# Ye Li

## Publications

##### 4 Taguchi-Based Surface Roughness Optimization for Slotted and Tapered Cylindrical Products in Milling and Turning Operations

**Authors:**
Ye Li,
Joseph C. Chen,
Vineeth G. Kuriakose

**Abstract:**

The research follows a systematic approach to optimize the parameters for parts machined by turning and milling processes. The quality characteristic chosen is surface roughness since the surface finish plays an important role for parts that require surface contact. A tapered cylindrical surface is designed as a test specimen for the research. The material chosen for machining is aluminum alloy 6061 due to its wide variety of industrial and engineering applications. HAAS VF-2 TR computer numerical control (CNC) vertical machining center is used for milling and HAAS ST-20 CNC machine is used for turning in this research. Taguchi analysis is used to optimize the surface roughness of the machined parts. The L_{9} Orthogonal Array is designed for four controllable factors with three different levels each, resulting in 18 experimental runs. Signal to Noise (S/N) Ratio is calculated for achieving the specific target value of 75 ± 15 µin. The controllable parameters chosen for turning process are feed rate, depth of cut, coolant flow and finish cut and for milling process are feed rate, spindle speed, step over and coolant flow. The uncontrollable factors are tool geometry for turning process and tool material for milling process. Hypothesis testing is conducted to study the significance of different uncontrollable factors on the surface roughnesses. The optimal parameter settings were identified from the Taguchi analysis and the process capability C_{p} and the process capability index C_{pk} were improved from 1.76 and 0.02 to 3.70 and 2.10 respectively for turning process and from 0.87 and 0.19 to 3.85 and 2.70 respectively for the milling process. The surface roughnesses were improved from 60.17 µin to 68.50 µin, reducing the defect rate from 52.39% to 0% for the turning process and from 93.18 µin to 79.49 µin, reducing the defect rate from 71.23% to 0% for the milling process. The purpose of this study is to efficiently utilize the Taguchi design analysis to improve the surface roughness.

**Keywords:**
surface roughness,
CNC milling,
CNC turning,
Taguchi analysis

##### 3 Applying p-Balanced Energy Technique to Solve Liouville-Type Problems in Calculus

**Authors:**
Lina Wu,
Ye Li,
Jia Liu

**Abstract:**

We are interested in solving Liouville-type problems to explore constancy properties for maps or differential forms on Riemannian manifolds. Geometric structures on manifolds, the existence of constancy properties for maps or differential forms, and energy growth for maps or differential forms are intertwined. In this article, we concentrate on discovery of solutions to Liouville-type problems where manifolds are Euclidean spaces (i.e. flat Riemannian manifolds) and maps become real-valued functions. Liouville-type results of vanishing properties for functions are obtained. The original work in our research findings is to extend the *q*-energy for a function from finite in *L ^{q}* space to infinite in non-

*L*space by applying

^{q}*p*-balanced technique where

*q*=

*p*= 2. Calculation skills such as Hölder's Inequality and Tests for Series have been used to evaluate limits and integrations for function energy. Calculation ideas and computational techniques for solving Liouville-type problems shown in this article, which are utilized in Euclidean spaces, can be universalized as a successful algorithm, which works for both maps and differential forms on Riemannian manifolds. This innovative algorithm has a far-reaching impact on research work of solving Liouville-type problems in the general settings involved with infinite energy. The

*p*-balanced technique in this algorithm provides a clue to success on the road of

*q*-energy extension from finite to infinite.

**Keywords:**
p-balanced growth,
differential forms,
holder inequality,
Liouville-type problems,
p-harmonic maps,
q-energy growth,
tests for series

##### 2 Discovering Liouville-Type Problems for p-Energy Minimizing Maps in Closed Half-Ellipsoids by Calculus Variation Method

**Authors:**
Lina Wu,
Ye Li,
Jia Liu

**Abstract:**

**Keywords:**
Bochner formula,
first and second variation formulas,
Liouville-type problem,
p-harmonic map,
Stokes’ Theorem,
Cauchy-Schwarz
Inequality,
Hardy-Sobolev type
inequalities

##### 1 Effects of Video Games and Online Chat on Mathematics Performance in High School: An Approach of Multivariate Data Analysis

**Authors:**
Lina Wu,
Wenyi Lu,
Ye Li

**Abstract:**

Regarding heavy video game players for boys and super online chat lovers for girls as a symbolic phrase in the current adolescent culture, this project of data analysis verifies the displacement effect on deteriorating mathematics performance. To evaluate correlation or regression coefficients between a factor of playing video games or chatting online and mathematics performance compared with other factors, we use multivariate analysis technique and take gender difference into account. We find the most important reason for the negative sign of the displacement effect on mathematics performance due to students’ poor academic background. Statistical analysis methods in this project could be applied to study internet users’ academic performance from the high school education to the college education.

**Keywords:**
gender difference,
correlation coefficients,
displacement effect,
multivariate analysis technique,
regression coefficients

## Abstracts

##### 7 Taguchi-Based Surface Roughness Optimization for Slotted and Tapered Cylindrical Products in Milling and Turning Operations

**Authors:**
Ye Li,
Joseph C. Chen,
Vineeth G. Kuriakose

**Abstract:**

_{9}Orthogonal Array is designed for four controllable factors with three different levels each, resulting in 18 experimental runs. Signal to Noise (S/N) Ratio is calculated for achieving the specific target value of 75 ± 15 µin. The controllable parameters chosen for turning process are feed rate, depth of cut, coolant flow and finish cut and for milling process are feed rate, spindle speed, step over and coolant flow. The uncontrollable factors are tool geometry for turning process and tool material for milling process. Hypothesis testing is conducted to study the significance of different uncontrollable factors on the surface roughnesses. The optimal parameter settings were identified from the Taguchi analysis and the process capability C

_{p}and the process capability index C

_{pk}were improved from 1.76 and 0.02 to 3.70 and 2.10 respectively for turning process and from 0.87 and 0.19 to 3.85 and 2.70 respectively for the milling process. The surface roughnesses were improved from 60.17 µin to 68.50 µin, reducing the defect rate from 52.39% to 0% for the turning process and from 93.18 µin to 79.49 µin, reducing the defect rate from 71.23% to 0% for the milling process. The purpose of this study is to efficiently utilize the Taguchi design analysis to improve the surface roughness.

**Keywords:**
surface roughness,
Taguchi parameter design,
CNC milling,
CNC turning

##### 6 [Keynote Talk]: Applying p-Balanced Energy Technique to Solve Liouville-Type Problems in Calculus

**Authors:**
Lina Wu,
Ye Li,
Jia Liu

**Abstract:**

*q*-energy for a function from finite in

*L*space to infinite in non-

^{q}*L*space by applying

^{q}*p*-balanced technique where

*q*=

*p*= 2. Calculation skills such as Hölder's Inequality and Tests for Series have been used to evaluate limits and integrations for function energy. Calculation ideas and computational techniques for solving Liouville-type problems shown in this article, which are utilized in Euclidean spaces, can be universalized as a successful algorithm, which works for both maps and differential forms on Riemannian manifolds. This innovative algorithm has a far-reaching impact on research work of solving Liouville-type problems in the general settings involved with infinite energy. The

*p*-balanced technique in this algorithm provides a clue to success on the road of

*q*-energy extension from finite to infinite.

**Keywords:**
p-balanced growth,
differential forms,
holder inequality,
Liouville-type problems,
p-harmonic maps,
q-energy growth,
tests for series

##### 5 An Equivalence between a Harmonic Form and a Closed Co-Closed Differential Form in L^Q and Non-L^Q Spaces

**Abstract:**

**Keywords:**
closed forms,
co-closed forms,
harmonic forms,
L^q spaces,
p-balanced growth,
simple differential k-forms

##### 4 E-Hailing Taxi Industry Management Mode Innovation Based on the Credit Evaluation

**Authors:**
Ye Li,
Tian Xia,
Yuan-Lin Liu

**Abstract:**

**Keywords:**
Credit,
mobile internet,
e-hailing taxi,
management mode,
weighted cluster

##### 3 A Breakthrough Improvement Brought by Taxi-Calling APPs for Taxi Operation Level

**Authors:**
Ye Li,
Tian Xia,
Yuan-Lin Liu

**Abstract:**

**Keywords:**
Credit,
taxi,
taxi-calling APPs,
scenario comparison

##### 2 [Keynote Talk]: Discovering Liouville-Type Problems for p-Energy Minimizing Maps in Closed Half-Ellipsoids by Calculus Variation Method

**Authors:**
Lina Wu,
Ye Li,
Jia Liu

**Abstract:**

**Keywords:**
Bochner formula,
Calculus Stokes' Theorem,
Cauchy-Schwarz Inequality,
first and second variation formulas,
Liouville-type problem,
p-harmonic map

##### 1 Effects of Video Games and Online Chat on Mathematics Performance in High School: An Approach of Multivariate Data Analysis

**Authors:**
Lina Wu,
Wenyi Lu,
Ye Li

**Abstract:**

**Keywords:**
correlation coefficients,
displacement effect,
multivariate analysis technique,
regression coefficients