bluuebunny/crossref_metadata_2025 huggingface dataset:
Web-Base Virtual Collaboration in E-Learning System
Authors: Kim Meekyeong , Hong Chu Leui
Published: March 2013

In this paper, we are proposing a web-based virtual collaboration system for e-learning system. We propose new multimedia presentation and recordable virtual collaboration which supports synchronized multimedia presentation using Synchronous Multimedia Integration Language (SMIL). It allows synchronization of the contents of a PowerPoint presentation file and a video file so that the presentation shows slides and video on the same topic at any given time. The resulting SMIL file is used to provide multimedia presentation for image intensive discussion. Participants can use text along with associated symbols during the discussion over the presented power point slides. The symbols such as arrows or polygons have x-y coordinates within the slides to represent associated participants’ questions and answers. Those can be set or removed dynamically to represent areas of questions in slides using so called layered architecture that separates slide layer from annotation layer. Those annotations can be easily hidden for training purposes. XML files are used to record participants’ questions and answers along with the associated elements such as arrows and polygons over some particular images.
Video Query Using Temporal Signature and Similarity Matching
Authors: Lo Shi Wei , Lin Fang Pang
Published: March 2013

Abstract. Large amount of video data is stored and distributed in wide variety of application. Due to the fast video material increases, manage and query of video become more and more important. In this paper, we address a temporal signature representation and similarity model to retrieval the similar video within database by video query. Experimental results on real date are presented. The experimental results show that the statistical approach permits accurate query of video clip, in particular, the performance of the approach was found extremely satisfactory with determine all similar video in database.
Axial Compression for Direct Capture of Carbon Dioxide (CO2)
Authors: Chan Hao Xian Malcolm , Yap Eng Hwa , Ho Jee Hou
Published: March 2013

One prospective method to retard the speed of climate change is Carbon Capture and Storage (CCS). It is known that reducing emissions through CCS on point sources can only slowdown the rate of increase of atmospheric CO2 concentration and not able to mitigate the CO2 that are already in the atmosphere by previous emissions. Hence, a complimentary method would be to extract CO2 directly from air – Direct Air Capture (DAC). This paper addresses a novel concept of DAC whereby an additional phase of axial compression is introduced to adapt atmospheric air to a level suitable for capture. An axial compression model was developed so that fluid simulation studies can be performed. These information are then utilized in a feasibility study to address several key issues: the additional energy penalty when applying axial compression and whether or not, increasing the capture input by compression would displace the elevated energy consumption.
Study of Biodegradable Polyurethane Foam as Carriers for Low C/N Ratio Wastewater
Authors: Tan Chong , Ma Fang , Qiu Shan , Zeng Hong Yun , Zhou Yi
Published: March 2013

In this study, the performance of nitrification and denitrification were investigated in a sequencing batch biofilm reactor (SBBR) with biodegradable polyurethane foam. The study aimed at solving the shortage of carbon sources for denitrification treating wastewater with a low C/N ratio. Ammonium, nitrite, nitrate, pH and Dissolved oxygen (DO) were carried out to monitor the process of nitrification-denitrification in every cycle. The results showed that Total nitrogen (TN) removal efficiency of 67.5% was achieved during a monitoring period of three months. The SBBR showed good behavior in terms of total nitrogen removal as the biodegradable polymer was an effective substrate providing reducing power for denitrification. According to scanning electron microscope, the biofilm from the inside of the Polyurethane (PU) carriers comprised predominately of small rod-shaped and spherical clusters were dominant, while clusters of filamentous form and few long rod shaped were observed on the surface. The used PU carriers after being washed with distilled water were found some cavities due to corrosion by microorganisms.
Temporal Navigation in a Session in a Mobile Distance Learning System
Authors: Lee Jang Ho
Published: March 2013

Typical mobile distance learning system allows students to download and play the video of lecture, which lacks synchronous capability. Although a few synchronous mobile e-learning systems enable students to experience the video and presentation materials of a lecture in real time and real-time interaction with the lecturer, they still have the problem of not allowing students to navigate and re-experience the lecture session including video and slides with annotation. Thus, we present a mobile distance learning system that enables students to join the ongoing lecture, watch video and annotated slides, interacts with the lecturer with text in real-time as well as to store the lecture session on their mobile device and play them later. During the play of a lecture session, a student can navigate the session in terms of time and re-experience the video, slides with annotation, and text-based interaction among the lecturer and students.
Learning for Shadow Puppet’s Action Control Inverse Kinematics Method
Authors: Fan Kuo Kuang , Hsiao Peng Wei
Published: March 2013

Puppet shadow is not only one of the oldest forms of performing, but also a very characteristic traditional folk performing art. Since the action skill is a family heirloom of puppet shadow troupes, they seldom teach outsiders so this issue is rarely discussed. The spatial and regional limitation makes the observation and learning of puppet-motion and action skill rather difficult. This study uses Flash CS4 to create the features and functions of puppets via inverse kinematics (IK) method. Using the concept of inverse kinematics constructs the movement of puppets and simulates the motion of puppets. On this platform, we construct the single-user-game-based digital learning system of puppet shadow. We design situational challenge competitions and interactive games to enhance the quality and pleasure of learning.
Dodge-Romig LTPD Single Sampling Plan under Quality Investment and Inspection Error
Authors: Chen Chung Ho
Published: March 2013

