• Korean Journal of Occupational Health Nursing
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• v.14 no.1
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• pp.56-70
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• 2005

Objectives: The purpose of this study is to develop a linking model between industrial injury insurance organs and local organizations providing social welfare health services, for the activation of medical rehabilitation services for industrial injury patients. Method: Research design for this study was a multi-step research through literature review, field research, and group interviews with persons in charge, to compare local society-oriented medical rehabilitation programs. The term of researches Sep.1 ~ Nov. 30, 2004. Results: 1. Home nurses from Workers Accident Medical Corporation have been taken to be adequate to case managers, who link industrial accident insurance institutions to local society services for the activation of medical rehabilitation services for industrial injury patients. They have been chosen for case managers because they have richer understanding and experiences of objects of industrial accidents than any other specialists, and because they have proved to be able to provide direct home services as a specialist. We have established the center for case management affairs within the workers accident general hospital, organized the committee for case management with doctors in charge, doctors in rehabilitation, rehabilitation consultants, social welfare workers, physical therapists, and nurses, determined objects of case managements from those of long-term recuperation, and constructed a course of case management containing from case management plans to evaluation. 2. We have made files of community resources, and organized the council of industrial accident administration to have it in charge of the adjustment and linking of services in case management affairs. 3. Because there are inequality of community resources between areas, differences in experiences in and bases for linking, and disparity of core organizations with active linking in the system of linking between public and civil sectors, we have taken a system of linking between parallel organs to be the core. In our linking model, workers accident general hospital, hospitals designated for industrial injury, and rehabilitation hospitals are linked in parallel, inadequate long-term recuperation managers are trusted to an workers accident medical corporations through examination by the examination committee in Korea Labor Welfare Corporation, and are dealt with by the committee for case management. Of the hospitals designated for industrial accidents, those running a home caring center provide home caring services for the handicapped at home from industrial injury. 4. Workers Accident Medical Corporation take part in medical rehabilitation, and Korea Labor Welfare Corporation in vocational/social rehabilitation. Furthermore, in the model, the latter should construct a system for job opportunities through Internet portals and provide cyber vocational consultation and introduction. Conclusion: Improvement of systems is needed to apply the linking model to practical affairs. Because this model is centered for practical affairs, it should be put under the analysis of effects, and evaluation of its adequacy to practical application, and its effects and efficiency through experimental running in the 8 workers accident general hospital in Korea.

• Polymer(Korea)
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• v.26 no.4
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• pp.422-430
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• 2002

The kinetics of polycondensation of bishydroxyethyl naphthalate has been studied in the range of 241 -$260^{\circ}C$ using antimony trioxide catalyst. The reaction was performed in a batch reactor and the concentration of reaction mixture was measured with HPLC. The activation energy values of forward and reverse reaction determined from molecular species model were found to be 19.7 and 31.4 kcal/mole, respectively, and the equilibrium constants were in the range of 1.4-2.0, which were larger than that of polycondensation of PET and varied to some degree with temperature. It was confirmed by applying the Flory's distribution function that the reaction rate of the hyroxyethyl group does not depend on the molecular size. By applying functional group model, we observed that there was few difference between the activation energy of the forward reaction and that of reverse reaction, therefore the equilibrium constant has almost constant value of 1.4. The rate constants obtained from functional group model was about 3-4 times larger than that from molecular species model, which showed that both model explains the reaction system well. Although the molecular species model should predict the concentration of as many as ten molecules, it fits for the experimental results well.

• YAKHAK HOEJI
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• v.41 no.1
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• pp.38-47
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• 1997

Using a concentric cylinder type, rheometer. the steady shear flow properties of vaseline were measured over the temperature range of 20~70${\circ}$C. In this paper, the shea rate and temperature dependencies of its flow behavior were investigated and the validity of some flow models was examined. In addition, the flow characteristics over a wide temperature range were quantitatively evaluated by calculating the various material parameters. Main findings obtained from this study can be summarized as follows: (1) At relatively lower temperature range, vaseline is a plastic fluid with a yield stress and its flow behavior shows shear-thinning characteristics. (2) As the temperature increases, the value of a yield stress and the degree of shear-thinning become smaller, consequently, the Newtonian flow behavior occurs at a lower shear rate range. (3) At temperature range lower than 45${\circ}$C, the flow behavior shows much stronger temperature dependence, and a larger activation energy is needed for flow. (4) The Herschel-Bulkley model is the most effective one g$^3$ to predict the flow behavior of vaseline having a yield stress. The validity of the Bingham and Casson models becomes more available with increasing temperature. The flow behavior of vaseline at temperature range higher than 45${\circ}$C can be perfectly described by the Newton model.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.66-71
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• 2001

