• Proceedings of the Botanical Society of Korea Conference
• /
• 1999.07a
• /
• pp.85-89
• /
• 1999

Somatic embryogendesis is one of good examples of the basic research for plant embryo development as well as an important technique for plant biotechnology. This paper describes the direct somatic embryogenesis from zygotic embryos of Panax ginseng is reversely related to normal axis growth of zygotic embryos by the experiment of various chemical treatments. Under the normal growth condition, the apical tips of embryo axis produced an agar-diffusible substance, which suppressed somatic embryo development from cotyledons. Although the cells of zygotic embryos were released from the restraint of embryo axis, various factors were still involved for somatic embryo development. Electron microscopic observation revealed that the ultrastructure of cells of cotyledon epidermis markedly changed before initiation of embryonic cell division, probably indicating reprogramming events into the cells embryogenically determined state. Polar accumulation of endogenous auxin or cell-cell isolation by plasmolysis pre-treatment is the strong inducer for the somatic embryo development. The cells for the process of somatic embryogenesis might be determined by the physiological conditions fo explants and medium compositions. Direct somatic embryos from cotyledons fo ginseng were originated eithrer from single or multiple cells. The different cellular origin of somatic embryos was originated either from single or multiple cell. The different cellular origin of somatic embryos was depended on various developmental stages of cotyledons. Immature meristematic cotyledons produced multiple cell-derived somatic embryos, which developed into multiple embryos. While fully mature cotyledons produced single cell-derived single embryos with independent state. Plasmolysis pretreatment of cotyledons strongly enhanced single cell-derived somatic embryogenesis. Single embryos were converted into normal plantlets with shoot and roots, while multiple embryos were converted into only multiple shoots. GA3 or a chilling treatment was prerequisite for germination and plant conversion. Low concentration of ammonium ion in medium was necessary for balanced growth of root and shoot of plantlets. Therefore, using above procedures, successful plant regeneration of ginseng was accomplished through direct single embryogenesis, which makes it possible to produce genetically transformed ginseng efficently.

• Transactions of the Korean hydrogen and new energy society
• /
• v.31 no.2
• /
• pp.169-176
• /
• 2020

There is a growing interest in hydrogen energy utilization since an alternative energy development has been demanded due to the depletion of fossil fuels. Hydrogen is produced by the reforming reaction of natural gas and biogas, and the electrolysis of water. An solid oxide electrolyte cell (SOEC) is reversible system that generates hydrogen by electrolyzing the superheated steam or producing the electricity from a fuel cell by hydrogen. If the water can be converted into steam by waste heat from other processes it is more efficient for high-temperature electrolysis to convert steam directly. The reasons are based upon the more favorable thermodynamic and electrochemical kinetic conditions for the reaction. In the present study, steam at over 180℃ and 3.4 bars generated from a boiler were converted into superheated steam at over 700℃ and 3 bars using a cylindrical steam superheater as well as the waste heat of the exhaust gas at 900℃ from a solid refuse fuel combustor. Superheated steam at over 700℃ was then supplied to a high-temperature SOEC to increase the hydrogen production efficiency of water electrolysis. Computational fluid dynamics (CFD) analysis was conducted on the effects of the number of 90° elbow connector for piping, insulation types and insulation layers of pipe on the exit temperature using a commercial Fluent simulator. For two pre-heater injection method of steam inlet and ceramic wool insulation of 100 mm thickness, the highest inlet temperature of SOEC was 744℃ at 5.9 bar.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.10C
• /
• pp.961-967
• /
• 2009

In this paper, the lossless compression method is proposed for an 8-bit bitplane of the input image. The lower bitplanes are not well compressed because of irregularity of pixels. To overcome these drawbacks, this paper propose a mixed coding method that using the block-based lossless compression and the bit-based losselss compression, introducing the H. 264 and the JBIG. First, to take advantage of the characteristics of the bitplanes, 8-bitplane against the top 4 bits and lower 4 bits were separated. Next, the JBIG compression method was used in separated top 4-bitplane because of a lot of correlation between bits. And a separated lower 4-bitplane was applied the improved method that using the H. 264 lossless prediction. A pre-processing method applied to the lower 4-bitplane then irregular distribution of pixel values are converted to regular. Using the proposed method to test for various test images were performed. Experimental results from a printer using 8-bit image compared to JBIG average 19%, lower 4bit image compression performance with an average of 11% could be obtained.

