Data-driven prognostics method for turbofan engine degradation using hybrid deep neural network

Bin Xue,Zhong-bin Xu,Xing Huang,Peng-cheng Nie 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.12

Powerful sequence modeling capability for massive multi-sensor data enables deep-learning-based methods to obtain accurate remaining useful life (RUL) estimations. Hybrid neural networks, with learned representations based on various networks, have enhanced the prognostics accuracies than single networks. However, assembly strategies that are limited to either parallel or serial, and insufficient utilization of single networks restrict the development of hybrid networks for more complex problems. This paper proposes a datadriven method using hybrid multi-scale convolutional neural network (MSCNN) and bidirectional long short-term memory (BLSTM) network (namely HMCB network) for RUL estimation. The framework of the network includes two parallel paths. One is composed of MSCNN and BLSTM in serial and the other is a BLSTM path. The HMCB network integrates the merits of multi-scale spatial feature extraction of MSCNN and sequence learning capacity of BLSTM. Validated by C-MAPSS dataset, the HMCB network demonstrates noticeably higher prognostic accuracy than other state-of-the-art methods.

A Study on the Efficiency of Container Terminals in Korea and China

Xue Bin Zheng,박남규 한국해운물류학회 2016 The Asian journal of shipping and Logistics Vol.32 No.4

The objective of this study is to derive implications required for efficiency improvement and management level enhancement by selecting container terminals within major large ports of Korea and China as comparison units, evaluating their relative efficiencies and analyzing the trend of changes in their efficiencies. Since the scope of comparison subjects has been narrowed down to container terminals unlike previous studies, it is expected that the study results would have significant meaning due to the fact that it would be possible to compare and analyze in more detail. To achieve the objective, 30 major container terminals in both countries are selected, input and output variables are defined for each terminal and the DEA (data envelopment analysis) model is used to conduct an analysis. The results show that the efficiency of major terminals in Korea (CCR: 0.815, BCC: 0.886) showed similar efficiency with China’s terminals (CCR: 0.817, BCC: 0.887). While previous studies conclude that the efficiency of ports in Korea is far lower than that of ports in China.

벼 이앙재배에서 유기질 복합비료 시용이 잡초억제와 벼 생육환경에 미치는 영향

Xue-Hua An,Xue-Ping Zhao,이상복(Sang-Bok Lee),임일빈(Il-Bin Im),Wen-Hao An 韓國雜草學會 2010 Weed&Turfgrass Science Vol.30 No.3

본 연구는 유기질 복합비료가 벼 재배 논에서 잡초 및 벼 생육에 미치는 영향을 파악하기 위하여 수행되었다. 실내 검정 시험에서 유기질 복합비료를 125-250㎏ 10a-1 처리시 이앙벼는 지상부가 10.3~27.2% 증가하였고, 피는 50.3-89.2%의 출현이 억제되었으며, 사마귀풀은 낮은 처리량에서도 높은 감수성을 보였다, 유기질 복합비료는 피, 물달개비, 사마귀풀에 대하여 담수심(1-5㎝)이 깊을수록 높게 억제하였으나, 올방개와 같은 사초과 잡초에 대해서는 억제 효과가 나타나지 않았다. 또 20-35℃의 비교적 높은 온도에서 피와 물달개비는 각각 75.4~92.2%, 49.5~81.6%의 높은 출현억제율을 나타냈다. 유기질 복합비료 시용 10일 후 낙수 시 피와 물달개비는 각각 33.7%, 23.0%의 출현억제율을 나타내었다. 포장시험에서 시험 후 토양의 유기물은 관행구애서 유기질 복합비료 시용구보다 약간 낮게 나타났다. 벼의 생육은 초장 및 경수가 관행구 대비 적었으며 그 차이는 생육후기에 더 많이 나타났고, 벼의 수량은 관행구 대비 4% 감소하였다. 논잡초 억제 효과는 유기질 복합비료 시용구에서 60.5%로 관행구 보다 낮게 나타났다. The effects of organic-compound fertilizer on weed control and rice growth in the transplanting rice cultivation were researched in this article. The results showed that the growth of transplanted rice was promoted (the increased rate was 10.3 - 27.2 %), but the plant number for Echinochloa crus-galli was controlled (the inhibition rate was 50.3~89.2%), besides, small amount of organic-compound fertilizer in controlling Aneilema keisak was highly effective when the transplanted rice was treated with 125~250 ㎏ 10a-1 organic-compound fertilizer. Moreover, E. crus-galli, Monochoria vaginalis and A. keisak were inhibited largely by increasing the water depth (1~5 ㎝), whereas Eleocharis kuroguwai and other sedges weeds were not effected by water depth. Compared with the temperature of 20~35℃, the plant occurrence of E. crus-galli and M. vaginalis at high temperature was inhibited (the inhibition rate were 75.4 -92.2% and 49.5% - 81.6%, respectively). When the transplanted rice was treated with the above organic-compound fertilizer after 10day, the inhibition rate of plant occurrence for E. crus-galli and M. vaginalis was 33.7% and 23.3%, respectively. Similarly, in the later period of rice growth, the plant height and the numbers of tiller grew slowly in conventional soil in comparison with the soil treated with organic-compound fertilizer. It has been found that the rice yield in experimental soil was decreased by 4%. This result in the field experiment showed that organic material contents in conventional soil were lower than that in soil which used the organic-compound fertilizer. Weed control in experimental soil showed 60.5% lower effects than that in conventional soil.

