• Journal of the Korean Geotechnical Society
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• v.24 no.6
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• pp.45-55
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• 2008

CFRD (Concrete Faced Rockfill Dam) has been world-widely constructed due to a lot of advantages which it has compared with rockfill dam and recently, sand/gravel materials, Instead of crushed rock materials, are also utilized as a main rockfill material to overcome geological and environmental problems. In Korea, two dams using sand/gravel materials as a main fill material were designed and are being constructed. In this research, the strength and deformation characteristics of the rockfill and sand/gravel materials taken from 2 dam sites were tested by using a laboratory large triaxial testing equipment for a total of 7 cases. From the results of large triaxial and compaction tests, it was observed that two kinds of materials show a little different compaction, shear strenght and deformation characteristics. It could be expected that the shear strength of sand/gravel material was not disadvantageous compared with that of rockfill materials, however, there was some difference between two materials with respect to behavior characteristics. On the other hand, smaller displacements were observed from numerical analysis based on the data from a large triaxial test when the sand/gravel is used as a main fill material compared with the case when the crushed rock material is used as a main fill material. Finally, in spite of a little different shear strength and behavior characteristic between two materials, it was concluded that it will not lead to a significant problem when the sand/gravel material is used as a main rockfill material.

• Clinical and Experimental Reproductive Medicine
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• v.51 no.2
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• pp.135-141
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• 2024

Objective: Recently, oral antioxidants in combined forms have been used to treat men with idiopathic infertility. This study aimed to evaluate the effects of treatment with vitamin C, vitamin E, selenium, zinc, arginine, L-carnitine, and coenzyme Q10 on sperm quality parameters, DNA integrity, reproductive hormones, and pregnancy rates in men with infertility and idiopathic oligoasthenoteratozoospermia (OAT). Methods: A prospective study was conducted on 420 men with infertility and idiopathic OAT who took an oral supplement of antioxidant SP-Power tablets twice daily for 6 months. Semen quality, reproductive hormones, and the DNA fragmentation index (DFI) were evaluated at baseline and at 3 and 6 months after supplementation, using the World Health Organization 2021 guidelines. Results: No significant difference was observed in volume or the percentage of typical morphology during treatment. A significant improvement in sperm concentration was observed after supplementation (8.67±1.41, 12.17±1.91, and 19.01±0.86 at baseline, 3, and 6 months respectively, p<0.01). The total motility, progressive motility, and total motile sperm count also increased significantly (p<0.01), whereas the DFI decreased after 6 months. There was an increase in normal FSH levels and testosterone levels after 6 months of supplementation of antioxidant SP-Power but these differences were not statistically significant (p=not significant and p=0.06, respectively). Conclusion: Supplementation with SP-Power tablets improved sperm quality parameters, sperm DFI, some reproductive hormones, and pregnancy rates in men with infertility and idiopathic OAT, which could be attributed to the supplement's synergistic antioxidant action. Further studies are needed to determine the effects of supplementation on oxidative stress markers.

• Journal of Technology Innovation
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• v.25 no.4
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• pp.189-209
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• 2017

Financial institutions around the world, including financially advanced nations, widely operate a credit information sharing system to ease off information asymmetry between financial institutions and financial consumers. This study analyzed the credit problem data that is actually being shared among financial institutions in Korea, and classified credit problem data into three categories; Frequency, Period, Amount. In survival analysis, this study analyzed how different types of credit problem influence on survival period of companies. Next, in comparative analysis, this study verified a difference between start-up companies and existing companies on classified conditions of the credit problems. After conducting a survival and comparative analysis of the credit information of 449,579 companies of 8 years' actual information sharing in Korea, it showed that the number of the frequency of accidents showed a positive(+) correlation with the survival period. This provides contrary evidence to the financial institutions' risk policies that the number of the frequency of accidents is a negative factor. Furthermore, since the start-up companies that are under 7 years old show more positive aspect in the survival period than existing companies, it draws a policy implication that the credit information sharing system need to be improved by taking account of characteristics of the start-up companies.

• Journal of the Korean association of regional geographers
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• v.16 no.4
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• pp.400-416
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• 2010

China's inbound tourism became one of the key drivers for economic growth with open-door policy in 1978 and has experienced the fast growth over the past three decades. In 2008, China, as one of the world's leading tourist destinations, is ranked the 4th globally in the number of inbound overnight tourists. Based on China tourism statistics, this paper aims to examine the growth of inbound tourist flows at the national level and the changing spatial distribution by comparing between 1995 and 2008 at the regional level (31 province-level regions) in China. In particular, the spatial distributions of tourist flows from the 6 main generating countries (South Korea, Japan, Singapore, U.S.A., Germany, and Russia) are more concretely analyzed. For five countries except Russia, with slight differences by country, while the eastern area of China is still the most popular destination and western part remains the least visited area, the central part is witnessing the increasing popularity. Russia shows an obvious difference, presenting the spatial pattern that tourist flows are mainly concentrated in the northern and the most southern part of China. This paper helps to understand the dynamics of China's regional changes from an inbound tourism perspective.

• Journal of the Korean Geotechnical Society
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• v.21 no.10
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• pp.5-16
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• 2005

Geosynthetic-reinforced and pile-supported embankments have been increasingly used and researched around the world. The inclusion of one or multiple geosynthetic reinforcements over the pile is intended to enhance the efficiency of load transfer from soft ground to piles, to reduce total and differential settlement and increase global or local stability. In this paper, the reinforcement effectiveness and arching effect of the geogrid-reinforced and pile-supported embankments have been studied in terms of field model tests and numerical analysis with varying the space between piles and reinforcement. 2-dimensional numerical analysis has been conducted using the FLAC (Fast Lagrangian Analysis of Continua) program. And load transfer mechanisms between soil-piles-geogrid were investigated. The mechanisms of load transfer can be considered as a combination of embankment soil arching, tension geogrid, and stress concentration due to the stiffness difference between pile and soft ground. Based on the field model test and numerical analysis results, it was found that the geosynthetic reinforcement slightly interferes with soil arching, and helps reduce differential settlement of the soft ground. Also. at the D/b=3 (D: spacing of pile cap, b: diameter of pile), the total settlement is reduced by about $40\%$ compared to that without reinforcement. For $D/b{\ge}6$, the effectiveness of geogrid reinforcement in reducing settlement is negligible.

• Journal of Navigation and Port Research
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• v.44 no.3
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• pp.195-202
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• 2020

The production of larger of ships is a survival strategy for global shipping companies to pursue the economics of scale. According to this strategy, to respond to this situation, many containers are loading/unloading simultaneously in the hub port. Additionally, the container terminals are promoting the introduction of automation to expand the terminal facilities and increase efficiency/productivity of the container yards. European ports have introduced automation to address rising labor costs and shortages of labor. Recently, the construction of fully automated container terminals is increasing in the United States and China to resolve problems such as the slow growth of the global economy, the emergence of large ships, air pollution, and safety accidents. Domestic ports are at an early stage compared to the world's advanced container terminals, and countermeasures are being prepared to respond to the changing ports. However, research on the recognition difference analysis that examines the opinions of stakeholders is insufficient. As a result of analyzing the recognition among the groups, it was found that container terminal operators reduced labor costs, improved shipping services for shipping companies, prevented safety accidents for port union labor, and increased service for port authority and government agencies. Thus, to closely examine the perception among the groups, one-way ANOVA was performed, and then the implications were deduced as the basic data for the smooth introduction of automation.

• Journal of Society of Preventive Korean Medicine
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• v.22 no.3
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• pp.1-10
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• 2018

Backgrounds : In 2017, National Health Insurance implemented the pilot insuring project for Chuna manual therapy(CMT). 65 Korean Medicine(KM) hospitals and clinics were selected in the project to monitor the provision of insured CMT. Objectives : This study aimed to evaluate the effectiveness of CMT for low back pain provided in the real world setting. Methods : Patients with low back pain who agreed to participated in the study were enrolled and requested to complete questionnaires. Patients who received CMT regardless of receiving other KM therapies were classified to Chuna group, and patient who received KM therapies without CMT to KM group. Pain(pain-VAS) and back function(KODI, Oswestry disability index-Korean version), quality of life were assessed at baseline, 4 weeks, and 8 weeks. Additionally, patients who received CMT twice and more, and who's pain-VAS 20 and over were included, and patients who used pain injection were excluded in the analysis. Results : Of 371 patients who completed all questionnaire (mean age=42.6years, SD=12.45; 61% female), 96 were excluded, 170 were in Chuna group, and 105 were in KM group. Proportions of patients who had low back pain for more than twelve weeks in the Chuna group and KM group were 57.7% and 24.8%, respectively. Pain and back function were significantly improved on 4weeks and 8weeks in both groups, but there was no difference between two groups. For the patients in the sub-acute and chronic stage(>=12 weeks), change of total KODI scores in the Chuna group was higher than KM group(p=0.013) at 4weeks. Conclusions : CMT with other KM therapies can improve back function in the sub-acute and chronic patients. For insurance policy decision, economic evaluation of CMT is needed.

