• Title/Summary/Keyword: impact element

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A Study on the Vibration Analysis of Spindle Housing with High Strength Aluminum of 2NC Head in Five-axis Cutting Machine Training (5축 절삭가공기 교육 중 2NC 헤드의 고강도 알루미늄을 적용한 스핀들 하우징의 극한 조건의 진동해석에 관한 연구)

  • Lee, Ji Woong
    • Journal of Practical Engineering Education
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    • v.14 no.1
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    • pp.119-125
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    • 2022
  • Materials used for education are materials such as SM20C, Al6061, and acrylic. SM20C materials are carbon steel and are often used in certification tests and functional competitions, but are also widely used in industrial sites. The Al6061 material is said to be a material that has lower hardness and stronger flexibility than carbon steel, so it is a material that generates a lot of compositional selection of tools. If students are taught practical training using acrylic materials, vibration occurs due to excessive cutting in some parts and damage to the tool occurs. In this process, we examine to what extent the impact on the 2NC head, which is a five-axis equipment, can affect precision control. The weakest part of the five-axis equipment can be said to be the weakest part of the head that controls the AC axis. When the accuracy and cumulative tolerance of this part occur, the accuracy of all products decreases. Therefore, the core part of the 2NC head, the spindle housing, was carried out using an Al7075 T6 (Alcoa, USA) material. In the process of vibration and cutting applied to this material, the analysis was conducted to find out the value applied to the finite element analysis under extreme conditions. It is hoped that this analysis data will help students see and understand the structure of 5-axis machining rather than 5-axis cutting.

Damage Analysis of Manganese Crossings for Turnout System of Sleeper Floating Tracks on Urban Transit (도시철도 침목플로팅궤도 분기기 망간크로싱의 손상해석)

  • Choi, Jung-Youl;Yoon, Young-Sun;Ahn, Dae-Hee;Han, Jae-Min;Chung, Jee-Seung
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.5
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    • pp.515-524
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    • 2022
  • The turnout system of the sleeper floating tracks (STEDEF) on urban transit is a Anti-vibration track composed of a wooden sleeper embedded in a concrete bed and a sleeper resilience pad under the sleeper. Therefore, deterioration and changes in spring stiffness of the sleeper resilience pad could be cause changes in sleeper support conditions. The damage amount of manganese crossings that occurred during the current service period of about 21 years was investigated to be about 17% of the total amount of crossings, and it was analyzed that the damage amount increased after 15 years of use (accumulated passing tonnage of about 550 million tons). In this study, parameter analysis (wheel position, sleeper support condition, and dynamic wheel load) was performed using a three-dimensional numerical model that simulated real manganese crossing and wheel profile, to analyze the damage type and cause of manganese crossing that occurred in the actual field. As a result of this study, when the voided sleeper occurred in the sleeper around the nose, the stress generated in the crossing nose exceeded the yield strength according to the dynamic wheel load considering the design track impact factor. In addition, the analysis results were evaluated to be in good agreement with the location of damage that occurred in the actual field. Therefore, in order to minimize the damage of the manganese crossing, it is necessary to keep the sleeper support condition around the nose part constant. In addition, by considering the uniformity of the boundary conditions under the sleepers, it was analyzed that it would be advantageous to to replace the sleeper resilience pad together when replacing the damaged manganese crossing.

The Effect of smart specialisation on the Regional Economy (스마트 특성화가 지역경제성과에 미치는 영향)

  • Minchul Kim;Byung-Keun Kim
    • Journal of Technology Innovation
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    • v.30 no.4
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    • pp.1-28
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    • 2022
  • Arguably many studies point out that regional innovation capabilities are accepted as a major source of growth for the sustainable regional economy. Recently, a smart specialisation strategy that should reflect regional characteristics in the policy implementation process of the regional innovation system has been proposed, but empirical studies have only presented limited results. This study attempts to overcome limitations by approaching smart specialisation as a supplementary strategy for existing regional innovation research. To this end, smart specialisation was not an alternative strategy for the regional innovation system, but rather the institutional elements of regional innovation capabilities, and the relationship between regional innovation capabilities and the local economy was analyzed to identify the impact of smart specialisation on the local economy. A study was conducted through a panel model consisting of 16 cities and provinces in Korea and 10 years from 2009-2018, and the FGLS model was finally used through the process of searching for an appropriate panel model. As a result of the study, smart specialisation consisting of industry related variety and non-related variety had a positive effect on the local economy. In addition, other regional innovation capabilities measured by dividing them into base and facilitating factors also had a positive effect on the local economy, reaffirming the results of positive research between existing regional innovation and the local economy. This study is meaningful in that smart specialisation lacking in domestic research was viewed as an institutional element of regional innovation capabilities, and it was measured through regional industry-related variety and non-related variety.

