3D Model-free Visual Localization System from Essential Matrix under Local Planar Motion

Visual localization plays a critical role in the functionality of low-cost autonomous mobile robots. Current state-of-the-art approaches for achieving accurate visual localization are 3D scene-specific, requiring additional computational and storage resources to construct a 3D scene model when facing a new environment. An alternative approach of directly using a database of 2D images for visual localization offers more flexibility. However, such methods currently suffer from limited localization accuracy. In this paper, we propose an accurate and robust multiple checking-based 3D model-free visual localization system to address the aforementioned issues. To ensure high accuracy, our focus is on estimating the pose of a query image relative to the retrieved database images using 2D-2D feature matches. Theoretically, by incorporating the local planar motion constraint into both the estimation of the essential matrix and the triangulation stages, we reduce the minimum required feature matches for absolute pose estimation, thereby enhancing the robustness of outlier rejection. Additionally, we introduce a multiple-checking mechanism to ensure the correctness of the solution throughout the solving process. For validation, qualitative and quantitative experiments are performed on both simulation and two real-world datasets and the experimental results demonstrate a significant enhancement in both accuracy and robustness afforded by the proposed 3D model-free visual localization system

Learning to Identify Top Elo Ratings: A Dueling Bandits Approach

The Elo rating system is widely adopted to evaluate the skills of (chess) game and sports players. Recently it has been also integrated into machine learning algorithms in evaluating the performance of computerised AI agents. However, an accurate estimation of the Elo rating (for the top players) often requires many rounds of competitions, which can be expensive to carry out. In this paper, to improve the sample efficiency of the Elo evaluation (for top players), we propose an efficient online match scheduling algorithm. Specifically, we identify and match the top players through a dueling bandits framework and tailor the bandit algorithm to the gradient-based update of Elo. We show that it reduces the per-step memory and time complexity to constant, compared to the traditional likelihood maximization approaches requiring O(t) time. Our algorithm has a regret guarantee of Õ(√T), sublinear in the number of competition rounds and has been extended to the multidimensional Elo ratings for handling intransitive games. We empirically demonstrate that our method achieves superior convergence speed and time efficiency on a variety of gaming tasks

On the Robustness of ChatGPT: An Adversarial and Out-of-distribution Perspective

ChatGPT is a recent chatbot service released by OpenAI and is receiving increasing attention over the past few months. While evaluations of various aspects of ChatGPT have been done, its robustness, i.e., the performance to unexpected inputs, is still unclear to the public. Robustness is of particular concern in responsible AI, especially for safety-critical applications. In this paper, we conduct a thorough evaluation of the robustness of ChatGPT from the adversarial and out-of-distribution (OOD) perspective. To do so, we employ the AdvGLUE and ANLI benchmarks to assess adversarial robustness and the Flipkart review and DDXPlus medical diagnosis datasets for OOD evaluation. We select several popular foundation models as baselines. Results show that ChatGPT shows consistent advantages on most adversarial and OOD classification and translation tasks. However, the absolute performance is far from perfection, which suggests that adversarial and OOD robustness remains a significant threat to foundation models. Moreover, ChatGPT shows astounding performance in understanding dialogue-related texts and we find that it tends to provide informal suggestions for medical tasks instead of definitive answers. Finally, we present in-depth discussions of possible research directions.Comment: Technical report; code is at: https://github.com/microsoft/robustlear

Mitigating Circumstances in International Criminal Sentencing

Since the establishment and operationalisation of the International Criminal Tribunal for the former Yugoslavia (‘ICTY’) and the International Criminal Tribunal for Rwanda (‘ICTR’), many elements of international criminal law have undergone significant development. Sentencing, however, remains a rather underdeveloped area. It still possesses few clear guidelines, and is surrounded by inconsistency and unpredictability. This chapter deals with one particular aspect in international criminal sentencing, namely mitigating circumstances. It attempts to sketch the evolution of the practice and law of mitigating circumstances from the post-Second World War international war crimes trials to two recent convictions and sentencing of the International Criminal Court (‘ICC’). This chapter examines the various mitigating circumstances considered in the judicial discourse of international criminal courts and tribunals in different eras, including war crimes trials after the Second World War, trials at the ICTY and ICTR, and finally the ICC. By means of this historical investigation, the analysis traces the development of the law in this area and identifies key trends. From this, it can be observed that the scope of mitigating circumstances considered by international courts and tribunals has expanded considerably. More importantly, behind this is an amplification of the underlying ideologies of international criminal justice and their goals and aims. In the early trials, the main focus in determining sentencing was the culpability of the accused person and proportionality of sentences. More recent practice, however, has paid more attention to broader goals, such as the accused’s contribution to the reconciliation of a given society. Yet there is no consistent approach as to which is the priority among the different, and at times contradictory, ideologies, and thus also no clear and consistent guidelines on the weight to be attached to the different mitigating circumstances. As a result, this tends to exacerbate the confusion and uncertainty in international criminal sentencing, making it even more inconsistent and unpredictable

