• The Journal of the Acoustical Society of Korea
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• v.15 no.6
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• pp.59-65
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• 1996

This paper proposes a 4 kbps PSI-VSELP(Pitch Synchronous Innovation-Vector Sum Excited Linear Prediction) speech coder which produces speech equivalent to that of the conventional 4.8 kbps VSELP. Since the 'half-rate' is differently defined from country to country, there may be a need to reduce the bit rate of conventional half-rate coder. To minimize the degradation of speech quality caused by bit-rate reduction, it is desirable to perform bit-allocation based on the carefull consideration of the effect of various transmission parameters. This paper adopts this analytical approach for bit-allocation at 4 kbps. To improve the quality of the VSELP coder at 4 kbps, basis vectors which play the most important role in the performance, are optimized by an iterative closed-loop training process and the PSI technique is employed in the VSELP performance, are optimized by an iterative closed-loop training process and the PSI technique is employed in the VSELP coder. To demonstrate the performance of the proposed speech coder, we peformed experiments under the noiseless and error free conditions. From experimental results, even though the proposed 4 kbps PSI-VSELP coder showed lower scores in the objective measure, higher scores in subjective measure was obtained compared with those of the conventional 4.8 kbps VSELp.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3389-3404
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• 2012

Based on the case study methods, the study analyzes emergence and ensuing typology of global ebook platforms such as Google eBook, Amazon Kindle, iBooks Store. Global ebook platforms show adaptation process responding to rapidly changing digital technological envirment and it's fitness landscape. The critical elements in its emerging process are the distinct selection criteria, the degree of resource abundance and the search process based on open innovation. Based on these critical elements, the global platforms show speciation process, so called niche creation and are evolving into a variety of the typology based on the initial condition of key resource which makes the platform emerge and grow. Each global ebook platforms is evolving into open platform, hybrid platform, closed platform. Google eBook has openness and extensibility due to a variety of devices based on Android and a direct involvement of actors. Amazon Kindle has developed from a online bookstore and into the hybrid platform which have not only closed quality but also openness with ebook devices and mobile network. iBooks Store has developed into the closed platform through the agency model based on competitive hardwares and closed quality with iphone and ipad.

• Journal of the Korean Society of Visualization
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• v.21 no.1
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• pp.12-17
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• 2023

Aortic valve stenosis is a heart valve disease caused by the accumulation of calcium in the valve, which can divide into tricuspid aortic valve (TAV) stenosis and bicuspid aortic valve (BAV) stenosis depending on the shape of natural valve. In this study, pig heart-based TAV and BAV ex vivo models were fabricated, and the flow characteristics behind a valve were analyzed using 4D flow MRI. Flow behind normal TAV was uniformly distributed, while BAV asymmetrically opened with an eccentric strong jet. Especially, BAV ex vivo model exhibited a secondary flow in the region where the valve closed. In addition, BAV had a 26% higher peak velocity while maintaining similar stroke volume compared with normal TAV. This study would be helpful for understanding the flow characteristics for BAV AS patients.

• International Journal of Quality Innovation
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• v.2 no.2
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• pp.101-120
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• 2001

In this paper jobshop scheduling problem was considered on automated manufacturing systems with the closed loop and unidirectional material handling system. The objective of this research is to develop and evaluate heuristic scheduling procedures to improve productivity by minimizing makespan. Especially travel time of material handling system as well as processing time was considered in the proposed algorithms, A new heuristic algorithms are proposed and illustrates the proposed algorithm. The heuristic algorithms are implemented for various cases. The results show that the proposed algorithms provide better solutions in productivity, frequency, job waiting time and the number of waiting jobs than the random scheduling algorithm.

• Journal of Communications and Networks
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• v.9 no.2
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• pp.185-191
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• 2007

Alpha stable distribution is better for modeling impulsive noises than Gaussian distribution in signal processing. This class of process has no closed form of probability density function and finite second order moments. In general, Wiener filter theory is not meaningful in S$\alpha$SG environments because the expectations may be unbounded. We proposed a new adaptive recursive least p-norm Kalman filtering algorithm based on least p-norm of innovation process with infinite variances, and a new robust multiuser detection method based on least p-norm Kalman filtering. The simulation experiments show that the proposed new algorithm is more robust than the conventional Kalman filtering multiuser detection algorithm.

