• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.12
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• pp.2258-2263
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• 2006

In this parer, hump characteristics of short-channel nMOSFETs induced by moistures of the ILD(inter-layer dielectric) layer in the shallow trench isolation (STI) process are investigated and the method for hump suppression is proposed Using nMOSFETs with various types of the gate and a measurement of TDS-APIMS (Thermal Desorption System-Atmospheric Pressure ionization Mass Spectrometry), hump characteristics were systematically analyzed and the systemic analysis based hump model was presented; the ILD layer over poly-Si gate of nMOSFET generates moistures, but they can't diffuse out of the SiN layer due to the upper SiN layer. Consequently, they diffuses into the edge between the gate and STI and induces short-channel hump. In order to eliminate moisture in the ILD layer by out-gassing method, the annealing process prior to the deposition of the SiN layer was carried out. As the result, short-channel humps of the nMOSFETs were successfully suppressed.

• The KIPS Transactions:PartB
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• v.17B no.2
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• pp.139-148
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• 2010

This paper shows a reinforcement post-processing method and feedback algorithm for improvement of assigning method in classification. Especially, we focused on complex documents that are generally considered to be hard to classify. A basis factors in traditional classification system are training methodology, classification models and features of documents. The classification problem of the documents containing shared features and multiple meanings, should be deeply mined or analyzed than general formatted data. To address the problems of these document, we proposed a method to expand classification scheme using decision boundary detected automatically in our previous studies. The assigning method that a document simply decides to the top ranked category, is a main factor that we focus on. In this paper, we propose a post-processing method and feedback algorithm to analyze the relevance of ranked list. In experiments, we applied our post-processing method and one time feedback algorithm to complex documents. The experimental results show that our system does not need to change the classification algorithm itself to improve the accuracy and flexibility.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.1
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• pp.47-52
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• 2008

As the packing density of IC devices gets ever higher, the thickness of the gate $SiO_2$ layer of the MOS devices is now required to be reduced down to 1 nm. For such a thin $SiO_2$ layer, the MOS device cannot operate properly because of tunneling current and threshold voltage shift. Hence there has been much effort to develop new dielectric materials which have higher dielectric constants than $SiO_2$ and is free from such undesirable effects. In this work, the physical and electrical characteristics of ALD $ZrO_2$ film have been studied. After deposition of a thin ALD $ZrO_2$ film, it went through thermal treatment in the presence of argon gas at $800^{\circ}C$ for 1 hr. The characteristics of morphology, crystallization kinetics, and interfacial layer of $Pt/ZrO_2/Si$ samples have been investigated by using the analyzing instruments like XRD, TEM and C-V plots. It has been found that the characteristics of the $Pt/ZrO_2/Si$ device was enhanced by the thermal treatment.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.616-624
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• 2011

The flow characteristics and heat transfer augment on the periodically arranged semi-circular ribs in a rectangular channel for turbulent flow has been investigated numerically. The aspect ratio of the rectangular channel was AR=5, the rib height to hydraulic diameter ratio were 0.07 and rib height to channel height ratio was set as e/H=0.117 for various PR(rib pitch-to-rib height rate) between 8~14, respectively. The SST k-${\omega}$ turbulence model and v2-f turbulence model were used to find out the heat transfer and the flow characteristics of near the wall which are suited to obtain realistic phenomena. The numerical analysis results show turbulent flow characteristics, heat transfer enhancement and friction factor as observed experimentally. The results predict that turbulent kinetic energy(k) is closely relative to the diffusion of recirculation flow. and v2-f turbulence model simulation results have a good agreement with experimental values.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.10
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• pp.659-665
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• 2017

When an electrically conducting fluid flows through a staggered tube bank, the heat transfer and fluid flow features are changed by the externally introduced magnetic field. This study provides a numerical investigation of this phenomenon. Heat and fluid flows are investigated for unsteady laminar flows at Reynolds numbers of 50 and 100 with the Hartmann number gradually increasing from zero to 100. As the Hartmann number increases, and owing to the effects of the introduced magnetic field, the velocity boundary layer near the tube wall is thinned, the flow separation is delayed downstream, and the shrinkage of a recirculation zone formed near the rear side is observed. Based on these thermo-fluid deformations, the resulting changes in the local and average Nusselt number are investigated.

