vault backup: 2025-01-20 18:23:18

1 Daily Notes/2025/2025-01-16.md

@@ -20,7 +20,7 @@ group by file.name
 ## What's the plan!
 - [ ] [[Homework 1]] 📅 2025-01-23 #ME2046 #Homework 
 - [ ] [[ME 2150 - High-Assurance Cyber-Physical Systems Homework 1]] 📅 2025-01-21 #ME2150 #Homework 
-- [ ] [[2025-01-16 HACMS Program Overview]] #ME2150 #Lecture 
+- [x] [[2025-01-16 HACMS Program Overview]] #ME2150 #Lecture [completion:: 2025-01-20]
 - [ ] Fix weekly note automatic day linking
 - [ ] [[2025-01-16 The Z Transform]] #ME2046 #Lecture 
 

1 Daily Notes/2025/2025-01-20.md

@@ -29,7 +29,7 @@ where completed
 group by file.name
 ```
 # Calendar Tasks
--  More 2150 [startTime:: 17:15]  [endTime:: 17:45]
+-  More 2150 [startTime:: 17:15]  [endTime:: 18:20]
 -  Walk Lewie [startTime:: 16:30]  [endTime:: 17:15]
 -  Lonch [startTime:: 13:00]  [endTime:: 15:00]
 -  Writing for ME 2150 [startTime:: 15:00]  [endTime:: 16:30]

1 Daily Notes/2025/2025-01-21.md

@@ -0,0 +1,38 @@
+---
+date: <% tp.file.title %>
+tags:
+---
+---
+date: 2025-01-21
+tags:
+---
+# Links to Other Pages
+## Yesterday | Tomorrow
+ << [[1 Daily Notes/2025/2025-01-20]] | [[1 Daily Notes/2025/2025-01-22 ]] >>
+## This Week's Weekly Note
+[[ Weekly Note 2025-01-15]]
+# Summary
+## What's Overdue!
+```dataview
+task
+from "1 Daily Notes" 
+where !completed 
+	and status != "-"
+	and file.name != this.file.name
+group by file.name
+```
+## What's the plan!
+
+## What's the results!
+```dataview
+task
+from "1 Daily Notes" 
+where completed
+	and completion = date(this.file.name)
+	and file.name != this.file.name
+group by file.name
+```
+# Calendar Tasks
+-  ANS Paper [startTime:: 15:30]  [endTime:: 17:00]
+-  Lunch [startTime:: 11:30]  [endTime:: 12:30]
+-  Gym [startTime:: 07:30]  [endTime:: 08:30]

1 Daily Notes/2025/2025-01-22.md

@@ -0,0 +1,35 @@
+---
+date: 2025-01-22
+tags:
+---
+# Links to Other Pages
+## Yesterday | Tomorrow
+ << [[1 Daily Notes/2025/2025-01-21]] | [[1 Daily Notes/2025/2025-01-23 ]] >>
+## This Week's Weekly Note
+[[ Weekly Note 2025-01-15]]
+# Summary
+## What's Overdue!
+```dataview
+task
+from "1 Daily Notes" 
+where !completed 
+	and status != "-"
+	and file.name != this.file.name
+group by file.name
+```
+## What's the plan!
+
+## What's the results!
+```dataview
+task
+from "1 Daily Notes" 
+where completed
+	and completion = date(this.file.name)
+	and file.name != this.file.name
+group by file.name
+```
+# Calendar Tasks
+-  ANS Paper [startTime:: 13:00]  [endTime:: 16:00]
+-  Lunch [startTime:: 12:00]  [endTime:: 13:00]
+-  ME 2046 HW1 [startTime:: 11:00]  [endTime:: 12:00]
+-  HACPS Reading [startTime:: 09:00]  [endTime:: 10:30]

300s School/ME 2150 - High Assurance Cyber-Physical Systems/ME 2150 - High-Assurance Cyber-Physical Systems Homework 1.md

@@ -4,10 +4,11 @@ Recently I have begun hosting a poker game. Poker is a beautiful game, as it con
 
 Alex sought out the position at the Wheelchair and Cushion Standards Group as an summer internship that was conveniently located in the East Liberty neighborhood. Her job would be multifaceted: as part of a small laboratory group, he responsibilities would change upon the day and she would be expected to wear many hats. One of her first tasks was running experiments on sets of wheelchair cushions using an expensive test fixture. 
 
-### Wheelchair cushions are actually a critical component
+### Wheelchair Cushion Standards
 Wheelchair cushions are a surprisingly sophisticated device, and far from only a piece of foam. Wheelchair cushions are critical for users who spend a large amount of time in their wheelchair, and an effective cushion can play a significant role in the overall health of the user. Cushions redistribute the weight of a wheelchair user evenly across their buttocks, while an insufficient cushion can create problems for wheelchair-bound individuals including ulcers, posture issues, and blood flow restrictions. These problems are even further magnified for individuals who have loss of feeling in their legs, as they can not detect the development of injuries until they are visibly apparent or manifest in greater health issues. For these reasons, regulatory standards exist for wheelchair cushions. Standards such as [ISO 16840-2](https://www.iso.org/standard/84862.html) exist to protect wheelchair users by providing a standard to which cushions can be tested. By using wheelchair cushions that meet these standards, users can have a degree of assurance that the product they're using will minimize risks associated with prolonged wheelchair use.
 
