• Design & Manufacturing
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• v.17 no.3
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• pp.15-20
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• 2023

In the fine blanking process, which is a press operation known for producing parts with narrow clearances and high precision through the application of high pressure, die roll often occurs during the shearing process when the punch penetrates the material. This die roll phenomenon can significantly reduce the functional surface of the parts, leading to decreased product performance, strength, and fatigue life. In this research, we conducted an in-depth analysis of the factors influencing die roll in the curvature area of the fine blanking process and identified its root causes. Subsequently, we designed and experimentally verified a die roll reduction process specifically tailored for the door latch manufacturing process. Our findings indicate that die roll tends to increase as the curvature radius decreases, primarily due to the heightened bending moment resulting from reduced shape width-length. Additionally, die roll is triggered by the absorption of initial punch energy by scrap material during the early shearing phase, resulting in lower speed compared to the product area. To mitigate the occurrence of die roll, we strategically selected the Shaving process and carefully determined the shaving direction and clearance area length. Our experiments demonstrated a promising trend of up to 75% reduction in die roll when applying the Shaving process in the opposite direction of pre-cutting, with the minimum die roll observed at a clearance area length of 0.2 mm. Furthermore, we successfully implemented this approach in the production of door latch products, confirming a significant reduction in die roll. This research contributes valuable insights and practical solutions for addressing die roll issues in fine blanking processes.

• Journal of the Korea Safety Management & Science
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• v.26 no.2
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• pp.23-31
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• 2024

In the military, ammunition and explosives stored and managed can cause serious damage if mishandled, thus securing safety through the utilization of ammunition reliability data is necessary. In this study, exploratory data analysis of ammunition inspection records data is conducted to extract reliability information of stored ammunition and to predict the ammunition condition code, which represents the lifespan information of the ammunition. This study consists of three stages: ammunition inspection record data collection and preprocessing, exploratory data analysis, and classification of ammunition condition codes. For the classification of ammunition condition codes, five models based on boosting algorithms are employed (AdaBoost, GBM, XGBoost, LightGBM, CatBoost). The most superior model is selected based on the performance metrics of the model, including Accuracy, Precision, Recall, and F1-score. The ammunition in this study was primarily produced from the 1980s to the 1990s, with a trend of increased inspection volume in the early stages of production and around 30 years after production. Pre-issue inspections (PII) were predominantly conducted, and there was a tendency for the grade of ammunition condition codes to decrease as the storage period increased. The classification of ammunition condition codes showed that the CatBoost model exhibited the most superior performance, with an Accuracy of 93% and an F1-score of 93%. This study emphasizes the safety and reliability of ammunition and proposes a model for classifying ammunition condition codes by analyzing ammunition inspection record data. This model can serve as a tool to assist ammunition inspectors and is expected to enhance not only the safety of ammunition but also the efficiency of ammunition storage management.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.558-564
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• 1999

A series of experiments were conducted to determine the effects of standard (ST), long-term (LT), and expander (EX) conditioners on nutritional value of phase-three nursery and finishing swine diets. In Exp. 1, 180 pigs (average initial BW of 11.7 kg) were fed com-soybean meal based diets (1.3% lysine) during a 28 d growth assay. Gain/feed was improved (p<0.004) with pelleting and pellet durability index (PDI) increased with degree of conditioning (LT>ST). However, there was no advantage for LT vs ST conditioning in rate or efficiency of gain (p>0.5). In Exp. 2, 180 pigs (average initial BW of 10.4 kg) were fed con-soybean meal based diets (0.9% lysine) during a 28 d growth assay, Pelleted diets tended to support greater ADG (p<0.08) and gain/feed (p<0.002) with no marked advantage from EX vs ST conditioning. In Exp 3, a total of 70 barrows (average initial BW of 54 kg) was used in a growth assay to determine the effects of feeding a com-soybean meal based diet processed with a standard (ST) steam conditioner, a long-term (LT) steam conditioner, and an expander (EX) conditioner. The conditioned diets were fed as mash (M) or pellets (P) to give a $2{\times}3$ factorial plus a meal control. PDI increased with degree of conditioning (EX>LT>ST). There was a trend (p<0.07) for greater ADG in pigs fed diets that had been thermally conditioned. Also, there was a general advantage in gain/feed with pelleting (p<0.04), but this advantage was pronounced only with standard conditioning. Indeed, the greatest gain/feed was observed for pigs fed the expander treatments (p<0.03) and the expander mash was used as efficiently as the expander pellets. There was no difference in backfat thickness among pigs fed the treatments (p>0.3). but the more extreme the processing technique. the greater the incidence and severity of stomach lesions (p<0.04). These results suggest maximum rate and efficiency of growth with pelleting after standard steam conditioning or simply feeding an expanded mash.

• Journal of Microbiology and Biotechnology
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• v.33 no.9
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• pp.1213-1227
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• 2023

Fetal growth restriction (FGR) is a prevalent obstetric condition. This study aimed to investigate the role of Toll-like receptor 9 (TLR9) in regulating the inflammatory response and gut microbiota structure in FGR. An FGR animal model was established in rats, and ODN1668 and hydroxychloroquine (HCQ) were administered. Changes in gut microbiota structure were assessed using 16S rRNA sequencing, and fecal microbiota transplantation (FMT) was conducted. HTR-8/Svneo cells were treated with ODN1668 and HCQ to evaluate cell growth. Histopathological analysis was performed, and relative factor levels were measured. The results showed that FGR rats exhibited elevated levels of TLR9 and myeloid differentiating primary response gene 88 (MyD88). In vitro experiments demonstrated that TLR9 inhibited trophoblast cell proliferation and invasion. TLR9 upregulated lipopolysaccharide (LPS), LPS-binding protein (LBP), interleukin (IL)-1β and tumor necrosis factor (TNF)-α while downregulating IL-10. TLR9 activated the TARF3-TBK1-IRF3 signaling pathway. In vivo experiments showed HCQ reduced inflammation in FGR rats, and the relative cytokine expression followed a similar trend to that observed in vitro. TLR9 stimulated neutrophil activation. HCQ in FGR rats resulted in changes in the abundance of Eubacterium_coprostanoligenes_group at the family level and the abundance of Eubacterium_coprostanoligenes_group and Bacteroides at the genus level. TLR9 and associated inflammatory factors were correlated with Bacteroides, Prevotella, Streptococcus, and Prevotellaceae_Ga6A1_group. FMT from FGR rats interfered with the therapeutic effects of HCQ. In conclusion, our findings suggest that TLR9 regulates the inflammatory response and gut microbiota structure in FGR, providing new insights into the pathogenesis of FGR and suggesting potential therapeutic interventions.

• Culinary science and hospitality research
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• v.22 no.5
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• pp.1-12
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• 2016

This study was carried out for the improvement of nutrition and quality of streamed bread. For this purpose, brown rice liquid starter and brown rice sourdough were made and steamed bread was made with different amounts of starter addition followed by a measurement of its physicochemical and sensory characteristics. The pH of dough and titratable acidity tended to decrease significantly according to brown rice sourdough. In addition, the titratable acidity of the control group had significant different by samples. As for the volume of dough, there was no significant difference between the control sample and each sample, but after 15 minutes of fermentation, the volume increased the most in the control sample, with sample D having the least volume. As for volume and specific volume of steamed bread, sample B had the largest at 3.34 and each sample had significant differences based on fermentation time. As for diameter, sample B was the largest at 88.11 and sample D was the smallest at 79.04, with significant differences among samples. As for height of steamed bread, the control group was the highest at 42.91 and sample D was the lowest at41.87, with significant differences among samples. As for the cross-section structure of steamed bread, the porous of sample B, which had the largest volume and specific volume, was the largest with uniform texture and even distribution. L value tended to be higher in the added sampleroups than in the control sample. a value increased as brown rice sourdough increased, and b value was lower when volume and specific volume of the steamed bread increased, which showed a similar trend with that a L value. As for hardness, viscosity, and chewing capacity, sample D was the highest and sample B was the lowest, with significant differences among samples. As a result of measurement of overall preference, sample B had the highest preference with the highest preference in flavor, taste, appearance and texture, and D had the lowest preference with the lowest preference in taste, appearance and texture, with significant differences among samples.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.101-105
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• 2011

Purpose: Estradiol in the menstrual cycle and ovulation induction as an important test of currently national nuclear medicine laboratory in the normal patients and patients with infertility tests are being performed. For the diagnosis of menopause is an important test with follicle stimulating hormone (FSH) and Luteinizing hormone (LH). Currently participating in external quality control of the nation's hospitals that is 54 percent of 37 hospitals, 20 hospitals have been using A's reagent. The kit's test results are highly different from other kit comes with the test results of specimens have been found. And for the phenomenon is to study the problem. Materials and Methods: Estraiol test were referred to our hospital which results of samples as more than 100pg/ml 75 specimens measured by radioimmunoassay(RIA) test with company A company B company C company D Kit, Chemiluminescent assay (CMIA) to examine and compare to the results from april to August in 2010. Results: Kit for each manufacturing company as measured by the results obtained using the average value of the correlation coefficient (R2) and A company 0.8906 B 0.9527 C 0.9547 and D company correlation coefficient of 0.873 showed a good correlation that measuring the results of A company high concentrations when Company B Company C Company D with CMIA test concentrations measured low results that the two cases were discovered specimens. Conclusion: Most of the test results of 75 samples came up with a similar trend, but two cases were reported in the patients very differently. A company result reported higher than 700 pg/ml, while the rest of other test results report was approximately 10 pg/ml. The common point of two samples more than 50 years patients are estimated to be diagnosed with cancer in postmenopausal patients receiving treatment and levels of FSH were found to be greater than 50 mIU/ml. Did not identify the exact cause. I suggest if you are using A company kit that need to again check when Estradiol result and follicle stimulating hormone results is higher.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.209-216
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• 1987

