• 제목/요약/키워드: attractive force

검색결과 186건 처리시간 0.037초

QFD 기반에 의한 제화류의 감성지향적 품질설계 요소도출에 관한 실증적 연구 (Development of Customer-Oriented Quality Design Elements of Shoes based on QFD)

  • 김진호;황인극
    • 품질경영학회지
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    • 제32권1호
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    • pp.130-143
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    • 2004
  • Although consumer needs for better products force manufactures to put emphasis on design, often development of a product has been done without the formal process to consider consumer needs. In order to identify the implicit needs of customers and the areas of potential demand on a product, several analysis scheme such as QFD (Quality Function Deployment) has been developed. QFD, also known as the House of Quality, is the efficient tool ever created to tie product and service design decisions directly to customer wants and needs, i.e. VoC (Voice of Customer) To utilize this tool on a product design, first of all, the consumers attributes and the engineering characteristics must be exactly investigated. However there were only few studies about them on shoe design. Hence in this paper we developed an innovative framework for shoes design based on QFD. As a result, we uncovered 29 dominant human satisfaction dimensions as the consumers attributes for customer-oriented quality evaluation of a comfortable shoes. Here, 29 human satisfaction dimensions for a shoe design were identified as the dimensions that represent the human sensitivity and psychological feeling on comfortable shoes. Also, we proposed 60 human interface elements as the engineering characteristics. The relationships between human satisfaction dimensions and human interface elements were investigated. This study will help the designers and manufacturers clarify the conceptual and abstract aspect of the design evaluation by proposing a more systematic and process-oriented method.

Analysis of Au-DNA Nanowires by Adding HCl to Change Charges of Au Nanoparticles

  • 정윤호;김대철;박현규;노용한
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.421.1-421.1
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    • 2014
  • Top-down processes based on photolithography technology have been developed by using light sources with short wavelength, however, the processes are expected to meet their limits in higher integration of semiconductor integrated circuits. To overcome the limits, researches on bottom-up processes have been proceeded. One of those, fabrication of nanodevices by using nanoparticles has been on research. But it is difficult to align nanoparticles at appropriate positions. To resolve this, studies has been proceeded to form nanowires by bonding DNA molecules which have self-assembly property and positive-charged functionalized gold nanoparticles. There are negative-charged phosphates in backbones of DNA molecules. By using the attractive force between the negative charge of the phosphates and the positive charge of gold nanoparticles, the Au-DNA nanowires are made. However, bonding Au nanoparticles only on DNA molecules, not other nanoparticles, is to be solved. So we studied to resolve this problem. In the formation of Au nanoparticles, we changed the charge of Au nanoparticles by adding HCl to control pH of the functionalized nanoparticles, measured zeta potential. Then we bonded the nanoparticles and DNA molecules and made observation by using FE-SEM and AFM.

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2차원 평면에서 이동장애물에 대한 항공기의 유도/회피기동 연구 (Aircraft Collision-Avoidance/Guidance Strategy in Dynamic Environments for Planar Flight)

  • 이인석
    • 한국항공우주학회지
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    • 제32권7호
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    • pp.69-75
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    • 2004
  • 비행중인 다른 항공기를 회피하며 항공기를 목표점까지 유도하는 문제를 2차원 평면에서 고려하였다. 항공기는 속도의 크기가 일정한 질점이며, 제어입력으로 측가속도를 사용하는 것으로 가정하였다. 이동장애물에는 척력 포텐셜함수를 목적점에는 인력 포텐셜함수를 인공적으로 부여하여 항공기에 척력과 인력이 작용하도록 하였다. 유도/회피명령은 이들 포텐셜력과 상대속도를 사용하여 실시간으로 구현 가능한 유도/회피법칙을 구현하였다. Log 형태의 포텐셜함수를 사용하면 구현된 유도법칙은 잘 알려진 비례항법유도법칙이 되며, 회피법칙은 장애물까지 도달시간에 반비례하고 시선각 변화의 반대 방향으로 항공기를 회전시킨다. 제안된 유도/회피법칙은 시뮬레이션을 통하여 타당성을 검증하였다.

