A Strategic Analysis of Algorithm Manipulation: a Lending Game perspective

Machine learning models are widely used in many business contexts, but there is a growing concern that strategic individuals may manipulate their features to obtain desirable outcomes from the machine learning models. This paper offers a theoretical analysis of the impact of feature manipulation on the performance of the machine learning models and the payoffs of firms in an online lending context. Contrary to the common belief, our interesting finding is that manipulation may not be harmful to a firm under some circumstances. Instead, it could increase the classification model\u27s performance and raise a firm\u27s payoff and the social welfare when high-quality individuals manipulate more. Overall, our findings suggest that manipulation can bring strategic value to machine learning models instead of just being a harmful activity. Our findings provide useful insights for feature engineering and lay a foundation for future research about optimal strategies to cope with manipulation activities

Overtrawlability and Mechanical Damage of Pipe-in-Pipe

Ph.DDOCTOR OF PHILOSOPH

Interaction Effects of Life Events and Hair Cortisol on Perceived Stress, Anxiety, and Depressive Symptoms Among Chinese Adolescents: Testing the Differential Susceptibility and Diathesis-Stress Models

The differential susceptibility model and the diathesis-stress model on the interaction effect between the individuals’ traits and environmental factors will be conducive to understand in depth whether the psychophysiological traits are the risk factors of child development. However, there is no study focusing on the activity of the hypothalamic-pituitary-adrenal (HPA) axis. We examined whether the HPA activity serves as a physiological marker of the differential susceptibility model or the diathesis-stress model by exploring the interactive effect of life events and hair cortisol on perceived stress, anxiety, and depressive symptoms among Chinese adolescents. The participants were 324 students in senior high school. They reported their psychological states with questionnaires in their first semester after a 3-month adaptation period; 2 weeks later, they provided 1-cm hair segments closest to the scalp. We measured hair cortisol concentration as a biomarker of HPA activity using high-performance liquid chromatography–tandem mass spectrometry. There was a significant interaction effect of academic events and hair cortisol on adolescents’ perceived stress, anxiety, and depression symptoms. We also observed a significant interaction between interpersonal events and hair cortisol on adolescents’ anxiety symptoms. Looking at the region of significance, proportion of interaction index, and proportion affected index, we found that adolescents with higher cortisol levels had a tendency to experience higher perceived stress and anxiety symptoms when they had high academic events scores, but lower perceived stress and anxiety symptoms when they had lower academic events scores. By contrast, adolescents with higher cortisol levels had a greater risk of experiencing high depressive symptoms only when they had higher academic events scores. Adolescents with higher cortisol levels also tended to have lower anxiety symptoms when they had higher interpersonal events scores, but greater anxiety symptoms when they had lower interpersonal events scores. These results suggested that HPA activity might serve as a biomarker of the differential susceptibility model for perceived stress and anxiety symptoms, while for depressive symptoms, it might serve as a marker of the diathesis-stress model

“Mn-locking” effect by anionic coordination manipulation stabilizing Mn-rich phosphate cathodes

High-voltage cathodes with high power and stable cyclability are needed for high-performance sodium-ion batteries. However, the low kinetics and inferior capacity retention from structural instability impede the development of Mn-rich phosphate cathodes. Here, we propose light-weight fluorine (F) doping strategy to decrease the energy gap to 0.22 eV from 1.52 eV and trigger a “Mn-locking” effect—to strengthen the adjacent chemical bonding around Mn as confirmed by density functional theory calculations, which ensure the optimized Mn ligand framework, suppressed Mn dissolution, improved structural stability and enhanced electronic conductivity. The combination of in situ and ex situ techniques determine that the F dopant has no influence on the Na+ storage mechanisms. As a result, an outstanding rate performance up to 40C and an improved cycling stability (1000 cycles at 20C) are achieved. This work presents an effective and widely available light-weight anion doping strategy for high-performance polyanionic cathodes

