• Journal of the Korean Society for Precision Engineering
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• v.16 no.4 s.97
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• pp.37-45
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• 1999

Many automated welding equipment are used in the industry. However, there are some problems to get quality welds because of the geometric error, thermal distortion, and incorrect joint fit-up. These factors can make the gap between base plates in case of a thick plate welding. The welding product with the quality welds can not be obtained without consideration of the gap. In this paper, the robot path and welding conditions are modified to get the quality weld by detecting the position and size of the gap. In this work, a low-priced laser range sensor is used. The 3-dimensional information is obtained using the motion of a robot, which holds a laser range sensor. The position and size of the gap is calculated using signal processing of the measured 3-dimensional information of joint profile geometry. The data measured by a laser range sensor is segmented by an iterative end point method. The segmented data is optimized by the least square method. The existence of gap is detected by comparing the data with the segmented shape of template. The effects of robot measuring speed and gap size are also tested. The recognizability fo the gap is verified as good by comparing the real joint profile and the calculated joint profile using the signal processing.

• Journal of Welding and Joining
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• v.27 no.1
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• pp.95-101
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• 2009

In case of manufacturing the high quality welds or pipeline, the full penetration weld has to be made along the weld joint. Thus the root pass welding is very important and has to be selected carefully. In this study, an experimental method for the selection of optimal welding condition was proposed in the root pass welding which was done along the V-grooved butt weld joint. This method uses the response surface analysis in which the width and height of back bead were chosen as the quality variables of the weld. The overall desirability function, which is the combined desirability function for the two quality variables, was used as the objective function for getting the optimal welding condition. In the experiments, the target values of the back bead width and the height are 6mm and zero respectively for the V-grooved butt weld joint of 8mm thickness mild steel. The optimal welding conditions could predict the back bead profile(bead width and height) as 6.003mm and -0.003mm. From a series of welding test, it was revealed that a uniform and full penetration weld bead can be obtained by adopting the optimal welding condition which was determined according to the method proposed.

• Animal Bioscience
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• v.35 no.10
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• pp.1616-1627
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• 2022

Objective: This work was conducted to investigate the effects of oxidative stress on meat quality, mitochondrial function, calcium metabolism and ferroptosis of broilers. Methods: In this study, a total of 144 one-day-old male Ross 308 chicks were divided into 3 groups (control group, saline group, and hydrogen peroxide [H₂O₂] group) with 6 replicates of 8 broilers each. The study lasted for 42 d. The broilers in the saline and H₂O₂ groups were intraperitoneally injected with 0.75% saline and 10.0% H₂O₂ on the 16th and 37th day of the experimental period respectively, the injection volumes were 1.0 mL/kg of broiler body weight. On the 42nd day of the experimental period, two chicks were randomly selected from each cage, a total of thirty-six chicks were stunned by electric shock and slaughtered to collect breast muscle samples. Results: The H₂O₂ exposure reduced pH value, increased drip loss and shear force of breast meat (p<0.05), impaired the ultrastructure and function of mitochondria. The H₂O₂ exposure damaged the antioxidant system in mitochondria, excessive reactive oxygen species carbonylation modified calcium channels on mitochondria, which impaired the activities of key enzymes on calcium channel, resulted in the increased calcium concentration in cytoplasm and mitochondria (p<0.05). In addition, the H₂O₂ exposure increased the iron content and lipid peroxidation (p<0.05), which induced ferroptosis. Conclusion: Oxidative stress could impair meat quality by causing mitochondrial dysfunction, resulting in calcium metabolism disorder and ferroptosis.

• Journal of Korea Multimedia Society
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• v.5 no.2
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• pp.147-157
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• 2002

Noise in image sequences is visually offensive and may mask important image detail. In addition to degradation of visual quality, the noise pattern increases the entropy of the image, and thus hinders effective compression. This paper proposes a spatial and a temporal joint filters to reduce the noise by jointly connecting two adaptive noise reducers with different characteristics, and we also propose an IIR-type 3D noise reduction litter scheme connecting the spatial and the temporal joint filters. The proposed 3D IIR filter not only strongly removes noise in uniform image regions while preserving edges and details but also effectively suppresses temporal flicker caused by noise. Experimental results show that the proposed scheme improves subjective quality as well as objective quality as compared with the various noise filtering techniques.

