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Prof. Dimitrios A. Karras, Phd, is Assoc. Prof. in “Digital Systems”, National and…
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27 χιλ. ακόλουθοι
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Dimitrios A. Karras το κοινοποίησεIn 1995, physicists Eric Cornell and Carl Wieman made a significant breakthrough in experimental physics by cooling a gas of rubidium atoms to temperatures just above absolute zero, creating a new state of matter called the Bose–Einstein condensate (BEC). This achievement was the first experimental proof of a phenomenon predicted by Satyendra Nath Bose and Albert Einstein decades earlier. The concept began in 1924 when Bose developed a method for counting photons, leading to a groundbreaking paper he sent to Einstein. Einstein recognized its importance, translated it into German, and arranged for its publication. He later extended Bose’s ideas to material particles, predicting that identical particles (bosons), at very low temperatures, would transition into a single quantum state, forming a BEC. Despite the theoretical prediction in the 1920s, creating BECs in the laboratory took many years due to the challenge of achieving the necessary low temperatures without solidifying the gas. In 1995, Cornell and Wieman, along with their team, succeeded in creating the first BEC by cooling rubidium-87 atoms using lasers and then applying a magnetic field in a method known as evaporative cooling. This process allowed them to reach temperatures below 10⁻⁷ kelvin. The formation of a BEC was directly observed when about two thousand rubidium atoms combined into a single state. Following this, other teams also produced BECs with different atoms, leading to larger condensates and confirming their coherent behavior. The Nobel Prize in Physics was awarded in 2001 to Cornell, Wieman, and Wolfgang Ketterle for this achievement, highlighting the significance of BECs in fields like quantum simulation, atom interferometry, and potential applications in quantum computing and cosmology. (𝘐𝘮𝘢𝘨𝘦: 𝘚𝘢𝘵𝘺𝘦𝘯𝘥𝘳𝘢 𝘕𝘢𝘵𝘩 𝘉𝘰𝘴𝘦 (𝘭𝘦𝘧𝘵) 𝘢𝘯𝘥 𝘈𝘭𝘣𝘦𝘳𝘵 𝘌𝘪𝘯𝘴𝘵𝘦𝘪𝘯 (𝘳𝘪𝘨𝘩𝘵). 𝘊𝘰𝘶𝘳𝘵𝘦𝘴𝘺: 𝘓𝘦𝘧𝘵: 𝘍𝘢𝘭𝘨𝘶𝘯𝘪 𝘚𝘢𝘳𝘬𝘢𝘳, 𝘤𝘰𝘶𝘳𝘵𝘦𝘴𝘺 𝘰𝘧 𝘈𝘐𝘗 𝘌𝘮𝘪𝘭𝘪𝘰 𝘚𝘦𝘨𝘳è 𝘝𝘪𝘴𝘶𝘢𝘭 𝘈𝘳𝘤𝘩𝘪𝘷𝘦𝘴. 𝘙𝘪𝘨𝘩𝘵: 𝘈𝘐𝘗 𝘌𝘮𝘪𝘭𝘪𝘰 𝘚𝘦𝘨𝘳è 𝘝𝘪𝘴𝘶𝘢𝘭 𝘈𝘳𝘤𝘩𝘪𝘷𝘦𝘴, 𝘞. 𝘍. 𝘔𝘦𝘨𝘨𝘦𝘳𝘴 𝘎𝘢𝘭𝘭𝘦𝘳𝘺 𝘰𝘧 𝘕𝘰𝘣𝘦𝘭 𝘓𝘢𝘶𝘳𝘦𝘢𝘵𝘦𝘴 𝘊𝘰𝘭𝘭𝘦𝘤𝘵𝘪𝘰𝘯.)
