• Title/Summary/Keyword: Optimized Path

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Optical System Design for Real-Time 3-Dimension Ophthalmoscope (실시간 3차원 검안경의 광학설계)

  • Lee, Soak-Hee;Yang, Yun-Sik;Choe, Oh-Mok;Sim, Sang-Hyun;Doo, Ha-Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.8 no.1
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    • pp.35-39
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    • 2003
  • The display technology on the retina is the key role in inspecting the condition of the patients. 2-dimensional retina image is widely used in the eye examination as of today. Recently, 3-dimensional retina image ones have been introduced to this area, but the quality of the image is not fully satisfied to the operator. For the purpose of developing 3-D retina imaging instrument, the optimization of a 3-D retina imaging system using Code-V tool was investigated in this thesis. He-Ne laser having the wavelength 632.8 nm was used to make a power source to detect the retina. Several lenses and mirrors installed on sledge which were developed to perform focus control on 3-D device were designed to make a beam focusing and direct line. Polygon scanner having 24 mirror facets and galvanometer making tilting movement were utilized to make a 2-D laser plane. Also, design of eye ball had been fulfilled to see the focus of the 2-D plane. Reflected ray from retina detected on the sensor array with the same path. All cognitive components were optimized for aberration correction in order to focus on retina. Results of optimization were compared to those of initial designed optics system. On the basis of above results, the result of third aberration has been corrected to stable values to the optical system. MTF evaluating the resolution of an image has been closely correlated to the diffraction limit and PSF indicating the strength distribution of an image has shown the SR value as 0.9998 having high performance. The possibility of new and powerful 3-D retina image instrument was verified by simulating each component of the instrument by Code-V.

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Design and Fabrication of Low Loss, High Power SP6T Switch Chips for Quad-Band Applications Using pHEMT Process (pHEMT 공정을 이용한 저손실, 고전력 4중 대역용 SP6T 스위치 칩의 설계 및 제작)

  • Kwon, Tae-Min;Park, Yong-Min;Kim, Dong-Wook
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.6
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    • pp.584-597
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    • 2011
  • In this paper, low-loss and high-power RF SP6T switch chips are designed, fabricated and measured for GSM/EGSM/DCS/PCS applications using WIN Semiconductors 0.5 ${\mu}m$ pHEMT process. We utilized a combined configuration of series and series-shunt structures for optimized switch performance, and a common transistor structure on a receiver path for reducing chip area. The gate width and the number of stacked transistors are determined using ON/OFF input power level of the transceiver system. To improve the switch performance, feed-forward capacitors, shunt capacitors and parasitic FET inductance elimination due to resonance are actively used. The fabricated chip size is $1.2{\times}1.5\;mm^2$. S-parameter measurement shows an insertion loss of 0.5~1.2 dB and isolation of 28~36 dB. The fabricated SP6T switch chips can handle 4 W input power and suppress second and third harmonics by more than 75 dBc.

Generation of Femtosecond Pulses in a Passively Mode-Locked 100 MHz Cr4+:YAG Laser (수동 모드 잠금된 100 MHz Cr4+:YAG 레이저에서의 펨토초 펄스 발생)

  • Cho, Won-Bae;Rotermund Fabian;Kim, Jong-Doo;Jeon, Min-Yong;Suh, Ho-Suhng
    • Korean Journal of Optics and Photonics
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    • v.16 no.6
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    • pp.535-541
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    • 2005
  • We report on the development of a passively mode-locked near-infrared femtosecond laser with Cr:YAG crystal that operates near room temperature. The laser wavelength could easily be tuned by using only the internal prism pair over 110 nm from 1400 nm to 1510 nm in cw and over about 30 nm in mode-locked operation, respectively Maximum cw output powers of 810 mW were obtained with $1.5 \%$ output coupler for absorbed pump powers of 7.6 W. For compensation of the internal group velocity dispersion, an IR graded prism pair was used. The Cr:YAG laser delivered nearly Fourier-transform limited pulses with a pulse duration as short as 64 fs at 100 MHz repetition rate. In the mode-locked regime, the laser was operating at 1510 nm with a spectral bandwidth of 44 nm. In order to avoid unstable mode-locking and power instabilities, self-built tubes were inserted into the beam path in the resonator and purged with N2 gas. Finally, output powers of the Cr:YAG laser were optimized to 250 mW fer long time stable mode-locked operation.

Enhanced PMIPv6 Route Optimization Handover using PFMIPv6 in Mobile Cloud Environment (모바일 클라우드 환경에서 PFMIPv6를 이용한 향상된 PMIPv6 경로 최적화 핸드오버 기법)

  • Na, Je-Gyun;Seo, Dae-Hee;Nah, Jae-Hoon;Mun, Young-Song
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.12
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    • pp.17-23
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    • 2010
  • In the mobile cloud computing, the mobile node should request and receive the services while being connected. In PMIPv6, all packets sent by mobile nodes or correspondent nodes are transferred through the local mobility anchor. This unnecessary detour still results in high delivery latency and significant processing cost. Several PMIPv6 route optimization schemes have been proposed to solve this issue. However, they also suffer from the high signaling costs and handover latency when determining the optimized path. We propose the route optimization handover scheme which adopts the prediction algorithm in PFMIPv6. In the proposed scheme, the new mobile access gateway establishes the bi-directional tunnel with the correspondent node's MAG using the context message when the mobile node's handover is imminent. This tunnel may eliminate the need of separate route optimization procedure. Hence, the proposed scheme can reduce the signaling cost than other conventional schemes do. Analytical performance evaluation is preformed to show the effectiveness of the proposed scheme. The result shows that our scheme is more effective than other schemes.

Human Tracking Technology using Convolutional Neural Network in Visual Surveillance (서베일런스에서 회선 신경망 기술을 이용한 사람 추적 기법)

  • Kang, Sung-Kwan;Chun, Sang-Hun
    • Journal of Digital Convergence
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    • v.15 no.2
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    • pp.173-181
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    • 2017
  • In this paper, we have studied tracking as a training stage of considering the position and the scale of a person given its previous position, scale, as well as next and forward image fraction. Unlike other learning methods, CNN is thereby learning combines both time and spatial features from the image for the two consecutive frames. We introduce multiple path ways in CNN to better fuse local and global information. A creative shift-variant CNN architecture is designed so as to alleviate the drift problem when the distracting objects are similar to the target in cluttered environment. Furthermore, we employ CNNs to estimate the scale through the accurate localization of some key points. These techniques are object-independent so that the proposed method can be applied to track other types of object. The capability of the tracker of handling complex situations is demonstrated in many testing sequences. The accuracy of the SVM classifier using the features learnt by the CNN is equivalent to the accuracy of the CNN. This fact confirms the importance of automatically optimized features. However, the computation time for the classification of a person using the convolutional neural network classifier is less than approximately 1/40 of the SVM computation time, regardless of the type of the used features.

An Empirical Study on the Effect of Market and Technology Orientation on the Innovation Performance of Global Firms (글로벌 기업의 시장지향성과 기술지향성이 기술혁신성과에 미치는 영향의 실증연구)

  • Hwang, Sang Don;Lee, Seong Hwan;Lee, Woon Seek
    • International Area Studies Review
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    • v.22 no.4
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    • pp.145-166
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    • 2018
  • This study is due to global competition, the wall between regions is disappearing, customer needs are diversified, and market and technology are rapidly changing. Future growth engines, the importance of convergence capabilities for industrial competitiveness is being emphasized more. Therefore, companies should seek innovative means to increase the efficiency of the company by establishing optimized global management environment and establishing direction and strategy for utilization of convergence technology by improving industrial competitiveness. Firms must adopt and utilize related new technologies by strengthening their convergence capabilities through dynamic capabilities that are internal resource bases for new product development and process innovation. Globalize markets and technologies can expect higher innovation performance when aligning strategic direction with formalized technology competencies held by the firm and incorporating the convergence capabilities needed for technological innovation into processes. The study focuses on the effects of market and technology orientation on technological innovation performance, whether dynamic and convergence capabilities affect technological innovation performance, and dynamic and convergence capabilities to mediate between market and technology orientation. For the study, we surveyed 51.4% of global and multinational corporations that are internationally active or headquartered overseas. Based on the previous studies, hypotheses were established and the collected data were analyzed through utilization path analysis and Sobel test.

Model Experiment for Evaluating Internal Erosion Resistance Around Embankment Box-culvert Using Biopolymer T reated Soil (바이오폴리머 혼합토를 활용한 제방 통문 주위 내부침식 저항성 평가를 위한 모형실험)

  • Kim, Minjin;Moon, Junho;Kim, Chanhee;Kim, Younguk
    • Journal of the Korean GEO-environmental Society
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    • v.22 no.12
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    • pp.65-70
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    • 2021
  • River-side Embankment collapse involves various causes. The embankment collapse due to internal erosion around embedded structures reaches up to more than 10% in Korea. Many studies are being attempted to prevent from the collapse of the embankment rooted from overtopping and instability as well as internal erosion. One of them is the study on the application of biopolymers. The application of biopolymers to soils are divided into enhancing strength, vegetation and erosion resistance. This study investigated the effect of biopolymer treated soil on erosion resistance. The main goal of the study is to obtain basic data for real-scale experiments to verify the effectiveness of biopolymer treated soil embankment including a review of the collapse pattern in the model embankment with various test conditions. The optimized experimental conditions were selected by examining the erosion patterns according to each induction path with three compaction degree of the model embankment. As a result of the experiment, the internal erosion rate in the embankment to which the biopolymer treated soil was applied is greatly reduced, and it could be concluded that it might be applied to the actual embankment. However, in this study, the conclusion was drawn only within the scaled-down model embankment. In order to practically apply the biopolymer treated soil to the embankment, the study considering the scale effect would be needed.

