• Journal of the Korean Wood Science and Technology
• /
• v.44 no.6
• /
• pp.809-820
• /
• 2016

The goal of this study was to predict lamina yield from logs of different diameter for production of cross laminated timber. Log characteristics of red pine (Pinus densiflora) and Japanese cedar (Cryptomeria japonica), including diameter, length, volume, and defects were used for statistical and geometrical analyses, along with the lamina characteristics, including width, thickness, and defects. Based on the data obtained, the strong factors influencing the yield and grade of lamina from the two species were statistically evaluated. A geometrical approach was used for analysis of the yield from logs of given diameters. Statistical analysis showed that lamina yield was dependent on target lamina size but the grade of lamina was not related to any of the log characteristics. The suggested yield equations from the geometrical approach indicated an accuracy of less than 20% difference.

• Journal of Animal Science and Technology
• /
• v.45 no.2
• /
• pp.335-342
• /
• 2003

This study was conducted to predict the carcass yield traits using ultrasound before slaughter and to enhance the prediction accuracy of carcass yield grade by applying various strategies. For this experiment, five hundred seventy three Hanwoo steers of 24 months of age were used. Difference between ultrasound result and carcass measure of BFT and LMA was 0.6$\pm$1.65mm and 0.7$\pm$5.56cm2, respectively. Correlation coefficient between ultrasound result and carcass measure of BFT and LMA was 0.86 and 0.82, respectively (p<0.001). Results for improving predictions of yield grade by four methods-the Korean yield grade index equation, fat depth alone, regression and decision tree methods were 80.3%, 81.3%, 80.1% and 81.8%, respectively. We conclude that the decision tree method can easily predict yield grade and is also useful for increasing prediction accuracy rate.

• Journal of Industrial Technology
• /
• v.9
• /
• pp.29-41
• /
• 1989

A general study on the upgrading of mica minerals which are mainly found in pegmatite deposits was carried out for the purpose of developing a technique for recovering mica in form of comercial grade products. By the way the grade one of about 5~6% $K_2O$ still is not developed. The target of this research work is to be establish a process for the efficient concentration of muscovite, containing more than 10% $K_2O$. The tests are applied to incraese the recovery and grade of concentrates in term of variations of conditions. The test sample consists of mainly muscovite and gangue mineral such as quartz, pyrite and chlorite. Decantation and shaking table tests were ineffective to up-grade this low grade one, but flotation method gave satisfactory result. By means of grade one, but flotation method gave satisfactory result. By means of grindability tests, an optimum result could be obtained from the sample ground to -48mesh feed size. The flotation result indicates that the dodecyl ammonium chloride used as a cationic collector is effective on the negatively charged surface, while the sodium dodecyl sulfate as an anionic collector is effective on the positively charged surface. Muscovite was floated by petroleum sulfonate as well as amine type collector, it also floated by MIBC as well as pine oil frother under well condition. Fine muscovite concentrates of about 10.68% $K_2O$ was obtained with 22.4% yield, by decantation, the muscovite concentrates of 10.10% $K_2O$ was obtained with 23.54% yield, by table concentration, the muscovite concentrates of 11.51% $K_2O$ was obtained with 23.0% yield by flotation.

• Journal of the Korean Ceramic Society
• /
• v.38 no.9
• /
• pp.822-828
• /
• 2001

Bayer process is based on the extraction of aluminium trihydroxide from bauxite. The process is operated with the several criteria such as primary crystal size, particle size distribution and yield etc.. In this study basing on the previous results, an investigation on the effect of chemical grade and smelting grade aluminium trihydroxide precipitation condition were undertaken. As a result, particle size was 42∼44${\mu}$m form chemical grade product and 74∼77${\mu}$m for smelting grade product. The yield and solubility by acid of chemical grade product was higher than smelting grade product. The attrition index of smelting grade product was lower than that of other commercial product because primary crystal size of the smelting grade product was small.

• Korean Journal of Food Science and Technology
• /
• v.39 no.4
• /
• pp.412-418
• /
• 2007

The physicochemical properties and mixograph characteristics of soft white winter (SWW) and club wheat, as well as their product potentiality, were investigated. There were no significant differences between the SWW wheat and club wheat regarding their Single Kernel Characterization System (SKCS) properties. The straight-grade flour yield, break flour yield, ash content, and milling score of the SWW wheat were similar to those of the club wheat, and the straight-grade flour yield had a significant positive correlation to the break flour yield (r = 0.805**). The Rapid Visco-Analyzer (RVA) peak viscosity and swelling volume of the SWW wheat flour were very similar to those of the club wheat flour, and there was a significant positive correlation between the RVA peak viscosity and the swelling volume (r = 0.662**). The average mixograph absorption of the SWW wheat was higher than that of the club wheat. The club wheat resulted in a higher cookie diameter than the SWW wheat, but the difference was not significant. The sponge cake volume using the SWW wheat flour was higher than that with the club wheat flour. In addition, there was a significant correlation between the cookie diameter and the sponge cake volume (r = 0.745**).

