scholarly journals On the Δ n 1 Problem of Harvey Friedman

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1477 ◽  
Author(s):  
Vladimir Kanovei ◽  
Vassily Lyubetsky
Keyword(s):  
Generic Extension ◽  
Special Character ◽  
Almost Disjoint ◽  
Definition Of

In this paper, we prove the following. If n≥3, then there is a generic extension of L, the constructible universe, in which it is true that the set P(ω)∩L of all constructible reals (here—subsets of ω) is equal to the set P(ω)∩Δn1 of all (lightface) Δn1 reals. The result was announced long ago by Leo Harrington, but its proof has never been published. Our methods are based on almost-disjoint forcing. To obtain a generic extension as required, we make use of a forcing notion of the form Q=Cℂ×∏νQν in L, where C adds a generic collapse surjection b from ω onto P(ω)∩L, whereas each Qν, ν<ω2L, is an almost-disjoint forcing notion in the ω1-version, that adjoins a subset Sν of ω1L. The forcing notions involved are independent in the sense that no Qν-generic object can be added by the product of C and all Qξ, ξ≠ν. This allows the definition of each constructible real by a Σn1 formula in a suitably constructed subextension of the Q-generic extension. The subextension is generated by the surjection b, sets Sω·k+j with j∈b(k), and sets Sξ with ξ≥ω·ω. A special character of the construction of forcing notions Qν is L, which depends on a given n≥3, obscures things with definability in the subextension enough for vice versa any Δn1 real to be constructible; here the method of hidden invariance is applied. A discussion of possible further applications is added in the conclusive section.

scholarly journals Models of Set Theory in which Nonconstructible Reals First Appear at a Given Projective Level

Mathematics ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 910 ◽  
Author(s):  
Vladimir Kanovei ◽  
Vassily Lyubetsky
Keyword(s):  
Lower Limit ◽  
Set Theory ◽  
Generic Extension ◽  
Projective Class ◽  
Almost Disjoint ◽  
Projective Hierarchy ◽  
Models Of Set Theory

Models of set theory are defined, in which nonconstructible reals first appear on a given level of the projective hierarchy. Our main results are as follows. Suppose that n ≥ 2 . Then: 1. If it holds in the constructible universe L that a ⊆ ω and a ∉ Σ n 1 ∪ Π n 1 , then there is a generic extension of L in which a ∈ Δ n + 1 1 but still a ∉ Σ n 1 ∪ Π n 1 , and moreover, any set x ⊆ ω , x ∈ Σ n 1 , is constructible and Σ n 1 in L . 2. There exists a generic extension L in which it is true that there is a nonconstructible Δ n + 1 1 set a ⊆ ω , but all Σ n 1 sets x ⊆ ω are constructible and even Σ n 1 in L , and in addition, V = L [ a ] in the extension. 3. There exists an generic extension of L in which there is a nonconstructible Σ n + 1 1 set a ⊆ ω , but all Δ n + 1 1 sets x ⊆ ω are constructible and Δ n + 1 1 in L . Thus, nonconstructible reals (here subsets of ω ) can first appear at a given lightface projective class strictly higher than Σ 2 1 , in an appropriate generic extension of L . The lower limit Σ 2 1 is motivated by the Shoenfield absoluteness theorem, which implies that all Σ 2 1 sets a ⊆ ω are constructible. Our methods are based on almost-disjoint forcing. We add a sufficient number of generic reals to L , which are very similar at a given projective level n but discernible at the next level n + 1 .

Sensitivity Analysis for the Junction Temperature Measurement of the LED 12

2012 ◽  
Vol 516-517 ◽  
pp. 425-432
Author(s):  
Yeun Ming Tzou ◽  
Wei Keng Lin ◽  
Bo Ruei Chen ◽  
Paul Wang
Keyword(s):  
Sensitivity Analysis ◽  
Steady State ◽  
Junction Temperature ◽  
Retrieval Time ◽  
Package Design ◽  
Optical Character ◽  
Special Character ◽  
Significant Difference ◽  
Definition Of ◽  
Residual Power

