• Korean Journal of Soil Science and Fertilizer
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• v.40 no.1
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• pp.51-56
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• 2007

The toxicities of contaminated soils with 8 consecutive year applications of three levels (12.5, 25.0, and $50.0t\;dry\;matter\;ha^{-1}yr^{-1}$) of four organic sludge [municipal sewage sludge (MSS), industrial sewage sludge (ISS), alcohol fermentation processing sludge (AFPS) and leather processing sludge (LPS)] on earthworm (Eisenia fetida) were examined by using microcosm container in the laboratory. Results were compared with those of pig manure compost (PMC) treated soil. In tests with three treatment levels (12.5, 25.0, and 50.0 t per plot), ISS treated soil showed higher contents of Cu (18.9~26.2 fold), Cr (7.7~34.7 fold), and Ni (14.8~18.8 fold) at 8 years post treatment, than PMC treated soil. LPS treated soil showed higher contents of Cr (35.7~268.0 fold) and Ni (4.5~7.6 fold) than PMC treated soil. There were no great differences in heavy metal contents among MSS, AFPS, and PMC treated soils. In these contaminated soils, earthworm mortalities of MSS and AFPS treated soils at 8 weeks post-exposure were similar to those of PMC treated soil regardless of each treatment level. Toxic effect (26.7~96.7 mortality) on the ISS and LPS treated soils was significantly higher than one of PMC treated soil, with an exception of LPS soil treated with 25.0 t per plot. At 16 weeks post-exposure, earthworm mortalities of AFPS' 12.5 and 25.0 t treated soils were similar to those of PMC treated soil. Toxic effect (53.3~100 mortality) on the 12.5, 25.0, and 50.0 t treated soils of MSS, ISS and LPS, and AFPS' 50.0 t treated soils was significantly higher than those of PMC treated soil. The data suggested that the 12.5, 25.0, and 50.0 t of MSS, ISS and LPS, and AFPS' 50.0 t treated soils were evaluated to have toxicity on earthworm.

• Korean Journal of Heritage: History & Science
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• v.49 no.3
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• pp.154-201
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• 2016

During the Incipient and Early Silla phases, which witnessed the establishment and development of the ancient Silla state, the Wolseong North Burial Ground functioned as not only the central burial ground in the Gyeongju region of the capital of Silla but also as the central burial ground of the whole Silla state. Wolseong North Burial Ground is where transformations in Silla funerary architecture first occurred. As such, an empirical study of the tombs constructed at this burial ground can be regarded as a starting point from which an understanding of the development of the tomb culture of the Silla state may be achieved. This paper therefore aims to examine the changing nature of the tomb culture of the Early Silla phase through the burial data of Wolseong North Burial Ground and the Gyeongju region. Wooden chamber tombs were constructed from the late phase of Saroguk. At Wolseong North Burial Ground, which eventually developed into the central burial ground of the Gyeongju region, wooden chamber tombs embellished with stone packing emerged during the Incipient Silla phase; wooden chamber tombs with stone mounds, on the other hand, first appeared in the Early Silla phase and eventually became established as the central tomb type. A key difference between the wooden chamber tomb embellished with stone packing and the wooden chamber tomb with stone mound is that, in the case of the latter, stones were packed not only around sides of the wooden structure that acted as the burial chamber but also on top of this structure. The addition of a high earthen mound surrounded by protective ring of stones is another distinctive feature of the latter, presenting a contrast to the low mound of the former. During the Early Silla phase, two types of wooden chamber tombs with stone mounds were constructed at Wolseong North Burial Ground: those with burial chambers located above ground and those with subterranean burial chambers. Also constructed during this phase were the wooden chamber tomb embellished with packed stones, the wooden chamber tomb embellished with packed clay, simple earth cut burials, which had been used since the Incipient Silla phase, as well as the stone-lined burials with vertical entrance which first appeared in the Early Silla phase. However, of these different types of burials, it was only the wooden chamber tomb with stone mound that was covered with a 'high mound.' Differentiation between the different tomb types can also be observed in terms of location, type of burial chamber used, construction method, and tomb size. It is therefore possible to surmise that stratification between the different tomb types, which first emerged in the Incipient Silla phase, became intensified during the Early Silla phase.

