• 전력전자학회논문지
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• 제10권5호
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• pp.494-500
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• 2005

본 논문에서는 플라이휠에너지를 이용한 다이나믹 UPS 시스템에서 유도기를 이용하여 플라이휠의 에너지를 저장 및 재생하는 시스템 제어 기법을 제시하였다. 유도발전기의 슬립주파수 제어와 벡터제어 기법의 특성을 비교하고, 또한 벡터제어 기법을 사용 시 전동 모드에서 발전 모드로의 전환할 때 직류링크 커패시터 전압의 과도 특성을 개선하는 기법을 개발하였다. 32비트 DSP를 사용한 실험을 통하여 이 기법의 성능을 확인하였다.

• 통상정보연구
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• 제10권4호
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• pp.321-350
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• 2008

The China has opened the distribution market completely since it joined the World Trade Organization on Dec 11 2001. The notable features of Chinese distribution market are the transition from the consumers' monolithic demand to diversification for the luxury goods, well-being products. The regional characteristics of consumers are smart, conservative, optimistic and advanced. and the open door policy has prompted the capitalistic economy gradually. We analyzed the Chinese distribution markets and came up with the following strategies. First, we recommend the setting of the key regional market not covering the whole chinese markets. then we can extend the main market step by step. Second, we need to cooperate and advance with the Korean distribution companies which entered into markets already. Third, we need to acquire the competitive and stable distribution channel in China. Fourth, we need to implement the localization strategy in terms of human resources and procurement. Fifth, the consignment management can be another strategy. I hope this research can be a little help to those who wish to expand to the Chinese markets.

• International Journal of Advanced Culture Technology
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• 제12권2호
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• pp.326-333
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• 2024

This is a descriptive correlational study aimed at determining the relationship between SOC strategy, life satisfaction, and successful aging in middle-aged women. The study population was middle-aged women aged 40-65 years living in one metropolitan city, and 295 data collected using a structured questionnaire were used to analyze the results. The collected data were analyzed using descriptive statistics, independent t-test, one-way ANOVA, and Pearson's correlation using SPSS WIN/PC 24.0 statistical program. In the results of this study, the general characteristics related to successful aging in middle-aged women were identified as age, occupation, religion, economic status, presence of chronic diseases, and health status perception, menopause as significant influencing variables. In addition, successful aging was positively related to SOC strategy and life satisfaction among the middle-aged women in this study (p<.05). In particular, life satisfaction was highly correlated with successful aging in this study, and in this regard, efforts should be made to develop various programs to help middle-aged women feel satisfied with their lives so that they can transition to successful aging.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2001년도 춘계학술발표회요약집
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• pp.80-80
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• 2001

• Bulletin of the Korean Chemical Society
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• 제29권6호
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• pp.1167-1172
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• 2008

We investigated the glass transition temperatures ($T_g$) of dendrons consisting of conformationally mobile aliphatic polyether dendritic cores plus glassy peripheral polystyrenes (PSs), and linear PSs in the molecular weight range of 1000-8500 g/mol. We compared their $T_g$ behavior depending on their polymeric architecture. The linear PSs show a typical growth of $T_g$ up to 92.5 ${^{\circ}C}$ as the molecular weight increases to 8300 g/mol, while the dendrons display nearly constant $T_g$ values of 58-61 ${^{\circ}C}$, despite the increase of molecular weight with each generation. The striking contrast of Tg behavior would be mainly attributed to the fact that the dendrons keep the ratio of $N_e$/M ($N_e$: number of peripheral chain ends, M: molecular weight) over all the generations. Additionally, for the influence of dendritic spacers on glass transition temperature we prepared dimeric PSs with different linkage groups such as aliphatic ether, ester and amide bonds. We found that the dimer with the ether spacer exhibited the lowest glass transition at 55.4 ${^{\circ}C}$, while the amide linked dimer showed the highest glass transition temperature at 74.2 ${^{\circ}C}$. This indicates that the peripheral PS chains are effectively decoupled by the conformationally flexible ether spacer. The results from this study demonstrated that polymeric architecture and dendritic core structures play a crucial role in the determination of glass transition behavior, providing a strategy for the systematic engineering of polymer chain mobility.

• 과학기술학연구
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• 제12권2호
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• pp.81-116
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• 2012

지속가능성이 전 지구적인 화두로 등장함에 따라 이를 목표로 한 시스템 전환 노력이 기후 에너지 주거 교통 바이오 등 다양한 영역에서 진행되고 있다. 본 연구에서는 시스템 전환과 그 관리의 수단으로 주로 활용되는 백캐스팅 사례로 네덜란드의 지속가능한 교통 식품 가정 시스템 전환 정책을 분석하였다. 분석결과 네덜란드는 지속가능한 교통 식품 가정 시스템으로의 전환을 시도하면서 현재의 상태에서 출발하는 점진적 변화 방식을 벗어나 지속가능한 미래 상태에 도달하기 위한 전향적인 정책 수단을 강구하여 왔다. 이 과정에서 과학기술 전문가뿐 아니라 인문사회과학 전문가가 함께 참여하는 다학제적 연구를 강조하고 있으며, 시나리오의 개발 및 평가 등의 과정에 다양한 이해관계자들을 참여시킴으로써 시민사회의 지식과 과학기술전문가들의 지식 융합을 추구하고 있다. 우리나라도 사회 및 정책 전반에 걸쳐 새로운 경로를 창출해야 하는 시스템 전환의 상황을 맞이하고 있는 만큼 다양한 주체의 합의에 기반을 두면서도 관련 정책을 통합적으로 고려하는 참여형 백캐스팅 관점의 도입이 필요하다.