LED have the special character that LED break out radiant power and heat when it is operating. Recently photo efficiency of LED is just 20% and almost residual power converts heat. But heat causes bad reliability and changes of electrical and optical character negatively. Therefore, the LED package design is the first issue for the solution of the heat problem. This study was to design a LED T-junction measurement platform which based on the required of JEDEC-51-1. The experiment results include four parts: (1) Manually retrieve VFss voltage, the temperature raised around 3~5°C between the chip junction temperature and LED pin; (2) Automatically retrieve VFss voltage, the temperature raised around 30~50°C for the same condition; (3) From trend of TJ vs. time, the definition of the steady state require at least 900 sec, but we would suggest 1200 sec in this study; (4) There is no significant difference of the TJ for the retrieval time 100 μs and 10μs. The important achievement of the results of this experiment can be used as a reference for TJ measurement.

scholarly journals Intellectual Fascism

Fascism ◽  
2014 ◽  
Vol 3 (2) ◽  
pp. 69-92
Author(s):  
Lena Berggren
Keyword(s):  
Formation Process ◽  
National Socialism ◽  
Important Influence ◽  
Original Form ◽  
Political Scientist ◽  
The Core ◽  
Core Cluster ◽  
Special Character ◽  
Core Concepts ◽  
Definition Of

The focus of this article is the ideological formation of so called ‘New-Swedish Socialism’, an indigenous form of fascist thought formulated by the Swedish ideologue Per Engdahl (1909–1994) in the early 1930s. New-Swedish Socialism should not be equated with either Italian-styled Fascism or National Socialism, but must be seen as an original form of fascist thought. This fascist variant can be described as comparatively flexible, low-key and intellectual. The present analysis of the formation of New-Swedish Socialism follows the model for ideological analysis suggested by the British political scientist Michael Freeden. Freeden’s analytical mode defines an ideology in terms of a core cluster of interrelated and ineliminable political concepts which are essentially contestable. Starting from a definition of generic fascism and using the core concepts that can be identified from this definition, the presence, de-contestation and interrelatedness of these core concepts within New-Swedish Socialism is studied and analyzed. This article addresses whether New-Swedish Socialism can correctly be labelled fascist as well as capturing its special character as a fascist variant in its own right. The study has been limited to the ideological formation process in the early and mid-1930s but Engdahl remained an important influence on Swedish as well as European fascism throughout his life.

Cohen-stable families of subsets of integers

2001 ◽  
Vol 66 (1) ◽  
pp. 257-270 ◽  
Author(s):  
Miloš S. Kurilić
Keyword(s):  
Countable Family ◽  
Generic Extension ◽  
Mad Families ◽  
Stable Splitting ◽  
Almost Disjoint ◽  
Maximal Almost Disjoint ◽  
Infinite Set ◽  
Families Of Subsets

AbstractA maximal almost disjoint (mad) family ⊆ [ω]ω is Cohen-stable if and only if it remains maximal in any Cohen generic extension. Otherwise it is Cohen-unstable. It is shown that a mad family. .is Cohen-unstable if and only if there is a bijection G from ω to the rationals such that the sets G[A]. A ∈ are nowhere dense. An ℵ0-mad family, . is a mad family with the property that given any countable family ℬ ⊂ [ω]ω such that each element of ℬ meets infinitely many elements of in an infinite set there is an element of meeting each element of ℬ in an infinite set. It is shown that Cohen-stable mad families exist if and only if there exist ℵ0-mad families. Either of the conditions b = c or a < cov() implies that there exist Cohen-stable mad families. Similar results are obtained for splitting families. For example, a splitting family. . is Cohen-unstable if and only if there is a bijection G from ω to the rationals such that the boundaries of the sets G[S], S ∈ are nowhere dense. Also. Cohen-stable splitting families of cardinality ≤ κ exist if and only if ℵ0-splitting families of cardinality ≤ κ exist.

scholarly journals On the ‘Definability of Definable’ Problem of Alfred Tarski

Mathematics ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 2214
Author(s):  
Vladimir Kanovei ◽  
Vassily Lyubetsky
Keyword(s):  
Generic Extension ◽  
Alfred Tarski ◽  
Almost Disjoint ◽  
Further Development

In this paper we prove that for any m≥1 there exists a generic extension of L, the constructible universe, in which it is true that the set of all constructible reals (here subsets of ω) is equal to the set D1m of all reals definable by a parameter free type-theoretic formula with types bounded by m, and hence the Tarski ‘definability of definable’ sentence D1m∈D2m (even in the form D1m∈D21) holds for this particular m. This solves an old problem of Alfred Tarski (1948). Our methods, based on the almost-disjoint forcing of Jensen and Solovay, are significant modifications and further development of the methods presented in our two previous papers in this Journal.