• Physical Therapy Rehabilitation Science
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• v.9 no.4
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• pp.215-221
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• 2020

Objective: Tension-type headaches usually occur with temporomandibular disorder, which increases the risk of the chronic tension-type headaches. This study was conducted to investigate the effect of additional temporalmandibular therapy compared to cerivcal joint therapy for tension-type headaches with pericranial tenderness. Design: Randomized controlled trial. Methods: Forty-one patients with chronic tension-type headaches and pericranial tenderness were randomized into the 3 groups, such as the temporomandibular joint therapy group (TMJT group, n=14), cervical manual therapy group (CMT group, n=14) and conservative therapy group (CT group, n=13). All patients were assessed at baseline and after each intervention during the three sessions. The participants in the TMJT group received the temporomadibular joint treatment and cervical manual therapy for 30 minutes, once a week, for 3 weeks. The participants in the CMT group received the cervical manual therapy, and those in the CT group received modalities during same time period. The outcome measurements used were the intensity of headaches measured on the Visual Analogue Scale (VAS), quality of life measured with the Headache Impact Test (HIT-6), and function of the cervical spine using the Neck Diability Index (NDI). Results: The TMJT group that received temporomandibular joint treatment and cervical manual therapy showed a significant decrease in VAS, HIT-6, and NDI compared with the other 2 groups (p<0.05). Conclusions: This study suggected that temporomandibular joint treatment combined with cervical manual therapy was more effective for the chronic tension-type headaches with pericranial tenderness than the usual cervical therapy alone.

• Journal of the Korean Wood Science and Technology
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• v.23 no.3
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• pp.8-15
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• 1995

This analytical study was carried out to make quality and productivity up in designing the frame-type furniture with semi-rigid joint by understanding the mechanical and structural behavior of the joint and by evaluating the validity of application of the time-saving Finite Element Method to its structural analysis. Slope deflection equation for rigid joint was modified to describe the moment-rotation behavior of semi-rigid joint and the joint stiffness factor(Z) could be calculated to lessen the experimental expense. It was proved that Finite Element Analysis with imaginary elements having equivalent MOE to the semi-rigid joint could be the alternative method for the structural analysis of the frame-type furniture, comparing the internal rotation of the 2-dimensional beam-to-column model with two-pin(wooden dowel) from the finite element method with other available theoretical and experimental rotation value.

• Journal of Korean society of Dental Hygiene
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• v.21 no.6
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• pp.731-740
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• 2021

Objectives: The purpose of this study was to examine the effects of oral and mental health status on temporomandibular joint disorders (TMDs) and the effects of TMD symptoms on quality of life using data from the 5th 2012 National Health and Nutrition Examination Survey. Methods: A total of 1,154 people were selected as subjects for the study. Temporomandibular joint (TMJ) sounds (672 persons), TMJ pain (227 persons), and TMJ dislocation (255 persons) were the factors studied. The complex sample chi-square test was performed to compare demographic characteristics according to the three groups of TMD symptoms. Complex sample logistic regression analysis was performed to confirm the effect of oral and mental health status on TMDs, and complex sample linear regression analysis was performed to check the effect of TMDs on the quality of life (EQ-5D). Results: After adjusting for demographic characteristics, those without TMJ sound symptoms had lower pain/discomfort (OR: 0.055, CI: -0.095 to -0.016) and anxiety/depression (OR: 0.053, CI: -0.092 to -0.014). Those without TMJ pain had lower pain/discomfort (OR: 0.119, CI: -0.192 to -0.046) and anxiety/depression (OR: 0.071, CI: -0.137 to -0.004). Pain/discomfort (OR: 0.063, CI: -0.125 to -0.001) was lower in those without TMJ dislocation symptoms. After adjusting for mental health status, pain/discomfort (OR: 0.088, CI: -0.161 to -0.014) was found to be lower in those without TMJ pain symptoms (p<0.05). Conclusions: Based on the results of this study, the treatment of TMDs, oral health, and also mental health, is needed to improve the quality of life.

