| 1. |
-
Imaging and assessing mobile technology for development
- 2024
-
Editorial collection (peer-reviewed)abstract
- Imaging and assessing mobile technology for development (M4D) means understanding the use of appropriate technologies and services, and how they directly or indirectly address socio-economic challenges. This book adopts various perspectives to identify the obstacles to affordable digital technologies in order to enable, enhance, and effect development. The book plays on the tension between success reports and optimistic projections, on one hand, and empirical evidence of technological belly splash, on the other hand. The areas covered include infusion of service education in computing education, the Rwandan establishment of African Centres of Excellence to promote the development of appropriate technology, the metaverse’s realisation in a mobile network-enabled “metaversity”, and difficulties detected when evaluating digitisation of distance learning, students’ security awareness, dissemination of agricultural information, and mobile payment. The decolonisation of community-based media and attempts to step outside the mobile network and Internet are also covered.
|
|
| 2. |
- Poon, Aubrey, 1987-
(author)
-
The transmission mechanism of Malaysian monetary policy : a time-varying vector autoregression approach
- 2017
-
In: Empirical Economics. - : Springer. - 0377-7332 .- 1435-8921. ; 55:2, s. 417-444
-
Journal article (peer-reviewed)abstract
- The aim of this paper is to determine whether the propagation and transmission mechanism of Malaysian monetary policy differed during the Asian Financial Crisis of 1997/1998 and the Global Financial Crisis of 2007/2008. The methodology employs a time-varying vector autoregression framework. The primary result is that despite having no evidence of time-variation within the propagation mechanism of Malaysian monetary policy the average contribution of a monetary policy shock to the variability of each macroeconomic variable: real GDP, inflation and the nominal effective exchange rate, differs between the two crises. This finding suggests that despite the propagation mechanism being relatively constant, Malaysia's monetary policy transmission mechanism evolves over time. We believe that the main mechanism driving this evolution is the time-variation in the variance-covariance matrix of the shocks of the model, not the coefficients. We also find some evidence that the implementation of capital controls reduced the influenceability of monetary policy on the Malaysian economy.
|
|
| 3. |
- Baxter, D., et al.
(author)
-
Recommended conventions for reporting results from direct dark matter searches
- 2021
-
In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 81:10
-
Journal article (peer-reviewed)abstract
- The field of dark matter detection is a highly visible and highly competitive one. In this paper, we propose recommendations for presenting dark matter direct detection results particularly suited for weak-scale dark matter searches, although we believe the spirit of the recommendations can apply more broadly to searches for other dark matter candidates, such as very light dark matter or axions. To translate experimental data into a final published result, direct detection collaborations must make a series of choices in their analysis, ranging from how to model astrophysical parameters to how to make statistical inferences based on observed data. While many collaborations follow a standard set of recommendations in some areas, for example the expected flux of dark matter particles (to a large degree based on a paper from Lewin and Smith in 1995), in other areas, particularly in statistical inference, they have taken different approaches, often from result to result by the same collaboration. We set out a number of recommendations on how to apply the now commonly used Profile Likelihood Ratio method to direct detection data. In addition, updated recommendations for the Standard Halo Model astrophysical parameters and relevant neutrino fluxes are provided. The authors of this note include members of the DAMIC, DarkSide, DARWIN, DEAP, LZ, NEWS-G, PandaX, PICO, SBC, SENSEI, SuperCDMS, and XENON collaborations, and these collaborations provided input to the recommendations laid out here. Wide-spread adoption of these recommendations will make it easier to compare and combine future dark matter results.
|
|
| 4. |
|
|
| 5. |
- Mukhopadhyay, Sagnik, et al.
(author)
-
Separation Between Deterministic and Randomized Query Complexity
- 2018
-
In: SIAM journal on computing (Print). - : Siam Publications. - 0097-5397 .- 1095-7111. ; 47:4, s. 1644-1666
-
Journal article (peer-reviewed)abstract
- Saks and Wigderson 27th FOGS, IEEE Computer Society, as Alamitos, CA, 1986, pp. 29-38] conjectured that R-0(f) = Omega (D(f)(0.753...)) for all Boolean functions f, here R-0 denotes the randomized complexity and D denotes 10 determinist is query CCATI p1exit;,yr. We,show t hat for the pointer function GPW(rxs) defined by Goos. Pitassi, arid Watson [in Proceedings of the 56th FOCS, IEEE, Piscataway, NJ, 2015, pp. 1077-1088] the following hold: s) s) and (b) R-1(GPW(rxs)) = Irs), cyhere R1 denotes the randomized one-sided error query complexity. These results imply that (i) R-0(GPW(s2xs)) = O(D(GPW(s2xs))2/3) t hereby refuting the; conjecture of Saks and Wigdorson, and (ii) R-1 (GPW(sxs))- O(R-0(GPW(sxs))(2/3)), thereby providing a polynomial separation between the randomized zero -error and one-sided error query complexity measures.
|
|
| 6. |
- Ohlson, Sten, et al.
