• Journal of the Optical Society of Korea
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• 제19권4호
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• pp.334-339
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• 2015

Terabit-per-second (Tb/s) transmission capacity for the next generation of long-haul communication networks can be achieved using multicarrier optical super-channel technology. In an elastic orthogonal frequency division multiplexing (OFDM) super-channel transmission system, demultiplexing a portion of an entire spectrum in the form of a subband with minimum power is critically required. A major obstacle to achieving this goal is the analog-to-digital converter (ADC), which is power-hungry and extremely expensive. Without a proper ADC that can work with low power, it is unrealistic to design a 100G coherent receiver suitable for a commercially deployable optical network. Discrete Fourier transform (DFT) is often seen as a primary technique for understanding partial demultiplexing, which can be attained either optically or electronically. If fairly comparable performance can be achieved with an all-optical DFT circuit, then a solution independent of data rate and modulation format can be obtained. In this paper, we investigate two distinct OFDM super-channel receiver models, based on electronic and all-optical DFT-technologies, for partial carrier demultiplexing in a multi-Tb/s transmission system. The performance comparison of the receivers is discussed in terms of bit-error-rate (BER) performance.

• 한국산학기술학회논문지
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• 제14권10호
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• pp.4739-4746
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• 2013

본 논문에서는 초고속 자기부상철도 추진 제어에 필수적인 차량의 위치검지에 있어서 위치신호 송신지연 및 송신주기가 추력에 미치는 영향을 수치적으로 분석하고 test bed를 이용한 실험을 통해 이를 확인하였다. 위치신호 송신문제를 해결하기 위한 방안으로서 위치신호 보상 및 추정 기법을 제시하였으며 제시된 방법을 test bed에 적용하여 효용성을 검증하였다. 적용 결과 추력이 크게 증가하였으며 이에 따라 차량의 가속도 및 속도 성능이 향상됨을 확인하였다. 본 방법은 향후 개발 예정인 한국형 초고속 자기부상철도의 위치검지시스템에 효과적으로 사용될 수 있을 것으로 판단된다.

• International Journal of Internet, Broadcasting and Communication
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• 제11권3호
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• pp.71-76
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• 2019

In this paper, we propose a simple one-click marketing solution for mobile devices which can advertise a product which is embedded in a mobile video while watching the video on a smartphone. If a specific product of interest appears in the video to the user, one can simply click on the product in the video and a pop-up window with information about the product is proposed. The implementation of the system is expected to enable users to gain real-time information about the product while watching the video without having to search for the product again after watching the movie, and thereby facilitating more mobile commerce. We use a two-fold system to prevent the failure of tracking which often occurs on a single online tracking system, so that the user cannot always get the commercial product information.

• Journal of applied mathematics & informatics
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• 제29권3_4호
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• pp.1011-1016
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• 2011

In this paper, our main purpose is to establish the existence of positive bounded entire solutions of second order quasilinear elliptic equation on $R^N$. we obtained the results under different suitable conditions on the locally H$\"{o}$lder continuous nonlinearity f(x, u), we needn't any mono-tonicity condition about the nonlinearity.

• 대한약침학회지
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• 제18권3호
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• pp.63-67
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• 2015

Objectives: This study was performed to analyze the single-dose oral toxicity of the super key (processed sulfur). Methods: All experiments were conducted at Medvill, an institution authorized to perform non-clinical studies, under the Good Laboratory Practice (GLP) regulations. In order to investigate the oral toxicity of super key. We administered it orally to Sprague-Dawley (SD) rats. The SD rats were divided into four groups of five male and five female animals per group: group 1 being the control group and groups 2, 3, and 4 being the experimental groups. Doses of super key 500 mg/kg, 1,000 mg/kg and 2,000 mg/kg were administered to the experimental groups, and a dose of normal saline solution, 10 mL/kg, was administered to the control group. We examined the survival rates, weights, clinical signs, gross findings and necropsy findings. This study was conducted under the approval of the Institutional Animal Ethics Committee. (Approval number: A01-14018). Results: No deaths or abnormalities occurred in any of the four groups. Although slight decreases in the weights of some female rats were noted, no significant changes in weights or differences in the gross findings between the control group and the experimental groups were observed. To check for abnormalities in organs, we used microscopy to examine representative histological sections of each specified organ; the results showed no significant differences in any of the organs. Conclusion: The results of this research showed that administration of 500 - 2,000 mg/kg of super key did not cause any changes in the weights or in the results of necropsy examinations. Neither did it result in any mortalities. The above findings suggest that treatment with super key is relatively safe. Further studies on this subject are needed to yield more concrete evidence.

