Chang, RichardOverview
Publication Timeline
Most widely held works by
Richard Chang
Stateoftheartreactor consequence analysis (SOARCA) report : draft report for comment
(
)
4 editions published in 2012 in English and held by 157 WorldCat member libraries worldwide
Contemporary criminal justice
by Harry W More
(
Book
)
2 editions published in 1974 in English and held by 148 WorldCat member libraries worldwide
Stateoftheartreactor consequence analyses (SOARCA) report
by Richard Chang
(
)
2 editions published in 2012 in English and held by 147 WorldCat member libraries worldwide
Historians and Meiji statesmen
by Richard Chang
(
Book
)
1 edition published in 1978 in English and held by 7 WorldCat member libraries worldwide
Historians and Taisho statesmen
by Richard Chang
(
Book
)
1 edition published in 1978 in English and held by 6 WorldCat member libraries worldwide
On the structure of NP computations under Boolean operators
by Richard Chang
(
Book
)
2 editions published in 1991 in English and held by 4 WorldCat member libraries worldwide A central theme of this thesis is the development of the hard/easy argument which shows intricate connections between the Boolean Hierarchy and the Polynomial Hierarchy. The hard/easy argument shows that the Boolean Hierarchy cannot collapse unless the Polynomial Hierarchy also collapses. The results shown in this regard are improvements over those previously shown by Kadin. Furthermore, it is shown that the hard/easy argument can be adapted for Boolean hierarchies over incomplete NP languages. That is, under the assumption that certain incomplete languages exist, the Boolean hierarchies over those languages must be proper (infinite) hierarchies. Finally, this thesis gives an application of the hard/easy argument to resolve the complexity of a natural problem  the unique satisfiability problem. This last refinement of the hard/easy argument also points out some longignored issues in the definition of randomized reductions
The Boolean hierarchy and the polynomial hierarchy : a closer connection
by Richard Chang
(
Book
)
2 editions published in 1989 in English and held by 4 WorldCat member libraries worldwide Abstract: "We show that if the Boolean hierarchy collapses to its k[superscript th] level, then the polynomial hierarchy collapses to the k[superscript th] level of the difference hierarchy of [formula] languages."
A relationship between difference hierarchies and relativized polynomial hierarchies
by Richard Beigel
(
Book
)
2 editions published in 1991 in English and held by 4 WorldCat member libraries worldwide Chang and Kadin have shown that if the difference hierarchy over NP collapses to level $k$, then the polynomial hierarchy (PH) is equal to the $k$th level of the difference hierarchy over $\Sigma_{2}[superscript]{p}$. We simplify their proof and obtain a slightly stronger conclusion: If the difference hierarchy over NP collapses to level $k$, then PH = $\left(P_{(k1)tt}[superscript]{NP}\right)[supers cript]{NP}$. We also extend the result to classes other than NP: For any class $C$ that has $\leq_{m}[superscript]{p}$complete sets and is closed under $\leq_{conj}[superscript]{p}$ and $\leq_{m}[superscript]{NP}$reductions, if the difference hierarchy over $C$ collapses to level $k$, then $PH[superscript]{C} = $\left(P_{(k1)tt}[superscript]{NP}\right)[supers cript]{C}$. Then we show that the exact counting class $C_{=}P$ is closed under $\leq_{disj}[superscript]{p}$ and $\leq_{m}[superscript]{coNP}$reductions. Consequently, if the difference hierarchy over $C_{=}P$ collapses to level $k$ then $PH[superscript]{PP}$ is equal to $\left(P_{(k1)tt}[superscript]{NP}\right)[supers cript]{PP}$. In contrast, the difference hierarchy over the closely related class PP is known to collapse
An example of a theorem that has contradictory relativizations and a diagonalization proof
by Richard Chang
(
Book
)
2 editions published in 1989 in English and held by 4 WorldCat member libraries worldwide Abstract: "We construct a computable space bound S(n), with n² [less than] S(n) [less than] n³ and show by diagonalization that DSPACE[S(n)] = DSPACE[S(n) log n]. Moreover, we show that there exists an oracle A such that DSPACE[superscript A][S(n)] [is not equal to] DSPACE[superscript A][S(n) log n]. This is a counterexample to the belief that if a theorem has contradictory relativizations, then it connot be proved using standard techniques like diagonalization [7]
On computing Boolean connectives of characteristic functions
by Richard Chang
(
Book
)
1 edition published in 1990 in English and held by 4 WorldCat member libraries worldwide Abstract: "We study the existence of polynomial time Boolean connective functions for languages. A language L has an AND function if there is a polynomial time f such that [formula]. L has an OR function if there is a polynomial time g such that [formula]. While all NPcomplete sets have these functions, we show that Graph Isomorphism, which is probably not complete, also has them. We characterize the complete sets for the classes D[superscript P] and [formula] in terms of AND and OR, and we relate these functions to the structure of the Boolean hierarchy and the query hierarchies
Random reductions in the Boolean hierarchy are not robust
by Richard Chang
(
Book
)
2 editions published in 1990 in English and held by 4 WorldCat member libraries worldwide Abstract: "We investigate random reductions from complete sets in the Boolean Hierarchy to their complements. We show that under the assumption that the Polynomial Hierarchy is infinite, the error probability of such reductions cannot be significantly lower than a constant. This constant depends on the classes in question. Thus, random reductions in the Boolean Hierarchy are not robust. We also show that the trivial random reductions between classes at the second level of the Boolean Hierarchy are optimal."
