• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.347-350
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• 2004

A space radiation analysis has been used to evaluate an ability of electronic equipment boxes or spacecrafts to endure various radiation effects, so it helps design thicknesses of structure and allocate components to meet the radiation requirements. A comparison study of space radiation dose analysis programs SPENVIS Sectoring Tool (SST) and SIGMA II is conducted through some structure cases, simple sphere shell, box and representative satellite configurations. The results and a discussion of comparison will be given. A general comparison will be shown for understanding those programs. The both programs use the same strategy, solid angle sectoring with ray-tracing method to produce an approximate dose at points in representative simple and complex models of spacecraft structures. Also the particle environment data corresponding to mission specification and radiation transport data are used as input data. But there are distinctions between them. The specification of geometry model and its input scheme, the assignment of dose point and the numbers, the prerequisite programs and ways of representing results will be discussed. SST is a web-based interactive program for sectoring analysis of complex geometries. It may be useful for a preliminary dose assessment with user-friendly interfaces and a package approach. SIGMA II is able to obtain from RSICC (Radiation Safety Information Computational Center) as a FOR-TRAN 77 source code. It may be suitable for either parametric preliminary design or detailed final design, e.g. a manned flight or radiation-sensitive component configuration design. It needs some debugs, recompiling and a tedious work to make geometrical quadric surfaces for actual spacecraft configuration, and has poor documentation. It is recommend to vist RSICC homepage and GEANT4/SSAT homepage.

• The Journal of the Korea Contents Association
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• v.6 no.7
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• pp.90-98
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• 2006

Digital watermarking is a technique embedding hidden information into multimedia data imperceptibly such as images and sounds. Generally an original image is transformed and coded watermark data is embedded in frequency domain watermarking models. In this paper, We propose a new color image watermarking technique using Fresnel transform. A watermark image is Fresnel - transformed and the intensity of transformed pattern is embedded into color image. In our watermarking model, an original image is converted from RGB components into YCrCb components and then the values of real number and imaginary number of a Fresnel-transformed pattern of a watermark image are embedded into Y component. The watermarking experiments were conducted to show the validity of the proposed method using PSNR value, and the results show that our method has the robustness against lossy compression like JPEG.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.705-712
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• 2001

It is of great importance to represent the directional ocean waves in a laboratory basin for hydraulic model tests. The directional ocean waves can be expressed as a linear superposition of a large number of component waves with different frequencies and propagating directions. The aim of the study is to check the wave generating characteristics by serpent-type wave generating system in PKNU (Pukyong National University) which is composed of 10 piston-type wave generators. In the experiment, spatial variation of irregular wave heights and propagating angles are measured in the multi-directional wave maker basin. Target wave directional spectrum is reproduced in the area of multi-directional wave maker basin. The directional spreading of the generated waves varied spacially in the basin. They differed from target spectrum as the measurement point becomes far from the center line normal to the generator face, The effective generation area where that target can be reproduced is limited to the triangular area attached the generator face. According to the results, it is emphasized that the effective experiment area in the basin considered wave generator characteristics should be determined in consideration of experimental conditions including structural shapes, water depth, wave directionality etc.

• The Journal of the Korea Contents Association
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• v.15 no.5
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• pp.47-54
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• 2015

The following research analyzes that the level of self-monitoring have an influence on user experience about website. For this research, university students participated in a survey where they evaluated user experience -usability, aesthetics, pleasure- about the new screen images of two homepages of differences in brand recognizability. The "self-monitoring(high/low, except for middle)" and the "brand recognizability(high/low, except for middle)" were set as independent variables and the "usability | deviation |", the "aesthetics | deviation |", the "pleasure | deviation |" were set as the dependent variables. Results, as with new screen images of homepage, there were significant differences in the usability and aesthetics based on the level in self-monitoring. Especially, when level of brand recognizability is low, there was more differences in the usability and aesthetics based on the level in self-monitoring. However, the influence of pleasure on self-monitoring was insignificant.

• Journal of KIISE:Software and Applications
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• v.28 no.12
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• pp.947-954
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• 2001

In this paper, we propose a method for the recognition of various head gestures with automata technique applied to the sequence of facial pose states. Facial regions as detected by using the optimum facial color of I-component in YIQ model and the difference of images adaptively selected. And eye regions are extracted by using Sobel operator, projection, and the geometric location of eyes Hierarchical feature analysis is used to classify facial states, and automata technique is applied to the sequence of facial pose states to recognize 13 gestures: Gaze Upward, Downward, Left ward, Rightward, Forward, Backward Left Wink Right Wink Left Double Wink, Left Double Wink , Right Double Wink Yes, and No As an experimental result with total 1,488 frames acquired from 8 persons, it shows 99.3% extraction rate for facial regions, 95.3% extraction rate for eye regions 94.1% recognition rate for facial states and finally 99.3% recognition rate for head gestures. .

