• Journal of the Korean Geographical Society
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• v.47 no.5
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• pp.677-699
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• 2012

Climate changes may cause substantial changes in spatial patterns and distribution of vector-borne diseases (VBD's), which will result in a significant threat to humans and emerge as an important public health problem that the international society needs to solve. As global warming becomes widespread and the Korean peninsula characterizes subtropical climate, the potentials of climate-driven disease outbreaks and spread rapidly increase with changes in land use, population distributions, and ecological environments. Vector-borne diseases are typically infected by insects such as mosquitoes and ticks, and infected hosts and vectors increased dramatically as the habitat ranges of the VBD agents have been expanded for the past 20 years. Medical geography integrates and processes a wide range of public health data and indicators at both local and regional levels, and ultimately helps researchers identify spatiotemporal mechanism of the diseases determining interactions and relationships between spatial and non-spatial data. Spatial epidemiology is a new and emerging area of medical geography integrating geospatial sciences, environmental sciences, and epidemiology to further uncover human health-environment relationships. An introduction of GIS-based disease monitoring system to the public health surveillance system is among the important future research agenda that medical geography can significantly contribute to. Particularly, real-time monitoring methods, early-warning systems, and spatial forecasting of VBD factors will be key research fields to understand the dynamics of VBD's.

• Korean Journal of Environmental Biology
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• v.33 no.1
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• pp.1-6
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• 2015

Increased harmful algal blooms by cyanobacteria are threatening public health and limiting human activities related with freshwater ecosystems. Phosphorus (P) has long been suggested as a critical nutrient for cyanobacterial bloom through field research in Canada during the 1970s, proposing a P-based freshwater management guideline. However, recently, nitrogen (N) has also been highlighted as an impacting nutrient on cyanobacterial harmful algal blooms (CyanoHABs). Due to the intensive and frequent observation of Microcystis, this kind of paradigm shift from P limitation to season-dependent N or P limitation has an important implication for a dual nutrient management strategy in eutrophic freshwaters. Through recent international researches, general strategies to control CyanoHABs in lakes and reservoirs are as follows: a dual nutrient (N & P) reduction, wastewater collection and treatment, pre-treatment of influent water in buffer zones, dredging of sediment, reduction of residence time, algal collection, and precipitation and flocculation of cyanobacteria. In addition, sustainable and integrative freshwater algae management should be carried out, based on the ecological aspect, because cyanobacteria are not the target organism to be eradicated, but an essential microbial member in the freshwater ecosystem.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4277-4283
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• 2012

Slip coefficient, whose value is dependent on the condition of contact surface at the friction joint of high tension bolt, is determined by slip load. Because contact area affects slip load, contact area that varies with bolt hole size is also related to the slip coefficient. In this study, we manufactured 32 specimens and performed bending and tension tests in order to examine changes in slip coefficient and load with material type, bolt diameter, and size of bolt hole. Slip load of specimens with oversize bolt hole had strength that was more than 80% higher than the slip load of specimens with standard bolt hole, and it also exceeded the design slip strength. In addition, we observed significant correlation between net-section ratio and slip ratio of specimens with oversize and standard bolt hole. However, some differences between the specimens are thought to have been caused by reduction in initial axial force of high tension bolt, which is an important parameter of slip coefficient. It is self-evident that increased bolt hole size would lead to decrease in design strength as it reduces both slip coefficient and bolt axial force. Nevertheless, we suggest that some flexibility in regulation of bolt hole, as long as it does not threaten the structural stability, may be a positive factor in terms of workability and efficiency.

