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

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2026-01-09 14:57:20 -05:00
parent 2879d1cb68
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3 changed files with 119 additions and 16 deletions
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@@ -12,7 +12,14 @@ tags:
## 2026-01-08 13:33 ## 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 #### Switchgear
@@ -23,17 +30,17 @@ Includes
* submetering * submetering
* coordination study * coordination study
#### Generators
> [!failure]
> Generators were erroneously broken down in switchgear.
[[switchgear-takeoff#Generator|Generator]]
#### Composite Cleanup #### Composite Cleanup
1 day per week 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 #### Temp Power
$10,000 per [[heavy-equipment#Swing Stage Scaffolding|swing stage]] $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 # 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] > [!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. > 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 $C$. Consider a construction project characterized by an intrinsic but unknown final cost $C$.
@@ -28,9 +35,12 @@ $$
C : \Omega \to [0,\infty) C : \Omega \to [0,\infty)
$$ $$
> Read as
> "C is a function from omega to the interval from zero to infinity, including zero."
with [distribution](https://en.wikipedia.org/wiki/Probability_distribution) $\mu_C$. with [distribution](https://en.wikipedia.org/wiki/Probability_distribution) $\mu_C$.
The distribution $\mu_C$ summarizes all available information at the time of bidding, The distribution $\mu_C$ accounts all available information at the time of bid,
including quantities, labor productivity uncertainty, including quantities, labor productivity uncertainty,
market conditions, subcontractor pricing variability, market conditions, subcontractor pricing variability,
and correlation structures inherent to the estimator's assumptions. and correlation structures inherent to the estimator's assumptions.
@@ -59,7 +69,7 @@ mapping a cost distribution $\mu_C$ to a **scalar** (a single value).
Examples of such functionals include: Examples of such functionals include:
### 1. Risk-neutral expectation ## 1. Risk-neutral expectation
$$ $$
\Phi(\mu_C) = \mathbb{E}[C], \Phi(\mu_C) = \mathbb{E}[C],
@@ -69,7 +79,7 @@ $$
where $\mathbb{E}[\cdot]$ denotes the [expected value](https://en.wikipedia.org/wiki/Expected_value). 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]}, \Phi(\mu_C) = \mathbb{E}[C] + \lambda\sqrt{\mathrm{Var}[C]},
@@ -80,9 +90,9 @@ $$
where $\mathrm{Var}[C]$ is the [variance](https://en.wikipedia.org/wiki/Variance) where $\mathrm{Var}[C]$ is the [variance](https://en.wikipedia.org/wiki/Variance)
and $\lambda>0$ is a risk-loading parameter. and $\lambda>0$ is a risk-loading parameter.
> This mirrors mean--variance pricing common in portfolio theory. > This mirrors mean-variance pricing common in portfolio theory.
### 3. Quantile-based pricing ## 3. Quantile-based pricing
$$ $$
\Phi(\mu_C) = Q_p(C), \Phi(\mu_C) = Q_p(C),
@@ -93,7 +103,7 @@ $$
where $Q_p$ is the $p$-[quantile](https://en.wikipedia.org/wiki/Quantile) where $Q_p$ is the $p$-[quantile](https://en.wikipedia.org/wiki/Quantile)
of the distribution. of the distribution.
### 4. Utility-maximizing bid ## 4. Utility-maximizing bid
Under a bidder [utility](https://en.wikipedia.org/wiki/Utility) function $U$, 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. > [$\arg\max$](https://en.wikipedia.org/wiki/Arg_max) is the value of $b$ that maximizes the expression.
*** ## Conclusion
The central tension is: The central tension is: