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Seamless handover between unicast and multicast multimedia streams

Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第10期15卷 929-942页

作者： Mau-Luen THAM Chee-Onn CHOW Yi-han XU khong neng choong Cheng Suan LEE Department of Electrical Engineering Faculty of Engineering University of Malaya College of Information Science and Technology Nanjing Forestry University Wireless Communication Cluster MIMOS BerhadKuala Lumpur 57000 Malaysia Power-All Networks Jalan AmpangKuala Lumpur 50450 Malaysia

With the deployment of heterogeneous networks, mobile users are expecting ubiquitous connectivity when using applications. For bandwidth-intensive applications such as Internet Protocol Television(IPTV), multimedia contents are typically transmitted using a multicast delivery method due to its bandwidth efficiency. However, not all networks support multicasting. Multicasting alone could lead to service disruption when the users move from a multicast-capable network to a non-multicast network. In this paper, we propose a handover scheme called application layer seamless switching(ALSS) to provide smooth real-time multimedia delivery across unicast and multicast networks. ALSS adopts a soft handover to achieve seamless playback during the handover period. A real-time streaming testbed is implemented to investigate the overall handover performance, especially the overlapping period where both network interfaces are receiving audio and video packets. Both the quality of service(QoS) and objective-mapped quality of experience(QoE) metrics are measured. Experimental results show that the overlapping period takes a minimum of 56 and 4 ms for multicast-to-unicast(M2U) and unicast-to-multicast(U2M) handover, respectively. The measured peak signal-to-noise ratio(PSNR) confirms that the frame-by-frame quality of the streamed video during the handover is at least 33 dB, which is categorized as good based on ITU-T recommendations. The estimated mean opinion score(MOS) in terms of video playback smoothness is also at a satisfactory level.

关键词： Experimental approach Multimedia session continuity Seamless handover Unicast/multicast switching Multimedia streaming

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Media Independent Handover Scheme with QoS Provision across UMTS and WiMAX Networks

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China Communications 2012年第7期9卷 55-70页

作者： Xu Yihan Chee-Onn Chow khong-neng choong Hiroshi Ishii Department of Electrical Engineering University of Malaya Lembah Pantai Kuala Lumpur 50603 Malaysia Wireless Communication Cluster MIMOS Berhad Technology Park Malaysia Kuala Lumpur 57000 Malaysia Professional Graduate School of Embedded Technology Tokai University Minato-ku Tokyo 108-8619 Japan

The rapid growth and innovation of the various mobile communication technologies have caused a change in the paradigm of internet access. Wireless technologies such as WiM AX, WiFi and UM T S/LTE networks have shown great p otential in dominating the wireless access markets. The ex istence of various access technologies requires a means for seamless internetworking to provide an ywhere, anytime services without interruption in the ongoing session, especially in multimedia

关键词： IEEE 802.21 vertical handover Quality of Services (QoS) provision heterogeneous network

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Metformin-associated lactic acidosis:A mini review of pathophysiology,diagnosis and management in critically ill patients

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World Journal of Diabetes 2024年第6期15卷 1178-1186页

作者： Kay choong See Department of Medicine National University HospitalSingapore 119228Singapore

Metformin is a common diabetes drug that may reduce lactate clearance by inhibiting mitochondrial oxidative phosphorylation,leading to metforminassociated lactic acidosis(MALA).As diabetes mellitus is a common chronic metabolic condition found in critically ill patients,pre-existing metformin use can often be found in critically ill patients admitted to the intensive care unit or the high dependency *** aim of this narrative mini review is therefore to update clinicians about MALA,and to provide a practical approach to its diagnosis and *** in critically ill patients may be suspected in a patient who has received metformin and who has a high anion gap metabolic acidosis,and confirmed when lactate exceeds 5 mmol/*** factors include those that reduce renal elimination of metformin(renal impairment from any cause,histamine-2 receptor antagonists,ribociclib)and excessive alcohol consumption(as ethanol oxidation consumes nicotinamide adenine dinucleotides that are also required for lactate metabolism).Treatment of MALA involves immediate cessation of metformin,supportive management,treating other concurrent causes of lactic acidosis like sepsis,and treating any coexisting diabetic *** MALA requires extracorporeal removal of metformin with either intermittent hemodialysis or continuous kidney replacement *** optimal time to restart metformin has not been *** is nonetheless reasonable to first ensure that lactic acidosis has resolved,and then recheck the kidney function post-recovery from critical illness,ensuring that the estimated glomerular filtration rate is 30 mL/min/1.73 m^(2) or better before restarting metformin.

