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The purpose of this paper is to propose a high‐mobility in‐pipe robot platform and its navigation strategy for navigating in T‐branch pipes efficiently.

For high mobility, this robot is developed based on inchworm locomotion. An extensor mechanism with flexible links and clamper mechanisms enable the robot to conduct both steering and inchworm locomotion. The locomotion of the robot is modeled based on a pseudo‐rigid‐body model. From the developed model, this paper introduces a navigation strategy based on defining relay points and generating a path from a main pipe to a T‐branch pipe.

With this navigation strategy, the robot can avoid collisions and enter T‐branch pipes effectively. The path generation algorithm is verified by experiment. In addition, both the navigation strategy and mobility of the robot are demonstrated by experiments conducted in a commercial pipe configuration.

This paper describes the mechanism of an inchworm‐type in‐pipe robot that is able to steer and adapt to pipe diameter changes. This paper also describes navigation strategy that enables a robot to avoid collisions and enter T‐branch pipes effectively. This research will help the construction of a fully autonomous in‐pipe robot that can navigate through various types of pipes.

The majority of the previous research on hot spots policing focuses on a single set of relatively small selected experimental areas. However, given limited resources, most law enforcement agencies dispatch hot spots intervention units to several areas on a rotation basis. The purpose of this paper is to examine policing activities in hot spots to determine if the various types of crimes were affected when deployment was applied on a rotation basis.

This study uses data from the Dallas Police Department. The differential influence of police activities, including stops, citations, and arrests, are observed against a number of aggregate crime measures (i.e. violent, property, nuisance offenses, and total index crimes). The impact of police activities have been observed for their immediate and lagged effects during the following week to measure residual deterrence effects.

It was found that the DPD's Disruption Unit's hot spots policing immediately affected violent crimes, nuisance offenses, and total index crimes, while there were no residual effects of hot spots policing. The Disruption Unit was engaged in policing activities that include motor vehicle and pedestrian stops, issuing citations, and making arrests. Among these activities, the number of police stops was the most significant factor for the reduction in violent crime and nuisance offenses.

The researchers use a patrol sector as a unit of analysis in order to compare the influence of various types of police activities on crime across a broader area. Future research should consider using an intermediate geographic unit of analysis (e.g. patrol beat).

The paper examines the differential influence of policing activities on different types of crime around hot spots when deployment was applied on a rotation basis. Both immediate and lagged effects were investigated to find residual deterrence effects of hot spots policing.

This paper investigates a retrospective on the Journal of Derivatives and Quantitative Studies (JDQS) on its 30th anniversary based on bibliometric. JDQSs yearly publications, citations, impact factors, and centrality indices grew up in early 2010s, and diminished in 2020. Keyword network analysis reveals the JDQS's main keywords including behavioral finance, implied volatility, information asymmetry, price discovery, KOSPI200 futures, volatility, and KOSPI200 options. Citations of JDQS articles are mainly driven by article age, demeaned age squared, conference, nonacademic authors and language. In comparison between number of views and downloads for JDQS articles, we find that recent changes in publisher and editorial and publishing policies have increased visibility of JDQS.