• International journal of advanced smart convergence
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• 제12권2호
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• pp.76-83
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• 2023

Squatting of agricultural work can cause musculoskeletal disorders due to excessive pressure and rotational force on the knee joint In order to improve the assistive chair used in squatting agricultural work so that it can be used in a narrow groove, it is intended to improve the musculoskeletal harm of squatting work by attaching a spring on the assistive chair. Therefore, in the presenty study, 3D drawing was done using ProEngineer (3D), and a mock-up was produced and tested. Using pro-Engineer, it was judged that it was rare for plastic to be broken by a spring, so the analysis was conducted with a focus on springs. It was found that the structure that can absorb the shock according to the rigidity of the tape spring and balance the body is that the power to withstand the load of the weight is distributed as a whole when five springs are used. Electromyography was measured using ME600 (Mega Electronics, Finland) Measuring equipment attached to the waist, thighs, calves, and shins. EMG values were measured and compared with the prototype in two ways, when the worker did not wear the product and when he wore an existing product on the market. As a result of the experiment when using the prototype, the maximum EMG value for each part is considered to be helpful in preventing musculoskeletal diseases as the amount of muscle used is reduced in the waist, thighs, calves, and shins.

• 아태비즈니스연구
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• 제14권1호
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• pp.93-112
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• 2023

Purpose - Due to the outbreak and spread of COVID-19, companies have reduced their hiring needs in the short term, reducing employment opportunities for most university students and putting pressure on their employment since 2019. This study aims to improve university students' employment options and increase the possibility of entrepreneurship. Design/methodology/approach - In this study, a research survey is conducted on 4-year Chinese university students who have received entrepreneurship education courses, and statistical tests are conducted using SPSS 26.0 and PROCESS 3.3 model 1. The main focus of the study is on the effects of risk perception and five personality factors on entrepreneurial intentions of Chinese university students and the effect of entrepreneurship education on the moderation of entrepreneurial intentions. Findings - The results of the study show that the risk perception of Chinese university students have a significant effect on the will to start a business. Five personality factors have a significant effect on entrepreneurial intentions. Entrepreneurship education has a moderating role in the relationship between risk perception and entrepreneurial intention, and the entrepreneurship education support has a moderating role in the relationship between the influence of five personality factors and entrepreneurial intentions. Research implications or Originality - The results of the study reveal that Chinese university students' exposure to entrepreneurship education support positively influenced entrepreneurial intentions. Such results imply that university students gain information and knowledge related to entrepreneurship through the entrepreneurship education support, which leads to positive perceptions and motivation towards entrepreneurship.

• Journal of Chest Surgery
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• 제23권6호
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• pp.1256-1262
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• 1990

Percutaneous pulmonary valvuloplasty was performed in 19 patients of congenital pulmonary valve stenosis. Pulmonary annulus diameter was estimated by cross sectional echocardiography and right ventricular cineangiography. The size of balloon dilatation catheter was chosen by the same size of the estimated pulmonary annulus in the first 3 patients and 20 \ulcorner30% greater than the annulus in the last 17 patients. After valvuloplasty a satisfactory results was obtained in most patients. Before dilatation, the right ventricular systolic pressure was 91.7 mmHg[range 58-150 mmHg] and it fell to 49.2mmHg[25-85 mmHg] after dilatation. The transvalvular gradient was 67.7 mmHg[33 \ulcorner120 mmHg] before dilatation and it fell to 23.7mmHg [5 \ulcorner62] after dilatation. Repeat cardiac catheterization has been scheduled in all patients 3 months after the initial valvuloplasty but follow up recatheterization was performed in only two patients; in one of them residual gradient of 50 mmHg was reduced to 30 mmHg by repeat valvuloplasty. The other patient showed no evidence of restenosis with transvalvular gradient of 20 mmHg The balloon used for valvuloplasty was single balloon for the first 10 cases and for the later 10 cases it was replaced by Trefoil balloon which was easier for inflation and deflation. There were no significant complications during and after the procedure. From our results, we conclude that balloon valvuloplasty for congenital pulmonary valve stenosis is the treatment of choice in most patients.

