머신 러닝을 활용한 효과적인 모터 고장 진단 모델의 구현과 실험

변준호,김정준,변시우 국제차세대융합기술학회 2024 차세대융합기술학회논문지 Vol.8 No.3

다양한 IoT 센서와 IT 응용 기술이 융합되어 산업 현장에서 활성화되고 있다. 그러나 시스템이 다양해지 고 복잡해짐에 따라 IoT 고장 진단과 분석 부담이 커지고 있다. 본 논문에서는 최근 산업 IoT 환경에서 발생하는 결함 진단 이슈를 설명하고, 고장 진단에 효과적으로 적용 가능한 기계 학습 기법을 분석한다. 또한 효과적인 센서 데이터의 필터링을 위하여 랜덤 포레스트 기법으로 고장 연관 인자들을 비교하고, kNN과 SVM 기법에 기반을 둔 고장 진단기를 Google Colab을 활용하여 구현하였다. 모터 고장 관련 공공 빅데이터를 기반으로 한 실험을 통하여 모델의 성능과 정확도를 측정하고 출력 결과를 분석하였다. 실험 분석 결과, 다양한 센서의 최적 조합이 SVM과 kNN 모델로 학습되어 예측 정확도가 95%로 증가하였다. 이 결과는 효과적인 머신 러닝이 실제 고장의 원인일 가 능성이 높은 센서 정보를 검출하여, 센서 데이터 저장 및 후속 수치 연산량의 절감함을 의미한다. 추가로 데이터 정밀도의 영향 분석을 통하여 개별 센서별로 정밀도를 선택하여 저장 공간 효율성과 예측 정확도를 더 높였다. Various IoT sensors and IT technologies are being combined and activated in industrial sites. However, as the system becomes more diverse and complex, the burden of IoT fault diagnosis and analysis is increasing. In this paper, we explain diagnosis issues that arise in recent industrial IoT environments and analyze machine learning techniques that can be effectively applied to fault diagnosis. For effective filtering of sensor data, fault-related factors were compared by random forest scheme, and failure diagnosis model based on kNN and SVM schemes were implemented using Google Colab. Through experiments using public big data based on motor failures, the performance and accuracy of the model are measured and the output results are analyzed. Based on the experimental analysis, the optimal combination of various sensors was trained by SVM and kNN models and the prediction accuracy increased. This result means that effective machine learning can detect sensor information likely to be the cause of actual failure, reducing sensor data storage and subsequent numerical computation. In addition, the storage efficiency and prediction accuracy were further increased by selecting optimal precision for each individual sensor using the impact analysis of sensor data precision.

Highly Sensitive and Room Temperature Detection of Acetone Gas by SWCNT@Polypyrrole@Phenyllactic Acid Core-Shell Nanorods Electrochemical Sensor

변준호,김지선,강효경,권가영,김진열 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.2

Chemical sensing based on semiconducting polymers has been largely proposed for acetone sensor, although some major technical challenges such as high operating temperature with moisture stability and reliable sensitivity to ppb levels still has remain unsolved. This work presents the development of an electrochemical sensor based on nanostructured the core-shell nanorod composites with a single-walled carbon nanotube (SWCNT) in the core and polypyrrole (PPy)/phenyl lactic acid (PLA) shells, SWCNT@PPy@PLLA, for acetone detection at room temperature. The core-shell nanorod composites were applied for acetone detection in the range of 0.05 to 5000 ppm at room temperature with humidity resistance for resistance changes proportional to acetone concentration. According to these results, the developed sensor showed reliable detection at a concentration of 50 ppb even at room temperature and have the potential to be practically applied to gas sensors.

High Sensitivity and Humidity Stability SWCNT/Polypyrrole/Phenyllactic Acid Core-shell Nanorods for Acetone and Ammonia Gas Sensing

변준호,김지선,신혜림,강효경,김진열 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.1

Conductive nano-carbon materials have shown great potential as gas sensor materials because they can be easily adjusted to detect various chemical compounds. In particular, the conductive polymers, such as polypyrrole and polyaniline, have the advantages of high sensitivity and fast response with selectivity for specific organic compounds, and as low-temperature reactants associated with organic conductors. In the last study, we were successfully synthesized the core-shell nanocomposites with a SWCNT in core and polypyrrole@PLLA shells with an average diameter of 60-80 nm via a simple one-port emulsion polymerization. The detection characteristics were observed in VOC gases such as ammonia and acetone at a concentration of 100 ppb even at room temperature. However, this material was not stable for humidity condition. Thus, in this study, we use C8F for SWCNT@PPY@PLLA nanorods to maintain detection properties of 100 ppb and to make materials stable material for humidity.

