In this blog post, we’ll explore criteria for making wise choices by examining the concept of opportunity cost hidden behind visible profits.   True investing begins only when you understand opportunity cost In a previous post on sunk costs, I explained that what you see isn’t the whole story, and that costs already incurred should not be factored into decision-making. The concept we’ll...

In this blog post, we’ll take a step-by-step look at the structure and fluid dynamics principles that allow blade-less fans to generate a strong breeze, even though they appear to have no external rotating blades.   Why Were Blade-Less Fans Invented? For families with children, traditional fans with blades are always a source of concern. Because there’s a risk that a child might stick their...

In this blog post, we’ll explore why mechanical and aerospace engineering is called the foundation of modern engineering by examining its core principles and various applications.   Since the late 2000s, interdisciplinary and convergent research—which combines multiple fields—has become increasingly important in academic research, and today, this approach has established itself as a standard...

In this blog post, we’ll explore the concepts of scientific design and optimal design as applied in mechanical engineering, as well as the role that optimal design plays in product design.   What Are Scientific Design and Optimal Design? In the past, the importance of product design garnered significant attention due to patent disputes surrounding smartphones. In the lawsuits between Samsung...

In this blog post, we’ll explore the concept, characteristics, limitations, and future direction of evidence-based medicine—an approach that evaluates medical decisions based on scientific evidence.   What Is Evidence-Based Medicine? A patient visited the hospital, distressed by a persistent cough and sleepless nights caused by it. After asking a few questions and conducting a physical...

In this blog post, we’ll examine the principles behind stealth technology applied to modern warships and the various ways it’s implemented, and explore what this technology means for naval power.   The Power of Stealth Demonstrated by Submarines   “We have lost more men than Admiral Nelson lost in all the battles he fought throughout his entire life.” This remark is said to have been...

In this blog post, we’ll explore why transit card readers are equipped with clocks by examining the principles behind electronic clocks and quartz oscillators.   Electronic Clocks and Quartz Oscillators Just a few decades ago, clocks were considered luxury items, but those days are long gone. Every room has at least one wall clock, and clocks are built into computers, smartphones, and...

In this blog post, we’ll examine the advancements in vehicle dynamics control technology and explore how advanced driver-assistance systems are helping to reduce traffic accidents.   The history of the automobile truly began with the development of the internal combustion engine. In 1860, Étienne Renoir of France developed a functional internal combustion engine, and in 1876, Nikolaus Otto...

In this blog post, we’ll examine the principles and processes by which traffic engineering uses real-time traffic information to reduce travel time during the holiday season.   During Seollal and Chuseok—the nation’s two major holidays—private vehicles heading to their hometowns congest the highways, leading to recurring traffic jams. Such traffic congestion causes significant losses not...

In this blog post, we will examine why the petition by the Committee for the Revision of Evolution Theory in Textbooks to remove evolution theory became controversial and what specific criticisms it faced.   The Petition by the Committee for the Revision of Evolution Theory in Textbooks and the Social Controversy In June 2012, the world-renowned scientific journal ‘Nature’...