Mathematical Formulation of an Optimal Execution Problem with Uncertain Market Impact

We study an optimal execution problem with uncertain market impact to derive a more realistic market model. We construct a discrete-time model as a value function for optimal execution. Market impact is formulated as the product of a deterministic part increasing with execution volume and a positive stochastic noise part. Then, we derive a continuous-time model as a limit of a discrete-time value function. We find that the continuous-time value function is characterized by a stochastic control problem with a Levy process.Comment: 17 pages. Forthcoming in "Communications on Stochastic Analysis.

地域における要支援・要介護高齢者のペット飼育に関する意義と課題(2)「喪失の語り」と「支援」をめぐる語り

In this study, the relationship between pets and elderly people who need care was examined through a narrative approach. Semi-structured interviews were conducted with four elderly residents of Nobeoka City, Miyazaki, and with professionals who have the ability to support elderly people\u27s caring for pets (i.e. a social worker, home-care workers, a pet sitter and administrative officers). The interviewer asked about the relationship between the elderly people and their pets, specifically about any benefits or difficulties in their daily life. The results of the interviews revealed that even those elderly people who had lost their pets linked their own life stories to their pets, structuring them according to their relationship with their pets. In contrast, the professionals often emphasized the difficulties for elderly people in caring for pets. The study suggests that we need to construct a social support network, in particular, a `narrative community\u27 to listen attentively to elderly people\u27s narratives as a way of supporting the relationship between the elderly and their pets

地域における要支援・要介護高齢者のペット飼育に関する意義と課題 : ナラティヴ・アプローチの視点から

In this study, the relationship between pet animals and elderly residents in need of care was examined using a narrative approach. Semi-structured interviews were conducted with seven elderly residents of Nobeoka-city, Miyazaki, and with the social workers assigned to them. The author enquired about the relationship between the elderly individuals and their pets and focused on the benefits or difficulties associated with the animals in daily life. The analysis of narratives focused not only on the narrative content, but also on the manner in which the stories were narrated. The narratives fell into two general categories: (1) narratives including attachment and emotional bonding with the pet, based on a"model story"about the pet, and (2) narratives of the individuals own life story structured by their relationship with their pets. It is suggested that relationships with pet animals may contribute to the process of reconstructing the life story of elderly individuals

「災害時におけるペット救援」に関する予備的考察 : 先行研究の概観及び新聞記事の量的分析より

This study focused on the social issues surrounding the rescue of companion animals during disaster relief efforts. It (1) reviewed previous reports on this topic and applicable laws and (2) performed a quantitative analysis of newspaper articles related to animal rescue in times of disaster from 1985 to 2011. The review was based on three perspectives: self-help, mutual assistance and public assistance. -Based on this review, future responses to animal rescue during disaster were considered

Theoretical and Numerical Analysis of an Optimal Execution Problem with Uncertain Market Impact

This paper is a continuation of Ishitani and Kato (2015), in which we derived a continuous-time value function corresponding to an optimal execution problem with uncertain market impact as the limit of a discrete-time value function. Here, we investigate some properties of the derived value function. In particular, we show that the function is continuous and has the semigroup property, which is strongly related to the Hamilton-Jacobi-Bellman quasi-variational inequality. Moreover, we show that noise in market impact causes risk-neutral assessment to underestimate the impact cost. We also study typical examples under a log-linear/quadratic market impact function with Gamma-distributed noise.Comment: 24 pages, 14 figures. Continuation of the paper arXiv:1301.648

平成28年熊本地震における「ペット同行避難」に関する予備的考察 : 益城町総合運動公園避難所の事例より

The present study examined the “evacuation with companion animals” in areas affected by theKumamoto earthquake. I joined the efforts to help refugees with companion animals at Mashiki CityGeneral Gymnasium shelter from April 16th. At this shelter, a facility for refugees with companionanimals, called “Mashiki-machi Wan-Nyan House” was set up. Support for “House” and “Home” wereprovided for the refugees and their companion animals at the facility. Based on these practices, theimportance of support for refugees with companion animals was considered

『地域猫』活動の長期的変遷に関する予備的考察 : 横浜市磯子区の実践グループ年次活動報告書に対する内容分析より

This study investigated the long-term transition of community conflict caused by cat breeding, especially the case of `community cats\u27 activity in Isogo, Yokohama-city. In this practice, residents treated `cat problem\u27 as `residents-relation problem\u27 thoroughly to manage community conflict, and established "guideline" including two divided claims (like/dislike cats). To examine the features of the long-term practice, content analysis on volunteers\u27 annual reports from 2001 to 2011 was performed. The results suggested that volunteers faced many difficulties during the `community cats\u27 activity and that appropriate communication in a community is vital in conducting the `community cats\u27 activity

「高齢者とペットとの関係」の支援に向けた「長期的視点」に関する予備的考察

The present study examined relationship between older persons and companion animals from a long-term perspective. In concrete, (1) Previous studies concerned with relationship between companion animals and elderly people from 1980 to 2013 were examined based on International Federation ofAfing(IFA)\u27s review, (2) Newspaper articles about this issue were collected from 1985 to 2014, and examined long-term tendency quantitatively. Based on this discu sion, importance of long-term perspective to support the relationship between older persons and companion animals were considered preliminarily