4,722 research outputs found
Regularization and Kernelization of the Maximin Correlation Approach
Robust classification becomes challenging when each class consists of
multiple subclasses. Examples include multi-font optical character recognition
and automated protein function prediction. In correlation-based
nearest-neighbor classification, the maximin correlation approach (MCA)
provides the worst-case optimal solution by minimizing the maximum
misclassification risk through an iterative procedure. Despite the optimality,
the original MCA has drawbacks that have limited its wide applicability in
practice. That is, the MCA tends to be sensitive to outliers, cannot
effectively handle nonlinearities in datasets, and suffers from having high
computational complexity. To address these limitations, we propose an improved
solution, named regularized maximin correlation approach (R-MCA). We first
reformulate MCA as a quadratically constrained linear programming (QCLP)
problem, incorporate regularization by introducing slack variables in the
primal problem of the QCLP, and derive the corresponding Lagrangian dual. The
dual formulation enables us to apply the kernel trick to R-MCA so that it can
better handle nonlinearities. Our experimental results demonstrate that the
regularization and kernelization make the proposed R-MCA more robust and
accurate for various classification tasks than the original MCA. Furthermore,
when the data size or dimensionality grows, R-MCA runs substantially faster by
solving either the primal or dual (whichever has a smaller variable dimension)
of the QCLP.Comment: Submitted to IEEE Acces
Naphthalimide Trifluoroacetyl Acetonate: A Hydrazine-Selective Chemodosimetric Sensor
The trifluoroacetyl acetonate naphthalimide derivative 1 has been synthesized in good yield. In acetonitrile solution, compound 1 reacts selectively with hydrazine (NH2NH2) to give a five-membered ring. This leads to OFF-ON fluorescence with a maximum intensity at 501 nm as well as easily discernible color changes. Based on a readily discernible and reproducible 3.9% change in overall fluorescence intensity, the limit of detection for 1 is 3.2 ppb (0.1 mu M), which is below the accepted limit for hydrazine set by the U.S. Environmental Protection Agency (EPA). Compound 1 is selective for hydrazine over other amines, including NH4OH, NH2OH, ethylenediamine, methylamine, n-butylamine, piperazine, dimethylamine, triethylamine, pyridine, and is not perturbed by environmentally abundant metal ions. When supported on glass-backed silica gel TLC plates, compound 1 acts as a fluorimetric and colorimetric probe for hydrazine vapor at a partial pressure of 9.0 mm Hg, with selectivity over other potentially interfering volatile analytes, including ammonia, methylamine, n-butylamine, formaldehyde, acetaldehyde, H2O2, HCl, and CO2 being observed. Probe 1 can also be used for the detection of hydrazine in HeLa cells and does so without appreciable interference from other biologically abundant amines and metal ions.U.S. National Science Foundation CHE-1057904Robert A. Welch Foundation F-1018CRI project grant from National Research Foundation of Korea (NRF)Korea government (MSIP) 2009-0081566Chemistr
Precarious working youth and pension reform in the Republic of Korea and Italy
This paper focuses on two aspects of the welfare state: the old age pension system and the labor market, where the majority of youth are working in precarious jobs. We discuss the interplay between pension funds and the increase in young atypical workers by studying the case of Italy and the Republic of Korea, closely analyzing the projected benefit level of both standard and nonstandard workers among the youth population in Korea in order to assess where young workers will find themselves after retirement age and what Korea can learn from the case of Italy.This work was supported by the National Research Foundation of Korea Grant funded
by the Korean Government (NRF-2012S1A3A2033416)
Estimates of Discharge Coefficient in Levee Breach Under Two Different Approach Flow Types
The amount of released water (discharge) in a levee breach is a primary input variable to establish an emergency action plan for the area next to the levee. However, although several studies have been conducted, there is still no widely applicable discharge coefficient formula; this needs to be known to estimate discharge amount through an opening caused by a levee breach. Sometimes, the discharge coefficient developed for a sharp crested side weir is used to rate the discharge, but, in case of a levee breach, the resulting geometry and flow types are similar to that over a broad crested weir. Thus, in this study, two different openingsโrectangular and trapezoidal shapeโare constructed in the center of a levee at a height of 0.6m to replicate levee breach scenarios, and the effect of two different approach flow typesโthe river type approach and reservoir type approachโare explored to suggest a discharge coefficient formula applicable for discharge rating for a levee breach. The results show that the ratio of head above the bottom of an opening and the opening width is a key variable for calculating the discharge coefficient of a reservoir type, but the approach Froude number should also be considered for a river type approach. The measured data are used to improve rating equations and will be useful in the future to validate computational fluid dynamics simulations of wave propagation during levee failure into the inundation area
Special Report - Smart Projects in Smart Asia
What is Smart?
