• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.888-895
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• 2015

For effective utilization of butter clam shell as a natural calcium resource, the optimal conditions for preparation of calcium acetate (BCCA) with high solubility were determined using response surface methodology (RSM). The polynomial models developed by RSM for pH, solubility, and yield were highly effective in describing the relationships between factors (P<0.05). Increased molar ratio of calcined powder (BCCP) from butter clam shell led to reduction of solubility, yield, color values, and overall quality. Critical values of multiple response optimization to independent variables were 2.70 M and 1.05 M for acetic acid and BCCP, respectively. The actual values (pH 7.04, 93.0% for solubility and 267.5% for yield) under optimization conditions were similar to predicted values. White indices of BCCAs were in the range of 89.7~93.3. Therefore, color value was improved by calcination and organic acid treatment. Buffering capacity of BCCAs was strong at pH 4.88 to 4.92 upon addition of ~2 mL of 1 N HCl. Calcium content and solubility of BCCAs were 20.7~22.8 g/100 g and 97.2~99.6%, respectively. The patterns of fourier transform infrared spectrometer and X-ray diffractometer analyses from BCCA were identified as calcium acetate monohydrate, and microstructure by field emission scanning electron microscope showed an irregular form.

• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.191-199
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• 2021

A distillation column, which is a main facility of the chemical process, separates the desired product from a mixture by using the difference of boiling points. The distillation process requires the optimization and the prediction of operation because it consumes much energy. The target process of this study is difficult to operate efficiently because the composition of feed flow is not steady according to the supplier. To deal with this problem, we could develop a data-driven model to predict operating conditions. However, data preprocessing is essential to improve the predictive performance of the model because the raw data contains outlier and noise. In this study, after optimizing the predictive model based long-short term memory (LSTM) and Random forest (RF), we used a low-pass filter and one-class support vector machine for data preprocessing and compared predictive performance according to the method and range of the preprocessing. The performance of the predictive model and the effect of the preprocessing is compared by using R2 and RMSE. In the case of LSTM, R2 increased from 0.791 to 0.977 by 23.5%, and RMSE decreased from 0.132 to 0.029 by 78.0%. In the case of RF, R2 increased from 0.767 to 0.938 by 22.3%, and RMSE decreased from 0.140 to 0.050 by 64.3%.

• Journal of Dental Rehabilitation and Applied Science
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• v.18 no.3
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• pp.145-155
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• 2002

The results of the present feasibility study are summarized as follows, 1. The three unit bridge of knitted material and UD fibre reinforcement has both the rigidity and the strength against a vertical occlusal load of 75N. 2. Stress concentration at the junctional area between the bridge and the abutments, i.e. between the pontic and the knitted caps was observed. In the case of the bridge with reinforcement straps, it was partly shown that the concentration problem could be improved by simply increasing the fillet size at the area. Further refining in the surface of the junctional area will be needed to ensure a further improvement in the stress distribution. This will require some trade off in the level of the stress and the available space. A parametric study will help to decide the appropriate size of the fillet. 3. Design refinement is a must to improve the stress distribution and realize the most favourable shape in terms of fabrication. The current straight bar with a constant cross section area can be redesigned to a tapered shape. The curve from the dental arch should also be placed on the pontic design. In accordance with design refinement, the resistance of the bridge frame to other load cases should be evaluated. 4. Although not included in the present feasibility study, it is estimated that bridges of the anterior teeth can be made strong enough with the knitted material without further reinforcement using unidirectional materials. In this regard, a feasibility study on design concepts and stress analysis for 3, 4, 5 unit bridge is suggested. 5. Two types of bridge were analysed in terms of fatigue. The safe life design concept, i.e. fatigue design concept, looks reasonable for the bridge where if cracks should form and propagate there is virtually nothing a dentist to do. The bridge must be designed so that no crack will be initiated during the life span. In the case of crowns, however, if constructed with composite resin with knitted materials, it might be possible to repair them, which in general is impossible for crowns of PFM or of metal. Therefore for composite resin crowns, a damage tolerance design concept can be applied and reasonably higher operational stresses can be allowed. In this case, of course, a periodic inspection program should be established in parallel. 6. Parts of future works in terms of structural viewpoint which need to be addressed are summarized as the following: 1) To develop processing technology to accommodate design concepts; 2) More realistic modelling of the bridge and analysis-geometry and loading condition. Thickness variation in the knitted material, taper in the pontic, design for anterior tooth bridge, the effect of combined loads, etc, will need to be included; 3) To develop appropriate design concepts and design goals for the fibre composite FPD aiming at taking the best advantage of knitted materials, including the damage tolerance design concept; 4) To develop testing method and perform test such as static ultimate load test, fatigue test, repair test, etc, as necessary.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.19-23
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• 2005

