• 제목/요약/키워드: EL performance

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Factors Affecting Employee Loyalty in Railway Rolling Stock Maintenance Companies in Thailand

  • LIEOPHAIROT, Ratchaphong;ROJNIRUTTIKUL, Nuttawut
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.10
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    • pp.115-127
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    • 2022
  • The study's goal was to investigate the levels of employee loyalty (EL) in two Thai railway rolling stock maintenance (RRSM) companies. Simple random sampling was used to obtain a final sample of 118 individuals from October 2021 through December 2021. The research instrument was a questionnaire with an expert IOC value between 0.67 to 1.00 and a questionnaire reliability Alpha (𝛼) average value of 0.82. Descriptive statistics included the mean and standard deviation (SD). SPSS for Windows Version 21 and Multiple Regression Analysis (MRA) was used for the analysis. Results showed that the 118 employee's overall perceptions of their RRSM employers' motivating factors, human resource management, satisfaction, and loyalty were high. HRM's performance evaluation had the most significant overall influence on EL. Moreover, from the analysis of the five EL questionnaire items, the most influential item was the employee's income as a contributing factor to their EL. This was followed by the suitability of their work. Also, it seems the employees had a high level of loyalty to their firms even if a better offer of more money was made. They also indicated a high level of pride in their respective firms.

Enhanced Privacy Preservation of Cloud Data by using ElGamal Elliptic Curve (EGEC) Homomorphic Encryption Scheme

  • vedaraj, M.;Ezhumalai, P.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.11
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    • pp.4522-4536
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    • 2020
  • Nowadays, cloud is the fastest emerging technology in the IT industry. We can store and retrieve data from the cloud. The most frequently occurring problems in the cloud are security and privacy preservation of data. For improving its security, secret information must be protected from various illegal accesses. Numerous traditional cryptography algorithms have been used to increase the privacy in preserving cloud data. Still, there are some problems in privacy protection because of its reduced security. Thus, this article proposes an ElGamal Elliptic Curve (EGEC) Homomorphic encryption scheme for safeguarding the confidentiality of data stored in a cloud. The Users who hold a data can encipher the input data using the proposed EGEC encryption scheme. The homomorphic operations are computed on encrypted data. Whenever user sends data access permission requests to the cloud data storage. The Cloud Service Provider (CSP) validates the user access policy and provides the encrypted data to the user. ElGamal Elliptic Curve (EGEC) decryption was used to generate an original input data. The proposed EGEC homomorphic encryption scheme can be tested using different performance metrics such as execution time, encryption time, decryption time, memory usage, encryption throughput, and decryption throughput. However, efficacy of the ElGamal Elliptic Curve (EGEC) Homomorphic Encryption approach is explained by the comparison study of conventional approaches.

Performance evaluation of submerged membrane bioreactor for model textile wastewater treatment

  • Guembri, Marwa;Saidi, Neila;Neifar, Mohamed;Jaouani, Atef;Heran, Marc;Ouzari, Hadda-Imene
    • Membrane and Water Treatment
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    • v.11 no.2
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    • pp.123-130
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    • 2020
  • Submerged Membrane bioreactor (SMBR) is one of the last techniques that allow a high quality of treated industrial effluents by coupling biological treatment and membrane separation. Thus, this research was an effort to evaluate performance of a SMBR treating a model textile wastewater (MTWW). Different SMBR operating parameters like mixed liquor suspended solids (MLSS) and Dissolved oxygen concentration, hydraulic retention time (HRT), and nutrients addition (N and P) have been investigated. MTWW (influent to the SMBR) was generated using the reactive azo-dye, Novacron blue FNG (100mg/L feed concentration). Results of MTWW treatment using SMBR under optimal operating conditions (MLSS, 4.2-13.3g/L; HRT, 4 days; pH, 6.9-7.2; conductivity, 400-900 μS/cm and temperature, 19.4-22.2 ℃) showed that COD and blue colour treatment performances are between 94-98% and 30-80%, respectively. It is concluded that SMBR can be used in large scale textile wastewater treatment plants to improve effluent quality in order to meet effluent discharge standards.

