• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4431-4446
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• 2023

A Multiphysics coupling framework, MPCORE, has been developed to analyze safety parameters using the best estimate codes. The framework contains neutron kinetics (NK), thermal hydraulics (TH), and fuel performance (FP) codes to analyze fuel burnup, radial power distribution, and coolant temperature (T_bc). Shuffling and rotation capabilities have been verified on the Watts Bar reactor for three cycles. This study focuses on two coupling approaches for TH and FP modules. The one-way coupling approach involves coupling the FP code with the NK code, providing no data to the TH modules but getting T_bc as boundary condition from TH module. The two-way coupling approach exchanges information from FP to TH modules, so that the simplified heat conduction solver of the TH module is not used. The power profile in both approaches does not differ significantly, but there is an impact on coolant and cladding parameters. The one-way coupling approach tends to over-predict the cladding hydrogen concentration (CHC). This research highlights the difference between one-way and two-way coupling on critical boron concentration, T_bc, CHC, oxide surface temperature, and pellet centerline temperature. Overall, MPCORE framework with two-way coupling provides a more accurate and reliable analysis of safety parameters for nuclear reactors.

• Journal of the Korean Society of Systems Engineering
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• v.14 no.1
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• pp.1-12
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• 2018

In the energy-guzzling industries such as steel making and cement, power plants utilizing waste heat have been attracting attention to increase energy efficiency. However, the existing economic analysis system doesn't consider the special working fluids and the cost models of the main equipment used in the waste heat recovery power plant. So it is difficult to estimate the plant economics accurately. Therefore, It is required to develop a economic analysis module that can more accurately evaluate for the power plant. In this study, the systems engineering approach was used to design and develop the module that systematically reflects the characteristics of the power plant and various requirements. Specifically, first, the special working fluids and main equipment applied to the power plant were investigated. Next, the cost models for each equipment were developed. Finally, the economic analysis module based on this was developed.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.5 no.1
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• pp.103-110
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• 2011

In this paper, we propose a gaze recognition interface for smart wheelchair. The gaze recognition interface is a user interface which recognize the commands using the gaze recognition and avoid the detected obstacles by sensing the distance through range sensors on the way to driving. Smart wheelchair is composed of gaze recognition and tracking module, user interface module, obstacle detector, motor control module, and range sensor module. The interface in this paper uses a camera with built-in infra red filter and 2 LED light sources to see what direction the pupils turn to and can send command codes to control the system, thus it doesn't need any correction process per each person. The results of the experiment showed that the proposed interface can control the system exactly by recognizing user's gaze direction.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.845-847
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• 2015

In this paper, we develope a detachable wearable device consisting of two parts: main module and accessary module including battery. The main module can display any tracking information and alarms related to the smart phone. In addition, it has small sensors such as heart rate sensor, NFC, T-money, and GPS that can be selected by user's requirement. The accessary module includes battery. The suggested wearable device can also solve the problems faced with today's many other wearable devices: 1) limited battery life 2) the lack of compatibility and expandability due to run on internal components designed for smart phone 3) the design has always been a crucial factor in determining the success of main stream consumer wearable devices.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.91-100
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• 2000

An operating principle of PID module was implemented using the load, where the integer in a PID measuring derivate equation were valid in the ranges of 500-9000, 60-1000, and 000-9000, for P, I and D, respectively. A load operation program was designed to investigate the PID theory and its realization process. With it, it was examined the process that the current PV tracts the target SV, By investigating the time when the PV approaches the SV and the rate at which the EV is varied, it is revealed that 1) larger (or Smaller) Kp leads to faster (or slower) approaching of PV to SV, 2) smaller (or larger) Ti results in faster (or slower) approaching of PV to SV, 3) larger (or smaller)$T_d$ causes smaller (or Larger) rate variation in the EV. These observation were found to coincide with those of PID operating characteristics. Though this implementation, it is known for the widespread use of PID module that an improvement should be made in the error of temperature. This, meanwhile, implies that the computational time of conventional manipulation valve must be faster than 0.1 second. It is demanded that an improved PID module including the A/D and D/A module, in itself must be used in conjunction with PLC.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.780-785
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• 2009

