• Korean Journal of Ecology and Environment
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• v.42 no.2
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• pp.221-231
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• 2009

This study was carried out to comparatively identify characteristics of turbid water influence in Imha Reservoir, Soyang Reservoir, and Daecheong Reservoir in Korea. We used 3 years dataset from 2002 to 2004 and analyzed seasonal water quality characteristics, particular parameters in association with turbidity, and light transparency to figure out the trends. All parameters to be used in the study were total phosphate (TP), total nitrogen (TN), chlorophyll-${\alpha}$ (Chl), suspended solids (SS), Secchi depth (SD), conductivity, and verticallight extinction coefficienct($K_d$), euphotic zone ($Z_{eu}$), and critical depth ($Z_p$). All parameters depend on season and watershed. Suspended solids from Soyang Reservoir were usually caused by TP, mainly related to living wastes and agricultures in upper stream. Daecheong Reservoir was influenced by organic matters related to large phytoplankton biomass in summer and inorganic suspended solids by nutrients in the winter. However, in case of Imha Reservoir, turbid water, consisted in silt and clay through heavy precipitation remained in the waterbody to decrease water transparency along with TP and caused the light limitation in winter. Overall results suggest that it was necessary to establish various management programs because the reasons occurring turbidity were varied according to the reservoir circumstances.

• International Journal of Industrial Entomology and Biomaterials
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• v.22 no.2
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• pp.45-49
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• 2011

The performance of five newly evolved cross breeds were evaluated across seasons to understand the genotype and environment interactions and their stability under fluctuating tropical environmental conditions along with control hybrids $PM{\times}CSR2$ and $APM1{\times}APS8$. The data was collected on eight economic traits namely fecundity, yield per 10,000 larvae by number, yield per 10,000 larvae by weight, survival rate, cocoon weight, cocoon shell weight, cocoon shell ratio and filament length. The data was subjected for Analysis of Variance (ANOVA) and relevant statistical methods. The performance data obtained was further subjected for multiple trait evaluation index method. The ranks were adjudicated based on the index values. The two hybrids viz., $MSO3{\times}APS45$ and $MSO1{\times}APS12$ performed well under diversified environmental conditions indicating their overall stability and superiority. These hybrids revealed highly significant (p < 0.01) improvement for the majority of the traits over the control hybrids.

• Geomechanics and Engineering
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• v.18 no.6
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• pp.575-584
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• 2019

The groundwater level (GWL) is an important subsoil condition for the design of foundation. GWL tends to fluctuate often with seasonal variation, which may cause unexpected, additional settlements with some reductions in the safety margin of foundation. In this study, the effects of fluctuating GWL on the load carrying and settlement behavior of footing were investigated and quantified. A series of model load tests were conducted for various GWL and soil conditions using a hydraulically-controlled chamber system. Changes in load level and rising and falling GWL fluctuation cycle were considered in the tests. Settlements during GWL rise were greater than those during GWL fall. The depth of the GWL influence zone ($\underline{d}_{w,inf}$) varied in the range of 0.3 to 1.5 times footing width and became shallower as GWL continued to fluctuate. Design equations for estimating GWL-induced settlements for footings were proposed. The GWL fluctuation cycle, load level and soil density were considered in the proposed method. Changes in settlement and factor of safety with GWL fluctuation were discussed.

• Fashion & Textile Research Journal
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• v.23 no.4
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• pp.480-490
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• 2021

Sales forecasting is crucial for many retail operations. For apparel retailers, accurate sales forecast for the next season is critical to properly manage inventory and plan their supply chains. The challenge in this increases because apparel products are always new for the next season, have numerous variations, short life cycles, long lead times, and seasonal trends. In this study, a sales forecasting model is proposed for apparel products using machine learning techniques. The sales data pertaining to outerwear items for four years were collected from a Korean sports brand and filtered with outliers. Subsequently, the data were standardized by removing the effects of exogenous variables. The sales patterns of outerwear items were clustered by applying K-means clustering, and outerwear attributes associated with the specific sales-pattern type were determined by using a decision tree classifier. Six types of sales pattern clusters were derived and classified using a hybrid model of clustering and decision tree algorithm, and finally, the relationship between outerwear attributes and sales patterns was revealed. Each sales pattern can be used to predict stock-keeping-unit-level sales based on item attributes.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.2
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• pp.711-724
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• 2021

The purpose of this paper is to investigate the profitability of the momentum effects on the Oman Stock Market (OSM). This study uses the monthly returns of all stocks listed on the OSM, with a total of 107 companies used in the study for the period from 2005 to 2018. According to the methodology developed by Jegadeesh and Titman (1993), this study builds momentum portfolios based on various sizes. Moreover, the January effect is also examined to recognize if this effect is related to the momentum effect. The results find that there is evidence of momentum returns and these returns are statistically and economically significant. The sub-periods confirmed the profitability of the momentum strategy. This paper shows that momentum returns are evident at different sizes; big, medium, and small-sized portfolios. Besides, the result shows that the classic January effect does not play an important role in the momentum returns. Thus, the implication is that the momentum should not take into account the annual, seasonal, and size returns. The capital asset pricing model (CAPM) or the three-factor model cannot explain momentum returns generated by individual stocks in the Oman Stock Market. These results are useful to academia and investors alike.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.64-72
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• 2021

The feeding habits of the Japanese jack mackerel Trachurus japonicus were studied in the Southern Sea of the Republic of Korea. To assess the effects of season, sampling was conducted in February (winter), May (spring), and August (summer), 2020. The total length of each fish was measured in 1 cm intervals. Diet composition showed the highest species diversity during winter. Diet composition changed from copepods to euphausiids as the total length of jack mackerel increased, except during winter. The most important seasonal prey were copepods in winter and summer and euphausiids in spring. Species diversity of the zooplankton community structure was highest in winter. Among the zooplankton communities, copepods were dominant in all seasons. Species with a high electivity index in all seasons were relatively large zooplankton of ≥2 mm. Jack mackerel had ontogenetic diet change, exhibited diet selectivity depending on size, and its feeding habits were affected by the zooplankton community structure.