• The Journal of Small Business Innovation
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• v.19 no.2
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• pp.37-52
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• 2016

Making efforts to break down the barriers between the intra-company departments as well as cooperating with external partners can become the driving force to create a successful innovation in the new product development (NPD) process. This study deals with how the key factors of collaborative innovation success are working in the process of NPD collaboration. Using case analysis of the NPD process, where a large retailer and small and medium-sized suppliers cooperate, we found that the small and medium-sized suppliers achieved greater 'short-term' performances in the collaboration than the large firm, although the long-term performance is not clear. Among the six antecedents of innovation success, relationship-specific investment played a critical role in motivating the supplier's participation in the NPD process. Adopting a 'closed' network in which the two suppliers interact directly with each other and create new knowledge for the NPD process played an important role in producing a quality product in a reduced development time. Unlike previous studies about the retailer-supplier cooperation for NPD in the food industry suggesting that position differences cause communication problems which is a major obstacle to the NPD success. This study suggests that large retailer's initiative role is a critical success factor in the NPD by the cooperation between small and medium-sized suppliers and large retailers.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.131-141
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• 2019

This study is an empirical analysis of the characteristics of the organization and the performance of the company. The characteristics that make up the culture of a company's organization determine its success. Overcoming the company's closed cultural characteristics, entrepreneurial orientation, delegation, openness of organizational culture, and R&D capabilities have a positive impact on the company's performance. These characteristics of the company also play a positive role in embracing open innovation to generate innovative results. The characteristics of a company positively consider the acceptance and utilization of external resources. These variables proved that the nature of a company's organization is a factor in generating a company's performance. In this process, open innovation and the acceptance of external resources also proved to be a positive factor in generating corporate performance. The contents of this study provide an academic basis for the variables that build corporate organizational culture and provide a practical attitude to the role of leaders in managing corporate organizational culture. This study is focused on women's SMEs. n future research, the overall characteristics of the company will be considered. In addition, this study attempts to verify by applying various variables for generating performance of domestic SMEs by reflecting overcoming regional limitations.

• Journal of Information Management
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• v.36 no.4
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• pp.199-215
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• 2005

Experts participating in the knowledge expert network externalize their implicit knowledge by providing information or writing reports. Almost all the members of the network share externalized knowledge and the network facilitate the dissemination and diffusion of knowledge. Individuals reproduce another implicit knowledge by internalizing shared knowledge through the network and re-created knowledge is externalized, establishing knowledge circulation. In this paper, we analyze the expert groups of the Global Network of Korean Scientists & Engineers(KOSEN, www.kosen21.org), the Korea's No. 1 science and engineering knowledge expert community, with the application of the theory of policy network proposed by Marsh & Rhodes. According to the principal standards of policy network classification such as the number of participants, interaction among participants, consistency, distribution of resources and dependency, we categorize the KOSEN expert groups as closed policy network and opened issue network, and divide closed policy network into core community and periphery community.

• Journal of Korea Water Resources Association
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• v.57 no.6
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• pp.385-392
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• 2024

By installing the gate at the estuary to prevent the inflow of seawater into the river, it was prevented the inflow of seawater into the river, but as a result, the velocity of the river was rapidly decreased, turning it into a river with almost stoped flow. Since a river must have flow to maintain its function, in this study, it examined improving the flow of the river through the operation of a gate in Simgok-cheon where is a river that has been closed by a hydrological system at the estuary and almost stoped flow. It was considered that if the gate are operated according to the tide level, it could be changed into a river through which water flows by raising it to 0.49 m/s, which is about 10 times faster than the current slow flow rate of 0.05 m/s while maintaining the highest or lowest target elevation.

• Journal of the Korean Society for Railway
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• v.14 no.3
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• pp.300-311
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• 2011

In this study, the differences of labor-management cooperation and corporation performance resulted from integrated human resource management types is investigated for 12 urban railroad corporations and then the effect of labormanagement cooperation on the corporation performance is also verified. The results show that the labor-management cooperation and the corporation performance of "closed immersion type" and "opened flexibility type" integrated human resource managements are higher than those of "conservative management type" and "poor management type" integrated human resource managements. As a result of the effect of labor-management cooperation on the corporation performance, it is revealed that "individual cooperation" affects all the corporation performances such as train operation stability, customer's satisfaction, management innovation, self-supporting management, and job satisfaction, whereas "collective cooperation" affects only two coporation performances, management innovation and job satisfaction.