• Journal of KIISE:Software and Applications
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• v.37 no.10
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• pp.745-750
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• 2010

To effectively retrieve mathematical documents including various equations, mathaware search engines are needed. In this paper, we propose a equation retrieval system which helps users effectively search structurally similar equations. The proposed system disassembles MathML equations into three types of heterogeneous indexing terms; operators, variables, and partial structures of equations. Then, it independently indexes the disassembled terms. When a user inputs a MathML equation, the proposed system searches and ranks equations using weighted sums of three language models for the heterogeneous indexing terms. In the experiments with 244,744 MathML equations, three proposed system showed reliable performances (a P@1 of 53% in the closed test and a P@1 of 63% in the open test).

• Korean Journal of Microbiology
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• v.26 no.1
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• pp.60-66
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• 1988

Dynamics of bacterial communities and its colonization under aerobic gemp retting were observed in air lift fermentor as a closed system, unlike conventional hemp retting as an open system. Dried hemp which was harvested in both 1986 and 1987 was retted at room temperature. Predominant community was facultatively anaerobic Gram-negative rods, and its density was increased from $3.0\times 10^{7}$ cells/ml to $9.0\times 10^{8}$ cells/ml. The density of facultatively nanerobic Gram-positive fods was maintained at the lovel of $5.0\times 10^{6}$ cells/m, and this Gram-positive bacterial community was not participated in retting. In the Gram-negative bacterial community during the retting, five types of colonieswere developed at early stage of pH7.0-8.0, and thereafter, only three types were colonized till later stage, shich were identified as pectolytic strain Erwinia salicis, Erwinia tracheiphila and Enterobacter agglomerans. A community of facultatively Gram-negative rods was mainly proliferated in stems and dispersed into liquor after 6-8 hours. Retting was terminated within 70-80 hours.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.658-662
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• 1990

In the air-fuel control of automotive engine to improve its efficiency, fuel economy and less emissions, conventional control methods using $O_{2}$ sensor or the lean air-fuel ratio sensor provide only open control in rich conditions. Control with a wide range air-fuel sensor makes it possible to employ closed loop control for all engine conditions including rich combustion. With a wide range A/F sensor and A/F transfer functions, a PID control system is constructed which employs an learning scheme. A/F controller is designed which enables to improve the ability of its compensation for sensors and actuators, and its control operation is evaluated by computer simulation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.929-929
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• 2005

In this study, computational demonstrations for the flutter suppression are presented for the 3-DOF airfoil system with oscillating flap. Advanced computational methods such as computational fluid dynamics (CFD) and computational structural dynamics (CSD) are used and a simultaneous coupling method has been developed to accurately conduct flutter analyses. In addition, optimal control theory is integrated into the CFD based flutter analysis method to construct the coupled aeroservoelastic analysis system for the airfoil with oscillating flap. For a well-defined typical section model, fundamental unsteady aerodynamics and flutter characteristics are investigated. Finally, to show the effectiveness of flutter control the physical aeroelastic responses are directly compared between the open loop and the closed loop systems.

• International Journal of Control, Automation, and Systems
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• v.2 no.1
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• pp.23-38
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• 2004

We proposed the infinity control principle to evaluate the Biological function. The H infinity control was applied to the Sodium (Na) ion selective gating channel on the excitable cellular membrane of the neural system. The channel opening, closing and inactivation processes were expressed by movements of three gates and one inactivation blocking particle in the channel pore. The rate constants of the channel state transition were set to be voltage dependent. The temporal changes in amounts per unit membrane area of the channel states were expressed by means of eight differential equations. The biochemical mimetic used to complete the Na ion selective channel was regarded as noise. The control inputs for ejecting the blocking particle with plugging in the channel pore were set for the active transition from inactivated states to a closed or open state. By applying the H infinity control, we computed temporal changes in the channel states, observers, control inputs and the worst case noises. The present paper will be available for evaluating the noise filtering function of the biological signal transmission system.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.3
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• pp.39-49
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• 1999

The objective of this study is to characterize the landscape retaining dynamic character through the distinction between the spatial structure and the landscape. In this study, the landscape was characterized by the image of environment viewed by human being. Firstly, the landscape was disscussed in terms of such three element as the environment viewed by human being, the psychological detachment from the environment and the meaning of image. Secondly, the dynamic character of the landscape was determined by the comparision between the spatial structure of the static elements and the landscape experience through the case study Soshe garden. In the study found that landscape experience depend on the dynamic viewpoint and human views while the spatial structure is stable and static. This study also found that landscape is an open system which can be diachronically transformed by human value, while spatial structure is a synchronic closed system.