Squamous cell carcinoma occurring with aspergillosis in the maxillary sinus: a case report and histological study

변준호,이정희,노규진,박봉욱,Byun, June-Ho,Lee, Jeong-Hee,Rho, Gyu-Jin,Park, Bong-Wook The Korean Association of Oral and Maxillofacial S 2010 대한구강악안면외과학회지 Vol.36 No.2

The coexistence of aspergillosis and squamous cell carcinoma (SCC) in the maxillary sinus was very rare. To our knowledge, this is the second report of coexistent SCC and aspergillosis in the maxillary sinus. A 58-year-old man underwent surgery for unilateral maxillary sinus infection with oroantral fistula. In the surgical specimen, SCC and aspergillosis were co-detected with routine and immunohistochemical stainings. Moreover, human papillomavirus 18 (HPV-18) was detected by polymerase chain reaction in the sinus specimen. The patient was re-operated with subtotal maxillectomy and has been followed up for two years without any evidence of recurrence or metastasis. Although it is not understood how aspergillosis could induce carcinoma formation, the chronic inflammation caused by prolonged fungal infection might be carcinogenic. Moreover, HPV-16 and -18 were another causative pathogens of SCC in the head and neck region. We recommend careful examination, including preoperative cytology, in patients with maxillary sinus fungal infections because of the potential for cancer development.

성견에서 하악골 신장술 후 하악과두 연골의 조직학적 변화와 Matrix Metalloproteinase-2 (MMP-2)와 Tissue Inhibitor of Matrix Metalloproteinase-2 (TIMP-2)의 발현

변준호,박봉욱,조영철,성일용,손재희,김종렬,Byun, June-Ho,Park, Bong-Wook,Cho, Yeong-Cheol,Sung, Iel-Yong,Son, Jae-Hee,Kim, Jong-Ryoul 대한악안면성형재건외과학회 2006 Maxillofacial Plastic Reconstructive Surgery Vol.28 No.5

Purpose : This study was to clarify the changes in mandibular condyle after unilateral mandibular distraction osteogenesis throughout histological changes and expression of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2). Materials & Methods : Intraoral distractors were placed via submandibular incision in 8 dogs. Two unoperated animals served as controls. Distraction was performed five days after osteotomy as a rate of 0.5 mm twice per day for 10 days. Two animals were sacrificed on 7, 14, 28, and 56 days after completion of distraction, respectively. Ipsilateral condyles were harvested and processed for histological and immunohistochemical examinations. Results : The condyle cartilage is separated into four layers: fibrous layer, proliferative layer, hypertrophic layer, and calcified layer. At 7 days and 14 days after distraction, the condylar cartilage showed the decreased thickness of the articular cartilage and reduced cellularity. At 28 days after distraction, there was an increase in cellularity of fibrous, proliferative, and hypertrophic layer. However, it demonstrated reduced cellularity compared to the control. At 56 days of after distraction, the articular cartilage was an almost normal histologic structure. Positive Safranin-O staining, indicative of sulfated proteoglycans, was examined in the condylar cartilge of nonloaded control. At 7 days and 14 days after distraction, the sulfated proteoglycans is almost completely depleted from the noncalcified part of the condylar cartilage. At 28 days after distraction, there was an increase in Safranin-O staining intensity. However, the staining intensity of the experimental condyle was weaker than that of the control. At 56 days of after distraction, the condylar cartilage showed almost normal Safranin-O staining pattern. In control condyle, MMP-2 immunostaining was seen in fibrous, proliferative, and hypertrophic layer of condylar cartilage, however, it demonstrated lack of staining in fibrous and proliferative layer. At 7 days and 14 days after distraction, strong MMP-2 immunoreactivity was seen in the fibrous, proliferative and hypertrophic layer of the condylar cartilage. At 28 days after distraction, MMP-2 immunostaining was seen in the fibrous and hypertrophic layer of condylar cartilage, however, their immunoactivity was reduced. At 56 days after distraction, MMP-2 immunoreactivity showed almost normal immunostaining pattern. In control condyle, TIMP-2 immunostaining was primarily seen in fibrous and hypertrophic layer of condylar cartilage, however, it demonstrated lack of staining in proliferative layer. At 7 days after distraction, very weak TIMP-2 immunoreactivity appeared in fibrous, proliferative and hypertrophic layer of the condylar cartilage. At 14 days after distraction, weak TIMP-2 immunoreactivity was seen in the fibrous, proliferative and hypertrophic layer of the condylar cartilage. At 28 days after distraction, TIMP-2 immunoreactivity was increased in the fibrous and hypertrophic layer of condylar cartilage. At 56 days after completion of distraction, TIMP-2 immunoreactivity showed almost normal immunostaining pattern. Conclusions : The results show that short-term outcome of physiologic distraction osteogenesis may lead to degenerative changes in the condylar cartilage. These alterations in the condylar cartilage may be considered as a pressure-related degeneration of the cartilage tissue. However, the long-term results suggest that the condylar cartilage display repair activity after mandibular distraction osteogenesis.

