Bibliographic record
Abstract
In 1922, E. Delassus found out four-bar linkages including parallel screw joints (or helical pairs), which are movable with one degree of freedom. The Delassus linkages can move only when geometric conditions based on the Euclidean metric are achieved; their mobility is said to be paradoxical. Delassus stated that there is no paradoxical four-bar linkage with three helical H pairs and one prismatic P pair. In fact, Delassus did one error of logical deduction. After the error detection, the paper introduces a new HHHP linkage with a paradoxical mobility. Its three H axes are parallel and intersect a plane that is orthogonal to the H axes in three points forming an isosceles triangle. The P pair is parallel to the triangle side, which has a variable length. The three pitches have to satisfy one scalar relation. Through the consideration of helical trajectories in relative motions, the new mechanism is related to a geometric property of the right helicoid. Helices with a pitch that is half the helicoid pitch can be drawn on the right helicoid.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.003 | 0.007 |
| Scholarly communication | 0.002 | 0.009 |
| Open science | 0.002 | 0.005 |
| Research integrity | 0.003 | 0.003 |
| Insufficient payload (model declined to judge) | 0.012 | 0.003 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".