In this study, the author proposes an economic design of quality investment for a Dodge-Romig single sampling inspection plan with inspection error. The optimal sampling inspection plan and quality investment level are jointly determined by minimizing the expected total cost of product under the specified consumer’s risk. Finally, the comparison of solution between the model with/without inspection error will be provided for illustration.
Identifying Constraints Regarding Power Usage Effectiveness for Data Centers Engaging in Demand Response Programs
Authors: Tang Cheng Jen , Dai Miau Ru
Published: March 2013

Demand response (DR) is an important ingredient and regarded as the killer application of the emerging smart grid. The continuously growing energy consumption of data centers makes data centers promising candidates with significant potential for DR. Participating in DR programs makes data centers have another finical resource in addition to service income. On the other hand, some government organizations also offer considerable incentives to promote energy saving actions for facilities with some certain certifications. Leadership in Energy and Environmental Design (LEED) rating system developed by U.S. Green Building Council (USGBC) is one of the most popular certification systems. LEED uses Power Usage Effectiveness (PUE) as one of the metrics for quantifying how energy efficient a data center is. The goal of PUE is to improve energy efficiency of a data center. DR programs require participants to temporarily reduce their power demand on some occasions with little concern regarding energy efficiency. To enjoy incentives from LEED certification, data center administrators need to know whether the participation of DR hampers the established PUE of their facilities or not. This paper examines the power consumption models from prior studies, and identifies the constraints introduced by PUE for data centers participating in DR programs. The examination reveals that the ratios of static power consumption to the dynamic power demand range of different types of data center equipment do affect PUE while taking demand reduction efforts. With this finding, facility managers of data centers have a clear picture of what to expect from the DR participation, and what to adjust of their data center equipment.
Long-Term Unit Commitment Solution Based on Load Pattern
Authors: Lu Tai Ken , Hsu Hao Hsuan , Chen Fung Fei , Kao Meng Fu
Published: March 2013

Power production plans are used by power companies to propose a feasible plan regarding the load requirements and system conditions of the following year, in which the arrangement of production material, such as the procurement of fuel required and delivery schedules, is clearly projected. Some of the factors involved in considering power production plans are common to those for short-term unit commitment, including system power balance, system security requirements, and unit characteristics; however, the limit on annual accumulation, which is not considered in short-term unit commitment, is not similar between the two. This study proposes an optimal mathematical model based on mixed-integer programming for long-term unit commitment to minimize the total system costs. To avoid the mixed-integer linear programming problems that increase the duration of computation because of numerous integer variables, the model proposed in this study applies the view of energy and power and integrates the similarities of load patterns and fuzzy logic to reduce the number of variables while adhering to all the constraints. The proposed algorithm can greatly improve the solution time compared with the complete UC model for the Taipower one week simulation case.
A Systematic Approach to Quality Function Deployment with Extension Method
Authors: Wu Chang Tzuoh , Liu Nien Te
Published: March 2013

The major procedure of QFD is to identify the customers’ needs for the product and then convert into appropriate technical measures to fulfill the needs based on the company’s competitive priorities. The priorities of product characteristics can be obtained by translating important technical measures into product characteristics. According to their characteristics to identify the relevant engineering parameters, the prior engineering parameters will be selected as the key requirements to redesign. This article will concentrate on the creativity way of thinking “matter-element theory and extension method”, with the help of this method to assist to translate customer requirements (CRs) into product design attributes and engineering characteristics (ECs) can provide effect assistance for the designer to conceive new products comprehensively and deeply. The system for design decision-making will be developed and an innovative design case, wheelchair for the elderly, successfully demonstrates that the proposed design process is feasible and efficient.
Application of PLS-SEM to Assess the Influence of Construction Resources on Cost Overrun
Authors: Rahman I.A. , Memon Aftab Hameed , Abdullah Nor Hazana , Azis Ade Asmi Abdul
Published: March 2013

Being resource-driven industry, success and failure of construction projects highly depend on resources. As construction industry is now-a-days facing major problem of cost overrun worldwide, this can be contributed by construction resource issues. Hence, this study aimed to assess impact of construction resource on project cost overrun. Structured questionnaire survey was carried out to understand the perception of construction practitioners. A total of 106 samples were collected. Partial Least Square (PLS) of Structural Equation Modeling (SEM) approach regarded as the graphical equivalent of a mathematical representation of relationship between dependant variable to explanatory variable was adopted for data analysis, as common methods of data analyze does not give insight of underlying relationships between various factors. In analyzing cause-effect relationships, PLS-SEM is a dominant approach to establish rigor in complex models. Smart PLS 2.0 software was used to test the relationship between resources and cost overrun. The developed structural model indicates that relationship between resource and cost overrun was satisfactory by having substantial explaining power (GoF=0.529) and 40% of the cost overrun was influenced with resources. The most significant resource was construction material. Hence, effective material planning and management is vital to improve potential construction cost overrun.
Improving Operability of SmartUAV in Navigable Airspace of Korea
Authors: Kim Do Hyun , Kim Woong Yi , Kim Joong Wook
Published: March 2013

