vault backup: 2026-01-09 14:57:19
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@@ -12,7 +12,14 @@ tags:
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## 2026-01-08 13:33
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### 2100 Crystal Drive
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### 2100 Crystal Drive Takeoff Review
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#### Generators
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> [!failure]
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> Generators were erroneously broken down in switchgear.
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[[switchgear-takeoff#Generator|Generator]]
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#### Switchgear
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@@ -23,17 +30,17 @@ Includes
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* submetering
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* coordination study
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#### Generators
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> [!failure]
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> Generators were erroneously broken down in switchgear.
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[[switchgear-takeoff#Generator|Generator]]
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#### Composite Cleanup
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1 day per week
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$$
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\text{Average Weeks Per Month} =
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$$
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> It occurs to me I don't know all the rules of our calendar
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> [Gregorian calendar - Wikipedia](https://en.wikipedia.org/wiki/Gregorian_calendar)
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#### Temp Power
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$10,000 per [[heavy-equipment#Swing Stage Scaffolding|swing stage]]
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@@ -0,0 +1,86 @@
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---
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id:
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aliases: []
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title: "2026-01-09"
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tags:
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- authorship/original
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- destiny/permanent
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- status/draft
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- type/daily
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---
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# 2026-01-09
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## 2026-01-09 10:00
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### 2100 Crystal Drive
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`#600 ? WHITE ?` had incorrect sort codes.
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#### Lighting Control
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I took of lighting per plans (E510)
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in spite of proposal stating "local control".
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Will have to be changed.
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#### Labor Factor
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Fire Alarm
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Switchgear
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Feeders
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Subfeeds
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Corridors
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Amenity
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Retail
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Units
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#### Fixtures
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> [!failure]
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> Several fixtures were erroneously based on NM cable.
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I built some fixtures with \#12/3 in areas with emergency lighting
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to be an unswitched hot.
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Joel is having me change them to \#12/2.
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#### Units
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> [!failure]
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> One unit type typical was missing `Area` quantities.
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> Another had no takeoff.
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#### Labor Plan
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$$
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\mathbb{E}\left[\frac{\text{Hours Per Unit}}{\text{Openings Per Unit}}\right] \approx .75~\text{Hours Per Opening}
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$$
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High Rise .110--.120 hr/sqft
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## 2026-01-09 12:00
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$$
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\frac{146097}{400} = 365.2425~\text{Days Per Year}
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\frac{20871}{400} = 52.1775~\text{Weeks Per Year}
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\frac{6957}{1600} = 4.348125~\text{Weeks Per Month}
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$$
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$$
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\frac{365.2425~\text{Days Per Year}}{7~\text{Days Per Week}}
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= 52.1775~\text{Weeks Per Year}
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$$
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$$
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\frac{52.1775~\text{Weeks Per Year}}{12~\text{Months Per Year}}
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= 4.348125~\text{Weeks Per Month}
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$$
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## 2026-01-09 14:45
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[[bid-price-modeling]]
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Suppose a true cost model,
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accounting for all relevant information available at time $t$.
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$C(t)$ returns a distribution whose [scale](https://en.wikipedia.org/wiki/Scale_parameter)
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decreases with $t$, and $C(0)$ maps to a single value.
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$t>0$ is time until the final payment.
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+18
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@@ -12,8 +12,15 @@ title: Modeling Bid Prices Under Intrinsic Cost Uncertainty
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---
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# Modeling Bid Prices Under Intrinsic Cost Uncertainty
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The cost of a construction project is inherently uncertain until it is completed,
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therefore the most accurate model of cost is a distribution of possible costs.
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Customers request bids as a single cost, however,
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so a contractor must determine some function
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to convert from the true cost model to a single bid price.
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> [!warning]
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> This text is almost entirely LLM output.
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> From this point forward,
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> this text is almost entirely LLM output.
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> I don't intend to keep or use any significant portions of it.
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Consider a construction project characterized by an intrinsic but unknown final cost $C$.
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@@ -28,9 +35,12 @@ $$
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C : \Omega \to [0,\infty)
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$$
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> Read as
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> "C is a function from omega to the interval from zero to infinity, including zero."
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with [distribution](https://en.wikipedia.org/wiki/Probability_distribution) $\mu_C$.
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The distribution $\mu_C$ summarizes all available information at the time of bidding,
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The distribution $\mu_C$ accounts all available information at the time of bid,
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including quantities, labor productivity uncertainty,
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market conditions, subcontractor pricing variability,
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and correlation structures inherent to the estimator's assumptions.
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@@ -59,7 +69,7 @@ mapping a cost distribution $\mu_C$ to a **scalar** (a single value).
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Examples of such functionals include:
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### 1. Risk-neutral expectation
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## 1. Risk-neutral expectation
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$$
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\Phi(\mu_C) = \mathbb{E}[C],
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@@ -69,7 +79,7 @@ $$
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where $\mathbb{E}[\cdot]$ denotes the [expected value](https://en.wikipedia.org/wiki/Expected_value).
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### 2. Risk-adjusted expectation
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## 2. Risk-adjusted expectation
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$$
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\Phi(\mu_C) = \mathbb{E}[C] + \lambda\sqrt{\mathrm{Var}[C]},
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@@ -80,9 +90,9 @@ $$
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where $\mathrm{Var}[C]$ is the [variance](https://en.wikipedia.org/wiki/Variance)
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and $\lambda>0$ is a risk-loading parameter.
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> This mirrors mean--variance pricing common in portfolio theory.
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> This mirrors mean-variance pricing common in portfolio theory.
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### 3. Quantile-based pricing
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## 3. Quantile-based pricing
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$$
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\Phi(\mu_C) = Q_p(C),
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@@ -93,7 +103,7 @@ $$
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where $Q_p$ is the $p$-[quantile](https://en.wikipedia.org/wiki/Quantile)
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of the distribution.
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### 4. Utility-maximizing bid
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## 4. Utility-maximizing bid
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Under a bidder [utility](https://en.wikipedia.org/wiki/Utility) function $U$,
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@@ -106,7 +116,7 @@ $$
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> [$\arg\max$](https://en.wikipedia.org/wiki/Arg_max) is the value of $b$ that maximizes the expression.
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***
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## Conclusion
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The central tension is:
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