• Journal of Drive and Control
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• v.12 no.3
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• pp.18-24
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• 2015

The plug-in hybrid electric vehicle has a high fuel economy and can be driven long distances. Its different modes include the electric vehicle, hybrid electric vehicle, and only engine operating mode. A power management strategy is important to determine which mode should be selected. The strategy makes the vehicle more efficient using appropriate power sources for driving. However, the strategy usually needs a driving speed profile which is future driving cycle. If the profile is known, the strategy easily determines which mode is driven efficiently. However, it is difficult to estimate the speed profile for a real system. To address this problem, this paper proposes a new power distribution strategy using a neural network. The average speed and driving range are used as input parameters to train the neural network system. The strategy determines a limit for the use of the battery and the desired power is distributed between the engine and the motor simultaneously. Its fuel economy can increase by improving the basic strategy.

• Smart Structures and Systems
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• v.29 no.1
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• pp.251-266
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• 2022

Structural Health Monitoring (SHM) of critical infrastructure comprises a major pillar of maintenance management, shielding public safety and economic sustainability. Although SHM is usually associated with data-driven metrics and thresholds, expert judgement is essential, especially in cases where erroneous predictions can bear casualties or substantial economic loss. Considering that visual inspections are time consuming and potentially subjective, artificial-intelligence tools may be leveraged in order to minimize the inspection effort and provide objective outcomes. In this context, timely detection of sensor malfunctioning is crucial in preventing inaccurate assessment and false alarms. The present work introduces a sensor-fault detection and interpretation framework, based on the well-established support-vector machine scheme for anomaly detection, combined with a coalitional game-theory approach. The proposed framework is implemented in two datasets, provided along the 1st International Project Competition for Structural Health Monitoring (IPC-SHM 2020), comprising acceleration and cable-load measurements from two real cable-stayed bridges. The results demonstrate good predictive performance and highlight the potential for seamless adaption of the algorithm to intrinsically different data domains. For the first time, the term "decision trajectories", originating from the field of cognitive sciences, is introduced and applied in the context of SHM. This provides an intuitive and comprehensive illustration of the impact of individual features, along with an elaboration on feature dependencies that drive individual model predictions. Overall, the proposed framework provides an easy-to-train, application-agnostic and interpretable anomaly detector, which can be integrated into the preprocessing part of various SHM and condition-monitoring applications, offering a first screening of the sensor health prior to further analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.170-177
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• 2020

This study examined the clamping force control method and the braking performance test results of an electromechanical brake (EMB) using braking test equipment. Most of the studies related to EMBs have been carried out in the automotive field, dealing mainly with the static test results for various control methods. On the other hand, this study performed a dynamic performance evaluation. The three-phase interior permanent magnet synchronous motor (IPMSM) was applied to drive the actuator of the EMB, and the analysis was verified by JMAG(Ver. 18.0), which is finite element method (FEM) software. The current control, speed control, and position control were used for clamping force control of the EMB, and the maximum torque per ampere (MTPA) control was applied to the current controller for efficient control. The EMB's emergency braking deceleration performance was tested in the same way as conventional pneumatic brake systems when the wheel of a train rotates at 110 km/h, 230 km/h, and 300 km/h. The emergency braking time, with the wheel stopped completely at the maximum rotational speed, was approximately 73 seconds. The similarity of the braking time and deceleration pattern was verified through a comparison with the performance test results of the pneumatic brake system applied to the next generation high-speed railway vehicle (HEMU-430X).

