Reactive Procedure for Robust Project Scheduling under the Activity Disruptions

Lei Li,Wanlin Liu,Yumeng Chen,Shun Yang 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.9

The baseline schedule may become infeasible when disruptions happen during the execution of project. This will lead to project delays and financial losses. In this paper, we developed a robust reactive optimization model. Our objective is to maximize the robustness of reactive schedule. Moreover, a robust reactive procedure is proposed for baseline schedule under a series of disruptions caused by activity duration. To test the proposed approach, sets of J60 and J90 instances from the Project Scheduling Library (PSPLIB) were used. Meanwhile, we tested the reactive project scheduling with the aim of minimizing makespan and compared the maximal robustness reactive schedule and the minimal makespan reactive schedule. We developed a reactive procedure involving genetic algorithm for reactive scheduling due to its non-deterministic polynomial hard (NP-hard). The results indicated that robust reactive scheduling has the advantage in maintaining the schedule’s ability of tolerating variabilities and reducing the impact of activity disruptions on the makespan. The research results can help project managers develop a robust schedule which can tolerate variabilities in a random environment.

Systematic characterization of A-to-I RNA editing hotspots in microRNAs across human cancers

Wang, Yumeng,Xu, Xiaoyan,Yu, Shuangxing,Jeong, Kang Jin,Zhou, Zhicheng,Han, Leng,Tsang, Yiu Huen,Li, Jun,Chen, Hu,Mangala, Lingegowda S.,Yuan, Yuan,Eterovic, A. Karina,Lu, Yiling,Sood, Anil K.,Scott, Cold Spring Harbor Laboratory Press 2017 Genome research Vol.27 No.7

<P>RNA editing, a widespread post-transcriptional mechanism, has emerged as a new player in cancer biology. Recent studies have reported key roles for individual miRNA editing events, but a comprehensive picture of miRNA editing in human cancers remains largely unexplored. Here, we systematically characterized the miRNA editing profiles of 8595 samples across 20 cancer types from miRNA sequencing data of The Cancer Genome Atlas and identified 19 adenosine-to-inosine (A-to-I) RNA editing hotspots. We independently validated 15 of them by perturbation experiments in several cancer cell lines. These miRNA editing events show extensive correlations with key clinical variables (e.g., tumor subtype, disease stage, and patient survival time) and other molecular drivers. Focusing on the RNA editing hotspot in miR-200b, a key tumor metastasis suppressor, we found that the miR-200b editing level correlates with patient prognosis opposite to the pattern observed for the wild-type miR-200b expression. We further experimentally showed that, in contrast to wild-type miRNA, the edited miR-200b can promote cell invasion and migration through its impaired ability to inhibit <I>ZEB1/ZEB2</I> and acquired concomitant ability to repress new targets, including <I>LIFR</I>, a well-characterized metastasis suppressor. Our study highlights the importance of miRNA editing in gene regulation and suggests its potential as a biomarker for cancer prognosis and therapy.</P>

Synthesis and structure of two-dimensional transition-metal dichalcogenides

Shi, Yumeng,Zhang, Hua,Chang, Wen-Hao,Shin, Hyeon Suk,Li, Lain-Jong Cambridge University Press (Materials Research Soc 2015 MRS bulletin Vol.40 No.7

<▼1><B>Abstract</B><P/></▼1><▼2><P>Two-dimensional (2D) transition-metal dichalcogenides (TMDCs) exhibit unique electrical, optical, thermal, and mechanical properties, which enable them to be used as building blocks in compact and lightweight integrated electronic systems. The controllable and reliable synthesis of atomically thin TMDCs is essential for their practical application. Recent progress in large-area synthesis of monolayer TMDCs paves the way for practical production of various 2D TMDC layers. The intrinsic optical and electrical properties of monolayer TMDCs can be defined by stoichiometry during synthesis. By manipulating the lattice structure or layer stacking manner, it is possible to create atomically thin van der Waals materials with unique and unexplored physical properties. In this article, we review recent developments in the synthesis of TMDC monolayers, alloys, and heterostructures, which shine light on the design of novel TMDCs with desired functional properties.</P></▼2>

Severe Acute Respiratory Syndrome Coronavirus 2 Detection in the Radiology Department of Hospitals in Wuhan, China

Tang Yumeng,Lei Ziqiao,Liu Sheng,Li Jing,Xie Shuguang,Niu Yantao,Tang Lijun 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.11

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Effects of zinc-bearing palygorskite on rumen fermentation in vitro

Mengjiao Chen,Yumeng Xi,Lin Zhang,Hanfang Zeng,Yeqing Li,Zhaoyu Han 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.1

