• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1540-1548
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• 2000

Sound intensity techniques and ODS(Operational Deflection Shape) techniques are applied to identify the acoustic noise source of a hard disk drive and its control system. The sound intensity is used to visualize the noise source locations, and the ODS information to visualize the vibration pattern and to obtain the dynamic characteristics of the noise sources. The measurement systems are customized to accurately measure the sound intensity and ODS distributions of HDD system in space domains as well as frequency domains. The measurement systems for the sound absorption and transmission loss of materials are also used to support the background data for the efficient noise control. Using the visual information of source locations and its dynamic characteristics, the partial noise barrier structure and optimum absorption are designed and its controlled sound power level is proved to be under 3.1 Bel(Idle)/3.3Bel (Seek) which is the lowest level in the disk drive industry.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.911-916
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• 2001

Structural acoustic modification method based on the structural mobility analysis is applied to reduce the structure-borne noise radiated from hard disk drive system. Sound intensity techniques and ODS(Operational Deflection Shape) techniques are also used in order to provide the structural acoustic information for the mobility modification. The sound intensity is for the acoustic visualization of the noise source locations, and the ODS is for the visualization of the vibration pattern and its dynamic characteristics of the noise sources. Using visualization information of sound and vibration, local structural input mobility is reduced in the frequency band of interest by designing asymmetrical wave-stringer structure in the wave-number domain as well as frequency domain. The overall sound pressure level is reduced by 4dB and its controlled sound power radiated from the disk drive is proved to under 2.8Bel in idle-spinning mode and 3.1 Bel in random-seeking mode, which are the lowest noise levels in the hard disk drive industry.

• Journal of Digital Convergence
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• v.15 no.6
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• pp.439-445
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• 2017

Summary. Most of American pop music, which are dominating the hegemony of the global pop music market, have been derived from the culture of African Americans, most of whom were slaves of European immigrants. The music of black slaves must be the one of the greatest undisputed achievements that have most influenced the American history. Indeed, All of the mainstream pop music works around the world, including those in America, are the descendants of the black music with the gene of the black people. We can say, therefore, the music born through the Afro-American culture has become the music that every person around the world enjoys in the present. Accordingly, K-Pop music culture, centered in idol group, is also based on the black music. This fact suggests that the K-Pop culture can be spread into people in different customs or traditions with little resistance. The success factor of Motown, at the very center of the black music, which integrated the whole global music, is not only their incredibly outstanding music works, but also the self-consciousness the musicians have that they are strongly reluctant to settle down to present reality. This shall lead to the necessity of self-reflection for the Korean music market, which are obsessed with present popularity and only taking advantage of teenager market, and for those engaged in music business in Korea, who are lack of the artistic value and the consciousness as artist.

• Journal of the Korean GEO-environmental Society
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• v.6 no.2
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• pp.61-73
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• 2005

In Korea, none of the design methods, which can consider the properties of hard soil, weathered rock and the condition of construction, are suggested. Therefore, the properties of geomaterial are simply classified into three categories such as sand, clay and rock for the resistance estimation of axially loaded drilled shafts in Korea. However, in America, O'Neill et al.(1996) presented design methods for a new category of geomaterial which is between soil and rock termed "intermediate geomaterials, IGM's". And FHWA(1999) adapted above most complete classification of geomaterials in its design manual. However, in Korea, these properties are depended on the engineer's judgement, the weathered rocks may be counted as soils, although they may be referred to as IGM's in America. In this study, the applicability of IGM method was investigated through the two construction sites in Korea. For the comparison, two geomaterial properties are applied, respectively. The one was sound soil condition and the other was IGM condition and classical design method and IGM method were applied, respectively. The results showed that the predicted bearing capacities of drilled shafts with IGM's were larger than the predicted values by the classical design method with sound soil condition.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.25 no.2
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• pp.53-64
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• 2014

Tic disorder is a childhood neuropsychological disorder characterized by abrupt, involuntary, and repetitive stereotyped muscle movement or vocal sound. Tourette's disorder shows a chronic prognosis, and can last for life if no treatment is applied. Although tic disorder has been known for ages, the underlying cause is still not well known. Non-pharmacological treatments have long been used for the tic disorder, but few clinical studies were conducted. However, the European Society for the Study of Tourette's Syndrome recently issued non-pharmacologic guidelines for treatment of tic disorders based on the research findings obtained so far. In addition, guidelines for non-pharmacologic evidence-based treatment were reported in Canada, North America. By synthesizing the newly reported foreign guidelines for treatment and review articles, the aim of this study is to investigate the non-pharmacologic therapies used for treatment of tic disorder or Tourette's disorder.