• Journal of Ginseng Research
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• v.42 no.4
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• pp.476-484
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• 2018

Background: Korean Red Ginseng (steamed and dried white ginseng, Panax ginseng Meyer) is well known for enhancing vital energy and immune capacity and for inhibiting cancer cell growth. Some clinical studies also demonstrated a therapeutic potential of ginseng extract for treating lung inflammatory disorders. This study was conducted to establish the therapeutic potential of ginseng saponins on the lung inflammatory response. Methods: From Korean Red Ginseng, 11 ginsenosides (Rb1, Rb2, Rb3, Rc, Rd, Re, Rf, Rg1, Rg2, Rg3, and Rh2) were isolated. Their inhibitory potential and action mechanism were evaluated using a mouse model of lung inflammation, acute lung injury induced by intranasal lipopolysaccharide administration. Their anti-inflammatory activities were also examined in lung epithelial cell line (A549) and alveolar macrophage (MH-S). Results: All ginsenosides orally administered at 20 mg/kg showed 11.5-51.6% reduction of total cell numbers in bronchoalveolar lavage fluid (BALF). Among the ginsenosides, Rc, Re, Rg1, and Rh2 exhibited significant inhibitory action by reducing total cell numbers in the BALF by 34.1-51.6% (n = 5). Particularly, Re showed strong and comparable inhibitory potency with that of dexamethasone, as judged by the number of infiltrated cells and histological observations. Re treatment clearly inhibited the activation of mitogen-activated protein kinases, nuclear factor-${\kappa}B$, and the c-Fos component in the lung tissue (n = 3). Conclusion: Certain ginsenosides inhibit lung inflammatory responses by interrupting these signaling molecules and they are potential therapeutics for inflammatory lung diseases.

• International Journal of Air-Conditioning and Refrigeration
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• v.13 no.1
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• pp.51-60
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• 2005

This paper reviews the studies on the pressure drop and the heat transfer in microchannels. Although a lot of studies about the single-phase flow have been done until now, conflicting results are occasionally reported about flow transition from laminar flow to turbulent flow, friction factor, and Nusselt number. Some studies reported the early flow transition due to relatively greater wall effect like surface roughness, but the other studies showed that the flow transition occurred at the Reynolds number of about 2300 and the early flow transition might be due to less accurate measurement of the channel geometry. Also, there have been arguments whether the conventional relation based upon continuum theory can be applied to the fluid flow and the heat transfer in microchannels without modification or not. The studies about the two-phase flow in microchannels have been mostly about investigating the flow pattern and the pressure drop in rectangular channels using two-component, two-phase flow like air/water mixture. Some studies proposed correlations to predict two-phase flow pressure drop in microchannels. They were mostly based on Lockhart-Martinelli model with modification on C-coefficient, which was dependent on channel geometry, Reynolds number, surface tension, and so on. Others investigated the characteristics of flow boiling heat transfer in microchannels with respect to test parameters such as mass flux, heat flux, system pressure, and so on. The existing studies have not been fully satisfactory in providing consistent results about the pressure drop and the heat transfer in microchannels. Therefore, more in-depth studies should be done for understanding the fundamentals of the transport phenomena in the microchannels and giving the basic guidelines to design the micro devices.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.75-81
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• 2012

Road identification is the important task for extracting a road region from the high-resolution satellite images, when the road candidates is extracted by the pre-processing tasks using a binarization, noise removal, and color processing. Therefore, we propose a noble approach for identifying a road using the orientation-selective spatial filters, which is motivated by a computational model of neuron cells found in the primary visual cortex. In our approach, after the neuron cell typed spatial filters is applied to the isolated connected-labeling road candidate regions, proposed method identifies the region of perceiving the strong orientation feature with the real road region. To evaluate the effectiveness of the proposed method, the accuracy&error ratio in the confusion matrix was measured from road candidates including road and non-road class. As a result, the proposed method shows the more than 92% accuracy.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.6
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• pp.16-25
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• 2009

In this paper we propose the block based image segmentation method using the cyclic properties of hue components in HSI color model. In proposed method we use center point instead of hue mean values as the hue representatives for regions in image segmentation considering hue cyclic properties and we also use directed distance for the hue difference among regions. Furthermore we devise the simple and effective method to get critical values through control parameter to reduce the complexity in the calculation of those in the conventional method. From the experimental results we found that the segmented regions in the proposed method is more natural than those in the conventional method especially in texture and red tone regions. In the simulation results the proposed method is better than the conventional methods in the in the evaluation of the human segmentation dataset presented Berkely Segmentation Database.

• Korean Journal of Computational Design and Engineering
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• v.10 no.5
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• pp.356-364
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• 2005

As a ritual of modern people is getting higher, the safety assessment of the structure related to people has become the most important part in the process of the design. Especially, in the case of a ship, as regulations about the safety of passengers and the pollution in the ocean are strictly reinforcing, the safety assessment has become the most important part in the process of the design. However, because the established safety assessment is mostly depend on the experienced theory, it is so difficult to assess the safety considering a lot of situations such as various ocean environments, the mistake of sailors and emergency situations. As the way to solve this problem, lately the study of the simulation using a computer has been processed. In this paper, we suggested network-based simulation system framework using HLA (High Level Architecture) among many kind of simulations to assess the safety of the ship. Because HLA has already become a standard of the future simulation system in the U.S. DoD(Department of Defense) and Korea army, we expect to raise the possibility in the future. In addition, because HLA makes a standard of documents and a reused component(Federate) of simulation(Federation) by OMT(Object Model Template) and RTI(Runtime Infrastructure), we expect that this study will be developing the safety assessment of ship as well as operation in warship and cooperation with another applications.