vault backup: 2023-12-22 12:45:16

Affected files:
.obsidian/graph.json
.obsidian/workspace-mobile.json
.obsidian/workspace.json
Christmas Movies.md
Politcs/Fascism.md
Politcs/Neoliberalism/Neoliberalism.md
STEM/AI/Neural Networks/CNN/Interpretation.md
STEM/CS/Languages/Python.md
STEM/IOT/OS/Composition.md
STEM/IOT/OS/Contiki.md
STEM/IOT/OS/OS.md
STEM/IOT/OS/README.md
STEM/img/iot-event-based.png
STEM/img/iot-os-stack.png
STEM/img/iot-thread-based.png

AI/Neural Networks/CNN/Interpretation.md

@@ -12,7 +12,7 @@
 		- Update image
 
 ![am-process](../../../img/am-process.png)
-## R3egulariser
+## Regulariser
 - Fit to natural image statistics
 - Prone to high frequency noise
 	- Minimise

CS/Languages/Python.md

@@ -16,7 +16,7 @@ Compiler
 Publication-quality Graphs
 
 [NLTK](https://www.nltk.org)
-NLP
+[NLP](../../Speech/NLP/NLP.md)
 
 If you are not getting good results, you should first check that you are using the right [classification](../../AI/Classification/Classification.md) algorithm (is your data well fit to be classified by a linear SVM?) and that you have enough training data. Practically, that means you might consider visualizing your dataset through PCA or t-SNE to see how "clustered" your classes are, and checking how your classification metrics evolve with the amount of data your classifier is given.
 

IOT/OS/Composition.md

@@ -0,0 +1,50 @@
+# Threading
+*Smallest sequence of programmed instructions that can be managed independently by a [scheduler](https://en.wikipedia.org/wiki/Scheduling_(computing))*
+From <[https://en.wikipedia.org/wiki/Thread_(computing)](https://en.wikipedia.org/wiki/Thread_(computing))>
+
+- Instructions run independently by scheduler
+- Single address space
+- One thread blocked for I/O
+	- Tasks run in other threads
+- Need locks and mutexes
+	- Coordination between threads
+- Complicated
+	- Deadlocks
+
+# Protothreads
+- Lightweight
+- Stack-less
+- Interruptible tasks for event-based
+- Conditional blocking statement
+	- Blocks until given statement is true
+- Use timer to manage
+- Invoked whenever process receives message from another process or timer
+
+# Events
+*Action or occurrence recognized by software, often originating asynchronously from the external environment, that may be [handled](https://en.wikipedia.org/wiki/Event_handler) by the software*
+From <[https://en.wikipedia.org/wiki/Event_(computing)](https://en.wikipedia.org/wiki/Event_(computing))>
+
+- Event loop
+	- Waits for events
+		- Inputs
+- On event
+	- Collects info
+		- Dispatches to call-back
+- Register handlers with OS scheduler
+- Kernel usually runs loop to poll for events
+- Blocking operation
+	- Register call-back
+		- Return control to scheduler
+
+# Radio Sleep
+- Energy efficiency
+- Congestion
+
+## Event-based
+![](../../img/iot-event-based.png)
+
+## Thread-based
+![](../../img/iot-thread-based.png)
+- Less complex
+- Faster
+	- Pointer-based

