bluuebunny/crossref_metadata_2025 huggingface dataset:
Flexible Hybrid Electronics on Wearable Healthcare Application
Authors: Chen Ming-Hung , Chang Wei-Hao , Pi Tun-Ching , Lee Wei-Chun , Kao Jen-Chieh , Yeh Yung-I
Published: March 2024

24/7 real-time body signal monitoring for decease check and life quality enhancement is becoming a megatrend these years. However, the precious yet limited clinical facility

and medical professionals cannot fulfill the emerging needs out-of-

hospital. A wearable device such like smart watch utilizing

biosensor-integrated System-in-Package (SiP) module can

provide a real time and personal-based bio data collection as well as better health management through AI assistance. For

performing a more comfortable experience, flexible hybrid electronics with ECG SiP embedded was proposed with lower

profile and higher structure flexibility. The patch durability by 100,000 times rolling test as simulating daily use condition was also examined.
Influence of Thermally Aged Underfill on Flip-Chip Packages
Authors: Cox Kevin , Abu-Hamdeh Ghassan , Borden Matt
Published: March 2024

Underfill material plays a crucial role in flip-chip package reliability, thus it necessary to accurately understand

the mechanical properties. The material itself is nonlinear and

is dependent on degree of cure, temperature, strain rate and thermal aging, among others. In this work, two underfill materials were characterized for thermal expansion and viscoelastic properties over a wide temperature range. A second

set of each material was thermally aged through flip-chip

processing steps and 250 thermal cycles and then characterized.

Temperature dependent thermal expansion and timetemperature

dependent moduli curves were generated to

represent each material type. These material models were then implemented into a nonlinear finite element model of a flip-chip package to evaluate package stress interaction through

processing steps and thermal cycling. The influence that each

underfill material had with and without thermal aging was analyzed with respect to typical package failure mechanisms.
Process Window of Mini-LED Display Panel Packaging using Laser Assisted Bonding Technology
Authors: Eom Yong-Sung , Choi Gwang-Mun , Jang Ki-Seok , Joo Ji-Ho , Lee Chan-Mi , Oh Jin-Heuk , Moon Seok-Hwan , Choi Kwang-Seong
Published: March 2024

For high-resolution display panels using mini-LEDs, high alignment accuracy and high yield of LED transfer and bonding technology are very important parameters of packaging technologies. These

parameters of packaging technologies are highly dependent on the interconnection material and bonding process. The use of laser assisted bonding (LAB) technology and epoxy-based interconnection materials has been introduced in mini-LED display panel packaging to improve bonding accuracy and yield. The bonding process of the entire display panel was performed by a tiling SITRAB process because the laser irradiation area is smaller than the LED bonding area on the substrate. For the SITRAB process, an

epoxy-based SITRAB material to remove oxide on the surface of solder bump has been developed as a

solvent free material. For good wetting of the solder bump during the SITRAB process, the temperature of the solder bumps must be higher than the melting temperature of solder. In general, the stage temperature of the laser process is determined to be around 100C in order to minimize the laser power.

However, if the stage temperature is high, the initial properties of the SITRAB material (such as low

viscosity and deoxidation function) may be lost due to the high temperature. In this study, the process

window of the SITRAB material was determined for a stable SITRAB process. The process window was

identified according to three different pot lifes: room temperature pot life (RPL), stage pot life (SPL), and laser pot life (LPL).
Characterization of a Novel Cost-efficient and Environmentally Friendly Graphene-enhanced Thermal Interface Material
Authors: Harr (Martinsen) Kristoffer , Guo Sihua , Chen Jiajia , Nkansah Amos , Shen Zhiyang , Murugesan Murali , Zhang Hongfeng , Almhem Lars , Ahtonen Arto , Chen Jin , Liu Johan
Published: March 2024

With the continuous development of electronic devices, effective heat dissipation has become a major factor affecting service life. Thermal interface materials (TIM) play a key role in controlling heat dissipation of electronic devices and have thus attracted widespread attention. In this study, we used

graphene flakes (GF) derived from graphene film that is wasted during the preparation of commercial large-scale graphene-enhanced TIMs as thermally conductive fillers to formulate a new TIM. The thermal conductivity of the developed TIM is 50% higher with GFs than without. Furthermore, the TIM has a tensile strength of 0.46 MPa with an elongation at break of 1225%, a maximum compression strength of 0.64 MPa at 50% compression, and high mechanical cycle stability. This report provides a cost-efficient and environmentally friendly approach

to producing high-performance TIMs for electronic cooling applications.
Practical Study to Demonstrate an Increase in the Reliability of Flip Chip Connections by Adding Nanoparticles to Solder
Authors: Harvey David M. , Manzanera Teresa Partida , Baishya Kangkana , Zhang Guangming , Arif Mohd Arif Anuar Mohd Salleh , Chan Y. C. , Ekere Nduka , Braden Derek
Published: March 2024

