Public Articles

FPGA Lab 8

Lab 8 explored the use of an RS232 port to communicate between the FPGA and pieces of circuits that are off of the board. I was able to compile a circuit which listened to the port and transmitted the incoming signal back over the RS232 port to display it on the serial port of a computer. This lab was very useful in showing how one would connect an FPGA to more complicated circuitry and transmit data between the two, allowing the FPGA to add as a central microprocessor for a more complicated lab.

FPGA Lab 7

Lab 7 instructed me to build an 8-bit triangle-wave and sine-wave generator. After building the triangle-wave generator I designed a sine-wave generator by using the output of the triangle wave as the read address for a ROM block which had the appropriate values in order to generate a since wave over the correct period. This lab was extremely useful in demonstrating how one can use a ROM block in order to save data that needs to be reproduced at a later time, an extremely common task in designing complicated circuits.

Authorea & Sumit Proposal

and 2 collaborators

#Introduction

- Knowledge transfer is one of the key aspects of understanding the world, as we pass on learnings from one generation to the other.
- International development is one of the critical sectors that needs major improvement in the way that we create, share, and apply knowledge.
- This is because international development, encapsulates our efforts to improve the basic living conditions and opportunities of marginalized and underserved people around the world.

FPGA Lab 6

Lab 6 instructed us to design a digital to analog converter in order to generate a square wave which would drive a speaker connected to the supplied FPGA. We also needed to be able to set the amplitude of the generated signal using the DIP switches present. This lab was very useful to show the basic theory behind digital to analog converters which need to turn digital values into actual signals. Also, this square wave generator is very useful in creating complicated audio signals which are composed of square waves of varying frequency.

FPGA Lab 5

Lab 5 instructed us to design a stopwatch using the supplied FPGAs. The circuit needed to be able to increment every tenth of a second and track the number of minutes and hours that had passed. While I was instructed to make a three-state machine that is driven by one button that causes the timer to stop/stop/reset in that order. However, I implemented a two-state system and attached the reset functionality to a second button in order to reflect the design of stopwatches that I had encountered. This lab was very useful in demonstrating the steps that are involved when creating a complete circuit. This included designing state machines as well as importing modules previously defined as external libraries which are extremely common when designing circuits.

FPGA Lab 3

Part 1 of this lab involved the implementation of a simple counter using a Quartus Megafunction. After hooking up the counter to the FPGA’s onboard clock, I tested that the counter worked as intended. Then, using Quartus’s simulation features, I was able to look at the individual logic states of the parts of my logic both by tying the line to an output line on the board as well as using registers which were able to provide byte level inspection at any location on the board. Using an iPhone, I was able to record the clock as it incremented. In the 10 seconds I recorded the counter, it incremented 1.99 × 10^{9} times which gives the clock a period of

$\frac{10}{1.9\times10^9} = 50.25 MHz$

Which is pretty close to the 50 MHz that is expected by the FPGA.

After timing the clock, I simulated its performance using the Quartus simulator and verified that the counter incrememented to the right value at the right time.

The 2^{nd} part of the lab involved the creation of a binary-coded decimal counter which was made out of 5 up counters with a modulus of 10 as described in Section 2.2. In order to drive the system every hundredth of a second, I connected the FPGA’s CLOCK_50 to a modulus 500000 counter whose cout went high at the desired frequency.

Part 3 of the lab involved the creation of a 4 bit counter from elementary gates and a D flop. I did use a Quartus megafunction in order to create a modulus counter that would drive the system every second. In constructing this diagram, I needed to create a 1 bit adder without a carry-in (done with an xor and and) 1 bit multiplexer (created with an inverter) which acts as the carry-in for the counter as a whole.

