• Journal of Advanced Marine Engineering and Technology
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• v.6 no.1
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• pp.25-33
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• 1982

The characteristics of the stator current and torque of a small three- phase squirrel cage induction motor and studied experimentally under the situation of a single-phase operation due to various causes. Through the experiments, the torque-slip and current-slip curve of single-phase circuit as well as three-phase circuit are obtained and the needed constants are determined. The stator current and torque are calculated by the current and torque equations derived by the unbalanced circuit theory. The numerical values obtained from the above methods are compared with the experimental values under the same conditions. The results of the study are summerized as follow; 1) The values computed by the unbalanced circuit theory generally come to approach the values recorded through experiments. 2) Near the rated load, speed drop is less than 1.2 per cent of the speed of three-phase induction motor and torque reduces less than 3 per cent of it of three-phase induction motor when three-phase induction motor is run under a single-phase. On the other hand, the stator current in a single-phase circuit is more than 1.9 times of it in three-phase circuit. 3) The stalling torque in a single-phase circuit is reduced to about 41 per cent of it in three-phase circuit while the corresponding slip is moved toward the synchroneous speed and the corresponding stator current is increased.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.69-79
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• 2021

Good Corporate Governance (GCG) has been implemented by companies, especially companies that have gone public. However, many local companies still have not applied the principles of GCG. This study examines the implementation of the CG concept which is not fully implemented in family businesses in Indonesia. Besides, this research also aims to find out the role of the Internal Audit function in enhancing GCG practices. This research is a qualitative study that uses in-depth interviews, observation, and data triangulation, to gather evidence from exploratory case studies conducted in three family business firms. The results of this study found that CG is essential for the successful run of family businesses. After analyzing the data, we developed a new theory called Islamic Integrity Governance. The Internal Auditor plays a key role in improving GCG and a vibrant and agile internal audit function can be an indispensable resource supporting sound corporate governance. The internal auditor provides objective assurance and insight on the effectiveness and efficiency of risk management, internal control, and governance processes. Therefore, the Internal Auditor is an important pillar for effective and efficient GCG implementation. This theory concludes several concepts such as THTCL (Trustworthy, Honest, Transparent, Creative, Loyal). Internal auditors are needed because the concept of control is useful for improving GCG in business.

• Coupled systems mechanics
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• v.11 no.2
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• pp.151-166
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• 2022

Peltier cells have low efficiency, but they are becoming attractive alternatives for affordable and environmentally clean cooling. In this line, the current article develops closed-form and semianalytical solutions to improve the temperature distribution of Bi₂Te₃ thermoelements. From the distribution, the main objective of the current work-the optimal electric intensity to maximize cooling-is inferred. The general one-dimensional differential coupled equation is integrated for linear and quadratic geometry of thermoelements, under temperature constant properties. For a general shape, a piece-wise solution based on heat flux continuity among virtual layers gives accurate analytical solutions. For variable properties, another piece-wise solution is developed but solved iteratively. Taking advantage of the formulae, the optimal intensity is directly derived with a minimal computational cost; its value will be of utility for more advanced designs. Finally, a parametric study including straight, two linear, barrel, hourglass and vase geometries is presented, drawing conclusions on how the shape of the thermoelement affects the coupled phenomena. A specially developed coupled and non-linear finite element research code is run taking into account all the materials of the cell and using symmetries and repetitions. These accurate results are used to validate the analytical ones.

• Journal of Information Science Theory and Practice
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• v.11 no.4
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• pp.1-13
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• 2023

Being one of the first and hardest hit countries by the coronavirus, Iran still continues to preserve its place among nations with the highest rates of infection and COVID-19 related deaths. While on the surface, such worrying status evinces the failure of the authorities in handling the crisis, at deeper levels, it points to the fundamentalist nature of the government and political system of the country. In this view, the current devastating condition in Iran is a clear indication of the all-out influence of the Islamic regime's ideologies on officials' decision-making and their political agendas throughout the pandemic. Accordingly, the staterun mainstream media, as the most preeminent institution of power, have been incessantly engaged in disseminating a series of ideology-laden information around the issues concerning the coronavirus, and in line with the developing political discourses during pandemic. Far from being based on factual accounts or scientific facts, these disseminated messages inevitably grew into a source of disinformation, ultimately resulting in overall public confusion and skepticism. Through examining the data gathered from some of the most prominent online news agencies run by the government, this study identifies five major discursive trends through which the mainstream media propagated ambiguous and manipulative information about COVID-19. These findings are then explained in the light of media system dependency theory, leading to the argument that within autocratic nation-states, public reliance on media during a national/global crisis brings about new opportunities for state exploitation, and further distressing consequences for the people.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.4
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• pp.345-355
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• 2014

This paper focuses on aerodynamic and inertial modeling of the propeller for its applications in flight dynamics analyses of a propeller-driven airplane. Unsteady aerodynamic and inertial loads generated by the propeller are formulated using the blade element method, where the local velocity and acceleration vectors for each blade element are obtained from exact kinematic relations for general maneuvering conditions. Vortex theory is applied to obtain the flow velocities induced by the propeller wake, which are used in the computation of the aerodynamic forces and moments generated by the propeller and other aerodynamic surfaces. The vortex lattice method is adopted to obtain the induced velocity over the wing and empennage components and the related influence coefficients are computed, taking into account the propeller induced velocities by tracing the wake trajectory trailing from each of the propeller blades. Aerodynamic forces and moments of the fuselage and other aerodynamic surfaces are computed by using the wind tunnel database and applying strip theory to incorporate viscous flow effects. The propeller models proposed in this paper are applied to predict isolated propeller performances under steady flight conditions. Trimmed level forward and turn flights are analyzed to investigate the effects of the propeller on the flight characteristics of a propeller-driven light-sports airplane. Flight test results for a series of maneuvering flights using a scaled model are employed to run the flight dynamic analysis program for the proposed propeller models. The simulations are compared with the flight test results to validate the usefulness of the approach. The resultant good correlations between the two data sets shows the propeller models proposed in this paper can predict flight characteristics with good accuracy.

