• 약학회지
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• 제55권5호
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• pp.398-403
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• 2011

Ligusticum chuanxiong (Umbelliferae) is a perennial herb that has been used for invigoration of blood in Korean traditional medicine. It is especially important in gynecological therapy of amenorrhea and dysmenorrhea. In this study, the essential oil of L. chuanxiong was obtained by steam distillation and its main components of L. chuanxiong, Z-ligustilide and butylidene phthalide, were isolated by silica gel column chromatography. We investigated the cytotoxic effects of the essential oil fraction of L. chuanxiong and its main components on MCF-7, HeLa and SK-Hep-1 cell lines by measuring the number of surviving cancer cells after treatment through direct cell counting and MTT analysis, and by examining the morphological changes under the microscope. The essential oil from the rhizomes of L. chuanxiong and its main components showed significant cytotoxic activities for all three tested cell lines. We also observed morphological changes of shrinking and blebbing in the membranes of the three cell lines, depending on the concentration of L. chaunxiong oil or its main components.

• 한국작물학회지
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• 제48권5호
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• pp.376-380
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• 2003

In order to examine the possibility that oil seed rape could be used as a forage fodder crop and to select the most suitable variety of forage rape at the southern area of Korea, two varieties of oil seed rape currently grown for oil production and six introduced varieties of forage rape with relatively high yield and high nutritional value were grown at the same condition their and yield components were observed. Forage rape was superior to oil seed rape in terms of yield components, plant fresh weight and plant dry mater weight. Velox was superior to any other variety of forage rape in these characters. When plant dry matter weight of the rape was subdivided into four components such as a main stem, branch stems, main stem leaves and branch leaves, contribution of these components to plant dry matter weight was in the order of branch stems, branch leaves, the main stem and main stem leaves. Dry matter percentage of the rape ranged from 9.32 to 11.08 percent, which was somewhat low value. There was no significant difference between two groups of the rape in terms of dry matter percentage. Velox showed somewhat higher value in dry matter percentage.

• Journal of Mechanical Science and Technology
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• 제16권8호
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• pp.1095-1101
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• 2002

The load characteristics of engine main bearing are very important in the design of crankshaft and engine block. The stiffness of crankshaft and block, or the optimal dimension of the bearing can be determined according to the load level. This paper presents the load characteristics of engine main bearing. Two components of the main bearing load are measured during engine firing and motoring. The vertical and horizontal load components are measured by using the dynamic load cell mounted in each main bearing cap bolt. The measured main bearing loads are compared with calculated results by using the statically determinate method. The theoretical results, provided in this study, agreed well with the experimental results. The presented results are very useful for achieving optimal design of engine.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.703-707
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• 2000

Machine tool errors have to be characterized and predicted to improve machine tool accuracy. A real-time error compensation system has been developed based on volumetric error synthesis model which is composed of machine tool errors. This paper deals with new algorithm about verification of machine tool errors. This new algorithm uses a simplified volumetric error synthesis model. This simplified model is constructed with only main components among the error components of the machines. This main error components are analyzed by three-dimensional helical ball bar test. By substituting result of helical ball bar test fer simplified model, we could find that obtained error components are closed to real error components.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권9호
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• pp.2312-2325
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• 2013

In this paper, we propose a preprocessing method that it is to correct the distortion of text area in Korean signboard images as a preprocessing step to improve character recognition. Distorted perspective in recognizing of Korean signboard text may cause of the low recognition rate. The proposed method consists of four main steps and eight sub-steps: main step consists of potential vertical components detection, vertical components detection, text-boundary estimation and distortion correction. First, potential vertical line components detection consists of four steps, including edge detection for each connected component, pixel distance normalization in the edge, dominant-point detection in the edge and removal of horizontal components. Second, vertical line components detection is composed of removal of diagonal components and extraction of vertical line components. Third, the outline estimation step is composed of the left and right boundary line detection. Finally, distortion of the text image is corrected by bilinear transformation based on the estimated outline. We compared the changes in recognition rates of OCR before and after applying the proposed algorithm. The recognition rate of the distortion corrected signboard images is 29.63% and 21.9% higher at the character and the text unit than those of the original images.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.296-299
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• 2007

KAERI is in the process of carrying out the Nuclear Hydrogen Development and Demonstration (NHDD) Program. The indirect cycle gas cooled reactors that produce heat at temperatures in the order of $950^{\circ}C$ are being considered in the NHDD program. For the indirect gas cooled reactors, the intermediate hear exchanger (IHX) and hot gas duct (HGD) are the main components. For the NHDD program we are in the process of establishing a conceptual design of the IHX and HGD. The pre-conceptual design activities in this study dealt with a preliminary design of the IHX and the HGD including strength and thermal expansion evaluation of the main components.

