Engineering Commons^™

Fine-Grained And Controllably Editable Data Sharing With Accountability In Cloud Storage, Huiying Hou, Jianting Ning, Yunlei Zhao, Robert H. Deng

Research Collection School Of Computing and Information Systems

With the increasing cloud storage service, users can enjoy non-interactive data sharing. Nonetheless, the data owner cannot timely update the shared data all the while. To ensure the timeliness and the authoritative source of the data, some users should be allowed to update the data on behalf of an authoritative data owner without changing data source. However, this allows harmful information to be injected into the data unnoticeably. How to efficiently realize editable cloud-based data sharing supporting malicious user tracing has not been fully explored. To address the problem, we propose a fine-grained and controllably editable cloud-based data sharing scheme …

Influence Of Defects On In-Plane Dynamic Properties Of Hexagonal Ligament Chiral Structures, Ning An, Xunwen Su, Dongmei Zhu, Mileta M. Tomovic

Engineering Technology Faculty Publications

Although the six-ligament chiral structure has many unique properties, due to its special structure, the stress concentration is prone to defects. In addition, additive manufacturing is also prone to defects. This paper studies the effect of defects, which is helpful for the better application of the six-ligament chiral structure. Several new six-ligament chiral structures with random and concentrated defects were designed to explore the effects of the defects on the in-plane dynamic properties. The structures were studied with the finite element ANSYS/LSDYNA numerical simulation and experimental methods. According to the defect-free six-ligament chiral structures exhibiting different deformation modes at different …

Computation Of Risk Measures In Finance And Parallel Real-Time Scheduling, Yajuan Li

Dissertations

Many application areas employ various risk measures, such as a quantile, to assess risks. For example, in finance, risk managers employ a quantile to help determine appropriate levels of capital needed to be able to absorb (with high probability) large unexpected losses in credit portfolios comprising loans, bonds, and other financial instruments subject to default. This dissertation discusses the computation of risk measures in finance and parallel real-time scheduling.

Firstly, two estimation approaches are compared for one risk measure, a quantile, via randomized quasi-Monte Carlo (RQMC) in an asymptotic setting where the number of randomizations for RQMC grows large, but …

Performance Analysis Of The Dominant Mode Rejection Beamformer, Enlong Hu

Dissertations

In array signal processing over challenging environments, due to the non-stationarity nature of data, it is difficult to obtain enough number of data snapshots to construct an adaptive beamformer (ABF) for detecting weak signal embedded in strong interferences. One type of adaptive method targeting for such applications is the dominant mode rejection (DMR) method, which uses a reshaped eigen-decomposition of sample covariance matrix (SCM) to define a subspace containing the dominant interferers to be rejected, thereby allowing it to detect weak signal in the presence of strong interferences. The DMR weight vector takes a form similar to the adaptive minimum …

Low-Reynolds-Number Locomotion Via Reinforcement Learning, Yuexin Liu

Dissertations

This dissertation summarizes computational results from applying reinforcement learning and deep neural network to the designs of artificial microswimmers in the inertialess regime, where the viscous dissipation in the surrounding fluid environment dominates and the swimmer’s inertia is completely negligible. In particular, works in this dissertation consist of four interrelated studies of the design of microswimmers for different tasks: (1) a one-dimensional microswimmer in free-space that moves towards the target via translation, (2) a one-dimensional microswimmer in a periodic domain that rotates to reach the target, (3) a two-dimensional microswimmer that switches gaits to navigate to the designated targets in …

Towards Ensuring Integrity And Authenticity Of Software Repositories, Sangat Vaidya

Dissertations

The software development process comprises a series of steps known as a software supply chain. These steps include managing the source code, testing, building and packaging it into a final product, and distributing the product to end users. Along this chain, software repositories are used for different purposes such as source code management (Git, SVN, mercurial), software distribution (PyPI, RubyGems, NPM) or for deploying software based on container images (Harbor, DockerHub, Artifact Hub). In the recent past, different types of repositories have increasingly been the target of attacks. As such, there is a need for mechanisms to ensure integrity and …

2022 Fall Engr333 Project Assignment, Matthew K. Heun

ENGR 333

The Fall 2022 ENGR333 project focused on sustainable heating for Calvin University.

I asked the students “What would it take to eliminate Calvin’s natural gas-related net CO2 emissions?”

Matt Kucinski (Calvin PR) wrote a story about the project. President Boer wrote a complementary post about the students’ work on LinkedIn.

Customer

The customer for this project was Dr. Wiebe Boer, President of Calvin University.

