• International Journal of Human Ecology
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• 제12권2호
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• pp.1-12
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• 2011

Many pharmaceutical products are available through prescription (Rx) only status. As a result, access to physicians and insurance coverage play a key role in the use of these products, and therefore may affect the population to whom advertising is targeted at. The movement of pharmaceutical products from prescription (Rx) to Over-the-Counter (OTC), or Rx-to-OTC switch changes the cost of acquiring the drug and therefore may change the incentives manufacturers have at targeting particular population segments. This study examines whether Rx-to-OTC switch changes the frequency and the distribution of who is exposed to pharmaceutical advertising. Using an archive of pharmaceutical advertisements and National Consumer Survey, this study examines how individuals with particular demographic characteristics are exposed to pharmaceutical advertisements before and after drugs are moved from Rx to OTC. The results provide evidence that individual's advertising exposure increases after Rx-to-OTC switch. Moreover, the increase in advertising exposure is greater for the low socioeconomic status (SES) consumers which implies they may get more information about the disease, treatment and product after the Rx-to-OTC switch through advertising. If low SES consumers have more exposure to the advertising after products switched to OTC, then FDA policies regulating this switch should recognize the potential role of advertising providing access to health-related information.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.472-476
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• 2003

In this paper, a new current control algorithm is proposed for four-switch three-phase brushless DC(BLU) motor drives, which are suitable for low cost applications. A current reference generation scheme is developed and Implemented to obtain high performance characteristics in the four-switch system, such as small torque ripple and fast dynamic speed/torque response. Moreover, the proposed scheme can successful1y eliminate the torque ripple during commutations, so that it can be expected that the four-switch system can be much more practically applied for the industrial application areas.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 학술대회 논문집 전문대학교육위원
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• pp.157-161
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• 2000

The electronic ballasts for low pressure discharge lamps are produced and commercialized. However, the electronic ballasts for high pressure lamps are now in progress because of poor reliability and high cost. The major case of troubles with electronic ballasts are thermal destruction of semiconductor output switches due to non ideal i-v characteristics of switch. The loss converts to heat and rises the temperature of switch and it increases proportionally to switching frequency and value of current and voltage. This study shows the variable frequency ballasts which can suppress the heating of switches efficiently. It is used for the limitation the switch current and the rising temperature of switch by impedance variation of lamp inductor. As a result, initial warm-up time of the proposed ballasts was faster than that of magnetic ballasts about 90 msec. Power factor of tested ballasts follow as ; input and output average of magnetic ballasts are 93 [%] and 86 [%], respectively, And proposed ballasts are 97 [%] and 99 [%], respectively.

• 전자공학회논문지S
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• 제35S권4호
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• pp.10-19
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• 1998

With the advent of high-speed networks, the increasingly stringent performance requeirements are being placed on the underlying switching systems. Under these circumstances, simulation methods for evaluating the performace of such a switch requires vast computational cost and accordingly the importance of anlytical methods increases. In general, the performance analysis of a switch architecture is also a very difficult task in that the conventional queueing system such as switching systems, which consists of a large numbe of queues which interact with each other in a fiarly complicated manner. To overcome these difficulties, most of the past research results assumed that multiple queues become decoupled as the switch size grows unboundely large, which enables the conventional queueing theory to be applied. In this apepr, w analyze a non-blocking space-division ATM swtich with input queueing, and prove analytically the pheonomenon that virtual queues formed by the head-of-line cells become decoupled as the switch size grows unboundedly large. We also establish various properties of the limiting queue size processes so obtained and compute the maximum throughput associated with ATM switches with input queueing.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.275-276
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• 2013

In this paper, we proposed the Z-source four-switch three-phase rectifier. As we know, the conventional Four-Switch Three-Phase Rectifier(FSTPR) has advantages of the lower cost and less complex switching control. However, The conventional FSTPR can only either perform buck or boost operation, it can only attain the buck-boost operation by adding another DC-DC converter. In addition, besides its narrow output voltage region, distortion of the input current is serious either. Thus, we proposed the Z-source FSTPR which has buck-boost function and better input current waveform by applying the Z-impedance network to the conventional FSTPR. The validity of the proposed system was confirmed by experiments.

