• Journal of Energy Engineering
• /
• v.8 no.2
• /
• pp.224-232
• /
• 1999

Latent heat storage system using micro-encapsuled phase change material is effective method for floor heating of house and building. The temperature profile in capsule block and flow rate of hot water are important parameters for the development of heat storage system. In the present study, a mathematical model based on 3-D, non-steady state, Navier-Stokes equations, scalar conservation equations and turbulence model ($\kappa$-$\varepsilon$), is used to predict the temperature profiles in capsule and the velocity vectors in hot water pipe. The multi-block grids and fine grids embedding are used to join the circle in hot water pipe and square in capsule block. The phase change process of the capsule is quite complex not only because the size of phase change material is very small, but also because phase change material is mixed with the cement to form thermal storage block. In calculation, it's assumed that the phenomena of phase change is limited only the thermal properties of phase change material and the change of boundary is not happened in capsule. The purpose of this study is to calculate the temperature profiles in capsule block and velocity vectors in hot water pipe using the numerical calculation. Two kinds of thermal boundary condition were considered, the first (case 1) is the adiabatic condition for the both outside surfaces of the wall, the second (case 2) is the case in which one surface is natural convection with atmosphere and another surface is adaibatic. Calculation results are shown that the temperature profile in capsule block for case 1 is higher than that for case 2 due to less heat loss in adaibatic surface. Specially, in the domain of near Y=0, the difference of temperature is greater in case 1 than in case 2. The detailed experimental data of capsule block on the temperature profile and the thermal properties such as specific heat and coefficient of heat transfer with the various temperature are required to predict more exact phenomena of heat transfer.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.11
• /
• pp.51-56
• /
• 2016

In this paper, we propose an Arduino-based plant monitoring system. The proposed system is based on the Arduino platform, using an environmental sensor and a pressure sensor for measuring temperature, humidity and illuminance in order to monitor the state of the environment and the facilities of the plant. Monitoring data are transmitted to a ZigBee coordinator connected to a server through a radio frequency transceiver. When using a pressure sensor and the environment sensor data stored on the host server, checking the pressure in the environment of the plant and equipment is intended to report any alarm status to the administrator. Using a grid line-based key distribution scheme, the authentication node dynamically generates a data key to protect the monitoring information. Applying a ZigBee wireless sensor network does not require additional wiring for the actual implementation of a plant monitoring system. Possible working-environment monitoring of an efficient plant can help analyze the cause of any failure by backtracking the working environment when a failure occurs. In addition, it is easy to expand or add a sensor function using the Arduino platform and an expansion board.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.19 no.1
• /
• pp.44-57
• /
• 2020

A dedicated short-range communications (DSRC) traffic information system is a detection system for a section of road using communication between roadside equipment and on-board High-Pass units to collect road traffic information and provide reliable traffic information to drivers. The Ministry of Land, Infrastructure, and Transport announced that a DSRC system must be supported to pass the performance evaluation of an intelligent transportation system (ITS), and the performance evaluation for DSRC systems installed in expressways and national highways is started. Currently, DSRC traffic information systems are only managed for maintenance and functional-monitoring purposes, which means that detailed criteria for the operation of a DSRC traffic information system, such as communication range, the direction of the antenna, and the power of the radio wave, etc., need to be established. In this paper, the criteria of the performance evaluation of a DSRC traffic information system are presented for different road types and road environments. The proposed performance evaluation criteria included the communication range and communication power of roadside equipment. In addition, installation criteria, such as the direction of the antenna, and the height and angle of the installed system, are presented for different road types and road environments. The criteria presented were evaluated for DSRC roadside equipment and documented to improve system maintenance and quality control of the communication system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.05a
• /
• pp.756-759
• /
• 2015

As the struggle to get a job becomes increasingly ferocious year after year, the website offering a range of employment information have continued to gain popularity. Those website, however, are not of much help when it comes to an interview to face the interviewer. Furthermore, many people suffer depression due to the heavy stress they are under while making preparations for employment or working for an organization. The current employment website do not have a team of professionals to deal with such issues. In an effort to solve those problems, the present study made arrangements to allow users to put in an enormous amount of employment information based on Google App Engine(GAE) and Google Web Toolkit(GWT) and upload interview videos. In addition, a Q&A board was created to help those who prepare for employment or current workers relieve their stress and provide them with access to a team of counseling professionals.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.1
• /
• pp.199-207
• /
• 2016

In this paper, we propose efficient smart indoor emotional lighting control system based on android platform using the biological signal. The proposed smart indoor smart emotional lighting control system were configured as the biological signal measurement device and removable smart wall pad, lighting driver, luminaire. The control system was extracts the emotional language by measured the biological signal, and it was transmitted a control signal to each lighting driver using a bluetooth in the wall pad. The lighting driver were designed to control the lighting device through an expansion board by collected control signal and the illuminance information the surrounding. In this case, the wall pad can be selecting of manual control and the bio signal mode by that indoor emotional lighting control algorithms, and it was implemented the control program that possible to partial control by selecting the wanted light. Experiment results of the proposed smart indoor emotional lighting control system, it were possible to the optional control about the luminaire of required area, and the manual control by to adjustable of color temperature with that the efficiently adjustable of lighting by to biological signal and emotional language. Therefore, were possible to effective control for improvement of concentration and business capability of indoor space business conduct by controlling the color and brightness that is appropriate for your situation. And, was reduced power consumption and dimmer voltage, lighting-current than the existing-emotional lighting control system.