关键词： Acid-base equilibrium Biguanides Oxidative phosphorylation Pyruvic acid Renal replacement therapy

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Prevention of complications in endourological management of stones:What are the basic measures needed before,during,and after interventions?

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Asian Journal of Urology 2024年第2期11卷 180-190页

作者： Eric Edison Giorgio Mazzon Vimoshan Arumuham Simon choong Department of Urology University College Hospital LondonLondonUK Department of Urology San Bassiano HospitalVicenzaItaly

Objective:This narrative review aims to describe measures to minimise the risk of complications during percutaneous nephrolithotomy(PCNL),ureteroscopy,and retrograde intrarenal ***:A literature search was conducted from the PubMed/PMC database for papers published within the last 10 years(January 2012 to December 2022).Search terms included“ureteroscopy”,“retrograde intrarenal surgery”,“PCNL”,“percutaneous nephrolithotomy”,“complications”,“sepsis”,“infection”,“bleed”,“haemorrhage”,and“hemorrhage”.Key papers were identified and included meta-analyses,systematic reviews,guidelines,and primary *** references of these papers were searched to identify any further relevant papers not included ***:The evidence is assimilated with the opinions of the authors to provide *** practice pathways for patient care in the pre-operative,intra-operative,and post-operative periods are described,including the identification and management of residual *** complications(sepsis and stent issues)that are relevant for any endourological procedure are then be ***-specific considerations are then *** measures for PCNL include optimising access to minimise the chance of bleeding or visceral *** role of endoscopic combined intrarenal surgery in this regard is *** measures for ureteroscopy and retrograde intrarenal surgery include planning and technique to minimise the risk of ureteric *** role of anaesthetic assessment is *** importance of specific comorbidities on each step of the pathway is highlighted as ***:This review demonstrates that the principles of meticulous planning,interdisciplinary teamworking,and good operative technique can minimise the risk of complications in endourology.

关键词： Endourology Ureteroscopy Retrogradeintrarenal surgery Percutaneous nephrolithotomy Complications Sepsis Stent

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A Review of Rechargeable Zinc-Air Batteries:Recent Progress and Future Perspectives

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Nano-Micro Letters 2024年第7期16卷 358-401页

作者： Ghazanfar Nazir Adeela Rehman Jong-Hoon Lee choong-Hee Kim Jagadis Gautam Kwang Heo Sajjad Hussain Muhammad Ikram Abeer AAlObaid Seul-Yi Lee Soo-Jin Park Department of Nanotechnology and Advanced Materials Engineering Hybrid Materials Research Center(HMC)Sejong UniversitySeoul 05006Republic of Korea Department of Chemical and Biomolecular Engineering Yonsei University50 Yonsei-RoSeodaemun-GuSeoul 03722Republic of Korea Department of Chemistry Inha UniversityIncheon 22212Republic of Korea Solar Cell Applications Research Lab Department of PhysicsGovernment College University LahoreLahore 54000 PunjabPakistan Department of Chemistry College of ScienceKing Saud UniversityP.O.Box 2455Riyadh 11451Saudi Arabia

Zinc-air batteries(ZABs)are gaining attention as an ideal option for various applications requiring high-capacity batteries,such as portable electronics,electric vehicles,and renewable energy *** offer advantages such as low environmental impact,enhanced safety compared to Li-ion batteries,and cost-effectiveness due to the abundance of ***,early research faced challenges due to parasitic reactions at the zinc anode and slow oxygen redox *** advancements in restructuring the anode,utilizing alternative electrolytes,and developing bifunctional oxygen catalysts have significantly improved *** have achieved battery reversibility over thousands of cycles,introduced new electrolytes,and achieved energy efficiency records surpassing 70%.Despite these achievements,there are challenges related to lower power density,shorter lifespan,and air electrode corrosion leading to performance *** review paper discusses different battery configurations,and reaction mechanisms for electrically and mechanically rechargeable ZABs,and proposes remedies to enhance overall battery *** paper also explores recent advancements,applications,and the future prospects of electrically/mechanically rechargeable ZABs.

