• Journal of Intelligence and Information Systems
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• v.25 no.1
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• pp.21-41
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• 2019

Thanks to the rapid development of information technologies, the data available on Internet have grown rapidly. In this era of big data, many studies have attempted to offer insights and express the effects of data analysis. In the tourism and hospitality industry, many firms and studies in the era of big data have paid attention to online reviews on social media because of their large influence over customers. As tourism is an information-intensive industry, the effect of these information networks on social media platforms is more remarkable compared to any other types of media. However, there are some limitations to the improvements in service quality that can be made based on opinions on social media platforms. Users on social media platforms represent their opinions as text, images, and so on. Raw data sets from these reviews are unstructured. Moreover, these data sets are too big to extract new information and hidden knowledge by human competences. To use them for business intelligence and analytics applications, proper big data techniques like Natural Language Processing and data mining techniques are needed. This study suggests an analytical approach to directly yield insights from these reviews to improve the service quality of hotels. Our proposed approach consists of topic mining to extract topics contained in the reviews and the decision tree modeling to explain the relationship between topics and ratings. Topic mining refers to a method for finding a group of words from a collection of documents that represents a document. Among several topic mining methods, we adopted the Latent Dirichlet Allocation algorithm, which is considered as the most universal algorithm. However, LDA is not enough to find insights that can improve service quality because it cannot find the relationship between topics and ratings. To overcome this limitation, we also use the Classification and Regression Tree method, which is a kind of decision tree technique. Through the CART method, we can find what topics are related to positive or negative ratings of a hotel and visualize the results. Therefore, this study aims to investigate the representation of an analytical approach for the improvement of hotel service quality from unstructured review data sets. Through experiments for four hotels in Hong Kong, we can find the strengths and weaknesses of services for each hotel and suggest improvements to aid in customer satisfaction. Especially from positive reviews, we find what these hotels should maintain for service quality. For example, compared with the other hotels, a hotel has a good location and room condition which are extracted from positive reviews for it. In contrast, we also find what they should modify in their services from negative reviews. For example, a hotel should improve room condition related to soundproof. These results mean that our approach is useful in finding some insights for the service quality of hotels. That is, from the enormous size of review data, our approach can provide practical suggestions for hotel managers to improve their service quality. In the past, studies for improving service quality relied on surveys or interviews of customers. However, these methods are often costly and time consuming and the results may be biased by biased sampling or untrustworthy answers. The proposed approach directly obtains honest feedback from customers' online reviews and draws some insights through a type of big data analysis. So it will be a more useful tool to overcome the limitations of surveys or interviews. Moreover, our approach easily obtains the service quality information of other hotels or services in the tourism industry because it needs only open online reviews and ratings as input data. Furthermore, the performance of our approach will be better if other structured and unstructured data sources are added.

• Radiation Oncology Journal
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• v.9 no.1
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• pp.1-6
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• 1991

The effect of 2-deoxy-d-glucose (2-DDG) on $C_3H$ mouse fibrosarcoma(FSall) was studied. Metabolic status, especially for energy metabolism, was studied using in vivo $^{31}P$-MRS, proliferative capacity was observed on flow cytometry(FC) and growth rate was measured after transplantation of $10^6$ viable tumor cells in the dorsum of foot of $C_3Hf/Sed$ mice. One gram of 2-DDG Per kg of body weight was injected intraperitoneally on 12th day of implantation. Average tumor size on 12th day of implantion was $250mm^3$. Growth rate of Fsall tumor was measured by tumor doubling time and slope on semilog plot. After 2-DDG injection, growth rate slowed down. Tumor doubling time between tumor age 5-12 days was 0.84 days with slope 0.828 and tumor doubling time between tumor age 13-28 days was 3.2 days with slope 0.218 in control group. After 2-DDG injection, tumor doubling time was elongated to 5.1 days with slope 0.136. The effect of 2-DDG studied in vivo $^{31}P$-MRS suggested that the increase of phosphomonoester (PME) and inorganic phosphate (Pi) by increasing size of tumor, slowed down after 2-DDG injection. Flow cytometry showed significantly increased S-phase and $G_2+M$ phase fraction suggesting increased proliferative capacity of tumor cells in the presence of 2-DDG. Authors observed an interesting effect of 2-DDG on FSall tumor and attempt to utilize as an adjunct for radiotherapy.

