Inparticular,standardmetricformulations as hierarchical k-center,k-means, andk-median received a lot of attention and the problems have been studied extensively in different models of computation.

Gardeners want to make their grass even greener. As petrol prices rocket and people become ever more conscious of their environmental impact, many are turning to the latest generation of lawnmowers to keep their gardens looking good. While the fronts of our houses are gradually seeing the replacement of petrol cars with electric vehicles, advances in lithium-ion batteries have meant that the trusted back garden mower has also been given a modern overhaul – but at a price. So is it time to replace your current mower with a battery-powered or "robot" version, stick with petrol despite the spiralling costs, or stay plugged in? The length and breadth of your garden will heavily influence what type of machine you need.

The Moon’s polar regions are home to craters and other depressions that never receive sunlight. Today, a group of researchers led by the Max Planck Institute for Solar System Research (MPS) in Germany presents the highest-resolution images to date covering 17 such craters in the journal Nature Communications. Craters of this type could contain frozen water, making them attractive targets for future lunar missions, and the researchers focused further on relatively small and accessible craters surrounded by gentle slopes. In fact, three of the craters have turned out to lie within the just-announced mission area of NASA's Volatiles Investigating Polar Exploration Rover (VIPER), which is scheduled to touch down on the Moon in 2023. Imaging the interior of permanently shadowed craters is difficult, and efforts so far have relied on long exposure times resulting in smearing and lower resolution. By taking advantage of reflected sunlight from nearby hills and a novel image processing method, the researchers have now produced images at 1-2 meters per pixel, which is at or very close to the best capability of the cameras.

It began with a pulled muscle. Each day after school, as the sun sank dusky purple over the hills of my hometown, I'd run with my track teammates. Even on our easy days, I'd bound ahead, leaving them behind. It wasn't that I thought myself better than them--it's that when I ran fast, and focused on nothing but the cold air burning my lungs and my feet pounding, my normally anxious thoughts turned to white noise. I limped a little, and then tried running again: sharp, hot pain radiated down my thigh. Panic flooded me, as I imagined weeks without running: weeks without a predictable break from my own thoughts, weeks immersed in adolescent loneliness.

Business professionals have traditionally viewed the world in concrete terms and sometimes even round numbers. That legacy perspective is black and white compared to the shades of gray that data science produces. Instead of producing a single number result such as 40%, the result is probabilistic, combining a level of confidence with a margin of error. In fact, there are several reasons why data science isn't an exact science, some of which are described below. "When we're doing data science effectively, we're using statistics to model the real world, and it's not clear that the statistical models we develop accurately describe what's going on in the real world," said Ben Moseley, associate professor of operations research at Carnegie Mellon University's Tepper School of Business.

The coding of medical diagnosis and treatment has always been a challenging issue. Translating a patient's complex symptoms, and a clinician's efforts to address them, into a clear and unambiguous classification code was difficult even in simpler times. Now, however, hospitals and health insurance companies want very detailed information on what was wrong with a patient and the steps taken to treat them-- for clinical record-keeping, for hospital operations review and planning, and perhaps most importantly, for financial reimbursement purposes. The current international standard for medical coding is ICD-10 (the tenth version of International Classification of Disease codes), from the World Health Organization (WHO). ICD‑10 has over 14,000 codes for diagnoses.