• Title/Summary/Keyword: Thermal Asymmetry

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Automatic Intelligent Asymmetry Detection Using Digital Infrared Imaging with K-Means Clustering

  • Kim, Kwang Baek;Song, Doo Hoen
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.15 no.3
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    • pp.180-185
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    • 2015
  • Digital infrared thermal imaging is a non-invasive adjunctive diagnostic technique that allows an examiner to visualize and quantify changes in skin surface temperature. The asymmetry of temperature differences between the diseased and the contralateral healthy body parts can be automatically analyzed and has been studied in many areas of medical science. In this paper, we propose a method for intelligent automatic asymmetry detection based on a K-means analysis and a YCbCr color model. The implemented software successfully visualizes an asymmetric distribution of colors with respect to the patients’ health status.

The Method of medical Infrared Thermographic imaging using an Infrared LED Lamps (적외선 LED 램프를 이용한 적외선 체열 영상 진단)

  • Song, M.J.;Ryu, S.M.;Soo, B.M.;Kim, J.S.;Choi, W.S.;Park, C.B.;Kim, T.W.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.282-282
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    • 2010
  • LED Device was designed of electronic circuits of electrical power part for used Pspice student version and used Infrared LED lamps of load part. LED was used Computerized Electronic Medical Infrared Thermographic Imaging System for body surface Investigation of variable Body thermal asymmetry. It was knowledge body thermal Asymmetry of body surface and quantity body surface of electromagnetic wave to inflow electrical power part.

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A Study on the Asymmetry Factor in Photophoresis (광영동에 있어서의 비대칭인자에 대한 연구)

  • Park, S.H.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.7 no.4
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    • pp.694-702
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    • 1995
  • When a small absorbing particle is exposed to a strong thermal radiation incidence, it moves towards or away from the radiation source due to the nonuniform internal absorption of the radiation. It is called the photophoretic phenomena and governed by the asymmetry factor. An asymmetry factor for the total wavelength range is calculated to estimate the photophoretic phenomena of a particle in a combustor or in the atmosphere and compared to that for a single wavelength. The samples are soot particulates, water droplets, ice particles, silicon particles, $SiO_2$ particles, aluminium oxide particles, whose spectral complex refractive index are available. Although differences between total and monochromatic asymmertry factors are not much for relatively uniform distribution of the spectral refractive index, they are great in general. Therefore the use of the monochromatic factor will considerably deteriorate the accuracy of the calculation of the photophoresis.

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Thermal Stability of Nanostructured Synthetic Ferrimagnets under Applied Magnetic Fields in the 45˚ Direction

  • Han, C.W.;Han, J.K.;Lim, S.H.
    • Journal of Magnetics
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    • v.15 no.3
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    • pp.116-122
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    • 2010
  • An accurate analytical equation for the total energy in the framework of the single domain model is used to study the thermal stability of nanostructured synthetic ferrimagnets. Elliptical cells are considered that have lateral dimensions of 160 nm (long axis)$\times$80 nm (short axis) and varying values of thickness asymmetry for the two magnetic layers. The direction of the applied magnetic field, which points to the $45^{\circ}$ direction, is in the opposite direction to the thicker layer magnetization. A significant difference is observed in the applied magnetic field dependencies of the equilibrium magnetic configuration and the magnetic energy barrier when using the simplifying assumption that the self-demagnetizing field is identical in magnitude to the dipole field. At a small thickness asymmetry of 0.2 nm, for example, the magnetic energy barrier is reduced from 68 kT (T=300 K) to 6 kT at the remanent state and a progressive switching behavior changes into a critical behavior, as the simplifying assumption is used. The present results clearly demonstrate the need for an accurate analytical equation for the total energy in predicting the thermal stability of nanostructured synthetic ferrimagnets.

The Study on Indoor Thermal Environment during Convection Heating - Thermal Comfort Sensation for Vertical Temperature Differences - (대류 난방시 실내열환경에 관한 연구 -상하온도차에 대한 온열쾌적감-)

  • Kim Dong-Gyu;Kum Jong-Soo
    • Journal of Environmental Science International
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    • v.14 no.2
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    • pp.215-220
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    • 2005
  • Thermal neutrality is not enough to achieve thermal comfort. The temperature level can be the optimal, and still people may complain. This situation is often explained by the problem of local discomfort. Local discomfort can be caused by radiant asymmetry, local air velocities, too warm and too cold floor temperature and vertical temperature difference. This temperature difference may generate thermal discomfort due to different thermal sensation in different body parts. Therefore, thermal comfort can not be correctly evaluated without considering these differences. This study investigates thermal discomfort sensations of different body parts and its effect on overall thermal sensation and comfort in air-heating room. Experimental results of evaluating thermal discomfort at different body parts in an air-heating room showed that thermal sensation on the shoulder was significantly related to the overall thermal sensation and discomfort. Although it is known that cool-head, warm-foot condition is good for comfort living, cool temperature around the head generated discomfort.