• 국제학술발표논문집
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.73-79
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• 2017

Rapidly expanding population in the Kingdom of Saudi Arabia has a massive impact to put pressure on the shortage of housing and existing infrastructure. With average population growth rate of 1,9% yearly, the population in Saudi Arabia is projected to increase from 31 million in 2015 to 37 million in 2025. According to the housing ministry, Saudi Arabia needs to provide 3.3 million units to meet the demand in 2025, which is about 300,000 unit a year. In the past 40 years, using the conventional construction method, the Saudi construction industry was only able to build about 150,000 units per year. To meet the demand gap for the housing shortage, a new approach and innovation in construction methods are needed. Industrialized construction as an approach in construction methods has been studied and implemented in some countries that experienced similar corncerns. Industrialized construction can be defined as the implementation of manufacturing methods to construction-related activities to improve quality, reduce cost and project duration. Compared to the conventional construction method, prefabrication as industrialized construction methods has reduced construction labor on-site by 9.5%, construction project duration by 20%, and construction waste by 56%. It improves the quality, durability and cost saving not only for construction project owners, but also construction contractors. This paper discusses the possibility of 'industrialization' of building system in the Kingdom of Saudi Arabia as a solution for the housing shortage. It is an initial part of a study aims to develop a framework to develop industrialized building system in the Kingdom of Saudi Arabia. The is paper based on extensive literature review and case studies.

• 한국심리학회지 : 문화 및 사회문제
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• 제18권2호
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• pp.153-167
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• 2012

본 연구는 서두름 행동의 5요인의 특성에 초점을 맞추어, 서두름 행동과 A형 행동의 관계를 바탕으로 서두름 행동의 5요인의 특성을 밝히고자 진행되었다. 이를 위해, 만 18세 이상 59세 이하 성인 207명이 서두름 행동 질문지와 A형 행동 질문지에 응답하였다. A형 행동 질문지는 A형 행동 및 성격을 측정하는 기존 문항을 바탕으로 총 136개 문항을 수집하였다. 그리고 요인분석을 통해 6개 요인으로 이루어진 29개 문항으로 축소되었다. A형 행동의 구성요인으로 성공추구, 인내부족, 실패불안, 과제몰입, 활동성, 민첩성이 나타났다. 서두름 행동요인분석 결과, 서두름 행동은 기존 연구와 동일한 5가지 요인으로 이루어져 있었다. 서두름 행동과 A형 행동의 상관분석 결과, 시간압력에서 나타나는 서두름 행동은 성공추구, 실패불안, 과제몰입, 민첩성과 정적상관을 보였다. 불편함에서 나타나는 서두름 행동과 고립에서 나타나는 서두름 행동은 인내심부족과 정적상관을 보였다. 지루함에서 나타나는 서두름 행동은 성공추구와 활동성 및 민첩성과 정적 상관이 있었다. 보상기대에서 나타나는 서두름 행동은 성공추구, 인내부족, 실패불안, 민첩성과 정적상관을 가지는 것으로 나타났다.

• 한국입자에어로졸학회지
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• 제19권3호
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• pp.63-76
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• 2023

An electrostatic precipitator (ESP) has a low pressure drop and a high collection efficiency but its collection efficiency can be reduced due to dust accumulation on the collection plates during long-term operations. In order to maintain the initial dust collection efficiency, it is necessary to periodically clean the collection plates. The common cleaning methods are using physical impacts or water sprays. These cleaning methods can lead to damage to the collection plate or generate wastewater. Herein, we implemented an electrodynamic screen (EDS) for ESP cleaning and evaluated its surface cleaning performance of particles. The EDS is an electrostatic system that can electrostatically repel particles on surfaces, allowing it to clean the ESP without causing damage and wastewater generation. Our evaluation included the analysis of the effects of AC voltage characteristics, electrode configuration and environmental conditions on the cleaning performance of the EDS with the aim of achieving effective surface cleaning. It has been demonstrated that activating the EDS cleans up to 65% of the particles on the surface, which indicates about 94% of our target cleaning zone.

• Design & Manufacturing
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• 제17권3호
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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.