What does Smart mean in todays context? Before technology, the term was used to
refer to human excellence in our actions, mannerisms, facial expressions, languages
and thoughts. More recently, its definition has been narrowed down to describe the
capacity of artificial intelligence. Smart is the new thing. Products that are not Smart
are now objects of the past and the future will be all about creating Smart-er products
and services. The rapid development of personal or family friendly technology such
as Smartphones, Smart tablets, Smart TV, etc. is analogous with the evolution from
using a broom to clean the living room to handling an automatic vacuum cleaner.
Smart scenarios and technological innovations of the future have already been
extensively studied and explored. The idea that hundreds of remote sensors will
receive information and analyze it with a microprocessor, and then carry out ones
unconscious command, is one that we can largely relate with a desirable and Smart
future. Yet are these complicated processes and automated actions really the Smart
environment we are looking for?
์ค๋งํธํ๋ค๋ ๊ฒ
์ค๋๋ ์ค๋งํธํ๋ค๋ ๊ฒ์ ๋ฌด์์ ์๋ฏธํ๋๊ฐ? ํ๋, ์ ์, ํ์ , ์ธ์ด, ์๊ฐ ๋ฑ ์ธ๊ฐ์ ์ด์ฑ๊ณผ
์ง์ฑ์ ๋ชจ๋ ๋ถ๋ถ์ ๊ฑธ์ณ ์ฐ์ํจ ์ง์นญํ๋ ์ด ํ์ฉ์ฌ๋ ์ธ๊ฐ์ด ์๋ ์ธ๊ณต์ง๋ฅ์ ๊ธฐ๋ฅ์ ์ฐ์
์ฑ์ ๋ปํ๋ ์ข์ ์๋ฏธ๋ก ๋ณํํ๋ค. ์ค๋งํธ๊ฐ ๊ด๊ฑด์ด๋ค. ์์ฆ ์๋์ ์ค๋งํธํ์ง ์์ ๋ฌผ๊ฑด
์ด๋ฉด ์๊ฒ์ด ๋๊ณ , ์ค๋งํธํ ์ ๋๊ฐ ๋ฏธ๋๋ฅผ ๋ง๋ค์ด๋ด๋ ์ฒ๋๊ฐ ๋์๋ค. ์ค๋งํธํฐ, ์ค๋งํธํ๋ธ
๋ , ์ค๋งํธTV ๋ฑ ๊ฐ์ธ์ฉ, ๊ฐ์ ์ฉ ์ ์์ ํ์ ์์ํ ์ํ์ ๋ฐ์ ์์ฉ๋๋ ์ค๋งํธํจ์ ์งํ
๋ ๋ง์น ์์ผ๋ก ๋ง๋ฃจ๋ฐ๋ฅ์ ํ์น๋ ์์ ์์ ์ฐ์
์ฌํ๋ฅผ ๊ฑธ์ณ ์ ๊ธฐ๊ธฐ๊ณ๋ฅผ ๊ฐ์ง ์ง๊ณต์ฒญ์๊ธฐ์
์งํ์ ๊ฑธ๋ง๋ค. ์ค๋งํธํ ํ๊ฒฝ์ ๋ํ ๊ธฐ์ ๊ฐ๋ฐ๊ณผ ๋ผ์ดํ์๋๋ฆฌ์ค๋ ์ด๋ฏธ ์ค๋์ ๋ถํฐ ์งํ๋
์ด ์๋ค. ์์ญ๊ฐ, ์๋ฐฑ๊ฐ์ ์ผ์๊ฐ ์ ๋ณด๋ฅผ ๋ฐ์๋ค์ด๊ณ ๋ง์ดํฌ๋ก ํ๋ก์ธ์๊ฐ ์ด๋ฅผ ๋ถ์ํ์ฌ ๋ด
๊ฐ ์ํ๋ ๋์์ ์ด๋ค ๋ช
๋ น์ด ์์ด๋ ์๊ฒฉ์ผ๋ก ์ ์ดํ๊ณ ๋ผ์ดํ์คํ์ผ์ ๊ด๋ฆฌํด ์ฃผ๋ ๋๋
ํ ํ๊ฒฝ์ด ์ธ๋ฅ๊ฐ ์ถ๊ตฌํ๋ ๋ฏธ๋๋ผ๋ ๊ฒ์ ์ฐ๋ฆฌ ๋ชจ๋๊ฐ ๋ค ์๊ณ ์๋ ๋ฐ์ด๋ค. ๊ทธ๋ฐ๋ฐ ์ฐ๋ฆฌ๊ฐ
์ํ๋ ์ค๋งํธํจ์ ์ด๋ ๊ฒ ๋ณต์กํ ํ๋ก์ธ์ค๊ฐ ์งํ๋๋ ํ๊ฒฝ์์ ๋ชจ๋ ๊ฒ์ด ์๋์ผ๋ก ์ผ์ด
๋๋ ๊ทธ๋ฐ ํ๊ฒฝ์ด ๋ง๋๊ฐ
Lookalike Targeting on Others\u27 Journeys: Brand Versus Performance Marketing
Lookalike targeting is a widely used model-based ad targeting approach that uses a seed database of individuals to identify matching โlookalikesโ for targeted customer acquisition. An advertiser has to make two key choices: (1) who to seed on and (2) seed-match rank range. First, we find that seeding on othersโ journey stage can be effective in new customer acquisition; despite the cold start nature of customer