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Full-Text Articles in Engineering

Data Extraction On Mtk-Based Android Mobile Phone Forensics, Joe Kong Jan 2015

Data Extraction On Mtk-Based Android Mobile Phone Forensics, Joe Kong

Journal of Digital Forensics, Security and Law

In conducting criminal investigations it is quite common that forensic examiners need to recover evidentiary data from smartphones used by offenders. However, examiners encountered difficulties in acquiring complete memory dump from MTK Android phones, a popular brand of smartphones, due to a lack of technical knowledge on the phone architecture and that system manuals are not always available. This research will perform tests to capture data from MTK Android phone by applying selected forensic tools and compare their effectiveness by analyzing the extracted results. It is anticipated that a generic extraction tool, once identified, can be used on different brands …

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Exploring The Use Of Plc Debugging Tools For Digital Forensic Investigations On Scada Systems, Tina Wu, Jason R.C. Nurse Jan 2015

Exploring The Use Of Plc Debugging Tools For Digital Forensic Investigations On Scada Systems, Tina Wu, Jason R.C. Nurse

Journal of Digital Forensics, Security and Law

The Stuxnet malware attack has provided strong evidence for the development of a forensic capability to aid in thorough post-incident investigations. Current live forensic tools are typically used to acquire and examine memory from computers running either Windows or Unix. This makes them incompatible with embedded devices found on SCADA systems that have their own bespoke operating system. Currently, only a limited number of forensics tools have been developed for SCADA systems, with no development of tools to acquire the program code from PLCs. In this paper, we explore this problem with two main hypotheses in mind. Our first hypothesis …

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Forensic Acquisition Of Imvu: A Case Study, Robert Van Voorst, M-Tahar Kechadi, Nhien-An Le-Khac Jan 2015

Forensic Acquisition Of Imvu: A Case Study, Robert Van Voorst, M-Tahar Kechadi, Nhien-An Le-Khac

Journal of Digital Forensics, Security and Law

There are many applications available for personal computers and mobile devices that facilitate users in meeting potential partners. There is, however, a risk associated with the level of anonymity on using instant message applications, because there exists the potential for predators to attract and lure vulnerable users. Today Instant Messaging within a Virtual Universe (IMVU) combines custom avatars, chat or instant message (IM), community, content creation, commerce, and anonymity. IMVU is also being exploited by criminals to commit a wide variety of offenses. However, there are very few researches on digital forensic acquisition of IMVU applications. In this paper, we …

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Tracking And Taxonomy Of Cyberlocker Link Sharers Based On Behavior Analysis, Xiao-Xi Fan, Kam-Pui Chow Jan 2015

Tracking And Taxonomy Of Cyberlocker Link Sharers Based On Behavior Analysis, Xiao-Xi Fan, Kam-Pui Chow

Journal of Digital Forensics, Security and Law

The growing popularity of cyberlocker service has led to significant impact on the Internet that it is considered as one of the biggest contributors to the global Internet traffic estimated to be illegally traded content. Due to the anonymity property of cyberlocker, it is difficult for investigators to track user identity directly on cyberlocker site. In order to find the potential relationships between cyberlocker users, we propose a framework to collect cyberlocker related data from public forums where cyberlocker users usually distribute cyberlocker links for others to download and identity information can be gathered easily. Different kinds of sharing behaviors …

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A Survey Of Botnet Detection Techniques By Command And Control Infrastructure, Thomas S. Hyslip, Jason M. Pittman Jan 2015

A Survey Of Botnet Detection Techniques By Command And Control Infrastructure, Thomas S. Hyslip, Jason M. Pittman

Journal of Digital Forensics, Security and Law

Botnets have evolved to become one of the most serious threats to the Internet and there is substantial research on both botnets and botnet detection techniques. This survey reviewed the history of botnets and botnet detection techniques. The survey showed traditional botnet detection techniques rely on passive techniques, primarily honeypots, and that honeypots are not effective at detecting peer-to-peer and other decentralized botnets. Furthermore, the detection techniques aimed at decentralized and peer-to-peer botnets focus on detecting communications between the infected bots. Recent research has shown hierarchical clustering of flow data and machine learning are effective techniques for detecting botnet peer-to-peer …