UAV operations have increased steadily during the past several years in both the public and private sectors in Korea. However, there are many limitations for installation of ground based navigation-aids in Korea because 70 percent of its geography is mountainous. Furthermore, airspace for civil aircraft operations is very limited due to military operating areas and restricted airspaces established by military. This paper is a study on measure for integrating SmartUAV safely and smoothly within current airspace for manned aerial vehicle operation and expanding SmartUAV’s operability. This study is approaching SmartUAV in operational side not developmental side, looking into ways of expanding UAV operability by adapting it to existing navigable airspace and ATS.
Research on the Synthesis Process of Ethylmaltol by Electrochemistry
Authors: Sun Jian Jun , Hao Mi , Wang Long , Cui Li Hong
Published: March 2013

Ethylmaltol was prepared from ethylfurfuryl alcohol by electrolysis, acidification, glycosidation, oxidation and acidolysis. The ultraviolet spectrophotometric method was used for quantitative determination of ethylmaltol. The chemical structures of the intermediates were characterized by mean of FTIR. The experimental results showed that the yield of ethylmaltol was greatly dependent on electrolyte, quantity of electricity, oxidation time, acidolysis time and acidolysis temperature. The appropriate conditions were electrolyte of NaBr, quantity of electricity of 1.6Ah, oxidation time of 3 hours, acidolysis timeof 3 hours, acidolysis temperature of 100°C and the highest yield of ethylmaltol was 66.76%.
Aeroelastic Behavior of Morphing Wing in Flutter Regions
Authors: Jung Yoo Yeon , Kim Ji Hwan
Published: March 2013

A morphing of a system is capable of changing the shape from the cruise to dash configurations. During the motion, the aerodynamic and structural characteristics can be varied tremendously, and the new shape will induce the different aeroelastic stability behavior. Thus, the purpose of this study is to investigate the flutter analysis of the folding wing structure including the effect of various parameters such as fold angles et al. of the composite laminates structures. For doing this these works, the aero-elastic analysis of folding wing is performed with respect to the parameters using PK method. Also, Finite Element Method is used in structural analysis, and Doublet Lattice Method is applied in aerodynamic analysis. Generally, the dynamic pressure and frequency during the flutter are sensitive to the structural characteristic, thus the flutter mode alteration is occurred by changed natural frequencies. Also, the alteration causes the flutter dynamic pressure variation. Therefore, results represent the aeroelastic stability variation due to the folding wing system including the effects of ply angles of composite laminates.
Frequency Dependence on Image Reconstruction for a Buried Conducting Cylinder
Authors: Chien Wei , Tseng Hsien Wei , Lee Yung Wen , Yen Liang Yu , Chiu Chien Ching
Published: March 2013

Frequency dependence on image reconstruction for a buried conducting cylinder is investigated. A conducting cylinder of unknown shape scatters the incident wave in free space and measured the scattered field. By using measured fields, the imaging problem is reformulated into an optimization problem and solved by the steady-state genetic algorithm (SSGA). Numerical results show that the reconstruction is quite well in the resonant frequency range. This work provides both comparative and quantitative information
Taguchi Optimization of Machining Quality in Step Drilling of Composites Based on Membership Function
Authors: Tsao Chung Chen , Lin You Qian
Published: March 2013

Delamination-free hole is expected for composite parts using optimized drilling parameters due to an increase in composite structures production and in the need for higher quality machining. The influence of the various machining parameters (step angle, stage ratio, feed rate and spindle speed) on thrust force and equivalent delamination factor in step drilling composites was investigated in this study. The use of membership function based on Taguchi method to obtain the optimization of the process parameters by considering multiple performance characteristics has been reported. Finds based on the membership function show that the lowest thrust force of step drilling composites to be about 25.6 N and equivalent delamination factor about 1.005 pixel/pixel.
The Membrane Thickness Prediction of Solder Paste Process by Phase-Shifting Projection
Authors: Chung Yu Fang , Tsai Kun Lin , Chen Tzer Long , Hsu Yen Chu , Yu Yi Hsuan
Published: March 2013

Electronic products have become lighter and thinner nowadays. SMT includes three basic steps, namely solder paste print, electronic component adhesion and reflow[1]. This research tends to capture the image of fringe projection based on CCD with optical grating and reconstruct the 3D surface image of solder paste use triangulation measurement. The main ideal is using fringe projection method to observe the distortion of the fringe phenomenon caused by different heights of the surface. Last, the depth of the surface is computed under test variation and the 3D image is reconstructed.
Analysis of a 3-DOF Rotationally Symmetric Hinge
Authors: Kim Hyo Young , Kim Jung Jae , Ahn Da Hoon , Gweon Dae Gab , Park Chan Gon , Hong Dong Pyo
Published: March 2013

