• The KSFM Journal of Fluid Machinery
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• v.19 no.1
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• pp.5-10
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• 2016

As a key component of a Francis turbine facility, the runner performance plays a vital role in the performance of the turbine. It is effective and successful to design a Francis turbine runner blade with good performance by one dimensional hydraulic design method. On the basis of one dimensional hydraulic analysis, there are a lot of parameters of the internal flow passage shapes determined by experience. Among those parameters, the effect of port area of blade on the performance of a Francis turbine is investigated in this study. A given Francis turbine model was selected for investigating the port area of blade on the performance. The result shows that the effect of port area of runner blade on the outflow angle from runner passage on the performance is quite significant. A correct exit flow angle reduces the energy loss at draft tube, which has the best efficiency of the turbine model.

• International Journal of Costume and Fashion
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• v.3
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• pp.13-24
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• 2003

The purpose of this study was to examine the changes brought by the upper body form using a three-dimensional human body measurement the gypsum method. The developed plane figure was constructed using paper replica to analyze the dimensional shape of the upper torso and to be able to design clothes suitable for elderly women's physical characteristics. The characteristics are analyzed and compared with existing patterns in order to extract the components for the pattern design. The examination was carried out based on the developed plane figures of upper body surface replicas. Type 1, the bent-forward body form, has a wide gap on the shoulder. In Type 2, the gap of waist line was wide at angulus scapulae point. Type 3 was the thin body form, and the girth of the chest, front interscye breadth and back interscye breadth were more level with one another, compared to the other types. In Type 4, the bent-backward body form, there was a wide gap on front shoulder. Comparison with the developed plane figure and existed pattern, items revealed differences in significance included the front and back interscye width between the measured values of the existed patterns and the developed plane figure. Therefore, the basic components of basic bodice pattern for old women were determined in the up-bust circumference and length of the back.

• The Korean Journal of Community Living Science
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• v.24 no.3
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• pp.399-409
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• 2013

The purpose of this study is to compare how the number of panels, the amount of flare and the flare starting point affect the silhouette of the gored skirt. This study consisted of (1) creation of 3D body representations (2) comparison of silhouette between 3D virtual gored skirt and actual gored skirt by pilot experiment (3) pattern drafting of twenty-seven different gored skirts for 3D body representations (4) a computer simulation of twenty-seven different gored skirts for visualization and assessment (5) visual inspection of twenty-seven different 3D virtual gored skirts (6) comparison of ham shapes and measurements for the node and size analysis. A visual inspection of twenty-seven different 3D virtual gored skirts showed clear differences by the amount of flare and the flare starting point ; however, there was notably less difference in the width of ham among six-piece, eight-piece and ten-piece panels. This demonstrated that there was less influence on the number of panels than the amount of flare width of ham and extent of ham for the 3D virtual gored skirt.

• Journal of the Korean Home Economics Association
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• v.17 no.2
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• pp.49-56
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• 1979

In Korean housing designs reflect uniqueness as a result of the influence of regional and atmospheric factors. In this regard, the early use of the hot floor (ondol) system is of special significance. This system is still in use today, not only for house-heating purposes in the homes of commoners, but also for cooking in the kitchen. The present study represents an investigation of the ondol structure since its earliest known usage. Methodology involves a documentary examination of the system. In point of time, this begins with the system's earliest usage and proceeds chronnologically down to the end of the Yi Dynasty. Research indicates that something very much like the ondol system appeared in the early tribal society of Mahan and its usage continued in the state of Koguryo (during the Three Kingdoms Period) in the homes of the poor. This unique system which had its origin in cold northern areas was utilized on a much broader basis during the Koryo Dynasty. Coming down to the Yi Dynasty it found acceptance and application in all parts of the peninsula. Variations in major component parts of the structure, such as the fuel hole, the flue, the draft , and the chimney, normally reflect regional dissimilarities. It is perhaps most significant that here-in contrast to other devices we have a system that serves concurrently for both heating and cooking purposes.

• Journal of Positioning, Navigation, and Timing
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• v.6 no.4
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• pp.211-221
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• 2017

Ellipsodially referenced survey (ERS) is considered as one of the challenging issues in the hydrographic surveys due to the fact that the bathymetric data collected by this technique can be readily transformed either to the geodetic or the chart datum by application of some geoscientific models. Global Navigation Satellite Systems (GNSS) is a preferred technique to determine the ellipsoidal height of a vessel reference point (RP) because it provides cost-effective and unprecedentedly accurate positioning solutions. Especially, the GNSS-derived heights include heave and dynamic draft of a vessel, so as for the reduced bathymetric solutions to be potentially free from these corrections. Although over the last few decades, differential GNSS (DGNSS) has been widely adopted in the bathymetric surveys, it only provides limited accuracy of the vertical component. This technical barrier can be effectively overcome by adopting the so-called GNSS carrier phase (CPH) based techniques, enhancing accuracy of the height solution up to few centimeters. From the positioning algorithm standpoint, the CPH-based techniques are categorized under absolute and relative positioning in post-processing mode; the former is precise point positioning (PPP) correcting errors by the global or regional models, the latter is post-processed kinematic positioning (PPK) that uses the differencing technique to common error sources between two receivers. This study has focused on assessment of achievable accuracy of the ellipsoidal heights obtained from these CPH-based techniques with a view to their applications to hydrographic surveys where project area is, especially, few tens to hundreds kilometers away from the shore. Some field trials have been designed and performed so as to collect GNSS observables on static and kinematic mode. In this paper, details of these tests and processed results are presented and discussed.

