INS/TRN 약결합 방식에서의 TRN 입력오차 보상 방안

박병수(ByungSu Park1),성창기(ChangKy Sung),남성호(SungHo Nam),이상우(SangWoo Lee) 한국항공우주학회 2018 한국항공우주학회 학술발표회 논문집 Vol.2018 No.11

사륜 독립구동 차량시스템의 제어입력 조정을 통한 결함진단

박성호(Sungho Park),박영진(Youngjin Park),박윤식(Youn-sik Park) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

In this research, quantitative measurement of fault isolation is defined to evaluate fault isolate performance in parity equation. If it is hard or impossible to isolate fault components with parity equation, fault diagnosis method by adjustment of input distribution is applied to overcome the limitation of parity equation method. Noticeable characteristic in four wheels independently driven vehicle system is that there are lots of input distribution to achieve equivalent control performance. In normal case, controller makes optimal input distribution. But if there exist probability to have fault components, fault diagnosis system makes input perturbation and analyze system response to isolate fault components.

Fault diagnosis with adjustment of input distribution and controller reconfiguration for over-actuated feedback control system

Sungho Park,Youngjin Park,Seongjin Yim 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

Over-actuated feedback control system has advantages of increasing maneuverability and robust performance in fault situation but probability of fault occurrence is also increase because of the increasing the number of actuators and sensors. Furthermore if there has no appropriate fault tolerant strategy, more hazardous accident could occur so fault tolerant strategy is highly emphasized in over-actuated system. In over-actuated system, the number of operable control input is greater than the controlled variable so control input distribution is not unique for achieve same control objectives. In this research, fault diagnoses with inherent over-actuated system characteristic and make controller reconfiguration to achieve robust performance in fault situation. If there are some probabilities to exist fault situation, fault diagnosis system makes input perturbation which satisfied holonomic constraint to achieve same control objective and diagnoses fault components by analysis system response. Because input perturbations satisfy constraint equation, there is no change in system response in normal situation. But if some critical faults are exist, unintended system response could appear. Proposed fault diagnosis method is applied to 4 wheels independently driven vehicle to verify effectiveness of that method and evaluate the performance of fault diagnosis and controller reconfiguration.

BMP-2와 IGF-101 사람 치수세포의증식과 분화에 미치는 영향

Sungho Park,주성숙,Je-Won Shin 대한구강해부학회 2005 대한구강해부학회지 Vol.29 No.2

This study was design어 to elucidate the effect of bone morphogenetic protein-2 (BMP-2) and insulin-like growth factor-I (IGF-I) on the proliferation and differentiation of cultured human dental pulp cells. MTT assay and alkaline phosphatase (ALP) activity assay was performed after 24-and 48 hours incubation of the human dental p비p cells with 1, 5, and 10 ng/l떼 of thE BMP-2 and IGF-I. The results were as follows: 1. The cell proliferation was increased after 24- and 48-hour incubation with BMP-2 dose dependent1y 2. The ALP activity was not changed after 24-hour incubation while that was increased after 48• hour incubation with BMP-2. The ALP activity decreased dose de야ndent1y. 3. IGF-I enhance the cell proliferation activity. 4. The ALP activity was not changed after 24-hour incubation while that was increased after 48-hour incubation with IGF-I The ALP ac디vity increased dose dependent1y. These results suggest that BMP-2 and IGF-I may promote the p비p regeneration and reparative dentin formation stimulating proJiferation and differentiation of the human pulp progenitor cel1s.

Designer composite materials fabricated from platinum and ruthenium nanoparticles

Park, Yong-Kyun,Kim, Tae-Heon,Park, Sungho Royal Society of Chemistry 2010 Journal of materials chemistry Vol.20 No.18

<P>This paper describes a new strategy for synthesizing electrocatalytically active bimetallic Pt and Ru nanoparticle (NP) composite films by combining Pt and Ru NP films. Each metal NP film could be generated at the water/oil interface and its subsequent transfer to conducting substrates allowed one to rationally design the contact ratio between Pt and Ru NPs. Significantly, each metal NP size could be predetermined by controlling the synthetic conditions, and the interparticle contact between Pt and Ru NPs could be tuned by altering the transfer order. The electrocatalytic activity of the resulting NP composite films toward methanol was investigated as a function of Pt and Ru NP contact ratios. It was found that the maximum contact between Pt and Ru NPs contributes to the minimization of CO poisoning on Pt surfaces, which leads to the maximum electrocatalytic activity toward methanol electrooxidation.</P> <P>Graphic Abstract</P><P>This paper describes a new strategy for synthesizing electrocatalytically active bimetallic Pt and Ru nanoparticle (NP) composite films by combining Pt and Ru NP films. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b921528j'> </P>

Gear fault diagnosis using transmission error and ensemble empirical mode decomposition

Park, Sungho,Kim, Seokgoo,Choi, Joo-Ho Elsevier 2018 Mechanical systems and signal processing Vol.108 No.-