일반화된 van der Waals 유체의 밀도 비이상성 (Density Anomalies of Generalized van der Waals Fluid)

  • 여상도
    • 공업화학
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    • 제7권4호
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    • pp.809-812
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    • 1996
  • 일반화된 van der Waals류의 3차 상태방정식에 사용되는 인력 및 반발력 상수항을 온도의존 함수로 나타내는 core-softening 이론을 도입하여 van der Waals 유체의 비이상적 열팽창, 즉 밀도 비이상성을 설명하였다. 온도의존 함수로는 온도의 증가에 따라 hard-core의 직경피 줄어드는 $db_r/dT_r<0$을 만족하는 형태와, 분자간의 반발력이 강해지는 $da_r/dT_r>0$을 만족하는 식을 사용하였다. 온도에 따른 밀도 최대점은 전자의 경우 전 범위의 압력하에서 나타났으며 후자의 경우 유체에 장력(tension)이 가해질때만 존재하였다.

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극한환경 MEMS용 2 inch 3C-SiC 기판의 직접접합 특성 (Direct Bonding Characteristics of 2 inch 3C-SiC Wafers for MEMS in Hash Environments)

  • 정연식;류지구;김규현;정귀상
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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    • pp.387-390
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    • 2002
  • SiC direct bonding technology is very attractive for both SiCOI(SiC-on-insulator) electric devices and SiC-MEMS(micro electro mechanical system) fields because of its application possibility in harsh environments. This paper presents pre-bonding techniques with variation of HF pre-treatment conditions for 2 inch SiC wafer direct bonding using PECVD(plasma enhanced chemical vapor deposition) oxide. The PECVD oxide was characterized by XPS(X-ray photoelectron spectrometer) and AFM(atomic force microscopy). The characteristics of the bonded sample were measured under different bonding conditions of HF concentration and an applied pressure. The bonding strength was evaluated by the tensile strength method. The bonded interface was analyzed by using IR camera and SEM(scanning electron microscope). Components existed in the interlayer were analyzed by using FT-IR(fourier transform infrared spectroscopy). The bonding strength was varied with HF pre-treatment conditions before the pre-bonding in the range of $5.3 kgf/cm^2$ to $15.5 kgf/cm^2$

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스카라 로봇을 위한 충돌 회피 경로 계획 (Collison-Free Trajectory Planning for SCARA robot)

  • 김태형;박문수;송성용;홍석교
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 G
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    • pp.2360-2362
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    • 1998
  • This paper presents a new collison-free trajectory problem for SCARA robot manipulator. we use artificial potential field for collison detection and avoidance. The potential function is typically defined as the sum of attractive potential pulling the robot toward the goal configuration and a repulsive potential pushing the robot away from the obstacles. In here, end-effector of manipulator is represented as a particle in configuration space and moving obstacles is simply represented, too. we consider not fixed obstacle but moving obstacle in random. So, we propose new distance function of artificial potential field with moving obstacle for SCARA robot. At every sampling time, the artificial potential field is update and the force driving manipulator is derived from the gradient vector of artificial potential field. To real-time path planning, we apply very simple modeling to obstacle. Some simulation results show the effectiveness of the proposed approach.

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화학적기계적연마 공정으로 제조한 PZT 캐패시터의 공정 조건에 따른 강유전 특성 연구 (Ferroelectric characteristics of PZT capacitors fabricated by using chemical mechanical polishing process with change of process parameters)

  • 전영길;정판검;고필주;김남훈;이우선
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.66-66
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    • 2007
  • Lead zirconate titanate (PZT) is one of the most attractive perovskite-type materials for ferroelectric random access memory (FRAM) due to its higher remanant polarization and the ability to withstand higher coercive fields. We first applied the damascene process using chemical mechanical polishing (CMP) to fabricate the PZT thin film capacitor to solve the problems of plasma etching including low etching profile and ion charging. The $0.8{\times}0.8\;{\mu}m$ square patterns of silicon dioxide on Pt/Ti/$SiO_2$/Si substrate were coated by sol-gel method with the precursor solution of PZT. Damascene process by CMP was performed to pattern the PZT thin film with the vertical sidewall and no plasma damage. The polarization-voltage (P-V) characteristics of PZT capacitors and the current-voltage characteristics (I-V) were examined by change of process parameters. To examine the CMP induced damage to PZT capacitor, the domain structure of the polished PZT thin film was also investigated by piezoresponse force microscopy (PFM).

