Essays by C. D. Pi_A Letter to Paris etc.

C. D. Pi,Yi H?ng-tak(번역자),Hwang Juck-ryoon(번역자) The Academy of Korean Studies 1970 Korea Journal Vol.10 No.12

One-year Oxford knee scores should be used in preference to 6-month scores when assessing the outcome of total knee arthroplasty

( N. D. Clement ),( N. Ng ),( D. MacDonald ),( C. E. H. Scott ),( C. R. Howie ) 대한슬관절학회 2020 대한슬관절학회지 Vol.32 No.-

Purpose: The primary aim of this study was to assess whether there was a clinically significant difference in the mean Oxford knee score (OKS) between 6 and 12 months after total knee arthroplasty (TKA). The secondary aim was to identify variables associated with a clinically significant change in the OKS between 6 and 12 months. Methods: A retrospective cohort study was undertaken using an established arthroplasty database of 1574 primary TKA procedures. Patient demographics, body mass index (BMI), comorbidities, OKS and EuroQoL 5- domain (EQ-5D) score were collected preoperatively and at 6 and 12 months postoperatively. A clinically significant change in the OKS was defined as 5 points or more. Results: There was a 1.1-point increase in the OKS between 6 and 12 months postoperatively, which was statistically significant (95% confidence (CI) 0.8-1.3, p < 0.0001). There were 381 (24.2%) patients who had a clinically significant improvement in their OKS from 6 to 12 months. After adjusting for confounding, patients with a lower BMI (p = 0.028), without diabetes mellitus (p < 0.001), a better preoperative OKS (p < 0.001) or a worse 6-month OKS (p < 0.001) were more likely to have a clinically significant improvement. A 6-month OKS < 36 points was a reliable predictor of a clinically significant improvement in the 6-month to 12-month OKS (area under the curve 0.73, 95% CI 0.70-0.75, p < 0.001). Conclusion: Overall, there was no clinically significant change in the OKS from 6 to 12 months; however, a clinically significant improvement was observed in approximately a quarter of patients and was more likely in those scoring less than 36 points at 6 months. Level of evidence: retrospective diagnostic study, level III.

One-year Oxford knee scores should be used in preference to 6-month scores when assessing the outcome of total knee arthroplasty

Clement N. D.,Ng N.,MacDonald D.,Scott C. E. H.,Howie C. R. 대한슬관절학회 2020 대한슬관절학회지 Vol.32 No.-

Purpose: The primary aim of this study was to assess whether there was a clinically significant difference in the mean Oxford knee score (OKS) between 6 and 12 months after total knee arthroplasty (TKA). The secondary aim was to identify variables associated with a clinically significant change in the OKS between 6 and 12 months. Methods: A retrospective cohort study was undertaken using an established arthroplasty database of 1574 primary TKA procedures. Patient demographics, body mass index (BMI), comorbidities, OKS and EuroQoL 5- domain (EQ-5D) score were collected preoperatively and at 6 and 12 months postoperatively. A clinically significant change in the OKS was defined as 5 points or more. Results: There was a 1.1-point increase in the OKS between 6 and 12 months postoperatively, which was statistically significant (95% confidence (CI) 0.8–1.3, p < 0.0001). There were 381 (24.2%) patients who had a clinically significant improvement in their OKS from 6 to 12 months. After adjusting for confounding, patients with a lower BMI (p = 0.028), without diabetes mellitus (p < 0.001), a better preoperative OKS (p < 0.001) or a worse 6-month OKS (p < 0.001) were more likely to have a clinically significant improvement. A 6-month OKS < 36 points was a reliable predictor of a clinically significant improvement in the 6-month to 12-month OKS (area under the curve 0.73, 95% CI 0.70–0.75, p < 0.001). Conclusion: Overall, there was no clinically significant change in the OKS from 6 to 12 months; however, a clinically significant improvement was observed in approximately a quarter of patients and was more likely in those scoring less than 36 points at 6 months. Level of evidence: retrospective diagnostic study, level III.

