Abstract: A complex number quantization-based audio signal encoding method may comprise: estimating a scale factor for each subband of an input audio signal; performing complex magnitude scaling for each subband based on the scale factor; and performing polar quantization on a complex frequency coefficient for each subband, wherein the performing the polar quantization for each subband comprises applying two or more different magnitude quantization techniques based on the magnitude of the complex frequency coefficient scaled for each subband.

Abstract: A fuel cell apparatus of the disclosure includes a case having defined therein a first accommodation space and a second accommodation space, which are isolated from each other by a partition wall, a first cover covering the first accommodation space in the case, a second cover covering the second accommodation space in the case, a power distribution unit disposed in the first accommodation space, and a power conversion unit disposed in the second accommodation space.

Abstract: The present disclosure relates to an apparatus for preparing an oligomer, the apparatus including: a reactor for oligomerizing a feed stream containing a fed monomer; a stirrer inserted into a hole formed in an upper portion of the reactor; and a solvent transfer line extending inward from a side of the reactor, wherein the stirrer includes a rotating shaft vertically extending downward from the upper portion of the reactor, and a blade having a conical shape whose vertex is positioned at a lower end of the rotating shaft and outer diameter increases from a bottom toward a top, and the solvent transfer line has a plurality of spray nozzles formed in a direction toward the blade.

Abstract: A fuel cell vehicle includes a cell stack, a DC level converter, an output unit, a first switching unit disposed between a positive output terminal of the DC level converter and a positive input terminal of the output unit, a second switching unit disposed between a negative output terminal of the DC level converter and a negative input terminal of the output unit, a resistor and a third switching unit connected to each other in series between the positive output terminal of the DC level converter and the negative output terminal of the DC level converter, a fourth switching unit disposed between a contact point between the resistor and the third switching unit and the positive input terminal of the output unit, and a controller for controlling switching operation of the first, second, third and fourth switching units according to an operation mode.

Abstract: Provided is an isomerization method of cyclohexane dicarboxylic acid using zirconia or titania as an isomerization catalyst.

Abstract: A silicon photodiode according to an embodiment of the present invention comprises: a silicon substrate having a first conductive area and a second conductive area horizontally spaced apart from the first conductive area; a plurality of randomly arranged metal nanoparticles formed on the silicon substrate; an antireflective layer covering the metal nanoparticles; a first contact passing through the antireflective layer and connected to the first conductive layer; and a second contact passing through the antireflective layer and connected to the second conductive layer.

Abstract: The present disclosure relates to a method for preparation of 1,4-cyclohexanedimethanol. According to the present disclosure, two step reduction reactions are conducted using terephthalic acid as starting material, and an isomerization process for increasing the rate of trans isomers of CHDA is introduced therebetween, thereby providing a method capable of stably preparing CHDM with high rate of trans isomers.

Abstract: This invention relates to a method for preparing 1,4-cyclohexanedimethanol(CHDM), more specifically to a method for preparing 1,4-cyclohexanedimethanol having a high rate of trans isomers without an isomerization reaction step.

Abstract: This invention relates to a method for preparing 1,4-cyclohexanedimethanol (CHDM), more specifically to a method for preparing 1,4-cyclohexanedimethanol having a high rate of trans isomers without an isomerization reaction step, wherein two-step hydrogenation reactions and a purification step are conducted using terephthalic acid as starting material.

Abstract: The present disclosure relates to a method for producing 1,4-cyclohexanedimethanol (CHDM) and, more specifically, provides a method for producing 1,4-cyclohexanedimethanol having a high proportion of trans isomers even without including an isomerization step, by adjusting the content of 1,4-cyclohexane dicarboxylic acid (CHDA) which is a reactant.

Abstract: The present disclosure relates to an isomerization method of a cyclohexane dicarboxylic acid (CHDA) and, more specifically, to a method for preparing a trans-cyclohexane dicarboxylic acid (t-CHDA) from a cis-cyclohexane dicarboxylic acid (c-CHDA) by means of catalytic isomerization. Particularly, an embodiment of the present disclosure provides a method for preparing, in high efficiency and high yield and at a low cost, a CHDA having a high t-CHDA content from a CHDA mainly containing c-CHDA, by using an isomerization catalyst containing zirconia and having a BET specific surface area of 50 m2/g or more.

