• 한국멀티미디어학회논문지
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• 제18권8호
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• pp.960-967
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• 2015

In this paper, we propose a user interface technique based on embedded sensors applying to apps in smart phone. Especially, we implement avata generation application using image filtering technique for photo image in smart phone. In the application, The embedded sensors are used as intuitive user interface to adjust the image filtering effect for making user satisfied effect in real time after the system produced the image filtering effect for avatar. This technique provides not a simple typed method of parameter values adjustment but a new intuitively emotional adjustment method in image filtering applications. The proposed technique can use sound values from embedded mike sensor for adjusting key values of sketch filter effect if the smart phone user produces sound. Similiarly the proposed technique can use coordinate values from embedded acceleration sensor for adjusting masking values of oil painting filter effect and use brightness values from embedded light sensor for adjusting masking values of sharp filter effect. Finally, we implement image filtering application and evaluate efficiency and effectiveness for the proposed technique.

• Corrosion Science and Technology
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• 제2권3호
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• pp.155-160
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• 2003

Plasma spraying technique was used to fabricate functionally graded coating (FGC) of NiCrAIY/YSZ 8wt%$Y_2O_3-ZrO_2$ on a Co-base superalloy (HAYNES 188) substrate. Six layers were coated on the substrate for building up compositionally graded architecture. Conventional thermal barrier coating (TBC) of NiCrAIY/SZ with sharp interface was also fabricated. As-coated FGC and TBC samples were exposed at the temperature of $1100^{\circ}C$ for 10, 50, 100 hours in air. Microstructural change of thermally exposed samples was examined. Pores and microcracks were formed in YSZ layer due to evolution of thermal internal stress at high temperature. The amount of pores and microcracks in YSZ layer were increased with increasing exposure time at high temperature. High temperature oxidation of coatings occurred mainly at the NiCrAIY/YSZ interface. In comparison with the case of TBC. the increased area of the NiCrAIY/YSZ interface in FGC is likely to attribute to forming the higher amount of oxides.

• 대한기계학회논문집B
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• 제32권6호
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• pp.429-445
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• 2008

Two-phase compressible flow fields of air-water are investigated numerically in the fixed Eulerian grid framework. The phase interface is captured via volume fractions of each phase. A way to model two phase compressible flows as a single phase one is found based on an equivalent equation of states of Tait's type for a multiphase cell. The equivalent single phase field is discretized using the Roe‘s approximate Riemann solver. Two approaches are tried to suppress the pressure oscillation phenomena at the phase interface, a passive advection of volume fraction and a direct pressure relaxation with the compressible form of volume fraction equation. The direct pressure equalizing method suppresses pressure oscillation successfully and generates sharp discontinuities, transmitting and reflecting acoustic waves naturally at the phase interface. In discretizing the compressible form of volume fraction equation, phase interfaces are geometrically reconstructed to minimize the numerical diffusion of volume fraction and relevant variables. The motion of a projectile in a water-filled tube which is fired by the release of highly pressurized air is simulated presuming the flow field as a two dimensional one, and several design factors affecting the projectile movement are investigated.

• 한국분말재료학회지
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• 제28권4호
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• pp.287-292
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• 2021

In this study, the layered structures of immiscible Fe and Cu metals were employed to investigate the interface evolution through solid-state mixing. The pure Fe and Cu powders were cold-consolidated by high-pressure torsion (HPT) to fabricate a layered Cu-Fe-Cu structure. The microstructural evolutions and flow of immiscible Fe and Cu metals were investigated following different iterations of HPT processing. The results indicate that the HPT-processed sample following four iterations showed a sharp chemical boundary between the Fe and Cu layers. In addition, the Cu powders exhibited perfect consolidation through HPT processing. However, the Fe layer contained many microcracks. After 20 iterations of HPT, the shear strain generated by HPT produced interface instability, which caused the initial layered structure to disappear.

• Journal of Magnetics
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• 제11권1호
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• pp.25-29
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• 2006

Recent experiments have demonstrated high TMR ratios in MTJs with the MgO barrier [1,2]. The CoFeB/MgO/CoFeB junctions showed better properties than the CoFe/MgO/CoFe junctions because the MgO layer had a good crystalline structure with (001) texture and smooth and sharp interface between CoFeB/MgO [3]. The amorphous CoFeB with 20 at%B starts the crystallization at $340^{\circ}C$ [4] and this crystallization of the CoFeB helps obtaining the high TMR ratio. In this work, the compositional changes in the MgO barrier and at the interface of CoFeB/MgO/CoFeB after the CoFeB crystallization were studied in annealed MTJs. XPS depth profiles were utilized. TEM analyses showed that the MgO barrier had (100) texture on CoFeB in the junctions. B in the bottom CoFeB layer diffused into the MgO barrier and B-oxide was formed at the interface of CoFeB/MgO/CoFeB after the CoFeB crystallization.