• Fire Science and Engineering
• /
• v.25 no.6
• /
• pp.168-177
• /
• 2011

The combustion test for real box of AC outdoor unit has been performed in this study in order to estimate the fire hazard in multi-system type of AC outdoor unit which is currently used for commercial use. The result showed that in test, there was explosion inside of AC outdoor unit, and flame erupted and fire spread through upper side grill. And then this fire burnt the combustibles such as wires, electronic control board, heat exchange copper plate and plastics etc inside the unit, refrigerant gas pipe was burst due to fire, and accelerated the explosion and flame eruption to outside while the refrigerant was erupting. It is found in this test that the maximum heat release rate of AC outdoor unit is 5,830 kW, the maximum internal temperature measured with infrared camera and thermocouple is $1,201^{\circ}C$, maximum ambient temperature is $881^{\circ}C$, and flame rose higher than about 5 m. It is concluded that the fire in AC outdoor unit cause fire to combustibles around the unit, and may give big damage by generating the secondary fire. It is expected that the result obtained from the test on the real object may be applied to fire realization of AC outdoor unit and estimation of fire spreading to the combustibles around in the future computer simulation.

• Journal of Animal Environmental Science
• /
• v.15 no.2
• /
• pp.131-138
• /
• 2009

This study was conducted to find ways to control environment with the difference between body temperature and background temperature based on swine activity, and to apply to the environment control system of swine barns based on the findings. Following are the results. 1. Swine activity related to background temperature was achieved as color images and swine activity status was categorized into cold, comfortable, and hot periods with visualization system (thermal image system). 2. Thermal image system consisted of an infrared CCD camera, an image processing board - DIF (TH3100), an main computer (400Hz, 128M, 586 Pentium model) with C++ program installed. 3. Thermal image system categorizing temperatures into cold, comfortable, and hot was applicable to the environment control system of swine barns 4. Feed intake was higher in cold temperature, and finishing weight and weight gain per day in cold temperature were lower than others (p<0.05).

• KIPS Transactions on Software and Data Engineering
• /
• v.11 no.3
• /
• pp.141-148
• /
• 2022

Recently, reinforcement learning combined with deep neural network technology has achieved remarkable success in various fields such as board games such as Go and chess, computer games such as Atari and StartCraft, and robot object manipulation tasks. However, such deep reinforcement learning describes states, actions, and policies in vector representation. Therefore, the existing deep reinforcement learning has some limitations in generality and interpretability of the learned policy, and it is difficult to effectively incorporate domain knowledge into policy learning. On the other hand, dNL-RRL, a new relational reinforcement learning framework proposed to solve these problems, uses a kind of vector representation for sensor input data and lower-level motion control as in the existing deep reinforcement learning. However, for states, actions, and learned policies, It uses a relational representation with logic predicates and rules. In this paper, we present dNL-RRL-based policy learning for transportation mobile robots in a manufacturing environment. In particular, this study proposes a effective method to utilize the prior domain knowledge of human experts to improve the efficiency of relational reinforcement learning. Through various experiments, we demonstrate the performance improvement of the relational reinforcement learning by using domain knowledge as proposed in this paper.

• Journal of KIISE:Computing Practices and Letters
• /
• v.6 no.5
• /
• pp.513-527
• /
• 2000

This paper describes our experience to design and implementation of a collaborative system framework that allows to develop certain collaborative applications such as 3D animation, computer game, and industrial design. The collaborative system enables users, who located in geographically long distance, to do collaborative work in a single virtual space. The proposed system basically consists of client and server system. The goal of proposed system is to support scalability, portability, and platform independent. In order to achieve these, the server is implemented in Java platform and is adopted to the hybrid architecture which takes the advantages both in centralized and decentralized collaborative system. We construct the server base on its functional characteristics so called User Manager Server (UMS), Session Manager Server (SMS), and Information Server (IS), The UMS manages the users who are taking part in the collaborative operations. The SMS supports the conferencing in the proposed system. The IS provides the connection methods among the UMSs. For user's convenience, we implement the client using Visual C++ in Windows. We also expend the functions of 3D Studio Max to distributed environment by means of the plug-in module, and facilitate the chatting and white board functions as well.

• 한국해양학회지
• /
• v.27 no.1
• /
• pp.19-34
• /
• 1992

Marine seismic refraction surveys have been carried out by Korea Institute of Geology, Mining and Materials(KIGAM) since 1984. The recording of refraction data was based on analog instrumentation. Therefore the resolution of refraction data was not good enough to distinguish many layers. The objective of the interpretation of seismic refraction data is the determination of intervals and critically refracted seismic wave propagation velocities through the layers beneath the sea floor. To determine intervals and velocities precisely, the resolution of refraction data should be enhanced. The intent of the study is to improve the quality of shallow marine refraction data by the digital technique using microcomputer- based acquisition and processing system. The system consists of an IBM AT microcomputer clone, an analog-digital(A/D) converter. A mass storage unit and a parallel processing board. The A/D converter has 12 bits of precision and 250 kHz of conversion rate. The magneto-optical disk drive is used for the mass storage of seismic refraction data. Shallow marine seismic refraction surveys have been carried out using the system at 6 locations off Ulsan and Pusan area. The refraction data were acquired by the radio sonobuoy. The refraction profiles have been produced by the laser printer with 300 dpi resolution after the basic computer processing. 5-9 layers were interpreted from digital refraction profiles, whereas 2-4 layers were interpreted from analog refraction profiles. the propagation velocities of sediments were interpreted as 1.6-2.1 km/sec. The propagation velocities of acoustic basement were interpreted as 2.4-2.7 km/sec off Ulsan area, 4.8 km/sec off Pusan area.