• Steel and Composite Structures
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• v.50 no.5
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• pp.595-608
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• 2024

In this study, aluminum lathe waste was used by replacing aggregates in certain proportions in order to obtain expansive concrete using recycled materials. For this reason, five different aluminum wastes of 1%, 2%, 3%, 4% and 5% were selected and also reference without aluminum waste was produced. Based on the mechanical tests conducted, which included slump, compression, splitting tensile, and flexural tests, it was evident that the workability of the material declined dramatically once the volume ratio of aluminum exceeded 2%. As determined by the compressive strength test (CST), the CS of concrete (1% aluminum lathe wastes replaced with aggregate) was 11% reducer than that of reference concrete. It was noted that the reference concrete's CS values, which did not include aluminum waste, were greater than those of the concrete that contained 5% aluminum. When comparing for splitting tensile strength (STS), it was observed that the results of STS generally follow the parallel inclination as the CS. The reduction in these strengths when 1% aluminum is utilized is less than 10%. These ratios modified 18% when flexural strength (FS) is considered. Therefore, 1% of aluminum waste is recommended to obtain expansive concrete with recycled materials considering minimum loss of strength. Moreover, Scanning Electron Microscope (SEM) analysis was performed and the results also confirm that there was expansion in the aluminum added concrete. The presence of pores throughout the concrete leads to the formation of gaps, resulting in its expansion. Additionally, for practical applications, basic equations were developed to forecast the CS, STS, and FS of the concrete with aluminum lathe waste using the data already available in the literature and the findings of the current study. In conclusion, this study establishes that aluminum lathe wastes are suitable, readily available in significant quantities, locally sourced eco-materials, cost-effective, and might be selected for construction using concrete, striking a balance among financially and ecological considerations.

• Journal of Korea Port Economic Association
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• v.27 no.1
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• pp.155-183
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• 2011

The purpose of this paper is to analyze competition status of Korean and Chinese vessels in the EU market. To achieve this purpose, this study uses Market Share Index, Export Bias Index, Trade Specialization Index, Export Similarity Index, and Market Share Expansion Ratio-Export Similarity Deepening Ratio as analyzing method. The statistical data used in this study are obtained from the trade statistics for 5 years(2005-2009) produced by Korean International Trade Association. The results of this study show that Korean ships are less competitive than Chinese ones in the EU export market in that Korea does not export various kinds of ships but export some restricted kinds of vessels even in the competitive ship, implying that Korea has been gradually losing its competitiveness. These results suggest that Korea should improve the competitiveness of shipbuilding industry by pursuing such differentiated strategies as exporting high value-added vessels while keeping on maintaining Korea's dominance over its competitive ships to overcome China's competitive advantage in the EU region.

• Korean Institute of Interior Design Journal
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• v.27 no.2
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• pp.55-67
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• 2018

There is a growing interest on and expansion of rights of people with disabilities. Among them, people with visual impairment show high adaptation to environments in comparison to people with other types of disabilities, thus a large percentage of them live in their own houses rather than residing in a care facility. According to the housing status of people with visual impairment, the ratio of their residence in rural areas is high. In rural areas people who have disabilities often live in poor residential environments, requiring much improvement. However, such improvement is too costly for them to pay, and home modification that does not fully consider the user, may cause less efficiency and another dangerous situation to people with disabilities. The purpose of this study is to delineate empirical lessons for direction of customized home modification for people with disabilities through analysis of process of home modification including the execution as a intervention. This study used qualitative method to examine and analyzed the entire customized home modification process. The conclusion of this study is as follows. First, home modification measures should be derived considering the suitability of the target building for the specific condition of residents. Second, discussions with various stakeholders from the early stage during which proper home modification measure is searched are essential for realizing appropriate customized home modification. This study has significance in that it provides the direction for customized home modification for people with disabilities as well as empirical data that could reduce trials and errors in the future.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.3
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• pp.17-25
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• 2016

This study aims to empirically examine serial entrepreneurship in Korea. Using the ICT startups survey data, I compare serial entrepreneurs with their novice counterparts in terms of business behaviors and performances. I found that serial entrepreneurs are more likely than novice ones to co-found a business with other entrepreneurs, enter a market with relatively large assets and expand their business into overseas market. They tend to put more importance on large-scale production and expansion strategy than first-time entrepreneurs. They are more likely to cooperate with suppliers and customers but less likely with the governments. From their experience of founding and operating businesses, the findings suggest that serial entrepeneurs are more market-oriented and more capable of managing internal human relations and external network of supply chain. Consequently, serial entrepreneurs show stronger early financial performance than novice entrepreneurs especially when they team up to found a business.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.E2
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• pp.63-73
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• 2008

