• Title/Summary/Keyword: physical theory

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Spiral Arm Features in Disk Galaxies: A Density-Wave Theory

  • Kim, Yonghwi;Ho, Luis C.
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.34.2-34.2
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    • 2019
  • Several observational results show a tighter pitch angle at wavelengths of optical and near-infrared than those that are associated with star formation, which is in agreement with the prediction of the density wave theory. In my recent numerical studies, the dependence of the shock positions relative to the potential minima is due to the tendency that stronger shocks form farther downstream. This causes a systematic variation of the perpendicular Mach number, with radius and makes the pitch angle of the gaseous arms smaller than that of the stellar arms, which supports the prediction of the density-wave theory, independently. However, some observations still give controversial results which show similar pitch angles at wavelengths, and there is no statistical study comparing observations and numerical models directly. By analyzing optical image of disk galaxies in the Carnegie-Irvine Galaxy Survey (CGS), I measured the physical values of stellar and gaseous arms such as their strength, length, and pitch angles. For direct comparison with numerical results, I analyzed more than 30 additional numerical models with varying the initial parameters in model galaxies. In this talk, I will present results both of observational and numerical samples and discuss the physical properties of spiral structures based on the density-wave theory.

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Critics on Ludwig Boltzmann's Methodology of Science (루드빅 볼츠만의 과학 방법론에 대한 역사-비판적 검토)

  • Moun, Jean-sou;Lee, Woo-buong
    • Journal of Korean Philosophical Society
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    • v.117
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    • pp.57-84
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    • 2011
  • As for the methodology of physical science, on the one side, Ludwig Boltzmann was declined to Scientific Realist and at the same time Epistemological Idealist. But on the other. He was neither fully nor consistently either one of them, because of rejecting the causal realism of the former and the belief in absolute certainty of the latter. Is there nevertheless any evidence that he had a coherent world view of his own? Yes. In short, he seems to identify his own position with what is called a mind-matter identity theory. In 1897, he supported that psychological processes are identical with certain processes in the brain(realism). And in 1903, he said : "Physics is not separated from psychology. They are only different sides." But Boltzmann did not explain concretely the possibility of this identity. So I tried to construct one theory of identity which is suitable for understanding problems n the physical world, though whether it would work for a full-scale world view which includes both physical and mental phenomena remains problematic. If light phenomena, for example, tend to be measured in terms of some contexts as if light were a wave and in others as if light were a particle, then one may be able to reasonably suppose that light has whatever characteristics in itself which it must have in order to seem like a wave under some conditions of measurement and like a particle in others. If this theory is provisionally to mental phenomena as well, it would mean that reality has those characteristics in itself which it must have to appear as it does to the various faculties of the mind and as it is measured in different physical situations. This is probably not what Boltzmann meant by his theory of identity, since it is very ontological and metaphysical. But in my opinion it is by far the most reasonable identity theory.

Control measures in Cyberspace in the light of Rimland theory (림랜드 이론으로 본 사이버공간 통제방안 (북한의 사이버전 사례연구를 중심으로))

  • Dong-hyun Kim;Soo-jin Lee;Wan-ju Kim;Jae Sung Lim
    • Convergence Security Journal
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    • v.22 no.4
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    • pp.11-16
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    • 2022
  • Development of science technology make integrated CPS(Cyber-Physical System) appear. In CPS era, cyberspace and physical-space are hard to separate anymore, that is developing toward integrated CPS. The reality is not stopping, that is consistently changing and the concept of space is developing too. But several articles are considering for cyberspace and physical-space separately, and they are developing tailed alternative each case. The theorical approaching that is not considering reality is dwelled on past, and is dangerous from dropping down to floating cloud that is not considering progressed reality. This article is suggested to consider rimland theory to control measures in cyberspace. That is dedicated to integrated approaching from physical-space to cyberspace. And that is developing concreted controling measures in cyberspace. Especially, this article is suggested to policy alternative by analyzing north korea cyber warfare from rimland theory including human sources. Simplicity is the ultimate sophistication. This article make integrated approaching effects about cyberspace and physical-space to preparing in the CPS era.

