• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.3
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• pp.482-490
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• 2017

This study surveys and discusses that to what extent consumers are understanding the benefits and which purpose of use they support more regarding the 700 MHz frequency band allocation for mobile communication use as well as public terrestrial UHD TV broadcasting use. The results of this study can be summarized as follow. First, consumers perceive not only advantages but disadvantages for the decision that 700 MHz frequency band is divided and utilized for both mobile communication and UHD TV broadcasting use. Second, 43% of consumers (the largest portion of opinions) say that they support government's final decision of 700 MHz frequency band allocation, which can be interpreted that government's long term discussion and final decision of frequency allocation policy is favorably accepted by the majority of consumers. The importance of this study is to survey consumers' perception of government's 700 MHz band frequency allocation policy from impartial point of view from either communication or broadcasting interest.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.5
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• pp.962-966
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• 2009

In this paper, N-way resistance power divider is described for wideband frequency characteristic. For this, we derived in design equation of a N-way resistance power divider using 3-way resistance power divider. We designed 8-way resistance power divider that can divide same power by 7 output and measurement result of fabricated resistance power divider is observed to prove the validity of derived design equation. Fabricated resistance power divider shown equal power division ratio and reflection loss displayed excellent characteristic by about -25dB in broadband from DC to 3GHz.

• Journal of Advanced Navigation Technology
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• v.20 no.1
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• pp.59-64
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• 2016

This paper presents a high dividing ratio unequal dualband divider using coplanar waveguide (CPW) and shunt connected open stub transmission lines. In order to implement transmission lines for a dualband divider using design equations, the low impedance lines of divider can be realized a shunt connected open stub transmission line. Also, the high impedance lines are realized by CPW transmission lines. To certify the validity of an unequal dualband divider using CPW and shunt connected open stub transmission lines, the 10:1 unequal dualband divider is implemented at operating frequency of 1 and 2 GHz. Good experimental performance at each frequency are obtained, which are in good agreement with the simulated results.

• Journal of Advanced Navigation Technology
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• v.15 no.2
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• pp.307-312
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• 2011

In the macro/femto cellular networks, the portion of channels assigned to each cell is a critical factor which sets the stability and the performance of the whole system. To grasp the concrete influence that the channel split portion have on the system, we present the queueing model for IP based macro/femto cellular networks, and find the stability conditions. Additionally we provide the strategy to decide the portion of channels allocated to each cell. Through the experiments, we prove that the proposed strategies operate feasibly in various network environments, and on the basis of these results we discuss the efficient system structure plan.

• Nuclear Engineering and Technology
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• v.26 no.4
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• pp.507-515
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• 1994

Fly ash and betonite samples were selected and characteristics of them were investigated. Fly ash was found to be similar to bentonite in particle size distribution but quite different in microstructure. The most special aspect of fly ash was high alkalinity of its solution. Distribution coefficients of Cs and Co on the samples were measured to survey the effects of mixing. Fly ash showed higher distribution coefficient of Co than that of Cs. Through various experiments, factors affecting the distribution coefficients of Co and Cs on mixture of bentonite and fly ash were identified. Comparison of the distribution coefficients of Cs on fly ash and bentonite mixture with those on sand and bentonite mixture suggests that fly ash would be useful as an efficient additive of backfill material if pertinent mixing ratio was chosen.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.341-343
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• 2021

현재 웹툰 시장이 크게 성장하고 있는 가운데, 과도한 매출 수수료 및 불공정 계약 등 부조리한 수익분배 문제가 불거지고 있다. 본 논문은 웹툰 플랫폼의 수익모델을 보완하는 NFT 기반 웹툰거래 및 수익분배 시스템을 소개하고자 한다. NFT 는 고유한 값을 가진 토큰으로, 디지털 자산에 대한 소유권 인증에 용이하며 블록체인 네트워크 상에서 구매 이력 등의 데이터 위변조가 어렵다는 특징이 있다. 또한 암호화폐처럼 손쉽게 거래할 수 있고 재판매가 가능하다는 장점 때문에 예술 분야에서 각광받고 있다. 이에 웹툰에 NFT 를 발행하여 웹툰을 소장 및 거래하고, NFT 소장 비율에 따라 해당 웹툰의 열람 수익을 나눠 가질 수 있는 시스템을 개발하여 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.1338-1341
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• 2021

현재 대한민국 운송업에서 두 번째로 큰 비율(19.2%)을 차지하고 있는 수상 운송업에서는 연간 많은 재해가 발생하고 있으며 그 손해는 4백억 원에 달한다. 본 연구는 수상 운송업에서의 재해율과 경제적 손실을 최소화하기 위해 신체 측정기기 및 항만 작업 분배시스템을 설계하였다. 신체 측정기기는 심박, 알코올, 적외선 온도 센서 등을 활용하여 작업자의 신체 정보를 측정한다. 이 결과를 아두이노로 전송한 뒤 사용자의 집중도와 피로도를 분석하여 적절한 작업 분배 서비스를 제공한다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.509-512
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• 2003

The Critical Path Method(CPM) is an effective tool used for planning and scheduling. One of strong point in the CPM is what can calculate float. Float is able to prolong without having an effect on overall schedule of project, however concept and scope about ownership is not definite, because it is a by-product of project. Thus participants have had many dispute in using float because of their interests. In recent years, a few theories have evolved in an attempt to solve this problem. But the prior research did not make a reasonable distribution of float because their criteria of distribution was based on ratio for total project time. Actually, an application of float is achieved by participant's delay risk. Therefore. this paper proposes criteria for float distribution using delay risks, and the framework for the assessment of the delay risks.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.74-80
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• 2004

If the withdrawal force of strand driven roll which is controlled with predetermined speed isn't distributed regularly in continuous casting process, mold level is changed cyclically and slab quality is not good. In this paper, both casting speed control and load sharing control algorithm of strand driven roll according to ratio which is set up by operator at same time is proposed. The proposed algorithm is to share the withdrawal force by following torque current of each driven roll as average torque current by changing speed reference of each driven roll motor. The load sharing control with anti-wind up for improvement transient state is adopted and the proposed algorithm is implemented in POSCO pilot caster.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.8
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• pp.721-728
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• 2009

Equal/unequal 4-way power divider suitable for satellite communication using SIW technology is presented in this paper. The control of positions of guiding posts provides equal or unequal power division ratios by maintaining the width of the SIW unchanged. In addition, the detailed descriptions for the proposed power divider include the general characteristics of radial waveguide, feeding part using coaxial cable, simple SIW structure, power-guiding posts, and transition for measurement. The comparison between the simulated and measured data shows a good agreement at a center frequency of 10 GHz. The measured input impedance bandwidths for equal and unequal power divisions are about 2.1 GHz and 3 GHz under the condition of less than VSWR 2:1, respectively.