• Title/Summary/Keyword: physical theory

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Design and Fabrication of Super Water-Saving Toilet System by Theory of Inventive Problem Solving (TRIZ) (창의적 문제해결 이론(TRIZ)를 활용한 초절수형 양변기 시스템의 설계 및 제작)

  • Lee, Kyeong-Won;Lee, Hong-Suk
    • Proceedings of the KSME Conference
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    • 2001.06c
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    • pp.376-379
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    • 2001
  • This paper describes the design and fabrication process of super water-saving toilet bowl system by the theory of inventive problem solving (TRIZ). The physical contradiction in TRIZ is defined to obtain the conceptual design for saving water in toilet bowl system with preventing the bad smell from septic tank. The super water-saving toilet bowl system is obtained by using the separation principle in time for resolving the physical contradiction. The consumption of water in the prototype system fabricated, is estimated about $3{\ell}$ comparing with $13{\ell}$ of that in conventional toilet bowl system. The noise from water in the prototype toilet bowl system is decreased by 1/3 of that in conventional toilet bowl system.

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Theory and Experiment for Electromagnetic Shaft Current in Rotation Machinery (회전기계의 전자기 축전류에 대한 이론 및 실험)

  • Kim, Chae-Sil
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.12
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    • pp.40-45
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    • 1999
  • Electrical damages to critical parts in rotation machinery have caused may machinery failures and hours of costly downtime. The problem of shaft currents generated in non-electrical machines have puzzled both users and manufacturers of these machines. The main solution for preventing electro- magnetic type damage is to demagnetize all of the machinery parts, however this is costly and time consuming. Therefore a thorough investigation into the causes and physical characteristics of electro- magnetic shaft currents is needed. In this paper, the self excitation theory was developed for a simple model, and axial flux Faraday disk machine surrounded by a long solenoid. Experimental tests were conducted to investigate the physical characteristics on an electromagnetic self excitation rig. The theory showed that the directions of both the shaft rotation and the coil turns should e identical if self excitation is to occur. From the tests, the electromagnetic type shaft current had both AC and DC components occurred at all vibration frequencies. This could point to the way to detect small instabilities or natural frequency locations by monitoring shaft currents.

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Theory and Experiment for Electromagnetic Shaft Current in Rotating Machinery

  • Kim, Chaesil;Park, Jong-Kweon
    • International Journal of Precision Engineering and Manufacturing
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    • v.3 no.1
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    • pp.20-25
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    • 2002
  • Electrical damages to critical parts in rotating machinery have caused many machinery failures and hours of costly downtime. The problem of shaft currents generated in non-electrical machines has puzzled both users and manufacturers of these machines. The main solution for preventing electromagnetic type damage is to demagnetize all of the machinery parts, however this is costly and time consuming. Therefore a thorough investigation into the causes and physical characteristics of electromagnetic shaft currents is needed. In this paper, the self excitation theory was developed far a simple model, an axial flux Faraday disk machine surrounded by a long solenoid. Experimental tests were conducted to investigate the physical characteristics on an electromagnetic self excitation rig. The theory showed that the directions of both the shaft rotation and the coil turns should be identical if self excitation is to occur. From the tests, the electromagnetic type shaft current had both AC and DC components occurred at all vibration frequencies. This could point to a way to detect small instabilities or natural frequency locations by monitoring shaft currents.

A refined hyperbolic shear deformation theory for bending of functionally graded beams based on neutral surface position

  • Zouatnia, Nafissa;Hadji, Lazreg;Kassoul, Amar
    • Structural Engineering and Mechanics
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    • v.63 no.5
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    • pp.683-689
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    • 2017
  • In this paper, a hyperbolic shear deformation theory is presented for bending analysis of functionally graded beams. This theory used in displacement field in terms of thickness co-ordinate to represent the shear deformation effects and does not require shear correction factor, and gives rise to transverse shear stress variation such that the transverse shear stresses vary parabolically across the thickness satisfying shear stress free surface conditions. The governing equations are derived by employing the virtual work principle and the physical neutral surface concept. A simply supported functionally graded beam subjected to uniformly distributed loads and sinusoidal loads are consider for detail numerical study. The accuracy of the present solutions is verified by comparing the obtained results with available published ones.