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Electrokinetic flow and electroviscous effect in a charged slit-like microfluidic channel with nonlinear Poisson-Boltzmann field

  • Chun, Myung-Suk;Kwak, Hyun-Wook
    • Korea-Australia Rheology Journal
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    • 제15권2호
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    • pp.83-90
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    • 2003
  • In cases of the microfluidic channel, the electrokinetic influence on the transport behavior can be found. The externally applied body force originated from the electrostatic interaction between the nonlinear Poisson-Boltzmann field and the flow-induced electrical field is applied in the equation of motion. The electrostatic potential profile is computed a priori by applying the finite difference scheme, and an analytical solution to the Navier-Stokes equation of motion for slit-like microchannel is obtained via the Green's function. An explicit analytical expression for the induced electrokinetic potential is derived as functions of relevant physicochemical parameters. The effects of the electric double layer, the zeta potential of the solid surface, and the charge condition of the channel wall on the velocity profile as well as the electroviscous behavior are examined. With increases in either electric double layer or zeta potential, the average fluid velocity in the channel of same charge is entirely reduced, whereas the electroviscous effect becomes stronger. We observed an opposite behavior in the channel of opposite charge, where the attractive electrostatic interactions are presented.

Numerical study on effect of integrity reinforcement on punching shear of flat plate

  • Ahsan, Raquib;Zahura, Fatema T.
    • Computers and Concrete
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    • 제20권6호
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    • pp.731-738
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    • 2017
  • Reinforced concrete flat plates consist of slabs supported directly on columns. The absence of beams makes these systems attractive due to advantages such as economical formwork, shorter construction time, less total building height with more clear space and architectural flexibility. Punching shear failure is usually the governing failure mode of flat plate structures. Punching failure is brittle in nature which induces more vulnerability to this type of structure. To analyze the flat plate behavior under punching shear, twelve finite element models of flat plate on a column with different parameters have been developed and verified with experimental results. The maximum range of variation of punching stress, obtained numerically, is within 10% of the experimental results. Additional finite element models have been developed to analyze the influence of integrity reinforcement, clear cover and column reinforcement. Variation of clear cover influences the punching capacity of flat plate. Proposed finite element model can be a substitute to mechanical model to understand the influence of clear cover. Variation of slab thickness along with column reinforcement has noteworthy impact on punching capacity. From the study it has been noted that integrity reinforcement can increase the punching capacity as much as 19 percent in terms of force and 101 percent in terms of deformation.

Investigation on vibration behavior of a high-speed railway bridge based on monitoring data

  • Qingxin Zhu;Hao Wang;Billie F. Spencer Jr
    • Smart Structures and Systems
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    • 제31권6호
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    • pp.585-599
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    • 2023
  • Field monitoring techniques offer an attractive approach for understanding bridge behavior under in-service loads. However, the investigations on bridge behavior under high-speed train load using field monitoring data are limited. The focus of this study is to explore the structural behavior of an in-service long-span steel truss arch bridge based on field monitoring data. First, the natural frequencies of the structure, as well as the train driving frequencies, are extracted. Then, the train-induced bearing displacement and structural strain are explored to identify the effects of train loads and bearings. Subsequently, a sensitivity analysis is performed for the impact factor of strain responses with respect to the train speed, train weight, and temperature to identify the fundamental issues affecting these responses. Additionally, a similar sensitivity analysis is conducted for the peak acceleration. The results indicate that the friction force in bearings provides residual deformations when two consecutive trains are in opposite directions. In addition, the impact factor and peak acceleration are primarily affected by train speed, particularly near train speeds that result in the resonance of the bridge response. The results can provide additional insight into the behavior of the long-span steel truss bridges under in-service high-speed train loads.