• Journal of KSNVE
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• v.9 no.6
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• pp.1227-1233
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• 1999

Modern technology depends on the reliability of extremely high technology equipments. In the production of semiconductor wafer, optical and electron microscopes, ion-beam, laser device must maintain their alignments within a nanometer. This equipment requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga and tera class semiconductor wafers. This high technology equipments require very strict environmental vibration standard, vibration criteria, in proportion to the accuracy of the manufacturing, inspecting devices. This paper deals with the structural dynamic design in high class semiconductor factory in order to be satisfied more strict vibration criteria for high sensitive equipment.

• Korean Institute of Interior Design Journal
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• v.15 no.4 s.57
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• pp.21-28
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• 2006

To promote environmentally responsible architectural practice, many nations have established their own green building rating system. Among other criteria, recently the indoor environmental quality section has been paid great attention due to Sick Building Syndrome, as this believed to caused by polluted indoor environment. In this context, indoor environmental quality is one of very important sections of each green building rating system and closely related to the very happiness of building users. The goal of this research is to compare and analyze the indoor environmental sections of three green building rating systems, GBCC, LEED v2.1, and BREEAM Office 2005, and find a direction for the improvement of GBCC. First, the three rating systems are analyzed in general to compare the importance of indoor environmental factors in each system. Second, the indoor environmental factors are reclassified within related sub-categories for the comparable analysis. Finally, based upon the comparable analysis, directions for the improvement of GBCC are as follows: 1. GBCC's h4r Environment Section needs to clarify its VOCs criteria based upon types of finish materials. 2. Sound Environment Section's noise control criteria needs to be revised based upon types of building usages and application method. 3. An indoor lighting related section needs to be included in GBCC, as even though light is the one of the most important factors in indoor environment, it has not been included in GBCC yet. 4. The sub-section of Confortable Indoor Environment Section related to the resting space and the universal accessibility are not in accord with the goal of green building rating system. These items need to be dealt within general building codes. 5. The rating evaluation structure and process need to be streamlined.

• Journal of KSNVE
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• v.7 no.2
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• pp.247-254
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• 1997

In the case of a precision equipment, it requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga class semiconductor wafers. This high technology equipments require very strict environmental vibration standard in proportion to the accuracy of the manufacturing, inspecting devices. The vibration criteria are usually obtained either by the real vibration exciting test on the equipment or by the analytical calculation. This paper proposes a new method to solve this problem at a time. The permissible vibration level to a precision equipment can be easily obtained by analyzing a process of Frequency Response Function. This paper also demonstrates its effectiveness by applying the proposed method to finding the vibration criteria of a Computer Hard Disk Driver by Impact Test.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.1026-1031
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• 2003

A vibration isolation system fur a large reverberation chamber (1,228㎥, 1,000ton) has been installed. The reverberation chamber generates loud noise and induces high level of vibration to perform spacecraft acoustic environmental tests. The isolation system prevents vibration transfer from the chamber to enclosure buildings. This paper describes logical design process and commissioning experiments of the system. Design criteria have been induced from rigid body model of the chamber. Finite element model has been employed to select the characteristics of rubber pads. A total of 21 rubber pads have been installed between the chamber and supporting pedestals. A sand bag of 800kg was dropped on the chamber floor to measure the natural frequency of the isolation system. Absolute transmissibility has been measured while generating 145㏈ in the chamber. The natural frequency of the chamber is 10.5㎐, which is 80% of estimated value. Overall transmissibility at working frequency range (25㎐-10,000㎐) is less than -6㏈.

• Journal of environmental and Sanitary engineering
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• v.13 no.1
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• pp.123-134
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• 1998

The study was performed to investigate the differences among various evaluation criteria for noise-induced hearing loss(NIHL). The subjects were 100 workers who had received detailed audiometric examinations after the periodic annual examination for hearing loss. The evaluation criteria included were as follows: The criterion I was NIHL of 50dB or greater at 4,000Hz in either ear which is one of the legal requirements for determining occupational hearing loss in Korea. The criterion II was NIHL of 40dB or greater by 4-divided classification(a+b+c+d/4 at 500Hz(a), 1,000Hz(b), 2,000Hz(c), 4,000Hz(d)) which is also one of the legal requirements for determining occupational hearing loss in Korea. The criterion III was NIHL of 31dB of greater by 6-divided classification(a+2b+2c+d/6) which is the workers' compensation standard. The criterion IV was NIHL of 40dB or greater by 6-divided classification(a+2b+2c+d/6), the criterion used to prohibite workers to be employed in the noisy workplace. The criterion V was NIHL of 40dB or greater by 3-divided classification(a+b+c/3) which is the guideline of the Japanes Labour Department. The results were as follows; 1. The percentage of workers with NIHL by the criterion I was the highest(96%) and covered all workers with NIHL diagnosed by other criteria. Therefore, this criterion was the most sensitive one for early detection of NIHL among various evaluation criteria. 2. The percentage of workers with NIHL by the criterion II was 29% of the subjects, but all of them could be diagnosed as having NIHL by the criterion I and 33.1% of the NIHL by the criterion III could not be covered by the criterion II. Thus, this criterion was not considered suitable as an initial step for determining occupational hearing loss. 3. The percentage of workers with NIHL by the criterion III was 45% of the subjects. This percentage was 46.9% of the NIHL by the criterion I and was estimated to cover 3.6% of all noise exposed workers. 4. The percentage of workers with NIHL by the criterion IV was 28% of the subjects, but 37.8% of the NIHL by the criterion III and 70.8% of the NIHL by the criterion I were not covered by the criterion. Therefore, these workers could have been employed in the noisy workplaces. 5. Employed relocation which was one of the post management methods was an option in the criterion I in Korea and in the criterion V in Japan. The number of NIHL by the criterion I was 6.7times greater than that by the criterion V. Thus, although employee relocation was not used exclusively, many more workers with NIHL could have been relocated. In conclusion, this study revealed that the criteria being used for managing occupational hearing loss showed a lack uniformity among them. In addition, since these criteria are all relied on the total threshold shifts caused by the noise exposure at the time of hearing test with no consideration given to the past noise exposure history nor age, it can be said that they are not an effective tool for occupational hearing loss management. Since legal requirements are usually followed after being diagnosed as having NIHL, it is recommended that a uniform diagnostic criterion should be used to minimize confusion. Pre-employment hearing tests should also be utilized so as to managing occupational hearing loss after employment rather than being used as a legal roadblock of prohibiting workers with mild hearing loss from being employed. Thus, what is needed is an establishment of a rational criterion for occupational hearing loss management rather than for legal requirements.