The effect of multi-phase-lag and Coriolis acceleration on a fiber-reinforced isotropic thermoelastic medium

  • Alharbi, Amnah M.;Said, Samia M.;Othman, Mohamed I.A.
    • Steel and Composite Structures
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    • v.39 no.2
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    • pp.125-134
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    • 2021
  • The three-phase-lag model, thermoelasticity without energy dissipation (G-N II) theory and thermoelasticity with energy dissipation (G-N III) theory are applied to study the effect of rotation on a fiber-reinforced thermoelastic medium. The exact expressions for the physical quantities were obtained by using the normal mode analysis. The numerical results for the field quantities are given in the physical domain and illustrated graphically in the absence and presence of rotation, Coriolis acceleration as well as reinforcement parameters.

A Study on Control of Posture and Balance (자세와 균형 조절에 관한 연구)

  • Jeong Dong-Hoon;Kwon Hyuk-Cheol
    • The Journal of Korean Physical Therapy
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    • v.11 no.3
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    • pp.23-36
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    • 1999
  • The very definitions of posture and balance have changed, as has our understanding of the underlying neural mechanisms, In rehabilitation science, there awe at least two different conceptual theories to describe the neural control of posture and balance : the reflex/hierarchical theory and system theory. A reflex/hierarchical theory suggests the posture and balance result from hierarchically organized reflex responses triggered by independent sensory systems. The systems approach suggests that action emerges from an interaction of the individual with the task and environment. That is to say, the systems approach implies that the ability to control our body's position in space emerges from a complex interaction of musculoskeletal and neural systems, collectively referred to as the postural control system. The specific organization of postural systems determined both by the functional task and the environment in which it is being performed, The postural control system is divided into three basic functional components for assessment : 1) musculoskeletal components, 2) motor coordination components, and 3) sensory organization components. It is proposed that a systemic functional understanding of human balance is critical to effective programs for balance rehabilitation. Thus, this article briefly reviews the basic functional components to consider in designing treatment plan and for the benefit of the balance assessment.

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Neighbor Discovery in a Wireless Sensor Network: Multipacket Reception Capability and Physical-Layer Signal Processing

  • Jeon, Jeongho;Ephremides, Anthony
    • Journal of Communications and Networks
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    • v.14 no.5
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    • pp.566-577
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    • 2012
  • In randomly deployed networks, such as sensor networks, an important problem for each node is to discover its neighbor nodes so that the connectivity amongst nodes can be established. In this paper, we consider this problem by incorporating the physical layer parameters in contrast to the most of the previous work which assumed a collision channel. Specifically, the pilot signals that nodes transmit are successfully decoded if the strength of the received signal relative to the interference is sufficiently high. Thus, each node must extract signal parameter information from the superposition of an unknown number of received signals. This problem falls naturally in the purview of random set theory (RST) which generalizes standard probability theory by assigning sets, rather than values, to random outcomes. The contributions in the paper are twofold: First, we introduce the realistic effect of physical layer considerations in the evaluation of the performance of logical discovery algorithms; such an introduction is necessary for the accurate assessment of how an algorithm performs. Secondly, given the double uncertainty of the environment (that is, the lack of knowledge of the number of neighbors along with the lack of knowledge of the individual signal parameters), we adopt the viewpoint of RST and demonstrate its advantage relative to classical matched filter detection method.

