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The purpose of this paper is to show how a critical realist paradigmatic stance and its associated research methodology can contribute to supply‐chain research by providing explanations for specific supply‐chain‐ and logistics‐related dynamic phenomena.

Initially, the case for a critical realist research paradigm is made, and then a retroductive pluralistic research methodology is used for demonstrating its application. Starting from an observation in the distribution part of a seasonal goods supply chain, ethnographic‐like field research suggested deeper social structures as being responsible for the events observed. The operation of event‐generating mechanisms related to these structures was matched to existing behavioural theories using dynamic modelling and simulation.

The adoption of the critical realist perspective and its pluralistic research methodology can bring into surface the root causes of, and explain, complex supply chain phenomena. In the particular case presented, it provided an explanation for the inventories observed in a supply chain of perishable seasonal goods as results of two underlying interacting mechanisms: one related to the promotions bias of the manufacturer, and one related to the risk management attitude of resellers.

As far as underpinning philosophy and research methodology are concerned, the research presented is globally significant and valid. Nevertheless, any supply‐chain management policies derived in the demonstrative case as results of the explanation may be significant only to specific industries and geo‐historical contexts.

Results obtained by employing the critical realist perspective may be used in managers' education for developing intellectual frameworks to better understand the causes of complex supply chain phenomena. Of the same importance to practitioners is the methodology and inference process used for explaining real abnormal situations and intervening accordingly.

The paper shows how a critical realist perspective and its associated methodology can be used for extracting/researching deeper mechanisms responsible for observed behaviours in supply chains. Such an approach is in the opposite direction with respect to the hypothetico‐deductive approaches that dominate supply chain research. The paper demonstrates the adoption of the critical realist perspective in supply chain research using a real case.

The purpose of this paper is to describe and test a quantitative harm-focused approach to offender selection for investigation and surveillance. The approach incorporates a measure of crime harm as well as a time-decay function that adjusts the score downward for offenders who desist from crime.

Across 10 of 21 high-crime police districts in the city of Philadelphia, the authors compare the mean harm scores of 60 prolific offenders selected by district analysts, 60 prolific offenders selected citywide by detectives assigned to the Gun Violence Reduction Task Force and the top 60 prolific offenders chosen from a harm-score generated list of known offenders in the ten high-crime districts.

The offenders on the harm-focused list have significantly greater mean harm scores than the offenders identified by the crime analysts or task force personnel. They have a significantly greater mean number of gun crime episodes in their offending history as well.

The harm-focused approach uses arrest data that may not accurately reflect convictions and which miss undetected criminal activity. A leader of a criminal organization who orchestrates criminal activities but does not engage directly may have a low harm score. Arrest data may also suffer from some inherent bias. The approach also requires the creation of a crime harm index. Determining the operational impact on overall crime reduction by focusing on offenders with higher harm scores will require further research.

Clinical methods of target selection based on officer intuition, opinion and experience may have limitations in terms of effectiveness and accuracy. They also lack transparency and may incorporate bias, a critical consideration given the current crisis in police-community trust and legitimacy. The actuarial method of weighing the harm of past offending with a crime harm score may be more acceptable and defendable to the community. It also identifies offenders with a higher frequency of involvement in gun crimes. Until methodological limitations are better understood, a compromise may be to start with the harm-score method (data-driven) and supplement this initial list through intelligence and investigative information.

The paper expands crime harm indices to quantify offender triage lists. The authors also empirically demonstrate through a case study that the approach is more effective at identifying harmful offenders than methods that solely rely on the experience or intuition of either crime analysts or detectives.

This paper aims to estimate the effects of gun possession arrests made by a specialized, proactive police patrol unit in the Houston Police Department (HPD).

Time series analyses are used to estimate the effects of weekly gun possession arrests on weekly counts of gun crimes in Houston, TX. Models isolate the effects of arrests made by the proactive patrol unit from gun possession arrests made by other HPD officers.

