• Journal of the Korean Society for Precision Engineering
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• v.17 no.8
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• pp.113-119
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• 2000

There are two major factors which affect the cam design : the pressure angle and the radius of curvature, Cam shape will have an instantaneous radius of curvature at every point. Even though the design constraint of the pressure angle has been satisfied the follower may still not complete the desired contact motion. If the radius of the follower roller is larger than the concave(negative) radius on the cam it occurs the gap between the cam and the follower roller at the contact point. And also if the curvature of the pitch curve of the cam is too sharp the cam profile may be undercut. This paper proposes a new approach which uses the relative velocity of the follower roller parallel to the tangent line at the contact point on the cam surface for determining the pressure angle and the relative acceeration for determining the radius of curvature.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.17 no.1
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• pp.23-32
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• 2021

Conventional wind power generators have limited installation sites due to low efficiency due to reverse resistance or high cut-in speed. To compensate for these problems, this study proposed another new type of tilting wind turbine. The key to this method is the structural design of a cylindrical cam with a guide groove that allows the blade to tilt. As the blade rotates by the cam, it tilts according to the angle. In the section that generates torque by receiving drag, the blade is made perpendicular to the wind. And it is a structure that creates a parallel state with the wind in the section where reverse resistance occurs. We prepared six types of cams considering the length of the section subject to drag, reverse resistance, tilting section. The performance was analyzed as the maximum value of the output, torque coefficient, and efficiency coefficient, which is indicated by setting different wind speed and low TSR.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.121-138
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• 2024

Artificial intelligence is crucial to manufacturing productivity. Understanding the difficulties in producing disruptions, especially in linear feed robot systems, is essential for efficient operations. These mechanical tools, essential for linear movements within systems, are prone to damage and degradation, especially in the LM guide, due to repetitive motions. We examine how explainable artificial intelligence (XAI) may diagnose wafer linear robot linear rail clearance and ball screw clearance anomalies. XAI helps diagnose problems and explain anomalies, enriching management and operational strategies. By interpreting the reasons for anomaly detection through visualizations such as Class Activation Maps (CAMs) using technologies like Grad-CAM, FG-CAM, and FFT-CAM, and comparing 1D-CNN with 2D-CNN, we illustrates the potential of XAI in enhancing diagnostic accuracy. The use of datasets from accelerometer and torque sensors in our experiments validates the high accuracy of the proposed method in binary and ternary classifications. This study exemplifies how XAI can elucidate deep learning models trained on industrial signals, offering a practical approach to understanding and applying AI in maintaining the integrity of critical components such as LM guides in linear feed robots.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.8
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• pp.896-905
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• 2012

Recently, the application of the plastic material to automotive components and structures has steadily increased to satisfy demands on the saving of overall weight and the improvement of energy efficiency. The objective of this paper is to investigate the development of a bumper back-beam using a thermoplastic olefin (TPO). The bumper back-beam was designed to be manufactured from the injection molding process. In order to obtain a proper design of the bumper back-beam, three-dimensional finite element analyses were performed for various design alternatives. Stress-strain curves for different strain rates were measured by high speed tensile tests of the TPO to consider strain rate effects in the FEA. The influence of the sectional shape and the rib formation on the contact force-intrusion curves, the deflection and the energy absorption rate of the bumper back-beam was examined. From the results of the examination, a proper design of the bumper back-beam was acquired. The bumper back-beam consisting of TPO was fabricated from the injection moulding process and the vibration welding. Pendulum crash tests were carried out using the fabricated bumper back-beam. The results of the tests showed that the designed bumper back-beam can satisfy requirements of the federal motor vehicle safety standard (FMVSS). Through the comparison of the previously designed bumper back-beam with the newly designed bumper back beam, it was noted that the weight of the designed bumper back-beam is lighter than that of the previously designed bumper back beam by nearly 16 %. In addition, it was considered that the newly designed bumper back beam can improve recycling of the bumper back-beam.

• Research in Community and Public Health Nursing
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• v.25 no.1
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• pp.1-11
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• 2014

Purpose: The purpose of this study is to obtain information of use of complementary and alternative medicines (CAMs) and any reported adverse effects of them on vulnerable elders in a community. Methods: 1,837 elderly subjects aged 65 or higher with health problems were selected from those who were enrolled in a public health care center and received visiting health management services. A proportional stratified sampling method was used. Data collection was completed by face to face interviews using a structured questionnaire. The descriptive statistics and ${\chi}^2$-test were used to analyze the data. Results: The prevalence of CAM use last year was 57.5%, and 10.4% of the subjects reported adverse effects of the therapies. The mean score of the subjects' attitudes towards CAM was $4.1{\pm}3.44$ (range 1~10). The major sources of advice and exposure to CAM therapies were most likely to be from family and friends (72.5%). The primary reason for choosing CAM was to manage symptoms and relieve pain (86.6%). Conclusion: These findings suggest the need to develop nursing strategies for reducing and preventing adverse effects of CAM use by promoting awareness of using safe and appropriate CAM therapies.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.8
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• pp.1527-1533
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• 2002

When a mechanism transfers a motion to an intersected shaft, a cylindrical cam mechanism may be the best choice among the mechanisms. The cylindrical cam with a roller follower provides to transfer the motions to the intersect shafts simply without other connecting equipments of the intersect shafts. Typical example may be a roller-gear-cam mechanism. But the shape of the cam must be exactly defined in order to satisfy the conditions for the prescribed motion of the follower. This paper proposes a new method for the shape design of the cylindrical cams and also a CAD program is developed by using the proposed method. The relative velocity method calculates the relative velocity of the follower versus the cam at a center of roller, and then determines a contact point by using the geometric relationships and the kinematic constraints. The constraint used in the relative velocity method is that the relative velocity must be parallel to a common tangent line at the contact point of two independent bodies, i. e. the cam and the follower. Then, the shape of the cam is defined by the coordinate transformation of the trace of the contact points. Finally, this paper presents an example in order to prove the accuracy of the proposed methods in this paper and the application of the CAD program"CamDesign".

