• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.381-389
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• 2004

To investigate changes of multi-purpose solutions for soft contact lens(MPS) depending on using period or keeping temperature, we evaluate four brands of MPS. No significant difference was seen in protein deposit removing efficacy after samples had used for 24 weeks and kept at $4^{\circ}C$, $20^{\circ}C$ or $30^{\circ}C$. The pH values of the samples of 4 brands measured weekly over the 24 week testing period. The initial average pH value of samples were 7.0, 7.5, 7.6 or 8.2. One brand of MPS was in the range of the threshold for ocular awareness, which is outside the zone of 6.6 ~ 7.8. During the testing period, the pH value were decreased in using period-dependent manner. At the 24th week, the average pH values of samples turned to 6.6, 7.2, 7.2 or 7.7. However, the difference of keeping temperature was not associated with decreased levels of pH values. After 24 weeks, one of total 36 samples was contaminated by bacteria. Furthermore, the change of components was shown after 24 weeks in the analysis using thin layer chromatography and the analysis of UV absorption pattern. The results of our study provides that the keeping temperature of MPS is not the important factor of changes of MPS, but the using period of MPS can cause contact lens wearers discomfort.

• Economic and Environmental Geology
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• v.43 no.6
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• pp.615-623
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• 2010

Seismic refraction survey is a geophysical method that delineates subsurface velocity structure using direct wave and critically refracted wave. The generalized reciprocal method(GRM) is an inversion technique which uses travel-time data from several forward and reverse shots and which can provide the geometry of irregular inclined refractors and structures underlain by hidden layer such as low velocity zone and thin layer. In this study, a simple Excel-GRM routine was tested for fast mapping of the interface between weathering layer and bedrock during the survey, with employing a pair of forward and reverse shots. This routine was proved to control the maximum dip of approximately $30^{\circ}C$ and maximum velocity contrast of 0.6, based on the panel tests in terms of dipping angle and velocity contrast for the two-layer inclined models. In contrast with conventional operation of five to seven shots with sufficient offset distance and indoor data analysis thereafter, this routine was performed in the field shortly after data acquisition. Depth to the bedrock provided by Excel-GRM, during the field survey for Cheongju granite area, correlates well with the elevation of the surface of soft rock from the drill core and SPS logging data. This cost-effective routine developed for quickly delineating the bedrock surface in the field survey will be readily applicable to mapping of weathering zone in narrow zone with small variation of elevation of bedrock.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.02a
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• pp.1-13
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• 1999

The use of Compaction Grouting evolved in the 1950's to correct structural settlement of buildings. Over the almost 50 years, the technology has developed and is currently used in wide range of applications. Compaction Grouting, the injection of a very stiff, 'zero-slump' mortar grout under relatively high pressure, displaces and compacts soils. It can effectively repair natural or man-made soil strength deficiencies in variety of soil formations. Major uses of Compaction Grouting include densifying loose soils or fill voids caused by sinkholes, poorly compacted fills, broken utilities, improper dewatering, or soft ground tunneling excavation. Other application include preventing liquefaction, re-leveling settled structures, and using compaction grout bulbs as structural elements of minipiles or underpinning. The technique replaced slurry injection, or 'pressure grouting', as the preferred method of densification grouting. There are several reasons for the increased use of Compaction Grouting which can be summarized in one word: CONTROL. The low slump grout and injection processes are usually designed to keep the grout in a homogeneous mass at the point of injection, while acceptable in some limited applications, tends to quickly get out of control. Hydraulic soil fracturing can cause extensive grout travel, often well beyond the desired treatment zone. So, on the basis of the two case history constructed in recent year, a study has been peformed to analyze the basic mechanism of the Compaction Grouting and verify the effectiveness of the ground improvement using some test methods.

• Geotechnical Engineering
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• v.6 no.4
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• pp.43-52
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• 1990

To investigate the effects of soil properties of the soft zone around a pile subjected 1,o the horizontal harmonic vibration, the parametric study is perfomed. The determination of the soil reaction or stiffness of the Winkler springs representing the soil around a pile is performed by dividing the soil profile into a number of homogeneous obtained from this study are as follows : 1) The real and imaginary parts of the stiffness show clear variations for the different shear modulus ratios, poisson's ratios, and distance retios to outer boundary as the dimensionless frequency increases. The differences are more pronounced for the imaginary part of the stiffness. 2) The stiffness of soil shows clear decrease. The real parts of the stiffness show larger as the frequency increases. On the other hand, the imaginary parts of the stiffness show smaller.

• The Korean Journal of Cytopathology
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• v.12 no.1
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• pp.67-71
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• 2001

Primary malignant lymphoma of the thyroid gland is uncommon malignancies. Its fine needle aspiration cytology (FNAC) findings are rarely described in the literature. This article highlights the FNAC diagnosis of primary malignant lymphoma of the thyroid gland. A 70-year-old female presented with a rapidly enlarging thyroid mass of five months' duration. FNAC smears showed low cellularity consisting of predominantly atypical enlarged lymphoid cells admixed with a few small lymphocytes, plasma cells, and oncocytic cells. Some disrupted lymphoid cells were also present. The tumor cells infiltrated into the thyroid follicular epithelium forming lymphoepithelial lesion, The cytologic appearance showed a diffuse mixture of cell types with only a few small, mature lymphocytes and many enlaraed lymphoid cells. The enlarged lymphoid cells were atypical and pleomorphic with nuclear clefting and irregularities. Grossly, the left lobe of the thyroid was nearly replaced by a diffuse firm to soft solid mass with smooth tan fish-flesh homogeneous cut surface. Histological diagnosis was diffuse large B-cell lymphoma with areas of marginal zone B-cell lymphoma of MALT type.