Falcon Neuro: An Event-Based Sensor On The International Space Station, Matthew G. Mcharg, Richard L. Balthazor, Matthew P. Borg, Brian J. Mcreynolds, David H. Howe, Colin J. Maloney, Daniel O'Keefe, Rayomand Bam, Gabriel Wilson, Paras Karki, Alexandre Marcireau, Gregory Cohen

Student Publications

We report on the Falcon neuro event-based sensor (EBS) instrument that is designed to acquire data from lightning and sprite phenomena and is currently operating on the International Space Station. The instrument consists of two independent, identical EBS cameras pointing in two fixed directions, toward the nominal forward direction of flight and toward the nominal Nadir direction. The payload employs stock DAVIS 240C focal plane arrays along with custom-built control and readout electronics to remotely interface with the cameras. To predict the sensor’s ability to effectively record sprites and lightning, we explore temporal response characteristics of the DAVIS 240C and …

Parameter Selection In Fully Homomorphic Encryption Schemes And Fhe Applications, Cavidan Yakupoglu

Dissertations

Quantum computing has been gaining momentum as a result of recent technological advances. Existing cryptographic systems rely on the difficult problems that can be solved by sufficiently powerful quantum computers. As the quantum age approaches, the desire to discover new difficult problems that cannot be solved by quantum systems has increased. Lattice-based cryptography is a prominent tool for the post-quantum era that facilitates the implementation of encryption systems for practical applications.

The Learning with Error (LWE) and Ring-LWE problems introduce new lattice hardness assumptions that have been incorporated into public-key cryptosystems to facilitate the implementation of numerous privacy-enhancing applications. Fully …

Coupled Oscillators: Protein And Acoustics, Angelique N. Mcfarlane

Theses

This work encompassed three different vibrational energy transfer studies of coupled resonators (metal, topological, and microtubule comparison) inspired by the lattices of microtubules from regular and cancerous cells. COMSOL Multiphysics 5.4 was utilized to design the experiment. The simulation starts with an acoustic pressure study to examine the vibrational modes present in coupled cylinders, representing α-, β-tubulin heterodimers. The Metal Study consisted of 3 models (monomer, dimer, and trimer) to choose the correct height (40 mm) and mode (Mode 1) for study. The Topological Study was run to predict and understand how the lattice structure changes over a parametric sweep …

Weather Routing For The Refined Management Of Passage, Guobao Gong

World Maritime University Dissertations

No abstract provided.

Decarbonization Of International Shipping Industry And Its Impact On China From The Perspective Of Economic Analysis, Haolin Peng

World Maritime University Dissertations

No abstract provided.

Research On Uncertainties And Challenges Of Cyber Security In Maritime Industry, Qianrong Chen

World Maritime University Dissertations

No abstract provided.

The Optimum Decarbonization Path For A Container Ship Company, Tao Wang

World Maritime University Dissertations

No abstract provided.

Research On The Detection Technologies Of Ship Exhaust Gas In Emission Control Areas, Binting Tu

World Maritime University Dissertations

No abstract provided.

Low-Crystallinity And Heterostructured Aupt-Ru@Cnts As Highly Efficient Multifunctional Electrocatalyst, Tuan-Jie Gan, Jian-Ping Wu, Shi Liu, Wen-Jun Ou, Ling Bin, Xiong-Wu Kang

Journal of Electrochemistry

The catalytic activity of the catalysts is strongly dependent on the structure of the catalysts, and the exploration of their correlation and structure-controlled synthesis of the high-performance catalysts are always at the central. Currently, platinum (Pt) is the optimum catalyst for hydrogen evolution reaction (HER), oxygen reduction reaction (ORR) and alcohol oxidation reaction, while ruthenium (Ru) behaves as the champion catalyst for oxygen evolution reaction (OER) during water splitting. Preparing alloy catalysts with these precious metals can modulate the catalytic activity of these catalysts from the perspective of strain effect, ensemble effect and ligand effect. Here, we developed a strategy …

Optimized Electrochemical Performance Of Si@C Prepared By Hydrothermal Reaction And Glucose Carbon Source, Si Chen, Song-Sheng Zheng, Lei-Ming Zheng, Ye-Han Zhang, Zhao-Lin Wang

Journal of Electrochemistry

Silicon (Si) has been considered as the potential material for the next-generation lithium-ion batteries (LIBs) for its high capacity (4200 mAh·g^-1, Li₂₂Si₅) and suitable working voltage (about 0.25 V vs. Li/Li⁺). However, the cycling stability and electrochemical performance of Si anode become significant challenges because of low intrinsic conductivity and huge volume variation (about 400%) during cycling processes. In addition, the repeated formation and destruction of surface solid electrolyte interphase (SEI) film will continuously consume the electrolyte and cause damage to LIBs. Carbon (C) materials, such as graphite, carbon spheres and tubes, …