• Korean Journal of Organic Agriculture
• /
• v.27 no.2
• /
• pp.225-235
• /
• 2019

The present study hypothesized that ratio between carcass traits components could be applied for the understanding of yield index in Hanwoo steer. A thousand data was generated based on average carcass weight (CW), loin area (LA) and backfat thickness (BT) of Hanwoo steer in December 2018 for analysis 1. Then yield index (YI) was calculated using newly established yield index equation. The correlation between yield index and each carcass traits was visualized. In the interaction between carcass traits components (LA, CW, BT) and YI, only the interactions including BT showed a regular pattern to YI. Then changes of YI according to ratio of carcass traits components were investigated. The observed interactions between LABT and CWBT were similar with Monod equation model. The changes of YI to LABT and CWBT were fitted to Monod equation, and yield constants (K1 for LABT; K2, CWBT) of each equation were calculated as 0.47 and 2.20, respectively. Carcass traits from 5 commercial Hanwoo steer farm were then employed in the second analysis. Yield constants of each farm were estimated. In estimation, R² value for K1 (LABT) showed greater than the K2 (CWBT). Finally, each farm was plotted based on their K1 and K2 values and it was found that greater yield index of Hanwoo steer was found as increased K1 and K2. As conclusion, the present study suggested the possibility of K1 and K2 values for understanding of yield grade equation and their application in the evaluation of new model for yield grade estimation and feeding strategy.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1997.10a
• /
• pp.189-193
• /
• 1997

The deformation characteristics of 50kgf/$\textrm{mm}^2$ grade steels were studied numerically and experimentally to investigate the effects of the size, shape, distribution and volume fraction of the second phase on mechanical properties. Flow curves of ferrite calculated by Tomota's experimental equation was modified to take into account yield point phenomena of steels. The predicted tensile properties by modified Tomota's method were in good agreements with measured data.

• Journal of the Korea Concrete Institute
• /
• v.24 no.2
• /
• pp.195-204
• /
• 2012

In the construction of high-rise buildings, bent re-bars are manually straightened to connect slabs to core-walls, which are usually cast before floor structures. During cold bending and straightening of re-bars, plastic deformation causing work hardening, Bauschinger effect and aging hardening is unavoidable. Tensile tests of coldly bent and straightened re-bars were conducted with test parameters of grade, diameter, and bend radius of re-bars as well as age between bending and straightening. Test results showed that proportional limits were lower and strain hardening occurred without yield plateaus. Inside and outside of re-bars with compression and tension deformations, respectively, during bending showed lower yield points due to Bauschinger effect and no yield plateaus due to work hardening, respectively. When re-bar grade was higher, yield point became significantly lower where Grade 400 re-bars had yield strengths lower than specified yield strength of 400 MPa. Because the surface of re-bar has higher strength than the core of re-bar, Bauschinger effect was more obvious for higher-grade re-bars. When age between bending and straightening was greater, yield strength increased and elongation decreased (i.e. embrittlement occurs). Using measured data, stress-strain relationship for straightened re-bars was developed based on Ramberg-Osgood model, which can be used to evaluate stiffness of joints when straightened re-bars are applied.

• Food Science of Animal Resources
• /
• v.28 no.5
• /
• pp.604-609
• /
• 2008

Analyses were conducted to estimate carcass component of yield grade factors by sex and live weight class and to develop the prediction equation of retail product weight by sex in Korean native cattle (Hanwoo). Data from 42,113 Hanwoo carcasses were used to estimate the traits of yield grade factor and an additional 1,066 carcasses were used to develop the prediction equation of retail meat weight. The average of fasting weight of cow, bull and steer were 529 kg, 596 kg, and 634 kg respectively. Carcass weight (CW), backfat thickness (BFT), loineye area (REA), Index score of wholesale meat and yield grade were significantly (p<0.01) affected by sex and live weight. The lean meat percentage, fat percentage and bone percentage based on the weight of cold carcasses were significantly different (p<0.05) between sex groups. The equation of predicting the retail meat product from this study could be expressed as a multiple regression $Y=-4.18+0.63{\times}CW\;(kg)-0.17{\times}BFT\;(cm)+0.16{\times}REA\;(cm^2)$, $R^2=0.93$. Among the independent factors, the BFT was the highest contributor to the prediction equation. Using the equation from this study should allow for rapid, precise and cost-effective assessment of the retail product in Hanwoo beef carcasses.

• Journal of Korean Society of Forest Science
• /
• v.99 no.4
• /
• pp.479-486
• /
• 2010

We analyzed the relationships between the daily yield and quality of pine-mushroom to predict the annual production pattern and unit price of the mushroom with the records of pine-mushroom trade at Yeongdeok forestry cooperative's market for nine years (2000~2008). Although there were some exceptions due to extreme drought or extraordinary temperature, the production ratio of high quality (first and second grade) was more than 50% in early stage and decreased, while that of low quality (pileus opened and defected ones) showed increasing pattern after the production reached in peak. The ratio of high quality and that of low quality were reversed 1~9 days before the mushroom production reached the acme of daily yield, which allowed us to predict that the mushroom production would be decreased when the ratio of low quality overcomes that of high quality. The ratio of high quality preceded about 3~4 days prior to that of daily yield, and the mushroom yield showed significant correlations with the ratio of high quality mushroom prior to 3~4 days of the day with the coefficient larger than 0.5 (r=0.51 for 3 days and r=0.54 for 4 days). Thus, we concluded that the analysis of grade distribution of pine-mushroom at the market may provide a significant clue to predict production pattern of the mushroom. In addition, the price of high quality pine-mushroom showed clear negative correlations with the yield. Thus, the analysis may take a good role for the trading of pine-mushroom with providing information for predicting the price of pine-mushroom.