• Journal of the Korean Society for Precision Engineering
• /
• v.10 no.2
• /
• pp.86-94
• /
• 1993

In heavy industries forces which are exceeding the range of available force standard machines have to be measured. Force measuring system using build-up procedure can be applied to measure large forces efficiently. In this study strain gage type force sensors are designed and fabricated, and the build-up force measuring system with 4.5 MN capacity using the developed force sensors is 0.03% or less over the range of 600 kN .approx. 1.5 MN and the force measuring system is less than 0.06% or less over the range of 500 kN .approx. 4.5 MN.

• Electronics and Telecommunications Trends
• /
• v.38 no.6
• /
• pp.75-83
• /
• 2023

Smart manufacturing in Industry 4.0 is developing toward autonomous manufacturing as a last-mile technology. We investigate development trends in manufacturing innovation technologies, review major industrial intelligence projects currently carried out at ETRI, and infer directions of future technology developments.

• Structural Engineering and Mechanics
• /
• v.90 no.4
• /
• pp.403-415
• /
• 2024

We looked at how the damping qualities of epoxy composites changed when different amounts of graphite nanoplatelets (GNP) were added, from 0% to 6% by weight. A mix of free and forced vibration tests helped us find the key GNP content that makes the damper ability better the most. We also created a Representative Volume Element (RVE) model to guess how the alloys would behave mechanically and checked these models against testing data. An Artificial Neural Network (ANN) was also used to guess how these compounds would react to motion. With proper hyperparameter tweaking, the ANN model showed good correlation (R²=0.98) with actual data, indicating its ability to predict complex material behavior. Combining these methods shows how GNPs impact epoxy composite mechanical properties and how machine learning might improve material design. We show how adding GNPs to epoxy composites may considerably reduce vibration. These materials may be used in industries that value vibration damping.

• Journal of agricultural medicine and community health
• /
• v.47 no.4
• /
• pp.275-282
• /
• 2022

Objective: This study intends to analyze the performance of LINC+ program for three years of the dental hygiene department at Ulsan college and to present the direction for the operation of the LINC 3.0 project to be conducted for 6 years. Methods: A survey was conducted on 87 human resources officers participating in the LINC+ project of dental hygiene department from July 2021 to August 30, 2021, and the IBM SPSS Statistics 24.0 program was used for data analysis. Results: In terms of the suitability of the curriculum, operation of clinical practice averaged 4.82 points and omnibus courses averaged 4.77 points, and it was identified that OJT course, clinical practice, and educational environment make effects on job adaptation period, education and training period, and the reduction of education and training costs(p<0.05). Conclusion: In order to produce graduates who are highly adaptable in the field, participation of industries in the development and operation of the curriculum must be expanded and jointly operated, and it was possible to confirm the importance of the same educational environment as the industry to shorten the job adjustment period.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.4
• /
• pp.567-573
• /
• 2008

This experiment examined the effect of dietary spray-dried bovine colostrum on intestinal histology and organ weights in early-weaned pigs. In a randomised complete block design, twelve 14-day-old weaner pigs were offered a diet containing either 5% spray-dried bovine colostrum or no colostrum (control). Diets were formulated to contain 14.8 MJ/kg DE, 1.26% available lysine and to meet or exceed requirements for other nutrients. Piglets were offered the diets for a period of 14 days. No effect of diet on growth rate or feed intake was observed (p>0.10). Small intestine weight was reduced by 12% in piglets consuming dietary bovine colostrum (p< 0.05). Villous height and crypt depth were increased and decreased, respectively, in the proximal jejunum, mid jejunum and distal ileum of pigs consuming dietary bovine colostrum (p<0.05). Mid-jejunal lamina propria $CD4^+$ and $CD8^+$ T lymphocyte density was increased by 28 and 37%, respectively, in piglets consuming dietary bovine colostrum (p<0.05). Diet did not affect thickness of tunica muscularis externa or tunica submucosa (p>0.10). Collectively, these results suggest a positive effect of dietary bovine colostrum on intestinal morphology and immune status in early-weaned pigs.

• Journal of the Korean Society of Safety
• /
• v.29 no.4
• /
• pp.168-171
• /
• 2014

The job stress is rising as a social issue in all industries. So many manufacturing companies have been trying to prevent the job stress. Recently, the job stress is the important cause which lead to WMSDs, depressive disorder, anxiety disorder and sleep disturbance. However, the cause of the job stress is very variety. So management is very difficult. The purpose of this study is to investigate the group of the job stress by Karasek model from workers in auto part manufacturing company. The survey was using Karasek job stress model and was administered to 181 workers of auto part manufacturing company. Job demand median and job decision median was in 30.0 and 50.0. From this study, following results were obtained. 1) The gender of workers according to the groups of job stress was statistically significant(p<0.05). 2) The duration of working of workers according to the groups of job stress was statistically significant(p<0.05). 3) The intensity of work of workers according to the groups of job stress was statistically significant(p<0.01). The result of this study will help to identify the group of job stress and improve personal coping ability, systematic measure of company.

