• The Journal of the Acoustical Society of Korea
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• v.39 no.6
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• pp.606-614
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• 2020

In this paper, we analyze the influences of ship traffic and marine weather information on underwater ambient noise. Ambient noise is an important environmental factor that greatly affects the detection performance of underwater sonar systems. In order to implement an automated system such as prediction of detection performance using artificial intelligence technology, which has been recently studied, it is necessary to obtain and analyze major data related to these. The main sources of ambient noise have various causes. In the case of sonar systems operating in offshore seas, the detection performance is greatly affected by the noise caused by ship traffic and marine weather. Therefore, in this paper, the impact of each data was analyzed using the measurement results of ambient noise obtained in coastal area of the East Sea of Korea, and public data of nearby ship traffic and ocean weather information. As a result, it was observed that the underwater ambient noise was highly correlated with the change of the ship's traffic volume, and that marine environment factors such as wind speed, wave height, and rainfall had an effect on a specific frequency band.

• The Research Journal of the Costume Culture
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• v.19 no.2
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• pp.283-295
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• 2011

This study deals with the interchange with art that is contained in the works of Yves Saint Laurent, and it is disclosed through his works that modern fashion is part of expressive art while pursuing creative function as a work of art. The study has been performed on the basis of the references, the pictures of his works and interviews posted in domestic and overseas fashion magazines such as Vogue, Fashion News, Mode & Mode, Gap, Collections, etc. Regarding the scope of this study, it specifically deals with works he created from 1958 until 2002, when he announced his last collection. The results of the study show that with respect to Post-Impressionism, his works were greatly affected by van Gogh(who had used colors as active media in depicting his internal mental state) which gave birth to gorgeous and handicraft-like 'Couture-style clothes'. With respects to Fauvism, the works of Matisse also had an impact on Yves Saint Laurent, who added a sense of fauvism in his works through the use of colors, motif, or full reproduction of images from paintings. We see the influence of cubism upon Laurent when we examine his works of 'clothes with artistic value,' which utilized applique, beaded decoration, patchwork, embroidered patterns, relief-like ornaments, etc. using motif or objet much as we see in the works of Picasso and Braque, artists who expressed a new dimension of the formative arts. Laurent's use of neoplasticism, or plainness of painting, demonstrates a new formative art on the three-dimensional human body by using the works of Mondrian, which consist of black lines and primary colors, although generally Laurent's 'neoplastic'works differed from the works of Mondrian by more actively utilizing the lines and colors when designing dress and its ornament. In addition, the paintings and poems of surrealism artists and poets were directly used in the clothes or their images were sometimes borrowed. In order to express respect toward the spirit of surrealism and its artists, the human body motifs such as lips and eyes(which were frequently used by the surrealism artists) were applied to embroidery, printing and beaded decoration. Finally, being inspired by such Pop artists as Andy Warhol, Roy Lichtenstein and Tom Wesselman, Laurent further emphasized the aesthetic value of the popular consumer image in his own work, resulting in the wide recognition of the designs of Yves Saint Laurent as representing the new wave of the Pop Art school.

• Journal of Preventive Medicine and Public Health
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• v.38 no.3
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• pp.283-290
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• 2005

Objectives : The aim of this paper was to examine the relationship between the summertime (June to August) heat index, which quantifies the bioclimatic apparent temperature in sultry weather, and the daily disease-related mortality in Seoul for the period from 1991 to 2000. Methods : The daily maximum (or minimum) summertime heat indices, which show synergetic apparent temperatures, were calculated from the six hourly temperatures and real time humidity data for Seoul from 1991 to 2000. The disease-related daily mortality was extracted with respect to types of disease, age and sex, etc. and compared with the time series of the daily heat indices. Results : The summertime mortality in 1994 exceeded the normal by 626 persons. Specifically, blood circulation-related and cancer-related mortalities increased in 1994 by 29.7% (224 persons) and 15.4% (107 persons), respectively, compared with those in 1993. Elderly persons, those above 65 years, were shown to be highly susceptible to strong heat waves, whereas the other age and sex-based groups showed no significant difference in mortality. In particular, a heat wave episode on the 22nd of July 2004 ($>45^{\circ}C$ daily heat index) resulted in double the normal number of mortalities after a lag time of 3 days. Specifically, blood circulation-related mortalities, such as cerebral infraction, were predominant causes. Overall, a critical mortality threshold was reached when the heat index exceeded approximately $37^{\circ}C$, which corresponds to human body temperature. A linear regression model based on the heat indices above $37^{\circ}C$, with a 3 day lag time, accounted for 63% of the abnormally increased mortality (${\geq}+2$ standard deviations). Conclusions : This study revealed that elderly persons, those over 65 years old, are more vulnerable to mortality due to abnormal heat waves in Seoul, Korea. When the daily maximum heat index exceeds approximately $37^{\circ}C$, blood circulation-related mortality significantly increases. A linear regression model, with respect to lag-time, showed that the heat index based on a human model is a more dependable indicator for the prediction of hot weather-related mortality than the ambient air temperature.

