• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.7
• /
• pp.3386-3411
• /
• 2019

Secured and reliable routing is a crucial factor for improving the performance of Wireless Mesh Networks (WMN) since these networks are susceptible to many types of attacks. The existing assumption about the internal nodes in wireless mesh networks is that they cooperate well during the forwarding of packets all the time. However, it is not always true due to the presence of malicious and mistrustful nodes. Hence, it is essential to establish a secure, reliable and stable route between a source node and a destination node in WMN. In this paper, a trust based secure routing algorithm is proposed for enhancing security and reliability of WMN, which contains cross layer and subject logic based reliable reputation scheme with security tag model for providing effective secured routing. This model uses only the trusted nodes with the forwarding reliability of data transmission and it isolates the malicious nodes from the providing path. Moreover, every node in this model is assigned with a security tag that is used for efficient authentication. Thus, by combining authentication, trust and subject logic, the proposed approach is capable of choosing the trusted nodes effectively to participate in forwarding the packets of trustful peer nodes successfully. The simulation results obtained from this work show that the proposed routing protocol provides optimal network performance in terms of security and packet delivery ratio.

• Journal of Internet Computing and Services
• /
• v.20 no.3
• /
• pp.85-92
• /
• 2019

In this paper, we extract the quantitative relation data of activities from the workflow event log file recorded in the XES standard format and connect them to rediscover the workflow process model. Extract the workflow process patterns and proportions with the rediscovered model. There are four types of control-flow elements that should be used to extract workflow process patterns and portions with log files: linear (sequential) routing, disjunctive (selective) routing, conjunctive (parallel) routing, and iterative routing patterns. In this paper, we focus on four of the factors, disjunctive routing, and conjunctive path. A framework implemented by the authors' research group extracts and arranges the activity data from the log and converts the iteration of duplicate relationships into a quantitative value. Also, for accurate analysis, a parallel process is recorded in the log file based on execution time, and algorithms for finding and eliminating information distortion are designed and implemented. With these refined data, we rediscover the workflow process model following the relationship between the activities. This series of experiments are conducted using the Large Bank Transaction Process Model provided by 4TU and visualizes the experiment process and results.

• Korean Journal of Childcare and Education
• /
• v.14 no.6
• /
• pp.171-185
• /
• 2018

Objective: This study aimed to investigate the influence of child care center managers' coaching leadership on teachers' motivational self-concepts via middle managers' coaching leadership. Teachers' motivational self-concepts consisted of personal self-concept and social self-concept. Methods: A questionnaire survey was conducted on 475 child care center teachers regarding teachers' recognition of the coaching leadership of managers and middle managers and motivational self-concepts of teachers. To analyze the collected data, the path was examined through descriptive statistics, correlation analysis, structural analysis using Amos, and the mediating effect was confirmed by conducting the Sobel Test. Results: The middle manager's coaching leadership was found to mediate the pathways from the manager's coaching leadership to the teacher's social self-concept, but did not mediate the personal self-concept of teachers. Conclusion/Implications: This study showed that the manager's coaching leadership was mediated by the middle manager's coaching leadership and that the manager's coaching leadership had an influence on the social self-concept of teachers. These results imply that both managers and middle managers need to develop coaching leadership skills in order to improve the motivational self-concept of teachers, which is important for work efficiency at child care centers.

• Advances in Computational Design
• /
• v.4 no.3
• /
• pp.295-305
• /
• 2019

The sealing cement of total hip arthroplasty is the most widely used binder in orthopedic surgery for anchoring implants to their recipient bones. Nevertheless, this latter remains a fragile material with weak mechanical properties. Inside this material cracks initiate from cavities. These cracks propagate under the effect of fatigue and lead to the failure of this binder and consequently the loosening of the prosthesis. In this context, this work consists to predict the position of cracks initiation and their propagations path using the Extended Finite Element Method (XFEM). The results show that cracks can only be initiated from a sharp edges of an ellipsoidal cavity which the ratio of the minor axis over the major axis is equal to 0.1. A maximum crack length of 19 ?m found for a cavity situated in the proximal zone position under a static loading. All cracks propagate in same(almost) way regardless of the cavity(site of initiation) position and its inclination in the proximal zone.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.23 no.2
• /
• pp.38-45
• /
• 2019

The present work suggests a numerical approach using a thermoacoustic network model for the eigenvalue calculation of thermoacoustic instability problems in an aero gas turbine combustor. The model is developed based on the conservation laws for mass, momentum, and energy between acoustic network elements with an area change. Acoustic field in a practical aero gas turbine combustor which has a complicated flow path is analyzed using the current model. The predictive capabilities of the current modeling approach are compared with the acoustic characteristics calculated using Helmholtz solver based on 3D finite element method(FEM).

