• Proceedings of the KSEEG Conference
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• 1999.04a
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• pp.254-256
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• 1999

• Design & Manufacturing
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• v.17 no.3
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• pp.1-7
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• 2023

Blow molding is a manufacturing process in which thermoplastic preforms are preheated and then pneumatically expanded within a mold to produce hollow products of various shapes. The two-step process, a type of blow molding method, requires the output of multiple infrared lamps to be adjusted individually, so the process of finding initial conditions hinders productivity. In this study, digital twin technology was applied to solve this problem. A blow molding simulation technique was established and simulation-based metadata was generated. A response surface ROM (Reduced Order Model) was built using the generated metadata. Then, a dynamic ROM was constructed using the results of 3D heat transfer analysis. Through this, users can quickly check the product wall thickness uniformity according to changes in the control value of the heating lamp for products of various shapes, and at the same time, check the temperature distribution of the preform in real time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.4C
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• pp.485-493
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• 2004

The system performance of 2-Dimensional wavelength hopping/time spreading optical CDMA systems is found to be limited by the occurrence of the beat noise between the components of the signal and the multiple user interference. This paper shows that the performance is analyzed under the beat noise and no beat noise to blow impact of the beat noise. To overcome this problem, the OHL(Optical Hard-Limiter) is used in the receiver. The performance is calculated for a optical CDMA system employing asymmetric and symmetric prime-hop 2-Dimensional codes, respectively The analysis results show that the performance improved 3.5 times of simultaneous users of before and after inserting OHL in the case of no beat noise. In the case of beat noise the performance improved 1.5 times of simultaneous users of before and after inserting OHL. The performance marked use of symmetric prime-hop code.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.1
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• pp.30-38
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• 2009

The objective of this study was to evaluate the effects of occupational exposure to styrene on the components of metabolic syndrome. We surveyed 263 employees, among whom 117workers we ere chronically exposed to styrene in glass-reinforced plastic boat manufacturing factories and 146 controls had never been occupationally exposed to styrene as will as hazardous chemicals. The general and job characteristics such as age, smoking and drinking habit, working hours and duration were not significant different except sleeping hours(p<0.05). Among the components of metabolic syndrome, the systolic blood pressure, total cholesterol, HDL-cholesterol and fasting glucose were significantly higher in exposed workers. On multiple logistic regression analysis for the components of metabolic syndrome, waist circumference was insulin (OR=1.129), blood pressure was MA(OR=14.724), fasting glucose(OR=1.191) and metabolic syndrome(OR=1.110) were significantly associated with insulin. The mean concentration of airborne styrene was $ 38.1{\pm}40.1$ ppm, blood concentrations of glucose and insulin and levels of HOMA-IR in over 50 ppm exposed group were higher than in blow 50 ppm exposed group. These results suggested that the exposure of styrene affects blood pressure, fasting glucose and insulin levels and that dysfunction and/or declination in glucose and insulin metabolism might induced ultimately insulin resistance and metabolic syndrome.

• Current Research on Agriculture and Life Sciences
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• v.9
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• pp.71-86
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• 1991

This study has tried to illuminate a shocking phenomenon, the import liberalization of agricultural products in the aspect of Consumer consciousness. It has been applied that Table Analysis by using computer programming for instance-MINITAB, and Correlation Analysis and Multiple Regression Analysis, things like that. The results of this study are as follows; 1. Comparing domestic and imported stuffs, Comsumers came to awareness that domestic products superior to foreign's in the cases of the degree of freshness, taste and pollution damage, in the meanwhile, inferior to the cases of price and wrapping. Food self-supplyment is considered as one of the most important things of all, moreover, by most comsumers and health food and conventional food are favored by high class people. 2. Bying imported stuffs could clearly be fatal blow to our agriculture is fully recognized among consumers, what is more, there would only be doomed to our agriculture, too. 3. The most mass-purchasing imported stuffs by consumers illustrates in order; Beef, Banana, Coffee and Tabacco etc. The most significant elements why consumers buy foreign product is that the prices of them are relatively lower than those of ours. Besides, the next causes lies to non-producing stuffs and curiosity. 4. It must've been generally conceived by most consumers that Open-the-market-policy has been progressed for USA's repression and our monopolistic capital. Therefore, they demand that our market should be contained against unadviciable wave, moreover, keep paying attention to the policy how it will work to protect Korean agriculture. 5. Consumer attitude toward buying imported agricultural products is double-faced, Never-buy occupied only 24.4 % among respondents, but overwhelming respondents say non-producing stuffs can be obtained selectively. In this case, however, never-buy-movement would be backed by consumers in proportion to their educational background. 6. Various consumer minds surrounding Open-the-market-situation, in the end, has been analized econometrics through eleven variables to approach accurate fulfillments.