In this study, neural network models (NNMs) were examined as alternatives to dispersion models in predicting the short-term $SO_2$ concentrations in a coastal area because the performances of dispersion models in coastal areas have been found to be unsatisfactory. The NNMs were constructed for various combinations of averaging time and prediction time in advance by using the historical data of meteorological parameters and $SO_2$ concentrations in 2002 in the coastal area of Boryeung, Korea. The NNMs were able to make much more accurate predictions of 1 hr $SO_2$ concentrations at ground level in the morning in coastal area than the atmospheric dispersion models such as fumigation models, ADMS3 and ISCST3 for identical conditions of atmospheric stability, area, and weather. Even when predictions of 24-h $SO_2$ concentrations were made 24 hours in advance, the predictions and measurements were in good accordance(correlation coefficient=0.65 for n=216). This accordance level could be improved by appropriate expansion of training parameters. Thus it may be concluded that the NNMs can be successfully used to predict short-term ground level concentrations averaged over time less than 24 hours even in complex terrain. The prediction performance of ANN models tends to improve as the prediction lagging time approaches the concentration averaging time, but to become worse as the lagging time departs from the averaging time.

• Journal of the Korean Operations Research and Management Science Society
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• v.33 no.2
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• pp.45-73
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• 2008

Quality has long been considered as an important factor in creating competitive advantage, and researches on quality have not been limited to off-line products but actively extended to e-services and information goods. However, given the nature of multi-dimensional aspect of quality, the systematic study on the quality of online service is still in its early stage. Especially, studies on the quality of ASP services have been rare in academic and professional journals despite the growth of ASP industry in its size and the rapid expansion in the range of application. In this paper we clarified the multi-dimensional quality aspects of the ASP service using a Garvin's framework (1984) which encompasses the service aspects of Products, and developed a measurement model for ASP service qualify. Then we empirically tested the effects of ASP service quality on user satisfaction and perceived firm performance using the data from 240 Korean small firms with less than 50 employees that had experienced the ASP service. Our results show that there are positive relationships among ASP service quality and personal performance, user satisfaction and perceived firm performance, and that product and service-related aspects of ASP service exert differential effects on performance measures so that the product-related aspects of the ASP service such as performance, features, reliability and conformance are considered to be more important in evaluating benefits from ASP services. Contrary to the approaches In literature where only the quality of online services is evaluated, our results emphasize the importance of differentiating Product and service-related aspects of ASP service and provide a basis for more comprehensive evaluation of ASP service quality.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.3
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• pp.31-38
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• 2014

Four actual cultivations were prepared and a variety of soybean was cultivated. A H-flume, an automatic water level gauge and an automatic water sampler were installed at the outlet of each plot equipped for the measurement of flow rate and its water quality. The amount of rainfall of the study area in 2013 was measured as 975.6 mm which was much lower than the annual average rainfall of 1,271.8 mm, resulting in less occurrences in rainfall-runoff events. Rainfall-runoff events were occurred three times during the rainfall event of 4~5 July, 23 and 24 August. The characteristics of NPS pollution discharge of the plots and the reduction effect of the selected BMPs were analyzed during these events. The reduction effect of straw mat and soil amendments (Polyacrylamide (PAM) and Gypsum) on runoff ratio ranged between 38.2 and 92.9% (average 71.6%). The NPS pollution load reduced between 27.7 and 95.1% (average 70.0%) by the application of rice straw mat and soil conditioner when compared with that of control plot. Soybean yield (2,133.3 kg/ha) of the straw mat covered plots increased by 14.3% when compared with control (1,866.7 kg/ha). The effect of straw mat on the yield was not economically viable if the material and accompanying labor costs were considered. The data collected and analyzed on different soil textures and crops in this study are expected to be a fundamental reference for the expansion of the results to the application nationwide and the development of NPS pollution management policies.

