382 research outputs found
Smart Pacing for Effective Online Ad Campaign Optimization
In targeted online advertising, advertisers look for maximizing campaign
performance under delivery constraint within budget schedule. Most of the
advertisers typically prefer to impose the delivery constraint to spend budget
smoothly over the time in order to reach a wider range of audiences and have a
sustainable impact. Since lots of impressions are traded through public
auctions for online advertising today, the liquidity makes price elasticity and
bid landscape between demand and supply change quite dynamically. Therefore, it
is challenging to perform smooth pacing control and maximize campaign
performance simultaneously. In this paper, we propose a smart pacing approach
in which the delivery pace of each campaign is learned from both offline and
online data to achieve smooth delivery and optimal performance goals. The
implementation of the proposed approach in a real DSP system is also presented.
Experimental evaluations on both real online ad campaigns and offline
simulations show that our approach can effectively improve campaign performance
and achieve delivery goals.Comment: KDD'15, August 10-13, 2015, Sydney, NSW, Australi
Lift-Based Bidding in Ad Selection
Real-time bidding (RTB) has become one of the largest online advertising
markets in the world. Today the bid price per ad impression is typically
decided by the expected value of how it can lead to a desired action event
(e.g., registering an account or placing a purchase order) to the advertiser.
However, this industry standard approach to decide the bid price does not
consider the actual effect of the ad shown to the user, which should be
measured based on the performance lift among users who have been or have not
been exposed to a certain treatment of ads. In this paper, we propose a new
bidding strategy and prove that if the bid price is decided based on the
performance lift rather than absolute performance value, advertisers can
actually gain more action events. We describe the modeling methodology to
predict the performance lift and demonstrate the actual performance gain
through blind A/B test with real ad campaigns in an industry-leading
Demand-Side Platform (DSP). We also discuss the relationship between
attribution models and bidding strategies. We prove that, to move the DSPs to
bid based on performance lift, they should be rewarded according to the
relative performance lift they contribute.Comment: AAAI 201
(Methanolato)(pyridine)[N 2,N 2′-(pyridine-2,6-diyldicarbonÂyl)diacetohydraÂzide(2–)]iron(III) methanol solvate
In the title complex, [Fe(C11H10N5O4)(CH3O)(C5H5N)]·CH4O, the FeIII ion has a distorted pentaÂgonal-bipyramidal geometry. In the crystal structure, molÂecules are linked into one-dimensional chains along [1
] via interÂmolecular O—H⋯O and N—H⋯O hydrogen bonds
Macroscopic and microscopic trans-scale characteristics of pore structure of mine grouting materials
The pore structure and porosity of three kinds of mine grouting materials were characterized based on a thin-section analysis and low-field nuclear magnetic resonance (NMR) technique. The macroscopic pore interconnectivity was investigated using binary images captured from thin sections and a random walk pore spectral dimension (RWPSD) algorithm. The experimental results show that the microstructure of the grouting materials used consisted of interlayer pores, gel pores, capillary pores, circular air holes, and small fractures, and tailings can fill some gaps in the hydration product structure and dense hydration products. There is a positive correlation between pore interconnectivity and curing time. In addition, there is a relationship between pore interconnectivity and porosity. With increasing porosity and pore interconnectivity, a non-uniform pore structure occurs in mine grouting materials with an accelerator and results in reduced setting time and later strength
Correlation between Myocardial Velocity Measured using Tissue Doppler Imaging in the Left Ventricular Lead-Implanted Segment and Response to Cardiac Resynchronization Therapy
OBJECTIVES: This study investigated whether tissue Doppler imaging parameters, especially the peak systolic velocity of the left ventricular lead-implanted segment (Ss), affect cardiac resynchronization therapy response. METHODS: In this case-control study, 110 enrolled patients were divided into cases (responder group, n=65) and controls (nonresponder group, n=45) based on whether their left ventricular end-systolic volume was reduced by X15% at 6 months after surgery. Preoperative clinical and echocardiographic data were collected. Multivariate logistic regression models were used to analyze the factors affecting the response to cardiac resynchronization therapy, and receiver operating characteristic curves were plotted