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Is “Green Dot” Always The Optimum Engines-Out Glide Speed On The Airbus A320 Aircraft?, Kivanc A. Avrenli, Barry J. Dempsey Jan 2015

Is “Green Dot” Always The Optimum Engines-Out Glide Speed On The Airbus A320 Aircraft?, Kivanc A. Avrenli, Barry J. Dempsey

Journal of Aviation/Aerospace Education & Research

The dual-engine failure checklist of the Airbus A320 states that the optimum airspeed at which the aircraft can be flown is the “green dot” speed when an engine restart is considered impossible. This is because the “green dot” speed maximizes the power-off glide range in wings-level flight. However, it is not known whether the “green dot” speed would still be the optimum airspeed if the power-off landing maneuver primarily consists of sharp turns. The objective of this study is to find out the optimum power-off glide speed for the A320 if the emergency landing maneuver primarily requires sharp turns rather …

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Properties Of Boards Made From Rice Husk And Portland Cement As Binders And Reinforced With Sisal Fibres, Alex Mrema Dec 2014

Properties Of Boards Made From Rice Husk And Portland Cement As Binders And Reinforced With Sisal Fibres, Alex Mrema

Tanzania Journal of Engineering and Technology (TJET)

A research study demonstrated that rice husks can be used to manufacture boards which can be used in low cost housing if bound by Portland limestone cement (CEM II/A-L/ 32.5R) and reinforced with sisal fibers to cater for their brittle behavior and that such boards can provide a substitute for wood panels. Boards made of rice husks and cement in the ratios of 1/3.3, 1/ 3.6 and 1/4 and with sisal fiber reinforcement contents of 0%, 0.4%, 0.5% and 0.8% were prepared and tested for their physical and mechanical properties. The results were compared with standard requirements for boards made …

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Assessment Of Quality Stability Of Composite Flours Produced By Dar Es Salaam Smes, Leonard Rweyemamu Dec 2014

Assessment Of Quality Stability Of Composite Flours Produced By Dar Es Salaam Smes, Leonard Rweyemamu

Tanzania Journal of Engineering and Technology (TJET)

A study was conducted to assess quality stability of cereal flours processed by food processing SMEs in Dar es Salaam. This product is obtained by mixing various cereal grains and is considered as of higher nutritional values in Tanzania. The shelf-life was predicted by determining water activity (aw) and moisture content (MC) levels and plotting the water sorption isotherms (MSI). Ninety per cent of investigated samples (N=78) were found packaged in the materials of various quality conditions. It was found that the packaging materials mostly used is plastic films (63%), paper packets/bags (26%), hard papers (3%), plastic jars (1%) and …

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Loss Modeling Of A Permanent Magnet Dc Motor Drive Water Pumping System, Nelson Lujara Dec 2014

Loss Modeling Of A Permanent Magnet Dc Motor Drive Water Pumping System, Nelson Lujara

Tanzania Journal of Engineering and Technology (TJET)

The paper presents an analytical approach to the determination of losses in each of the sub-systems of the Photovoltaic (PV) Permanent Magnet DC Motor (PMDC) drive water pumping system with and without maximum power tracking. The losses of the system at varying heads are firstly, determined using parameters from the data sheets and then validated by experimental results. The results are used to establish the head and the flow rate optimal operating point of the system.