• Current Photovoltaic Research
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• v.8 no.1
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• pp.17-26
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• 2020

It is clear that monocrystalline Silicon (Si) ingots are the key raw material for semiconductors devices. In the present industries markets, most of monocrystalline Silicon (Si) ingots are made by Czochralski Process due to their advantages with low production cost and the big crystal diameters in comparison with other manufacturing process such as Float-Zone technique. However, the disadvantage of Czochralski Process is the presence of impurities such as oxygen or carbon from the quartz and graphite crucible which later will resulted in defects and then lowering the efficiency of Si wafer. The heat transfer plays an important role in the formation of Si ingots. However, the heat transfer generates convection in Si molten state which induces the defects in Si crystal. In this study, a crystal growth simulation software was used to optimize the Si crystal growth process. The furnace and system design were modified. The results showed the melt-crystal interface shape can affect the Si crystal growth rate and defect points. In this study, the defect points and desired interface shape were controlled by specific crystal growth rate condition.

• Journal of Mechanical Science and Technology
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• v.19 no.2
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• pp.520-528
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• 2005

In this study, a new mathematical dynamic model of displacement sensitive shock absorber (DSSA) is proposed to predict the dynamic characteristics of automotive shock absorber. The performance of shock absorber is directly related to the vehicle behaviors and performance, both for handling and ride comfort. The proposed model of the DSSA has two modes of damping force (i.e. soft and hard) according to the position of piston. In this paper, the performance of the DSSA is analyzed by considering the transient zone for more exact dynamic characteristics. For the mathematical modeling of DSSA, flow continuity equations at the compression and rebound chamber are formulated. And the flow equations at the compression and rebound stroke are formulated, respectively. Also, the flow analysis at the reservoir chamber is carried out. Accordingly, the damping force of the shock absorber is determined by the forces acting on the both side of piston. The analytic result of damping force characteristics are compared with the experimental results to prove the effectiveness. Especially, the effects of displacement sensitive orifice area and the effects of displacement sensitive orifice length on the damping force are observed, respectively. The results reported herein will provide a better understanding of the shock absorber.

• Journal of Communications and Networks
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• v.7 no.2
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• pp.178-191
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• 2005

Fourth-generation (4G) wireless networks will be the IP-based cellular networks integrating Internet with the existing cellular networks. Two important issues should be concerned in the IP-based cellular networks, IP mobility, and quality-of-service (QoS) guarantees. In this paper, we proposed two mechanisms to solve the problems with IP mobility and RSVP-based QoS provisioning. First, virtual-IP (VIP) allocation scheme in areas with a large rate of handoff can minimize the wireless signaling overhead due to IP mobility. The access routers (ARs) create dynamically the VIP zone by using the measured handoff rate derived from the history of the handoff into neighboring ARs. We show that VIP allocation scheme reduces the binding update messages in the wireless link than hierarchical mobile IPv6. Second, the new advance resource reservation protocol called proportional aggregate RSVP (PA-RSVP) can minimize waste of bandwidth and soft state refresh overhead due to IP mobility. It allocates the bandwidth in advance between the mobility anchor point and neighboring ARs using proportional aggregate reservation. We also show that PA-RSVP provides an improved performance over existing protocols.

• Archives of Craniofacial Surgery
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• v.19 no.3
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• pp.200-204
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• 2018

Fibrous dysplasia (FD) is a rare, benign bone disease with abnormal bone maturation and fibroblastic proliferation. Optimal treatment of zone 1 craniofacial FD is radical resection and reconstruction. To achieve of structural, aesthetic, and functional goals, we use three-dimensionally designed calvarial bone graft for reconstruction of zygomatic defect after radical resection of FD. The authors used a rapid-prototyping model for simulation surgery for radical resection and immediate reconstruction. Donor site was selected from parietal bone reflect shape, contour, and size of defect. Then radical resection of lesion and immediate reconstruction was performed as planned. Outcomes were assessed using clinical photographs and computed tomography scans. Successful reconstruction after radical resection was achieved by three-dimensional calvarial bone graft without complications. After a 12-month follow-up, sufficient bone thickness and symmetric soft tissue contour was well-maintained. By considering three-dimensional configuration of zygomaticomaxillary complex, the authors achieved satisfactory structural, aesthetic and functional outcomes without complications.

• Journal of the Korean GEO-environmental Society
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• v.6 no.1
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• pp.63-72
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• 2005

From the geological and engineering point of view, the limestone is so rigid that it is able to act as a bedrock but if there are some unstable elements which are solubility cavity and cracking zone in the ground, the settlement and bearing capacity of a structure will be required to long-term stability investigations and countermeasures about those problems. When comparing the allowable bearing capacity, the results of Bell's method and the Bowles' method are similar but the results of Hoek-Brown's method are very larger than the others. For weathered limestone, stability is changed by size and depth of the cavity of limestone, but soft and hard rock are stable regardless of size and depth of the cavity.