Impact of a shock wave on a structure strengthened by rigid polyurethane foam

  • Mazek, Sherif A.;Mostafa, Ashraf A.
    • Structural Engineering and Mechanics
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    • v.48 no.4
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    • pp.569-585
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    • 2013
  • The use of the rigid polyurethane foam (RPF) to strengthen sandwich structures against blast terror has great interests from engineering experts in structural retrofitting. The aim of this study is to use the RPF to strengthen sandwich steel structure under blast load. The sandwich steel structure is assembled to study the RPF as structural retrofitting. The filed blast test is conducted. The finite element analysis (FEA) is also used to model the sandwich steel structure under shock wave. The sandwich steel structure performance is studied based on detonating different TNT explosive charges. There is a good agreement between the results obtained by both the field blast test and the numerical model. The RPF improves the sandwich steel structure performance under the blast wave propagation.

Characterization and Performance Evaluation of Advanced Aircraft Electric Power Systems

  • Eid, Ahmad;El-Kishky, Hassan;Abdel-Salam, Mazen;El-Mohandes, Mohamed T.
    • Journal of Power Electronics
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    • v.10 no.5
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    • pp.563-571
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    • 2010
  • A model of an advanced aircraft electric power system is developed and studied under variable-speed constant-frequency (VSCF) operation. The frequency of the generator's output voltage is varied from 400-Hz to 800-Hz for different loading scenarios. Power conversions are obtained using 12-pulse power converters. To reduce the harmonic contents of the generator output waveforms, two high-pass passive filters are designed and installed one at a time at the generator terminals. The performance of the two passive filters is compared according to their losses and effectiveness. The power quality characteristics of the studied VSCF aircraft electric power system are presented and the effectiveness of the proposed filter is demonstrated through compliance with the newly published aircraft electrical standards MIL-STD-704F.

Modeling of a Four-Quadrant Switched Reluctance Motor Drive on EMTDC/PSCAD

  • El-Samahy, Ismael;Marei, Mostafa I.;El-Saadany, Ehab F.
    • Journal of Electrical Engineering and Technology
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    • v.3 no.1
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    • pp.68-78
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    • 2008
  • This paper introduces a complete package for SRM drive on Power System Computer-Aided Design/Electromagnetic Transients (PSCAD/EMTDC). A three-phase SRM drive is modeled and simulated on PSCAD. The motor is modeled using an accurate nonlinear analytical model that takes into consideration the machine nonlinearities. A current control algorithm is applied for torque ripple minimization to achieve a smooth output torque which is necessary for high performance applications. The motor drive is tested for four-quadrant operations. The modeled SRM is capable of operating as a motor or generator during clockwise and counterclockwise motions. The proposed package helps in understanding the operational principles of switched reluctance motors, investigating the dynamic characteristics of SRM drives, and achieving a high performance dynamic control task.

Entrepreneurial Orientation, Access to Financial Resources and SMEs' Business Performance: The Case of the United Arab Emirates

  • ZARROUK, Hajer;SHERIF, Mohamed;GALLOWAY, Laura;EL GHAK, Teheni
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.12
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    • pp.465-474
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    • 2020
  • This study investigates how financial resources and entrepreneurial orientation (EO) may influence the performance of small- and medium-sized enterprises (SMEs) in the United Arab Emirates (UAE). Twenty-seven interviews were conducted and evaluated using the method of GABEK® (A GAnzheitliche BEwältigung von Komplexität - holistic processing of complexity). The research demonstrated that access to financial resources has significantly mediated EO's effect on the SMEs' performance. The study found that financial autonomy, enhanced through both personal financing and availability of external finance sources, plays a central role in supporting the EO dimension of autonomy and enhancing the SMEs' performance. In particular, the other EO dimension of risk-taking is stymied by lack of funds with which to take commercial and market opportunities. However, when an innovation strategy is pursued and adopted, access to finance can be facilitated, either through financial institutions or through other governmental funding programs attracting high potential innovators. Furthermore, financial barriers, difficulties accessing bank financing, and legal issues have a detrimental impact on SMEs' growth. The study has implications for policy-makers in the UAE, specifically in terms of sending a signal for lending institutions to consider strategies that provide access to affordable financial services to satisfy SMEs' needs.

