• Korean journal of food and cookery science
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• v.23 no.6
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• pp.977-986
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• 2007

This study was conducted to evaluate the mechanical (texture and color) and sensory characteristics of mulberry leaf sulgi (MLS) and lotus leaf sulgi (LLS) that contained different ratios of ingredients. MLS and LLS with final concentrations of 0%, 1%, 3% and 5% of powdered mulberry and lotus leaf respectively, were prepared. The texture characteristics (hardness, adhesiveness, springiness, cohesiveness, gumminess, chewiness), color values (lightness, redness, yellowness), and sensory characteristics (color, flavor, moistness, taste, brittleness, chewiness and after-taste) of the different sulgis were then measured and compared. With the exception of gumminess and chewiness, the texture characteristics of 0% MLS, 1% MLS and 3% MLS were not significantly different. The sensory characteristics of 0% MLS had the highest scores, whereas those of 5% MLS were the lowest for all factors except for brittleness. However, with the exception of chewiness, the scores obtained from 0% and 1 % MLS did not differ significantly. In addition, 1% MLS and 3% MLS were not significantly different from each other. Furthermore, the texture characteristics of 0% LLS and 1 % LLS were not different significantly, although the characteristics of 1% LLS were significantly different from those of 3% and 5% LLS when springiness, cohesiveness, and chewiness were considered. Additionally, the sensory characteristics of 0% LLS and 1% LLS were not significantly different, with the exception of brittleness, and the characteristics of 1% LLS and 3% LLS were not significantly different, with the exception of taste and after-taste.

• Geomechanics and Engineering
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• v.16 no.2
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• pp.195-204
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• 2018

Based on theories of rock mechanics, rock fragmentation, mechanics of elasto-plasticity, and energy dissipation etc., a method is presented for evaluating the rock fragmentation efficiency by using plastic energy dissipation ratio as an index. Using the presented method, the fragmentation efficiency of rocks with different strengths (corresponding to soft, intermediately hard and hard ones) under indentation is analyzed and compared. The theoretical and numerical simulation analyses are then combined with experimental results to systematically reveal the fragmentation mechanism of rocks under indentation of indenter. The results indicate that the fragmentation efficiency of rocks is higher when the plastic energy dissipation ratio is lower, and hence the drilling efficiency is higher. For the rocks with higher hardness and brittleness, the plastic energy dissipation ratio of the rocks at crush is lower. For rocks with lower hardness and brittleness (such as sandstone), most of the work done by the indenter to the rocks is transferred to the elastic and plastic energy of the rocks. However, most of such work is transferred to the elastic energy when the hardness and the brittleness of the rocks are higher. The plastic deformation is small and little energy is dissipated for brittle crush, and the elastic energy is mainly transferred to the kinetic energy of the rock fragment. The plastic energy ratio is proved to produce more accurate assessment on the fragmentation efficiency of rocks, and the presented method can provide a theoretical basis for the optimization of drill bit and selection of well drilling as well as for the selection of the rock fragmentation ways.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.1
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• pp.89-95
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• 2009

This study was conducted to evaluate the textural and sensory properties of Kong-sulgidduk prepared with two types of soyflour (yellow and black) according to the amount of added glutinous riceflour. The rheological properties of Kong-sulgidduk were changed by the amount of added glutinous riceflour. When the amount of added glutinous riceflour was increased from 10% to 40%, hardness, gumminess, and brittleness were significantly increased in the sulgidduk prepared with yellow soyflour. In the case of black soyflour, the addition of 10% glutinous riceflour began to increase in the gumminess and brittleness. The addition of 30% glutinous riceflour effected a significant increase in hardness. The addition of yellow soyflour resulted in higher cohesiveness, gumminess and brittleness scores than those of black soyflour. The results of color assessments demonstrated that the more glutinous riceflour was added to the sulgidduk, the lower were the L-values; however, as the b- and a-values of the sulgidduk prepared with yellow soyflour increased. The addition of the same quantity of glutinous riceflour to the sulgidduk prepared with black soyflour resulted in a reduction in a- and b-values as compared to the sulgidduk prepared with yellow soyflour. In our sensory evaluation, with to the increasing quantities of added glutinous riceflour, the moisture and chewiness values clearly increased. However, the addition of 10% glutinous rice flour resulted in the highest overall quality. Also, the addition of 20% and 30% black soyflour resulted in better scores than the yellow soyflour samples in terms of color, moisture, and overall acceptability. These results demonstrated that the addition of glutinous riceflour to Kong-sulgidduk improves the textual and sensory properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.11 no.4
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• pp.37-41
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• 1982

In order to determine the optimal condition for making Yugwa (one of the Korean traditional cake) the textures in various conditions were studied by sensory test and texturometer. The changes of texture and fat content in the cake were measured along the period of storage. The results were as follows: (1) The cake were classified in 3 groups according to the leavening agent used in the procedure, namely refined rice wine (W), distilled liquor (L) and yeast group (Y). It was the refined rice wine group that had been 'the best' by sensory test. Its brittleness $(1.40{\pm}0.27)$ was higher than those of L and Y. (2) Crispness measured by bend test prior to soaking into syrup were 1.19, 1.23 and 1.63 in W, L, Y, respectively. (3) Chemical composition (%dry basis)) of Yugwa leavened with W included 9.3 of moisture, 1.3 crude protein, 6.7 crude lipid, 66.4 carbohydrate and 16.3 crude ash. (4) Brittleness decreased gradually along the period of storage while the rancidity increased. From the 40th days of storage, the change of brittleness and rancidity were marked as well as the scores of sensory test decreased significantly. (5) Content of linoleic acid in Yugwa decreased along the period of storage from 52.5% of total fatty acid on the first day to 10.9% on the 50th days Main fatty acids in Yugwa were oleic acid, palmitic acid and stearic acid, all of which were also decreased in content along the period of storage. One remarkable change was the appearance of an unknown fatty acid with 19.54 of retention time, in 50% of total fatty acid, on the 50th day of storage.