유니텍스 구조의 차음성능 향상기술 개발

변준호,이중혁,김석현,이재준,기호철,Byeon, Jun-Ho,Lee, Joong-Hyeok,Kim, Seockhyun,Lee, Jae-Joon,Ki, Ho-Cheol 대한기계학회 2016 대한기계학회 논문집. Transactions of the KSME. C, 산업기술과 혁신 Vol.4 No.2

유니텍스는 높은 강도과 우수한 단열성, 긴 수명 및 간편한 시공에 따른 저렴한 제작비 때문에 대부분의 도시철도 차량의 바닥 구조로 널리 사용되고 있다. 그러나 여러 가지 우수성에도 불구하고, 이 구조는 차량 적층재에서 중요한 차음성능 측면에서는 여전히 문제점을 갖고 있다. 기존 제품은 중량대비 차음성능의 척도인 질량법칙 투과손실치에 비해 현저히 낮은 투과손실을 보인다. 최근 차량 제작사와 시공사는 차음성능을 높이기 위하여 많은 노력을 시도하여왔으나 큰 효과가 없었다. 이에 본 산학협동 연구에서는 기존 제품 대비 5dB 이상 차음성능을 향상시키는 것을 목표로, 적층재의 구조개선 방안을 도출하고 개선효과를 실험적으로 검증한다. Unitex is widely used for the floor structure of urban railway vehicles because it shows good structural safety and heat insulation, has long life, and lowers the cost owing to easy installation. However, in spite of these merits, Unitex has a limit to the sound insulation performance, which is very important in vehicle structure. It shows a sound transmission loss considerably lower than the mass law value, which indicates the sound insulation performance per unit weight. Recently, railway vehicle manufacturers and Unitex supplier have tried to improve the sound insulation performance of Unitex, but meaningful results have not been achieved yet. Through the industry-university collaborative research, we propose structural improvement methods to increase the sound transmission loss by more than 5dB and we then verify the effect by performing experiments.

경북지역 개와 고양이에서 methicillin-resistant Staphylococcus. pseudintermedius (MRSP) 검출률 조사

변준호,손준형,이영미,정효훈,오태호 한국동물위생학회 2018 韓國家畜衛生學會誌 Vol.41 No.4

Identification of antibiotic resistant bacteria isolated from animals is necessary for seeking a proper treatment and for preventing the spread of the bacteria among animals. Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is of worldwide concern in veterinary medicine. This study was conducted to investigate the antimicrobial susceptibility of Staphylococcus pseudintermedius (S. pseudintermedius) isolated from dogs and cats. Out of the total number of 150 specimens, 35 isolates (23.3%) were identified as S. pseudintermedius when tested by MALDI-TOF MS (Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectroscopy). Among them, 5 isolates (14.3%) were the case of MRSP. In the results of the antimicrobial susceptibility test, the isolates of S. pseudinterme-dius were susceptible to amikacin (100%), cephalothin (100%), vancomycin (100%), amoxicillin (85.7%), oxacillin (85.7%), enrofloxacin (82.8%), chloramphenicol (80%). On the other hand, they were resistant to penicillin (71.4%), tetracycline (48.6%), ampicillin (37.1%), kanamycin (31.5%), eryth-romycin (31.4%), respectively.