关键词： Zinc-air batteries Energy storage Affordability Reversibility

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Measurement of very low-molecular weight metabolites by traveling wave ion mobility and its use in human urine samples

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Journal of Pharmaceutical Analysis 2024年第5期14卷 733-743页

作者： Alongkorn Kurilung Suphitcha Limjiasahapong Khwanta Kaewnarin Pattipong Wisanpitayakorn Narumol Jariyasopit Kwanjeera Wanichthanarak Sitanan Sartyoungkul Stephen choong Chee Wong Nuankanya Sathirapongsasuti Chagriya Kitiyakara Yongyut Sirivatanauksorn Sakda Khoomrung Siriraj Center of Research Excellent in Metabolomics and Systems Biology(SiCORE-MSB) Faculty of Medicine Siriraj HospitalMahidol UniversityBangkok10700Thailand Siriraj Metabolomics and Phenomics Center Faculty of Medicine Siriraj HospitalMahidol UniversityBangkok10700Thailand Department of Biomedical Informatics University of Arkansas for Medical SciencesLittle RockAR72205USA SingHealth Duke-NUS Institute of Biodiversity Medicine National Cancer Centre Singapore168583Singapore Waters Pacific Pte. Ltd.Singapore117528Singapore Program in Translational Medicine Faculty of Medicine Ramathibodi HospitalMahidol UniversityBangkok10400Thailand Chakri Naruebodindra Medical Institute Faculty of Medicine Ramathibodi HospitalMahidol UniversitySamut Prakan10540Thailand Department of Medicine Ramathibodi HospitalMahidol UniversityBangkok10400Thailand Department of Biochemistry Faculty of Medicine Siriraj HospitalMahidol UniversityBangkok10700Thailand Center of Excellence for Innovation in Chemistry(PERCH-CIC) Faculty of ScienceMahidol UniversityBangkok10400Thailand

The collision cross-sections(CCS)measurement using ion mobility spectrometry(IMS)in combination with mass spectrometry(MS)offers a great opportunity to increase confidence in metabolite ***,owing to the lack of sensitivity and resolution,IMS has an analytical challenge in studying the CCS values of very low-molecular-weight metabolites(VLMs250 Da).Here,we describe an analytical method using ultrahigh-performance liquid chromatography(UPLC)coupled to a traveling wave ion mobility-quadrupole-time-of-flight mass spectrometer optimized for the measurement of VLMs in human urine *** experimental CCS values,along with mass spectral properties,were reported for the 174 *** experimental data included the mass-to-charge ratio(m/z),retention time(RT),tandem MS(MS/MS)spectra,and CCS *** the studied metabolites,263 traveling wave ion mobility spectrometry(TWIMS)-derived CCS values(TWCCSN2)were reported for the first time,and more than 70%of these were CCS values of *** TWCCSN2 values were highly repeatable,with inter-day variations of<1%relative standard deviation(RSD).The developed method revealed excellent TWCCSN2 accuracy with a CCS difference(DCCS)within±2%of the reported drift tube IMS(DTIMS)and TWIMS CCS *** complexity of the urine matrix did not affect the precision of the method,as evidenced by DCCS within±1.92%.According to the Metabolomics Standards Initiative,55 urinary metabolites were identified with a confidence level of *** these 55 metabolites,53(96%)were *** larger number of confirmed compounds found in this study was a result of the addition of TWCCSN2 values,which clearly increased metabolite identification confidence.

关键词： Very low-molecular-weight metabolites Traveling wave ion mobility Collision cross-section Human urine

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Diagnosis and management of severe pulmonary and extrapulmonary tuberculosis in critically ill patients:A mini review for clinicians

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World Journal of Critical Care Medicine 2024年第2期13卷 106-115页

作者： Dominic Ti Ming Tan Kay choong See Department of Medicine National University HospitalSingapore 119228Singapore

Among critically ill patients,severe pulmonary and extrapulmonary tuberculosis has high morbidity and ***,it is a diagnostic challenge given its nonspecific clinical symptoms and signs in early stages of the *** addition,management of severe pulmonary and extrapulmonary tuberculosis is complicated given the high risk of drug-drug interactions,drug-disease interactions,and adverse drug *** help clinicians acquire an up-to-date approach to severe tuberculosis,this paper will provide a narrative review of contemporary diagnosis and management of severe pulmonary and extrapulmonary tuberculosis in critically ill patients.

