Stable feature screening for ultrahigh dimensional data

Peng Lai,Fengli Song,Yufei Gao 한국통계학회 2019 Journal of the Korean Statistical Society Vol.48 No.2

This paper is concerned with the stable feature screening for the ultrahigh dimensional data. To deal with the ultrahigh dimensional data problem and screen the important features, a set-averaging measurement is proposed. The model averaging technique and the conditional quantile method are used to construct the weighted set-averaging feature screening procedure to identify the relationships between the possible predictors and the response variable. The proposed screening method is model free, stable and possesses the sure screening property under some regular conditions. Some Monte Carlo simulations and a real data application are conducted to evaluate the performance of the proposed procedure.

Patterns and Trends with Cancer Incidence and Mortality Rates Reported by the China National Cancer Registry

Chen, Peng-Lai,Zhao, Ting,Feng, Rui,Chai, Jing,Tong, Gui-Xian,Wang, De-Bin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

National cancer registration reports provide a huge potential for identifying patterns and trends of important policy, research, prevention and treatment significance. As summary reports written on an annual basis, the China Cancer Registry Annual Reports (CCRARs) fall short from fully addressing their potential. This paper attempts to explore part of the patterns and trends hidden behind published CCRARs. It extracted data for cancer incidence rates (IRs) and mortality rates (MRs) for 2004, 2006 and 2009 from relevant CCRARs and portrayed 4 kinds of indicators in line graphs. The study showed that: a) all of the line graphs of age-specific IRs and MRs characterized typical "growth curves or histogram"; b) graphs of IRs and MRs for males and urban areas had higher peaks than that for females and rural regions; c) most of the line graphs of IR/MR ratios comprised a starting peak, a secondary peak and a decreasing tail and the secondary peaks for females and urban areas were higher than those for males and rural areas; d) most of the urban versus rural IR ratios valued above one, but most the urban versus rural MR ratios, below one; e) the accumulative IRs and MRs showed a stable increasing trend from 2004 to 2009 for urban areas, but mixed for rural regions.

Preliminary analysis of geographical distribution based on cold hardiness for Evergestis extimalis (Scopoli) (Lepidoptera: Pyralidae) on Qinghai–Tibet Plateau

You‐Peng Lai,Ke Tao,Taiping Hou 한국곤충학회 2019 Entomological Research Vol.49 No.1

Evergestis extimalis (Scopoli) is a pest insect present in spring rape fields of the Qinghai–Tibet plateau. A survey of its distribution and analysis of its physiological and biochemical variances of its overwintering larvae were conducted in this study. Prior to 2006, Evergestis extimalis Scopli appeared only sporadically at the east agricultural district of Qinghai Province at 2,100 m elevation; after 2006, there have been frequent outbreaks at 2,200 m or so height. The insect's distribution has extended continuously toward higher altitudes yearly, and the scope of its damage reached 2,800 m height in 2010. These changes indicate that the cold hardiness of E. extimalis is on the rise. Physiological and biochemical analyses were performed for the insect's overwintering larvae from November 2011 to March 2012. The supercooling point (SCP) and freezing point (FP) ranged from −6.85°C to −12.49°C and from −6.23°C to −8.17°C, respectively, and both were at their respective lowest points in January 2012; the lowest points of water and fat contents (which did not vary to any extreme degree throughout the test period) were also observed in January 2012. Glycogen content varied from 2.42 mg/g to 4.56 mg/g. Protein content increased gradually at the first two months and reached its peak in January 2012 before dropping slightly. The activity of protective enzymes POD, CAT, and SOD varied with changes in environmental temperature, and each was at its lowest point in January 2012. With the exception of protein and glycerol content, other physiological and biochemical variances were generally parallel with environmental temperature, strongly indicating that E. extimalis has indeed developed cold hardiness.

