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59 items with this tag.

Nov 03, 2026
LIT-1975: Adjustable robust solutions of uncertain linear programs
- operations-research
- mathematics
Nov 03, 2026
THEORY-1303: For an uncertain linear program, a decision fixed before the data are revealed must satisfy every realization at once (the robust counterpart, ∃ solution ∀ data), while a decision that may adjust after them need only have a feasible adjustment for each (the adjustable robust counterpart, ∀ data ∃ adjustment); the second is never more conservative and can be feasible where the first is not, the two coincide when each constraint's uncertainty is its own, and decisions may be restricted between them by what part of the data they read or by the form of the rule
- operations-research
- mathematics
Oct 30, 2026
CLAIM-500: The governance-induced kind of frustration is not idle: some failures of an organization's actual updates to meet demands that an admissible update would meet are explained by how influence is allocated, and not by step size, curvature, noise, conditioning or a fixed weighting rule
Oct 30, 2026
QUESTION-340: When does a cache replacement value based on distance from the current query beat recency-based eviction: does a competitive analysis, or an analysis under a stated distribution of query paths, say so, and do experiments in another system that vary cycle length relative to cache size recover the crossover with MRU?
- databases
- operations-research
Oct 30, 2026
QUESTION-347: On another database and web stack with native materialized views and queries of graded cost, does a stored query result kept current on every update lose to recomputation exactly when reading it costs about as much as recomputing it and its refresh runs on the resource that serves requests, and win otherwise?
- databases
- operations-research
Oct 27, 2026
CLAIM-465: An organization's flexibility among regimes depends on the conditions under which a regime gives up authority as well as those under which it takes it, so escalation without a release condition leaves authority with a regime after the demand that justified it has passed
Oct 27, 2026
LIT-1613: Engineering a Safer World: Systems Thinking Applied to Safety
- operations-research
- complex-systems
Oct 27, 2026
TERM-085: correctability, of an institutional arrangement for a corrective objective: the chance that the arrangement, starting from the description of the problem it actually has, finds, authorizes, coordinates and carries out a plan achieving the objective before the deadline and within its resources
Oct 22, 2026
CASE-127: United 173 and Crew Resource Management: a crew whose concern about the fuel did not reach the captain as a demand to act, and the training that followed, which asked for participative captains and assertive crews
Oct 22, 2026
CASE-135: The Brookhollow Apartments fire, Wichita, 2023: a mayday after a stair roof collapses on two companies opens a second emergency inside a search for a trapped resident, and an independent review finds an unorganized rescue effort without finding that it changed the outcome
Oct 22, 2026
CASE-138: Challenger to Columbia: NASA corrected its launch decisions and its safety organization after 1986, and the Columbia board found in 2003 that related organizational failure mechanisms had recurred, while its lessons-learned system was little used in between
Oct 22, 2026
CLAIM-422: A successful corrective act, an executable procedure and a maintained organizational capacity are three different things, so an organization can record a correction, even rewrite its rules, without the corrected capacity being maintained
Oct 22, 2026
LIT-1365: National Incident Management System, Third Edition
Oct 22, 2026
LIT-1371: Aircraft Accident Report: United Airlines, Inc., McDonnell-Douglas DC-8-61, N8082U, Portland, Oregon, December 28, 1978
- operations-research
- agency
Oct 22, 2026
LIT-1374: Post-Incident Analysis: Independent Review of the Brookhollow Apartment Fire
Oct 22, 2026
LIT-1378: NASA: Better Mechanisms Needed for Sharing Lessons Learned
- operations-research
- society-and-governance
Oct 22, 2026
LIT-1386: The Evolution of Crew Resource Management Training in Commercial Aviation
Oct 22, 2026
LIT-1393: Report of the Presidential Commission on the Space Shuttle Challenger Accident
Oct 20, 2026
QUESTION-224: Is Bruno and Chaudhuri's single-index online tuner within some constant, such as 3 + 2f, of the offline optimum on every workload whose per-statement savings and losses are at most a fraction f of the build cost?
- databases
- operations-research
Oct 20, 2026
QUESTION-227: Does the widen-on-push, narrow-on-fetch rule for a cached interval's width converge to within a stated factor of the best fixed width, and does it hold its cost against the best fixed width and an adaptive cache-or-not rule on data other than its authors' traces?
- databases
- operations-research
Oct 19, 2026
QUESTION-194: How far is a periodic greedy that switches a capped number of page fragments between caching and materializing, to keep the share of fresh fragments served above a threshold, from the best plan that meets the same threshold?