Synthesis of GaN nanowires on gold-coated substrates by pulsed laser ablation

D.K.T. Ng,L.S. Tan,M.H. Hong 한국물리학회 2006 Current Applied Physics Vol.6 No.3

GaN nanowires were grown on gold-coated sapphire substrates by pulsed laser ablation of a target of GaN powder in low-pressurenitrogen gas. The laser ablation induced Ga and N plasma directly towards the substrate to initialize the vaporliquidsolid (VLS)growth mechanism. The morphological and structural properties of the GaN nanowires were studied using scanning electron microscopy(SEM), transmission electron microscopy (TEM) and X-ray diraction (XRD). The nanowires formed crystalline and have lengths fromthe VLS growth mechanism. In addition, the electrical properties of these nanowires were also examined.

Hospital Roon 205

Edward D. Rockstein(번역자),CH’OE CH?NG-H?I The Academy of Korean Studies 1972 Korea Journal Vol.12 No.11

DESIGN ANALYSIS AND COMPARISON BETWEEN STANDARD AND ROTARY PORTING SYSTEMS FOR IC ENGINE

R. PALMISANO,H. D. NG 한국자동차공학회 2012 International journal of automotive technology Vol.13 No.2

Many porting systems for internal combustion engines have been tried and tested over the years, however the basic spring actuated poppet valve system has prevailed over the last century. In the goal to lower engine output parasitic losses, a simple rotary valve porting system design is proposed and analyzed. The proposed design concept takes into consideration and combines all the prominent advantages of many ealier mutlitiple design variations over the past century. The inherent primary advantage of such a rotary porting system is the elimination of reciprocating components, thus lowering vibration, and removal of highly stiff springs which contribute to considerable system power loss. Comparable sized 3-D representations of both systems are constructed in CAD (Computer Aided Design) software in order to run mechanical and fluid simulations to validate the efficiency advantage of a rotary valve porting system. Using Pro/Engineer Mechanism Dynamics module, the minimum torque required to actuate both systems at 2000 rpm and 3000 rpm is determined. Fluid simulations are performed using a commercial software CFDesign V10. Volumetric flow rates are compared during the intake stroke as well as turbulence intensity factors which characterizes a systems ability to properly mix the Air/Fuel mixture and the combustion efficiency. Some possible improvement on the rotary geometry is suggested.

CASCADE STATE CONTROL OF ROBUST AC-DRIVES

R.Schonfeld,D.H.Dat,H.Lorenz,Ng.Ph.Quang 전력전자학회 1992 ICPE(ISPE)논문집 Vol.1992 No.4

Powerful processors enable to use the state-control in practical applications. To control AC-Drives, the cascade state control is used (Fig. 1) ?<br/> The torque proportional current component is the output value of the outer control loop and the leading value of the inner control loop. This signal is limited. The advantages of this structure, compared to traditional controlmethods are<br/> - very fast torque inpression, based on current-state-control<br/> - robustness against changings of rotor flux coupling<br/> - torque control in the full range of torquelimitation<br/> - aperiodic motion control via an elastically coupled mechanical transmission system<br/> - limitation of the application of sensors by use of state- and disturbance-observers<br/> - robustness against parameter-changings and nonlinearities of the mechanical transmission system<br/> - use of an effective selfcommissioning strategy under respect of the laws of matrix-algebra<br/> - use of an unificated hardware and a unificated software structure for induction motors and synchronous motors<br/> The theoretical analysis is based on discrete state equations. The discretisation of the state equations is combined with a linearisation of the problem. We get useful algorithm to adapt the controllermatrix to the observermatrix automatically.<br/>

