• Journal of Ocean Engineering and Technology
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• v.27 no.3
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• pp.67-72
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• 2013

In this study, numerical analyses that considered the dynamic interaction effects between the flow and a turbine were carried out to investigate the power output performance of an H-type Darrieus turbine rotor, which is one of the representative lifting-type vertical-axis tidal-current turbines. For this purpose, a commercial CFD code, Star-CCM+, was utilized for an example three-bladed turbine with a rotor diameter of 3.5 m, a solidity of 0.13, and the blade shape of an NACA0020 airfoil, and the optimal tip speed ratio (TSR) and corresponding maximum power coefficient were evaluated through exhaustive simulations with different sets of flow speed and external torque conditions. The optimal TSR and maximum power coefficient were found to be approximately 1.84 and 48%, respectively. The torque and angular velocity pulsations were also investigated, and it was found that the pulsation ratios for the torque and angular velocity were gradually increased and decreased with an increase in TSR, respectively.

• Journal of the Korea Society of Computer and Information
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• v.19 no.10
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• pp.125-133
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• 2014

This paper develops a bankruptcy prediction model on an Artificial Neural Network for hotel management. A bankruptcy prediction model has a specific feature to predict a bankruptcy of the whole hotel business after evaluate bankruptcy possibility on the basis of business performance data of each branch. here are many traditional statistical models for bankruptcy prediction such as Multivariate Discriminant Analysis or Logit Analysis. However, we chose Artificial Neural Network because the method has accuracy rates of prediction better than those of other methods. We first selected 100 good enterprises and 100 bankrupt enterprises as experimental data and set up a bankruptcy prediction model by use of a tool for Artificial Neural Network, NeuroShell. The model and its experiments, which demonstrated high efficiency, can certainly provide great help in decision making in the field of hotel management and in deciding on the bankruptcy or financial solidity of each branch of serviced residence hotel.

• Korean Chemical Engineering Research
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• v.55 no.5
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• pp.646-651
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• 2017

Size and shape of carbon nanotube (CNT) agglomerates in the dilute phase of a bubbling fluidized bed ($0.15m\;i.d{\times}2.6m\;high$) have been determined by the laser sheet technique. Axial solid holdup distribution of the CNT particles showed S curve with dense phase and dilute phase in bubbling fluidization regime. Heywood diameter and Feret diameter of the CNT agglomerates in the dilute phase of bubbling fluidized bed increased with increasing gas velocity. The CNT particle number in the agglomerates increased with increasing of gas velocity. Aspect ratio increased and circularity, roundness and solidity decreased with increasing of gas velocity. A possible mechanism of agglomerates formation was proposed based on the obtained information.

• Journal of the Korean Geosynthetics Society
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• v.16 no.4
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• pp.221-230
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• 2017

We developed a polymer pouch using PVP that is water soluble in the precedent study. Yet melt viscosity was so low that it was not possible to produce hemispheric type which is essential for mass production, therefore we used another material to make the polymer pouch. It enabled to figure out a water-soluble transition and mechanic physical property of PEG that is newly chosen, and to blend the PEG with LLDPE and TALC followed by result. So, we could implement an evaluating property on blended proportion. It is important to find out a proper blending ratio throughout an experiment since its property is different or varied followed by each proportion as a water soluble character is conflict to a solid character. With the blending technique we were able to produce the polymer pouch enhanced for a tensile force and an impact intensity maintaining a water soluble character. We could identify a ground solidity effect of the polymer pouch as a result of a direct shear test using the product developed.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.1
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• pp.46-50
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• 2015

Restoration of a patient with thin and low residual ridges using a removable partial denture cannot provide proper anterioposterior stability and support, so it results in patient discomfort and severe occlusal force. Also, when a small number of residual teeth are far apart from one another, it is difficult to splint. When these teeth are not splinted, they become solitary abutments, which is not a wise treatment decision. In this case, telescopic system reduces severe lateral load on abutments resulting from a clasp denture and it provides stable and definite retention and solidity. In this case report, a patient exhibited full edentulism in maxilla, and a small number of residual teeth in mandible, which were restored with a complete denture and a telescopic denture respectively. In treatment planning, it was concluded that a patient was restored with a telescopic denture since it was highly probable that a clasp denture would create discomfort and difficulty due to a small number of residual teeth located far apart and residual ridges without proper support.