Introductory paper

1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan
Keyword(s):  
Line Intensity ◽  
Classification Scheme ◽  
Two Dimensional ◽  
Spectral Classification ◽  
Dimensional Array ◽  
Rr Lyrae ◽  
Metallic Line ◽  
Introductory Paper ◽  
Parameter Varying ◽  
Definition Of

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.

2.2. Working Group 2: Conceptual Definitions of Reference Coordinate Systems for Earth Dynamics

1975 ◽  
Vol 26 ◽  
pp. 21-26
Keyword(s):  
Coordinate System ◽  
Working Group ◽  
General Character ◽  
Coordinate Systems ◽  
Reference Coordinate System ◽  
Group 2 ◽  
Definition Of ◽  
Earth Dynamics

An ideal definition of a reference coordinate system should meet the following general requirements:1. It should be as conceptually simple as possible, so its philosophy is well understood by the users.2. It should imply as few physical assumptions as possible. Wherever they are necessary, such assumptions should be of a very general character and, in particular, they should not be dependent upon astronomical and geophysical detailed theories.3. It should suggest a materialization that is dynamically stable and is accessible to observations with the required accuracy.

Symbiotic Stars at Optical, Infrared and Radio Wavelengths

1979 ◽  
Vol 46 ◽  
pp. 125-149 ◽  
Author(s):  
David A. Allen
Keyword(s):  
Temperature Regime ◽  
Type Star ◽  
Stellar Systems ◽  
Symbiotic Stars ◽  
Lower Excitation ◽  
Definition Of ◽  
Original Type

No paper of this nature should begin without a definition of symbiotic stars. It was Paul Merrill who, borrowing on his botanical background, coined the termsymbioticto describe apparently single stellar systems which combine the TiO absorption of M giants (temperature regime ≲ 3500 K) with He II emission (temperature regime ≳ 100,000 K). He and Milton Humason had in 1932 first drawn attention to three such stars: AX Per, CI Cyg and RW Hya. At the conclusion of the Mount Wilson Ha emission survey nearly a dozen had been identified, and Z And had become their type star. The numbers slowly grew, as much because the definition widened to include lower-excitation specimens as because new examples of the original type were found. In 1970 Wackerling listed 30; this was the last compendium of symbiotic stars published.

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

Initial Polymerization Sites Indicated During Mitochondrial Oxidation of Diaminobenzidine after Toluene Treatment

1977 ◽  
Vol 35 ◽  
pp. 408-409
Author(s):  
W. A. Shannon ◽  
M. A. Matlib
Keyword(s):  
Membrane Permeability ◽  
Cytochrome Oxidase ◽  
Rat Liver ◽  
Precise Definition ◽  
Cytochemical Localization ◽  
Oxidative Reaction ◽  
Mitochondrial Oxidation ◽  
Definition Of ◽  
Exogenous Substrates

Numerous studies have dealt with the cytochemical localization of cytochrome oxidase via cytochrome c. More recent studies have dealt with indicating initial foci of this reaction by altering incubation pH (1) or postosmication procedure (2,3). The following study is an attempt to locate such foci by altering membrane permeability. It is thought that such alterations within the limits of maintaining morphological integrity of the membranes will ease the entry of exogenous substrates resulting in a much quicker oxidation and subsequently a more precise definition of the oxidative reaction.The diaminobenzidine (DAB) method of Seligman et al. (4) was used. Minced pieces of rat liver were incubated for 1 hr following toluene treatment (5,6). Experimental variations consisted of incubating fixed or unfixed tissues treated with toluene and unfixed tissues treated with toluene and subsequently fixed.

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