• The Journal of the Acoustical Society of Korea
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• v.24 no.2
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• pp.97-102
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• 2005

Acoustic experiments were performed with Zostera marina to study the characteristics of backscattering of seagrass living in the bottom interface. Field experiments were conducted in the Dongdae man, Namhae for day and night to consider the effects of air-bubble from photosynthesis of seagrass. The multi-frequency (30$\~$120 kHz) responses were measured and the distributions of back scattering strength due to the movement of seagrass were Presented by PDF (probability density function) at 120 120 kHz. The results were shown both the frequency dependence and diurnal variation of the backscattering strength between day and night. This diurnal variation may be caused by the amount of oxygen in dissolved bubbles formed by Photosynthesis of seagrass.

• Tunnel and Underground Space
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• v.14 no.5
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• pp.318-326
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• 2004

In this study, a new direct shear apparatus was developed to investigate the shear characteristics of the rock joints at various conditions. Using the developed apparatus, various experiments on filled rock joints were carried out considering the asperity angle, the normal stress, the type and thickness of filling material and to investigated the basic shear characteristics of filled rock joints were analyzed. According to the experiments performed under the constant normal stress condition by varying the asperity angle, the type and thickness of filling material, it was shown that the behavior and strength of filled rock joint could be defined by the type and thickness of the filling material. The dilation angle of the filled joints was found to be smaller than that of unfilled rock joint, and thereby, the effect of roughness was also reduced due to the filling material. And critical thickness ratio varied according to stress level and roughness as well as the type of filing materials.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.11
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• pp.1185-1198
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• 1992

In this paper, the differential weighted algorithm proposed in order to improve th noise smoothing characteristics of conventional Median filter and FIR-Median Hybrid filter. Performance of some image restoration filter(median filter, FIR-Median Hybird filter, FIR-Median Hybrid filter to proposed differential weighted algorithm) are compared and evaluated on the noise smoothing characteristics and sharp edge conservation characteristics. Test and Real images used in this paper are Lenna and Urological images corrupted by impulse, gaussian, exponential and laplacian noise. Experimental results show that the FIR-Median Hybrid filter applied to the differential weighted algorithm are comparatively superior to others. But the filter orders have increased, the more time consumed to image processing. Hence if the adequate filtering by the type of image is selected. now after a great support will be take consideration into the various parts of application by computer science and of medical image processing.

• Journal of Korean Association for Spatial Structures
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• v.11 no.2
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• pp.111-118
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• 2011

Single-layer latticed domes with rigid-joint have an advantage in the construction cost and the aesthetic. But, in single-layer latticed domes, the joints are hard to discriminate between pin-joint and rigid-joint, and consisted of semi-rigid joint in practical. And the erection of large roof structures requires special techniques. As one of these special techniques is the Step-Up erection method. This paper verified buckling characteristics of single-Layer lamella domes according to the Joint flexibility under construction by Step-up method. The results are follows: As erection steps increase, the buckling strength decreases. It is occurred the joint buckling by snap through on the top of dome when the joint flexibility close the rigid. And large tensile stress distribution appeared in circumferential member of bottom boundary when the step of construction is low. As the step of construction increase, large compressive stress distribution showed in the top of dome.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.4
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• pp.52-57
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• 1984

The electrical properties and their instability of InP tunnel MIS diodes fabricated by inserting the chemically grown oxide between metal and n-lnP (100) surface have been in-vestigated. The structure of the gown oxide was the mixture of In2O3 and P2O5, as was other low-temperature grown oxide, and its thickness was estimated to be the order of 200 $A^{\circ}$. The forward and reverse currents increased even with slight heat treatment of diodes in vacuum, and they were reduced when the diodes were exposed to humid ambient. It was discussed that the observed instability in I-V characteristics is due to a change of the physicochemical properties of the oxide film and of the interface states between oxide and InP according to the absorption of H2O.