• Journal of the Korean Institute of Gas
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• v.19 no.1
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• pp.6-11
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• 2015

This paper is to study the examples for rubber damage and weaken reliability of timing belt, constant velocity joint boot and weather strip in vehicle. The first example, when the service man replaced the new timing-belt of rubber material, he assembled the belt that was weaken it's contact surface because of material transform. He knew the abnormally tearing failure by friction action between belt and sprocket. The second example, it certified the fact that the grease is leaked out boot protecting of constant velocity joint by split of rubber surface because of durability badness. The third example, the weather stripe took the minutely tearing because of damage produced the material transform by crack of chemistry change. It certified the production phenomenon of a tiny noise by coming with outside air because of overlapped the rubber of weather stripe when driving after closing the door. Therefore, the driver must always manage the rubber system part of vehicle.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.6
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• pp.575-593
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• 2012

This paper briefly introduces the scope and objectives of SKB Task 8, which is an international cooperative research project. In addition, the hydraulic behaviors of bentonite buffer focusing on the interactions between bentonite and a rock mass with a joint were investigated using TOUGH2 code as part of a sub-mission of Task 8a. The effects of a rock joint and high capillary pressure of bentonite on the re-saturation properties and pressure distribution in a buffer were identified and successfully incorporated in the TOUGH2 code. Based on the numerical results, it was found that the speed of re-saturation in bentonite surrounded by a rock mass with a joint is 2.5 to 12 times faster than that in a condition without a rock joint, while the degree of saturation in the lower part of the buffer material is generally higher than in the upper part in both the cases of with and without a joint. It can be anticipated that the results obtained from this study can be applied to an estimation of the full saturation time and a determination of optimum thickness with regard to the design of the bentonite buffer in a high level waste disposal system.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.1
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• pp.75-82
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• 2007

As one of the main support systems, rock bolts play a crucial role in the reinforcement of tunnels. Numerical and experimental studies using a transmission method of ultrasonic guided waves are performed to evaluate the integrity of rock bolts encapsulated by grouting paste. Numerical simulations using "DISPERSE" are carried out for the selection of the optimal experimental setup, i.e. non-destructive testing (NDT) system of the rock bolt. Based on results of the numerical simulation, the calculated frequency range for NDT testing is between 20kHz and 70kHz with the first longitudinal L(1) mode. Laboratory transmission tests are performed by attaching the piezo electric sensor at the tip of the rock bolt before embedding. Both of analytical and experimental results show that the amplitude of signals as well as the wave velocity increases with increase in the defect ratio of grouting paste. The defect in grouting paste means that the space around the rock bolt is not fully filled with the grouting paste. Experimental results also show that the increase of the wave velocity is more sensitive to the defect ratio increase than that of the amplitude. This study demonstrates that the transmission technique of ultrasonic guided waves may be a valuable tool in the evaluation of the rock bolt integrity.

• Journal of Distribution Research
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• v.16 no.5
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• pp.63-84
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• 2011

There are about 1,500 small or large traditional markets in Korea. Those conventional markets have been struggling for survival in rapidly changing market environment with highly intensified competition by accelerating the entrance of the Large-scale Discount Store and Super Supermarket which are managed and supported by Large companies like Samsung and Lotte. The loosing power of conventional markets have threatened the local merchants' survival and have influenced local economics falling down. To create better value for the customers who have more preference for department store and discount stores than conventional markets, conventional markets should have market orientation, which has three sub dimensions; customer orientation, competitor orientation and inter-functional coordinations. First objective of study is to find the appropriate roles of conventional markets in local areas. Second is to find out the market orientation functions for conventional markets to be survival in local markets in the long terms. Finally, this study will suggest some policies for the appropriate types of successful conventional markets considering various local situations. To achieve those objectives, we did the following procedure. First, we review the previous reports and studies of policies for conventional markets and local economy development, and propose some pros and cons of the previous policies. Secondly, we develop a market orientation framework of conventional markets, in which we suggest the developmental types and functions of market-orientation of conventional markets in accordance with the characteristics of local market and economic conditions of local areas. Then we formulate and discuss the study's contributions, managerial implications, and directions for future policy development. Especially for the policy development, we suggest the efficiency and economical effects of policy, human being development and management system, and the role of government and protection of local merchants in the development process.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.2
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• pp.159-173
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• 2017