- databases
- operations-research
Oct 18, 2026
CLAIM-351: A zero aggregate gradient does not show that the demands it aggregates are reconciled: with positive weights it holds both when every demand's own gradient vanishes and when nonzero gradients cancel, and in the second case no update improves them all to first order; even the first is only joint first-order stationarity, which a demand's maximum or saddle also has
Oct 18, 2026
CLAIM-357: The frustration residual and governance regret separate structural infeasibility, realized violation and minimax suboptimality, and identify none of them as thwarting: a positive residual says no admissible update meets every declared requirement, a positive regret only that the actual update's worst residual exceeds the best achievable, which can hold while every requirement is met, and actual violation needs regret above the negative residual; aggregate performance does not tell infeasibility from realized violation, and the multipliers that certify infeasibility need not be the weights governance assigns
Oct 18, 2026
CLAIM-365: On a norm-ball update set the local frustration residual Φ_r = min over ‖d‖ ≤ r of max_i(ε_i + g_iᵀd) equals the maximum over the simplex of Σλ_iε_i − r‖Σλ_ig_i‖_*, so infeasibility of the declared improvements has a certificate, and any admissible actual update exceeds Φ_r by a nonnegative governance regret
Oct 18, 2026
LIT-1212: Multiple-gradient descent algorithm (MGDA) for multiobjective optimization
Oct 18, 2026
LIT-1217: Practical Byzantine Fault Tolerance
- network-science
- operations-research
Oct 16, 2026
LIT-1155: The geometry of graphs and some of its algorithmic applications
- mathematics
- operations-research
Oct 16, 2026
THEORY-501: In weekly waste collection where each point's visit days are free and its bin capacity must cover the longest gap between visits, a genetic algorithm that searches visit schedules and derives bins from them builds routes about 6% cheaper than eight-hour Gurobi incumbents but buys about 20% more bin capacity, ending level on overall cost at its best of 30 runs and 4–6% worse on a typical run, on five 12-point instances where the incumbents' own optimality gaps are 26–32%
- operations-research
Oct 16, 2026
THEORY-654: For full-state linear-quadratic regulation of a single-input plant, the return-difference identity keeps the sensitivity at or below 1 at every frequency, so the loop tolerates any gain increase, a gain cut to one half and at least 60° of phase error for any Q ≥ 0 and r > 0; the guarantee does not carry over when the state is replaced by an observer's estimate
- mathematics
- operations-research
Oct 16, 2026
THEORY-668: When the encoder is restricted to prunings of one fixed hierarchy of nested partitions, any non-negatively weighted sum of relevant information, irrelevant information and compression decomposes into per-node terms, so a bottom-up recursion finds the unique optimal tree with fewest leaves exactly in linear time, while greedy top-down splitting can miss information lying below a level that carries none; penalising irrelevant information only prunes the information-bottleneck tree
- information-theory
- operations-research
Oct 15, 2026
LIT-1080: Selection of Views to Materialize in a Data Warehouse
- databases
- operations-research
Oct 15, 2026
LIT-1083: An Efficient, Cost-Driven Index Selection Tool for Microsoft SQL Server
- databases
- operations-research
Oct 15, 2026
LIT-1084: Physical database design for relational databases
- databases
- operations-research
Oct 15, 2026
LIT-1091: Selection of views to materialize in a data warehouse
- databases
- operations-research
Oct 15, 2026
LIT-1092: Selection of Views to Materialize Under a Maintenance Cost Constraint
- databases
- operations-research
Oct 15, 2026
LIT-1094: Implementing data cubes efficiently
- databases
- operations-research
Oct 15, 2026
LIT-1101: Effective Page Refresh Policies for Web Crawlers
Oct 15, 2026
LIT-1105: Balancing Performance and Data Freshness in Web Database Servers
- databases
- operations-research
Oct 15, 2026
LIT-1109: Adaptive Precision Setting for Cached Approximate Values
- databases
- operations-research
Oct 15, 2026
LIT-1117: Offering a Precision-Performance Tradeoff for Aggregation Queries over Replicated Data
- databases
- operations-research
Oct 15, 2026
LIT-1118: WebView Materialization
- databases
- operations-research
Oct 15, 2026
LIT-1119: Synchronizing a Database to Improve Freshness
Oct 15, 2026
QUESTION-114: Is sorting a collection amortized search, and does physical database design, where a table is stored in one order and every further index is paid for in space and upkeep, give the joint cost model that the question on amortized retrieval lacks?