关键词： Tuberculosis Severe tuberculosis Mycobaterium tuberculosis Critical care Intensive care Diagnosis of tuberculosis Management of tuberculosis

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Potential effects of future adoption of the REDD mechanism as a preventive measure against deforestation and forest degradation in North Korea

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Journal of Mountain Science 2016年第9期13卷 1645-1651页

作者： Hong Chul PARK choong Hyeon OH Korea National Park Research Institute Korea National Park Service Department of Biological and Environmental Science Dongguk University

This study assesses potential effects of adaption to climate change in the future as a carbon related value using a baseline and credit approach, considering the implementation of the Reducing Emissions from Deforestation and forest Degradation （REDD） mechanism. Basic data were obtained for implementing the REDD mechanism in the Democratic People＇s Republic of Korea （DPRK） for scientific decision-making to prevent deforestation and forest degradation. The potential effects according to the implementation of the REDD mechanism in the DPRK based on forest status data （the latest） are as follows. If the deforestation rate is reduced to a level below 6% through a 20-year REDD mechanism beginning in 2011, 0.01-11.64 C-tons of carbon credit per ha could be issued for DPRK. Converted into C02-tons per ha, this amounts to 0.03-42.68 C02-tons, which translates to a minimum of 226,000 CO2-tons and a maximum of 289,082,000 C02-tons overall for forests in DPRK. In terms of carbon price, this measures up to 1.1o million USD- 1.4 billion USD, considering that the REDD carbon price in voluntary carbon markets in 2010 was around 5 USD.

关键词： Climate change Global warming Baseline approach Carbon Credit

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Naturalization of Landscaping Woody Plant, Magnolia obovata Potentially Invasive Species

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Journal of Mountain Science 2015年第1期12卷 30-38页

作者： KWON Oh Jung OH choong Hyeon Graduate School Department of Biological and Environmental Science Dongguk University Department of Biological and Environmental Science Dongguk University

Magnolia obovata, a tree species native to Japan, is a traditional landscaping tree that has also been introduced to various countries. M. obovata individuals have recently emerged in non-planting areas in Korea, prompting us to investigate its distribution by establishing Dosolsan in an urban forest of Daejeon City as the target site. In order to determine its naturalization, the study explored the status of population growth by examining the diameter at breast height of the individuals, and diameter diminution quotient was calculated. Cores of the trees were collected, and the age distribution was estimated by regression analysis. Reproduction possibility was analyzed by verifying the flowerblooming and fruit-bearing. Spontaneous colonization was investigated in the other potential sites which have different location and environment, *** diameter distribution showed a reverse J-shaped curve, and the diminution quotient was ≥ 1.8. The population was composed of different generations,thus confirming the growth of the population. The distributed M. obovata grew and flowered normally,and followed a normal life cycle. The same phenomenon was observed in other planting areas,residual forests in urban or rural areas, alluvial islands, and mountain forests. The continuous spread of M. obovata in new ecosystems may be attributable to its long-term distribution by birds, relatively fast growth, and maturity time. Investigations on the naturalization and spread of M. obovata in Korea, as well as in various countries, are warranted.

关键词： Magnolia obovata Diameterdistribution Diminution quotient Invasive plant Naturalized plant

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Glycemic targets in critically ill adults: A mini-review

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World Journal of Diabetes 2021年第10期12卷 1719-1730页

作者： Kay choong See Division of Respiratory and Critical Care Medicine Department of MedicineNational University HospitalSingapore 119228Singapore

Illness-induced hyperglycemia impairs neutrophil function,increases pro-inflammatory cytokines,inhibits fibrinolysis,and promotes cellular *** turn,these mechanisms lead to pneumonia and surgical site infections,prolonged mechanical ventilation,prolonged hospitalization,and increased *** optimal glucose control,blood glucose measurements need to be done accurately,frequently,and *** choosing glycemic targets,one should keep the glycemic variability<4 mmol/L and avoid targeting a lower limit of blood glucose<4.4 mmol/*** upper limit of blood glucose should be set according to casemix and the quality of glucose control.A lower glycemic target range(i.e.,blood glucose 4.5-7.8 mmol/L)would be favored for patients without diabetes mellitus,with traumatic brain injury,or who are at risk of surgical site *** avoid harm from hypoglycemia,strict adherence to glycemic control protocols and timely glucose measurements are *** contrast,a higher glycemic target range(i.e.,blood glucose 7.8-10 mmol/L)would be favored as a default choice for medical-surgical patients and patients with diabetes *** targets may be modified if technical advances for blood glucose measurement and control can be achieved.

关键词： Brain injuries Traumatic Critical care Diabetes mellitus Glycemic control Insulin infusion systems Sepsis

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