• Title/Summary/Keyword: many-body interactions

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Ion Transport and High Frequency Dielectric Absorption (이온 전송 및 고주파 유전 흡수)

  • Yun, Ju-Ho;Choi, Yong-Sung;Hwang, Jong-Sun;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.379-380
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    • 2008
  • Molecular Dynamics (MD) simulations have been used to model the dynamics of the charge-compensating sodium ions in the non-stoichiometric hollandite Nax$(Ti_{8-x}Cr_x)O_{16}$. These interstitial ions reside in 'tunnels' in the crystal structure and move under the forces of both the ions making up the cage structure and the many body interactions of the other sodium ions in the tunnel. The Velocity Autocorrelation Function (VAF) of the sodium ions is calculated for a range of temperature from 250K to 1000K and converted into the linear ac-conductivity and ac-susceptibility response via Fourier transformation. A peak is found in the conductivity around $6\times10^{12}$ Hz that has some of the character of a Poley absorption. Here it is shown to be due to an harmonically coupled site vibrations of the sodium atoms, which extend only over a limited range. At frequencies below the peak the conductivity tends towards a constant i.e. dc value corresponding to a constant flow of ions through the simulation cell. At high temperatures the conductivity due to this ion transport process behaves like a metal with an insulator to metal transition occurring around a specific temperature.

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Backbone hydrogen bonding interaction of the inactive isoform of type III antifreeze proteins studied by 1H/15N-HSQC spectra

  • Seo-Ree, Choi;Sung Kuk, Kim;Jaewon, Choi;Joon-Hwa, Lee
    • Journal of the Korean Magnetic Resonance Society
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    • v.26 no.4
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    • pp.46-50
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    • 2022
  • Antifreeze proteins (AFPs) bind to the ice crystals and then are able to inhibit the freezing of body fluid at subzero temperatures. Type III AFPs are categorized into three subgroups, QAE1, QAE2, and SP isoforms, based on differences in their isoelectric points. We prepared the QAE2 (AFP11) and SP (AFP6) isoforms of the notched-fin eelpout AFP and their mutant constructs and determined their temperature gradients of amide proton chemical shifts (𝚫δ/𝚫T) using NMR. The nfeAFP11 (QAE2) has the distinct 𝚫δ/𝚫T pattern of the first 310 helix compared to the QAE1 isoforms. The nfeAFP6 (SP) has the deviated 𝚫δ/𝚫T values of many residues, indicating its backbone conformational distortion. The study suggests the distortion in the H-bonding interactions and backbone conformation that is important for TH activities.

Multimodal Attention-Based Fusion Model for Context-Aware Emotion Recognition

  • Vo, Minh-Cong;Lee, Guee-Sang
    • International Journal of Contents
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    • v.18 no.3
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    • pp.11-20
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    • 2022
  • Human Emotion Recognition is an exciting topic that has been attracting many researchers for a lengthy time. In recent years, there has been an increasing interest in exploiting contextual information on emotion recognition. Some previous explorations in psychology show that emotional perception is impacted by facial expressions, as well as contextual information from the scene, such as human activities, interactions, and body poses. Those explorations initialize a trend in computer vision in exploring the critical role of contexts, by considering them as modalities to infer predicted emotion along with facial expressions. However, the contextual information has not been fully exploited. The scene emotion created by the surrounding environment, can shape how people perceive emotion. Besides, additive fusion in multimodal training fashion is not practical, because the contributions of each modality are not equal to the final prediction. The purpose of this paper was to contribute to this growing area of research, by exploring the effectiveness of the emotional scene gist in the input image, to infer the emotional state of the primary target. The emotional scene gist includes emotion, emotional feelings, and actions or events that directly trigger emotional reactions in the input image. We also present an attention-based fusion network, to combine multimodal features based on their impacts on the target emotional state. We demonstrate the effectiveness of the method, through a significant improvement on the EMOTIC dataset.

Modeling dynamic interactions between the support foot and the ground in bipedal walking

  • Jung, Moon-Ryul
    • Journal of the Korea Computer Graphics Society
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    • v.1 no.2
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    • pp.201-212
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    • 1995
  • This paper presents a new method of dynamics-based synthesis of bipedal, especially human, walking. The motion of the body at a time point is determined by ground reaction force and torque under the support foot and joint torques of the body at that time point. Motion synthesis involves specifying conditions that constrain ground reaction force and torque, and joint torques so that a given desired motion may be achieved. There are conditions on a desired motion which end-users can think of easily, e.g. the goal position and orientation of the swing foot for a single step and the time period of a single step. In this paper, we specify constraints on the motion of the support foot, which end-users would find difficult to specify. They are constraints which enforce non-sliding, non-falling, and non-spinning the support foot. They are specified in terms of joint torques and ground reaction force and torque. To satisfy them, both joint torques and ground reaction force and torque should be determined appropriately. The constraints on the support foot themselves do not give any good clues as to how to determine ground reaction force and torque. For that purpose, we specify desired trajectories of the application point of vertical ground reaction force (ground pressure) and the application point of horizontal ground reaction (friction) force. The application points of vertical pressure and friction force are good control variables, because they are indicators to kinds of walking motions to synthesize. The synthesis of a bipedal walking motion, then, consists of finding a trajectory of joint torques to achieve a given desired motion, so that the constraints are satisfied under the condition of the prescribed center of pressure and center of friction. Our approach is distinguished from many other approaches, e.g. the inverted-pendulum approach, in that it captures and formulates dynamics of the support foot and reasonable constraints on it.