 For a wheelchair cushion to pass this standard, it must be experimentally tested. This testing is commonly done by companies that specialize in standards testing. The sensors and equipment required to do ISO testing can be very expensive, and prohibitive for individual manufacturers of items like wheelchair cushions to create test fixtures of their own. Pitt's Wheelchair and Cushion Standards group does such testing for this particular wheelchair cushion standard using a testing rig that is described in the following image.
+### Testing Setup
 
 ![[press.png]]
 
@@ -15,6 +16,8 @@ This testing fixture consists of a hydraulic press with a specific CNC-machined
 
 The positions of sensors on the wooden buttocks are of particular interest. These sensors are spread throughout the surface of the contoured shape. Ideally, these sensors should have similar values of pressure for a given load if the cushion is doing a good job supporting the load. These sensors have different heights relative to the displacement of the press. As a result, the sensors on the very bottom of the buttocks model first experience pressure, while the sensors on the sides of the buttocks eventually catch up in pressure measurement as displacement is increased.
 
+### The Failure
+
 The testing procedure Alex was specifically performing when the failure occurred was a fatigue failure test. In this test, the buttocks would descend upon the cushion until a proscribed pressure is achieved on all sensors, hold for a certain amount of time, and then ascend until zero pressure is achieved again. This cycle is then repeated for a very large number of cycles. Performance of the cushion is then determined as to how the pressure distribution changes over time--more performant cushions will retain their cushioning properties for longer than less performant cushions. 
 
 One of the first cushions Alex was tasked with testing was a cushion that was described as being similar construction of a cheap air-mattress. Alex was instructed on how to start the test, where the E-Stop button lived, and what should be expected. Once the person instructing her left, the test began. 
@@ -25,6 +28,8 @@ After the first repetition, the lower sensors in the buttocks were broken. Inste
 
 This whole process has happened in a time span of about 5 seconds. At this point, Alex realizes this is definitely not supposed to be happening and reaches for the E-Stop button. Before she could activate the E-Stop, the press descended the wooden buttocks with such ferocity that the wooden model splits in half as if the cushion itself were an axe. The ideal testing force is supposed to be around 400 lbf, but it was estimated that the fixture applied over a thousand pounds of force when the buttocks were destroyed. Finally, the E-Stop was activated before further damage was created.
 
+### Reflection
+
 The part of this failure that makes it a cyber-physical failure is the fact that while a pressure based controller was implemented, it was never validated for a use-case where the cushion does not achieve a sufficient pressure on all of the buttock sensors. This case was realized when the buttocks made contact with the steel frame with this particular low quality cushion. 
 
 Another control was implemented in case of extreme pressure readings on the buttocks sensors, but that control also experienced a cyber-physical failure. The controller assumed a model of the sensors that would continuously report correct values even in the case of extreme loading. This assumption proved to be incorrect, which essentially nullified the over-pressure control once the model of the sensors was invalidated.