The experiments were carried out in lab. as well as in pots, to develop the agricultural usage of water swellable polymer, a kind of polyacrylic acid(K-sorb) synthesized by the Korea Advanced Institute of Science & Technology (KAIST) recently. The changes of soil physical properties and the influences to crops were investigated with various levels of K-sorb. When the K-sorb mixed with soils and soaked up distilled water, the volume of soils increased with the increase of soil available water contents and increase of K-sorb application levels. The rate increase of soil available water was higher in the coarse textured soils than in the fine while the swelling rate of soil volume showed adverse tendencies. A positive linear regression was observed between the contents of available soil water and levels of K-sorb. K-sorb application decreased bulk density and hardness due to the increase of porosity after soybean cultivation. The permeability in coarser textured soils such as sandy and coarse loamy families was decreased with the increase of K-sorb but in the medium textured soils it was opposite. At higher levels of K-sorb, about 0.5%, the permeability abruptly decreased due to dispersion and vertical movement in silty soils, while it was not changed in fine clayey soils but has the same trend with silty soils. In the plot of 0.3% of K-sorb application, the growth of soybean such as number of pods and stem length etc. increased and the yield also increased about 1.2-1.8 times of control. The optimum amounts of K-sorb were slightly different according to soil texture but estimated from regression curves were about 0.2% to 0.35% of soils in dry weight bases.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.2
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• pp.19-34
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• 2021

The government budget for promoting startup have been skyrocketed as catching up with increasing demands for high-tech startup by disruptive innovation resulted from rapid technology change. However, major trend of startup have still fallen on self-employed type of startup due to the lack of expertise and fund in spite of desperate government policy efforts. In reality, the access to high-tech startup has been very limited and too high huddle to would-be entrepreneur. This paper implement empirical analysis on the effects of entrepreneur competency and satisfaction level to government support, considering these as the KSF for the growth and success of high-tech startup, to the performance of the company. In particular, it focus on defining unique characteristics of high-tech startup through differential proving by the backgrounds of entrepreneur such as major, R&D experience, patent possession, CTO possession. This research carry out survey to 217 entrepreneurs in high-tech company in Daejon and Daegue at R&D Special Innopolis Zone. Research results are as follow. First, entrepreneurial achievement competencies, conceptualization competencies, network competencies and market recognition competencies positively affect the financial and non-financial performance and organizational and technical competencies, while organizational and technological competencies only positively impact on non-financial performance. Second, the satisfaction level of government support showed a positive moderating effect on entrepreneurial achievement competencies and financial performance, while no significant effect in other competencies. Third, positive differential effect by the technological background of entrepreneur such as Major, R&D experience, patent possession, CTO possession) have been confirmed. This paper deliver several significant implications and contributions, First, it propose classified and systematized entrepreneur competency through the domestic and foreign literature reviews. Second, it proves the need for the wider spread of team based startup culture rather then sole startup. Third, it also proves the important role of technological background of entrepreneur among the characteristics of high-tech startup.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.4
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• pp.77-83
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• 2016

The objectives of this study was to investigate the difference between organic-farming and conventional-farming soils relatives to soil chemical properties and microbial flora. Fifteen soil sampling sites were chosen from the certified organic upland farm, considered with its location, crop and application of organic compost types. Soil chemical properties were analyzed by standard methods established by National Institute of Agricultural Sciences, Rural Development Administration. For the soil chemical properties, the values of pH were ranged from 4.5 to 7.3. The values of electrical conductivity (EC) in the sampling sites were below 2 dS/m of convention cultivation soil. For analyzing the microbial flora, the bacillus(16S rDNA) and cladothricosis(18S rDNA) were analyzed by using PCR-DGGE (Denaturing Gradient Gel Electrophoresis) in the soil of 15 sampling sites. Cluster analysis of biodiversity index was performed by using pattern of DGGE. DGGE patterns and clustering analysis of bacterial DNA from soil extracts revealed that the bacterial community was differentiated between less than 5 years and more than 5 years depending on the cultivation history. But there was no consistent tendency between cultivation history and regional trend in the case of molds. Therefore, it would be very effective to analyze bacterial clusters of organically cultivated soils in long - term cultivated soil for more than 5 years.

• Journal of Industrial Convergence
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• v.19 no.6
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• pp.11-19
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• 2021

The purpose of this study is to explore trends in research at home and abroad related to "Sport Facilities", and seek the direction of further research. 1,801 abstracts of papers including "Sport Facilities" were collected from the SCOPUS DB from 2016 to 2020. Topic modeling techniques based on Latent Dirichlet Allocation (LDA) algorithm implemented in R language, TD-IDF techniques, and word cluds using Tagxedo was conducted to analyze the data. As a result, 8 topics were optimally determined, and "sports", "facilities", "health", "physical", "data", and "using" were derived as the main keywords for topics. This results indicated that studies on physical activity, health and using facilities regarding sports facilities at home and abroad have been actively carried out in recent years. This indicates that papers in SCOPUS DB are paying attention to the instrumental value of sport facilities, such as health promotion and improving the quality of life. Therefore, various studies that help participants who use sport facilities for a healthy life should be continuously conducted in the future.