• Fire Science and Engineering
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• v.34 no.2
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• pp.103-109
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• 2020

This study aims to investigate the improvement in basic CPR quality on the basis of the hip joint angle of the rescuer among students in the Department of Emergency Medical Technology who completed a basic CPR curriculum. In this study, we carried out a comparative analysis using SimPad SkillReporter and Resusci Anne® QCPR® to measure the quality of CPR (depth of chest compressions, full relaxation, compression speed, and more) on the basis of the rescuer's hip joint angle in accordance with the 2015 AHA Guidelines and conducted chest compressions and CPR 5 times in a 30:2 ratio. It was found that maintenance of the rescuer's hip joint angle at 90 degrees while compressing and relaxing the chest made a statistically significant difference in both the experimental and control groups. Moreover, this indicated that the closer the hip joint angle was to 90 degrees, the better was the quality of basic CPR. However, there was no significant difference in the hip joint angle, degree of CPR, depth of chest compressions, chest compression speed, chest compression and relaxation percentages (%), accuracy of chest compressions, hands-off time during CPR, and percentage of chest compression time (p > 0.05). Maintaining the hip joint angle at 90 degrees for basic CPR was not significantly different from not maintaining this angle. Nonetheless, good results have been obtained at moderate depth and 100% recoil. Therefore, good outcome and high-quality CPR are expected.

• Journal of Oral Medicine and Pain
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• v.45 no.3
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• pp.56-64
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• 2020

Purpose: Temporomandibular disorders (TMD) is a mosaic of clinical signs and symptoms that can be regarded as a set of phenotypes that are affected by various factors including pain sensitivity, pain disability, sleep and psychological functioning. The aims of this study were to evaluate association of pain experience, sleep quality and psychological distress with different phenotypes of TMD patients. Methods: This retrospective study included a cohort (n=1,858; 63.8% for female, mean age=34.9±15.9 years) of patients with TMD. A set of self-administered questionnaires concerning pain interference (Brief Pain Inventory), pain disability (Graded Chronic Pain Scale), sleep quality (Pittsburg Sleep Questionnaire Index), psychological distress (Symptom Checklist-90 revised), and pain catastrophizing (Pain Catastrophizing Scale) were administered to all participants at the first consultation. All TMD patients were classified into four groups including TMD with internal derangement without pain (TMD_ID, n=370), TMD with joint pain (TMD_J, n=571), TMD with muscle pain (TMD_M, n=541) and TMD with muscle-joint combined pain (TMD_MJ, n=376). Results: The female ratio was particularly high in the group with TMD_MJ (p=0.001). The patients with muscle pain and both muscle and joint pain had longer symptom duration (p=0.004) and presented significantly higher scores in pain experience (p<0.001), subjective sleep quality (p<0.001), pain catastrophizing (p<0.001) and psychological distress (p<0.05) except for paranoid-ideation than the groups with only joint problems. Conclusions: The results of this study highlight the importance of multi-dimensional approach that consider pain disability, sleep quality, and psychological functioning in the management of TMD with muscle component. This study would contribute to a better understanding of interaction between heterogeneous TMD and multiple risk factors in order to build tailored treatment based on different phenotypes.

• Journal of Korean Medicine Rehabilitation
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• v.26 no.2
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• pp.51-59
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• 2016

Objectives We studied long-term preservation in stability of a mixed preparation of distilled and 70% alcohol extracted Hwangnyunhaedok-tang pharmacopuncture to establish standards for expiration date and quality control. Methods Three lots of consecutively prepared Hwangnyunhaedok-tang pharmacopuncture were each tested in triplicate to a total 5 tests at 3 month intervals over a period of 12 months for analysis of appearance, pH, specific gravity, index component content, endotoxins, microbial sterility, residual organic solvents, heavy metals, and pesticides. Items with no difference by elapsed time were tested at the initial and final timepoints, and data of items with potential difference by elapsed time were analyzed for trends to establish individual quality control standards. Results All tested items were stable over the study period, and therefore the expiration date was set as 12 months. pH quality control standards were set as 3.66~5.69, and that of specific gravity as 0.802~1.203, respectively. In index component content standards, berberine was set at $4.96{\sim}8.98{\mu}g/vial$, baicalin at $6.47{\sim}10.31{\mu}g/vial$, and geniposide at $116.03{\sim}189.55{\mu}g/vial$, respectively. Standards for other items with no difference by elapsed time were set according to general Korean herbal medicine standards in the Korean Pharmacopoeia. Conclusions Manageable expiration date and quality control standards were established through long-term preservation testing of Hwangnyunhaedok-tang pharmacopuncture, furthering standardization of Korean medicine pharmacopuncture.