• The Journal of the Acoustical Society of Korea
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• v.38 no.1
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• pp.39-46
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• 2019

In this paper, combining features is proposed as a way to enhance the classification accuracy of sounds under noisy environments using the CNN (Convolutional Neural Network) structure. A robust log Mel-filter bank using Wiener filter and PNCCs (Power Normalized Cepstral Coefficients) are extracted to form a 2-dimensional feature that is used as input to the CNN structure. An ebird database is used to classify 43 types of bird species in their natural environment. To evaluate the performance of the combined features under noisy environments, the database is augmented with 3 types of noise under 4 different SNRs (Signal to Noise Ratios) (20 dB, 10 dB, 5 dB, 0 dB). The combined feature is compared to the log Mel-filter bank with and without incorporating the Wiener filter and the PNCCs. The combined feature is shown to outperform the other mentioned features under clean environments with a 1.34 % increase in overall average accuracy. Additionally, the accuracy under noisy environments at the 4 SNR levels is increased by 1.06 % and 0.65 % for shop and schoolyard noise backgrounds, respectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.1
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• pp.57-75
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• 2019

Soundscapes have the potential to help people experience the historical background and cultural traditions by the scenery of a local area and to be used as a cultural and tourism resource. This concept was first explained in detail by M. Schafer and has been developed as a new way of experiencing landscapes using various senses. This research studied the soundscape of Kyodong Island, the so-called "Island of Peace" and designed new cultural acoustic content for education and tourism. Kyodong Island is located right below the Northern Limit Line and the whole island is in the Civilian Controlled Area. The political and economic status of the island has been changed dynamically by the Korean War and the division of the country. These days, the island needs to realize the vision of the "Island of Peace" in a more creative way using local resources, including its "cold war landscape" and the natural scenery of the region. This research applied the concept of a soundscape to document the island, and to reproduce it in an artistic way. A workshop was conducted to learn concepts and techniques of soundscapes with a sound artist. Listening, recording, conducting interviews, and literature research was used to study the soundscape of the island. After that, this research reconstructed the soundscape of the island through a soundscape composition. The main theme of the composition story was the "Hope and Wish for the Harmony and Peace" to show the vision of the "Island of Peace". The initial sub-theme for the introduction part was "First Encounter with Kyodong Island" arranging the representative soundscape, which could be the first impression of the region. The second sub-theme was "War and Tension" using several soundscapes as a metaphor for the tragedy of the Korean War. The third sub-theme was "Everyday Life of Kyodong Island" which described the energy of the present day, after the wounds of the war have healed. The final sub-theme was "Harmony and Peace" using traditional music and keynote sounds of the region as a reminder of the peaceful past, before the war. The recording files were documented as two types of sound maps. One was a two-dimensional map to show the soundscapes from one point of view, and the other used the online application called "Sound Around You". The final artwork was displayed at an exhibition and uploaded on YouTube to be shared publicly. Through this project, we discovered the potential of soundscapes as a medium to preserve the history and local identity, as well as presenting a new vision. The artwork will be exhibited at historically and culturally meaningful places on the Island to utilize the underused places as local tourist attractions and educational resources.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.2
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• pp.101-111
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• 2006

In the present work, life cycle assessments (LCA) of various waste-plastic recycling methods (material recycling, refused derived fuel (RDF), recycling on furnace, and pyrolytic oil production) were carried out to investigate their impacts on the environment. Six types of impacts were considered. While the impact on global warming was found to be significant, the impact on others were negligible. The impact values on the global warming caused by the material recycling, RDF, and the recycling on furnace were negative, which implied that their impacts could be noticeably reduced when waste-plastic are used as an alternative to newly drawn plastics. The pyrolytic oil production, however, showed positive value, which may be due to the carbon dioxide produced during electric power generation. The pyrolytic oil production had the largest impact on the ozone layer destruction, which was due to ozone depleting substances produced from the process itself. These results can be used as a useful data for the enhancement of waste-plastic recycling.

• Environmental and Resource Economics Review
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• v.14 no.3
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• pp.595-626
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• 2005

The purpose of this paper is to estimate technical efficiency, scale efficiency, and environmental efficiency by income level of Korean farms, and analyze the factors to decide three efficiencies. Depending on the non-parametric methods, we estimate technical using inputs and outputs of total farms without assuming of goods or behavior of optimization. The average technical efficiency of total firms under constant return to scale and strong disposability is 0.437. The technical inefficiency was caused by 47.7% in pure technical inefficiency, 11.3% in scale failure, and 3.2% in environmental inefficiency. The number of firms under increasing return to scale occupied almost 70% and 27% of total firms respectively. Higher are income class, middle debt & long debt per asset, and N effluents per cultural land, higher technical efficiency. The increases of BOD discharges per cultural land and machines per cultural land deteriorate environmental efficiency.