Citywide and beat‐level analyses show that the proactive unit made meaningful contributions to existing levels of illegal possession arrests. Time series analyses using weekly data show that these additional arrests are associated with significant declines in offences committed with guns. Findings support existing evidence that shows police can affect serious crimes by targeting firearms that are illegally possessed and carried.

The analysis can not precisely determine whether additional patrol presence or arrests are the precise mechanisms that might be influencing gun crimes.

The findings are consistent with existing evidence and suggest that focused police work to seize illegally possessed firearms from the streets and arrest those in illegal possession of firearms will impact offences committed with firearms.

The analysis extends existing work that tests the effects of proactive patrol activities on offences committed with firearms. The analysis is distinct from existing research on this topic because it estimates the effects of gun possession arrests rather than the effects of gun seizures.

Studies of gang violence typically use police reports to investigate the structure of gang conflict, but overreliance on a singular data source could impede crime control efforts. Extending networked criminology, this study aims to explore what court records reveal about the directionality of gang conflicts.

Controlling for the presence of a civil gang injunction (CGI), the authors use multivariate quadratic assignment procedure regression models to disentangle factors thought to account for structural patterns of gang violence mapped from 933 prosecutions involving 307 gangs associated with violent conflict affecting the City of Los Angeles (1998–2013). Specifically, the authors compare competitive advantage to the explanatory power of turf proximity.

One measure of turf proximity outperforms all other explanatory factors – gangs with turf centrally positioned in a turf adjacency matrix are significantly more likely to launch attacks, be victimized and exhibit the highest levels of imbalance in their violent involvements. Regarding competitive advantage, the number of cliques and level of internal conflict are significant. Finally, being subject to a CGI is associated with initiating violence.

Court cases offer a feasible alternative to police data when investigating patterns of intergroup street gang violence.

The purpose of this study is to design a flight control model for a control surface-less (CSL) tri-tilt-rotor (TTR) unmanned aerial vehicle (UAV) based on a Proportional Integral Derivative (PID) controller to stabilize the altitude and attitude of the UAV subjected to various flying conditions.

First, the proposed UAV with a tilting mechanism is designed and analyzed to obtain the aerodynamic parameters. Second, the dynamics of the proposed UAV are mathematically modeled using Newton-Euler formation. Then, the PID controller is implemented in the simulation model to control flight maneuvers. The model parameters were implemented in a mathematical model to find the system’s stability for various flight conditions. The model was linearized to determine the PID gain values for vertical take-off and landing, cruise and transition mode. The PID controller was tuned to obtain the desired altitude and attitude in a short period. The tuned PID gain values were implemented in the PID controller and the model was simulated.

The main contribution of this study is the mathematical model and controller for a UAV without any control surface and uses only a thrust vector control mechanism which reduces the complexity of the controller. The simulation has been carried out for various flight conditions. The altitude PID controller and the attitude PID controller for CSL-TTR-UAV were tuned to obtain desired altitude and attitude within the optimum duration of 4 s and deviation in the attitude of 8%, which is within the allowable limit of 14%. The findings obtained from the simulation revels that the altitude and attitude control of the CSL-TTR-UAV was achieved by controlling the rpm of the rotor and tilt angle using the PID controller.

A novel CSL TTR UAV mathematical model is developed with a dual tilting mechanism for a tail rotor and single axis tilt for the rotors in the wing. The flight control model controls the UAV without a control surface using a PID controller for the thrust vector mechanism.

This study explores the applicability of Anderson's (1999) code of the street framework to an Asian context by examining the relationship between residents' perceptions of police ineffectiveness, nationality, and street codes in foreigner-concentrated areas in South Korea.

The authors used survey data from 1,865 residents of diverse nationalities living in 20 foreigner-concentrated areas in South Korea. Mixed-effects ordinary least squares (OLS) regression and moderation analysis were used to examine (1) the association between residents' perceptions of police ineffectiveness and their street codes and (2) how this association varies across nationality groups.