• KDI Journal of Economic Policy
• /
• v.12 no.1
• /
• pp.69-91
• /
• 1990

A major change in tariff rates was made in January 1989 in Korea. The benchmark tariff rate, which applies to about two thirds of all commodity items, was lowered to 15 percent from 20 percent. In addition, the variation in tariff rates among different types of commodities was reduced. This paper examines the economic impact of the tariff reform using a multisectoral general equilibrium model of the Korean economy which was introduced by Lee and Chang(1988), and by Lee(1988). More specifically, this paper attempts to find the changes in imports, exports, domestic production, consumption, prices, and employment in 31 different sectors of the economy induced by the reform in tariff rates. The policy simulations are made according to three different methods. First, tariff changes in industries are calculated strictly according to the change in legal tariff rates, which tend to over-estimate the size of the tariff reduction given the tariff-drawback system and tariff exemption applied to various import items. Second, tariff changes in industries are obtained by dividing the estimated tariff revenues of each industry by the estimated imports for that industry, which are often called actual tariff rates. According to the first method, the import-weighted average tariff rate is lowered from 15.2% to 10.2%, while the second method changes the average tariff rate from 6.2% to 4.2%. In the third method, the tariff-drawback system is internalized in the model. This paper reports the results of the policy simulation according to all three methods, comparing them with one another. It is argued that the second method yields the most realistic estimate of the changes in macro-economic variables, while the third method is useful in delineating the differences in impact across industries. The findings, according to the second method, show that the tariff reform induces more imports in most sectors. Garments, leather products, and wood products are those industries in which imports increase by more than 5 percent. On the other hand, imports in agricultural, mining and service sectors are least affected. Domestic production increases in all sectors except the following: leather products, non-metalic products, chemicals, paper and paper products, and wood-product industries. The increase in production and employment is largest in export industries, followed by service industries. An impact on macroeconomic variables is also simulated. The tariff reform increases nominal GNP by 0.26 percent, lowers the consumer price index by 0.49 percent, increases employment by 0.24 percent, and worsens the trade balance by 480 million US dollars, through a rise in exports of 540 million US dollars and a rise in imports of 1.02 billion US dollars.

• Journal of the Korean Society of Safety
• /
• v.19 no.4 s.68
• /
• pp.20-24
• /
• 2004

Antifatigue failure technology take an important the part of current industries. Currently, the shot peening is used for removing the defect from the surface of steel and improving the fatigue strength on surface. Therefore in this paper the effect of compressive residual stress by shot peening on fatigue crack growth characteristics in stress ratio(R=0.1, 0.3, 0.6)was investigated with considering fracture mechanics. There is difference between shot peening specimen and unpeening specimen. Fatigue crack growth rate of shot peening specimen was lower than that of unpeening specimen. Fatigue lift shows more improvement in the shot peening material than in the unpeening material. And compressive residual stress of surface on the shot peening processed operate resistance force of fatigue crack propagation. That is the constrained force about plasticity deformation was strengthened by resultant stress, which resulted from plasticity deformation and compressive residual stress in the process of fatigue crack propagation.

• Advances in materials Research
• /
• v.13 no.3
• /
• pp.195-202
• /
• 2024

Aluminum alloy is a material that is frequently used in the aerospace and transportation industries due to its high mechanical and corrosion resistance qualities. Unfortunately, aluminum alloys are prone to corrosion, limiting their application in some harsh situations such as when submerged in aqueous environments. The purpose of this study is to investigate how anodizing can increase the corrosion resistance of 6061 Aluminum alloy. The anodizing process was carried out using two different parameters which are voltage (5V, 10V, 15V) and electrolyte sulfuric acid (H₂SO₄) concentration (0.3M, 0.5M) for 1 hour. The anodized samples were performed using several analyses such as X-ray diffraction (XRD) analysis, morphology analysis, and corrosion test. From this study, it is found that the difference in anodizing parameters affects the corrosion resistance of the samples. Sample anodized at 15V, 0.5M gives the best corrosion resistance.

• Journal of Marine Bioscience and Biotechnology
• /
• v.2 no.2
• /
• pp.113-119
• /
• 2007

In this study, we investigated antimicrobial and cytotoxicity effects of Gelidium amansii L., which using methanol, dichloromethane and ethanol were extracted and fractionated into four different types : methanol (GAMM), hexane (GAMH), butanol (GAME) and aqueous (GAMA). The antimicrobial activity was increased in proportion to its concentration by the paper disc method. Among the solvent fractions, The methanol partition layer (GAMM) showed the strongest antimicrobial activities and cytotoxic effects on all cancer cell lines. We also observed quinone reductase (QR) induced effects in all fraction layers of GA on HepG2 cells. The QR induced effects of GAMM on HepG2 cells at $40{\mu}g/mL$ concentration indicated 2.5 with a control value of 1.0.