• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.463-467
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• 2004

Rosette-type diffusers with four-ports per riser are constructed in relatively shallow water in Korea. However, the trajectorial bending phenomena due to lower-pressure inside the surrounded buoyant jets on the riser was not considered in most models and was not observed without any experimental results. The buoyant jet behavior affected by the bending effect where there have been growing interests need to be verified experimentally and need to be preceded in the analysis of the characteristics of the buoyant jets oil a riser. The hydraulic model experiments have been carried out to investigate the characteristics of the behavior of horizontal buoyant jets discharged from a Rosette-type riser with four ports as well as single port over a certain range of the experimental conditions including initial momentum and initial buoyancy using LIF (Laser Induced Fluorescence) system to obtain concentration fields. The intensity of the fluorescent light in each pixel on the images obtained from LIF system with the tracer of Rhodamine H was converted to the local dye concentration with a set of calibration procedures to account for the non-uniform distribution of light intensity and the attenuation of light energy by water medium. The experimental results shows that the trajectories from Your ports tend to bend more and more to the inner side with the increase of the densimetric Froude number while the buoyant jet from a single port rises up without any bending phenomena. The previous models, VISJET and Seo et al. (2002), do not simulate the trajectories well except the region before the bending section. This study will focus on the analysis of the behavior of the buoyant jets for mainly a Rosette-type riser by conducting hydraulic model experiments using LIF system.

• Korean Journal of Materials Research
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• v.9 no.9
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• pp.890-895
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• 1999

The recent important issue in solar cell fabrication is to adopt thin film silicon solar cells on cheap substrates. However, thin cells demand new grid design concept that all the contacts(to the emitter and base) be located on the front surface. Hence, the aim of the investigation presented in this paper was to determine the potential and the basic limitation of the design. With this concept, an interdigitated front grid structure was realized and cells were fabricated through a set of photolithography processes. Confirmed efficiencies of up to 11.5% were achieved on bonded SOI wafers with a cell thickness of 50$\mu\textrm{m}$ in the case of finger spacing more than $\mu\textrm{m}$ and a base width of 35$\mu\textrm{m}$. It was also shown from the results that the design rules for optimizing the base fraction and reducing the shadowing fraction are noted as an important technique to realize high-efficiency thin silicon solar cells.

• Journal of the Institute of Convergence Signal Processing
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• v.13 no.3
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• pp.119-129
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• 2012

In the medical field, the hardening of tissues is one of important informations used in diagnosis or understanding progress of disease, a quantitative measuring method of hardening is important for objective diagnosis. It has been proposed MRE(Magnetic Resonance Elastography) method that measures an index of hardening, viscoelastic properties in a noninvasive. Because the S/N ratio of MRE images go down when measuring viscoelastic properties from local wavelength and local damping factor of a propagating wave in MRE method, methods using multiple phase MRE images have been examined to decrease the effect of noise. We propose a method measuring viscoelastic properties after Fitting a function for multiple phase MRE images in this research. This proposed method has a advantage to set up arbitrarily the variation rate of a space direction of viscoelastic properties or the spatial resolution of measuring values according to changing of the noise included in images, though it applies viscoelastic wave for multiple phase MRE images. We confirmed the effectiveness of a proposed method by experiment using simulation images and experiment using silicone-gel phantom.

• Journal of Biosystems Engineering
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• v.19 no.2
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• pp.124-137
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• 1994

Visual features of a mushroom(Lentinus Edodes, L.) are critical in grading and sorting as most agricultural products are. Because of its complex and various visual features, grading and sorting of mushrooms have been done manually by the human expert. To realize the automatic handling and grading of mushrooms in real time, the computer vision system should be utilized and the efficient and robust processing of the camera captured visual information be provided. Since visual features of a mushroom are distributed over the front and back sides, recognizing sides and states of the stalk including the stalk orientation from the captured image is a prime process in the automatic task processing. In this paper, the efficient and robust recognition process identifying the front and back side and the state of the stalk was developed and its performance was compared with other recognition trials. First, recognition was tried based on the rule set up with some experimental heuristics using the quantitative features such as geometry and texture extracted from the segmented mushroom image. And the neural net based learning recognition was done without extracting quantitative features. For network inputs the segmented binary image obtained from the combined type automatic thresholding was tested first. And then the gray valued raw camera image was directly utilized. The state of the stalk seriously affects the measured size of the mushroom cap. When its effect is serious, the stalk should be excluded in mushroom cap sizing. In this paper, the stalk removal process followed by the boundary regeneration of the cap image was also presented. The neural net based gray valued raw image processing showed the successful results for our recognition task. The developed technology through this research may open the new way of the quality inspection and sorting especially for the agricultural products whose visual features are fuzzy and not uniquely defined.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.47 no.2
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• pp.139-145
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• 2011

Hydro-acoustic survey was carried out to estimate a fish distribution at marine ranching area and aggregated fish schools at artificial reef area in Oeyeondo, Korea. The survey system was set up with DGPS system, scientific echo sounder (EK60, Simrad Co.), and ECDIS (Mecys. Co. LTD). A track survey and a random survey was respectively applied to the marine ranching area (474.4ha) and to the artificial reef area (within a radius of 300m). As the result, fish distribution and MVBS values in marine ranching area showed that created fisheries resources didn't come to be abundant yet as to appear fish distribution in all of the area. In the artificial reef area, it was, however, able to detect many fish school signals on the top of and around artificial reefs and to confirm the luring effect of artificial reefs.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.189-194
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• 2006