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Application Of Trip Generation Models For Urban Transport Planning In A Data Scarce Developing Country City: The Case Of Dar Es Salaam, Hannibal Bwire Dec 2014

Application Of Trip Generation Models For Urban Transport Planning In A Data Scarce Developing Country City: The Case Of Dar Es Salaam, Hannibal Bwire

Tanzania Journal of Engineering and Technology (TJET)

With the increase in travel demand and traffic management problems in many developing countries cities, travel demand forecasting models are being employed increasingly to make informed decisions about the operational improvements to the existing transportation system and the design and performance of future transportation systems. The main advantage of using travel demand forecasting models for such purposes is that they are capable of capturing the interactive effects of different components of the system under study. However, for some time now there have been concerns about the application of transport planning models in developing countries. The concerns have been mainly in …

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New Challenges For The Archiving Of Digital Writing, Heiko Zimmermann Dec 2014

New Challenges For The Archiving Of Digital Writing, Heiko Zimmermann

CLCWeb: Comparative Literature and Culture

In his article "New Challenges for the Archiving of Digital Writing" Heiko Zimmermann discusses the challenges of the preservation of digital texts. In addition to the problems already at the focus of attention of digital archivists, there are elements in digital literature which need to be taken into consideration when trying to archive them. Zimmermann analyses two works of digital literature, the collaborative writing project A Million Penguins (2006-2007) and Renée Tuner's She… (2008) and shows how the ontology of these texts is bound to elements of performance, to direct social interaction of writers and readers to the uniquely subjective …

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Towards Digital Art In Information Society, Montse Arbelo, Joseba Franco Dec 2014

Towards Digital Art In Information Society, Montse Arbelo, Joseba Franco

CLCWeb: Comparative Literature and Culture

In their article "Towards Digital Art in Information Society" Montse Arbelo and Joseba Franco propose the development of the platform of a Network of Experimental Centers be formed by small groups of people who are qualified and who seek optimal operational effectiveness and who dedicate their resources to the production of digital content and we offer artechmedia <http://www.artechmedia.org> as a base point of departure. Such an international network in a collaborative structure based on national networks would make possible to coordinate existing resources to develop social networks, generate and promote content, engage in forums of discussion and creativity workshops, and …

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Platinum Hollow Nanospheres With Different Sizes: Controllable Synthesis And Electrocatalytic Oxidation Toward Methanol, Xuan Lin, Mei-Qin Cheng, Zhong-Jin Shang, Ting Xiong, Xian-Tu Zhang, Wei Tian, Jian-Yun Lin, Qi-Ling Zhong, Bin Ren Dec 2014

Platinum Hollow Nanospheres With Different Sizes: Controllable Synthesis And Electrocatalytic Oxidation Toward Methanol, Xuan Lin, Mei-Qin Cheng, Zhong-Jin Shang, Ting Xiong, Xian-Tu Zhang, Wei Tian, Jian-Yun Lin, Qi-Ling Zhong, Bin Ren

Journal of Electrochemistry

The selenium (Se) templates and hollow platinum (Pthollow) nanospheres with different sizes were controllably synthesized by adjusting the concentration of sodium dodecyl sulphonate (SDSN) (CSDSN, μmol·L-1) which was used as a surfactant. Accordingly, the Pthollow nanospheres modified glassy carbon (GC) electrode (Pthollow/GC) was prepared. The morphology and composition of Pthollow nanospheres were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDX), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and X-ray diffraction (XRD) techniques. The electrocatalytic activities of Pthollow/GC and electrodeposited Pt nanoparticles modified glassy carbon electrode (Ptnano/GC) toward methanol oxidation …

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Comparison In Factors Affecting Electrochemical Properties Of Thermal-Reduced Graphene Oxide For Supercapacitors, Peng Xiao, Da-Hui Wang, Jun-Wei Lang Dec 2014

Comparison In Factors Affecting Electrochemical Properties Of Thermal-Reduced Graphene Oxide For Supercapacitors, Peng Xiao, Da-Hui Wang, Jun-Wei Lang

Journal of Electrochemistry

In this paper, thermal-reduced graphene oxide (T-RGO) materials are synthesized by modified Hummer’s method, followed by thermal reduction under argon atmosphere at different temperatures. Electrochemical investigations show that, for T-RGO electrodes, good electrical conductivity is necessary and the surface functional groups play more significant role than the specific surface area in determining the electrochemical capacitance. The T-RGO obtained at 900 °C (T-RGO900) with a relatively high Brunauer-Emmett-Teller (BET) surface area (314 m2·g-1) and a high electrical conductivity (2421 S·m-1) shows a low specific capacitance of 56 F·g-1. In comparison, the T-RGO obtained …

