vault backup: 2026-01-09 14:57:19

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2026-01-09 14:57:20 -05:00
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## 2026-01-08 13:33
### 2100 Crystal Drive
### 2100 Crystal Drive Takeoff Review
#### Generators
> [!failure]
> Generators were erroneously broken down in switchgear.
[[switchgear-takeoff#Generator|Generator]]
#### Switchgear
@@ -23,17 +30,17 @@ Includes
* submetering
* coordination study
#### Generators
> [!failure]
> Generators were erroneously broken down in switchgear.
[[switchgear-takeoff#Generator|Generator]]
#### Composite Cleanup
1 day per week
$$
\text{Average Weeks Per Month} =
$$
> It occurs to me I don't know all the rules of our calendar
> [Gregorian calendar - Wikipedia](https://en.wikipedia.org/wiki/Gregorian_calendar)
#### Temp Power
$10,000 per [[heavy-equipment#Swing Stage Scaffolding|swing stage]]
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---
id:
aliases: []
title: "2026-01-09"
tags:
- authorship/original
- destiny/permanent
- status/draft
- type/daily
---
# 2026-01-09
## 2026-01-09 10:00
### 2100 Crystal Drive
`#600 ? WHITE ?` had incorrect sort codes.
#### Lighting Control
I took of lighting per plans (E510)
in spite of proposal stating "local control".
Will have to be changed.
#### Labor Factor
Fire Alarm
Switchgear
Feeders
Subfeeds
Corridors
Amenity
Retail
Units
#### Fixtures
> [!failure]
> Several fixtures were erroneously based on NM cable.
I built some fixtures with \#12/3 in areas with emergency lighting
to be an unswitched hot.
Joel is having me change them to \#12/2.
#### Units
> [!failure]
> One unit type typical was missing `Area` quantities.
> Another had no takeoff.
#### Labor Plan
$$
\mathbb{E}\left[\frac{\text{Hours Per Unit}}{\text{Openings Per Unit}}\right] \approx .75~\text{Hours Per Opening}
$$
High Rise .110--.120 hr/sqft
## 2026-01-09 12:00
$$
\frac{146097}{400} = 365.2425~\text{Days Per Year}
\frac{20871}{400} = 52.1775~\text{Weeks Per Year}
\frac{6957}{1600} = 4.348125~\text{Weeks Per Month}
$$
$$
\frac{365.2425~\text{Days Per Year}}{7~\text{Days Per Week}}
= 52.1775~\text{Weeks Per Year}
$$
$$
\frac{52.1775~\text{Weeks Per Year}}{12~\text{Months Per Year}}
= 4.348125~\text{Weeks Per Month}
$$
## 2026-01-09 14:45
[[bid-price-modeling]]
Suppose a true cost model,
accounting for all relevant information available at time $t$.
$C(t)$ returns a distribution whose [scale](https://en.wikipedia.org/wiki/Scale_parameter)
decreases with $t$, and $C(0)$ maps to a single value.
$t>0$ is time until the final payment.
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@@ -12,8 +12,15 @@ title: Modeling Bid Prices Under Intrinsic Cost Uncertainty
---
# Modeling Bid Prices Under Intrinsic Cost Uncertainty
The cost of a construction project is inherently uncertain until it is completed,
therefore the most accurate model of cost is a distribution of possible costs.
Customers request bids as a single cost, however,
so a contractor must determine some function
to convert from the true cost model to a single bid price.
> [!warning]
> This text is almost entirely LLM output.
> From this point forward,
> this text is almost entirely LLM output.
> I don't intend to keep or use any significant portions of it.
Consider a construction project characterized by an intrinsic but unknown final cost $C$.
@@ -28,9 +35,12 @@ $$
C : \Omega \to [0,\infty)
$$
> Read as
> "C is a function from omega to the interval from zero to infinity, including zero."
with [distribution](https://en.wikipedia.org/wiki/Probability_distribution) $\mu_C$.
The distribution $\mu_C$ summarizes all available information at the time of bidding,
The distribution $\mu_C$ accounts all available information at the time of bid,
including quantities, labor productivity uncertainty,
market conditions, subcontractor pricing variability,
and correlation structures inherent to the estimator's assumptions.
@@ -59,7 +69,7 @@ mapping a cost distribution $\mu_C$ to a **scalar** (a single value).
Examples of such functionals include:
### 1. Risk-neutral expectation
## 1. Risk-neutral expectation
$$
\Phi(\mu_C) = \mathbb{E}[C],
@@ -69,7 +79,7 @@ $$
where $\mathbb{E}[\cdot]$ denotes the [expected value](https://en.wikipedia.org/wiki/Expected_value).
### 2. Risk-adjusted expectation
## 2. Risk-adjusted expectation
$$
\Phi(\mu_C) = \mathbb{E}[C] + \lambda\sqrt{\mathrm{Var}[C]},
@@ -80,9 +90,9 @@ $$
where $\mathrm{Var}[C]$ is the [variance](https://en.wikipedia.org/wiki/Variance)
and $\lambda>0$ is a risk-loading parameter.
> This mirrors mean--variance pricing common in portfolio theory.
> This mirrors mean-variance pricing common in portfolio theory.
### 3. Quantile-based pricing
## 3. Quantile-based pricing
$$
\Phi(\mu_C) = Q_p(C),
@@ -93,7 +103,7 @@ $$
where $Q_p$ is the $p$-[quantile](https://en.wikipedia.org/wiki/Quantile)
of the distribution.
### 4. Utility-maximizing bid
## 4. Utility-maximizing bid
Under a bidder [utility](https://en.wikipedia.org/wiki/Utility) function $U$,
@@ -106,7 +116,7 @@ $$
> [$\arg\max$](https://en.wikipedia.org/wiki/Arg_max) is the value of $b$ that maximizes the expression.
***
## Conclusion
The central tension is: