• Title/Summary/Keyword: gain enhancement

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Recent Progress in Luminescent Lanthanide Complexes for Advanced Photonics Applications

  • Kim, Hwan-Kyu;Oh, Jae-Buem;Baek, Nam-Seob;Roh, Soo-Gyun;Nah, Min-Kook;Kim, Yong-Hee
    • Bulletin of the Korean Chemical Society
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    • v.26 no.2
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    • pp.201-214
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    • 2005
  • We have designed and developed novel luminescent lanthanide complexes for advanced photonics applications. Lanthanide(III) ions (Ln$^{3+}$) were encapsulated by the luminescent ligands such as metalloporphyrins and naphthalenes. The energy levels of the luminescent ligands were tailored to maintain the effective energy transfer process from luminescent ligands to Ln$^{3+}$ ions for getting a higher optical amplification gain. Also, key parameters for emission enhancement and efficient energy transfer pathways for the sensitization of Ln$^{3+}$ ions by luminescent ligands were investigated. Furthermore, to enhance the optophysical properties of novel luminescent Ln$^{3+}$ complexes, aryl ether-functionalized dendrons as photon antennas have been incorporated into luminescent Ln$^{3+}$ complexes, yielding novel Ln(III)-cored dendrimer complex. The novel Ln(III)-cored dendrimer complex has much higher PL intensity than the corresponding simple complex, due to the efficient site-isolation effect. In this article, we will deal with recent progress in the synthesis and photophysical studies of inert and stable luminescent Ln$^{3+}$ complexes for advanced photonics applications. Also, our review will include the exploratory investigation of the key parameters for emission enhancement and the effective energy transfer pathways from luminescent ligands to Ln$^{3+}$ ions with Ln(III)-chelated prototype complexes.

A Study on Nonnative Expectation of Emotional Process in Children′s Textbooks of the Chosen Dynasty (I) (조선시대 아동교육용 문헌에 나타난 정서과정에 대한 규범적 기대(I))

  • 신양재
    • Journal of the Korean Home Economics Association
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    • v.42 no.8
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    • pp.147-167
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    • 2004
  • The purpose of this study was to investigate the nonnative expectations of anger, sadness, fear, and shame in Korean culture by analyzing the textbooks for children's education in the Chosen Dynasty period. The method of this study was document analysis and the materials for analysis were the following four textbooks for children's education that involved individual ethics in everyday life based on Confucianism: 'Dongmongsenspj, 'Gyukmongyogyulj, 'Myungsimbogamj, and 'Sohakj. The analysis was focused on the antecedent events, emotional consequences, and emotional regulations in the emotional processes of anger, sadness, fear, and shame. According to the analysis, anger was caused by ought violations, especially sociomoral violations, and the expression of anger brought about undesirable results, and the inhibition of anger was expected as the regulation rule. Also, many methods of regulating anger were encouraged in the textbooks. For example, one of the regulating methods was to appraise a situation in such a way that anger would not arise. in other hand, sadness was allowed to be expressed only at the death of parents, and the expression of sadness stood for filial piety. Meanwhile, the antecedents of fear were the events to threaten self-esteem, which was mainly focused on keeping moral and social standards. Also the social consequence of fear led to observance of the social norms, and thereby could gain social approval. Therefore, the regulation rule was the enhancement of fear because of anticipated advantageous effects. Finally, the main cause of shame arousal was negative evaluation of self caused by bad performance of ethical or social standards. Accordingly, having shame could prevent wrong behaviors or transgressions which might break interpersonal connectedness, and the regulation rule of shame was to enhance this because of contributing to collective relationship.

Enhancement of cell-mediated immunity by administration of plasma protein in pigs 1. Proportion of leukocyte subpopulations and cells expressing adhesion molecules in peripheral blood (돼지에서 plasma protein에 의한 세포성면역 증진효과에 관한 연구 1. 혈액내 백혈구 아군 및 세포별 분포율)

  • Yang, Chang-kun;Kim, Soon-jae;Moon, Jin-san;Jung, Suk-chan;Park, Yong-ho
    • Korean Journal of Veterinary Research
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    • v.34 no.2
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    • pp.275-286
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    • 1994
  • Plasma protein which has been known as one of nonspecific immunostimulators was added to feedstuff to examine its effect on the enhancement of cellular immune response in porcine immune system. A total of 40 piglets, 20 male and 20 female each, were fed for 30 days with or without plasma protein. The peripheral blood were collected and analyzed for the investigation of leukocyte subpopulations and their activities by using a panel of monoclonal antibodies specific to porcine leukocyte differentiation antigens and flow cytometry. The results obtained as follows. 1. Total weight gain, daily feed intake and feed conversion rate for 10 days were significantly improved to 56%, 20% and 22% in the piglets fed plasma protein, respectively. 2. A significant increase in N (null or non T/non B) cells was also noticed. Leukocyte proportion from piglets fed plasma protein was 20.2-24.7%, otherwise that from piglets fed without plasma protein was 12.3-13.4%, respectively. 3. A significant increase in the proportion of B cells and cells expressing poCD1 was not found in piglets fed plasma protein. 4. Reaction with monoclonal antibodies specific to adhesion molecules, poCD11a, poCD11b, poCD44 and poCD45A and poCD45B, has shown that leukocyte subpopulation from piglets fed plasma protein did not significantly higher than that from piglets fed without plasma protein. 5. Total proportion of granulocytes and monocytes was about 50% in both group and the proportion after treated with Hypaque/Ficoll was 2.7% and 5.8% in each group, respectively.