Clinicopathologic Characteristics and Prognoses for Multicentric Occurrence and Intrahepatic Metastasis in Synchronous Multinodular Hepatocellular Carcinoma Patients

Li, Shi-Lai,Su, Ming,Peng, Tao,Xiao, Kai-Yin,Shang, Li-Ming,Xu, Bang-Hao,Su, Zhi-Xiong,Ye, Xin-Ping,Peng, Ning,Qin, Quan-Lin,Chen, De-Feng,Chen, Jie,Li, Le-Qun Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.1

Background: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and the outcomes for patients are still poor. It is important to determine the original type of synchronous multinodular HCC for preoperative assessment and the choice of treatment therapy as well as for the prediction of prognosis after treatment. Aims: To analyze clinicopathologic characteristics and prognoses in patients with multicentric occurrence (MO) and intrahepatic metastasis (IM) of synchronous multinodular hepatocellular carcinoma (HCC). Methods: The study group comprised 42 multinodular HCC patients with a total of 112 nodules. The control group comprised 20 HCC patients with 16 single nodular HCC cases and 4 HCC cases with a portal vein tumor emboli. The mitochondrial DNA (mtDNA) D-loop region was sequenced, and the patients of the study group were categorized as MO or IM based on the sequence variations. Univariate and multivariate analyses were used to determine the important clinicopathologic characteristics in the two groups. Results: In the study group, 20 cases were categorized as MO, and 22 as IM, whereas all 20 cases in the control group were characterized as IM. Several factors significantly differed between the IM and MO patients, including hepatitis B e antigen (HBeAg), cumulative tumor size, tumor nodule location, cirrhosis, portal vein and/or microvascular tumor embolus and the histological grade of the primary nodule. Multivariate analysis further demonstrated that cirrhosis and portal vein and/or microvascular tumor thrombus were independent factors differentiating between IM and MO patients. The tumor-free survival time of the MO subjects was significantly longer than that of the IM subjects ($25.7{\pm}4.8$ months vs. $8.9{\pm}3.1$ months, p=0.017). Similarly, the overall survival time of the MO subjects was longer ($31.6{\pm}5.3$ months vs. $15.4{\pm}3.4$ months, p=0.024). The multivariate analysis further demonstrated that the original type (p=0.035) and Child-Pugh grade (p<0.001) were independent predictors of tumor-free survival time. Cirrhosis (p=0.011), original type (p=0.034) and Child-Pugh grade (p<0.001) were independent predictors of overall survival time. Conclusions: HBeAg, cumulative tumor size, tumor nodule location, cirrhosis, portal vein and/or microvascular tumor embolus and histological grade of the primary nodule are important factors for differentiating IM and MO. MO HCC patients might have a favorable outcome compared with IM patients.

Isoamylamine Induces B16-F1 Melanoma Cell Autophagy by Upregulating the 5′ Adenosine Monophosphate-Activated Protein Pathway

Yen-Chun Peng,Soo-Ray Wang,Yi-Fang Lai,Nu-Man Tsai,Keh-Liang Lin,Shyh-Jye Lin,Tzi-Peng Yang 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.2

Isoamylamine (IA) is an aliphatic monoamine molecule present in cheese, eggs, and wine. It belongs to the family of polyamines and also can be synthesized endogenously. It has been known that regulation of polyamines in cells is related to cell cycle and tumor formation. Malignant melanoma is difficult to treat and easily resistant to chemotherapy/radiotherapy through autophagy. In this study, we aim to clarify whether IA has a growth control effect on melanoma tumor cells and the regulatory mechanism. We treated B16-F1 melanoma cells with IA at concentrations of 0, 200, 400, and 600 ppm for 24 h. The 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay was checked for cell viability and results showed that IA has an inhibitory effect on B16-F1 melanoma cells. The signaling molecules, which included Raf/MEK/ERK, were activated, while MSK1 and protein kinase B (AKT) were suppressed. Autophagy was also confirmed to be induced by IA. The acridine orange stain-positive cells were increased and BECN-1/LC3 upregulated. The data also showed that the autophagy regulatory molecule, 5′-adenosine monophosphate-activated protein kinase (AMPK), was induced after IA treatment, so we used dorsomorphin to inhibit AMPK and found that it could suppress autophagy. In conclusion, IA has an effect of inducing autophagy in B16-F1 cells and it is regulated through AMPK.

