• Proceedings of the KSRS Conference
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• v.2
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• pp.892-895
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• 2006

The atmospheric effects on the retrieval of sea ice concentration from passive microwave sensors are examined using simulated data typical for the Arctic summer. The simulation includes atmospheric contributions of cloud liquid water and water vapor and surface wind on surface emissivity on the microwave signatures. A plane parallel radiative transfer model is used to compute brightness temperatures at SSM/I frequencies over surfaces that contain open water, first-year (FY) ice and multi-year (MY) ice and their combinations. Synthetic retrievals in this study use the NASA Team (NT) algorithm for the estimation of sea ice concentrations. This study shows that if the satellite sensor’s field of view is filled with only FY ice the retrieval is not much affected by the atmospheric conditions due to the high contrast between emission signals from FY ice surface and the signals from the atmosphere. Pure MY ice concentration is generally underestimated due to the low MY ice surface emissivity that results in the enhancement of emission signals from the atmospheric parameters. Simulation results in marginal ice areas also show that the atmospheric and surface effects tend to degrade the accuracy at low sea ice concentration. FY ice concentration is overestimated and MY ice concentration is underestimated in the presence of atmospheric water and surface wind at low ice concentration. In particular, our results suggest that strong surface wind is more important than atmospheric water in contributing to the retrieval errors of total ice concentrations over marginal ice zones.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.41.2-41.2
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• 2011

Recently, scaling down of ULSI (Ultra Large Scale Integration) circuit of CMOS (Complementary Metal Oxide Semiconductor) based electronic devices become much faster speed and smaller size than ever before. However, very narrow interconnect line width causes some drawbacks. For example, deposition of conformal and thin barrier is not easy moreover metallization process needs deposition of diffusion barrier and glue layer. Therefore, there is not enough space for copper filling process. In order to overcome these negative effects, simple process of copper metallization is required. In this research, Cu-V thin alloy film was formed by using RF magnetron sputter deposition system. Cu-V alloy film was deposited on the plane $SiO_2$/Si bi-layer substrate with smooth and uniform surface. Cu-V film thickness was about 50 nm. Cu-V layer was deposited at RT, 100, 150, 200, and $250^{\circ}C$. XRD, AFM, Hall measurement system, and XPS were used to analyze Cu-V thin film. For the barrier formation, Cu-V film was annealed at 200, 300, 400, 500, and $600^{\circ}C$ (1 hour). As a result, V-based thin interlayer between Cu-V film and $SiO_2$ dielectric layer was formed by itself with annealing. Thin interlayer was confirmed by TEM (Transmission Electron Microscope) analysis. Barrier thermal stability was tested with I-V (for measuring leakage current) and XRD analysis after 300, 400, 500, 600, and $700^{\circ}C$ (12 hour) annealing. With this research, over $500^{\circ}C$ annealed barrier has large leakage current. However V-based diffusion barrier annealed at $400^{\circ}C$ has good thermal stability. Thus, thermal stability of vanadium-based thin interlayer as diffusion barrier is good for copper interconnection.

• Korean Journal of Optics and Photonics
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• v.13 no.3
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• pp.189-196
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• 2002

The components and alignment parameters of a flat-field soft x-ray spectrometer used in the wavelength range below 50 $\AA$ are determined, and the characteristics of the spectrometer are analyzed. It consists of a toroidal mirror, a slit, a varied line-spacing concave grating, and a soft x-ray detector. The space-resolved spectral image of a source is formed on a single plane using the tordidal mirror and the 2400-grooves/mm varied line-spacing concave grating. The former is used to compensate for the astigmatism caused by the grazing incidence of soft x-ray light on the concave grating. The spectral and spatial resolutions of the spectrometer are calculated by applying the wave front aberration theory, and the diffraction efficiency is calculated by applying the scalar diffraction theory.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.296-301
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• 2005

This paper describes the kinematics, dynamics and control of a 6-DOF shaking table with a bell crank structure, which converts the direction of reciprocating movements. In this shaking table, the bell crank mechanism is used to reduce the amount of space needed to install the shaking table and create horizontal displacement of the platform. In kinematics, joint design is performed using $Gr{\ddot{u}}bler's$ formula. The inverse kinematics of the shaking table is discussed. The derivation of the Jacobian matrix is presented to evaluate singularity conditions. Considering the maximum stroke of the hydraulic actuator, collision between links and singularity, workspace is computed. In dynamics, computations are based on the Newton-Euler formulation. To derive parallel algorithms, each of the contact forces is decomposed into one acting in the direction of the leg and the other acting in the plane orthogonal to the direction of the leg. Applying the Newton-Euler approach, the solution of inverse dynamics is almost completely parallel. Only one of the steps-the application of the Newton-Euler equations to the platform-must be performed on one single processor. Finally, the efficient control scheme is proposed for the tracking control of the motion platform.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.3 s.303
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• pp.41-50
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• 2005

A novel image mosaicking technique suitable for 3D urban visualization is proposed. It is not effective to apply 2D image mosaicking techniques for urban visualization when, for example, one is filming a sequence of images from a side-looking video camera along a road in an urban area. The proposed method presents the roadside scene captured by a side-looking video camera as a continuous set of textured planar faces, which are termed 'multiple planes' in this paper. The exterior parameters of each frame are first calculated through automatically selected matching feature points. The matching feature points are also used to estimate a plane approximation of the scene geometry for each frame. These planes are concatenated to create an approximate model on which images are back-projected as textures. Here, we demonstrate algorithm that creates efficient image mosaics in 3D space from a sequence of real images.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.18.1-18.10
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• 2019

