• Management Science and Financial Engineering
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• v.13 no.1
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• pp.121-126
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• 2007

Among many graphs, directed acyclic graph(DAG) attracts many researchers due to its nice property of existence of topological sort. In some classic graph problems, it is known that, if we use the aforementioned property, then much efficient algorithms can be generated. So, in this paper, new algorithm for the all-pairs shortest path problem in a DAG is proposed. While the algorithm performing the iteration, it identifies the set of essential arcs which requires in a shortest path. So, the proposed algorithm has a running time of $O(m^*n+m)$, where m, n and $m^*$ denote the number of arcs, number of node, and the number of essential arcs in a DAG, respectively.

• Journal of the Korean Wood Science and Technology
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• v.48 no.1
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• pp.95-106
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• 2020

The purpose of this study was to determine the effects of coniferous essential oils (EOs) blended films on insect repellence and crop productivity. Low-density polyethylene (LDPE) film is widely used, especially in agriculture and for food packaging. Ethylene vinyl acetate was blended with LDPE to reduce volatilization of EOs. An EO from Japanese cypress (Chamaecyparis obtusa) was incorporated into the blend film to conduct field research on antimicrobial and insect repellent properties. Among the various concentrations of EO, the highest concentration (2.5%) showed the highest efficiency in terms of pesticidal activity. The ability to inhibit microbial growth can be explained by the lipophilic properties of the EO component, and many studies have already demonstrated this. Agricultural films containing all types of EO have been tested on various crops such as chili, cucumber, Korean melon and have been able to verify their effectiveness in avoiding pests and increasing yields. From these results, it was found that it is reasonable to use a modified film such as a composite film containing an EO for agriculture. Thus, the modified film containing EO has undoubtedly shown impressive potential for reducing the use of pesticides in a variety of ways, not only for agricultural mulching film but also for food and agricultural product packaging. This product is an environmentally friendly chemical and is safe for agricultural and industrial and food packaging applications, among others. In particular, the use of agricultural films significantly reduces the use of pesticides, suggesting that farmers can increase their incomes by reducing working hours and costs, and increasing production.

• The Journal of Korean Physical Therapy
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• v.15 no.1
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• pp.82-95
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• 2003

Our health is intimately connected to the health of our environment. The contemporary world view which sees a radical distinction between humans as subjects and world as object can obscure our recognition of how much we rely on nature for health and survival. Indigenous traditions and contemporary scholars remind us that we live in a universe in which all things are connected, and in which nature continues to offer its gifts in co-creative partnership for the health and wellbeing of all. Living in awareness of our relationship with nature enables us to open more to the experience of nature's nurturing. Many complementary therapies derive from ancient practices that involve nature in healing partnership. Essential oils have been used for thousands of years. Hippocrates claimed that the way to health was through aromatic baths and massages. Much anecdotal evidence exists regarding aromatherapeutic positive effects on recipients. Aromatherapy is a branch of complementary or alternative therapy which is increasing in popularity, yet has scant scientific credibility. Aromatherapy should be defined as treatment using odors and practised as such. However, essential oils are usually used in conjunction with therapeutic massage and often combined with counselling of some kind. Aromatherapy complements and enhances the therapeutic powers of massage. Massage is one of the most wonderful ways to relax and is throughly beneficial to health. Massage can help unknot tense and aching muscles and other minor symptoms of stress, leaving patients fresh and energized. As the use of aromatherapy within a health care setting has grown so rapidly in recent years, and will continue to do so, the need for suitable training has become apparent. No health service can afford the risk of having staff who are inadequately trained in the practice of aromatherapy using essential oils incorrectly on those in a state of ill-health, especially if the essential oils used are not to a standard suitable for therapeutic use. Training to an acceptable level in aromatic therapy is essential for safety and effectiveness. Knowledge of the nature and make-up of essential oils, their effect on the body and the emotions, and how, when, and where to apply them is imperative in order for them to be beneficial to a patient's health. In order to achieve best practice, further research is necessary to explore the use of aromatherapy in the management of multiple disorder.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.195-198
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• 2008