• Culinary science and hospitality research
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• v.9 no.4
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• pp.69-80
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• 2003

To develope natural food preservatives antimicrobial effect of the natural products against food-related bacteria and yeast The purpose of this study was evaluate antimicrobial effect of the citrus seeds. antimicrobial activities of methanol extracts from the citrus seeds investigate against Escherichia coli O26, Staphylococcus aureus 6358, Saccharomyces cerevisiae IBM 4274, Bacillus licheuiformis 9945a and Alcoligenes faecalis. Citrus seeds is containing to moisture 4∼6.5%, curd protein 11∼15%, curd lipid 32∼46%, curd carbohydrate 22∼45 % and ash 2∼4 %, that is containing to flavornoid 12∼48mg% and phenolic compound 22∼53mg%. Solidity content of the methanol extract from the citrus seeds was 0.8∼1.2%. Almost all of the methanol extracts from citrus seeds exhibited growth inhibiting activities for most of microorganisms tested. The methanol extracts from Citrus grandis, C. sunki, C. sulcata showed the growth inhibitory effects against Escherichia coli O26. The methanol extracts from C. obovoidea, C. sulcata, C. aurantium showed the growth inhibitory effects against Staphylococcus aureus 6358. The methanol extracts from C. obovoidea, C. sulcata, C. tangerina showed the growth inhibitory effects against Saccharomyces cerevisiae IBM 4274. The methanol extracts from C. obovoidea, C sunki, C. sulcata, C. tangerinan, C. natsudaidai, C. iyo, C. aurantium showed the growth inhibitory effects against Bacillus licheuiformis 9945a. The methanol extracts from C. obovoidea, C sunki, C. sulcata, C. aurantium showed the growth inhibitory effects against Alcoligenes faecalis. Among this especially, Showed growth inhibiting activity of the methanol extracts from Citrus sulcata that about microorganisms investigated. If apply searching suitable application method about such the citrus seeds antimicrobial activity, role as good antimicorbial material in storage or cooking of food, processing is expected.

• The KSFM Journal of Fluid Machinery
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• v.4 no.1 s.10
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• pp.7-13
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• 2001

In developing a multistage compressor, the stage matching is one of the critical design issues. The mismatching can be often observed even if each stage has been proven good and then used as part of a compression system. A good matching among the stages can be achieved by changing various design parameters (i.e., passage cross sectional areas, blades angles, stagger angles, curvature, solidity, etc.). Therefore, designers need to find out what parameters must be changed and how much. In this study, a method to search the design parameters for optimum stage matching has been used based on an 1-D mathematical model of a compressor, which uses the data obtained from the preliminary test to identify the design parameters. This methodology is applied with a two-stage axial compressor, which was originally designed for a helicopter gas turbine engine. After identifying design parameters using preliminary test data, an optimization process has been employed to achieve the best matching between the stages (i.e., maximum efficiency of the compressor at its operation modes within a given range of the rotor speed under given restrictions for required stall margins and mass flow). 3-D flow calculations have been performed to confirm the usefulness of the corrections based on the 1-D mathematical model. Calculational results agree well with the experimental data in view of the performance characteristics. Some promising results were produced through the methodology proposed in this paper in conjunction with flow calculations.

• Journal of Korea Multimedia Society
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• v.14 no.2
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• pp.329-338
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• 2011

Recent augmentation reality demands more realistic multimedia data with the mixture of various media. High-technology for multimedia data which combines existing media data with various media such as audio and video dominates entire media industries. In particular, there is a growing need to serve augmentation reality, 3-dimensional contents and realtime interaction system development which are communication method and visualization tool in Internet. The existing services do not correspond to generate depth value for 3-dimensional space structure recovery which is to form solidity in existing contents. Therefore, it requires research for effective depth-map generation using 2-dimensional video. Complementing shortcomings of existing depth-map generation method using 2-dimensional video, this paper proposes an enhanced depth-map generation method that defines the depth direction in regard to loss location in a video in which none of existing algorithms has defined.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.416-423
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• 1993

Milk powders were made by several drying methods and raw materials, and rheological properties of milk powders were investigated by an Instron Universial Testing Machine. The results obtained are summarised as follows. Bulk density of the drum dried whole milk powder was $0.382\;g/cm^3$ and was higher than that of other milk powders. The Hausner ratio, angle of repose and compressibility of the spray dried skim milk powder were 1.127, $32.5^{\circ}$ and 0.029 respectively. This result indicated that skim milk powder showed free flowing characterristics. The compressibility of the drum dried whole milk powder was decreased by the decrease of moisture content. Compressibility of the milk granule was 0.056 and was lower than that of milk powder. The spray dried milk powder of a grobular shape had higher solidity than the freeze or drum dried milk powder. The drum dried milk powder particles consist of irregular shape.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.11
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• pp.74-79
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• 2005

Computational studies on the hydrodynamic behavior of the forward-sweep inducers for the rocket-engine turbopump are presented in comparison with the conventional backward- sweep inducers. In the present study, two kinds of forward-sweep inducers are designed and numerically investigated. Forward-sweep inducers have bigger tip solidity compared to backward-sweep inducers even with shorter axial length due to their forward-sweep leading edge profiles. It is shown that back flows at the inlet decreases dramatically for forward- sweep inducers. And the low pressure region at the back flow are also decreased, which is assumed to promote the suction performance of the inducers. It seems that the hub located upstream of the tip at the leading edge induces pre whirl at the inlet blade tip for the backward sweep inducer. And this pre whirl leads to the big back flow.