• The Journal of Korean Medicine
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• v.28 no.3 s.71
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• pp.261-272
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• 2007

Objectives : This study was conducted to determine the analgesic effect of Acanthopanax sessiliflorus using the model of neuropathic pain and formalin-induced pain. Methods : A model of neuropathic pain was made by injuring the tibial nerve and sural nerve while the common peroneal nerve was maintained. After 2 weeks, the Acanthopanax sessiliflorus was orally administered to rats. The author performed behavioral teststo try out mechanical allodynia using von frey filament and cold allodynia using acetone, which are calculated by counting withdrawal response on foot. Thirty minutes after the Acanthopanax sessiliflorus injection in the abdominal cavity, the formalin test was performed. 2% formalin in a volume of $20{\mu}l$was injected subcutaneously into the plantar surface of the hindpaw with 26-G needle. To access formalin-induced pain behavior, paw licking time was measured every 5 min. Results : The Acanthopanax sessiliflorus 400mg/10ml/kg group showed significant decrease the withdrawal response of mechanical allodynia using von frey filament in the 10min, 30min, 60min and 120min increments compared with the control group. There were no significant differences in each group in the withdrawal response of cold allodynia using acetone. The Acanthopanax sessiliflorus group showed significant decrease in the formalin-induced pain behavior in the 15min, 20min and 25min increments compared with the control group. Conclusions : The Acanthopanax sessiliflorus may have a significant analgesic effect on the general pain as well as nerve injury pain.

• Journal of the Korean Society of Safety
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• v.31 no.2
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• pp.18-25
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• 2016

The incandescent lamp is an electric light fixture with a tungsten filament heated to a high temperature, by passing an electric current through it, until it glows with visible light. The hot filament is protected from oxidation with a glass bulb that is filled with inert gas. The incandescent lamp has fire risk when combustible materials are close to its glass bulb. Because its lamp has the property which converts 90~95 percents of the electric power to heat energy. 2015 national fire statistics show that fires caused by lighting fixtures were 652 cases, and incandescent lamps(44 cases) and halogen lamps(53 cases) accounted for 15 percents in those of high heating light fixtures. Since incandescent lamp fires account for about 45 percents in the high heating light fixture, we could not overlook the fire risks by the incandescent lamp. Although many studies related with those have been conducted, incandescent lamp fires are continuously occurred. This study was carried out to study the fire risk of ignition of wood due to radiant heat of incandescent lamp. Radiant heat flux of the incandescent lamp was predicted by applying point source model, and critical distance for ignition of wood was calculated by applying integral model. The results from this study could applied to fire prevention activities related to light bulb, and it could be used in fire cause investigations related to radiant heat of incandescent lamp.

• Journal of radiological science and technology
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• v.41 no.1
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• pp.61-66
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• 2018

The recent 3D printing technology is used in various medical, manufacturing, and education fields and is more efficient in terms of production process, time, and cost than existing production. Especially in fracture surgery, interest and research have been focused on improving accuracy, shortening of operation time and recovery time, and reducing reoperation. However, because of the financial and technical problems of the 3D printer and the file conversion program, the 3D printing is made directly at the hospital, and it is not generally used for diagnosis of fracture and surgical research. In this study, to solve those problems, clavicle CT imaging was switched into Osirix Open Source DICOM Viewer, Stereolithography file conversion programs and commercial Terarecon 3D DICOM Viewer, file conversion programs, and then clavicle fracture model was directly made through 3D printer of fused filament fabrication wire additive processing method, and then the accuracy of the shape was compared and analyzed. Clavicle fracture models printed in two methods were blind-tested on clinicians of general hospitals' orthopedics and radiologic technicians with over 10 years of experiences, and then their analysis opinions of resolution reviews were analyzed. The result showed no difference. The 3D printing model with open source DICOM STL file conversion program used was applicable to clinical, so it is considered useful in precision diagnosis of fracture and operation plans.

• Journal of Acupuncture Research
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• v.26 no.6
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• pp.67-76
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• 2009

Objectives : The purpose of this study is to examine if Radix Aconiti herbal acupuncture may be effective to the neuropathic pain(mechanical allodynia, cold allodynia) in a rat model of neuropathic pain. Methods : To produce the model of neuropathic pain, under isoflurane 2.5% anesthesia, L5 spinal nerve was ligated by 6-0 silk thread. After neurophathic surgery, the author examined if the animals exhibited the behavioral sign of allodynia. The allodynia was assessed by stimulating the medial malleolus with von frey filament and acetone. Three days after the neuropathic surgery, Radix Aconiti herbal acupuncture was injected at Hwando($GB_{30}$) one time per two days for 2 weeks. After that, the author examined the withdrawal response of neuropathic rats' legs by von frey filament and acetone stimulation. And also the author examined c-Fos in the midbrain central gray of neuropathic rats and the change of WBC, RBC, HGB, HCT count in the blood of neuropathic rats. Results : The Radix Aconiti herbal acupuncture injected Hwando($GB_{30}$) decreased the withdrawal response of mechanical allodynia that assessed with von frey filament in RA1-$GB_{30}$, RA2-$GB_{30}$ group as compared with control group. The Radix Aconiti herbal acupuncture injected Hwando($GB_{30}$) decreased the withdrawal response of chemical allodynia(cold allodynia) that assessed with acetone in RA1-$GB_{30}$, RA2-$GB_{30}$ group as compared with control group. The Radix Aconiti herbal acupuncture injected Hwando($GB_{30}$) showed the significant between control group and RA2-$GB_{30}$ group in the c-Fos expression. The Radix Aconiti herbal acupuncture injected Hwando($GB_{30}$) did not show the significant between control group and RA1-$GB_{30}$ group, RA2-$GB_{30}$ group and RA3-$GB_{30}$ group in the WBC, RBC, HGB, HCT count. Conclusions : We have noticed that Radix Aconiti herbal acupuncture at Hwando($GB_{30}$) decreased mechanical allodynia and cold allodynia in the model of neuropathic pain compared with the control group. C-fos expression in the central gray of that group was also decreased compared with the control group. This study can be used as a basic resource on a study and a treatment of pain.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1050-1059
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• 2019