• Proceedings of the Korean Geotechical Society Conference
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• 1993.06a
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• pp.73-82
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• 1993

Ground-borne vibration is one of the main causes of environmental impact from subway systems. The vibration resulting from track-train interaction is transuutted through the tunnel structure and the surrounding ground to adjacent buildings. This paper provides a summary of proposed noise and vibration criteria, a review of the ground vibration propagation mechanism and the theoretical isolation effectivenesss of each of the following underground transit systems : track, tunnel and vehicle itself.

• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.1
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• pp.9-17
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• 2022

As the COVID-19 pandemic situation worsens, the time spent indoors increases, and the exposure to indoor environmental pollution such as indoor air pollution and noise also increases, causing problems such as deterioration of human health, stress, and discord between neighbors. This paper designs and implements a system that measures and monitors indoor air quality and noise, which are representative evaluation criteria of the indoor environment. The system proposed in this paper consists of a particulate matter measurement subsystem that measures and corrects the concentration of particulate matters to monitor indoor air quality, and a noise measurement subsystem that detects changes in sound and converts it to a sound pressure level. The concentration of indoor particulate matters is measured using a laser-based light scattering method, and an error caused by temperature and humidity is compensated in this paper. For indoor noise measurement, the voltage measured through a microphone is basically measured, Fourier transform is performed to classify it by frequency, and then A-weighting is performed to correct loudness equality. Then, the RMS value is obtained, high-frequency noise is removed by performing time-weighting, and then SPL is obtained. Finally, the equivalent noise level for 1 minute and 5 minutes are calculated to show the indoor noise level. In order to classify noise into direct impact sound and air transmission noise, a piezo vibration sensors is mounted to determine the presence or absence of direct impact transmitted through the wall. For performance evaluation, the error of particulate matter measurement is analyzed through TSI's AM510 instrument. and compare the noise error with CEM's noise measurement system.

• Journal of the Korean Society for Library and Information Science
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• v.34 no.3
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• pp.133-156
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• 2000

A fundamental issue to consider when searching Web information is the quality of information itself and of service. If a Quality Information System (QIS) of Digital Library is sought, new measurement criteria and evaluation index for Web information service are required. Reliance on the existing evaluation criteria is not acceptable if data retrieved are not information and the service is only noise to end-user. Applying existing evaluation criteria of online database to Environmental & Energy Engineering Web DB revealed the limitations and provided a practical and case-based information for improvement. No attempt was made to survey comprehensively all of the evaluation methods that could possibly be relevant. Instead, this discussion concentrates on the information service evaluation index being developed in the KDPC Project. The research found that domestic Web-DB service are still woefully insufficient to conduct comprehensive investigations on environmental topics. More qualified and specialized R&D Web information service and the development of new evaluation criteria based on this investigation(research I.) will be discussed in follow-up research II.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.196-203
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• 2013

Environmental problems like global warming have now become important issues that should be considered in all industries, including construction. In South Korea, many studies have been conducted to achieve the government's goals of reduction in environmental impacts. However, the research on buildings has only focused on CO₂ emission as a research target despite the fact that other environmental impacts resulting from ozone depletion and acidification should also be considered, in addition to global warming. In this regard, this study attempted to propose assessment criteria and methods to evaluate the environmental performance of the structures from various aspects. The environmental impact category can be divided into global impacts, regional impacts, and local impacts. First, global impacts include global warming, ozone layer depletion, and abiotic resource depletion, while regional impacts include acidification, eutrophication, and photochemical oxidation. In addition, noise and vibration occurring in the building construction phase are defined as local impacts. The evaluation methods on the eight environmental impacts will be proposed after analyzing existing studies, and the methods representing each environmental load as monetary value will be presented. The methods presented in this study will present benefits that can be obtained through green buildings with a clear quantitative assessment on structures. Ultimately, it is expected that if the effects of green buildings are clearly presented through the findings of this study, the greening of structures will be actively expanded.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.153-160
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• 2003

While the interests on the environmental problem during the construction are increasing, the use of low noise-vibration auger-drilled pilling is increasing to solve noise and vibration problem in pilling. Therefore, in Korea, SIP(Soil-Cement Injected Precast Pile) method is mainly used as auger-drilled pilling. However, there is no proper design criteria compatible with the ground condition of Korea, so which is most wanted. To improve and supplement this situation, direct shear tests between SIP pile skin interface and soil were executed on various conditions. Through the analysis of test results, skin resistance characteristics of SIP were investigated thoroughly. Also, the nonlinear unit skin resistance capacity model with SM, SC soil were suggested.