• Applied Biological Chemistry
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• v.46 no.1
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• pp.50-54
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• 2003

Polygonum cuspidatum has been used as a fork medicine for a long time. Emodin was purified from the root of P. cuspidatum by thin layer chromatography (TLC) and preparative high perfomance liquid chromatography (HPLC). The effects of emodin on the migration of endothelial cells and in vitro angiogenesis stimulated with vascular endothelial cell growth factor (VEGF) were examined, using human umbilical vein endothelial cells (HUVECs) and porcine pulmonary arterial endothelial cells (PPAECs). Emodin potently inhibited the VEGF-induced migration of (HUVECs) at relatively low cocentrations $(0.1-10\;{\mu}g/ml)$; the inhibition of endothelial cells by emodin was 75.4% at $0.1\;{\mu}g/ml$ and about 90% at $1\;{\mu}g/ml$. Emodin also inhibited VEGF-induced sprout formation in vitro at concentrations of $0.1-10\;{\mu}g/ml$. Emodin was also evaluated for the inhibitory potential on in vivo angiogenesis in a growing chick embryo chorioallantoic membranes (CAM). At a concentration of $1.0\;{\mu}g/ml$ Per disc, emodin was able to induce avacular zone in the CAMs. These findings suggest that emodin is a potent angiogenesis inhibitor and P. cuspidatum is a useful herb in the development of therapeutics for angiogenesis dependent diseases.

• Toxicological Research
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• v.22 no.2
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• pp.127-133
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• 2006

Recently, we have reported that the environmental pollutant 2-bromopropane (2-BP) induces a significant embryo-fetal developmental toxicity in rats. However, the cause of developmental toxicity and the relationship between maternal and developmental toxicities could not be elucidated because the developmental toxicity of 2-BP was observed only in the presence of maternal toxicity The in vitro teratogenicity study using whole embryo culture was carried out to understand the teratogenic properties and the possible mechanism of teratogenicity induced by 2-BP in rats. Rat embryos aged 9.5 days were cultured in vitro for 48 hrs at medium concentrations of 0, 1, 3, or 10 mg/ml of 2-BP. Embryos were evaluated for growth, differentiation, and morphological alterations at the end of the culture period. At 10 mg/ml, 2-BP caused a delay in the growth and differentiation of embryos and an increase in the incidence of morphological alterations, including altered yolk sac circulation, abnormal axial rotation, craniofacial hypoplasia, open neuropore, absent optic vesicle and kinked somites. At 3 mg/ml, only a delay in the growth and differentiation of embryos was observed. There were no adverse effects on embryonic growth and development at the concentration of 1 mg/ml. The results showed that the exposure of 2-BP to rat embryos results in a developmental delay and morphological alterations at dose levels of 3 mg/ml culture media or higher and that 2-BP can induce a direct developmental toxicity in rat embryos.

• Nutrition Research and Practice
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• v.5 no.5
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• pp.381-388
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• 2011

We compared the effects of genistein and daidzein on the expression of chemokines, cell adhesion molecules (CAMs), and endothelial nitric oxide synthase (eNOS) in tumor necrosis factor (TNF)-${\alpha}$-stimulated human umbilical vascular endothelial cells (HUVECs). TNF-${\alpha}$ exposure significantly increased expression of monocyte chemoattractant protein (MCP)-l, vascular adhesion molecule (VCAM)-1, and intercellular adhesion molecule-1. Genistein significantly decreased MCP-l and VCAM-l production in a dose-dependent manner, whereas CAM expression was not significantly lowered by genistein treatment. However, daidzein slightly decreased MCP-l production. The effects of genistein and daidzein on MCP-l secretion coincided with mRNA expression. Pre-treatment with either genistein or daidzein elevated eNOS expression and nitric oxide production disturbed by TNF-${\alpha}$ exposure. A low concentration of isoflavones significantly inhibited nuclear factor (NF)${\kappa}$B activation, whereas a high dose slightly ameliorated these inhibitive effects. These results suggest that genistein had a stronger effect on MCP-l and eNOS expression than that of daidzein. Additionally, NF${\kappa}$B transactivation might be partially related to the down-regulation of these mRNAs in TNF-${\alpha}$-stimulated HUVECs.

• BMB Reports
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• v.49 no.4
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• pp.214-219
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• 2016

A nucleosomal protein, high mobility group box 1 (HMGB1) is known to be a late mediator of sepsis. Dabrafenib is a B-Raf inhibitor and initially used for the treatment of metastatic melanoma therapy. Inhibition of HMGB1 and renewal of vascular integrity is appearing as an engaging therapeutic strategy in the administration of severe sepsis or septic shock. Here, we examined the effects of dabrafenib (DAB) on the modulation of HMGB1-mediated septic responses. DAB inhibited the release of HMGB1 and downregulated HMGB1-dependent inflammatory responses by enhancing the expressions of cell adhesion molecules (CAMs) in human endothelial cells. In addition, treatment with DAB inhibited the HMGB1 secretion by CLP and sepsis-related mortality and pulmonary injury. This study demonstrated that DAB could be alternative therapeutic options for sepsis or septic shock via the inhibition of the HMGB1 signaling pathway.