Abstract: A method for testing burning performance of a dark-colored cigarette using a dark-colored cigarette paper is provided. The dark-colored cigarette paper has a grayscale less than 255. The method includes: simulating, by a robotic arm, a cigarette smoking process and environment; acquiring, by a full-vision camera system, an image of a burn line and ash column region of the dark-colored cigarette; and analyzing a burning performance indicator of the dark-colored cigarette according to coordinate information of the burn line and ash column region. The method is based on a surface reflection characteristic of the dark-colored cigarette paper and a principle of optical reflection to light and highlight an edge of the dark-colored cigarette sample by a light source at a certain angle from a side. In this way, the method forms a chromatic aberration to localize the dark-colored cigarette sample, thereby testing the burning performance of the dark-colored cigarette sample.

Abstract: A linearity compensation method for a sound producing device (SPD) includes steps of: applying a test signal on a first SPD; obtaining an acoustic measurement result generated from the first SPD according to the test signal; generating a compensation curve according to the acoustic measurement result; and performing a linearity compensation operation on a second SPD according to the compensation curve.

Abstract: A method for comprehensively analyzing and/or evaluating cigarette burning quality index is disclosed. The steps include collecting cigarette burning quality index data, filtering the cigarette burning quality index data, standardizing cigarette data, and measuring cigarette burning quality. The importance of the cigarette burning quality indicators can also be evaluated. The method for comprehensively analyzing and/or evaluating cigarette burning quality indicators can reflect general laws more accurately by maintaining the sample distribution through a singularity detection method, and analyzing correlations of each index with cigarette performance from multiple perspectives, to fuse them into a comprehensive measurement value. The importance ranking and weight of indicators can be obtained more completely and stably.

Abstract: A method for testing burning performance of a dark-colored cigarette using a dark-colored cigarette paper is provided. The dark-colored cigarette paper has a grayscale less than 255. The method includes: simulating, by a robotic arm, a cigarette smoking process and environment; acquiring, by a full-vision camera system, an image of a burn line and ash column region of the dark-colored cigarette; and analyzing a burning performance indicator of the dark-colored cigarette according to coordinate information of the burn line and ash column region. The method is based on a surface reflection characteristic of the dark-colored cigarette paper and a principle of optical reflection to light and highlight an edge of the dark-colored cigarette sample by a light source at a certain angle from a side. In this way, the method forms a chromatic aberration to localize the dark-colored cigarette sample, thereby testing the burning performance of the dark-colored cigarette sample.

Abstract: The present invention provides an experimental platform for simulating a coal rock disaster of a coal mine extraction, including a base device, a coal simulation device, an immediate roof simulation device, a hydraulic support and a removable impact device. The coal simulation device is fixedly disposed on the base device; the hydraulic support is fixed on the base device and is located at one side of the coal simulation device; the immediate roof simulation device is disposed above the coal simulation device and the hydraulic support; the removable impact device is disposed above the immediate roof simulation device; the immediate roof simulation device is a rectangular frame; the rectangular frame is configured to pave a bulk simulation material and an immediate roof simulation material sequentially from the bottom up; and the removable impact device can impact the immediate roof simulation material and the bulk simulation material.

Abstract: Disclosed are systems and methods for acquiring movement information of a high-level rock stratum (HLRS) in a coal mine stope. The system includes information acquisition, information acquisition transfer, information storage and rock stratum position-state information analysis modules that are sequentially connected wireles sly; the information acquisition module is disposed in a drill hole of the HLRS; the information acquisition transfer module is disposed below the information acquisition module; the information storage module is disposed in a working area of the stope; the rock stratum position-state information analysis module is disposed in a haulage roadway of the stope.

Abstract: The present invention provides an experimental platform for simulating a coal rock disaster of a coal mine extraction, including a base device, a coal simulation device, an immediate roof simulation device, a hydraulic support and a removable impact device. The coal simulation device is fixedly disposed on the base device; the hydraulic support is fixed on the base device and is located at one side of the coal simulation device; the immediate roof simulation device is disposed above the coal simulation device and the hydraulic support; the removable impact device is disposed above the immediate roof simulation device; the immediate roof simulation device is a rectangular frame; the rectangular frame is configured to pave a bulk simulation material and an immediate roof simulation material sequentially from the bottom up; and the removable impact device can impact the immediate roof simulation material and the bulk simulation material.

Abstract: Embodiments of the present disclosure disclose an overlay key including at least two overlay marks each having a first sub-mark and a second sub-mark centro-symmetrical to each other, the first sub-mark and the second sub-mark each including two bar patterns that are perpendicular to each other and have a common end. At least two of the overlay marks are located in different layers. Also disclosed is a method of forming the overlay key and a method of measuring overlay accuracy.

Abstract: Embodiments of the present disclosure disclose an overlay key including at least two overlay marks each having a first sub-mark and a second sub-mark centro-symmetrical to each other, the first sub-mark and the second sub-mark each including two bar patterns that are perpendicular to each other and have a common end. At least two of the overlay marks are located in different layers. Also disclosed is a method of forming the overlay key and a method of measuring overlay accuracy.