F. D. I. 대표 Dr. Yap 연설문

J. H. Yap 대한치과의사협회 1970 대한치과의사협회지 Vol.8 No.10

Uncertainty estimation in diffusion MRI using the nonlocal bootstrap.

Yap, Pew-Thian,An, Hongyu,Chen, Yasheng,Shen, Dinggang Institute of Electrical and Electronics Engineers 2014 IEEE transactions on medical imaging Vol.33 No.8

<P>In this paper, we propose a new bootstrap scheme, called the nonlocal bootstrap (NLB) for uncertainty estimation. In contrast to the residual bootstrap, which relies on a data model, or the repetition bootstrap, which requires repeated signal measurements, NLB is not restricted by the data structure imposed by a data model and obviates the need for time-consuming multiple acquisitions. NLB hinges on the observation that local imaging information recurs in an image. This self-similarity implies that imaging information coming from spatially distant (nonlocal) regions can be exploited for more effective estimation of statistics of interest. Evaluations using in silico data indicate that NLB produces distribution estimates that are in closer agreement with those generated using Monte Carlo simulations, compared with the conventional residual bootstrap. Evaluations using in vivo data demonstrate that NLB produces results that are in agreement with our knowledge on white matter architecture.</P>

The Influence of Explicit Morphological Instruction on Reading Comprehension among Malaysian Primary ESL Learners

Yap Soon Li,Tan Kok Eng,Rohaya Abdullah 아시아영어교육학회 2020 The Journal of Asia TEFL Vol.17 No.3

This study aims to examine the significant difference in reading comprehension performance after explicit instruction in morphology. This quasi-experimental study investigated specifically the effect of explicit teaching on compounding, inflectional and derivational morphological awareness upon Malaysian primary school learners’ reading comprehension in the ESL context. Convenience sampling was applied in recruiting 125 pupils from two government primary schools in a suburb area. The experimental group was given the explicit instruction in morphology during their reading lessons for 12 consecutive weeks, and the control group had been taught without this intervention. After controlling for learners’ pre-test scores, ANCOVA statistical result concluded that the experimental group could achieve higher scores in their post-tests, which indicated a significant difference in reading comprehension performance. Therefore, it is essential for curriculum developers to give recognition of the importance of morphology. Educational practitioners and academics should explore further the teaching of morphology in order to improve their learners’ reading comprehension skill.

A Simplified Synchronous Reference Frame for Indirect Current Controlled Three-level Inverter-based Shunt Active Power Filters

Yap Hoon,Mohd Amran Mohd Radzi,Mohd Khair Hassan,Nashiren Farzilah Mailah,Noor Izzri Abdul Wahab 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5

This paper presents a new simplified harmonics extraction algorithm based on the synchronous reference frame (SRF) for an indirect current controlled (ICC) three-level neutral point diode clamped (NPC) inverter-based shunt active power filter (SAPF). The shunt APF is widely accepted as one of the most effective current harmonics mitigation tools due to its superior adaptability in dynamic state conditions. In its controller, the SRF algorithm which is derived based on the direct-quadrature (DQ) theory has played a significant role as a harmonics extraction algorithm due to its simple implementation features. However, it suffers from significant delays due to its dependency on a numerical filter and unnecessary computation workloads. Moreover, the algorithm is mostly implemented for the direct current controlled (DCC) based SAPF which operates based on a non-sinusoidal reference current. This degrades the mitigation performances since the DCC based operation does not possess exact information on the actual source current which suffers from switching ripples problems. Therefore, three major improvements are introduced which include the development of a mathematical based fundamental component identifier to replace the numerical filter, the removal of redundant features, and the generation of a sinusoidal reference current. The proposed algorithm is developed and evaluated in MATLAB / Simulink. A laboratory prototype utilizing a TMS320F28335 digital signal processor (DSP) is also implemented to validate effectiveness of the proposed algorithm. Both simulation and experimental results are presented. They show significant improvements in terms of total harmonic distortion (THD) and dynamic response when compared to a conventional SRF algorithm.

