• Communications for Statistical Applications and Methods
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• v.4 no.1
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• pp.317-325
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• 1997

Group testing is an efficient method to classify units from a population as infected or non-infected and useful in estimating the infection rate when the population infection rate is small. Upper bounds are the focus of interest in group testing, but has not been studied extensively. In this paper, the upper bound derived from the uniformly most powerful test is proposed and compared with the classical approachers, Thompson's and Bhattacharyya et al.'s methods.

• The Korean Journal of Ecology
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• v.15 no.1
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• pp.81-102
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• 1992

The forest of kadok islet was investigated from aug. 1 1990 through oct. 30, 1990. The results obtained are summarized as follow : a floristic community. Most of the investigated area is occupied by arable land and pinus thunbergii forest, quercus serrata forest with only small area of camellia japonica forest of the eastern units. pinus thunbergii community subunit : eurya japonica rhododendron mucronulatum var. ciliatum elaeagnus umbellata typical quercus serrata community subunit : stephanandra incisa rhus chinensis typical quercus autissima community camellia japonica community zelkova serrata-acer mono community carpinus coreana community

• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.101-109
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• 2015

SMRs (standardized mortality rates) for major diseases, accidents, cancer are considered in small areas of administrative units such as Eup/Myeon/Dong from years 2005 to 2008. Due to small sample issue in small areas, the precision of directly estimated crude SMR for each area can be low. In this study, we consider the HGLM (hierarchical generalized linear model) with MRF (Markov random field) to account for the spatial correlations among the small areas. The effects of covariates for cause of mortality by Dongs in Seoul and disease maps based on the estimated SMR are presented. The results suggest how we analyze and interpret the difference in mortalities by small areas such as Dongs by revealing the spatial patterns.

• Bulletin of the Society of Naval Architects of Korea
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• v.3 no.1
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• pp.25-32
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• 1966

For preliminary estimation of ships' machinery weights, many papers giving well-judged data and discussions for rational method of estimation, such as [1], [2], [3], [4], [5], [6], are available, however, they are mostly concerned with large ships propelled by power more than about 2, 000 horsepower. Regarding the medium and small-sized ships, as far as the author is aware, fragmental data and vague discussions found in various technical literature are the all available. In this paper, available data concerned with machinery weights of commercial ships propelled by direct-drive diesel plants of power below 3, 000 horsepower with single screw propeller are collected and analysed to obtain systematic data Fig. 1 and Fig. 2 as weight to power ratio versus power per shaft diagrams together with suplementary data Fig. 1 and Fig. 3. Influences of various factor such as revolutions per minute, mean effective pressure, type and construction of the main units on machinery weights are also investigated in detail to give a better guidance for logical and rational utlization of the proposed diagrams in preliminary estimation of machinery weights.

• The Journal of Korea Robotics Society
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• v.2 no.2
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• pp.137-142
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• 2007

In an information-oriented society, visually impaired persons also should obtain the information with relative ease. They tend to receive the information of letters by tactile sensation through braille display systems. Several types of braille display systems have been suggested so far, but none of them have been widely used yet. The braille display system should provide multiple lines of braille units to improve the level of understanding. In this paper, we propose a cell type braille unit with $3{\times}2$ dots, each of which consists of a piezoelectric linear motor. A braille cell is small and lightweight enough to be portable, and it can be easily assembled in multiple lines. The preliminary tests using the proposed braille display system show that it can provide the information that can be well perceived by visually impaired persons.

• International Journal of Reliability and Applications
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• v.4 no.1
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• pp.13-26
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• 2003

This paper presents a comparative study of a few commonly used maintenance scheduling methods for small utilities that consists solely of thermal generating plants. Two deterministic methods and a stochastic method are examined. The deterministic methods employ the leveling of reserve capacity criterion, of which one uses a heuristic rule to level the deterministic equivalent load obtained by using the product of the unit capacity and its corresponding forced outage rate. The stochastic method simulates the leveling of risk criterion by using the peak load carry capacity of available units. The results indicate that for the size and type of the maintenance scheduling problem described In this study, the stochastic method does not produce a schedule which is significantly better than the deterministic methods.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.1
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• pp.63-68
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• 2010