Flexure hinges have been widely used as mechanisms for high precision positioning stages that have a micrometer or nanometer resolution. This paper describes the analysis of a 3-DOF rotationally symmetric hinge for the vertical mask aligner stage. The vertical mask aligner stage was designed to overcome the bending of masks by gravity. In order to align the mask and the wafer, the vertical mask aligner stage has one linear motion and yaw rotating motions (Z, Θx, Θy). The new vertical mask aligner stage will try to use rotationally symmetric hinges. These rotationally symmetric hinges would act as guide mechanisms. However, the exact 6-DOF stiffness analysis of the rotationally symmetric hinge did not use these hinges as guide mechanisms. Therefore, this paper focuses on the stiffness analysis of the rotationally symmetric hinges.
Conceptual Design of Integrated Brushless Permanent-Magnet Motors and Planetary Gear Trains
Authors: Wu Yi Chang
Published: March 2013

Integrated designs of brushless permanent-magnet (BLPM) motors and basic planetary gear trains (PGTs) are described in this paper. The kinematic characteristics of the basic PGT and the typical topologies of the BLPM motor are studied first. Then, design requirements are concluded to rationalize the integrated designs. Four novel integrated devices with interior and exterior topologies are synthesized subject to design requirements. The unique characteristics and application fields of the proposed designs are also indicated.
Construction of an Elementary Model for the Dynamic Analysis of a Pressurized Water Reactor
Authors: Tsai Chiung Wen , Shih Chun Kuan , Wang Jong Rong
Published: March 2013

A lumped-parameter numerical model was constructed based on the conservation laws of mass and energy and the point neutron kinetics with 6 groups of delayed neutron to represent the dynamics of primary loop of a pressurized water reactor (PWR) core. On the viewpoint of control theory, the coupled phenomenon of neutron kinetics and thermohydraulics can be recognized as a dynamic system with feedback loops which is caused by the Doppler effect and the coolant temperature difference. Scilab was implemented to representing the equivalent transfer functions and associated feedback loops of a PWR core. The dynamic responses were performed by the perturbations of coolant inlet flow, coolant inlet temperature, and reactivity insertion.
Design of Dual Layer Liner with Deformable Semi-Spherical Convex for Bicycle Helmet
Authors: Teng Tso Liang , Liang Cho Chung , Nguyen Van Hai
Published: March 2013

Bicycle helmets aim to reduce the risk of injury due to impacts on the head. Generally, a bike helmet consists of the outer shell, liner, vents and straps. The liner helps absorb the effects of the impact to keep that force away from your head. To satisfy the functions of helmet liner, several criteria should be considered. The ideal liner would be stiffer in hard impacts, softer in lighter impacts, light, cheap, reliable to manufacture and easy to ventilate. Currently, there are many different design trends and concepts in the design of helmet liner. Researchers have tended to focus on the liner material. The Expended Polystyrene (EPS) foam is the most popular choice for liner material of helmet. The EPS foam is commonly used in helmets as an energy absorbing liner. However, EPS has some disadvantages, such as the difficulty to optimize energy absorbing in different areas of head and inferior effect of heat dissipation. Moreover, EPS is generally too brittle. In order to overcome its drawback, to search a better alternative is necessary. In this study, a dual layer liner is proposed to yield enhanced impact absorption, that is to say, the liner is constructed by two layers of polycarbonate with deformable semi-spherical convex. The energy absorbed by deformation of convexes which is described by a combination of folding and collapsing. The main advantages of this liner design not only show the energy absorbing capabilities like EPS foam but also gain a better optimization of energy absorbing for different sites. This study focuses on assessment of a helmet with dual layer liner based on the shock absorbing test of CPSC’s standard. Finite element method (FEM) is available contribution greatly to helmet test modeling. This study performs finite element analyses of helmet impact tests using LS-DYNA software. The simulation of helmeted headform drop test is implemented for the four kinds of liner thickness. To confirm the energy absorbing capabilities of dual layer liner, the resultant CG linear acceleration of the headform is measured from the helmet test simulation. According to the CPSC’s standard specification, the acceleration of headform should be less than 300 g's during the impact.
Design Techniques for Reducing Cogging Torque in SPM Motors Using Shifted Slot Opening
Authors: Cheng Shih Ping , Hwang Chang Chou , Chang Chia Ming
Published: March 2013

Skewing is one of the most common methods to reduce the cogging torque of permanent magnet synchronous motors. This technique may cause manufacturing troubles such as impossible automatic slot filling due to skewing stator slot. One method to overcome this problem is to use the step twisted stator structure with shifted slot opening. Compared to other methods of skewing, in the presented method, the stator slots are still straight slots and the skewing effect is implemented by shifting slot openings coupled with a step twisted stator design. This paper discusses the use of the step twisted stator structure with shifted slot opening and the associated effects on machine performance. We address the cogging torque, average torque, torque ripple, and back-EMF and its total harmonic distortion (THD). We examine the results using finite element analysis (FEA).
Experimental Investigation of Airflow Distribution for a Novel Combustor Mode
Authors: Li Qiong , Zhao Meng Meng , Xing Fei
Published: March 2013