The self diffusion, hole volume, and flow thermodynamic parameters of polyamide fibers were calculated from rheological parameters and crystallite size in order to study of flow segments in amorphous region. The stress relaxation of polyamide filament fibers were carried out in air and various solvents at various temperatures using the tensile tester with the solvent chamber. The rheological parameters were obtained by applying the experimental stress relaxation curves to the theoretical equation of the Ree-Eyring and Maxwell non-Newtonian model. It was observed that the rheological parameters of these polyamide filament fibers are directly related to the relaxation spectra, self diffusion, viscosities, and activation energies of flow segments.

• Elastomers and Composites
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• v.55 no.2
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• pp.108-113
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• 2020

Wear particles of the model tread compounds for bus and truck tires were made using a laboratory abrasion tester and characterized based on their size distributions, shapes, and crosslink densities. The influence of the carbon black contents and rubber compositions (NR= 100 and NR/BR= 80/20) on the production of wear particles was investigated. The wear particles were separated according to size using a sieve shaker. The shape properties of the wear particles were analyzed using an image analyzer and scanning electron microscopy (SEM). Their shapes were observed as tiny stick cookies or sausages with bumpy surfaces. The particle size distribution tended to be smaller with increasing carbon black content. Moreover, the particle size distributions of the NR = 100 samples were larger than that of the NR/BR blend samples. There were different filaments in the wear particles. The filament diameters tended to be thinner with increasing carbon black content. The crosslink density increased with increasing carbon black content, and the crosslink densities of the NR= 100 samples were lower than those of the NR/BR blend ones. The particle size distribution tended to be smaller with increasing crosslink density. Based on the experimental results, the wear particles can be produced by detaching debris from the main body through repetitive strain and recovery.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.7
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• pp.437-443
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• 2004

In this work the AC loss measurement setup based on an iron core background magnet, not used in a conventional one, has been successfully developed. To prove its validity, a round-robin test for the same Bi-2223 tape sample among three institutes has been done. The results show that the self-field and magnetization losses from the developed setup well agree with the losses measured at two other institutes of Korea Basic Science Institute and Yokohama National University. The measured magnetization losses for parallel or perpendicular fields can be well predicted from the slab model or the strip model for a filamentary region. However the magnetization losses for longitudinal fields can be rather predicted by the slab model for a decoupled filament. The self-field losses are well explained by the Norris ellipse model.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.6
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• pp.132-139
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• 2012

It is generally needed to test durability and lifetime when we develop parts in new technology. In this paper, the accelerated degradation analysis methods are developed to test them. This study is presented robust model estimation method that is less affected by outlier in regresstion model estimation. In addition, the lifetime can be predicted by Degradation-stress relationship in stress level.

• Bulletin of the Korean Chemical Society
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• v.13 no.4
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• pp.413-419
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• 1992

The theoretical equation for the relaxation spectrum of nonlinear viscoelastic polymeric material was derived from the Ree-Eyring and Maxwell non-Newtonian model. This model consists of infinite number of hyperbolic sine law Maxwell elements coupled in parallel plus a spring without a dashpot. Infinite number of nonlinear viscoelastic Maxwell elements can be used by specifying distribution of relaxation times, hole volumes, molecular weights, crystallite size and conformational size, etc. The experimentals of stress relaxation were carried out using the tensile tester with the solvent chamber. The relaxation spectra of nylon 6 filament fibers in various electrolytic solutions were obtained by applying the experimental stress relaxation curves to the theoretical equation of relaxation spectrum. The determination of relaxation spectra was performed from computer calculation.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.10
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• pp.1146-1152
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• 2011

Ink transfer process is very important to determine quality of printed pattern, therefore its mechanism should be understood to control printing quality. Although there have been many attempts to understand ink transfer mechanism by numerical simulation and experimental studies, their model was too much simple to model realistic printing process and our understanding is not enough yet. In this paper we designed ink transfer visualization system to present flow visualization of ink transfer process for gravure offset printing. We considered rotational effect of blanket roll which is related with printing speed and used non-Newtonian fluid as working fluid such as Ag paste. For printing unit, cantilever-type blanket roll is used for convenient visualization of ink transfer. Serial images were captured continuously by using high-speed CMOS camera and long range microscope. We investigated the effects of various design parameters such as printing speed and pattern angle on the ink transfer process. We found more stretched ink filament for non-Newtonian fluid than Newtonian fluid. As increasing printing speed, length of stretched ink filament and height of break-up point are also increased. We also compared ink transfer process between CD and MD pattern and its relationship with ink transfer mechanism.