• Ocean and Polar Research
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• v.26 no.1
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• pp.1-10
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• 2004

Ice cliff retreat and sea-ice formation around King Sejong Station in King George Island were analysed and compared with air temperature change. Analysis of 33-year (1969-2001) air temperature records at Bellingshausen Station has revealed regional atmospheric warming, and the increasing rate of air temperature Is equivalent to a warming of $1^{\circ}C$ for 27-year period. Here we present time-series of observations for the areal extent of the ice cliff and ice sheet, showing that they have retreated dramatically in the past 45 years (1956-2001). Retreat of 1,050 m in length of the ice clifr has changed the Marian Cove into a low rectangular form of 4 km in length and 1 to 1.3km in width. The retreat rates have since increased from 6 m/yr of the Primary investigated Period to 54 and 81m/yr in the recent years. Exceptionally, the ice cliff had been advanced of 21m in length for a year between 1987 and 1988 of cold winters. Ice sheet in King George Island also shows a similar decrease, and the decreasing extent is much larger at the southern part of the Main Cove, relatively more exposed to the sun, than at the northern part. Comparing sea-ice formation in winter with air temperature data shows a pattern starting to freeze below $-5^{\circ}C$ and to thaw over $-3^{\circ}C$. It is conclusively estimated that the patterns and magnitudes of ice cliff retreat and sea-ice formation are consistent with fluctuations of the air temperature, and that the recent rapid retreat of ice cliff and less formation of sea-ice are caused especially by the warming trends in autumn accompanied with expansion of summer thawing period.

• Health Policy and Management
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• v.20 no.2
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• pp.17-39
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• 2010

This study explored the impact on the DRG(Diagnosis-Related Groups)-based prospective payment system(PPS) operated by voluntarily participation providers. We analyzed whether the provides in the DRG-based PPS and in traditional fee-for-service(FFS) systems showed different the degree of variation in length of stay(LOS), and the providers' behaviors depending on the differences according to the varied participation periods. The study sample included all data 2,061 institutions participated in DRG-PPS in 2007 and all cases 473 FFS institutions which reported fee-for-service claims were reviewed same diagnosized diseases at least 10cases claims during three months We compared the differences of the LOS among health care institutions according to their type, region, and size. For DRGs showing significant differences in LOS, multiple regression analyses were performed to find out factors associated with LOS and interaction effect participation and hospital types or participation periods. The result provide the evidence that the DRG payment system operated by volunteering health care institutions had impact on resources use, which can reduce the institutions' the length of stay. While some DRGs had no correlation between participation periods and LOS, other DRGs, DRG participation period reversely linear relationship with LOS. That is to say, the longer participation year, the less reducing the LOS. These results support the future expansion of the DRG-based PPS plan to all health care services in Korea.

• Journal of Information Technology Applications and Management
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• v.27 no.6
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• pp.53-73
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• 2020

Many prior studies have been conducted that positive reviews increase the intention to purchase. However, there are very few papers that have studied the impact of review search on purchase satisfaction. It is meaningful to study the impact of review search on purchase satisfaction as it can lead the business successfully by inducing repurchase. There is also no study of how review search have different effects on purchase satisfaction among countries. Given the growing number of cross-border e-commerce, we believe that the need for research is high because identifying these differences between countries can have a very important impact on a company's successful overseas expansion. Therefore, in this study, the impact of positive and negative review search on purchase satisfaction and the national impact were set up as a research model. In order to verify this research model, the survey was distributed to those who experienced online purchase in Korea and China, and a total of 234 copies were collected, including 125 copies in Korea, 109 copies in China, and the research model was verified using Smart-PLS structural equation analysis tools. First, positive review search has been shown to positively affect purchase satisfaction. Second, it has been shown that negative review search also has a positive effect on purchase satisfaction. Third, the impact of positive and negative review search on purchase satisfaction was different between Korea and China. While Korea is more aggressive in review search than China due to its high tendency to avoid uncertainty, China is less likely to avoid uncertainty than Korea and is more likely to rely on brand familiarity. Therefore, according to the uncertainty avoidance moderation effect the impact of positive and negative review search on purchase satisfaction was higher in Korea than in China. In this study, Shopping mall managers need to take strategic measures to maximize shopping mall performance by recognizing positive aspects of negative review search on purchase satisfaction. Companies and managers in Korea and China can establish strategies to promote product sales when companies enter the global market.