• Journal of Broadcast Engineering
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• v.13 no.1
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• pp.152-161
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• 2008

We investigate that when we restrict the encoding modes on the enhancement layer based on that of the base layer exploiting the high correlation between the best modes at base and enhancement layers, we should determine the set of surviving search modes to yield the minimum excessive RD-cost caused by the restriction. Based on these sets, we implement a fast mode decision algorithm for H.264 Scalable Extension (SE). Simulation results show that the proposed algorithm is superior in the sense of the RD-performance to the conventional mode restriction method which is based on the conditional probabilities of the best modes.

• 한국벤처창업학회:학술대회논문집
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• 2019.04a
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• pp.191-194
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• 2019

최근 수십 년 동안 음악 산업처럼 빠르게 변하고 많은 도전에 직면한 산업군도 드물 것이다. 디지털 기술의 발전은 CD와 같은 실물을 통한 음악 소비를 mp3와 같은 음원 소비 방식으로 바꿔 놓았다. 더 나아가 스마트폰의 보급과 무선 인터넷의 발달은 스트리밍을 통한 음원 소비 방식을 가능하게 하였다. 음원 스트리밍 시장은 IT 기술의 발전으로 빠른 성장을 거듭하여 스트리밍 이용 수가 급격히 증가한 반면, 음원 다운로드 수는 감소하는 추세를 보여 음원 소비가 소유방식에서 접근방 식으로 변화 중이라고 할 수 있다. 음원 소비 방식이 달라지면 소비 행태가 달라질 수 있음에도 불구하고 음원 다운로드와 음원 스트리밍 소비 행태의 차이를 분석한 연구는 미진한 실정이다. 따라서 본 연구는 국내의 음원 서비스 회사의 음원 스트리밍과 음원 다운로드 관련 데이터를 분석하여 음원 소비 방식에 따른 행태 차이를 살펴봄을 목적으로 하였다. 분석 결과, 음악을 듣는 탐색비용과 한계비용이 훨씬 적은 스트리밍이 다운로드에 비해 틈새시장(niche market)에 속하는 음악을 들을 가능성이 높아 소비자들이 다양한 음악을 청취할 것이라는 선행 연구와는 다르게 스트리밍이 다운로드에 비해 차트 상위권 음원집중도가 높은 것으로 나타났다. 제공하는 서비스의 특성에 따라 스트리밍 산업에서의 매출집중도가 달라질 수 있다는 것을 기업 데이터를 통해 실증하였다는 것에 의의가 있다고 할 수 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.196-196
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• 2021

상수관망은 많은 관을 통해 물의 수요가 있는 곳으로 물을 공급해주는 역할을 하는 사회기반 시설물이다. 상수관망 설계의 요점은 두 가지로 구분할 수 있다. 첫 번째 요점은 다양한 종류의 관배치로 인한 상수관망 설계안의 많은 경우의 수이다. 두 번째 요점은 상수관망 내 절점의 최저 요구수압 등의 제약조건이다. 두 가지 요점이 있는 상황에서 상수관망 설계비용의 최소화를 위한 상수관망 최적설계는 많은 계산이 요구된다. 많은 계산이 요구되기 때문에 상수관망 최적설계에 최적화 기법을 적용할 수 있다. 본 연구에서 상수관망 최적설계를 위해 적용된 최적화 기법은 Hybrid Rate(HR)를 개선한 Hybrid Vision Correction Algorithm(HVCA)이다. HVCA는 Vision Correction Algorithm(VCA)을 기반으로 추가적인 전역탐색을 실행하는 Centralized Global Search(CGS)의 적용 및 자가적응형 매개변수인 Hybrid Rate(HR)를 적용하여 사용성과 성능을 개량한 알고리즘이다. HVCA의 기존 HR은 선형적으로 증가하는 형태이다. 선형적으로 증가하는 HR로 인해 HVCA는 최적해 탐색과정에서 지역해에 빠지는 문제가 발생하였다. HVCA의 문제를 해결하기 위해 HR을 비선형적으로 증가하는 형태로 개량하였다. HR이 개량된 HVCA를 수자원공학 문제인 상수관망 최적설계 문제에 적용하여 결과를 비교하였다. 적용결과 HR이 개량된 HVCA가 기존의 HVCA보다 낮은 설계 비용을 나타내었다. 상수관망 최적설계 적용결과를 바탕으로 HR이 개량된 HVCA는 상수관망 최적설계 이외의 수자원공학 문제에도 적용가능할 것이다.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.1
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• pp.27-34
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• 2013

IT has been receiving increasing attention for cloud computing services. However, despite a lot of attention, there are limitations of existing research on cloud computing services. There are researches respectively about the benefits and costs that would occur if you choose a cloud computing services. However, in real life, consumers should be considered about the benefits and costs at the same time if they choose and use a cloud computing service. Therefore, this study examines the interaction effect of benefits and costs on cloud computing service. The findings demonstrate that three independent variables(usefulness, social influence, and innovativeness) positively(+) affect the perceived value. However, showed the benefits and costs of interaction effects analysis, usefulness and innovation on the cost influence the perceived value in statistics. The interaction of the usefulness & cost shows negative(-) effect and the interaction of the innovativeness & cost has positve(+) effect on the perceived value. In conclusion, this study provide that consumers need to consider costs with benefits when they use a cloud computing service.

