• Fibers and Polymers
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• v.6 no.2
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• pp.156-161
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• 2005

The gray line-profile method is introduced to find fabric density. Some patterned fabrics like stripe design as well as solid fabrics of basic weave structures are used to verify the efficiency and accuracy of the method. The approach is compared with Fourier transform method. Although the gray line-profile method is concise, it shows good results in both solid and patterned fabrics. In addition, it does not require a pre-processing or filtering technique in space or frequency domain to enhance the image suitable for the analysis. However, the approach is slightly influenced by the filter size for finding the local minimums of profile graph.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.6
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• pp.1175-1180
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• 2022

STI has been studied a lot as a process technology for wide area planarization according to miniaturization and high integration of semiconductor devices. In this study, as methods for improving the STI profile, wet etching of pad oxide using hydrofluorine solution and dry etching of O₂+CF₄ after STI dry etching were proposed. This process technology showed improvement in profile imbalance and leakage current between patterns according to device density compared to the conventional method. In addition, as a result of measuring the HLD thickness after CMP for a device having the same STI depth and HLD deposition, the measured value was different depending on the device density. It was confirmed that this was due to the difference in the thickness of the nitride film according to the device density after CMP and the selectivity of the slurry.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.10
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• pp.781-787
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• 2016

We introduce FEST (Flight Environment Simulation Test) procedures for precise guided missiles to reliably improve systems. Flight vibration specification was established based on power spectral density curves calculated from flight test data of a high speed precise guided missile. A FEST pre-profile was developed according to flight vibration specification and delivered to a precise guided missile assembly. Vibration responses were measured by installing accelerometers on electronic components vulnerable to dynamic forces. The FEST profile was adjusted by comparing the vibration responses and the flight vibration specification. Subsequently, the FEST profile was repeatedly modified through trial and error, because the responses were similar to the flight environment. The modified FEST profile enabled performance testing of assembled precise guided missiles under simulated flight conditions on the ground, where unexpected errors could be corrected before the flight tests, leading to cost and risk reduction in the development of the precise guided missile system.

• Journal of Magnetics
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• v.6 no.4
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• pp.109-118
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• 2001

A computer simulation, utilizing the Landau-Lifshitz-Gilbert equation, of ultra-high- density recording on continuous longitudinal media is carried out. The two important features of this work are the use of a planar-type head, which enables a high write field of 14183 Oe ts be generated at the center of the recording medium, and the media with very high coercivities up to 13010 Oe. From a systematic investigation, it is found that the optimum write field is higher than the medium coercivity by only 3400 Oe over a wide coercivity range. This new finding allows one to write an a medium with a very high coercivity by using a planar-type head. It is demonstrated that a reasonably good bit pattern with a bit density of 605 kfci is generated on the medium with a coercivity of l1720 Oe, and, combined with a high track pitch density of 100 ktpi, a recording density of 60 Gb/in$^2$can be obtained in a single layer medium. With an improved write- head designs even a higher recording density of 75 Gb/in$^2$may be possible since comparison of the results for the bit pattern from the present head profile and the ideal Lindholm profile indicates an increase in the track pitch density of about 27%. Even at this density, the thermal stability parameter (KV/kT) at room temperature is high enough (60) to provide ample room for thermal stability.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1310-1319
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• 2005

This experiment was conducted to determine the effects of cage density (CD) and humate supplementation (HS) on laying performance, metabolic profile, and egg quality during the peak production period in hens. Lohman layers (n = 180, 46 wks of age) were blocked according to the location of cages and then allocated randomly to two levels of CD (4 or 6 hens per cage or 540 vs. 360 $cm^2$/hen) and three levels of HS (0, 0.15, and 0.30%). Egg production (EP) and feed consumption (FC) were measured daily; egg weight was measured bi-weekly; and BW was measured before and after the experiment. Blood and additional egg samples were obtained at the end of the experiment for determination of metabolic profile and egg quality. The data were analyzed using two-way ANOVA as repeated measures. Except for FC, CD did not affect laying performance parameters. Hens placed in high-density cages had lower FC than hens placed in normal-density cages. Increasing HS level linearly increased FC, EP, and feed conversion ratio (FCR). There was a CD by HS interaction effect on FC and EP. Hens placed in high-density cages had greater serum glucose, total protein, albumin, globulin, Ca, and P concentrations and tended to have greater serum corticosterone concentration than hens placed in normaldensity cages. Increasing HS level linearly increased serum glucose, total protein, albumin, globulin, creatine, and Ca concentrations and linearly decreased serum triglyceride and very low-density lipoprotein concentrations. There was a CD by HS interaction effect on serum glucose and albumin concentrations. There were no alterations in egg quality parameters in response to increasing CD. Albumen index and Haugh unit decreased linearly and other egg quality parameters did not change as HS level increased. In conclusion, increased caging density adversely affected metabolic profile, despite insignificantly deteriorating laying performance. Moreover, benefits from humate supplementation seem to be more noteworthy for hens housed in stressing conditions than for hens housed in standard conditions.

