• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.993-998
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• 2006

We earlier suggested a hierarchical regulatory network using defined modeling symbols and weights in order to improve the flux balance analysis (FBA) with regulatory events that were represented by if-then rules and Boolean logic. In the present study, the simulation results of the models, which were developed and improved from the previou model by incorporating a hierarchical regulatory network into the FBA, were compared with the experimental outcome of an aerobic batch growth of E. coli on glucose and tryptophan. From the experimental result, a diauxic growth curve was observed, reflecting growth resumption, when tryptophan was used as an alternativee after the supply of glucose was exhausted. The model parameters, the initial concentration of substrates (0.92 mM glucose and 1 mM tryptophan), cell density (0.0086 g biomass/1), the maximal uptake rates of substrates (5.4 mmol glucose/g DCW h and 1.32 mmol tryptophan/g DCW h), and lag time (0.32 h) were derived from the experimental data for more accurate prediction. The simulation results agreed with the experimental outcome of the temporal profiles of cell density and glucose, and tryptophan concentrations.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.2
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• pp.121-131
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• 2001

The failure of network and/or node on which server object is executed is a single point of system failure in the CORBA application. One of the possible ways to overcome such problem is to replicate server objects to several independent nodes. The replicated objects executing same tasks are called object group. In order to provide fault tolerance of server object, this paper proposes and implements new CORBA model that supports the object group based on active replication. The proposed model not only provides interoperability with existing CORBA application but also minimizes additional application interface required to support object group because it uses nop to exchange messages between client and server. And this paper extends IDL structure. Depending to application logic, it makes possible to prevent performance degradation caused by consistency maintenance. At present, this paper supports only active replication. But it can be easily extended to provide warm ancVor cold passive replication without modification of architecture required for active replication.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.9B
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• pp.1057-1065
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• 2011

In order to achieve the ease of development and to facilitate the maintenance of codes for complex Ajax (Asynchronous Java Script and XML)-based web clients, this paper proposes a CVC (Communicator-View-Controller) architecture pattern by modifying the well-known MVC (Model-View-Controller) framework. By composing the Communicator of codes for asynchronous data retrieval, which is common to Ajax-based clients, the proposed architecture pattern is able to cut out the graphic design related codes to constitute the View layer. Based on such declarative generalization of complex web-client codes, Ajax-related codes can be easily modularized and efficiently reused in development and maintenance stages, and graphics design can be done separately regardless of the other business logic related codes development, resulting in highly efficient development and maintenance of complex Ajax-based web clients.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8B
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• pp.646-656
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• 2008

In this paper, we design and verify the MAC chip of the two-stage AWG-based WDM-PON which considers 128 ONUs and 32 wavelengths. Each wavelength with the capacity of 1Gbps is allocated to ONU for downstream transmission but each wavelength for upstream transmission can be shared by four ONUs. Therefore, MAC protocol is required to avoid the collision and use the network resource efficiently among ONUs which are sharing the same wavelength. To design a request/permit-based MAC protocol, we define a unit-chip module called sub-MAC. The WDM-PON with 128 ONUs can be implemented by using 32 sub-MAC modules. The sub-MAC consists of one control unit, one receipt unit and four transmission units. The state transition diagram of the module is described by the internal/external control signals among the functional units. The function of the sub-MAC module is verified through logic simulation using ModelSIM.

• Journal of the military operations research society of Korea
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• v.37 no.1
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• pp.87-97
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• 2011

In this paper, we propose a new close combat expert system to overcome the difference of combat damage assessments between combat units belong to their own model in Combined Arms Integrated Interoperability System(CAIIS) which will be deployed in the early future. When it happens to engage in a battle among combat units belong to their own model in CAIIS, the result of damage assessment is different severely. This is related to CAIIS's confidence and need to be overcome. We propose the expert system for close combat damage assessment with a decision tree. Simulation results show that the proposed expert system is valid well. Because the proposed expert system is made not as an independent system but as an inner module type of CAIIS, CAIIS will be simpler system than we expect. And we will hope to reduce the cost of CAIIS.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.1
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• pp.1-8
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• 2016

The Nuclear Power Plants(: NPP) are being protected as national infrastructure, and instrumentation and control(: I&C) systems are one of the principle facilities of the NPP, which perform the protection, control, and monitoring function. The I&C systems are being evolved into digitalization based on computer and network technology from analog system. In addition, the I&C systems are mostly employ the specialized logic controllers which are dedicated for the NPP, but the usage of generalized IT resources are steadily increased. The cyber security issues for the NPP are being emerged due to cyber incidents by Stuxnet and various accidents in the NPP. In this paper, hybrid access control model is proposed which are applicable to I&C system by analyzing the access control requirements specified in regulatory guides. The safety of in-service and under construction of NPP are effectively increased by applying proposed hybrid model.