• Natural Product Sciences
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• 제10권6호
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• pp.325-329
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• 2004

The composition of essential oil from O. javanica was analyzed by gas chromatography-mass spectrometry. Using the broth dilution method and disk diffusion test, anti-microbial activities of the oil fraction and its main components were evaluated against various antibiotic-susceptible and resistant strains of pathogenic microorganisms. As a result of GC-MS analysis, 57 compounds, including ${\alpha}-terpinolene$ (28.1%), dl-limonene (16.0%), ${\gamma}-terpinene$ (10.3%), ${\beta}-pinene$ (9.7%) and ${\alpha}-pinene$ (6.0%) were identified in the essential oil fraction. The essential oil fraction of O. javanica and its main components exhibited significant inhibitory activities, particularly against Candida albicans (antibiotic-susceptible strains) and Streptococcus pneumoniae (antibiotic- susceptible and resistant strains). The main components of the O. javanica oil fraction displayed different patterns of activity against the three tested Candida species as exemplified by the differential minimum inhibiting concentration (MIC) values. The disk diffusion test showed that the activities were dose dependent.

• Natural Product Sciences
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• 제11권2호
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• pp.92-96
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• 2005

The antifungal activities of essential oils from the leaves of Glehnia littoralis, which is cultivated in Korea, were evaluated against pathogenic Trichophyton species by the broth dilution method and the disk diffusion test. Additionally, the effects of the oils together with ketoconazole were tested by the checkerboard titer test. The essential oil fraction and its main components showed significant inhibition of the tested Trichophyton fungi, with minimal inhibitor concentrations (MICs) in the range of 16-32 mg/ml. The results suggest that activities of this oil are based mainly on the contents of ${\alpha}-pinene$ (22.17%), the next prominent component of the oil fraction, while the first main components ${\beta}-pinene$ (57.83%) have relatively mild activity. The MICs of ${\alpha}-pinene$ and ${\beta}-pinene$ were 1-4 mg/ml and 4-32 mg/ml, respectively. Additionally the Glehnia oil fraction and its main components as well, exhibited significant synergism with ketoconazole against Trichophyton rubrum.

• 한국식품조리과학회지
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• 제8권2호
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• pp.73-82
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• 1992

This study investigated conditions necessary for factory production of traditional Korean soy sauce flavors, using Bacillus licheniformis SSA3-2M1. We determined whether the flavors were good or bad by comparing sensory evaluation values and the contents of the main taste components of traditional Korean soy sauce with those of the manufactured soy sauce. The soy broth was cultured by Bacillus licheniformis SSA3-2M1. By providing from 1/3 vvm to 2/3 vvm of air, and a culturing time of 412 hours at 30$^{\circ}C$, we produced the taste of traditional Korean soy sauce; moreover its PH was in the PH range of traditioal Korean soy sauce. The distributions of the main taste components and the amino acids, free sugars, and organic acids in the manufactured soy sauce were similar to tradituioal Korean soy sauce.

• Archives of Pharmacal Research
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• 제28권8호
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• pp.897-901
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• 2005

The in vitro inhibitory activities of essential oils from Thymus magnus and T. quinquecostatus as well as their main constituents were evaluated against susceptible and resistant species of Streptococcus pneumoniae, Staphylococcus aureus, Salmonella enteritidis, and Salmonella typhimurium. Notably, the essential oil fraction of T. magnus and its main components displayed significant inhibitory action against both antibiotic-susceptible and resistant strains of S. pneumoniae, S. aureus, and S. typhimurium with minimum inhibitory concentrations (MICs) ranging from 0.125 to 8 mg/mL. The differential MIC values imply that the oil fraction and its main components exhibit distinct patterns of activity against the tested bacterial species. Moreover, the disk diffusion test revealed that the inhibitory activities of oil fraction and components were dose-dependent. Data from the checkerboard titer test confirmed synergism between the antibiotic, norfloxacin, and T. magnus oil or thymol, particularly against the resistant strains of S. aureus.