Using \LaTeX\{\} to write papers is concise and convenient. However, for
writing in life, complicated \LaTeX\{\} style-files (e.g., elegantpaper)
are difficult to access, or submission style-files (e.g., journal or
conference) are not free indeed. To tackle these problems and satisfy an
elegant and straightforward scientific writing,
\textbf{paperlighter.sty}, a one-column style-file, is designed. This
document is edited from icml2022.sty and provides a basic paper
template. Compared to icml2022.sty, paperlighter.sty contain fewer
operations, reducing adjustment while keep graceful.
\textbf{\textit{Notably, the paper's main content only describes the format of icml2022.sty. We place the content to show the actual effect of paperlighter.sty.}}
Acknowledgements is an unnumbered section at the end of the paper.
Typically, this will include thanks to colleagues who contributed to the
ideas, and to funding agencies and corporate sponsors that provided
financial support.
# Basic properties of protein and nucleic acids
## Basic principle of protein
### Unit structure of protein
There are 4 levels of protein organization:
* Primary structure \
It consists of a chain arrangement/sequence of amino acids that are joined together to make protein. It usually uses abbreviations for the amino and residues. The example in figure (1) is Polypeptide amino.
* Secondary structure \
This is the region within the long protein chains organized into regular structures known as alpha-helices ($\alpha$-helices) and beta sheet.
* Tertiary structure \
Tertiary structure is a description of the way that whole chain from one or several units folds and forms 3-dimensional shape, called domain.
* Fourth order structure \
This structure is formed from several tertiary structure proteins or domains with more complex shape.
![Structure of protein](./Figures/Figure1)
<!--
\begin{figure}[h!]
\centering
\includegraphics[width=0.7\linewidth]{Figure1}
\caption{Structure of protein}
\label{fig:figure1}
\end{figure}
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### Basic motif of protein
There are two types of secondary structure for hydrophobic type:
* $\alpha$-helix\
This is one of common motif in secondary structure of protein. It consists of hydrogen bond with conformation of N-H group donates a hydrogen bond to the C=O group of amino acid. This structure has small Coulomb interaction in hydrogen bond and has dipole moment.
* $\beta$ sheet\
Beta sheet is also one of common motif in protein, consist of $\beta$ strands connected hydrogen bonds, forming a generally twisted and pleated sheet.
![Secondary alpha-helix and beta sheet structures](./Figures/Alpha_beta_structure_full)
\caption{Self-organization of phospholipids: a spherical liposome, a micelle, and a lipid bilayer.}
\label{fig:phospholipid}
\end{figure}
-->
# Molecular dynamics simulation
## Simulation (Computational science)
Simulation is the one that connect the theory and experiment in science.
When the theory contributes in analysis and prediction, and experiments are contributing in confirming the theory and developing, simulation takes part in calculation in advanced theoretical and virtual simulation experiment.
Simulation is using the computer to do things, such as reproduce, understand, and predict the theory and also the experiment.
Simulation is applied in many fields, such as science, pharmacy, climate, earthquake, finance and social, and many other things.
## Supercomputer\
Supercomputer is a computer with high level of performance.
One of the biggest supercomputer in Japan is K Computer, located in Kobe, is having 705,024 cores and 10.510 PFlops (floating-point operations per second).
Supercomputer is practically used in computational science, such as biological, material, earth, and fundamental physical sciences.
Also, supercomputer is used in simulation of next-generation technology.
## Computational science in biology\
Computational science is usually used in exploring phenomena in biological system; substances, structure and functions of proteins, membranes, and enzymes, energy and chemical reaction, and signal transduction.
These can be modeled using molecular dynamics (MD) simulation.
The fundamental parts in MD are analytical mechanics (Newton's equation), Schrodinger's equation in quantum mechanics, statistical mechanics, and electromagnetization principle.
### _Brownian Dynamics_
Brownian dynamics describes the physical phenomena of zig-zag motion of particle. The motion is arising from collision between the particles. This motion resulted diffusion equation that obeys the law of mass conservation, formulated in the equation:
where $\rho (x,t)$ is density of material and $J (x,t)$ is flux, the rate of flow.
### _Langevin Equation_
This equation describes the \textit{Brownian motion} that uses Newton's equation of motion and degree of freedom. $\varrho$ is denoted as the friction coefficient.