Abstract: Disclosed are a safety service system and a method thereof. The safety service system comprises: a collection unit for collecting position information and image information related to a protected person who is registered by a protector; and a service providing unit for providing the position information and the image information to one or both of the protector and a security company upon detection of a signal that the protected person is in danger.

Abstract: An optical imaging system includes a first lens having a convex image-side surface, a second lens having a concave object-side surface, a third lens, a fourth lens, and a fifth lens disposed sequentially from an object side. The optical imaging system satisfies 4.8<f/IMG_HT<9.0, where f is a focal length of the optical imaging system, and IMG_HT is half a diagonal length of an imaging surface of an image sensor.

Abstract: An optical imaging system includes an optical system including at least six lenses, sequentially disposed from an object side toward an image side, an image sensor configured to convert light incident through the optical system into an electronic signal, and a variable stop configured to change an incident hole diameter and disposed toward the object side of a lens of the optical system closest to the object side, wherein TTL is a distance to an imaging plane of the image sensor from an object-side surface of the lens closest to the object side and 4.7 mm <TTL <6.00 mm, and wherein Ri is a radius of curvature of an object-side surface of a lens of the optical system second closest to the image sensor, Rj is a radius of curvature of an image-side surface of the lens that is second closest to the image sensor, and ?0.5<(|Ri|?|Rj|)/(|Ri|?|Rj|)/(|Ri|+|Rj|)<0.5.

Abstract: An optical imaging system includes a first lens having an object-side surface that is convex; a second lens having a refractive power and a refractive index of 1.65 or more; a third lens having a refractive power; a fourth lens having a refractive power and an object-side surface that is convex; a fifth lens having a refractive power; a sixth lens having a positive refractive power; and a seventh lens having an object-side surface that is convex, wherein the first lens through the seventh lens are sequentially disposed in numerical order from an object side of the optical imaging system toward an imaging plane of the optical imaging system, and two or more of the first lens and the third lens through the seventh lens have a refractive index of 1.6 or more.

Abstract: An optical imaging system includes a plurality of lenses disposed along an optical axis from an object side of the optical imaging system toward an imaging plane of the optical imaging system. The lenses are separated from each other by respective air gaps along the optical axis between the lenses. The lenses include a first lens closest to the object side of the optical imaging system. The conditional expressions 1.5 mm<Gmax, TL<12.0 mm, and 0.15<R1/f are satisfied, where Gmax is a maximum air gap along the optical axis among all of the air gaps, TL is a length of the optical imaging system along the optical axis from an object-side surface of the first lens to the imaging plane, R1 is a radius of curvature of the object-side surface of the first lens, and f is a focal length of the optical imaging system.

Abstract: A ceramic electronic component includes a body including a dielectric layer and an internal electrode, and an external electrode disposed on the body and connected to the internal electrode. The dielectric layer includes a plurality of dielectric grains, and at least one of the plurality of dielectric grains has a core-dual shell structure having a core and a dual shell. The dual shell includes a first shell surrounding at least a portion of the core, and a second shell surrounding at least a portion of the first shell, and a concentration of a rare earth element included in the second shell is more than 1.3 times to less than 3.8 times a concentration of a rare earth element included in the first shell.

Abstract: An optical imaging system includes a first lens having an image-side surface that is concave; a second lens having a refractive power; a third lens having an object-side surface that is convex; a fourth lens having an image-side surface that is concave; a fifth lens having a refractive power; and a sixth lens having a refractive power and an image-side surface having an inflection point, wherein the first lens through the sixth lens are sequentially disposed in numerical order from an object side of the optical imaging system toward an imaging plane of the optical imaging system, and the optical imaging system satisfies TL/(2Y)?1.01 and 1.2?tan ?, where TL is a distance from an object-side surface of the first lens to the imaging plane, 2Y is a diagonal length of the imaging plane, and ? is half a field of view of the optical imaging system.

Abstract: An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially disposed in ascending numerical order along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging surface of an image sensor, wherein a conditional expression f/f2+f/f3<?0.4 is satisfied, where f is a focal length of the optical imaging system, f2 is a focal length of the second lens, and f3 is a focal length of the third lens, and a conditional expression TTL/(2*IMG HT)<0.69 is satisfied, where TTL is a distance along the optical axis from an object-side surface of the first lens to the imaging surface of the image sensor, and IMG HT is one-half of a diagonal length of the imaging surface of the image sensor.

Abstract: An optical imaging system includes a first lens having a convex image-side surface, a second lens having a concave object-side surface, a third lens, a fourth lens, and a fifth lens disposed sequentially from an object side. The optical imaging system satisfies 4.8<f/IMG_HT<9.0, where f is a focal length of the optical imaging system, and IMG_HT is half a diagonal length of an imaging surface of an image sensor.

Abstract: An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially disposed in ascending numerical order along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging surface of an image sensor, wherein a conditional expression f/f2+f/f3<?0.4 is satisfied, where f is a focal length of the optical imaging system, f2 is a focal length of the second lens, and f3 is a focal length of the third lens, and a conditional expression TTL/(2*IMG HT)<0.69 is satisfied, where TTL is a distance along the optical axis from an object-side surface of the first lens to the imaging surface of the image sensor, and IMG HT is one-half of a diagonal length of the imaging surface of the image sensor.

Abstract: A negative electrode active material as well as a method of preparing a negative electrode active material which includes preparing a silicon-based compound including SiOx, wherein 0.5<x<1.3; disposing a polymer layer including a polymer compound on the silicon-based compound; disposing a metal catalyst layer on the polymer layer; heat treating the silicon-based compound on which the polymer layer and the metal catalyst layer are disposed; and removing the metal catalyst layer, wherein the polymer compound includes any one selected from the group consisting of glucose, fructose, galactose, maltose, lactose, sucrose, a phenolic resin, a naphthalene resin, a polyvinyl alcohol resin, a urethane resin, polyimide, a furan resin, a cellulose resin, an epoxy resin, a polystyrene resin, a resorcinol-based resin, a phloroglucinol-based resin, a coal-derived pitch, a petroleum-derived pitch, a tar and a mixture of two or more thereof.

Abstract: An optical imaging system includes an optical system including at least six lenses, sequentially disposed from an object side toward an image side, an image sensor configured to convert light incident through the optical system into an electronic signal, and a variable stop configured to change an incident hole diameter and disposed toward the object side of a lens of the optical system closest to the object side, wherein TTL is a distance to an imaging plane of the image sensor from an object-side surface of the lens closest to the object side and 4.7 mm<TTL<6.00 mm, and wherein Ri is a radius of curvature of an object-side surface of a lens of the optical system second closest to the image sensor, Rj is a radius of curvature of an image-side surface of the lens that is second closest to the image sensor, and ?0.5<(|Ri|?|Rj|)/(|Ri|+|Rj|)<0.5.

Abstract: Provided are a system and method for identifying a peer-to-peer (P2P) application service. The method includes the steps of: (a) collecting an Internet protocol (IP) packet and generating a flow; (b) identifying the P2P application service on the basis of a port number using the generated flow; (c) when the P2P application service is identified in step (b), verifying the identified application service; (d) when it is verified that the identification is not correct, or the P2P application service is not identified in step (b), identifying the P2P application service on the basis of a payload; (e) when the P2P application service is identified in step (d) or it is verified in step (c) that the identification is correct, generating a SET table using a flow of the identified P2P application service; and (f) identifying the P2P application service for a flow not identified in either step (b) or step (d) using the SET table.