• Journal of Information Processing Systems
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• 제19권6호
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• pp.817-829
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• 2023

Variable wireless channel is a big challenge for real-time video applications, and the rate adaptation of realtime video streaming becomes a hot topic. Intra-video coding is important for high-quality video communication and industrial video applications. In this paper, we proposed a novel adaptive scheme for real-time video transmission with intra-only coding over a wireless network. The key idea of this scheme is to estimate the instantaneous remaining capacity of the network to adjust the quality of the next several video frames, which not only can keep low queuing delay and ensure video quality, but also can respond to bandwidth changes quickly. We compare our scheme with three different schemes in the video transmission system. The experimental results show that our scheme has higher bandwidth utilization and faster bandwidth change response, while maintaining low queuing delay.

• 한국정보시스템학회지:정보시스템연구
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• 제24권3호
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• pp.133-154
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• 2015

연구목적 컴퓨터 기반의 아이디어 생산 그룹들이 그렇지 않은 그룹들에 비해 여러 면에서 월등한 퍼포먼스를 보여 왔다고 컴퓨터 기반 브레인스토밍 연구들은 주장한다. 하지만 다른 연구들은 컴퓨터 기반 아이디어 생산 중에 발생하는 인지자극 시너지가 노미널 그룹과 비교했을 때 예상치보다 크지 않다고 지적한다. 컴퓨터 환경 하에서는 개인의 성향 차이에 따라 긍정적이고 부정적인 영향력이 다르게 작용한다. 따라서 본 연구는 아이디어가 생산될 때 발생하는 타임 스탬프를 분석하여 개인의 성향 차이가 아이디어 생산과정에서 어떤 영향을 미치는지를 관찰한다. 방법론 외향성/내향성 개인차와 아이디어 자극수위 (0/20/40/80개 아이디어)를 결합한 이원요인계획법을 사용하였다. 각 실험참가자는 무작위로 8개의 실험조건 중 하나에 할당되었다. 그룹시뮬레이터를 이용하여 실험참가자들의 퍼포먼스를 관찰하였다. 데이터베이스에 모아진 아이디어들 가운데 중복되지 않은 아이디어와 각 아이디어의 타임 스템프를 분석에 사용하였다. 결과 실험결과 (1) 내향성 집단은 외향성 집단에 비해 아이디어 세션 중반부 이후 생산성이 현저히 떨어지는 양상을 보인다. (2) 내향성 집단은 외향성 집단에 비해 현저히 적은 범주의 아이디어 생산 양상을 보인다. 따라서 컴퓨터 기반 브레인스토밍은 외향성 집단의 생산성 향상에 더 적합한 방법으로 보여진다.

• 한국항만경제학회지
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• 제21권3호
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• pp.259-270
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• 2005

This study applies the Analytic Hierarchy Process (AHP) to evaluate service quality of Third-Party Logistics (3PL) providers. For this, 3PL service quality is conceptualized and measured using SERVQUAL's five dimensions such as tangibles, reliability, responsiveness, assurance and empathy. Then, the AHP method is applied to determining the relative importance of five service quality dimensions and eventually selecting the best 3PL provider. Finally, this study conducts an empirical case study on four companies providing 3PL services in Korea to demonstrate the basic idea suggested in this paper. The results obtained in the present study indicate that responsiveness to customers is the most important factor perceived by 3PL customers and 3PL C is the best 3PL provider according to the overall service quality scores. In contrast to some previous researches, this study examined issues of service quality from the perspective of 3PL customers as opposed to the perspective of 3PL providers. In order for this study to be more complete, future research is needed in establishing a set of metrics to quantify each dimension of 3PL service quality proposed.