Abstract: A MEMS device according to an example embodiment of the present disclosure includes: a lower substrate; an infrared sensor formed on the lower substrate; and a lower bonding pad disposed to cover the infrared sensor. The infrared sensor includes: a metal pad formed on an upper surface of the lower substrate and electrically connected to a detection circuit; a reflective layer formed on the upper surface of the lower substrate and reflecting an infrared band; an absorption plate disposed to be spaced apart from an upper portion of the reflective layer and absorbing infrared rays to change resistance; and an anchor formed on the metal pad to support the absorption plate and to electrically connect the metal pad and the absorption plate to each other. The reflective layer has a curved or stepped shape such that a distance between the reflective layer and the absorption plate varies depending on a position of the reflective layer.

Abstract: The present disclosure relates to a method for preparation of 1,4-cyclohexanedimethanol. According to the present disclosure, two step reduction reactions are conducted using terephthalic acid as starting material, and an isomerization process for increasing the rate of trans isomers of CHDA is introduced therebetween, thereby providing a method capable of stably preparing CHDM with high rate of trans isomers.

Abstract: Provided is a preparation method for a cyclohexane dimethanol (CHDM), which can have a high trans content through particular conditions, additive addition, or reactant addition, which is controlled in a cyclohexane dicarboxylic acid (CHDA) hydrogenation reaction, and a cyclohexane dimethanol prepared thereby.

Abstract: A MEMS device according to an example embodiment of the present disclosure includes: a lower substrate; an infrared sensor formed on the lower substrate; and a lower bonding pad disposed to cover the infrared sensor. The infrared sensor includes: a metal pad formed on an upper surface of the lower substrate and electrically connected to a detection circuit; a reflective layer formed on the upper surface of the lower substrate and reflecting an infrared band; an absorption plate disposed to be spaced apart from an upper portion of the reflective layer and absorbing infrared rays to change resistance; and an anchor formed on the metal pad to support the absorption plate and to electrically connect the metal pad and the absorption plate to each other. The reflective layer has a curved or stepped shape such that a distance between the reflective layer and the absorption plate varies depending on a position of the reflective layer.

Abstract: Provided is an isomerization method of cyclohexane dicarboxylic acid using zirconia or titania as an isomerization catalyst.

Abstract: Provided is a preparation method for a cyclohexane dimethanol (CHDM), which can have a high trans content through particular conditions, additive addition, or reactant addition, which is controlled in a cyclohexane dicarboxylic acid (CHDA) hydrogenation reaction, and a cyclohexane dimethanol prepared thereby.

Abstract: The present invention relates to a perovskite-based solar cell using graphene as a material for a transparent conductive electrode. The perovskite-based solar cell achieves a maximum conversion efficiency of ?17% through an appropriate combination of energy bands of a graphene electrode, a hole transport layer, a perovskite, an electron transport layer, and a metal electrode.

Abstract: A perovskite solar cell of the present invention has a structure in which an electron transport layer including a fullerene or a fullerene derivative is formed on a first electrode including a transparent conductive substrate and a blocking layer, such as a BCP layer, is absent, achieving improved electron transporting properties. The fullerene or fullerene derivative can perform a role as a blocking layer. Therefore, the use of the fullerene or fullerene derivative enables rapid fabrication of the solar cell with high efficiency.

Abstract: The provided is a method for preparing a platinum-tin-metal-alumina catalyst by comprising: as an active ingredient, platinum which has a high activity in a direct dehydrogenation reaction of n-butane, tin which can increase the catalyst stability by preventing carbon deposition; additionally metal for reducing the level of catalyst inactivation over the reaction time; and an alumina carrier for supporting said components. Further, provided is a method for producing a high value product, C4 olefins from low cost n-butane by using the catalyst prepared by the method according to the present invention in a direct dehydrogenation reaction.