• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.84-89
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• 2014

Data-driven method for fault diagnostics system often use machine learning technique. To use such technique proper signal processing should be implemented such as time synchronous averaging (TSA) for ball bearing systems. However, for journal bearing diagnostics systems not much has been researched, and yet a proper signal processing method has not been studied. Therefore, in this research an optimal datum unit for a reliable journal bearing diagnostics system along with angular resampling process is being suggested. Before extracting time and frequency domain features, angular resampling is applied to each cycle of vibration data. As to preserve the characteristics of vibration signal, averaging method is replaced by finding the optimal datum unit which strengthens statistical characteristics of vibration signal. Then 20 features were extracted for various cases, and those features are being evaluated by two criteria, separability and classification accuracy.

• 항공우주시스템공학회지
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• 제11권1호
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• pp.35-40
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• 2017

항공기 진단계통은 항공기 각 계통의 고장을 식별 및 탐지하고, 비행안전을 저해시키는 위험요소를 제거 및 개선함으로 사고를 미연에 방지하기 위한 계통이다. 해당 계통은 항공기 제작기술이 첨단화 될수록 필요성이 커지고 있다. 또한 여러 항공선진국에서는 진단계통에 대한 다양한 연구와 개발이 진행되고 있으나, 국내에서는 아직 진단계통에 대한 연구 및 응용 실적이 매우 적은편이다. 본 논문에서는 항공기 진단계통의 정의와 범위를 제안하고, 군용항공기 비행안전성 확보를 위한 접근방법을 고찰해 보고자 한다.

• Tribology and Lubricants
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• 제11권5호
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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.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.97-98
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• 2014

Vibration signal has been widely utilized in the diagnostics of rotating mechanical system. Diagnostics systems in rotating machinery are depends on the vibration data which are acquired from the system. However, the characteristics of acquired data can be vary according to the position of anomaly installed or the position of data acquired. In this research, the coordinate transform of journal bearing vibration signal was proposed to overcome the limitation mentioned above. Journal bearing systems are equipped two gap sensors with ninety degree angles, and it can enable to generate coordinate transformed signals in arbitrary angle domain. More abundant information for each normal or anomaly conditions are obtained from coordinate transformation than only the data of the existing measuring position, then we have developed a reliable and robust diagnosis algorithm for journal bearing system.

• Smart Structures and Systems
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• 제7권3호
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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.

• 대한한의진단학회지
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• 제20권1호
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• pp.1-13
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• 2016

Objectives The aim of this study is to develop diagnostic and assessable questionnaires for cervical movement system impairment syndromes. Methods We reviewed the previous study and literature, and organized various checkable items for differential diagnosis of four different cervical movement system impairment syndromes. Next, we selected items which can be developed as questionnaire items. Finally, we conducted a face validity study with twelve Korean medical doctors and carried out survey research to evaluate the importance score of the items with three experts. Results We developed a diagnostic and assessable questionnaire as follows: 9 items for cervical extension syndrome; 5 items for cervical flexion syndrome; 9 items for cervical rotation syndrome. By conducting 2 rounds of survey research, we were able to bridge the differences in the importance score of each item. Conclusions A questionnaire for the diagnosis and assessment of movement system impairment syndromes was developed. This questionnaire holds promising applications for objective diagnosis and assessment of cervical movement system impairment syndromes. This tool may also be used for detecting the sub-health status of musculoskeletal systems.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1990년도 제11회 학술강연회초록집
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• pp.7-31
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• 1990

Tribologicsl diagnostics as the ensemble of means and methods of continuous monitoring of the state of friction characteristics of moving junctions is playing an ever important part in the development of friction, lubrication, and wear theory end practice. The scheme presenting the main areas of tribological diagnostics is given in Fig. I. This growing part of TD is determined by the general tendency of modern technology, expressed in an attempt to organically combine the functions of measuring, evaluating,and predicting the parameters and characteristics of the processee taking place in the operating device. The logical result of this integration in future is the closed system correcting its operation in accordance with sn established program. Unfortunately, tribotechnicsl devices are still very far from such an ideal system at the present time. While in the friction assemblies with hydrodynamic lubrication it is possible in the first approximation to realize feed-backs in the lubricant circulation system with the aid of monitoring of the pressure, temperature and filtration, in the systems operating without lubrication and with boundary lubricetion even the process of selection of the diagnostic parameters has not been completed.

• 한국재료학회지
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• 제26권1호
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• pp.1-7
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• 2016

The graphene oxides (GOs) were tested as a fluorescent quencher in the field of DNA-diagnostics. The various suspensions of GO nanoplates were prepared by changing the synthesis conditions. The suspensions were stable for at least 6 weeks by differing degrees of functionalization of various oxygen-containing groups of atoms. Depending on the properties of GO nanoplates, their fluorescent quenching abilities, which were determined by the amount of the tagged immobilized oligonucleotide, were also changed. GO suspension synthesized at $75^{\circ}C$ of reaction mixture showed the fluorescent quenching of 16.39 nmol/mg, which would be a potential substitution of molecular fluorescent quencher in test-systems for DNA-diagnostics.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1913-1919
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• 2007

Substantive provisions of the concept of an estimation and safety of complex technical systems are envisaged. New problems are assume orientation to use of the formalized methods of an estimation of residual resources of reliability of objects, and also development of other methodological base in creation of complex technical systems that is connected with detailed elaboration of attention to a safety at all stages of creation of systems: from designing until operation. In this connection existing large objects should be provided by the developed systems of engineering monitoring and diagnostics.

• 대한한의진단학회지
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• 제16권3호
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• pp.23-32
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• 2012

Objectives: The objective of this study is to investigate and valuate currently provided database management systems (DBMS) of traditional Korean medical knowledge. Methods: We searched DBMS on the web and smart device application markets (Apple App Store and Google Play Store). Key words for searching were 'traditional medicine', 'acupuncture', 'moxibustion', 'herbal medicine', and '한의학'. We looked into each DBMS to find out its scopes and limits, and each was valuated according to its functionality, accessibility, and utility. Results: 186 DBMS of traditional Korean medical knowledge were investigated and 91% of them were applications for smart devices. Almost all DBMS provided acupuncture and herb information, and a small amount of DMBS provided prescription and research paper information. Functionality, accessibility, and utility valuation were performed by using scoring system from 0 to 2. Mean values of functionality, accessibility, and utility were 0.86, 1.29, and 1.09. Conclusions: On the whole, high accessibility and low functionality were found, and various data-calculating functions were not implemented. Further researches and developments about traditional Korean medical knowledge DBMS are necessary to provide correct traditional Korean medical information and to support the studies about Korean medicine.