매복 상악 중절치의 강제 견인 후 치아길이에 영향을 미치는 요소

장진명,송제선,최형준,최병재,김성오 대한소아치과학회 2018 大韓小兒齒科學會誌 Vol.45 No.1

본 연구의 목적은 다중 회귀 분석을 이용하여 상악 매복 중절치를 교정적 견인한 후 치료 결과에 영향을 미치는 요소를 확인하는 것이다. 2005년 1월부터 2015년 12월까지 연세대학교 치과대학병원 소아치과에서 상악 매복 중절치에 버튼 부착 수술을 동반한 교정적 치료를 받은 소아∙청소년 환자 총 83명을 대상으로 환자 정보와 치료 전, 후 방사선학적 정보를 이용하여 연구를 진행하였다. 치료 후 인접한 중절치의 길이에 대한 견인한 중절치의 길이의 비율에 대해 성별, 연령 등 환자 정보의 영향 및 치아 발육 단계, 매복 치아의 높이와 위치, 각도 등 방사선학적 정보의 영향을 다중 회귀 분석을 통하여서 평가하였다. 다중 회귀 분석 결과, stem cell from apical papilla (SCAP)의 높이가 높아질수록 치료 후 치아길이비율은 0.345 단위 증가하였으나(p < 0.01), 성별, 치아 발육 단계, 매복치아와 중심선과의 거리 및 각도, 매복치아의 절단면의 높이는 치료 후 치아길이비율과 통계학적으로 유의미한 차이를 보이지 않았다(p > 0.05). 매복 중절치 교정적 견인 치료 시 견인한 치아의 길이는 초기 SCAP의 높이의 영향을 받으나, 성별, 치아 발육 단계, 중심선과의 각도, 절단면의 높이에 따른 영향은 보이지 않았다. The purpose of this study is to identify the factors affecting the treatment outcome after surgical-orthodontic treatment of the maxillary impacted incisors using multiple regression analysis. The study enrolled 83 patients who had surgical-orthodontic treatment in impacted maxillary central incisor between January 2005 and December 2015. Possible explanatory variables related to the prognosis of impacted incisor were age, gender, tooth developmental stage, height, position and angle of the teeth. The results of multiple regression analysis showed that as the height of the stem cell from apical papilla (SCAP) increased, the tooth length ratio increased by 0.345 units (p < 0.01). There was no statistically significant difference in gender, tooth development stage, distance and angle between the center line and the tooth, and the height of incisal tip of the tooth. In conclusion, the height of the SCAP of the impacted central incisor is factor affecting the tooth length after orthodontic traction.

인적요인을 고려한 머신러닝 활용 산림화재 예측

장진명,김주찬,김화중,김광태 한국산업정보학회 2023 한국산업정보학회논문지 Vol.28 No.5

대형 산림화재를 예방하기 위해 산림화재의 조기발견은 매우 중요하다. 조기발견을 위한 하나의 방안으로 산림화재 발생 예측이 고려되고 있으며 다양한 관련 연구가 진행되었다. 그러나 대다수의 선행연구가 산림화재의 주요 발화 원인 중의 하나인 인적요인을 고려하지 않고 기상요인과 지리적 요인만을 주로 다루고 있다. 따라서 본 연구는 기상 및 지리적 요인뿐만 아니라 인적요인을 고려한 산림화재 예측모형을 개발하기 위해 2003년부터 2020년까지의 강원도 산림화재 데이터를 활용하여 로지스틱 회귀모형과 다양한 머신러닝 기법 기반의 예측모형을 개발하고 성능을 비교분석하였다. 성능분석 결과, 머신러닝 기법인 랜덤 포레스트(AUC=0.920)와 XG Boost 모형(AUC=0.925)이 가장 우수한 성능을 나타냈다. 운영시사점을 도출하기 위해 순열특성중요도 분석을 활용하여 요인들의 상대적 중요도를 분석하였으며, 기상요인이 인적요인보다 높은 영향도를 나타냈지만 다양한 인적요인도 유효한 것으로 확인되었다. Early detection of forest fires is essential in preventing large-scale forest fires. Predicting forest fires serves as a vital early detection method, leading to various related studies. However, many previous studies focused solely on climate and geographic factors, overlooking human factors, which significantly contribute to forest fires. This study aims to develop forest fire prediction models that take into account human, weather and geographical factors. This study conducted a comparative analysis of four machine learning models alongside the logistic regression model, using forest fire data from Gangwon-do spanning 2003 to 2020. The results indicate that XG Boost models performed the best (AUC=0.925), closely followed by Random Forest (AUC=0.920), both of which are machine learning techniques. Lastly, the study analyzed the relative importance of various factors through permutation feature importance analysis to derive operational insights. While meteorological factors showed a greater impact compared to human factors, various human factors were also found to be significant.