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The design for therapeutic agents of Leucine Rich Repeat protein using bioinformatics

  • Kim, Seong Yeol;Park, Beom Seok
    • International Journal of Advanced Culture Technology
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    • v.7 no.4
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    • pp.156-162
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    • 2019
  • Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by progressive joint deterioration; Furthermore, RA can also affect body tissues, including the skin, eyes, lungs, heart and blood vessels. The early stages of RA can be difficult to diagnose because the signs and symptoms mimic those of many other diseases. It is not known exactly what triggers the onset of RA and how to cure the disease. But recent discoveries indicate that remission of symptoms is more likely when treatment begins early with strong medications known as disease-modifying anti-rheumatic drugs (DMARDs). Tumor necrosis factor (TNF) inhibitors are typical examples of biotherapies that have been developed for RA. The substances may occur naturally in the body or may be made in the laboratory. Other biological therapies care biological response modifiers (BRMs)such as monoclonal antibodies, interferon, interleukin-2 (IL-2) and a protein binder using repeat units. These substances play significant anti-inflammatory roles. Proteins with recurrent, conserved amino acid stretches mediate interactions among proteins for essential biological functions; for example, ankyrin (ANK), Heat repeat protein (HEAT), armadillo repeat protein (ARM) and tetratricopeptide repeats (TPR). Here, we describe Leucine rich repeats (LRR) that ideally fold together to form a solenoid protein domain and is more applicable to our current study than the previously mentioned examples. Although BRMs have limitations in terms of immunogenicity and effector functions, among other factors, in the context therapeutic use and for proteomics research, We has become clear that repeat-unit-derived binding proteins will increasingly be used in biotechnology and medicine.

Global performances of a semi-submersible 5MW wind-turbine including second-order wave-diffraction effects

  • Kim, H.C.;Kim, M.H.
    • Ocean Systems Engineering
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    • v.5 no.3
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    • pp.139-160
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    • 2015
  • The global performance of the 5MW OC4 semisubmersible floating wind turbine in random waves was numerically simulated by using the turbine-floater-mooring fully coupled and time-domain dynamic analysis program FAST-CHARM3D. There have been many papers regarding floating offshore wind turbines but the effects of second-order wave-body interactions on their global performance have rarely been studied. The second-order wave forces are actually small compared to the first-order wave forces, but its effect cannot be ignored when the natural frequencies of a floating system are outside the wave-frequency range. In the case of semi-submersible platform, second-order difference-frequency wave-diffraction forces and moments become important since surge/sway and pitch/roll natural frequencies are lower than those of typical incident waves. The computational effort related to the full second-order diffraction calculation is typically very heavy, so in many cases, the simplified approach called Newman's approximation or first-order-wave-force-only are used. However, it needs to be justified against more complete solutions with full QTF (quadratic transfer function), which is a main subject of the present study. The numerically simulated results for the 5MW OC4 semisubmersible floating wind turbine by FAST-CHARM3D are also extensively compared with the DeepCWind model test results by Technip/NREL/UMaine. The predicted motions and mooring tensions for two white-noise input-wave spectra agree well against the measure values. In this paper, the numerical static-offset and free-decay tests are also conducted to verify the system stiffness, damping, and natural frequencies against the experimental results. They also agree well to verify that the dynamic system modeling is correct to the details. The performance of the simplified approaches instead of using the full QTF are also tested.

APP Tail 1 (PAT1) Interacts with Kinesin Light Chains (KLCs) through the Tetratricopeptide Repeat (TPR) Domain (APP tail 1 (PAT1)과 kinesin light chains (KLCs)의 tetratricopeptide repeat (TPR) domain을 통한 결합)

  • Jang, Won Hee;Kim, Sang-Jin;Jeong, Young Joo;Jun, Hee Jae;Moon, Il Soo;Seog, Dae-Hyun
    • Journal of Life Science
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    • v.22 no.12
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    • pp.1608-1613
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    • 2012
  • A conventional kinesin, KIF5/Kinesin-I, transports various cargoes along the microtubule through interaction between its light chain subunit and the cargoes. Kinesin light chains (KLCs) interact with many different cargoes using their tetratricopeptide repeat (TPR) domain, but the mechanism underlying recognition and binding of a specific cargo has not yet been completely elucidated. We used the yeast two-hybrid assay to identify proteins that interact with the TPR domain of KLC1. We found an interaction between the TPR domain of KLC1 and an amyloid precursor protein (APP)-binding protein PAT1 (protein interacting with APP tail 1). The yeast two-hybrid assay demonstrated that the TPR domain-containing region of KLC1 mediated binding to the C-terminal tail region of PAT1. PAT1 also bound to KLC2 but not to kinesin heavy chains (KIF5A, KIF5B, and KIF5C) in the yeast two-hybrid assay. These protein-protein interactions were also observed in the glutathione S-transferase (GST) pull-down assay and by co-immunoprecipitation. Anti-PAT1 antibody as well as anti-APP anti-body co-immunoprecipitated KLC and KHCs associated with PAT1 from mouse brain extracts. These results suggest that PAT1 could mediate interactions between Kinesin-I and APP containing vesicles.

