• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.1
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• pp.23-28
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• 2016

In this paper, a Multi-Band Ku-band down converter was designed for reception of multi-band digital satellite broadcasting. The Multi-band low-nose down converter was designed to form four local oscillator frequencies (9.75, 10, 10.75 and 11.3GHz) representing a low phase noise due to VCO-PLL with respect to input signals of 10.7 to 12.75GHz and 3-stage low noise amplifier circuit by broadband noise matching, and to select an one band of intermediate frequency (IF) channels by digital control. The developed low-noise downconverter exhibited the full conversion gain of 64dB, and the noise figure of low-noise amplifier was 0.7dB, the P1dB of output signal 15dBm, and the phase noise -73dBc@100Hz at the band 1 carrier frequency of 9.75GHz. The low noise block downconverter (LNB) for receiving four-band digital satellite broadcasting designed in this paper can be used for satellite broadcasting of vessels navigating international waters.

• Journal of the Korean Home Economics Association
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• v.43 no.8 s.210
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• pp.69-81
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• 2005

The purpose of this study is to design high school boy's uniforms, which fit well and express the traditional aesthetics of Korean clothing. Korean traditional clothing is getting ground for the use as active wear as well as formal wear such as wedding or special holiday clothing. This is partly due to the introduction of western clothing in Korea because of the practical nature of this type of clothing. This study was carried out as follows: 1. First, 197 high school boys from 5 different high schools were surveyed. All of these schools use Korean style school uniforms. The survey asked the students about their satisfaction with the current designs, problems and design preferences for Korean style high school uniforms. In general, the boys are not satisfied with the aesthetic and fashionable aspects of their uniforms. 2. The second survey dealt with design preferences from a variety of design options of Korean-style school uniforms. The design options were presented to the students as in the form of 10 different types jackets and 6 different types of pants. Using the results of the second survey as a guideline, the designs of Korean style school uniforms were developed. 3. In order to make the test garments, a block bodice pattern for the Korean style school uniforms was developed. Using the developed bodice block pattern, 6 designs were made of wool. The 6 test designs consisted of 3 different types of jackets and 3 different types of pants. 4. Incorporating the most preferred design features, school boy Korean style school uniform designs were developed. The characteristics of the design include neck line opening and its finishing, AH and sleeve shape, embroidered traditional patterns and fastenings. In this study we were able to develop comfortable clothing, which expressed the traditional aesthetics of Korean clothing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.20-27
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• 2020

In general, a nonlinear system is linearized in the form of a multiplication of the 1st and 2nd order system. This paper reports a design method of a weighting matrix and control law of LQ control to move the double poles that have a Jordan block to a pair of complex conjugate poles. This method has the advantages of pole placement and the guarantee of stability, but this method cannot position the poles correctly, and the matrix is chosen using a trial and error method. Therefore, a relation function (𝜌, 𝜃) between the poles and the matrix was derived under the condition that the poles are the roots of the characteristic equation of the Hamiltonian system. In addition, the Pole's Moving-range was obtained under the condition that the state weighting matrix becomes a positive semi-definite matrix. This paper presents examples of how the matrix and control law is calculated.

• Journal of Technologic Dentistry
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• v.38 no.3
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• pp.127-133
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• 2016

Purpose: Currently advanced in Dental CAD/CAM technology increase a use of Co-Cr sinter metal block at Dental CAD/CAM part traditionally it has been being used with metal casting method. There is an advantage that can leave out a step of investment and casting as well as reducing a working time to compare with conventional casting method in a dry milling. Methods: In this research, compare a deformation of before and after sinter result of Co-Cr sinter metal block. Design a specimen figure by 3D CAD software and transformed it to a STL file can be used at Dental CAD/CAM. With a transformed STL file, milled a Co-Cr sinter metal specimen by using a Dental CAD/CAM dry milling machine. It arrived at the following conclusions after measuring an outer form and thickness of a machined specimen and then after sinter measure it again in a way of before sinter measurement method. Results: It is confirmed that there is no error while a 3D design figure specimen is transformed to a Dental CAD data. It is observed that there is no error at Co-Cr sinter metal specimen which consider a length of single coping and bridge. Conclusion: It is observed that there is no deformation at a specimen of AS05 and AB05 are made of 0,5mm thickness. On the other hand, the out of range of deformation is observed at a specimen of AS10 and AB10 which are made of 1mm thickness.

• BMB Reports
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• v.37 no.2
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• pp.254-259
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• 2004

The wild-type and temperature-sensitive (ts) repressor genes were cloned from the temperate mycobacteriophage L1 and its mutant L1cIts391, respectively. A sequencing analysis revealed that the $131^{st}$ proline residue of the wild-type repressor was changed to leucine in the ts mutant repressor. The 100% identity that was discovered between the two DNA regions of phages L1 and L5, carrying the same sets of genes including their repressor genes, strengthened the speculation that L1 is a minor variant of phage L5 or vice versa. A comparative analysis of the repressor proteins of different mycobacteriophages suggests that the mycobacteriophage-specific repressor proteins constitute a new family of repressors, which were possibly evolved from a common ancestor. Alignment of the mycobacteriophage-specific repressor proteins showed at least 7 blocks (designated I-VII) that carried 3-8 identical amino acid residues. The amino acid residues of blocks V, VI, and some residues downstream to block VI are crucial for the function of the L1 (or L5) repressor. Blocks I and II possibly form the turn and helix 2 regions of the HTH motif of the repressor. Block IV in the L1 repressor is part of the most charged region encompassing amino acid residues 72-92, which flanks the putative N-terminal basic (residues 1-71) and C-terminal acidic (residues 93-183) domains of L1 repressor.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.1 no.1
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• pp.63-69
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• 1998

