• Korean Journal of Agricultural Science
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• v.8 no.1
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• pp.3-10
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• 1981

In order to analyze growth and yield of rice population at the stand point of productive ecology, productive structure and growth rate of rice plants and effects of their related factors were studied. The results obtained were summarized as follows: 1. High crop growth rate was maintained throughout growing season when rice plants grew in population compared to a single rice plant. Since crop growth rate in rice stands were also higher at ripening stage, higher yields were obtained. 2. Higher crop growth rate of rice plants in population was maintained by the increase of leaf area rather than by net assimilation rate. 3. As the overgrowth of upper leaves of plant population in some rice varieties transmission of light into lower leaves was inhibited and thus most of them were eventually died before flowering. 4. In the case of rice population, the ratio of productive organ to non-productive organ, light transmission rate and nitrogen contents of active leaf blade were lower than individual rice plants under isolated condition.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1443-1451
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• 2020

The objective of this study is to design a robust power control system for a small pressurized water reactor (PWR) to achieve stable power operations under conditions of external disturbances and internal model uncertainties. For this purpose, the multiple-input multiple-output transfer function models of the reactor core at five power levels are derived from point reactor kinetics equations and the Mann's thermodynamic model. Using the transfer function models, five local reactor power controllers are designed using an H infinity (H_∞) mixed sensitivity method to minimize the core power disturbance under various uncertainties at the five power levels, respectively. Then a multimodel approach with triangular membership functions is employed to integrate the five local controllers into a multimodel robust control system that is applicable for the entire power range. The performance of the robust power system is assessed against 10% of full power (FP) step load increase transients with coolant inlet temperature disturbances at different power levels and large-scope, rapid ramp load change transient. The simulation results show that the robust control system could maintain satisfactory control performance and good robustness of the reactor under external disturbances and internal model uncertainties, demonstrating the effective of the robust power control design.

• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1626-1637
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• 2020

This work covers an important point of the benchmark released by the expert group on Uncertainty Analysis in Modeling of Light Water Reactors. This ambitious benchmark aims to determine the uncertainty in light water reactors systems and processes in all stages of calculation, with emphasis on multi-physics (coupled) and multi-scale simulations. The Gesellschaft für Anlagen und Reaktorsicherheit methodology is used to propagate the thermal-hydraulic uncertainty of macroscopic parameters through TRACE5.0p3/PARCSv3.0 coupled code. The main innovative points achieved in this work are i) a new thermal-hydraulic model is developed with a highly-accurate 3D core discretization plus an iterative process is presented to adjust the 3D bypass flow, ii) a control rod insertion occurrence -which data is obtained from a real PWR test- is used as a transient simulation, iii) two approaches are used for the propagation process: maximum response where the uncertainty and sensitivity analysis is performed for the maximum absolute response and index dependent where the uncertainty and sensitivity analysis is performed at each time step, and iv) RESTING MATLAB code is developed to automate the model generation process and, then, propagate the thermal-hydraulic uncertainty. The input uncertainty information is found in related literature or, if not found, defined based on expert judgment. This paper, first, presents the Gesellschaft für Anlagen und Reaktorsicherheit methodology to propagate the uncertainty in thermal-hydraulic macroscopic parameters and, then, shows the results when the methodology is applied to a PWR reactor.

• Journal of Korean Elementary Science Education
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• v.32 no.3
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• pp.327-345
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• 2013

This study aims to investigate how pre-service elementary school teachers understand 'something scientific', 'being scientific', 'scientific events' and 'scientific questions' through semantic network analysis. To achieve this purpose, this study carried out a central analysis of the frequency and density of words and the degree of connection between key words, a concentric analysis, a click analysis and a common network analysis through text semantic network analysis by using NetMiner 4.0 Program. Based on the results of these analyses, this study came to the following conclusions. Firstly, in perceiving 'something scientific', pre-service elementary school teachers recognized 'verification', 'objective' and 'experiment' as most important words. In other words, they perceived that main grounds for something scientific should be provided through clear facts, possible to be verified and accompanied by an exact and logical theoretical system. In regard to 'being scientific', they perceived 'explanation', 'objective' and 'verification' as most important words, while having a traditional point of view that science is a set that can be explained objectively. Secondly, in regard that the term, 'observation', is contained in 'scientific events', they showed a high rate of understanding it as a scientific event. In regard to scientifical reasons, they showed the highest frequency of 'observation', and for unscientific reasons, they showed the highest frequency of 'behavior'. In perceiving 'scientific questions', they showed the highest frequency of determining bacteria-related questions as scientific. As a reason why they thought as scientific, they mentioned 'observation' most frequently like 'scientific events', while mentioning 'value judgement' as a reason why they thought as unscientific most frequently. From the results of integrated network analysis, this study found out that words pre-service teachers commonly used in stating scientific events or scientific questions were overlapped with words they mentioned for scientific events or scientific questions. As a result, it was found there were many pre-service teachers having interpreted scientific words without clearly distinguishing scientific events or scientific questions.

