• Journal of Broadcast Engineering
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• v.15 no.3
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• pp.380-390
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• 2010

The most recent standard video codec, H.264/AVC achieves significant coding efficiency by using a rate-distortion optimization(RDO). The RDO is a measurement for selecting the best mode which minimizes the Lagrangian cost among several modes. As a result, the computational complexity is increased drastically in encoder. In this paper, a method for fast intra prediction mode decision is proposed to reduce the RDO complexity. To speed up Intra$4{\times}4$ and Chroma Intra encoding, the proposed method decides the case that MPM (Most Probable Mode) is the best prediction mode. In this case, the RDO process is skipped, and only MPM is used for encoding the block in Intra$4{\times}4$. And the proposed method is also applied to the chroma Intra prediction mode in a similar way to the Intra$4{\times}4$. The experimental results show that the proposed method achieves an average encoding time saving of about 63% with negligible loss of PSNR (Peak Signal-to-Noise Ratio).

• Journal of Broadcast Engineering
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• v.17 no.4
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• pp.611-624
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• 2012

'Gesture' is the most intuitive means of communication except the voice. Therefore, there are many researches for method that controls computer using gesture input to replace the keyboard or mouse. In these researches, the method of user detection and main body parts estimation is one of the very important process. in this paper, we propose user objects detection and main body parts estimation method on inaccurate depth information for pose estimation. we present user detection method using 2D and 3D depth information, so this method robust to changes in lighting and noise and 2D signal processing 1D signals, so mainly suitable for real-time and using the previous object information, so more accurate and robust. Also, we present main body parts estimation method using 2D contour information, 3D depth information, and tracking. The result of an experiment, proposed user detection method is more robust than only using 2D information method and exactly detect object on inaccurate depth information. Also, proposed main body parts estimation method overcome the disadvantage that can't detect main body parts in occlusion area only using 2D contour information and sensitive to changes in illumination or environment using color information.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.2
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• pp.55-63
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• 2017

Crowdfunding recently receives a great deal of attentions as an alternative finance for small and medium-sized enterprises or business ventures that suffer from financial constraints. Crowdfunding is a new form of platform that enables a large number of people to invest a small amount of money for promising new business items directly. We analyzed the effect of type, period, method of projects on crowdfunding outcomes. We measure the outcome in terms of the ratio of the collected to the target amount. We collected data from three Korean crowdfunding platform companies, and the data consisted of 239 projects from 2012 to 2014. We use both logit and ordinary least square method for evaluation. Generally, the amount of target itself has no effect on the outcome. Equity crowdfunding shows higher success rate and better outcome than rewards crowdfunding. All or Nothing method leads to the higher ratio of the collected to the target amount than Keep It All. There is an inverted U-shape between the number of investors and the ratio of the collected to the target amount. Finally, the ratio of the collected to the target amount is decreasing in a crowdfunding period.

• Journal of Korean Society of Forest Science
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• v.82 no.3
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• pp.246-253
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• 1993

The composition of the nitrogen forms of the organic layer and mineral soil horizons of 8 differing soil type was measured to find a clue to elucidate the problem on the fertility and nitrogen availabilities of forest soils. The ratio of inorganic $N(NH_4-N+NO_3-N)$ to total N was very low in every 0 layer and its maximum was only about 2%. And the inorganic N concentration of every mineral soil horizon was low, and the maximum of its rate to N was 3.7% in surface horizon and about 4.1% in lower horizon. Organic N form of O layer were characterized by the decrease of aminoacid-N, and the increased of hexosamine-N and amide-N according to the advance of decomposing process. The ranges of hydrolyzable-N of every flesh litter, F and H layer of the selected soils were about 80-90% and they- were hardly affected by the differences of tree species and decomposing process. The organic N form of every litter was similar and it was follows : aminoacid-N was not abundant and it ranges were about 40-50%, more than half of hydrolyzable-N. The hexosamine-N was eery poor and it ranged to only 2-7%. The amide-N teas low and about 10-23%. No distinguished difference was seen between the organic N forms of the O layer and surface horizon of dry and wet soils in brown forest soils.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6604-6610
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• 2015

In this paper, an efficient Wireless Access in Vehicular Environment (WAVE) packet transmission scheme for railroad communication is proposed. WAVE communication is a wireless local area network (WLAN) based communication and it is developed to be suitable for vehicular communication. There has been a lot of study on WAVE's applicability to Intelligent Transport System (ITS). As one of main transportation methods, by using WAVE, quality of railroad communication including WLAN based Communication Based Train Control (CBTC) can be enhanced and variety of railroad communication systems can be integrated into WAVE. However, there are technical challenges to adopt WAVE in railroad communications. For the simplest single-PHY WAVE, time division alternation of 50ms between Control Channel (CCH) and Service Channel (SCH) is required. Since there are delay sensitive railroad traffic types, alternation operation of CCH and SCH may cause performance degradation. In this paper, after identifying a couple of problems based on detailed analysis, a novel packet transmission scheme under railroad environment is proposed. In order to verify if the proposed scheme meets the requirement of railroad communication, WAVE transmission is mathematically modeled.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.257-263
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• 2010