• 한국CDE학회논문집
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• 제18권2호
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• pp.83-92
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• 2013

IFC based open BIM has internationally developed as a solution for interoperability problem among different software applications. Despite much interest and effort, the open BIM technologies are rarely introduced to the construction industry and need more technical development for a practical application as well. This research aims to develop automated code checking modules for quality assurance process of BIM data. The research have analyzed domestic regulations focusing on super-tall buildings and developed open BIM-based code checking modules for the evacuation regulations. The modules are able to validate evacuation regulations such as installation of emergency elevator and fire safety zone. The authors expect to improve the process of BIM quality assurance and enhance the quality of BIM data by this research on automated checking system.

• 대한기계학회논문집
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• 제19권4호
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• pp.941-949
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• 1995

An efficient method based on analytic solutions is applied to solve anti-plane Mode III crack problems. The analytic technique developed earlier by the present authors for Laplace's equation in a simply-connected region is now extended to general Mode III crack problems. Unlike typical numerical methods which require fine meshing near crack tips, the present method divides the cracked bodies, typically non-convex or multiply-connected, into only a few super elements. In each super element, an element stiffness matrix, relating the series coefficients of the traction and displacement, is first formed. Then an assembly algorithm similar to that used in the finite elements, is first formed. Then an assembly algorithm similar to that used in the finite elements, is developed. A big advantage of the present method is that only the boundary conditions are to be satisfied in the solution procedure due to the use of analytic solutions. Several numerical results demonstrate the efficiency and accuracy of the present method.

• Journal of applied mathematics & informatics
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• 제5권2호
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• pp.507-516
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• 1998

In this study we are concerned with the problem of ap-proximating a locally unique solution of an equation on a Banach space. A semilocal convergence theorem is given for the Super-Halley method in Banach spaces. Earlier results have shown that the order of convergence is four for a certain class of operators [4] [5] [8] These results were not given in affine invariant form and made use of a real quadratic majorizing polynomial. Here we provide our re-sults in affine invariant form showing that the order of convergence is at least four. In cases that it is exactly four the rate of convergence is improved. We achieve these results by using a cubic majorizing polynomial. Some numerical examples are given to show that our error bounds are better than earlier ones.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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• pp.76-79
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• 2008

본 연구에서는 초고층 건축물에서의 화재 발생시 피난상의 문제점을 분석하여 재실자의 안전을 도모할 수 있는 수단으로서 피난공간을 제시하고 필요성을 고찰하였다. 또한 피난공간의 기준 마련을 위해서 고려해야 할 인자들을 도출하고 도출된 인자들을 각각의 해결방안에 의한 논증을 통해 피난공간의 기준을 제안하였다.

• 에너지공학
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• 제29권3호
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• pp.34-41
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• 2020

Used disposable diapers have been considered for a long time as a type of waste difficult to recycle and valorize due to their composite nature including plastic, cellulose pulp, a super absorbent polymer and either urine, feces or both. Therefore, the fate of disposed diapers often is either incineration or landfill burial which both have various adverse environmental impacts. However, used disposable diapers contain nutrients: cellulose is an organic matter while urine and feces contain non negligible amounts of nitrogen, phosphorus and potassium which are primary nutrients included in most chemical fertilizers used in agriculture. In a scope of waste recycling and valorization, this study focuses on developing a method to achieve nutrient solution extraction from used disposable diapers. The experiment essentially consists in shredding the diapers and letting them macerate in solutions of sodium hydroxide with various concentrations to allow breaking down of the cellulose and super absorbent polymer and release of urine and feces before sterilizing the solutions in an autoclave to remove potential coliform bacteria. At the end of the experiment, a set of parameters is measured for the final solution to identify concentrations of nutrients as well as presence or absence of harmful substances. Results are discussed and directions for future studies are suggested, which include mechanization of the diapers shredding process or added aeration to enhance nitrification and absorption of extracted nutrients from plants.