Development and Effects of Smartphone App-Based Exercise Program for Hemodialysis Patients (혈액투석 대상자를 위한 스마트폰 앱 기반 운동프로그램 개발 및 효과)

  • Ki, Eun Jeong;So, Hyang Sook
    • Journal of Korean Academy of Nursing
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    • v.50 no.1
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    • pp.52-65
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    • 2020
  • Purpose: To examine the effects of a smartphone application-based exercise program on self-efficacy expectations (SEE) and outcome expectations regarding exercise (OEE), physical fitness, activity level, physiological indices, and health-related quality of life in a sample of hemodialysis patients. Methods: A quasi-experimental control group pre-test post-test design was used. Subjects were recruited from two university hospitals in G city. The subjects were assigned randomly by coin toss: 33 participants to the experimental group and 30 to the control group. A literature review and the self-efficacy theory were used to develop the smartphone program. Experts designed and verified the program to be userfriendly and in consideration of user interaction. Data were collected through a self-report pre-test post-test questionnaire and online medical records. Results: In the experimental group, the levels of physical fitness and physical activity were significantly improved post-test, but the scores on health-related quality of life and the physical indices did not improve. In the experimental group, the SEE and OEE post-test scores were also significantly higher than the pre-test scores, but the control group's scores did not change. Conclusion: The smartphone application-based exercise program based on self-efficacy theory significantly improved the level of physical fitness and activity, SEE, and OEE for hemodialysis patients. The use of this application-based exercise program for hemodialysis patients might be an effective nursing intervention tool for improving SEE, OEE, level of physical fitness, and physical activity.

Decoupling of Background and Resonance Scatterings in Multichannel Quantum Defect Theory and Extraction of Dynamic Parameters from Lu-Fano Plot

  • Lee, Chun-Woo
    • Bulletin of the Korean Chemical Society
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    • v.30 no.4
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    • pp.891-896
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    • 2009
  • Giusti-Suzor and Fano introduced translations of the scales of Lu-Fano plots by phase renormalization in order to decouple the intra- and inter-channel couplings in multichannel quantum defect theory (MQDT). Their theory was further developed by others to deal with systems involving a larger number of channels. In different directions, MQDT was reformulated into forms with a one-to-one correspondence to those in Fano's configuration mixing theory of resonance for photofragmentation processes involving one closed and many open channels. In this study, the theory was further developed to fully reveal the coupling nature, decoupling of the background and resonance scattering in physical scattering matrices as well as to further extract the dynamic parameters undiscovered by Fano and his colleagues. This theory was applied to the photoabsorption spectrum of $H_2$ observed by Herzberg's group.

Numerical Simulation of Electromagnetic Wave Scattering from Offshore Wind Turbine (해상 풍력발전기의 전자기파 산란에 관한 수치 시뮬레이션)

  • Kim, Kook-Hyun;Cho, Dae-Seung;Choi, Gil-Hwan
    • Journal of the Society of Naval Architects of Korea
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    • v.46 no.5
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    • pp.536-544
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    • 2009
  • The performance of radars operated near an offshore wind farm region may be degraded due to the distorted signals by wind turbines. This degradation of radar systems includes ghost effects and doppler effects by a tower, nacelle, and turbine blades consisting of the wind turbine. In this paper, electromagnetic wave backscatterings from a offshore wind turbine are numerically simulated in terms of temporal radar cross section and radar cross section spectra, using a quasi-static approach based on physical optics and physical theory of diffraction. The simulations are carried out at 3.05 GHz for the seven yaw angles and four blade pitch angles. From the results, radar cross section values and doppler effect as turbine blades rotate are investigated.

Phenomenological References : Arguments for Mentalistic Natural Language Semantics

  • Jun, Jong-Sup
    • Language and Information
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    • v.8 no.2
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    • pp.113-130
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    • 2004
  • In a prevailing view of meaning and reference (cf. Frege 1892), words pick out entities in the physical world by virtue of meaning. Linguists and philosophers have argued whether the meaning of a word is inside or out-side language users' mind; but, in general, they have taken it for granted that words refer to entities in the physical world. Hilary Putnam (1975), based on his famous twin-earth thought experiment, argued that the meaning of a word could not be inside language users' head. In this paper, I point out that Putnam's argument makes sense only if words refer to entities in the physical world. That is, Putnam did not provide any argument against mentalistic semantics, since he erroneously assumed that meaning, but not reference, was inside our mind in mentalistic semantics. Mentalistic semanticist, however, assume that words pick out their references inside our head (instead of a possible outside world). A number of arguments for the mentalistic position come from psychology: studies on emotion and visual perception provide numerous cases where words cannot pick out entities from the physical world, but inside our head. The mentalistic theory has desirable consequences for the philosophy of language in that some classical puzzles of language (e.g. Russell's (1919) well-known puzzle of excluded middle) are explained well in the proposed theory.

