• Explosives and Blasting
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• v.21 no.4
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• pp.37-42
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• 2003

The source of rock breakage by explosive blasting is the energy released from an explosive. It is transmitted to the surrounding rock mass causing various types of fracture of rock material. The reaction of explosives and the resulting action on the surrounding rock mass are completed in very short tine, making it almost impossible to observe the processes occurring in the interior of the rock mass. In this study several input parameters are investigated by numerical modelling of blast source and dynamic response of rock mass. It is shown that damping coefficient and rising time are major parameters affecting dynamics response of rock mass.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.5
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• pp.41-48
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• 2005

The Rotating transmission is made up of belts, mass disks and gears. This transmission is controlled electro-mechanically by the motor and operation program. The control strategy of the system can be to change belts' stiffness and the masses of mass disk and gear. This system can be modeled as a rigid body, and also finds broad application in such diverse fields as machine tools, the cruise control system In automobiles, and control in the attitude and gimbals of spacecraft. This Transmission proves the necessity and effect of a closed loop control. The study of the Rotating Transmission excited by its base motion is able not only to predict the rotational performance, but to obtain the fundamental data for vibration isolation. In this research, we compared the response characteristics of the two controllers by means of the experiments on PD controller and PID controller added on integral action. Furthermore, we studied the response abilities such as steady state error, overshoot, and ect. and the response velocities such as rising time, settling time, and ect. in the rotating transmission.

• The Korean Journal of Pharmacology
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• v.20 no.2
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• pp.7-14
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• 1984

In pithed rats, rising in diastolic blood pressure by clonidine, when intravenously injected, is expressed as the postsynaptic action, and inhibitory action on electrical stimulation-induced tachycardia by clonidine is expressed as the presynaptic inhibitory action. In this study it was aimed to observe the inhibitory effect of imipramine caused by a single and chronic administration on both postsynaptic and presynaptic action of clonidine in pithed rats, and discussed in relation with the mechanism of antidepressant action of imipramine. 1) A rise of diastolic blood pressure by clonidine was not antagonized by prazosin, but by both phentolamine and piperoxan. 2) The inhibition by clonidine of tachycardia which was induced by electrical stimulation was also antagonized by phentolamine and piperoxan, but not by prazosin. 3) The increase in diastolic blood pressure in response to clonidine was inhibited by both a single or chronic administration with imipramine (20 mg/kg). It was more pronounced in the latter. 4) The inhibitory action of clonidine on the tachycardia was markedly inhibited by both types of administration with imipramine, between which there showed little difference. It is concluded that the presynaptic ${\alpha}_2-adrenoceptor$ is rather sensitively affected by a single administration with imipramine, and a long-term imipramine treatment may inhibit both pre- and postsynaptic ${\alpha}_2-adrenoceptors$, simultaneously. Furthermore, it was seemed unlikely that these results provide the evidence :to support the fact that the subsensitivity of presynaptic ${\alpha}_2-adrenoceptor$ may be the mechanism of action of tricyclic antidepressant.

• Journal of the Korea Society of Computer and Information
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• v.28 no.12
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• pp.33-40
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• 2023

As South Korea enters the realm of an super-aging society, the demand for elderly welfare services has been steadily rising. However, the current shortage of welfare personnel has emerged as a social issue. To address this challenge, there is active research underway on elderly care robots designed to mitigate the social isolation of the elderly and provide emergency contact capabilities in critical situations. Nonetheless, these functionalities require direct user contact, which represents a limitation of conventional elderly care robots. In this paper, we propose a solution to overcome these challenges by introducing a care robot system capable of interacting with users without the need for direct physical contact. This system leverages commercialized elderly care robots and cameras. We have equipped the care robot with an edge device that incorporates facial expression recognition and action recognition models. The models were trained and validated using public available data. Experimental results demonstrate high accuracy rates, with facial expression recognition achieving 96.5% accuracy and action recognition reaching 90.9%. Furthermore, the inference times for these processes are 50ms and 350ms, respectively. These findings affirm that our proposed system offers efficient and accurate facial and action recognition, enabling seamless interaction even in non-contact situations.

• Steel and Composite Structures
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• v.26 no.4
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• pp.407-420
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• 2018

Experiments were performed to explore the hysteretic performance of steel reinforced concrete (SRC) cross-shaped columns. Nine specimens were designed and tested under the combined action of compression, flexure, shear and torsion. Torsion-bending ratio (i.e., 0, 0.14, 0.21) and steel forms (i.e., Solid - web steel, T - shaped steel, Channel steel) were considered in the test. Both failure processes and modes were obtained during the whole loading procedure. Based on experimental data, seismic indexes, such as bearing capacity, ductility and energy dissipation were investigated in detail. Experimental results suggest that depending on the torsion-bending ratio, failure modes of SRC cross-shaped columns are bending failure, flexure-torsion failure and torsion-shear failure. Shear - displacement hysteretic loops are fuller than torque - twist angle hysteretic curves. SRC cross-shaped columns exhibit good ductility and deformation capacity. In the range of test parameters, the existence of torque does not reduce the shear force but it reduces the displacement and bending energy dissipation capacity. What is more, the bending energy dissipation capacity increases with the rising of displacement level, while the torsion energy dissipation capacity decreases.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.3
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• pp.467-476
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• 2022

The Bank of Korea raised the benchmark interest rate by a quarter percentage point to 1.75 percent per year, and analysts predict that South Korea's policy rate will reach 2.00 percent by the end of calendar year 2022. Furthermore, because market volatility has been significantly increased by a variety of factors, including rising rates, inflation, and market volatility, many investors have struggled to meet their financial objectives or deliver returns. Banks and financial institutions are attempting to provide Robo-Advisors to manage client portfolios without human intervention in this situation. In this regard, determining the best hyper-parameter combination is becoming increasingly important. This study compares some activation functions of the Deep Deterministic Policy Gradient(DDPG) and Twin-delayed Deep Deterministic Policy Gradient (TD3) Algorithms to choose a sequence of actions that maximizes long-term reward. The DDPG and TD3 outperformed its benchmark index, according to the results. One reason for this is that we need to understand the action probabilities in order to choose an action and receive a reward, which we then compare to the state value to determine an advantage. As interest in machine learning has grown and research into deep reinforcement learning has become more active, finding an optimal hyper-parameter combination for DDPG and TD3 has become increasingly important.

