• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.587-592
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• 2005

Hydrolyzates from lignocellulosic biomass contain a mixture of simple sugars; the predominant ones being glucose, cellobiose and xylose. The fermentation of such mixtures to ethanol or other chemicals requires an understanding of how each of these substrates is utilized. Candida lusitaniae can efficiently produce ethanol from both glucose and cellobiose and is an attractive organism for ethanol production. Experiments were performed to obtain kinetic data for ethanol production from glucose, cellobiose and xylose. Various combinations were tested in order to determine kinetic behavior with multiple carbon sources. Glucose was shown to repress the utilization of cellobiose and xylose. However, cellobiose and xylose were simultaneously utilized after glucose depletion. Maximum volumetric ethanol production rates were 0.56, 0.33, and 0.003 g/L h from glucose, cellobiose and xylose, respectively. A kinetic model based on cAMP mediated catabolite repression was developed. This model adequately described the growth and ethanol production from a mixture of sugars in a batch culture.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1114-1116
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• 1999

This paper presents a new algorithm which evaluates production cost and reliability indices under various constraints of the thermal generation system. In order to consider the operational constraints of thermal units effectively, the proposed algorithm is based on Monte Carlo techniques instead of analytical ones which have difficulty in modelling the units with additional constraints. At that point, generating units are modelled into two types, base load units and peaking units. These generating unit models are used in state duration sampling simulation for which approach can readily consider the peaking unit operating cycles and easily calculates frequency-duration indices. The proposed production simulation algorithm is applied to the IEEE Reliability Test System, and performs the production simulation under the given constraints. The results show that the proposed algorithm is accurate, reliable and useful.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.683-690
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• 2003

This purpose of this research is an attempt to measure and comparatively analyze the efficiencies and RTS(Returns to Scale) using panel data of OECD countries including Korea. In order to achieve this purpose, at first this study used efficient production frontier estimation combined with DEA for obtaining parameter estimates of a efficient production frontier. secondly using estimated results, measured R&D productivity and RTS(Returns to Scale) on all of the OECD countries. thirdly using time-series data related to R&D activity of korea, measured R&D productivity and RTS(Returns to Scale). Finally based on the results of R&D productivity and RTS(Returns to Scale) using efficient production frontier, some policy implications for enhancing the R&D competitiveness and the technological capabilities are discussed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.32
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• pp.177-186
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• 1994

Economic Lot size decision is studied on this thesis foe the muti-product small batch production system. Even though economic lot size decision has been studied for the MRP system. this could be applied at the industry under the multi-product small batch production system because of very complicate and manager's lack of understand. Therefore, this technique is applied at the industry in order to minimize ordering cosy based on optimal quantity and period, and holding cost according to optimize inventory level under the muti-product small batch production system. After that, lot size decision technique is compared with lot size decision technique which has been used for analyzing and emphasizing productivity

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.1
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• pp.144-154
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• 2008

The rumen microbial ecosystem produces methane as a result of anaerobic fermentation. Methanogenesis in the rumen is thought to represent a 2-12% loss of energy intake and is estimated to be about 15% of total atmospheric methane emissions. While methanogenesis in the rumen is conducted by methanogens, PCR-based techniques have recently detected many uncultured methanogens which have a broader phylogenetic range than cultured strains isolated from the rumen. Strategies for reduction of methane emissions from the rumen have been proposed. These include 1) control of components in feed, 2) application of feed additives and 3) biological control of rumen fermentation. In any case, although it could be possible that repression of hydrogen-producing reactions leads to abatement of methane production, repression of hydrogen-producing reactions means repression of the activity of rumen fermentation and leads to restrained digestibility of carbohydrates and suppression of microbial growth. Thus, in order to reduce the flow of hydrogen into methane production, hydrogen should be diverted into propionate production via lactate or fumarate.

• Journal of the Korea Safety Management & Science
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• v.13 no.1
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• pp.115-119
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• 2011

To help the corporations ensure more efficient production management, the Enterprise Resource Planning (ERP) system has been introduced in operation, together with a variety of approaches to make improvements in terms of quality and productivity issues. Yet, with the different types of ERP systems in operation, many companies are going through many difficulties not only in having greatly reduced work efficiency but also in making prompt decisions from the entire group-based integrated information. In this study, the analysis was made on their own ERP systems and working processes operated by a company running the multiple number of productions from the domestic and the overseas suppliers, in order to support their interacted work flow regarding their products and help improve the work efficiency by establishing standardized ERP system. Through this, it is expected to ensure more competitive system in operation by securing the flexibility in the production as well as efficient resource distribution under the corporate context of cost reduction and quality improvement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.4726-4731
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• 2011

This paper proposed the algorithm to select optimal grinding condition for plunge grinding in the batch production unit. In order to apply to the proposed algorithm, the state variable for plunge grinding process was defined and the optimal grinding condition for each cycle in batch production was decided by genetic algorithm. Based on the optimized grinding condition in each cycle, the optimal grinding condition for whole batch production was selected by dynamic programming. The proposed algorithm was evaluated by computer simulation.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.8
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• pp.37-44
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• 2008

Nowadays, the increasing global competition forces manufacturer to reduce the cost and time for implementation of manufacturing system. The AR(augmented reality) technology as a new human-machine interface introduces a noteworthy perspective for a new manufacturing system design. Using AR technology, a physically existing production environment can be superimposed with virtual planning objects. Therefore, the planning tasks can be validated without modeling the surrounding environment of the production domain during short process planning time. In this paper, we introduce the construction of AR browser and determine the optimal environment parameters for field application of AR system through lots of tests. And, many methods such as multi-marker coordinate system, division of virtual objects and so on, are proposed in order to solve the problems suggested from initial field test. Based on these tests and results, the test-bed of C/Pad assembly system is configured and robot program for C/Pad assembly is generated based on AR system.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.280-280
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• 2000

In this paper, we propose a method of constructing equation using bio-inspired emergent and evolutionary concepts. This method is algorithm that is based on the characteristics of the biological DNA and growth of plants. Here is. we propose a constructing method to make a DNA coding method for production rule of L-system. L-system is based on so-called the parallel rewriting mechanism. The DNA coding method has no limitation in expressing the production rule of L-system. Evolutionary algorithms motivated by Darwinian natural selection are population based searching methods and the high performance of which is highly dependent on the representation of solution space. In order to verify the effectiveness of our scheme, we apply it to one step ahead prediction of Mackey-Glass time series.

• Journal of Internet Computing and Services
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• v.2 no.2
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• pp.117-126
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• 2001

This paper presents fuzzy Pr/T nets to represent the fuzzy production rules of a knowledge-based system in the level of first-order predicate logic. The fuzzy Pr/T nets are fuzzy extension of the Pr/T nets. Based on the fuzzy Pr/T net, we propose a fuzzy reasoning algorithm. This algorithm is much closer to human intuition and reasoning than other methods because of using the proper belief functions according to fuzzy concepts in fuzzy production rules.