Earticle

The term “sweet spot” is commonly used in analog/RF engineering to describe an operating region where multiple, often competing, requirements are satisfied simultaneously. This paper presents a practical sweet-spot framework that treats bias selection as a constrained multi-objective problem and explicitly connects device inversion level to distortion, noise, power/current, bandwidth-related loading, and robustness against process-voltage-temperature (PVT) drift. A step-by-step, equation-based analysis is given for IM3 shaping using a main path and an auxiliary path that controls the IM3 amplitude ratio and phase error at a combining node, clarifying how a “dip” in IM3 can be created and widened into a tunable sweet-spot region. Finally, a sweet-spot-aware parallel-path architecture is proposed to make the sweet spot tunable and repeatable under realistic excitation.

This study focuses on isolating and characterizing novel polyhydroxybutyrate (PHB) depolymerase-producing bacteria to enable efficient PHB biodegradation. PHB is a promising biodegradable alternative to petroleum-based plastics, requires PHB depolymerase to facilitate its effective depolymerization and mineralization in the environment. We identified Janibacter terrae COS4-44 from oil contaminated tidal flat in Taean, Republic of Korea, demonstrating high PHB degradation efficiency via clear zone formation and enzymatic activity. Scanning electron microscopy (SEM) revealed increased surface roughness and porosity in degraded PHB films, while Fourier-transform infrared spectroscopy (FTIR) confirmed the cleavage of ester bonds, indicating enzymatic breakdown. The PHB depolymerase gene was successfully cloned and expressed in E. coli, yielding a functional 58 kDa enzyme. Optimal degradation conditions were 40°C, pH 8.0, and 96 h incubation, with 0.15% PHB concentration. Glucose and yeast extract enhanced enzyme activity, whereas heavy metals like Zn²⁺ and Co²⁺ slightly stimulated depolymerase production. These findings highlight Janibacter terrae COS4-44 as a potent PHB degrader, offering potential for sustainable plastic waste management. Further research on degradation metabolites and enzyme engineering could enhance industrial applications.

This study analyzes the evolution of South Korean unification movement non-governmental organizations and evaluates how multilevel governance can serve as an alternative framework for future unification policy. While Cold War dynamics constrained inter-Korean relations, the post-Cold War environment diversified actors and interests, exposing the limitations of state-centered governance. Drawing on European multilevel governance theory, this paper argues that unification governance must expand beyond hierarchical state control to include local governments, civil society, international organizations, and private corporations. The analysis highlights structural limitations in existing governance models and proposes a multi-actor, cross-border governance framework suitable for the complex geopolitical environment of the Korean Peninsula. Policy recommendations are offered to strengthen institutional design, enhance non-governmental organization capacity, and promote regional cooperation.

Synthesized in this paper are published geological, paleoclimate, archaeological, and genetic findings to evaluate hypotheses linking long-term Earth evolution with opportunities and constraints for human cultural development and dispersal. Presented here are phanerozoic CO2 and temperature, tephrochronological evidence for the Kikai-Akahoya eruption, and ancient NA and obsidian provenance studies relevant to Jomon period mobility. The atmospheric CO2 content had decreased to the lowest level of about 0.02 % over the last 420 million years by around 20 thousand years ago well before humans started to use fossil energy in a large scale, possibly increasing the atmospheric CO2 level. Antarctica moved to the South Pole and started accumulating ice around 35-40 million years ago to become the largest ice reservoir and a buffer to control the sea level by accumulating more ice at higher atmospheric temperatures. The Kikai-Akahoya eruption around 5250 BC could have forced some Jomon people to emigrate westward from the southwestern Japan, possibly as far as Middle East, forming Sumerian and Israeli cultures and bringing them back to Japan. Preservation of such ancient cultures and genetic information to date may have been possible only in geographically isolated locations such as Ethiopia, Tibet, and Japan.

Historically minimized as an artifact of data corruption or suboptimal sensing, stochastic noise is undergoing a paradigm shift across the cognitive and computational sciences. Traditional deterministic frameworks have treated noise as a strict limitation—an error term to be eliminated to minimize empirical risk. This thought paper challenges the elimination paradigm by examining the functional role of noise in two primary fields: machine learning and neuroscience. We trace the conceptual evolution of noise from ongoing epistemic inquiries regarding its physical nature to pragmatic inquiries regarding its algorithmic utility. In neuroscience, empirical findings of trial-by-trial neuronal and behavioral variability have revealed that the brain actively leverages non-deterministic variance for exploration and predictive coding. In machine learning, the injection of noise has evolved from a structural regularizer preventing catastrophic overfitting in descriptive models into the generative “sampling seed” of modern probabilistic architectures. Ultimately, by applying Ashby’s Principle of Requisite Variety, this paper posits that intelligent systems do not merely tolerate environmental variance; they actively internalize noise as a functional mechanism to perceive, predict, and generalize within an unpredictable world.

This article explores interreligious dialogue as a key tool for peacebuilding in post-conflict African societies. It employs a hermeneutical-philosophical lens to advocate for an ethics of understanding as the basis for healing and reconciliation. Drawing on the philosophical perspectives of Hans-Georg Gadamer and African ethical traditions, the study highlights how dialogical engagement across religious and cultural lines can foster mutual recognition and restore dignity to affected communities. It emphasizes the importance of narrative, memory, and meaning in shaping interreligious ethics. By advancing a transformative approach to dialogue, the article challenges instrumental views of religion and calls for deeper epistemological shifts in peacebuilding practices on the continent.

Large language models (LLMs) have demonstrated remarkable capabilities across a range of tasks, from complex reasoning to creative writing. Yet, these systems remain prone to hallucination, rely entirely on static training data, and risk homogenizing scientific thought through mode collapse. Retrieval-augmented generation (RAG) addresses these limitations by conditioning model outputs on dynamically retrieved external knowledge, tethering the immense generative capacity of LLMs to verifiable, human-curated corpora. This survey traces the development of RAG from its foundational formulations as a simple hallucination- mitigating pipeline to contemporary, highly adaptive architectures. We examine the core components—retrieval, re-ranking, and grounded generation—and survey advanced techniques including active retrieval, hierarchical memory, and multimodal extensions. Crucially, we highlight how LLM is evolving beyond a mere fact-checking mechanism into a collaborative, creative thinking partner. By feeding pluralistic evidence into the generation loop rather than relying on monolithic statistical patterns, multi-layered agentic RAG frameworks actively mitigate systemic biases, safeguard intellectual diversity, and amplify human reasoning. Ultimately, RAG represents an essential epistemological bridge for human-AI symbiosis, empowering users to make fairer and balanced decisions and accelerating the realization of co-prosperity in future society.