• Journal of Digital Convergence
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• v.17 no.3
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• pp.281-290
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• 2019

The purpose of this study was to examine the effect of emotional labor, resilience, nursing work environment on turnover intentions of comprehensive nursing care medical service ward nurses. The data were collected from 186 subjects using a structured self-report questionnaires and analyzed using SPSS WIN Version 22.0. The mean score of emotional labor, resilience, nursing work environment, and turnover intentions were 3.66, 3.52, 2.62, and 3.82. Turnover intentions had significant correlation with emotional labor, resilience and nursing work environment. The influencing factors on turnover intentions were sex, emotional labor, resilience and nursing work environment of comprehensive nursing care medical service ward nurses. These result indicates that in order to reduce the turnover intentions of comprehensive nursing care medical service ward nurses, it is necessary to develop and apply an intervention programs considering sex, emotional labor, resilience, and nursing work environment.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.43-49
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• 2024

This study is tried to confirm the effect of practical education environment and practical stress perceived by nursing college students who have experienced clinical practice on department adaptation. The subjects of the study were 154 nursing students who experienced clinical practice at nursing universities in Area C. As a result of the study, there was a positive correlation between the practical education environment perceived by nursing students and department adaptation (r=.43, p=.001), a negative correlation between practical stress and department adaptation (r=-.15, p=.012). The practical education environment and practical stress were identified as factors influencing nursing students' adaptation to the department. Therefore, in order to positively improve the practical education environment, it is necessary to continuously train related factors that can help adapt to field practice and prepare measures to improve the practical education environment through close cooperation with practice institutions.

• Journal of Technology Innovation
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• v.24 no.2
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• pp.177-205
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• 2016

Growing competition is forcing firms to unceasingly achieve innovation for survival. In a response to increased competition, firms invest in R&D. In this vein, this study focuses on the relation between competition and R&D investments of firms. To this end, we decompose competition into actual and potential competition first and then empirically examine effects of each competition on firms' R&D investments. Further, this study also focuses on moderating roles of firms' performance relative to their aspiration level on these relations. By using Compustat data, we found that actual competition hinders firms' R&D investments, but potential competition enhances R&D investments. In addition, the effects of actual and potential competition were moderated by firms' performance relative to their aspiration level. Specifically, negative performance strengthens the negative effect of actual competition on R&D investments, but attenuates the positive effect of potential competition. Moreover, positive performance moderates the effects of each competition in the same direction, but its moderating effects are stronger than negative performance. As such, this research seeks to identify the relations between actual and potential competition and R&D investments of firms and the moderating role of performance relative to aspiration level.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.6
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• pp.1055-1061
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• 1996

This study was conducted to assess meal management and nutrient intake of 357 elderlies in Ulsan. 114 male and 243 female elderlies over 65 year old were recruited from July 5 to August 13, 1995. Questionnaires for general characteristics of the subjects(such as family size, living cost, pocket money and health condition) and for meal management were used. The levels of depression and anxiety were measured by CED-S and Spielbuger's STAI-S, respectively In addition, nutrient intakes were conducted by convenience methods. Nutrient intake of male and female showed the average daily intake of energy, Protein, vitamin A, vitamin $B_2, $ and vitamin C were lower than Korean recommended dietary allowances(RDA). But other nutrient intake were higher than RDA except that calcium intake of female was lower. Most nutrient intakes were positively correlated with family size, living cost, pocket money and health condition. Depression and anxiety scores were also negatively correlated with most of nutrient intakes. The pattern of meal management could predict nutrient intakes as expected : regularity and pleansantness of eating were positively correlated with nutrient intakes, whereas unbalanced meal and eating lonely were negatively correlated with them.

• The Journal of the Acoustical Society of Korea
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• v.16 no.5
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• pp.96-104
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• 1997

In this paper, we proposed new methods for estimation of time delay and time-frequency delay in impulsive noise environment. The proposed methods are developed using the theory of ${\alpha}-stable$ distribution, including the fractional negative order moment(FNOM) and minimum dispersion(MD), which are formulated for the time delay estimation and the fractional negative order ambiguity function and complex minimum dispersion, which are difined for the joint estimation of time delay and frequency delay. Through simulation work, its performance was compared with various other algorithms. As a result, while the conventional approaches based on second-order statistics are only verified in Gaussian noise environent ($S{\alpha}S$ noise with ${\alpha}$=2) and also the recently proposed robust methods by Nikias[7] are verified only in limited impulse noise ($S{\alpha}S$ noise with the range of $1<{\alpha}{\le}2$), the methods proposed are able to estimate the time delay in Gaussian and any impulsive noise environments($S{\alpha}S$ noise with the range of $0<{\alpha}{\le}2$).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.56-65
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• 2019

This study empirically analyzes the effect of weather on pedestrian volume in an urban space. We used data from the 2009 Seoul Flow Population Survey and constructed a model with the pedestrian volume as a dependent variable and the weather and physical environment as independent variables. We constructed 28 models and compared the results to determine the effects of weather on pedestrian volume by season, land use, and time zone. A negative binomial regression model was used because the dependent variable did not have a normal distribution. The results show that weather affects the volume of walking. Rain reduced walking volume in most models, and snow and thunderstorms reduced the volume in a small number of models. The effects of the weather depended on the season and land use, and the effects of environmental factors depended on the season. The results have various policy implications. First, it is necessary to provide semi-outdoor urban spaces that can cope with snow or rain. Second, it is necessary to have different policies to encourage walking for each season.