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.167-178
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• 2003

Damage and overbreak of the remaining rock induced by blasting can not be avoided during tunnel construction which may result in either short-term or long-term tunnel instability. Therefore, in this paper, a methodology to take into account the effect of blast-induced damage in tunnel stability assessment is proposed. Dynamic numerical analysis was executed to evaluate damage and overbreak of the remaining rock for the most common blasting pattern in road tunnel. Rock damage was quantified by utilizing the damage variable factor which is adopted proposed in continuum damage mechanics. The damaged rock stiffness and the damaged failure criteria are used to consider the effect of rock damage in tunnel stability analysis. The damaged geological strength index of the damaged rock was newly proposed from the relationship between deformation modulus and geological strength index. Also the Hoek-Brown failure criteria of the damaged rock was obtained using the damaged geological strength index. Analysing the tunnel stability with the consideration of the blast-induced damage of remaining rock, it was found that the extend of plastic zone and deformation increased compared to the undamaged rock. Therefore the short-term or long-term tunnel stability will be threatened when the rock damage from blasting is ignored in the tunnel stability analysis.

• Convergence Security Journal
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• v.14 no.3_2
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• pp.83-91
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• 2014

International society got a severe shock from terrorism of hostage, abduction and murder that was committed on a target of Israel athlete delegation in Munich Olympics, West Germany by Black September, a Palestine terrorism organization. Korea with 1986 Asian Games and 1988 Olympics ahead was directly and indirectly exposed to threats of North Korea's nation-support terrorism, a military provocation and a local war limited warfare. This study explores the roles of the police at the time of the National Police Headquarters with regard to counter-terrorism, and analyzed academic research trends of Studies of Counter-terrorism published by the same office between 1983 and 1990. Looking into them shows a fact firstly, that the most frequently appearing key words in common were "terrorism," "hostages," "measures," and "international," etc. Secondly, before and after 1988 Olympics, the key word "Olympics" was frequently addressed. Thirdly, looking at the difference by the year, the key word, "policies of defense and borderlands" was frequently addressed between 1983 and 1984, "terrorism against South Korea," and "civil aircraft" frequently addressed in 1985, and "corporate" in 1986. In 1987, the key word "terrorism trends" was addressed, and in 1990, "international terrorism," and "separatism" were used.

• Journal of the Korean GEO-environmental Society
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• v.21 no.3
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• pp.5-11
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• 2020

Recently, ground pits that have been occurring frequently in urban areas are hindering traffic flow and causing property damages and loss of human life, acting as factors that are threatening the safety of citizens. Therefore, sunken ground must be quickly restored and provisions must be made for additional damage but current domestic detailed standards regarding ground pits and accurate definitions regarding causes and measures to be taken for reoccurrences are lacking. Restoration methods of sunken ground include backfilling by reusing sunken soil or other fill material and paving the road and while this is the most often used method, this only prevents ground from sinking temporarily and can not serve as a fundamental solution. Also, additional ground pits can occur on ground that is reinforced using this method due to faulty backfill material or faulty hardening. This study used Eco-friendly High-Strength Material (EHSM) as restoration material that can be used in the restoration of underground cavities that have occurred due to ground subsidence to analyze the engineered characteristics of modified dredging clay and test pieces made from changed ratios of EHSM and weathered granite soil were uniaxial compression tests were conducted and freezing-thawing tests were conducted to study strength properties according to environmental changes of restoration material, and after tests were concluded by each level, uniaxial compression tests and dynamic elasticity tests were conducted for intensity analysis. Also, to evaluate strength characteristics of the restored ground, dynamic plate load tests were conducted to verify the improvement effectiveness of the restored ground.

• Korean Journal of Organic Agriculture
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• v.23 no.1
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• pp.123-131
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• 2015