• Journal of Satellite, Information and Communications
• /
• v.8 no.2
• /
• pp.88-93
• /
• 2013

The wideband chirp signal generator to enhance the resolution of synthetic aperture radar of obtaining the earth observation image is needed. This paper deals with designing, manufacturing and testing the wideband digital chirp signal generator having high resolution for LEO earth observation satellite. The wideband digital chirp signal generator is implemented with the memory-map based structure which is mostly applied in the satellite, and consists of the digital module to generate the digital chirp signal and the RF module to perform the quadrature modulation. The I/Q signals stored in the memory of the digital module are D/A converted and delivered to be quadrature modulated with the reference signal of 1275 MHz in the RF module. Furthermore, the test bench and GUI to validate the signal generator function are also developed. It is found that the requirement of 144 MHz bandwidth for the digital chirp signal generator is well met. Finally it is noteworthy that the distortion occurred in the chirp signal generator was compensated by the pre-distortion compensation.

• Journal of Fashion Business
• /
• v.12 no.5
• /
• pp.94-110
• /
• 2008

The main objective of this research was to understand the characteristics of separation color coordination of contemporary female fashion through the analysis of 'pre-a-porter Collections' of four collections (i. e. cities) - Paris, Milan, New York, London - from the periods of 2004 S/S to 2008/9 A/W. The data collection of 265 was done by reviewing 'pre-a-porter Collections' magazine and total 265 observations were made. Statistical analysis of frequency and also qualitative interpretation of separation color coordination characteristics were completed. The main findings were; (1) In separation color coordination of contemporary women's fashion collections, there were three main types of color scheme which were classified into seven detailed categories of color combination. First was the achromatic color & one chromatic separation color scheme which was classified into four categories of - black & white, black & grey, white & grey, and grey & grey - color combination. Second was the chromatic colors & one achromatic separation color scheme which classified into two categories of achromatic & chromatic color & one achromatic separation color combination, and chromatic colors & one achromatic separation color combination. Third was chromatic colors and one chromatic separation color combination. (2) The achromatic colors and one chromatic separation color scheme showed two phases of reinforcing the strong and modern image, or softening the hard and dull image of achromatic color combination. In color schemes which used more than two chromatic colors, the separation color frequently converted the tedious and monotonous fashion image, which caused by identical or similarity in color or tone harmony, into more attractive and interesting. (3) In conclusion, through the various use and coordination of various color schemes, color harmony and separation colors, the separation color coordination in contemporary female fashion has been suggested the effective way of color combination which can lead the visual pleasure and the vitality along with the unity and the harmony. This characteristics can create various images and visual diversity for fashion. The types and the use of color scheme and separation color showed different trends in four collections.

• Journal of Korean Neurosurgical Society
• /
• v.60 no.5
• /
• pp.550-559
• /
• 2017

Objective : Subsidence is a frequent complication of anterior cervical discectomy and fusion. Postoperative segmental micromotion, thought to be a causative factor of subsidence, has been speculated to increase with uncinate process resection area (UPR). To evaluate the effect of UPR on micro-motion, we designed a method to measure UPR area based on pre- and postoperative computed tomography images and analyzed the relationship between UPR and subsidence as a proxy of micro-motion. Methods : We retrospectively collected clinical and radiological data from January 2011 to June 2016. A total of 38 patients (53 segments) were included. All procedures included bilateral UPR and anterior plate fixation. UPR area was evaluated with reformatted coronal computer tomography images. To reduce level-related bias, we converted UPR area to the proportion of UPR to the pre-operative UP area (pUPR). Results : Subsidence occurred in 18 segments (34%) and positively correlated with right-side pUPR, left-side pUPR, and the sum of bilateral pUPR (sum pUPR) (R=0.310, 301, 364; p=0.024, 0.029, 0.007, respectively). Multiple linear regression analysis revealed that subsidence could be estimated with the following formula : $subsidence=1.522+2.7{\times}sum\;pUPR$($R^2=0.133$, p=0.007). Receiver-operating characteristic analysis determined that sum $pUPR{\geq}0.38$ could serve as a threshold for significantly increased risk of subsidence (p=0.005, area under curve=0.737, sensitivity=94%, specificity=51%). This threshold was confirmed by logistic regression analysis for subsidence (p=0.009, odds ratio=8.471). Conclusion : The UPR measurement method confirmed that UPR was correlated with subsidence. Particularly when the sum of pUPR is ${\geq}38%$, the possibility of subsidence increased.