This study was carried out to compare the rice quality between domestic brand rice and imported Chinese rice. In the appearance of grain, head rice rates were $96.1\%$ in domestic brand rice (Ilpumbyeo), $94.1\%$ in Jingguan (Chinese brand rice) and $86.5\%$ in Xiaozhandao(Chinese brand rice). In case of Chinese parboiled rice, the head rice rate was $0\%$ because the cracked and broken rice occupied about $95.5\%$. The low protein contents in Ilpumbyeo and Xiaozhandao as 6.5 and $6.7\%$ show relatively high palatability as 81.9 and 71.4. However, high protein contents in Jingguan and Chinese parboiled rice as 7.5, $7.4\%$ show low palatability as 64.3 and 55.6. In viscosity characteristics, peak viscosity, break down and final viscosity were higher in Ilpumbyeo and Xiaozhandao, midium in Jingguan and lowest in Chinese parboiled rice. And the set back value, which was negatively related with amylose content, was lowest in Ilpumbyeo and highest in Chinese parboiled, suggesting slow deterioration in Ilpumbyeo and rapid deterioration in Chinese parboiled rice. Overall physical components of cooked rice measured by Texture Analyser were higher in Ilpumbyeo than those in Chinese parboiled rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.3
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• pp.153-162
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• 2016

We investigated the physicochemical properties and starch structure of various rice varieties including 15 colored cultivars. NKHC showed the highest level of protein, lipid, and total dietary fiber levels. Reddish brown rice showed higher lipid content than that in black rice cultivars. Apparent amylose content of waxy and non-waxy colored rice varieties was within the range of 3~5% and 15~18%, respectively. IP exhibited the highest total starch (TS) content, whereas, NKHC and HJJ showed lower TS content than that in other cultivars. Pasting temperature of all colored rice cultivars, except IP, was about $68^{\circ}C$. Peak viscosity of IP, JJJ, Hong, and GGHM showed high values of 138, 130, 128, and 124, respectively. All the colored rice cultivars presented A-type X-ray diffraction pattern and polygonal shapes of starch granules were observed using scanning electron micrographs (SEM). Major groups of amylopectin chain lengths were B (12 < DP ${\leq}$ 24) and A (DP ${\leq}$ 12). SMHC showed the highest B chain content and the lowest A chain content (P < 0.05). These experimental results provided useful information for scientists and the food industry regarding colored rice starches.

• Journal of Preventive Medicine and Public Health
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• v.21 no.2 s.24
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• pp.224-237
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• 1988