The Weather Research and Forecast (WRF) - Community Multiscale Air Quality (CMAQ) system was applied to investigate the influence of major point sources located in Chungcheongnam-do (CN) on surface $PM_{2.5}$ (Particulate Matter of which diameter is $2.5{\mu}m$ or less) concentrations in its surrounding areas. Uncertainties associated with contribution estimations were examined through cross-comparison of modeling results using various combinations of model inputs and setups; two meteorological datasets developed with WRF for 2010 and 2014, and two domestic emission inventories for 2010 and 2013 were used to estimate contributions of major point sources in CN. The results show that contributions of major point sources in CN to annual $PM_{2.5}$ concentrations over Seoul, Incheon, Gyeonggi, and CN ranged $0.51{\sim}1.63{\mu}g/m^3$, $0.71{\sim}1.62{\mu}g/m^3$, $0.63{\sim}1.66{\mu}g/m^3$, and $1.04{\sim}1.86{\mu}g/m^3$, respectively, depending on meteorology and emission inventory choice. It indicates that the contributions over the surrounding areas can be affected by model inputs significantly. Nitrate was the most dominant $PM_{2.5}$ component that was increased by major point sources in CN followed by sulfate, ammonium, and others. Based on the model simulations, it was estimated that primary $PM_{2.5}$ $(PPM)-to-PM_{2.5}$ conversion rates were 41.3~50.7 ($10^{-6}{\mu}g/m^3/TPY$) for CN, and 12.4~18.3 ($10^{-6}{\mu}g/m^3/TPY$) for Seoul, Incheon, and Gyeonggi, respectively. In addition, spatial gradients of PPM contributions show very steep trends. $NO_X$-to-nitrate conversion rates were 7.61~12.3 ($10^{-6}{\mu}g/m^3/TPY$) for CN, and 3.94~11.3 ($10^{-6}{\mu}g/m^3/TPY$) for the sub-regions in the SMA. $SO_2$-to-sulfate conversion rates were 4.04~5.28 ($10^{-6}{\mu}g/m^3/TPY$) for CN, and 3.73~4.43 ($10^{-6}{\mu}g/m^3/TPY$) for the SMA, respectively.

• Journal of Advanced Navigation Technology
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• v.18 no.1
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• pp.84-89
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• 2014

Worldwide Interoperability for Microwave Access (WiMAX) is an efficient technology for 20th century communication system. The technology provides broadband speed without the need for cables and is based on the IEEE 802.16 standard(also called Wireless MAN). Mobile WiMAX is defined as IEEE802.16e which is advanced and efficient technology for mobile telecommunication rather than GSM, CDMA technology. In this work link budget calculation for WiMAX have been done. Cell range have been calculated over digital modulations and they are BPSK, QPSK and QAM. Here different types of models like Cost 231 model have been used for different types of areas like open, rural and urban areas and Erceg-Greenstein model for sub-urban areas. Effect of various parameters like frequency, base station antenna height, transmission power and SNR over cell range have been studied. Analysis have done for both uplink and downlink.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.1
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• pp.138-148
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• 2018

Objective: Fusarium mycotoxins deoxynivalenol (DON) and zearalenone (ZEN), common contaminants in the feed of farm animals, cause immune function impairment and organ inflammation. Consequently, the main objective of this study was to elucidate DON and ZEN effects on the mRNA expression of pro-inflammatory cytokines and other immune related genes in the kidneys of piglets. Methods: Fifteen 6-week-old piglets were randomly assigned to three dietary treatments for 4 weeks: control diet, and diets contaminated with either 8 mg DON/kg feed or 0.8 mg ZEN/kg feed. Kidney samples were collected after treatment, and RNA-seq was used to investigate the effects on immune-related genes and gene networks. Results: A total of 186 differentially expressed genes (DEGs) were screened (120 upregulated and 66 downregulated). Gene ontology analysis revealed that the immune response, and cellular and metabolic processes were significantly controlled by these DEGs. The inflammatory stimulation might be an effect of the following enriched Kyoto encyclopedia of genes and genomes pathway analysis found related to immune and disease responses: cytokine-cytokine receptor interaction, chemokine signaling pathway, toll-like receptor signaling pathway, systemic lupus erythematosus (SLE), tuberculosis, Epstein-Barr virus infection, and chemical carcinogenesis. The effects of DON and ZEN on genome-wide expression were assessed, and it was found that the DEGs associated with inflammatory cytokines (interleukin 10 receptor, beta, chemokine [C-X-C motif] ligand 9, CXCL10, chemokine [C-C motif] ligand 4), proliferation (insulin like growth factor binding protein 4, IgG heavy chain, receptor-type tyrosine-protein phosphatase C, cytochrome P450 1A1, ATP-binding cassette sub-family 8), and other immune response networks (lysozyme, complement component 4 binding protein alpha, oligoadenylate synthetase 2, signaling lymphocytic activation molecule-9, ${\alpha}$-aminoadipic semialdehyde dehydrogenase, Ig lambda chain c region, pyruvate dehydrogenase kinase, isozyme 4, carboxylesterase 1), were suppressed by DON and ZEN. Conclusion: In summary, our results indicate that high concentrations of DON and ZEN suppress the inflammatory response in kidneys, leading to potential effects on immune homeostasis.

• Knowledge Management Research
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• v.19 no.1
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• pp.59-77
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• 2018

The tourism industry is now changing to smart tourism, which maximizes tourists' overall tourism experience with the use of advanced mobile technologies and emphasizes the utilization of tourism information. Despite the quantitative expansion of the tourism industry, there is a lack of academic and practical discussion on tourism safety. Especially, in the context of walking tourism, tourists are more likely to be exposed to natural or social disasters and emergencies. Therefore, it is necessary to build a system that can provide walking tourists with safety information not only on dangerous factors which are anticipated to be confronted during a walking trip in advance but also on specific dangers in real time. Under the circumstances, this study seeks to identify the types of tourism safety information that can be offered by using publicly available open data, drawing on the safety information framework on the walking tourism that is presented in Choi et al. (2017)'s study. More specifically, this study focuses on the use of open data which is provided by the Korean government. Furthermore, this study verifies the types of safety information that are most urgently needed in walking travel situations. Specifically, this study aims to derive the importance and priority of each type of safety information for a walking trip by applying the analytic hierarchy process (AHP) analysis. For this, we collected 35 questionnaires from walking tour operators (practitioners) and walking tourists. The main results are as follows. First, natural disaster information is the most important factor in the top-level factor of safety information for walking tourists, followed by social disaster, life safety, and exhibition (security crisis) information. Second, information on natural disasters, environmental pollution, and weather is considered to be important at the sub-level factor. Lastly, the noteworthy result of this study is that the importance of each type of safety information varies depending on the walking tour operators (practitioners) and the walking tourists. That is, there is a recognition difference between the operator (practitioner) and the user in the importance and priority of the safety information of the walking trip. Therefore, it is necessary to develop policies and services reflecting the opinions of potential users when providing safety information so that the most importantly recognized information can be provided first.

• Biomedical Science Letters
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• v.6 no.1
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• pp.73-82
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• 2000

Blunt-end DNA fragments can be inserted in two different orientations. Conventionally, their directions are determined by restriction enzyme digestion or by DNA sequencing, however, these methods are often limited in their use due to the lack of appropriate enzyme sites or large sample numbers, respectively. In the present study, a novel strategy and the corresponding protocol for the simple determination of insert orientation is introduced. Using conventional sequencing primers and PCR primers that have been used for amplification of the insert, single clones, which have inserted the fragment in the desired orientation, were easily identified by this PCR-based method. The fidelity of this system was confirmed by cloning of a tar urocortin cDNA, which is a recently discovered neuropeptide. Recombinant clones identified by this method were further shown to be fully functional, and using these, for the first time, urocortin was recombinantly expressed in eukaryotic cells.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.5
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• pp.197-208
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• 2015

This study is to suggest a system to increase workers' job satisfaction by analyzing the impact of conflicts in their families and work places to the satisfaction of work and the effects of personality types affecting job satisfaction. For this study, a questionnaire targeting 450 workers was conducted. As a result of this study, firstly, it was revealed that both conflicts of the family-work place and the work place-family have statistically negative interrelationships and impacts with/on job satisfaction. In terms of sub-fact categories, it is revealed that work itself has more impacts than personal persuasion based on people's value. Secondly, the results of this study concerning the conflicts in a family and the workplace shows the same result with the previous studies. They are formed by mutual interactions of cause and effect. Thirdly, it turned out that differences in Enneagram Personality Types have statistically significant impacts on job satisfaction. The result also shows that thinking-centered personalities and behavior-centered personalities have more impacts on job satisfaction than emotion-centered personalities. Study result indicates that more wide use of a psychology consultation program for workers and their families, EPA(Employee Assistant Program). It also shows that introductions of personality trainning programs and personality coaching programs are required.