• Asia Marketing Journal
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• v.9 no.2
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• pp.23-47
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• 2007

A new chi-square test is proposed to assess significance of attributes for nonparametric conjoint models. The key idea is to form subsets of rankings and test the dependence between the attribute levels and the sets of rankings. The null hypothesis states that the rankings for profiles with the focal attribute are distributed randomly among the sets of rankings. The approach is simple, easy to use, and can be applied at the individual level as well as at the aggregate level. It can be used for the trade-off approach as well as for the full profile approach.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.10a
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• pp.49-52
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• 1996

In this article, we develop a 'dynamic' approach to manufacturing improvement, based on perspectives of manufacturing learning and decision theory. First, we present an alternative definition of production system consistent with a decision-theoretic perspective: the system consists of structural, infra-structural, and decision making constructs. A primary proposition is that learning capability possessed by a manufacturing system be prerequisite for the system to improve its manufacturing performance through optimal controlling of the three constructs. To support the proposition, we elaborate on a mathematical representation of "learning" as defined in an applied setting. We show how the learning capability acts as an integrating force ameliorating the trade-off between two key manufacturing capabilities, i.e., process controllability and process flexibility.exibility.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.3
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• pp.287-299
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• 2000

In this paper, we classify multicast methods into three categories, i.e., tree-based, path-based, and hybrid-based multicasts, for a multicomputer employing the bidirectional torus network and wormhole routing. We propose the dynamic partition multicast routing (DPMR) as a path-based algorithm. As a hybrid-based algorithm, we suggest the hybrid multicast routing (HMR), which employs the tree-based approach in the first phase of routing and the path-based approach in the second phase. Performance is measured in terms of the average latency for various message length to compare three multicast routing algorithms. We also compare the performance of wormhole routing having variable buffer size with virtual cut-through switching. The message latency for each switching method is compared using the DPMR algorithm to evaluate the buffer size trade-off on the performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3293-3311
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• 2015

Cloud services are required to be composed as a single service to fulfill the workflow applications. Service composition in Cloud raises new challenges caused by the diversity of users with different QoS requirements and vague preferences, as well as the development of cloud computing having geographically distributed characteristics. So the selection of the best service composition is a complex problem and it faces trade-off among various QoS criteria. In this paper, we propose a Cloud service composition approach based on evolutionary algorithms, i.e., NSGA-II and MOPSO. We utilize the combination of multi-objective evolutionary approaches and Decision-Making method (AHP) to solve Cloud service composition optimization problem. The weights generated from AHP are applied to the Crowding Distance calculations of the above two evolutionary algorithms. Our algorithm beats single-objective algorithms on the optimization ability. And compared with general multi-objective algorithms, it is able to precisely capture the users' preferences. The results of the simulation also show that our approach can achieve a better scalability.

• The Korean Journal of Financial Management
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• v.1 no.1
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• pp.119-131
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• 1985

Although Korea is short of capital technology, and natural resources, she has achieved an outstanding progress by the export-drive policies by Korean government and the creative endeavor of Korean firms. As a result of that, Korean economy and enterprises are in the same file of newly industrialized countries and Korea is ready for an economic take-off as a developed country. But in the early 1980s, each country strengthens protective trade theory and resources nationalism, and this has a great influence on the field of international trade environment. In spite of that, to continue the same high development as that of the past. Korea must try to secure and find export markets, solve trade barriers, make sure of the long-term security of resources, develop technology, and strengthen economic cooperations. To satisfy these desires by 2000s, we must try to make Korean enterprises have the global competitive power and them grow strongly among world wide firm through capital and technology accumulated during the passed years, and to do so, there must be a foreign production and marketing management, too, this can be achieved only through foreign overseas direct investment. This investment has various forms, to say, verifical integrated, horizontal integrated. conglomerate integrated forms, and the amount of investment in each country from 18 century to today reaches 500 billion dollars. This investment is done by strategic, behavioral economic, and financial motives. So I am going to approach the fields of like these; in spite of the differences among political, economical, caltural, and social systems, and many risk compared with domestic enterprises, why do Korean firms witsh to transfer the productive facilities to overseas countries and run them there? What is the comparative advantage of foreign direct investment compared with domestic investment ?. why is the factor of comparative advantage transferred through foreign direct investment?, what is the motive of foreign overseas direct investment?, and last the ownership-specific factors and the theory of internalization, and the location specific factors were analysed chiefly. But in consideration of the given condition in Korea, Korean overseas direct investment must be propelled rationally on the basis of the above mentioned theory.

