• The Journal of Asian Finance, Economics and Business
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• 제8권8호
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• pp.85-91
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• 2021

This research aims to analyze the impact of Financial Risk (FR), Information Asymmetric (IA), and Earning Power (EP) on Real Earning Management (REM) of listed trading companies in IDX Indonesia. This study aims to analyze the influence of FR, IA, EP, on REM through Operating Cash Flow, Production expense, and Discretionary Expense. The study employs an unbalanced panel of data set from 2014 to 2018 on the activity of all trading companies (15 in total) as selected samples of 48 feasible samples from 144 existing data. The sample used a non probability sampling method with a purposive sampling technique. This research was classified as causative and tested by multiple linear regression model with cross-sectional analysis. The result indicated a significant impact of FR on REM through PROD and DISX but not through COF. How ever, IA, and EP showed significant impact on REM by means of COF but not go by PROD and DISX..The findings in this study contribute to the users of financial reports particularly the stakeholders in defining the determinants of real earning management practices among firms when it comes to decision making.

• Journal of the Korea Institute of Military Science and Technology
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• 제24권2호
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• pp.204-210
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• 2021

In this paper, we studied a method of wirelessly checking up the POD for captive flight tests which is performed during the development of guided weapons systems. The wireless power transfer module, the power distribution device, and the battery pack were designed to wirelessly power the captive flight test POD, and the communication device was designed to enable wireless communication between the POD and the check-up device. The communication device was designed to enable WiFi, IR communication, and laser diode communication, so that various communication methods could be tested. Through the performance test, it was confirmed that power was stably supplied to the captive flight test POD, and the wireless communication performance was verified by measuring the delay time and error rate. As a result, by using our system the POD check-up for the captive flight test was performed wirelessly and the data of the captive equipment could be obtained effectively.

• Ocean Systems Engineering
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• 제10권4호
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• pp.359-371
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• 2020

The performance of a multi-level overtopping wave energy converter (OWEC) has been numerically and experimentally investigated in a two-dimensional wave tank in order to study the effects of opening width of additional reservoirs. The device is a fixed OWEC consisting of an inclined ramp together with several reservoirs at different levels. A particle-based numerical simulation utilizing the Lattice Boltzmann Method (LBM) is used to simulate the flow behavior around the OWEC. Additionally, an experimental model is also built and tested in a small wave flume in order to validate the numerical results. A comparison in energy captured performance between single-level and multi-level devices has been proposed using the hydraulic efficiency. The enhancement of power capture performance is accomplished by increasing an overtopping flow rate captured by the extra reservoirs. However, a noticeably large opening of the extra reservoirs can result in a reduction in the power efficiency. The overtopping flow behavior into the reservoirs is also presented and discussed. Moreover, the results of hydrodynamic performance are compared with a similar study, of which a similar tendency is achieved. Nevertheless, the LBM simulations consume less computational time in both pre-processing and calculating phases.

• Journal of Korean Society of Industrial and Systems Engineering
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• 제43권4호
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• pp.33-40
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• 2020

In order to satisfy customers, it is important to identify the quality elements that affect customers' satisfaction. The Kano model has been widely used in identifying multi-dimensional quality attributes in this purpose. However, the model suffers from various shortcomings and limitations, especially those related to survey practices such as the data amount, reply attitude and cost. In this research, a model based on the text sentiment analysis is proposed, which aims to substitute the survey-based data gathering process of Kano models with sentiment analysis. In this model, from the set of opinion text, quality elements for the research are extracted using the morpheme analysis. The opinions' polarity attributes are evaluated using text sentiment analysis, and those polarity text items are transformed into equivalent Kano survey questions. Replies for the transformed survey questions are generated based on the total score of the original data. Then, the question-reply set is analyzed using both the original Kano evaluation method and the satisfaction index method. The proposed research model has been tested using a large amount of data of public IT service project evaluations. The result shows that it can replace the existing practice and it promises advantages in terms of quality and cost of data gathering. The authors hope that the proposed model of this research may serve as a new quality analysis model for a wide range of areas.

• Journal of the Korean Society of Industry Convergence
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• 제24권4_2호
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• pp.421-434
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• 2021

The expansion of information sharing activities using online can increase the threat of information exposure by increasing the diversity of approaches to information within an organization. The purpose of this study is to present conditions for improving the information security compliance intention of insiders to improve the level of information security within the organization. In detail, the study applies the theory of planned behavior that clearly explains the cause of an individual's behavior and proposes a way to increase the compliance intention by integrating the social control theory and goal-setting theory. The study presented research models and hypotheses based on previous studies, collected samples by applying a questionnaire technique, and tested hypotheses through structural equation modeling. As a result, information security attitude, subjective norms, and self-efficacy had a positive influence on the intention to comply. Also, attachment, commitment, and involvement, which are the factors of social control theory, formed a positive attitude toward information security. Goal difficulty and goal specificity, which are the factors of goal setting theory, formed a positive self-efficacy. The study presents academic and practical implications in terms of suggesting a method of improving the information security compliance intention of employees.