Happy Valentine's Day!

and 1 collaborator

**Words are important.
**

**Passion, love, discovery,
**

**And when we write,
**

**To Love, passion, discovery. To words.
**

Happy Writing,

- Matteo and The Authorea Team

FPGA Lab 4

Lab 4 emphasized common situations that one would encounter when building complex digital circuits. The first part looked at positive edge triggers which are a very useful way of getting a short pulse to start the logic for a particular circuit without having to worry about the length of time with which the original signal is high. The second part applied this positive edge trigger in the context of a debouncing element which is an extremely useful cirtcuit when using a switch or some other imperfect interface to start your circuit. And finally, the third section illustrated the ability of quartus to design submodules that can be replicated without the need to think about the underlying logic. This capability is extremely powerful and increases the overall readability and reusability of the designs.

FPGA Lab 1 and 2

These labs covered the basics of implementing digital circuitry using a field-programmable gate array (FPGA). We reviewed how one builds the program in Quartus and compiles it onto the FPGA. We also reviewed how one can constructs complex circuits very easily in Quartus and show the result using a 7-segment display. This lab was very helpful in providing the necessary building blocks for future projects involving FPGAs as it showed how one can encode the necessary logic to execute a desired task.

Planes toy models

The standard picture of the evolution of substructure in the Universe involves the collapse of dark matter into halos, which may host luminous galaxy. Such halos may exist within the bounds of larger halos; in these cases the galaxies they may host are typically called satellite galaxies, and their evolution differs substantially from galaxies that are not satellites in ways not fully understood. Analysis of the spatial and kinematic distributions of such galaxies can inform our ideas of how satellites and the systems in which they are found evolve. Substantial evidence exists that satellite galaxies are not isotropically distributed around their hosts. \cite{West2000,Bailin_2008}. This is also seen in simulations; subhaloes of hosts typically are typically distributed anisotropiclly in both position and velocity space \cite{VDB99,Knebe,Zentner_2005,Faltenbacher_2010}.

Local group satellites are highly anisotropically distributed both around the Milky Way and M31. The disk-like arrangement of MW satellites was first pointed out by \citet{Lynden-Bell74}. Later studies argued further for the existence of a disk-like structure of Milky Way satellites \cite{Metz07,Metz09}, and argued that the MW satellite disk was rotationally supported \cite{Metz08}. \citet{Kroupa_2005} further argues that the distribution of satellite galaxies around the MW is not predicted by LCDM. Around M31, dramatic evidence has been found for a disk of satellites, many of which exhibit coherent rotation along the line of sight \cite{Ibata_2013}. The M31 structure seems particularly difficult to square with our picture of galaxy evolution; \cite{Ibata_2014} argues that \cite{Ibata_2014} that alignments similar to the one found around M31 are essentially non-existant in numerical simulations.

Much recent work has gone into investigating the possibility of similar satellite distributions around galaxies outside of the local group. Recently, work by \citet{Ibata_2014} (hereafter I14) pointed to the possibility of corotation seen in diametrically opposed satellite pairs in Sloan Digital Sky Survey (SDSS), finding 20 out of 22 oppositely aligned satellite pairs corotating along the line of sight. This result was contested by \citet{Cautun14}, arguing that the results of \citet{Ibata_2014} are strongly dependant on selection criteria and are not robust. The original authors then claimed that less-massive satellites than originally considered exhibit a spacial over-density consistent with the claimed existence of co-rotating sturctures frequently seen in SDSS \cite{2014arXiv1411.3718I}. Still, the consensus on the prevelence of co-rotating satellite disks in the non-local Universe is unclear.

In this paper we examine kinematic evidence for the existence of rotating planes. We compare the kinematic results we obtain from selection criteria modelled after that of I14 to simple numerical models of satellite behavior. The structure of the paper is as follows: In Section [sec:data] we discuss the selection of the observational sample and the presense of the co-rotation signal. In Section [sec:models] we introduce our numerical models and compare the mock observations derived from the models to the true observational data. In Section [sec:discuss] we discuss our results in the context of the search for M31-like planes elsewhere in the Universe. Throughout our analysis, we employ a *Λ* cold dark matter (*Λ*CDM) cosmology with WMAP7+BAO+H0 parameters *Ω*_{Λ} = 0.73, *Ω*_{m} = 0.27, and *h* = 0.70 \cite{Komatsu_2011}, and unless otherwise noted all logarithms are base 10.