The aims of the research are to improve the

reliability and lifetimes of solder joints to contribute to the green economy, by reducing waste and extending recycling times. The objectives of the work are; to improve the materials properties

of various solders used for attaching die/flip chip packages to

PCBs by adding nanoparticles to the mix, to fabricate industrial test samples using flip chips soldered to PCBs, to test the

reliability of the solder through accelerated testing, to examine

failure modes and lifetime extensions.
Initial Life Test of Silicone Encapsulated FR 4 Printed Circuit Boards for Pre-Clinical Active Implants
Authors: Lancashire Henry T. , Ali Ishpa , Xue Fei , Henriquez Carlos Perez , Niederhoffer Thomas , Idil Ahmad Shah , Jiang Dai
Published: March 2024

Silicone encapsulated FR 4 printed circuit boards may provide a rapid solution for protecting pre-clinical prototype implant electronics. Interdigitated electrodes (IDE s)

with and without solder coating were manufactured on Cu-FR 4 laminates and silicone encapsulated (N = 14). IDEs were aged in saline and change in impedance was measured. Solder coated IDEs had stable 1 kHz impedances throughout the aging period with promising lifetimes for pre-clinical prototypes. A single

uncoated IDE failed with a fall in impedance and verdigris. Other uncoated IDEs showed increasing impedance and dark

copper(II) oxide. Failures attributable to contaminants and

moisture ingress are under investigation.
Enhanced Reliability for Power Modules via a New Ag/Si Sinter Joining Strategy
Authors: Liu Yang , Chen Chuantong , Nakayama Koji S. , Ueshima Minoru , Sakamoto Takeshi , Takuya Naoe , Nishikawa Hiroshi , Suganuma Katsuaki
Published: March 2024

In this work, with an appropriate adding amount of 20 vol% Si, the novel Ag-Si sintering demonstrated

enhanced reliability during thermal shock cycling, specifically including the improved bonding strength stability as well as good microstructure maintenance. The high reliability can be attributed to the reduced CTE value of composited Ag-Si

sintering inhibition of thermomechanical stress generation,

allowing for the ultra-stable joining structure without

coarsening, delamination and deformation. Additionally, the

well-adhered interface between sintered Ag and Si additive was also verified by examining the microstructure, ensuring the reliable bonding characteristics of the Ag/Si sintered joint.
Pick and Place of Sensitive Chips with Vacuum-Free Gecomer® Tools
Authors: Lorenz Lukas , Ludewig Thomas , Swiecinski Kai Chong , Ollmann Henrik , Razkordanisharahi Amirabbas , Bock Volker
Published: March 2024

To cope the lack of suitable pick and place methods for sensitive chips, we present a new process using a

gripper tool from the company INNOCISE called Gecomer®.

The tool, made of polymer pillars, is using Van der Waals forces to create adhesion between the gripping tool and the chip surface. Hence, the tool works without any vacuum. While

placing, the Van der Waals interactions are reduced by buckling those pillars resulting in a decreased contact area. The challenge

is to find the right parameters to avoid a re-gripping of the chip during the Gecomer®-movement away from the chip. In this

paper we present results on the placement accuracy including the reproducibility compared to a standard vacuum tool for different process parameters. For that, we used a pick and place machine with built-in inspection camera to examine the deviation from the target position. It is revealed that both

vacuum and polymer gripper have a similar deviation of

approx. ±15 μm. Hence, the placing accuracy is not negatively influenced by the Gecomer® tool and depends only on the

machine parameters. Furthermore, we analyze the surfaces of the chips, whether there are any residues of the gripping tool. In

a first optical inspection, no damages or residues could be found.

The new vacuum-free pick and place process has the potential to open new opportunities in the assembly of sensitive (MEMS)-

chips regarding reproducibility, accuracy, and process throughput.
Analysis and Characterization of Castellated Holes as RF Interconnects for Modular Millimeter-Wave Devices
Authors: Perlwitz Paul , Tschoban Christian , Ndip Ivan , Pötter Harald , Schneider-Ramelow Martin
Published: March 2024

This paper presents an innovative approach to the use of Castellated Holes or Plated Half Holes (PHH) as transmission elements for high frequency interconnections

between printed circuit boards in a frequency range of up to 40 GHz. The basic design was examined using commonly used

design parameters for PCB modules with Castellated Holes which were then investigated and subsequently optimized to

improve their RF performance, with a particular focus on

design considerations according to today’s industrial manufacturing capabilities. Therefore the FEM-based full wave

simulation technique was used to compare and optimize the design parameters in the aim to improve the capability of PHHs

as low-loss, low-disturbant RF interconnection alternative in

modular PCB designs. Based on these results test samples were

developed, which were subsequently measured and thus verified the findings of the simulation. To provide a general

comparability, this study focused on the S-Parameter to

quantify the performance in terms of transmission losses and reflection. With an optimized design feasible results were

achieved with a maximum transmission loss of less than 2 dB at

the maximum of the desired frequency range and about 1dB at 20 GHz over the entire signal path. These insights make PHHs suitable for seamless integration into modular designs in RF and millimeter-wave applications.
High Speed Transmission Characteristics on Glass Based Interposers
Authors: Kuramochi Satoru , Tanaka Masaya , Tai Takahiro
Published: March 2024

Interposers for system in package will became more and more important for advanced

electronic systems. As the industry moves toward HPC

(High Performance Computing) for huge data transmission with low power consumption. The major engineering requirements for HPC application are highdensity,

high speed data transmission, low loss, precision

manufacturing and low cost. On the 2.5D heterogenous

package structure, key technology is fine wiring connected with CPU chip and HBM chips. The fine wires

needed high speed transmission.