Power, Degree and Selection Information-Aware Connected Dominating Set Construction Algorithm in Ad-hoc Wireless Networks (무선 Ad-hoc 네트워크에서 전력, 연결강도 및 이력 정보를 고려한 Connected Dominating Set 구성 방법)

  • Ha, Deok-Kyu;Song, Young-Jun;Kim, Dong-Woo;Kim, Young-Joon;Lee, In-Sung
    • The Journal of the Korea Contents Association
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    • v.9 no.8
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    • pp.49-56
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    • 2009
  • In this paper, we propose a method of energy level, node degree and selection information based CDS(Connected Dominating Set) construction algorithm for more efficient routing in ad-hoc wireless networks. Constructing CDS in ad-hoc wireless network, it is necessary to make more efficient algorithm that is faster, more simple and has low power consumption. A CDS must be minimized because nodes in the CDS consume more energy in order to handle various bypass traffics than nodes outside the set. It is better not to reconstruct CDS after constructing the most efficient CDS. To overcome this problem, we proposed the CDS construction algorithms based on EL+ND+Sel method. We compared and estimated the performance in each situation of EL + ND and EL + ND + Sel.

Morphological and Hemodynamic Parameters for Middle Cerebral Artery Bifurcation Aneurysm Rupture Risk Assessment

  • Qin, Hao;Yang, Qixia;Zhuang, Qiang;Long, Jianwu;Yang, Fan;Zhang, Hongqi
    • Journal of Korean Neurosurgical Society
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    • v.60 no.5
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    • pp.504-510
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    • 2017
  • Objective : To investigate the morphological and hemodynamic parameters associated with middle cerebral artery (MCA) bifurcation aneurysm rupture. Methods : A retrospective study of 67 consecutive patients was carried out based on 3D digital subtraction angiography data. Morphological and hemodynamic parameters including aneurysm size parameters (dome width, height, and perpendicular height), longest dimension from the aneurysm neck to the dome tip, neck width, aneurysm area, aspect ratio, Longest dimension from the aneurysm neck to the dome tip (Dmax) to dome width, and height-width, Bottleneck factor, as well as wall shear stress (WSS), low WSS area (LSA), percentage of LSA (LSA%) and energy loss (EL) were estimated. Parameters between ruptured and un-ruptured groups were analyzed. Receiver operating characteristics were generated to check prediction performance of all significant variables. Results : Sixty-seven patients with MCA bifurcation aneurysm were included (31 unruptured, 36 ruptured). Dmax (p=0.008) was greater in ruptured group than that in un-ruptured group. D/W (p<0.001) and the percentage of the low WSS area ($0.09{\pm}0.13$ vs. $0.01{\pm}0.03$, p<0.001) were also greater in the ruptured group. Moreover, the EL in ruptured group was higher than that in unruptured group ($6.39{\pm}5.04$ vs. $1.53{\pm}0.86$, p<0.001). Multivariate regression analysis suggested D/W and EL were significant predictors of rupture of MCA bifurcation aneurysms. Correlation analyses revealed the D/W value was positively associated with the EL (R=0.442, p<0.01). Conclusion : D/W and EL might be the most two favorable factors to predict rupture risk of MCA bifurcation aneurysms.

Performance of self-curing concrete as affected by different curing regimes

  • El-Dieb, A.S.;El-Maaddawy, T.A.
    • Advances in concrete construction
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    • v.9 no.1
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    • pp.33-41
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    • 2020
  • In this study, polyethylene glycol (PEG) and polyacrylamide (PAM) have been used as self-curing agents to produce self-curing concrete (SC). Compressive strength, ultrasonic pulse velocity (UPV), bulk electrical resistivity, chloride ion penetrability, water permeability, and main microstructural characteristics were examined under different curing regimes, and compared to those of the control concrete mixture with no self-curing agents. One batch of a control mixture and one batch of a SC mixture were air-cured in the lab to act as non-water-cured samples. The water curing regimes for the control mixture included continuous water curing for 3, 7, and 28 days and periodical moist curing using wetted burlap for 3 and 7 days. Curing regimes for the SC mixtures included 3 days of water curing and periodical moist curing for 3 and 7 days. SC mixtures showed better microstructure development and durability performance than those of the air-cured control mixture. A short water curing period of 3 days significantly improved the performance of the SC mixtures similar to that of the control mixture that was water cured for 28 days. SC concrete represents a step towards sustainable construction due to its lower water demand needed for curing and hence can preserve the limited water resources in many parts of the world.