• Korea Science and Art Forum
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• v.37 no.1
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• pp.249-260
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• 2019

Recently, the proportion of single-person households is on the increase in Korea, expected to reach 34.6% in 2035. Among the single-person households, Young single family households are facing greater difficulties due to high house prices in Korea. The government is expanding its support to Young single family, executing various policies such as public lease housings, private lease housings for youth, youth dormitory, etc. The purpose of this study is to understand the exact housing requirement of Young single family households who have different lifestyles with other age groups and provide base line data for youth house planning which will be in use later on. Study methods are shown below. First, this research studied the status and characteristics of Young single family households by looking into literature. Second, by studying previous studies concerned with life style and housing preferences of youth, the tool for investigating preferences and needs of housing environment by Young single family households was composed. Third, survey on characterstics of space usage, preferences and needs on flat composition, and preferences of interior design were conducted based on lifestyle of Young single family-households. The survey was conducted as an online survey using SNS for 150 Young single family holds from the age of 20 and 39, including students and office workers from December 2018 to January 2019. The results are as following. (1) Looking into the space usage characteristics, considering that various activities other than basic functions take place in bedroom and living room of small-sized Young single family households, we need to consider this additionally when planning the housing. (2) Looking into the preferences and composite needs of flat composition, the subjects demand separate bed room and more living room space, and also demand expansion of living room space where various activities take place and additional storage such as dress room in bed room (3) The preferences toward interior design show preferences toward modern style and achromatic color, a representative color. The subjects also prefer floor finishing materials normally used for living spaces, and indirect, soft lighting that uses wall. Also, there are differences between interior design preferences between students (20's) and office workers(30's) due to their different lifestyles. Research is needed to propose practical residential environment requirements and plans through a case study of actual public rental housing and a wider range of users.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.172-178
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• 2021

In the ship repair market, interest in maintenance and repair is steadily increasing due to the reinforcement of prevention of environmental pollution caused by ships and the reinforcement of safety standards for ship structures. By reflecting this effect, the number of requests for repairs by foreign shipping companies increases to repair shipbuilders in the Southwest Sea. However, because most of the repair shipbuilders in the southwestern area are small and medium-sized companies, it is difficult to lead to the integrated synergy effect of the repair shipbuilding companies. Moreover, the infrastructure is not integrated; hence, using the infrastructure jointly is a challenge, which acts as an obstacle to the activation of the repair shipbuilding industry. Floating docks are indispensable to operating the repair shipbuilding business; in addition, most of them are operated through renovation/repair after importing aging caisson docks from overseas. However, their service life is more than 30 years; additionally, there is no structure inspection standard. Therefore, it is vulnerable to the safety field. In this study, the finite element analysis program of ANSYS was used to evaluate the structural safety of the modified caisson dock and obtain additional structural reinforcement schemes to solve the derived problems. For the floating docks, there are classification regulations; however, concerning structural strength, the regulations are insufficient, and the applicability is inferior. These insufficient evaluation areas were supplemented through a detailed structural FE-analysis. The reinforcement plan was decided by reinforcing the pontoon deck and reinforcement of the side tank, considering the characteristics of the repair shipyard condition. The final plan was selected to reinforce the side wing tank through the structural analysis of the decision; in addition, the actual structure was fabricated to reflect the reinforcement plan. Our results can be used as reference data for improving the structural strength of similar facilities; we believe that the optimal solution can be found quickly if this method is used during renovation/repair.

• 한국노년학
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• v.40 no.3
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• pp.543-563
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• 2020

As people age and their physical functions are declined, they stay longer in the home, thus being more affected by the home environment. Many studies have shown the association between the home environment and health. However, little is known about the effect of the home environment on disability and depression of older people with functional limitation. This study, therefore, aimed to examine the moderating effect of the home environment on the pathway between walking limitation and instrumental activity of daily living(IADL) disability, and the relationship between IADL disability and depression. We performed logistic regression and multiple linear regression analyses with data on 3,027 participants from the 2018 Seoul Aging Survey. As results, first, older people who lived home with poor conditions showed a higher risk of walking limitation(OR=1.487, 95% CI: 1.250 - 1.770), IADL disability(OR=1.594, 95% CI: 1.303 - 1.949), and depression(OR=1.943, 95% CI: 1.553 - 2.430). Second, the home environment moderated the relationship between walking limitation and IADL disability. Older people with walking limitation who lived in poor housing condition experienced more IADL disability than others. Third, after controlling for walking limitation, the home environment had significant moderating effect on the relationship between IADL disability and depression. Elderly with IADL disability living in poor home experienced higher risk of depression. Based on these results, the study suggests the necessity of home modification intervention targeting functional limitation of older adults as strategy for preventing disability and depression, and enabling aging in place.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.337-345
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• 2023

