• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.2
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• pp.43-63
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• 2013

Remanufacturing is a process of recovering end-of-life products into serviceable parts for producing new products. Due to the limited supply of recovery cores to remanufacture, a remanufacturing firm also needs to produce or procure new parts for fulfilling the demand. This paper is targeted for solving the problem of determining the optimal amount of newly produced and remanufacturing parts, which is called production and remanufacturing planning (PRP) problem, under uncertain supply of recovery cores. The new production mitigates the risk of insufficient core supply while it takes more costs than the remanufacturing. The PRP model in this paper also considers disassemble-to-order (DTO) environment, in which multiple kinds of parts are remanufactured from multiple products on order of the parts. Whereas existing studies presents only heuristic solutions for DTO remanufacturing, this paper provides an exact solution for this problem and analytical sensitivity of the involved cost parameters, adopting multi-dimensional newsvendor modeling and stochastic linear programming techniques. The result shows that production and remanufacturing plans for multiple products are mutually dependent, and a change of cost parameters involved in only one part is propagated to all other parts.

• International Journal of Aeronautical and Space Sciences
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• v.11 no.2
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• pp.98-109
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• 2010

This paper deals with a new method of unmanned aerial vehicle (UAV) recovery when a UAV fails to get a global positioning system (GPS) signal at an unprepared site. The proposed method is based on the simultaneous localization and mapping (SLAM) algorithm. It is a process by which a vehicle can build a map of an unknown environment and simultaneously use this map to determine its position. Extensive research on SLAM algorithms proves that the error in the map reaches a lower limit, which is a function of the error that existed when the first observation was made. For this reason, the proposed method can help an inertial navigation system to prevent its error of divergence with regard to the vehicle position. In other words, it is possible that a UAV can navigate with reasonable positional accuracy in an unknown environment without the aid of GPS. This is the main idea of the present paper. Especially, this paper focuses on path planning that maximizes the discussed ability of a SLAM algorithm. In this work, a SLAM algorithm based on extended Kalman filter is used. For simplicity's sake, a blimp-type of UAV model is discussed and three-dimensional pointed-shape landmarks are considered. Finally, the proposed method is evaluated by a number of simulations.

• Journal of Wetlands Research
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• v.3 no.2
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• pp.133-142
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• 2001

Growth of cities and an increase in population result in the development-oriented policy, urban streams to lose their natural characteristics and functions by channelization, parking lot construction, and so forth. The streams fall into urban drains, which is the current status of urban streams. Recently, the interest in the stream environment and the ecosystem has been increased, and the efforts have been made to improve the traditional maintenance program for small streams. These efforts lead to the application of the natural recovery systems. This study applied the 240-meter model reach along the Oncheon stream, which locates in Dongrae-gu, Busan city. to analyze the natural recovery system. The efficiency of each system has been analyzed and the future improvements for the systems are presented. The results show that the stream maintenance program should consider the ecological environment. thereby minimizing the environmental effects. When the changes are inevitable, the maintenance program should adopt the methods. which closely simulate the original environmental elements. or are more favorable to the ecosystem.

• KIEAE Journal
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• v.15 no.4
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• pp.77-84
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• 2015

Purpose: In 2008, As the green growth policy was presented, Green Building is made any effort to propagation. In this paper, the respective technologies that are able to considerably reduce the energy demands for heating, cooling, hot-water, lighting and ventilation among the variety of technologies were selected. Method: Design factors such as (1) External insulation, (2) Triple glazing window, (3) LED lighting, (4) External venetian blind, (5) Geothermal and (6) Heat recovery ventilator were derived. In addition, energy saving effects in terms of energy demand, energy consumption and energy cost were investigated using EnergyPlus, building energy analysis tool. Result : The results were as follows. (1) It can be seen that high insulated triple glazing window, heat recovery ventilator and external insulation technology is excellent for energy demand. (2) Unlike energy demand, saving effect of energy consumption and energy cost was shown in order of Geothermal > Triple Window > Heat recovery Ventilation> Insulation> LED Lighting > EVB Blind.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.785-790
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• 2008

Our Digital Carousel enables user to share media objects through media synchronization mechanism. We implemented the Digital Carousel so that the users participated in collaborative work may refer shared media or error objects as the same view to others. In this paper, we discuss a method for increasing reliability through fault tolerance. We describe the design and implementation of the ER running on distributed multimedia environment. ER is a system which is able to recover automatically a software error based on distributed multimedia. This paper explains a performance analysis of an error recovery system running on distributed multimedia environment using the rule-based DEVS modeling and simulation techniques. In DEVS, a system has a time base, inputs, states, outputs, and functions.