• Environmental and Resource Economics Review
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• v.19 no.4
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• pp.805-828
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• 2010

Korea also plans to introduce Renewable Portfolio Standard (RPS) for strengthening market functions after 2012 as United States and several members of EU countries did. Through the introduction of RPS, it requires energy industry to supply new and renewable energy at fixed rate. Therefore, it will contribute to the distribution of new and renewable energy. This paper analyzed the economic effect of the introduction of RPS using CGE. The summary of the paper on the analysis of the economic effect based on endogenous growth theory under imperfect market competition by using CGE is as follows; Since RPS possibly regulates the amount of new and renewable energy, it can achieve the target amount of new and renewable energy without fail. As achieving the target amount accurately, the distribution of more advanced skills can be expected. However, GDP reduction can occur because investment cost increases due to the requirement of new and renewable energy supply. Therefore, in the long run, it is appropriate to introduce RPS because it contributes to the distribution of new and renewable energy and can be utilized as a new growth engine to encourage economic growth.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.317-320
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• 2006

The optimum mobile phase condition for analysis of the six purine derivatives (caffeine, guanine, hypoxanthine, purine, theobromine, and theophylline) were determined by a HCI program. Reversed-phase HPLC system was used with the binary mobile phase, water and methanol. Three retention models (Snyder, Langmuir, and Binary polynomial) were considered to predict the retention factors. The elution profiles were calculated by the plate theory based on the binary polynomial retention model. From the final calculated results, the binary polynomial retention model showed the best agreements between the calculated and experimental data. In the isocratic mode, the optimum mobile phase composition of water/methanol is 93/7(v/v). However, we used step-gradient mode to decrease the run-time ($1^{st}$ mobile phase : water/methanol = 93/7 (v/v), gradient time : 5 min, $2^{nd}$ mobile phase : water/methanol = 75/25 (v/v)). The experimental and simulated profiles of above the two conditions show a good agreement.

• Journal of Science Education
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• v.37 no.2
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• pp.278-293
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• 2013

The purpose of this study was to analyze the characteristics of multiple-choice test items used in assessment of high school integrated science according to 2009 revised curriculum. For the analysis of the tendency of item setting, we devised an analytic framework specific to integrated science, and analyzed the characteristics of items by applying the devised framework and item response theory. The results of the tendency of item setting revealed that most of items run counter to the intent of integrated science in terms of item resource, integration extent, and cognitive level, which means teachers are stick to separative method in teaching-learning and assessment of integrated science. The results of the analysis applying item response theory showed that item difficulty was appropriate and item discrimination was considerably high. However, there was no relevance between the tendency of item setting and qualitative characteristics of the items. We also discussed some agendas to improve the teaching-learning and assessment of integrated science based on the results of this study.

• International Journal of Advanced Culture Technology
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• v.10 no.3
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• pp.104-110
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• 2022

This paper aims to analyze discourse metaphors by paying attention to Seoul mayoral by-election, mainly focusing on election campaign and its related news articles. The 2021 Seoul mayoral by-election was held because the former mayor died in an apparent suicide after he was accused of years of sexual harassment to a former secretary. But in the run-up to the by-election, the newly coined word 'alleged victim' from the ruling party caused a big controversy because the party attempted to deny the authenticity of the secretary's claim by calling her "an alleged victim," instead of "a victim" to defend the former mayor who is a member of the ruling party, implying that the woman's claim is just an allegation with no proof. Thus, this paper has analyzed how news stories were reported with regard to the word 'alleged victim' poser on news stories in two Korean quality newspapers, a conservative newspaper (Chosun Ilbo) and a liberal newspaper (Hankyoreh) from March 1 to April 1, 2021 and analyzed them with the framework of Lakoff and Johnson's Conceptual Metaphor Theory(1980). The findings are as follows: (i) the conservative newspaper reports this issue much more than the liberal newspaper; (ii) both quality newspapers follow the metaphor principles by Conceptual Metaphor Theory; (iii) the conservative newspaper is more likely to follow the Strick Father model (a conservative model) while the liberal newspaper is to follow the Nurturant Parent model (a liberal model), thus indicating that each newspaper's ideology is well represented by the models of Conceptual Metaphor Theory

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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• pp.3689-3700
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• 2016

It is not practically feasible to apply hardware-based fault-tolerant schemes, such as hardware replication, in mobile devices. Therefore, software-based fault-tolerance techniques, such as checkpoint and rollback schemes, are required. In checkpoint and rollback schemes, the optimal checkpoint interval should be applied to obtain the best performance. Most previous studies focused on minimizing the expected execution time or response time for completing a given task. Currently, most mobile applications run in real-time environments. Therefore, it is extremely essential for mobile devices to employ optimal checkpoint intervals as determined by the real-time constraints of tasks. In this study, we tackle the problem of determining the optimal inter-checkpoint interval of checkpoint and rollback schemes to maximize the deadline meet ratio in real-time systems and to build a probabilistic cost model. From this cost model, we can numerically find the optimal checkpoint interval using mathematical tools. The performance of the proposed solution is evaluated using analytical estimates.