• Journal of the Korean Geotechnical Society
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• v.21 no.4
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• pp.51-63
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• 2005

Concrete pavement may suffer from material deterioration or structural problems, which lead to surface cracks and deflection of a concrete pavement. Degraded concrete pavement, when it is still under operation, should be recovered by an urgent maintenance to avoid the discontinued service leading to the significant traffic problems and economic loss. Seismic techniques are good tools to assess the structural integrity of concrete runway. It is because seismic techniques can evaluate engineering properties nondestructively and quickly and the evaluation can be extended to subgrade. In this study, a series of numerical simulations of stress-wave propagation were performed to verify feasibility of seismic techniques as an assessment tool. Based on the results of the numerical simulation, a framework of using seismic techniques was presented fur the nondestructive integrated assessment fur structural integrity of concrete runway. And the presented framework was applied to $\bigcirc\bigcirc$ concrete runway with surface cracks, which required urgent maintenance, to identify the causes of the surface cracks. The results obtained from the structural integrity assessment were compared with the measurements of the cores collected from the same runway for verification of the presented framework.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.11
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• pp.891-899
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• 2013

This paper suggests a test and evaluation procedure of conformal load-bearing antenna structure(CLAS) for high speed military jet application. A log periodic patch type antenna was designed for multi-band communication and navigation antenna. Carbon/Glass fiber reinforced polymer was used as a structure supporting aerodynamic loads and honeycomb layer was used to improve antenna performance. Multi-layers were stacked and cured in a hot temperature oven. Gain, VSWR and polarization pattern of CLAS were measured using anechoic chamber within 0.15~2.0 GHz frequency range. Tension, shear, fatigue and impact load test were performed to evaluate structural strength of CLAS. Antenna performance test after every structural strength test was conducted to check the effect of structural test to antenna performance. After the application of new test and evaluation procedure to validate a new CLAS, a design improvement was found.

• Journal of Biosystems Engineering
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• v.37 no.3
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• pp.155-165
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• 2012

This study was performed to offer the data for design of the seedling bed transfer equipment to make the automation of working process in a plant factory. The seedling bed transfer equipment pushing the seedling bed with bearing wheels on the rail for interconnecting each working process by a pneumatic cylinder was made and examined. The examined transfer force to push the seedling bed with a weight of 178.9 N by the pneumatic cylinder with length of 60 cm and section area of 5 $cm^2$ was measured by experiments. The examined transfer forces was compared with theoretical ones calculated by the theoretical formula derived from dynamic system analysis according to the number of the seedling bed and pushing speed of the pneumatic cylinder head at no load. The transfer function of the equipment with the input variable as the pushing speed $V_{h0}$(m/s) and the output variable as the transfer force f(t)(N) was represented as $F(s)=(V_{h0}/k)(s+B/M)/(s(s^2+Bs/M+1/(kM))$ where M(kg), k(m/N) and B(Ns/m) are the mass of the bed, the compression coefficient of the pneumatic cylinder and the dynamic friction coefficient between the seedling bed and the rail, respectively. The examined transfer force curves and the theoretical ones were represented similar wave forms as to use the theoretical formular to design the device for the seedling bed transfer. The condition of no vibration of the transfer force curve was $kB^2>4M$. The condition of transferring the bed by the repeatable impact and vibration force according to difference of transfer distance of the pneumatic cylinder head from that of the bed was as $Ce^{-\frac{3{\pi}D}{2\omega}}<-1$, where ${\omega}=\sqrt{\frac{1}{kM}-\frac{B^2}{4M^2}}$, $C=\{\frac{\frac{B}{2M}-\frac{1}{kB}}{\omega}\}$, $D=\frac{B}{2M}$. The examined mean peak transfer force represented 4 times of the stead state transfer force. Therefore it seemed that the transfer force of the pneumatic cylinder required for design of the push device was 4Bv where v is the pushing speed.