Mode Change of a Gamma-Ray Pulsar, PSR J2021+4026

Zhao, J.,Ng, C. W.,Lin, L. C. C.,Takata, J.,Cai, Y.,Hu, C.-P.,Yen, D. C. C.,Tam, P. H. T.,Hui, C. Y.,Kong, A. K. H.,Cheng, K. S. American Astronomical Society 2017 The Astrophysical journal Vol.842 No.1

<P>A glitch of a pulsar is known as a sudden increase in the spin frequency and spin-down rate (frequency time derivative), and it can be caused by a sudden release of the stress built up in the solid crust of the star or pinned vortices in the superfluid interior. PSR J2021+4026 is the first pulsar that shows a significant change in the gamma-ray flux and pulse profile at the glitch that occurred around 2011 October 16. We report the results of timing and spectral analysis of PSR J2021+4026 using similar to 8 yr Fermi. Large Area Telescope data. We find that the pulsar stayed at a high spin-down rate (similar to 4% higher than the pre-glitch value) and a low gamma-ray state (similar to 18% lower) for about 3 yr. after the glitch. Around 2014 December, the spin-down rate and gamma-ray flux gradually returned to pre-glitch values within a timescale of a. few months. The phase-resolved spectra and pulse profiles after the relaxation are also consistent with those before the glitch. The observed long-term evolution of the spin-down rate and the gamma-ray flux indicates that the glitch triggered a mode change in the global magnetosphere. We speculate that the glitch changed. the local magnetic field structure around the polar cap and/or the inclination angle of the. dipole axis, leading to. a change in the electric current circulating in the. magnetosphere.</P>

On the influence of vector design on antibody phage display

Soltes, Glenn,Hust, Michael,Ng, Kitty K.Y.,Bansal, Aasthaa,Field, Johnathan,Stewart, Donald I.H.,Dü,bel, Stefan,Cha, Sanghoon,Wiersma, Erik J. Elsevier 2007 Journal of biotechnology Vol.127 No.4

<P><B>Abstract</B></P><P>Phage display technology is an established technology particularly useful for the generation of monoclonal antibodies (mAbs). The isolation of phagemid-encoded mAb fragments depends on several features of a phage preparation. The aims of this study were to optimize phage display vectors, and to ascertain if different virion features can be optimized independently of each other.</P><P>Comparisons were made between phagemid virions assembled by g3p-deficient helper phage, Hyperphage, Ex-phage or Phaberge, or corresponding g3p-sufficient helper phage, M13K07. All g3p-deficient helper phage provided a similar level of antibody display, significantly higher than that of M13K07. Hyperphage packaged virions at least 100-fold more efficiently than did Ex-phage or Phaberge. Phaberge's packaging efficiency improved by using a SupE strain.</P><P>Different phagemids were also compared. Removal of a 56 base pair fragment from the promoter region resulted in increased display level and increased virion production. This critical fragment encodes a lacZ′-like peptide and is also present in other commonly used phagemids.</P><P>Increasing display level did not show statistical correlation with phage production, phage infectivity or bacterial growth rate. However, phage production was positively correlated to phage infectivity.</P><P>In summary, this study demonstrates simultaneously optimization of multiple and independent features of importance for phage selection.</P>

Enhancement of mechanical properties of grade 4 titanium by equal channel angular pressing with billet encapsulation

Li, Y.,Pang Ng, H.,Jung, H.D.,Kim, H.E.,Estrin, Y. North-Holland 2014 Materials letters Vol.114 No.-

Commercial purity titanium (Grade 4) was processed by encapsulation-aided equal-channel angular pressing. Encapsulation in a copper cartridge made it possible to carry out the process repeatedly, up to 8 passes, at a relatively low temperature of 300<SUP>o</SUP>C. Extremely high values of yield strength and tensile strength close to record literature values for this titanium grade and matching, or even surpassing, the levels for conventional Ti-6Al-4V alloy were obtained. A bi-modal grain structure observed may be responsible for a favorable combination of strength and ductility the processed material exhibits.