Estimating the rice heading date is one of the most crucial agricultural tasks related to productivity. However, due to abnormal climates around the world, it is becoming increasingly challenging to estimate the rice heading date. Therefore, a more objective classification method for estimating the rice heading date is needed than the existing methods. This study, we aimed to classify the rice heading stage from various images using a CNN classification model. We collected top-view images taken from a drone and a phenotyping tower, as well as slanted-view images captured with a RGB camera. The collected images underwent preprocessing to prepare them as input data for the CNN model. The CNN architectures employed were ResNet50, InceptionV3, and VGG19, which are commonly used in image classification models. The accuracy of the models all showed an accuracy of 0.98 or higher regardless of each architecture and type of image. We also used Grad-CAM to visually check which features of the image the model looked at and classified. Then verified our model accurately measure the rice heading date in paddy fields. The rice heading date was estimated to be approximately one day apart on average in the four paddy fields. This method suggests that the water head can be estimated automatically and quantitatively when estimating the rice heading date from various paddy field monitoring images.

• The Journal of the Acoustical Society of Korea
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• v.42 no.6
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• pp.603-616
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• 2023

In this study, machine learning-based clustering and classification of residential noise in apartment buildings was conducted using frequency and temporal characteristics. First, a residential noise source dataset was constructed . The residential noise source dataset was consisted of floor impact, airborne, plumbing and equipment noise, environmental, and construction noise. The clustering of residential noise was performed by K-Means clustering method. For frequency characteristics, L_eq and L_max values were derived for 1/1 and 1/3 octave band for each sound source. For temporal characteristics, Leq values were derived at every 6 ms through sound pressure level analysis for 5 s. The number of k in K-Means clustering method was determined through the silhouette coefficient and elbow method. The clustering of residential noise source by frequency characteristic resulted in three clusters for both L_eq and L_max analysis. Temporal characteristic clustered residential noise source into 9 clusters for L_eq and 11 clusters for L_max. Clustering by frequency characteristic clustered according to the proportion of low frequency band. Then, to utilize the clustering results, the residential noise source was classified using three kinds of machine learning. The results of the residential noise classification showed the highest accuracy and f1-score for data labeled with L_eq values in 1/3 octave bands, and the highest accuracy and f1-score for classifying residential noise sources with an Artificial Neural Network (ANN) model using both frequency and temporal features, with 93 % accuracy and 92 % f1-score.

• Korean Journal of Environment and Ecology
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• v.37 no.5
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• pp.327-336
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• 2023