Kinetic parameters for the texture degradation of three varieties of sweet potato during heating were determined using two alternative methods, the biphasic model and the fractional conversion method. The texture degradation of sweet potatoes during heating could be expressed by two simultaneous first order reactions using the biphasic method, whose activation energies were ranged $71.0{\sim}75.1\;kJ/mol\;and\;48.4{\sim}59.6\;kJ/mol$ for the initial fast texture degradation reaction and the slow texture degradation reaction at a prolonged heating period, respectively. However, the whole texture degradation phenomena of sweet potatoes during heating could also be explained by a single first order reaction using the fractional conversion method. The activation energies were $67.5{\sim}75.3\;kJ/mol$, which were comparable with those of the first phase reaction for the texture degradation determined by the biphasic model. A kinetic compensation effect shown between the kinetic parameters determined by both methods indicates that both methods can be conveniently used to determine kinetic parameters for the texture degradation of sweet potatoes by heating.

• Journal of radiological science and technology
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• v.45 no.1
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• pp.41-47
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• 2022

The purpose of this study is to apply a deep learning model that can distinguish lung perfusion and lung ventilation images in nuclear medicine, and to evaluate the image classification ability. Image data pre-processing was performed in the following order: image matrix size adjustment, min-max normalization, image center position adjustment, train/validation/test data set classification, and data augmentation. The convolutional neural network(CNN) structures of VGG-16, ResNet-18, Inception-ResNet-v2, and SE-ResNeXt-101 were used. For classification model evaluation, performance evaluation index of classification model, class activation map(CAM), and statistical image evaluation method were applied. As for the performance evaluation index of the classification model, SE-ResNeXt-101 and Inception-ResNet-v2 showed the highest performance with the same results. As a result of CAM, cardiac and right lung regions were highly activated in lung perfusion, and upper lung and neck regions were highly activated in lung ventilation. Statistical image evaluation showed a meaningful difference between SE-ResNeXt-101 and Inception-ResNet-v2. As a result of the study, the applicability of the CNN model for lung scintigraphy classification was confirmed. In the future, it is expected that it will be used as basic data for research on new artificial intelligence models and will help stable image management in clinical practice.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.2
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• pp.37-41
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• 2008

Melatonin has been reported to protect neurons from a variety of neurotoxicity. However, the underlying mechanism by which melatonin exerts its neuroprotective property has not yet been clearly understood. We previously demonstrated that melatonin protected kainic acid-induced neuronal cell death in mouse hippocampus, accompanied by sustained activation of Akt, a critical mediator of neuronal survival. To further elucidate the neuroprotective action of melatonin, we examined in the present study the causal mechanism how Akt signaling pathway is regulated by melatonin in a rat primary astrocyte culture model. Melatonin resulted in increased astrocytic Akt phosphorylation, which was significantly decreased with wortmannin, a specific inhibitor of PI3K, suggesting that activation of Akt by melatonin is mediated through the PI3K-Akt signaling pathway. Furthermore, increased Akt activation was also significantly decreased with luzindole, a non-selective melatonin receptor antagonist. As downstream signaling pathway of Akt activation, increased levels of CREB phoshorylation and GDNF expression were observed, which were also attenuated with wortmannin and luzindole. These results strongly suggest that melatonin exerts its neuroprotective property in astrocytes through the activation of plasma membrane receptors and then PI3K-Akt signaling pathway.

• Herbal Formula Science
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• v.29 no.4
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• pp.167-179
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• 2021

Objectives : Oxidative stress is a important cause of liver disease, and regulation of oxidative stress is essential to maintain the normal metabolic function of the liver. Until a recent date, there has been no studies on the hepatoprotective effect of Ikwiseungyang-tang (IWSYT). Therefore, this study aims to demonstrate the hepatoprotective effect of IWSYT and its related molecular mechanisms on arachidonic acid (AA) + iron induced oxidative stress model in HepG2 cells. Methods : To determine the cytoprotective effect of IWSYT against AA + iron-induced oxidative stress, cell viability, apoptosis-related proteins, intracellular reactive oxygen species (ROS), GSH, and mitochondrial membrane potential (MMP) were measured. Nuclear factor erythroid 2-related factor 2 (Nrf2) activation was analyzed by immunoblot analysis. In addition, Nrf2 transcription activation through ARE binding was measured by reporter gene assays, and the expression of the Nrf2 target antioxidant genes were confirmed by immunoblot analysis. Results : IWSYT increased cell viability from cell death induced by AA + Iron, and inhibited apoptosis by regulating apoptosis-related proteins. Furthermore, IWSYT protected cells by inhibiting intracellular ROS production, GSH depletion, and MMP degradation. Nrf2 activation was increased by IWSYT, and Nrf2 target genes were activated by IWSYT too. Conclusions : These results suggest that IWSYT can protect hepatocytes from oxidative stress through Nrf2 activation and can be potentially applied in the prevention and treatment of liver damage.

