• Journal of Soil and Groundwater Environment
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• v.14 no.5
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• pp.10-17
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• 2009

Bioremediation has been applied as a proven technology in remediation of TPH contaminated soil. However, the efficiency of biodegradation is dependent on temperature as microbial activity is depressed at lower temperature ranges ($30^{\circ}C{\sim}80^{\circ}C$). The objective of this study was to develop microbes with enhanced activities at the stated temperature conditions and to evaluate the remediation effectiveness of these microbes in TPH contaminated soil. Experiments were conducted to isolate hydrocarbon degradable microbial consortia cultured under different temperature conditions. It was found that there were 5 strains of mesophilic ($30^{\circ}C$) and 3 strains of psychrophilic ($80^{\circ}C$) microbes. The TPH concentration was reduced from 4,044 mg/kg to 1,084 mg/kg, (73.2%) in 10 days by using mesophilic microbial consortia and from 5,427 mg/kg to 1,756 (67.6%) in 50 days with psychrophilic microbial consortia in laboratory cultures under controlled conditions. This rate determination excluded physical degradation such as venting and dilution. A field study was then performed to examine the feasibility of applying these microbes in the land-farming process. In this case, 87.1% of the 2,560 mg/kg TPH contaminated soil was degraded in 56 days. The biodegradation rate coefficient (k) was $0.0374\;day^{-1}$. Findings of this study provide viable options for applying microbes for bioremediation of TPH in lower temperature conditions.

• International Journal of Human Ecology
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• v.8 no.1
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• pp.67-78
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• 2007

The aim of this paper was to compare differences and similarities of farmhouses between Denmark and Korea as a cross-cultural study. Farmhouses built during the 18th and 19th centuries in Denmark, and ones from Chosun Dynasty (AD. 1392-1910) in Korea were targets of this study. Literature study and field trips to districts and open-air museums in both countries were used. Field trips were carried out during summer of 2005 in Denmark, and fall of 2005 in Korea. Detailed comparisons focused on farmhouse plans, the use of rooms and furnishing, and building materials. As a conclusion, some differences were found between the two countries. In terms of farmhouse plans, square types with four wings, and parallel types were the most frequent forms in Denmark, while a few types, such as the "I", "L", "U" shapes and square types, were more frequently found in Korea. In Denmark, the most important room was the dwelling-room, in which daily family life took place. Every member of the family slept, ate, and worked here, and kept geese and young animals during the winter season. Therefore, this room was laid out in the center of the house. However, Anbang, the most important room in Korea, was not situated in the best part of the house. Instead, the Daechung-maru occupied the center and the best place because the daechung-maru, in which the ancestral ceremony was held, was thought of as more important than a place for live people. Also the use of rooms and furnishing was quite different between the two countries, reflecting each life style. Danish furnishings represented practical daily life, while Korean furnishings reflected more conceptual aspects. It might have resulted from Confucianism in the Chosun Dynasty, which ruled daily life and even influenced use of rooms and furnishings. In other word, philosophy influenced common peoples' daily life and living environment. With reference to building materials, there was rarely a difference between the two countries. Major materials for farmhouse were quite common, such as half-timbering wood and clay, but the difference was in bricks and roof coverings. Bricks were rarely used in Korean farmhouses, while rice-straw was rare for the roof of a Danish farmhouse. Of course, the choice of materials was strongly affected by the local surroundings and overall environment. This result can give some clues for design ideas when architects and interior designers plan housing that is adapted for local peoples. This kind of cross-cultural study can also contribute to one's understanding of foreign culture, especially in housing and culture. And, it can broaden one's insight of design ideas for designers who have to compete frequently with designers in foreign countries.

• The KIPS Transactions:PartD
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• v.9D no.2
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• pp.235-242
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• 2002

We propose an advanced transaction scheduling protocol for concurrency control of multilevel secure databases in wireless mobile network environment. Wireless communication is characterized by frequent spurious disconnections. So short-lived transaction must quickly access database without any delay by long-lived one. We adapted two-phase locking protocol, namely traditional syntax-oriented serializability notions, to multilevel secure databases in wireless mobile network environment. Altruistic locking, as an advanced protocol, has attempted to reduce delay effect associated with lock release moment by use of the idea of donation. An improved form of a1truism has also been deployed for extended a1truistic locking. This is in a way that scope of data to he early released is enlarged to include even data initially not intended to be donated. Our protocol is based on extended altruistic locking, but a new method, namely bi-directional donation locking for multilevel secure databases (MLBiDL), is additionally used in order to satisfy security requirements and concurrency. We showed the Simulation experiments that MLBiDL outperforms the other locking protocols in terms of the degree of throughput and average waiting time.