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Dimitrios A. Karras το κοινοποίησεNotebookLM, a Really important AI tool!!Dimitrios A. Karras το κοινοποίησεNotebookLM is probably the most versatile free AI tool out there. And most people barely scratch the surface. They use it to summarize. That is the weakest use case. NotebookLM is a research engine. It only answers from your uploaded sources. No hallucinations. No made up citations. Here is what it actually does well. → Find trends and gaps across dozens of papers. → Turn dense research into audio you can replay. → Surface contradictions with direct quotes. → Turn raw notes into clean outlines. → Translate academic jargon into plain language. → Stress test your arguments before review. NotebookLM does not replace researchers. It makes good researchers faster. __________________________________________ Master the Top AI Tools for Research Explore 30+ step-by-step AI courses Get 40% off with code IRF40 at checkout! 👇 https://lnkd.in/dYkbmMxg --------------------------------------------- Subscribe to my free newsletter for tips on AI in academic research! 👇 https://lnkd.in/dTZesqZA
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Dimitrios A. Karras το κοινοποίησεImportant insight from President Obama, a leader who was logical, informed, competent, and rational.
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Dimitrios A. Karras το κοινοποίησεBirds can navigate using the Earth’s magnetic field thanks to special proteins in their eyes called cryptochromes, particularly Cry4. When blue light hits these proteins, it triggers a tiny quantum reaction known as the radical pair mechanism. This reaction is highly sensitive to magnetic fields, allowing it to change based on the direction of the Earth’s magnetism. As a result, birds may actually “see” the magnetic field as patterns or visual cues layered over their normal vision. This remarkable ability helps them orient and migrate across vast distances with incredible precision. More details Many birds, especially migratory species, can "see" the Earth's magnetic field to navigate, a phenomenon known as magnetoreception. They likely visualize magnetic field lines as a visual pattern, such as light or dark spots (like a heads-up display), superimposed over their normal vision, primarily using specialized proteins called cryptochrome 4 (Cry4) found in their retinas. How Birds "See" Magnetic Fields The Protein Mechanism (Cry4): Research focuses on the protein cryptochrome 4 (Cry4), which is sensitive to blue light and located in the bird's eye. This protein is believed to be activated by magnetic fields, allowing birds to detect magnetic field lines. Quantum Action (Radical Pair): The magnetic sensing mechanism involves quantum physics, specifically the creation of "radical pairs"—short-lived molecular fragments sensitive to magnetic fields that are formed in the eye when light hits cryptochrome. Light Sensitivity: The magnetic sense is light-dependent, usually requiring the blue light spectrum. Processing in the Brain: Evidence suggests this magnetic information is transmitted through the optic nerve to a specific part of the brain responsible for vision (such as Cluster N), allowing the bird to interpret the field as a visual sensation. Additional Mechanisms Beak Sensors: Some birds, such as pigeons, are believed to also use magnetite-based sensors, perhaps in their beaks, to sense magnetic intensity in addition to direction. Direction and Navigation: This sense works as an "inclination compass," allowing birds to tell the difference between poleward and equatorward directions, helping them orient themselves during long flights. Birds Confirmed to Have This Sense European Robins Zebra Finches Migratory Garden Warblers Pigeons Owls This complex process enables birds to navigate thousands of miles with incredible accuracy, relying on the environment's light and magnetic fields to find their way.
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Dimitrios A. Karras το κοινοποίησεHaing S. Ngor: A Life of Courage and Tragedy Under the Khmer Rouge In the heart of Cambodia's dark history, Haing S. Ngor, an OB/GYN, made an unimaginable choice that would forever shape his life. In the midst of the Khmer Rouge regime’s reign of terror, his medical knowledge would have cost him everything. His wife and unborn child perished, not from a lack of skill, but from the dangerous reality of living under an oppressive regime that demanded silence. In the 1970s, Cambodia fell under the brutal rule of the Khmer Rouge, led by Pol Pot. The regime sought to erase any trace of intellectual or medical expertise, and anyone suspected of being educated was forced into labor or executed. Haing, a respected OB/GYN, knew the dangers that his medical training posed, so he hid his knowledge to protect his life. However, when his wife went into labor with their first child, Haing faced an agonizing decision: perform the life-saving caesarean section she needed, or risk exposing his medical expertise and condemning his entire family. Unable to take the risk, Haing’s wife and unborn child tragically died. The loss haunted him, a reminder of the horrific choices forced upon people under a genocidal regime. Haing’s survival was a testament to his resourcefulness and courage, yet it came at an unbearable cost. This tragedy, however, was not the end of his story, as he would later rise to global recognition in a way no one could have anticipated. Haing’s journey from survivor to Oscar-winning actor is a story of resilience and unexpected triumph. After surviving the horrors of the Khmer Rouge regime, he eventually became an actor and starred in the 1984 film The Killing Fields, a film based on the real-life experiences of journalists and Cambodians during the genocide. His portrayal of the character Dith Pran earned him the Academy Award for Best Supporting Actor, cementing his legacy not just as a survivor, but as a remarkable figure in both the entertainment world and in the broader story of human survival. Haing’s life remains a powerful reminder of the extreme choices people are sometimes forced to make in times of terror, and how human strength and talent can emerge even from the most unimaginable circumstances. His Oscar win wasn’t just a personal triumph—it was a tribute to the millions who suffered under the Khmer Rouge and to the survival of the human spirit against all odds. As we remember Haing S. Ngor's extraordinary life, we reflect on the immense sacrifices that often go unnoticed. His story challenges us to consider the cost of knowledge, the value of life, and the immense weight of survival under oppression. It’s a call to honor the resilience of those who lived through unimaginable horrors and continue to contribute to our shared history in ways we may never fully understand.