A Study on the Reception of Semper's Architectural Theory through Schmarsow to Giedion - A Geneology of the Modern Theory of Architecture - (젬퍼 건축이론의 수용에 관한 연구 - 젬퍼에서 슈마르조와 기디온에 이르는 건축이론의 계보를 중심으로 -)

  • Kim, Young-Cheol
    • Journal of architectural history
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    • v.33 no.2
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    • pp.29-39
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    • 2024
  • In contemporary architectural discourse, the concept of space is ubiquitous, yet its historical genesis and theoretical underpinnings in Gottfried Semper's seminal theoretical work remain under explored. This study investigates the reception and integration of Semper's architectural theory into modern discourse, tracing its trajectory from August Schmarsow, to Nikolaus Pevsner, to Sigfried Giedion. While Semper's "cladding theory" had initially been understood in terms of both its relation to physical properties and structural and functional values, leading to an expansion of cladding as a new genre of art, i.e. arts and crafts, Semper's "architectural theory" instead explained cladding theory in terms of space. In disseminating Semper's theoretical work, Schmarsow was especially important as he himself played an increasingly prominent role in expanding the boundaries of modernist architectural theory and practice from the beginning of the 20th century on.

Effects of Dietary Program based on Self-efficacy Theory on Dietary Adherence, Physical Indices and Quality of Life for Hemodialysis Patients (혈액투석 환자의 자기효능이론 기반 식사관리 프로그램이 식사관리이행, 신체상태 및 삶의 질에 미치는 효과)

  • Yun, Kyung Soon;Choi, Ja Yun
    • Journal of Korean Academy of Nursing
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    • v.46 no.4
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    • pp.598-609
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    • 2016
  • Purpose: The purpose of this study was to examine effects of a dietary program based on self-efficacy theory on dietary adherence, physical status and quality of life (QoL) in hemodialysis patients. Methods: A non-equivalent control group pre-post test design was used. The intervention group received the dietary program for 8 weeks from August 4 to September 26, 2014. The control group received only usual care. Results: ANCOVA showed that dietary adherence (F=64.75, p <.001) was significantly different between the two groups. Serum albumin (F=12.13, p =.001), interdialytic weight gain (F=56.97, p <.001), calories (F=15.80, p <.001) as physical status indices were significantly different, but serum potassium (F=2.69, p =.106) and serum phosphorus (F=1.08, p =.303) showed no significant difference between the two groups. In terms of health-related QoL, the physical component scale (F=10.05, p =.002) and the mental component scale (F=16.66, p <.001) were significantly different between the two groups. In addition, in terms of diet related QoL, diet level (F=35.33, p <.001) and satisfaction level (F=15.57, p <.001) were significantly different between the two groups, but dietary impact level (F=1.23, p =.271) was not significantly different. Conclusion: Findings show that the dietary program based on self-efficacy theory is an effective nursing intervention program to improve adherence to diet, and to maintain physical status and QoL for hemodialysis patients.

Suggestion of the morphological characteristic parameters according to the Lee's physical constitution theory using X-ray computed tomography (X선 CT화상을 이용한 사상체질의 형태학적 특징 파라메타의 제안)

  • Jo, Bong-Kwan;Bae, Jong-Il;Ko, Byung-Hee;Saito, Masao
    • Proceedings of the KOSOMBE Conference
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    • v.1993 no.11
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    • pp.13-16
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    • 1993
  • In this paper the morphological characteristic parameters according to the Lee's physical constitution theory are suggested using the X-ray computed tomography. The Lee's physical constitution theory is classify into 4 physical constitutional types by the relative degree of visceral function: those are macro-negative(strong liver- weak lung), micro-negative(strong kidney- weak spleen), micro-positive(strong spleen- weak kidney) and macro-positive(string lung- weak liver). The morphological characteristic parameters are the following. The AA-line is the distance between Rt. & Lt. acupuncture point keug-cheun. The BB-line is the length of lung. The CC-line is the longest width of thorax. The DD-line is the vertical distance between the CC-line and the EE-line. The EE-line is the distance between the Rt. and Lt. anterior superior iliac spines. As the results macro-negative(strong liver-weak lung) has the longest CC-line and the short BB-line. Micro-negative(strong kidney-weak spleen) has the longest EE-line and the short CC-line. Micro-positive(strong spleen-weak kidney) has the longest DD-line and the short BB-line. And macro-positive(strong lung-weak kidney) has the longest BB-line and the short EE-line.

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