5,591 research outputs found

    The Role of Farm Households and the Agro-Food Sector in Korean Rural Economy

    Get PDF
    This paper aims to review the role of farm households and the agro-food sector in the economy of rural areas in Korea. It discusses definition of rural area, share of agricultural and agro-food sectors in Korean economy, the income situation of farm households and non-farming activities, and multiplier effects of agriculture in Korea. Rural areas mean Eup and Myeon, whereas Dong means urban area. Rural population in Korea has continued to decrease over the years. In 2005, 18.3% of total land area, or 1,824thousand ha, was used for paddy and dry fields. The share of GRDP of agricultural, forestry, and fishing sectors was about 10% in 1985, but dropped to slightly over 3% in 2005. Thirty seven percent of farmers have a second employment in the non-farm sector and 67.2% of part-time farmers are more devoted to their non-farm activities than farming for farm household income. Rural tourism provides diverse opportunities for rural and urban residents to exchange products, services, information, and culture. New demands are arising toward rural areas: leisure and relaxation spaces, rural tourism, nature and ecology, rural amenity, and safe and fresh local foods.rural areas, agriculture, agro-food sector, farm household income, rural tourism, Korea, Agribusiness, Agricultural and Food Policy, Community/Rural/Urban Development, Consumer/Household Economics,

    First-principles study of the switching mechanism of [2]catenane molecular electronic devices

    Get PDF
    We present a first-principles study of the coherent charge transport properties of bistable [2]catenane molecular monolayers sandwiched between Au(111) electrodes. We find that conduction channels around the Fermi level are dominated by the two highest occupied molecular orbital levels from tetrathiafulvalene (TTF) and dioxynaphthalene (DNP) and the two lowest unoccupied molecular orbital levels from tetracationic cyclophane (CBPQT(4+)), and the OFF to ON switching results from the energetic shifts of these orbitals as CBPQT(4+) moves from TTF to DNP. We show that the superposition principle can be adopted for predicting the function of the composite device

    Learning to Select Pre-Trained Deep Representations with Bayesian Evidence Framework

    Full text link
    We propose a Bayesian evidence framework to facilitate transfer learning from pre-trained deep convolutional neural networks (CNNs). Our framework is formulated on top of a least squares SVM (LS-SVM) classifier, which is simple and fast in both training and testing, and achieves competitive performance in practice. The regularization parameters in LS-SVM is estimated automatically without grid search and cross-validation by maximizing evidence, which is a useful measure to select the best performing CNN out of multiple candidates for transfer learning; the evidence is optimized efficiently by employing Aitken's delta-squared process, which accelerates convergence of fixed point update. The proposed Bayesian evidence framework also provides a good solution to identify the best ensemble of heterogeneous CNNs through a greedy algorithm. Our Bayesian evidence framework for transfer learning is tested on 12 visual recognition datasets and illustrates the state-of-the-art performance consistently in terms of prediction accuracy and modeling efficiency.Comment: Appearing in CVPR-2016 (oral presentation

    Conformations and charge transport characteristics of biphenyldithiol self-assembled-monolayer molecular electronic devices: A multiscale computational study

    Get PDF
    We report a computational study of conformations and charge transport characteristics of biphenyldithiol (BPDT) monolayers in the (sqrt(3)Ɨsqrt(3))R30Ā° packing ratio sandwiched between Au(111) electrodes. From force-field molecular-dynamics and annealing simulations of BPDT self-assembled monolayers (SAMs) with up to 100 molecules on a Au(111) substrate, we identify an energetically favorable herringbone-type SAM packing configuration and a less-stable parallel packing configuration. Both SAMs are described by the (2sqrt(3)Ɨsqrt(3))R30Ā° unit cell including two molecules. With subsequent density-functional theory calculations of one unit cell of the (i) herringbone SAM with the molecular tilt angle theta[approximate]15Ā°, (ii) herringbone SAM with theta[approximate]30Ā°, and (iii) parallel SAM with theta[approximate]30Ā°, we confirm that the herringbone packing configuration is more stable than the parallel one but find that the energy variation with respect to the molecule tilting within the herringbone packing is very small. Next, by capping these SAMs with the top Au(111) electrode, we prepare three molecular electronic device models and calculate their coherent charge transport properties within the matrix Green's function approach. Currentā€“voltage (Iā€“V) curves are then obtained via the Landauerā€“BĆ¼ttiker formula. We find that at low-bias voltages (|V|~0.5 V), the Iā€“V characteristics of the three models show noticeable differences due to different phenyl band structures. We thus conclude that the BPDT SAM Iā€“V characteristics in the low-bias voltage region are mainly determined by the Siā€“Au interaction within the individual molecule-electrode contact, while both intramolecular conformation and intermolecular interaction can affect the BPDT SAM Iā€“V characteristics in the high-bias voltage region

    The role of agriculture and farm household diversification in the rural economy of Korea

    Get PDF
    ė…øķŠø : This report reviews information on the role of agriculture and farm household diversification in the rural economy of Korea. It was prepared by consultants, Dr. Jang Heo and Dr. Yong-Lyoul Kim of the Korea Rural Economic Institute

    Possible performance improvement in [2]catenane molecular electronic switches

    Get PDF
    Mechanically interlocked bistable supramolecular complexes are promising candidates of molecular electronics. Applying a multiscale computational approach, here we study the coherent charge transport properties of catenane monolayers sandwiched between Cu(111) electrodes. We demonstrate the robust nature of electrical switching behavior with respect to the variations in the monolayer packing density and the type of electrodes, as well as the thermal fluctuations of the molecules. We propose that the asymmetry of molecule-electrode barriers can be utilized to improve the switching ratio
    • ā€¦
    corecore