• Journal of Industrial and Engineering Chemistry
• /
• v.67
• /
• pp.358-364
• /
• 2018

An isotropic pitch precursor for fabricating carbon fibres was prepared by co-carbonization of ethylene bottom oil(EBO) and polyvinyl chloride (PVC). Various pre-treatments of EBO and PVC, and a high heating rate of $3^{\circ}C/min$ with no holding time, were evaluated for their effects on the oxidative stabilization process and the mechanical stability of the resulting fibres. Our stabilization process enhanced the volatilization, oxidative reaction and decomposition properties of the precursor pitch, while the addition of PVC both decreased the onset time and accelerated the oxidative reaction. Aliphatic carbon groups played a critical role in stabilization. Microstructural characterization indicated that these were first oxidised to carbon-oxygen single bonds and then converted to carbon-oxygen double bonds. Due to the higher heating rate and lack of a holding step during processing,the resulting thermoplastic fibers did not completely convert to thermoset materials, allowing partially melted, adjacent fibres to fuse. Fiber surfaces were smooth and homogeneous. Of the various methods evaluated herein, carbon fibers derived from pressure-treated EBO and PVC exhibited the highest tensile strength. This work shows that enhancing the naphthenic component of a pitch precursor through the co-carbonization of pre-treated EBO with PVC improves the oxidative properties of the resulting carbon fibers.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.5
• /
• pp.600-608
• /
• 2020

Machine learning constructs an objective function from learning data, and predicts the result of the data generated by checking the objective function through test data. In machine learning, input data is subjected to a normalisation process through a preprocessing. In the case of numerical data, normalization is standardized by using the average and standard deviation of the input data. In the case of nominal data, which is non-numerical data, it is converted into a one-hot code form. However, this preprocessing alone cannot solve the problem. For this reason, we propose a method that uses ontology to normalize input data in this paper. The test data for this uses the received signal strength indicator (RSSI) value of the Wi-Fi device collected from the mobile device. These data are solved through ontology because they includes noise and heterogeneous problems.

• Industrial Engineering and Management Systems
• /
• v.11 no.2
• /
• pp.188-195
• /
• 2012

This paper presents a new mode of expressing a 3D assembly work for creating a 3D CG animation without judgment by human from minimal required information. In the field of manufacturing, there are favorable movements in the utilization of 3D CAD for 3D simulation to shorten lead time for product development and pre-production. But simulating an assembly work has troubles to need huge quantity of manually input data. This paper discusses what minimal necessary information for creating 3D CG animations of assembly works is, focusing on the features of assembly works. Furthermore, a new mode of expressing a 3D assembly work is proposed as "state/change transition diagrams" (SCTD), which express arbitrary scenes in an assembly work as "state" and describe a sequential assembly work with "state" and "change", and the outline of its stepwise generation algorithm is also described. SCTD can be converted to a 3D CG animation of an assembly work without judgment by human. This paper focuses on the creating 3D CG animation of assembly works which workers use only their both hands.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.24 no.6
• /
• pp.685-690
• /
• 2011

This paper describes a seismic analysis of chemical pump using automated mesh generation system. The use of an automated analysis system, involving FE codes together with CAD systems and FE pre- and post-processors, has provided an important step towards shortening the design process and structural optimization. The FE model, which is a FE mesh accompanied with the analysis condition, is automatically converted from the analysis model. The FE models are then automatically analyzed using the FE analysis code. This integrated FE simulation system is applied to an analysis of three-dimensional complex solid structures such as a chemical pump.