Quantitative Lithium Composite As 3d Lithium Foam Anode For Lithium Metal Battery, Hu-Dong Li, Wei-Shang Jia, Xin-Xiu Yan, Yao-Yue Yang

Journal of Electrochemistry

Lithium (Li) metal as an anode material for batteries has extremely high specific capacity and extremely low redox potential, which can significantly improve the energy density of the battery. However, the main problems faced by the use of Li metal anodes are Li dendrite growth, interfacial side reaction and volumetric change of electrode. Herein, a strategy to prepare the three-dimensional (3D) Li foam by combining 3D scaffold with quantitative Li was proposed to suppress Li dendrites growth and alleviate electrode volumetric change. The 3D Li foam facilitated the efficient utilization of Li metal by suppressing the Li dendrite growth, mitigating …

Facile One-Step Solid-State Synthesis Of Ni-Rich Layered Oxide Cathodes For Lithium-Ion Batteries, Jing-Yue Wang, Rui Wang, Shi-Qi Wang, Li-Fan Wang, Chun Zhan

Journal of Electrochemistry

Nickel-rich layered oxide is one of the dominate cathode materials in the lithium ion batteries, due to its high specific energy density meeting the range requirement of the electric vehicles. Typically, the commercial Ni-rich layered oxides are synthesized from co-precipitated precursors, while precision control is required in the co-precipitation process to ensure the atomic level mixing of the cations such as Ni, Co and Mn, et.al. In this work, a one-step solid-state method was successfully applied to synthesize the Ni-rich layered oxide materials with ultra-high Ni content. By choosing the nickel hydroxides as the precursor with layered structure similar to …

Design Of Novel Metalloenzymes And Investigation Of Protein-Metal Interactions, Alona Kulesha

Dissertations - ALL

Metalloproteins are the proteins that utilize metals or metal complexes as cofactors and exhibit a wide range of functions from oxygen transport and regulation of transcription to hydroxylation of alkanes and water splitting, even though they employ a limited set of metals and metal-binding ligands. The investigation of metalloprotein amino acid sequence, structure and function relationships can uncover the principles behind natural metalloprotein design and opens the possibility of their implication as scaffolds for the design of novel catalysts and biomaterials. Protein engineering is a set of techniques that allows to install new functionalities into existing proteins or to design …

Rocket Measurements Of Electron Energy Spectra From Earth’S Photoelectron Production Layer, Glyn A. Collinson, Alex Glocer, Dennis Chornay, Robert Mitchell, Rob Pfaff, Tim Cameron, Et. Al.

Publications

Photoelectrons are crucial to atmospheric physics. They heat the atmosphere, strengthen 28 planetary ambipolar electric fields, and enhance the outflow of ions to space. However, 29 there exist only a handful of measurements of their energy spectrum near the peak of 30 photoproduction. We present calibrated energy spectra of pristine photoelectrons at their 31 source by a prototype Dual Electrostatic Analyzer (DESA) instrument flown on July 11 32 2021 aboard the Dynamo-2 sounding rocket (NASA № 36.357). Photopeaks arising from 33 30.4nm He-II spectral line were observed throughout the flight above 120km. DESA also 34 successfully resolved the rarely observed …

Girls In Stem! Elementary Afterschool Six-Week Curriculum, Jess Li, Samavi Rafique

Honors Program: Expanded Learning Clubs

No abstract provided.

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Experimental Study On The Mechanical Properties Of Coal-Like Materials For Hydraulic Fracturing Simulation, Zhai Cheng, Zheng Yangfeng, Yu Xu, Xu Jizhao, Sun Yong, Cong Yuzhou, Tang Wei, Li Yujie, Zhu Xinyu, Chen Aikun

Coal Geology & Exploration

Simulation experiments on hydraulic fracturing of the coal seam in the laboratory are an effective method to study the mechanism of fracturing and enhancing permeability of coal-rock mass by hydraulic fracturing in coal mines. However, the technology in-situ sampling for large-size coal mass is immature, and the existing large-size coal samples are mostly taken from the stress-relaxation area, which can be further damaged in the transportation and preparation processes, causing large dispersion in test results. Therefore, The use of coal-like materials is a viable option to replace large-size raw coal for hydraulic fracturing simulation experiments. The mechanical properties of coal-like …

High-Efficiency Regional Gas Drainage Model After Hydraulic Fracturing Of Comb-Shaped Long Boreholes In The Roof Of Broken Soft And Low Permeability Coal Seam, Chen Dongdong, Wang Jianli, Jia Bingyi, Xi Jie

