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Identifying, mitigating, and confronting human resources risks is essential for organizational excellence. This study aims to identify, analyze, and provide strategies to deal with risks in one of the government organizations in Isfahan province. The present study is mixed, where the resilience strategies are presented using FMEA and FAAO methods, and the number of resilience is calculated quantitatively. The statistical population of this study is human resource experts. Due to the limitations of the statistical society, all employees were selected as samples. All risks were obtained through the study of research literature and in-depth interviews with experts. The interviews were coded using thematic analysis. In the first phase of this study, thirty four risks were identified, and among them, ten most significant risks were selected, and strategies for dealing with them were presented. In order to retrieve, three risks were selected: long-term illness, staff dissatisfaction, and exit of experience and skill without experience transfer. A total of nine strategies were presented to return to the pre-risk state or more desirable. The resiliency ratio of the organization’s human resources department was 0.66 before the occurrence of risk and 0.84 after the occurrence of the risk.

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In this paper, a new high dynamic range Digitally-Controlled Oscillator (DCO) for All-DPLL systems is proposed. The proposed DCO is based on using a ΔΣ modulator as a Digital-to-Analog converter. Using ΔΣ DAC can provide a very high resolution (18-bit) control on the DCO. The ΔΣ DAC output is a 2-level pulse signal that needs to be filtered for cancelling the out of band shaped noise. The used ΔΣ modulator is a 4^th order MASH ΔΣ modulator working with the OSR of 128 and the sampling frequency of 450MHz. the proposed DCO is used in a PLL to synthesize the frequency in the range of 1700MHz to 1800MHz for GSM-1800 application. The achieved phase noise for this PLL based synthesizer in whole the range is -115 dBc/Hz at the offset frequency of 500 kHz. The designed ADPLL including the DCO is simulated in ADS with 0.18µm CMOS technology.

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Thermal energy storing technologies are a new approach in reducing energy costs, managing demand side, pick shaving and increasing portion of renewable energies in energy production. In spite of lots of advantages of thermal energy storage techniques, there are still major challenges in the path of Latent heat thermal storages (LHTS). One of the challenges is the low charge and discharge rate of heat transfer in LHTS. In the current study charging rate of a shell and tube LHTS is numerically studied by enthalpy-porosity numerical technique. Exact positioning of the heat transfer tubes and thermal fins has great impact on the natural convection flows. In this study effect of increasing heat transfer tubes (HTF), lower positioning of tubes in four tubes configuration, changing upper tubes distance and using interconnected axial fins has been studied and compared to each other. Moreover, velocity and temperature contours have been analyzed. Results demonstrated that increasing number of tubes could not solve the slowing rate of charging at the end of process and tubes need to be positioned lower in the tube. In addition, it was observed that heat transfer axial fins can decelerate convection flows and develop stationary areas inside the shell. Prediction results revealed by lowering tubes and closing them to the shell wall, introduced in this article, it is possible to decrease charging time of 0.95 of storage capacity to one fourth of similar time in a one tube LHTS.

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Various solutions have been suggested to overcome the issue when cooling peak hours and electric energy consumption coincide. One of the solutions is to store the cooling load at off-peak hours. One of the most conventional types of storage systems is the ice-on-coil storage system. The low heat transfer rate in this system is one of the challenges. Since the conduction heat transfer coefficient of ice is low, by starting the ice formation, the heat transfer between the refrigerant inside the coil and the reservoir’s water will reduce. One idea to increase the heat transfer rate is to postpone the starting time of the freezing process to keep active the natural convection mechanism. In the present study, mechanical vibration has been used to linger freezing initiation in ice-on-coil energy storage system. The effect of longitudinal and lateral positioning of the probe, on the amount of temperature and initiation time of freezing as well as the amount and structure of formed ice has been investigated. The results revealed that placing the vibrator at the middle of coil over its two ends leads to further increase in the amount of formed ice. It is found that applying mechanical vibration can postpone the initiation time of the freezing process and decrease the subcooling temperature. Moreover, it is shown that the amount of ice formation is a function of subcooling temperature and initiation time of freezing. Finally, the energy consumption of the vibrator and the energy consumption reduction in peak-hour are calculated.

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Cold storage is a commonly used form of the energy storage systems. A major drawback in this type of energy storage is its low heat-transfer rate caused by the low thermal conduction of the phase change material and/or inefficiency of the components utilized in the thermal system. In the present experimental research, straps fins are used to improve the solidification rate of an ice storage system equipped with coiled tubes. Furthermore, the effect of employing straps fins in improving the ice-formation process is compared to that of the strorage system equipped with wavy coil tubes. The results indicate that wavy tube demonstrate a superior performance in increasing the ice formation rate. Comparing the ice-thicknesses obtained from using either of these methods approves the better peoformance characterstics of the wavy tubes. Employing wavy tubes is shown to increase to stored ice volume by 21.08% compared to the use of straps fins. The required power consumption per one liter of ice produced in the system equipped with straps finned tube and wavy coil tube is 0.72 kWh and 0.62 kWh, respectively. Also, in the crest area of the wavy tube configuration, the ice formed on the lower tube surface is generally thicker than that on the upper tube surface. The ice formation behaviour is opposite in the troughs where the ice thickness on the upper surface is 25% higher that on the lower surface. Finally, the difference in the ice thicknesses measured in horizontal and vertical directions is less than 1%.

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Hybrid simulation is a relatively new and efficient tool that uses the advantages of both numerical and experimental methods to evaluate the performance of structures under different loadings. In this paper, a hybrid simulation framework has been developed, in which OpenSees was considered as finite element software for modeling numerical part, OpenFresco as middleware for data exchange and LabVIEW as data collector and actuator movement controller. Utilizing OpenFresco in the developed framework, would be facilated conducting geographically distributed hybrid simulations. As the connection between OpenFresco and LabVIEW is hand shaking, the processing speed is very high and the delay between sending displacement and receiving force is only due to the dynamics and movement of the engine and the bandwidth of the sensor, so there is no interruption during this process and in this case, there is no need to define the predictor-corrector algorithm to keep the actuator movement continuous. To validate the accuracy and efficiency of the developed framework, an improved widened flange beam-column connection was considered in a one story one bay steel moment frame, and the mentioned frame was divided into two numerical and experimental substructures in such a way that half of the frame was modeled two-dimensionally in OpenSees and the other half was constructed in the laboratory. The horizontal acceleration of the Tabas earthquake was subjected to the frame. The accuracy of the control system which was used in the developed framework was investigated by comparing the measured and the command displacements, and the small value of HSEM indicated the proper performance of the control process. To evaluate the performance of hybrid simulation, a coupled numerical simulation (virtual hybrid simulation) was considered as a reference model. In this fully numerical simulation, ABAQUS and OpenSees were used as finite element software and OpenFresco as middleware. Results of coupled numerical simulation and hybrid simulation were compared with each other and the obtained accuracy index (ε^rms) indicated the accuracy and appropriate performance of the developed hybrid simulation framework.