This paper presents the demonstration of Glass-based twin type interposers, Glass interposer with fine pitch metalized through via and RDL interposer with low loss dielectrics on Glass carrier. We compare twin types of Interposes fabrication process capability with panel size format 300x400mm. Finally, we compare the

transmission characteristics using eye diagram for

heterogenous integration application.

Glass Interposer has low loss glass via, it is effective vertical interconnection. RDL interposer has low loss dielectric layers, excellent transmission characteristics

obtained on fine pitch trace area.
Adhesive Solutions for Closed Cavity Packaging
Authors: Schirmer Patrick , Ringelstetter Severin
Published: March 2024

The trend towards autonomous driving demands continuously increasing safety requirements and hence reliable

components such as CMOS image sensors or communication

devices. To provide such components, manufactures are facing ever greater challenges as the sensor packages need to be airtight

sealed over their whole lifetime. Typical defects that can be observed when using conventional lid attach materials for closed cavity packages in tests at automotive level (e.g., according to AEC Q100) are pop-up effects and delamination. To avoid these defects

and to meet the increasing reliability requirements of the

semiconductor industry, DELO Industrial Adhesives has developed special adhesives that not only ensure reliable bonding

while keeping narrow and high bondlines, but also improve process stability. Features such as light/heat B-stage or light fixation help to keep the attached lid in place during heat curing

and other subsequent steps like temperature cycling, humidity storage and even reflow.
Advances in Parylene Adhesive Bonding for the Realization of Biocompatible Microsystems
Authors: Selbmann Franz , Roscher Frank , Wiemer Maik , Kuhn Harald , Joseph Yvonne
Published: March 2024

Wafer to wafer and chip to wafer bonding technologies are a key enabling processes for the fabrication of

microsystems. The presented paper focuses on the latest

research results of Parylene adhesive bonding. Given the

established wafer bonding processes based on Parylene C in vacuum, research on how the bonding process alters the

Parylene material was performed using x-ray diffraction.

Doing so, a significant increase of the crystalline fraction of Parylene was observed. In order to further develop the

Parylene bonding beyond its state of the art, new process

variants were successfully established with advanced features:

Wafer bonding using Parylene C at increased pressure; Wafer bonding using Parylene N and Parylene F, respectively, to

address a different bonding temperature range; as well as chip

bonding using Parylene C in air.
Laser-Assisted Bonding Approach for Photonic Integration Processes
Authors: Vlasov Aleksandr A. , Uusitalo Topi , Lepukhov Evgenii , Virtanen Heikki , Ojanen Samu-Pekka , Viheriälä Jukka , Guina Mircea
Published: March 2024

Current development trends concerning

miniaturizing of electronics and photonics systems are aiming at

assembly and 3D co-integration of a broad range of technologies

including MEMS, microfluidics, wafer level optics, and silicon photonics. To this end, on-chip integration using siliconphotonics

platform offers a wide range of possibilities

addressing passive optics functionality, active optoelectronic

devices, and compatibility with CMOS fabrication. On the other hand, the hybrid technology enabling volume manufacturing of

such system-on-chip components it is still in an early

development stage. In this work, the original LAB setup with a coaxial bottom irradiation architecture was developed. The

setup allows a rapid and energy-effective process with the ability to produce successful electrical bonds with negligible thermalinduced

stress and warpage to bonded surfaces. The proposed

machine-vision based temperature sensor is validated for photonic integration assembly processes.
Application of Reactive Bonding Methods on LTCC Substrates
Authors: Wiss Erik , Schulz Alexander , Yuile Adam , Mueller Jens , Wiese Steffen
Published: March 2024

This paper discusses the application of reactive bonding for the area of Low Temperature Cofired Ceramics (LTCC) assemblies. The goal is to reduce the thermal-mechanical stresses during soldering by transferring heat only locally to the solder joints without heating the entire component. Such a reactive multilayer system (RMS) consists of alternating nanolayers (10-300 nm) of at least two metal components which produce an exothermal reaction after ignition. Although the deposition of an RMS is established on silicon substrates for the use in micro-electromechanical systems (MEMS), it is very challenging to create them on LTCC substrates. One of the main obstacles is to overcome all issues connected with the significant roughness, becasue it is not an optimum territory to deposit nanolayers. In this paper, different methods like chemical mechanical polishing (CMP) and laser ablation, to modify the surface morphology, are presented. A direct relation between the morphology and the exothermal reaction can be observed. In addition, 3-D Computational Fluid Dynamics (CFD) simulations were conducted to analyze the process in more detail. These simulations make use of a shoebox model with different layers and an adjustable user-defined function for the heat release of the RMS to adapt the reaction front velocity and the combustion temperature to the experimental values.
A Nationwide Study on HER2-Low Breast Cancer in South Korea: Its Incidence of 2022 Real World Data and the Importance of Immunohistochemical Staining Protocols
Authors: Kim Min Chong , Cho Eun Yoon , Park So Yeon , Lee Hee Jin , Lee Ji Shin , Kim Jee Yeon , Lee Ho-chang , Yoo Jin Ye , Kim Hee Sung , Kim Bomi , Kim Wan Seop , Shin Nari , Maeng Young Hee , Kim Hun Soo , Kwon Sun Young , Kim Chungyeul , Jun Sun-Young , Kwon Gui Young , Choi Hye Jeong , Lee So Mang , Choi Ji Eun , An Ae Ri , Choi Hyun Joo , Kim EunKyung , Kim Ahrong , Kim Ji-Young , Shim Jeong Yun , Gong Gyungyub , Bae Young Kyung
Published: March 2024

