• The Journal of Korean Physical Therapy
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• v.27 no.4
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• pp.190-195
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• 2015

Purpose: The aim of this study was to determine the effects of isokinetic eccentric training (IET) on lower extremity muscle activation and walking velocity according to slow velocity and fast velocity of isokinetic eccentric training in stroke patients. Methods: Thirty subjects were randomly divided into three groups: experimental group I (n=10), group II (n=10), and control group III (n=10). Each group was provided intervention under three conditions, as follows: isokinetic eccentric training + slow velocity (group I), isokinetic eccentric training + fast velocity (group II), and sit to stand training (group III). The training program was conducted for eight weeks (five times per week; 30 minutes per day). Subjects were measured on lower extremity muscle (vastus lateralis, vastus medialis, gastrocnemius) activation and walking velocity. Analysis of covariance (ANCOVA) were performed for comparison of lower extremity muscle activation and walking velocity between different intervention methods. Results: Significant difference in lower extremity muscle activation and walking velocity was observed in experimental group I and group II compared with the control group III (p<0.01). Results of post-hoc analysis showed a significant in lower extremity muscle activation and walking velocity in group I compared with group II and group III. Conclusion: Findings of this study suggest that slow velocity and fast velocity using isokinetic eccentric training may have a beneficial effect on improvement of lower extremity muscle activation and walking velocity in stroke patients.

• Physical Therapy Korea
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• v.31 no.1
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• pp.18-28
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• 2024

Background: Lateral instability of the ankle is one of the most common causes of musculoskeletal ankle injuries. The peroneus longus (PL) and peroneus brevis (PB) contribute to ankle stability. In early rehabilitation, isometric exercises have been selected for improvement of ankle stability. To effectively train the peroneal muscles during eversion, it is important to consider ankle and body posture. Objects: This study aimed to compare activation of the PL, PB, and biceps femoris (BF) muscles during eversion in different ankle postures (neutral [N], plantarflexed [PF]) and body postures (sitting and side-lying). Methods: Thirty healthy individuals with no history of lateral ankle sprains within the last 6 months were included in the study. Maximal isometric strength of eversion and muscle activation were measured simultaneously. Muscle activation at submaximal eversion was divided by the highest value obtained from maximal isometric eversion among the four postures (percent maximal voluntary isometric contraction [%MVIC]). To examine the differences in muscle activation depending on posture, a 2 × 2 repeated measures analysis of variance (ANOVA) was conducted. Results: There were significant interaction effects of ankle and body postures on PL muscle activation and evertor strength (p < 0.05). The PL muscle activation showed a significantly greater difference in the side-lying and PF conditions than in the sitting and N conditions (p < 0.05). Evertor strength was greater in the N compared to the PF condition regardless of body posture (p < 0.05). In the case of PB and BF muscle activation, only the main effects of ankle and body posture were observed (p < 0.05). Conclusion: Among the four postures, the side-lying-PF posture produced the highest muscle activation. The side-lying-PF posture may be preferred for effective peroneal muscle exercises, even when considering the BF muscle.

• Elastomers and Composites
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• v.39 no.4
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• pp.281-285
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• 2004

In this paper, the simple way to evaluate the value of the activation energy for the overall rate of free radical polymerization by using DSC thermograms was studied using free radical polymerization or butylacrylate as a model. Activation ehergies were determined at heating rates of 1, 2, 5, and $10^{\circ}C/min$ by applying the multiple scanning-rate methods of Kissinger, Osawa, and half-width methods as well as the single rate method of Barrett. The value of the overall activation energy measured was closely matched with the values calculated from individual data. This work also demonstrated that the use of the isoconversional method was a simple and effective way to estimate the activation energy for the overall free radical polymerization.

• Fire Science and Engineering
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• v.33 no.1
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• pp.1-6
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• 2019

The activation energy of CPVC (Chlorinated Poly Vinyl Chloride) used for non-metallic synthetic resin piping in fire-fighting was measured by thermogravimetric analysis (TGA). The activation energy was determined using by TGA kinetic methods, such as Kissinger and Flynn-Wall-Ozawa method. The calculated activation energy was 128.07 kJ/mol (Kissinger method) and 145.60 kJ/mol (Flynn-Wall-Ozawa method). The difference in activation energies calculated by the Kissinger method and Flynn-Wall-Ozawa method was not considered to be significant considering that the different analysis methods. The combustion characteristics will be tested in a future study through an evaluation of thermal deterioration using an accelerated deterioration and air oven aging test and the lifetime of CPVC will be predicted.

