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in-body medical device 2

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wireless capsule endoscopy 2

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A Bayesian modeling approach to bi-directional pedestrian flows in carnival events

WONG, William H. K. LAM

Frontiers of Engineering Management 2017, Volume 4, Issue 4,   Pages 483-489 doi: 10.15302/J-FEM-2017023

Abstract: Bi-directional pedestrian flows are common at crosswalks, footpaths, and shopping areas. However, the properties of pedestrian movement may vary in urban areas according to the type of walking facility. In recent years, crowd movements at carnival events have attracted the attention of researchers. In contrast to pedestrian behavior in other walking facilities, pedestrians whose attention is attracted by carnival displays or activities may slow down and even stop walking. The Lunar New Year Market is a traditional carnival event in Hong Kong held annually one week before the Lunar New Year. During the said event, crowd movements can be easily identified, particularly in Victoria Park, where the largest Lunar New Year Market in Hong Kong is hosted. In this study, we conducted a video-based observational survey to collect pedestrian flow and speed data at the Victoria Park Lunar New Year Market on the eve of the Lunar New Year. Using the collected data, an extant mathematical model was calibrated to capture the relationships between the relevant macroscopic quantities, thereby providing insight into pedestrian behavior at the carnival event. Bayesian inference was employed to calibrate the model by using prior data obtained from a previous controlled experiment. Results obtained enhance our understanding of crowd behavior under different conditions at carnival events, thus facilitating the improvement of the safety and efficiency of similar events in the future.

Keywords： pedestrian flow model     bi-directional interactions     empirical studies     Bayesian inference    

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Novel quantum-inspired firefly algorithm for optimal power quality monitor placement

Ling Ai WONG,Hussain SHAREEF,Azah MOHAMED,Ahmad Asrul IBRAHIM

Frontiers in Energy 2014, Volume 8, Issue 2,   Pages 254-260 doi: 10.1007/s11708-014-0302-1

Abstract: The application of a quantum-inspired firefly algorithm was introduced to obtain optimal power quality monitor placement in a power system. The conventional binary firefly algorithm was modified by using quantum principles to attain a faster convergence rate that can improve system performance and to avoid premature convergence. In the optimization process, a multi-objective function was used with the system observability constraint, which is determined via the topological monitor reach area concept. The multi-objective function comprises three functions: number of required monitors, monitor overlapping index, and sag severity index. The effectiveness of the proposed method was verified by applying the algorithm to an IEEE 118-bus transmission system and by comparing the algorithm with others of its kind.

Keywords： quantum-inspired binary firefly algorithm     topological monitor reach area     power quality    

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MicroRNA-142-3p and microRNA-142-5p are downregulated in hepatocellular carcinoma and exhibit synergistic effects on cell motility

Felice Ho-Ching Tsang,Sandy Leung-Kuen Au,Lai Wei,Dorothy Ngo-Yin Fan,Joyce Man-Fong Lee,Carmen Chak-Lui Wong,Irene Oi-Lin Ng,Chun-Ming Wong

Frontiers of Medicine 2015, Volume 9, Issue 3,   Pages 331-343 doi: 10.1007/s11684-015-0409-8

Abstract:

MicroRNAs (miRNAs), an important class of small non-coding RNAs, regulate gene expression at the post-transcriptional level. miRNAs are involved in a wide range of biological processes and implicated in different diseases, including cancers. In this study, miRNA profiling and qRT-PCR validation revealed that miR-142-3p and miR-142-5p were significantly downregulated in hepatocellular carcinoma (HCC) and their expression levels decreased as the disease progressed. The ectopic expression of miR-142 significantly reduced HCC cell migration and invasion. Overexpression of either miR-142-3p or miR-142-5p suppressed HCC cell migration, and overexpression of both synergistically inhibited cell migration, which indicated that miR-142-3p and miR-142-5p may cooperatively regulate cell movement. miR-142-3p and miR-142-5p, which are mature miRNAs derived from the 3′- and 5′-strands of the precursor miR-142, target distinct pools of genes because of their different seed sequences. Pathway enrichment analysis showed a strong association of the putative gene targets of miR-142-3p and miR-142-5p with several cell motility-associated pathways, including those regulating actin cytoskeleton, adherens junctions, and focal adhesion. Importantly, a number of the putative gene targets were also significantly upregulated in human HCC cells. Moreover, overexpression of miR-142 significantly abrogated stress fiber formation in HCC cells and led to cell shrinkage. This study shows that mature miR-142 pairs collaboratively regulate different components of distinct signaling cascades and therefore affects the motility of HCC cells.