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Effect of Self-monitoring Rehabilitation Program after Stroke on Physical Function, Self-efficacy and Quality of Life (뇌졸중 환자의 자가감시 재활 프로그램이 신체적 기능, 자기효능감 및 삶의 질에 미치는 효과)

  • Kwon, Young Sun;Choi, Ja Yun
    • The Korean Journal of Rehabilitation Nursing
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    • v.18 no.2
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    • pp.107-117
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    • 2015
  • Purpose: This study was conducted to identify the effects of a self-monitoring rehabilitation program based on the Bandura's self-efficacy theory on the activities of daily living (ADL), 6-minute walking distances, self-efficacy and quality of life (QoL) among stroke patients after three to six months. Methods: The participants consisted of 29 patients in the experiment group and 28 patients in the control group who admitted at rehabilitation specific hospital. Self-monitoring program developed by the researcher lasted twice a week for 8 weeks from August to September, 2013. Results: ANCOVA showed that all of dependent variables of this study, ADL and 6-minute walking distances as a physical function, self-efficacy and QoL for intervention group were higher than those for control group(p<.001). Conclusion: The self-monitoring rehabilitation program based on the self-efficacy theory was found to be effective in improving physical function, self-efficacy and QoL for early post-stroke patients. Early rehabilitation program for stroke patients was recommended to consider the self-monitoring of current physical and psychosocial status as a strategy of self-management.

Comparative Study on the Protective Functions of Clothes (의복의 보호론에 관한 이론적 고찰)

  • Lim Sook Ja
    • Journal of the Korean Society of Clothing and Textiles
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    • v.9 no.3
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    • pp.71-78
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    • 1985
  • This research is designed to systemize the protection theory as well as to supplement the missing theory by organizing various studies on the protective functions of celothes by domestic and foreign scholers of clothing. Human environments is classified two standpoints : (1) Physical environments, and (2) man built psychological environments including socio-physical environments, socio-biological environments, behavioral environments, socio-psychological environments and institution environments. Clothes acting as a physical protection might be of (1) extreme air temperature: Parka; (2) high relative humidity: raincoat; (3) air movement: windbreaker; (4) radiation: space suit; (5) atmospheric pressure: deep sea diver suit; (6) mechanical agent: bullet proof vest; (7) physical agent: (8) chemical agent: (9) biological agent: surgeon's gown, cap, and mask. Also dresses act to support the body comfort, health and the well-being; corset for bad back patient, wrist band for people with weak wrist, bottom half of pressure suit for people with low blood pressure. Clothes acting as a psychological protection might be of (1) influence of magic and of spirits: (2) moral danger; (3) the general unfriendliness of the world as a whole; a reassurance against the lack of love. Clothes should provide the maximum of satisfaction in accordance with the full recognition of reality. The reality should aim at the formulation of general laws concerning the most pleasing forms, colors, and styles to suit. The complex physiological anatomical and psychological aspects of individual personalities.

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Honeypot game-theoretical model for defending against APT attacks with limited resources in cyber-physical systems

  • Tian, Wen;Ji, Xiao-Peng;Liu, Weiwei;Zhai, Jiangtao;Liu, Guangjie;Dai, Yuewei;Huang, Shuhua
    • ETRI Journal
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    • v.41 no.5
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    • pp.585-598
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    • 2019
  • A cyber-physical system (CPS) is a new mechanism controlled or monitored by computer algorithms that intertwine physical and software components. Advanced persistent threats (APTs) represent stealthy, powerful, and well-funded attacks against CPSs; they integrate physical processes and have recently become an active research area. Existing offensive and defensive processes for APTs in CPSs are usually modeled by incomplete information game theory. However, honeypots, which are effective security vulnerability defense mechanisms, have not been widely adopted or modeled for defense against APT attacks in CPSs. In this study, a honeypot game-theoretical model considering both low- and high-interaction modes is used to investigate the offensive and defensive interactions, so that defensive strategies against APTs can be optimized. In this model, human analysis and honeypot allocation costs are introduced as limited resources. We prove the existence of Bayesian Nash equilibrium strategies and obtain the optimal defensive strategy under limited resources. Finally, numerical simulations demonstrate that the proposed method is effective in obtaining the optimal defensive effect.