This paper investigated the airflow distribution performance of the combustor which utilized trapped vortex in the cavity to improve the flame stability. Hole-filling method was used to study trapped vortex combustor airflow distribution at normal temperature and pressure condition. The influence of inlet velocity and mainstream flow-passage height were investigated. The results show that, inlet velocity hardly impacts the airflow distribution of trapped vortex combustor, but chamber height is a key parameter for airflow distribution. The size, number and opening area of the holes in trapped vortex combustor are important to airflow distribution, and increasing cavity back body air flow could bring well lean blowout limit. The research results may serve as a useful reference in further development and engineering application of trapped vortex combustor.
Heat Transfer Enhancement of Vertical Heat Sinks with a Piezofan
Authors: Shyu Jin Cherng , Syu Jhih Zong
Published: March 2013

This study examines several effects, including the piezofan positions, and piezofan arrangements, as well as piezofan height, on the heat transfer enhancement of two typical types of vertical heat sink. Either 30-mm-high or 10-mm-high heat sink having 11 plate-fins or 100 square pin-fins is tested with a running piezofan. The piezofan having Mylar blade is either vertically or horizontally placed above the heat sinks vibrating with resonant frequency of 31 Hz and tip mean-to-peak amplitude of 7.2 mm. The heat transfer coefficient is measured at five different fan locations with fan heights of 12 mm and 16 mm. Results show that the piezofan located at x/L = 0.5 usually performs the highest heat transfer enhancement for a given heat sink, while piezofan located at x/L = 1 usually shows the worst heat transfer enhancement. Depending on the fan arrangements and positions, heat transfer coefficient of the present 10-mm-high plate-fin heat sink shows 1.2 – 2.4 times higher than that under natural convection, while the enhancement factor ranges from 1.1 to 2.6 for 10-mm-high pin-fin heat sink.
In Situ Spacing Fluctuation Monitoring of Hard Disk Drive with Thermal Asperity Sensors
Authors: Zhao Da Peng , Wei Xiong Fei , Liu Bin , Wang Yu , Chen Sheng Xiang , Lan Lin Hua
Published: March 2013

This paper presents an investigation of spacing fluctuation characterization (SFC) of Hard Disk Drive (HDD) using thermal asperity (TA) sensor. Firstly, the spacing fluctuation monitored by TA sensor is correlated with that monitored by a Laser Doppler Vibrometer (LDV). Secondly, a series of experiments are conducted to study the factors affecting the spacing fluctuation, including disk distortion, head crown sensitivity, ZH sensitivity. Good disk assembly and small crown sensitivity and ZH sensitivity will be helpful to reduce spacing fluctuation.
Mechanical Efficiency Analysis of a 16-Speed Bicycle Transmission Hub
Authors: Wu Yi Chang , Ren Pei Wun
Published: March 2013

This paper proposes an analytical method to evaluate the mechanical efficiency of the bicycle transmission hub. A 16-speed transmission hub, which consists of two transmission units and one differential unit, is presented first. By applying the concept of fundamental circuits, a step by step analysis process is then described to numerically calculate the angular speed, ideal torque and power flow, and actual torque and power flow by considering the gear-mesh loss of each link of the planetary gear train. Based on the power flow diagram, the mechanical efficiency at each speed of the transmission hub can be estimated.
A Study of Micro Injection for Unibody Array LED Lampshade with Multi-Cavities
Authors: Lin Jui Chang , Lee King Sun , Yeh Chen Hsi , Tung Chien Jung , Ku Cheng Chi , Hsu Kuahg Wei
Published: March 2013

The unibody of LED lampshade is the expansion of a lampshade array from single-LED in order to decrease assembly time, the forming technique is complicated. This study employ solid model to build micro mold, and find out the optimal design parameters, such as gate position, running system, cooling system and holding pressure system. The improvement of gate system can reach flowing equilibrium when molten plastic flows into cavity, and no welding line is produced. In the cooling stage, the cooling speed at each cavity is also steady and balance in order to reduce residual stress and lens defects. This study utilizes multi-gate system and multi-stage holding pressure aided forming to decrease welding line and residual stress. This study improves traditional mold design to fit more multi-cavity LED mold design which includes cooling system redesigning, cavities layout, flowing balance in runner and reducing shear stress. The Taguchi method and orthogonal array are used in the study for each group of experiment; many factors are applied to obtain the minimum shear stress, minimum warp, reduction of flow mark and uniform stress distribution. The results can provide for industry reference.
Multi-Objective Optimal Mechanical Power for Turbine of River Current Power Generation Using Fuzzy Dominant Directed-Graph Method
Authors: Kuo Jian Long , Chao Kai Lun
Published: March 2013

Abstract. The fuzzy dominant directed graph (fuzzy DDG) method is proposed in this paper to solve the multi-objective optimal mechanical turbine power of river current (RC) power generation system. Recently, there is great potential for the RC power generation system in renewable energy. The experimental Taguchi method is used to find the optimal solution for the power generation system. The optimization problem for the AC generator in RC power generation system is studied. The optimal output power with respect to three selected control factors is studied. By using Taguchi method, five cases are discussed. The testing case is the optimal output power problem. It is convinced that this method is applicable and easy to find the optimal solution quickly.
Natural Convection Heat Transfer of Annular Metal Porous Medium Heat Sink of LED
Authors: Tzeng Sheng Chung , Jeng Tzer Ming , Yeh Zhi Ting
Published: March 2013

