• Journal of Animal Environmental Science
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• v.13 no.2
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• pp.121-128
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• 2007

To develop the composting system to reduce the use of bulking agent, continuous composting was performed with farmer scale facility, The plant comprises a horizontal pit reactor closed inside a greenhouse and equipped with a turning machine moving on rails. The pit was 9m wide and 50m long and the maximum height of loaded materials was $1.8m^2$. The materials remained in the reactor for 5 months. During the composting process, temperature and water content measured and water balance was evaluated. The reaction temperature of composting was changed $30{\sim}50^{\circ}C$ and high in the middle and low in under composting piles. The moisture contents of the compost were approximately 70% during the experiment. The amount of effluent was 10.6% and $3.16m^3$ of pig slurry per $1m^3$ of bulking agent was treated during continuous composting process. BOD and SS reduction of the effluent in continuous composting was 86.5% and 92.2%, respectively. Indoor relative humidity in night time was changed between 80 and 100%.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.92-94
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• 2003

The autotransformer currently used on the electric railway system is made of class A insulation material and uses the paper insulation method. As a power converter supplying power to the trolley wire, the autotransformer is one of critical equipment in the railway system. In the autotransformer, load irregularly changes and overload often occurs. These cause overheating of the autotransformer and facilitate deterioration of the autotransformer resulting in burnout accidents due to insulation breakdown. Also, the current autotransformer has poor insolation and short-circuit strength which often badly affect the service life of the transformer, and needs to improve its quality urgently. To overcome one of existing shortcomings of the mold transformer, manufacturers use epoxy resins that have superior flame retardancy to get rid of fro and explosion possibilities during accidents. Currently, new mold transformers are used in indoor distribution facilities with fire-fighting equipments. Coils molded in epoxy resins do not have their insulation performance compromised by humidity, dust, etc enabling easy inspection and maintenance. Comparing to the oil immersed transformer, the mold transformer does not have any concern about environmental pollutions by oil leak or replacement Therefore, to reduce breakdowns and improve reliability of the autotransformer, it is necessary to develop a new mold autotransformer with low loss suitable for our environment to suppress breakdowns of the autotransformer and improve the reliability. This study is about development of a low-loss mold autotransformer necessitated by reasons mentioned earlier.

• Journal of environmental and Sanitary engineering
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• v.22 no.2
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• pp.53-60
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• 2007

A pilot study was conducted in order to investigate the concentration of formaldehyde at elementary school, middle school, the high school (108 classrooms) located in Chungchong-namdo during February - September, 2006. Also, divide by (45 classroom) General Classroom and (63 classrooms) Stateroom. The average concentrations of formaldehyde(HCHO) in the general classroom was high by $22.87\;{\pm}\;20.61\;{\mu}g/m^3$ elementary school, $22.08\;{\pm}\;12.70\;{\mu}g/m^3$ high school, $13.58\;{\pm}\;6.60\;{\mu}g/m^3$ middle school. The average concentrations of formaldehyde(HCHO) in the Stateroom was high by $27.58\;{\pm}\;30.5{\mu}g/m^3$ elementary school, $22.03\;{\pm}\;19.12\;{\mu}g/m^3\;22.87\;{\pm}\;20.61\;{\mu}g/m^3$ middle school, $24.92\;{\pm}\;28.15\;{\mu}g/m^3$ high school. There was correlation between formaldehyde concentrations and temperature, humidity in general classroom (P<0.05).

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.6
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• pp.617-623
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• 2016

Recently, IoT technology has been applied to the control of appliances in the home, and information about temperature, humidity, etc. is collected and the application of the system to control the indoor environment automatically is increasing. Currently, the network configuration of IoT devices is mainly used to connect IoT devices to the Internet through wireless gateways. Since such a method is dependent on a gateway, there are limitations in providing various services. Therefore, this paper proposes an independent method of gateway by using IoT network without using gateway by applying long distance wireless communication technology. IoT devices using the proposed long distance wireless internet technology can connect to a remote server and provide mobility that can not be supported by existing methods, thereby providing more various services. The performance evaluation of the proposed network configuration method is compared with the delay time and the amount of data generated in the existing network method constituted by the gateway and the proposed network configuration method respectively. Experimental results show that the proposed method decreases the delay time and the amount of data generated by the gateway.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1658-1663
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• 2015

To control the indoor humidity, humidifier is installed in an air handling unit. Up to now, foreign product made of glasswool has been widely used as a humidifying element. In this study, a new humidifying element made of cellulose and PET was tested, and the performance was compared with Glasdek element, which is made of glasswool. Mass transfer rates and pressure drops were measured from the element which was installed at the entrance of the suction-type wind tunnel. Results show that, $j_m$ and f factors of the new element are 33%~39% larger and 0%~51% smaller than those of Glasdek. Large water absorption capacity and the smoothness of the new element appear to be responsible for the large $j_m$ and small f factor. The mass transfer effectivenesses ($j_m/f^{1/3}$) of the new element are 36%~63% larger than those of Glasdek.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.287-289
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• 2015

Internet of Things(IoT) is promising futuristic technology and the relevant market is expected to grow explosively. So, many company develop the product or service that is applied IoT in various fields. The objective of this paper is design and development of collaboration system for enterprise based on beacon to improve efficiency in office environment. We construct Indoor Positioning System(IPS) that using by beacon and mobile device and then develop the related service that utilize IPS data. Thus, we expect that this study contribute to improving productivity of domestic company, is used widely to develop new IoT service that applying various sensors such as beacon, temperature, humidity and so on.