• The Journal of Internal Korean Medicine
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• v.16 no.1
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• pp.17-32
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• 1995

The purpose of this is to understand the concept of Sacho on the basis of 'Sa-Sang philosophy(四象哲學)'. In oder to achieve this purpose, Sanjiao and Sacho were investigated, centering on the philophicalbasis, region. action. The conclusion would be summerized as follows. 1. Viewed in the light of a philosophical basis, Sanjiao is first recorded in Nae-Kyung(內經), a concept that Yin-Yang(陰陽), Oh-Hang(五行) in Nae-Kyung Medcine, the cosmos's order and it's moving rule could be directly applied to human body. On the contrary Sacho is a term first used by Lee Jae-Ma, a human-oriented concept that formed in Confucianism system. based on Sa-Sang type classifying in Sa-Sang Medicine. 2. Viewd in the light of a region, the upper part of Sacho is similar to the upper-jiao of Sanjiao, the mid-upper part of Sacha to the middle-jiao of Sanjiao, the mid-lower and the lower parts of Sacha to the lower-jiao of Sanjiao. But these regions are not equal to anatomical regions. Sanjiao and Sacha is similar concept from the view point of the upper and lower oder, but Sanjiao has only a concept of the upper and lower order, doesn't have a concept of the front and the rear, inside and outside. 3. Viewed in the light of a action, Sanjiao and Sacho is a similar concept from the view point of a large boundary in the life activity.Sanjiao explains the region of human body, setting imfortance on the viscera physiology, on the contrary Sacho explains the whole function of human body including one's heart's desire, physical constitution and the visceral physiolosy. 4. Viewed in the light of produsing-wasting activity. sanjiao and Sacho have both produsing action and wasting action. but Sacho has a more concrete concept of produsing action by using a term-Sa Hae(四海) 5. Viewed in the light of vital energy(氣)'s action, Sajiao give the first consideration to the rising and falling action of vital energy, on the contrary Sacho give the first consideration to the transversal circulation of vital energy and the deviation of it in each part. According to the above results, Sacho must be discussed separately from Sanjiao, it is recommended that further study is necessary to understand the concept of Sacho on the basis of Sa-Sang philosophy.

• Journal of Broadcast Engineering
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• v.20 no.1
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• pp.110-121
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• 2015

The digital app-book is an advanced form of the electronic book (e-book), which attracts a lot of interests by the help of video, sound, sensors and a variety of interactions. As mobile devices have evolved, the demand of digital app-books is also rising substantially. However, the distribution of digital app-book contents is hard to meet the demand because the digital app-book requires a lot of programming cost for the interaction. To resolve this problem, Was verified and implementation as a library function of the interaction between device and user. The proposed library consists of three parts (user action recognition, device action, and content action) and provides various user-device interaction functions by combining methods of each part, which can support source code reusability, easy understanding and availability, and wide expandibility. The library was used in the development of natural science education app-book contents. As a result, it could reduce a lot of code lines and facilitate more rapid app-book development.

• Journal of The Korean Association For Science Education
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• v.24 no.4
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• pp.785-801
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• 2004

A Typically-Perceived-Situation(TPS) is a situation which might be useful for conceptual learning of science, rising spontaneously in an individual's mind when someone is thinking about, or in relation to, any object such as physical object, concept, situation, etc. But, for a discussion about the TPS' usefulness in depth, we need to analyze the specific features of the TPS in relation to conceptual learning of science. This study investigated four elementary school students' TPSs related to the topic of the action of force, especially (a) 'the situation where force is being acted on an object', and (b) 'the situation where force is not being acted on an object', with an interview as well as with a drawing-and-explanation type questionnaire. Their TPSs were then compared with their concepts, checked by a misconception questionnaire of choice-and-explanation type. The results showed that the students' TPSs illustrated not only their conceptions about the action of force, but also gave more fruitful details of their ideas, including (a) clues of their conceptions, (b) concrete situations, and (c) their past experiences with emotional components. On the whole, the TPS's appeared to be rather stable, affected by their past experiences, and needed to be analyzed into their sub-units for more subtle details. Finally, some practical ways of how to apply the ideas of the TPS to the conceptual learning of science are suggested.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.3073-3078
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• 2011

Driverless Train Control System has been recently introduced and commercialized in Korea. It is expected that the vehicle with driverless operation system will be used in new lines such as Sinbundang line soon. Therefore it is necessary to change the system operation and conception of the existing train operation system and the necessity of driverless vehicle monitoring system meeting a new paradigm is rising. In order to dispel concerning about safety issues caused by driverless train operation, the importance to establish vehicle error detection, useful fault diagnosis and rapid action plans is higher than ever. For this, efficient and higher level of vehicle supervision & control system should be essentially supported. In this study, remote driverless vehicle monitoring system using by radio communication is suggested to be used for monitoring and controlling important parts of the vehicle and diagnose and take quick actions when vehicles are in trouble at control tower at real time.