Probiotics Increase Intramuscular Fat and Improve the Composition of Fatty Acids in Sunit Sheep through the Adenosine 5'-Monophosphate-Activated Protein Kinase (AMPK) Signaling Pathway

  • Yue Zhang;Duo Yao;Huan Huang;Min Zhang;Lina Sun;Lin Su;LiHua Zhao;Yueying Guo;Ye Jin
    • Food Science of Animal Resources
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    • v.43 no.5
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    • pp.805-825
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    • 2023
  • This experiment aims to investigate the impact of probiotic feed on growth performance, carcass traits, plasma lipid biochemical parameters, intramuscular fat and triglyceride content, fatty acid composition, mRNA expression levels of genes related to lipid metabolism, and the activity of the enzyme in Sunit sheep. In this experiment, 12 of 96 randomly selected Sunit sheep were assigned to receive the basic diet or the basic diet supplemented with probiotics. The results showed that supplementation with probiotics significantly increased the loin eye area, and decreased plasma triglycerides and free fatty acids, increasing the content of intramuscular fat and triglycerides in the muscle and improving the composition of the fatty acids. The inclusion of probiotics in the diet reduced the expression of adenosine 5'-monophosphate-activated protein kinase alpha 2 (AMPKα2) mRNA and carnitine palmitoyltransferase 1B (CPT1B) mRNA, while increasing the expression of acetyl-CoA carboxylase alpha (ACCα) mRNA, sterol regulatory element-binding protein-1c (SREBP-1c) mRNA, fatty acid synthase mRNA, and stearoyl-CoA desaturase 1 mRNA. The results of this study indicate that supplementation with probiotics can regulate fat deposition and improves the composition of fatty acids in Sunit sheep through the signaling pathways AMPK-ACC-CPT1B and AMPK-SREBP-1c. This regulatory mechanism leads to an increase in intramuscular fat content, a restructuring of muscle composition of the fatty acids, and an enhancement of the nutritional value of meat. These findings contribute to a better understanding of the food science of animal resources and provide valuable references for the production of meat of higher nutritional value.

The Effect of Resilience by Emotional Intelligence of Hotel Employees in China on Organizational Effectiveness (중국 호텔 종사원의 감성지능에 의한 회복탄력성이 조직유효성에 미치는 영향)

  • Jeong, Gap-Yeon;Seo, Min-Kyo
    • Korea Trade Review
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    • v.43 no.6
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    • pp.161-192
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    • 2018
  • The hotel industry in China has shown great growth both in terms of quantity and quality, but management of the most important element of the success of the hotel company is still not enough. The purpose of this study is to investigate the effects of emotional intelligence including self emotional appraisal, others' emotional appraisal, regulation of emotion, use of emotion on Chinese hotel employees' resilience to improve job satisfaction, organizational commitment, and to reduce turnover intention. Also, the relationship between job satisfaction, organizational commitment, and turnover intention was investigated. In order to analyze this, we surveyed 322 employees of Shanghai 4, 5star hotel in China. Empirical analysis showed that self emotional appraisal, regulation of emotion, and use of emotion of Chinese hotel employees had a positive effect on resilience, but others' emotional appraisal did not affect resilience. In addition, the resilience showed a positive effect on job satisfaction and organizational commitment, but not on turnover intention. Also, job satisfaction has a significant negative effect on organizational commitment and turnover intention, and organizational commitment has a significant negative impact on turnover intention. This study aims to provide a better understanding of emotional intelligence and resilience, and to provide effective management of human resources management.