The slope revegetation methods in Korea are generally the hydroseeding mixed with perennial herbs, soil, fibers, and fertilizer in consideration of scenic landscape rather than ecological and engineering effect. But perennial herbs can't protect the slope from deep surface erosion and they are not tall enough to create the original naturalness at the boundary parts of existing woodlands. This study is about the slope revegetation method using nutritional propagation capacity of plants and the experimental construction was carried out on the cut-slope of Yongin Hoam C.C. We dug several trenches to a depth of 80cm and at intervals of 150cm from each other. After placing various kinds of live branches(Salix species) into the trench, we backfilled with the excavated soils and finally sprayed water mixed with soil-stabilizer, fertilizer. As six months passed, we made a vegetation research and check the slope surface erosion. Vegetation research was performed in examining the frequency of each block using transect method. 31 kinds of plant species appeared in total area($113.6m^2$) and the dominant species are Setaria viridis, Artemisia rubripes, Persicaria pubescens, Plantago asiatica, Cyperus amuricus, Commelina communis. Among the examined blocks, '아', the top part of the slope, showed the ratio of 1.4 as the highest Alpha-diversity. With regard to life form, therophytes were shown dominant distribution of 58% of total species and neophytes relatively low distribution of 16%. It can be estimated that there is no ecological stabilization of this slope, because of ruderal species' occupation of 74% in total area. Regarding the slope stabilization, the serious surface erosion didn't take place in spite of heavy rainfall this year, but a little surface erosion took place at the block where no other species coming from outside of the site were found.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.11
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• pp.2067-2072
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• 2016

Recently, due to the development of attack techniques that can circumvent existing information protection systems, continuous threats in a form unrecognized by the user have threatened information assets. Therefore, it is necessary to support the prompt responses to anticipated attempts of APT attacks, bypass access attacks, and encryption packet attacks, which the existing systems have difficulty defending against through a single response, and to continuously monitor information protection systems with a defense strategy based on Indicators of Attack (IOA). In this paper, I suggest a centralized intelligent information protection system to support the intelligent response to a violation by discerning important assets through prevention control in a performance impact assessment about information properties in order to block the attack routes of APT; establishing information control policies through weakness/risk analyses in order to remove the risks in advance; establishing detection control by restricting interior/exterior bypass networks to server access and monitoring encrypted communications; and lastly, performing related corrective control through backup/restoration.

• Journal of Korea Water Resources Association
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• v.52 no.spc2
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• pp.823-833
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• 2019

This study presents the impact of natural flow patterns on downstream fish habitat and economic outcomes in the Dal Stream, Korea. The study reach is 3.35 km long, located downstream form the Goesan Dam. To assess such impact, this study performed physical habitat simulations. The River2D model was used for the computation of the flow and the HSI model for the habitat simulation. Two physical habitat variables, flow depth and velocity, were used. The Zacco platypus, Zacco temminckii, Coreoleuciscus splendidus, and Opsariichthys bidens were selected as the target species in the study area. Using the building block approach (BBA), the scenarios for the hydropeaking mitigation were presented. Scenario 1 and scenario 2 were proposed by using the magnitude - duration concept and averaged the hydrologic data over the each month, respectively. Simulation results indicated that the scenarios effects significantly increased by about 18.6% for the weighted usable area (WUA). In addition, hydroelectric power benefits with both scenarios were investigated. It was revealed that the change of storing and releasing water decreased by about 27% for hydroelectric power benefits. In order to increase economic benefits, the scenario was modified with the discharges corresponding to the hydropeaking condition except the flood season. As a result, the hydroelectric power benefits were almost the same, however the aquatic habitat for the target species increased by about 5%. The change of dam re-operations through natural flow patterns provides an opportunity to minimize environmental and economic benefits in order to balance water management.

• Journal of Ship and Ocean Technology
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• v.10 no.4
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• pp.1-11
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• 2006

The finite volume based multi-block RANS code, WAVIS developed at MOERI is applied to the numerical self-propulsion test. WAVIS uses the cell-centered finite volume method for discretization of the governing equations. The realizable $k-{\epsilon}$ turbulence model with a wall function is employed for the turbulence closure. The free surface is captured with the two-phase level set method and body forces are used to model the effects of a propeller without resolving the detail blade flow. The propeller forces are obtained using an unsteady lifting surface method based on potential flow theory. The numerical procedure followed the self-propulsion model experiment based on the 1978 ITTC performance prediction method. The self-propulsion point is obtained iteratively through balancing the propeller thrust, the ship hull resistance and towing force that is correction for Reynolds number difference between the model and full scale. The unsteady lifting surface code is also iterated until the propeller induced velocity is converged in order to obtain the propeller force. The self-propulsion characteristics such as thrust deduction, wake fraction, propeller efficiency, and hull efficiency are compared with the experimental data of the practical container ship. The present paper shows that hybrid RANS and potential flow based numerical method is promising to predict the self-propulsion parameters of practical ships as a useful tool for the hull form and propeller design.

• Journal of Internet Computing and Services
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• v.20 no.4
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• pp.29-38
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• 2019

Currently, information society is rapidly changing and demands innovation and creativity in various fields. Therefore, the importance of mathematics, which can be the basis of creativity and logic, is emphasized. The purpose of this paper is to develop a math education application that can further expand the logical thinking of mathematics and allow voluntary learning to occur through the use of readily available teaching aid for children to form motivation and interest in learning. This paper provides math education applications using a smartphone and blocks for children. The main function of the application is to shoot with the camera and show the calculated values. When a child uses a block to make a formula and shoots a block using a camera, you can directly see the calculated value of your formula. The preprocessing process, text extraction, and character recognition of the photographed images have been implemented using OpenCV libraries and Tesseract-OCR libraries.