• Journal of the Korean housing association
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• v.23 no.5
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• pp.95-102
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• 2012

We studied in order to find out suitable amounts of board by visual effects to establish indoor boards and human psychological effects by several board designs. Thirty students of C university were tested in constant temperature/humidity room and interviewed after tests. The experimental visual images were projected from 54' TV. As a result, the board length that showed high preference and satisfaction was the 90cm both horizontal and vertical direction. We found that vertical board gave an impression of a linear and narrow shape and the horizontal board gave wide space and cool feeling from psychological analytical study. The factors affecting satisfaction in horizontal direction were refreshing, intimacy, beauty, area, splendor and those in vertical direction were a sense of security, beauty, texture, intimacy, continuity, extensity, natural feeling. We got 5 factors from the result of factor analysis in order to get psychological factor axis. Those were pleasantness, artificiality, openness, dynamics, refinement. By multiple regression analysis, the factor pleasantness had the highest impact on visual satisfaction on scenary. The study on psychological factor difference by analysis of variance showed that psychologically feeling amount about pleasantness, artificiality, dynamics, refinement, and openness had statistically meaningful difference despite of board direction. We found that the 90cm had a tendency as a changing point leading image change by the investigative analysis of board direction based on factor points.

• Journal of the Korea Society of Computer and Information
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• v.16 no.1
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• pp.47-52
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• 2011

This paper collect sleep environment data of bedroom to sleeping, and analyzing the relationship between conditions with obtained data and sleep. We provide the optimal sleep environment of individual by extracting the simulation model based on it. The experiments was using temperature/humidity sensor(SHT11) and ambient light sensors(GL5507). For extraction of tossing and turning, we use difference image method in motion extraction from video. In addition, the information of weight can affect to sleep, it was entered such as ratio of fatigue, drinking, empty stomach. As a result, we are able to extract the optimal sleep environment. The future, we will try to improve to help to lead more pleasant daily life providing proper indoor environment changes depending on the situation even a partial of organic ubiquitous living environments such as eating, work ete. as well as certain sleep circumstances.

• Journal of the Korean Society of Industry Convergence
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• v.2 no.2
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• pp.11-21
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• 1999

This objective of this paper is to investigate the evaluation and indiction of human thermal comfort in building environment. The issue of defining the boundaries of acceptable thermal comfort conditions in buildings and urban may have significant implication for building design and also may have urban design by climate considerations. And then it is to apply the thermal comfort condition to environmental design by using passive methods in Korea. Since 1920. architects have conducted studies to measure thermal comfort in houses under hot and humid conditions, while industrial hygienists have studied the effects of temperature and humidity on the performance of factory workers. Thermal comfort can be influenced by many variables. This paper conducted to review the previous researches and the human heat balance equation, and to analyse in order to reveal the meaning and usage of the thermal comfort index in two traditional essays, Fanger's PMV and Gagge's ET* Their comfort indexes compared with each other. They were based on human heat balance equation and psychological and physiological responses in the laboratory tests. The researchers and the architectural engineers using thermal comfort index shall be careful in decided the use of indexes and be necessary to recognize the value concept of the design criteria for thermal comfort. Therefore, The opinion of the authors is that different comfort standards have to apply for each building and urban with different climatic conditions.

• Fire Science and Engineering
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• v.29 no.6
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• pp.98-108
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• 2015

An integrated command system is critical for the safety of firefighters and effective work in the headquarters of a special disaster areas such as natural disaster or large man-made hazard. The integrated command system requires environmental information such as temperature, humidity, and $CO_2$ levels, as well as personal physical information such as pulse and air respirator levels. An Analog to Digital Converter (ADC) chip converts sensed information into digital signals, and a Micro Controller Unit (MCU) transmits the digital signals to a transmission board using serial communication through a Serial Peripheral Interface (SPI). The digital signals are saved in a transmission board and transmitted to the integrated command system by a Radio Frequency (RF) unit. The location of fire-fighters in a building are determined using a gyro sensor and an inertial sensor. The collected information is applied to the integrated command system for firefighter safety and to ensure that they can effectively carry out their duties. Tthis study theoretically and experimentally investigated the technologies of RF transmission, indoor position, and an integrated command system that supports decision making using the transmitted information.