scholarly journals Strategic Bidding Behaviors in Nondecreasing Sponsored Search Auctions

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Chen-Kun Tsung ◽  
Hann-Jang Ho ◽  
Sing-Ling Lee

To realize the specific results in the sponsored search auctions, most advertisers submit particular bid prices. The bidding behaviors with specific purposes are called as the strategic bidding. However, some strategic bidding behaviors will result in negative effects, such as the elimination of the equilibrium and the payment increase for some advertisers. The bidding behaviors with negative results are termed as the vindictive bidding. We survey four strategic bidding behaviors which include a rational bidding and three vindictive bidding strategies. In this paper, we study the relationship between the effects resulted by the vindictive bidding and the valuations of the vindictive advertisers. In our experiments, the search engine provider (SEP) is benefited by all vindictive bidding behaviors, and the increment of the SEP's revenue is proportional to the degree of the vindictiveness. Bidding vindictively without sacrificing the own utility improves the advertiser's utility with high probability. Moreover, we observe that the SEP's revenue is improved by the following situations. First, the vindictive advertiser with low valuation in the keywords with high market value results in more SEP's revenue than that in the keywords with low market value. The second case is to raise the bidding competition between advertisers.

2020 ◽  
Vol 34 (02) ◽  
pp. 2236-2243 ◽  
Author(s):  
Weiran Shen ◽  
Binghui Peng ◽  
Hanpeng Liu ◽  
Michael Zhang ◽  
Ruohan Qian ◽  
...  

In many social systems in which individuals and organizations interact with each other, there can be no easy laws to govern the rules of the environment, and agents' payoffs are often influenced by other agents' actions. We examine such a social system in the setting of sponsored search auctions and tackle the search engine's dynamic pricing problem by combining the tools from both mechanism design and the AI domain. In this setting, the environment not only changes over time, but also behaves strategically. Over repeated interactions with bidders, the search engine can dynamically change the reserve prices and determine the optimal strategy that maximizes the profit. We first train a buyer behavior model, with a real bidding data set from a major search engine, that predicts bids given information disclosed by the search engine and the bidders' performance data from previous rounds. We then formulate the dynamic pricing problem as an MDP and apply a reinforcement-based algorithm that optimizes reserve prices over time. Experiments demonstrate that our model outperforms static optimization strategies including the ones that are currently in use as well as several other dynamic ones.


2019 ◽  
pp. 46-64 ◽  
Author(s):  
Vladimir V. Klimanov ◽  
Sofiya М. Kazakova ◽  
Anna A. Mikhaylova

The article examines the impact of various socio-economic and financial indicators on the resilience of Russian regions. For each region, the integral index of resilience is calculated, and its correlation dependence with the selected indicators is revealed. The study confirms the relationship between fiscal resilience and socio-economic resilience of the regions. The analysis of panel data for 75 regions from 2007 to 2016 shows that there are significant differences in the dynamics of indicators in different periods. In particular, the degree of exposure to the negative effects of the crises of 2008—2009 and 2014—2015 in non-resilient regions is higher than in resilient ones.


2017 ◽  
Vol 7 (2) ◽  
pp. 159
Author(s):  
Eva Krisna

“Batombe” is an oral tradition of the Nagari Abai society at Sangir Batanghari Subdistrict, South Solok District, West Sumatra Province. Batombe is exchanging rhymes (berbalas pantun) which is performed as an entertainment on the wedding party (baralek). Batombe is identical with Great House (Rumah Gadang) Nagari Abai which is a unique house because it is a long traditional custom house that has many rooms. It reaches 21 rooms. The rhymes in batombe tends to deliver a feeling of lilting so the singers often drift into the atmosphere of the show. Therefore, as part of community life, batombe often cause a negative effects for the singers soul. This paper describes various things, such as: who batombe singer is; the time to perform this activity; the relationship between batombe and Great House (Rumah Gadang) at Nagari Abai; and the negative effects caused by batombe for the singers. This paper based on the fact that in oral tradition there is a close relationship between text and the speakers and text with context (place, time and atmosphere), a multidisciplinary approach is used in this paper, such as historical, sociological, anthropological, and psychological approach. The method used is descriptive analysis method.AbstrakBatombe adalah tradisi lisan masyarakat Nagari Abai, Kecamatan Sangir Batanghari, Kabupaten Solok Selatan, Provinsi Sumatra Barat. Batombe adalah tradisi berbalas pantun yang dilakukan sebagai hiburan pada pesta pernikahan (baralek). Batombe identik dengan rumah gadang Nagari Abai yang unik, yakni rumah adat dengan ruangan yang sangat panjang hingga 21 ruangan. Pantun-pantun batombe cenderung menyampaikan perasaan yang mendayu-dayu sehingga para pedendangnya sering hanyut ke dalam suasana pertunjukan. Oleh sebab itu, sebagai bagian dari kehidupan masyarakat, seringkali batombe menyebabkan efek negatif bagi (kejiwaan) para pedendangnya. Tulisan ini mendeskripsikan berbagai hal, seperti penutur batombe, waktu untuk melakukan batombe, hubungan batombe dengan rumah gadang di Nagari Abai, dan efek negatif yang ditimbulkan batombe bagi pedendangnya. Tulisan ini bertolak dari kenyataan bahwa pada tradisi lisan terdapat hubungan erat, antara lain seperti teks dengan penutur dan teks dengan konteks (tempat, waktu, dan suasana). Pendekatan multidisipliner digunakan pada tulisan ini, yakni pendekatan historis, sosiologis, antropologis, dan psikologis. Metode yang digunakan adalah metode analisis deskriptif.