Properties of Thiotimoline

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Inverse and Exchange Matrix, Quantum Mechanics, Slater Determinants

For a 3x3 non-singular matrix *A* with a determinant |*A*| defined by \begin{equation}
A=\begin{bmatrix}
a_{11} & a_{12} & a_{13} \\ a_{21} & a_{22} & a_{23} \\ a_{31} & a_{32} & a_{33}
\end{bmatrix}
\end{equation} we can calculate the inverse as \begin{equation}
A^{-1}=\frac{1}{|A|}
\begin{bmatrix}
\begin{vmatrix} a_{22} & a_{23} \\ a_{32} & a_{33}\end{vmatrix} &
\begin{vmatrix} a_{13} & a_{12} \\ a_{33} & a_{32}\end{vmatrix} &
\begin{vmatrix} a_{12} & a_{13} \\ a_{22} & a_{23}\end{vmatrix} \\
\begin{vmatrix} a_{23} & a_{21} \\ a_{33} & a_{31}\end{vmatrix} &
\begin{vmatrix} a_{11} & a_{13} \\ a_{31} & a_{33}\end{vmatrix} &
\begin{vmatrix} a_{13} & a_{11} \\ a_{23} & a_{21}\end{vmatrix} \\
\begin{vmatrix} a_{21} & a_{22} \\ a_{31} & a_{32}\end{vmatrix} &
\begin{vmatrix} a_{12} & a_{11} \\ a_{32} & a_{31}\end{vmatrix} &
\begin{vmatrix} a_{11} & a_{12} \\ a_{21} & a_{22}\end{vmatrix}
\end{bmatrix}
\end{equation}

If we define an operation that is *R**C**R*_{ij}(*A*):=*R*_{ij}, remove the *i*^{th} column and the *j*^{th} row of *A*, then this is expressible as \begin{equation}
A^{-1}=\begin{bmatrix}
|R_{11}| & |R_{12}J| & |R_{13}| \\ |R_{21}J| & |R_{22}| & |R_{23}J| \\ |R_{31}| & |R_{32}J| & |R_{33}|
\end{bmatrix}
\end{equation}

Where \begin{equation} J=\begin{bmatrix} 0 & 1 \\ 1 & 0 \end{bmatrix} \end{equation}

Clearly the condition for a right multiplication of the *J* matrix being *i* + *j* = *o**d**d*.

Alternatively \begin{equation} |A|(A^{-1})_{ij}=|R_{ij}J^{(i+j-1)}|=|J^{(i+j-1)R_{ij}}| \end{equation}

This likely works because for any 2x2 matrix |*A*|= − |*A**J*_{2}|= − |*J*_{2}*A*|=|*J*_{2}*A**J*_{2}|. This property |*A*|= − |*A**J*_{2}| also appears to hold for a 3x3 matrix.

Extrapolating backwards for a two by two matrix we get the correct formula on the proviso we define *J*_{1} ≡ −1. This makes some sense, as for any *J*_{n}*J*_{n} = *I* and *J*_{n}*J*_{n}*A* = *A*.

We can further extrapolate to the inverse of a 1x1 matrix *A* = *A*_{11}, taking the *R*_{11} element to be the zero matrix, the determinant of this matrix is 1 and the reciprocal of the determinant of *A* is then just the reciprocal of *A*_{11}, which again is the inverse of the 1x1 matrix.

Proof *J*_{1} = −1:

For any *J*_{n}, *n* > 1, |*J*_{n}|= − 1 as *J*_{n} is defined to be an antidiagonal matrix.

|*A**B*|=|*A*||*B*|.

Therefore |*A**J*_{n}|= − |*A*|.