The photovoltaic/thermal collectors (PV/T collectors) combine the solar thermal collector and photovoltaic modules. They can produce thermal energy in the form of hot air or hot water, and converts solar radiation into electricity. The collecctors can improve the electrical performance of PV modules as the heat from the PV module carried away by the thermal part of the system keeping temperatures lower. The basic water cooled PVT collector has metallic water pipes attached to the back of a PV collector. There are main parameters affecting the performance (electrical and thermal) of PVT collectors. This paper analyzed the experimental performance of glazed water PVT module, considering the parameters of solar radiation, inlet water temperature and ambient temperature. It found that solar radiation is the dominant factor for the electrical performance of the collector, and for the thermal performance the inlet water temperature and ambient temperature appeared to be more related.

• Smart Structures and Systems
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• v.13 no.6
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• pp.1041-1063
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• 2014

This work introduces a two-module robotic pipe inspection system with ultrasonic NDE device to evaluate the integrity of pipe structures. The proposed robotic platform has high mobility. The two module mobile robot platform overcomes pipe obstacle structures such as elbow, or T-branch joints by cooperative maneuvers. Also, it can climb up the straight pipeline at a fast speed due to the wheel driven mechanism. For inspection of pipe structure, SH-waves generated by EMAT are applied with additional signal processing methods. A wavelet transform is implemented to extract a meaningful and specific signal from the superposed SH-wave signals. Intensity ratio which is normalized the defect signals intensity by the maximum intensity of directly transmitted signals in the wavelet transforms spectrum is applied to evaluate defects quantitatively. It is experimentally verified that the robotic ultrasonic inspection system with EMAT is capable of non-destructive inspection and evaluation of defects in pipe structure successfully by applying signal processing method based on wavelet transform.

• Journal of the Korean Solar Energy Society
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• v.27 no.4
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• pp.105-111
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• 2007

Hybrid PV/Thermal systems consisting of photovoltaic module and thermal collector can produce the electricity and thermal energy. The solar radiation increases the temperature of PV modules, resulting in the decrease of their electrical efficiency. Accordingly hot air can be extracted from the space between the PV panel and roof, so the efficiency of the PV module increases. The extracted thermal energy can be used in several ways, increasing the total energy output of the system. This study describes a basic type of PV/T collector using water. In order to analyze the performance of the collector, the experiment was conducted. The result showed that the thermal efficiency was 17% average and the electrical efficiency of the PV module was about $10.2%{\sim}11.5%$, both depending on solar radiation, inlet water temperature and ambient temperature.

• The Transactions of the Korea Information Processing Society
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• v.2 no.3
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• pp.299-313
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• 1995

Object-Oriented design method decomposes the program into object that establish the relationship between objects. It is the technique of object centered decomposition unlike function oriented legacy system. Since existing Object- Oriented design method doesn't fully explain of the design method of module and decomposition, and need to implement the Object-Oriented software as a total system init. It has many problems that whole object design method and application programs should be analyzed for the understanding an Object-Oriented software component. Therefore, this study provides a procedure for Object-Oriented module design and criteria of decomposition to practically support the complex and large system development. Futhermore, it shows a consistency between design model and implementation through a case study applying these module decomposition criteria to the real system.

• International journal of advanced smart convergence
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• v.6 no.1
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• pp.76-81
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• 2017

This paper presents a low cost and flexible IoT enabled smart LED controller using Arduino that is used for emergency exit signs. The Internet of Things (IoT) is become a global network that put together physical objects using network communications for the purpose of inter-communication of devices, access information on internet, interaction with users as well as permanent connected environment. A crucial point in this paper, is underlined on the potential key points of applying the Arduino platform as low cost, easy to use microcontroller with combination of various sensors applied in IoT technology to facilitate and establishment of intelligent products. To demonstrate the feasibility and effectiveness of the system, devices such as LED strip, combination of various sensors, Arduino, power plug and ZigBee module have been integrated to setup smart emergency exit sign system. The general concept of the proposed system design discussed in this paper is all about the combination of various sensor such as smoke detector sensor, humidity, temperature sensor, glass break sensors as well as camera sensor that are connected to the main controller (Arduino) for the purpose of communicating with LED exit signs displayer and dedicated PC monitors from integrated system monitoring (controller room) through gateway devices using Zig bee module. A critical appraisal of the approach in the area concludes the paper.