• Korean Journal of Veterinary Research
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• v.61 no.1
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• pp.7.1-7.7
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• 2021

The levels of aflatoxin (AFT) and ochratoxin (OCT) were assessed at different seasons in raw materials, different feed manufacture processing stages, and animal feeds in feed mills in Korea implementing the hazard analysis and critical control point (HACCP) system. Two hundred samples were collected in all four seasons from five feed mills implementing the HACCP system and examined for AFT and OCT contents. The AFT and OCT levels were analysed by using HPLC method to provide information on raw material and product stage. The AFT content of raw ingredients in the spring season was highest in corn gluten (3.84 ppb) and lowest in corn (1.82 ppb) The AFT content of corn was highest in the winter season (2.17 ppb). The content of OCT in wheat was highest in the winter season. The amounts of AFT and OCT at processing stages were higher than in the raw materials or feed. In particular, AFT content was higher in the transfer stage (3.88 ppb) than in the mixing (2.86 ppb) or filling stages (3.45 ppb) in the summer season. The means of AFT and OCT level in laying hen feed was 3.41 ppb and 1.14 ppb for broiler feed, respectively. The means of AFT and OCT level in and broiler feeds was 3.44 ppb and 1.17 ppb for broiler feed, respectively.

• Food Science of Animal Resources
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• v.42 no.1
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• pp.111-127
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• 2022

This study examined how chicken breed affects consumer behavior. The breeds evaluated were a Korean native chicken (KNC) and a commercial broiler (CB). Consumer behavior was measured by evaluating sensory attributes (taste, odor, and texture) and purchase behaviors [satisfaction, purchase intention, and willingness to pay (WTP)]. The sensory evaluation was conducted using healthy Korean consumers (n=100). The chicken was cooked in baeksuk (Korean traditional chicken soup), which is a seasonal summer health food in Korea. The participants evaluated sensory attributes and purchase behaviors between blinded samples of baeksuk (CB) and unblinded samples of baeksuk (KNC). The sensory evaluation involved chicken breasts and legs. The participants considered KNC as having a more umami taste, a chewier and juicer texture, and a less metallic odor than CB. Moreover, when participants were given KNC breed information, they expressed higher satisfaction, purchase intention, and WTP. The results of this study contribute to consumer behavior literature by revealing the effects of breed information on consumer sensory perceptions and purchase behaviors. Furthermore, the findings provide evidence that branding KNC is one way to increase its demand and low market share while contributing to sustainable consumption.

• Journal of Integrative Natural Science
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• v.15 no.3
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• pp.111-122
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• 2022

The purpose of this study was to investigate the ecological impact of wetlands by changing the species diversity of benthic macroinvertebrates and birds following the creation of an artificial wetland with a size of 30 m*30 m on bare land in reclaimed land in Haenam-gun, Korea. We investigated monthly fauna of benthic macroinvertebrates and birds in and outside wetlands and physicochemical indicators for 7 months from March to September 2014. During the study period, the water temperature and dissolved oxygen levels were consistently higher in wetlands than lakes. Many species of benthic macroinvertebrates were observed in summer (16 species in July) due to seasonal effects, and the species diversity index was highest in July and then gradually decreased. Thirteen species of birds were observed in March, 6 species in April, 5 species in July, and 1 species in June, where most winter birds and migratory birds were observed around wetlands in spring. The species diversity index also decreased after being high in July except for spring. This suggests that the abiotic environment in the wetland can be improved by creating an artificial wetland in the reclaimed land, and the increase in benthic macroinvertebrates can ultimately be a basic direction to restore the wetland ecosystem in the reclaimed land.

• Journal of Wellbeing Management and Applied Psychology
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• v.5 no.3
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• pp.19-25
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• 2022

Purpose: As interest in odor increases, odor complaints are also rapidly increasing. Traditional markets are not included in malodor control areas and are not easy to manage, so measure the odor substances generated in traditional markets and analyze the cause of high concentration points. Research design, data and methodology: The average value was presented by continuously measuring the combined odor, TVOC, hydrogen sulfide, and ammonia for 5 minutes at 100m intervals in Joong-ang traditional market, Jayu traditional market, Doraemi traditional market, and Sundae Alley in Wonju, Gangwon-do. In each market, up to the third highest concentration point for each measurement item was marked and analyzed. Results: The Joong-ang traditional market, Doraemi traditional market, and Sundae Alley had high readings at the intersection. The Jayu traditional market had high measurements around restaurants and clothing stores. In addition, the concentration of complex malodors was also high at the points where the hydrogen sulfide concentration was measured. Conclusions: Odor generated in traditional markets is an important indicator for merchants and consumers. Therefore, in future studies, analysis that can supplement the limitations of measurement data and seasonal effects is needed.