• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.4
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• pp.289-296
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• 2012

The aim of this study is to investigate the performance of a heating and cooling system with aquifer thermal energy storage(ATES heat pump system) known as one of the underground thermal energy storage application systems. The ATES system was composed of heat pump unit and ATES, which was installed in a factory building located in Anseoung. The system represented very high heating and cooling performance, and showed nearly constant COP at each heating and cooling season due to the stability of EWT. The economic analysis about an ATES system and a conventional system was also executed. The conventional system adopted an air-conditioner in the summer season and a LNG boiler in the winter season. The payback period of the ATES system was estimated by 6.62 years.

• Journal of the Korean housing association
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• v.14 no.4
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• pp.69-76
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• 2003

Considering the present development situation of rental apartment since 1982, the supply of rental housing for low-income dwellers has contributed a amount of quantities, but has been deficient qualities in housing policy. To propose the device of remodeling for low-income dwellers in deteriorated apartment, this study investigated the characteristics of maintenance cost and the residents'consciousness of remodeling by rental apartment types. The results of this study were as follows; The annual maintenance cost of permanent rental apartment was 14,249 won/$\textrm{m}^2$$.$yr, that of fifty years period rental apartment was 13,372 won/$\textrm{m}^2$$.$yr. In the case of remodeling in deteriorated heating system, the principal decision factor of choice was showed “economics” as priority. Residents in rental apartment preferred remodeling to reconstruction, and unit heating system to central heating system.

• Journal of the Korean Society of Industry Convergence
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• v.13 no.3
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• pp.145-151
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• 2010

This study is for getting basic data through grasping the obtained heat by structure of each unit and the effects of environment improvement based on judgement for whether or not a solar heating system of renewable energy installations is possible to set up in village hall public buildings as community center and senior citizen center. Conducting a survey of community center and senior citizen center in Ibam-Myon, Yeongyang-Gun, Gyeongsangbuk-Do and the analysis, obtained solar heat of 414,309,678 kcal every year and from this, effects of 131.48995 $TCO_2$. These figure equate to 26,298 pines effect. These results show that the advantage of reducing building operating costs in the long run besides effects of environment improvement.

• Journal of Aerospace System Engineering
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• v.14 no.6
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• pp.10-17
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• 2020

The Korean medical evacuation helicopter was developed based on the Korean Utility Helicopter (hereafter referred to as 'Surion'). It uses an auxiliary power unit and engine for heating during winter operation. The helicopter maintains the internal temperature of the aircraft using its bleed air to satisfy its operational capability. However, due to the air inflow through the gap between the aircraft skin and door, additional heating for operating the portable medical equipment and preventing hypothermia in evacuated patients is required. Accordingly, an electric auxiliary heater was developed for additional heating during winter operation, and environmental, durability, and performance tests were conducted per MIL-STD-810G and MIL-STD-461F. The auxiliary heater was verified per the tailored airworthiness certification criteria.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.1
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• pp.75-80
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• 2012

The integrated protection unit of CHEONGUNG is composed of chemical-biological equipment and air conditioner equiped heating element. The protection capabilities against chemical-biological agent were measured by using simulant agents such as n-Hexane, KM5 Screening Smokes and CS agent. The experimental test results with simulant agents verify the protective performance of the integrated protection unit.

• Journal of the Korean housing association
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• v.15 no.1
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• pp.175-183
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• 2004

The purpose of this study was to identify the actual condition of residential environment for the elderly residing in Daejeon. The data were collected through interviews and structured questionnaires. The sujects were 583 elderly people over the age of 65 in Daejeon. Sociodemographic characteristics, living characteristics, housing characteristics, neighborhood environment types, actual usage condition of neighborhood environment, relationship between sociodemographic characteristics and actual usage of neighborhood environment, actual condition of unit interior, were surveyed. The data were analyzed with frequency, percentage, χ²-test, mean using the SPSS package. The major findings were as follows. Features of unit interior which pointed generally were deterioration, soundproofing and size. Features of unit interior which need to be carefully planned were removal of height difference of entrance, removal of the thresholds, installation of emergency bell and room heating control facility. The facilities provided highly within the subject's residential environment were the eldery facility, church, hospital, bank, restaurant, beauty salon/barbershop, supermarket. and the facilities provided lowly were recreational facility, library, elderly school.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.537-546
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• 2019

