• Journal of Biosystems Engineering
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• v.21 no.2
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• pp.134-145
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• 1996

Since the skid-steer loader is able to work for excavating, lifting and transporting load even at the narrow space, they are widely used in the regular farm and the livestock farm. The skid-steer loader normally adopts the hydrostatic transmission because the power to move the machine backward and forward should be delivered independently on both sides of wheels. Contrast to the mechanical system such as chain and belt transmissions, however, the hydrostatic transmission is less efficient in the use of energy and more difficult in the maintenance. This study was intended to investigate the feasibility of using triangular-type belt clutch and V-belt transmission for the newly developed skid-steer loader in order to overcome the problems stated in the hydrostatic transmission. In the developed triangular-type belt clutch, the centers of driving, driven and idler sheaves are arranged in the triangular shape in a plane, and V-belts were loaded loosely on three sheaves. The power is transmitted by pressing the idler connected to a lever on the loosened V-belt. Contrast to the normal belt clutch using two sheaves, the newly developed belt clutch has the characteristics of small contact-angle of the driving sheave at no bucket load and increasing contact-angle at the time of power transmission. The results of research can be summarized as follows: 1) The developed triangular-type belt clutch adopted a spring-loaded slackside idler which could transmit more power than a fixed idler could by sacrificing the belt life. The life of V-belt used in the power transmission reached at 500 hours(6 months) when the engine power of 11.8 ㎾ was transmitted. Also, it was feasible to develop the large industrial skid-loader with the V-belt transmission by using the proper set of sheaves. 2) The developed skid-steer loader changed the rotating radius and speed with bucket loads as the conventional skid steer loader did. The rotating speed was 47 deg/s at the maximum bucket load of 2.74 kN when the minimum rotating radius was 1.5m. 3) The power required in turning at the bucket load of 2.74 kN was 4 ㎾ and the slippage of V-belt was less than 1%.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.2
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• pp.80-87
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• 1998

Since groundwater flow paths have one of the major roles to transport the radioactive nuclides from the radioactive waste repository to the biosphere, the discrete fracture network model is used for the rock block scale flow instead of the porous continuum model. This study aims to construct a three dimensional discrete fracture network to interpret the groundwater flow system in the study site. The modeling work includes the determination of the probabilistic distribution function from the fracture geometric and hydraulic parameters, three dimensional fracture modeling and model calibration. The results of the constant pressure tests performed in a fixed interval length at boreholes indicate that the flow dimension around boreholes shows mainly radial to spherical flow pattern. The fracture transmissivity value calculated by Cubic law is 6.12${\times}$10$\^$-7/ ㎡/sec with lognormal distribution. The conductive fracture intensity estimated by FracMan code is 1.73. Based on this intensity, the total number of conductive fractures are obtained as 3,080 in the rock block of 100 m${\times}$100 m${\times}$100 m.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.1_2
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• pp.52-61
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• 2006

A crossword puzzle is one of the popular word games around the world in which you work out the answers and write them in the white squares of a pattern of small black and white squares. As the technology of computers develops, some people worked about making and solving crossword puzzle games, which led them to a commercial use. However, almost all of these commercial programs are ones where you do ready-made puzzles with a fixed size because it is very difficult to make puzzles in a certain size, picking up some among a great number of words to fit for them. Furthermore, these programs are only for a very few languages, such as English, French, not for Korean. Accordingly, ore took a look at what should be considered to make an automatic puzzle-generating program for Korean, and in this paper we implemented Korizzle, a system making the puzzles automatically. We introduce the algorithm used for Korizzle and evaluate the its performance.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.43.2-43.2
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• 2013

The local environmental effects on the triggering of active galactic nucleus(AGN) activity has been studied with many authors, but there still be controversy. We perform statistical analysis for nearby(0.01 < z < 0.05) volume limited(Mr < -19) samples with visual inspection based on Sloan Digital Sky Survey Data Release7. We inspect ~60,000 galaxy images visually to find peculiar objects which show not only ongoing merging features and tidal features, but also post merging features like ring or shell structures. We found that these peculiar features were shown at least 2 times more frequently among AGN host galaxies than non AGN galaxies, and this trend was still visible when galaxy properties such as color or stellar mass are fixed. Furthermore, L[OIII] and L(Ha) of peculiar galaxies are found to be more increased than those of normal galaxies. In order to ensure this results, we also checked it for a smaller subsample with ~2mag deeper monochromatic images provided from SDSS Stripe82 database, and found consistent results. At last, we perform the same work for pair(r_p<80kpc/h, delta_v<200km/s) systems. Because of some pair systems which do not interact gravitationally in actuality but fulfill the criteria for identification of pair system, the trends are found to be slightly weaker. We also found that line luminosities are increased consistently as projected distance between central and companion galaxy decreased, and as companion color gets bluer. Overall, the results of this study tell us that the local environment of galaxies affect the frequency as well as the strength of AGN activity. Local environmental effects, however, may not be the dominant triggering mechanism for AGN activity since the majority of peculiar galaxies are non AGN galaxies.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.771-780
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• 2013