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Dimitrios A. Karras το κοινοποίησεNice!Dimitrios A. Karras το κοινοποίησεStop treating Transformers like a black box. 🛑📦 Everyone is talking about Large Language Models, but how many people actually understand the linear algebra under the hood? If you want to move beyond the hype, you need to understand Attention mechanisms. Luckily, Michel Fabrice Serret just published an incredible breakdown designed specifically for applied mathematicians. Here is how text transforms into vectors, and how models actually "pay attention" to semantic meaning 👇
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Dimitrios A. Karras το κοινοποίησεTHESE INCREDIBLE FEATHERED SOULS ARE NOT ONLY DEVOTED PARTNERS — THEY ARE HIGHLY INTELLIGENT AND COMPLEX BEINGS. People don’t know that pigeons have tiny magnetic crystals in their beaks that act like biological compasses. This allows them to sense Earth’s magnetic field and navigate thousands of miles. They can also detect sounds too low for humans to hear and read polarized light patterns in the sky. Studies have found that pigeons can count, recognize themselves in mirrors, learn abstract concepts, and even understand probability. In fact, they rank among the top ten most intelligent beings on the planet — and they could outperform young children on some cognitive tests. While humans see only three primary colors, pigeons see four, including ultraviolet light. This allows them to see patterns completely invisible to us. These amazing birds can fly over 60 mph in sustained flight. They form lifelong partnerships, although their “divorce rate” increases under environmental stress. Pigeons use different types of calls for specific purposes, and they can recognize individual voices over long distances. They even have specific “words” for danger, territory, and courtship. Pigeons have helped humans in times of war. One famous bird, Cher Ami, lost one of her legs while delivering a message tied to her remaining leg — saving 194 soldiers in the process. They need our help. Once domesticated, pigeons were abandoned and left to survive in the wild. They’ve stayed close to humans in cities because they are used to us. Please feed them and leave water out for them. PIGEONS ARE NOT "PESTS" — THEY ARE HIGHLY ADVANCED AND THOUGHTFUL SOULS WHO DESERVE OUR EMPATHY AND CARE. THEY SHOULD BE CHERISHED. — Animal Freedom Fighter Pigeons possess remarkable cognitive abilities, including advanced visual memory, self-awareness, and categorization skills, often on par with primates. They can recognize themselves in mirrors, differentiate between human faces, and identify cancer in medical images. These birds demonstrate sophisticated navigation and can memorize hundreds of images over years. Key Mental Capabilities: Advanced Visual Memory and Recognition: Pigeons can identify letters, recognize human faces, and distinguish between styles of art (e.g., Monet vs. Picasso). Exceptional Spatial Navigation: They use complex "mental maps" combining landmarks, magnetic fields, and sun cues to navigate. Self-Awareness & Social Cognition: Pigeons can identify themselves in mirrors and differentiate between individuals who have mistreated them versus those who have fed them. Categorization and Numerical Ability: They can distinguish between objects (e.g., chairs, people, cars) and learn abstract, logical rules. Medical Diagnostics: Research has shown trained pigeons can accurately spot cancerous lesions in histological slides and mammograms. Long-Term Memory: Pigeons can store vast amounts of information, remembering locations and complex patterns for years.