• Journal of Preventive Medicine and Public Health
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• v.6 no.1
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• pp.71-76
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• 1973

1) The oxygen consumption was studied with albino rats under normal environment after they were given Cytochrome C intravenously (10mg/kg). The cosumption was 74.6cc/kg min. with that of control, 75.4cc/kg. min. The difference of the consumptions was not statistically significant. However, under 0.5% CO environment, the oxygen consumption of the Cytochrome C treated rats (62.5cc/kg min) was significantly greater than the control (42.1cc/kg min.) 2) The recovery time of rat acutely poisoned by 1% CO was studied. The recovery time of the Cytochrome C treated group was 37.2 minutes and in control group it was 52.2 minutes. Also significant difference of fatality was noted between the treated group (21.8%) and the untreated group (49.7%) 3) The combined effects of the hyperbaric oxygenation (100% $O_2$ at 3 atmospheric pressures) and the Cytochrome C administration was compared with the effect of the simple hyperbaric oxygenation. There was no significant difference of recovery time between the experimental group while the fatality of the experiment group was lower than control group.

• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.122-127
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• 2006

Fundamental studies were carried out for an effective removal and recovery of silver from waste photo-developing solution by solvent extraction. The organic solvents examined for silver-extraction were ALIQUAT 336, D2EHPA, KELEX 100, and TBP. ALIQUAT 336, which is an anionic exchanger, was found to be efficient for the extraction of silver and the reason for this was considered to be due to the chloride ion contained in its structure. The extent of silver extraction was examined to increase with the concentration of ALIQUAT 336 until it reached 0.6 M and no more extraction was observed above this concentration. The extraction of silver by ALIQUAT 336 was found to reach its pseudo-equilibrium within a few minutes after the reaction started and additional slight increase in silver extraction was observed until 30 minutes of reaction time. The observed differences in silver extraction for artificial and actual waste solutions were considered to be based upon the different ionic form of silver-containing species in these solutions.

• Journal of Korean Society on Water Environment
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• v.28 no.5
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• pp.723-728
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• 2012

In this study, zeolites were synthesized by a fusion and a hydrothermal methods using a coal fly ash and a waste catalyst. The recovery performance of metal ions on the structure property of synthetic zeolites was evaluated as comparing the adsorption kinetics (Lagergen 2nd order model) and isotherm (Langmuir model) of $Co^{2+},\;Ni^{2+}$, and $Cu^{2+}$ ions. The synthetic zeolites (Z-C1 and Z-W5) were similarly assigned to XRD peaks in a reagent grade Na-A zeolite (Z-WK : $Na_{12}Al_{12}Si_{12}O_{48}\;27.4H_2O$). Adsorption rates of Z-W5 and Z-C1 were in the order of $Cu^{2+}\;>\;Co^{2+}\;>\;Ni^{2+}\;and\;Ni^{2+}\;>\;Cu^{2+}\;>\;Co^{2+}$, respectively. They had influenced upon structure properties of zeolite. Selectivities of metal ions and maximum equilibrium adsorption capacities, $q_{max}$, in Z-C1 and Z-W5 were in the order of $Ni^{2+}$ (127.9 mg/g) > $Cu^{2+}$ (94.7 mg/g) > $Co^{2+}$ (82.6 mg/g) and $Cu^{2+}$ (141.3 mg/g) > $Co^{2+}$ (122.2 mg/g) > $Ni^{2+}$ (87.6 mg/g), respectively. The results show that the synthetic zeolites, Z-C1 and Z-W5, are able to recover metal ions selectively in wastewater.

• The KIPS Transactions:PartA
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• v.11A no.5
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• pp.313-318
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• 2004

In this paper, we suggest a checkpoint and recovery facility for the fault-tolerable process which is expected to be executed for a long time. The basic concept of the suggested facility is to allow the process to be executed continuously, when the process was stopped due to a System fault, by storing the execution status of the process periodically and recovering the execution status prior to the fault was occurred. In the suggested facility, it does not need to modify the source code for the fault-tolerable process. It was designed for the user to specify directly the file name and the checkpoint frequency, and two system calls(save, recover) were added. finally, it was implemented on the Linux environment(kernel 2.4.18) for checking the feasibility.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.140-145
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• 2014

Exploitation of renewable energies is on the increase to mitigate the reliance on fossil fuels and other natural gases with rocketing prices currently due to the depletion of their reserves not to mention their diverse consequences on the environment. Divergently, there are lots of industries "throwing" heat at higher temperatures as by products into the environment. This waste heat can be recovered through organic Rankine systems and converted to electrical energy with a waste heat recovery organic Rankine cycle system (WHR-ORC). This study uses the annual average condenser effluent from Namhae power plant as heat source and surface seawater as cooling source to analyze a waste heat recovery organic Rankine cycle using the Aspen HYSYS simulation software package. Hydrocarbon mixtures are employed as working fluid and varied in a ratio of 9:1. Results indicate that Pentane/Isobutane (90/10) mixture is the favorable working fluid for optimizing the waste heat recovery organic Rankine cycle at the set simulation conditions.