Inspection system which was performed in the past selected the final winning bidder by separating Pre-Qualification, the basic design evaluation and price evaluation. However, turnkey and alternative bidding construction has selected way to determine the successful bidder as the best design and the most low cost method, comprehensive evaluation method (bid price adjustment, design score adjustments, weights standard), the best design and the fixed amount method from january 1, 2010 to the present. Due to these institutional problems, orders institutions were often a way to determine the successful bidder to apply differently for identical or similar construction. Therefore this study winning bidder selection criteria through analysis of construction the number and construction order performance, order performance by work division and institutional orders, the weights bidder order performance and orders status of turnkey alternative tendering construction to civil part performed in domestic.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.347-357
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• 2020

This study intended to examine the nature of image which uses the network as the medium in the context of 'post-internet art' and categorize and analyze the cases of applications within art images. In the post-internet art which embraces the background of Web 2.0 and extended digital and network environment, image is transformed and re-mediated into various formats beyond fixed forms. Hito Steyerl defined the image, copied, downloaded, and reedited digitally in low quality as 'poor image.' Young artists, the digital native generation, capture and re-contextualize the changed network environment and depict it in various images. In this context, the application of image in post-internet art can be categorized and analyzed into the 'Image Collected as Material' produced by collecting and recomposing images found in social media, operating system, and website, 'Image Processed through Work' which is newly processed and re-contextualized by using editing programs, and 'Combined Digital-Reality Image' which represents the section of the digital society as the film and image that combine virtuality and reality.

• Journal of KIISE:Databases
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• v.31 no.4
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• pp.384-394
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• 2004

Recently, to relieve the performance degradation caused by the bottleneck between CPU and main memory, cache conscious multi-dimensional index structures have been proposed. The ultimate goal of them is to reduce the space for entries so as to widen index trees and minimize the number of cache misses. The existing index structures can be classified into two approaches according to their entry reduction methods. One approach is to compress MBR keys by quantizing coordinate values to the fixed number of bits. The other approach is to store only the sides of minimum bounding regions (MBRs) that are different from their parents partially. In this paper, we propose a new index structure that exploits the properties of the both techniques. Then, we investigate the existing multi-dimensional index structures for main memory database system through experiments under the various work loads. We perform various experiments to show that our approach outperforms others.

• Journal of Intelligence and Information Systems
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• v.9 no.3
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• pp.65-79
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• 2003

In general, the extraction and recognition of identifier is very hard work, because the scale or location of identifier is not fixed-form. And, because the provided image is contained by camera, it has some noises. In this paper, we propose methods for automatic detecting edge using canny edge mask. After detecting edges, we extract regions of identifier by detected edge information's. In regions of identifier, we extract each identifier using contour tracking algorithm. The self-generation supervised learning algorithm is proposed for recognizing them, which has the algorithm of combining the enhanced ART1 and the supervised teaming method. The proposed method has applied to the container images. The extraction rate of identifier obtained by using contour tracking algorithm showed better results than that from the histogram method. Furthermore, the recognition rate of the self-generation supervised teaming method based on enhanced ART1 was improved much more than that of the self-generation supervised learning method based conventional ART1.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.10
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• pp.975-983
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• 2009

This paper presents the work being carried out in order to deduce hover performance of a small-scale single rotor blade as a preliminary study of a small coaxial rotor helicopter development. As an initial research, a test stand capable of measuring thrust and torque of a small-scale rotor blade in hover state was constructed and fabricated. The test stand consists of three parts; a rotating device, a load measuring sensor and a data acquisition system. Thrust and torque were measured with varying collective pitch angle at fixed RPM. Through this research, hover performance tests were conducted for a small-scale single rotor blade operating in low Reynolds number ($Re\;{\approx}3{\times}10^5$), as well as for verifying the test stand itself for acquiring hover performance.

• Journal of Environmental Science International
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• v.28 no.9
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• pp.797-806
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• 2019

The purposes of this study are to comprehend the importance of policy in improving the operation of the public arboretum and survey the program satisfaction of participants and operators based on the case of the Daegu arboretum. According to the order of policy priority regarding the Daegu arboretum, the expansion of the education program topped the list with 0.155 points, followed by the establishment of a vision and goal, and the reestablishment of function, which scored 0.135 and 0.135 points, respectively. Fostering citizens' participation through volunteer work was in the upper ranks with 0.131 points. Building networks among public arboretums and constructing a research cooperation system with universities turned up with 0.09 and 0.075 points. As the result of program satisfaction, participants' satisfaction was around 0.66 points higher than that of operators' satisfaction. In the case of participants, comprehensive satisfaction, including that with the program operation method, was very high at 4.85 points. Out of the entire program, the operators were the most satisfied with the benefits. This study aims to share improvement plans for public arboretums constructed in urban areas, analyzing policy priorities and satisfaction related to the Daegu arboretum. The results of this study can be utilized as data for the improvement plans of public arboretums. If improvement plans for public arboretums are modeled with other follow-up case studies, it will help ensure that public arboretums become evolving rather than fixed areas for citizens.