• Title/Summary/Keyword: negative transfer

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Modulation of the Cytochrome c Oxidase Activity by ATP: Implications for Mitochondrial Respiratory Control

  • Park, Nan-Hyang;Chun, Sun-Bum;Han, Tae-Young;Han, Sang-Hwa
    • BMB Reports
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    • v.29 no.4
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    • pp.300-307
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    • 1996
  • ATP and ADP are potential regulators of mitochondtial respiration and at physiological concentrations they affect the rate of electron transfer between cytochrome c and cytochrome c oxidase. The electron transfer, however, depends on the electrostatic interaction between the two proteins. In order to exclude any nonspecific ionic effects by these polyvalent nucleotides, we used 2'-O-(2,4,6)trinitro(TNP)-derivatives of ATP and ADP which have three orders of magnitude higher affinity for cytochrome c oxidase. A simple titration of the fluorescence intensity of TNP by cytochrome c oxidase showed a binding stoichiometry of 2:1 cytochrome c:cytochrome c oxidase. Higher ionic strength was required for TNP-ATP than for TNP-ADP to be dissociated from cytochrome c oxidase, indicating that the negative charges on the phosphate group are at least partially responsible for the binding. In both spectrophotometric and polarographic assays, addition of ATP (and ADP to a less extent) showed an enhanced cytochrome c oxidase activity. Both electron paramagnetic resonance and fluorescence spectra indicate that there is no Significant change in the cytochrome c-cytochrome c oxidase interaction. Instead, reduction levels of the cytochromes at steadystate suggest that the increased activity of nucleotide-bound cytochrome c oxidase is due to faster electron transfer from cytochrome ${\alpha}$ to cytochrome ${\alpha}_3$, which is known to be the fate limiting step in the oxygen reduction by cytochrome c oxidase.

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Experimental Study on High Frequency Vibration Transfer Characteristic of Underwater Cylindrical Shell (수중 원통형 쉘 구조물의 고주파 진동 전달특성에 대한 실험적 연구)

  • Jung, Hyung-Gi;Min, Cheon-Hong;Park, Han-Il
    • Journal of Ocean Engineering and Technology
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    • v.25 no.5
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    • pp.58-63
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    • 2011
  • Underwater vehicles such as UUVs (Unmanned Underwater Vehicles) and ROVs (Remotely Operated Vehicles) use sonar to detect their underwater environment or other underwater vehicles. The underwater vehicles designed recently have an electrical power system with high rotational speed. This system can generate high frequency vibrations above 10 kHz, and these vibrations can cause bad (negative) effects on the performance of the sonar. In many previous investigations, numerical analyses have been used for high frequency vibration problems. In this study, an experimental analysis was carried out, and a circular cylindrical shell was considered as the hull structure of an underwater vehicle. Frequency transfer functions for the circular cylindrical shell were identified using an experimental vibration analysis in the air and in a fully-submerged condition. We compare the frequency transfer functions in the air and water to obtain hydro-elastic effects. It is found that the dynamic characteristics of the circular cylindrical shell are changed by varying the response position.

Heat Transfer Analysis of Hydropneumatic Suspension Unit By Finite Element Method (유한요소법을 이용한 유기압 현수장치의 열전달 해석)

  • Bae, Jing-Do;Cho, Jin-Rae;Lee, Hong-Woo;Song, Jung-In;Lee, Jin-Kyoo
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.531-536
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    • 2004
  • In-arm type hydropeumatic suspension unit(ISU) is an equipment of armed tracked vehicle to absorb impact load and vibration from the irregular ground. During the operation of ISU, main piston moves forward and backward and oil flowing through damper transmits the external impact load to floating piston. Heat is generated in ISU by the oil pressure drop through the damper orifice and the friction between cylinder wall and two pistons. On the other hand, internal heat dissipatis outside via heat convection. Occurrence of high temperature can deteriorate durability of major components and basic function of ISU. And, it can cause fatal problem in the ISU life time and the sealing performance of piston rings. As well, the spring constant change of nitrogen gas that is caused by the temperature rise exerts the negative effect to the vehicle stability. Therefore, in this paper, we analyze the heat transfer analysis of the entire ISU unit, by finite element method, with the outside flow velocities 8m/s and 10m/s.

