• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.459-460
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• 2002

This article discusses a diagnostics method based on models, and information theory. From an extensive system dynamics bond graph model of a gearbox [1], simulated were various cases germane to this diagnostics approach, including the response of an ideal gearbox, which functions perfectly to designer's specifications, and degraded gearboxes with tooth root cracking. By comparing these cases and constructing a signal flow analogy between the gearbox and a communication channel, Shannon' s information theory [2], including theorems, was applied to the gearbox to assess system health, in terms of ability to function.

• Tribology and Lubricants
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• v.11 no.5
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• pp.15-19
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• 1995

Learning from the failure of mechanical systems is a necessity, given that it is the understanding of how and why things fail that generates effective redesign. This subsequently enables the technology that surrounds us to become more reliable, safer, and more economical by extending component life and minimizing the wasteful decisions made to replace systems that am either sound for continued operation could be easily repaired. Considerations for cost-effective decision making, so as to promote healthy machinery, equipment, and structures, are discussed in terms of learning from failure analysis, improving via reliability engineering, and achieving longevity through integrated diagnostics.

• Biomedical Science Letters
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• v.26 no.3
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• pp.170-178
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• 2020

Mycobacterium tuberculosis (MTB) continues to be one of the main causative agents of tuberculosis (TB); moreover, the incidence of nontuberculous mycobacteria (NTM) infections has been rising gradually in both immunocompromised and immunocompetent patients. Precise and rapid detection and identification of MTB and NTM in respiratory specimens are thus important for MTB infection control. Molecular diagnostic methods based on the nucleic acid amplification test (NAAT) are known to be rapid, sensitive, and specific compared to the conventional acid-fast bacilli (AFB) smear and mycobacterial culture methods. In the present study, the clinical performances of three commercial molecular diagnostic assays, namely TB/NTM PCR (Biocore), MolecuTech Real MTB-ID^® (YD Diagnostics), and REBA Myco-ID^® (YD Diagnostics), were evaluated with a total of 92 respiratory specimens (22 AFB smear positives and 67 AFB smear negatives). The sensitivity and specificity of TB/NTM PCR were 100% and 75.81%, respectively. The corresponding values of MolecuTech Real MTB-ID^® and REBA Myco-ID^® were 56.52% and 90.32%, and 56.52% and 82.26%, respectively. TB/NTM PCR showed the highest sensitivity; however, the concordant rate was 10% compared with sequence analysis. Although MolecuTech Real MTB-ID^® showed lower sensitivity, its specificity was the highest among the three methods. REBA Myco-ID^® allowed accurate classification of NTM species; therefore, it was the most specific diagnostic method. Of the three PCR-based methods, MolecuTech Real MTB-ID^® showed the best performance. This method is expected to enable rapid and accurate identification of MTB and NTM.

• Smart Structures and Systems
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• v.22 no.5
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• pp.587-609
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• 2018

There is greater significance in identifying the incipient damages in structures at the time of their initiation as timely rectification of these minor incipient cracks can save huge maintenance cost. However, the change in the global dynamic characteristics of a structure due to these subtle damages are insignificant enough to detect using the majority of the current damage diagnostic techniques. Keeping this in view, we propose a hybrid damage diagnostic technique for detection of minor incipient damages in the structures. In the proposed automated hybrid algorithm, the raw dynamic signatures obtained from the structure are decomposed to uni-modal signals and the dynamic signature are reconstructed by identifying and combining only the uni-modal signals altered by the minor incipient damage. We use these reconstructed signals for damage diagnostics using ARMAX model. Numerical simulation studies are carried out to investigate and evaluate the proposed hybrid damage diagnostic algorithm and their capability in identifying minor/incipient damage with noisy measurements. Finally, experimental studies on a beam are also presented to compliment the numerical simulations in order to demonstrate the practical application of the proposed algorithm.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.10 no.2
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• pp.79-87
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• 2006

Objective : Biologic responses to color stimulation was observed and analyzed in relation with Korean medicine diagnostics. Methods : Twelve volunteers participated and completed the questionnaire on Hanyeol or Joseup patterns of Korean medicine diagnostics. Standard deviation of RR intervals (SDNN), an overall indicator of heart rate variability, was measured while wearing partially transparent acetate film glasses of various colors: (1) transparency or black, (2) red, green, or blue, or (3) cyan, or yellow. Results : Different responses to the color environmental stimulation were observed. Yeol pattern score was inversely related with the SDNN value under red color stimulation. Conclusion : This line of observations may serve as a basis of clinical application of color therapy, in particular, in relation with pattern diagnosis of Korean medicine, and may be applied in combination with existing electrodermal meridian measurement systems for better evaluation of Gi (life energy) phenomenon.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.5
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• pp.1055-1062
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• 2009