• Korean Journal of Heritage: History & Science
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• v.49 no.2
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• pp.104-121
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• 2016

Royal tombs in Neungsan-ri had been studied several times during the Japanese Colonial era. But, conceiving the general complexion of them is difficult for lack of data and analysis of previous studies are still insufficient. Thus, necessity of new approach and understanding in Royal tombs in Neungsan-ri are emphasized by the reviewing existing studies and conservation history. The Serial numbers of the Royal tombs in Neungsan-ri has been registered arbitrarily without clear guidelines from Japanese Colonial era until present time. It means previous studies were devoid of consideration for serial number changes. And, research has shown that Royal tombs in Neungsan-ri counts at least twenty, taking No.8 tomb of recent study into consideration. Moreover, in case of eastern tombs it needs changes in the existing perception that Royal tombs in Neungsan-ri consist of only six-tombs because there was no difference between eastern tombs and central sixtombs considering the burial chamber and lacquered wooden(koyamaki) Coffin. Ultimately, current state of Royal tombs in Neungsan-ri doesn't have authenticity because they had been found and regulated in the Japanese Colonial era. Consequently, it is required to overall study into entrance to burial chamber and covered burial stone marker and exaggerated mounds, ignored another tombs other than six-tombs in the center.

• Journal of the Korean Society for Library and Information Science
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• v.55 no.1
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• pp.365-392
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• 2021

In order to assess the state of library and information science (LIS) research in Korea, the study analyzed bibliometric data of papers published in past 18 years in Korea Citation Index (KCI) and Social Science Citation Index (SSCI) journals. The analysis of study data, which consisted of 6,301 KCI journal papers with 26,474 citations and 86,727 SSCI journal papers with 1,196,961 citations from 2002 to 2020, involved comparison of research productivity and impact, collaboration trends, and key areas of research between domestic and international LIS scholars with normalizations by units of analysis for size differences. Even with size normalization, the study found a marked difference in citation patterns between domestic and international LIS research. Korean LIS authors were twice as productive as international LIS authors but a little over a half as impactful. The results also showed a much higher level of skewness in international research, where a fraction of top authors, institutions, and journals received a lion's share of citations. The trend of increasing co-authorship was much more pronounced among international publication, where the recent popularity of larger collaboration groups suggests multi-disciplinary and increasingly complex nature of modern LIS research in the world stage. The keyword analysis revealed a much more diverse subject area in international than domestic LIS research with a recent shift towards technology, such as big data, blockchain, and altmetrics. Keywords in SSCI journals also exhibited a less connection between popularity and impact than KCI keywords, where popular keywords did not necessarily correspond to impactful keywords.

• Journal of the Economic Geographical Society of Korea
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• v.25 no.3
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• pp.281-298
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• 2022

The COVID-19 pandemic has so far given the world a great shock and fear that cannot be compared to other infectious diseases, and local economies are experiencing a serious economic crisis accordingly. This paper examines the regional characteristics of economic recession and resilience due to the COVID-19 pandemic, focusing on the employment fluctuations in 85 cities nationwide. Although the overall trend is in line with national employment indicators, there are some differences in the shock response and the recovery of employment in individual cities. The difference between cities is somewhat greater in the resilience of the recovery stage than the resistance, which is the shock-response stage. In terms of resilience, cities in the capital area have relatively good condition compared to cities in the non-capital area. The weak resilience of large cities such as Seoul, which has a high population density, can be explained to be the effect of the COVID-19 pandemic of infectious diseases. Regarding the economic structure of the city, the ratio of service and sales workers, wholesalers and retailers, and food and lodging businesses are analyzed as valid explanatory variables for the resilience of cities.