• Coupled systems mechanics
• /
• v.8 no.2
• /
• pp.129-146
• /
• 2019

The main goal of this work is to develop a numerical simulator to study an isothermal single-phase two-component flow in a naturally fractured oil reservoir, taking into account advection and diffusion effects. We use the Peng-Robinson equation of state with a volume translation to evaluate the properties of the components, and the discretization of the governing partial differential equations is carried out using the Finite Difference Method, along with implicit and first-order upwind schemes. This process leads to a coupled non-linear algebraic system for the unknowns pressure and molar fractions. After a linearization and the use of an operator splitting, the Conjugate Gradient and Bi-conjugated Gradient Stabilized methods are then used to solve two algebraic subsystems, one for the pressure and another for the molar fraction. We studied the effects of fractures in both the flow field and mass transport, as well as in computing time, and the results show that the fractures affect, as expected, the flow creating a thin preferential path for the mass transport.

• The Korean Journal of Health Service Management
• /
• v.12 no.3
• /
• pp.63-78
• /
• 2018

Objectives: To construct a structural equation model to explain and predict nursing performance in advanced beginner-stage nurses. Methods: This study was conducted from September 1 to October 10, 2017. Participants in this study were 220 nurses recruited from general hospitals with over 300 beds in P and K cities. Confirmatory factor and path analyses were conducted using AMOS 18.0. Results: Nursing performance was affected by self-leadership and self-efficacy; self-efficacy (${\beta}=.794$, p=.025) had a greater effect. Problem-solving competency was affected byself-leadership and self-efficacy ;self-efficacy(${\beta}=.712$, p=.016) had a greater effect. Self-leadership was affected byself-efficacy(${\beta}=.820$, p=.013). Conclusion: Based on the results of this study, it is recommended that a new program be developed and applied to improve advanced beginner-stage nurses' self-leadership and self-efficacy to enhance nursing performance.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.26 no.3
• /
• pp.176-182
• /
• 2021

This research proposes a high-frequency circuit that can accurately predict the differential mode noise of single-phase inverters at the circuit design stage. Proposed single-phase inverter high frequency circuit in the work is a form in which harmonic impedance components are added to the basic single-phase inverter circuit configuration. For accurate noise prediction, parasitic components present in each part of the differential noise path were extracted. Impedance was extracted using a network analyzer and Q3D in the measurement range of 150 kHz to 30 MHz. A high-frequency circuit model was completed by applying the measured values. Simulations and experiments were conducted to confirm the validity of the high-frequency circuit. As a result, we were able to predict the resonance point of the differential mode voltage extracted as an experimental value with a high-frequency circuit model within an approximately 10% error. Through this outcome, we could verify that differential mode noise can be accurately predicted using the proposed model of the high-frequency circuit without a separate test bench for noise measurement.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.2
• /
• pp.1147-1156
• /
• 2021

This study aims to examine the role of resilience in academic engagement and also to evaluate the theoretical model of the relationships between resilience and engagement. A survey of faculty members in 20 study programs from 12 universities in Jakarta was conducted, Where 247 questionnaires were returned from the 495 distributed. Furthermore, 240 valid data were available for evaluation in order to test the model, and a confirmatory Structural Equation Modelling was conducted, using AMOS 20. Criteria of goodness-fit demonstrated the relatively adequate model, and the coefficient of structural path describes the potential of the links. Three out of four paths available significantly showed the role of developmental persistency and positive emotions on work engagement. The participants of the study include only constituted academics of private universities in Indonesia. Thus there is a need for better care in interpreting the level of resilience and engagement, as engagement may vary when used in a different context. The study suggests interventions for practitioners, not only for academia in the higher education context but also for other professionals in managing engagement at the individual or team level. Therefore, combining resilience and engagement programs may contribute to an enhancement in the productivity of employees.

• Korean Journal of Clinical Pharmacy
• /
• v.31 no.4
• /
• pp.293-300
• /
• 2021

Background: This study aims to determine whether the new 6-year pharmacy curriculum is designed to help students in their career path based on the employment status of the current 2+4 pharmacy school graduates. Methods: An online survey was conducted to the pharmacists who graduated from Woosuk University College of Pharmacy between 2015 and 2021. The survey questions included the current employment status of the graduates and their feedback on the clinical pharmacy curriculum at Woosuk University. Results: There were a total of 104 graduates who responded to the survey out of 312 graduates of whom the school had current contact information. Most of the graduates are currently working in a community pharmacy (63.5%), followed by hospital pharmacy (27.9%) and pharmaceutical industry (4.8%). Although most graduates were satisfied with clinical pharmacy courses at our college, many thought there needs to be a reinforcement or improvement in the curriculum, including pharmacotherapy and pharmacy practice experiences as well as social pharmacy courses. Conclusion: Based on our study, clinical and social pharmacy are the courses that teach the knowledge and skills required in community and hospital pharmacy and yet, are most in need of improvement. As most graduates work in a community or hospital pharmacy, it is necessary to improve our pharmacy curriculum so that they can learn and demonstrate their clinical skills effectively.