Purpose Notable effectiveness of trastuzumab deruxtecan in patients with human epidermal growth factor receptor 2 (HER2)–low advanced breast cancer (BC) has focused pathologists’ attention. We studied the incidence and clinicopathologic characteristics of HER2-low BC, and the effects of immunohistochemistry (IHC) associated factors on HER2 IHC results.Materials and Methods The Breast Pathology Study Group of the Korean Society of Pathologists conducted a nationwide study using real-world data on HER2 status generated between January 2022 and December 2022. Information on HER2 IHC protocols at each participating institution was also collected.Results Total 11,416 patients from 25 institutions included in this study. Of these patients, 40.7% (range, 6.0% to 76.3%) were classified as HER2-zero, 41.7% (range, 10.5% to 69.1%) as HER2-low, and 17.5% (range, 6.7% to 34.0%) as HER2-positive. HER2-low tumors were associated with positive estrogen receptor and progesterone receptor statuses (p < 0.001 and p < 0.001, respectively). Antigen retrieval times (≥ 36 minutes vs. < 36 minutes) and antibody incubation times (≥ 12 minutes vs. < 12 minutes) affected on the frequency of HER2 IHC 1+ BC at institutions using the PATHWAY HER2 (4B5) IHC assay and BenchMark XT or Ultra staining instruments. Furthermore, discordant results between core needle biopsy and subsequent resection specimen HER2 statuses were observed in 24.1% (787/3,259) of the patients.Conclusion The overall incidence of HER2-low BC in South Korea concurs with those reported in previously published studies. Significant inter-institutional differences in HER2 IHC protocols were observed, and it may have impact on HER2-low status. Thus, we recommend standardizing HER2 IHC conditions to ensure precise patient selection for targeted therapy.
Graphs of curves and arcs quasi-isometric to big mapping class groups
Authors: Schaffer-Cohen Anschel
Published: March 2024

Following the works of Rosendal and Mann and Rafi, we try to answer the following question: when is the mapping class group of an infinite-type surface quasi-isometric to a graph whose vertices are curves on that surface? With the assumption of tameness as defined by Mann and Rafi, we describe a necessary and sufficient condition, called translatability, for a geometrically non-trivial big mapping class group to admit such a quasi-isometry. In addition, we show that the mapping class group of the plane minus a Cantor set is quasi-isometric to the loop graph defined by Bavard, which we believe represents the first known example of a hyperbolic mapping class group that is not virtually free.
Proper proximality among various families of groups
Authors: Ding Changying , Kunnawalkam Elayavalli Srivatsav
Published: March 2024

In this paper, the notion of proper proximality (introduced by Boutonnet, Ioana, and Peterson [Ann. Sci. Éc. Norm. Supér. (4) 54 (2021), 445–482]) is studied and classified in various families of groups. We show that if a group acts non-elementarily by isometries on a tree such that, for any two edges, the intersection of their edge stabilizers is finite, then

G

is properly proximal. We show that the wreath product

G\wr H

is properly proximal if and only if

H

is non-amenable. We then completely classify proper proximality among graph products of non-trivial groups. Our results generalize the recent work of Duchesne, Tucker-Drob, and Wesolek classifying inner amenability for these families of groups. Our results also recover some rigidity results associated to the group von Neumann algebras by virtue of being properly proximal. A key idea in the proofs of our theorems is a technique to upgrade from relative proper proximality using computations in the double dual of the small at infinity boundary.
Optimal and instance-dependent guarantees for Markovian linear stochastic approximation
Authors: Mou Wenlong , Pananjady Ashwin , Wainwright Martin J. , Bartlett Peter L.
Published: March 2024

We study stochastic approximation procedures for approximately solving a

d

-dimen­sional linear fixed-point equation based on observing a trajectory of length

n

from an ergodic Markov chain. We first exhibit a non-asymptotic bound of the order

t_{\mathrm{mix}}\frac{d}{n}

on the squared error of the last iterate of a standard scheme, where

t_{\mathrm{mix}}

is a mixing time. We then prove a non-asymptotic instance-dependent bound on a suitably averaged sequence of iterates, with a leading term that matches the local asymptotic minimax limit, including sharp dependence on the parameters

(d, t_{\mathrm{mix}})

in the higher-order terms. We complement these upper bounds with a non-asymptotic minimax lower bound that establishes the instance-optimality of the averaged SA estimator. We derive corollaries of these results for policy evaluation with Markov noise—covering the

\mathrm{TD}(\lambda)

family of algorithms for all

\lambda \in [0, 1)

—and linear autoregressive models. Our instance-dependent characterizations open the door to the design of fine-grained model selection procedures for hyperparameter tuning (e.g., choosing the value of