드론 활용 혈액 배송 및 재고 결합 최적화 모형

장진명,김광태,김화중 대한산업공학회 2019 대한산업공학회 추계학술대회논문집 Vol.2019 No.11

텍스트 마이닝 기반 수차 설비 상태 감시체계 초기 설계 가이드라인 개발 절차 제안

장진명,선경호,정준하,신윤호 한국안전학회 2021 한국안전학회지 Vol.36 No.6

Hydroelectric power generation is currently gaining popularity as the core of the eco-friendly energy and power sector, and a large number of hydroelectric power generation facilities are in operation both at home and abroad. Failures or abnormalities in hydroelectric power facilities occur for various reasons, and studies on condition monitoring to prevent them have been actively conducted in recent years. Furthermore, this study extracted key terms from domestic and foreign hydro-turbine monitoring related data using R-studio text mining for the aim of proposing guidelines for the hydro-turbine facility condition monitoring system and used them to construct and analyze the most recent detailed data. Big data was constructed and analyzed by examining the most recent detailed data, such as sensors types and abnormal phenomena that can be detected by sensors. The HCMS (Hydro-turbine Condition Monitoring System) guideline table summarizes the analyzed contents and shows the status of hydro turbine facility condition monitoring using sensors in two ways: facility component standards and sensor standards. If the table is used, it will provide convenience and efficiency in determining the sensor type to use for condition monitoring, attachment location, and target components, as well as aid in the initial design of the hydro-turbine facility condition monitoring system. -

의류기업의 품질 개선 방안 연구: Quality 4.0 매트릭스를 활용한 쿠트스마트 사례

장진명,서승주,이윤아,김연성 한국품질경영학회 2019 품질경영학회지 Vol.47 No.1

Purpose: The concept of quality is changing in the quality 4.0 era with the fourth industrial revolution in the world. This research aims to understand the characteristics of well-adapted companies against the quality 4.0 era and to improve the quality of clothing companies. Methods: We analyzed companies that responded well to the quality 4.0 era, especially Kutesmart using Quality 4.0 Matrix. We focused on the service process of Kutesmart and we suggested modified service process to improve quality. We also interviewed an expert to verify this process is valid. Results: We found that two types are classified of well-adapted companies against the quality 4.0 era. Especially, Kutesmart has built a smart factory and introduced new technologies like 3D scanner and big data analysis. However, Kutesmart has a weakness in post-purchase process like other clothing companies. Kutesmart could solve this problem with modular production method for damaged part of customer. Conclusion: This research can be used for better understanding of the characteristics of well-adapted companies against the quality 4.0 era and service process of Kutesmart that is custom clothing company for providing information for benchmarking in this industry. This study suggests that further empirical researches on the costs and the efficiencies of applying the new technologies are necessary.

