http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Pulse GMAW에서 용접선 추적용 아크 센싱 신호 선정에 관한 연구
서보욱(Bo Wook Seo),정영철(Young Cheol Jeong),조영태(Young Tae Cho) 대한용접·접합학회 2020 대한용접·접합학회지 Vol.38 No.2
Gas Metal Arc Welding (GMAW) is one of the most widely used industrial welding methods because it can be easily automated. However, during automatic welding it is necessary to trace the weld seam line, because the weld line can be improperly formed due to thermal deformation of the weld. In addition, most welding machines currently provide complicated pulse current and voltage synergic signals. This makes it essential to construct an arc characteristic database for arc seam tracking. In this study, the arc sensing characteristics of various pulse modes of the Fronius TPS-320i welding machine were analyzed, and seam tracking performance was evaluated. To measure the welding current and voltage, Hall sensor and decompression circuits were constructed and data was collected using a PC-based DAQ board. A Labview algorithm was developed to classify the measured data into peak, average and base pulse currents and voltages. Based on the collected data, the variation in the width of the current and voltage signals with changes in the Contact Tip to Work Distance (CTWD) was confirmed by regression analysis. The standard deviation was obtained and the SN ratio of each peak, average and base data was confirmed. Finally, the average current was determined as the arc seam tracking signal.
탠덤 용접에서의 용접선 추적용 아크길이 예측을 위한 머신러닝 알고리즘에 관한 연구
서보욱(Bo Wook Seo),정영철(Young Cheol Jeong),조영태(Young Tae Cho) 대한용접·접합학회 2020 대한용접·접합학회지 Vol.38 No.3
A tandem welding process is frequently used in the welding of large structures with the aim of improving productivity and deposition rate. However, in this process, considerable thermal deformation of the base material occurs owing to two arc heat sources, thereby deteriorating the welding quality. Seam tracking in tandem welding is essential to improve the welding quality. However, in tandem welding, there are several issues in selecting a welding line tracking signal owing to arc interaction. Therefore, in this study, machine learning was applied to select signals for seam tracking in tandem welding. The existing seam tracking signal selection method predicts the contact tip to work distance(CTWD) by measuring the welding current and voltage. The CTWD, varies depending on the welding current and voltage signal; in this study, it was predicted to perform regression analysis and signal-to-noise(SN) ratio analysis. Through the SN ratio analysis, the highest SN ratio was selected as the seam tracking signal. Subsequently, machine learning linear models and regression tree models were trained. As a result of comparing the difference between the machine learning model and the regression analysis, the prediction equation of the regression tree model is appropriate as the welding line tracking equation.
우리나라 국립공원 탐방 프로그램의 계절별 현황 및 겨울철 탐방객 인식에 관한 연구
서보욱(Seo, Bo-Wook),김도연(Kim, Do-Yeon),전부기(Jeoun, Bu-Gi),이주형(Lee Ju-Hyoung) 한국산림휴양복지학회 2016 한국산림휴양학회지 Vol.20 No.3
본 연구는 국립공원 탐방 프로그램의 계절별 현황 및 겨울철 탐방객 인식에 관한 연구를 통해 겨울철 탐방 프로그램 개발의 필요성에 대해 규명하고자 수행하였다. 2012년부터 2014년까지 한라산 국립공원을 제외한 산악형 국립공원 15곳의 탐방 프로그램 운영횟수와 참여자수를 분석하고, 이를 바탕으로 덕유산 국립공원 탐방객의 겨울철 탐방 프로그램에 대한 인식조사를 실시하였다. 연구 결과, 겨울철 탐방 프로그램의 운영횟수에 대한 참여자수 비율이 다른 계절에 비해 크게 나타나 참여의사가 높은 것으로 판단되며, 탐방객의 61.4%가 겨울철 탐방 프로그램에 참여한 경험이 있는 것으로 나타났다. 겨울철 탐방 프로그램의 참여 동기에 대한 요인분석에서 휴양 · 일상탈출, 자기탐구, 건강증진이 추출되었다. 국립공원 탐방 프로그램에 대한 탐방객 인식조사에서 겨울과 여름이 유사한 선호도로 조사되었으나, 겨울철 프로그램의 개발 및 공급은 미비한 것으로 분석되었다. 겨울철 탐방 프로그램에 대한 탐방객의 참여비율과 참여의사, 선호도가 높게 분석되므로 겨울철 국립공원탐방 프로그램의 지속적인 개발과 운영 확대가 필요한 것으로 판단된다. The study was conducted with aims to shed light on the current status of national park visiting programs by season and the necessity of development of visiting programs for the winter based on research on visitor perception in the winter. Analyses were conducted on the frequency of operations of visiting programs in 15 mountainous national parks except for Hallasan National Park and the number of participants from 2012 to 2014, and visitors’ perception on winter visiting programs in Deogyusan National Park was examined based on it. As a result of the research, it was found out that the ratio of the number of winter visiting programs to the number of participants in the winter was higher than other seasons, which indicates a strong intention of participation. In addition, 61.4% of visitors turned out to have experiences in winter visiting programs. As a result of factor analyses on motivation for participating in winter visiting programs, recreation, escape, self-visiting and promotion of health were extracted. As a result of analyses on visitors’ perception on national park visiting programs, it was found out that similar preferences were indicated in the winter and in the summer whereas development and in supply of winter visiting programs were insufficient. As the rate of visitors’ participation in winter visiting programs is high and the intention of participation and preferences are strong, it is deemed necessary to continuously develop winter national park visiting programs and enhance operation.