• Journal of Radiation Protection and Research
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• v.41 no.2
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• pp.117-121
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• 2016

Background: Definition and grouping of initiating events (IEs) are important basics for probabilistic safety assessment (PSA). An IE in a spent fuel reprocessing plant (SFRP) is an event that probably leads to the release of dangerous material to jeopardize workers, public and environment. The main difference between SFRPs and nuclear power plants (NPPs) is that hazard materials spread diffusely in a SFRP and radioactive material is just one kind of hazard material. Materials and Methods: Since the research on IEs for NPPs is in-depth around the world, there are several general methods to identify IEs: reference of lists in existence, review of experience feedback, qualitative analysis method, and deductive analysis method. While failure mode and effect analysis (FMEA) is an important qualitative analysis method, master logic diagram (MLD) method is the deductive analysis method. IE identification in SFRPs should be consulted with the experience of NPPs, however the differences between SFRPs and NPPs should be considered seriously. Results and Discussion: The plutonium uranium reduction extraction (Purex) process is adopted by the technics in a model reprocessing plant. The first extraction cycle (FEC) is the pivotal process in the Purex process. Whether the FEC can function safely and steadily would directly influence the production process of the whole plant-production quality. Important facilities of the FEC are installed in the equipment cells (ECs). In this work, IEs in the FEC process were identified and categorized by FMEA and MLD two methods, based on the fact that ECs are containments in the plant. Conclusion: The results show that only two ECs in the FEC do not need to be concerned particularly with safety problems, and criticality, fire and red oil explosion are IEs which should be emphatically analyzed. The results are accordant with the references.

• Korean Journal of Construction Engineering and Management
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• v.11 no.2
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• pp.74-82
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• 2010

A government agency has been announced to increase 23,663 hundred million wons by cost of design change which occurred in the pre-construction and construction phase. As design change is a phenomenon to occur by means of a characteristic of the building design that standardization is difficult, even if it is said that a perfect design is done in design phase, design change is prevented, and it is going to decrease, and there is a limit. Because there are some causes in all of the construction project, it is change order of client, relative system, unfit design and field condition, etc. In this study, we are suggested logic and basic model of the decision making support process model that it should selecting the optimal alternative through complex and quantitative analyzed: that is cost, performance and constructability as respect Owner or CMr is executing project under the CM delivery system construction project which it occurred design change.

• Journal of The Korean Digital Architecture Interior Association
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• v.9 no.3
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• pp.95-102
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• 2009

An architectural space can be considered a life form that interconnects a number of architectural elements such as the humans who live in it. It is difficult to understand and evaluate the complexity of the interrelation between each element, but there have been various attempts to understand and evaluate this architectural space. The Space Syntax that emerged in 1980s has been studied and used more frequently than other methods. Space Syntax is the space analysis tool that analyzes the physical structure of space and represents it as a graph. Space syntax enables its various applications in space analysis by quantifying each spatial property of a whole structure, analyzing it systemically and objectively based on mathematical logic, and representing the results as a quantitative value. Integration of Space Syntax, a widely used index, reflects human behavior in spatial configuration. Meanwhile, there have been various studies in the field of architectural environmental psychology about the relationships between space and human behavior by applying behavioral science to architectural plan. One of the most widely used one is spatial behavior simulation which uses models and simulates the behavioral characteristics to anticipate practical situations and investigate the behavior related spatial problems. In this study, which focuses on the accessibility of the space syntax model, the usefulness of space will be analyzed through the simulation of human behavior that moves through each space. Furthermore, the validity of index will be verified by displaying several examples and compared with integration in space syntax, which represents the usefulness of space.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.7
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• pp.920-926
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• 2004

The human being receives a new information from outside and the information shows gradual oblivion with time. But the information remains in memory and isn't forgotten for a long time if the information is read several times over. For example, we assume that we memorize a telephone number when we listen and never remind we may forget it soon, but we commit to memory long time by repeating. If the human being received new information with strong stimulus, it could remain in memory without recalling repeatedly. The moments of almost losing one's life in an accident or getting a stroke of luck are rarely forgiven. The human being can keep memory for a long time in spite of the limit of memory for the mechanism mentioned above. In this paper, we propose a model to explain the mechanism mentioned above using a neural network and fuzzy.