텍스트 마이닝 기반 국내외 수차 설비 상태감시체계 현황 분석

장진명(Jin Myoung Jang),정준하(Joon Ha Jung),선경호(Kyung Ho Sun),신윤호(Yun-ho Shin) 한국유체기계학회 2022 한국유체기계학회 학술대회 논문집 Vol.2022 No.6

드론 활용 혈액 재고/배송계획 휴리스틱

장진명(Jin-Myeong Jang),김화중(Hwa-Joong Kim),손동훈(Dong-Hoon Son) 한국산업경영시스템학회 2021 한국산업경영시스템학회지 Vol.44 No.3

This paper considers a joint problem for blood inventory planning at hospitals and blood delivery planning from blood centers to hospitals, in order to alleviate the blood service imbalance between big and small hospitals being occurred in practice. The joint problem is to determine delivery timing, delivery quantity, delivery means such as medical drones and legacy blood vehicles, and inventory level to minimize inventory and delivery costs while satisfying hospitals’ blood demand over a planning horizon. This problem is formulated as a mixed integer programming model by considering practical constraints such as blood lifespan and drone specification. To solve the problem, this paper employs a Lagrangian relaxation technique and suggests a time efficient Lagrangian heuristic algorithm. The performance of the suggested heuristic is evaluated by conducting computational experiments on randomly-generated problem instances, which are generated by mimicking the real data of Korean Red Cross in Seoul and other reliable sources. The results of computational experiments show that the suggested heuristic obtains near-optimal solutions in a shorter amount of time. In addition, we discuss the effect of changes in the length of blood lifespan, the number of planning periods, the number of hospitals, and drone specifications on the performance of the suggested Lagrangian heuristic.

분해옵션 포함 서비스부품 로트사이징 휴리스틱

장진명(Jin-Myeong Jang),김화중(Hwa-Joong Kim),손동훈(Dong-Hoon Son),이동호(Dong-Ho Lee) 한국산업경영시스템학회 2021 한국산업경영시스템학회지 Vol.44 No.2

Due to increasing awareness on the treatment of end-of-use/life products, disassembly has been a fast-growing research area of interest for many researchers over recent decades. This paper introduces a novel lot-sizing problem that has not been studied in the literature, which is the service-parts lot-sizing with disassembly option. The disassembly option implies that the demands of service parts can be fulfilled by newly manufactured parts, but also by disassembled parts. The disassembled parts are the ones recovered after the disassembly of end-of-use/life products. The objective of the considered problem is to maximize the total profit, i.e., the revenue of selling the service parts minus the total cost of the fixed setup, production, disassembly, inventory holding, and disposal over a planning horizon. This paper proves that the single-period version of the considered problem is NP-hard and suggests a heuristic by combining a simulated annealing algorithm and a linear-programming relaxation. Computational experiment results show that the heuristic generates near-optimal solutions within reasonable computation time, which implies that the heuristic is a viable optimization tool for the service parts inventory management. In addition, sensitivity analyses indicate that deciding an appropriate price of disassembled parts and an appropriate collection amount of EOLs are very important for sustainable service parts systems.

드론 활용 혈액 운송시스템의 효과 분석

장진명 ( Jin-Myeong Jang ),손동훈 ( Dong-Hoon Son ),김화중 ( Hwa-Joong Kim ) 한국로지스틱스학회 2021 로지스틱스연구 Vol.29 No.3

Drones, which were developed for military activities such as surveillance and attack on behalf of people in dangerous areas, are used in various social areas such as broadcasting photography, leisure activities, surveillance activities, and lifesaving. In addition, the value of utilization of these drones is prominent in the field of emergency transportation such as medicines, relief supplies, and blood products, and research on this is actively being studied in related fields. In particular, the drone-utilized blood transportation system in the city, which faces traffic congestion problems, is drawing attention as an alternative method in that it can respond more quickly to urgent blood demand than conventional road transportation. Thus, this study proposes integer programming models for three transportation systems to compare and analyze them in terms of required cost and time. These systems are a conventional transport system and two transport systems that utilize drones at only the blood center, and at the blood center and drone depots. Drone depots are installed at some of hospitals to decrease transportation distance. This paper performs a case study on the Korean National Red Cross in Seoul city and conducts sensitivity analysis to draw operational implications from the development of drone technology and the number of drone depots.

데이터 맵 기반 수차 설비 상태감시 센서 위치 선정

장진명(Jin Myoung Jang),선경호(Kyung Ho Sun),강준구(Joon Gu Kang),신윤호(Yun-ho Shin) 한국유체기계학회 2022 한국유체기계학회 학술대회 논문집 Vol.2022 No.11