Paradigm of the Transformation of Potential-Forming Space Under the Impact of Intellectual-Innovation Determinants

  • Khanin, Semen;Derhaliuk, Marta;Stavroyany, Serhii;Kudlasevych, Olga;Didkivska, Lesia
    • International Journal of Computer Science & Network Security
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    • v.22 no.1
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    • pp.340-346
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    • 2022
  • The article examines the formation of the scientific paradigm of transformation of the potential-forming space of the regional economy under the influence of intellectual and innovative determinants. Based on the study of different scientific views on the nature and properties of potential-forming space through the study of approaches to understanding the concept of "space" clarified the complexity and multifaceted nature of the phenomenon and found that its characteristics are relevant to the industrial development model. It is revealed that the leading modern trends related to the spread of globalization and regionalization, rapid development of information and communication technologies, diffusion of innovations accompany the transition from industrial to post-industrial development and its development, which leads to new development: changes production, nature and relations between business entities, etc. It is proved that under such conditions, the region as a key element of the economic system, acquires a leading role in achieving sustainable and balanced development. These processes significantly affect the potential-forming space of the regional economy under the influence of intellectual and innovative determinants, leading to the need for its transformation and change in accordance with modern realities, which is reflected in thorough research on the formation of scientific paradigm based on the formation of its theoretical foundations and methodological basis. This study reveals the essence, role, functions, structure, process of formation of the scientific paradigm of transformation of the potential-forming space of the regional economy under the influence of intellectual and innovative determinants. It is proved that the formation of the modern scientific paradigm of transformation of the potential-forming space of the regional economy under the influence of intellectual and innovative determinants occurs in the context of building a post-industrial model of development, accompanied by consideration of the region as a spatial object territories from the physical plane to the spatial environment in which the development of human capital, innovation and self-development of the region. Taking into account the above, the article outlines the prerequisites and factors of formation of the scientific paradigm of transformation of the potential-forming space of the regional economy under the influence of intellectual and innovative determinants.

Modification of SPT-Uphole Method using Two Component Surface Geophones (2방향 지표면 속도계를 활용한 SPT-업홀 기법 개선 연구)

  • Bang, Eun-Seok;Kim, Jong-Tae;Kim, Dong-Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.2C
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    • pp.109-120
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    • 2006
  • SPT-Uphole test is a seismic field test using receivers on ground surface and a SPT (Standard penetration test) source in depth. Even though this method is simple and economic, it makes hesitate to apply in real field that it is difficult to obtain reliable travel time information of shear wave because of the characteristics of SPT impact source. To overcome this shortcoming, in this paper, modified SPT-Uphole method using two component surface geophones was suggested. Numerical analysis was performed using finite element method for understanding the characteristics of surface motion induced by in-depth vertical source, and comparison study of the various methods which determine the travel time information in SPT-Uphole method was performed. In result, it is thought that the most reasonable method is using the first local maximum point of the root mean square value signals of vertical and horizontal component in time domain. Finally, modified SPT-Uphole method using two component surface geophones was performed at the site, and the applicability in field was verified by comparing wave velocity profiles determined by the SPT-Uphole method with the profiles determined by SASW method and SPT-N values.

The Influence of the Relationship between Consumer and Tie-in Promotion on Loyalty: Focusing on the Difference between Target Customers and Non-target Customers of Tie-in Promotion

  • Lee, Eun Mi;Park, Hyun Hee;Jeon, Jung Ok
    • Asia Marketing Journal
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    • v.16 no.2
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    • pp.39-57
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    • 2014
  • There has been recognition of the increasing importance of cooperation as an element of marketing strategy. Such cooperation is confined to four levels based on product development, sales promotion, pricing arrangements, and place (or distribution) mechanisms as the usual marketing 4Ps mixed (Varadarajan 1986). At present, however, little is known about the nature of tie-in promotion as a cooperative sales promotion comparing three other levels. The primary goal of this study is to examine the effect of consumer - tie-in promotion relationship on loyalty. The construct of consumer - tie-in promotion relationship is based on the previous research on consumer-brand relationship. In addition, this study divides the concept of loyalty into host brand loyalty and partner brand loyalty to reflect the characteristics of tie-in promotion including program in order to determine the effect of the consumer - tie-in promotion relationship on loyalty. The results showed that the three dimensions of the consumer - tie-in promotion relationship (i.e., commitment, intimacy, and interdependence) had significantly positive effect on program loyalty. The effect of program loyalty is significantly on both host and partner brand loyalty. This study empirically tested the relationships among consumer - tie-in promotion relationship, program loyalty, host brand loyalty, and partner brand loyalty, and then compared with the difference in the suggested model for the target customers and non-target customers. As a result, for target customers, intimacy and interdependence among dimensions of consumer - tie-in promotion relationship had significantly positive influence on program loyalty. In case of non-target customers, however, commitment and interdependence among dimensions of consumer - tie-in promotion relationship had significantly positive influence on program loyalty. Also, program loyalty had significantly positive impact on host brand loyalty and partner brand loyalty in both target and non-target customers. This study has significance in that it addresses the need to identify research and academic implications by analyzing the consumer - tie-in promotion relationship to determine the relationship between tie-in promotion and loyalty, which has not been clearly described by previous studies. Furthermore, this study builds a foundation for firms and managers actively using tie-in promotion to establish tie-in promotion strategies that can maximize loyalty for both host and partner brands from the consumers' point of view.