A Study on Flow and Heat Transfer in One Directional Periodic-Oscillating Cylinder (일방향 주기적 진동하는 원통 내의 유동 및 열전달 연구)

  • Park, Jun-Sang
    • The KSFM Journal of Fluid Machinery
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    • v.13 no.5
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    • pp.22-28
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    • 2010
  • A study has been made of cool-down process on an incompressible fluid contained in a periodically oscillating cylinder when an abrupt cooling of wall temperature is imposed. Characteristics of flow and heat transfer are investigated along the variations of oscillating frequency and amplitude. One found the flow regimes are divided into 4-modes : 1 thermal island mode, 2 thermal island mode, 4 thermal island mode and asymmetry mode. Comprehensive analysis for each mode are given with a physical mechanism on cool-down process.

Thermal-hydraulic behavior simulations of the reactor cavity cooling system (RCCS) experimental facility using Flownex

  • Marcos S. Sena;Yassin A. Hassan
    • Nuclear Engineering and Technology
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    • v.55 no.9
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    • pp.3320-3325
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    • 2023
  • The scaled water-cooled Reactor Cavity Cooling System (RCCS) experimental facility reproduces a passive safety feature to be implemented in Generation IV nuclear reactors. It keeps the reactor cavity and other internal structures in operational conditions by removing heat leakage from the reactor pressure vessel. The present work uses Flownex one-dimensional thermal-fluid code to model the facility and predict the experimental thermal-hydraulic behavior. Two representative steady-state cases defined by the bulk volumetric flow rate are simulated (Re = 2,409 and Re = 11,524). Results of the cavity outlet temperature, risers' temperature profile, and volumetric flow split in the cooling panel are also compared with the experimental data and RELAP system code simulations. The comparisons are in reasonable agreement with the previous studies, demonstrating the ability of Flownex to simulate the RCCS behavior. It is found that the low Re case of 2,409, temperature and flow split are evenly distributed across the risers. On the contrary, there's an asymmetry trend in both temperature and flow split distributions for the high Re case of 11,524.

Influence of laminated orientation on the mechanical and thermal characteristics of carbon-fiber reinforced plastics

  • Shin, Hee-Jae;Kwac, Lee-Ku;Lee, Min-Sang;Kim, Hong-Gun
    • Carbon letters
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    • v.16 no.4
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    • pp.241-246
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    • 2015
  • Rapid industrial development in recent times has increased the demand for light-weight materials with high strength and structural integrity. In this context, carbon fiber-reinforced plastic (CFRP) composite materials are being extensively used. However, laminated CFRPs develop faults during impact because CFRPs are composed of mixed carbon fiber and epoxy. Moreover, their fracturing behavior is very complicated and difficult to interpret. In this paper, the effect of the direction of lamination in CFRP on the absorbed impact energy and impact strength were evaluated, including symmetric ply (0°/0°, −15°/+15°, −30°/+30°, −45°/+45°, and −90°/+90°) and asymmetric ply (0°/15°, 0°/30°, 0°/45°, and 0°/90°), through drop-weight impact tests. Further, the thermal properties of the specimens were measured using an infrared camera. Correlations between the absorbed impact energy, impact strength, and thermal properties as determined by the drop-weight impact tests were analyzed. These analyses revealed that the absorbed impact energy of the specimens with asymmetric laminated angles was greater than that of the specimens with symmetric laminated angles. In addition, the asymmetry ply absorbed more impact energy than the symmetric ply. Finally, the absorbed impact energy was inversely proportional to the thermal characteristics of the specimens.

Effect of Simultaneous Implementation of Thermal and Massage Therapy on Patients (척추 측만증에 대한 온열-마사지의 동시 적용 효과 : 증례보고)

  • Kim, Yu-Mi;Lee, Kwang-Jae;Yoon, Yong-Soon
    • Journal of Industrial Convergence
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    • v.20 no.1
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    • pp.107-114
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    • 2022
  • Scoliosis is defined as a condition in which the spine curves more than 10 degrees in frontal plane. However, it is complicated because it involves transverse and sagittal components as well as the frontal plane. Curvature can progress to growing children and cause serious problems. Treatments of Scoliosis, including observation, are casting, braces, physical therapy, exercise, and surgery. The goal of scoliosis management is to achieve minimal asymmetry by maintaining low angle values. However, it is difficult for adolescents to receive continuous treatment due to study and lack of time. We report cases of scoliosis that have experienced improvement of Cobb's angle through spinal thermal massage management at home.