This study was carried out to investigate the potential use of Zanthoxylum schinifolium and Zanthoxylum piperitum A.P. DC. as a source of antimicrobial agents against food borne pathogens. Essential oils of Z. schinifolium and Z. piperitum A.P. DC. were collected by steam distillation and analyzed by GC-MS. The antimicrobial activity of the essential oils was examined using the agar diffusion and micro-dilution assays. The effectiveness of Z. schinifolium essential oil was greater against Bacillus cereus, Staphylococcus aureus, and Vibrio parahaemolyticus than other pathogens, and the minimal inhibitory concentration (MIC) values were 1.25, 2.5, and 1.25, 2.5, and $1.25\;{\mu}g/mL$, respectively. Z. piperitum A.P. DC. essential oil was the most effective against all pathogens tested except for Escherichia coli O157:H7, and the MIC values against B. cereus, Salmonella choleraesuis, and V. parahaemolyticus were 1.25, 2.5, and $1.25\;{\mu}g/mL$, respectively. Limonene, the major component of Z. piperitum A.P. DC. essential oils, had the highest inhibitory activity toward V. parahaemolyticus with a MIC value of $0.15\;{\mu}g/mL$. Meanwhile, citronellal and geranyl acetate, major components of both essential oils, displayed antibacterial activity against only B. cereus with MIC values of 1.25 and $5\;{\mu}g/mL$, respectively. Therefore, these essential oils could be useful as antimicrobial agents against foodborne pathogens.

• Korean journal of food and cookery science
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• v.33 no.3
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• pp.256-263
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• 2017

Purpose: Essential oils are secondary metabolites of herbs and have antibacterial activities against foodborne pathogens. However, their applications for food protection are limited due to the hydrophobic and volatile natures of essential oils. Methods: In this study, essential oil nanoemulsions of rosemary and lavender were formulated with non-ionic surfactant Tween 80 and water using ultrasonic emulsification, and their antibacterial effects were determined. Results: The antibacterial activities of nanoemulsions were evaluated against 12 strains of 10 bacterial species, and significant antibacterial effects were observed against four Gram-positive and four Gram-negative bacteria but not against Streptococcus mutans and Shigella sonnei. In the disc diffusion test, the diameter of the inhibition zone proportionally increased with the concentration of nanoemulsions. Using cell turbidity measurement, minimum bactericidal concentration (MBC) of the nanoemulsions, which is the lowest concentration reducing viability of the initial bacterial inoculum by ${\geq}99.9%$, was significantly higher than the minimum inhibitory concentration (MIC) of the nanoemulsions. The largest bactericidal effects of lavender and rosemary essential oil nanoemulsions were observed against S. enterica and S. aureus, respectively. Conclusion: Nanoemulsion technique could improve antibacterial activity of essential oil nanoemulsions by increasing the solubility and stability of essential oils. Our findings shed light on the potential use of essential oil nanoemulsions as an alternative to chemical sanitizers in food protection.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.462-465
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• 2006

In order to extend the shelf life of sliced raw flatfish, the antimicrobial effects of natural essential oil from mustard and a mixture of ginger and mustard essential oils were tested at various temperatures. In addition, volatile components of the mixed essential oils were analyzed using gas chromatography and gas chromatography mass spectrometry. The viable cell counts of Vibrio parahaemolyticus treated with mixed essential oils from ginger and mustard was 0.7-1.3 log CFU/g lower than those of other treatments during storage at $5^{\circ}C$. During storage at $20^{\circ}C$, the viable cell counts of V. parahaemolyticus, V. vulnificus 01, and V. vulnificus 02 treated with the essential oils increased slightly from 6.53-6.64 log CFU/g at initial stages to 6.77-7.72 log CFU/g after 24-hr of storage, however they were 1.38-1.97 log CFU/g lower than those of the control group (8.74-9.10 log CFU/g). These results show that the growth of V. parahaemolyticus and V. vulnificus inoculated on sliced raw flatfish could be inhibited by treatment with natural essential oils from ginger and mustard at $5^{\circ}C$ of storage. However, the antibacterial effects of the essential oils on Vibrio species observed in this study were not sufficient to merit their use in sliced raw flatfish at temperatures exceeding $20^{\circ}C$.