• Bulletin of the Korean Chemical Society
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• v.27 no.12
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• pp.2061-2063
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• 2006

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.63-71
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• 2024

Deep reinforcement learning (RL) significantly influences autonomous vehicle development by optimizing decision-making and adaptation to complex driving environments through simulation-based training. In deep RL, an activation function is used, and various activation functions have been proposed, but their performance varies greatly depending on the application environment. Therefore, finding the optimal activation function according to the environment is important for effective learning. In this paper, we analyzed nine commonly used activation functions for RL to compare and evaluate which activation function is most effective when using deep RL for autonomous vehicles to learn highway merging. To do this, we built a performance evaluation environment and compared the average reward of each activation function. The results showed that the highest reward was achieved using Mish, and the lowest using SELU. The difference in reward between the two activation functions was 10.3%.

• Animal cells and systems
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• v.1 no.4
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• pp.603-608
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• 1997

Analysis of the 5'-regulatory sequence of the caprine ${\beta}$-lactoglobulin (BLG) gene promoter revealed that two different types of activation were mediated by discrete regions, from -740 to -470 and from -205 to 109, in cultured mammary HC11 cells. Activation mediated by the proximal region was observed regardless of cell growth status. Distal activation, however, was observed only after confluent growth of the cells and was enhanced by the lactogenic hormones. This activation was accompanied by appearance of binding activity of proteins to these regions in the mammary HC11 cells. The binding motifs were broadly distributed over the upstream regulatory sequence. Comparison of the binding regions and mutation analysis suggest that a binding motif homologous to the ${\gamma}$-interferon responsive element (${\gamma}$-IRE) is responsible for transcriptional activation by hormonal induction in the mammary HC11 cells. The multiple ${\gamma}$-IRE homologous motifs seem to play a significant role in enhancing mammary cell-specific activation of the caprine BLG gene.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.5
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• pp.761-773
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• 2023

This paper proposes a method to increase the power-analysis resistance of the neural network model's feedforward process by replacing the exponential-based activation function, used in the deep-learning field, with an approximated function especially at the multi-layer perceptron model. Due to its nature, the feedforward process of neural networks calculates secret weight and bias, which already trained, so it has risk of exposure of internal information by side-channel attacks. However, various functions are used as the activation function in neural network, so it's difficult to apply conventional side-channel countermeasure techniques, such as masking, to activation function(especially, to exponential-based activation functions). Therefore, this paper shows that even if an exponential-based activation function is replaced with approximated function of simple form, there is no fatal performance degradation of the model, and than suggests a power-analysis resistant feedforward neural network with exponential-based activation function, by masking approximated function and whole network.

• Journal of Korean Physical Therapy Science
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• v.31 no.3
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• pp.89-99
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• 2024

Background: Squats are well-known for their effectiveness in strengthening the quadriceps femoris muscle. Flexibility and stability of the ankle joint are critical factors in performing squats correctly. Ankle instability can lead to injuries owing to compensatory actions. The role of the soleus muscle in maintaining ankle balance is crucial to minimize the risk of injury. Moreover, squats on unstable surfaces have gained attention for their potential to enhance balance and stability, which in turn helps prevent injuries. Therefore, this study aims to investigate the correlation between the soleus and quadriceps femoris muscles during squat exercises on various support surfaces. Design: Simple regression analysis Methods: Participants performed three different types of squats. Prior to commencing the exercises, we conducted electromyography (EMG) measurements to assess the activity of both the soleus and quadriceps femoris muscles. The order of the exercise execution was randomized. The squats were performed in a Full Squat format, and a one-minute rest was provided between each exercise type. Results: Our analysis of the results revealed significant differences in the activation levels of the soleus and quadriceps femoris across different squat types (p<.05). The regression analysis revealed an inverse relationship between the activity levels of the soleus and quadriceps femoris. Specifically, the quadriceps femoris exhibited the highest activation during squats using a wedge, while its activation was lowest during squats using the TOGU. In contrast, the soleus muscle demonstrated its highest activation during squats using the TOGU. Conclusion: Compared to traditional floor squats, the disparities in soleus and quadriceps femoris muscle activation observed during Wedge or TOGU squats can be attributed to the influence of ankle stability and balance. As the surface instability increased during squats, the soleus muscle's activity increased while the activation of the quadriceps femoris muscle decreased. These findings suggest that heightened soleus activation on unstable surfaces can significantly impact the activation of the quadriceps femoris muscle during squat exercises.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.11a
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• pp.464-468
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• 2008

The purpose of this study was to analyze the meaning about community and programs of community cases for community activation program development. Data were collected from literature and internet about community. Analyze community connection virtue research and domestic outside community cases and used content analysis method. The results of this study were showed as followings ; First, community which could preserve social interaction and continuous relation developing community activation program. Second, community could divide to ecotype community, life style community, school style community, bloc economy type community. Third, program of enforcing community activation was education, residing, employment connection program mainly.