The internal construction industry is not situation of cost reduction based on low wages anymore by the increase in wages as insufficient supply of stilled workers. Recently remodeling constructions that only need to change facilities as to stay the existing structures are on the increase. Now the method of piping facility used to remodeling construction needs stilled workers, large work space and a variety of tools. These complex construction process have a difficulty of high-quality and economical construction. In addition it have the hish incidence of warranty and a problem of cost increase as a commitment of manpower by warranty repair. In order to solve these problems it is necessary for appropriate new technology to the internal construction environment. Piping fittings by Insert & Coupling Joint is a method that unskilled workers can be easily constructed though one touch set up and it is convenient to maintain for repair work of piping facility. This technology show the effect of 3 percentages labor cost reduction as compared with piping fittings by press joint on apartment 500 households. Therefore this technology is supposed that attain a cost reduction though the technical and economical construction and a client satisfaction though the high-quality construction on the present construction market.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.2
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• pp.258-273
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• 2012

The purpose of this study is to analyze the effectiveness of the community development by the community involvement level of the corporate social contribution activities. This study classified Korean company's best social contribution activities according to the community involvement level and the effectiveness of the community development was analyzed on selected case activities. As a result, corporations that working on high level of community involvement show positive effectiveness of community development. Networking and communication with local people on the corporate social contribution activities have an effect on the community development of the economy, safety, convenience, comfortability, socio-cultural factor. It is necessary for the participation and communication with local people to develop corporate social contribution consistently. Furthermore, intermediary organization is needed to be set up various networks of stakeholders, especially community.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.9
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• pp.89-96
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• 2005

This paper discusses the daytime atmospheric conditions and the possibility of daytime star detection with the purpose of practical use of the star sensor for daylight navigation. In order to estimate the daytime atmospheric data, we use the standard atmospheric model (LOWTRAN 7), from which atmospheric transmittance and radiance from background sky are calculated. Assuming the star sensor with an optical filter to reduce background radiation, different separation angles between the star sensor and the sun are set up to express the effect of the solar radiation. As considerations of field of view (FOV) of the star sensor, the variation of the sky background radiation and the star density of the detectable star are analyzed. In addition, the integration time to achieve a required signal-to-noise ratio and the number of the radiation-caused electrons of the charge coupled detector(CCD) working as the limit to daylight application of the star sensor are calculated.

• Journal of the Korea Society of Computer and Information
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• v.13 no.4
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• pp.273-280
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• 2008

This paper is thing for a quantitive quality evaluation in national Defense Human Resource Management Information S/W system development. Apply a quantitive quality evaluation way to be based on an international standard to admonish at ISO/IEC 9126. Proposed 6 basis of count, and set up sub 27 items detailed functionality, reliability, use anger, efficiency, maintenance anger, a transplant result, and inspection of quality table wrote the Matrix measured S/W quality to a chart. Studied a quantitive evaluation plan of a Defense Human Resource Management Information S/W system to see weight by the priority order that reflected a characteristic of a national defense business to a Purpose of a subject user, and Presented. It is 80% in quantitive quality evaluation application satisfied under 8, Very Satisfied 7(87.5%) Satisfied 1(12.5%) of Defense Human Resource Managers and judgment worked as marked so that satisfaction of reliability and a user regarding functionality was high and there will be contribute to an elevation of defense capabilities as analyze efficient national defense S/W use and effect.

• PNF and Movement
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• v.14 no.2
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• pp.83-91
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• 2016

Purpose: The purpose of this study was both to examine the effects of proprioceptive neuromuscular facilitation (PNF) lower leg taping and treadmill training on the gait and balance abilities of patients with hemiplegia resulting from a stroke and to provide a taping method based on the PNF concept. Methods: Twenty patients with hemiplegia resulting from a stroke were randomly and equally assigned to a control group (n=10), which received treadmill training, and to an experimental group (n=10), which received PNF lower leg taping and treadmill training. The intervention was conducted five times per week for six weeks. In order to measure changes in the gait ability of the subjects, a 10-meter walking test (10MWT) and a 6-minute walking test (6MWT) were conducted, and in order to measure changes in the subjects' balance ability, a timed up and go test (TUG) was performed. In order to compare differences within each group before and after the intervention, a paired-t test was carried out, and in order to compare differences between the two groups, the analysis of covariance was utilized. All statistical significance levels were set at ${\alpha}=0.05$. Results: There were significant differences before and after the intervention within both groups in changes of 10MWT, 6MWT, and TUG (p<0.01). Regarding differences between the two groups, the experimental group underwent more effective changes than the control group in 6MWT and TUG (p<0.05). Conclusion: This study applied PNF lower leg taping and treadmill training to patients with hemiplegia resulting from a stroke, and this resulted in improvement in the subjects' gait and balance abilities. Taping and treadmill training based on the PNF concept is considered to be usefully applied as one of the programs to improve hemiplegic patients' gait and balance abilities.