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Nafion/Thionine/Platinum Nanowires-Modified Electrode For Electrocatalyzing Glucose, Yu-Ping Lin, You-Xiu Lin, Qian Zhou, Dian-Ping Tang Dec 2014

Nafion/Thionine/Platinum Nanowires-Modified Electrode For Electrocatalyzing Glucose, Yu-Ping Lin, You-Xiu Lin, Qian Zhou, Dian-Ping Tang

Journal of Electrochemistry

A new amperometric biosensor based on Nafion, thionine and latinum nanowires was developed for sensitive detection of glucose. Initially, positively charged thionine molecules were immobilized onto the surface of Nafion-modified glassy carbon electrode through the interaction between -SO3- and -NH3+, and glucose oxidase was then assembled on the modified electrode by using platinum nanowires as the cross-linkage. The preparation process was characterized by using cyclic voltammetry. Two enzymatic biosensors modified with and without platinum nanowires were used for the detection of glucose, and the improved analytical properties were obtained with platinum nanowires. Experimental results indicated …

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Synthesis Of Namnpo4 By Spraying Drying-High Temperature Sintering And Its Electrochemical Performance, Xiao-Chen Lin, Xiao-Biao Wu, Xu Hou, Yong Yang Dec 2014

Synthesis Of Namnpo4 By Spraying Drying-High Temperature Sintering And Its Electrochemical Performance, Xiao-Chen Lin, Xiao-Biao Wu, Xu Hou, Yong Yang

Journal of Electrochemistry

As a cathode material for sodium ion batteries, NaMnPO4/C nanocomposite is successfully synthesized by the combination of spraying drying and high temperature sintering methods. The crystal structure of the as-synthesized phosphate material is confirmed as the natrophilite NaMnPO4, which possesses orthorhombic symmetry and Pmnb space group. It is shown that the precursors are hollow spherical particles and the obtained product consists of micro-scaled secondary particles, which are composed of NaMnPO4 nanocrystallites (tens of nanometres) and amorphous carbon networks. The ionic and electronic conductivities of NaMnPO4 are both effectively enhanced with the help of this …

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One-Step Synthesis Of Pani/Nihcf Hybrid Film Using Unipolar Pulse Electrodeposition And Its Electrocatalytic Reduction Performance For H2O2 Detection, Sen-Liang Liao, Xiu-Min Li, Xiao-Gang Hao, Yan-Hong Wang, Chun-Feng Xue, Yong-Hong Wang Dec 2014

One-Step Synthesis Of Pani/Nihcf Hybrid Film Using Unipolar Pulse Electrodeposition And Its Electrocatalytic Reduction Performance For H2O2 Detection, Sen-Liang Liao, Xiu-Min Li, Xiao-Gang Hao, Yan-Hong Wang, Chun-Feng Xue, Yong-Hong Wang

Journal of Electrochemistry

Organic–inorganic hybrid films composed of polyaniline/nickel hexacyanoferrate (PANI/NiHCF) were fabricated on platinum substrates using unipolar pulse one-step electrodeposition. The deposition mechanism of hybrid film was proposed: Due to high potential of unipolar pulse electrodeposition, which avoided the reduction of Fe(CN)63-, the films with high electrocatalytic property and “insoluble” form of NiHCF were achieved. The morphology and composition of PANI/NiHCF hybrid film were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FT-IR). The effect of pulse potential on the electrochemical performance of hybrid film was investigated in detail. Results showed that …

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Electrochemical Applications Of Single-Walled Carbon Nanohorns, Su-Ping Li, Huai-Min Guan, Shu-Yun Zhu, Muhammad Rehan Hassan Shah Gilani, Saima Hanif, Guo-Bao Xu, Yue-Jin Tong Dec 2014

