• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2014년도 추계학술대회 논문집
• /
• pp.90-93
• /
• 2014

In this paper, we have developed a new fault detection method based on vibration signal for rotor machinery. Generally, many methods related to detection of rotor fault exist and more advanced methods are continuously developing past several years. However, there are some problems with existing methods. Oftentimes, the accuracy of fault detection is affected by vibration signal change due to change of operating environment since the diagnostic model for rotor machinery is built by the data obtained from the system. To settle a this problems, we build a rotor diagnostic model by using feature residual based on vibration signal. To prove the algorithm's performance, a comparison between proposed method and the most used method on the rotor machinery was conducted. The experimental results demonstrate that the new approach can enhance and keeps the accuracy of fault detection exactly although the algorithm was applied to various systems.

• Journal of Plant Biotechnology
• /
• 제38권2호
• /
• pp.143-150
• /
• 2011

1994년 처음으로 GM 토마토인 Flavr Savr가 시장에 나온 이후, 2010년 현재 140여 품목의 GM식물이 전 세계적으로 상업화되었다. GM식물들에 대한 안전성 승인여부의 확인 및 표시제관리를 위하여 이들 GM식물내로 도입된 삽입유전자의 정보를 이용한 검정방법이 도입되었으며, 또한 도입유전자의 발현된 단백질을 분석하기 위하여 정성 및 정량을 위한 면역학적 방법이 도입되었다. 본 총설에서는 국내 외적으로 개발된 콩, 옥수수, 카놀라, 면화 등의 GM식물에 적용된 multiplex PCR, real-time PCR 방법과 최신 개발 중인 microarray, 나노기술 등을 활용한 방법들을 조사하였다.

• 한국소음진동공학회논문집
• /
• 제18권1호
• /
• pp.47-56
• /
• 2008

This paper presents a detecting technique for the improvement in quality by appling the various vibrational characteristics theory. The object of this study is to objectively point out faulty gear by developing the program which can be used to analyze and predict the vibrational characteristics caused by gear wear, deformation and nick of auto-transmission. The fault detection methods by vibrational signal analysis of gear have been progressed in the various fields of industry. These methods have the advantage of being easy to attach the accelerometer without discontinuance of the structure. But not all the methods are efficient for finding early faults. So in the thesis, we completed development of the inspection system of vibration by appling the most efficient detecting methods and verified the system's reliability through experiments.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제13권9호
• /
• pp.4814-4832
• /
• 2019

Plagiarism detection is increasingly exploiting text alignment. Text alignment involves extracting the plagiarism passages in a pair of the suspicious document and its source document. The heuristics have achieved excellent performance in text alignment. However, the further improvements of the heuristic methods mainly depends more on the experiences of experts, which makes the heuristics lack of the abilities for continuous improvements. To address this problem, machine learning maybe a proper way. Considering the position relations and the context of text segments pairs, we formalize the text alignment task as a problem of sequence labeling, improving the current methods at the model level. Especially, this paper proposes to use the probabilistic graphical model to tag the observed sequence of pairs of text segments. Hence we present the sequence labeling approach for text alignment in plagiarism detection based on Conditional Random Fields. The proposed approach is evaluated on the PAN@CLEF 2012 artificial high obfuscation plagiarism corpus and the simulated paraphrase plagiarism corpus, and compared with the methods achieved the best performance in PAN@CLEF 2012, 2013 and 2014. Experimental results demonstrate that the proposed approach significantly outperforms the state of the art methods.

• Computers and Concrete
• /
• 제27권5호
• /
• pp.447-455
• /
• 2021

Research on damage detection methods in structures began a few decades ago with the introduction of methods based on structural vibration frequencies, which, of course, continues to this day. The value of important structures, on the one hand, and the countless maintenance costs on the other hand, have led researchers to always try to identify more accurate methods to diagnose damage to structures in the early stages. Among these, one of the most important and widely used methods in damage detection is the use of time-frequency representations. By using time-frequency representations, it is possible to process signals simultaneously in the time and frequency domains. In this research, the Short-Time Fourier transform, a known time-frequency function, has been used to process signals and identify the system. Besides, a new damage index has been introduced to identify damages in concrete piers of bridges. The proposed method has relatively simple calculations. To evaluate the method, the finite element model of an existing concrete bridge was created using as-built details. Based on the results, the method identifies the damages with high accuracy.

• Mass Spectrometry Letters
• /
• 제13권4호
• /
• pp.95-105
• /
• 2022

Amatoxin-induced mushroom poisoning starts with nonspecific symptoms of toxicity but hepatic damage may follow, resulting in the rapid development of liver insufficiency and, ultimately, coma and death. Accurate detection of amatoxins, such as α-, β-, and γ-amanitin, within the first few hours after presentation is necessary to improve the therapeutic outcomes of patients. Therefore, analytical methods for the identification and quantification of α-, β-, and γ-amanitin in biological samples are necessary for clinical and forensic toxicology. This study presents a literature review of the analytical techniques available for amatoxin detection in biological matrices, and established an inventory of liquid chromatography (LC) techniques with mass spectrometry (MS), ultraviolet (UV) detection, and electrochemical detection (ECD). LC-MS methods using quadrupole tandem mass spectrometry, time-of-flight mass spectrometry, and orbitrap MS are powerful analytical techniques for the identification and determination of amatoxins in plasma, urine, serum, and tissue samples, with high sensitivity, specificity, and reproducibility compared to LC with UV and ECD, enzyme-linked immunoassay, and capillary electrophoresis methods.

• 한국미생물·생명공학회지
• /
• 제43권3호
• /
• pp.177-186
• /
• 2015

국내 식품공전에 기술되어 시행중인 식품 내 벤조피렌 분석법은 회수율, 검출 및 정량 한계, 효용성과 정확성 등이 검증되어 적용되고 있다. 그러나, 기존의 시험법에는 시료의 추출 및 분리, 정제 등의 복잡한 전처리 과정이 포함되어 있다. 환경 및 식품 내 위해물질 검출법의 연구 및 개발의 현 추세는 시험비용과 시간소모를 최소화하고 시험과정을 단순화할 수 있는 비표지, 비파괴 분석법을 통해 관리 현장에서의 신속대응을 지향하고 있다. 본 총설에서는 현행의 벤조피렌 분석법에 대해 정리하고, 그 한계점을 극복하기 위한 새로운 시도로 라만 분광법을 이용한 벤조피렌 검출법에 대해 소개하고자 한다.

• Computers and Concrete
• /
• 제14권1호
• /
• pp.73-90
• /
• 2014

The traditional destructive tests in damage detection require high cost, long consuming time, repairing of damaged members, etc. In addition to these, powerful equipments with advanced technology have motivated development of global vibration based damage detection methods. These methods base on observation of the changes in the structural dynamic properties and updating finite element models. The existence, location, severity and effect on the structural behavior of the damages can be identified by using these methods. The main idea in these methods is to minimize the differences between analytical and experimental natural frequencies. In this study, an application of damage detection using model updating method was presented on a one storey reinforced concrete (RC) building model. The model was designed to be 1/2 scale of a real building. The measurements on the model were performed by using ten uni-axial seismic accelerometers which were placed to the floor level. The presented damage identification procedure mainly consists of five steps: initial finite element modeling, testing of the undamaged model, finite element model calibration, testing of the damaged model, and damage detection with model updating. The elasticity modulus was selected as variable parameter for model calibration, while the inertia moment of section was selected for model updating. The first three modes were taken into consideration. The possible damaged members were estimated by considering the change ratio in the inertia moment. It was concluded that the finite element model calibration was required for structures to later evaluations such as damage, fatigue, etc. The presented model updating based procedure was very effective and useful for RC structures in the damage identification.

• 한국식품과학회지
• /
• 제44권2호
• /
• pp.141-147
• /
• 2012

BA은 치즈, 와인, 젓갈, 소시지, 된장 등 미생물에 의한 발효과정을 거치는 식품뿐만 아니라 채소류, 과일, 육류와 같은 비발효 식품군에서도 발견된다. 식품 내 BA 오염에 대한 관리를 목적으로 제조공정 및 유통과정에서 신속하게 다량의 시료를 분석하고 제품에 대한 항시 모니터링 기술이 요구된다. 이를 위해 BA 특이항체 및 BA 분해효소를 이용하는 BA 검출 및 센싱 기술이 개발되고 있다. HisN 특이 항체를 이용한 ELISA 키트는 상용화 되었으며 다양한 식품에 적용되고 있다. 산화적 탈아미노반응을 촉매하는 아민산화효소는 항체기반의 ELISA 방식에 비해 다양한 BA 분석에 사용되고 있으며, 효소반응에 의해 생성되는 $H_2O_2$의 산화환원반응에 의해 발생하는 전류를 측정함으로써 BA의 함량을 정량할 수 있는 전류측정식 바이오센서 개발에 적용되고 있다. BA 신속검출을 위한 바이오센서의 개발 연구 동향에 발맞추어 국내 전통발효식품에 적합한 기술개발이 요구되며, 산업현장 적용 연구를 거쳐 국내 전통발효식품의 안전성을 확보해야 할 것으로 판단된다.

• Journal of Periodontal and Implant Science
• /
• 제47권1호
• /
• pp.41-50
• /
• 2017

Purpose: The aims of the present study were to compare the image quality and visibility of tooth cracks between conventional methods and swept-source optical coherence tomography (SS-OCT) and to develop an automatic detection technique for tooth cracks by SS-OCT imaging. Methods: We evaluated SS-OCT with a near-infrared wavelength centered at 1,310 nm over a spectral bandwidth of 100 nm at a rate of 50 kHz as a new diagnostic tool for the detection of tooth cracks. The reliability of the SS-OCT images was verified by comparing the crack lines with those detected using conventional methods. After performing preprocessing of the obtained SS-OCT images to emphasize cracks, an algorithm was developed and verified to detect tooth cracks automatically. Results: The detection capability of SS-OCT was superior or comparable to that of trans-illumination, which did not discriminate among the cracks according to depth. Other conventional methods for the detection of tooth cracks did not sense initial cracks with a width of less than $100{\mu}m$. However, SS-OCT detected cracks of all sizes, ranging from craze lines to split teeth, and the crack lines were automatically detected in images using the Hough transform. Conclusions: We were able to distinguish structural cracks, craze lines, and split lines in tooth cracks using SS-OCT images, and to automatically detect the position of various cracks in the OCT images. Therefore, the detection capability of SS-OCT images provides a useful diagnostic tool for cracked tooth syndrome.