Magnolia obovata exhibit several beneficial effects including anti-oxidant effects. Magnolia obovata is used as a therapeutic agent to stop hemorrhages and a tonic to promoted health in Korean and Chinese medicine. The pharmacokinetic profiles of the main Magnolia obovata is still not accurately investigated. In present study, I examined the effects of water extracts of Magnolia obovata on atherosclerosis induced high cholesterol diet in rats in serum and abdominal aorta. A total of 3-week old 9 male rats of Sprague-Dawley were divided into 3 groups and fed with the basal diet (normal group), high cholesterol diet (atherosclerosis induced group) for 8 weeks, high cholesterol diet supplemented with water extracts of Magnolia obovata (Magnolia obovata group) for 2 weeks. And rats were sacrificed, serum lipid level, abodominal aortic anti-oxidant activities and lipid peroxide were measured. These results indicated that serum total cholesterol, LDL-cholesterol, triglycerides concentration significantly lower in Magnolia obovata group than high cholesterol diet group. But HDL-cholesterol concentration had significantly higher in Magnolia obovata group than high cholesterol diet group. In conclusion, Magnolia obovata controls of lipid level of hyperlipidemia and hypercholesterolemia, thus suppresses the proliferation of intima in endothelial cells, which is risk factors of atherosclerosis induced high cholesterol diet in rats. I consider as Magnolia obovata is worth to using as atherosclerosis treatment.

• The Journal of the Korea Contents Association
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• v.19 no.3
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• pp.365-374
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• 2019

Unlike benign tumors, malignant tumors are capable of metastasis, easy to relapse, poor survival, and low quality of life. In Korea, here is a tendency to treat the tumors collectively according to the General Principles of Cancer Chemotherapy(GPCC) of the Health Insurance Review & Assessment Service (HIRA). But recently, companion diagnostics(CDx) is recommended rather than unilateral medication because biomarker-based molecular diagnostics is possible to predict the drug response of patients before drug treatment. Not only domestic but also overseas Food and Drug Administratio (FDA) recommends the development of the CDx system at the stage of drug development to ensure the responsiveness and safety of medicines. In this study, I focused on the necessity of CDx development direction as well as CDx development status through literature review. Furthermore I also discussed CDx types according to the molecular diagnostic technology such as immunohistochemistry (IHC), polymerase chain reaction (PCR), in situ hybridization (ISH), and next-generation sequencing (NGS) not only in the approved CDx but also in the developing one by US FDA. And I suggested the technology issue of CDx development process such as a selection of molecular diagnostics at the time of release, a clear understanding of the CDx mechanism, and a convergence of drug with CDx development. The necessity of social insurance system also was proposed for CDx development.

• Journal of Korean Society on Water Environment
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• v.24 no.2
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• pp.164-168
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• 2008

Perchlorate, which is still unregulated, is found in tap water, posing a threat to public health. In and out of Korea, there is no clear standard for drinking water quality or discharge. To make matters worse, Perchlorate study is in its infancy in Korea. This research tracked fresh water and purified water of water purification facility A and B located at the city of D, where Nak-dong River is being utilized as the purified water. And it was found that purified water shows no particular pattern in Perchlorate concentrations but represented a higher level of concentration compared to fresh water. With utilizing the research results, the study sought the impact of activated-carbon treatment process on Perchlorate elimination and found out that Perchlorate concentrations increased 38% after the process. The result proves that conventional water purification process can't eliminate Perchlorate. Therefore, it is reasonable that Perchlorate discharge from sources should be minimized.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.19 no.1
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• pp.35-45
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• 2015

Objective The aim of this study was to investigate stress-related factors. Method: The subjects were 22,937 persons who had received health examination by Korean Medicine and submitted questionnaires for 8 months from March to November in 2011. The stress was measured by heart rate variability in an automobile manufacturing industry. We analyzed the relationship between stress and other factors including ages, smoke amount, drinking frequency, exercise frequency, occupational category, conjugal condition by multivariate analysis with SPSS ver. 19.0. Results: Comparing "normal" to "very bad" and "bad" level of stress, ages, drinking frequency, conjugal condition are not significant difference(p>0.05). But smoking amount and occupational category are significant difference(p<0.05). Whereas comparing "normal" to "very good" and "good" level of stress, ages, occupational category, conjugal condition, smoking amount, drinking frequency are not significant difference(p>0.05). Exercise is significant difference(p<0.05). Conclusion: The results of this study suggest that smoke is affected to stress negatively, whereas exercise is affected to stress positively.

• Smart Structures and Systems
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• v.7 no.3
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• pp.229-240
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• 2011

Recent developments in Smart Structures with very large scale embedded sensors and actuators have introduced new challenges in terms of data processing and sensor fusion. These smart structures are dynamically classified as a large-scale system with thousands of sensors and actuators that form the musculoskeletal of the structure, analogous to human body. In order to develop structural health monitoring and diagnostics with data provided by thousands of sensors, new sensor informatics has to be developed. The focus of our on-going research is to develop techniques and algorithms that would utilize this musculoskeletal system effectively; thus creating the intelligence for such a large-scale autonomous structure. To achieve this level of intelligence, three major research tasks are being conducted: development of a Bio-Inspired data analysis and information extraction from thousands of sensors; development of an analytical technique for Optimal Sensory System using Structural Observability; and creation of a bio-inspired decision-making and control system. This paper is focused on the results of our effort on the first task, namely development of a Neuro-Morphic Engineering approach, using a neuro-symbolic data manipulation, inspired by the understanding of human information processing architecture, for sensor fusion and structural diagnostics.