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Some Properties About the Root Loci for Unity Negative Feedback Control Systems (단일 부궤환 제어시스템의 근궤적에 관한 특성)

  • Kang, Hwan-Il
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.1005-1008
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    • 1996
  • We consider the interval of a gain within which it is guaranteed that a feedback control system is stable. This paper presents the condition under which either a unity feedback control system is stable for a connected gain interval with a proportional compensator cascaded with an open loop forward transfer function. By the connected interval we mean that all the numbers between any two numbers in the connected interval belongs to the connected interval. The condition may be described by a frequency inequality in terms of the denominator and/or numerator of the closed loop transfer function. We also consider the conditions for the discrete-time control systems and the time delay continuous-time control systems. We show that this condition cannot be extended for the transfer function having complex coefficients via a counterexample.

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Breast Tumor Cell Nuclei Segmentation in Histopathology Images using EfficientUnet++ and Multi-organ Transfer Learning

  • Dinh, Tuan Le;Kwon, Seong-Geun;Lee, Suk-Hwan;Kwon, Ki-Ryong
    • Journal of Korea Multimedia Society
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    • v.24 no.8
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    • pp.1000-1011
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    • 2021
  • In recent years, using Deep Learning methods to apply for medical and biomedical image analysis has seen many advancements. In clinical, using Deep Learning-based approaches for cancer image analysis is one of the key applications for cancer detection and treatment. However, the scarcity and shortage of labeling images make the task of cancer detection and analysis difficult to reach high accuracy. In 2015, the Unet model was introduced and gained much attention from researchers in the field. The success of Unet model is the ability to produce high accuracy with very few input images. Since the development of Unet, there are many variants and modifications of Unet related architecture. This paper proposes a new approach of using Unet++ with pretrained EfficientNet as backbone architecture for breast tumor cell nuclei segmentation and uses the multi-organ transfer learning approach to segment nuclei of breast tumor cells. We attempt to experiment and evaluate the performance of the network on the MonuSeg training dataset and Triple Negative Breast Cancer (TNBC) testing dataset, both are Hematoxylin and Eosin (H & E)-stained images. The results have shown that EfficientUnet++ architecture and the multi-organ transfer learning approach had outperformed other techniques and produced notable accuracy for breast tumor cell nuclei segmentation.

Effect of the Attributes of Corporate Knowledge on Knowledge acquisition, Transfer, Application and Management Performance (기업 지식의 특성이 지식획득, 이전, 활용과 경영성과에 미치는 영향)

  • Moon, Jae Young;Lee, Won Hee
    • The Journal of the Korea Contents Association
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    • v.13 no.11
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    • pp.845-855
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    • 2013
  • In today's knowledge-based industries, knowledge can be said to be a significant factor that has a decisive impact on corporate competitiveness. Recently, Korean construction companies have been going through a difficult period of time because of various negative domestic and foreign factors, such as economic decline and a continued sluggish domestic construction market, mainly due to the Korean government's real estate regulations and increasing competition from overseas companies with improved technologies. To help domestic construction companies navigate such an environment, this study empirically analyzes how the nature of corporate knowledge impacts the acquisition, transfer and deployment of knowledge within the organization of a company. Through such empirical analysis, we looked into how internal attributes of corporate knowledge affect the acquisition, transfer and application of such knowledge for domestic construction companies, with the application of the structural equation modeling (SEM). According to the results of this study, it is clear that the attributes of corporate knowledge have a significant impact on the acquisition, transfer and application of corporate knowledge, and therefore on the managerial performance of domestic companies.

Retrospective study of single vitrified-warmed blastocyst transfer cycles according to the presence of morphokinetic variables

  • Hur, Yong Soo;Ryu, Eun Kyung;Hyun, Chang Seop;Yang, Seong Ho;Yoon, San Hyun;Lim, Kyung Sil;Lee, Won Don;Lim, Jin Ho
    • Clinical and Experimental Reproductive Medicine
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    • v.45 no.1
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    • pp.52-55
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    • 2018
  • This study retrospectively assessed whether time-lapse data relating to developmental timing and morphology were associated with clinical outcomes, with the eventual goal of using morphokinetic variables to select embryos prospectively for cryopreservation. In this study, we examined the clinical outcomes of single vitrified-warmed blastocyst transfer cycles that were cultured in a time-lapse incubation system. The morphokinetic variables included uneven pronuclei, an uneven blastomere, multinucleation, and direct, rapid, and irregular division. A total of 164 single vitrified-warmed blastocyst transfer cycles were analyzed (102 cycles of regularly developed blastocysts and 62 cycles of blastocysts with morphokinetic variables). No significant differences in the age of females or the standard blastocyst morphology were found between these two groups. The regularly developed blastocysts showed significantly higher implantation and clinical pregnancy rates than the blastocysts exhibiting morphokinetic variables (30.4% vs. 9.7% and 37.3% vs. 14.5%, respectively; p< 0.01). The blastocysts that exhibited morphokinetic variables showed different mean development times compared with the regularly developed blastocysts. Although morphokinetic variables are known to have fatal impacts on embryonic development, a considerable number of embryos developed to the blastocyst stage. Morphokinetic variables had negative effects on the implantation and clinical pregnancy rates in vitrified-warmed blastocyst transfer cycles. These findings suggest that blastocysts cultured in a time-lapse incubation system should be considered for selective cryopreservation according to morphokinetic variables.