• Journal of the Korea Institute of Building Construction
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• v.4 no.3
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• pp.125-131
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• 2004

Nowadays, it seems we are in the high time of construction design because development of construction technology widen the option of construction exterior closing materials and deepen the high-tech construction method with all various materials. When we see the flow of construction market, the mainstream is the high-rise intelligent building, which makes the best use of the small midtown area efficently. Therefore, Alum curtain wall is becoming the main material of exterior construction, the concept of which is changing from just a simple window frame to an outer wall which has comprehensive function and capability. As we think of the importance of Curtain wall as a comprehensive outer wall, We should do thorough technical examination and verification at the stage of construction design and plan of carrying out construction.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1995.11a
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• pp.153-165
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• 1995

When an automatic course-keeping is introduced as is quite popular in modern navigation the closed-loop steering system consists of autopilot device power unit(or telemotor unit) steering gear ship dynamics and magnetic or gyro compass. We derive the mathematical model of each element of the automatic steering system. We provide a method of theoretical analysis on propulsive energy loss related to automatic steering of ships inthe open seas taking account of the on-off mechanism of power unit. Also we paid attention to dead band mechanism of autopilot device which is normally called weather adjustment. Next we make numerical calculation of the effects of autopilot control constants ont he propulsive energy loss for two kinds of ship a fishing boat and an ore carrier. Realistic sea and wind disturbances are employed in the calculation.

• Journal of Korean Elementary Science Education
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• v.26 no.5
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• pp.551-557
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• 2007

The purpose of this study was to examine the questions in the 'Matter' units of elementary science textbooks under the 7th curriculum. For the analysis, a total of 338 questions were extracted from 15 units. Six criteria (recalling, recognizing, predictive, applied, divergent, and evaluative question) were reconstructed for textbook question analysis based on Blosser(1973)'s question category system for science. The results were as follows. First, there were more closed (recalling, recognizing, predictive, or applied) questions (72.2%) than open (divergent or evaluative) questions (27.8%) in elementary science textbooks. Second, cognitive-memory (recalling or recognizing) question type was the most frequently asked in all grade levels. Open (divergent or evaluative) questions increased according to grade level whereas convergent (predictive or applied) questions decreased. Third, question types were applied based on the characteristics of each unit rather than on children's developmental characteristics. Educational implications were discussed based on the results.

• Architectural research
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• v.13 no.3
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• pp.3-10
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• 2011

The Characteristics of space are determined by several factors; however, the element that determines the physical characteristic of floors, walls, and ceiling is the structure. This study constructs a wall to analyze the direct effect that the layout of an exhibition wall has on the element of the wall followed by the structural process and visibility of descriptive analysis and examples of art museums that the shift from a perceptional wall to an experiential wall affected circulation. For elements and formation methods of the wall, first, it is made up of open and closed type exhibition spaces, and it can give abundance in qualitative space rather than a quantitative aspect. Secondly, the directivity of space changes according to the development of the visible axis, thus, directly affects the change in visibility. Thirdly, the difference between spatial structure and visual structure is the difference between the visual axis and spatial structure. The wall formation type followed by the combination method, the simple visible structure, which is the type that possesses the simple combination (Room, Zone, Cluster), repeatedly uses the same size of units of space that is orderly and has few spatial axes and the classification of simple type and simple cluster type, which has few visible axes, also exists. Also, with the complex structure of the maze type it displays the reiterated form of the cluster, which is the space with disorderly combination and has much visible axes and spatial axes. Also, these can be divided into three types: 1) Maze Cluster Type, 2) Cross Road Type, and 3) Open Flexible Type. These wall types lead the various changes in circulation, and even each of the arrangement qualities of the exhibitions should be researched according to its exhibition place type.