• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.6
• /
• pp.1877-1891
• /
• 2022

As a part of cloud computing technology, algorithms for cloud task scheduling place an important influence on the area of cloud computing in data centers. In our earlier work, we proposed DeepEnergyJS, which was designed based on the original version of the policy gradient and reinforcement learning algorithm. We verified its effectiveness through simulation experiments. In this study, we used the Proximal Policy Optimization (PPO) algorithm to update DeepEnergyJS to DeepEnergyJSV2.0. First, we verify the convergence of the PPO algorithm on the dataset of Alibaba Cluster Data V2018. Then we contrast it with reinforcement learning algorithm in terms of convergence rate, converged value, and stability. The results indicate that PPO performed better in training and test data sets compared with reinforcement learning algorithm, as well as other general heuristic algorithms, such as First Fit, Random, and Tetris. DeepEnergyJSV2.0 achieves better energy efficiency than DeepEnergyJS by about 7.814%.

• Korea journal of population studies
• /
• v.26 no.1
• /
• pp.171-194
• /
• 2003

The present study investigates the effects of lopsided regional policy and social prejudice on homeownership disparities by household's place of birth of household head in Seoul. The present study utilizes individual household-level census data (2% sample) to evaluate households' residential well-being denoted by homeownership status during the period of 1980-2000. Decomposition techniques based on tenure choice models were used to provide evidences of the home-ownership disparities caused by regional policy and prejudice. We found that households from Gangwon and Honam provinces represent a disproportionately small percentage of homeownership compared with those originated from other provinces. In the statistical analysis, the present study found that having controlled for the factors traditionally thought to influence households' choice of housing tenure, as well as other housing market characteristics in Seoul, place of birth has played a primary role in determining whether or not households become a homeowner. Most strikingly, while most of the disparity in homeownership ratios between households from Youngnam and households from Gangwon in the housing market is due to the endowment differences in human capitals they bring to the market, those between households from Youngnam and households from Honam is largely due to residual differences explained mainly by social discrimination and prejudice against people from Honam. The present study summarized that place of birth has played a primary role in determining whether or not households become a homeowner in Korea. The present study concluded with some policy issues relevant to this study and suggested some future studies.

• Journal of Digital Convergence
• /
• v.9 no.6
• /
• pp.389-397
• /
• 2011

With the growing acceptance of the educational benefits for the use of robot- based teaching, their use in classrooms is increasing. However, the vast majority of studies taking place are based within normal classroom environment. Therefore, this study was focused on the adaptations that need to be made for the use of robot-based teaching within a special-needs environment, specifically a program for pre-service teachers of a special needs Elementary school. The results indicate robot-based teaching has a place within special education and it is hoped that this study will spur further investigation into the field.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.2
• /
• pp.1-10
• /
• 2020

In this paper, we propose an efficient disk buffer replacement policy which improves hit ratio and reduces writing operations of flash based storages. The flash based storage has many advantages, including a small form factor, non-volatility and high reliability, but there are problems caused by own limitations, like not-in-place update, short life cycle and asymmetric I/O latencies. To redeem these problems, this paper proposes the write weighted probability of reference(2WPR) policy. 2WPR policy predicts re-referencing probability and calculates localities of each page. Furthermore, by weighting write operations to every pages, 2WPR can reduce write operations to flash based storage. In addition, we can improve the performance with higher hit ratio and reduce the number of write operations and consequently shorten the latencies of each operation. The results show that our policy provides improvements of up to 10% for the hit ratio with the reduction of up to 5% for the flash writing operation compared with other policies.

• IE interfaces
• /
• v.23 no.4
• /
• pp.327-336
• /
• 2010

We consider a supply chain consisting of a make-to-order manufacturer and N component suppliers and study the impacts of the number of suppliers on component inventory management. The manufacturer has full information and continuously observes the state of both component inventory level and customer backorders. Based on this information, the manufacturer determines whether or not to place a component purchasing order to a supplier among N suppliers even though some orders are in process by other suppliers. The goal of this paper is to numerically identify the manufacturer's purchasing policy which minimizes the total supply chain cost and the best choice of N. Our model contributes to the current literature in that the problem of simultaneously considering multiple outstanding orders and incorporating order setup cost into the model has not been covered yet. From numerical experiment, we investigate how much the policy with N suppliers can contribute to reducing the supply cost compared to the policy with a single supplier.