The Role of Angiogenesis in Obesity (비만에서의 혈관신생의 역할)

  • Yoon, Michung
    • Journal of Life Science
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    • v.24 no.5
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    • pp.573-587
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    • 2014
  • Angiogenesis, the formation of new capillary blood vessels, is a tightly regulated process. Under normal physiological conditions, angiogenesis only takes place during embryonic development, wound healing, and female menstruation. Dysregulation of angiogenesis is associated with many diseases, such as cancer, rheumatoid arthritis, psoriasis, and proliferative retinopathy. The growth and expansion of adipose tissue require the formation of new blood vessels. Adipose tissue is probably the most highly vascularized tissue in the body, as each adipocyte is surrounded by capillaries, and the angiogenic vessels supply nutrients and oxygen to adipocytes. Accumulating evidence shows that capillary endothelial cells communicate with adipocytes via paracrine signaling pathways, extracellular components, and direct cell-cell interactions. Activated adipocytes produce multiple angiogenic factors, including VEGF, FGF-2, leptin, and HGF, which either alone or cooperatively stimulate the expansion and metabolism of adipose tissue by increasing adipose tissue vasculature. Recently, it was demonstrated that antiangiogenic herbal Ob-X extracts and Korean red ginseng extracts reduce adipose tissue mass and suppress obesity by inhibiting angiogenesis in obese mice. Thus, angiogenesis inhibitors provide a promising therapeutic approach for controlling human obesity and related disorders.

Study On The Theory of The Interrelation of Yin and Yang in The Nei Ching ("황제내경(黃帝內徑)"에 나타난 음양상호관계론(陰陽相互關係論) 약고(略考))

  • Won, Jong-Sil
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.1
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    • pp.1-7
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    • 2005
  • In Chinese philosophy, the concept of Yin and Yang, in the era of the Early China, applies to many more philosophical categories than merely the relationship between the sunny side and the shady side of the sun. A whole series of possible interactions between the Yin and Yang in life is contained in the Chinese Book of Changes, the I Ching. The philosophical theory and the origin of natural sciences of the I Ching is imbued in the Nei Ching. having absorbed and developed the essence of Book of Changes, the Nei Ching reflects the spirit of science. Under the influence of Book of Changes, as well as its idea of Yin and Yang, peculiar at the time, the Nei Ching adapts the essences of the theory of Yin and Yang. The contribution made by the Nei Ching to the development of the philosophical concepts of Yin and Yang lies in that it combines those philosophical concepts with medicine and makes this the basic theory of Chinese medicine. In the Nei Ching, the Yin and Yang theory asserts that the human body is an organic whole, and there exists an organic connection between all tissues and structures. Therefore, the Yin and Yang functions as an essential life that plays a major role of the organic interrelation, the mutual control, and the mutual assistance. Yet, at the same time, each of them can be divided into the opposite aspects of yin and yang. Yin and yang depend on each other for existence. Without yin, there would be no yang, Without yang, there would be no yin. Neither can exist in isolation. Thus the interrelation of Yin and Yang is premised on the two opposite forces and aspects as the underlying cause of all change of Yin and Yang.

What is Epigenetics? -Focusing on Basic Concepts and Mechanisms- (최근 보건의료분야에서 활발하게 연구되고 있는 "Epigenetics"란 무엇인가? -기본개념 및 기전을 중심으로-)

  • Lee, Sun-Dong;Park, Sung-Kyun;Ko, Seong-Gyu;Shin, Heon-Tae;Kim, Myung-Dong
    • Journal of Society of Preventive Korean Medicine
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    • v.14 no.2
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    • pp.1-12
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    • 2010
  • The individual differences in disease development and susceptibility have been researched primarily on the subject of genes, environment or the interaction between genes and the environment respectively. However, there have been limitations in explaining complex diseases, and the differences in health and diseases in monozygotic and dizygotic twins. Fortunately, thanks to active research on the relationship between genes and the environment, and epigenetics, there has been much progress in the understanding of body's reactions and changes. Epigenetics is referred to as a study of gene expression through the interactions of DNA methylation, chromatin's histone and the change of structure in tail, RNA editing without any change in DNA sequence. In this paper, we introduce the basic concepts and mechanisms of epigenetics. The result of the epigenetics is heritable ; can regulate gene expressions ; is reversible ; and has many variable forms depending on cell types. The influences of epigenetics occur throughout life, but it is mainly determined in utero during early pregnancies. Diseases occur or the risk rises if these influences continue after birth until adult life when problems occur in excess/lack of nutrition, environmental plasticity, or already inputted data. Therefore, there is a need for change and innovation, especially in interest and investment in health education for young women near pregnancies and correct treatment of epigenetic-related diseases.