In this paper, a system that integrates a home concentrate unit(HCU) in a smart electricity meter to collects water, gas, hot water, and heating usage required for AMI has been proposed. The collected data could be transmitted to the in house display(IHD) and server to provide a more economical AMI system. The developed system is less expensive in the network configuration than the existing system, which could reduce the operating cost, and be easy to install. By applying the developed system, the usage of electricity, water, gas, hot water and heating could be measured and these make it easier to apply AMI system. The main contents of the development are the smart electricity meter and embedding of HCU into the smart electricity meter, and transferring these data to IHD and server to structure the AMI system. The each developed unit has been networked to structure the AMI system to perform the actual meter reading operation and show the result.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.7
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• pp.81-86
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• 2005

Proposed induction-heated system is innovative system which applied special high-frequency power circuit technique for thermal converse technique and IH(Induction-Heating) magnetic induction heating generated from induction-heated metallic package that is for distillation unit. In this occurs not burning, so that the working environment can be improved. This electromagnetic induction heating technique is used high frequency inverter. By using high frequency inverter high frequency alternative current (HFAC) in the range of [kHz] can be made with conventional alternative current In this contribution IGBT module is used for high frequency inverter. In this paper are discussed action analysis and characteristics analysis of 1.5[kW]-Class half-bridge resonant inverter system and resonant metallic packaged. In addition, by using this system,t how two step heating superheated steam generator is developed and application of system are also discussed.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.4
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• pp.355-361
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• 2011

The power control of the existing heating element has been using the On-Off control, phase control, and PWM control. In case of controlling power PTC heating element developed recently with the existing method, the temperature is unable to be precisely controlled or the harmful electromagnetic wave to human body is generated. In this paper, We suggest the power control of PTC heating cable using variable AC Cycles. This regards the AC cycle of N as the unit of the power control. It determines On-Off for each cycle. It is the AC power control method in which it arranges the on-cycle in N cycles in the random and it supplies the current continuously. At this time. the minimal electric power amount becomes 1/N. The maximum current amount becomes 1 and sets up the number of on cycles according to the set value and can control the electric power with the step of N consistently. In the PTC heating system, we show that proposed power control method is superior in the EMI and temperature control property using MATLAB simulation, experiments and measurements.

• Journal of the Korean Solar Energy Society
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• v.27 no.4
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• pp.167-173
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• 2007

This study analyzed by simulation using TRNSYS as well as by experiment on the solar district heating system installed for the first time for the district heating system in Bundang. Simulation analysis using TRNSYS focused on the thermal behavior and long-term thermal efficiency of solar system. Experiment carried out for the reliability of simulation system. This solar system where the circuits of two different collectors, flat plate and vacuum tube collector, are connected in series by a collector heat exchanger, and the collection characteristics of each circuit varies. Therefore, these differences must be considered for the system's control. This system uses variable flow rate control in order to obtain always setting temperature of hot water by solar system. Specifically, this is a system that heats returning district heating water (DHW) at approximately $60^{\circ}C$ using a solar collector without a storage tank, up to the setting temperature of approximately $85{\sim}95^{\circ}C$ To realize this, a flat plate collector and a vacuum tube collector are used as separate collector loops. The first heating is performed by a flat plate collector loop and the second by a vacuum tube collector loop. In a gross collector area basis, the mean system efficiency, for 4 years, of a flat plate collector is 33.4% and a vacuum tube collector is 41.2%. The yearly total collection energy is 2,342GJ and really collection energy per unit area ($m^2$) is 1.92GJ and 2.37GJ respectively for the flat plate vacuum tube collector. This result is very important on the share of each collector area in this type of solar district heating system.