To determine the causes of and related factors to childhood injuries, the emergency room records and inpatient medical records were reviewed for 4,849 injured children out of 15,790 pediatric patients(<15 years old) who visited the emergency rooms of 3 university hospitals and 2 general hospitals in Taegu from 1 January to 31 December 1987. Out of total injured children, 54.675 were 3-8 years old and the male to female ratio of the total injured children was about 2:1. The leading causes of injury were falls and slips (29.1%) and traffic accident(28.2%). The frequency of injury was higher in May-October than the rest of months and 51.6% of the injuries occurred between 15 and 20 o'clock. Falls and slips took place most frequently at the stairway(25.7%). The most common interpersonal violence was inflicted injuries(85.6%) and there were 11 child rapes. Dog bites accounted for 67.6% of all biting injuries and it occured 2.9 times more in male than in female. CO intoxication was the most common cause of poisoning (45.3%) and scalding accounted for 85.2% of all burns. Common places of drownings were river (32.2%), swimming pool (22.6%) and construction site(19.3%). To prevent childhood injuries, it is recommended to eliminate the hazardous environmental factors, to provide safe playgrounds, to educate the children for safety from kindergarten and the general public through mass communication, to establish a strict safety standard for houses, public buildings and facilities, and playgrounds.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1293-1301
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• 2016

Hulled oat (Chohan) and naked oat (Choyang) flours were analyzed according to particle size to investigate nutritional components and physicochemical properties. Particle size of naked oat flours was larger than that of hulled oat flours. As the mesh of the crushed ones decreased, particle sizes increased in value. The content of total ${\beta}$-glucan was highest in hulled oat flour (4.23%) with 60 mesh and in naked oat flour (4.26%) with 100 mesh. Most total ${\beta}$-glucan was soluble ${\beta}$-glucan in both flours (over 76%). Total starch of hulled oat flours (63.64~69.82%) was higher than that of naked oat flours (52.45~63.71%). Whereas amylose contents showed a negative correlation with total starch contents. Contents of free amino acids increased according to particle size, and each component was dependent on each type of amino acid. Moreover, while fatty acid composition was not significant, the content of most naked oats was higher than that of hulled oats. Besides, the ratio of unsaturated fatty acids (oleic acid and linoleate) in both types of oat flours was relatively higher than that of other grains. The pasting properties of peak viscosity, trough, and breakdown showed the highest value in both oats with 100 mesh. Further, the values of final viscosity and the setback were higher with relatively larger particle size. In addition, peak time exhibited a lower value with larger particle size, whereas it showed the opposite value for pasting temperature. Starch digestibility did not show any specific trend according to particle size, whereas expected glycemic index of hulled oats was lower than that of naked oats. Moreover, lower values were investigated at larger particle sizes. The results of this study provide basic useful information for processing of oat products to improve consumption of oats grown in Korea.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.2
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• pp.166-179
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• 2008

Excessive concentration of stress which is occurred in occlusion around the implant in case of the implant supported fixed partial denture has been known to be the main cause of the crestal bone destruction. Therefore, it is essential to evaluate the stress analysis on supporting tissue to get higher success rates of implant. The purpose of this study was to evaluate the effects of stress distribution and deformation in 3 different types of three-unit fixed partial denture sup-ported by two implants, using a three dimensional finite element analysis in a three dimensional model of a whole mandible. A mechanical model of an edentulous mandible was generated from 3D scan, assuming two implants were placed in the left premolars area. According to the position of pontic, the experiments groups were divided into three types. Type I had a pontic in the middle position between two implants, type II in the anterior posi-tion, and type III in the posterior position. A 100-N axial load was applied to sites such as the central fossa of anterior and posterior implant abutment, central fossa of pontic, the connector of pontic or the connector between two implants, the mandibular boundary conditions were modeled considering the real geometry of its four-masticatory muscular supporting system. The results obtained from this study were as follows; 1. The mandible deformed in a way that the condyles converged medially in all types under muscular actions. In comparison with types, the deformations in the type II and type III were greater by 2-2.5 times than in the type I regardless of the loading location. 2. The values of von Mises stresses in cortical and cancellous bone were relatively stable in all types, but slightly increased as the loading position was changed more posteriorly. 3. In comparison with type I, the values of von Mises stress in the implant increased by 73% in Type II and by 77% in Type III when the load was applied anterior and posterior respectively, but when the load was applied to the middle, the values were similar in all types. 4. When the load was applied to the centric fossa of pontic, the values of von Mises stress were nearly $30{\sim}35%$ higher in the type III than type I or II in the cortical and cancellous bone. Also, in the implant, the values of von Mises stress of the type II or III were $160{\sim}170%$ higher than in the type I. 5. When the load was applied to the centric fossa of implant abutment, the values of von Mises stress in the cortical and cancellous bone were relatively $20{\sim}25%$ higher in the type III than in the other types, but in the implant they were 40-45% higher in the type I or II than in the type III. According to the results of this study, musculature modeling is important to the finite element analysis for stress distribution and deformation as the muscular action causes stress concentration. And the type I model is the most stable from a view of biomechanics. Type II is also a clinically accept-able design when the implant is stiff sufficiently and mandibular deformation is considered. Considering the high values of von Mises stress in the cortical bone, type III is not thought as an useful design.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.799-805
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• 1998