This study aimed to propose an effective method for surveying wild birds by comparing the results of bioacoustic detection with those obtained through a field survey. The study sites were located at Dongbaek-dongsan and a 1100-altitude wetland in Jeju-do, South Korea. The bioacoustic detection was conducted over the course of 12 months in 2020. For the bioacoustic detection, a Song-meter SM4 device was installed at each study site, recording bird songs in 1-min per hour, .wav, and 44,100 Hz format. The findings of the field survey were taken from the 「Long-term trends of Bird Community at Dongbaekdongsan and 1100-Highland Wetland of Jeju Island, South Korea.」 by Banjade et al. (2019). The results of this study are as follows. First, the avifauna identified using bioacoustic detection comprised 29 families and 46 species in Dongbaek-dongsan, and 16 families and 25 species in the 1100-altitude wetland. Second, based on the song frequency, the dominant species in Dongbaek-dongsan were Hypsipetes amaurotis (Brown-eared Bulbul, 33.62%), Horornis diphone (Japanese Bush Warbler, 12.13%), and Zosterops japonicus (Warbling White-eye, 9.77%). In the 1100-altitude wetland the dominant species were Corvus macrorhynchos (Large-billed Crow, 27.34%), H. diphone (19.43%), and H. amaurotis (16.56%). Third, in the field survey conducted at Dongbaek-dongsan, the number of detected bird species was 39 in 2009, 51 in 2012, 35 in 2015, and 45 in 2018, while the bioacoustic detection identified 46 species. In the field survey conducted in the 1100-altitude wetland, the number of detected bird species was 37 in 2009, 42 in 2012, 34 in 2015, and 38 in 2018, while the bioacoustics detection identified 25 species. Overall, 43.6% of the 78 species detected in the field survey in Dongbaek-dongsan (34 species) were identified using bioacoustic detection, and 38.3% of the 47 species detected in the field survey in the 1100-altitude wetland (18 species) were identified using bioacoustic detection. Fourth, the bioacoustic detection identified 9 families and 12 species of birds in Dongbaek-dongsan, and 3 families and 7 species of birds in the 1100-altitude wetland. No results from field survey were available for these species. The identified birds were predominantly nocturnal, including Otus sunia (Oriental Scops Owl) and Ninox japonica (Northern Boobook), passage migrants, including Larvivora cyane (Siberian Blue Robin), L. sibilans (Rufous-tailed Robin), and winter visitors with a relatively small number of visiting individuals, such as Bombycilla garrulus (Bohemian Waxwing) and Loxia curvirostra (Red Crossbill). Fifth, the birds detected in the field survey but not through bioacoustic detection included 18 families and 48 species in Dongbaek-dongsan and 14 families and 27 species in the 1100-altitude wetland; the most representative families were Ardeidae, Accipitridae, and Muscicapidae. This study is significant as it provides essential data supporting the possibility of an effective survey combining bioacoustic detection with field studies, given the increasing use of bioacoustic devices in ornithological studies in South Korea.

• Journal of Distribution Research
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• v.16 no.4
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• pp.1-27
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• 2011

Introduction: Sales of private labels(PU have been growing m recent years. Globally, PLs have already achieved 20% share, although between 25 and 50% share in most of the European markets(AC. Nielson, 2005). These products are aimed to have comparable quality and prices as national brand(NB) products and have been continuously eroding manufacturer's national brand market share. Stores have also started introducing premium PLs that are of higher-quality and more reasonably priced compared to NBs. Worldwide, many retailers already have a multiple-tier private label architecture. Consumers as a consequence are now able to have a more diverse brand choice in store than ever before. Since premium PLs are priced higher than regular PLs and even, in some cases, above NBs, stores can expect to generate higher profits. Brand extensions and private label have been extensively studied in the marketing field. However, less attention has been paid to the private label extension. Therefore, this research focuses on private label extension using the Multi-Attribute Attitude Model(Fishbein and Ajzen, 1975). Especially there are few studies that consider the hierarchical effect of the PL's two parent brands: store brand and the original PL. We assume that the attitude toward each of the two parent brands affects the attitude towards the extended PL. The influence from each parent brand toward extended PL will vary according to the perceived fit between each parent brand and the extended PL. This research focuses on how these two parent brands act as reference points to one another in the consumers' choice consideration. Specifically we seek to understand how store image and attitude towards original PL affect consumer perceptions of extended premium PL. How consumers perceive extended premium PLs could provide strategic suggestions for retailer managers with specific suggestions on whether it is more effective: to position extended premium PL similarly or dissimilarly to original PL especially on the quality dimension and congruency with store image. There is an extensive body of research on branding and brand extensions (e.g. Aaker and Keller, 1990) and more recently on PLs(e.g. Kumar and Steenkamp, 2007). However there are no studies to date that look at the upgrading and influence of original PLs and attitude towards store on the premium PL extension. This research wishes to make a contribution to this gap using the perceived fit difference between parent brands and extended premium PL as the context. In order to meet the above objectives, we investigate which factors heighten consumers' positive attitude toward premium PL extension. Research Model and Hypotheses: When considering the attitude towards the premium PL extension, we expect four factors to have an influence: attitude towards store; attitude towards original PL; perceived congruity between the store image and the premium PL; perceived similarity between the original PL and the premium PL. We expect that all these factors have an influence on consumer attitude towards premium PL extension. Figure 1 gives the research model and hypotheses. Method: Data were collected by an intercept survey conducted on consumers at discount stores. 403 survey responses were attained (total 59.8% female, across all age ranges). Respondents were asked to respond to a series of Questions measured on 7 point likert-type scales. The survey consisted of Questions that measured: the trust towards store and the original PL; the satisfaction towards store and the original PL; the attitudes towards store, the original PL, and the extended premium PL; the perceived similarity of the original PL and the extended premium PL; the perceived congruity between the store image and the extended premium PL. Product images with specific explanations of the features of premium PL, regular PL and NB we reused as the stimuli for the Question response. We developed scales to measure the research constructs. Cronbach's alphaw as measured each construct with the reliability for all constructs exceeding the .70 standard(Nunnally, 1978). Results: To test the hypotheses, path analysis was conducted using LISREL 8.30. The path analysis for verification of the model produced satisfactory results. The validity index shows acceptable results(${\chi}^2=427.00$(P=0.00), GFI= .90, AGFI= .87, NFI= .91, RMSEA= .062, RMR= .047). With the increasing retailer use of premium PLBs, the intention of this research was to examine how consumers use original PL and store image as reference points as to the attitude towards premium PL extension. Results(see table 1 & 2) show that the attitude of each parent brand (attitudes toward store and original pL) influences the attitude towards extended PL and their perceived fit moderates these influences. Attitude toward the extended PL was influenced by the relative level of perceived fit. Discussion of results and future direction: These results suggest that the future strategy for the PL extension needs to consider that positive parent brand attitude is more strongly associated with the attitude toward PL extensions. Specifically, to improve attitude towards PL extension, building and maintaining positive attitude towards original PL is necessary. Positioning premium PL congruently to store image is also important for positive attitude. In order to improve this research, the following alternatives should also be considered. To improve the research model's predictive power, more diverse products should be included in study. Other attributes of product should also be included such as design, brand name since we only considered trust and satisfaction as factors to build consumer attitudes.

• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.698-708
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• 2018

The purpose of this study was to investigate differences in the breeding call characteristics of cicada species found in urban and forest areas in the central region of Korea by examining the interspecific effects and environmental factors affecting the breeding calls and breeding call patterns. The selected research sites were Gyungnam Apartment in Bangbae-dong, Seoul for the urban area and Chiak Mountain National Park in Wonju for the forest area. The research method for both sites was to record cicada breeding calls for 24 hours with a recorder installed at the site and analyze the results. Data from the Korea Meteorological Administration were used for environmental factors. The research period was from June 19, 2017 to September 30, 2017. As a result of the study, there were differences in the emergence of species between the two research sites: while Platypleura kaempferi, Hyalessa fuscata, Meimuna opalifera, Graptopsaltria nigrofuscata, and Suisha coreana were observed at both sites, Cryptotympana atrata was observed in the urban area and Leptosemia takanonis in the forest area only. The emergence periods of cicadas at the two sites were also different. The activities of P. kaempferi and L. takanonis were noticeable in the forest area. In the urban area, however, L. takanonis was not observed and the duration of activity of P. kaempferi was short. In the urban area, C. atrata appeared and sang for a long period; H. fuscata, M. opalifera, and G. nigrofuscata appeared earlier than in the forest area. S. coreana appeared earlier in the forest area than in the urban area. According to the daily call cycle analysis, even cospecific cicada showed a wide variation in their daily cycle depending on the region and the interspecific effects between different cicadas, and the environmental differences between the urban and forest areas affected the calls of cicadas. The results of correlation analysis between each cicada breeding calls and environmental factors of each site showed positive correlation with average temperature of most cicadas except P. kaempferi and C. atrata. The same species of each site showed positive correlations with more diverse weather factors such as solar irradiance. Logistic regression analysis showed that cicadas with overlapping calling times had significant effects on each other's breeding calls. C. atrata, which appeared only in the urban area, had a positive effect on the calling frequency of H. fuscata, M. opalifera, and G. nigrofuscata, which called in the same period. Additionally, L. takanonis, which appeared only in the forest area, and P. kaempferi had a positive effect on each other, and M. opalifera had a positive effect on the calling frequency of H. fuscata and G. nigrofuscata in the forest area. For the environmental factors, the calling frequency of cicadas was affected by the average temperatures of the urban and forest areas, and cicadas that appeared in the forest area were also affected by the amount of solar radiation. According to the results of statistical analysis, urban cicadas with similar activity periods are influenced by species, especially with respect to urban dominant species, C. atrata. Forest cicadas were influenced by species, mainly M. opalifera, which is a forest dominant species. The results of the meteorological impact analysis were similar to those of the correlation analysis, and were influenced mainly by the temperature, and the influence of the insolation was more increased in the forests.