Statistical Optimization of Production Medium for Enhanced Production of Itaconic Acid Biosynthesized by Fungal Cells of Aspergillus terreus (Aspergillus terreus에 의해 생합성되는 이타콘산의 생산성 증가를 위한 통계적 생산배지 최적화)

  • Jang, Yong-Man;Shin, Woo-Shik;Lee, Do-Hoon;Kim, Sang-Yong;Park, Chul-Hwan;Jeong, Yong-Seob;Chun, Gie-Taek
    • KSBB Journal
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    • v.24 no.1
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    • pp.30-40
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    • 2009
  • Statistical optimization of the production medium was carried out in order to find an optimal medium composition in itaconic acid fermentation process. Itaconic acid utilized in the manufacture of various synthetic resins is a dicarboxylic acid biosynthesized by fungal cells of Aspergillus terreus in a branch of the TCA cycle via decarboxylation of cis-aconitate. Through OFAT (one factor at a time) experiments, six components (glucose, fructose, sucrose, soluble starch, soybean meal and cottonseed flour) were found to have significant effects on itaconic production among various carbon- and nitrogen-sources. Hence, using these six factors, interactive effects were investigated via fractional factorial design, showing that the initial concentrations of sucrose and cottonseed flour should be high for enhanced production of itaconic acid. Furthermore, through full factorial design (FFD) experiments, negative effects of $KH_2PO_4$ and $MgSO_4$ on itaconic acid biosynthesis were demonstrated, when excess amounts of the each component were initially added. Based on the FFD analysis, further statistical experiments were conducted along the steepest ascent path, followed by response surface method (RSM) in order to obtain optimal concentrations of the constituent nutrients. As a result, optimized concentrations of sucrose and cottonseed flour were found to be 90.4g/L and 53.8g/L respectively, with the corresponding production level of itaconic acid to be 4.36 g/L (about 7 fold higher productivity as compared to the previous production medium). From these experimental results, it was assumed that optimum ratio of the constituent carbon (sucrose) and nitrogen (cottonseed flour) sources was one of the most important factors for the enhanced production of itaconic acid.

Development of Intelligent ATP System Using Genetic Algorithm (유전 알고리듬을 적용한 지능형 ATP 시스템 개발)

  • Kim, Tai-Young
    • Journal of Intelligence and Information Systems
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    • v.16 no.4
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    • pp.131-145
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    • 2010
  • The framework for making a coordinated decision for large-scale facilities has become an important issue in supply chain(SC) management research. The competitive business environment requires companies to continuously search for the ways to achieve high efficiency and lower operational costs. In the areas of production/distribution planning, many researchers and practitioners have developedand evaluated the deterministic models to coordinate important and interrelated logistic decisions such as capacity management, inventory allocation, and vehicle routing. They initially have investigated the various process of SC separately and later become more interested in such problems encompassing the whole SC system. The accurate quotation of ATP(Available-To-Promise) plays a very important role in enhancing customer satisfaction and fill rate maximization. The complexity for intelligent manufacturing system, which includes all the linkages among procurement, production, and distribution, makes the accurate quotation of ATP be a quite difficult job. In addition to, many researchers assumed ATP model with integer time. However, in industry practices, integer times are very rare and the model developed using integer times is therefore approximating the real system. Various alternative models for an ATP system with time lags have been developed and evaluated. In most cases, these models have assumed that the time lags are integer multiples of a unit time grid. However, integer time lags are very rare in practices, and therefore models developed using integer time lags only approximate real systems. The differences occurring by this approximation frequently result in significant accuracy degradations. To introduce the ATP model with time lags, we first introduce the dynamic production function. Hackman and Leachman's dynamic production function in initiated research directly related to the topic of this paper. They propose a modeling framework for a system with non-integer time lags and show how to apply the framework to a variety of systems including continues time series, manufacturing resource planning and critical path method. Their formulation requires no additional variables or constraints and is capable of representing real world systems more accurately. Previously, to cope with non-integer time lags, they usually model a concerned system either by rounding lags to the nearest integers or by subdividing the time grid to make the lags become integer multiples of the grid. But each approach has a critical weakness: the first approach underestimates, potentially leading to infeasibilities or overestimates lead times, potentially resulting in excessive work-inprocesses. The second approach drastically inflates the problem size. We consider an optimized ATP system with non-integer time lag in supply chain management. We focus on a worldwide headquarter, distribution centers, and manufacturing facilities are globally networked. We develop a mixed integer programming(MIP) model for ATP process, which has the definition of required data flow. The illustrative ATP module shows the proposed system is largely affected inSCM. The system we are concerned is composed of a multiple production facility with multiple products, multiple distribution centers and multiple customers. For the system, we consider an ATP scheduling and capacity allocationproblem. In this study, we proposed the model for the ATP system in SCM using the dynamic production function considering the non-integer time lags. The model is developed under the framework suitable for the non-integer lags and, therefore, is more accurate than the models we usually encounter. We developed intelligent ATP System for this model using genetic algorithm. We focus on a capacitated production planning and capacity allocation problem, develop a mixed integer programming model, and propose an efficient heuristic procedure using an evolutionary system to solve it efficiently. This method makes it possible for the population to reach the approximate solution easily. Moreover, we designed and utilized a representation scheme that allows the proposed models to represent real variables. The proposed regeneration procedures, which evaluate each infeasible chromosome, makes the solutions converge to the optimum quickly.