A Comparative Study between Islamic and Conventional Exchange-Traded Funds: Evidence from Global Market Indices

YAP, Kok-Leong,LAU, Wee-Yeap,ISMAIL, Izlin Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.2

This study investigates whether the Islamic Exchange-Traded Funds (ETFs) provide significant benefit to investors relative to conventional ETFs. Six pairs of Islamic and conventional ETFs with 10-year daily price data from 2010 to 2019 have been selected from major market indices like MSCI World Index, MSCI Emerging Markets, MyETF Dow Jones Islamic Market Malaysia, MSCI South East Asia and Wahed FTSE Shariah USA Index for this study. For ETFs that are launched after 2010, the price data from launch date to 2019 are used. Our results show: First, Islamic ETFs are more likely to trade at a premium rather than at a discount, implying the investors are willing to pay a premium. Second, it is also found that Islamic ETFs have a relatively shorter period of price deviation from the benchmark, implying more price stability. Third, conventional ETFs have higher return and lower tracking errors relative to Islamic ETFs. These new findings add to the stylized facts of Islamic ETFs in the extant literature for investors, plan sponsors and regulators as to the differences between the ETFs. As policy suggestion, asset management companies can design new investment products to bridge the gap between conventional and Islamic finance.

An Ileal Amino Acid Digestibility Assay for the Growing Meat Chicken-Effect of Feeding Method and Digesta Collection Procedures

Yap, K.H.,Kadim, I.T.,King, R.D.,Moughan, P.J. Asian Australasian Association of Animal Productio 1997 Animal Bioscience Vol.10 No.6

The objective was to evaluate method of feeding (free access or intubation), method of slaughter (carbon dioxide gas or barbiturate) and digesta flushing medium (distilled water or physiological saline), in the development of an ileal amino acid digestibility assay for 4 week-old broiler chickens. Three diets were used (commercial (C), semi-synthetic meat-and bone meal (MBM) or wheat (W)). For the coarser C and W diets but not for the MBM diet, feeding method had a significant effect on concentrations of chromium (Cr), nitrogen (N), acid detergent fibre (ADF) and neutral detergent fibre (NDF) in the crop contents at a set time after a meal. There appeared to be a selection of food particles under free-access feeding. For birds receiving the wheat diet there was an effect (p < 0.05) of sampling time after feeding on the concentrations of Cr, N, ADF and NDF/Cr in the crop contents. Flushing ileal digesta with distilled water or saline led to similar apparent ileal N digestibility coefficients. Birds given the MBM diet, and killed by inhalation of $CO_2$, had significantly (p < 0.05) lower apparent ileal N digestibility coefficients (73 versus 80%) than those killed by barbiturate overdose.

Brain metastases in Asian HER2-positive breast cancer patients: anti-HER2 treatments and their impact on survival

Yap, Y S,Cornelio, G H,Devi, B C R,Khorprasert, C,Kim, S B,Kim, T Y,Lee, S C,Park, Y H,Sohn, J H,Sutandyo, N,Wong, D W Y,Kobayashi, M,Landis, S H,Yeoh, E M,Moon, H,Ro, J Nature Publishing Group 2012 The British journal of cancer Vol.107 No.7

<P><B>Background:</B></P><P>In Asia, large-scale studies on anti-HER2 treatment in HER2-positive breast cancer patients with brain metastases are limited. We studied the treatment patterns of these patients in Asia to evaluate the impact of anti-HER2 treatment on the time to occurrence of brain metastases (TTBM) and survival after brain metastasis (BM).</P><P><B>Methods:</B></P><P>A retrospective study of HER2-positive breast cancer patients diagnosed with BM between January 2006 and December 2008 in six Asian countries was conducted. Demographics, tumour characteristics, treatment details, and events dates were collected from medical records.</P><P><B>Results:</B></P><P>Data from 280 patients were analysed. Before BM, 63% received anti-HER2 treatment. These patients had significantly longer TTBM than those without anti-HER2 treatment (median 33 <I>vs</I> 19 months; <I>P</I><0.002). After BM, 93% received radiotherapy, 57% received chemotherapy, and 41% received anti-HER2 treatment (trastuzumab and/or lapatinib). Use of both anti-HER2 agents, primarily sequentially, after BM demonstrated the longest survival after BM and was associated with a significant survival benefit over no anti-HER2 treatment (median 26 <I>vs</I> 6 months; hazard ratio 0.37; 95% CI 0.19–0.72).</P><P><B>Conclusion:</B></P><P>Anti-HER2 treatment before BM was associated with longer TTBM. Anti-HER2 treatment after BM was associated with a survival benefit, especially when both trastuzumab and lapatinib were utilised.</P>

Face changing companion of the redback millisecond pulsar PSR J1048+2339

Yap, Y. X.,Li, K. L.,Kong, A. K. H.,Takata, J.,Lee, J.,Hui, C. Y. Springer-Verlag 2019 Astronomy and astrophysics Vol.621 No.-