In present paper, we examined the flayer constituents and functionality of two stage enzyme hydrolysates (TSEH) of purplish clam and oyster, and also examined reappearance of oyster flavors through repreparation of individual flayer constituents. Total free amino acid contents in TSEH was $1943.0mg\%$ for purplish clam and was $5066.2 mg\%$ for oyster, respectively, Major free amino acids in purplish clam extracts were taurine, glutamic acid, glycine, alanine, Iysine and arginine, and in oyster extracts were taurine, asparagine, glutamic acid, valine, leucine, alanine, Iysine and arginine. As for nucleotides and related compounds, AMP was the principal component though small amounts in TSEH of purplish clam and oyster, and also contents of TMAO, total creatinine, and betaine were $41.2 mg\%,\;35,9 mg\%$ and $220.9 mg\%$ for that of purplish clam and $3.51 mg\%,\;33.4 mg\%$ and $380.9 mg\%$ that of oyster, respectively. The major inorganic ions in TSEH of both samples were Na, K, P, Cl and $PO_4$, and major non-volatile organic acid was succinic acid. The TSEH of purplish clam and oyster revealed very higher inhibition effect ($84.1\%,\;77.0\%$) in ACE inhibition than that ($0\~44.7\%$) of water and autolytic extract. A synthetic oyster extract prepared from pure chemicals on the basis of the analytical data on the TSEH, satisfactorily reproduced the taste of the natural extract except for a slight lack of mildness and odor. From the omission test the major taste compounds of oyster extract were free amino acid and inorganic ions. The quaternary ammonium bases, nucleotides and related compounds seemed to net an auxiliary role in taste of that.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.3
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• pp.184-192
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• 2017

Rice flours from five rice (Oryza sativa L.) varieties with different amylose content were prepared by both wet and dry milling processes. The moisture content of wet-milled rice flours (WMR) was approximately three-times higher than that of dry-milled rice flours (DMR). Water absorption index (WAI), water solubility index (WSI), and swelling power (SP) increased in proportion to temperature. The WAI, WSI and SP values of DMR were higher than those of WMR. Baeokchal (BOC), which is a waxy rice cultivar, had a significantly high WSI value. Pasting properties of DMR, except for the BOC cultivar, resulted in an increase in peak, trough, final, and setback viscosities. The levels of resistant starch in four cultivars, except for Dodamssal (DDS), were under 1%, irrespective of the milling process, whereas the resistant starch contents of DMR and WMR in DDS were 9.18% and 6.27%, respectively. In vitro digestibility of WMR was higher than that of DMR, and the estimated glycemic index of the rice flour varieties ranged from 57.6 to 81.3. Damaged starch content of WMR was less than that of DMR; in addition, a negative correlation was observed between the amylose and damaged starch contents of WMR. These results suggest that the properties of rice flour vary depending on the milling method and flour variety, and could be a reference for selecting the appropriate processing method.