• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.65-70
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• 2001

We consider a hyper-redundant system that consists of many uniform units. The hyper-redundant system has many degrees of freedom and it can accomplish various tasks. Applysing the reinforcement learning to the hyper-redundant system is very attractive because it is possible to acquire various behaviors for various tasks automatically. In this paper we present a new reinforcement learning algorithm "Q-learning with propagation of motion". The algorithm is designed for the multi-agent systems that have strong connections. The proposed algorithm needs only one small Q-table even for a large scale system. So using the proposed algorithm, it is possible for the hyper-redundant system to learn the effective behavior. In this algorithm, only one leader agent learns the own behavior using its local information and the motion of the leader is propagated to another agents with time delay. The reward of the leader agent is given by using the whole system information. And the effective behavior of the leader is learned and the effective behavior of the system is acquired. We apply the proposed algorithm to a snake-like hyper-redundant robot. The necessary condition of the system to be Markov decision process is discussed. And the computer simulation of learning the locomotion is demonstrated. From the simulation results we find that the task of the locomotion of the robot to the desired point is learned and the winding motion is acquired. We can conclude that our proposed system and our analysis of the condition, that the system is Markov decision process, is valid.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.4
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• pp.155-160
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• 2008

End part of the brake tube formed with the shape of snake head is important for the braking of automobile in safety because it has to prevent crack, fracture and defects occurred during the forming process. Especially, the shape of tube end has influence on the ability of brake. Based on the procedure of process design, in this paper, the forming operation is done by finite element method and the design variables are analyzed by Taguchi method. Design variables such as the outer angle of tube end with the shape of snake head(A), the inner angle to make a hole at tube end with the shape of snake head(B) and the forming distance at tube end(C) are used. Optimization of design variables is performed to minimize the damage factor of the tube end occurred during the forming process. The value of damage factor of 0.327 was obtained under the optimal condition like $A=114^{\circ},\;B=80^{\circ}$ and C=5.3mm, respectively.

• The Korean Journal of Pharmacology
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• v.11 no.1 s.17
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• pp.15-18
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• 1975

The effect of skin extracts of Korean amphibian, poisonous snake and fresh-water fish were determined for their caerulein-like action on rabbit gall bladder strips. The isolated gall bladder strips were prepared according to the technique described by Amer and Becvar(1969). The strips were placed in a bath containing 100ml of Locke-Ringer solution maintained at $38^{\circ}C$. Oxygen was continuously bubbled through the solution. The tension of the muscle strip was initially adjusted to 0.7g. The contractile response was measured isometrically by a force-displacement transducer connected to a polygraph. In this rabbit gall bladder strip caerulein produced contraction of CCK-PZ type. The skin extract of Korean amphibian also elicited similar contraction as caerulein, which extracted from Australian amphibian, Hyla caerulea, by Erspamer et al. The calculated amount was approximately $2{\mu}g$ caerulein per gram of skin tissue in Korean amphibian and the potency was about 1/200 of that seen in Australian amphibian. The contraction of gall bladder strip by our amphibians occurs in decreasing order; Rana Nigromaculata coreana Okada, Rana nigromaculata Hallowell, Hyla arborea japonica Gunther and Bombina orientalis Boulenger. The skin extracts of poisonous snake and fresh-water fish produced no caerulein-like activity.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.399-402
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• 2003

This paper deals with the making avatar like a caricature from human face image which is made by web camera. Generally, the Image made by web camera is not low quality but also, there are always various lights and backgrounds. So, It is impossible to recognize a human face's contour by some methods which only find some feature points of a image. Therefore, In this paper, we propose a new method for overcoming defeat of that methods. First, we got the area of human face roughly by color information. And then, we could find the exact human face's contour by using B-spline Snake.

• International Journal of Control, Automation, and Systems
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• v.4 no.5
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• pp.660-667
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• 2006

This paper presents a novel region-based snake method for vessel segmentation. According to geometric shape analysis of the vessel structure with different scale, an efficient statistical estimation of vessel branches is introduced into the energy objective function, which applies not only the vessel intensity information, but also geometric information of line-like structure in the image. The defined energy function is minimized using the gradient descent method and a new region-based speed function is obtained, which is more accurate to the vessel structure and not sensitive to the initial condition. The narrow band algorithm in the level set framework implements the proposed method, the solution of which is steady. The segmentation experiments are shown on several images. Compared with other geometric active contour models, the proposed method is more efficient and robust.