Oct 15, 2026
THEORY-332: For one index with no space limit, Bruno and Chaudhuri's online tuner, which builds the index once the savings it would have given have risen by its build cost above their last low and drops it once they have fallen by the build cost below their last high, is not three-competitive: when every statement's saving or loss is at most a fraction f of the build cost, a repeated workload makes it cost nearly 3 + 2f times the offline optimum, and one statement whose saving exceeds the build cost makes the ratio unbounded; no upper bound is shown
- databases
- operations-research
Oct 15, 2026
THEORY-345: Choosing indexes for a known mix of queries and updates, to minimize query cost plus a per-index upkeep, is NP-hard as the number of attributes and query types grows, and the tools built for it choose one stored order and a set of secondary indexes per table by searching configurations costed with the query optimizer's own estimates, optimal at best relative to those estimates, with no proved guarantee for their heuristics and no term for the one-time cost of building
- databases
- operations-research
Oct 15, 2026
THEORY-350: Under a budget on maintenance time, a stored view's upkeep depends on which other views are stored, so upkeep is not additive and adding a view can lower it, and greedily adding the single view of best saving per unit of upkeep can be arbitrarily bad; on OR view graphs a greedy over inverted tree sets gets 1 − 1/e of the saving of an optimum given as much upkeep, using up to twice the budget, if no tree-piece of the optimum alone exceeds the budget
- databases
- operations-research
Oct 15, 2026
THEORY-356: When stored views are never updated, greedily storing the view of largest marginal saving in query cost gets at least 1 − 1/e of the optimal saving on a data-cube lattice or any OR or AND view graph, against the optimum for the same number of views or for the space the greedy ends up using, which may exceed the budget by one view
- databases
- operations-research
Oct 15, 2026
THEORY-364: When each cached value is an interval its source guarantees to contain the current value, and a query must return an answer interval no wider than R whatever the true values, choosing the cheapest set of exact reads for a SUM is a 0/1 knapsack problem, NP-complete in general and solved by taking the narrowest intervals first when read costs are equal, and for a COUNT with a selection predicate the cheapest choice is the ⌈|T?| − R⌉ cheapest undecided tuples
- databases
- operations-research
Oct 15, 2026
THEORY-375: In one simulator evicting whole query-shaped cache regions, no replacement value function was best on every workload: a value based on distance from the current query beat LRU where queries clustered around a hot region or wandered with loops, while MRU was best on regular cyclic paths, by up to 2.3 times over the distance value and 9.6 times over LRU; none of the functions weighs what a region would cost to fetch again, and nothing is proved
- databases
- operations-research
Oct 15, 2026
THEORY-377: In Olston, Loo and Widom's simulations, a rule that multiplies a cached interval's width by 1 + α on a pushed refresh with probability min{ρ, 1}, and divides it by 1 + α on a query's exact fetch with probability min{1/ρ, 1}, settled within 1% of the best fixed width on one random walk and within 5% over eight walk settings; on a 50-host network-traffic trace, restricted to exact copies, it almost matched a tuned adaptive cache-or-not rule, and with a 50-value cache, where queries tolerated imprecision, it cost less; that it converges to the best width is argued, not proved
- databases
- operations-research
Oct 15, 2026
THEORY-378: When items change as independent Poisson processes with known rates and a fixed total refresh rate is shared among them, refreshing every item equally keeps the copy at least as fresh and at most as old, averaged over time, as refreshing in proportion to change rate, for any spread of rates; the freshness-optimal share rises and then falls with change rate and gives nothing to items that change too fast for the budget
Oct 15, 2026
THEORY-382: When a web server keeps each page fragment either cached and invalidated by updates or stored and refreshed after them, materializing trades staleness for response time, and in one synthetic simulation with fixed costs a periodic greedy that moves a capped number of fragments between the two, to keep the share of fresh fragments served above a set threshold, tracked that threshold by the authors' reading of its curves, answered faster than caching alone and recovered from overload by materializing everything; no bound on its distance from the best plan is shown
- databases
- operations-research
Oct 15, 2026
THEORY-383: On one Apache and Informix server answering cheap indexed selections over 1000 pages, a page whose query result was stored in the DBMS and refreshed on every update answered more slowly than one recomputed on each request at five or more updates per second, which the authors explain by reading the stored result costing about as much as recomputing it and its refresh loading the same DBMS, while a finished page stored at the web server and rewritten on every update answered 10 to 230 times faster than either
- databases
- operations-research
Oct 15, 2026
THEORY-386: When a cached interval of width W is kept valid by its source, which pushes a refresh at cost C_vr whenever the value leaves it, and queries fetch the exact value at cost C_qr whenever it is too wide, and the chances of the two per step go as 1/W² and as W, the expected refresh cost is least at W* = (ρK₁/K₂)^(1/3) with ρ = 2C_vr/C_qr, where ρ times the chance of a pushed refresh equals the chance of a fetch
- databases
- operations-research
Oct 09, 2026
LIT-868: A Generalized Information-Theoretic Framework for the Emergence of Hierarchical Abstractions in Resource-Limited Systems
- information-theory
- operations-research
Sep 29, 2026
LIT-352: A numerical algorithm for block-diagonal decomposition of matrix *-algebras with application to semidefinite programming
- mathematics
- operations-research
Sep 25, 2026
LIT-008: Modeling and solving an integrated periodic vehicle routing and capacitated facility location problem in the context of solid waste collection
- operations-research
Sep 25, 2026
LIT-050: Mean-Field-Type Game Theory with Rosenblatt Noise
Sep 25, 2026
LIT-051: Lecture Notes on Control System Theory and Design
- mathematics
- operations-research

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