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Dimitrios A. Karras το κοινοποίησεKarl Pearson Correlation Coefficient It explains how two variables reveal their hidden relationship by treating their paired values like synchronized dancers moving along a line. As each pair of values is observed, we look at how they shift together—whether they rise and fall in harmony, move in opposite directions, or show no clear pattern at all. Each value is compared to its average, and the differences are multiplied to see whether they reinforce or cancel each other. When both variables move above or below their averages together, their combined effect strengthens the relationship. When one rises while the other falls, their effects oppose and weaken it. At the end, all these interactions are balanced and scaled into a single number between −1 and +1. A value close to +1 signals a strong positive alignment, like perfectly synchronized steps. A value near −1 shows a strong negative alignment, like mirror-opposite movements. A value around 0 suggests no consistent rhythm at all. This coefficient becomes a precise tool for scientists and analysts to measure how strongly two variables are connected—and in what direction their relationship flows.
Dimitrios A. Karras απάντησε σε ένα σχόλιο
3 ημ.
Tiffany Ann Gerck you are right! Fake news and hype are everywhere nowadays and we should be very careful. I am searching for real science and engineering and I try always to fact check everything before posting. But you know as I know. We are not there in the event. Even high quality media report with mistakes. I trust only high quality scientific and popular science journals. If they provide as many details as possible. But again we are not there in the source. And there is no a high quality publication. I am always sceptical about such conditions but i know very well the capabilities of technology in many branches. But of course always, if there is no a rigorous publication, the hype is there a bit hidden.... Take care!
Dimitrios A. Karras απάντησε σε ένα σχόλιο
4 ημ.
Tiffany Ann Gerck the links are from legitimate newspapers. They are a bit incomplete. The full story with more details is here
https://www.the-scientist.com/chatgpt-and-alphafold-help-design-personalized-vaccine-for-dog-with-cancer-74227
Hype is something else. The issue that the newspapers links do not write all details this is not hype, sorry. You can check this scientist link which has all basic details including the collaboration with experts. Obviously a data scientist cannot play with biological labs producing drugs alone. Its a team work. But he managed major details. This work is not a simple product of a lab research. Without the management of the data scientist would be impossible. I hope you understand this.
Dimitrios A. Karras απάντησε σε ένα σχόλιο
4 ημ.
MADISON NEWELL obviously you don't check links. The links i provided are from official newspapers during mid March. Not 1st April. You can believe whatever you want, it's your right, but not without evidence. Before any opinion just check. It doesn't harm....
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Dimitrios A. Karras πρόσθεσε επισήμανση «Μου αρέσει»Dimitrios A. Karras πρόσθεσε επισήμανση «Μου αρέσει»NotebookLM is probably the most versatile free AI tool out there. And most people barely scratch the surface. They use it to summarize. That is the weakest use case. NotebookLM is a research engine. It only answers from your uploaded sources. No hallucinations. No made up citations. Here is what it actually does well. → Find trends and gaps across dozens of papers. → Turn dense research into audio you can replay. → Surface contradictions with direct quotes. → Turn raw notes into clean outlines. → Translate academic jargon into plain language. → Stress test your arguments before review. NotebookLM does not replace researchers. It makes good researchers faster. __________________________________________ Master the Top AI Tools for Research Explore 30+ step-by-step AI courses Get 40% off with code IRF40 at checkout! 👇 https://lnkd.in/dYkbmMxg --------------------------------------------- Subscribe to my free newsletter for tips on AI in academic research! 👇 https://lnkd.in/dTZesqZA
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Dimitrios A. Karras πρόσθεσε επισήμανση «Μου αρέσει»Dimitrios A. Karras πρόσθεσε επισήμανση «Μου αρέσει»Stop treating Transformers like a black box. 🛑📦 Everyone is talking about Large Language Models, but how many people actually understand the linear algebra under the hood? If you want to move beyond the hype, you need to understand Attention mechanisms. Luckily, Michel Fabrice Serret just published an incredible breakdown designed specifically for applied mathematicians. Here is how text transforms into vectors, and how models actually "pay attention" to semantic meaning 👇
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National and Kapodistrian University of Athens, Greece
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