\lambda

when running the

\mathrm{TD}(\lambda)

algorithm).
Tax Exemptions, Spaghetti, and the Devil: The Perils of Ambiguous Limitations on Religion and a Proposed Definition for Legally Acknowledged Systems of Faith
Authors: Cho Hyun Jai
Published: March 2024

This paper will analyze the scope of what the United States legal system as well as their international counterparts recognize and therefore, define as religion (part 2), to develop an argument supporting the potential need for limitations on unorthodox religions in the modern era (part 3) as exemplified in the instances of the following: the practice of LaVeyan Satanism, Scientology, and Pastafarianism (part 4). For the purposes of specificity, the following analysis will focus on the United States government and federal courts’ opinions regarding the topic at hand.
Prawo europejskie a polska tożsamość konstytucyjna (aspekty prawno-polityczne)
Authors: Wawrzyniak Jan
Published: March 2024

The article’s research aims to answer whether constitutional identity (as well as numerous doctrinal studies concerning constitutional identity) may substantially help solve problems regarding the relationship between European law and national law. The article discusses the hypothesis that the identity and the studies multiply doubts and uncertainty rather than answer the pragmatic questions in constitutional law. The author deals with identity as a social construct and convention created by academics and constitutional courts. Identity belongs primarily to the dictionary of academic language. It is rarely used in normative acts, in particular in constitutional provisions. The constitutional identity seems to be also vague and controversial for the author. Nevertheless, studies on identity may – as the article suggests – realise at least one (constitutionally important) aim. It is a better self-consciousness of constitutional law scholars, which may help them – at the end of the day – to discuss the relationship between European law and national law in more and more precise terms.
KARAKTER GURU ISLAM DAN BARAT (Analisis Komparatif Pemikiran Imam az-Zarnuji Dan John Dewey)
Authors: Dariyanto  , Ibnu Soleh Muhammad , Amaliya Majid Fitri
Published: March 2024

This research aims to conduct a comparative analysis of the character of teachers in Islam and the West through the thoughts of Imam az-Zarnuji and John Dewey. Imam az-Zarnuji was an Islamic scholar and educator who lived in the 12th century AD, while John Dewey was a Western philosopher and educator who lived in the early 20th century AD. These two figures have different views on education, but both have made significant contributions to the development of educational thought. This study adopts a descriptive-analytical approach to analyze Imam az-Zarnuji and John Dewey's views on teacher character in the context of Islamic and Western education. Through analysis of the texts by these two figures, we identify similarities and differences in their conceptions of the characteristics and role of a teacher. The research results show that Imam az-Zarnuji emphasized the importance of diversity in the characteristics of a teacher, including wisdom, patience and religious exemplification. Meanwhile, John Dewey emphasized the importance of direct experience and a scientific approach to teaching, as well as the role of the teacher as a facilitator of learning. From this analysis, it can be concluded that although there are differences in cultural context and thought, the concept of teacher character in Islam and the West has striking points of similarity, such as the importance of morality, wisdom, and dedication in teaching. However, practical approaches and learning methodologies may vary according to individual cultural and philosophical contexts. It is hoped that this study will provide deeper insight into the character of teachers in Islam and the West, as well as contribute to the development of cross-cultural and inter-religious education. In addition, this research also provides a foundation for a better understanding of the principles underlying educational practices in various global contexts
On Classical Multiplier Sequences
Authors: Al-Hamdani Summer , Leon Alexandra
Published: March 2024

We provide the detailed proofs of two recent claims of Csordas and Forgács asserting that two particular Bessel-type functions generate classical multiplier sequences whose generic terms are Cauchy-products of Laguerre polynomials and hypergeometric functions, respectively. The way these sequences are generated involves functions from the Laguerre-Pólya class. We address the question whether these functions are unique in any way as generators of a given classical multiplier sequence.
Grim on Complete Multipartite Graphs
Authors: Barretto Sam , Basi Jagdeep , Miyake Matthew
Published: March 2024

Grim is a deletion game played on the vertices of a graph. In this paper we will examine strategies for when Grim is played on complete multipartite graphs.
Diplomatic Dynamics of International Treaty Negotiations
Authors: Dong Tianhang , Zeng Robin , Ma Timmy
Published: March 2024

The negotiation process of international treaties is heavily influenced by socioeconomic factors. In this paper, we aim to answer the question of how to quantify the influential factors among countries. We do so by categorizing them into different interest groups based on their attitudes towards the treaty as well as their socioeconomic statuses and modeling the movement of countries between these interest groups. This model is based on an epidemiological approach to quantifying influence. Through our research, we discovered two equilibrium points, which reveal the conditions under which all countries would either support or oppose a treaty. We also ran simulations under several hypothetical scenarios under which equilibria would occur, demonstrating the practical applications of our model. We further analyze the model's real life application and the influence of certain parameters through two case studies: the first is on the Basel Convention's negotiation process and the second is on the spread of carbon pricing.
On the Monotonicity of the Number of Positive Entries in Nonnegative Four Element Matrix Powers
Authors: Brower Cole Rubin , Ponomarenko Vadim
Published: March 2024

Let A be a nonnegative square matrix of order m and let F(A) denote the number of positive entries in A. We consider conditions on A to make the sequence {F(An)}n≥1 monotone. This is known for F(A) ≤ 3 and F(A) ≥ m2-2m+2; we extend this to F(A)=4.
The Inverse Gamma Distribution and Benford's Law
Authors: Durst Rebecca F. , Huynh Chi , Lott Adam , Miller Steven J. , Palsson Eyvindur A. , Touw Wouter , Vriend Gert
Published: March 2024

According to Benford's Law, many data sets have a bias towards lower leading digits (about 30% are 1's). The applications of Benford's Law vary: from detecting tax, voter and image fraud to determining the possibility of match-fixing in competitive sports. There are many common distributions that exhibit such bias, i.e. they are almost Benford.

