• Industrial Engineering and Management Systems
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• v.12 no.3
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• pp.281-287
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• 2013

In this paper, we introduce a roots method that uses the roots inside the unit circle of the associated characteristics equation to evaluate the steady-state system-length distribution at three epochs (pre-arrival, arbitrary, and post-departure) and sojourn-time distribution in GI/PH/1 queueing model. It is very important for an air base to inspect airplane oil because low-quality oil leads to drop or breakdown of an airplane. Since airplane oil inspection is composed of several inspection steps, it sometimes causes train congestion and delay of inventory replenishments. We analyzed interarrival time and inspection (service) time of oil supply from the actual data which is given from one of the ROKAF's (Republic of Korea Air Force) bases. We found that interarrival time of oil follows a normal distribution with a small deviation, and the service time follows phase-type distribution, which was first introduced by Neuts to deal with the shortfalls of exponential distributions. Finally, we applied the GI/PH/1 queueing model to the oil train congestion problem and analyzed the distributions of the number of customers (oil trains) in the queue and their mean sojourn-time using the roots method suggested by Chaudhry for the model GI/C-MSP/1.

• Journal of the Korean Wood Science and Technology
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• v.48 no.4
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• pp.503-512
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• 2020

Using Na₂CO₃ versus NaCl as chemical activator, we compared the quality of activated carbon produced from oil palm fronds as raw material. These activators were selected for comparison because both are readily available and are environmentally friendly. In the manufacturing, we used Indonesian National Standard (SNI 06-3730-1995) parameters. For the quality comparison, we determined activated-carbon yield, moisture, ash, volatiles, and fixed-carbon contents; and adsorption capacity of iodine. The best characteristics, assessed by morphological surface analysis and Fourier transform infrared (FTIR) spectral analysis, were observed in the carbon activated by Na₂CO₃ at an activator concentration of 10% and carbonization temperature of 400 ℃. The results were as follows: activated-carbon yield, 84%; water content, 8.80%; ash content, 2.20%; volatiles content, 14.80%; fixed-carbon content, 68.60%; and adsorption capacity of iodine, 888.51 mg/g. Identification using the FTIR spectrophotometer showed the presence of the functional groups O-H, C=O, C=C, C-C, and C-H in the Na₂CO₃-activated carbon.

• Applied Chemistry for Engineering
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• v.25 no.6
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• pp.639-644
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• 2014

Domestic vehicle companies have been selling genuine engine oils with higher price than that of the same grade of regular engine oils. In this study, our group investigated the properties of engine oils for 14 kinds of the genuine and equivalent regular engine oil (KS product) species under a fresh as well as used condition recovered after 10,000 km driving. From analytic results, genuine engine oils had similar physical properties to regular engine oils under the fresh condition. But recovered regular engine oils had better properties in lubricity, kinematic viscosity and acid number change than those of recovered genuine engine oils.

• Clean Technology
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• v.22 no.4
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• pp.299-307
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• 2016

These days, coal is one of the most important energy resources used for transportation, industry, and electricity. There are two types of coal: high-rank and low-rank. Low-rank coal has a low calorific value and contains large amounts of useless moisture. The quality of low-rank coal can be increased by simple drying technology and it needs to be stabilized by hydrocarbons (e.g. palm acid oil, PAO) to prevent spontaneous combustion and moisture re-adsorption. Spontaneous combustion becomes a major problem during coal mining, storage, and transportation. It can involve the loss of life, property, and economic value; reduce the quality of the coal; and increase greenhouse gas emissions. Besides spontaneous combustion, moisture re-adsorption also leads to a decrease in quality of the coal due to its lower heating value. In this work, PAO was used for additive to stabilize the upgraded coal. The objectives of the experiments were to determine the stabilization characteristic of coal by analyzing the behavior of upgraded coal by drying and PAO addition regarding crossing-point temperature of coal, the moisture behavior of briquette coal, and thermal decomposition behavior of coal.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.6
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• pp.894-899
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• 2020

This study investigated the effects of inclusion of pollock oil (PO) in the diet of broodstock on the egg and larval quality of Walleye Pollock Gadus chalcogrammus. The experimental diet comprised of semi-moist pellets prepared either with or without PO (control; Con). The fish assigned to each diet were fed to visual satiation (two meals per day) for 12 weeks. Eggs spawned from both groups of fish were sampled during the spawning season (three months) and the egg and larval quality was determined. Total egg volume, fertilization, and hatchability of eggs from the PO group were higher than those of the Con group. Fatty acid composition of fertilized eggs was not affected by the experimental diet. Oleic acid, eicosapentaenoic acid, and docosahexaenoic acid content in larvae of the PO group was higher than that in larvae of the Con group. These results demonstrate the beneficial effects of including PO in the broodstock diet of Walleye Pollock, specifically on the quality of the eggs (total egg volume, fertilization, and hatchability) and larvae (fatty acid composition).