Keywords： hepatocellular carcinoma     microRNA     metastasis     cytoskeletal reorganization    

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Ingestible wireless capsules for enhanced diagnostic inspection of gastrointestinal tract

Mahdi RASOULI, Andy Prima KENCANA, Van An HUYNH, Eng Kiat TING, Joshua Chong Yue LAI, Kai Juan WONG,

Frontiers of Mechanical Engineering 2011, Volume 6, Issue 1,   Pages 40-44 doi: 10.1007/s11465-011-0204-4

Abstract:

Wireless capsule endoscopy has become a common procedure for diagnostic inspection of gastrointestinal tract. This method offers a less-invasive alternative to traditional endoscopy by eliminating uncomfortable procedures of the traditional endoscopy. Moreover, it provides the opportunity for exploring inaccessible areas of the small intestine. Current capsule endoscopes, however, move by peristalsis and are not capable of detailed and on-demand inspection of desired locations. Here, we propose and develop two wireless endoscopes with maneuverable vision systems to enhance diagnosis of gastrointestinal disorders. The vision systems in these capsules are equipped with mechanical actuators to adjust the position of the camera. This may help to cover larger areas of the digestive tract and investigate desired locations. The preliminary experimental results showed that the developed platform could successfully communicate with the external control unit via human body and adjust the position of camera to limited degrees.

Keywords： wireless capsule endoscopy     ingestible medical device     in-body medical device     miniature actuator     medical robot     medical imaging    

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Towards a respondent-preferred ki-anonymity model

Kok-Seng WONG,Myung Ho KIM

Frontiers of Information Technology & Electronic Engineering 2015, Volume 16, Issue 9,   Pages 720-731 doi: 10.1631/FITEE.1400395

Abstract: Recently, privacy concerns about data collection have received an increasing amount of attention. In data collection process, a data collector (an agency) assumed that all respondents would be comfortable with submitting their data if the published data was anonymous. We believe that this assumption is not realistic because the increase in privacy concerns causes some respondents to refuse participation or to submit inaccurate data to such agencies. If respondents submit inaccurate data, then the usefulness of the results from analysis of the collected data cannot be guaranteed. Furthermore, we note that the level of anonymity (i.e., -anonymity) guaranteed by an agency cannot be verified by respondents since they generally do not have access to all of the data that is released. Therefore, we introduce the notion of -anonymity, where is the level of anonymity preferred by each respondent . Instead of placing full trust in an agency, our solution increases respondent confidence by allowing each to decide the preferred level of protection. As such, our protocol ensures that respondents achieve their preferred -anonymity during data collection and guarantees that the collected records are genuine and useful for data analysis.

Keywords： Anonymous data collection     Respondent-preferred privacy protection     k-anonymity    

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SHM-based F-AHP bridge rating system with application to Tsing Ma Bridge

Qi LI, You-lin XU, Yue ZHENG, An-xin GUO, Kai-yuen WONG, Yong XIA

Frontiers of Structural and Civil Engineering 2011, Volume 5, Issue 4,   Pages 465-478 doi: 10.1007/s11709-011-0135-5

Abstract: This paper aims at developing a structural health monitoring (SHM)-based bridge rating method for bridge inspection of long-span cable-supported bridges. The fuzzy based analytic hierarchy approach is employed, and the hierarchical structure for synthetic rating of each structural component of the bridge is proposed. The criticality and vulnerability analyses are performed largely based on the field measurement data from the SHM system installed in the bridge to offer relatively accurate condition evaluation of the bridge and to reduce uncertainties involved in the existing rating method. The procedures for determining relative weighs and fuzzy synthetic ratings for both criticality and vulnerability are then suggested. The fuzzy synthetic decisions for inspection are made in consideration of the synthetic ratings of all structural components. The SHM-based bridge rating method is finally applied to the Tsing Ma suspension bridge in Hong Kong as a case study. The results show that the proposed method is feasible and it can be used in practice for long-span cable-supported bridges with SHM system.

Keywords： structural health monitoring (SHM)     bridge rating method     fuzzy based analytic hierarchy approach     criticality and vulnerability rating     Tsing Ma Bridge    

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Capsule endoscopy—A mechatronics perspective

Lin LIN, Mahdi RASOULI, Andy Prima KENCANA, Su Lim TAN, Kai Juan WONG, Khek Yu HO, Soo Jay PHEE

Frontiers of Mechanical Engineering 2011, Volume 6, Issue 1,   Pages 33-39 doi: 10.1007/s11465-011-0203-5

Abstract:

The recent advances in integrated circuit technology, wireless communication, and sensor technology have opened the door for development of miniature medical devices that can be used for enhanced monitoring and treatment of medical conditions. Wireless capsule endoscopy is one of such medical devices that has gained significant attention during the past few years. It is envisaged that future wireless capsule endoscopies replace traditional endoscopy procedures by providing advanced functionalities such as active locomotion, body fluid/tissue sampling, and drug delivery. Development of energy-efficient miniaturized actuation mechanisms is a key step toward achieving this goal. Here, we review some of the actuators that could be integrated into future wireless capsules and discuss the existing challenges.