We studied about the difference of division public announcements by corporation size and ownership structure from 1999 to 2005. The results is as follow : First, we found most positive numbers in division corporation's CAR. This supports the existing research that corporation division is evaluated positively in the market. We found CAR as largest shareholders' holding more than 40%, which is greater than 0-20% & 20-40%, that shows relatively more negative CAR. So, the exceeded largest shareholders' holding rate (i.e., over 40%) can be a factor for decreasing corporations' value. Also, most positive CAR shows relatively small variation regarding corporation size knowing that big sized corporations have relatively small variation than small sized corporations. Second, we studied about relationship between corporate ownership structure and division public effects and found relatively a little effect by large shareholders, foreign investors' holding variables on division public.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.437-445
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• 2020

Smoke grenades are the primary means of protection used by tanks to disrupt enemy detection systems. Such smoke grenades are a critical factor that determines the survival of tanks in the engagement of ground weapon systems, but it can only be used once. Owing to its destructive property, the performance and safety of the smoke grenade cannot be confirmed prior to use. Therefore, the reliability of smoke grenades can be evaluated through various tests during the storage period. This paper presents the results of estimating the reliability and shelf life of IR screening smoke grenade launchers based on the result of the Ammunition Stockpile Reliability Program conducted in 2019. Among the smoke grenade launcher lots currently stored, 16 lots and samples were selected for each year of manufacture and tested. The reliability and shelf life were estimated by examining the number of defects and the change in quality characteristics of each test item. The results of this study can be used to assess the reliability of the smoke grenade launchers and to improve the quality of manufacturing sites.

• Journal of the Korean association of regional geographers
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• v.13 no.3
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• pp.301-320
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• 2007

In Korean academic societies, old maps has not yet been properly investigated in terms of their genealogy, classification, detailed place names, historical backgrounds and the other aspects. With publication of the bibliographies and papers on old maps reserved in museum and library, the scope of research enlarged gradually its scope from 1970s. In 1980s, with the development of theoretical geography, scientific analysis were applied to investigate the projection method of Daedongyeo-jido. The 1990s proved a prominent decade for researches. The photo-copies of old maps enabled researchers to investigate the in-depth comparative study. The more important thing is that old maps became to be powerful instrument in the research of historical geography, such as territorial disputes and marine name(東海). And county old maps compiled by region became to be regional-cultural contents of local areas. Important issues in old map research in Korean academic societies are about Cheonha-do which is unique old world map in Korea, grid-system projection in old county maps and the genealogy of Daedongyeo-jido(manuscript and block print edition). This study shows that bibliography of all old maps preserved in each library and museum should be standardized. This could enable the exchange of information of old maps between institutes. The more important thing is that conciliation of human, social and natural sciences should be applied in the research of old maps.

• Journal of Energy Engineering
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• v.25 no.3
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• pp.104-113
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• 2016

This study analyzes correlation between methane gas production and injection of food waste water to motivate to expand renewable energy as a way of GHG (Green House Gas) mitigation to achieve the national GHG target proposed for the climate agreement in Paris last year. Pretreatment of food waste water was processed with pH 6 at $35^{\circ}C$ and used the fixed-bed upflow type reactor with the porous media. As a result of operation of pilot-scaled bioreactor with food waste water, the methane gas production was 6 times higher than the methane gas production of control group with rain water. The average production of methane was $56{\ell}/day/m^3$ which is possible to produce $20m^3$ of methane in $1m^3$ of landfill. As a way of energy source, when it is applied to the landfill over $250,000m^3$, it is also able to achieve financial feasibility along with GHG reduction effect. GHG reductions of $250,000m^3$ scale landfill were assessed by registered CDM project and the annual amount of reductions was 40,000~50,000 $tCO_2e$.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.5
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• pp.40-47
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• 2003

This study examined the improved effect of wear tolerance of warm-season turfgrass overseeded with cool-season turfgrasses. Also, it investigated the improved effect of crumb rubber on wear tolerance and the difference anmong cultivars regarding the wear of Zoysia spp. In wear experiment during summer, the warm-season turfgrass overseed with cool-season turfgrasses had a higher visual rating on the ground than the monostand of Cynodon dactylon. Moreover, in wear experiment in winter, barrenness showed significant progress in the monostand of C. dactylon, while the barrenness did not appear at all in overseeded turf with cool-season turfgrasses. As a result of investigating the bulk density was increased in the monostand of C. dactylon, but not in the overseed turf with cool-season turfgrasses. From the above result, the wear tolerance effcect of turfgrasses appeared year round through warm-season and cool-season turfgrass mixtures. Also, it was found that the method of topdressing crumb rubber on the ground was effective as a physical assistant device alleviating damage of turfgrasses. The possibility of improving wear tolerance was accepted by adding soil amendments such as perlite, pamis, etc., in order to promote the growth of turfgrass.