摘要:
Provided is an optimum resource allocation method in distributed medium access control in a wireless personal area network, including: defining needed parameters in advance; calculating an overhead AckOverhead needed for an acknowledgement policy and calculating an overhead MasOverhead generated per medium access slot by using the calculated overhead AckOverhead and an amount of the medium access slots which remain after transmitting a frame; calculating the number of frame bits to be transmitted per superframe; determining the number of medium access slots primarily needed per the superframe by using the calculated number of frame bits and the calculated overhead MasOverhead generated per the medium access slot; and optimizing the number of medium access slots finally needed per the superframe.
摘要:
A method for operating a device in a personal area network (PAN), includes: obtaining physical layer information regarding a physical layer; scanning a channel on the basis of the physical layer information; selecting a channel on the basis of channel information obtained through the channel scanning process; determining whether or not there is a PAN coordinator with respect to the selected channel; and when a PAN coordinator does not exist in the selected channel, transmitting a beacon signal including information regarding a superframe structure, wherein the superframe structure includes at least one sub-superframe, and the information regarding the superframe structure includes information regarding the number of beacon slots for transmitting a beacon signal in each sub-superframe, the number of data slots for transmitting data in each sub-superframe, and the number of sub-superframes.
摘要:
A method for operating a device in a personal area network (PAN), includes: obtaining physical layer information regarding a physical layer; scanning a channel on the basis of the physical layer information; selecting a channel on the basis of channel information obtained through the channel scanning process; determining whether or not there is a PAN coordinator with respect to the selected channel; and when a PAN coordinator does not exist in the selected channel, transmitting a beacon signal including information regarding a superframe structure, wherein the superframe structure includes at least one sub-superframe, and the information regarding the superframe structure includes information regarding the number of beacon slots for transmitting a beacon signal in each sub-superframe, the number of data slots for transmitting data in each sub-superframe, and the number of sub-superframes.
摘要:
A gas sensor includes a sensor element having a specific function, and a housing containing the sensor element therein and including a thread section, and a sealing surface which forms a sealing section together with an installation section at a position deeper than the thread section in a direction in which the sensor element is inserted. When the housing is screwed into the installation section, the release torque of the housing at 850° C. (1123 K) is 9 N·m or more, and an estimated value of a gap formed between the sealing surface and the installation section at 850° C. (1123 K) that is calculated according to a specific equation is 31 μm or less.
摘要:
An ammonia concentration detection sensor 100, has: a sensor element 110 capable of detecting the ammonia concentration of a measurement target gas; and a protective cover 120 that regulates the inflow of the measurement target gas into the sensor element 110 and protects the sensor element 110. The protective cover 120 is coated with a coating layer.
摘要:
A technology which makes it possible to prolong the service life of a porous electrode constituted by a sintered body of an electrode metal material and a ceramic material, and the service life of an NOx sensor element having the porous electrode. The porous electrode is produced so as to have a total pore volute of at least 0.013 ml/g and a peak pore diameter of at least 0.31 μm as measured by mercury penetration method, by a process wherein a composition which includes the electrode material and the ceramic material and to which a vanishable solid material that vanishes by firing is formed into a thin film, which is then fired to form the sintered body which consists of the electrode material and the ceramic material and which has a multiplicity of pores formed as a result of vanishing of the vanishable solid material.
摘要:
A gas sensor includes an internal space, diffusion control part, pumping cell, and measuring cell. The diffusion control part communicates with the internal space and has a slit-like shape with a smaller thickness than that of the internal space. The pumping cell pumps out oxygen from the internal space when voltage is applied between a first electrode formed on a surface of the internal space and a second electrode formed outside the internal space. The measuring cell measures a current flowing between a third and fourth electrodes when a voltage is applied between the third and fourth electrodes. The third electrode is formed in the diffusion control part, and can reduce an oxide gas component in a predetermined gas component to which a predetermined diffusion resistance has been applied by the diffusion control part. The fourth electrode is formed in a part different from the diffusion control part.
摘要:
A gas sensor having a sensor element that includes an inner space for introducing a measurement gas therein from an external space and a pump cell which has a first electrode formed on a surface of the inner space and a second electrode formed in a space different from the inner space and is provided to pump oxygen out of the inner space by applying a predetermined voltage between the first electrode and the second electrode. Assuming that the length of the inner space in a short-side direction of the sensor element as viewed from the front end portion side thereof is x1 and the length of the inner space in a longitudinal direction of the sensor element as viewed from the front end portion side thereof is x2, the following inequality is satisfied: 0.05≦x1/x2≦0.25.
摘要:
A flow path from outer gas introduction apertures 144a to inner gas introduction apertures 134a has a narrower-width flow passage formed by an inner wall member 150. This structure effectively lowers the probability that a liquid, such as water, entering from the outer gas introduction apertures 144a passes through a gas inflow chamber 122 and reaches a sensor element 110, compared with a structure without the inner wall member 150. The inner wall member 150 is formed as a solid member that is capable of storing the surrounding heat. Even if there is a certain event that has the potential of causing a temperature decrease of the sensor element 110, for example, an abrupt change in flow rate of an object gas, the heat stored in the inner wall member 150 effectively prevents a temperature decrease of the sensor element 110. This structure prevents the occurrence of cracking in the sensor element 110, compared with a conventional sensor structure having a double-layered protective cover.
摘要:
An ammonia concentration detection sensor 100, has: a sensor element 110 capable of detecting the ammonia concentration of a measurement target gas; and a protective cover 120 that regulates the inflow of the measurement target gas into the sensor element 110 and protects the sensor element 110. The protective cover 120 is coated with a coating layer.