• Earthquakes and Structures
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• v.26 no.4
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• pp.261-267
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• 2024

With the increase in the exploitation depth of offshore oil and gas, it is possible to control the global buckling of deep-sea pipelines by the snake lay method. Previous studies mainly focused on the analysis of critical buckling force and critical temperature of pipelines under the snake-like laying method, and pipelines often suffer structural failure due to seismic disasters during operation. Therefore, seismic action is a necessary factor in the design and analysis of submarine pipelines. In this paper, the seismic action of steel pipes in the operation stage after global buckling has occurred under the active control method is analyzed. Firstly, we have established a simplified finite element model for the entire process cycle and found that this modeling method is accurate and efficient, solving the problem of difficult convergence of seismic wave and soil coupling in previous solid analysis, and improving the efficiency of calculations. Secondly, through parameter analysis, it was found that under seismic action, the pipe diameter mainly affects the stress amplitude of the pipeline. When the pipe wall thickness increases from 0.05 m to 0.09 m, the critical buckling force increases by 150%, and the maximum axial stress decreases by 56%. In the pipe soil interaction, the greater the soil viscosity, the greater the pipe soil interaction force, the greater the soil constraint on the pipeline, and the safer the pipeline. Finally, the pipeline failure determination formula was obtained through dimensionless analysis and verified, and it was found that the formula was accurate.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.234.2-234.2
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• 2015

Recently, the electromagnetically-induced transparency (EIT)-like effect in metamaterials has attracted enormous interest. Metamaterial analogs of EIT enable promising applications in slow-light devices, low-loss metamaterial, quantum optics, and novel sensors. In this work, we experimentally and numerically studied a bilayer metamaterial for controllable EIT-like spectral response at microwave frequencies. Bilayer metamaterial consists of two snake-shape resonators (SSRs) with one and two bars. The transmission spectra were measured in a frequency range of 4 - 8 GHz in an anechoic chamber at normal incidence. It is found that two SSRs in the metamaterial are activated in bright modes, and the coupling between two bright modes leads to the EIT-like effect, which results in the enhanced transmission at 5.61 GHz. Furthermore, we confirm that the EIT-like feature could be controlled by adjusting the geometric parameters of metamaterial structure. Our work provides a way to tunable EIT-like effect and various potential applications including filters, sensors, and other microwave devices.

• The Journal of Art Theory & Practice
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• no.6
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• pp.77-99
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• 2008

The purpose of this study is to show that the reason behind the ambivalent characteristic displayed in Niki de Saint Phalle's works is in her trauma and how such characteristic can be extracted from her works. During her creative years, Saint Phalle worked on various materials from different genres such as assemblages, shooting paintings, a series on Bride and Monster, 'Nana', 'Tarot Garden'and public sculptures. One commonality found among her various works is the ambivalent characteristic that contains contrasting elements simultaneously. Saint Phalle suffered a terrible psychological damage inflicted by her parents during her childhood. Specifically, she was sexually assaulted by her father and emotionally neglected by her mother, the trauma that affected her for the rest of her life. As a result, she came to develop extreme love- hate relationships with her parents and this became the main reason for the ambivalent characteristic displayed in her works. The love-hate relationship Saint Phalle developed can be identified through various researches done on the subject of the affect of sexual assault. It is common for incest victims to develop ambivalent feelings towards the perpetrator and Saint Phalle was no exception. Dissociation disorder and a snake well explain the trauma from her father. It is a generally accepted belief in the field of psychology that dissociation disorder commonly occurs to children who experience incest. And dissociation disorder is similar to the characteristic of ambivalence in the sense that a single entity contains more than two contrasting elements at the same time. In addition, the amputated doll objects used in her assemblages coincide with the expression of body detachment of people with dissociation disorder. These facts clearly indicate that the trauma from her father is showing through in her works. A snake is a subject matter that reflects the ambivalent tendency of Saint Phalle that resulted from her trauma. She remembers her father's rape as an image of a snake which is related to a phallic symbol in mythology or art reflecting her trauma. Moreover, she displays a similar pattern of ambivalent emotion like love and hate or fear towards a snake and her father. This is also confirmed by her portrayal of a snake as a monster or reversely as a creature with fundamental vitality in her works. The lack of affection from her mother can be explained by her mother's maternal deprivation. It appears that Saint Phalle's mother possessed all the causes for maternal deprivation such as maternal separation, personality disorder and inappropriate attitude towards child rearing. Especially, a study that shows mother's negative attitude towards child breeding tends to increase dissociation experience of children is another important evidence that supports Saint Phalle's dissociation tendency. These traces of Saint Phalle's trauma are clearly revealed in her assemblages and shooting paintings. The violent objects in her assemblages such as a hammer, razor, nail represent the rage and defensiveness towards her father. The objects such as fragments of broken plates of feminine patterns, pots and mirrors that her mother used symbolize the affection towards her mother. On the other hand, the destructed objects can be interpreted as her hate and resentment towards her mother. Shooting paintings contain her extreme fury and hate. Things such as acts of shooting and the image associated with blood after shooting are blunt expressions of her bursts of emotions. I have tried to define and classify the ambivalent characteristics shown in her assemblages and shooting paintings as hate, rage, violence, calm, love and pleasure according to the frame of Thanatos and Eros. Out of the six, hate, rage, violence and clam are associated with Thanatos while love and pleasure are associated with Eros and they correspondingly form an ambivalent structure. These ambivalent characteristics can be found in her assemblages and shooting paintings. The objects in her assemblages such as a razor, saw, hammer imply hate, rage, violence and the silence felt throughout her works represent calmness. And, as mentioned, the feminine objects can be seen as symbolizing love. In shooting paintings, hate, rage, violence can be found in the use of force and in the traces of watercolor after shooting, and a sense of pleasure in her feelings of catharsis after her shooting. Moreover, a shielded calmness can be found on the plywood all covered with plaster before the shooting. This study looked into the ambivalent characteristic of Saint Phalle's works by examining her trauma to find its correlation, and a meaning of this study can be found from the fact that it refocused the origin of Saint Phalle who is generally known as a feminist artist. Additionally, a meaning of the study can be found also from the fact that it examined the ambivalent characteristics of her works through a frame of Thanatos and Eros.