In this study, viral disease samples were obtained between 2006 and 2010 from pepper fields in 11 major pepper-growing districts in Gangwon-do, and in 83 areas from other provinces, with the exception of Gyeongsangnam-do and Jeju island in Korea. In order to assess the type of infection, field surveys were conducted with regard to viral disease severity and virus type, based on typical symptoms on leaves. The means of single and mixed-virus infections were 46.6% and 48.0%, respectively, during those periods, suggesting that viruses are the agents that most severely decrease pepper production in field cultivation in Korea. In terms of single infection, Cucumber mosaic virus (CMV) was the most prevalent virus based on its disease severity ratings (34.8%). Next, Pepper mild mottle virus (PMMoV) and Pepper mottle virus (PepMoV) were shown to cause severe viral diseases in pepper, with disease severities of around 5-10%. On the other hand, Tomato spotted wilt virus (TSWV) occurs in a limited area in Chungcheongnam-do and Jeollanam-do. Thus, the viral disease caused by CMV, PMMoV, and PepMoV in pepper can be severe, and these virus types should remain considered critical reasons for decreased pepper production in field cultivation in Korea. In addition to single infection, mixed infections are frequently observed in collected pepper samples from all areas. The ratios of mixed infection were therefore studied to evaluate the disease severity of mixed infections and to define individual virus types. These data showed that different types of viruses were present, and CMV was the most abundant virus for mixed infection, as in the case of single infection. Among mixed infections, the highest disease severity was seen with CMV+Broad beam wilt virus 2 (BBWV2), followed by other types of mixed infection such as CMV+PepMoV and CMV+PMMoV. However, further work is needed to reduce the severe damage caused by viruses and to assess mixed infection types involving three or more viruses.

• Journal of dental hygiene science
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• v.1 no.1
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• pp.7-11
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• 2001

Streptococcus mutans is one of the primary bacteria that cause dental caries which further result in plaque build up. Acid production resulted from carbohydrate metabolism can threaten survival of the bacteria. However some populations of S. mutans which are exposed to low acidic condition for a period of time would develop resistance and tolerance of cells to acidity that will enhance the chance of survival. Similar acid tolerances has been reported in case of Salmonella enterica serovar typhimurium, E. coli, Shigella flexneri. These acid tolerance responses(ATR) have been evolved in a similar manner as S. mutans. The protein produced in acidic condition has been proven to be important for ATR and confirmed by using chloramphenicol procedure. We hypothesize here that proteins synthesized in response to acid shock and other elements are important for ATR of cells. In this study we have confirmed that S. mutans developed acid tolerance and resistance against anaerobic condition. Mutational DNA analysis responsible for acid tolerance should be additionally required in the future. Since the development of acid tolerance that is essential for the survival of S. mutans and development of dental caries, ATR of S. mutans shoule be farther to prevent dental caries.

• Journal of Korea Port Economic Association
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• v.35 no.3
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• pp.19-40
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• 2019

Ports have been facing the adverse impacts of the global recession. In terms of imports, with a vast consumption hinterland, the Incheon Port has developed as the metropolitan's gateway. Additionally, the port's exports to China has been increasing due to a consistent increase in the demand of cold chain foods in the country. Considering the short distance between the Incheon Port and the ports in Northern China, the Incheon Port can serve as a logistics hub and a distribution center for exporting processed foodstuffs to China. The establishment of a cold chain logistics system at the Incheon Port will prove to be a robust strategy. After reviewing studies and interviews from various departments, this study suggested strengths, weaknesses, opportunities, and threats (SWOT) facing the Incheon Port, based on a SWOT analysis; it also recommended competitive strategies for the port. Additionally, the study used the analytic hierarchy process (AHP) to identify important factors such as the infrastructural, operational, cost, and technology factors. This study identified the infrastructural factor to be highly critical to the activation of the Incheon Port's cold chain system. Based on the results, the study proposed policies and strategy directions.

• Journal of Life Science
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• v.25 no.4
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• pp.481-485
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• 2015

Retroviruses genes have been inserted into the human genome for millions of years. These retroviruses are now inactive due to mutations such as deletions or nonsense mutations. After mutation, retroviruses eventually became fixed in the genome in their endogenous forms and existed as traces of ancient viruses. These retroviruses are called endogenous retroviruses (ERVs), with the human form known as human endogenous retrovirus. HERV cannot become a fully active virus, but a number of viral proteins or even virus particles are expressed under various conditions. Compared to endogenous retroviruses, some exogenous retroviruses are still infectious and can threaten human life. Among these, human immunodeficiency virus (HIV) is one of the most well-known and best-studied. Recent studies have shown some elements of HERV were activated by HIV infection and interact with HIV-derived proteins. In addition, many studies have attempted to use HERV as vaccination against HIV infection. This review will describe the regulation and interaction between HERV and HIV infection and mention the development of vaccines and therapeutic agents against HIV infection by using HERV elements.