• 대한전자공학회논문지TC
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• 제44권12호
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• pp.34-43
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• 2007

최근에 이동 단말들의 급격한 증가와 함께 이동 노드에 다양한 무선 접속 기술들의 사용이 가능해졌다. 또한 IPv6 기술이 네트워크에 도입되면 하나의 단말이나 인터페이스에 여러 개의 공중 IP주소를 가지는 멀티호밍 (multi-homing) 단말이 일반화될 것이다. 이에 맞추어 다중 인터페이스 멀티호밍 단말에 대한 이동성 관리기술 연구가 무선 인터넷 분야에서 활발히 진행 중이다. 본 논문에서는 다중 인터페이스를 지원하는 FMIPv6의 FBU 메시지를 대신하여, "tunnel destination" 이동성 옵션과 이 옵션을 표시하는 'T' flag를 이용하는 MFBU 메시지를 새로 정의하여, NAR이 아닌 특정 터널링 목적지로 핸드오버 동안 패킷을 터널링 시키는 다중 인터페이스 fast handover Mobile IPv6 절차의 확장을 제안한다. 이는 기존의 FMIPv6를 이용하여 핸드오버절차를 수행하는 동안 TCP 플로우의 패킷 도착순서가 바뀌어 세 개의 중복 ACK에 의한 불필요한 혼잡 제어로 성능이 저하되는 것을 완화하여 핸드오버 성능을 향상시키게 된다. 본 논문에서는 그 성능을 검증하기 위해 기존의 단일 인터페이스 MIPv6 NS-2 시뮬레이터를 확장하여 다중 인터페이스 FMIPv6 시뮬레이터를 구현하였으며, TCP 트래픽을 이용한 시뮬레이션을 통해 핸드오버 성능 향상을 확인하였다.

• 접착 및 계면
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• 제4권2호
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• pp.1-9
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• 2003

Epoxy-amine liquid prepolymers are extensively applied onto metallic substrates and cured to obtain painted materials or bonded joint structures. Overall performances of such systems depend on the created interphase between the organic layer and the substrate. When epoxy-amine liquid mixtures are applied onto more or less hydrated metallic oxide layer, concomitant amine chemical sorption and hydroxide dissolution appear lending to the chelate formation. As soon as the chelate concentration is higher than the solubility product, these species crystallize as sharp needles. Moreover, intrinsic and thermal residual stresses are developed within painted or bonded systems. When residual stresses are higher than the organic layer/substrate adhesion, buckling, blistering, debonding may occur leading to a catastrophic drop of system performances. Practical adhesion can be evaluated with either ultimate parameters (Fmax or Dmax) or the critical strain energy release rate, using the three point flexure test (ISO 14679-1997). We observe that, for the same system, the ultimate load decreases while residual stresses increase when the liquid/solid time increases. Ultimate loads and residual stresses depend on the metallic surface treatment. For these systems, the critical strain energy release rate which takes into account the residual stress profile and the Young's modulus gradient remains quite constant whatever the metallic surface treatment was. These variations will be discussed and correlate to the formation mechanisms of the interphase.

• 한국자기학회지
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• 제5권5호
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• pp.442-446
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• 1995

Electronic structures of Fe overlayers on Cr(Fe/Cr) films, with an Fe coverage of $1-20{\AA}$, have been investigated by using photoemission spectroscopy. Experimental results are compared with supercell band structure calculations for a system with monolayer (ML) Fe on each side of five layer Cr, Fe(1ML)/Cr(5ML)/Fe(1ML). The extracted Fe 3d partial spectral weight in Fe/Cr exhibits very interesting features for very thin Fe overlayers. First, a sharp emissionnear the Fermi energy is observed, which is expected to originate primarily from hybridization between Fe and Cr 3d electrons at the Fe/Cr interface, and partially from the Fe 3d surface states in the Fe overlayer. Second, other structures are observed at higher binding energies which resemble the Cr 3d valence bands, also suggesting large hybridization between Fe and Cr 3d states at the Fe/Cr interface. These conjectures are confirmed by band structure calculations for Fe(1ML)/Cr(5ML)/Fe(1ML).

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2002년도 학술발표회 논문집(II)
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• pp.1034-1040
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• 2002

A rainwater recharge model, which is combined with the quasi-three dimensional unconfined groundwater flow, is proposed in the present paper. The water budget in the catchments of the planned new campus of Kyushu University is evaluated by the present method that calculates both the surface runoff and groundwater flow simultaneously. The results obtained in the present study reveal that the calculated monthly and annual runoff discharges agree reasonably well with the observed discharge. Combining the rainwater recharge model, the two-phase groundwater flow equation is numerically solved f3r the entire area including the low land where the salt water intrusion is observed. The calculated depth of the salt-fresh interface agrees reasonably well with the observed ones at several cross sections. On the other hand, however, it is found that the calculated water budget remains uncertain because of lack of information on the accurate potential evapotranspiration including rainfall interception. In conclusion, however, it is found that the proposed method is applicable for the areas where the horizontal flow is dominant and the interface is assumed to be sharp.

• Journal of Biosystems Engineering
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• 제22권1호
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• pp.41-48
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• 1997

A nondestructive quality inspection technique using acoustic impulse response method was studied to investigate the feasibility of egg shell inspection. An experimental system was built to generate impact force, to measure the response signal and to analyze the frequency spectrum. This system includes an impulse generating unit, an egg holding seat, a microphone with preamplifier, and a digital oscilloscope connected to Personal Computer by RS-232C interface. The factors such as impulse generating method, egg holding method, and sensor location were evaluated by analyzing the power spectrum density of the measured signal. The results obtained are summarized as follows : 1. From the sampled eggs, the proper conditions for detecting damaged eggs were found as followings; ceramic for the impact ball material, rubber for egg seat material, 20 degrees for an impact angle of pendulum, 10mm for the distance between egg and sensor, the sharp side for impacting part, and 180 degrees for the location of sensor. 2. Examination of the Fourier transformed analysis in beth normal and damaged eggs revealed that those factors such as the resonant frequency, a number of peak frequencies and the magnitude of power spectrum were important to detect damaged eggs.