SHU Yoshifumi envzhu

MacBookAir9,1(2020)への Ubuntu 20.04 のインストール (installing Ubuntu 20.04 to MacBookAir9,1(2020))

MacBookPro でも動作すると思います。(The followings work on other MacBookPro.)

自分の環境では、以下は動作しませんでした。(WiFi on MacBookAir does not work on my machine.)

WiFi : USB の外付け WiFi アダプタで代用 (I use USB WiFi Adapter instead of WiFi on MacBookAir.)

This simple script will take a picture of a whiteboard and use parts of the ImageMagick library with sane defaults to clean it up tremendously.

The script is here:

#!/bin/bash
convert "$1" -morphology Convolve DoG:15,100,0 -negate -normalize -blur 0x1 -channel RBG -level 60%,91%,0.1 "$2"

People

	Copyright 2026 Thiago de Arruda Padilha

	Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

	The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES

	#!/bin/bash

	rm -rf /home/yen3/ubuntu.qcow2
	qemu-img create -f qcow2 /home/yen3/ubuntu.qcow2 10G

	virsh undefine ubuntu1604arm64 --nvram

	install_from_localtion() {
	virt-install -n ubuntu1604arm64 --memory 1024 --arch aarch64 --vcpus 1 \
	--disk /home/yen3/ubuntu.qcow2,device=disk,bus=virtio \

	-- Description:
	-- ------------
	--
	-- This is an example schema for storing collectd metrics in a TimescaleDB
	-- dabase (see https://www.timescale.com/). It is based on the PostgreSQL
	-- schema contributed by Sebastian Harl.
	--
	-- Prerequisities:
	-- ---------------
	--

	#!/usr/bin/env bash

	# --slave /usr/bin/$1 $1 /usr/bin/$1-\${version} \\

	function register_clang_version {
	local version=$1
	local priority=$2

	update-alternatives \
	--install /usr/bin/llvm-config llvm-config /usr/bin/llvm-config-${version} ${priority} \

	lxc launch ubuntu:16.04 ubu1

	apt install qemu-kvm libvirt-bin bridge-utils

	lxc config set ubu1 security.privileged true
	lxc config device add ubu1 kvm disk path=/dev/kvm source=/dev/kvm



	---

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD