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Assessing the motion of moving objects from video footage captured using multiple recording devices requires precise timing and location data, which remains equally important in mobile recording systems. Although capturing high-precision clocks and analyzing these images are effective methods for obtaining accurate time information, a definitive method for precisely determining the capture time from images of rapidly time-varying clocks at various exposure durations is currently lacking. This paper introduces a design method for a dynamic optical marker called the Optical Clock Beacon (OCB), which indicates the current time by integrating multiple point light sources. Our goal is to enable accurate determination of the capture time from images. We present a method for estimating this time using image analysis and validate its accuracy. The simplest OCB configuration translates the binary representation of the current time into a Gray code, with each bit’s state indicated by light sources of positive and negative logic. This approach allows the determination of an image capture time with precision matching of the exposure duration. Furthermore, we outline a design strategy that improves the time accuracy by making the light source configuration of each digit redundant, thus providing substantial design flexibility for the OCB. We also detail the prototype hardware and the image analysis system of the developed OCB, demonstrating through evaluation experiments that the anticipated time accuracy is achievable.

Reduction mechanisms of oxygen molecule to water molecules in the fully reduced (FR) and mixed-valence (MV) bovine cytochrome 𝑐 oxidases (C𝑐O) have been systematically examined based on the B3LYP calculations. The catalytic cycle using four electrons and four protons has been also shown consistently. The MV C𝑐O catalyses reduction to produce one water molecule, while the FR C𝑐O catalyses to produce two water molecules. One water molecule is added into vacant space between His240 and His290 in the catalytic site. This water molecule constructs the network of hydrogen bonds of Tyr244, farnesyl ethyl, and Thr316 that is a terminal residue of the K-pathway. It plays crucial roles for the proton transfer to the dioxygen to produce the water molecules in both MV and FR C𝑐Os. Tyr244 functions as a relay of the proton transfer from the K-pathway to the added water molecule, not as donors of a proton and an electron to the dioxygen. The reduction mechanisms of MV and FR C𝑐Os are strictly distinguished. In the FR C𝑐O, the Cu atom at the CuB site maintains the reduced state Cu(I) during the process of formation of first water molecule and plays an electron storage. At the final stage of formation of first water molecule, the Cu(I) atom releases an electron to Fe-O. During the process of formation of second water molecule, the Cu atom maintains the oxidized state Cu(II). In contrast with experimental proposals, the K-pathway functions for formation of first water molecule, while the D-pathway functions for second water molecule. The intermediates, PM, PR, F, and O, obtained in this work are compared with those proposed experimentally.