These include the exponential and the Weibull distributions. Motivated by these examples and the fact that the underlying distribution of factors in protein structure follows an inverse gamma distribution, we determine the closeness of this distribution to a Benford distribution as its parameters change.
Exploring the Effect of Chicano Studies Courses on Student Success at CSU Channel Islands
Authors: Brunk Avery , Lovekin Katherine , Martos Andrew , Soderlund Christina
Published: March 2024

California State University, Channel Islands (CSUCI) has long embraced the ideal of access to education while seeking to provide high quality degrees for its students. The success of obtaining Hispanic-Serving Institutions grants has been helpful in providing resources for programs offering educational interventions for both Hispanic students and for those from other backgrounds. We have seen anecdotal evidence that Hispanic students who enroll in Chicano Studies courses tend to find community and consequently success. In this project, we use the enormous storehouse of CSUCI data to explore the effectiveness of specific Chicano Studies courses on student success. We apply regression analysis, hypothesis tests for proportions, t-tests, and tests of independence to investigate the quantitative evidence for what we have seen anecdotally.
Permanents of 2 x 2 Matrices Modulo n
Authors: Bohra Ayush , Arikatla Satyanarayana Reddy
Published: March 2024

In this article we compute the number of invertible two by two matrices with integer entries modulo n whose permanents are congruent modulo n to a given integer x.
Generalizing Ruth-Aaron Numbers
Authors: Jiang Yanan , Miller Steven J.
Published: March 2024

A Ruth-Aaron number is such that the sum of its prime divisors, counted with multiplicity, equals the sum of the prime divisors of its successor. They have been an interest of many number theorists since the famous 1974 baseball game gave them the elegant name after two baseball stars. Many of their properties were first discussed by Erdős and Pomerance in 1978. We generalize their results in two directions: by raising prime factors to a power and allowing a small difference between the two sums. We prove the density of power Ruth-Aaron numbers is zero (we provide a precise bound in terms of iterations and powers of logarithms), and prove similar results for almost Ruth-Aaron numbers (these are pairs of integers such that the sum of their prime powers differ by a fixed, slowly growing function). Moreover, we further the discussion of the infinitude of Ruth-Aaron numbers and provide a few possible directions for future study.
The Limiting Spectral Measure for an Ensemble of Generalized Checkerboard Matrices
Authors: Chen Fangu , Lin Yuxin , Miller Steven J. , Yu Jiahui
Published: March 2024

Random matrix theory successfully models many systems, from the energy levels of heavy nuclei to zeros of L-functions. While most ensembles studied have continuous spectral distribution, Burkhardt et al. introduced the ensemble of k-checkerboard matrices, a variation of Wigner matrices so that entries in a checkerboard pattern are some fixed constant. In this family, N - k of the eigenvalues are of order square-root of N, and were called bulks, while the rest are tightly contrained around certain multiples of N and were called blips.

We extend their work by allowing the fixed entries to take different constant values. We can construct ensembles with blip eigenvalues at any multiples of N we want and with any multiplicity. For example, we can have the blips occur at sequences such as the primes or the Fibonaccis. The presence of multiple blips creates technical challenges to separate them and to look at only one blip at a time. We overcome this by choosing a suitable weight function which allows us to localize at each blip, and then exploiting cancellation to deal with the resulting combinatorics to determine the average moments of the ensemble; we then apply standard methods from probability to prove that almost surely the limiting distributions of the matrices converge to the average behavior as the matrix size tends to infinity. For blips with just one eigenvalue in the limit we have convergence to a Dirac delta spike, while if there are k eigenvalues in a blip we again obtain hollow k by k GOE behavior.
Manifolds With Bounded Integral Curvature and no Positive Eigenvalue Lower Bounds
Authors: Anderson Connor , Ramos Olivé Xavier , Spinelli Kamryn
Published: March 2024

We provide an explicit construction of a sequence of closed surfaces with uniform bounds on the diameter and on Lp norms of the curvature, but without a positive lower bound on the first non-zero eigenvalue of the Laplacian λ1. This example shows that the assumption of smallness of the Lp norm of the curvature is a necessary condition to derive Lichnerowicz and Zhong-Yang type estimates under integral curvature conditions.
Hurwitz Orbits of Equal Size
Authors: Pirillo Colin , Sabar Seth
Published: March 2024

