Taiwan Association of Engineering and Technology Innovation: E-Journals
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Weighted Random Forests for Evaluating Financial Credit Risk
Get PDFCredit evaluation of customers is a critical issue in financial organizations. Classification algorithms have beenproposed for credit evaluation in recent years, and the class distribution in the financial data for those studies are not skewed. However, only a small proportion of customers will be the cases for bad credit. Financial records should be considered as an imbalanced data set for analyzing credit risk. Ensemble algorithms that make predictions by group decisions generally have relatively high accuracy than the ones inducing only one model from data. This study introduces a mechanism based on the weighted random forest to improve the prediction accuracy on the records with bad credit. This mechanism is tested on two financial data sets to demonstrate that it can achieve relatively high performance in evaluating credit risk and that the number of decision trees in a forest is not helpful. Critical attributes are also identified to provide practical meanings for credit risk analysis
Analysis of 2017 Gartner’s Three Megatrends to Thrive the Disruptive Business, Technology Trends 2008-2016, Dynamic Capabilities of VUCA and Foresight Leadership Tools
Get PDFNowadays, digitalization is the key element of business competition. This paper analyzes the concept of dynamic capabilities in the context of technological and business digitalization. We investigate the dynamic competence needed to create and manage a new Digital business, which is emerging from the technological transformation. Firstly, in this paper, we analyze the data of Gartner Hype Cycles 2008-2017. Thus, we present a comparative analysis of the changes in the Gartner hype cycle. Secondly, our aim is to present Gartner´s three distinct megatrends. We will present a summary of these Gartner evaluations and discuss key tendencies and trends of technological changes. Thirdly, the special focus of this article is the challenges of orchestration of dynamic capabilities in the special conditions of VUCA business disruptive business competition. Further, we define the role of competence gap identification inside a firm. Finally, we are presenting some useful tools to manage dynamic capabilities
Simulation of III-V Material Based Steep Slope Tunnel FET for RF Harvester Application
Get PDFDue to the limitation of Sub-threshold Swing (SS) of 60 mV/dec in CMOS, alternately Tunnel FETs (TFETs) are more attractive in recent years since it has high energy efficiency and better switching performance even at a reduced voltage level. Because it has the benefits of Band to Band Tunneling (BTBT) behavior of operating mechanism and achieved a steep slope characteristic of less than 60 mV/dec. Despite these merits due to the band to band tunneling, the conventional Silicon based TFET is suffered from very low and limited ON-state current due to indirect and large energy gap feature. In the indirect band gap, the conservation of momentum occurs only when the absorption and emission of a photon are required which makes the absorption coefficient lower and limits the flow of electron. To address this problem, in this paper, a Hetero-Junction Tunnel FET (HTFET) devices employing with different lower bandgap materials (InAs/GaSb and InGaAs/InP) are designed by using Silvaco TCAD device simulator. The overall DC and analog/RF performance of HTFET devices are being extracted and investigated suitable for RF energy harvesting applications. The InAs/GaSb HTFET has shown a superior in characteristics by achieving a higher ON-state current of 2.3 mA/μm at Vgs = 1V, OFF current leakage of 4.18 x 10-11 A/μm, SS of 22.18 mV/dec and cut-off frequency range from MHz to GHz in operation. Under very low ambient RF level or sub-milliwatt (< 0 dBm) level conditions, the conventional CMOS based rectifier in RF harvester shows very poor performance and probably fails to convert RF signal into DC output voltage. This is due to the SS limitation of 60 mV/dec. Hence, HTFET based RF harvester is proposed and implemented in the circuit level by using the Keysight ADS software. The result indicates that a two-stage Dickson voltage multiplier design using InAs/GaSb HTFET can able to produce a DC output of 1.9 V, 1.6 μA @ 0 to -10 dBm, maximum efficiency of 59 % @ -14 dBm, operating frequency of 850 MHz at 10 kΩ loads with a sensitivity of 0 to -25 dBm
Dynamic Poisson's Ratio and Modulus of Elasticity of Pozzolana Portland Cement Concrete
Get PDFAn experimental investigation was carried out to determine the dynamic Poisson's ratio and modulus of elasticity of pozzolana Portland cement concrete. Large numbers of concrete cubes were prepared and tested in the laboratory for investigation. The destructive and non-destructive tests were conducted on concrete cubes at different ages. The destructive test was conducted to obtain the compressive strength of concrete cubes. Ultrasonic pulse velocity of cube specimens was derived according to IS 13311 (Part 1) and the transit time of longitudinal and shear waves transmission was recorded. The recorded values are used to determine the dynamic values of Poisson's ratio and elastic modulus of concretes. Based on experimentally obtained data and analysis, a few relationships are proposed to correlate the water/cement ratio, Poisson's ratio, elastic moduli and compressive strength of concretes. Several interesting findings are observed from the correlations of the coefficients while analyzed by regression analysis. This study helps to determine the static properties of concrete from the dynamic ones
Simple Communication Interface for a Radar Detector in the Moments Space
