Adversarial Sampling and Training for Semi-Supervised Information Retrieval

Ad-hoc retrieval models with implicit feedback often have problems, e.g., the imbalanced classes in the data set. Too few clicked documents may hurt generalization ability of the models, whereas too many non-clicked documents may harm effectiveness of the models and efficiency of training. In addition, recent neural network-based models are vulnerable to adversarial examples due to the linear nature in them. To solve the problems at the same time, we propose an adversarial sampling and training framework to learn ad-hoc retrieval models with implicit feedback. Our key idea is (i) to augment clicked examples by adversarial training for better generalization and (ii) to obtain very informational non-clicked examples by adversarial sampling and training. Experiments are performed on benchmark data sets for common ad-hoc retrieval tasks such as Web search, item recommendation, and question answering. Experimental results indicate that the proposed approaches significantly outperform strong baselines especially for high-ranked documents, and they outperform IRGAN in NDCG@5 using only 5% of labeled data for the Web search task.Comment: Published in WWW 201

Pyroelectric effect enhancement through product property under open circuit condition

An analytical model for the pyroelectric (PY) effect under open circuit condition and 2-2 connectivity laminates of various pairs of PY and nonpyroelectric (NP)/elastic materials has been developed. It is evident from our analysis that there indeed is a substantial dissimilarity between the PY coefficients and figure of merit for efficiency for various PY-NP pairs under short circuit and open circuit conditions. We believe this implies that there should be a greater distinction made between the PY coefficients under these two electrical conditions than previously thought. The indicators for various PY-NP material pairs that can be utilized to determine their PY coefficient enhancement potential under open circuit condition have been identified. The investigated PY materials are lead zirconate titanate (PZT-5H and PZT-5A), barium titanate, lithium tantalate, lithium niobate, and polyvinylidene fluoride (PVDF), while the NP materials are stainless steel, polytetrafluoroethylene (PTFE or Teflon), chlorinated polyvinyl chloride thermoplastic (CPVC), aluminum, zinc, and Invar 36. Extraordinarily large PY coefficient of 97×10-4 C m-2 K-1 at minimum thickness ratio Rmin is expected for PZT-5H-CPVC pair while PVDF-CPVC could show increase in the secondary PY coefficient of up to 350%. In addition, where the figure of merit for efficiency is concerned, for the same volume of the composite PZT-5A-PTFE pair it reaches 24, a 24-fold increase in efficiency at Rmin. Our analysis techniques should provide a methodological way for appraising the potentials of particular PY material and its 2-2 laminates for applications under open circuit condition such as PY X-ray generation, electron accelerator, and nuclear fusion

Expanding RTAs, Trade Flows, and the Multinational Enterprise

We test the relationship between the size of regional trade agreements (RTA) and openness by using a gravity equation with multilateral trade factors. Our sample includes eleven RTAs, seven with constant membership and four with expanding membership. Regional trade bias declines with the size of the club; three of the four expanding RTAs have already surpassed their ‘optimal’ size. We also explore the link between openness of the RTA and the geographic strategy of the multinational enterprise. We find strong evidence in favor of the regionalization strategy, which has been enhanced by the presence of RTAs.Trade Blocks, Regional Integration, Multinational Enterprises (MNEs), Plurilateral RTAs, Trade Creation, Trade Diversion

Size of Regional Trade Agreements and Regional Trade Bias

We test the relationship between size of regional trade agreement (RTA) and regional trade bias using a gravity equation on a large sample of 143 countries for the period 1980-2003. We find that regional trade bias declines with the size of the club and that three of the four expanding RTAs have already surpassed their ‘optimal’ sizes. There is no evidence that RTAs have set protection levels against outsiders noncooperatively.RTA, regional trade bias, trade flows

On the Relationship Between RTA Expansion and Openness

We test the relationship between the size of regional trade agreements (RTA) and openness using a gravity equation with multilateral trade factors on a large sample of 143 countries over period 1980-2003. Our sample includes eleven RTAs, seven with constant membership and four with an expanding membership. In the first group, there are more stumbling blocs than building blocs to freer global trade. In the second group, the opposite holds. We also find that regional trade bias declines with the size of the club and that three of the four expanding RTAs have already surpassed their ‘optimal’ size.gravity equation, plurilateral RTAs, size, trade creation, trade diversion

Regional Multinationals and the Korean Comestics Industry

This paper analyzes the market penetration and expansion strategy of cosmetics and toiletries multinational enterprises (MNEs) in South Korea from the perspective of regional strategy as developed recently by Rugman. We find that MNEs have different market entry and expansion strategies in the home region and in the foreign region. Home region MNEs (Japanese MNEs in this case), in general, utilize their firm-specific advantages (FSAs) better than foreign region MNEs (European and MNEs from the Americas in this case). Due to differences in transaction costs, home region MNEs exploit downstream FSAs while foreign region MNEs develop upstream FSAs. Market similarity also leads to a greater incentive to operate in the home region rather than in foreign regions. The home region effect significantly increases the likelihood of entry into foreign markets as the host country’s “diamond” significantly affects the market entry strategies of MNEs.regional strategy, market penetration, cosmetics industry, double diamond, South Korea

The Regional Sales of Multinationals in the World Cosmetics Industry

This paper analyzes the regional characteristics and strategies of multinational enterprises (MNEs) in the world cosmetics and toiletries industry, based on the new work by Rugman on regional strategy. We test the proposition that MNEs may asymmetrically develop their upstream and downstream firm specific advantages (FSAs). We find that the upstream activities of the MNEs in cosmetics are home region based but that downstream activities are less so. Further, the asymmetry of FSAs in the world cosmetics industry is mainly due to the atypical Asian entry strategies of North American and West European cosmetics MNEs. Two case studies confirm how variations in FSAs can affect regional strategy.regionalism, regional strategy, cosmetics industry, firm specific advantage, Avon, Gucci