• Journal of the Korean Geotechnical Society
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• v.36 no.12
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• pp.107-116
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• 2020

The compaction grouting technique is widely used to improve the liquefaction resistance of loose sands that are liquefaction-prone. Particularly, the horizontal injection of compaction grout is proposed for the liquefiable ground with an overlying structure as it does not allow the vertical compaction grouting. However, there has been limited number of researches on the horizontal compaction grouting. Therefore, this study explores the grout bulb shape and expansion direction in loose sand. A series of scaled two-dimensional experiments on the horizontal compaction grouting was conducted varying the overburden stress. The results show that the grout bulb grows in an elliptical shape though its directivity of major axis changes with the overburden effective stress and relative density. The grout bulb expands faster in a horizontal direction under a low overburden stress with a small relative density. The higher overburden stress and the greater relative density cause the more circular shape with the faster expansion in a vertical direction. The presented finding is expected to contribute to accurate and efficient design of the horizontal compaction grouting method.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.1
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• pp.45-53
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• 2016

The interaction between the hull of ship and free surface of water generates important loads during slamming motion. In the present study, the slamming load applied on the sectional surface of two-dimensional arbitrary bodies has been investigated under several falling velocities. This simulation has been done with the commercial CFD software ANSYS FLUENT^®. Through the conventional MARINTEK experiments for the benchmark of the simulation, we verified the impact pressure values between the experiments and simulation results. Two arbitrary ship bow section models, Panamax-like(with small convex bulb and flare) and Post panamax-like(with large convex bulb and flare) are also investigated. Simulation results show that a maximum impact pressure on the Post panama-like shape is higher than the Panamax-like shape. According to both a lump of water generated by arbitrary shape and various dead-rise angles of the shape, the pressure picks were enhanced in the simulation.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.375-380
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• 1999

It is required efficient section shape like bulb-tee girders with high strength concrete to construct long span bridges economically. However, the trpical design method for PSC I-girders include bulb-tees, the concrete girder prestressed only one time at same time. But in this paper, new design method prestress increases as each load-stress stage. The incrementally prestressed concrete (IPC) girders can reduce the required area of grider section and extend span length by additional prestress. So it is able to construct long span bridges economically by using IPC girders.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.3
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• pp.191-198
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• 2019

This case report presents a closed hollow bulb obturator made by 3D printing for a maxillectomy patient. Final impression was taken according to the instructions and impression trays provided by the Magic $denture^{TM}$ system. Vertical dimension, facial appearance, and retention had been checked with the try-in denture. The try-in denture was corrected and adjusted to fulfill the demand of the patients, then these were reflected to the final design of the denture. The defect area was designed as a closed hollow bulb shape to reduce the weight and to provide uniform thickness of the denture. The patient satisfied with the esthetics and function of the denture.

• Special Issue of the Society of Naval Architects of Korea
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• 2005.06a
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• pp.31-37
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• 2005

An attempt to improve the speed performance through the minimizing in wave resistance has been done by an application of gooseneck and no bulb type to bulbous bow for the DSME 78,500 Class LPG Carrier on the basis of the CFD calculation and comparatives model tests. The hydrodynamic characteristics according to the variation of the shape of Cp-curve, design load water line, frame line and bulbous bow that have an important effect on the wave resistance has been evaluated/calculated by ship-flow code. A wide variety in hull variation have been tried to have a good hull form with three types of fore-body hull forms mainly classified by the shape of bulbous bow. The speed performances for the three final hull forms with different bulbous bows have been evaluated through the model tests.

• The Plant Pathology Journal
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• v.21 no.1
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• pp.83-85
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• 2005

Ditylenchus acris was isolated from diseased strawberry plants. Frequently, D. acris and Aphelenchoides fragariae occur together in a strawberry plant. Both species appeared very similar in the shape, length, swimming behavior and causing symptoms, and difficult to distinguish them by a stereomicroscope. But they were easily distinguished under a compound microscope especially by their tail shape, median bulb, vulva position, and bursa.