IOT/OS/Contiki.md

@@ -0,0 +1,78 @@
+- Linux-based
+- Small memory (~20 kB)
+- Wide network stacks
+	- TCP/IP
+		- IPv6
+	- 6LoWPAN
+		- IPv6-based
+		- Header compression
+	- CoAP
+		- Application layer protocol
+	- RPL
+		- Routing for low power
+		- Lossy networks
+	- SSL/TLS
+	- RIME
+		- Own communication solution
+- Instant Contiki
+	- Dev environment
+	- Whole VM
+
+# Functional
+- Separates basic system from dynamically loadable and programmable services
+	- Processes
+- Event-driven kernel
+	- Multi-threading supported by library
+	- Hybrid OS
+	- No hardware abstractions
+- Services communicate by posting kernel events
+- Refer to stack with pointer to process state
+	- Each service has state in private memory space
+
+![](../../img/iot-os-stack.png)
+
+# Process
+- Cooperative
+	- Code running sequentially with respect to other coop code
+- Pre-emptive
+	- Temporarily stops cooperative code
+- Normal processes run cooperatively
+	- Interrupts and real-time timers run pre-emptively
+		- Higher priority
+- Programs are processes
+	- Started on boot
+	- When module containing process loaded
+- Processes run on timer firing or external events
+
+# Timers
+- Libraries
+	- Used by applications and system
+- Check for timer completion
+- Waking system from low power
+- Real-time task scheduling
+- Allows cooperation when threads sleep
+	- Low power mode
+- timer and stimer
+	- Simplest
+	- See if time period passed
+	- Need querying
+- etimer
+	- Event timers
+	- Scheduling
+	- Uses clock time from clock module
+	- struct etimer
+## Clock
+- System time starts from zero when the Contiki system starts
+- clock_time()
+	- In ticks
+- clock_seconds()
+	- In seconds
+- CLOCK_SECOND
+	- Ticks per second
+
+# Power Saving Mode
+- Kernel does not provide any power saving abstractions
+- Need to implement in application
+- To help an application decide when to power down the system
+	- The event scheduler exposes the size of event queue
+	- If there were not events scheduled, this information can be used to power down the processor

IOT/OS/OS.md

@@ -0,0 +1,87 @@
+- Thin software layer
+- Basic programming abstractions
+- Interact with hardware
+	- Schedule and prioritise tasks
+- Mediate between applications and services requiring resources
+[Comparison of Operating Systems TinyOS and Contiki](https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.636.3680&rep=rep1&type=pdf)
+
+# Environment
+- Energy efficiency
+- Restricted code
+	- Compared to full OS
+
+# Features
+- Memory management
+- Power management
+- File management
+- Networking
+- Dev environment and tools
+	- Commands
+	- Interpreters
+	- Compilers
+- Entry points for sensitive resources
+	- Input components
+- Functional aspects
+	- Scheduling
+	- Multi-threading
+	- Interrupts
+	- Memory allocation
+
+# Dynamic Programming
+- Program parts of application after deployment
+	- Settings and requirements not known prior to deployment
+		- Can change over time
+	- Bug fixes or update requirements wile in operation
+	- Manual updates maybe not possible
+- Needs boundaries between application and OS
+- OS receive software updates and store in active memory
+	- Check this is an updated version
+	- Install and configure new version
+
+# Paradigm
+- Node-centric
+	- Focuses on software for each node
+	- Operating individually
+- Application-centric
+	- Treat nodes as one application
+	- Requires collaboration between nodes
+		- Collection
+		- Dissemination
+		- Analysis and/or processing of generated and collected data
+
+# Deploy to Mote
+- Compile
+	- make TARGET=xm1000 _____
+- Deploy
+	- make TARGET=xm1000 _____.upload
+		- As root
+- Terminal
+	- make TARGET=xm1000 login
+
+# TinyOS
+*Embedded, component-based operating system and platform for low-power wireless devices, such as those used in [wireless sensor networks](https://en.wikipedia.org/wiki/Wireless_sensor_network) (WSNs), [smartdust](https://en.wikipedia.org/wiki/Smartdust), [ubiquitous computing](https://en.wikipedia.org/wiki/Ubiquitous_computing), [personal area networks](https://en.wikipedia.org/wiki/Personal_area_network), [building automation](https://en.wikipedia.org/wiki/Building_automation), and [smart meters](https://en.wikipedia.org/wiki/Smart_meter)*
+
+From <[https://en.wikipedia.org/wiki/TinyOS](https://en.wikipedia.org/wiki/TinyOS)>
+
+- Written in nesC
+	- Network Embedded Systems C
+	- Component-based
+		- Wired together to run applications
+	- Event-driven
+	- Extension to C
+- Non-blocking
+	- One stack
+	- No abstraction between OS and application
+- No dynamic programming
+- I/O ops longer than hundreds of milliseconds are async
+- Mainly event-based
+
+# FreeRTOS
+- Minimal ROM, RAM, processing overhead
+- Bin image 6K - 12K
+- 3 C files
+- Smaller & easier real-time processing alternative
+- Port layer
+	- Architecture specific part of port
+	- Officially supported or contributed
+- Good for AWS

IOT/OS/README.md

@@ -0,0 +1 @@
+OS.md