• Journal of Life Science
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• v.21 no.5
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• pp.720-728
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• 2011

Garlic (Allium sativum) has been used as a source food as well as a traditional folk medicine ingredient since ancient times. Aged black garlic is a type of fermented garlic and is expected to have stronger anticancer and antioxidant activities than raw garlic. However, the mechanisms of their inhibitory effects on adipocyte differentiation and adipogenesis are poorly understood. In the present study, the effects and mechanisms of water extracts of raw garlic (WERG) and aged black garlic (WEABG) on adipocyte differentiation and adipogenesis in 3T3-L1 preadipocytes were investigated. Treatment with WEABG significantly suppressed terminal differentiation of 3T3-L1 preadipocytes in a dose-dependent manner as confirmed by a decrease in lipid droplet number and lipid content through Oil Red O staining, however WERG had no such effect. In addition, WEABG reduced accumulation of cellular triglyceride, which is associated with a significant inhibition of key pro-adipogenic transcription factors including peroxisome proliferator-activated receptor ${\gamma}$ (PPAR${\gamma}$), cytidine-cytidine-adenosine-adenosine-thymidine (CCAAT)/enhancer binding proteins ${\alpha}$ (C/EBP${\alpha}$) and C/EBP${\beta}$. Taken together, these results provide important new insight that aged black garlic might inhibit adipogenesis by suppressing the pro-adipogenic transcription factors in 3T3-L1 preadipocytes, and further studies will be needed to identify the active compounds that confer the anti-obesity activity of aged black garlic.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.3
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• pp.169-179
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• 2011

There are two types of nuclear reactors in Korea and they are PWR type and CANDU type. The safe management of the spent fuels from these reactors is very important factor to maintain the sustainable energy supply with nuclear power plant. In Korea, a reference disposal system for the spent fuels has been developed through a study on the direct disposal of the PWR and CANDU spent fuel. Recently, the research on the demonstration and the efficiency analyses of the disposal system has been performed to make the disposal system safer and more economic. PWR spent fuels which include a lot of reusable material can be considered being recycled and a study on the disposal of HLW from this recycling process is being performed. CANDU spent fuels are considered being disposed of directly in deep geological formation, since they have little reusable material. In this study, based on the Korean Reference spent fuel disposal System (KRS) which was to dispose of both PWR type and CANDU type, the more effective CANDU spent fuel disposal systems were developed. To do this, the disposal canister for CANDU spent fuels was modified to hold the storage basket for 60 bundles which is used in nuclear power plant. With these modified disposal canister concepts, the disposal concepts to meet the thermal requirement that the temperature of the buffer materials should not be over $100^{\circ}C$ were developed. These disposal concepts were reviewed and analyzed in terms of disposal effective factors which were thermal effectiveness, U-density, disposal area, excavation volume, material volume etc. and the most effective concept was proposed. The results of this study will be used in the development of various wastes disposal system together with the HLW wastes from the PWR spent fuel recycling process.

• Journal of Nutrition and Health
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• v.49 no.2
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• pp.99-110
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• 2016

Purpose: The current study was conducted in order to identify health and nutritional status of Korean underweight women in their twenties by comparing with normal, overweight, and obese women. Methods: Data from the 2010~2012 Korea National Health and Nutrition Examination Survey were used in this study. Subjects were 897 women aged 20~29 years. Subjects were classified according to underweight, normal weight, overweight, and obese groups based on body mass index. Health status was assessed using data from the health questionnaire and examination. Nutritional status was assessed using data from 24-hour dietary recall and a food frequency questionnaire. Results: The underweight group had higher education and exercised less than the obese group. Means of blood chemistry and blood pressure of the underweight group did not differ from those of the normal weight group. Means of fasting glucose, insulin, lipid profiles, blood cell counts, and blood pressure in the underweight group were different from those of the overweight or obese group. Proportions of delivery, breast feeding, and irregular menstruation in the underweight group were lower compared with the other groups. Except retinol intake, means of nutrient intake did not differ among four groups. There were significant differences among four groups in the intakes of cereals and eggs and frequency of consumption of dairy products. Conclusion: The current findings showed that health and nutritional status of underweight women in their twenties did not differ from those of normal weight women. In particular, health status of underweight women in their twenties was better than that of obese women of the same ages. Further study on health and nutritional status of extremely underweight women is necessary.