• Korean Journal of Plant Taxonomy
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• v.37 no.3
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• pp.275-308
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• 2007

For 20 taxa of Korean Allium, including 16 species and 5 varieties, examined were morphological characters (i.e. sexuality, structure and shape of underground part, types and growing patterns of leaf and scape, and shapes of perianth, filament and pistil). The specialization and the evolutionary trends of taxonomic characters were inferred from morphological examination. Taxonomic relationships and system of Korean Allium were also studied. The characters showing evolutionary trends were the structure and shape of underground part including rhizome and bulb, leaf, scape, inflorescens, filament and ovary. It seemed that thin and short rhizome developed from thick and long one, and the membranous simple bulb tunic evolved into fibrous reticulate one. The presence of hyaline sheath in A. monanthum of sect. Microscordum was apomorphic. Both angular leaf blade with 2-rowed vascular bundle and flat blade with 1-rowed vascular bundle were developed from terete one with 2-rowed vascular bundle. The base of filament have differentiated from entire to toothed, and 2-ovuled ovary as well as erect scape before flowering was plesiomorphic type. In addition, sexuality, structure of underground part, the presence of hyaline sheath and cross-section structure of leaf were taxonomic characters with the level of the subgenus in this genus. Shape of rhizome, bulb, leaf, scape and pedicel discriminated each section from other ones in the subgenera easily. The shape and arrangement of perianth and filaments were the diagnostic characters for species level along with shape of ovary and stigma.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.399-406
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• 2004

This paper is experimental study on the effect of improved soil strength which was grouted by pressure grouting method for prevent collapse the tunnel's face during excavate tunnel. This study performs to investigate the proper grouting pressure and grouting method through pressure grouting laboratory model tests using loose dense sandy soil using specially designed and fabricated device($180cm{\times}220cm{\times}300cm$) under changing condition of injection in this test The investigation is carried out through measuring the size and shape of grout bulb, elastic modulus by pressure-meter test Elastic modulus was estimated using relation stress with strain which is result the uni-direction compressive strength test for cured grouted bulb under water during 28days. From these test results, the amount of increased elastic modulus of grouted zone was suggested.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.1
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• pp.100-114
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• 2015

This paper deploys optimization techniques to obtain the optimum hull form of KSUEZMAX at the conditions of full-load draft and design speed. The processes have been carried out using a RaPID-HOP program. The bow and the stern hull-forms are optimized separately without altering neither, and the resulting versions of the two are then combined. Objective functions are the minimum values of wave-making and viscous pressure resistance coefficients for the bow and stern. Parametric modification functions for the bow hull-form variation are SAC shape, section shape (U-V type, DLWL type), bulb shape (bulb height and size); and those for the stern are SAC and section shape (U-V type, DLWL type). WAVIS version 1.3 code is used for the potential and the viscous-flow solver. Prior to the optimization, a parametric study has been conducted to observe the effects of design parameters on the objective functions. SQP has been applied for the optimization algorithm. The model tests have been conducted at a towing tank to evaluate the resistance performance of the optimized hull-form. It has been noted that the optimized hull-form brings 2.4% and 6.8% reduction in total and residual resistance coefficients compared to those of the original hull-form. The propulsive efficiency increases by 2.0% and the delivered power is reduced 3.7%, whereas the propeller rotating speed increases slightly by 0.41 rpm.

• Korean Journal of Plant Resources
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• v.13 no.3
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• pp.219-226
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• 2000

The experiments were conducted to investigate the characteristics of the seed germination and the bulb dormancy in Korean-native Allium victorialis L. by the physicochemical treatments. The characteristics of two Allium victorialis seeds was similar in shape, color and threshing but different in other characters. Weight of 1,000 grains in Ullrung-native was 14.8g corresponding to 2.1 times as compared with Odae-native. Seeding immediatly after seed collection of Ullrung-native only germinated and chemicals didn't affect in germination improvement. The germination rate, average days to germination and coefficient of germination of Ullrung-native was 86%, 42 days and 2.05 at the dark condition of control, respectively. The germination rate, average days to germination and coefficient of germination of Odae-native was 70%, 47 days and 1.5 at the dark condition of control and 82%, 47 days, 1.75 at the light condition after 5$^{\circ}C$ prechilling for 30 days, respectively. The bedding days to reduce the physiological dormancy in the bulb of Odae-native assumed to be appropriate up to 45 days after the first prechilling.