treated (n = 10) by sandblasting (250 ${\mu}$ alumina particles), monomer treatment (for 180 sec) and control (no surface treatment). Resilient liners were processed between 2 poly(methyl methacrylate) surfaces, in the dimensions of $10{\times}10{\times}3$ mm. Tensile strength was determined with Instron Universal testing machine, at a crosshead speed of 5 mm/min; and the modes of failure (adhesive, cohesive or mixed) were recorded. The data were analyzed using one-way ANOVA, followed by Tukey HSD test (${\alpha}$= 0.05). RESULTS. Monomer pretreatment of acrylic resin produced significantly higher bond strengths when compared to sandblasting and control for both resilient liners (P < .001). Sandblasting significantly decreased the bond strength for both the liners when compared to monomer pretreatment and control (P < .001). Mean bond strength of Super-Soft lined specimens was significantly higher than Molloplast-B in various surface treatment groups (P < .05). CONCLUSION. Surface pretreatment of the acrylic resin with monomer prior to resilient liner application is an effective method to increase bond strength between the base and soft liner. Sandblasting, on the contrary, is not recommended as it weakens the bond between the two.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2009년도 춘계학술대회 논문집
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• pp.200-200
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• 2009

• Archives of Plastic Surgery
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• 제43권5호
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• pp.438-445
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• 2016

Background The goal of reconstruction is to provide coverage of exposed vital structures with well-vascularized tissue for optimal restoration of form and function. Here, we present our clinical experience with the use of the scapular fascial free flap to correct facial asymmetry and to reconstruct soft tissue defects of the extremities. Methods We used a scapular fascial free flap in 12 cases for soft tissue coverage of the extremities or facial soft tissue augmentation. Results The flaps ranged in size from $3{\times}12$ to $13{\times}23$ cm. No cases of total loss of the flap occurred. Partial loss of the flap occurred in 1 patient, who was treated with a turnover flap using the adjacent scapular fascial flap and a skin graft. Partial loss of the skin graft occurred in 4 patients due to infection or hematoma beneath the graft, and these patients underwent another skin graft. Four cases of seroma at the donor site occurred, and these cases were treated with conservative management or capsulectomy and quilting sutures. Conclusions The scapular fascial free flap has many advantages, including a durable surface for restoration of form and contours, a large size with a constant pedicle, adequate surface for tendon gliding, and minimal donor-site scarring. We conclude that despite the occurrence of a small number of complications, the scapular fascial free flap should be considered to be a viable option for soft tissue coverage of the extremities and facial soft tissue augmentation.

• 한국지반환경공학회 논문집
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• 제10권6호
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• pp.69-77
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• 2009

연약지반은 해성점토, 실트질, 사질토 등과 같은 지반으로 항만, 공항, 교량과 같은 구조물의 축조시 지지력 부족 및 침하, 전단변형 등의 문제점을 가진다. 이러한 문제점을 개선하고 연약지반의 조기 침하 및 강도증진을 위해 다양한 지반개량공법들이 적용되고 있으며 연약지반의 압밀에 소요되는 시간을 단축시키기 위해 연직배수공법이 많이 사용되고 있다. 특히, 연직배수공법에서 가장 많이 사용되는 배수재는 PBD(Plastic Board Drain)이다. 본 연구에서는 대심도 연약지반에 적용될 PBD공법에 대해 복합통수능실험을 실시하여 거동특성을 평가하였다. 그 결과, 상재압력의 증가에 따라 침하는 점진적으로 발생하였으며, 상재압력 $500kN/m^2$ 이후에는 간극수압의 소산에 따라 압밀침하가 진행되었다. 따라서 재하단계별 침하량의 변화는 간극수압의 소산에 따른 것임을 확인할 수 있었다. 또한, 연직 배수재의 통수능은 압력이 증가할수록 또 시간이 경과함에 따라 현저히 감소함을 알 수 있었다.