• Journal of the Korean Society of Food Culture
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• v.34 no.3
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• pp.343-352
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• 2019

The aim of this study was to optimize the best recipe to make acorn bread containing milk as a functional food. The color value, textural, and sensory properties of the acorn bread added with 10~40% ratio of milk were measured to develop the best recipe. As a result, the L-value of color increased with the amount of milk added, but the a- and b-values decreased. As the textural measurement, the hardness increased with increasing milk added. Cohesiveness and springiness decreased, but the gumminess and brittleness increased with the addition of 20% milk, and decreased with further addition. The sensory evaluation revealed color, taste, and overall acceptances to have high scores at 20% addition of milk. Softness and chewiness were good at 10% addition. During the storage periods at room temperature, the L- and b-values increased with the addition of milk, whereas a-value decreased. In freezer storage, the L-value increased with milk content added, but the a- and b-values decreased during the storage periods. The textural properties increased during the storage at room temperature. The addition of milk decreased the cohesiveness and springiness, but the gumminess and brittleness increased significantly after one day storage. In freezer storage, all textural properties increased significantly during the storage periods, but the hardness decreased after two days storage. With the increasing amount of milk added increased the cohesiveness, springiness, and the gumminess except for four days, but decreased hardness and brittleness after two days storage. Therefore the addition of milk in acorn bread improved the textural properties significantly.

• Geomechanics and Engineering
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• v.33 no.3
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• pp.279-289
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• 2023

Brittleness index (BI) is an important property of rocks because it is a good index to predict rockburst. Due to its importance, several empirical and soft computing (SC) models have been proposed in the literature based on the punch penetration test (PPT) results. These models are very important as there is no clear-cut experimental means for measuring BI asides the PPT which is very costly and time consuming to perform. This study used a novel Multivariate Adaptive regression spline (MARS), M5P, and white-box ANN to predict the BI of rocks using the available data in the literature for an improved BI prediction. The rock density, uniaxial compressive strength (σ_c) and tensile strength (σ_t) were used as the input parameters into the models while the BI was the targeted output. The models were implemented in the MATLAB software. The results of the proposed models were compared with those from existing multilinear regression, linear and nonlinear particle swarm optimization (PSO) and genetic algorithm (GA) based models using similar datasets. The coefficient of determination (R²), adjusted R² (Adj R²), root-mean squared error (RMSE) and mean absolute percentage error (MAPE) were the indices used for the comparison. The outcomes of the comparison revealed that the proposed ANN and MARS models performed better than the other models with R² and Adj R² values above 0.9 and least error values while the M5P gave similar performance to those of the existing models. Weight partitioning method was also used to examine the percentage contribution of model predictors to the predicted BI and tensile strength was found to have the highest influence on the predicted BI.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.337-341
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• 2006

The quality characteristics of a surimi-based product with sea tangle single cell detritus (SCD) were studied in order to utilize SCD from sea tangle as a food additive. Mixture design and regression models were applied to optimize the processing conditions and to investigate the interaction between surimi and the other ingredients. Surimi and SCD decreased hardness and cohesiveness of surimi gels, and then increased them. Water increased hardness and then decreased it, whereas cohesiveness was reversed. Surimi and water increased gumminess and brittleness of surimi gels, but SCD decreased them. SCD increased water retention ability (WRA) and whiteness of surimi gels, whereas water decreased it. Hardness and cohesiveness fitted nonlinear models by ANOVA, but gumminess, brittleness, WRA and whiteness fitted linear models. The response constraint coefficient showed that surimi influenced hardness and whitenessmore than water and SCD, whereas water influenced WRA more than surimi and SCD. Moreover, SCD influenced cohesiveness, gumminess and brittleness more than surimi and water. Hardness and cohesiveness fitted nonlinear models with interaction terms for surimi-SCD and surimi-water, respectively. Optimum mixed ratio values of surimi, water, and SCD were 36.80, 57.07 and 4.14%, respectively, by mixture model.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.10
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• pp.13-18
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• 2007

• Explosives and Blasting
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• v.35 no.1
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• pp.27-33
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• 2017

In this study, two fracture toughness test procedures are modelled for selected metal and rock on LS-DYNA, which is a commercial finite element code. The tests are conducted by using the 3-point bend test procedure for rectangular bar specimen. Because it takes a relatively long time to conduct the test, the implicit solver based on the Newmark method is adopted for the analyses. The values of stress intensity factor obtained from the analyses are 73 and $0.3MPa.m^{0.5}$ for the metal and rock material, respectively. It can be thought that the resulting small value of the fracture toughness of the rock material model well represents the brittleness of rock material.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.2
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• pp.191-195
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• 2012

Heavy flint optical glass(SF57HHT) is new material that has extremely high transmittance. Due to brittleness and high hardness, optical glass is one of the most difficult to materials for ultra-precision turning. According to the hypothesis of ductile machining, all materials, regardless of their hardness and brittleness, will undergo transition from brittle to ductile machining region below critical undefromed chip thickness. In this study, cutting test was carried out to evaluate cutting performance of heavy flint glass using ultra-precision machine with single crystal diamond bite. The machined workpiece surface topography, tool wear and surface roughness were examined using AFM and SEM. The experimental results indicate that the machining mode become the brittle mode to ductile mode, when the maximum undeformed chip thinkness is large than critical value. Tool wear mainly occurs on the flank face and its wear mechanism is dominated by abrasion. This study demonstrates the feasibility of SF57HHT by diamond turning.