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Importance Sampling Embedded Experimental Frame Design for Efficient Monte Carlo Simulation (효율적인 몬테 칼로 시뮬레이션을 위한 중요 샘플링 기법이 내장된 실험 틀 설계)

  • Seo, Kyung-Min;Song, Hae-Sang
    • The Journal of the Korea Contents Association
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    • v.13 no.4
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    • pp.53-63
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    • 2013
  • This paper presents an importance sampling(IS) embedded experimental frame(EF) design for efficient Monte Carlo (MC) simulation. To achieve IS principles, the proposed EF contains two embedded sub-models, which are classified into Importance Sampler(IS) and Bias Compensator(BC) models. The IS and BC models stand between the existing system model and EF, which leads to enhancement of model reusability. Furthermore, the proposed EF enables to achieve fast stochastic simulation as compared with the crude MC technique. From the abstract two case studies with the utilization of the proposed EF, we can gain interesting experimental results regarding remarkable enhancement of simulation performance. Finally, we expect that this work will serve various content areas for enhancing simulation performance, and besides, it will be utilized as a tool to understand and analyze social phenomena.

Supplementation of Conjugated Linoleic Acid with γ-Oryzanol for 12 Weeks Effectively Reduces Body Fat in Healthy Overweight Korean Women

  • Kim, Jung-Hee;Kim, Ok-Hyun;Ha, Yeong-Lae;Kim, Jeong-Ok
    • Preventive Nutrition and Food Science
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    • v.13 no.3
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    • pp.146-156
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    • 2008
  • The enhancement of the human body fat reduction of conjugated linoleic acid (CLA) with the supplementation of $\gamma$-oryzanol (OZ) was investigated on overweight Korean women (n=51, BMI> 23). Subjects were divided into 4 groups of control, CLA, glyceride form of CLA (GCLA), and CLA plus OZ (CLA-OZ). The soft-gel capsule (500 mg) was used to deliver control (500 mg olive oil), CLA (500 mg CLA), GCLA (500 mg GCLA) and CLA-OZ (500 mg CLA plus 50 mg OZ). Three capsules were taken twice a day for 12 weeks. The CLA-OZ supplementation reduced 1.35% body fat that was 0.34% enhancement against CLA supplementation. As considered subject variations, CLA-OZ reduced body fat ranged from 7.9% to -2.7%, equivalent to 5.6 kg loss to 0.7 kg gain in body fat mass, against CLA. The CLA-OZ reduced body weight and body mass index (BMI), relative to control, but the reductions by CLA-OZ were not different from those by CLA and GCLA. All biochemical markers analyzed for safty were not significantly different within or between groups and were within the normal range. The CLA-OZ supplementation significantly reduced blood pressure, as compared to the supplementation of CLA, GCLA and control. These results suggest that OZ could be a useful ingredient to mix with CLA for the reduction of human body fat.

Image-based Soft Drink Type Classification and Dietary Assessment System Using Deep Convolutional Neural Network with Transfer Learning

  • Rubaiya Hafiz;Mohammad Reduanul Haque;Aniruddha Rakshit;Amina khatun;Mohammad Shorif Uddin
    • International Journal of Computer Science & Network Security
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    • v.24 no.2
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    • pp.158-168
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    • 2024
  • There is hardly any person in modern times who has not taken soft drinks instead of drinking water. The rate of people taking soft drinks being surprisingly high, researchers around the world have cautioned from time to time that these drinks lead to weight gain, raise the risk of non-communicable diseases and so on. Therefore, in this work an image-based tool is developed to monitor the nutritional information of soft drinks by using deep convolutional neural network with transfer learning. At first, visual saliency, mean shift segmentation, thresholding and noise reduction technique, collectively known as 'pre-processing' are adopted to extract the location of drinks region. After removing backgrounds and segment out only the desired area from image, we impose Discrete Wavelength Transform (DWT) based resolution enhancement technique is applied to improve the quality of image. After that, transfer learning model is employed for the classification of drinks. Finally, nutrition value of each drink is estimated using Bag-of-Feature (BoF) based classification and Euclidean distance-based ratio calculation technique. To achieve this, a dataset is built with ten most consumed soft drinks in Bangladesh. These images were collected from imageNet dataset as well as internet and proposed method confirms that it has the ability to detect and recognize different types of drinks with an accuracy of 98.51%.