Keywords： wireless capsule endoscopy     ingestible medical device     in-body medical device     medical robot     miniature actuator    

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Erosion-corrosion failure of REAC pipes under multiphase flow

Ping TANG, Jian YANG, Jinyang ZHENG, Shizheng HE, Jianjun YE, Guofu OU, Ieong WONG, Yanbao MA,

Frontiers in Energy 2009, Volume 3, Issue 4,   Pages 389-395 doi: 10.1007/s11708-009-0045-6

Abstract: By using computational fluid dynamics (CFD) modeling and simulation, a predictive method was proposed to explore the erosion failure of reactor effluent air cooler (REAC) pipes with liner under multiphase flow. A theoretical model based on the erosion-corrosion effects of REAC on mixture turbulent flow was proposed for multiphase flow. Effects of various working conditions, liner shapes, and structures, as well as flow parameters on numerical simulations were investigated. Besides, the pipe’s erosion-corrosion rules under multiphase flow and the relationship between multiphase flow and erosion-corrosion under dangerous working conditions were studied. By CFD numerical simulations, the exact position where some typical pipes thinned and failed rapidly by erosion was found and the main factors causing erosion-corrosion failure were discussed. Finally, numerical results obtained by using the proposed method were compared with experimental results.

Keywords： multiphase flow     erosion-corrosion     pipes     reactor effluent air cooler (REAC)     computational fluid dynamics (CFD)    

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Microbial responses to combined oxidation and catalysis treatment of 1,4-dioxane and co-contaminants in groundwater and soil

Wong, Shaily Mahendra

Frontiers of Environmental Science & Engineering 2018, Volume 12, Issue 5, doi: 10.1007/s11783-018-1071-6

Abstract:

Groundwater microbial community was altered after catalysis and chemical oxidation.

The coupled treatment train removed 90% 1,4-dioxane regardless of co-contaminants.

Dynamics of microbial populations varied along with different treatment stages.

Many microbial taxa exhibited resilience against oxidative and catalytic treatments.

Metagenomic analysis will be valuable for long-term management of polluted sites.

Keywords： Coupled treatments     Chlorinated solvents     Diethylene ether     Biological diversity     Microbial populations     Biomarkers    

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A dual-polarized Fabry–Pérot antenna with high gain and wide bandwidth for millimeter-wave applications

Qingyi Guo, Hang Wong,guo_qingyi@163.com,hang.wong@cityu.edu.hk

Frontiers of Information Technology & Electronic Engineering 2021, Volume 22, Issue 4,   Pages 599-608 doi: 10.1631/FITEE.2000514

Abstract: We introduce a dual-polarized (DP) rot cavity (FPC) antenna operating at the millimeter-wave (mmWave) frequency band with and characteristics. A DP feeding source and a partially reflective surface (PRS) integrated with a Fresnel zone lens are suggested to realize dual-polarization wave radiation over a wide impedance bandwidth. The feeding source provides vertical and horizontal polarizations while keeping high isolation between the two polarizations. PRS is used to realize Fabry cavity to produce a directive beam radiation. The integrated Fresnel zone rings are introduced for phase correction, leading to a significant gain enhancement for the antenna. For verification, a 60-GHz FPC antenna prototype with DP radiation is designed and fabricated with measurement results. It consists of a feeding source, a PRS integrated with a Fresnel zone lens, a quasi-curved reflector, and four three-dimensional printed supporters. The results illustrate that the peak gains of vertical and horizontal polarizations are 18.4 and 17.6 dBi, respectively. The impedance matching bandwidth for the two polarizations is 14%. The performance ensures that the proposed DP FPC antenna is a promising candidate for the fifth-generation wireless communication systems in the mmWave band.