Background: Temporomandibular joint (TMJ) ankylosis during early childhood may lead to disturbances in growth and facial asymmetry and to serious difficulties in eating as well as in breathing during sleep. The purpose of this study is to describe the effectiveness of an interocclusal splint (IOS) for active mouth opening exercises in the treatment of TMJ ankylosis. Methods: A total of nine patients with 13 instances of TMJ ankylosis from 2008 to 2010 were included in this study, of which five patients were male and four patients were female. Five patients demonstrated unilateral ankylosis, while five patients showed bilateral symptoms. Ankylosed mass resection with coronoidectomy, fibrotic scar release, and resection of stylohyoid ligament calcification was performed with gap arthroplasty without an interpositional graft, and all patients were assessed for maximum mouth opening (MMO) during a mean 6.6-year follow-up period. Results: All patients were subjected to postoperative mouth opening exercises from the day of the operation with the help of an IOS, which was based on an impression taken during surgery. All patients were sufficiently comfortable moving their mandible according to the IOS's guiding plane and impingement, and satisfactory results were achieved, in which MMO was improved by 35 mm more than 6 years after surgery. Conclusions: Complete and adequate resection of the ankylosed mass and postoperative active mouth opening exercises are essential in the treatment of TMJ ankylosis. Moreover, a more comfortable mouth opening guide and interdigitation can be achieved using an IOS, and newly organized fibrosis in the gap space between the newly made resected condylar head and temporal fossa can be suggested.

• Tunnel and Underground Space
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• v.12 no.3
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• pp.171-178
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• 2002

A dynamic analysis of a horseshoe_shaped tunnel near to cavity was performed to study the effect of the cavity on the dynamic behavior of the tunnel. In order to obtain the dynamic response of the tunnel embedded in a semi-infinite domain, a hybrid numerical technique was primarily developed. A dynamic fundamental solution in frequency domain for multi-layered half planes was derived and subsequently incorporated in the boundary element method. Coupling of the boundary element method for the far field with the finite element method for the near field is made by imposing compatibility condition of a displacement at the interface. The boundary element method is then coupled with the finite element method, which is utilized to model the near field including the tunnel and the cavity. In order to demonstrate the validity of the proposed technique, dynamic responses of single and multiply-layered semi-infinite structural systems are obtained by using the Kicker waveform and investigated in the limestone layer to find how the being and the location of the cavity affect the dynamic characteristics of the system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.2
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• pp.152-163
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• 2010

In this paper, a cavity-backed high gain dual band microstrip antenna with Frequency Selective Surface space(FSS) for WLAN is proposed. The proposed antenna that operates in IEEE 802.11a/b bands with similar radiation pattern and gain is fabricated on RO4003 substrate with a dielectric constant of 3.38. The size of the antenna is $71.5{\times}42.0{\times}6.6\;mm^3$, and the FSS size is $120.0{\times}120.02\;mm^3$. The ground plane size including cavity is $150.0{\times}145.0\;mm^3$. The antenna is fed by coaxial cable. The simulated bandwidths of the antenna are 2.369~2.517 GHz and 5.608~5.833 GHz for VSWR<2. The gains are 11.23 dBi and 12.60 dBi, respectively, for the lower and upper bands.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.1 s.92
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• pp.66-77
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• 2005

This paper proposed a novel broadband PIFA(Planar Inverted-F Antenna) for IMT-2000/WLAN/DMB terminal. Two branch lines for meander line were utilized in order to improve the characteristics of PIFA which usually has a narrow band. The shorting strip between the ground plane and meander-type radiation elements were used in order to minimize the size of the antenna. The -10 dB return loss bandwidth of a realized antenna was $38.2{\%}$(1.84~2.71 GHz), which contains the broadband bandwidth with triple band. And the simulated and measured values of 1 g and 10 g averaged peak SAR on human head caused by the triple band PIFA mounted on folder-type handsets were analyzed and discussed. As a result, the measured 1 g and 10 g averaged peak SARs of PIFA were similar with the simulated values and were lower than the 1.6 W/kg and 2 W/kg of 1 g and 10 g averaged peak SAR limits.

• Journal of the Korean Institute of Rural Architecture
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• v.18 no.1
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• pp.19-28
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• 2016

This research aimed to suggest a standard design that reflects Hanok design tendency, and present a selective design that can fulfill a building owner's intention beyond the simple function of building permit or report. In addition, this research attempted to become a standard by establishing a criterion in calculating the measurements of section design or primary framework members, in order to be a guideline for designing Hanok in different sizes and forms. The results are as follows. The building area of Hanok standard design was set to be below $85m^2$, with a straight type of $83.16m^2$ and an L-shape of $84.24m^2$. By dividing the plane into a straight type and L-shape, two straight types were suggested: 'general type' and 'large living room type.' The upper floor space, along with the main room and small room, was proposed as an option to be changed into a room where an underfloor heating is installed depending on the building owner's intention. In addition, a criterion for side design and calculation of framework measurements was suggested and applied, while a five-girder design without high pillars was suggested for material-assembling structure. Two types of pillars-circumference and square cylinder-were proposed for the building owner to choose from, and a pointed beam house and ikgong(orthogonally-projected bracket) house were suggested for pojak bracket structure so either of them could be chosen according to the building owner's taste and economic condition. Finally, the sectional size of main materials were divided according to the form of pojak bracket structure to be proposed.