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Instructional Effects of Elementary Science Classes Using Metaverse and Perceptions of Students: 'Structure and Function of Plants' Unit in Sixth Grade (메타버스를 활용한 초등 과학 수업의 효과 및 학생들의 인식 - 6학년 '식물의 구조와 기능' 단원을 중심으로 -)

  • Wang, Taejoe;Lim, Heejun
    • Journal of Korean Elementary Science Education
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    • v.42 no.4
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    • pp.591-604
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    • 2023
  • This study investigated the impact of elementary science classes using metaverse on the academic achievement, positive experience in science, and digital literacy of elementary school students. In addition, we examined their perceptions. The respondents were derived from two classes in the sixth grade at an elementary school in Gyeonggi-do, who were selected designated as the experimental (n=29 students) and comparative (n=29) groups, respectively. Across five lessons under the "Plant Structure and Function" unit, the experimental group conducted science classes using the metaverse, whereas the comparative group conducted general textbook-based classes. To investigate instructional effects, the study performed ANCOVA using the pre-test score as a covariate, a survey on the perception of students about science classes using metaverse, and conducted interviews with a number of subjects. The result demonstrated that science classes using metaverse exerted no significant effect on scientific academic achievement and digital literacy. However, the study observed a statistically significant effect on science learning emotion which is a sub-element of positive experiences in science. The students were positively aware of science classes using metaverse in terms of interesting and diverse activities, and free expression of inquiry results and perceived the instability of smart devices and network connections as regrettable. Finally, the study posed the implications of the use of metaverse in science classes.

Phenolic acids in Panax ginseng inhibit melanin production through bidirectional regulation of melanin synthase transcription via different signaling pathways

  • Jianzeng Liu ;Xiaohao Xu ;Jingyuan Zhou;Guang Sun ;Zhenzhuo Li;Lu Zhai ;Jing Wang ;Rui Ma ;Daqing Zhao;Rui Jiang ;Liwei Sun
    • Journal of Ginseng Research
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    • v.47 no.6
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    • pp.714-725
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    • 2023
  • Background: Our previous investigation indicated that the preparation of Panax ginseng Meyer (P. ginseng) inhibited melanogenesis. It comprised salicylic acid (SA), protocatechuic acid (PA), p-coumaric acid (p-CA), vanillic acid (VA), and caffeic acid (CA). In this investigation, the regulatory effects of P. ginseng phenolic acid monomers on melanin production were assessed. Methods: In vitro and in vivo impact of phenolic acid monomers were assessed. Results: SA, PA, p-CA and VA inhibited tyrosinase (TYR) to reduce melanin production, whereas CA had the opposite effects. SA, PA, p-CA and VA significantly downregulated the melanocortin 1 receptor (MC1R), cycle AMP (cAMP), protein kinase A (PKA), cycle AMP-response element-binding protein (CREB), microphthalmia-associated transcription factor (MITF) pathway, reducing mRNA and protein levels of TYR, tyrosinase-related protein 1 (TYRP1), and TYRP2. Moreover, CA treatment enhanced the cAMP, PKA, and CREB pathways to promote MITF mRNA level and phosphorylation. It also alleviated MITF protein level in α-MSH-stimulated B16F10 cells, comparable to untreated B16F10, increasing the expression of phosphorylation glycogen synthase kinase 3β (p-GSK3β), β-catenin, p-ERK/ERK, and p-p38/p38. Furthermore, the GSK3β inhibitor promoted p-GSK3β and p-MITF expression, as observed in CA-treated cells. Moreover, p38 and ERK inhibitors inhibited CA-stimulated p-p38/p38, p-ERK/ERK, and p-MITF increase, which had negative binding energies with MC1R, as depicted by molecular docking. Conclusion: P. ginseng roots' phenolic acid monomers can safely inhibit melanin production by bidirectionally regulating melanin synthase transcription. Furthermore, they reduced MITF expression via MC1R/cAMP/PKA signaling pathway and enhanced MITF post-translational modification via Wnt/mitogen-activated protein kinase signaling pathway.