• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.236-237
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• 2021

In the waterproofing of the rooftop of reinforced concrete buildings, it is difficult to solve perfectly according to the proficiency of waterproofing materials, methods, and mechanics. Therefore, this study applies a Tricot Fabric Mesh to the behavior of the bottom concrete. In addition, it responds to the behavior of the concrete cracking, and the waterproofing and protective layer has developed a method to provide convenience for rooftop floor use by adhesion between the base and the waterproof layer with the use of high viscosity urethane to effectively move the surface deformation and surface vapor and install a airvent device on the wall.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.3
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• pp.389-396
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• 2008

The hybrid model can be used to predict the initial near field mixing and the far field transport of the buoyant jets, which are discharged from the submerged wastewater ocean outfall. In the near field, the jet integral model can be used for single port diffusers while the ${\sigma}$ transformed particle tracking model was used in the far field. In this study, the experimental study was performed to verify the developed hybrid model in the previous research. The developed hybrid model properly predict the surface and vertical concentration distribution of the single buoyant jets with various effluent and ambient conditions. The hybrid model can also simulate the surface concentration distribution of the rosette diffuser except for the parallel diffuser with the higher densimetric Froude number due to the assumption that dynamic effects of the effluent plumes are negligible in the far field. The application of the hybrid model to rosette diffusers can predict the concentration near the diffuser more accurately when the line-plume approximation is used.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.9C
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• pp.581-588
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• 2011

In this paper, we propose a novel unambiguous code tracking scheme for cosine phased binary offset carrier (BOC) signals. We first obtain the sub-correlation functions composing the BOC autocorrelation function, and then, re-combine the sub-correlation functions generating a correlation function with no side-peak. Finally, by using the correlation function with no side-peak in the delay lock loop, the proposed scheme performs unambiguous signal tracking. Numerical results demonstrate that the proposed scheme provides a performance improvement over the conventional unambiguous scheme in terms of the tracking error standard deviation (TESD).

• Applied Microscopy
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• v.29 no.4
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• pp.451-457
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• 1999

Ultrastructure of adult Drosophila ocellus was compared with conventional electron microscopic method and osmium impregnation. When osmium impregnation was applied, some organelles of cells were strongly stained. Especially, subrhabdomeric cisternae (SRC) were strongly stained and showed network-iike structure as in compound eye. Other organelles including SSC, ER, nuclear envelope, pigment granules and mitochondria were also strongly stained. These organelles are known as a general calcium ion reservoir. In conclusion, the strong effect of light and shade by osmium impregnation was regarded as a result of strong binding between calcium ion and osmium tetroxide. Thus, we agree to the opinion that osmium impregnation is very useful methods to the comparative morphology of cell organelles.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.1
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• pp.67-73
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• 2008

The most common method of pipeline inspection is to use a remote-controlled-machine equipped with a CCTV, which, however, has many limitations to accurately inspect pipeline condition. In case of a typical CCTV, since the camera looks at the end point of the pipe, the locations of the defects and distance-readings are often different. In addition, the quality and accuracy of the inspection is highly dependent on the operator's skill and experience. In this research a new system is developed by use of the image processing techniques and the lens combination. The image acquisition system is developed that acquires the front and the side view of the pipe simultaneously. Side view unwrapping and stitching technology using image process techniques are developed which delivers high resolution image data.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.9
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• pp.888-895
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• 2004

This paper proposes new miniaturization method of parallel coupled line filter by using capacitors and grounding. Proposed method can reduce resonator size by using only a small number of capacitor and grounding of parallel coupled line filter which is conventional in field of RF filters because of its design and fabrication simplicity. This paper applies the miniaturization method of transmission line and parallel coupled line to parallel coupled line filter, and presents that grounding can reduce the number of shut capacitors. Presented miniaturized method has merits of miniaturization of parallel coupled line, harmonic suppression, and improvement of high frequency skirt with harmonic suppression. For verification of proposed method, this paper presents a hairpin filter, which has 900 MHz center frequency and 10 % FBW, miniaturized to λ/4 by proposed method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.2
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• pp.156-164
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• 2019