to evaluate their diagnostic values. RESULTS: The proportion of patients with left bundle branch block in the case group was higher than that in the control group. The control group showed a higher left atrial volume index, E/A ratio and E/Em ratio but lower Ss than that of the case group. A multivariate regression analysis showed that left bundle branch block, Ss, and an E/Em ratio414 were independent risk factors affecting the response to cardiac resynchronization therapy. Ss=4.1 cm/s was the best diagnostic threshold according to the receiver operating characteristic curve. CONCLUSIONS: Ss is an important factor affecting the response to cardiac resynchronization therapy. Patients with heart failure associated with Sso4.1 cm/s have a higher risk of nonresponse
Antioxidant Activity and Characterization of One New Polysaccharide Obtained from Perigord Truffle
As a medicinal and edible fungus parasitizing on the trees, Perigord Truffle (Tuber huidongense) is well known for its delicious taste, unique smell, and high medical value for healthcare. One new water-soluble nonstarch polysaccharide (PST-W with the yield of 0.41%) from Perigord Truffle (Tuber huidongense) was purified and identified on structural characteristics for the first time. The characterizations of PST-W were studied on physicochemical properties, main components of monosaccharide(s), and molecular structure. The monosaccharide compositions of PST-W were studied and identified as glucan, only containing D-glucoses with the molecular structure of [→6) α-D-Glcp (1→6)  α-D-Glcp (1→]n by methylation analysis and NMR. In the determination of total reducing capacity, the reducing abilities of polysaccharide extracts could be listed as vitamin C > PST-W > crude polysaccharides-3 > crude polysaccharides-2 > crude polysaccharides-1. All of PST-W, crude polysaccharides-2, and crude polysaccharides-3 were relatively good scavenger for 1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl radicals with IC50 of 2.81, 4.17, and 3.44 mg/mL, respectively. However, O2-∙ clearing abilities of PST-W and crude polysaccharides were obviously weaker. The activities of total crude extract were the worst, indicating that the impurities might negatively affect the antioxidant activity. Thus, the separation and purification of polysaccharides were significant to increase the antioxidant activity in some degree
Progress in Research and Application of Insect-resistant Packaging for Grain Storage
Stored grain is extremely vulnerable to the storage insects during storage and processing. At present, chemical control is still the main method for controlling stored grain insects. However, the increasing resistance of insects caused by long-term use of chemical control raises unprecedented challenges. Insect-repellent packaging, as a traditional and emerging physical insect prevention method, has increasingly attracted widespread attention among people. The types and characteristics of food packaging materials, the types and application of insect-repellent packaging, the research and evaluating methods of insect-repellent packaging at home and abroad, and the problems existing in the practical application of insect-repellent packaging were reviewed, and the development trend of insect-repellent packaging was prospected, so as to provide reference information for the scientific and efficient use of insect-repellent packaging, development of new insect-repellent packaging to control stored grain insects in the future
Cross-scale characteristics of backfill material using NMR and fractal theory
This paper analyzed the pore structure, quantified the pore fractal dimension, calculated the grading index (GI) of mixed aggregate, and studied the relationship among GI, pore structure, and strength to describe the cross-scale characteristics of backfill, which is made from stone powder and cemented tailing. A series of experiments were conducted on stone powder cement tailings backfill (SPCTB). The GI formulas for mixed aggregates, containing stone powder and tailings, were derived based on the Füller theory. The nuclear magnetic resonance (NMR) fractal dimensions of backfills were derived using fractal geometry principles. Compared to the mesopore and macropore fractal dimensions, the correlation between micropore fractal dimension and macro-properties in terms of NMR porosity, pore structure complexity, uniaxial compression strength (UCS), and GI is the most significant. Macropore fractal dimension is generally correlated with UCS and GI and the other properties such as the shape of mixed aggregates also have an impact on fractal dimension. However, mesopore fractal dimension has no obvious relationship with macro-properties. Finally, the relationship between GI and UCS was studied, which contributed to improving backfill’s strength and optimizing gradation
- …