• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.3
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• pp.235-244
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• 2007

In the case of the fire outburst within a partitioned space, it can disappear inside it through smoldering process if the fire cannot obtain sufficient imflammability. On the contrary, if it obtains it, the fire is not restricted within the room, spreading to the higher levels beyond outside windows and the compartment room. The method to prevent the fire spread through windows is considered to build a balcony or equip with sprinkler facilities. This case study is to identify which effects and controlibility a balcony brings about on the spread of fire through a full scale model experiment. In order to understand the effects of fire spread on the upper levels of the room on fire by changing the length of balcony, the temperature was measured, radiant heat was investigated, and products of combustion were analyzed. The result showed that when fire occured, longer length of the balcony, which linked to the outside wall of the apartments, led to the blocking of the fire spread, lower level of radiant heat, and significantly less transfer of toxic gases, and the driving force of the outburst of flame was identified as the attractive force due to the turbulence of uncombusted gases, which exist on the upper level of the outbursting flame.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.1
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• pp.46-56
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• 2017

Recently, the spread of IoT technology has been spreading, and it has been applied to all industrial fields such as home / home appliance / medical care. Due to the low specification, low power consumption characteristic and communication data characteristic of IoT, implementation of existing algorithm is difficult thing. From this reason, we have proposed for the first time that encryption and decryption can be proceeded by introducing a kind of variable length bit XOR operation method which changes a variable the bit length value by using carry up and carry down method. We confirmed the practicality of encrypting short message data frequently processed by IoT device / QR code / RFID / NFC without changing the size of data before and after encryption.

• Applied Microscopy
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• v.20 no.2
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• pp.57-70
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• 1990

Characterization and electron microscopic visualization of the plasmid and the gene expression of Escherichia coli were carried out. Transcriptional units of active structural genes were observed after lysis of Escherichia coli cells. The ribosomes attached to the E. coli genome on mRNA molecule as polyribosomes. From this gradient of polyribosome length, we estimated location of mRNA synthesis initiation site. In this experiment, a granule is ofen present which may correspond to a RNA polymerase at the promoter site. pOX1, pOX7, pOX7A, $pOX7{\Delta}1$, pSTP36, pSTP21, pBR322, and pJH12 were visualized by way of electron microscope, and their estimated sizes were determined to be $5.70{\pm}0.08{\mu}m,\;2.15{\pm}0.10{\mu}m,\;2.14{\pm}0.12{\mu}m,\;7.39{\pm}0.08{\mu}m,\;4.03{\pm}0.04{\mu}m,\;1.50{\pm}0.03{\mu}m\;and\;1.25{\pm}0.09{\mu}m$ respectively. One micrometer of measured length corresponded to about 3.0 Kb. Mica-press adsorption method that allows selectivs visualization of the plasmid DNA released in situ from the bacterial cell is rapid and useful for visualization of plasmids. The released plasmid DNA was adsorbed preferently on mica in a divalent cation-free solution. Miller chromatin-spreading method was useful to observe the plasmid and transcripts. BAC method and cytochrome C monolayer were useful to observe the plasmid DNA. Our ability to visualize ultrastructural aspects of the expression of E. coli has given us a unique tool with which to study the regulation the level of an individual gene.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.4
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• pp.310-319
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• 2019

Although mud shrimp (Upogebia Major) provides benefits on the tidal flat ecosystem, it is causing the mass mortality of Manila clam (Tapes philippinarum) and large economic loss to the aquaculture farmer due to spreading in the entire coastal clam farm area of the West Sea of Korea. In this study, a mud shrimp blocking box for cultivating clam was tested to prevent the mud shrimp from invading the habitat of the clam. To determine the effect of the blocking box, the growth characteristics of the clams under various culture conditions were investigated. The shell length, total weight, condition index, the presence of mud shrimp in the box, and the soil decay in the box were examined according to whether the clams were raised in the box or in natural state, whether the box is covered with a net or not and the gap size of the box. As a result, no significant differences in shell length, total weight, and condition index were found between the clam grown in the box and the natural state (P>0.05) without any evidence of invading of mud shrimp to the box. In addition, the soil inside the box was in good condition, not decayed. Therefore, using the mud shrimp blocking box, mud shrimp can be prevented from propagating to the habitat of the clam, thereby contributing to the normal production of the clam and thus to restoring the clam farming.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.4
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• pp.318-321
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• 2006

This study was conducted in 2002 and 2003 to investigate variation on rice quality associated with cooking, and eating qualities under the three different fertilizer levels, none fertilizer level($N-P_2O_{5-}K_2O=0-0-0kg/ha$), ordinary fertilizer level($N-P_2O_{5-}K_2O=1l0-45-57kg/ha$), and heavy fertilizer level($N-P_2O_{5-}K_2O=180-90-110kg/ha$). The eight resistant near-isogenic lines(NILs) for bacterial blight in rice were examined for grain appearances, several physicochemical properties, and palatability value measured by Toyo taste meter. Significant variations in NILs(V), Years(Y), and VxY interaction were recognized in grain length and palatability value under the none fertilizer cultivation, in grain width under the heavy fertilizer cultivation, and in white belly ratio under the three different fertilizer cultivations, respectively. According to increase the fertilizer application rate, variation in grain length and grain width were not significant, but grain thickness was thinner under the ordinary and heavy fertilizer cultivations than under the none fertilizer cultivation. On the other hand, white belly ratio, protein content and Mg/K ratio increased, while amylose content and palatability value lowered. Alkali spreading value lowed under the heavy fertilizer cultivation than under the none and ordinary fertilizer cultivations. Palatability value was significantly low in the line carrying XalJ than in the other lines under the ordinary fertilizer cultivations.

