• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.4
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• pp.305-310
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• 2014

In this study, a non-destructive evaluation (NDE) mothod is proposed for ball bearings contaminated with micro foreign substances, which were inserted into a ball bearing to create a defective specimen. The non-contact quantitative infrared thermographic technique was applied for NDE condition monitoring. Passive thermographic experiments were conducted to perform early fault diagnosis, for bearings operated at optimized torque status under a dynamic load condition. The temperature profiles for normal and defective specimens were quantitatively compared, and the thermographic data analyzed. Based on the NDE results, the temperature characteristics and abnormal fault detection of the ball bearing were quantitatively analyzed according to the rise in temperature.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.2
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• pp.116-120
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• 2010

The wheelset, an assembly of wheel and axle, is one of important parts in railway bogie, directly related with the running safety of railway rolling stock. In this investigation, the tensile failure behavior of railway axle materials was investigated. The tensile coupons were prepared from the actual rolling stock parts, which were operated over 20 years. The tensile testing was performed according to the KS guideline. During tensile testing, an infrared camera was employed to monitor temperature changes in specimen as well as demonstrate temperature contour in terms of infrared thermographic images. The thermographic images of tensile specimens showed comparable results with mechanical behavior of tensile materials. In this paper, the failure mode and behavior of railway axle materials were provided with the aid of infrared thermography technique.

• Journal of the Korean Society of Visualization
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• v.18 no.3
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• pp.61-68
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• 2020

Thermographic phosphor (TP) thermometry is a noncontact optical measurement method and has been applied in many fields such as combustion and heat transfer. However, due to the limitation of bonding technology and measurement method, most TP thermometry studies were conducted only on the air environment with water-soluble binders. In this paper, a temperature measurement technology in water using TP is proposed by coatings of manganese activated magnesium fluorogermanate (Mg4FGeO6:Mn4+, MFG) with Polydimethylsiloxane (PDMS). Four MFG-PDMS coatings with different thicknesses were prepared. The lifetime of MFG was not affected by the thickness of the coating as a result of the experiment and analysis of phosphor intensity using a photomultiplier tube. To measure the surface temperature field of an immerged body in water, a cylinder-type cartridge heater was coated with MFG doped PDMS. Transient surface temperature field was successfully measured even the initial temperature is higher than the boiling point of water.

• Journal of the Korean Vacuum Society
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• v.20 no.1
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• pp.22-29
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• 2011

An infrared thermographic imaging module of [$320{\times}256$] focal-plane array (FPA) based on [InAs/GaSb] strained-layer superlattice (SLS) was fabricated, and its images were demonstrated. The p-i-n device consisted of an active layer (i) of 300-period [13/7]-ML [InAs/GaSb]-SLS and a pair of p/n-electrodes of (60/115)-period [InAs:(Be/Si)/GaSb]-SLS. FTIR photoresponse spectra taken from a test device revealed that the peak wavelength (${\lambda}_p$) and the cutoff wavelength (${\lambda}_{co}$) were approximately $3.1/2.7{\mu}m$ and $3.8{\mu}m$, respectively, and it was confirmed that the device was operated up to a temperature of 180 K. The $30/24-{\mu}m$ design rule was applied to single pixel pitch/mesa, and a standard photolithography was introduced for [$320{\times}256$]-FPA fabrication. An FPA-ROIC thermographic module was accomplished by using a $18/10-{\mu}m$ In-bump/UBM process and a flip-chip bonding technique, and the thermographic image was demonstrated by utilizing a mid-infrared camera and an image processor.