• 한국통신학회논문지
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• 제37A권12호
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• pp.1085-1092
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• 2012

이동통신 시스템은 무선 자원과 배터리 전력을 효율적으로 관리하기 위해 사용자 상태 천이 방식을 정의하고 있다. 이러한 상태 천이 방식에서는 에너지 소비가 많은 상태가 기본적으로 짧은 접속 지연을 제공하므로 에너지와 지연 성능 사이에 트레이드오프 관계가 존재한다. 본 논문에서는 이동 응용 서비스의 트래픽 속성을 고려하여 UMTS 시스템의 사용자 상태 천이 방식을 분석한다. 상태 천이 방식의 마르코프 모델링을 통하여 에너지 소비량과 활성 지연을 수학적으로 도출하고 운용 파라미터에 따라 이들의 트레이드오프 관계를 파악한다. 분석 결과로 도출된 에너지-지연 트레이드오프 곡선은 주어진 상태 천이 방식이 달성 가능한 성능 한계를 보여주며 지연 요구사항을 보장하면서 에너지 소비를 최소화하는 최적 운용 전략을 제시한다.

• 한국농촌건축학회논문집
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• 제8권1호
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• pp.101-110
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• 2006

During high speed economic growth period in Korea, our society has focused it's energy on the economic and social development based on the strategy of demolition and destruction of all our natural and man-made environment. In progress with that trend, our small cities in Korea also have just followed the metropolitan physical development pattern and considered that imitation of those metropolitan cities' or western cities' changes be the same meaning of "modernization". Therefore, our valuable urban and architectural heritages have been constantly destructed and that situation has been same in Anseong. Now in the new trend of environmentally sustainable urban design and at the new millenium period, we have to focus our attention on the retaining strategy of city's historicity as a city planner or an architect, and the first step for this strategy shall be to clarify the transition process of urban structure, especially of C.B.D. area of small cities since pre-industrial period.

• Journal of Communications and Networks
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• 제16권2호
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• pp.193-201
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• 2014

In cognitive radio networks, the packet transmissions of the secondary users (SUs) can be interrupted randomly by the primary users (PUs). That is to say, the PU packets have preemptive priority over the SU packets. In order to enhance the quality of service (QoS) for the SUs, we propose a spectrum access strategy with an ${\alpha}$-Retry policy. A buffer is deployed for the SU packets. An interrupted SU packet will return to the buffer with probability ${\alpha}$ for later retrial, or leave the system with probability (1-${\alpha}$). For mathematical analysis, we build a preemptive priority queue and model the spectrum access strategy with an ${\alpha}$-Retry policy as a two-dimensional discrete-time Markov chain (DTMC).We give the transition probability matrix of the Markov chain and obtain the steady-state distribution. Accordingly, we derive the formulas for the blocked rate, the forced dropping rate, the throughput and the average delay of the SU packets. With numerical results, we show the influence of the retrial probability for the strategy proposed in this paper on different performance measures. Finally, based on the trade-off between different performance measures, we construct a cost function and optimize the retrial probabilities with respect to different system parameters by employing an iterative algorithm.

• Strategy21
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• 통권33호
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• pp.37-64
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• 2014

The year 2010 has been regarded as a year of China's assertive diplomacy. A series of China's behavior--including China's critical reaction to the U.S. for its sales of weapons to Taiwan, the Dalai Lama's visit to President Obama, China's arbitrary designation of 'core interests' over the South China Sea, China's inordinate reactions to the sinking of the Cheonan and Yeonpyeong bombardment, and China's activities in the Senkaku/Diaoyu island areas--has served as the witnesses to China's assertive diplomacy in 2010. The major causes of China's assertive diplomacy can be summed up by three factors: potential power transition from U.S. to China; emerging China's nationalism; and the recession of the Tao Guang Yang Hui as a diplomatic principle. But a majority of Western sinologists claim that China's assertive diplomacy is defensive in terms of its character. China's neighboring states, however, perceive its assertive diplomacy as diplomatic threat. Due to these states' geographical proximity and capability gaps with China, these neighbors experience difficulties in coping with China's behavior. In particular, China's coercive economic diplomacy, in which China tends to manipulate the neighbors' economic dependency on China for its diplomatic leverage, is a case in point for China's assertive diplomacy. China's assertiveness seems to be continued even after the inauguration of Xi Jinping government. Although the Xi government's diplomatic rhetorics in "New Type of Great Power Relationship" and the "Convention for Neighboring States Policy" sound friendly and cooperative, its subsequent behavior, like unilateral announcement of Chinese Air Defense Identification Zone (CADIZ), does not conform with its rhetoric. Overall, China's assertiveness has been consolidated as a fashion of its diplomacy, and it is likely to continue in its relations with neighbors. As a neighboring state, the ROK should approach to it with more balanced attitude. In addition, it needs to find out a new diplomatic leverage to deal with China in accordance with its security environment, in which China plays a growing role.