• Journal of Intelligence and Information Systems
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• v.13 no.4
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• pp.121-135
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• 2007

Constraint directed scheduling techniques, representing problem constraints explicitly and constructing schedules by constrained heuristic search, have been successfully applied to real world scheduling problems that require satisfying a wide variety of constraints. However, there has been little basic research on the representation and optimization of the objective value of a schedule in the constraint directed scheduling literature. In particular, the cost objective is very crucial for enterprise decision making to analyze the effects of alternative business plans not only from operational shop floor scheduling but also through strategic resource planning. This paper aims to explicitly represent and optimize the total cost of a schedule including the tardiness and inventory costs while satisfying non-relaxable constraints such as resource capacity and temporal constraints. Within the cost based scheduling framework, a cost propagation algorithm is presented to update cost information throughout temporal constraints within the same job.

• International Commerce and Information Review
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• v.16 no.4
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• pp.333-362
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• 2014

This study uncovered some issues that have constrained the development of logistics performance in Cambodia. Firstly, literature review was narrowed down to include studies involving the relationship between Logistics and transportation, the relationship between the infrastructure and economic growth and the important role of logistics on economic growth and poverty reduction. Then the next step the study identified some issues related to transport infrastructure that were assumed to cause the enhancement of logistics sector. Moreover, a case study about cost and time analysis was used to address some issues of logistics cost in Cambodia comparing to its neighboring countries: Thailand and Vietnam. Based on the time and cost analysis, it revealed that the logistics cost in Cambodia is much high than Thailand and Vietnam. In addition, some logistics issues were found through other two case studies about the export and trade facilitation. The participants raised some issues related to issuance of certificate of origin, the availability of information about agreements, laws, rules, and regulations, checkpoints along the corridor and opening hours of logistics service providers and slow processes. Then the authors suggested some appropriate solutions to answer to the current issues related to transport infrastructure and logistics sector in Cambodia.

• Journal of Broadcast Engineering
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• v.17 no.5
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• pp.781-788
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• 2012

In HEVC, the fast search method is used for reducing the complexity of the motion prediction procedure. It is consisted of the sub-sampled SAD which reduce the complexity of Sum of Absolute Differences(SAD) calculation and the simplified bi-prediction method which reduce the iterations of the uni-prediction for the bi-prediction. The computational complexity is largely decreased by the fast search method but the coding gain is also decreased. In this paper, the simplified bi-prediction is extended to compensate the performance loss and the prediction cost based complexity reduction methods are also proposed to reduce the complexity burden by the extended bi-prediction method. A prediction cost based complexity reduction method is consisted of early termination method for the extended bi-prediction and the bi-prediction skipping method. Compare with HM 6.0 references S/W, the average 0.42% of BD-bitrate is decreased by both the extended bi-prediction method and the prediction cost based complexity reduction methods with negligible increasement of the complexity.

• Journal of the Korea Convergence Society
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• v.9 no.12
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• pp.159-167
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• 2018

As the popularity of single-person media content increases, We investigated the causal relationship between perceived value and intention to recommend to others. Individuality was studied on the tendency to sensation seeking and novelty seeking, which is a tendency to take boredom sensitive to monotonous and repetitive daily routines, and novelty seeking refers to new information and stimuli. The hypothesis was that high sensation seeking and high novelty seeking would perceived emotional value, epistemic value, and economic value for a single person 's media content. Hypothesis testing was performed using multiple regression analysis using SPSS21. As a result of the hypothesis test, The novelty seeking has a positive effect on emotional value, epistemic value, and economic value. Users who want to explore and enjoy new things could perceived the emotional value of having fun, fun, and sadness through single-person content, perceived a epistemic value and enjoy new information and situations as a tool to recognize new stimuli and know what they didn't know. And it could be seen that users perceive the economic value that they can enjoy at low cost or free service. The sensation seeking has a significant effect on epistemic value, but it did not affect emotional value and economic value significantly. Those who have a high tendency to sensation seeking can perceive curiosity about one-person media contents, so that they can perceive epistemic value. However, those who feel that they have not significant influence on economic value and emotional value can easily understand that expecting one's content does not feel bored by paying for a low cost or free service.

• Journal of Distribution Research
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• v.6 no.2
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• pp.109-133
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• 2002

This article examines how consumers in online environments depend on brand in making purchase decisions by product types. Previous research explains that the characteristics of online environments decrease the dependence on brand due to inexpensive search costs and affluent information quantity. But it is likely that in online environment, the dependence on brand will be differentiated by product types. We found that in search product, the availability of information decreased consumer's uncertainty, which, in turn, increased the dependence of brand. However, in experience products, the weakness of multi-sensory increased consumer's uncertainty, which resulted in the increase of the dependence of brand.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.12
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• pp.1133-1140
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• 2011

Current design process for the Hall effect thruster has relied on expensive experimental method based on the limited historical data. In this study, a proper design space for the Hall effect thruster is chosen and associated design space exploration is conducted based on a recently proposed numerical method in order to improve current design process. According to the results of the design space exploration, performance envelope is determined for the given design space and the correlations between performance metrics are analyzed. Further analysis shows that main factors in performances for the Hall effect thruster are the anode mass flow rate and the discharge voltage.