• ETRI Journal
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• 제28권1호
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• pp.31-44
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• 2006

In a packet switching network, congestion is unavoidable and affects the quality of real-time traffic with such problems as delay and packet loss. Packet fair queuing (PFQ) algorithms are well-known solutions for quality-of-service (QoS) guarantee by packet scheduling. Our approach is different from previous algorithms in that it uses hardware time achieved by sampling a counter triggered by a periodic clock signal. This clock signal can be provided to all the modules of a routing system to get synchronization. In this architecture, a variant of the PFQ algorithm, called digitized delay queuing (DDQ), can be distributed on many line interface modules. We derive the delay bounds in a single processor system and in a distributed architecture. The definition of traffic contribution improves the simplicity of the mathematical models. The effect of different time between modules in a distributed architecture is the key idea for understanding the delay behavior of a routing system. The number of bins required for the DDQ algorithm is also derived to make the system configuration clear. The analytical models developed in this paper form the basis of improvement and application to a combined input and output queuing (CIOQ) router architecture for a higher speed QoS network.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2010년도 춘계학술대회
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• pp.283-290
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• 2010

This paper suggest that the derivation of good and practical ideas is important for the successful use of Kano model. Wish List, Bug List and Forced Connection Method as well as Brainstorming were applied to PMP(Portable Multimedia Player) in order to derive customer attributes. Wish List and Bug List are variants of Brainstorming, which are contrary to each other. Forced Connection Method is designed to bring about bisociation which is a typical characteristic of creative thinking.

• 품질경영학회지
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• 제45권3호
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• pp.309-326
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• 2017

Purpose: The purpose of this study is to propose useful idea and data by association analyzing MRA results of defense research and development. Methods: The collected data through the DTaQ MRA system are analyzed using three association analysis measurements. Results: The results of this study are as follows; some evaluation items are very highly associated according to confidence and lift. The result is also meaningful as contents of evaluation items. The result of this study suggests a direction for improvement of MRA system. Conclusion: Some evaluation items of MRA are meaningfully associated. Therefore, the result can support the improvement of MRA system.

• International Journal of Control, Automation, and Systems
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• 제6권4호
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• pp.596-606
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• 2008

In this paper, we present a co-design methodology of dynamic optimal network-bandwidth allocation (ONBA) and adaptive control for networked control systems (NCSs) to optimize overall control performance and reduce total network-bandwidth usage. The proposed dynamic co-design strategy integrates adaptive feedback control with real-time scheduling. As part of this co-design methodology, a "closed-loop" ONBA algorithm for NCSs with communication constraints is presented. Network-bandwidth is dynamically assigned to each control loop according to the quality of performance (QoP) information of each control loop. As another part of the co-design methodology, a network quality of service (QoS)-adaptive control design approach is also presented. The idea is based on calculating new control values with reference to the network QoS parameters such as time delays and packet losses measured online. Simulation results show that this co-design approach significantly improves overall control performance and utilizes less bandwidth compared to static strategies.

• 대한안전경영과학회지
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• 제8권3호
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• pp.11-25
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• 2006

It is necessary to deal with the process capability index carefully because it has been developed with certain assumptions. Companies make a decision on processes through the results obtained by using and treating data extracted from the processes. However if they have incorrect or wrong results, they cannot lead to proper outputs but also bring to loss of the competition in quality. Therefore, this study will show a method to analysis Cp (process capability ; CP) and an idea of mass-production on Pp (process performance ; PP) based on the Sigma Estimate which is one of the uncertainty in the process capability index and makes a lot of error. To apply this method, it is essential to understand and to analyze the processes exactly. Especially, it is required to establish the more accurate process capability index that can quickly and properly respond to changes on processes to recognize the small changes on the process which lies in specification in mass production system that the continual monitoring of quality managers is required.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.242-245
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• 2000

In this paper we present new idea to highly compress the images. The previous image is transformed with wavelet and the transformed data are transmitted. The previous image is subtracted from the next image. Then difference values per pixel are scanned to search motion areas and boundaries. In the motion boundaries, motion vectors and error values are transformed with wavelet and transmitted. We also include camera motion estimation and compensation. In this method this system has advantages of more compressive data, better quality of picture and shorter processing time compared to MPEG2, MPEG4.

• 한국음향학회지
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• 제8권5호
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• pp.7-22
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• 1989

This paper presents basic data on loudness level and loudness along with data obtained by the authors, and describes an application of the idea of masked loudness to perception of music in the presence of noise. It is shown that timbre or sound quality of music is well explained by masked loudness vs frequency characteristic.