• Journal of Internet Computing and Services
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• v.10 no.1
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• pp.145-158
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• 2009

No other change in Kora has offered gredter chalenges and opportunities than the emergence of the Internet and its related Information Technology. In the technology for accessing the ever growing wave of information. The quality of the silver generation is increasingly difficult to achieve because of the complexities of life in today's ICT(Information & Comunication Technology) dependent society, Life is more interesting when one knows what is going on, what opportunities exist, and when alternatives to current practices can be discovered and utilized with ease. The purpose of this study is to identify the determinants of attitude and planned behavior toward using internent for the quality of life. This study employ the intention to use internet, perceived ease of use, perceived usefuiness, self-efficacy, stress factor, generation gap, and income as major research variables, and collected 288 survey responses from senior citizen over 55. The results indicate that the perceived usefuiness and ease of use influence the intention to use internet, and that the self-efficacy, the ease of use and generation gap has some impact on the attitude, but the stree factor and the income level do not appear significant to the attitude. It was also found that the self-efficacy and the income level determine the level of ease of use. In addition, some useful suggestions concerning the continuing education program for silver generations are presented.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.5
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• pp.506-513
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• 2020

Due to climate change, there is an increasing risk of complex (hybrid) disasters, comprising rising sea-levels, typhoons, and torrential rains. This study focuses on Marine City, Busan, a new residential city built on a former landfill site in Suyeong Bay, which recently suffered massive flood damage following a combination of typhoons, storm surges, and wave overtopping and run-up. Preparations for similar complex disasters in future will depend on risk impact assessment and prioritization to establish appropriate countermeasures. A framework was first developed for this study, followed by the collection of data on flood prediction and socioeconomic risk factors. Five socioeconomic risk factors were identified: (1) population density, (2) basement accommodation, (3) building density and design, (4) design of sidewalks, and (5) design of roads. For each factor, absolute criteria were determined with which to assess their level of risk, while expert surveys were consulted to weight each factor. The results were classified into four levels and the risk level was calculated according to the sea-level rise predictions for the year 2100 and a 100-year return period for storm surge and rainfall: Attention 43 %, Caution 24 %, Alert 21 %, and Danger 11 %. Finally, each level, indicated by a different color, was depicted on a complex disaster risk map.

• Journal of Technology Innovation
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• v.25 no.4
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• pp.239-261
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• 2017

This paper analyzes how corporate product innovation affects firms' revenue and financial stability, and thereby draws the implications for the corporate strategy for sustainable growth. Corporate product innovation is defined as the development of new products within the firm, including bought-in products. Corporate revenue is measured by per capita sales and its growth rate, while financial stability is measured by debt-to-equity ratio and liquidity ratio. In the empirical analysis, the two-stage estimation method was used to control for the endogeneity of new product development. The data are drawn from the first (2005) to the sixth (2015) wave of the Human Capital Corporate Panel (HCCP) Survey, which are matched to the data from the Korea Investors Service (KIS). The results of the first-stage estimation indicate that product innovation of the firm is promoted by the firm's knowledge capital stock, human resources investment, and market-leading strategy. The second-stage estimation results indicate a positive relationship between the firm's level of activity in product innovation and short-term revenue (per capita sales and its growth), and financial stability (lower debt-to-equity ratio and higher liquidity ratio). These findings confirm that the firm's investment in technology innovation and subsequent product innovation are important strategies to enhance both short-term corporate revenue and long-term financial stability.

• Atmosphere
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• v.26 no.3
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• pp.357-372
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• 2016

Northeast Asian regions have recently become the main source of anthropogenic and natural aerosols. Measurement of aerosols on the sea in these regions have been rarely conducted since the experimental campaigns such as ACE-ASIA (Asian Pacific Regional Aerosol Characterization Experiment) in 2001. Research vessel observations of aerosol mass and chemical composition were performed on the Yellow and south sea around the Korean peninsula. The ship measurements showed six representative cases such as aerosol event and non-event cases during the study periods. On non-event cases, the anthropogenic chemical and natural soil composition on the Yellow sea were greater than those on the south sea. On aerosol event cases such as haze, haze with dust, and dust, the measured mass concentrations of anthropogenic chemical and element compositions were clearly changed by the events. In particular, methanesulfonate ($MSA^-$, $CH_3SO_3^-$), a main component of natural oceanic aerosol important for sulfur circulation on Earth, was first observed by the vessel in Korea, and its concentration on the Yellow sea was three times that on the south sea during the study period. Sea salt concentration important to chemical composition on the sea is related to wind speed. Coefficients of determination ($R^2$) between wind speed and sea salt concentration were 0.68 in $PM_{10}$ and 0.82 in $PM_{2.5}$. Maximum wave height was not found to be correlated to the sea salt concentration. When sea-salt comes into contact with pollutants, the total sea-salt mass is reduced, i.e., a loss of $Cl^-$ concentration from NaCl, the main chemical composing sea salt, is estimated by reaction with $HNO_3$(gas) and $H_2SO_4$(gas). The $Cl^-$ concentration loss by $SO_4^{2-}$ and $NO_3^-$ more easily increased for $PM_{10}$ compared to $PM_{2.5}$. The results of this study will be applied to verifying a dust-haze forecasting model. In addition, continued vessel measurements of aerosol data will become important to research for climate change studies in the future.