Passenger facility charge vs. airport improvement program funds: A dynamic network DEA analysis for U.S. airport financing

Chang, Y.T.,Park, H.,Zou, B.,Kafle, N. Elsevier Science Ltd ; Pergamon ; Elsevier Science 2016 TRANSPORTATION RESEARCH PART E-LOGISTICS AND TRANS Vol.88 No.-

<P>Passenger Facility Charge (PFC) and the Airport Improvement Program (AIP) are two major sources to finance U.S. airports. This paper develops a novel dynamic network DEA framework to investigate the substitutability between PFC and AIP funds. We find that the studied U.S. airports can substitute PFC for 8-35% of the current AIP funds and contribute significantly to the proposed plan of the US congress to cut AIP funding. In addition, the amount of PFC-for-AIP funds substitution negatively correlates with the productive efficiency of airports. The findings send an important message for future policy reforms on U.S. airport financing. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Supply chain coordination with a single supplier and multiple retailers considering customer arrival times and route selection

Moon, I.,Feng, X. Elsevier Science Ltd ; Pergamon ; Elsevier Science 2017 TRANSPORTATION RESEARCH PART E-LOGISTICS AND TRANS Vol.106 No.-

<P>We address a novel decentralized supply chain with one supplier and multiple independent retailers based on the practice of several supply chains in the real world. Coordination of such a supply chain has rarely been studied. Despite overcoming the well-known double marginalization, the supplier's route selection can obstruct supply chain coordination. We present a wholesale-price-and-carpooling contract to coordinate such a supply chain. We demonstrate supply chain coordination under such a contract and show that the profit along the supply chain can be arbitrarily allocated. We show that the popular revenue-sharing contract may lose flexibility in profit allocations. (C) 2017 Elsevier Ltd. All rights reserved.</P>

Warehouse capacity sharing via transshipment for an integrated two-echelon supply chain

Feng, X.,Moon, I.,Ryu, K. Elsevier Science Ltd ; Pergamon ; Elsevier Science 2017 TRANSPORTATION RESEARCH PART E-LOGISTICS AND TRANS Vol.104 No.-

<P>Warehouse capacity constraint has been one obstacle to achieving the channel-wide optimal decision in inventory management. We studied an integrated inventory model consisting of a single vendor and multiple buyers with warehouse capacity sharing via transshipment. We proposed an optimal transshipment policy by developing nonlinear programming models and genetic algorithms as well as obtaining Karush-Kuhn-Tucker points. This inventory policy can significantly reduce the channel-wide cost and the performance is influenced by the consideration of fixed transshipment costs. Sensitivity analyses show that parameters have different impacts on the channel-wide cost and the performances of the algorithms. (C) 2017 Published by Elsevier Ltd.</P>

Dilute oxalic acid pretreatment for biorefining giant reed (Arundo donax L.)

Scordia, D.,Cosentino, S.L.,Lee, J.W.,Jeffries, T.W. Pergamon ; Elsevier Science Ltd 2011 Biomass & bioenergy Vol.35 No.7

Biomass pretreatment is essential to overcome recalcitrance of lignocellulose for ethanol production. In the present study we pretreated giant reed (Arundo donax L.), a perennial, rhizomatous lignocellulosic grass with dilute oxalic acid. The effects of temperature (170-190 <SUP>o</SUP>C), acid loading (2-10% w/w) and reaction time (15-40 min) were handled as a single parameter, combined severity. We explored the change in hemicellulose, cellulose and lignin composition following pretreatment and glucan conversion after enzymatic hydrolysis of the solid residue. Two different yeast strains, Scheffersomyces (Pichia) stipitis CBS 6054, which is a native xylose and cellobiose fermenter, and Saccharomyces carlsbergensis FPL-450, which does not ferment xylose or cellobiose, were used along with commercial cellulolytic enzymes in simultaneous saccharification and fermentation (SSF). S. carlsbergensis attained a maximum ethanol concentration of 15.9 g/l after 48 h at pH 5.0, while S. stipitis, at the same condition, took 96 h to reach a similar ethanol value; increasing the pH to 6.0 reduced the S. stipitis lag phase and attained 18.0 g/l of ethanol within 72 h.

Computational analysis of supercritical CO₂ Brayton cycle power conversion system for fusion reactor

Halimi, B.,Suh, K.Y. Pergamon ; Elsevier Science Ltd 2012 Energy conversion and management Vol.63 No.-

The Optimized Supercritical Cycle Analysis (OSCA) code is being developed to analyze the design of a supercritical carbon dioxide (S-CO<SUB>2</SUB>) driven Brayton cycle for a fusion reactor as part of the Modular Optimal Balance Integral System (MOBIS). This system is based on a recompression Brayton cycle. S-CO<SUB>2</SUB> is adopted as the working fluid for MOBIS because of its easy availability, high density and low chemical reactivity. The reheating concept is introduced to enhance the cycle thermal efficiency. The helium-cooled lithium lead model AB of DEMO fusion reactor is used as reference in this paper.

Real-time gait subphase detection using an EMG signal graph matching (ESGM) algorithm based on EMG signals

Ryu, J.,Kim, D.H. Pergamon ; Elsevier Science Ltd 2017 expert systems with applications Vol.85 No.-

This study presents a gait subphase recognition method using an electromyogram (EMG) with a signal graph matching (ESGM) algorithm. Existing pattern recognition and machine learning using EMG signals has several innate problems in gait subphase detection. With respect to time domain features, their feature values may be analogous because two different gait steps may have similar muscle activation. In addition, the current gait subphase might not be recognized until the next gait subphase passes because the window size needed for feature extraction is larger than the period of the gait subphase. The ESGM algorithm is a new approach that compares reference EMG signals and input EMG signals according to time variance to solve these problems and considers variations of physiological muscle activity. We also determined all the elements of the ESGM algorithm using kinematic gait analysis and optimized the algorithm using experiments. Therefore, the ESGM algorithm reflects better timing characteristics of EMG signals than the time domain feature extraction algorithm. In addition, it can provide real-time and user-adaptive recognition of the gait subphase by using only EMG signals. Experimental results show that the average accuracy of the proposed method is 13% better than existing methods and the average detection latency of the proposed method was 5.5 times lower than existing methods.