2018 ◽  
Vol 64 (6) ◽  
pp. 799-804
Author(s):  
Darya Ryzhkova ◽  
M. Poyda

Purpose: To study the diagnostic value of PET-CT with 68Ga-PSMA-11 in the diagnosis of a primary prostate cancer, preoperative staging, and the detection of recurrence of prostate cancer (PCa). Methods: 28 patients aged 64.7 ± 8.74 years were included. 10 patients primary prostate cancer, and 18 patients with biochemical recurrence of the disease after radical treatment were examined. All patients underwent PET-CT with 68Ga-PSMA-11 according the whole body protocol. Interpretation of images was performed visually and quantitatively by calculation of SUL max. Results: High focal or diffuse 68Ga-PSMA-11 uptake was found in prostate parenchyma in patients with primary prostate cancer. Additionally metastases in regional lymph nodes were diagnosed in 4 patients and bone metastases were found in one patient. The correlation between 68Ga-PSMA-11 uptake level and Gleason index in the primary tumor (R Spearmen = 0.25, p = 0.57) was not observed. PET-positive results were obtained in 14 patients and PET-negative results in 4 patients with biochemical recurrence of PCa. The relationship between the frequency of PET-positive results and Gleason index was not revealed (R Spearmen = 0.2, p = 0.39). We found a weak but significant correlation between the frequency of PET-positive results and the prostate tumor stage according to the T category (R Spearmen = 0.49, p = 0.049). In patients with low values of PSA (less than 1.0 ng/ml) in 4 out of 9 cases, PET-negative results were obtained. In patients with PSA level more than 1.0 ng/ml PET-positive results were obtained in all cases. Conclusions: PET/CT with 68Ga-PSMA-11 allows to diagnose the primary prostate cancer, to establish the stage of the disease in categories N and M, and also to determine the localization and dissemination of the tumor in patients with biochemical recurrence of prostate cancer. The relationship between 68Ga-PSMA-11 uptake in primary tumor and Gleason index was not found. The probability of obtaining PET-positive results in cases of biochemical recurrence is affected by a PSA level above 1 ng/ml and a high stage of the disease according to the T category (T3-T4).


2020 ◽  
Vol 26 ◽  
Author(s):  
Jun-Jie Tang ◽  
Shuang Feng ◽  
Xing-Dong Chen ◽  
Hua Huang ◽  
Min Mao ◽  
...  

: Neurological diseases bring great mental and physical torture to the patients, and have long-term and sustained negative effects on families and society. The attention to neurological diseases is increasing, and the improvement of the material level is accompanied by an increase in the demand for mental level. The p75 neurotrophin receptor (p75NTR) is a low-affinity neurotrophin receptor and involved in diverse and pleiotropic effects in the developmental and adult central nervous system (CNS). Since neurological diseases are usually accompanied by the regression of memory, the pathogenesis of p75NTR also activates and inhibits other signaling pathways, which has a serious impact on the learning and memory of patients. The results of studies shown that p75NTR is associated with LTP/LTD-induced synaptic enhancement and inhibition, suggest that p75NTR may be involved in the progression of synaptic plasticity. And its pro-apoptotic effect is associated with activation of proBDNF and inhibition of proNGF, and TrkA/p75NTR imbalance leads to pro-survival or pro-apoptotic phenomena. It can be inferred that p75NTR mediates apoptosis in the hippocampus and amygdale, which may affect learning and memory behavior. This article mainly discusses the relationship between p75NTR and learning memory and associated mechanisms, which may provide some new ideas for the treatment of neurological diseases.