Kinetic and Mechanism of the Addition of Benzylamines to α-Phenyl-β-thiophenylacrylonitriles in Acetonitrile

  • Hwang, Jae-young;Yang, Ki-yull;Koo, In-Sun;Sung, Dae-Dong;Lee, Ik-choon
    • Bulletin of the Korean Chemical Society
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    • v.27 no.5
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    • pp.733-738
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    • 2006
  • Nucleophilic addition reactions of p-substitutedbenzylamines $(XC _6H_4CH _2NH _2)$ to $\alpha$-phenyl-$\beta$-thiophenyl-acrylonitriles ($YC _4SH _2CH=C(CN)C_6H_4$Y') have been studied in acetonitrile at 25.0, 30.0, and 35.0 ${^{\circ}C}$. The reactions take place in single step in which the $C_\beta$ -N bond formation and proton transfer to $C_\alpha$ of $\alpha$-phenyl-$\beta$-thiophenylacrylonitriles occur concurrently with four-membered cyclic transition structure. These mechanistic conclusions are drawn based on (i) the large negative $\rho$x and large positive $\rho$Y' values and also large magnitude of $\rho$X, (ii) the negative sign and large magnitude of the cross-interaction constants ($\rho$XY), (iii) the normal kinetic isotope effects ($k_H/k_D$ > 1.0), and (iv) relatively low $\Delta H ^\neq$ and large negative $\Delta S ^\neq$ values.

An Efficient Variable Rearrangement Technique for STT-RAM Based Hybrid Caches

  • Youn, Jonghee M.;Cho, Doosan
    • IEMEK Journal of Embedded Systems and Applications
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    • v.11 no.2
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    • pp.67-78
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    • 2016
  • The emerging Spin-Transfer Torque RAM (STT-RAM) is a promising component that can be used to improve the efficiency as a result of its high storage density and low leakage power. However, the state-of-the-art STT-RAM is not ready to replace SRAM technology due to the negative effect of its write operations. The write operations require longer latency and more power than the same operations in SRAM. Therefore, a hybrid cache with SRAM and STT-RAM technologies is proposed to obtain the benefits of STT-RAM while minimizing its negative effects by using SRAM. To efficiently use of the hybrid cache, it is important to place write intensive data onto the cache. Such data should be placed on SRAM to minimize the negative effect. Thus, we propose a technique that optimizes placement of data in main memory. It drives the proper combination of advantages and disadvantages for SRAM and STT-RAM in the hybrid cache. As a result of the proposed technique, write intensive data are loaded to SRAM and read intensive data are loaded to STT-RAM. In addition, our technique also optimizes temporal locality to minimize conflict misses. Therefore, it improves performance and energy consumption of the hybrid cache architecture in a certain range.

Interrelation of Alert Feedback and Immersion on Mobile Contents (모바일 콘텐츠에서의 Alert피드백과 몰입의 상호관계)

  • Bang, Green;Sung, Bokyung;Ko, Ilju
    • Journal of Korea Game Society
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    • v.14 no.5
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    • pp.61-68
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    • 2014
  • In the generalization of mobile content use, feedback is a kind of alert that affects content immersion. An alert leads to separation from the content currently being used to transfer to content that raises the alert. Immersive interference can be recognized as a problem in mobile contents use. In this paper, we propose a serious game for overcomes immersion. interference from feedback and the foundation for interrelation research between feedback and immersion. The proposed serious game has been designed to present three kinds of feedback, specifically positive, negative, and hybrid feedback, through social information about the user. We also conducted an experiment to examine the correlation between three kinds of feedback and immersion while consuming digital content. The result of the experiment showed that negative feedback leads to higher immersion than positive feedback.