Genomic heterogeneity of multiple synchronous lung cancer

Multiple synchronous lung cancers (MSLCs) present a clinical dilemma as to whether individual tumours represent intrapulmonary metastases or independent tumours. In this study we analyse genomic profiles of 15 lung adenocarcinomas and one regional lymph node metastasis from 6 patients with MSLC. All 15 lung tumours demonstrate distinct genomic profiles, suggesting all are independent primary tumours, which are consistent with comprehensive histopathological assessment in 5 of the 6 patients. Lung tumours of the same individuals are no more similar to each other than are lung adenocarcinomas of different patients from TCGA cohort matched for tumour size and smoking status. Several known cancer-associated genes have different mutations in different tumours from the same patients. These findings suggest that in the context of identical constitutional genetic background and environmental exposure, different lung cancers in the same individual may have distinct genomic profiles and can be driven by distinct molecular events

Effect of Different Harvest Maturity on the Nutritional Quality of Midknight Valencia Orange Fruit

Midknight Valencia Orange is one of the most important late maturing citrus varieties. In order to study the effect of different harvest maturity on the nutritional quality of this variety and to determine its optimal harvesting period, the quality indexes of Midknight Valencia Orange, including color difference, firmness, carotenoid, soluble sugars, organic acids, free amino acids, mineral elements, flavonoid and total phenol content were measured and a correlation analysis was performed. The result showed that different harvest maturity had significant effects on the quality of Midknight Valencia Orange. With the delay of harvesting time, the coloration process of the peel gradually changed from the stem end to the bottom end and the peel showed a bright yellow after 360 days of flowering. The contents of carotenoid, ascorbic acid, total phenol and flavonoid increased, while the content of soluble solid increased first and then decreased, and the titrable acid content decreased significantly. The main soluble sugars in Midknight Valencia Orange fruit were glucose, sucrose, fructose, talose and inositol, and the contents of glucose and sucrose showed an increasing trend during harvesting. The main organic acids were citric acid, malic acid and quinic acid, and the content of citric acid decreased during harvesting. The main free amino acids were proline, arginine and serine, which showed an increasing trend during harvesting. Based on the evaluation indexes prescribed above, 360~400 days (April~May) after flowering is the appropriate harvesting time for Midknight Valencia Orange. Besides, the correlation analysis results showed that, as the indicator often used to judge the maturity of fruit, the firmness and titratable acid content of Midknight Valencia Orange have highly correlation with the content of carotenoid, soluble sugars, organic acids, free amino acids, mineral elements, flavonoid and total phenol. The firmness, titratable acid content and TSSC/TA ratio of Midknight Valencia can be used for the determination of harvesting time, namely fruit with a firmness 1.33~1.03 kg, titratable acid content 1.77%~1.30% and 5.41~6.96 TSS/TA ratio showed a good quality. The results of this study can provide a scientific basis for the determination the suitable harvesting period of Midknight Valencia Orange

Overtrawlability and mechanical damage of pipe-in-pipe

10.1115/1.4024877Journal of Applied Mechanics, Transactions ASME813-JAMC

Study on dynamic mechanical properties and microscopic damage mechanisms of granite after dynamic triaxial compression and thermal treatment

As underground mining operations gradually extend deeper, the conditions for orebody occurrence become increasingly complex, and various geological disasters occur frequently. Rock masses are prone to different degrees and types of damage, making it impractical to continue using intact rock as a reference. To study the dynamic mechanical properties of damaged rock under actual conditions, this study subjected granite samples to impact and high-temperature damage. Detailed observations were made of the samples' surface morphology and microstructure before and after damage, and the patterns of damage changes were investigated. Subsequently, uniaxial compression tests at different loading rates were conducted on the damaged samples. By calculating the loading rate effect sensitivity, it was found that as the damage increased, the rate effect gradually diminished. In addition, this study also summarized the influence of damage and loading rate on the macroscopic failure characteristics of the samples. The novelty of this study lies in focusing on damaged rock, which more closely resembles the actual rock conditions encountered in most underground mining operations today. This research can provide a reference for stability assessment and safe construction in deep mining rock engineering and offers important insights into the feasibility of non-explosive extraction of damaged rock