Electrochemical Applications Of Single-Walled Carbon Nanohorns, Su-Ping Li, Huai-Min Guan, Shu-Yun Zhu, Muhammad Rehan Hassan Shah Gilani, Saima Hanif, Guo-Bao Xu, Yue-Jin Tong

Journal of Electrochemistry

Single-wall carbon nanohorns (SWCNHs) have unique properties, such as a large specific surface area, good electrical conductivity and biocompatibility. It has been widely utilized in many fields. In the present review, the progress in electrochemistry study of SWCNHs has been summarized and the future research trends have been proposed.

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Direct Electrochemistry And Glucose Biosensing Of Glucose Oxidase-Gold Nanoparticles Composite Synthesized By Enzyme Method, Fang He, Xiao-Li Qin, Ying-Chun Fu, Chao Chen, Qing-Ji Xie, Shou-Zhuo Yao Dec 2014

Direct Electrochemistry And Glucose Biosensing Of Glucose Oxidase-Gold Nanoparticles Composite Synthesized By Enzyme Method, Fang He, Xiao-Li Qin, Ying-Chun Fu, Chao Chen, Qing-Ji Xie, Shou-Zhuo Yao

Journal of Electrochemistry

Glucose oxidase (GOx)-gold nanoparticles (AuNPs) composite was synthesized by the one-pot enzyme reaction in the mixture solution of NaAuCl4, GOx and glucose, and a Nafion/GOx-AuNPs/glassy carbon electrode was fabricated by the cast-coating method to examine the direct electrochemistry of GOx and the biosensing performance on this electrode. Such a GOx-AuNPs composite showed good direct-electrochemistry activity and bioactivity of GOx, probably because the enzyme-mediated AuNPs are close to the redox active centers of GOx. This enzyme electrode exhibited a linear amperometric response to glucose concentration (0.54 mmol·L-1) at -0.4 V (vs. SCE), and a detection limit of …

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Preparation Of Surface Molecularly Imprinted Magnetic Nanoparticles For Hemoglobin Sensing, Chun-Fang Huang, Gui-Hong Yao, Jian-Ding Qiu Dec 2014

Preparation Of Surface Molecularly Imprinted Magnetic Nanoparticles For Hemoglobin Sensing, Chun-Fang Huang, Gui-Hong Yao, Jian-Ding Qiu

Journal of Electrochemistry

Surface molecularly imprinted magnetic nanoparticles (NPs) were prepared by employing dopamine (DA) as a functional monomer, hemoglobin (Hb) as a template, H2PtCl6 as an oxidant triggered DA polymerization on the surface of the Fe3O4 NPs. The Hb and the formed platinum nanoparticles (PtNPs) were embedded into the polydopamine (PDA). After removal of the Hb, the surface molecularly imprinted magnetic nanoparticles (imprinted Fe3O4/PDA-PtNPs) were formed, and then simply immobilized on the magnetic glassy carbon electrode (imprinted Fe3O4/PDA-PtNPs/MGCE) for Hb sensing. The imprinted Fe3O4/PDA-PtNPs …

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Resolve Mono-Electronic Process In The Voltammetric Behaviors Of Multi-Redox Bis-Coenzyme Q0, Hao Zhou, Yi-Tao Long Dec 2014

Resolve Mono-Electronic Process In The Voltammetric Behaviors Of Multi-Redox Bis-Coenzyme Q0, Hao Zhou, Yi-Tao Long

Journal of Electrochemistry

A widely held concept in electrochemistry is that truly elementary electron-transfer reactions always involve the exchange of one electron, therefore, an overall process involving a change of n electrons must involve n distinct electron-transfer steps. It is highly desirable to resolve multiple-step electron transfer reactions into each electron transfer step. The electrochemical behaviors of coenzyme Q0 and methylene-bridged Bis-coenzyme Q0 were investigated by cyclic voltammetry and square wave voltammetry in nonaqueous dichloromethane containing 0.15 mol·L-1 Bu4NClO4 as the supporting electrolyte. The redox reaction of coenzyme Q0 is well described as two chemically reversible …