• Journal of the Mineralogical Society of Korea
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• v.30 no.3
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• pp.93-102
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• 2017

Heavy mineral provide an important information for sediment provenance as well as a potential submarine mineral resources. We compared the heavy mineral characteristics between Southeastern Yellow Sea Mud (SEYSM) and Southwestern Cheju Island Mud (SWCIM) surface sediments. We separated heavy minerals from 28 surface sediments in each mudbelt, and then carried out stereo-microscopic, field-emission scanning electron microscopic, energy dispersive spectroscopic and electron probe microanalysis to characterize the type, abundance, mineralogical properties and distribution pattern of heavy mineral. Amphibole and epidote, which are two major heavy minerals, account for more than 70% of total heavy minerals. Zircon and sphene contents are more abundant in SEYSM, whereas apatite and rutile contents are more abundant in SWCIM. Monazite only occurs in some area of SEYSM. Sphene and monazite content decrease to the south in SEYSM. Both garnet-zircon index (GZi) and rutile-zircon index (RuZi) are low in SEYSM but high in SWCIM. Amphiboles in SEYSM primarily correspond to hornblende, however those in SWCIM represent variable composition from pargasite, tshermakite, hornblende to tremolite. Garnets in SEYSM have high Mg and low Ca, but those in SWCIM have low Mg with variable Ca. Different heavy mineral characteristics between SEYSM and SWCIM suggests that sediments in each mudbelt have different provenances. Although this study implies that SEYSM sediment may mostly come from nearby Korean western rivers such as the Keum and Han rivers, this study does not suggest any idea of the source area of SWCIM sediment. Further study is needed to interpret the provenance and transportation mechanism of mudbelt sediments through the heavy mineral research for the river sediments flowing into the Yellow Sea and much more marine sediments.

• Journal of Environmental Policy
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• v.10 no.1
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• pp.49-70
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• 2011

The numerous efforts have been made in understanding generation and transportation mechanism of nonpoint source pollutants from agricultural areas. Also, the water quality degradation has been exacerbated over the years in many parts of Korea as well as other countries. Nonpoint source pollutants are transported into waterbodies with direct runoff and baseflow. It has been generally thought that groundwater quality is not that severe compared with surface water quality. However its impacts on groundwater in the vicinity of stream quality is not negligible in agricultural areas. The SWAT model has been widely used in hydrology and water quality studies worldwide because of its flexibilities and accuracies. The spatial property of each HRU, which is the basic computational element, is not presented. Thus, the SWAT HRU mapping module was developed in this study and was applied to the study watershed to evaluate recharge rate and $NO_3-N$ loads in groundwater. The $NO_3-N$ loads in groundwater on agricultural fields were higher than on forests because of commercial fertilizers and manure applied in agricultural fields. The $NO_3-N$ loads were different among various crops because of differences in crop nutrient uptake, amount of fertilizer applied, soil properties in the field. As shown in this study, the SWAT HRU mapping module can be efficiently used to evaluate the pollutant contribution via baseflow in agricultural watershed.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.6
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• pp.111-122
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• 2017

This study analyzes the current state of entrepreneurship education and start-up foundations by country in order to find ways to improve the domestic entrepreneurial environment and to promote the recognition of desirable entrepreneurship practices. It also investigates the relationship between entrepreneurship, entrepreneurial will, and the level of opportunity-based entrepreneurships, by using data from the 2016 Global Entrepreneurship Trend Report (GETR). First, the results show the urgent need for the expansion of entrepreneurship education in Korea. In the GETR category of 'experience of entrepreneurship education in elementary, middle and high schools', Korea was ranked very low (19th place), among the 20 countries. In the 'college' and 'lifelong entrepreneurship education' categories, it procured a mid-level ranking (15th). While entrepreneurship education for all ages is being promoted globally, entrepreneurship education for middle-aged individuals in Korea is relatively weak. This implies that the expansion of entrepreneurship education to lifelong education and education for employees and retirees is required. Second, the individual's entrepreneurial intention in Korea was 3.8 points, implying a mid-level ranking (15th), and it ranked the lowest in terms of opportunity-based entrepreneurship (20th). In comparison to China (4.55) and the United States (4.01), the entrepreneurial intention of Koreans was found to be low. The level of opportunity-driven entrepreneurship was also found to be very low, compared to China (4.35), Japan (4.04) and the United States (4.59). In general, the proportion of the level in opportunity-driven entrepreneurship, increases from the factor-driven and efficiency-driven, to the innovation-driven type. In Korea, the percentage of entrepreneurial ventures centered around involuntary entrepreneurship and small businesses is high. It is also interpreted that opportunity-based entrepreneurships are low in number because of this high proportion of involuntary start-up and small businesses. Last, the entrepreneurial intention in all types (factor-driven, efficiency-driven, and innovation-driven) was exceptionally high. It has been confirmed that exposure to all entrepreneurship education (elementary, junior high, university, and lifelong education) in innovation-driven countries, greatly increases entrepreneurial intention. In the case of Korea, which is an innovation-driven country, qualitative improvement based on quantitative expansion of entrepreneurship education is expected to be a major driving force for individuals' entrepreneurial intention to obtain a mid-level ranking (15th).