Coal Geology & Exploration

Advanced management of gas enrichment area is an important guarantee to realize safe, efficient and intelligent mining in coal mine. Aiming at the problem of high-efficiency gas drainage in broken and soft coal seam region, taking No.3 coal seam in Hancheng mining area as the research object, a gas drainage mode of comb-shaped long borehole hydraulic fracturing in the roof of coal seam is proposed. The applicability of the model is verified by means of theoretical analysis, numerical simulation and field test, and the fracture propagation law, gas drainage mechanism, and fracturing curve features of comb-shaped borehole in adjacent roof …

Experimental Study Of Hydraulic Fracture Evolution With Materials Similar To The Structural Plane, Li Quangui, Wu Xiaobin, Hu Qianting, Liu Le, Shi Jialin, Song Mingyang

Coal Geology & Exploration

The structural plane extensively occurs in coal measures, and is one of the key factors affecting the hydraulic fracturing effect of coal/rock. The fabrication time and filling material types of the structural plane were adjusted to obtain the coal/rock specimens without the filling structural plane, or the coal/rock specimens with the filling structural plane. The physical experiment for hydraulic fracturing was carried out to find out the effect and action mechanism of the structural plane type and injected flow rate on hydraulic fracture extension. As indicated by the result, in the condition of the injected flow rate of 50 mL/min, …

Research On Hydraulic Fracturing Technology And Equipment Of Directional Long Drilling With Sand In Coal Seam Roof, Zhang Jian, Liu Le, Zhao Jizhan, Sun Siqing, Wang Chenyang

Coal Geology & Exploration

Due to low permeability, fast gas-rate decline, uneven fracturing, easy fracture closure, it is difficult to perform advance gas extraction in broken-soft coal seams. Aimed at these issues, this study has been proposed a new idea to enhance the coalbed permeability and eventually the gas extraction, which is based on roof-supporting, long-reach directional drilling, and hydraulic fracturing. Corresponding equipment including fracturing pump unit, directional sandblasting perforation assembly, sand control packer and tools have been developed. Specifically, the pumping unit is capable of a pumping rate up to 90 m³/h, a pumping pressure up to 70 MPa, and a …

Optimized Design And Surface Additive Technology Of Pdc Bit For Hard Rock Directional Drilling, Wang Chuanliu, Jin Xin, Gao Xiaoliang, Zhang Peng

Coal Geology & Exploration

Directional long drilling is the main technical means of gas and water hazard control in coal mines, and the performance of PDC directional bit is an important factor which affects the drilling efficiency in hard rock. In view of frequent tripping and low that caused by the broken PDC bit body and PDC tooth collapse in the construction of directional long drilling in the roof and floor of coal seams, the principle of equal cutting teeth distribution is used to optimize the blade teeth distribution to reduce the impact damage of the cutter. Through the simulated analysis of fluid mechanics, …

Research Progress And Development Trend Of Staged Hydraulic Fracturing Technology In Long-Borehole Underground Coal Mine, Sun Siqing, Li Wenbo, Zhang Jian, Chen Dongdong, Zhao Jizhan, Zheng Kaige, Long Weicheng, Wang Chenyang, Jia Bingyi, Du Tianlin, Liu Le, Yang Huan, Dai Nan

Coal Geology & Exploration

Since the “13th Five-Year Plan”, significant progress has been made in the directional long-borehole staged hydraulic fracturing technology, equipment development and engineering demonstration application of underground coal mine through the technical research, equipment development and engineering test with directional long-borehole and staged hydraulic fracturing technology in combination, focusing on the two major issues of regional permeability enhancement, efficient gas drainage and rock weakening treatment of hard roof for coal seams in underground coal mine in China. It is mainly manifested in the following four aspects: (1) Two staged hydraulic fracturing technologies and tools with/without rig movement have been developed. Specifically, …

Dynamic Disaster Evolution Mechanism Of High Mine Pressure At Hard Roof And Advance Area Prevention And Control Technology, Zheng Kaige, Wang Lintao, Li Bingang, Li Yanjun, Yang Huan, Yang Sen, Dai Nan, Wang Haojie, Wang Zeyang, Xi Jie

Coal Geology & Exploration

The overlying roof on the hard roof working bench is usually not likely to fall off, while tends to form dynamic pressure disaster. The stress evolution characteristics and roof breaking mechanism before and after hard roof weakening were analyzed and revealed using the methods of numerical simulation and theoretical analysis, and the advance area prevention and control technology were proposed and applied in the field practice, for the typical dynamic disaster problem of high mine pressure that was caused by the hard roof against the background of the Buertai Coal Mine in the Shendong Mine Area. As indicated by the …