Study on Corner Reflectors Identification in Highway Deformation Monitoring

Xue Min Xing,De Bao Wen,Fang Bin Zhou 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.12

CRInSAR is a newly developed technique to monitor ground deformation. In CRInSAR algorithm, the identification of Corner Reflectors in SAR images is necessary. Due to the uncertainty of traditional identification method, a new method based on the intensity and correlation coefficient of each CR candidates in SAR images is presented. The method has been successfully used to determine the locations of 11 CRs installed along a highway in six SAR images over the study area. The results show that the identification accuracy of the new method is about 1 pixel. It is effective and reliable especially in the area with lots of lightspots around the CR points. The method proposed can play important role in the highway deformation monitoring within CRInSAR algorithm.

Study on the Currency of International Trade of the Sogdian Merchants on the Silk Road

Xue Bin,Li Wei 한중경제문화학회 2019 한중경제문화연구 Vol.13 No.-

Supper Efficiency DEA와 Malmquist 생산성 지수를 활용한 한 · 중 컨테이너터미널의 효율성 비교

정학빈(Zheng, Xue-Bin),김율성(Kim, Yul-Seong) 한국항만경제학회 2016 韓國港灣經濟學會誌 Vol.32 No.3

본 연구는 세계 20위권 컨테이너항만 중에서 한국과 중국 항만들의 개별 컨테이너터미널을 단위로 SE-DEA와 Malmquist 생산성지수법으로 2012년-2015년 사이의 효율성 및 생산성 변화추이를 분석하고자 하였다. 기존연구들에 비해 본 연구에서는 연구대상의 범위를 항만 내 터미널로 좁혀 더욱 세부적인 분석을 진행하여 실제 운영에 더욱 의미 있는 시사점을 제시하고자 하였다. SE-DEA 분석결과, 기존 연구와 달리 부산항 신항 주요 터미널은 중국 못지않은 효율성 및 생산성을 나타내고 있음을 밝혔다. 또한, Malmquist 생산성지수법 분석결과, 한국터미널의 평균 MPI지수는 1.051로 생산성이 연간 5.1% 향상되었고, 중국 터미널의 평균 MPI지수는 1.049로 생산성이 연간 4.9% 향상되었다. 2012년-2015년 한 · 중 양국 터미널의 평균 TCI지수는 각각 1.032와 1.0318로 MPI지수 변화에 중요한 요소로 작용하였다. 즉 생산성 제고는 운영효율성 개선보다 장비투입이나 기술개진을 통해 실현하였음을 설명한다. 미래에 경영의사결정을 함에 있어서 적극적인 시장개척을 통한 물량확보 증가와 운영효율성 제고를 통해 생산성을 개선하여야 한다. 향후 연구에서는 방법론의 다양화와 터미널 재무능력, 서비스 수준 등을 고려한 종합적인 효율성 분석이 필요할 것이다. The objective of this study was to select world top 20 major container terminals that belong to Korea and China as comparison units to analyze their efficiency and productivity trend. Super Efficiency Data Envelopment Analysis(SE-DEA) and Malmquist Productivity Index(MPI) models were applied to this study. Compared with previous studies, we narrowed down the scope of the comparison units to terminals and conducted more detailed analysis to present more meaningful implications to the actual operation. The different result from existing studies, SE-DEA analysis implied that the major terminals of Busan New Port showed similar efficiency and productivity with China’s terminals. In MPI analysis, the average index of Korean and China’s terminals is 1.051 and 1.049. The analysis indicates that the productivity was improved 5.1% and 4.9% annually. From 2012 to 2015, the average terminal TCI index of South Korea and China were 1.032 and 1.0318-the main factor which influences MPI. This means improving productivity mainly rely on investment in new equipment and technology upgrades rather than improve operational efficiency over the past few years. Future management decisions should consider more aggressive marketing to increase the volume and improve operational efficiency to enhance productivity. Further research should apply the overall efficiency of the methodology considering the financial diversification, terminal capacity, service levels, and other factors.