• Korean Journal of Remote Sensing
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• v.35 no.6_4
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• pp.1319-1326
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• 2019

The KARI(Korea Aerospace Research Institute) operates the government satellite information application consultation to cope with ever-increasing demand for satellite images in the public sector, and carries out various support projects including the generation and provision of mosaic images on the Korean Peninsula every year to enhance user convenience and promote the use of satellite images. In particular, the government has wanted to increase the utilization of mosaic images on the Korean Peninsula and seek to classify and update mosaic images so that users can use them in their businesses easily. However, it is necessary to test and verify whether the classification results of the mosaic images can be utilized in the field since the original spectral information is distorted during pan-sharpening and color balancing, and there is a limitation that only R, G, and B bands are provided. Therefore, in this study, the reliability of the classification result of the mosaic image was compared to the result of KOMPSAT-3 image. The study found that the accuracy of the classification result of KOMPSAT-3 image was between 81~86% (overall accuracy is about 85%), while the accuracy of the classification result of mosaic image was between 69~72% (overall accuracy is about 72%). This phenomenon is interpreted not only because of the distortion of the original spectral information through pan-sharpening and mosaic processes, but also because NDVI and NDWI information were extracted from KOMPSAT-3 image rather than from the mosaic image, as only three color bands(R, G, B) were provided. Although it is deemed inadequate to distribute classification results extracted from mosaic images at present, it is believed that it will be necessary to explore ways to minimize the distortion of spectral information when making mosaic images and to develop classification techniques suitable for mosaic images as well as the provision of NIR band information. In addition, it is expected that the utilization of images with limited spectral information could be increased in the future if related research continues, such as the comparative analysis of classification results by geomorphological characteristics and the development of machine learning methods for image classification by objects of interest.

• Economic and Environmental Geology
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• v.49 no.4
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• pp.249-267
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• 2016

The Hongseong area of the central-western Korean Peninsula is considered to be a part of collision zone that is tectonically correlated to the Qinling-Dabie-Sulu belt of China. The area includes the elliptical-shaped serpentinized ultramafic bodies, together with mafic rocks. The studied bodies are in contact with the surrounded Neoproterozoic alkali granites at the Baekdong and Wonnojeon bodies and the Paleoproterozoic Yugu gneiss at the Bibong body. The Baekdong body contains the blocks of the Neoproterozoic alkali granites and the Late Paleozoic metabasites. The Bibong body also includes the Neoproterozoic alkali granite blocks. The Mesozoic intrusive rocks are also recognized at the Baekdong, Wonnojeon and Bibong bodies. On the other hand, the Early Cretaceous volcanic rocks are occurred at the Bibong body. The detrital zircon SHRIMP U-Pb ages of the serpentinites at three bodies range variously from Neoarchean to Middle Paleozoic at the Baekdong body, and from Neoarchean to Early Cretaceous at the Wonnojeon and Bibong bodies. Although serpentinization does not generally produce minerals suitable for direct isotopic dating, the youngest Middle Paleozoic age at the Baekdong body and the Early Cretaceous age at the Wonnojeon and Bibong bodies indicate the possible upper age limit for the (re)serpentinization. Especially, the Early Cretaceous serpentinization ages may be related to the widespread Early Cretaceous igneous activity in the central-southern Korean Peninsula. Age results for the serpentinite bodies and the included blocks of the studied serpentinized ultramafic bodies in the Hongseong area, therefore, provide several possible interpretations for the serpentinization ages of the ultramafic rocks as well as the geotectonic implications of serpentinization, requiring more detailed study including other serpentinized ultramafic bodies in the Hongseong area.