If one extrapolates to the case *n* = 1, For the above to remain true, *J*_{1} = −1

Looking at the same formula we can define four 3x3 matrices, top left, top right, bottom left, bottom right \begin{equation} A^{TL}=\begin{bmatrix} a_{22} & a_{13} & a_{12} \\ a_{23} & a_{11} & a_{13} \\ a_{21} & a_{12} & a_{11} \end{bmatrix} \\ A^{TR}=\begin{bmatrix} a_{23} & a_{12} & a_{13} \\ a_{21} & a_{13} & a_{11} \\ a_{22} & a_{11} & a_{12} \end{bmatrix} \\ A^{BL}=\begin{bmatrix} a_{32} & a_{33} & a_{22} \\ a_{33} & a_{31} & a_{23} \\ a_{31} & a_{32} & a_{21} \end{bmatrix} \\ A^{BR}=\begin{bmatrix} a_{33} & a_{32} & a_{23} \\ a_{31} & a_{33} & a_{21} \\ a_{32} & a_{31} & a_{22} \end{bmatrix} \end{equation}

These matrices are constructed from the rows of the original matrix as such, if R_i is the ith row of the original matrix, and P_n is an operator which cycles that row forward n times we have \begin{equation} A^{TL}=\begin{bmatrix} R_2^TP_2 & R_1^TP_1 & R_1^TP_2 \end{bmatrix} =A^{r(211)}_{p(212)}\\ A^{TR}=\begin{bmatrix} R_2^TP_1 & R_1^TP_2 & R_1^TP_1 \end{bmatrix} =A^{r(211)}_{p(121)}\\ A^{BL}=\begin{bmatrix} R_3^TP_2 & R_3^TP_1 & R_2^TP_2 \end{bmatrix} =A^{r(332)}_{p(212)}\\ A^{BR}=\begin{bmatrix} R_3^TP_1 & R_3^TP_2 & R_2^TP_1 \end{bmatrix} =A^{r(332)}_{p(121)} \end{equation}

These matricies are then such that \begin{equation} \frac{1}{|A|}(A^{TL} \circ A^{BR} - A^{TR} \circ A^{BL}) = A^{-1} \end{equation}

Where ∘ is the Hadamard product or element-wise product.

APPLYING MEMORY FORENSICS TO ROOTKIT DETECTION

and 1 collaborator

Igor Korkin **1** , Ivan Nesterov **2**

**1** National Research Nuclear University Moscow Engineering & Physics Institute (NRNU MEPhI), Moscow, 115409, Russia

**2** Moscow Institute of Physics and Technology (MIPT), Moscow Region 141700, Russia

# Corresponding author: igor.korkin@gmail.com

PDF-version and slides - https://www.academia.edu/7380266/Applying_Memory_Forensics_to_Rootkit_Detection

Measurements of Index of Refraction of the Whistler Wave Using Appleton's Equation

and 2 collaborators

Radio emission from the ionosphere can produce a whistling sound in the audio frequency that can be heard[1]. The whistling sounds are described as groups of descending tones which are called the whistler mode. When lightning hits the southern hemisphere it produces a range of radio waves, some of which can travel along the earths magnetic field lines from the southern hemisphere to the northern hemisphere[1].These waves are called extraordinary waves .The extraordinary waves emit two solutions to the wave equation named L and R waves.The L and R refer to left and right hand circularly polarized. The waves that describe the whistling sound are R waves and they will be detected in the north and the different frequencies of these waves will travel at different speeds. For $\omega<\frac{\omega_{ce}}{2}$ the phase and group velocities increase with frequency, where $\omega_{ce}=\frac{eB}{m}$ is the electron cyclotron frequency[1]. Due to this, the lower frequencies will arrive at the northern hemisphere later than the higher frequencies will, causing the descending tone in the whistler mode. These R waves waves that travel along the magnetic field lines are called whistler waves and these waves can only propagate for $\omega<\frac{\omega_ce}{2}$. This lab seeks out to measure the dispersion relation of the whistler waves and to find the wave patterns theoretically and experimentally in the inductively coupled plasma device using Appletons equation.