This study used metal porous medium heat sink to replace traditional cooling fins to form a high performance LED cooling system. The metal foamed material has high permeability and cooling area as large as several times of that of traditional fins. With a proper configuration design, it can improve the heat transfer capability of natural convection effectively. This study experimentally investigated the natural convection heat transfer characteristics of the annular metal foamed material, and determined the optimal configuration. The experimental results showed that 1) the heat transfer coefficient (h) increased with ΔT; 2) the (h) decreased as PPI (pores per inch) increased when the thickness (t) of the annular metal foams equaled 5 mm, but the (h) increased as PPI increased when t=11 and 14.5 mm; 3) the (h) increased and then decreased as (t) increased, and there was better heat transfer effect when t=11 mm as shown in the experimental data.
On the Design of Planetary Gear Reducer with Simple Planet Gears
Authors: Hsieh Long Chang , Chen Tzu Hsia
Published: March 2013

Planetary gear trains are commonly used in various transmissions due to the following reasons: compact size, light weight, and multi-degrees of freedom. For example, planetary gear trains can be designed for following functions: gear reducers for power machinery, internal gear hubs for bicycle, gear increasers for wind generator, gear reducers for robot. In general, the reduction of non-coupled planetary gear train is less than 10. The purpose of this paper is to introduce the planetary gear train with high reduction ratio. Coupled planetary gear train can be designed to has high reduction ratio. Hence, this paper focuses on innovative, kinematic, and engineering design of coupled planetary gear train with high reduction ratio. The coupled planetary gear train synthesized in this paper is a planetary gear train with simple planet gears. It can be used as the gear reducer for a robot. Refer to the train value equation, the reduction-ratio equation of coupled planetary gear train is derived for the design purpose. Then, the coupled planetary coupled gear train with simple planet gears is synthesized based on the above reduction-ratio equation. Finally, the corresponding engineering design drawing is accomplished.
Pressure Drop of Two-Fluid Mixtures in a Y-Typed Microchannel with Varying Cross-Section Area
Authors: Fu Ben Ran
Published: March 2013

The present study investigates experimentally and numerically the single-phase flow of two-fluid mixtures (H2SO4 and NaHCO3 solutions) and of water in a Y-typed micromixer with uniform, converging, and diverging cross-sections. The mean hydraulic diameter of the three kinds of main channel is approximately 174 µm. The experimental data of pressure drop agree with the theoretical predictions and CFD simulation results within 10%. Furthermore, the pressure distribution prediction for converging and diverging microchannels is consistent with that from CFD results. The pressure falls rapidly in the diverging microchannel near the entrance and slowly near the outlet. Such the pressure distribution may enable the forward flow of a bubble in a diverging microchannel.
Simulation of Airflow in the Engine Compartment of a Light Aircraft
Authors: Liu Hsu Jeng , Su Chih Chun , Huang Sheng Liang
Published: March 2013

This paper applies the software of Computational Fluid Dynamics (CFD)-FLUENT to analyze the flow field in the engine compartment of a light aircraft. The simulation results of the prototype model indicates that the airflow rapidly flows to the back of the engine compartment along the inside cowling after entering the engine compartment, rather than to the engine cylinder which will result in a very high cylinder temperature. Hence, this paper designs the air inlet, air duct, guide vane, and air outlet to improve the airflow in the engine compartment according to the drawbacks of the prototype model. The results show that the air duct and the guide vane help lead the airflow to the cylinder, and the air outlet effectively reduces the pressure in the engine compartment so that the airflow accelerates through the engine compartment, which is considered a feasible and economic improvement method in terms of the production cost.
Structural Optimization on Composite Blades of Large-Scale Wind Turbines
Authors: Chen Kun Nan , Gau Wei Hsin
Published: March 2013

Turbine blades used in large-scale, horizontal-axis wind turbines are usually made from composite materials to reduce the weight while attaining a reasonable strength to weight ratio. The design of large wind turbine blades must consider both their aerodynamic efficiency and structural robustness. This paper presents an optimum design scheme for composite wind turbine blades. The first optimization phase produces the aerodynamic outer shape of a blade framed by airfoils with optimum cord lengths and twist angles along the blade spanwise direction. The second phase provides optimal material distribution for the composite blade. Loadings on the blade are simulated using wind field and wind turbine dynamics codes. The maximum loads on the turbine blade are then extracted and applied to a parameterized finite element model. A design example of a 3 MW wind turbine blade considering one critical load case with a mean wind speed of 25 m/s is demonstrated. The optimization result shows that although the initial blade model is an infeasible design, the optimization process eventually converges to a feasible solution with an optimized mass of 8750.2 kg.
The Analysis of The Dynamic Characteristics on Seed Plate of The Vacuum Planters for Precision Sowing
Authors: Lee Jae Wan , Kim Young Joo , Kang Seong Il , Kim Joon Yong , Hong Dong Pyo
Published: March 2013