<P><B>Abstract</B></P> <P>Classification of spall and crack faults of gear teeth is studied by applying the ensemble empirical mode decomposition (EEMD) to the transmission error (TE) measured by the encoders of the input and output shafts. Finite element models of the gears with the two faults are built, and TE’s are obtained by simulation of the faulty gears under loaded contact to identify the different characteristics. A simple test bed for a pair of spur gears is prepared to illustrate the approach, in which the TE’s are measured for the gears with seeded spall and crack, respectively. EEMD is applied to extract fault features under the noise from the measured TE. The differences of the spall and crack are clearly identified by the selected features of the intrinsic mode functions based on the class separability criterion. The k-nearest neighbor method is applied for the classification of the faults and normal gears using the features. The proposed method is advantageous over the existing practices in the sense that the TE signal measures the gear faults more directly with less noise, enabling successful diagnosis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new approach is proposed to identify the two faults: spall and crack. </LI> <LI> The method is based on the transmission error measurement. </LI> <LI> Ensemble empirical mode decomposition is applied to extract features from the measured signals. </LI> <LI> Fault type is identified via the FEA and virtual signal processing. </LI> <LI> The method is useful since the TE gives faulty signal more directly and FEA is used for the fault identification. </LI> </UL> </P>

Electrochemical Synthesis of Dumbbell-like Au-Ni-Au Nanorods and Their Surface Plasmon Resonance

Park, Yeon Ju,Liu, Lichun,Yoo, Sang-Hoon,Park, Sungho The Korean Electrochemical Society 2012 Journal of electrochemical science and technology Vol.3 No.2

In this report, we demonstrate that the longitudinal localized surface plasmon resonance mode can be suppressed when the nanorods were in dumbbell shape. The seed nanorods were synthesized by electrochemical deposition of metals into the pores of anodic aluminum oxide templates. The dumbbell-like nanorods were grown from seed Au-Ni-Au nanorods by a rate-controlled seed-mediated growth strategy. The selective deposition of Au atoms onto Au blocks of Au-Ni-Au nanorods produced larger diameter of Au nanorods with bumpy surface resulting in dumbbell-like nanorods. The morphology of nanorods depended on the reduction rate of $AuCl_4^-$, slow rate producing smooth surface of Au nanorods, but high reduction rate producing bumpy surface morphology. Through systematic investigation into the UV-Vis-NIR spectroscopy, we found that the multiple localized surface plasmon resonance (LSPR) modes were available from single-component Au nanorods. And, their LSPR modes of Au NRs with bumpy surface, compared to the smooth seed Au NRs, were red-shifted, which was obviously attributed to the increased electron oscillation pathways. While the longitudinal LSPR modes of smoothly grown Au NRs were blue-shifted except for a dipole transverse LSPR mode, which can be interpreted by decreased aspect ratio. In addition, dumbbell-like nanorods showed an almost disappeared longitudinal LSPR mode. It reflects that the plasmonic properties can be engineered using complex nanorods structure.

Whole Life Performance Bid Evaluation in the Korean Public Sector

Park, Kenneth Sungho,임형철 한국건축시공학회 2012 한국건축시공학회지 Vol.12 No.6

Over the last several years, Korea has increasingly adopted design-build for public construction projects. There is a much greater awareness of the need to change to a system based on ‘Value for Money’, which is high on the government's agenda. A whole life performance bid evaluation model is proposed to aid decision makers in the selection of a design-builder. This is based on the integration of a framework using an analytic hierarchy process, as the bid awarding system is being changed from one based on the lowest price to one based on best value over the life-cycle. Key criteria such as whole life cost, service life planning and design quality are important through the key stages of the evaluation process. The model uses a systematic and holistic approach, which enables the public sector client to make better decisions in design-builder selection, which will deliver whole life benefits based on long-term cost-effectiveness.

An Empirical Study on the Effectiveness of Customer Experience Marketing Using Free Samples in a Multi-Channel Distribution Environment

Sungho Park(박성호) 대한산업공학회 2022 대한산업공학회 춘계학술대회논문집 Vol.2022 No.6

THE SENSITIVITY OF STRUCTURAL RESPONSE USING FINITE ELEMENTS IN TIME

Park, Sungho,Kim, Seung-Jo The Korean Society for Energy 2002 Journal of Theoretical and Applied Mechanics Vol.3 No.1

The bilinear formulation proposed earlier by Peters and Izadpanah to develop finite elements in time to solve undamped linear systems, Is extended (and found to be readily amenable) to develop time finite elements to obtain transient responses of both linear and nonlinear, and damped and undamped systems. The formulation Is used in the h-, p- and hp-versions. The resulting linear and nonlinear algebraic equations are differentiated to obtain the first- and second-order sensitivities of the transient response with respect to various system parameters. The present developments were tested on a series of linear and nonlinear examples and were found to yield, when compared with results obtained using other methods, excellent results for both the transient response and Its sensitivity to system parameters. Mostly. the results were obtained using the Legendre polynomials as basis functions, though. in some cases other orthogonal polynomials namely. the Hermite. the Chebyshev, and integrated Legendre polynomials were also employed (but to no great advantage). A key advantage of the time finite element method, and the one often overlooked in its past applications, is the ease In which the sensitivity of the transient response with respect to various system parameters can be obtained. The results of sensitivity analysis can be used for approximate schemes for efficient solution of design optimization problems. Also. the results can be applied to gradient-based parameter identification schemes.