• Culinary science and hospitality research
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• v.9 no.2
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• pp.148-175
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• 2003

As mentioned above, Korean restaurant's menu price is to be decided by combining various factors. Korean restaurant is demanded to decide menu price more carefully than other restaurants do, because the number of Korean restaurant is the largest in Korea and Korean food is the most popular among the Korean people. Korean restaurant cannot neglect price competitiveness and is often given complaints from its customers. Because of such management difficulties, the number of Korean restaurant has recently decreased at special class hotels as well as common hotels. Korean restaurant managers are demanded to make efforts to inherit Korean tradition and culture by keeping pride and responsibility. Until now, Korean restaurants are thought to decide the menu prices in short-sighted, non-scientific and haphazard way of thinking. Such price decision factors have established traditions and have been generally accepted to let Korean restaurant managers lose carefulness at the menu price decision. In advanced countries, however, they recognized the importance of the price decision since the 1960's or earlier to research the menu price systematically and scientifically. Before deciding the menu prices, Korean restaurant managers are demanded to investigate various kinds of factors carefully and spend a lot of time to calculate direct costs, that is, one of the most important factors of cost calculations. The managers are demanded to decide the menu prices in reasonable and future-oriented way by keeping not private thinking but correct information and judgment. The sale of each menu has difference, while the menu price increase has been evaluated to be successful from overall point of view. Despite of increased total sale, there was not much difference of net profit because of increased material costs. However, higher level of the customers produced comfortable and cozy atmosphere of the restaurant enough to satisfy customers, and improved service quality much more. Not only customer satisfaction but also improved service quality is thought to play an important role in invitation of future customers.

• The Journal of Korean Association of Computer Education
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• v.13 no.6
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• pp.91-98
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• 2010

NAC(Network Access Control) has been developed as a solution for the security of end-point user, to be a target computer of worm attack which does not use security patch of OS and install Anti-Virus, which spreads the viruses in the Intra-net. Currently the NAC products in market have a sufficient technology of pre-connect, but insufficient one of post-connect which detects the threats after the connect through regular authentication. Therefore NAC users have been suffered from Zero-day attacks and malware infection. In this paper, to solve the problems in the post-connect step we generate the normal behavior profiles using the traffic information of each host, host information through agent, information of open port and network configuration modification through network scanner addition to authentication of host and inspection of policy violation used before. Based on these we propose the system to detect the hosts infected malware.

• Convergence Security Journal
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• v.6 no.4
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• pp.67-73
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• 2006

The method which research a standardization from real time cyber threat is finding the suspicious indication above the attack against cyber space include internet worm, virus and hacking using analysis the event of each security system through correlation with the critical point, and draft a general standardization plan through statistical analysis of this evaluation result. It means that becomes the basis which constructs the effective cyber attack response system. Especially at the time of security accident occurrence, It overcomes the problem of existing security system through a definition of the event of security system and traffic volume and a concretize of database input method, and propose the standardization plan which is the cornerstone real time response and early warning system. a general standardization plan of this paper summarizes that put out of threat index, threat rating through adding this index and the package of early warning process, output a basis of cyber threat index calculation.

• Journal of IKEEE
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• v.22 no.2
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• pp.242-249
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• 2018

In this paper, we identify the code vulnerabilities that can be automatically detected through Visual Studio (VS) compiler and code analyzer based on a secure coding rule set which is optimized for development of battlefield information system. Then we describe a weak point item that can be dealt with at the implementation stage without depending on the understanding or ability of the individual programmer's secure coding through the implementation of the secure coding library. Using VS compiler and the code analyzer, the developers can detect only about 38% of security weaknesses. But with the help of the proposed secure coding library, about 48% of security weaknesses can be detected and prevented in the proactive diagnosis in the development stage.

• ETRI Journal
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• v.21 no.4
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• pp.52-64
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• 1999

QoS monitoring is a kind of real-time systems which allows each level of the system to track the ongoing QoS levels achieved by the lower network layers. For these systems, real-time communications between corresponding transport protocol objects is essential for their correct behavior. When two or more entities are employed to perform a certain task as in the case of communication protocols, the capability to do so is called interoperability and considered as the essential aspect of correctness of communication systems. This paper describes a formal approach on modeling and interoperability test case generation of a real-time QoS monitoring protocol. For this, we specify the behavior of flow monitoring of transport layer QoS protocol, i.e., METS protocol, which is proposed to address QoS from an end-to-end's point of view, based on QoS architecture model which includes ATM net work in lower layers. We use a real-time Input/Output finite State Machine to model the behavior of real-time flow monitoring over time. From the modeled real-time I/OFSM, we generate interoperability test cases to check the correctness of METS protocol's flow monitoring behaviors for two end systems. A new approach to efficient interoperability testing is described and the method of interoperability test cases generation is shown with the example of METS protocol's flow monitoring. The current TTCN is not appropriate for testing real-time and multimedia systems. Because test events in TTCN are for message-based system and not for stream-based systems, the real-time in TTCN can only be approximated. This paper also proposes the notation of real-time Abstract Test Suite by means of real-time extension of TTCN. This approach gives the advantages that only a few syntactical changes are necessary, and TTCN and real-time TTCN are compatible. This formal approach on interoperability testing can be applied to the real-time protocols related to IMT-2000, B-ISDN and real-time systems.

• The Journal of the Korea Contents Association
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• v.10 no.2
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• pp.89-98
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• 2010

The enterprise system is becoming more complex and larger. With the changes of the times, the system is developing to object-oriented programming method(OOP). However, the same code inserts to the core class repetitiously in the OOP, that causes a decrease in productivity and a trouble of application of another requirement. To solve this weak point, we propose a weaving mechanism what applies to metadata and crosscutting concern. For a class optimization and an integration between different languages, we take the following way. This paper uses three ways, those are, metadata generation using reflection, transformation to Abstract Syntax Tree, and mapping through crosscutting information specified XML. Through the proposed theory, class optimization can be accomplished by solving a functional decentralization and a confusion of codes.