Recently, to accelerate the Ubiquitous generation, the input interface of the mobile machinery and tools are actively being researched. In addition with the existing interfaces such as the keyboard and curser (mouse), other subdivisions including the handwriting, voice, vision, and touch are under research for new interfaces. Especially in the case of small-sized mobile machinery and tools, there is a increasing need for an efficient input interface despite the small screens. This is because, additional installment of other devices are strictly limited due to its size. Previous studies on handwriting recognition have generally been based on either two-dimensional images or algorithms which identify handwritten data inserted through vectors. Futhermore, previous studies have only focused on how to enhance the accuracy of the handwriting recognition algorithms. However, a problem arisen is that when an actual handwriting is inserted, the user must select the classification of their characters (e.g Upper or lower case English, Hangul - Korean alphabet, numbers). To solve the given problem, the current study presents a system which distinguishes different languages by analyzing the form/shape of inserted handwritten characters. The proposed technique has treated the handwritten data as sets of vector units. By analyzing the correlation and directivity of each vector units, a more efficient language distinguishing system has been made possible.

• Journal of the Korea Society of Computer and Information
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• v.25 no.10
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• pp.1-14
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• 2020

In this paper, we propose to solve the problem of increasing system memory usage due to an increase in the number of mapping information management when using a NAND flash memory-based storage device in an existing sector-based file system. The proposed technique is to store only mapping information in page units based on index blocks and manage them in block units. To this end, the proposed technique uses a sequential offset for storing and managing a plurality of mapping information in one page in a small block, and a reverse offset for a spare page corresponding to a change in mapping information in the block. Through this, the proposed technique has the advantage that the number of block-unit deletions is less than that of the existing technique, and the system memory usage required for mapping information management is low. Reduced by about 32%.

• Journal of Korean Elementary Science Education
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• v.17 no.2
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• pp.79-90
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• 1998

The purpose of this study is to investigate degree of the concept formation on cell in elementary school teachers and to clarify the patterns of their misconceptions. Data were collected by interview with 120 elementary school teachers, ranged from twenties to fifties in age, working in Taegu city. The instrument was developed by researchers and was categorized into four: cell as the basic units of life, morphology of cell, function of cell, growth of individual from the viewpoint of cell. The results are as follows: First, about 80% of teachers had two perspective outcome of cell: Cells are the basic units of life on earth. But the potato and meat, which we used to eat as food, are not constructed of cells but aggregated of nutrients. Second, most of elementary school teachers recognized that shapes of the cell in organisms were diverse, but some of them only could present several kinds of shape on cell. The 35% of teachers had misconception that shape of cell is all the same in a individual. It shows that this result is caused by lack of opportunity to observe the various kinds of cells. Third, most teachers understood tell can be seen only through a microscope. Yet in comparison with relative size, it was revealed that misconception of cell size was induced by the term of 'basic unit'. In addition, they thought that large organisms are built from large cells, and small organisms from small cells. Fourth, Elementary school teachers used to confuse the terms between chloroplast and chlorophyll, and believed that the genetic material was contained only in the reproductive cells and seeds. It was also revealed that they thought the nutrients such as starch and fat are located at intercellular space. Fifth, the 60% of teachers conceived correctly that growth of individual depends on mitosis and increase in cell number. The rest of them, however, misunderstood that it is due to the increase of tell volume.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.4 s.111
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• pp.71-78
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• 2005

The purpose of this study is the practical application of landscape ecological indices to establishment of eco-village planning methodology. Planning an eco-village has to be carried out in the boundary of a small watershed that is defined by homogeneous ecological character. Because the small watershed is a landscape unit it can have unique ecological character. On this viewpoint, the spatial structure is analyzed by the ecological attributes of form, distribution arrangement and composition of the sub-landscape units. Among all of the sub-landscape units, a green tract of land is the main subject of the analyzing entity. Woodland or forest as a green tract of land is a source of biological species and materials. Therefore the ecological attributes of green patches are especially analyzed by landscape ecological indices. The selected landscape ecological indices are elongation, lobes, interior area ratio, convolution of perimeter and proximity of the green patches. These indices represent the state of ecological conditions and they will be the evaluation factors of the landscape ecological planning. These frameworks for landscape ecological planning apply to Obok and Ganggeum villages in Wanju-gun, Korea. A proposed planning was evaluated by the selected landscape ecological indices. Among the selected landscape ecological indices of green patches, perimeter convolution and proximity were increased. It means that the ecological condition of peen paches will be mon sound and green areas of the village will be expanded naturally. In addition to this connectivities among green patches will also be improved.