This study was carried out to analyze the dynamic characteristics of the seed plate which is the main part of the vacuum precision planter. The vacuum precision planter is a working machine which is attached to a tractor. The vacuum pump is operated by PTO-shaft which rotates in three types; 540 rpm (9 Hz), 750 rpm(12.5 Hz) and 1,000 rpm(16 Hz). Seeds are sucked into the holes of the seed plate by vacuum, and then they are transported by rotation. At that time, the mode shape of seed plate is important because dynamic characteristics of the seed plate decide seeding rates. If the natural frequency of seed plate corresponds with the frequency of PTO-shaft, the resonance occurs. For this reason, modal analysis of the seed plate was made with FlexPDE(PDE solutions, inc) and ANSYS(ANSYS, inc). Mode shape was observed for 5th mode. First, modal analysis of the seed plate was performed by FlexPDE. According to the result of FlexPDE, natural frequency of each mode was obtained 35.7 Hz, 35.8 Hz, 45.3 Hz, 60.8 Hz and 61.0 Hz respectively. The other modal analysis of the seed plate was performed by ANSYS. As a result of the ANSYS analysis, natural frequency of each mode was obtained 35.6 Hz, 36.0 Hz, 45.6 Hz, 60.9 Hz and 61.1 Hz respectively. The results of the FlexPDE and ANSYS were similar. Natural frequency of the seed plate was confirmed by the above results. So, it was confirmed that the resonance didn't happen by comparing the frequency of PTO-shaft and natural frequency of seed plate. In conclusion, the vacuum precision planter is expected to efficiently sow.
Effects of Carbon Co-Implantation on Transient Enhanced Diffusion and Performances of the Phosphorus Doped Ultra-Shallow Junction Nano NMOSFET
Authors: Chiu Hung Yu , Fang Yean Kuen , Juang Feng Renn
Published: March 2013

The carbon (C) co-implantation and advanced flash anneal were employed to form the ultra shallow junction (USJ) for future nano CMOS technology applications. The effects of the C co-implantation process on dopant transient enhanced diffusion (TED) of the phosphorus (P) doped nano USJ NMOSFETs were investigated in details. The USJ NMOSFETs were prepared by a foundry’s 55 nano CMOS technology. Various implantation energies and doses for both C and P ions were employed. Results show the suppression of the TED is strongly dependent on both C and P implantation conditions. Besides, the mechanisms of P TED and suppression by C ion co-implantation were illustrated comprehensively with schematic models.
A Research on Detection and Identification of Harmful Gas Utilizing Cataluminescence-Based Sensor Array
Authors: Zhou Li Shan
Published: March 2013

A novel cataluminescence(CTL)-based sensor array consisting of 9 types of catalytic nanomaterials was developed for the determination and identification of harmful gas. The sensing nanomaterials, including nano-sized metal oxides, carbonates and decorated nanoparticles, have been selected carefully. A 3 x 3 array was integrated by depositing these nanosized catalysts onto the ceramic chip. Dynamic and static analysis methods were utilized to characterize the performance of the sensor array to 4 kinds of harmful gas. Each compound gives its unique CTL pattern after interact with the sensor array, which can be employed to recognize ether, acetone, chloroform, and toluene. PCA was conducted to classify the harmful gas and the plots showed that the groups were well classified. In addition, the patterns obtained at different working temperature and the analytical characteristics of array were investigated. The CTL-based sensor array shows promising perspective for the recognition and discrimination of harmful gas.
An Automobile Exhaust Sensor Utilizing Cataluminescence on Nanosized Fe3O4/SiO2
Authors: Zhou Li Shan
Published: March 2013

Instrumentation was constructed for the detection of automobile exhaust utilizing cataluminescence method on nanosized Fe3O4/SiO2.The microspheres with a diameter of about 450 nm, were synthesized by the hydrolyzation of tetraethyl orthosilicate (TEOS). The scanning electronic microscopy (SEM), transmission electronmicroscopy (TEM) and energy dispersive spectroscopy (EDS) were employed to characterize the microspheres. Automobile exhaust, a harmful gas, was selected as a model to investigate the cataluminescence sensing properties of the SiO2/Fe3O4 microspheres in the current work. Results indicated that the microspheres exhibited outstanding cataluminescence properties. The performance of the SiO2/Fe3O4 microspheres based sensor instrument suggested the promising application of the SiO2/Fe3O4 nanomaterials for the detection of automobile exhaust.
Overview Study of Multi-Dynamic Coupling Drive System on EV
Authors: Wu Xiao Hua , Li Wei
Published: March 2013

