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The rebels at the front line of Myanmar's civil war
In the five years since Myanmar's military chief led a coup to overthrow the democratically elected government, civil war has torn the country apart. Thousands have been killed and millions displaced by the conflict between the military and an alliance of ethnic and rebel groups. More than two years ago, the rebels made a series of sweeping gains, but things have taken a turn for the worse for them. Forced conscription and increased drone power has put the military on the offensive in most parts of the country. The BBC's Quentin Sommerville travelled to Myanmar without the permission of the authorities - the only way to report from rebel-held territory.
After decades risking arrest, South Korea's tattoo artists step into the limelight
After decades risking arrest, South Korea's tattoo artists step into the limelight When Kim Tae-nam took the stage last Saturday in Seoul, it was a moment he had long been waiting for - the career he had chosen was no longer illegal. He couldn't stop smiling, the relief spilling into his voice: This was only possible because of our effort, all your sweat and tears. Let's hear it from everyone: Tattoos are art! They had gathered on a rooftop in Seongsu, a hip Seoul neighbourhood, for Ink Bomb: more than 90 local tattooists and artists openly celebrating body art, which had thrived in the shadows for decades. Just days before, South Korea's top court had overturned its 1992 ruling that defined tattooing as a medical act - bringing to an end Korean tattooists' decades-long fight for legitimacy.
Watch: Moment rescuers find five people trapped in Laos cave
Rescuers in Laos have found five villagers alive inside a flooded cave after they were trapped for a week following heavy rain and landslides. Two people are still missing, rescue teams said. Footage shared by the rescuers showed cave divers crawling through narrow, muddy passageways. The seven people were part of a group of villagers who had gone into the cave in search of gold deposits and wildlife, but could not get out as the cave's entrance was blocked. Could a football match soften North Korea-South Korea relations?
BBC at the site of China's worst mining disaster in more than a decade
At least 82 people have been killed and two are missing after a coal mine blast in northern China, officials have said. The gas explosion at the Liushenyu Coal Mine is the worst mining disaster in China since 2009, and Chinese President Xi Jinping said no effort must be spared in the search and rescue operation. Early on Sunday morning, rescuers deployed mine inspection robots underground, equipped with gas sensors and infrared cameras, state media reported. The BBC's China correspondent Stephen McDonell is at the scene of the blast in Shanxi province. Could a football match soften North Korea-South Korea relations?
Zipf-Gramming: Scaling Byte N-Grams Up to Production Sized Malware Corpora
Raff, Edward, Curtin, Ryan R., Everett, Derek, Joyce, Robert J., Holt, James
A classifier using byte n-grams as features is the only approach we have found fast enough to meet requirements in size (sub 2 MB), speed (multiple GB/s), and latency (sub 10 ms) for deployment in numerous malware detection scenarios. However, we've consistently found that 6-8 grams achieve the best accuracy on our production deployments but have been unable to deploy regularly updated models due to the high cost of finding the top-k most frequent n-grams over terabytes of executable programs. Because the Zipfian distribution well models the distribution of n-grams, we exploit its properties to develop a new top-k n-gram extractor that is up to $35\times$ faster than the previous best alternative. Using our new Zipf-Gramming algorithm, we are able to scale up our production training set and obtain up to 30\% improvement in AUC at detecting new malware. We show theoretically and empirically that our approach will select the top-k items with little error and the interplay between theory and engineering required to achieve these results.
X-Troll: eXplainable Detection of State-Sponsored Information Operations Agents
Tian, Lin, Zhang, Xiuzhen, Kim, Maria Myung-Hee, Biggs, Jennifer, Rizoiu, Marian-Andrei
State-sponsored trolls, malicious actors who deploy sophisticated linguistic manipulation in coordinated information campaigns, posing threats to online discourse integrity. While Large Language Models (LLMs) achieve strong performance on general natural language processing (NLP) tasks, they struggle with subtle propaganda detection and operate as ``black boxes'', providing no interpretable insights into manipulation strategies. This paper introduces X-Troll, a novel framework that bridges this gap by integrating explainable adapter-based LLMs with expert-derived linguistic knowledge to detect state-sponsored trolls and provide human-readable explanations for its decisions. X-Troll incorporates appraisal theory and propaganda analysis through specialized LoRA adapters, using dynamic gating to capture campaign-specific discourse patterns in coordinated information operations. Experiments on real-world data demonstrate that our linguistically-informed approach shows strong performance compared with both general LLM baselines and existing troll detection models in accuracy while providing enhanced transparency through expert-grounded explanations that reveal the specific linguistic strategies used by state-sponsored actors. X-Troll source code is available at: https://github.com/ltian678/xtroll_source/.
Turning Adversaries into Allies: Reversing Typographic Attacks for Multimodal E-Commerce Product Retrieval
Multimodal product retrieval systems in e-commerce platforms rely on effectively combining visual and textual signals to improve search relevance and user experience. However, vision-language models such as CLIP are vulnerable to typographic attacks, where misleading or irrelevant text embedded in images skews model predictions. In this work, we propose a novel method that reverses the logic of typographic attacks by rendering relevant textual content (e.g., titles, descriptions) directly onto product images to perform vision-text compression, thereby strengthening image-text alignment and boosting multimodal product retrieval performance. We evaluate our method on three vertical-specific e-commerce datasets (sneakers, handbags, and trading cards) using six state-of-the-art vision foundation models. Our experiments demonstrate consistent improvements in unimodal and multimodal retrieval accuracy across categories and model families. Our findings suggest that visually rendering product metadata is a simple yet effective enhancement for zero-shot multimodal retrieval in e-commerce applications.
LLM-Enhanced Black-Litterman Portfolio Optimization
Lee, Youngbin, Kim, Yejin, Kim, Juhyeong, Kim, Suin, Lee, Yongjae
The Black-Litterman model addresses the sensitivity issues of tra- ditional mean-variance optimization by incorporating investor views, but systematically generating these views remains a key challenge. This study proposes and validates a systematic frame- work that translates return forecasts and predictive uncertainty from Large Language Models (LLMs) into the core inputs for the Black-Litterman model: investor views and their confidence lev- els. Through a backtest on S&P 500 constituents, we demonstrate that portfolios driven by top-performing LLMs significantly out- perform traditional baselines in both absolute and risk-adjusted terms. Crucially, our analysis reveals that each LLM exhibits a dis- tinct and consistent investment style which is the primary driver of performance. We found that the selection of an LLM is therefore not a search for a single best forecaster, but a strategic choice of an investment style whose success is contingent on its alignment with the prevailing market regime. The source code and data are available at https://github.com/youngandbin/LLM-BLM.
DeepAries: Adaptive Rebalancing Interval Selection for Enhanced Portfolio Selection
Kim, Jinkyu, Yi, Hyunjung, Gim, Mogan, Choi, Donghee, Kang, Jaewoo
We propose DeepAries , a novel deep reinforcement learning framework for dynamic portfolio management that jointly optimizes the timing and allocation of rebalancing decisions. Unlike prior reinforcement learning methods that employ fixed rebalancing intervals regardless of market conditions, DeepAries adaptively selects optimal rebalancing intervals along with portfolio weights to reduce unnecessary transaction costs and maximize risk-adjusted returns. Our framework integrates a Transformer-based state encoder, which effectively captures complex long-term market dependencies, with Proximal Policy Optimization (PPO) to generate simultaneous discrete (rebalancing intervals) and continuous (asset allocations) actions. Extensive experiments on multiple real-world financial markets demonstrate that DeepAries significantly outperforms traditional fixed-frequency and full-rebalancing strategies in terms of risk-adjusted returns, transaction costs, and drawdowns. Additionally, we provide a live demo of DeepAries at https://deep-aries.github.io/, along with the source code and dataset at https://github.com/dmis-lab/DeepAries, illustrating DeepAries' capability to produce interpretable rebalancing and allocation decisions aligned with shifting market regimes. Overall, DeepAries introduces an innovative paradigm for adaptive and practical portfolio management by integrating both timing and allocation into a unified decision-making process.
GuruAgents: Emulating Wise Investors with Prompt-Guided LLM Agents
Kim, Yejin, Lee, Youngbin, Kim, Juhyeong, Lee, Yongjae
This study demonstrates that GuruAgents, prompt-guided AI agents, can systematically operationalize the strategies of legendary investment gurus. We develop five distinct GuruAgents, each designed to emulate an iconic investor, by encoding their distinct philosophies into LLM prompts that integrate financial tools and a deterministic reasoning pipeline. In a backtest on NASDAQ-100 constituents from Q4 2023 to Q2 2025, the GuruAgents exhibit unique behaviors driven by their prompted personas. The Buffett GuruAgent achieves the highest performance, delivering a 42.2\% CAGR that significantly outperforms benchmarks, while other agents show varied results. These findings confirm that prompt engineering can successfully translate the qualitative philosophies of investment gurus into reproducible, quantitative strategies, highlighting a novel direction for automated systematic investing. The source code and data are available at https://github.com/yejining99/GuruAgents.