Mode Test By GMM and Excess Mass Methods

and 2 collaborators

\label{sec:methods}

\label{sec:methods-gmm}

GMM (Gaussian mixture modeling) method maximizes the likelihood of the data set using EM (expectation-maximization) method.

1. Assume that data has unimodal distribution: **x** ∼ *N*(*μ*, *σ*^{2}). Calculate *μ* and *σ*^{2}

2. Assume that data has bimodal distribution: **x** ∼ *N*(*μ*_{1}, *μ*_{2}, *σ*_{1}^{2}, *σ*_{2}^{2}, *p*)

Initial guess: *μ*_{1} = *μ* − *σ*, *μ*_{2} = *μ* + *σ*, *σ*_{1}^{2} = *σ*_{2}^{2} = *σ*^{2}, *p* = 0.5

*n*= number of observations

*θ* = (*μ*_{1}, *μ*_{2}, *σ*_{1}, *σ*_{2}, *p*) **z** = (*z*_{1}, ..., *z*_{n}) categorical vector, *z*_{i} = 1, 2

**x** = (*x*_{1}, ..., *x*_{n}) observations, (*x*_{i}|*z*_{i} = 1)∼*N*(*μ*_{1}, *σ*_{1}^{2}), (*x*_{i}|*z*_{i} = 2)∼*N*(*μ*_{2}, *σ*_{2}^{2})

*E-step* *P*(*z*_{1})=*p*, *P*(*z*_{2})=1 − *p*

Marginal likelihood: *L*(**θ**; **x**; **z**)=*P*(**x**, **z**|**θ**)=$\prod\limits_{i=1}^n P(Z_i=z_i)f(x_i|\mu_{j}, \sigma^2_{j})$

*Q*(**θ**|**θ**^{(t)})=*E*_{z|x, θ(t)}(log*L*(**θ**; **x**; **z**))

$T^{(t)}_{j,i}=P(Z_i=j|X_i=x_i,\theta^{(t)})=\frac{P(z_{j})f(x_i|\mu^{(t)}_{j}, \sigma^{2(t)}_{j})}{p^{(t)} f(x_i|\mu^{(t)}_{1}, \sigma^{2(t)}_{1})+(1-p^{(t)})f(x_i|\mu^{(t)}_{2}, \sigma^{2(t)}_{2})}$

$Q(\mathbf{\theta}|\mathbf{\theta^{(t)}})=E_{\textbf{z}|\textbf{x},\mathbf{\theta^{(t)}}}(\log L(\mathbf{\theta};\textbf{x};\textbf{z})) = \sum\limits_{i=1}^n E[( \log L(\mathbf{\theta};x_{i};z_{i})] =$

$= \sum\limits_{i=1}^n \sum\limits_{j=1}^2 T^{(t)}_{j,i}[\log P(z_{j}) -\frac{1}{2}\log(2\pi) - \frac{1}{2}\log\sigma^{2}_{j} - \frac{(x_{i}-\mu_{j})^2}{2\sigma^{2}_{j}}]$

*M-step* *θ*^{(t + 1)} = argmax*Q*(*θ*|*θ*^{(t)})

$\hat{p}^{(t+1)} = \frac{1}{n} \sum\limits_{i=1}^n T^{(t)}_{1,i}$, $\mu^{(t+1)}_{1} = \frac{\sum\limits_{i=1}^n T^{(t)}_{1,i}x_i}{\sum\limits_{i=1}^n T^{(t)}_{1,i}}$, $\sigma^{2(t+1)}_{1} = \frac{\sum\limits_{i=1}^n T^{(t)}_{1,i}(x_i-\mu^{(t+1)}_{1})^2}{\sum\limits_{i=1}^n T^{(t)}_{1,i}}$

Continue iterations t until |log*L*^{(t + 1)} − log*L*^{(t)}|<10^{−3}

Conclusion about data is made based on 3 tests. *H*_{0} distribution is unimodal, *H*_{1} distribution is bimodal:

1. LRT (Likelihood ratio test) −2ln*λ* = 2[ln*L*_{bimodal} − ln*L*_{unimodal}]∼*χ*^{2} (LRT is the main test among all 3 tests for making conclusion about bimodality of data. The bigger −2ln*λ* is, the more we are convinced that distribution is bimodal).