• Journal of Cadastre & Land InformatiX
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• v.46 no.2
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• pp.297-312
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• 2016

The current government strives to train those supposed to drive the national economy, and bridge the gap between qualification and industrial sites through competency-based qualification systems, not the educational background. In this regards, the government is planning to adopt the course evaluation qualification system. The course evaluation qualification system, on a basis of the NCS, is a system to qualify certain people completing the education and training fulling a specific requirement for a national technical qualification in case they meet the internally and externally assessed criteria. This can be seen as an attempt to practically link between job training and qualifications. The NCS model and learning module in the cadastral field are already utilized as the training and eduction in the specialized school and colleges. However, the current national technical qualification system is considered as a main system because the course evaluation qualification system has not been introduced yet. This study analyzed the process of the course evaluation qualification system, and conducted a survey to solicit feedback on introduction of course evaluation qualification system, Besides, the NCS evaluation model is presented in order for the introduction of course evaluation qualification system in the cadastral fields.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.9
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• pp.947-954
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• 2011

Drive-train friction loss in a vehicle may account for 4% of its total fuel consumption loss. An ATF W/C (auto-transmission fluid warmer/cooler) plate-fin heat exchanger is a type of heat exchanger that uses metal plates to transfer heat between the auto-transmission fluid and coolant. The use of an ATF W/C heat exchanger can result in a fuel economy improvement of about 1% in vehicles. An experimental setup for testing the thermal performance of an ATF W/C plate-fin heat exchanger is developed. In this study, the influence of the ATF and coolant, flow rates, and temperature on the efficiency of an ATF W/C heat exchanger are investigated experimentally. From the experimental data, a simple correlation for predicting the efficiency of an ATF W/C heat exchanger is proposed. On the basis of this correlation, the fuel economy of a vehicle with and without an ATF W/C heat exchanger is compared by using Simulink. Finally, it is shown that the fuel economy is improved by 0.992% when an ATF W/C heat exchanger is installed in the vehicle.

• Quality Improvement in Health Care
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• v.10 no.1
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• pp.58-76
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• 2003

Background : Aim of this study is focused on the analysis of the needed abilities of medical representatives resulting in building up the market and increasing sales. It is to propose methods to increase this ability ensuring continuous growth in market share and profit. Methods : A survey was conducted between January 6 and May 31, 2003. Using SPSS(Version 10.0), the collected data was analyzed by Hotelling T2, factor analysis. Some hypotheses were selected to include the conclusion. Some questionnaires for physicians working in hospitals or clinics and the medical representatives working in a pharmaceutical company were created and asked to them to either prove or reject those hypotheses. The results were analyzed to find the primary factors that effect the interactions between physician and the medical representatives. These factors were also studied along with the theoretical research based on published references. Results : The results were as follows. The main reasons for the physician to meet with a medical representatives were collection of product informations needed for patient treatment and collection of informations on current medical issue and as well as personal interests. The main parameters by which physicians evaluate the medical representatives are human relationship including sincerity and manners and supply of accurate and unbiased information on products. Overall, the medical representatives' perception on the importance of medical knowledge and ability to deliver it are lower than that expected by physicians. Conclusion : Medical and pharmaceutical companies' environment are changed rapidly. And those changes forced medical representatives to set new roles and competency. In order to drive away from the past 'rule of thumb' and 'adaptation to circumstance', optimal method and systemic development to train and support the medical representatives should be quipped. They will help medical representatives to be specialists in medical knowledge and to understand the exact need of health care professions. Product competitiveness will be increased and eventually successful business can be achieved through it.

• Journal of Korean Society of Forest Science
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• v.104 no.4
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• pp.607-614
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• 2015

This study aims to analyze the current status of timber production operation and the effects of the forestry mechanization projects on timber production. In order to increase the domestic timber production, it is necessary to propel forestry mechanization project, improve policy and institution, broaden forest-road network, enlarge the number of forest workers, enhance timber production and supply system, provide forestry machines, establish forest operation system, and train forest workers. In addition, the reestablishment of policy goals, the consistency of policy, and the rearrangement of laws and institution are considered more important. To improve the results and effects of forestry mechanization project, it is necessary to drive of forestry mechanization project, the spread of forestry machines, the cultivation of trainer ability, the development of training materials, and the teaching of field skill. In order to meet timber buyersí preference, timber needs to be produced through whole tree logging operation system. Expanding the proportion of domestic timber among total timber demand in Korea requires price competitiveness, and the supply ability of high quality product from the perspective of length and width.