• Parasites, Hosts and Diseases
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• v.29 no.2
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• pp.173-180
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• 1991

A SEM study was performed on the surface of adult P. habayashii Park, 1940, recovered from the snake, Elaphe rufodorsata. The anterior part of the worms was cup-shape and equipped with oral, ventral suckers, pseudosuckers, and tribocytic organ, and the posterior one was finger-like and round-ended, The tegument of the anterior body was covered with 3~4 pointed small spines on the midventral surface and 1~2 pointed ones on the lateral surface. Sensory papillae such as type II, dome-shape ones, and papillae with an opening were distributed over the ventral surface of the anterior portion. The round tribocytic organ was bearing small stout spines laterally, whereas the surface Which comes in contact with the host tissues consisted of numerous long fibrillar fibers. The lip of the oral sucker contained type II papillae. Lateral margin of the anterior body revealed type III papillae.

• Molecules and Cells
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• v.43 no.6
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• pp.572-580
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• 2020

Transient receptor potential ankyrin 1 from rattlesnakes (rsTRPA1) and boas (bTRPA1) was previously proposed to underlie thermo-sensitive infrared sensing based on transcript enrichment in infrared-sensing neurons and hyper-thermosensitivity expressed in Xenopus oocytes. It is unknown how these TRPA1s show thermosensitivities that overwhelm other thermoreceptors, and why rsTRPA1 is more thermosensitive than bTRPA1. Here, we show that snake TRPA1s differentially require Ca²⁺ for hyper-thermosensitivity and that predisposition to cytosolic Ca²⁺ potentiation correlates with superior thermosensitivity. Extracellularly applied Ca²⁺ upshifted the temperature coefficients (Q10s) of both TRPA1s, for which rsTRPA1, but not bTRPA1, requires cytosolic Ca²⁺. Intracellular Ca²⁺ chelation and substitutive mutations of the conserved cytosolic Ca²⁺-binding domain lowered rsTRPA1 thermosensitivity comparable to that of bTRPA1. Thapsigargin-evoked Ca²⁺ or calmodulin little affected rsTRPA1 activity or thermosensitivity, implying the importance of precise spatiotemporal action of Ca²⁺. Remarkably, a single rattlesnake-mimicking substitution in the conserved but presumably dormant cytosolic Ca²⁺-binding domain of bTRPA1 substantially enhanced thermosensitivity through cytosolic Ca²⁺ like rsTRPA1, indicating the capability of this single site in the determination of both cytosolic Ca²⁺ dependence and thermosensitivity. Collectively, these data suggest that Ca²⁺ is essential for the hyper-thermosensitivity of these TRPA1s, and cytosolic potentiation by permeating Ca²⁺ may contribute to the natural variation of infrared senses between rattlesnakes and boas.