2. (Bandwidth test) $D = \frac {|\mu_1 - \mu_2|}{(\sigma^2_1+\sigma^2_2)/2)^{0.5}}$ (*D*(*d**i**s**t**a**n**c**e*)>2 is necessary for a clear separation of 2 peaks).

3. (Kurtosis test) *k**u**r**t**o**s**i**s* < 0 should be negative for a bimodal distribution.

In some hard cases *D* and *k**u**r**t**o**s**i**s* fail to detect bimodality. That is why our main test is LRT. For example on the next 2 plots distributions are bimodal, however on 1 plot D<2 (it is hard to distinguish 2 peaks) and on the 2 plot kurtosis is positive and that corresponds to unimodal distribution (it happens because distribution is biased):

Molecular dynamics simulation of single crystal copper with silver impurities.

and 1 collaborator

Through molecular dynamics simulations we have investigated the behavior of a single crystal copper dopped with silver impurities (0.1, 0.2 and 0.4 at % Ag) ranged at different temperatures (0.1, 100 and 300 K) under the action the stress tensor . The stress tensor is applied along of the surface in the crystallographic plane(100). Silver atoms are placed randomly on the copper, by replacing. The simulation shows thermodynamic stability properties and altering the sample fractures the crystal structure of this .

The Internet as a (WorldWide) Telescope

What famous observatory has no lens and no mirror? Such research institutions weren't uncommon in centuries past - Claudius Ptolemy constructed such an observatory at Alexandria in the 2nd century, and in the 16th century, Tycho Brahe built Uraniborg ("the castle of Urania") and Stjerneborg ("star castle") to study the night sky. Now the modern age has its own version: the internet.

The wealth of astronomical data available online grows every day, collected from spacecraft such as Hubble, Spitzer, and Chandra, as well as smaller, groundbased observatories around the globe. And there's a portal through which anyone can access these data to view the universe in its multiwavelength glory: the WorldWide Telescope (WWT).

This software runs on almost any computer or tablet via its web browser. You can also download an application to your Windows desktop. The WorldWide Telescope accesses the internet's amazing treasure-trove to provide beautiful all-sky imagery at dozens of wavelengths, as well as detailed images of many celestial targets. In addition, it offers links to in-depth information about individual objects, using diverse databases ranging from Wikipedia to NASA's Astrophysics Data System, which holds all astronomical literature published since the 1800s. WWT basically functions as an interactive web browser for the sky, a sky browser of sorts. Oh, and it's free.

Proposal to join LSST at LUPM

and 4 collaborators

The Large Synoptic Survey Telescope (LSST) is a wide-field, ground-based telescope, designed to image a substantial fraction of the sky in six optical bands every few nights. It is planned to operate for a decade, starting in 2021, allowing the stacked images to detect galaxies to redshifts well beyond unity. The LSST is designed to achieve a very broad science roadmap, that can be articulated around four major science themes:

Probing Dark Energy and Dark Matter;

Taking an inventory of the Solar system;

Exploring the transient optical sky;

Mapping the Milky Way.

This document outlines the current work plan that the LSST team at LUPM is putting forward to officially join the LSST project and efficiently start their scientific and technical activities. It is intended to serve as a support to the Scientific Council of LUPM, in preparation to the review on October 1-2 2014. In the first part of the document, we summarize the LSST project, the Dark Energy Science Collaboration (DESC), and the LSST-France activities. The second part shortly introduces the LUPM team, and we devote the third section to a presentation of the LSST project and activities at LUPM.