Collaborative optimization for ring-stiffened composite pressure hull of underwater vehicle based on lamination parameters

BIN LI,Yong-jie Pang,Yan-xue Cheng,Xiao-meng Zhu 대한조선학회 2017 International Journal of Naval Architecture and Oc Vol.9 No.4

A Collaborative Optimization (CO) methodology for ring-stiffened composite material pressure hull of underwater vehicle is proposed. Structural stability and material strength are both examined. Lamination parameters of laminated plates are introduced to improve the optimization efficiency. Approximation models are established based on the Ellipsoidal Basis Function (EBF) neural network to replace the finite element analysis in layout optimizers. On the basis of a two-level optimization, the simultaneous structure material collaborative optimization for the pressure vessel is implemented. The optimal configuration of metal liner and frames and composite material is obtained with the comprehensive consideration of structure and material performances. The weight of the composite pressure hull decreases by 30.3% after optimization and the validation is carried out. Collaborative optimization based on the lamination parameters can optimize the composite pressure hull effectively, as well as provide a solution for low efficiency and non-convergence of direct optimization with design variables.

Synthesis and Functionalization of Copper-Doped Indium Phosphate Quantum Dots with Ratiometric Fluorescence

Bin Xu,Jingwen Xue,Jun Huang,Haojun Jin,Peng Shen,Qingjiang Sun 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.15 No.01

The doped quantum dots (QDs) that feature dual emission in one nanocrystal and long fluorescence lifetime have gained great interest in biosensing and bioimaging applications. In this work, we report the synthesis and functionalization of copper ion-doped indium phosphate (Cu:InP) QDs that exhibit simultaneous green InP emission and red Cu2+ emission. The oil-soluble QDs were synthesized by adsorbing Cu2+ onto InP core, followed by growing zinc selenide (ZnSe) shell via the successive ion layer adsorption reaction. During the synthesis, fluorescence ratiometry (and resultant multiple fluorescence colors) can be generated by changing either the dopant amount or the shell-growth time, but they act in a different manner: increasing the Cu2+ amount results in quenched InP emission and oppositely improved Cu2+ emission; the increase of shell-growth time leads to continuously improved Cu2+ emission relative to constant InP emission. Further, functionalization of the oil-soluble Cu:InP QDs with dihydrolipoic acid-polyethylene glycol (DHLA-PEG) via ligand exchange produces the water-soluble and biocompatible dual-emission QDs. The PEGylated Cu:InP QDs present desirable charge neutrality and excellent thermal stability and photostability, thereby holding high potential in a diversity of biomedical applications.

A Resilience Model for Engineered Slopes Subject to Anchor Corrosion

Xue-You Li,Zeng-Bin Fan,Tao Lu,Te Xiao,Li-Min Zhang 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.3

Many high engineered slopes are stabilized using anchors, which may corrode over time. Proper maintenance is essential to recover the system performance and upkeep slope functions. This paper presents a resilience model for maintenance decision by analysing the degradation of an anchor-stabilized slope due to corrosion and evaluating the recovery of slope performance after maintenance. Failure probability is used as an indicator to characterize the evolution of slope performance within its service life. The timing for maintenance is determined when the failure probability reaches an intolerable value. Information obtained from regular inspections is used to reduce the uncertainty in the determined maintenance time. The effectiveness of possible repair schemes is measured by a resilience index for the slope attained after maintenance, which considers the reduction in the failure probability and the duration over which the failure probability remains acceptable. A benefit index, which incorporates both the effectiveness and cost of a repair measure, is defined and used to quantitatively evaluate possible maintenance schemes. The proposed model is illustrated using an anchor-stabilized rock slope example, which provides a means to quantitatively assess different repair measures and enables engineers to select an effective and economic measure for slope maintenance.

Functional analysis of Autographa californica multiple nucleopolyhedrovirus ac78 and ac79

Xue Ying Tao,Jae Young Choi,Jae Su Kim,Qin Liu,Jong Bin Park,Joo Hyun Lee,Soo Dong Woo,Byung Rae Jin,Yeon Ho Je 한국응용곤충학회 2011 한국응용곤충학회 학술대회논문집 Vol.2011 No.10

Among 154 putative ORFs of Autographa californica multiple nucleopolyhedrovirus (AcMNPV), ac78 and ac79 are highly conserved genes in baculovirus, but their functions in the virus life cycle have been unknown so far. To determine their roles in AcMNPV replication, knockout mutants, ac78KO and ac79KO, were constructed using the plasmid capture system (PCS). Real-Time PCR analysis showed that both of ac78 and ac79 transcripts were first detected at 6 hours post-infection, and accumulated to maximum at 24 hours post-infection, suggesting that both of ac78 and ac79 are belong to late gene. When the genomic DNA of ac78KO was transfected into Sf9 cells, viral replication was restricted to a single cell infection. These results demonstrated that the ac78 play an important role in BV production, and therefore is essential for AcMNPV to mount a successful infection. Whereas Sf9 cells infected with the ac79KO showed normal viral symptoms such as rounding and swelling, OBs were not observed from majority of infected cells. These results suggested that the ac79 might play an important role in OB production.