diff --git a/2026-01-08.md b/2026-01-08.md index 1034d79..55746f0 100644 --- a/2026-01-08.md +++ b/2026-01-08.md @@ -12,7 +12,14 @@ tags: ## 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]] diff --git a/2026-01-09.md b/2026-01-09.md new file mode 100644 index 0000000..13cc4c7 --- /dev/null +++ b/2026-01-09.md @@ -0,0 +1,86 @@ +--- +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. diff --git a/bid-price-modeling.md b/bid-price-modeling.md index 30a1af1..df5a4fc 100644 --- a/bid-price-modeling.md +++ b/bid-price-modeling.md @@ -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: