Abstract: Provided are an apparatus and method for liquefying natural gas. The apparatus for liquefying natural gas includes a gas compressor configured to receive and compress the natural gas from a natural gas feed stream, a heat exchanging unit configured to cool a high-pressure natural gas passing through the gas compressor through heat exchange, an expansion valve configured to expand the cooled natural gas passing through the heat exchanging unit, a hold-up drum configured to phase-separate a gas-liquid mixture produced by passing through the expansion valve and divide the gas-liquid mixture into a liquefied natural gas and a cryogenic recycle gas having nitrogen content greater than that of the liquefied natural gas so as to discharge the liquefied natural gas and the cryogenic recycle gas, and a bypass line configured to provide the recycle gas discharged from the hold-up drum to the heat exchanging unit.

Abstract: Provided is a piston for an internal combustion engine. The piston includes a body including, at an upper part of the body, a crown including a combustion chamber where fuel is burnt and including, at a lower part of the body, a piston pin boss into which a piston pin is inserted and a skirt corresponding to a cylinder wall, and a cooling channel including a refrigerant channel, a refrigerant inlet provided at a side of the refrigerant channel, and a refrigerant outlet provided at the other side of the refrigerant channel, wherein a cross section of the cooling channel has an overall elliptic shape to reduce stress occurring at an upper side of the cooling channel when the fuel is burnt in the internal combustion engine, and at least one of arcs of the ellipse is configured as a first elliptical arc of a quadratic curve.

Abstract: Provided are an apparatus and method for liquefying natural gas. The apparatus for liquefying natural gas includes a gas compressor configured to receive and compress the natural gas from a natural gas feed stream, a heat exchanging unit configured to cool a high-pressure natural gas passing through the gas compressor through heat exchange, an expansion valve configured to expand the cooled natural gas passing through the heat exchanging unit, a hold-up drum configured to phase-separate a gas-liquid mixture produced by passing through the expansion valve and divide the gas-liquid mixture into a liquefied natural gas and a cryogenic recycle gas having nitrogen content greater than that of the liquefied natural gas so as to discharge the liquefied natural gas and the cryogenic recycle gas, and a bypass line configured to provide the recycle gas discharged from the hold-up drum to the heat exchanging unit.

Abstract: A substrate inspection apparatus includes a light irradiating unit irradiating first light to an inspection target on a stage, a light detecting unit detecting second light reflected by the inspection target, a spectrum generator generating a first spectrum from the second light, a noise filter module removing a noise signal from the first spectrum to generate a second spectrum, a spectrum analyzer determining a first calibration parameter and a first calibration value thereof from the second spectrum, and a hardware controller adjusting at least one of the stage, the light irradiating unit and the light detecting unit using the first calibration parameter and the first calibration value.

Abstract: A method of manufacturing a semiconductor device comprising: obtaining a raw light signal by selecting a predetermined wavelength band of light reflected from a wafer on which a plurality of patterns are formed; converting the raw light signal into a frequency domain; obtaining a first detection signal having a first frequency band from the raw light signal converted into the frequency domain; obtaining a second detection signal having a second frequency band from the raw light signal converted into the frequency domain, the second frequency band being different from the first frequency band; obtaining a representative value using the first detection signal, the representative value representing a profile of the plurality of patterns; and obtaining a distribution value using the second detection signal, the distribution value representing a profile of the plurality of patterns using the second detection signal.

Abstract: Provided is a piston for an internal combustion engine. The piston includes a body including, at an upper part of the body, a crown including a combustion chamber where fuel is burnt and including, at a lower part of the body, a piston pin boss into which a piston pin is inserted and a skirt corresponding to a cylinder wall, and a cooling channel including a refrigerant channel, a refrigerant inlet provided at a side of the refrigerant channel, and a refrigerant outlet provided at the other side of the refrigerant channel, wherein a cross section of the cooling channel has an overall elliptic shape to reduce stress occurring at an upper side of the cooling channel when the fuel is burnt in the internal combustion engine, and at least one of arcs of the ellipse is configured as a first elliptical arc of a quadratic curve.

Abstract: A method of manufacturing a semiconductor device comprising: obtaining a raw light signal by selecting a predetermined wavelength band of light reflected from a wafer on which a plurality of patterns are formed; converting the raw light signal into a frequency domain; obtaining a first detection signal having a first frequency band from the raw light signal converted into the frequency domain; obtaining a second detection signal having a second frequency band from the raw light signal converted into the frequency domain, the second frequency band being different from the first frequency band; obtaining a representative value using the first detection signal, the representative value representing a profile of the plurality of patterns; and obtaining a distribution value using the second detection signal, the distribution value representing a profile of the plurality of patterns using the second detection signal.

Abstract: Provided is a piston for an internal combustion engine, the piston including a body having a piston pin boss for inserting a piston pin thereinto, and a skirt corresponding to a cylinder wall, and a cooling channel provided in the body to allow a refrigerant for cooling the body, to flow therethrough, and having a ring shape including a first channel provided from a refrigerant inlet to a refrigerant outlet along a first outer circumferential direction of the body, and a second channel provided from the refrigerant inlet to the refrigerant outlet along a second outer circumferential direction of the body.