• Journal of the Economic Geographical Society of Korea
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• v.16 no.4
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• pp.567-584
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• 2013

This study aims to explore an evolutionary path of the IT service industry in Fairfax County using the Cluster Adaptive Cycle model in economic geography. The analysis is based on detailed historical and industrial information obtained through a variety of data sources including local archival materials, economic census, and interviews. This study also performs a shift-share analysis during the period of 1990 to 2011. Using the adaptive cycle model, the local IT service industry is indicated by a trajectory of constant cluster mutation. The evolution of the local IT service industry has been closely related to federal government policy due to the regional specificity of the National Capital Region and the proximity of the Department of Defense. Although the economic downturn of the late 2000s, the local IT service industry has been notable resilience and adapted to a changing market and technological environment. This constant mutation of the local industry is resulted from not only high resilience which is based on the large government procurement market, the reinforcement of adaptive capacity of the local firms and the network of economic agents such as firm and supporting institutions, but also high flexibility of the knowledge-based service industry to a changing business environment.

• (The)Korea Educational Review
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• v.23 no.1
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• pp.183-204
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• 2017

Since the development of Smart technology and the advent of various Smart media, a learning environment for individual learners and the school has been changing. In the stream of changing learning environments, in 2011, the government announced SMART education strategies, introducing the term officially, "SMART education." With the governments' efforts to develop and implement SMART education in school, many policies has been enacted and many research has been conducted and increased gradually. However, as policies of SMART education have initiated in situation where there is no clear understanding in regard of SMART education, many researchers and teachers confused of SMART education and its identity and attributes, even though it has been 6 years since the concept was introduced. Unfortunately, SMART education has been implemented as one type of instructional methodology as utilizing Smart technology. Thus, in this research, we tried to build theoretical foundation of SMART education through analyzing former research on SMART education to define the attributes of SMART education. To examine how SMART education has been implemented in terms of its attributes, also, we analyzed research that conducted instructional design and implementation on SMART education in actual learning environments. As the results of former research analysis, the attributes of SMART education include Information and Communication Technology, open learning environment, self-directed learning, customized learning, and social learning. In majority of research, SMART education focused on utilizing Smart technology and media in teaching and learning environments but self-directed, and customized learning were less adapted in SMART learning environments. In the following research, how to improve educational benefits of SMART education through adapting original attributes of SMART education need to be examined.

• Journal of Ecology and Environment
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• v.45 no.1
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• pp.54-61
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• 2021

Background: The sunfleck is an important light environmental factor for plants that live under the shade of trees. Currently, the smartfarm has a system that can artificially create these sunfleks. Therefore, it was intended to find optimal light conditions by measuring and analyzing photosynthetic responses of Eutrema japonica (Miq.) Koidz., a plant living in shade with high economic value under artificial sunflecks. Results: For this purpose, we used LED pulsed light as the simulated sunflecks and set the light frequency levels of six chambers to 20 Hz, 60 Hz, 180 Hz, 540 Hz, 1620 Hz, and 4860 Hz of a pulsed LED grow system in a plant factory and the duty ratio of the all chambers was set to 30%, 50%, and 70% every 2 weeks. We measured the photosynthetic rate, transpiration rate, stomatal conductance, and substomatal CO2 partial pressure of E. japonica under each light condition. We also calculated the results of measurement, A/Ci, and water use efficiency. According to our results, the photosynthetic rate was not different among different duty ratios, the transpiration rate was higher at the duty ratio of 70% than 30% and 50%, and stomatal conductance was higher at 50% and 70% than at 30%. In addition, the substomatal CO2 partial pressure was higher at the duty ratio of 50% than 30% and 70%, and A/Ci was higher at 30% than 50% and 70%. Water use efficiency was higher at 30% and 50% than at 70%. While the transpiration rate and stomatal conductance generally tended to become higher as the frequency level decreased, other physiological items did not change with different frequency levels. Conclusions: Our results showed that 30% and 50% duty ratios could be better in the cultivation of E. japonica due to suffering from water stress as well as light stress in environments with the 70% duty ratio by decreasing water use efficiency. These results suggest that E. japonica is adapted under the light environment with nature sunflecks around 30-50% duty ratio and low light frequency around 20 Hz.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.3
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• pp.253-259
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• 2012

