Abstract: A circuit, including a first impedance unit having an impedance value based on a first impedance code and configured to drive a first node coupled with a resistor with a first voltage, a first code generation unit configured to generate the first impedance code so that an impedance value of the first impedance unit and an impedance value of the resistor are at a ratio of X:Y, dummy impedance units that receive the first impedance code and drive a second node with the first voltage, a second impedance unit having an impedance value based on a second impedance code and configured to drive the second node with a second voltage, and a second code generation unit configured to generate the second impedance code so that an overall impedance value of the dummy impedance units and an impedance value of the second impedance unit are at a ratio of X:Y.

Abstract: Provided is a tube railway system that reduces noise and air resistance using a sealed evacuated tube as a passage for a tube railway, thereby allowing a train to run at a higher speed. A vacuum division management system and a vacuum blocking screen device for a tube railway system required to maintain vacuum are provided, in which the vacuum blocking screen device is operated to rapidly block a passage for a tube railway in response to an operation signal, is installed at every certain section or at a designated section of the tube railway, and is operated in a specific section when a vacuum maintenance problem occurs, or when the vacuum needs to be released, or when the train needs to stop immediately, thereby allowing the specific section to be isolated from other sections to have a degree of vacuum different from those of the other sections.

Abstract: A circuit, including a first impedance unit having an impedance value based on a first impedance code and configured to drive a first node coupled with a resistor with a first voltage, a first code generation unit configured to generate the first impedance code so that an impedance value of the first impedance unit and an impedance value of the resistor are at a ratio of X:Y, dummy impedance units that receive the first impedance code and drive a second node with the first voltage, a second impedance unit having an impedance value based on a second impedance code and configured to drive the second node with a second voltage, and a second code generation unit configured to generate the second impedance code so that an overall impedance value of the dummy impedance units and an impedance value of the second impedance unit are at a ratio of X:Y

Abstract: Provided is a tube railway system that minimizes noise and air resistance using a sealed evacuated tube as a passage for a tube railway., thereby allowing a train to run at a very high speed. More particularly, provided is a vacuum division management system and vacuum blocking screen device for a tube railway system required to maintain vacuum (1/3 to 1/1000 of atmospheric pressure), in which the vacuum blocking screen device serves to rapidly block a passage for a tube railway with an operation signal, is installed in every fixed section or in some designated sections of the tube railway, and is driven in a specific section where problems with maintenance of the vacuum occur, where the vacuum is intentionally released, for instance, due to maintenance, or where a train is urgently stopped, thereby allowing the specific section to be isolated from the other sections and to be managed with a degree of vacuum different from those of the other sections.

Abstract: Provided is a magnetic core having an appropriate range of permeability and a high magnetic flux density, thereby being configured to have a small phase difference and a small size. The magnetic core can be use for electric current sensors. The magnetic core is made of an amorphous alloy having a composition represented by the general formula: FeaMbSicBdM?e, in which M is at least one element that is selected from Ni and Co, and M? is Cr, and a to e are atomic % and numbers satisfying 30?a?80, 1?b?50, 0.1?c?20, 0.1?d?20, and 0?e?10, respectively, and wherein the amorphous alloy has a magnetic flux density of 1.2 T to 1.7 T, and a permeability of 1,000 to 4,000.