• International Journal of Industrial Entomology and Biomaterials
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• v.32 no.1
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• pp.26-34
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• 2016

The present study was developed in order to evaluate the effect of five essential oils on the workers of the leaf-cutting ants; Atta sexdens rubropilosa and Acromyrmex subterraneus molestans by contact with a treated surface and ingestion with a treated leaves.. The essential oils of cinnamon, clove and mustard had generally more effective with 5, 10 and 15% concentrations after 24, 48, 72 and 96 h against workers of A. sexdens rubropilosa and A. subterraneus molestans in contact bioassay, but mustard was the most effective in ingestion bioassay on both species. On the other hand, there was no significant difference among the essential oils with 1% concentration and control after 24, 48 and 72 h of treatment in contact and ingestion bioassays against workers of A. sexdens rubropilosa . However, Andiroba oil had less efficiency values in all concentrations been used. Therefore, the essential oils of mustard, cinnamon and clove have contact and ingestion effects on workers of A. sexdens rubropilosa and A. subterraneus molestans, and may be promising on the leaf-cutting ant control.

• Journal of Microbiology and Biotechnology
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• v.5 no.6
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• pp.364-369
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• 1995

Effect of two-phase culture on Mentha piperita cell growth and essential oil formation was investigated using shake flask and air-lift bioreactors. LiChroprep RP-B(RP-B) addition did not impair M. piperita cell growth, but resulted in stimulated formation of essential oils and increased ratios of extracellular oil to intracellular oil formation. However, the combined use of RP-B and chitosan elicitor was not synergistic. Volumetric productivity of essential oils in RP-B treated culture using cell-recycled air-lift bioreactor was $6.9\;\mu\textrm{g}/l{\cdot}day$ which was substantially higher than that obtainable from the control. Our results demonstrate the potential of a second phase to enhance overall productivity for M. piperita cell culture.

• Journal of the Korea Furniture Society
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• v.16 no.2 s.30
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• pp.85-93
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• 2005

There are several way to classify the furniture. The furniture can be classified into use, style, and function, but if the furniture is classified into the way of production, it can be the industrial furniture and the studio furniture. Especially, technology and function of the furniture are important elements in industrial furniture. However, it could be considered artists' character and concept as more important elements in the studio furniture. The studio furniture had come out one of the historical movement in American furniture field after the World War II. This case to apply found objects began to increase after the 1970s. Using objects In furniture design field had built up sprightly after end of 1950s. This expression could be the statement of new expression that essential properties of matter in objects is removed. I try to suggest original and interesting furniture design to apply found objects in this thesis. Especially, I use the Korean traditional objects for the furniture and try to make their essential function to be changed. Also, I focus on furniture design to have formative element in their shapes.

• Journal of Haehwa Medicine
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• v.9 no.1
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• pp.461-467
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• 2000

After analyzing the datas to propose the rightful recognition and research direction for the long used charcoal, the following conclusions are obtained. 1. The 'soot' is pure Korean which has the meaning of 'fresh power' and is translated in English as charcoal which is composition of china and cool meaning good. 2. The main dispositions of the charcoal are 85% of carbon, 10% of water, 4% of minerals and 2% of essential so that the understanding of properties and effects of carbon are essential. 3. It is usually appeared that there are purifying and detoxifying effects of the woods and the room in practical use of charcoal. 4. In everyday life, it removes the odors, regulates the humidity and prevents the decaying. 5. It is often used medically for activating liver fuctions, regulating digestive fuctions and for diseases with inflammations, fever or bleeding. 6. The charcoal is used in medical treatment internally as well as externally. Above conclusions shows that the objective research is needed for clinical use considering the physical and chemical properties in future.