The study findings overall indicated that higher resident perceptions of police as ineffective tended to correspond with greater levels of street codes. However, the interaction analysis results found that this relationship was conditioned by nationality. Specifically, perceptions of police ineffectiveness were associated with greater levels of street codes among foreign residents, particularly Korean-Chinese residents, whereas this was not the case among Korean residents.

The relationship between perceptions of the police and street codes described by Anderson (1999) has primarily been examined in the context of the U.S. To the best of the authors' knowledge, this study represents the first attempt to explore the link between residents' perceptions of the police and street codes by different nationality groups within an Asian setting.

The purpose of the study is to examine gun violence prevention practices among urban police in the USA, assessing their scope, effectiveness, limitations, and impacts.

A national survey was conducted with police agencies serving cities of 100,000 or more people.

Strategies used most frequently and rated as most effective include targeted efforts focussed on high‐risk places and groups, as well as multi‐agency problem‐solving efforts, particularly those involving federal authorities. However, most agencies make limited use of proactive strategies to reduce gun crime, and there are substantial gaps in the enforcement of many gun laws. Results also suggest that gun crime is lower in places where police engage in more intensive gun‐related enforcement and prevention efforts.

The survey focussed only on large US cities. Implementation of the strategies could not be examined in detail, and assessments of the effectiveness of strategies reflect the views of practitioners. There is a need for more in‐depth research on gun‐related enforcement and prevention practices, their effectiveness, and the organizational and environmental factors that facilitate or hinder them.

The study highlights strategies that should be given priority consideration in policy decisions. The findings also suggest that police efforts to address gun crime can be enhanced considerably – and that doing so may produce demonstrable reductions in gun crime. Further examination of policy changes necessary to facilitate these efforts is warranted.

This study represents the first national survey of gun violence reduction efforts by police in the USA.

This paper examines the President's Task Force on 21st Century Policing's recommendation that police promote trust and legitimacy by creating a culture of transparency and accountability.

The study is based on a panel survey of 841 Chicago residents that was interrupted between the waves by a momentous local policing event that proved to be known to virtually every participant. The reinterview period encompassed this event, its political repercussions and subsequent efforts to hold Chicago Police accountable and increase transparency. The authors examine whether these events and reform efforts improved African Americans' assessments of police legitimacy and trust relative to other respondents.

Trust in Chicago Police improved by 21%, and trust in neighborhood police increased 30% among Black residents. In contrast, views of Whites became more negative, declining by 62% in their assessments about Chicago Police and by 39% regarding neighborhood police.

Events occurring between the waves of a panel survey created an opportunity to examine the impact of events on residents of a large and diverse city. The authors discuss why reforms promoting transparency and police accountability can alter levels of trust in the police but in different and politically consequential ways.

This paper is designed to critically review and analyze the body of research on a popular gang reduction strategy, implemented widely in the United States and a number of other countries, to: (1) assess whether researchers designed their evaluations to align with the theorized causal mechanisms that bring about reductions in violence; and (2) discuss how evidence on gang programs is generated and consumed. That review and assessment is then used to frame a research agenda for studying gang interventions.

A case study design is used to generate a multi-faceted understanding of the possible avenues for evaluation research on the law enforcement-based strategy known as the Group Violence Intervention. The paper discusses questions that remain to be answered about the strategy, such as “what type of deterrence is operating?” and if the model actually works by the threat of deterrence, and not by removing high-risk offenders and shootings from the street, what activities are needed to maintain the effect?

Across roughly two dozen impact evaluations of GVI, none have examined the likely cause and effect components of this multi-partner strategy in reducing the violence. Furthermore, there are many issues related to the production and generation of criminal justice evaluation research that have adversely pushed the balance of evidence on what works in gang reduction toward law enforcement programming. However, there are many strategies that researchers can use to think broadly about appropriate and holistic research and evaluation on gangs and gang programming.

The recommendations for research, if implemented, can help build a body of knowledge to move toward community-based and restorative models of gang violence reduction.

This original piece is one of the first essays to contextualize and discuss how aspects of the production of social science research on gangs may directly impact what programs and strategies are implemented on the ground.