• The KSFM Journal of Fluid Machinery
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• v.18 no.3
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• pp.46-52
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• 2015

Pump-turbine system is widely used by the hydropower industry for stabilizing the electrical grid in the vast growing economy of most developed countries. This study only investigates the Fluid-structure Interaction (FSI) analysis of the pump-turbine system at various operating conditions. The FSI analysis can show how reliable each component of the system is by providing the engineer with a better understanding of high stress and deformation points, which could reduce the lifespan of the pump-turbine. Pump-turbine components are categorized in two parts, pressurized static parts and movable stressed parts. The fixed parts include the spiral casing, top and bottom cover, stay vane and draft tube. The movable parts include guide vanes and impeller blades. Fine hexahedral numerical grids were used for CFD calculation and fine tetrahedral grids were used for structural analysis with imported load solution mapping greater than 90 %. The maximum equivalent stress are much smaller than the material yield stress, and the maximum equivalent stress showed an increasing tendency with the varying of operating conditions from partial to excessive at both modes. In addition, the total deformation of all the operating conditions showed a small magnitude, which have quite small influence on the structural stability. It can be conjectured that this system can be safely implemented.

• Journal of Ginseng Research
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• v.29 no.4
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• pp.206-214
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• 2005

The health function food law has been carried into effect from January 31, 2004 just after the proposal of 'a draft of a proposed law concerning the health function foods for the promotion of a nation health' on November 29, 2000 in Korea. After enforcement of health functional food law, there have been difficult market penetration with overall stagnancy of business activities and the current of health functional food within the country divided two groups. In standardized health functional foods the present condition, nutrition supplementary products (938 items) and red ginseng products (351 items) are prevalent and total 32 products are registered containing lactobacilli (297 items), glucosamine (295 items), ginseng (182 items), yeast(136 items) so on. In 2005, five products (products containing green tea extract, soybean protein, plant sterol, fructooligo sugar and Monascus sp. products are newly notified and raw material or component of total 21 products containing xylitol, teanin extract, sardine peptide are recognized as individual authorized health functional foods. Efficacies of ginseng are studied in many-sided researches but benefits of the ginseng in the health functional food law limited to 3 items (staminaresume, immune enhancement, nourishment robustness). To enlarge functionalities of ginseng it needs raw material and ingredient approval through data application to Korea Food and Drug Administration and this procedure acts as barrier of the functional food development in the ginseng industry. It is necessary to develop the authorized health functional foods for leading health functional food market in the future.

• Journal of the Korean Wood Science and Technology
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• v.41 no.2
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• pp.158-163
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• 2013

Cross laminated timber (CLT) has been an rising issue as a promising building material replacing steel-concrete in mid story rise construction. But, there was no specific standard for CLT because it had been developed in industrial section. Recently, new draft for requirements of CLT was proposed by EN which suggested to evaluate the performance of adhesive in CLT by the same method as glulam. But, it has been reported that shear performance of cross laminated timber is governed by rolling shear. Therefore, block shear tests were carried out to compare parallel to grain laminating and cross laminating using commercial one component PUR (Poly urethane resin). The result showed that the current glulam standard for evaluating bonding performance is not appropriate for CLT. Beacause shear strength of cross laminating decreased to 1/3 of parallel to grain laminating and this strength was representing shear performance of wood itself not the bond. However, cross laminating showed no significant effect on wood failure. Thus, wood failure can be used as a requirement of CLT bonding. Based on the results, cross laminating effect should be included when evaluating adhesive performance of CLT correctly and should be considered as an important factor.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5B
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• pp.539-549
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• 2006

The performance of a pontoon-type floating breakwater (FB) is investigated numerically with the use of a second-order time domain model. The model has been developed based on potential theory, perturbation theory and boundary element method. This study is focused on the effects of weakly nonlinear wave on the hydrodynamic characteristics of the FB. Hydrodynamic forces, motion responses, surface elevation, and wave transmission coefficient around the floating breakwater are evaluated for various wave and geometric parameters. It is shown that the second-order wave component is of significant importance in calculating magnitudes of the hydrodynamic forces, mooring forces and the maximum response of a structure. The weak non-linearity of incident waves, however, can have little influence on the efficiency of the FB. From numerical simulations, the ratio of draft and depth, the relationship of wave number and width are presented for providing an effective means of reducing wave energy.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.701-710
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• 2004

Uncertainty was quantified to evaluate calcium determination result in infant formula with AAS (Atomic Absorption Spectrometry) and ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry). Uncertainty sources in measurand, such as sample weight, final volume of sample, sample dilution and the instrumental result were identified and used as parameters for combined standard uncertainty based on the GUM (Guide to the expression of uncertainty in measurement) and Draft EURACHEM/CITAC Guide. Uncertainty components of each sources in measurand were identified as resolution, reproducibility and stability of chemical balance, standard material purity, standard material molecular weight, standard solution concentration, standard solution dilution factor, sample dilution factor, calibration curve, recovery, instrumental precision, reproducibility, and stability, Each uncertainty components were evaluated by uncertainty types and included to calculate combined uncertainty. The kinds of uncertainty sources and components in the analytical method by AAS and ICP-AES were same except sample dilution factor for AAS. The analytical results and combined standard uncertainties of calcium content were estimated within the certification range $(367{\pm}20\;mg/100g)$ of CRM (Certified Reference Material) and were not significantly different between method by AAS followed by ashing and method by ICP-AES followed by acid digestion as $359.52{\pm}23.61\;mg/100g\;and\;354.75{\pm}16.16\;mg/100g$, respectively. Identifying uncertainty sources related with precision, repeatability, stability, and maintaining proper instrumental conditions as well as personal proficiency was needed to reduce analytical error.