Keywords： 双极化；法布里—珀罗腔天线；与菲涅耳带透镜集成的部分反射面；毫米波波段；高增益；宽带    

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Studies on Externalization of Application of Tongue Inspection of TCM

Wong Weiliang,Huang Shijing

Strategic Study of CAE 2001, Volume 3, Issue 1,   Pages 78-82

Abstract:

Xiyuan Hospital of China Academy for TCM, cooperated with other units, on the basis of making use of computer image technology and combining TCM theory of tongue inspection, developed the expert system of tongue inspection of TCM and accomplished the quantitative analysis of tongue inspection. The system was used in quantification study on the tongue body and tongue coating for 927 patients. The results showed that each kind of tongue body and tongue coating had its corresponding quantitative RGB (three basic color, R is redness, G is greenness, B is blueness) characteristic. RGB value of tongue coating is related not only to the color, but also the thickness, curdy appearance, greasinessl of tongue fur and so on significantly. RGB value between different tongue fur is different significantly. The percentage of tongue coating area can basically reflect the tongue coating covering area. Therefore, the application of tongue inspection of TCM on the quantificational diagnosis of the tongue body and tongue coating can provide objective references for clinic of TCM.

Keywords： tongue inspection     externalization     expert system    

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The impact of hypoxia in hepatocellular carcinoma metastasis

Carmen Chak-Lui Wong, Alan Ka-Lun Kai, Irene Oi-Lin Ng

Frontiers of Medicine 2014, Volume 8, Issue 1,   Pages 33-41 doi: 10.1007/s11684-013-0301-3

Abstract:

Hypoxia is a common phenomenon in hepatocellular carcinoma (HCC). Hypoxia stabilizes transcription factor, hypoxia-inducible factor (HIF), to activate gene transcription. Expression of HIF is closely associated with metastasis and poor prognosis in HCC. HIF mediates expression of genes that are involved in every step of HCC metastasis including epithelial-mesenchymal transition, invasion of the extracellular matrix, intravasation, extravasation, and secondar y growth of the metastases. Because HIF is the central regulator of HCC metastasis, HIF inhibitors are attractive tools when used alone or as combined treatment to curb HCC metastasis. This review will summarize the current findings on the impact of hypoxia/HIF in HCC, with a particular focus on cancer metastasis.

Keywords： hypoxia     hepatocellular carcinoma (HCC)     metastasis     hypoxia-inducible factor (HIF)    

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Two-step gate-recess process combining selective wet-etching and digital wet-etching for InAlAs/InGaAs InP-based HEMTs Article

Ying-hui ZHONG, Shu-xiang SUN, Wen-bin WONG, Hai-li WANG, Xiao-ming LIU, Zhi-yong DUAN, Peng DING, Zhi

Frontiers of Information Technology & Electronic Engineering 2017, Volume 18, Issue 8,   Pages 1180-1185 doi: 10.1631/FITEE.1601121

Abstract: A two-step gate-recess process combining high selective wet-etching and non-selective digital wet-etching techniques has been proposed for InAlAs/InGaAs InP-based high electron mobility transistors (HEMTs). High etching-selectivity ratio of InGaAs to InAlAs material larger than 100 is achieved by using mixture solution of succinic acid and hydrogen peroxide (H2O2). Selective wet-etching is validated in the gate-recess process of InAlAs/InGaAs InP-based HEMTs, which proceeds and automatically stops at the InAlAs barrier layer. The non-selective digital wet-etching process is developed using a separately controlled oxidation/de-oxidation technique, and during each digital etching cycle 1.2 nm InAlAs material is removed. The two-step gate-recess etching technique has been successfully incorporated into device fabrication. Digital wet-etching is repeated for two cycles with about 3 nm InAlAs barrier layer being etched off. InP-based HEMTs have demonstrated superior extrinsic transconductance and RF characteristics to devices fabricated during only the selective gate-recess etching process because of the smaller gate to channel distance.

Keywords： High electron mobility transistors (HEMTs)     Gate-recess     Digital wet-etching     Selective wet-etching    

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United Algorithm for Dynamic Subcarrier, Bit and Power Allocation in OFDM System

Gao Huanqin,Feng Guangzeng,Zhuqi

Strategic Study of CAE 2006, Volume 8, Issue 3,   Pages 62-65

Abstract:

A realtime united algorithm for dynamic subbcarrier, bit and power allocation according to the change of channel (UA) is presented in this paper, which can be used into the down-link of multi-user orthogonal frequency division multiplexing (OFDM) system. With the algorithm the total transmission power is the minimum while the data rate of each user and the required BER performance can be achieved. Comparing to the subcarrier allocation algorithm (WSA) , the simulation results show that the algorithm presented in this paper has better performance while both have equal calculating complexity.