The multi-dynamic coupling drive system can coordinate the operating characteristics of all power sources, optimize the total efficiency and driving characteristic of the drive system, and hence improve the performance of electric vehicles. Therefore, it has greater energy saving potential and better prospects. Under the premise of meeting the needs of electric vehicle performance, how to synthesis and decompose the output power of the different power sources reasonablely and efficiently is the core problem. There are a number of driving modes existing in the the multi-dynamic coupling drive electric vehicles. The coordination control of the torque of related power sources during the transition among different modes is essential to vehicle’s power and ride comfort performance. It is meaningful to improve the system efficiency and drivability performance by control strategy, while ensuring the capability of energy saving and emission reduction.
Study on Powertrain Matching Based on Driving Cycle for Hybrid Electric Vehicle
Authors: Wang Xi Ming , He Hong Wen , Tang Heng Lu , Qin Hong Zhou , Peng Jian Kun
Published: March 2013

The performance of fuel economy and emissions reduction of hybrid electric vehicles (HEVs) strongly depends on the powertrains’ matching and its energy control strategy. The theoretic matching method only based on the theoretical equation of kinetic equilibrium, which is a traditional method, could not take fully use of the advantages of HEV under a certain driving cycle because it doesn’t consider the target driving cycle. In order to match the hybrid powertrain that operates more efficiently under the target driving cycle, the matching method based on driving cycle is presented. The powertrain of a hybrid electric bus is matched, modeled and simulated on the CRUISE, a forwards simulation platform from AVL. The simulation results show that the matching method based on driving cycle presented in this paper could not only meet the requirements of the power performance, but also operate efficiently under the target driving cycle.
Research on Electromagnetic Actuator of Small Anti-Submarine Weapon
Authors: Xiong Jian
Published: March 2013

For the application advantages of electromagnetic actuator in anti-submarine weapon, this paper studied two kinds of electromagnetic actuator system and their work modes. It described the working principle, configuration and structure of two systems. It analyzed the electromagnetic properties of electromagnetic actuator and selected the material. When the rudder was the electromagnetic actuator of excitation mode, it possessed many characteristics of small volume, simple structure and good control. The study provided a new scheme of the rudder for small anti-submarine weapon.
Review of Methods of Mechanical Digital Design Based on Topology Optimization
Authors: Wang Xiu Ye , Zhao Han , Zhang Zu Fang , Wang Yong
Published: March 2013

The basic mathematical model of topology optimization of continuum structures is introduced at first. Then the authors focus on reviewing the development of PDE methods and optimization algorithms. This paper details the development and applications of Finite Element Method, Boundary Element Method and Finite Volume Method. This paper also illustrates several typical applications and achievements of optimization algorithms, such as Optimality Criteria method, mathematical programming method and intelligent algorithm. Based on our research, this paper finally summarizes the process of the structural topology optimization and describes the directions of the topology optimization in the field of mechanical digital design.
Efficiency Modeling and Experimental Verification of Minicar Transmission System
Authors: Wang Wang Ping
Published: March 2013

Through the analysis of factors affecting the efficiency of auto transmission system, the power loss models of all parts of the transmission system were established, and the formula of the transmission efficiency was obtained. On the basis of formulating the minicar transmission efficiency test standard, the transmission system was tested. Test results indicated that the transmission efficiency values which obtained theoretically by calculation were in reasonable agreement with experimental results, the relative errors were less than 6%，especially in commonly used input torque and input speed range. This model provides theory basis for the design and optimization of auto transmission system.
Study on Structural Performance of the Cylindrical Pressure Hull for Underwater Vehicles
Authors: Mao Zhao Yong , Wei Chao , Fan Yu , Huang Wei Chao
Published: March 2013

The pressure hull is a very important for the overall performance of underwater vehicles, this paper investigates the structural performance of cylindrical pressure hull for underwater vehicles. Taking into account that there are much factors affect the performance of pressure hull, and these factors exists some coupling relationship between each other for pressure hull performance, so the orthogonal design method has been used in this paper, which can establish the representative test program. The ultimate strength of pressure hull is calculated with the finite element method. A design of experiments is performed to evaluate the effect of geometry parameters to the ultimate strength of the pressure hull. Through this study, the designers can clearly understand the influence degree of geometry parameters for pressure hull performance, which can provide reference for the structural design of cylindrical pressure hull.
The Acoustic Enclosure Design of the Refrigeration Compressor
Authors: Zhang Li , Zhang Shuo , Nie Guang Yuan
Published: March 2013

In this paper, in order to reduce the external radiation of food refrigeration compressors noise, the main noise frequency analysis based on the theoretical calculation and practical experiment is carried out and the acoustic enclosure design is conducted. Conventional sound-absorbing material adopts rock wool and glass wool which have poor environmental protection. In the design process the environmental friendly melamine cotton is chosen as the sound-absorbing material that has not ever been massively adopted. Whats more, with a consideration of ventilation and heat dissipation, acoustic enclosure interior is designed with muffler air duct and the low-speed and low-noise fan. Therefore, both the normal operation of the compressor and the sound insulation of the acoustic enclosure are ensured in this way. Then with the sound level meter the noise A-weighted SPLs of the compressor with and without the enclosure are measured and are compared with each other. The results show that after covering the acoustic enclosure the compressors noise is less than 60 dB, which meets the design requirements of noise control. Therefore, it is easy to conclude that the sound insulation of the acoustic enclosure reaches the design standards and the acoustic enclosure design is feasible.