(author)
-
Weak affinity chromatography
- 1993. - 1
-
In: Handbook of affinity chromatography. - New York : Marcel Dekker. - 0824789393 ; , s. 299-314
-
Book chapter (other academic/artistic)
|
|
| 7. |
- Poon, Aubrey, 1987-, et al.
(author)
-
Do Recessions and Bear Markets Occur Concurrently across Countries? A Multinomial Logistic Approach
- 2024
-
In: Journal of Financial Econometrics. - : Oxford University Press. - 1479-8409 .- 1479-8417.
-
Journal article (peer-reviewed)abstract
- We introduce a novel multinomial logistic model for detecting and forecasting concurrent recessions and bear markets across multiple countries. Our framework leverages cross-country panel features and provides additional information for robust analysis. Through a comprehensive simulation study, we demonstrate the computational efficiency and accuracy of our model, even when handling multiple binary indicators. Applying our framework to empirical data from the United States, the UK, and Euro Area, we find that the multinomial logistic model produces superior medium-term forecasting of concurrent recession and bear market events across countries compared to multiple independent single logistic models. Additionally, our counterfactual analysis reveals that specific events, such as a recession and bear market in the United States, along with the tightening of financial conditions and a negative interest rate spread in the United States, increase the probability of concurrent and individual recession and bear market occurrences in the UK and Euro Area.
|
|
| 8. |
|
|
| 9. |
- Poon, Jia-Fei, et al.
(author)
-
Azastilbenes : a cut-off to p38 MAPK inhibitors
- 2013
-
In: Organic and biomolecular chemistry. - 1477-0520 .- 1477-0539. ; 11:27, s. 4526-4536
-
Journal article (peer-reviewed)abstract
- Inhibitors with vicinal 4-fluorophenyl/4-pyridine rings on a five- or six-membered heterocyclic ring are known to inhibit the p38 mitogen-activated protein kinase (MAPK), which is a potential target for rheumatoid arthritis and several different types of cancer. Several substituted azastilbene-based compounds with vicinal 4-fluorophenyl/4-pyridine rings were designed using computational docking, synthesized, and evaluated in a cell-free radiometric p38[small alpha] assay. The biochemical evaluation shows that the best inhibition (down to 110 nM) is achieved for azastilbene-based compounds having an isopropylamine substituent in the 2-position of the pyridine ring. The inhibition of p38 signaling in human breast cancer cells was observed for two of the compounds.
|
|
| 10. |
- Risse, Kilian, 1991-
(author)
-
On Long Proofs of Simple Truths
- 2022
-
Doctoral thesis (other academic/artistic)abstract
- Propositional proof complexity is the study of certificates of infeasibility. In this thesis we consider several proof systems with limited deductive ability and unconditionally show that they require long refutations of the feasibility of certain Boolean formulas. We show that the depth $d$ Frege proof system, restricted to linesize $M$, requires proofs of length at least $\exp\bigl(n/(\log M)^{O(d)}\bigr)$ to refute the Tseitin contradiction defined over the $n \times n$ grid graph, improving upon the recent result of Pitassi et al. [PRT21]. Along the way we also sharpen the lower bound of Håstad [Hås20] on the depth $d$ Frege refutation size for the same formula from exponential in $\tilde{\Omega}(n^{1/59d})$ to exponential in$\tilde{\Omega}(n^{1/(2d-1)})$. We also consider the perfect matching formula defined over a sparse random graph on an odd number of vertices $n$. We show that polynomial calculus over fields of characteristic $\neq 2$ and sum of squares require size exponential in $\Omega(n/\log^2 n)$ to refute said formula. For depth $d$ Frege we show that there is a constant $\delta > 0$ such that refutations of these formulas require size $\exp\bigl(\Omega(n^{\delta/d})\bigl)$. The perfect matching formula has a close sibling over bipartite graphs: the graph pigeonhole principle. There are two methods to prove resolution refutation size lower bounds for the pigeonhole principle. On the one hand there is the general width-size tradeoff by Ben-Sasson and Wigderson [BW01] which can be used to show resolution refutation size lower bounds in the setting where we have a sparse bipartite graph with $n$ holes and $m \ll n^2$pigeons. On the other hand there is the pseudo-width technique developed by Razborov [Raz04] that applies for any number of pigeons, but requires the graph to be somewhat dense. We extend the latter technique to also cover the previous setting and more: for example, it has been open whether the functional pigeonhole principle defined over a random bipartite graph of bounded degree and $\poly(n) \ge n^2$ pigeons requires super-polynomial size resolution refutations. We answer this and related questions. Finally we also study the circuit tautology which claims that a Boolean function has a circuit of size $s$ computing it. For $s = \poly(n)$ we prove an essentially optimal Sum of Squares degree lower bound of $\Omega(s^{1-\eps})$ to refute this claim for any Boolean function. Further, we show that for any $0 < \alpha < 1$ there are Boolean functions on $n$ bits with circuit complexity larger than$2^{n^\alpha}$ but the Sum of Squares proof system requires size $2^{\bigl(2^{\Omega(n^\alpha)}\bigr)}$ to prove this. Lastly we show that these lower bounds can also be extended to the monotone setting.
|
|