Keywords： OFDM     Wong's subcarrier allocation (WSA)     UA    

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Profiling the Antimalarial Mechanism of Artemisinin by Identifying Crucial Target Proteins Article

Peng Gao, Jianyou Wang, Jiayun Chen, Liwei Gu, Chen Wang, Liting Xu, Yin Kwan Wong, Huimin Zhang, Chengchao

Engineering 2023, Volume 31, Issue 12,   Pages 86-97 doi: 10.1016/j.eng.2023.06.001

Abstract:

The widespread use of artemisinin (ART) and its derivatives has significantly reduced the global burden of malaria; however, malaria still poses a serious threat to global health. Although significant progress has been achieved in elucidating the antimalarial mechanisms of ART, the most crucial target proteins and pathways of ART remain unknown. Knowledge on the exact antimalarial mechanisms of ART is urgently needed, as signs of emerging ART resistance have been observed in some regions of the world. Here, we used a combined strategy involving mass spectrometry-coupled cellular thermal shift assay (MS-CETSA) and transcriptomics profiling to identify a group of putative antimalarial targets of ART. We then conducted a series of validation experiments on five prospective protein targets, demonstrating that ART may function against malaria parasites by interfering with redox homeostasis, lipid metabolism, and protein synthesis processes. Taken together, this study provides fresh perspectives on the antimalarial mechanisms of ART and identifies several crucial proteins involved in parasite survival that can be targeted to combat malaria.

Keywords： Artemisinin     Antimalaria     Target identification     MS-CETSA     Transcriptomics    

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Title Author Date Type Operation

A Bayesian modeling approach to bi-directional pedestrian flows in carnival events

WONG, William H. K. LAM

Journal Article

Novel quantum-inspired firefly algorithm for optimal power quality monitor placement

Ling Ai WONG,Hussain SHAREEF,Azah MOHAMED,Ahmad Asrul IBRAHIM

Journal Article

MicroRNA-142-3p and microRNA-142-5p are downregulated in hepatocellular carcinoma and exhibit synergistic effects on cell motility

Felice Ho-Ching Tsang,Sandy Leung-Kuen Au,Lai Wei,Dorothy Ngo-Yin Fan,Joyce Man-Fong Lee,Carmen Chak-Lui Wong,Irene Oi-Lin Ng,Chun-Ming Wong

Journal Article

Ingestible wireless capsules for enhanced diagnostic inspection of gastrointestinal tract

Mahdi RASOULI, Andy Prima KENCANA, Van An HUYNH, Eng Kiat TING, Joshua Chong Yue LAI, Kai Juan WONG,

Journal Article

Towards a respondent-preferred ki-anonymity model

Kok-Seng WONG,Myung Ho KIM

Journal Article

SHM-based F-AHP bridge rating system with application to Tsing Ma Bridge

Qi LI, You-lin XU, Yue ZHENG, An-xin GUO, Kai-yuen WONG, Yong XIA

Journal Article

Capsule endoscopy—A mechatronics perspective

Lin LIN, Mahdi RASOULI, Andy Prima KENCANA, Su Lim TAN, Kai Juan WONG, Khek Yu HO, Soo Jay PHEE

Journal Article

Erosion-corrosion failure of REAC pipes under multiphase flow

Ping TANG, Jian YANG, Jinyang ZHENG, Shizheng HE, Jianjun YE, Guofu OU, Ieong WONG, Yanbao MA,

Journal Article

Microbial responses to combined oxidation and catalysis treatment of 1,4-dioxane and co-contaminants in groundwater and soil

Wong, Shaily Mahendra

Journal Article

A dual-polarized Fabry–Pérot antenna with high gain and wide bandwidth for millimeter-wave applications

Qingyi Guo, Hang Wong,guo_qingyi@163.com,hang.wong@cityu.edu.hk

Journal Article

Studies on Externalization of Application of Tongue Inspection of TCM

Wong Weiliang,Huang Shijing

Journal Article

The impact of hypoxia in hepatocellular carcinoma metastasis

Carmen Chak-Lui Wong, Alan Ka-Lun Kai, Irene Oi-Lin Ng

Journal Article

Two-step gate-recess process combining selective wet-etching and digital wet-etching for InAlAs/InGaAs InP-based HEMTs

Ying-hui ZHONG, Shu-xiang SUN, Wen-bin WONG, Hai-li WANG, Xiao-ming LIU, Zhi-yong DUAN, Peng DING, Zhi

Journal Article

United Algorithm for Dynamic Subcarrier, Bit and Power Allocation in OFDM System

Gao Huanqin,Feng Guangzeng,Zhuqi

Journal Article

Profiling the Antimalarial Mechanism of Artemisinin by Identifying Crucial Target Proteins

Peng Gao, Jianyou Wang, Jiayun Chen, Liwei Gu, Chen Wang, Liting Xu, Yin Kwan Wong, Huimin Zhang, Chengchao

Journal Article