Author(s):  
Borja Romero-Gonzalez ◽  
Jose A. Puertas-Gonzalez ◽  
Raquel Gonzalez-Perez ◽  
Marta Davila ◽  
Maria Isabel Peralta-Ramirez

Abstract Stress during pregnancy has been widely studied and associated to different variables, usually with negative results for the health of the mother and the newborn, such as having a higher risk of suffering postpartum depression, premature birth, obstetrics complications or low birthweight, among others. However, there are not many lines of research that study the role that the sex of the baby plays on this specific stress and vice versa. Thus, the main objective was to analyse the relationship between the sex of the offspring and the stress of the mothers in the first trimester of pregnancy. In order to achieve this, 108 women had their biological stress measured (trough hair cortisol levels) and psychological stress evaluated (the Prenatal Distress Questionnaire (PSS), the Perceived Stress Scale (PDQ) and the Stress Vulnerability Inventory (IVE)). The results revealed significant differences in maternal hair cortisol levels in the first trimester based on the sex of the baby they had given birth to (t = −2.04; P < 0.05): the concentration of the hormone was higher if the baby was a girl (164.36:54.45-284.87 pg/mg) than if it was a boy (101.13:37.95-193.56 pg/mg). These findings show that the sex of the future baby could be conditioned, among many other variables, by the mother´s stress levels during conception and first weeks of pregnancy. Further research is needed in this area to support our findings.


2021 ◽  
pp. 097226292098629
Author(s):  
Rupjyoti Saha ◽  
Kailash Chandra Kabra

In view of ongoing reforms in India with emphasis on improving transparency of corporate, the present study aims to examine the influence of voluntary disclosure on the market value of India’s top-listed firms. To this end, the study uses a sample of top 100 non-financial and non-utility firms listed at Bombay Stock Exchange based on market capitalization over a 5-year period (2014–2018). To control potential endogeneity in the relationship between voluntary disclosure and firms’ market valuation, fixed effect panel data model and two-stage least squares model of estimation have been employed. The result obtained from the analysis suggests that enhanced level of voluntary disclosure significantly improves the market value of sample firms. The study further undertakes additional analysis by categorizing voluntary disclosure into its sub-components wherein the findings reveal that three components of voluntary disclosure such as corporate and strategic disclosure, forward looking disclosure and corporate governance disclosure make positive contribution towards market value of firms, while the remaining components of voluntary disclosure such as human and intellectual capital disclosure and financial and capital market disclosure do not appear to have any significant influence on the same. Overall, the finding suggests that voluntary disclosure made by sample firms is considered relevant by investors. However, value relevance of different components of voluntary disclosure varies with the nature and extent of information disclosed. The study offers some important policy implications.


Healthcare ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 630
Author(s):  
Satoshi Shimo ◽  
Yuta Sakamoto ◽  
Takashi Amari ◽  
Masaaki Chino ◽  
Rie Sakamoto ◽  
...  

Chronic pain and fatigue have negative effects on the health, ADL, work, and hobbies of the elderly. As the proportion of people 65 years of age and older in the population increases, chronic pain and disability research regarding this group is receiving more consideration. However, little empirical evidence of the association between chronic pain, fatigue, and physical disability between the sexes is available. This study investigated the association between chronic pain, fatigue, and instrumental activities of daily living among community-dwelling elderly people by sex in Japan. Concerning the presence of chronic pain, 61% of males and 78% of females reported chronic pain, indicating that many elderly people living in the community suffer from chronic pain and fatigue on a daily basis. The number of sites of chronic pain was higher in females than in males (p = 0.016), with more chronic pain in the knees (p < 0.001) and upper arms (p = 0.014). Regarding chronic pain, males showed a higher correlation with QuickDASH-DS (rs = 0.433, p = 0.017) and QuickDASH-SM (rs = 0.643, p = 0.018) than females. Furthermore, fatigue also showed a higher correlation with QuickDASH-W (rs = 0.531, p = 0.003) in males than in females. These results indicate that the association between chronic pain, fatigue, and QuickDASH differed between the sexes among community-dwelling elderly people in Japan. A better understanding of the risk factors for elderly chronic pain and fatigue among sexes will facilitate the development of elderly healthcare welfare and policies.


2017 ◽  
Vol 59 (3) ◽  
pp. 239-256 ◽  
Author(s):  
Ángela Martínez-Pérez ◽  
Marie-Michele Beauchesne

Despite the recognized importance of tourism as an engine of economic growth in developed countries, research on the antecedents of innovation in this sector has been sparse, especially in the context of tourism clusters. Scholars have suggested that social capital is a key determinant of firm innovation in the context of tourism clusters, but empirical evidence has been lacking. The aim of this article is to empirically study the interplay between social capital and innovation in the context of tourism clusters at firm level. More specifically, we analyzed the effects of closed networks and diverse networks on firm innovation using a sample of 215 hospitality and tourism firms located in the World Heritage Cities of Spain. Results showed an inverted-U-shaped relationship between closed networks and firm innovation. Consistent with existing literature, these findings suggest that whereas a certain degree of strength and density helps to promote innovation, a critical point may exist beyond which innovation stabilizes or deteriorates when the information of the network becomes too redundant. In addition, we found that diverse networks positively moderated the relationship between closed networks and firm innovation. In other words, structural holes appear to mitigate the negative effects arising from excess strength and density and encourage the development of innovations beyond what a firm relying solely on closed networks could achieve. In practice, these results suggest firms in tourism clusters should not exclusively focus on typical closed networks but also create connections with diverse agents to maximize their potential for innovation.


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