Determinants of customer satisfaction with parcel locker services in last-mile logistics

Lai Po-Lin,Jang Hyunmi,FANG MINGJIE,Peng Ke 한국해운물류학회 2022 The Asian journal of shipping and Logistics Vol.38 No.1

Based on the service quality (SERVQUAL) model and logistics service quality (LSQ) model, this study investigates the antecedents of customer satisfaction with parcel locker services in last-mile logistics. Data were collected from a survey of 321 consumers in China and analyzed using structural equation modeling. The results indicate that timeliness is the strongest predictor that positively impacts customer satisfaction with parcel locker services, while reliability and security are the predictive coefficients for the same, followed by responsiveness and tangibility, respectively. This study enriches the literature on SERVQUAL and LSQ by providing implications for logistics service providers. © 2021 The Authors. Production and hosting by Elsevier B.V. on behalf of The Korean Association of Shipping and Logistics, Inc. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/). CC_BY_NC_ND_4.0

Friction behavior modeling and analysis in micro/meso scale metal forming process

Peng, Linfa,Lai, Xinmin,Lee, Hye-Jin,Song, Jung-Han,Ni, Jun Elsevier 2010 Materials & design Vol.31 No.4

<P><B>Abstract</B></P><P>Currently, a lot of know-how in conventional metal forming process cannot be directly applied to micro/meso forming processes due to so-called size effects. As a very important phenomenon in metal forming process, friction size effects are observed with an increasing degree of miniaturization. For microforming application, the input data of friction behaviors becomes critical to obtain accurate results for process simulation and traditional friction models are not reliable.</P><P>In this paper, the evolution of friction behaviors from micro size to macro size is studied and a new uniform friction model is proposed based on the assumption of open-close lubricant pockets. A function ofreal contact area (RAC) <SUB>αRC</SUB> and normal press p/<SUB>σ0</SUB> is established by introducing size/scale factor λ to describe the influence of size effects. Therefore, the development of the friction behavior from micro/meso scale to macro scale could be depicted by this new uniform friction model. It indicates that the friction curves of micro/meso size are between those of the dry friction (upper boundary) and conventional lubricant friction (lower boundary). Moreover, finite element (FE) simulations are performed, based on the new friction model, to analyze the friction size effects in ring compression process. It is found that the radial friction forces with the change of inner and outer diameters are totally different and their tendencies are in good accordance with the experimental results. The new uniform friction model enables more flexible modeling of friction behaviors.</P>

Efforts of Changes in Monetary Policy under Managed Dual Exchange Rates

Lai, Ching-Chong,Chang, Wen-Ya,Chu, Yun-Peng 세종대학교 국제경제연구소 1988 Journal of Economic Integration Vol.3 No.2

This paper analyzes how the commercial and financial exchange rates adjust over time under the regime of managed dual rates, following an unanticipated increase in the money supply. It is shown that if the official intervention is light, the commercial rates will first rise, then fall either directly or cyclically to its long-run equilibrium. The financial rates will first overshoot, then deviate further from its long-run equilibrium before it finally returns to the equilibrium either directly or cyclically. These two patterns of adjustment are very different from those under the "pure" dual exchange rates.

Sequential pattern load modeling and warning-system plan in modular falsework

Peng, Jui-Lin,Wu, Cheng-Lung,Chan, Siu-Lai Techno-Press 2003 Structural Engineering and Mechanics, An Int'l Jou Vol.16 No.4

This paper investigates the structural behavior of modular falsework system under sequential pattern loads. Based on the studies of 25 construction sites, the pattern load sequence modeling is defined as models R (rectangle), L and U. The study focuses on the system critical loads, regions of largest reaction forces, discrepancy between the pattern load and the uniform load, and the warning-system plan. The analysis results show that the critical loads of modular falsework systems with sequential pattern loads are very close to those with the uniform load used in design. The regions of largest reaction forces are smaller than those calculated by the uniform load. However, the regions of largest reaction forces of three models under sequential pattern loads can be considered as the crucial positions of warning-system based on the measured index of loading. The positions of the sensors for the warning-system for these three different models are not identical.

Generation of green frequency comb from chirped χ⁽²⁾ nonlinear photonic crystals

Lai, C.-M.,Chang, K.-H.,Yang, Z.-Y.,Fu, S.-H.,Tsai, S.-T.,Hsu, C.-W.,Yu, N. E.,Boudrioua, A.,Kung, A. H.,Peng, L.-H. American Institute of Physics 2014 Applied Physics Letters Vol.105 No.22