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Density Functional Theory Study On The Structures Of Solvent-Ion In The Electrolyte Of Lithium Ion Battery, Li-Dan Xing, Ru Yang, Xian-Wen Tang, Wen-Na Huang, Qi-Feng Liu, Qi-Peng Yu, Wei-Shan Li Dec 2014

Density Functional Theory Study On The Structures Of Solvent-Ion In The Electrolyte Of Lithium Ion Battery, Li-Dan Xing, Ru Yang, Xian-Wen Tang, Wen-Na Huang, Qi-Feng Liu, Qi-Peng Yu, Wei-Shan Li

Journal of Electrochemistry

In this work, the possible structures of solvent-ion complex, resulting from the electrostatic interaction in the propylene carbonate (PC) base electrolyte of lithium ion battery, have been investigated using the density functional theory. The calculated results show that the structure of solvent-ion complex depends on the solvent number. In the PC base electrolyte, maximum number of PC solvents that coexist in the Li+-solvent sheath is four. Additionally, the salt anion exists in a complex with the positively charged alkyl group of PC rather than in a free state. The calculated results give a good explanation to the reported …

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Preface, Wen-Hsiang Hsieh Dec 2014

Preface, Wen-Hsiang Hsieh

Journal of Marine Science and Technology–Taiwan

No abstract provided.

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Contour Data Acquisition System For Electric Vehicle Distance Estimation System, Kuew Wai Chew, Chee Ken Leong Dec 2014

Contour Data Acquisition System For Electric Vehicle Distance Estimation System, Kuew Wai Chew, Chee Ken Leong

Journal of Marine Science and Technology–Taiwan

The conventional distance estimation system only uses a constant speed and a constant level of road elevation to estimate the driving range of a vehicle. This technique leads to low prediction accuracy. In this project, a new estimation technique namely the Contour Positioning System (CPS) for an electric vehicle is proposed. The CPS provides a more reliable estimation of the electric vehicle battery energy usage by taking into consideration additional factors such as road elevation and regenerative braking energy. In order to perform the CPS calculation, first and foremost, the elevation profile of the selected destination must be determined. In …

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Periodic Damage Evaluation Of Aging Offshore Jackets Based On Continuous Dynamic Tests, Fu-Shun Liu, Hong-Chao Lu, Wei-Ying Wang, Dong-Ping Yang Dec 2014

Periodic Damage Evaluation Of Aging Offshore Jackets Based On Continuous Dynamic Tests, Fu-Shun Liu, Hong-Chao Lu, Wei-Ying Wang, Dong-Ping Yang

Journal of Marine Science and Technology–Taiwan

This study proposes a new method for evaluating the damage of aging offshore platforms, based on dynamic tests. The proposed method involves a new damage indicator for reducing the effects of occurred damages accumulated before the first measurement. One theoretical improvement is that the requirement of using the stiffness matrix of the finite element model to replace that of the measured model can be ignored in calculating the modal strain energy of the measured model. The other development is that the proposed approach can be used for providing reasonable evaluations of damages that occurred between two adjacent dynamic tests. This …

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Development Of An Intelligent Energy Saving Heat Pump For Water Heater With Fuzzy Logic Controller, Cong-Hui Huang Dec 2014

Development Of An Intelligent Energy Saving Heat Pump For Water Heater With Fuzzy Logic Controller, Cong-Hui Huang

Journal of Marine Science and Technology–Taiwan

There is a growing awareness of the importance of using clean and environmentally friendly sources of energy. This paper presents the development of an intelligent energy saving heat pump for a water heater with a fuzzy logic controller that analyzes the heating efficiency of the heat pump heater. The fuzzy logic controller is employed for developing a heating algorithm to raise the efficiency of the heat pump heater and suppress unnecessary heating at high temperatures. Experimental results show that our heat pump heater produces an energy saving of 60% of total energy input, compared to the 23% for a gas …