Abstract: The present invention provides a mooring apparatus for an offshore construction that makes it easy to install a mooring chain and can moor an offshore construction stably against external force such as waves and wind. The mooring apparatus for an offshore construction includes; a floating member generating buoyancy; and fixing frames coupled to a side of the floating member and combined with a plurality of fixing arms radially extending and being stretchable and retractable, in which mooring chains which are connected to the bottom of the sea are fixed to free ends of the fixing arms respectively, so that as the fixing arms stretches/retracts on the fixing frame, the positions of the mooring chains change.

Abstract: Provided is a piston for an internal combustion engine, the piston including a body having a piston pin boss for inserting a piston pin thereinto, and a skirt corresponding to a cylinder wall, and a cooling channel provided in the body to allow a refrigerant for cooling the body, to flow therethrough, and having a ring shape including a first channel provided from a refrigerant inlet to a refrigerant outlet along a first outer circumferential direction of the body, and a second channel provided from the refrigerant inlet to the refrigerant outlet along a second outer circumferential direction of the body.

Abstract: In an optical measuring method, a first spectrum and a second spectrum are obtained from a pattern and a thin layer formed on the pattern by a deposition process using an ellipsometer respectively. A skew spectrum is obtained between the first spectrum and the second spectrum. A fourier transform operation is performed on the skew spectrum to calculate a thickness of the thin layer on the pattern.

Abstract: In an optical measuring method, a reflected light from a structure on a substrate is detected by a measuring tool to obtain a raw spectrum. The raw spectrum in a wavelength range having spectrum sensitivity to process variation is analyzed to determine a process variation of an actual process performed on the substrate. The raw spectrum is corrected according to a spectrum offset for the measuring tool which is determined based on the process variation.

Abstract: In an optical measuring method, a first spectrum and a second spectrum are obtained from a pattern and a thin layer formed on the pattern by a deposition process using an ellipsometer respectively. A skew spectrum is obtained between the first spectrum and the second spectrum. A fourier transform operation is performed on the skew spectrum to calculate a thickness of the thin layer on the pattern.

Abstract: Methods for measuring a thickness of an object including acquiring at least one of a wavelength domain spectrum for an amplitude ratio (?) and a phase difference (?) of reflected light from a film material, converting the wavelength domain spectrum into a 1/wavelength domain spectrum, acquiring a resulting spectrum by performing fast fourier transform (FFT) on the 1/wavelength domain spectrum, and measuring a thickness of the film material from the resulting spectrum may be provided.

Abstract: In an optical measuring method, a reflected light from a structure on a substrate is detected by a measuring tool to obtain a raw spectrum. The raw spectrum in a wavelength range having spectrum sensitivity to process variation is analyzed to determine a process variation of an actual process performed on the substrate. The raw spectrum is corrected according to a spectrum offset for the measuring tool which is determined based on the process variation.

Abstract: A method of inspecting a semiconductor device includes measuring an inspection pattern formed on a semiconductor substrate using a measurer configured to measure optical signals reflected from the inspection pattern to obtain a signal expressed by a matrix including spectrum data associated with the inspection pattern, obtaining a first element including a first spectrum from the signal and obtaining a second element including a second spectrum from the signal, obtaining a skew spectrum using a difference between the first and second spectrums, and obtaining an asymmetric signal associated with the inspection pattern using the skew spectrum, the obtaining of the asymmetric signal including obtaining a polarity of the skew spectrum in a wavelength range, and obtaining a numerical value associated with an area of the skew spectrum.

Abstract: Methods for measuring a thickness of an object including acquiring at least one of a wavelength domain spectrum for an amplitude ratio (?) and a phase difference (?) of reflected light from a film material, converting the wavelength domain spectrum into a 1/wavelength domain spectrum, acquiring a resulting spectrum by performing fast fourier transform (FFT) on the 1/wavelength domain spectrum, and measuring a thickness of the film material from the resulting spectrum may be provided.

Abstract: Apparatus and method for manufacturing a semiconductor device through a layer material dimension analysis increase productivity. The method includes performing a semiconductor manufacturing process of at least one reference substrate and at least one target substrate in a semiconductor process device, detecting a reference spectrum and a reference profile for the reference substrate, determining a relation function between the detected reference spectrum and reference profile, detecting a real-time spectrum of the target substrate, and determining in real time a real-time profile of the target substrate processed in the semiconductor process device by using the detected real-time spectrum as a variable in the determined relation function.

Abstract: Apparatus and method for manufacturing a semiconductor device through a layer material dimension analysis increase productivity. The method includes performing a semiconductor manufacturing process of at least one reference substrate and at least one target substrate in a semiconductor process device, detecting a reference spectrum and a reference profile for the reference substrate, determining a relation function between the detected reference spectrum and reference profile, detecting a real-time spectrum of the target substrate, and determining in real time a real-time profile of the target substrate processed in the semiconductor process device by using the detected real-time spectrum as a variable in the determined relation function.

Abstract: An apparatus for inspecting a wafer includes a light source, a detecting part and a signal analyzing part. The light source emits a light onto the wafer, and the detecting part detects a radiation light emitted from the wafer by the light and generates a signal. The signal analyzing part analyzes the signal generated by the detecting part and determines whether a defect has been formed on the wafer.