• Journal of Animal Science and Technology
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• v.50 no.5
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• pp.721-732
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• 2008

Pressed ham was manufactured to investigate the effects of grape seed oil on the quality characteristics of pressed ham. Five treatments were divided based on differences in the amount of grape seed oil added into the pressed ham. For control, 10% of back fat was only added without grape seed oil. For the first treatment, 10% of grape seed oil among the lard component added into the pressed ham was replaced. For the 2nd, 3rd and 4rd treatments, 20%, 30% and 40% of grape seed oil was respectively replaced. Pressed ham manufactured using grape seed oil was vacuum packaged and then stored for 1, 7, 14, 21 and 28 days at 4℃. Samples were analyzed for shear force value, sensory properties, TBARS and fatty acid composition. In the 1, 21 and 28 days of storage, shear force value of grape seed oil treatment (T4) was significantly lower than that of control (P<0.05). No remarkable differences were found in sensory properties among control and grape seed oil treatment groups. The TBARS value was significantly higher in control than in grape seed oil treatment group(T4) at 28 days of storage (P<0.05). The TBARS of control and grape seed oil treatment groups increased significantly as the storage period increased(P<0.05). The linoleic acid(C18:2) content of grape seed oil treatment groups was significantly higher than that of control(P<0.05). But the contents of C10:0～C20:4 were decreased significantly by grape seed oil additive (P<0.05). Saturated and monounsaturated fatty acid content of control was significantly higher than that of grape seed oil treatment groups(P<0.05). Whereas the increase level of grape seed oil additive resulted in the significantly higher polyunsaturated fatty acid content(P<0.05). Based on these findings, we conclude that the sensory properties and lipid oxidation(TBARS) of manufactured pressed ham were not affected by grape seed oil addition. Also, our results indicate that high-quality pressed ham can be manufactured with strengthen of polyunsaturated fatty acid content.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.6
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• pp.1693-1703
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• 2015

This study is aimed to retain objectivity and generality against consumer perception about seafood of Hebei Spirit oil spill incident area, and analyze gap of consumer perception in according to confidence level of seafood using ordinal logit model. As results, This article have three implications. First, Consumer don't have high confidence level in comparison with previous research. Second, It is important to retain confidence of quality for purchasing seafood of oil spill incident area. Third, Consumer perception is improved positively against seafood of oil spill area. But This study has limits that don't take regional opinion and situation into account.

• Korean Journal of Remote Sensing
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• v.33 no.1
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• pp.61-67
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• 2017

The detection of oil spills using radar image has been studied extensively. However, most of the proposed techniques have been focused on improving detection accuracy through the advancement of algorithms. In this study, research has been conducted to improve the accuracy of oil spill detection by improving the quality of radar images, which are used as input data to detect oil spills. Thresholding algorithms were used to measure the image improvement both before and after processing. The overall accuracy increased by approximately 16%, the producer accuracy increased by 40%, and the user accuracy increased by 1.5%. The kappa coefficient also increased significantly, from 0.48 to 0.92.

• Journal of the Korean Society of Food Culture
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• v.13 no.1
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• pp.27-35
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• 1998

Consumption of edible oil at food service institutions in Inchon was surveyed to provide basic data for continuous education of dietitians. Manufacturing industry was the major food service institution(78.8%) in Inchon followed by schools, hospitals and social welfare service centers. Most dietitians were at the age of twenties and college graduates with professional careers of 1-5 years. Oil was purchased on the basis of its quality within 1-3% of total food costs four times a month. Proper frying temperature was determined by dropping salt or food coating materials into the oil. Soybean oil was the most frequently used and commercial frying mix powder and flour and eggs in water were the most common food coating materials. Fish and commercial frozen foods were the most frequently used materials for frying. Fried foods were stored with covers in a basket and consumed within 30 minutes after cooking. Frying oils were used one more time after filtering and color was the index for determination of re-use.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.10a
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• pp.115-118
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• 1997

Recently, hot rolling oil lubrication technology is required to face with the new environments such as the rapid introduction of high wear resistent high speed steel roll the development of continuous hot rolling technology. In the hot strip mill, according to rolling and quality required conditions are constrict, Roll material of hot rolling finishing stand is changing Hi-Cr Roll to High Speed Steel [HSS] Roll. The problem of HSS Roll of roll force and strip scale defects are increasing in hot strip mill, So we have tested HSS Roll in hot rolling simulator as rolling condition, rolling speed, draft, hot oil concentration. To reduce roll force and prevent scale defects. We get some merit rolling force, rolling torque, roll wear reduction, roll and strip surface roughness and hot rolling critical oil concentration 0.4%. Finally we are going to investigate the effect of hot rolling oil of on rolling with HSS Roll.