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A Study On Optimization Of Ship Hull Form Based On Neuro-Response Surface Method (Nrsm), Soon-Sub Lee, Jae-Chul Lee, Sung-Chul Shin, Soo-Young Kim, Hyun-Sik Yoon Dec 2014

A Study On Optimization Of Ship Hull Form Based On Neuro-Response Surface Method (Nrsm), Soon-Sub Lee, Jae-Chul Lee, Sung-Chul Shin, Soo-Young Kim, Hyun-Sik Yoon

Journal of Marine Science and Technology–Taiwan

Building large and eco-friendly ships has become a clear trend in the ship building industry. Research to minimize ship resistance has actively been investigated for energy savings and environmental protection. However, optimization of the full geometry, while taking into account the hydrodynamic performance is difficult because extensive time is needed to calculate the performance factors, such as the resistance and propulsion. Hence we suggest an optimal design framework based on the neuro-response surface method (NRSM) for optimal shape design in consideration of hydrodynamic performance. The optimization algorithm of the constructed framework consists of the back-propagation neural network (BPN) and the …

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Research On Sealing Performance Of Hydrostatic Pressure Mechanical Seal, Wei-Bing Zhu, He-Shun Wang, Sheng-Ren Zhou Dec 2014

Research On Sealing Performance Of Hydrostatic Pressure Mechanical Seal, Wei-Bing Zhu, He-Shun Wang, Sheng-Ren Zhou

Journal of Marine Science and Technology–Taiwan

The hydrostatic pressure mechanical seal has many advantages, and it can be used in rotating machines with lower speed. Based on the externally pressurized stable gas lubrication theory, the control equation of end face flow field for hydrostatic pressure mechanical seal with orifice compensation was established. The functional extremum algorithm and the finite element method were used to solve this equation. The effects of gas film thickness, air supply pressure, throttle orifice number and diameter, on face opening force and gas film stiffness were discussed in detail. The results show that the opening force decreases with the widening of face …

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Performance Evaluation Of Three Types Of Passive Micromixer With Convergent-Divergent Sinusoidal Walls, Arshad Afzal, Kwang-Yong Kim Dec 2014

Performance Evaluation Of Three Types Of Passive Micromixer With Convergent-Divergent Sinusoidal Walls, Arshad Afzal, Kwang-Yong Kim

Journal of Marine Science and Technology–Taiwan

A passive split-and-recombination micromixer with convergent-divergent channel walls of sinusoidal variation has been investigated using numerical simulations. With water and ethanol as working fluids, the analysis was performed using Navier-Stokes equations with convection-diffusion model in a Reynolds number range, 10  Re  70. Performances of three configurations with different split-and-recombination arrangements were evaluated in terms of mixing index and pressure drop. A parametric study was also conducted with two geometrical parameters, i.e., the ratios of throat-width to diameter of circular wall and diameter of circular wall to amplitude. The results showed a significant dependence of the mixing performance on …

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Design Of A New Electromagnetic Valve With A Hybrid Pm/Em Actuator In Si Engines, Ly Vinh Dat, Yaojung Shiao Dec 2014

Design Of A New Electromagnetic Valve With A Hybrid Pm/Em Actuator In Si Engines, Ly Vinh Dat, Yaojung Shiao

Journal of Marine Science and Technology–Taiwan

Numerous devices have been developed for controlling valve timings in SI engines. Among them, the electromagnetic valve train (EMV) actuator can fully control valve timings to improve fuel consumption and emission. In addition, an EMV with a permanent-magnet and electromagnetic-coil (PM/EM) hybrid actuator has several advantages of control, energy consumption, and time response compared over conventional EMVs. This paper proposes a novel EMV with a PM/EM hybrid actuator that differs considerably from existing EMVs. Finite element analysis was used for analyzing the EMV design. The optimization was based on criteria that ensured the EMV to satisfy holding forces in closed …

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