The projection on the demand for seafarers is seen to continue to rise in consonance with the world's fleet increasing tonnage. It is also expected that recurring officer shortages is paramount when global markets bounce off from the economic downturn it experienced for the last few years. In BIMCO/ISF(The Baltic and International Maritime Conference/International Shipping Federation) report for 2010, a continuous effort to produce competent seafarers should be adapted and as much as possible, reduce the wastage in the industry to address the looming scenario. The Republic of Korea, an OECD member, is a powerhouse in shipbuilding industry and has also had continued to show also an expanding trend in its fleet. On the other hand, the Philippines is still acknowledged as the main source of manpower for ocean-trading vessels. In this paper, a statistical comparison of maritime graduates' career path between the two countries is presented. In conclusion, it is suggested that a mutual co-operation between the Republic of Korea and the Philippines can be established with focusing on international maritime education and training collaboration.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.7
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• pp.884-891
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• 2016

A secondary injection system in a diesel engine has benefits: it can be controlled independently without interrupting engine control, it can be adapted to various layouts for exhaust systems, and it pose no reductant dilution problems compared to post injection systems in the combustion chamber or other supplemental reductant injections. In a secondary injection system, the efficiency of the catalyst depends on the method of reducing the supply. The reductant needs to be maintained and optimized with constant pressure, the positions and angles of injector is a very important factor. The concentration and amount of reductant can be changed by adjusting secondary injection conditions. However, secondary injection is highly dependent upon the type of injector, injection pressure, atomization, spray technology, etc. Therefore, it is necessary to establish injection conditions the spray characteristics must be well-understood, such as spray penetration, sauter mean diameter, spray angle, injection quantity, etc. Uniform distribution of the reductant corresponding to the maximum NOx reduction in the DeNOx catalyst system must also assured. With this goal in mind, the spray characteristics and impingement plate types of a secondary injector were analyzed using visualization and digital image processing techniques.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.519-526
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• 2018

In this study, an algorithm to predict evacuation routes in support of shipboard lifesaving activities is presented. As the first step of algorithm development, the feasibility and necessity of an evacuation route prediction algorithm are shown numerically. The proposed algorithm can be explained in brief as follows. This system continuously obtains and analyzes passenger movement data from the ship's monitoring system during non-disaster conditions. In case of a disaster, evacuation route prediction information is derived using the previously acquired data and a prediction tool, with the results provided to rescuers to minimize casualties. In this study, evacuation-related data obtained through fire evacuation trials was filtered and analyzed using a statistical method. In a simulation using the conventional evacuation prediction tool, it was found that reliable prediction results were obtained only in the SN1 trial because of the conceptual and structural nature of the tool itself. In order to verify the validity of the algorithm proposed in this study, an industrial engineering tool was adapted for evacuation characteristics prediction. When the proposed algorithm was implemented, the predicted values for average evacuation time and route were very similar to the measured values with error ranges of 0.6-6.9 % and 0.6-3.6 %, respectively. In the future, development of a high-performance evacuation route prediction algorithm is planned based on shipboard data monitoring and analysis.

• Genes and Genomics
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• v.40 no.11
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• pp.1169-1180
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• 2018

Cave shrimps from the genera Typhlatya, Stygiocaris and Typhlopatsa (TST complex) comprises twenty cave-adapted taxa, which mainly occur in the anchialine environment. Anchialine habitats may undergo drastic environmental fluctuations, including spatial and temporal changes in salinity, temperature, and dissolved oxygen content. Previous studies of crustaceans from anchialine caves suggest that they have possessed morphological, behavioral, and physiological adaptations to cope with the extreme conditions, similar to other cave-dwelling crustaceans. However, the genetic basis has not been thoroughly explored in crustaceans from anchialine habitats, which can experience hypoxic regimes. To test whether the TST shrimp-complex hypoxia adaptations matched adaptive evolution of mitochondrial OXPHOS genes. The 13 OXPHOS genes from mitochondrial genomes of 98 shrimps and 1 outgroup were examined. For each of these genes was investigated and compared to orthologous sequences using both gene (i.e. branch-site and Datamonkey) and protein (i.e. TreeSAAP) level approaches. Positive selection was detected in 11 of the 13 candidate genes, and the radical amino acid changes sites scattered throughout the entire TST complex phylogeny. Additionally, a series of parallel/convergent amino acid substitutions were identified in mitochondrial OXPHOS genes of TST complex shrimps, which reflect functional convergence or similar genetic mechanisms of cave adaptation. The extensive occurrence of positive selection is suggestive of their essential role in adaptation to hypoxic anchialine environment, and further implying that TST complex shrimps might have acquired a finely capacity for energy metabolism. These results provided some new insights into the genetic basis of anchialine hypoxia adaptation.