• Journal of Acupuncture Research
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• v.17 no.2
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• pp.31-39
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• 2000

Object : This study is designed to evaluate the correlation between the data of DITI(Digital Inrared Thermographic Imaging) examination and the changes of clinical symptoms after the therapy of acupuncture in the patients with spondylolisthesis. Contents : The conservative therapy with acupuncture was performed during 3-4weeks. The acupuncture points of BL23, BL24, BL25, BL40, BL57, BL60, BL62, GB30, GB31, ST36, TE3 was used. In the pre- and post therapy, DITI examinations were performed in patients who had spondylolisthes in L-spine X-ray and were treated by acupuncttare simultaneously, and then tried to correlate the results of clinical symptoms with the difference of thermographic findings at pre-and post acupuncture. Setting : The standard routine thermographic exanninations were performed with thermography (DITI) in the 22 patients with spondylolisthesis at pre- and post acupuncture. Patients : Thermographic imaging of 22 cases was analyzed. They had diagnosed spondylolisthes in L-spine X-ray. They were treated by acupuncture and moxibustion therapy in Wonkwang Oriental Hospital from May, 1998 to May, 2000. Results : 1) The causes were congenital (4.5%), overwork (31.85%), trauma (13.65%), degenerative factor(50%) 2) The DITI results showed 45.4% below $0.3^{\circ}C$, 36.4% between 0.3 and $0.5^{\circ}C$, 4.5% between 0.5 and $0.7^{\circ}C$, 9.1% between 0.7 and $0.9^{\circ}C$, and 4.5% over $0.9^{\circ}C$. 3) The results of treatment using pain scale showes that 27.3% of patientsachieved excellent recovery and 54.6% achieved good recovery. After compairing the DITI results before and after treatment, we found 45.4% of patients achieved excellent recovery and 36.4% achieved good recovery. Conclusion : Acupuncture showed good results over 81.9% in clinical evaluation and 81.8% in DITI. Thermographic examination was valuable in the evaluation of therapeutic effect of acupuncture treatment.

• Journal of Korean Neurosurgical Society
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• v.38 no.2
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• pp.144-146
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• 2005

Herein, a case of missed upper lumbar disc herniation, diagnosed by thorough neurological examination, digital infrared thermographic imaging[DITI], and repeated magnetic resonance[MR] image study, is reported. A 36-year-old female presented with intractable leg pain on left anterior thigh. Although she underwent lumbar MR image at other hospital, she was misdiagnosed as acute sprain. Neurological examination suggested the possibility of upper lumbar disc herniation, which was confirmed by DITI, MRI, and selective root block. After operation, her leg pain was significantly improved. It should be considered that upper lumbar disc herniation might be misdiagnosed as an acute sprain, as in our case. A high index of suspicion based on thorough neurological examination is most important in such cases. Then, multi-access such as DITI, MR image, and selective block, base on thorough neurological examination, are warranted.

• Journal of Chest Surgery
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• v.35 no.9
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• pp.701-703
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• 2002

The result of compensatory sweating after surgical treatment for essential hyperhidrosis had problems in objectivity and validity because it mainly depended on the subjective symptoms of patients. Therefore, we tried to evaluate more precisely and objectively, the distribution and degree of compensatory sweating by D.I.T.I.(Digital Infrared Thermographic Imaging) with subjective symptoms.

• 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.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.3
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• pp.296-301
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• 2012

This paper describes an analytic method for infrared thermography to detect surface cracks in thin plates. Traditional thermographic method uses the spatial contrast of a thermal field, which is often corrupted by noise in the experiment induced mainly by emissivity variations of target surfaces. This study developed a robust analytic approach to crack detection for thermography using the holomorphic function of a temperature field in thin plate under steady-state thermal conditions. The holomorphic function of a simple temperature field was derived for 2-D heat flow in the plate from Cauchy-Riemann conditions, and applied to define a contour integral that varies depending on the existence and strength of singularity in the domain of integration. It was found that the contour integral at each point of thermal image reduced the noise and temperature variation due to heat conduction, so that it provided a clearer image of the singularity such as cracks.

• Journal of Welding and Joining
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• v.18 no.6
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• pp.55-61
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• 2000

Dynamic monitoring of weld pool formation and seam deviations using infrared vision is described in this paper. Isothermal contours representing heat dissipation characteristics during the process of arc welding were analysed and processed using imaging techniques. Maximum bead width and penetration were recorded and the geometric position in relation to the welding seam was measured at each sampling point. Deviations from the desired bead geometry and welding path were sensed and their thermographic representations were digitised and welding path were sensed and their thermographic representations were digitised and subsequently identified. Evidence suggested that infrared thermography can be utilized to compensate for inaccuracies encountered in real-time during robotic arc welding.