• Journal of Korea Multimedia Society
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• v.17 no.11
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• pp.1270-1278
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• 2014

The modern infrared (IR) imaging systems use mainly one or more wavelength bands among short wavelength IR (SWIR), middle wavelength IR (MWIR), and long wavelength IR (LWIR) bands. In the process of IR image synthesis and modeling, IR image wavelength-band conversion which transforms arbitrary band image to other band one is required. The wavelength-band conversion procedure includes a temperature estimation process of an object surface. However, in this procedure, an approximated Planck's radiation equation causes errors in estimated temperature. In this paper, we propose an estimation temperature error attenuation method in IR image band conversion procedure. The estimated temperature is corrected with a slope information of radiance according to it. The corrected temperature is used for generation of the other band IR image. The verification of proposed method is demonstrated through the simulation.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.11_12
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• pp.646-653
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• 2005

This paper proposes that wavelength assignment algorithm maximizes residual links considering more real wavelength conversion in the WDM network. The existing algorithms are inefficient that they ignore wavelength conversion ability in each nodes and fixed uniformly wavelength conversion ability on all nodes. Proposed method makes a ring shape that maximize available residual links considering wavelength conversion ability in each nodes. Maximizing residual links can assign a wavelength for any path require. Then blocking probability is reduced by the maximum 19 percent and wavelength conversion number is improved by about 40 percent. These can be showed in performance evaluation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.83-88
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• 2012

This paper studies the effects of wavelength conversion on self-healing optical networks. We examined the effects of wavelength conversion capability on the backup routing and the spare wavelength utilization. The efficiency of spare wavelength utilization is proportionally increased as the wavelength conversion capability increases, different from the call blocking probability for which about 30% of wavelength conversion capability shows nearly the same performance as full wavelength conversion capability. The spare resource utilization efficiency can be improved by using alternate routing and wavelength assignment algorithms.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.11
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• pp.699-704
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• 2017

The amount of electric power for photovoltaic power generation depends on the location of the power plant and the direction of solar cell. The solar cell controls the generation of solar power plants. Therefore, the structure of solar cell, manufacturing method, and optic technology were factors contributing to increased solar cell efficiency; however, the technical limit has been reached. Herein, we propose a new method to increase the solar cell efficiency using a wavelength conversion technology that converts ultraviolet and infrared rays, which are not effectively used in solar cells, into effective wavelength of solar cell. We used fluoride $Na(Ca)YF_4$ phosphor for wavelength conversion. Then, a wavelength-conversion fluorescent paste, prepared using an organic-silicon binder, was used to prepare a film that was applied to Si solar cells. It was confirmed that conversion efficiency improved by 5% or more.

• Journal of Korean Institute of Industrial Engineers
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• v.26 no.4
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• pp.296-305
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• 2000

Virtual wavelength path (VWP) is the optical path when a wavelength conversion is possible in a wavelength division multiplexing (WDM) network that is transmission infrastructure for the next generation high speed backbone networks. To achieve efficient design for VWP networks, we must consider VWP routing, wavelength assignment, and wavelength conversion while satisfying many technical constraints of the WDM networks. In this study we propose an integrated model for efficient VWP design in WDM networks. We also develope a 3-phase algorithm, each of which deals with routing, wavelength assignment and route and wavelength reassignment, respectively. In our computational experiments, phase 1 algorithm can solve the problem to the optimality for medium size test networks. Phase 2 algorithm is an efficient heuristic based on a reduced layered network and can give us an effective wavelength assignment. Finally, phase 3 algorithm reconfigure VWP routing and its wavelength assignment to concentrate wavelength conversion nodes in the suggested VWP network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11B
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• pp.1596-1606
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• 2010

In this paper, we present a new analytical model that can precisely estimate the blocking performance of wavelength-routed WDM networks with sparse-partial-limited wavelength conversion (SPLWC). The proposed model accounts for the two sources of call blocking in a wavelength converter: range blocking originated from the limited conversion range of a wavelength converter; and capacity blocking induced from the limited number of wavelength converters. Based on the proposed model, we also present a new converter placement algorithm that minimizes the amount of wavelength conversion capability, while satisfying the given constraint on the network-wide blocking probability. From the numerical results obtained from the EON, we demonstrate that the blocking probability of the analytical model closely matches with that of the simulation. We also show that, by efficiently combining the existing sparse, partial, and limited wavelength conversion, the SPL WC can achieve the required blocking performance with the least amount of wavelength conversion cost.

• The Journal of Korean Association of Computer Education
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• v.9 no.1
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• pp.97-106
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• 2006

In the next-generation Internet backbone network, DWDM technology was appeared as an alternative to solve circuit shortage of existing TDM-based Internet. In this DWDM Network, it is inevitable to consider wavelength-conversion function as well as RWA in case of setting up connection for the efficient use of resources and customer satisfaction. This study is to describe an efficient strategy for the wavelength-conversion function with a limited range and for the use of a wavelength converter with the selected node, and to verify the optimum use of a wavelength converter through the performance test.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.156-157
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• 2003

The wavelength converter is considered to be a key element of future dense WDM optical networks. It enables wavelength reuse and resolves contention problem. Moreover, the tunability of the wavelength converter enhance the flexibility of network systems by facilitating reconfigurable dynamic wavelength routing. In order to achieve optically tunable wavelength conversion, we recently proposed and experimentally demonstrated wavelength conversion and tuning based on cascaded sum and difference frequency generation in a Ti：PPLN channel waveguide. (omitted)

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4B
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• pp.394-402
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• 2009

In this paper, we present a new analytical model for estimating the blocking performance of multi-fiber WDM networt:s with sparse and limited wavelength conversion (SLWC). The proposed model is a reduced-load approximation model that can obtain accurate estimates of blocking probability of such networks. Our model employs three new recurrence formulae to obtain the free wavelength distribution on a multi-fiber link, the free wavelength distribution after limited-range wavelength conversion and the end-to-end blocking probability of a multi-hop path, respectively. From the numerical results on the NSFNET, we demonstrate that the blocking performance of two-fiber NSFNET with three wavelength-convertible nodes, each of which translates an input wavelength to its adjacent output wavelengths, closely approximates the blocking performance of full wavelength conversion.

• Current Optics and Photonics
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• v.1 no.6
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• pp.579-586
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• 2017

In this paper, we theoretically demonstrate that semiconductor optical amplifiers (SOAs) with strong wavelength dependence of gain and phase are capable of all-optical inverted and non-inverted wavelength conversion (WC) over a wide range, with the assistance of an optical filter. First, the gain dynamics and phase dynamics in a common quantum well (QW) SOA with the $In_{0.53}Ga_{0.47}As/In_{0.7322}Ga_{0.2678}As_{0.5810}P_{0.4190}$ material system are found to be strongly dependent on wavelength, which is mainly related to the wavelength dependence of the differential gain and the differential refractive-index change. Second, the wavelength dependence in an all-optical wavelength converter based on the QW SOA cascaded with a detuning band pass filter is studied. Simulations show that the quality of the converted signal has little dependence on the operation wavelength. Both inverted and non-inverted WC can be achieved, over a large wavelength range. Therefore, although the gain and phase change are strongly wavelength-dependent, the effects of this dependence can be erased by appropriate optical filtering.