• Health Policy and Management
• /
• v.29 no.3
• /
• pp.323-331
• /
• 2019

Background: The purpose of this study is to analyze the effect of impartiality in providing public health services on subjective health happiness and the mediated effects of public health service quality. Based on this, this study intends to present policy implications to improve public health services. Methods: The research method is multiple linear regression analysis. The analysis of the mediating effects is performed by Baron & Kenny's test, Sobel-Goodman's test, and Bootstrap. Results: The impartiality of public health services and the quality of public health services are shown to have a statistically significant effect on subjective health happiness. Quality of public health service appears to be mediating the relationship between impartiality in providing public health care and subjective health happiness. Conclusion: To promote people's subjective health happiness, it is necessary to secure impartiality in providing public health services in the first place and improve the quality of public health services.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.22 no.1
• /
• pp.13-31
• /
• 2019

Green spaces are recognised for the benefits. They bring to the quality of people's lives. However, since the 1980s there has been a general increase in poorly-managed green spaces. In an attempt to address this issue, green space policy has changed its focus on green space management through the gradual introduction of green space evaluation tools, such as the Green Flag Award (GFA). The GFA, as an established green space evaluation tool in the UK, reflects a shift in policy drivers of green spaces management. However, there is a lack of research investigating the contextualisation between a wide range of policy contexts and such green space evaluation tools (the GFA in this study). The aims of this study are therefore to explore the development of green space evaluation since the late 1990s, with respect to the growth of the GFA and its impact on other evaluation tools across the UK and several countries. To address the aims, this study employs in-depth literature reviews on UK green space policy mainly conducted by government. In addition, case studies are presented, focusing on the GFA and independent green space evaluation tools intrinsically derived from the GFA in the UK's cities and Nordic countries. Results show that based on the awareness of the severity of declining standards of green spaces, newly emerging policy arrangements have been adopted to address negative issues, which affect the standard of green spaces such as the transfer of responsibility for green space management, the implementation of Compulsory Competitive Tendering and ongoing budget cuts. Significantly, the GFA's indicators reflect the emerging changes of economic and social contexts associated with green spaces management where, in particular, the prospect of continuous budget cuts, which encourages communities to become involved in green space management. The GFA has widely contributed to leading such UK's cities and other countries to be able to create their independent green space evaluation tools in different approaches based on stakeholders' (mainly community) involvement in the decision-making process of green space evaluation. In conclusion, this study implies that successful green space evaluation tools do embody the value of green spaces and address drivers of emerging green space management with correspondence to the context of policy arrangements. Importantly, stakeholders have an opportunity to be involved in a partnership in the decision-making process through some green space evaluation tools. It is hoped that for well-managed green spaces this study will contribute valuable knowledge to our existing understanding of green space management in an era of austerity.

• Journal of the Korean Institute of Educational Facilities
• /
• v.21 no.1
• /
• pp.3-11
• /
• 2014

The policies is always changes according to the changing times, and changes take place in educational facilities welfare policy. Early childhood facilities, is no exception. Recent, increase in the number of kindergarten and kindergarten children according to policy changes of government's active welfare. This change in pattern, policy changes and increased support to know the impact on the community, and this is not just a simply agenda that they need to be recognized social change. In addition, it can be seen changes in relevant laws and educational process according to childhood policy change flow and depending on social change. In this study, comparative study infants and installation of the facility based on criteria, ensuring standards of early childhood facility site, facilities of evolution of infants care act, act infants, infants of activities safety management. And Standards and facilities that are required to change the direction of the revision is for the purpose of research through changes in kindergarten curriculum to respond the policies flow. Research methods are literature on the various laws and research analysts, leading comparison of different child care and child care policy changes in laws and regulations to review materials are analyzed.

• Journal of the Economic Geographical Society of Korea
• /
• v.14 no.4
• /
• pp.486-505
• /
• 2011

The Korean miracle of economic growth or development has been quite well known across the world up to now, while being subject to theorization of its model. Compared with this, however, it is quite surprising to see how little about the spatial aspect of Korean development has been exposed in the field of development studies. In fact, for Korea, competent regional policy has turned out to be an important success factor for the spatial upgrading of a low-tech growth regime into a hi-tech one. This paper dissects Korea's regional policy experiences in three aspects from which it draws up a three-tier lesson. The first aspect is the conventional (overall) regional spatial upgrading policy of a developmental regime put in place since the 1960s onwards. The second is the new regional policy tailored to the regionalization of technological and industrial diffusion for new knowledge-based economy. The third is the prospective regional policy for the future advancement of the Korean economy.

• Proceedings of the Korean Information Science Society Conference
• /
• 2008.06b
• /
• pp.24-29
• /
• 2008

여러 개의 작업이 동시에 작동 할 때 서로 다른 작업에서 특정한 로봇이나 장치를 사용하기 위하여 상대방의 작업이 끝나기를 기다리는 상태를 교착상태라 하며 생산공정에서는 효율성과 경제성 제고에 가장 중요한 문제 중 하나다. 지금까지 이러한 교착상태 확인은 도달성(reachability)기법이나 서브넷(Subnet)으로 분리하여 분석하는 기법 등이 가장 많이 사용 되었으나, 분석에 필요한 시간과 노력, 복잡성과 효율성에 있어서 효과적이지 못한 단점을 가지고 있다. 본 연구는 페트리넷(Petri Net)에서 모든 플레이스(Place) 간의 관계를 나타내는 추이(Transitive)행렬을 이용하여 교착상태가 나타날 가능성이 있는 자원공유 플레이스(Place)를 분석하여 교착상태를 검증하는 정책을 제시한다. 이를 위하여 교착상태를 확인할 수 있는 자원공유 플레이스의 관계를 정의하고, FMS(Flexible Manufacturing System) 모델을 이용하여 제안한 알고리즘의 성과를 검증한다.