• Journal of environmental and Sanitary engineering
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• v.21 no.1 s.59
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• pp.58-65
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• 2006

This study is measured in at ozone concentrated places in school and outside of school where places that use copy machine and the others do not use one. Library copy room, Search room, Y-Copy, J-copy, R-shop are the places using copy machines and Search room, K-apt, J-billiard hall are the opposite. The measurement was held three times a day-the morning, the afternoon and the evening-once for each at indoor and outdoor. 8 places were lower than domestic ozone concentration standard(0.06ppm). The indoor ozone concentration average was the highest in Search room of school and was the lowest in Library restroom. The outdoor ozone concentration average was the highest in J-billiard hall.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.701-705
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• 2007

The equipment noise of machine room that generates at the building where human-being is living, is becoming to an object of strong civil appeal, and because it influences to the residential space through the floor or wall, its damage is very serious level. Accordingly, while an efficient forming of the sound insulating measures is earnest, as most of the transmission loss data was the material measured in laboratory, in case when it was applied to the job site, due to the precision difference of constructing work and the influence of detoured transmitting sound, the case of disaccord is the most. Therefore, this thesis has intended to present a fundamental data for an efficient establishment of sound insulation measure, by means of comparison analysis with the existing transmission loss data, after measurement of the transmission loss on the object of various walls, at the construction equipment machinery room.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.964-968
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• 2007

The measurement of floor impact sound have been standardized in KS 2810-1 and 2. The height of receiving microphones position is specified in the standard as 1.2m which is almost half height of apartment rooms as a listening position. In this study, receiving positions are investigated by measuring the distribution of sound pressure levels at 792 receiving microphone positions in the standard testing building. Standard impact sources, tapping machine and impact ball, are driven on the center position in the source room where is located at the above floor. It was found that the distribution of sound pressure levels in the receiving room indicates significant deviation at different frequencies there is more than 5dB drop at 63Hz but 2dB rise at 125Hz at a height of 1.2m when the impact ball is driven, in the other case of a generating tapping machine there is more than 2dB rise at 125Hz at a height of 1.2m due to room modes.

• KIEAE Journal
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• v.9 no.4
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• pp.23-28
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• 2009

Standard sound source currently used in heavy-weight floor impact sounds that cause many social problems has excessive low-frequency energy within a range from 63 Hz to 125 Hz, and is difficult to evaluate and measure. To solve these problems, studies are widely performed using a new impact source, the impact ball. In this study, the sound fields in a receiving room were compared and analyzed according to the current impact source, the bang machine, and the impact ball. And deviation of sound pressure level according to the impact source positions were compared. In case of impact ball, the sound pressure level was lower at 63 Hz and below and higher at 125 Hz and above. The same trend was observed at the low-frequency range on the horizontal and vertical planes, regardless of the type of the impact source, which showed the influence of the room mode. There was a problem with the variations in the sound pressure level according to the size or shape of the receiving room. And it also shows that change of source positions may effect the single number rating scheme.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.4
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• pp.475-482
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• 2016

The active control of noise generated by the compressor and transmitted out of the machine room through the windows is implemented based on the FIR filter. The machine room contains most of noise sources of electric home appliances, air-conditioners and refrigerators, for example. To actively reduce the noise from the machinery room. In this paper, the transfer function of the controller for minimization of the acoustic power transmitted through the windows is mathematically formulated. The transfer functions required for implementation of the active controller are the measured. The measurements are conducted in this initial stage under the operation of the compressor with no load. For improvement of the reliability of the transfer function of the compressor to the acoustic power, additional operational measurements are performed. The real time controller is implemented based on the FIR filter using the measured transfer functions and the performance of the active controller is estimated. Control performance is measured about 3 dB ~ 10 dB in reduction of the sound power at the peaks of the compressor noise.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.2
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• pp.160-165
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• 1998

The Joint curing barns for flue-cured tobacco is a favorite with the tobacco farmers in Korea. However, most of farmer utilizing the joint curing barns indicated many problems such as high temperature and noise in the working room and a dry of cured leaves in the storage room. A structure of Joint curing barns has been modified to meet the needs of tobacco farmers. Compared with the unimproved joint curing barns, the improved one showed that the noise of workshop decreased about 7.7～10.8db, the amount of $CO_2$ decreased 40～50ppm in a working room and 80～100ppm in a machine room. Ammonia gas decreased 0.29mg/㎥ and the temperature of a working room dropped about 2.1～3.5$^{\circ}C$. The amount of air flow in a working room increased 23.2% at a site being 2m away from the entrance and 30.8% at a center. The inner temperature of the improved storage room showed that maximum temperature dropped about 3$^{\circ}C$, minimum temperature was high about 2$^{\circ}C$. The highest relative humidity was low 6%, the lowest one increased high about 10% when compared with the unimproved joint curing barns.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.7
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• pp.872-880
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• 2007

The development of a Marine Engine Room Simulator system for training and research is described. Development objectives of the system are for both student training, research and development work. The system includes a distributed server/client architecture for 1 to 1, or 1 to many client simulation operation through OPC server, complete separation of visual elements from the controlling routines and the ability to work on the mathematical model independent of the controller and visual systems. A graphical user interface for the man-machine interface has been developed and the mathematical model has been updated. Various engine room operational situations can be simulated. The use of marine engine room simulator for training of sea going engineers and its competency for STCW-95 is discussed.

• Journal of the Korean Institute of Rural Architecture
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• v.14 no.1
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• pp.1-8
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• 2012

This study was to analyze physical condition on the dormitory high school in Jeonju City, and find out users' satisfaction on that. This was going to contribute to the directions of it's physical environmental improvement. This was performed by a questionnaire survey method. Data were collected from 200 students, who had been dwelling 4 high school dormitories in Jeonju City. Through analyzing those data about library, diningroom, laundry room, break room, computer room, restroom, shower room, hall lounge, and snack bar in a dormitory, the results are as follows. First, students thought some physical conditions to be inconvenient in an distracted study atmosphere and hard furniture of library, a bad location of diningroom, a short laundry machine, lack of tables in a break room, a short performance and supply computer, a small space and short toilet in restroom, and a short of hall lounge and snack bar. Second, the students' satisfaction of common public areas in dormitory was 3.39 score. Students were concerned with library and restroom shower room through analyzing satisfied and unsatisfied areas. Third, they needed to improve heating, cooling, and noise in common areas of dormitory, and needed to support a breakroom and snack bar. Conclusively, library, restroom shower room, break room, and snack bar were important common areas, and indoor environmental elements - heating, cooling and noise- were important in high school dormitory.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.613-618
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• 2023

In this paper, a monitoring program that can automatically determine whether a patient admitted to an isolation room acts out of a stable state through a screen photographed in real time is described. The motion recognition model of this program was built by learning through transfer learning. 900 images were used for the three movements, and this program was developed for the web to support all environments. The model was determined with high accuracy to determine the state of the subject hospitalized in the isolation room, and can be applied by applying it to the existing isolation room monitoring system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.947-950
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• 2007

In this study, vibration analysis of a refrigerator was carried out to reduce vibration by considering grommet. When the refrigerator machine room is modeled by finite element method, spring elements are added to constructions of the FEmodel for each component and update. To design the grommet of refrigerator, FEmodel must have vibration characteristics of each components such as baseplate, pipe and compressor it self. The modal analyses are conducted to validate suggested approach when the components of machine room are assembled together. And, in this study, optimal design of grommet is conducted to avoid the resonance at the operating frequency of refrigerator. The experimental and FEM result of suggested design showed good agreement and are presented here.