• 폴리머
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• 제34권5호
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• pp.450-453
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• 2010

Iron(III) p-toluenesulfonate(FTS)를 개시제로 한 pyrrole의 중합에서 용액 중합법(LPP)과 기상 중합법(VPP)으로 제조된 PPy 박막의 전기/광학적 특성 및 표면구조를 비교하였다. LPP에 비해서 VPP 방법으로 제조된 PPy 박막은 우수한 전기적 특성을 보여주었다. 표면 특성분석을 이용하여 제조된 PPy 필름의 표면 모폴로지와 표면저항과의 상관관계를 검토하였다. VPP 방법으로 제조된 PPy 박막의 표면이 LPP로 제조된 것보다 평탄하였다. VPP를 응용한 잉크젯 프린팅과 소프트 리소그래피를 사용하여 미세 패턴된 PPy 박막을 효과적으로 제조할 수 있었다.

• Geomechanics and Engineering
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• 제15권3호
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• pp.823-831
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• 2018

The most important issue during shield TBM tunneling in soft ground formations is to appropriately control ground surface settlement. Among various operational conditions in shield TBM tunneling, the face pressure and backfill pressure should be the most important and immediate measure to restrain surface settlement during excavation. In this paper, a 3-D hydro-mechanical coupled FE model is developed to numerically simulate the entire process of shield TBM tunneling, which is verified by comparing with real field measurements of ground surface settlement. The effect of permeability and stiffness of ground formations on tunneling-induced surface settlement was discussed in the parametric study. An increase in the face pressure and backfill pressure does not always lead to a decrease in surface settlement, but there are the critical face pressure and backfill pressure. In addition, considering the relatively low permeability of ground formations, the surface settlement consists of two parts, i.e., immediate settlement and consolidation settlement, which shows a distinct settlement behavior to each other.

• 한국해양공학회지
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• 제20권3호
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• pp.54-60
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• 2006

For optimal design of a deep-sea ocean mining collector system, based on self-propelled mining vehicle, it is imperative to develop and validate the dynamic model of a tracked vehicle traveling on soft deep seabed. The purpose of this paper is to evaluate the fidelity of the dynamic simulation model by means of response surface methodology. Various statistical techniques related to response surface methodology, such as outlier analysis, detection of interaction effect, analysis of variance, inference of the significance of design variables, and global sensitivity analysis, are examined. To obtain a plausible response surface model, maximum entropy sampling is adopted. From statistical analysis and prediction for dynamic responses of the tracked vehicle, conclusions will be drawn about the accuracy of the dynamic model and the performance of the response surface model.

• 대한치과보철학회지
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• 제44권4호
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• pp.466-476
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• 2006

Purpose : Colonization of denture soft lining materials by Candida albicans can result in clinical problem, and deterioration of the materials. This study aimed to compare the retention and penetration of C. albicans into four denture soft lining materials commonly used. Materials and methods : Four denture soft lining materials (Coe-comfort$^{(R)}$, Coe-soft$^{(R)}$, GC soft liner$^{(R)}$, and Tissue conditioner$^{(R)}$) discs were prepared to glass slide and dental stone. Adherence of yeast to surfaces was monitored after one hour incubation of standardized washed cell suspension with test disc surfaces. Adherent cells stained with acridine orange were counted fluorescence microscopy. Penetration of yeast into materials bonded with acrylic resin after 1, 2, 3,4, 5, 6 and 7 days incubation was observed through sections stained using acridine orange and estimated to quantitative analysis using radioisotope. Results : There was statistical significance in cell numbers between smooth and rough surfaces(p<0.05). Higher numbers of cells were observed on rough surfaces. There was statistical significance in adherent cell numbers into smooth and rough surfaces individually(p<0.05). According to the increase of incubation periods, the cells penetrated into denture soft lining materials were shown to increase. The differences among all kinds of soft liner were statistically significant(p<0.05),and the largest number of cells penetrated into soft liners was observed in the Coe-soft$^{(R)}$. Conclusion : Initial adherence and penetration of yeast into denture soft lining materials has been influenced by surface roughness and chemical composition of them. The selection of appropriate materials and their fabrication may promote clinical performance.