Optically Controlled Silicon MESFET Fabrication and Characterizations for Optical Modulator/Demodulator

  • Chattopadhyay, S.N.;Overton, C.B.;Vetter, S.;Azadeh, M.;Olson, B.H.;Naga, N. El
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.10 no.3
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    • pp.213-224
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    • 2010
  • An optically controlled silicon MESFET (OPFET) was fabricated by diffusion process to enhance the quantum efficiency, which is the most important optoelectronic device performance usually affected by ion implantation process due to large number of process induced defects. The desired impurity distribution profile and the junction depth were obtained solely with diffusion, and etching processes monitored by atomic force microscope, spreading resistance profiling and C-V measurements. With this approach fabrication induced defects are reduced, leading to significantly improved performance. The fabricated OPFET devices showed proper I-V characteristics with desired pinch-off voltage and threshold voltage for normally-on devices. The peak photoresponsivity was obtained at 620 nm wavelength and the extracted external quantum efficiency from the photoresponse plot was found to be approximately 87.9%. This result is evidence of enhancement of device quantum efficiency fabricated by the diffusion process. It also supports the fact that the diffusion process is an extremely suitable process for fabrication of high performance optoelectronic devices. The maximum gain of OPFET at optical modulated signal was obtained at the frequency of 1 MHz with rise time and fall time approximately of 480 nS. The extracted transconductance shows the possible potential of device speed performance improvements for shorter gate length. The results support the use of a diffusion process for fabrication of high performance optoelectronic devices.

Preprocessing method for enhancing digital audio quality in speech communication system (음성통신망에서 디지털 오디오 신호 음질개선을 위한 전처리방법)

  • Song Geun-Bae;Ahn Chul-Yong;Kim Jae-Bum;Park Ho-Chong;Kim Austin
    • Journal of Broadcast Engineering
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    • v.11 no.2 s.31
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    • pp.200-206
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    • 2006
  • This paper presents a preprocessing method to modify the input audio signals of a speech coder to obtain the finally enhanced signals at the decoder. For the purpose, we introduce the noise suppression (NS) scheme and the adaptive gain control (AGC) where an audio input and its coding error are considered as a noisy signal and a noise, respectively. The coding error is suppressed from the input and then the suppressed input is level aligned to the original input by the following AGC operation. Consequently, this preprocessing method makes the spectral energy of the music input redistributed all over the spectral domain so that the preprocessed music can be coded more effectively by the following coder. As an artifact, this procedure needs an additional encoding pass to calculate the coding error. However, it provides a generalized formulation applicable to a lot of existing speech coders. By preference listening tests, it was indicated that the proposed approach produces significant enhancements in the perceived music qualities.

A Design and Implementation of 4×10 Gb/s Transimpedance Amplifiers (TIA) Array for TWDM-PON (TWDM-PON 응용을 위한 4×10 Gb/s Transimpedance Amplifier 어레이 설계 및 구현)

  • Yang, Choong-Reol;Lee, Kang-Yoon;Lee, Sang-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.7
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    • pp.440-448
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    • 2014
  • A $4{\times}10$ Gb/s Transimpedance Amplifier (TIA) array is implemented in $0.13{\mu}m$ CMOS process technology, which will be used in the receiver of TWDM-PON system. A technology for bandwidth enhancement of a given $4{\times}10$ Gb/s TIA presented under inductor peaking technology and a single 1.2V power supply based low voltage design technology. It achieves 3 dB bandwidth of 7 GHz in the presence of a 0.5 pF photodiode capacitance. The trans-resistance gain is $50dB{\Omega}$, while 48 mW/ 1channel from a 1.2 V supply. The input sensitivity of the TIA is -27 dBm. The chip size is $1.9mm{\times}2.2mm$.

Matching Network Design for Improving the Bandwidth of Microstrip Antenna (마이크로스트립 안테나의 대역폭 개선을 위한 정합회로설계)

  • 전성근;이종룡;이우재;이문수
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.9 no.3
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    • pp.305-316
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    • 1998
  • The impedance matching network with the simplfied real frequency technique (SRFT) is proposed as a method for bandwidth enhancement of microstrip antenna. The validity of the technique is based on the relative frequency insensitivity of the radiation pattern and gain characteristics as compared to the resonant behaviour of the input impedance. The most significant feature of this technique is that there is no need to find any analytical description of the antenna and generator, and it only utilizes directly real frequency generator and load data over the prescribed frequency band. Furthermore, it is not necessary to invent an analytic form of the system transfer function to assume a matching network topology in advance. In this paper, the transmission line model is used to investigate the rectangular microstrip antenna, and based on the Fano's bandwidth-enlargement theory, the SRFT is introduced to design the matching networks of microstrip antennas in order to obtain a constant gain over the frequency band of interest. Two representative microstrip antnnas with different structure are fabricated and tested. From these procedures, it is obtained that the proposed impedance matching networks of microstrip antenna improve the impedance bandwidth nearly three times compared to the antenna without them.

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