On the structure of bounded queries to arbitrary NP sets
by Richard Chang
(
Book
)
2 editions published in 1988 in English and held by 4 WorldCat member libraries worldwide Abstract: "In [Kad87b], Kadin showed that if the Polynomial Hierarchy (PH) has infinitely many levels, then for all k, [formula]. In this paper, we extend Kadin's technique to show that a proper query hierarchy is not an exclusive property of SAT. In fact, for any A [formula], if PH is infinite, then [formula]. Moreover, for the case of parallel queries, we show that P[formula] is not contained in P[formula]. We claim that having a proper query hierarchy is a consequence of the oracle access mechanism and not a result of the 'hardness' of a set. To support this claim, we show that assuming PH is infinite, one can construct an intermediate set B [formula] so that [formula]. That is, the query hierarchy for B grows as 'tall' as the query hierarchy for SAT
On the structure of uniquely satisfiable formulas
by Richard Chang
(
Book
)
1 edition published in 1990 in English and held by 4 WorldCat member libraries worldwide Abstract: "This paper presents some new results on the computational complexity of the set of uniquely satisfiable Boolean formulas (USAT). Valiant and Vazirani showed that USAT is complete for the class D[superscript P] under randomized reductions. In spite of the fact that the probability bound of this reduction is low, we show that USAT captures many properties possessed by D[superscript P] manyone complete sets. We show that the structure of USAT can affect the structure of D[superscript P] and the entire Polynomial Hierarchy (PH) as well. That is, 1. if USAT [formula], then D[superscript P] = coD[superscript P] and PH collapses
Historians and the Taisho Statesmen
by Richard T Chang
(
)
2 editions published in 1984 in No Linguistic content and English and held by 2 WorldCat member libraries worldwide This data collection contains data from questionnaire sent to 68 historians in Japan for their assessments of 18 statesmen active during the Taisho period in Japan (19121926). The data include biographical information on the respondents, such as birthplace, year of birth, Marxist or nonMarxist affiliation, university of graduation, status (e.g., professor, assistant professor, or doctoral candidate), faculty (discipline), and academic specialization. The file also includes the historians' assessments of the Taisho statesmen on an interval scale of five, from most important, most influential to least important, least influential. For a related data collection, see HISTORIANS AND THE MEIJI STATESMEN (ICPSR 7653)
Optimizing customer value
(
Visual
)
1 edition published in 1997 in English and held by 2 WorldCat member libraries worldwide Explains ways you organization can enhance its quality to service customers better, and increase the perceived value of your products and services
The church at the millennium : eight bishops respond
(
Visual
)
1 edition published in 2000 in English and held by 2 WorldCat member libraries worldwide
The Passion plan putting your passion to work
(
Visual
)
1 edition published in 2001 in English and held by 2 WorldCat member libraries worldwide Designed to increase one's selfawareness of their true passion in life, and to illustrate how cultivating this passion opens doors to both personal and professional success. Provides guidelines for developing one's own Passion Plan and vignettes throughout highlight individuals as they progress through the Passion Plan sevenstep process
Historians and the Meiji Statesmen
by Richard Chang
(
)
2 editions published in 1984 in No Linguistic content and English and held by 2 WorldCat member libraries worldwide This data collection contains survey information for 127 historians in Japan and 14 historians in England and the United States on their assessments of 40 Meiji statesmen active in the Meiji period in Japan (18681912). Part 1 contains data collected from the Japanese respondents, including their rankings of the statesmen on a fivepoint interval scale (from most important, most influential, to least important, least influential) and a cumulative ranking on a tenpoint interval scale. Part 1 also includes biographical information about the interview respondents, i.e., birthplace, year of birth, university of graduation, and field of study. Part 2 contains data collected from the English and American respondents, including their rankings of the Meiji statesmen on the fivepoint interval scale. For a list of the 40 Meiji statesmen, details of the five ranks, and a description of the criteria for the tenpoint interval scale, see Appendices C and D, and Table 16 in Chang, Richard. HISTORIANS AND MEIJI STATESMEN. Gainesville, FL: University of Florida Press, 1970. For a related data collection, see HISTORIANS AND THE TAISHO STATESMEN (ICPSR 7608)
On the superelastic response of nickeltitaniumalloy archwires in flexure
by Richard Chang
(
Book
)
1 edition published in 1994 in English and held by 2 WorldCat member libraries worldwide
Near speedoflight onchip electrical interconnects
by Richard Chang
(
Book
)
1 edition published in 2002 in English and held by 1 WorldCat member library worldwide more
fewer
Audience Level
Related Identities
Associated Subjects
Algebra, Boolean Anglican CommunionForecasting Assistance in emergencies Bishops Computational complexity Computer programming Computer scienceMathematics Consumer satisfaction Criminal justice, Administration of Customer services Emergency management Episcopal Church Historians Industrial safety Japan Machine theory Nuclear facilitiesSafety measures Nuclear power plantsSafety measures Orthodontic appliances Peach Bottom Atomic Power Station (Pa.) Polynomials Selfactualization (Psychology) Set theory Statesmen SuccessPsychological aspects United States

Languages