설암의 술전 조직표본에서 악성도와 혈관내피세포성장인자 발현과의 상관관계

변준호,박봉욱,정인교,김종렬,김욱규,박봉수,김규천,Byun, June-Ho,Park, Bong-Wook,Chung, In-Kyo,Kim, Jong-Ryoul,Kim, Uk-Kyu,Park, Bong-Soo,Kim, Gyoo-Cheon 대한악안면성형재건외과학회 2005 Maxillofacial Plastic Reconstructive Surgery Vol.27 No.6

Angiogenesis is important for the growth and metastasis of solid tumors. Some growth factors, inflammatory cytokines, and angiogenin are known to promote tumor angiogenesis. Among them, Vascular endothelial growth factor (VEGF) is the most intriguing factor in regard to tumor angiogenesis. Inhibition of VEGF activity by neutralizing antibodies or by the introduction of dominant negative VEGF receptors into endothelial cells of tumor-associated blood vessels resulted in the inhibition of tumor growth and in tumor regression, indicating that VEGF is a major initiator of tumor angiogenesis. VEGF promotes angiogenesis through their receptors, Flt-1 and Flk-1/KDR. on vascular endothelial cells. These two receptors were usually believed to be expressed specifically on vascular endothelial cell. Several reports have now shown that VEGF is not only significantly associated with microvessel density but also has prognostic value in both node-negative and node-positive oral squamous cell carcinoma. For many years several histologic features of the neoplasms are being considered when assessing the influence of malignancy grading on recurrence and prognosis. Among the characteristics investigated, degree of keratinization, nuclear pleomorphism, mode of invasion, microscopic depth of invasion, intravascular invasion, lymphocyte infiltration, and number of mitoses have been considered as important prognostic factors. So, this study was conducted to evaluate the correlation of vascular endothelial growth factor expression with malignancy in paraffin-embedded biopsy specimens from 11 patients with tongue cancers. Our results showed that high immunoreactivity specimens of VEGF expression were significantly lower keratinization degree and more pronounced nuclear pleomorphism than in low immunoreactivity specimens. Thus, VEGF expression could be used as a prognostic marker in tongue cancer.

심하게 흡수된 상악골에서 자가 장골 이식술과 동시에 시행한 임프란트 치료의 안정성에 대한 연구

변준호,박봉욱,정희찬,김종렬,Byun, June-Ho,Park, Bong-Wook,Jeong, Hee-Chan,Kim, Jong-Ryoul 대한악안면성형재건외과학회 2006 Maxillofacial Plastic Reconstructive Surgery Vol.28 No.6

A severely atrophic maxilla may disturb the proper implant placement. The various bone graft techniques are required for simultaneous or delayed implantation in the cases of atrophic alveolar ridges. We present 11 consecutive patients treated with simultaneous implantation using the autogenous inlay and/or onlay bone grafts from iliac crest to the floor of the maxillary sinus and the alveolar crest. In the cases of atrophic maxilla, a total 69 implants were simultaneously placed with autogenous iliac bone graft. 40 fixtures were inserted in the sinus floor simultaneously with subantral block bone graft, the other 29 fixtures were placed in the anterior or premolar areas with block or particulate bone graft. The vertical alveolar bone height was measured with Dental CT at the preoperation and 6 months postoperation. Moreover, the implant stability quotients (ISQ) were measured by $Osstell^{TM}$ during second implant surgery at 6 months later of first implantation. All implants were obtained successful osseointegration with the grafted bone. The mean vertical increases were 3.9mm in the anterior ridges and 12.8mm in the posterior ridges. During the second implant surgery, mean ISQ were 62.95 in the anterior ridge and 61.32 in the posterior ridge. We concluded that the simultaneous implantation with autogenous iliac bone graft were stable and available methods for severely atrophic maxilla.

양성 및 악성 타액선 근상피종: 증례보고 및 면역조직화학적 연구

변준호,이종실,김종렬,박봉욱,Byun, June-Ho,Lee, Jong-Sil,Kim, Jong-Ryoul,Park, Bong-Wook 대한악안면성형재건외과학회 2009 Maxillofacial Plastic Reconstructive Surgery Vol.31 No.1

Benign myoepithelioma (BME) and malignant myoepithelioma (MME) of the salivary gland are very rare and its biologic behavior has not been clarified fully. Although, cases reports for BME and MME were increased in recent, their diagnostic criteria were not completely established. We describe herein a case of BME of the parotid gland and a case of MME of the palatal minor gland, respectively. Histologically, multinodular growth pattern, infiltration to adjacent tissues, and hyalinized and myxoid matrix were observed in MME, that were different histologic features compared with BME. Strong immunoreactivities for the S-100 protein and vimentin were detected in the tumor cells of BME and MME. In specimen of MME, moderately expressed p53 and strongly expressed p63 were detected. However, in specimen of BME, p53 was negatively and p63 was weakly expressed, respectively. In conclusion, the expression patterns of p53 and p63 as well as histologic aggressiveness might be used to diagnose the MME.