N-Body Simulation of a Proto-Solar System with a Neptune-like Object

#Introduction

The widely-accepted explanation for the initial formation of the Solar System is known as the Nebular Hypothesis, that the Sun formed from a collapsing, dense region of an interstellar molecular cloud, with the remainder of material gravitationally accreting and flattening into an orbiting circular disk. This excess material eventually coalesced to form the small solar system bodies, including planets, moons, asteroids, and comets. After their initial formation, however, the orbital parameters of small bodies were not static. Due to complex gravitational interactions and interchanges of orbital energy between particles, planets, remaining small-bodies, and particles experienced 'migration' – periods during which their orbital parameters evolved substantially, particularly in their orbital radii (Semi-Major Axis). Migration is believed to account for the current configuration of planets in the solar system, including the gas giants. Additionally, it offers a likely explanation for the small orbital radii and, consequently, short orbital periods of “Hot Jupiter” planets which have been detected in extrasolar planetary systems, as it suggests that their orbits may have undergone an inward migration and eventual stabilization. Evidence suggests that migration could account for the current orbit of Neptune, since the orbit periods of a number of small solar system bodies appear to be in resonance, which must be the result of gravitational interactions with Neptune.

A numerical simulation of a gas-less, solar-like proto-planetary disk was performed by Rodney S Gomes et. al. (Planetary Migration in a Planetesimal Disk: Why Did Neptune Stop at 30 AU? - 2004) to investigate Neptune's migration. The result was an outward migration of Neptune, which stabilized at a semi-major axis of approximately 30 AU from the central star, remarkably close to it's actual semi-major axis of 29.21 AU. Migration was found to be sensitive to the mass density of the proto-planetary disk. Outlying material, representing an initially close-in 'Kuiper Belt', quickly dispersed and lost a significant portion of its mass before Neptune stabilized into its final orbit, thus placing Neptune, effectively, on the edge of the disk after it ceased migrating. This result was obtained by setting the initial radius of the disk to ~35 AU, with a linear mass density of ~1.5 Earth masses per AU. When the mass density of the disk was increased (relatively massive disk), Neptune showed a runaway migration out to very large distances, due to interaction with particles that continually “fed” its migration. In a previous simulation of 10,000 particles, with a disk which encompassed 60 Earth masses of material between 20 and 45 AU, and and r^-(1.5) surface density profile, Gomes (2003) observed an outward migration of Neptune and stabilization at 45 AU.

MagPen: A Novel Method of Digitizing Notes Using Magnets

and 1 collaborator

This paper presents a novel method of digitizing notes and/or diagrams that are drawn on a sheet of paper. Most modern phones contain magnetometers that output the strength of the surrounding magnetic field in the x, y, and z direction. If a magnet is brought closer to the device (and the magnetometer), the values from the magnetometer will be altered. By determining the change in the altered magnetic field, we can determine the position of the magnet. With the position, we can determine the location of the magnet relative to the phone. We have created a magnet based pen (MagPen) and built an android application that allows users to write notes on a sheet of paper while their mobile phone automatically digitizes. Users will also be able to perform certain actions using the button on the pen and select various pen attributes using the MagPen.

**Author Keywords**

Pen input, magnetometer, mobile devices, notes

**ACM Classification Keywords**

H.5.2 [Information interfaces and presentation]: User

Interfaces: Input Devices and Strategies.

Master thesis research proposal: How do daily household practices affect food wastage? Empirical insights from 100 Dutch households in the context of the 100 100 100 campaign

Name: Robert Orzanna

Title: How do daily household practices affect food wastage? Empirical insights from 100 Dutch households in the context of the 100 100 100 campaign

Contact: r.orzanna@students.uu.nl

Supervisor: Prof. dr. Ernst Worrell

2^nd reader: dr. ir. Wina Crijns-Graus