Objective: The aim of the study was to investigate the effect of zinc-bearing palygorskite (Zn-Pal) on rumen fermentation by in vitro gas-production system. Methods: In trial, 90 incubators were evenly divided into five groups: control (0% Zn-Pal), treatment I (0.2% Zn-Pal), treatment II (0.4% Zn-Pal), treatment III (0.6% Zn-Pal), and treatment IV (0.8% Zn-Pal). The contents of zinc for treatments were 0, 49, 98, 147, 196 mg/kg, respectively. The main chemical composition and microstructure of Zn-Pal was investigated by X-ray diffraction. The physicochemical features were evaluated by Zeta potential analysis, cation-exchange capacity, ethylene blue absorption and specific surface area (the Brunauer–Emmett–Teller method). In vitro gas production (GP) was recorded at 3, 6, 9, 12, 18, 24, 36, 48, 60, and 72 h incubation. Incubation was stopped at 0, 6, 12, 24, 48, and 72 h and the inoculants were tested for pH, microbial protein yield (MCP), NH3-N, volatile fatty acids (VFAs), lipopolysaccharide (LPS). Results: The results showed that the GP in the treatment groups was not significantly different from the control groups (p>0.05). Compared to the control group, pH was higher at 24 h, 48 h (p<0.05), and 72 h (p<0.01) (range 6 to 7). The concentration of NH3-N in the three treatment groups was higher than in the control group at 24 h (p<0.01), meanwhile, it was lower at 48 h and 72 h (p<0.01), except in the treatment IV. The concentration of MCP in treatment I group was higher than in the control at 48 h (p<0.01). Compared with control, the LPS concentration in treatment III became lower at 12 h (p<0.05). Total VFAs in treatments were higher than in the control at 24 h, 48 h (p<0.05). Conclusion: These results suggest that the addition of Zn-Pal can improve the rumen fermentation, especially when adding 0.2% Zn-Pal.

Measurement of Lateral and Interfacial Thermal Conductivity of Single- and Bilayer MoS₂ and MoSe₂ Using Refined Optothermal Raman Technique

Zhang, Xian,Sun, Dezheng,Li, Yilei,Lee, Gwan-Hyoung,Cui, Xu,Chenet, Daniel,You, Yumeng,Heinz, Tony F.,Hone, James C. American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.46

<P>Atomically thin materials such as graphene and semiconducting transition metal dichalcogenides (TMDCs) have attracted extensive interest in recent years, motivating investigation into multiple properties. In this work, we demonstrate a refined version of the optothermal Raman technique1,2 to measure the thermal transport properties of two TMDC materials, MoS<SUB>2</SUB> and MoSe<SUB>2</SUB>, in single-layer (1L) and bilayer (2L) forms. This new version incorporates two crucial improvements over previous implementations. First, we utilize more direct measurements of the optical absorption of the suspended samples under study and find values ∼40% lower than previously assumed. Second, by comparing the response of fully supported and suspended samples using different laser spot sizes, we are able to independently measure the interfacial thermal conductance to the substrate and the lateral thermal conductivity of the supported and suspended materials. The approach is validated by examining the response of a suspended film illuminated in different radial positions. For 1L MoS<SUB>2</SUB> and MoSe<SUB>2</SUB>, the room-temperature thermal conductivities are 84 ± 17 and 59 ± 18 W/(m·K), respectively. For 2L MoS<SUB>2</SUB> and MoSe<SUB>2</SUB>, we obtain values of 77 ± 25 W and 42 ± 13 W/(m·K). Crucially, the interfacial thermal conductance is found to be of order 0.1–1 MW/m<SUP>2</SUP> K, substantially smaller than previously assumed, a finding that has important implications for design and modeling of electronic devices.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-46/acsami.5b08580/production/images/medium/am-2015-085805_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b08580'>ACS Electronic Supporting Info</A></P>

A Comparative Analysis of Chinese and Korean Tourism Legislation

Jianhong Wang,Xinmiao Yang,Yumeng Li 아시아사회과학학회 2023 Jornal of Asia Social Science Vol.10 No.3

In the face of today's thriving global tourism sector, China and South Korea, as two Asian tourism powerhouses, have each adopted unique laws, rules, and policies to manage their thriving tourism industries. Although both countries have achieved impressive accomplishments in tourism development, their tourism management legislation differs, which may result in differing management outcomes. This paper investigates the similarities and differences in tourism management legislation in China and South Korea, and provides a comparative analysis across a variety of dimensions, including legislative background, laws and regulations, regulatory bodies, and the protection of tourists' rights and interests. This paper uses a comparative research methodology to provide valuable insights for tourism policymakers, practitioners, and scholars to help them better understand the characteristics of tourism management in the two countries, to promote the improvement of tourism management legislation in China and South Korea, to facilitate the sustainable development of the tourism industry, to improve service quality, and to protect the rights and interests of tour operators.

Enhancing the conductivity of transparent graphene films via doping

Kim, Ki Kang,Reina, Alfonso,Shi, Yumeng,Park, Hyesung,Li, Lain-Jong,Lee, Young Hee,Kong, Jing IOP Pub 2010 Nanotechnology Vol.21 No.28

<P>We report chemical doping (p-type) to reduce the sheet resistance of graphene films for the application of high-performance transparent conducting films. The graphene film synthesized by chemical vapor deposition was transferred to silicon oxide and quartz substrates using poly(methyl methacrylate). AuCl<SUB>3</SUB> in nitromethane was used to dope the graphene films and the sheet resistance was reduced by up to 77% depending on the doping concentration. The p-type doping behavior was confirmed by characterizing the Raman G-band of the doped graphene film. Atomic force microscope and scanning electron microscope images reveal the deposition of Au particles on the film. The sizes of the Au particles are 10–100 nm. The effect of doping was also investigated by transferring the graphene films onto quartz and poly(ethylene terephthalate) substrates. The sheet resistance reached 150  Ω/sq at 87% transmittance, which is comparable to those of indium tin oxide conducting film. The doping effect was manifested only with 1–2 layer graphene but not with multi-layer graphene. This approach advances the numerous applications of graphene films as transparent conducting electrodes. </P>