In this paper, we propose an efficient dynamic slot re-assignment scheme for swarming drone networks in which networks members merged and split frequently. The leader drone of each network recognizes the slot allocation information of neighbor networks by periodic information exchange among between the drones. Using the information, the leader drone makes a decision how to reallocate the slots between members in case of network merge. The non-competitive method in the proposed scheme can re-assign the slots without any slot collision and shows always superior performance than competitive scheme. The competitive method in the proposed scheme reduces the number of slots that should be re-assigned in case of network merge. The experimental performance analysis shows that the proposed scheme performs better or at least equal to the performance of the competitive scheme in a swarming drone network.

• Korean Journal of Food Science and Technology
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• v.11 no.4
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• pp.291-297
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• 1979

The experimentally cultivated potatoes of 4 varieties, Irish Cobbler, Warba, Shimabara, and Saco were dried in a frozen state, powdered subsequently and subjected to the extraction of free and bound lipids. Constituents of the prepared lipids were fractionated, quantified, and compared by the methods of column and gas-liquid chromatographies. The results were summarized as follows : 1. The total crude lipid content in potato on a dry weight basis was 0.57 % of which 0.2 % was free lipid and 0.37 % was bound lipid. 2. The neutral lipid content in the free lipid was 14.9 %, approximately 3 times as much as the 4.5 % contained in the bound lipid, whereas the glycolipid content in the free lipid was 15.1 %, slightly less than 22.2 % contained in the bound lipid. However, the phospholipid content was 33.9 % in the bound lipid, approximately 4.5 times as much as the 7.2 % contained in the free lipid. This fact revealed that the bound lipid consisted mainly of polar lipid, while the free lipid consisted of neutral lipids, glycolipids and phospholipids in about the same proportion. 3. The main fatty acids constituting more than 90 % in the free and bound lipids were linoleic, palmitic and linolenic acids. The content of the saturated fatty acid was slightly less in the free lipid than in the bound lipid, whereas the unsaturated fatty acids were more abundant in the free lipid.

• Journal of the Korean Society of Propulsion Engineers
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• v.1 no.1
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• pp.33-45
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• 1997

Axisymmetric shear layers around a free jet is forced by co-flowing and counter-flowing secondary jets from/to an annular tube around the jet nozzle. The jet potential core extends far downstream with co-flowing secondary jets due to inhibited vortex developing and pairing. For counter-flowing cases, the axisymmetric shear layer around the jet transits from convective instability to absolute instability for velocity ratios R＝1.3～l.65 for the uniform velocity jets. Consequently, the jet potential core length increases and the turbulence level in the jet core is reduced significantly. The jets are controlled better with extension collars attached to the outer nozzle exit because the annular secondary flow is guided well by the extension collars. For the vectoring of jet, the annular tube around the jet is divided in two parts and the only one part is used for suction. The half suction makes the different shear layer around the jet and vectoring the jet by Coanda effect. The vectoring and turbulent components are varied significantly by the suction ratio. The experiments are carried out to investigate the characteristics of forced free jets using flow visualization, velocity and turbulence measurements.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.2
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• pp.177-186
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• 2002

This paper describes the magnetic flux leakage(MFL) type non-destructive testing(NDT) system to detect the 3D defects in underground gas pipe. Magnetic systems with permanent magnets and yokes are analyzed by 3D non-lineal finite element method(FEM) with optimum design. In case of under-saturation of gas pipe, sensing signals are too weak to detect. In case of over-saturation, the changes of the sensing signals are too low to detect the defects sensitively. So, the operating points of the magnetic system are optimized to increase the changes of the MFL signals. The effects of the depth and size of the defects on the sensing signals are analyzed to define the range and resolution of the MFL sensors. To increase the sensor's sensitivity, the back-yoke sensors are introduced and tested.