스테인리스강 절삭용 엔드밀 공구의 절삭력 주파수 분석을 통한 공구 마모 및 파손의 진단에 관한 연구
이태경(Tae Gyung Lee),서보욱(Bo Wook Seo),손휘준(Hwi Jun Son),김석(Seok Kim),조영태(Young Tae Cho) 한국기계가공학회 2023 한국기계가공학회지 Vol.22 No.12
Cutting tools are mounted on machine tools for use, and the fracture or wear of such tools that occurs during cutting processing directly affects the precision or completeness of the product. In milling processes, end mills experience more frequent fractures and expedited wear than tools employed in turning and drilling. This heightened susceptibility to damage is due to the cyclical engagement and disengagement of the cutting edge with the workpiece. Consequently, the advancement of technologies to precisely detect tool defects such as fracture and wear is crucial for enabling the implementation of effective response strategies. In this study, an end mill tool was used for cutting stainless steel. The cutting force data generated were used to confirm that the magnitude and cycle of the cutting force changed depending on the defect of the tool. Furthermore, this study introduces a diagnostic method for tool defects based on a time and frequency domain analysis of cutting force. This method utilizes variations in magnitude and frequency characteristics that correlate with the tools condition. The process was verified through a series of tests using a TaeguTec end mill, which substantiated the tools operational normalcy.
김도연(Kim, Do-yeon),전부기(Jeoun, Bu-Gi),서보욱(Seo, Bo-Wook),이주형(Lee, Ju-Hyoung) 한국산림휴양복지학회 2016 한국산림휴양학회지 Vol.20 No.1
본 연구는 자연휴양림 자연체험 프로그램의 다양성과 개별성을 확보하고, 방문객의 만족도를 높이기 위한 야간경관 요소를 규명하고자 수행하였다. 칠보산 자연휴양림에서 방문객을 대상으로 자연적 요소와 인공적 요소로 구분하여 개발한 13문항의 설문지를 통해 야간경관에 대한 중요도-만족도를 조사하였다. 자연휴양림에서 21시와 24시30분에 조사를 수행하였다. IPA분석을 통해, ‘별’, ‘별자리’, ‘은하수’, ‘도시 불빛’ 요소에 대한 방문객의 만족도가 높게 나타났다. 야간경관에 대한 응답자의 만족도에는 빛공해의 영향이 조사되었는데, ‘숙소동 불빛’과 ‘야영장 불빛’ 요소로 나타났다. 방문객의 만족도를 높이기 위해서 야간 경관 해설 프로그램의 개발이 필요하고 자연휴양림에 빛공해를 줄이는 방안이 필요한 것으로 판단된다. This study is carried out to identify factors that make up the night scape in order to ensure the diversity and individuality of natural experience programs conducted in Recreation Forest and to improve visitors’ satisfaction. For this study, visitors to the Chilbosan Recreation Forest were given a survey of 13 questions classified into the subjects of natural factors and artificial factors related to the importance and satisfaction of the night scape. Survey respondents observed Night Scape at the Recreation Forest on 21:00 and 24:30. Result from IPA analysis, ‘Stars’, ‘Constellations’, ‘Milky way’, ‘Light from distant cities’ are satisfied by visitors. The effects of light pollution were surveyed, ‘Accommodations lights’and ‘Campsite lights’ are factor of light pollution. It is suggested that an interpretation program for the night scape in Recreation Forest needs to be developed and a measure for lightpollution reduction in Recreation Forest is needed in order to improve visitors’ satisfaction.