• 한국재료학회지
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• 제34권1호
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• pp.12-20
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• 2024

This study successfully prepared high-porosity aluminosilicate fibrous porous ceramics through vacuum suction filtration using aluminosilicate fiber as the primary raw material and glass powder as binder, with the appropriate incorporation of glass fiber. The effects of the composition of raw materials and sintering process on the structure and properties of the material were studied. The results show that when the content of glass powder reached 20 wt% and the samples were sintered at the temperature of 1,000 ℃, strong bonds were formed between the binder phase and fibers, resulting in a compressive strength of 0.63 MPa. When the sintering temperatures were increased from 1,000 ℃ to 1,200, the open porosity of the samples decreased from 89.08 % to 82.38 %, while the linear shrinkage increased from 1.13 % to 10.17 %. Meanwhile, during the sintering process, a large amount of cristobalite and mullite were precipitated from the aluminosilicate fibers, which reduced the performance of the aluminosilicate fibers and hindered the comprehensive improvement in sample performance. Based on these conditions, after adding 30 wt% glass fiber and being sintered at 1,000 ℃, the sample exhibited higher compressive strength (1.34 MPa), higher open porosity (89.13 %), and lower linear shrinkage (5.26 %). The aluminosilicate fibrous porous ceramic samples exhibited excellent permeability performance due to their high porosity and interconnected three-dimensional pore structures. When the samples were filtered at a flow rate of 150 mL/min, the measured pressure drop and permeability were 0.56 KPa and 0.77 × 10^-6 m² respectively.

• 동의생리병리학회지
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• 제37권6호
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• pp.165-171
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• 2023

COVID-19 infection heightens the risk of thromboembolism. To see the similarities between the COVID-19 infection and Taeyang blood retention pattern, we conducted a PubMed search using specific terms related to blood circulation issues in the context of COVID-19, summarizing findings from 13 cases and 4 observational studies involving actual patients. Patients with COVID-19 are at risk of blood coagulation due to factors such as viral-induced cytokine storms, vascular endothelial dysfunction, reduced mobility in bedridden or isolated individuals, and resulting constipation. Additionally, cytokine storms and severe inflammation can lead to delirium in COVID-19 patients. The Taeyang blood retention pattern manifests as symptoms arising from delirium and an increased blood coagulation tendency in patients with a robust immune response. According to the Sanghan theory, certain herbal treatments can alleviate symptoms in patients with a tight lower abdomen who do not experience urinary issues. Studies show that components like Persicae Semen and Rhei Redix et Rhizoma in these prescriptions enhance blood circulation and reduce hypercoagulability. Additionally, these treatments aim to promote blood flow by relieving abdominal pressure through facilitating bowel movements. The excessive inflammation and heightened blood coagulation tendency in COVID-19 resemble the Taeyang blood retention pattern, although they are caused by different pathogens. Reinterpreting classical oriental medicine's principles in a modern context may enhance our understanding of traditional East Asian Medicine and foster future developments.

• 한국운동역학회지
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• 제34권2호
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• pp.93-103
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• 2024

Objective: The purpose of this study was to investigate whether dancers with chronic ankle instability (CAI) exhibit different characteristics in dynamic postural control ability and ankle joint laxity compared to dancers without CAI and non-dancers with CAI. Method: Twelve dancers with CAI, 14 dancers without CAI, and 12 non-dancers with CAI participated in the study. Dynamic balance was evaluated using the Star Excursion Balance Test (SEBT) and the single-leg hop balance. The laxity of the ankle joint was evaluated through the anterior drawer test and the talar tilt test. SEBT measured maximum reach distances in anterior, posteromedial, and posterolateral directions. Single-leg hop assessed center of pressure (COP) and time-to-boundary (TTB) outcomes. One-way ANOVA and Chi-square tests were performed to compare the outcome variables among the three groups. Results: Dancers with CAI demonstrated greater reach distance in the posterolateral direction compared to non-dancers with CAI during SEBT (p=.014). Secondly, dancers without CAI showed greater reach distance in the posterolateral (p<.001) and posteromedial (p=.001) directions during SEBT compared to non-dancers with CAI. Additionally, dancers without CAI exhibited better postural control with higher TTB AP mean of minima (p=.003) and TTB AP standard deviation of minima (p=.012) during single-leg hop compared to nondancers with CAI. Thirdly, dancers with CAI showed a lower positive rate during the anterior drawer test compared to non-dancers with CAI (p=.019). Conclusion: Dancers with CAI demonstrated better ankle function and reduced mechanical instability compared to non-dancers with CAI. Therefore, to elucidate the underlying mechanisms of lateral ankle sprain and CAI development exacerbation in dancers, additional factors that can affect ankle sprain, such as visual dependence during postural control and evaluation in dance movements, should be explored.