• 기술혁신학회지
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• 제18권1호
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• pp.176-203
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• 2015

클라우드 컴퓨팅은 지속적 성장세를 보이고 있고, 개인 클라우드 컴퓨팅 서비스의 중요성이 확대되고 있다. 이러한 중요성에 견주어, 본 연구의 목적은 어떤 이유로 기존 컴퓨팅 환경에서 클라우드 컴퓨팅 환경으로 전환을 하는 것인지, 또 어떤 요인들이 전환을 저해하는지에 대한 판단의 근거를 탐색하고자 한다. 본 연구에서는 사회교환이론을 연구의 이론적 프레임워크로 하여, 지각된 가치와 전환의도와의 관계를 실증적으로 분석하였다. 이를 위해 선행연구를 기초로 클라우드 컴퓨팅 서비스의 특성요인을 도출하였고, 이러한 요인들이 지각된 가치를 매개로 전환의도에 영향을 주는지를 파악하는 연구모형을 설정하였다. 총 7개의 연구가설을 제안하였으며, 총 204개의 데이터를 SmartPLS를 통해 가설을 검증하였다. 검증결과, 제안한 7개의 가설 중, 5개의 가설이 지지되었다. 동기요인 중에서는 효율성과 경제성이 지각된 가치를 매개로 전환의도에 영향을 미치는 것으로 나타났고, 저해요인 중에서는 전환 비용과 보안우려가 전환의도의 선행요인임을 규명하였다. 본 연구는 실무적 차원 혹은 조직관점에서 논의되어 온 클라우드 컴퓨팅 서비스를 개인 수준에서 접근하였다는데 의의가 있다. 또한 클라우드 컴퓨팅 서비스로의 전환의도를 동기요인과 저해요인의 이요인 관점에서 논의하였다는데 또 다른 의의를 갖고 있다.

• Journal of Power Electronics
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• 제3권4호
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• pp.249-258
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• 2003

This paper presents a high-efficient and cost effective three-phase AC/DC-DC/AC power conversion system with a single two-switch type active Auxiliary Resonant DC Link (ARDCL) snubber circuit, which can minimize the total power dissipation. The active ARDCL snubber circuit is proposed in this paper and its unique features are described. Its operation principle in steady-state is discussed for the three phase AC/DC-DC/AC converter, which is composed of PWM rectifier as power factor correction (PFC) converter, sinewave PWM inverter. In the presented power converter system not only three-phase AC/DC PWM rectifier but also three-phase DC/AC inverter can achieve the stable ZVS commutation for all the power semiconductor devices. It is proved that the proposed three-phase AC/DC-DC/AC converter system is more effective and acceptable than the previous from the cost viewpoint and high efficient consideration. In addition, the proposed two-switch type active auxiliary ARDCL snubber circuit can reduce the peak value of the resonant inductor injection current in order to maximize total system actual efficiency by using the improved DSP based control scheme. Moreover the proposed active auxiliary two-switch ARDCL snubber circuit has the merit so that there is no need to use any sensing devices to detect the voltage and current in the ARDCL sunbber circuit for realizing soft-switching operation. This three-phase AC/DC-DC/AC converter system developed for UPS can achieve the 1.8% higher efficiency and 20dB lower conduction noise than those of the conventional three-phase hard-switching PWM AC/DC-DC/AC converter system. It is proved that actual efficiency of the proposed three-phase AC/DC-DC/AC converter system operating under a condition of soft switching is 88.7% under 10kw output power.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.74-78
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• 2002

In this study, We propose equations which can determine the number of sectionalizing switches for minimizing the outage and switch installation cost.

• 한국IT서비스학회지
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• 제14권1호
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• pp.145-158
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• 2015

Currently, Social Commerces have increasingly gained popularity with the growth of Social Network Services (SNS). As the applications of smartphones are being applied in widespread areas, social commerces in the smartphone environment have entered a new chapter. The applications of social commerces on smartphones are widely used, which has increased the market share of social commerces exponentially. Thus, we tried to find out factors which may affect the user acceptance of social commerces in the smartphone environment. We develop a research model to examine how social commerces in the smartphone environment are accepted by users based on the academic factors-switch costs, trend-seeking tendency, richness in media. The theoretical model is validated through an survey of social commerce users in the smartphone environment from the undergraduates and the graduates in Seoul, Korea. The structural equation analysis is conducted based on the partial least square (PLS) approach. The results reveal that the switch cost will have positive mediating influences to the intention to use social commerce in the smartphone environment. We also find that the perceived usefulness of the smartphone is affected by the media richness. The results also suggest that the trend-seeking tendency has no influences to the users of social commerces in the smartphone environment. Also, theoretical and practical implications are discussed. The findings are believed to increase our understanding an interesting mobile phenomenon, as well as making contributions.

• 전자공학회논문지D
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• 제34D권5호
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• pp.52-60
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• 1997

Photonic switching systems with throughput above Tbit/s are reuried to transport vast amounts of information for the coming B-ISDN. In this paper, we proposed a new time-division hybrid WDM photonic swithc architecture, the proposed basic switch module has simple configuratin consisted of frequency routers for wavelength division and cell coders and star couplers for time division. Through the comparison with other sysems in field of switching capacity, hardware complexity and cost effect of implemetnation, we proved that the proposed system is suitable for large-capacity photonic switching system.