• Journal of KIISE
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• v.43 no.10
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• pp.1131-1143
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• 2016

How can we effectively compress big graphs composed of billions of edges? By concentrating non-zeros in the adjacency matrix through vertex rearrangement, we can compress big graphs more efficiently. Also, we can boost the performance of several graph mining algorithms such as PageRank. SlashBurn is a state-of-the-art vertex rearrangement method. It processes real-world graphs effectively by utilizing the power-law characteristic of the real-world networks. However, the original SlashBurn algorithm displays a noticeable slowdown for large-scale graphs, and cannot be used at all when graphs are too large to fit in a single machine since it is designed to run on a single machine. In this paper, we propose a distributed SlashBurn algorithm to overcome these limitations. Distributed SlashBurn processes big graphs much faster than the original SlashBurn algorithm does. In addition, it scales up well by performing the large-scale vertex rearrangement process in a distributed fashion. In our experiments using real-world big graphs, the proposed distributed SlashBurn algorithm was found to run more than 45 times faster than the single machine counterpart, and process graphs that are 16 times bigger compared to the original method.

• Environmental and Resource Economics Review
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• v.14 no.2
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• pp.291-336
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• 2005

This paper investigates how oil price changes have an impact on the Korean manufacturing production activities. For this investigation, we use a structural VAR motel to estimate impulse response functions of industrial production, producer price and export price to an oil price increase over manufacturing industries. It finds that in most manufacturing industries, an oil price increase leads to decreases in industrial productions and domestic prices except energy intensive industries, but to increases in industrial export prices except non-metallic (26), computers and offic machinery (30), electronic components, radio, television and communication (32) industries. This result explains that an oil price increase makes negative impacts on the manufacturing production activities not only through demand slowdown in the domestic markets but also through supply contraction in the export markets.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.5
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• pp.135-144
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• 2018

Recently, discussions about social economy have been actively promoted, and the establishment of social cooperatives, which is an axis of social economy, is being activated. However, because of the economic slowdown, social cooperative activities are often shrinking, and a case study is conducted on how to make social cooperatives sustainable. The results are as follows. In order for social cooperatives to cope with social change adaptation and market diversity, it is necessary to organize networks or participate in existing networks. It is also necessary that social cooperatives form different types of social cooperatives into separate organizational forms as needed. In addition, social cooperatives should make efforts to improve the quality of services and goods provided by each organization, and focus on attracting local people's empathy and participation to change the culture and atmosphere of the region. If such efforts are made, it will be possible for social cooperatives to become a sustainable economic organization.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.563-567
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• 2008

Recently, the Busan Economy has been depressed because of the constant economic slowdown. This also causes severe damage to the construction industry. This study focuses on The Apartment Building Type-Factory Business Incubator in the university paying attention to the construction company who struggles to make a new item of business in this aggravated state of the building business. There are no universities who operate The Apartment Building Type-Factory Business Incubator until now and there are no related data or researches at all. With this in mind, this study is to perform a feasibility study on inducement of The Apartment Building Type-Factory Business Incubator in the University in Busan area. In consequence, feasibility of Policy was sufficient and this study could draw a result of stable returns. Through this business, this study expects that schools, construction companies and enterprises who want to start a business can get the synergy among each other.

• Journal of the Korean Data and Information Science Society
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• v.26 no.6
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• pp.1377-1386
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• 2015

GDP gap is closely related with economic activity of a country as a whole, especially with the economic fluctuations which is called business cycle. GDP gap is regarded as an important variable for the monetary policy of the central bank because it provides information on the excess demand pressures and employment matters. However, GDP gap may not provide enough information of the effect of recent economic structural change or the environmental change of domestic and external economic condition. In this paper, the GDP is decomposed by statistical filtering techniques and various models are fitted to estimate the influence of GDP gap on Inflation and see if it has been changed. Analysis results show that the influence of GDP gap on inflation decreased in the 2000s while that of global GDP gap increased. These results also support that recent low inflation rate is due to the change of overseas economic condition, such as a slowdown in exports resulting from the global recession, as well as domestic factors.

• Current Optics and Photonics
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• v.1 no.5
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• pp.474-490
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• 2017

Since the recent slowdown in the smartphone market, studies for wearable devices are briskly being carried out to find new markets, such as virtual reality devices. In this paper, a head-mounted display (HMD) which provides expanded virtual images before human eyes by enlarging images of a small display was designed, and the tolerance analysis method for a focus-adjustable HMD based on afocal optical systems was studied. There are two types of HMDs: a see-through type that allows the user to view the surroundings, and a see-close type where the user can only view the display screen; the former is used in this study. While designing the system, we allowed a lens within the system to be shifted to adjust its focus from +1 to -4 D (diopters). The yield of the designed systems was calculated by taking the worst-case scenario of a uniform distribution into account. Additionally, a longitudinal aberration was used rather than MTF for the tolerance analysis with respect to system performance. The sensitivity of the designed system was calculated by assigning a certain tolerance, and the focus lens shift was calculated to adjust the image surface variations resulting from the tolerance. The smaller the tolerance, the more expensive the unit price of the products. Very small tolerances may even be impossible to fabricate. Considering this, the appropriate tolerance was assigned; the maximum shift of the focus lens in which the image surface can be adjusted was obtained to find the changes in aberration and a good yield.