Recognizing the Limits of Victims Participation: A Comparative Examination of the Victim Participation Schemes at the ECCC and the ICC

Victim participation is considered a great innovation of the Rome Statute, and an improvement from the previous international criminal tribunals that failed to attend to victims’ needs and interests. This article compares the victim participation regimes at the ICC and the ECCC. Through this comparative examination, it detects a common trend towards a more streamlined approach despite of the fundamental differences between the victim participation regimes at these two courts. It is then submitted that this trend is unavoidable given the inherent limits of criminal proceedings. Any attempts to refine the victim participation regime have to take into consideration these limits, and to recognize the fact that criminal proceedings is not a panacea. It can only be part of the combined efforts by various mechanisms to truly uphold victims’ rights

War Crimes Trials in China after the Second World War: Justice and Politics

When examining the war crimes trials after the Second World War, many have criticised the involvement of political elements in these trials. Asia, in particular, seems to suffer most from the “illness” or “abnormality” of political involvement in the judicial process, from Tokyo to today’s international criminal justice endeavours, such as in Cambodia, East Timor and so forth. The Chinese trials of Japanese war criminals after the war have not received much attention because of the lack of first-hand records and many other reasons. But the political considerations in these trials are also obvious and have often been criticised by commentators. By contrast, others defend these trials by emphasising their adherence to judicial guarantees despite the political dimensions. Both attitudes are based on the same presumption, that is, politics is an “evil” that should be separated from judicial processes. The latter should be “pure” and “just”, and that means staying away from “dirty” politics. This chapter considers it over-simplistic to make such a clear-cut separation between justice and politics, and to render it as a black-andwhite dichotomy. By examining the trials of Japanese war criminals by both the Nationalist government in the immediate aftermath of the Second World War and by the People’s Republic of China (‘PRC’) in the 1950s, the chapter seeks to demonstrate how politics plays out in the design and operation of judicial mechanisms. It argues that in a complex social background as existed at the end of a war, judicial proceedings are only one of the means available to meet the various needs of society. Justice might not be the sole, or the most important, goal of the judicial process, which might be designed and used by the decision makers to facilitate other priorities, such as the very existence of the nation or regime, or the maintenance of order and stability..

Historical War Crimes Trials in Asia

The book examines the historical trials from different perspectives, including the legal concepts used and debates that took place; the infl uence of the trials within a broader social context, both at their time and later; the collection of evidence; and preservation, compilation and research of historical documents. It not only analyses the trials in their historical and social contexts, but emphasises their present day signifi cance, also as regards the prevention of core international crimes, especially in Asia. The book offers insights on retaining and compiling historical materials concerning these trials as important historical records and new developments in evidence collection in contemporary international criminal courts

Single-Switch High Step-Up Zeta Converter Based on Coat Circuit

By the negative influence of parasitic parameters from the components, the voltage step-up capacity of basic dc-dc converters is limited at extremely high duty cycle. Which makes the traditional dc-dc converters are difficult to be applied to renewable energy generation systems such as fuel cell and photovoltaic (PV) systems. In this study, a single-switch high step-up Zeta converter is proposed based on the basic Zeta converter and corresponding coat circuit. By using the coat circuit, the proposed converter not only can achieve higher voltage gain, but also acquire lower voltage stress on the semiconductor devices. Therefore, the devices with lower conduction resistances can be used to improve the efficiency. Furthermore, the coat circuit is composed of passive components, which does not change the continuous output current characteristic of the basic Zeta converter. And the proposed converter has only one active switch, the drive and control circuits are simple. The operation principle and the performance analysis of the proposed Zeta converter are described in detail, and a 300 W closed-loop experimental prototype has been developed for verification

Unreliable determination of in situ stress orientation by cross multipole array acoustic logging in fractured shale reservoirs

Abstract With the development of shale gas exploration in China, the use of conventional logging tools has been introduced, and cross multipole array acoustic logging tools have gradually been used to determine the stress orientation in shale. The direction of fast shear waves (FSWs) is generally parallel to the horizontal maximum principal compression stress (SHmax). However, the azimuth of FSWs is found to be parallel to the main strike (but not to the SHmax) direction of structural fractures in shale reservoirs. Outcrop and image logging data indicate that the natural fractures in this area strike NE‒SW. If the shear wave anisotropy is caused by only the stress around the borehole and the FSWs are known to be NE‒SW, SHmax should be parallel to NE‒SW; however, according to statistics of land movement in adjacent areas, anelastic strain recovery, earthquake focal mechanism, borehole breakouts, hydraulic fracturing data, deviated well data, and drilling‐induced fracture data in local regions, SHmax is oriented in the NW‒SE direction, and the directions of FSWs are generally parallel to the structural fracture direction. This contradiction indicates that the development of structural fractures may affect the orientation of FSWs. Therefore, it is not reliable to use XMAC (Cross‐Multipole Array Acoustilog) logging only to determine the direction of in situ stress in fractured shale reservoirs. In addition, the direction of the FSWs in the middle of thick mudstones is NW‒SE, which may represent accurate information about the in situ stress direction