• The korean journal of orthodontics
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• v.51 no.1
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• pp.32-42
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• 2021

Objective: To investigate the three-dimensional forces created by clear aligners on mandibular teeth during differential activation with en-masse retraction and/or intrusion in vitro. Methods: Six sets of clear aligners were designed for differential en-masse retraction and/or intrusion procedures in a first premolar extraction model. Group A0 was a control group with no activation. Groups A1-5 underwent different degrees of retractions and/or intrusions. Each group consisted of 10 aligners. Aligner forces were measured on a multi-axis force/torque transducer measurement system in real-time. Results: In the en-masse retraction groups (A1 and A2), lingual and extrusive forces were observed on the incisors; the canines mainly received distal forces; intrusive forces were seen on the second premolars; and the molars received mesial forces. In the en-masse retraction and intrusion groups (A3, A4, and A5), incisors also received lingual and extrusive forces; canines received distal and intrusive forces; mesial and extrusive forces were seen on the second premolars; and the second molars received distal and intrusive forces. The vertical forces on the incisors did not differ significantly among groups A1, A3, and A5. However, the vertical forces on the second premolars reversed from intrusion in group A1 to extrusion in groups A3 and A5. Conclusions: With clear aligners, the "bowing effect" is seen during en-masse anterior teeth retraction and can be partially relieved by performing en-masse retraction accompanied by anterior teeth intrusion. Vertical control of incisors remained unsolved during en-masse retraction, even when intrusive activation was added to the anterior teeth.

• The Korean Journal of Pain
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• v.36 no.1
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• pp.51-59
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• 2023

Background: This study investigated the effect of an excess and a deficit of spinal 5-hydroxytryptamine (5-HT) on the mechanical allodynia and neuroglia activation in a rodent pain model of carrageenan inflammation. Methods: Male Sprague-Dawley rats were implanted with an intrathecal (i.t.) catheter to administer the drug. To induce an excess or deficit of 5-HT in the spinal cord, animals were given either three i.t. 5-HT injections at 24-hour intervals or a single i.t. injection of 5,7-dihydroxytryptamine (5,7-DHT) before carrageenan inflammation. Mechanical allodynia was measured using the von Frey test for 0-4 hours (early phase) and 24-28 hours (late phase) after carrageenan injection. The changes in the activation of microglia and astrocyte were examined using immunofluorescence of the dorsal horn of the lumbar spinal cord. Results: Both an excess and a deficit of spinal 5-HT had no or a minimal effect on the intensity of mechanical allodynia during the early phase but prevented the attenuation of mechanical allodynia during the late phase, which was observed in animals not treated with i.t. 5-HT or 5,7-DHT. Animals with an excess or deficit of 5-HT showed stronger activation of microglia, but not astrocyte, during the early and late phases, than did normal animals. Conclusions: Imbalance in the descending 5-HT pathway in the spinal cord could aggravate the mechanical allodynia and enhance the activation of microglia, suggesting that the spinal 5-HT pathway plays an essential role in maintaining the nociceptive processing in balance between facilitation and inhibition in inflammatory pain caused by carrageenan inflammation.

• KIPS Transactions on Software and Data Engineering
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• v.9 no.10
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• pp.303-308
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• 2020

The ReLU(Rectified Linear Unit) function has been dominantly used as a standard activation function in most deep artificial neural network models since it was proposed. Later, Leaky ReLU, Swish, and Mish activation functions were presented to replace ReLU, which showed improved performance over existing ReLU function in image classification task. Therefore, we recognized the need to experiment with whether performance improvements could be achieved by replacing the RELU with other activation functions in the super resolution task. In this paper, the performance was compared by changing the activation functions in EDSR model, which showed stable performance in the super resolution task. As a result, in experiments conducted with changing the activation function of EDSR, when the resolution was converted to double, the existing activation function, ReLU, showed similar or higher performance than the other activation functions used in the experiment. When the resolution was converted to four times, Leaky ReLU and Swish function showed slightly improved performance over ReLU. PSNR and SSIM, which can quantitatively evaluate the quality of images, were able to identify average performance improvements of 0.06%, 0.05% when using Leaky ReLU, and average performance improvements of 0.06% and 0.03% when using Swish. When the resolution is converted to eight times, the Mish function shows a slight average performance improvement over the ReLU. Using Mish, PSNR and SSIM were able to identify an average of 0.06% and 0.02% performance improvement over the RELU. In conclusion, Leaky ReLU and Swish showed improved performance compared to ReLU for super resolution that converts resolution four times and Mish showed improved performance compared to ReLU for super resolution that converts resolution eight times. In future study, we should conduct comparative experiments to replace activation functions with Leaky ReLU, Swish and Mish to improve performance in other super resolution models.