• Journal of the Korea Computer Graphics Society
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• v.28 no.2
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• pp.21-28
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• 2022

ASTC is one of the standard texture formats supported in OpenGL ES 3.2 and Vulkan 1.0 (and later versions), and it has been increasingly used on mobile platforms (Android and iOS). ASTC's most important feature is the block size configuration, thereby providing a trade-off between compression quality and rates. With the higher number of textures, however, it is difficult to manually determine the optimal block sizes of each texture. To solve the problem, we present a new approach based on PSNR values to automatically determine the ASTC block size. A brute-force approach, which compresses a texture on all block sizes and compares the PSNR values of the compressed textures, can increase the compression time by up to 14 times. In contrast, our three-step approach minimizes the compression-time overhead. According to our experiments on a texture set including 64 various textures, our method determined the block sizes from 4×4 to 12×12 and reduced the size of compressed files by 68%.

• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.239-253
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• 1983

This study attempted to introduce Fei-Ranis's agricultural development theory and discuss its problem for the rural development of less developed world. Fei-Ranis systematized the development process of Western European economy on the ground of dualism. They divided the process into 4 stages by the concept of 'mode of operation'. Paticularly, they consider agrarian mercantilism as take-off stage and its development were achieved by the increase of trade margin and labor productivity. Especially, they thought that only agricultural revolution through the diffusion of internal exchange economy and construction of tree-star system can accomplish favorable transition to industrial capitalism. In order to promote this agricultural development, less developed world must abolish short-run agricultural policy and propel 'learning by the contact' strategy through 'tree-star system' and 'parellel development.' In reality, it was problematic that the contemporary less developed world is trying, in the course of a few decades, to imitate Western European experience with development over the last four centuries. But Fei-Ranis ignored qualitative aspects of agricultural development by tree-star system and also it is criticized that they considered agricultural development process of less developed world follows only that of Western European classical process.

• Earthquakes and Structures
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• v.10 no.5
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• pp.1067-1087
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• 2016

In this paper, a decoupled proportional-integral-derivative (PID) control approach for seismic control of smart structures is presented. First, the state space equation of a structure is transformed into modal coordinates and parameters of the modal PID control are separately designed in a reduced modal space. Then, the feedback gain matrix of the controller is obtained based on the contribution of modal responses to the structural responses. The performance of the controller is investigated to adjust control force of piezoelectric friction dampers (PFDs) in a benchmark base isolated building. In order to tune the modal feedback gain of the controller, a suitable trade-off among the conflicting objectives, i.e., the reduction of maximum modal base displacement and the maximum modal floor acceleration of the smart base isolated structure, as well as the maximum modal control force, is created using a multi-objective cuckoo search (MOCS) algorithm. In terms of reduction of maximum base displacement and story acceleration, numerical simulations show that the proposed method performs better than other reported controllers in the literature. Moreover, simulation results show that the PFDs are able to efficiently dissipate the input excitation energy and reduce the damage energy of the structure. Overall, the proposed control strategy provides a simple strategy to tune the control forces and reduces the number of sensors of the control system to the number of controlled stories.

• Journal of Internet Computing and Services
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• v.15 no.3
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• pp.1-10
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• 2014

The cloud computing paradigm introduced pay-per-use models in which IT services can be created and scaled on-demand. However, service providers are still concerned about the constraints imposed by their physical infrastructures. In order to keep the required QoS and achieve the goal of upholding the SLA, virtualized resources must be efficiently consolidated to maximize system throughput while keeping energy consumption at a minimum. Using ANN, we propose a predictive SLA-aware approach for consolidating virtualized resources in a cloud environment. To maintain the QoS and to establish an optimal trade-off between performance and energy efficiency, the server's utilization threshold dynamically adapts to the physical machine's resource consumption. Furthermore, resource-intensive VMs are prevented from getting underprovisioned by assigning them to hosts that are both capable and reputable. To verify the performance of our proposed approach, we compare it with non-optimized conventional approaches as well as with other previously proposed techniques in a heterogeneous cloud environment setup.

• Journal of Internet Computing and Services
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• v.14 no.5
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• pp.39-48
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• 2013

A cloud system has to deal with highly variable workloads resulting from dynamic usage patterns in order to keep the QoS within the predefined SLA. Aside from the aspects regarding services, another emerging concern is to keep the energy consumption at a minimum. This requires the cloud providers to consider energy and performance trade-off when allocating virtualized resources in cloud data centers. In this paper, we propose a resource provisioning approach based on dynamic thresholds to detect the workload level of the host machines. The VM selection policy uses utilization data to choose a VM for migration, while the VM allocation policy designates VMs to a host based on its service reputation. We evaluated our work through simulations and results show that our work outperforms non-power aware methods that don't support migration as well as those based on static thresholds and random selection policy.