• International Journal of Internet, Broadcasting and Communication
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• 제14권2호
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• pp.47-54
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• 2022

For safe driving of autonomous vehicles, road damage detection is very important to lower the potential risk. In order to ensure safety while an autonomous vehicle is driving on the road, technology that can cope with various obstacles is required. Among them, technology that recognizes static obstacles such as poor road conditions as well as dynamic obstacles that may be encountered while driving, such as crosswalks, manholes, hollows, and speed bumps, is a priority. In this paper, we propose a method to extract similarity of images and find damaged road images using OpenCV image processing and CNN algorithm. To implement this, we trained a CNN model using 280 training datasheets and 70 test datasheets out of 350 image data. As a result of training, the object recognition processing speed and recognition speed of 100 images were tested, and the average processing speed was 45.9 ms, the average recognition speed was 66.78 ms, and the average object accuracy was 92%. In the future, it is expected that the driving safety of autonomous vehicles will be improved by using technology that detects road obstacles encountered while driving.

• Imaging Science in Dentistry
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• 제52권2호
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• pp.187-195
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• 2022

Purpose: This study developed a convolutional neural network (CNN) model to diagnose maxillary sinusitis on panoramic radiographs(PRs) and cone-beam computed tomographic (CBCT) images and evaluated its performance. Materials and Methods: A CNN model, which is an artificial intelligence method, was utilized. The model was trained and tested by applying 5-fold cross-validation to a dataset of 148 healthy and 148 inflamed sinus images. The CNN model was implemented using the PyTorch library of the Python programming language. A receiver operating characteristic curve was plotted, and the area under the curve, accuracy, sensitivity, specificity, positive predictive value, and negative predictive values for both imaging techniques were calculated to evaluate the model. Results: The average accuracy, sensitivity, and specificity of the model in diagnosing sinusitis from PRs were 75.7%, 75.7%, and 75.7%, respectively. The accuracy, sensitivity, and specificity of the deep-learning system in diagnosing sinusitis from CBCT images were 99.7%, 100%, and 99.3%, respectively. Conclusion: The diagnostic performance of the CNN for maxillary sinusitis from PRs was moderately high, whereas it was clearly higher with CBCT images. Three-dimensional images are accepted as the "gold standard" for diagnosis; therefore, this was not an unexpected result. Based on these results, deep-learning systems could be used as an effective guide in assisting with diagnoses, especially for less experienced practitioners.

• Journal of the Korean Society for Aviation and Aeronautics
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• 제30권2호
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• pp.24-33
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• 2022

This study analyzed and derived a plan to reduce fuel consumption of domestic aircraft. Specifically, this study tested fuel consumption in the short-distance flights of B737. Fuel consumption was calculated by substituting the simulation variable values into Matlab. The strength of this study is that the actual operating environment was reflected by collecting the B737 flight data. As a result of the study, the domestic fuel consumption rate in the computed flight plan was less than the current fuel consumption rate. Existing limitations of this study is that it was difficult to reflect the various variables constituting the flight environment, and thus there can be errors in the measurement of the fuel consumption. There are two major expected applications from this study. First, applying the plans from this study will lead to a reduction in the amount of fuel and thus provide positive economic effects for commercial airlines. Second, the plan from this study will provide a basis for pilots to predict fuel consumption more accurately. In conclusion, this study proposes a fuel saving plan with useful applications for pilots and airlines.

• The Transactions of the Korean Institute of Power Electronics
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• 제27권4호
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• pp.348-355
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• 2022

A bipolar DC distribution system suffers from an imbalance in voltages when asymmetric loads are connected at the outputs. Dedicated voltage balancers are required to address the imbalance in bipolar voltage levels. However, additional components eventually increase the cost and decrease the efficiency and power density of the system. Therefore, to deal with the imbalance in output voltages without adding any extra components, this study presents a coupled inductor-based voltage balancing technique with a dual-output CLL resonant converter. The proposed coupled inductor does not require extra magnetic components to balance the output voltages because it is the result of resonant inductors of the CLL tank circuit. It can also avoid complex control schemes applied to voltage balancing. Moreover, with the proposed coupled inductor, the CLL converter acquires good features including zero voltage and zero current switching. Detailed analysis of the proposed coupled inductor is presented with different load conditions. A 3.6-kW hardware prototype was built and tested to validate the performance of the proposed coupled inductor-based voltage balancing technique.

• Journal of Microbiology and Biotechnology
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• 제32권5호
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• pp.672-679
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• 2022

Microbial lipases are used widely in the synthesis of various compounds due to their substrate specificity and position specificity. 4-Ethyl malate (4-EM) made from diethyl malate (DEM) is an important starting material used to make argon fluoride (ArF) photoresist. We tested several microbial lipases and found that Photobacterium lipolyticum M37 lipase position-specifically hydrolyzed DEM to produce 4-EM. We purified the reaction product through silica gel chromatography and confirmed that it was 4-EM through nuclear magnetic resonance analysis. To mass-produce 4-EM, DEM hydrolysis reaction was performed using an enzyme reactor system that could automatically control the temperature and pH. Effects of temperature and pH on the reaction process were investigated. As a result, 50℃ and pH 4.0 were confirmed as optimal reaction conditions, meaning that M37 was specifically an acid lipase. When the substrate concentration was increased to 6% corresponding to 0.32 M, the reaction yield reached almost 100%. When the substrate concentration was further increased to 12%, the reaction yield was 81%. This enzyme reactor system and position-specific M37 lipase can be used to mass-produce 4-EM, which is required to synthesize ArF photoresist.