• Macromolecular Research
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• v.8 no.6
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• pp.276-284
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• 2000

A wettability chemogradient on poly(L-lactide-co-glycolide) (PLGA) films was prepared by treating the films in air with corona from a knife-type electrode whose power increases gradually along the sample length. The PLGA surfaces oxidized gradually with the increasing corona power, and the wettability chemogradient was created on the surfaces as evidenced by the measurement of water contact angles and electron spectroscopy for chemical analysis. The wettability chemogradient PLGA surfaces were used to investigate the interaction of four different types of cells such as hepatoma (Hep G2), osteoblast (MG 63), bovine aortic endothelial (CPAE), and fibroblast (NIH/3T3) cells in terms of the surface hydrophilicity/hydrophobicity of PLGA. The cells adhered and grown on the chemogradient surface along the sample length were counted and observed by scanning electron microscopy. It was observed that the cells were adhered, spread, and grown more onto the positions with moderate hydrophilicity of the wettability chemogradient PLGA surface than the more hydrophobic or hydrophillic positions, regardless of the cell types used. The maximum adhesion and growth of the cells appeared at around water contact angles of 53～55°. This result seems closely related with the serum protein adsorption on the surface; the serum proteins were also adsorbed more onto the positions with moderate hydrophilicity of the wettability chemogradient surface. It seems that the wettability plays important roles for cell adhesion, spreading and growth on the PLGA surface. The surface modification technique used in this study may be applicable tothe area of tissue engineering for the improvement of tissue compatibility of films- or scaffold-type substrates.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.2
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• pp.42-54
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• 2021

The Aft-deck is being applied to the latest unmanned aircraft for the purpose of shielding the gas turbine exhaust plume or spreading jets to increase the mixing rate with the ambient air, thereby reducing the temperature of exhaust gases. In this study, we would like to find out how the performance of the nozzle is affected by the design variables of the Aft-deck. The design variables of aft-deck are selected as length, expansion angle and upper deck shape. The correlation between thrust and plume shielding rate with the length variable is presented. And the correlation between the thrust and the jet diffusion range is presented according to the expansion angle. In addition, the thrust increase effect is confirmed by the removal of the upper deck and the characteristics of transverse velocity vector determined mixing performance with external flow.

• Korean Journal of Plant Resources
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• v.32 no.6
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• pp.644-668
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• 2019

Dysphania ambrosioides (L.) Mosyakin & Clemants which belongs to Chenopodiaceae/Amaranthaceae sensu in APG system has been known as a useful plant in various fields as well as an invasive species spreading all over the world. To understand its phylogenetic relationship with neighbour species, we completed chloroplast genome of D. ambrosioides collected in Korea. Its length is 151,689 bp consisting of four sub-regions: 83,421 bp of large single copy (LSC) and 18,062 bp of small single copy (SSC) regions are separated by 25,103 bp of inverted repeat (IR) regions. 128 genes (84 protein-coding genes, eight rRNAs, and 36 tRNAs) were annotated. The overall GC content of the chloroplast genome is 36.9% and those in the LSC, SSC and IR regions are 34.9%, 30.3%, and 42.7%, respectively. Distribution of simple sequence repeats are similar to those of the other two Dysphania chloroplasts; however, different features can be utilized for population genetics. Nucleotide diversity of Dysphania chloroplast genomes 18 genes including two ribosomal RNAs contains high nucleotide diversity peaks, which may be genus or species-specific manner. Phylogenetic tree presents that D. ambrosioides occupied a basal position in genus Dysphania and phylogenetic relation of tribe level is presented clearly with complete chloroplast genomes.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.409-413
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• 2005

Even though the relative importance of length scale of flow system allow us to simplify three dimensional flow problem to one or two dimensional representation, many systems still require three dimensional analysis. The objective of this study is to develop an efficient and accurate finite element model for analyzing and predicting three dimensional flow features in natural rivers and to offend to model spreading of pollutants and transport of sediments in the future. Firstly, three dimensional Reynolds averaged Navier-Stokes equations with the hydrostatic pressure assumption in generalized curvilinear coordinates were combined with the kinematic free-surface condition. Secondly. to simulate realistic high Reynolds number flow, the model employed the Streamline Upwind/Petrov-Galerkin(SU/PG) scheme as a weighting function for the finite element method in conjunction with an appropriate turbulence model(Smagorinsky scheme for the horizontal plain and Mellor-Yamada scheme for the vertical direction). Several tests is performed for the purpose of validation and verification of the developed model. A simple rectangular channel, 5-shaped and U-shaped channel are used for tests and comparisons are made with RMA-10 model. Runs for each case is converged stably without a oscillation and calculated water-surface deformation, longitudinal and transversal velocities, and velocity vector fields are in good agreement with the results of RMA-10 model.

• Journal of Advanced Navigation Technology
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• v.14 no.1
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• pp.49-56
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• 2010

Severe energy constraints and the low power consumption require the significance of the energy efficient error control mechanisms in wireless sensor network (WSN). In this paper, an automatic repeat request (ARQ) methodology for the analysis of error control schemes in WSN is presented such that the effects of packet length, the modulation scheme and the interference effect of the wireless channel are investigated. Moreover, an analyis of ARQ error control is provided by considering two major architectures for wireless sensor network, i.e., Mica2 and MicaZ sensor nodes. And the throughput performance of WSN with asynchronous FSK signal and DSSS-OQPSK signal with selective repeat ARQ scheme are analyzed in multiple interference environment, and the probability of receiving a correct bit and packet from target node to sink node is evaluated as a function of the channel parameter, the number of wireless sensor node, and the spreading factor.