• Journal of Astronomy and Space Sciences
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• v.23 no.3
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• pp.237-244
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• 2006

We produced the electron density distribution in the ionosphere over South Korea using the data from nine permanent GPS (Global Positioning System) stations which have been operated by KASI (Korea Astronomy and Space Science Institute). The dual-frequency GPS receiver data was used to precisely estimate the electron density in the ionosphere and we obtained the precise electron density profile based on two-dimensional TEC (Total Electron Contents). We applied ART (Algebraic Reconstruction Technique), which is one of the most commonly used algorithms to develop the tomography model. This paper presented the electron density distribution over South Korea with time. We compared with the electron density profiles derived from the GPS tomography reconstruction, Ionosonde measurement data obtained by observations, and the IRI-2001 values. As a result, the electron density profile by GPS reconstruction was in excellent agreement with the electron density profile obtained by Ionosonde measurement data.

• Journal of the Korean Vacuum Society
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• v.7 no.2
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• pp.155-160
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• 1998

It is necessary to use Arc layer and DUV resist to define 0.25 $\mu \textrm{m}$ line and space for 256 MDRAM devices. Poly-Si etching with Arc layer and different resists has been performed in a TCP-9408 etcher with variation of gas chemistries; $Cl_2/O_2, Cl_2/N_2, Cl_2$/HBr . DUV resist causes more positive etch profile and CD gain compared to I-line resist because the sidewall passivation is more stimulated by increasing polymerization through the loss of resist. When Arc layer is applied, CD hain also increases due to the polymeric mask formed after thching Arc layer. From the point of gas chemistry effects, the etch profile and CD gain is not improved using $Cl_2/O_2$ gas, since polymerization is accelerated in this gas. however, the vertical profile and less CD gain is obtained using $Cl_2$/HBr gas. Furthermore, HBr gas is very effective to suppress the difference of profile and CD variation between dense pattern and isolated pattern by minimizing non-uniformity of side wall passivation with pattern density.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.54.3-55
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• 2016

We model the spectral energy distribution (SED) of the Class 0 protostar L1527 IRS using a dust continuum radiative transfer code RADMC-3D to study the initial condition of gravitational collapse. To constrain the envelope structure, we use the data obtained by Herschel /PACS, which covers the far-infrared regime ($55-190{\mu}m$) where the SED of L1527 IRS peaks. According to our modeling, a more flattened density profile fits the far-infrared SED of L1527 IRS better than the density profile of a rotating and infalling envelope. Thus, we employ the density structure of a Bonnor-Ebert sphere, which consists of the inner flat-topped and the outer power-law regions and is often used for describing the density structure of the youngest sources in the low mass star formation process. A Bonnor-Ebert sphere fits very well the observed SED at ${\lambda}$ > $10{\mu}m$, suggesting that L1527 IRS might collapse from an unstable Bonnor-Ebert sphere rather than a singular isothermal sphere.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.1
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• pp.136-145
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• 1997

To analyzed ride quality and to predict durability in vehicle dynamics, it is essential to describe a road surface profile precisely. This paper presents a technique to generate road surface profiles in a spatial domain by using a power spectral density function. A single track power spectral density function is proposed to describe a road surface profile, which is also applicable for multi-track vehicle response analysis, The derived road surfaces are compared to ISO(International Organization for Standardization) standards and classifications, proposed by the MIRA(Motor Industry Research Association). The methodology in this paper is also proposed to generate road roughness description with a limited external data. A small amount of external curve data is combined with an internal PSD function to generate road surface roughness in a spatial domain.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.98-101
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• 2003

As the ultra precision grinding can be applied to wafering process by the refinement of the abrasive. the development of high stiffness equipment and grinding skill, the conventional wafering process which consists of lapping, etching, 1st, 2nd and 3rd polishing could be exchanged to the new process which consists of precision surface grinding, final polishing and post cleaning. Especially, the ultra precision grinding of wafer improves the flatness of wafer and the efficiency of production. Futhermore, it has been not only used in bare wafer grinding, but also applied to wafer back grinding and SOI wafer grinding. This paper focused on the flatness of the ground wafer. Generally, the ground wafer has concave profile because of the difference of wheel path density, grinding temperature and elastic deformation of the equiptment. Tilting mathod is applied to avoid such non-uniform material removes. So, in this paper, the geometric analysis on grinding process is carried out, and then, we can predict the profile of th ground wafer by using profile simulation.