• Journal of Korea Foundry Society
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• v.22 no.3
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• pp.121-129
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• 2002

According to the investigation of waste $CO_2$ molding sand in the 15 steel foundries in Busan and Gyeong area, about 1 ton of waste $CO_2$ molding sand per ton of steel castings production was produced In order to reduce amount of $Na_2O$, Loss of Boiling (L.O.B), Loss of Ignition (L.O.I), Conductivity and PH which are present in the waste $CO_2$ molding sand below the reclamation effect, more than 50% of elimination for reclamation was required. It was found that the waste $CO_2$ molding sand does not contain a harmful component designated by industrial waste materials. Reclamation of the waste $CO_2$ molding sand was practically achieved by an abrasive-dry reclamation process. According to bench time of the sodium silicate-bonded $CO_2$ molding sand, reduction of compressive strength and surface stability index(S.S.I) become slowdown. Therefore, the reclaimed sand could be allowed the reuse of molding sand in $CO_2$ molding process including core sand.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.3797-3806
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• 2015

A population decline in rural area is correlated with the number of household, with agricultural workers, as a result, affects the farming income. Agricultural population is a foundation of agriculture structure. Agricultural population decline influences agricultural policies to be implemented for the future and there is concern about slowdown in productivity. The purpose of this study is to build the ability to use the model and conduct applied analyses of various kinds and to make rational agricultural policies by forecasting and analyzing agricultural population change. Unlike previous studies, which have some assumptions about the giving-up farming rate (GFR) of the key points on the agricultural population model or, After estimating only one equation with respect to the total population, and then distribute by sex and age. This study was conducted to investigate the reactions are different from the farmhouse, gender, age by estimating giving-up farming rate (GFR) equations each gender & age. Through this research, we can find that Farm Population changes of the simulation can be performed for a variety of agricultural policy in conjunction with existing agricultural simulation models as well.

• Journal of the Korea Society of Computer and Information
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• v.26 no.9
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• pp.1-12
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• 2021

In this paper, we propose a tool called ARCAV (Atomatic Recovery of CUDA Atomicity violation) to automatically repair atomicity violations in GPU (Graphics Processing Unit) program. ARCAV monitors information of every barrier and memory to make actual memory writes occur at the end of the barrier region or to make the program execute barrier region again. Existing methods do not repair atomicity violations but only detect the atomicity violations in GPU programs because GPU programs generally do not support lock and sleep instructions which are necessary for repairing the atomicity violations. Proposed ARCAV is designed for GPU execution model. ARCAV detects and repairs four patterns of atomicity violations which represent real-world cases. Moreover, ARCAV is independent of memory hierarchy and thread configuration. Our experiments show that the performance of ARCAV is stable regardless of the number of threads or blocks. The overhead of ARCAV is evaluated using four real-world kernels, and its slowdown is 2.1x, in average, of native execution time.

• Journal of People, Plants, and Environment
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• v.21 no.6
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• pp.533-543
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• 2018

This study aimed to examine how the horticultural therapy that was originated in the US has influenced South Korea and Japan and developed in the two countries as an interim check to promote qualitative growth of horticultural therapy with the growing social attention. It also aimed to look into the background of how horticultural therapy was introduced in Japan (which introduced horticultural therapy around the same time as Korea), and the process of the introduction, and compare them with those of Korea in order to set the direction for horticultural therapy. Data was collected to prepare the chronological table of horticultural therapy in Korea and Japan and investigate the flow. Interviews were conducted with the professors who first opened a horticultural therapy course in university so as to determine the introduction background. The analysis results are summarized as follows: Horticultural therapy was created to give mental comfort and emotional purification to those concerned with horticulture that had concerns over social phenomena. In Korea, there had been a process of finding a way of getting mental comfort and emotional purification in the economic slowdown in the late 1990s. Since 2001, there have been more attention and demand for horticultural therapy. As a result, there has been a tendency of studying general horticultural welfare activities and professional horticultural therapy separately. In Japan, the environmental pollution that has arisen since 1970s led to a concern over social orientation in the relation between plants and humans. The academic conference of global researchers to establish the horticultural therapy studies influenced the introduction of horticultural therapy in Korea and Japan. Both countries had no operations and system, and developed them independently. They had similar directions to seek, such as the department of horticultural therapy, need for professional education, active introduction of hospital practice (internship), and security of operating budget. Horticultural therapy has many competencies and thus requires constant research and expansion.