Distributed implementation of generation scheduling algorithm on interconnected power systems

Chung, K.H.,Kim, B.H.,Hur, D. Pergamon ; Elsevier Science Ltd 2011 Energy conversion and management Vol.52 No.12

The emphasis in this paper is on investigating a new generation scheduling algorithm for the interconnected power systems. In general, the generation scheduling problem formulated as a mixed integer nonlinear programming (MINLP) can be efficiently computed by the generalized Benders decomposition (GBD) technique which decouples an original problem into the master problem and subproblems to allow remarkably fast and accurate solutions of very large problems. In order to ferret out efficient inter-temporal optimal power flow subproblems, we will propose a regional decomposition framework based on auxiliary problem principle (APP). Obviously, this scheme can find the most economic dispatch (ED) schedule under the power transactions for a multi-utility system without the exchange of each utility's own private information and major disruption to existing ED or optimal power flow (OPF) constructed by individual utilities.

Evolutionary-modified fuzzy nearest-neighbor rule for pattern classification

Kassani, P.H.,Teoh, A.B.J.,Kim, E. Pergamon ; Elsevier Science Ltd 2017 expert systems with applications Vol.88 No.-

This paper presents an improved version of the well-established k nearest neighbor (k-NN) and fuzzy NN (FNN), termed the multi-objective genetic-algorithm-modified FNN (MOGA-MFNN). The MFNN design problem is converted into a multi-modal objective maximization problem constrained by four objective functions. Thereafter, the associated parameter set of the MFNN and the feature attributes can be determined optimally and automatically via the non-dominated sorting genetic algorithm II. We introduce two new objective functions termed the Margin-I and Margin-II, which are used to improve the generalization capability of the MFNN for the unknown data, along with two existing performance functions: the geometric mean and the area under the receiver-operated characteristic curve for the training accuracy. Moreover, we proposed a novel data-dependent weight-assignment technique for local class membership functions of the MFNN. The technique enables the MFNN to determine its local neighbors adaptively through the MOGA algorithm. To expedite the classification, the MOGA-MFNN is implemented on a graphical processing unit (GPU), which significantly increases the computation speed. Furthermore, the local class-membership function of the MFNN can be computed in advance, rather than delaying it to the classification stage. This again can improve the classification speed. The MOGA-MFNN is evaluated on 20 datasets obtained from the repository of the University of California, Irvine (UCI). The experiments with rigorous statistical significance tests demonstrate that the proposed method performs competitively with the existing methods.

Quantifying drivers' acceptance of renewable fuel standard: Results from a choice experiment in South Korea

Huh, S.Y.,Kwak, D.,Lee, J.,Shin, J. Pergamon ; Elsevier Science Ltd 2014 TRANSPORTATION RESEARCH PART D-TRANSPORT AND ENVIR Vol.32 No.-

The production and use of renewable fuels in the transport sector are rapidly increasing. Renewable fuel standard (RFS) is a strong regulatory component and quantitative policy expected to have a significant market impact. In Korea, RFS implementation was agreed upon in July 2013 and will be enforced beginning in July 2015. Drivers' acceptance is the most important consideration for RFS introduction and sustainable implementation. This study analyzed Korean customer preferences for RFS and quantified their acceptance level according to policy design. A choice experiment was analyzed with a mixed logit model to reflect the heterogeneity of respondents' preferences. Respondents were relatively sensitive to the price increase, while other attributes had little effect on acceptance of RFS. Differences between the influences of attributes on drivers' acceptance should be considered when designing RFS implementation. Furthermore, it is recommended that the price of transportation fuels should be limited to an increase between KRW 10 and 20/liter (USD 8.879x10<SUP>-3</SUP> and 1.776x10<SUP>-2</SUP>/liter) to ensure high acceptance level, secure a budget for infrastructure, and achieve substantial environmental improvement.

Fabrication, growth mechanism and antibacterial activity of ZnO micro-spheres prepared via solution process

Wahab, R.,Mishra, A.,Yun, S.I.,Hwang, I.H.,Mussarat, J.,Al-Khedhairy, A.A.,Kim, Y.S.,Shin, H.S. Pergamon ; Elsevier Science Ltd 2012 Biomass & bioenergy Vol.39 No.-

This paper presents the high antibacterial activity of ZnO micro-spheres prepared via solution process using zinc nitrate hexahydrate, (+) l-cysteine, HMT and sodium hydroxide against four pathogenic bacteria Staphylococcus aureus, Escherichia coli, Salmonella typhimurium and Klebsiella pneumoniae. The antibacterial activity of ZnO micro-spheres was studied via nutrient broth medium at different concentrations (5μg/ml-45μg/ml) of ZnO micro-spheres. Our investigation reveals that the lowest concentration of micro-spheres solution inhibits the growth of microbial strain, which was found to be 5μg/ml for S. aureus, S. typhimurium and K. pneumoniae whereas for E. coli, it was calculated to be 15μg/ml. The diameter of each micro-sphere lie between 2 and 3μm as observed from FESEM and Transmission electron microscopy. The composition of synthesized material was analyzed by FTIR spectroscopy and it shows the band of ZnO at 462cm<SUP>-1</SUP>. Additionally, on the basis of morphological and chemical observations the growth mechanism of ZnO micro-spheres was also proposed.