We provide a variety of cases in which two factorizations have Hurwitz orbits of the same size. We begin with prototypical results about factorizations of length two, and show that cycling elements or flipping and inverting elements in any factorization preserves Hurwitz orbit size. We prove that "double reverse" factorizations in groups with special presentations have Hurwitz orbits of equal size, and end with applications to complex reflection groups.
Polynomial Generalizations of Knot Colorings
Authors: He Rachael , Ho Austin , Kalir Dorian , Miller Jacob , Zevenbergen Matthew
Published: March 2024

In the field of knot theory, knot invariants are properties preserved across all embeddings and projections of the same knot. Fox n-coloring is a classical knot invariant which associates to each knot projection a system of linear equations. We generalize Fox’s n-coloring by using two, not necessarily distinct, polynomials over a field F, which we say form a (g,f)F coloring. We introduce a sufficient condition, called strong, for a pair of polynomials to form a  (g,f)F coloring. We confirm a family of pairs of linear polynomials each of which form a (g,f)F coloring. We prove that there are no strong pairs containing an irreducible quadratic polynomial over a field F not of characteristic two. Furthermore, we find a method to produce polynomials with unbounded degree that form colorings over suitable fields.
Avoiding Small Monochromatic Distances
Authors: Waknine Tom
Published: March 2024

Is it true that for any coloring of the points of R in two colors there is an ε >0 such that one of the color classes contains pairs of points at every distance smaller than ε ? We show that the answer to this question is no.
Blowup of Solutions to a Damped Euler Equation with Homogeneous Three-Point Boundary Condition
Authors: Obi-Okoye Ikechukwu , Sarria Alejandro
Published: March 2024

It is known that solutions to the inviscid Proudman-Johnson equation subject to a homogeneous three-point boundary condition can develop singularities in finite time. Given the regularizing effect that damping can have, in this paper we consider the possibility of finite-time singularity formation in solutions of the generalized inviscid Proudman-Johnson equation with damping subject to the same homogeneous three-point boundary condition. In particular, we will derive criteria the initial condition must satisfy in order for solutions to blowup in finite time under the effect of a smooth time-dependent damping term.
Upper Bounds for the Hausdorff Dimension of Weierstrass Curves
Authors: Alexander Ted , Murphy Tommy
Published: March 2024

We produce an upper bound for the Hausdorff dimension of the graph of a Weierstrass-type function. Whilst strictly weaker than existing results, it has the advantage of being directly computable from the theory of hyperbolic iterated function systems (IFS).
A Motion Planning Algorithm in a Figure Eight Track
Authors: Jardon Cristian , Sheppard Brian , Zaveri Veet
Published: March 2024

We design a motion planning algorithm to coordinate the movements of two robots along a figure eight track, in such a way that no collisions occur. We use a topological approach to robot motion planning that relates instabilities in motion planning algorithms to topological features of configuration spaces. The topological complexity of a configuration space is an invariant that measures the complexity of motion planning algorithms. We show that the topological complexity of our problem is 3 and construct an explicit algorithm with three continuous instructions
Investigations in Patterns in Last Digits of Square Numbers and Higher Powers
Authors: Miller Steven J. , Wiley Elizabeth , Wiley Julia
Published: March 2024

It is interesting to see what patterns exist in the final digits of powers of integers; the goal of this work is to introduce some new problems and results, which are ideally suited for interested readers to pursue further. We start our investigation with squares and say a square is a k-square good number if its last k digits base 10 are the same non-zero number, and the last k + 1 digits are not identical. We completely analyze k-square good numbers; when k = 1 we can have final digits of 1, 4, 5, 6 and 9 (with the second to last digit different), when k = 2 we can end with 44 but not 444, when k = 3 we can end with 444 but not 4444, and there are no 4-square good numbers. We then generalize these arguments to look at k-cube and k-fourth good numbers, completely analyzing these cases. Noting that any even power 2m is the same as squaring an mth power, we can extend our results to even powers more easily than to odd, as the behavior has to be a subset of what we have seen for squares. There are complications arising from powers of 2 dividing our numbers, but using results from elementary number theory (in particular concerning the totient function and Euler’s theorem), we reduce the problem for even powers to a tractable finite computation, and completely resolve this case, and then end with a list of accessible next problems.
Zoonotic Diseases: A Changing Landscape Demands Global Action
Authors: Naithani Priyanka , Bahurupi Yogesh , Singh Meenu
Published: March 2024

During recent years, the globe-wide zoonotic disease landscape has evolved drastically posing significant challenges to the health of the individual and environmental sustainability. Zoonotic illnesses, which occur in animals and are transmission-capable to people, have been an ever-present risk throughout history. According to the “World Health Organization (WHO)”, an estimated 60% of known infectious diseases and around 75% of new or emerging infectious diseases are zoonotic in origin. These illnesses have the potential to inflict widespread morbidity and mortality, along with severe economic losses. However, today's dynamics of our changing environment, which include urbanization, climate change, and growing human-animal interaction, are increasing the probability of zoonotic spillover occurrences. (1) The worldwide spread of the consequences of zoonotic illnesses underscores the critical need for collective effort through international leadership frameworks integrating government, private industry, and civil society. “The Global Health Security Agenda (GHSA)” and the WHO are collaborating on projects to address these concerns and improve global health security. The WHO launched the "One Health Joint Plan of Action," which intends to inscribe health hazards to humans, animals, plants, and the environment. It emphasizes the interconnection of human, animal, and environmental health. (2)
Influence of feeding practices on Childhood illness
Authors: Lokesh Nagendra , Kulkarni Praveen , Basheer Sayana , Rajaram Pragadesh , Anbu Vanmathi , Kumar Doddaiah Sunil
Published: March 2024