<P>We present optical observations of the redback millisecond pulsar PSR J1048+2339, which is a 4.66 ms radio pulsar in a compact binary with an orbital period of six hours. We obtained high-quality light curves of PSR J1048+2339 with the Lulin 1 m Telescope. The system shows two distinct six-hour orbital modulations, in which an ellipsoidal modulation changes into a sinusoidal-like profile in less than 14 days. In addition to the change, the brightness of the companion increased by one magnitude, suggesting that the latter type of modulation is caused by the pulsar wind heating of the companion and that the heating became dominant in the system. While the changes are not unexpected, such a timescale is the shortest among similar systems. We performed modeling analysis to extract the properties of the system. We obtained a derived pulsar mass of 2.1 <I>M</I>⊙ and a companion star mass of 0.4 <I>M</I>⊙ for the system. The irradiation power increased by a factor of 6 during which the pulsar wind heating dominates. We also report on the two archival <I>Chandra</I> X-ray observations and discuss several possibilities that might cause the varying heating on the companion.</P>

Exploring Chemotherapy-Induced Toxicities through Multivariate Projection of Risk Factors: Prediction of Nausea and Vomiting

Yap, Kevin Yi-Lwern,Low, Xiu Hui,Chan, Alexandre Korean Society of ToxicologyKorea Environmental Mu 2012 Toxicological Research Vol.28 No.2

Many risk factors exist for chemotherapy-induced nausea and vomiting (CINV). This study utilized a multivariate projection technique to identify which risk factors were predictive of CINV in clinical practice. A single-centre, prospective, observational study was conducted from January 2007~July 2010 in Singapore. Patients were on highly (HECs) and moderately emetogenic chemotherapies with/without radiotherapy. Patient demographics and CINV risk factors were documented. Daily recording of CINV events was done using a standardized diary. Principal component (PC) analysis was performed to identify which risk factors could differentiate patients with and without CINV. A total of 710 patients were recruited. Majority were females (67%) and Chinese (84%). Five risk factors were potential CINV predictors: histories of alcohol drinking, chemotherapy-induced nausea, chemotherapy-induced vomiting, fatigue and gender. Period (ex-/current drinkers) and frequency of drinking (social/chronic drinkers) differentiated the CINV endpoints in patients on HECs and anthracycline-based, and XELOX regimens, respectively. Fatigue interference and severity were predictive of CINV in anthracycline-based populations, while the former was predictive in HEC and XELOX populations. PC analysis is a potential technique in analyzing clinical population data, and can provide clinicians with an insight as to what predictors to look out for in the clinical assessment of CINV. We hope that our results will increase the awareness among clinician-scientists regarding the usefulness of this technique in the analysis of clinical data, so that appropriate preventive measures can be taken to improve patients' quality of life.

Clinical Prognostic Factors and Survival Outcome in Renal Cell Carcinoma Patients - A Malaysian Single Centre Perspective

Yap, Ning Yi,Ng, Keng Lim,Ong, Teng Aik,Pailoor, Jayalakshmi,Gobe, Glenda Carolyn,Ooi, Chong Chien,Razack, Azed Hassan,Dublin, Norman,Morais, Christudas,Rajandram, Retnagowri Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Background: This study concerns clinical characteristics and survival of renal cell carcinoma (RCC) patients in University Malaya Medical Centre (UMMC), as well as the prognostic significance of presenting symptoms. Materials and Methods: The clinical characteristics, presenting symptoms and survival of RCC patients (n=151) treated at UMMC from 2003-2012 were analysed. Symptoms evaluated were macrohaematuria, flank pain, palpable abdominal mass, fever, lethargy, loss of weight, anaemia, elevated ALP, hypoalbuminemia and thrombocytosis. Univariate and multivariate Cox regression analyses were performed to determine the prognostic significance of these presenting symptoms. Kaplan Meier and log rank tests were employed for survival analysis. Results: The 2002 TNM staging was a prognostic factor (p<0.001) but Fuhrman grading was not significantly correlated with survival (p=0.088). At presentation, 76.8% of the patients were symptomatic. Generally, symptomatic tumours had a worse survival prognosis compared to asymptomatic cases (p=0.009; HR 4.74). All symptoms significantly affect disease specific survival except frank haematuria and loin pain on univariate Cox regression analysis. On multivariate analysis adjusted for stage, only clinically palpable abdominal mass remained statistically significant (p=0.027). The mean tumour size of palpable abdominal masses, $9.5{\pm}4.3cm$, was larger than non palpable masses, $5.3{\pm}2.7cm$ (p<0.001). Conclusions: This is the first report which includes survival information of RCC patients from Malaysia. Here the TNM stage and a palpable abdominal mass were independent predictors for survival. Further investigations using a multicentre cohort to analyse mortality and survival rates may aid in improving management of these patients.