Get PDFThe method of Radar Target Detection by Analysis and Statistical Classification of the Cellular Emission (DRACEC) can be functionally divided into three fundamental stages: Acquisition, Adaptation, and Detection. During Acquisition it is required to continuously exchange information between the hardware in FPGA and the software, without affecting the performance of the latter. This paper proposes the simplest communication interface that satisfies these requirements when DRACEC is applied to a small searching window. The solution is implemented on the serial port and ensures that samples stored in FPGA are available at the computer for the remaining processing stages. One fundamental characteristic of the proposal is a protocol designed to control the communication flow, which is implemented through a dedicated program thread. This allows software performance to not deteriorate during communication and lays the foundations for using multithreading techniques to develop the stages of DRACEC
Investigation of Cross-Coupling in Piezoelectric Transducer Arrays and Correction
Get PDFCross-coupling in piezoelectric transducer arrays is an undesirable phenomenon which decreases the performance of these devices. Indeed, when one element of a transducer is driven, it generates parasitic displacement fields at the radiating surfaces of the neighboring elements, which changes the directivity of the array. The objective of this paper is to investigate the cross-coupling effects on the piezoelectric transducer arrays performance and to propose solutions to reduce this parasitic phenomenon. In this context, it is demonstrated that a filling material having high mechanical losses contributes to the reduction of cross-coupling. In addition to this, a procedure of active cancellation of cross-coupling is successfully tested in the case of two transducer arrays vibrating in the transverse mode for the first prototype and thickness mode for the second one. Finally, the ability of the method is demonstrated even when the displacement at the radiating surface of the transducer array is not uniform
Implementation of Adaptive Embedded Controller for a Temperature Process
Get PDFThe paper proposed and carried out an adaptive embedded control strategy with the help of Arduino open hardware platform. The proposed control strategy is to carry out a cost-effective interface between the simulation software and a real-time process. The data acquisition and control is done with the help of Arduino Uno which has been interfaced with MATLAB Simulink The control algorithms developed in Simulink model can be downloaded into the Arduino Uno, working as a standalone controller. In this paper, various control algorithms are used to control the temperature process, including embedded Modified Model Reference Adaptive Control (MMRAC). Its performance is compared to other control algorithms. The result shows that the MMRAC scheme improves the transient performance of the temperature control system
A Controlled Fermentation Environment for Producing Quality Soya Sauce
Get PDFSoy sauce fermentation under controlled temperature is a way to shorten the fermentation time. An energy-saving fermentation system was developed to power a heat pump for maintaining the temperature of sauce moromi at 37±1°C during fermentation. The chemical properties of the sauce moromi and the sensory properties of the soy sauce produced using the controlled fermentation system were evaluated and compared to those of the sauce moromi fermented outdoors without temperature control. The sauce moromi processed using the controlled fermentation system had significantly higher total nitrogen, formal nitrogen, amino nitrogen, reducing sugar and organic acid contents than the moromi fermented outdoor. However, no significant difference was found in overall liking score between two soy sauces. The soy sauce fermented under the control temperature showed higher Brix and salt concentration, but lower pH value than the sauce fermented outdoor. It was possible that the beneficial effects of reducing sugar and organic acid contents were rebuffed by the disadvantage of salt concentration. It was concluded that a controlled fermentation environment deserves the potential to produce a high quality soy sauce
Impact of DFIG in Wind Energy Conversion System for Grid Disturbances
Get PDFIn this work, a grid-connected DoublyFed Induction Generator (DFIG) is studied for the transient and steady response. The vector control technique controls the Pulse Width Modulation (PWM) of both the back-to-back converters interfacing rotor to the grid. Reactive power supply and DC bus voltage are managed by the grid-side inverter. Active power and rotor angular speed are adjusted by the machine side inverter facilitating power generation for varying wind. The effect of voltage and frequency deviation from the grid on the control is observed. The controllers are found to work satisfactorily except for large frequency variation. The current harmonics are also within the allowed limit. The proposed controllers are expected to satisfy the revised grid code for wind energy
Secure Intrusion Detection System for MANETs Using Triple-DES Algorithm
Get PDFNetworking is the process of accessing, exchanging or sharing the information. Packet switching plays a vital role in data transfer. Compared to wired network, wireless network has more data transferring. MANETs and WSN are the most common forms of Wireless media; in MANETs nodes are deployed or distributed in Ad-hoc way and they are communicating or exchange message using wireless Transmission. Security is a measure concern in Mobile Ad-hoc Network because MANETs have wide distribution of node and open medium; therefore, it becomes vulnerable and is easy for malicious hackers to attack