Background: The phase between a child's birth and the age of two years is crucial for ensuring the child’s growth and development through optimal feeding habits. Breastfeeding is considered one of the most effective methods for ensuring the health and survival of children. Aim & Objective: This study aims to access the influence of feeding practices on childhood illness. Methodology: A cross-sectional study was done among 280 mothers having children less than 2 years of age attending primary health centres adopted by the Department of Community Medicine JSS medical college, Mysuru. Data regarding feeding practices and childhood illnesses were collected using a pre-tested questionnaire prepared based in Infant and Young Child Feeding guidelines by interviewing the mothers. Result: Among the study population, 75.4% of children in urban and 75.7% of children in rural suffered from childhood illness. It was observed that childhood illness was more common among children with poor feeding practices (75.7% in rural and 93.5% in urban) and the association was found to be statistically significant. Conclusion: The study sheds light on the importance of appropriate feeding practices, which have a higher influence on a child's health.
Prediksi Beban Daya Listrik (W) Menggunakan Metode Support Vector Machine (SVM) Pada Listrik Token Rumah Tangga
Authors: Dwi cahyo Andika , Anardani Sri , Yuda Yoga Prisma
Published: March 2024

Electricity is an essential need that cannot be separated from daily human life, especially in the modern era where many devices require electrical energy. The demand for electrical energy is increasing over time, thus the electricity providers must have sufficient capacity to meet the demand. However, there is still a lot of wasted energy due to the mismatch between the demand and the supplied amount of electricity, leading to significant electricity wastage. In this regard, appropriate calculations are needed to determine the amount of electrical power required, hence the need for a prediction method to determine the required power in real-time. The Support Vector Machine method is expected to predict the electrical load accurately, enabling users to determine the required load for the next period. It is hoped that this prediction will achieve an accuracy rate above 85%.
Dinâmica de acumulação de canabinoides e o potencial anti- inflamatório de raiz, caule, folha e flor de plantas femininas e masculinas de maconha (Cannabis sativa L.)
Authors:   , Espósito Laura Grandíllia Araújo
Published: March 2024

A maconha (Cannabis sativa L.), ou cânhamo, industrialmente tem muitas aplicações, dentre elas a produção de têxteis, extratos agrícolas, produtos nutricionais enriquecidos com canabinoides e terpenos, naturalmente presentes na planta. Neste estudo, objetivou-se avaliar a dinâmica da distribuição e da acumulação dos 11 principais fitocanabinoides presentes nos tecidos de raiz, caule e folha de plantas femininas e masculinas, e flores de plantas femininas, bem como a sua bioatividade anti- inflamatória. Pretende-se, assim, contribuir com a tomada de decisão do melhor local e momento para a colheita, visando determinado fitocomposto, levando ao possível incremento da produtividade por planta, dos teores dos canabinoides de interesse, bem como contribuir no suporte para a produção de finalidade terapêutica, considerando seu potencial anti-inflamatório. Ao determinar o perfil fitoquímico dos extratos integrais de diferentes tecidos de plantas masculinas e femininas de maconha, foram observadas maiores concentrações dos canabinoides nos tecidos das plantas femininas (de 30-50%), sendo os maiores níveis registrados nos tecidos de flores, para a maioria dos canabinoides quantificados (CBDA; CBG; CBD; ∆9-THC; THCA). À exceção, o CBDV e o CBN apresentaram concentrações semelhantes em tecidos de folhas oriundas de plantas masculinas e femininas e o THCV e CBC apresentaram maiores teores em tecidos de plantas masculinas. A maioria dos canabinoides não foi detectada nos tecidos de raízes, embora baixas concentrações de canabinoides (CBDA e THCA) nas raízes de ambos os sexos tenham sido observadas, especialmente considerando a moderada capacidade anti-inflamatória dos extratos radiculares. Enquanto em todos os extratos de tecidos da espécie tenham sido observadas propriedades anti-inflamatórias moderadas, nos de flores femininas foram detectadas as maiores atividades. Associada ao CBD, foi observada a atividade anti-inflamatória mais forte, com a supressão da produção de óxido nítrico em 2 μg/mL, e as expressões reduzidas dos genes pró- inflamatórios COX-2, IL-6 e TNF-α em concentrações tão baixas quanto 2 ng/mL. Os extratos totais das inflorescências tópicas de maconha (1–50 μg/mL) e CBD sozinho (20–200 ng/mL) também estimularam respiração mitocondrial. Esses dados auxiliam o desenvolvimento de técnicas de manejo agrícola para a produção de maconha com perfis metabólicos específicos, a fim de apoiar seletivamente o campo da saúde, fornecendo informações qualificadas sobre este insumo industrial. Palavras-chave: Cannabis sativa; Cânhamo; Maconha; CBD; Anti-inflamatório.