acquisition using Lookalike audiences, third parties can indeed identify factors unobserved to the advertiser that move individuals along the journey and can be correlated with the lookalikes. Further, while journey-based seeding adds no incremental value for brand marketing (click-through), seeding on more downstream stages improves performance marketing (donation) outcomes. Second, we evaluate audience expansion strategies by lowering match ranks between the seed and lookalikes to increase acquisition reach. The drop in effectiveness with lower match rank range is much greater for performance marketing than for brand marketing. Performance marketers can alleviate the problem by making the ad targeting explicit, and thus increase perceived relevance; however, it has no incremental impact for higher match lookalikes. Increasing perceived targeting relevance makes acquisition cost comparable for both high and low match ranks
Lookalike Targeting on Others\u27 Journeys: Brand Versus Performance Marketing
Lookalike Targeting is a widely used model-based ad targeting approach that uses a seed database of individuals to identify matching โlookalikesโ for targeted customer acquisition. An advertiser has to make two key choices: (1) who to seed on and (2) seed-match rank range. First, we assess if and how seeding by othersโ journey stages impact clickthrough (upstream behavior desirable for brand marketing) and donation (downstream behavior desirable in performance marketing). Overall, we find that lookalike targeting using otherโs journeys can be effective-third parties can indeed identify factors unobserved to the advertiser merely from othersโ journey stage to improve targeting. Further, while it is sufficient to seed on upstream journey stages for brand marketing, seeding on more downstream stages improves performance marketing outcomes. Second, we assess the effectiveness of expanding the target audience with lower match ranks between seed and lookalikes. The drop in effectiveness with lower match rank range is much greater for performance marketing (donation) than for brand marketing (click-through). However, performance marketers can alleviate the reduction in ad effectiveness for low match ranks by making targeting more salient; but increasing salience has little impact for high match rank. Overall, by increasing salience, performance marketers can make acquisition cost comparable for high and low match ranks
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