• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.315-318
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• 2002

In this paper, we studied a now VDSL frequency plan mode 6 for improved\ulcorner symmetric 10MDSL service. The frequency plan 998 for asymmetric and frequency plan 997 for symmetric have arc not optimally designed for 10MDSL service. To improve reach and rates of 10MDSL, we proposed for a now frequency plan. According to the results of our simulation studios of newly Proposed mode 6 frequency plan which compared to plan 998, 997, and ethers[2], the new scheme gives an improved performance in rates and reach.

• 산업기술연구
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• 제22권B호
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• pp.169-173
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• 2002

In this paper, we discussed an effective VDSL frequency plan for symmetric 10MDSL service. The frequency plan 998 and plan 997 for asymmetric VDSL services have been not optimally designed for 10MDSL services. To obtain the reaches and data rates of 10MDSL, we proposed two frequency allocation schemes : Static method and dynamic method. We can select frequency bands with their fixed boundaries in static method while with their variable boundaries in dynamic method. To show the effectiveness of our proposed methods, we performed some simulations about plan 997 and plan 998, new static method, and new dynamic method. According to the simulation results, the proposed dynamic method can provide the best data rates and reaches for 10 Mbps symmetric VDSL services.

• Spatial Information Research
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• 제23권2호
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• pp.83-93
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• 2015

최근 U-City 계획을 수립한 지자체의 U-서비스는 시설 및 도시 관리 위주의 서비스로 구현되고 있으며, 시민 맞춤형 U-서비스는 계획에만 그치고 있는 실정이다. 이에 본 연구는 U-City 종합계획과 U-City 계획의 U-서비스 내용을 네트워크 텍스트 분석과 단어 빈도 분석을 통해 비교 검토하여 향후 시민 맞춤형 U-서비스 제공을 위한 시사점을 제시하였다. 제1, 2차 U-City 종합계획과 4개 지방자치단체의 U-City 계획 중 U-서비스 계획 내용을 추출하여 주요 단어들을 산출하였고, 도출된 단어를 통해 네트워크 텍스트 분석과 단어 빈도 분석을 실시하였다. 분석 결과를 바탕으로 향후 U-City 종합계획에서는 지자체의 특색에 따른 서비스 추가와 정책 재정 지원 및 시민의 필요사항을 반영하여 다양한 분야의 시민 맞춤형 U-서비스 개발과 같은 시사점을 도출하였으며, 이를 통해 U-City에 대한 시민들의 인식 또한 증가될 것으로 기대할 수 있다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.211-214
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• 2004

In railway system, the transportation plan corresponds to master plan for transport services. This service plan must be constructed to minimize operational cost or maximize revenue considering transportation demands and resource capacities in the operation company, and includes several sub-planning activities such as train operation frequency plan, train (schedule) plan, train capacity assignment plan, and rolling stock requirement plan. In this paper, we present profitability evaluation system for current transportation plan. The proposed system can be used for evaluating profitability by estimating train service revenue considering customer demands.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1538-1545
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• 2004

In the train schedule plan corresponds to a master plan for transport services. This service plan must be constructed to minimize operational cost or maximize revenue considering transportation demands and resource capacities in the operation company, and it includes several sub-planning activities such as train operation frequency plan, train schedule plan, train capacity assignment plan, and rolling stock requirement plan. In this paper, we present profitability evaluation system for the current train schedule plan. The proposed system can be used for evaluating profitability by estimating train service revenue considering customer demands.

• 한국안전학회지
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• 제33권5호
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• pp.127-133
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• 2018

The Saemangeum master plan includes dredging and waterproofing materials, construction projects that can change the hydraulic characteristics of the Saemangeum and Mangyeong and Dongjin River basins. In this study, the river safety of 2030 when the Saemangeum master plan was completed for 100 year frequency, 500 year frequency and 100 year frequency applied RCP 8.5 scenario was examined using Delft3D. As a result of the analysis, it was confirmed that there was no overflowing point at the 100 year frequency, but the difference between the flood level and the river bank elevation was relatively small at the curved and river joint part. At the 100-year frequency with the 500-year frequency and the RCP 8.5 scenario, the possibility of overflowing at several locations was confirmed. The possibility of river bed loss due to fast velocity appears in the upstream part of Mankyung River and it is necessary to monitor the safety of hydraulic structures continuously. In addition, it is expected that the expansion of the area showing the characteristics of the lake due to dredging will affect the sediment mechanism and water quality, so detailed and diverse studies will be needed.

• 전기학회논문지
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• 제67권2호
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• pp.194-198
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• 2018

The government established the 8th national energy plan that electricity energy from renewables in 2030 will be 20%. The frequency stability problem is one of the key issues to overcome for accomplishing the energy plan. Frequency quality deteriorates due to short term variations of renewables output. Battery energy storage system(BESS) is considered as a good alternative to improve the frequency quality due to its quick response. In this paper, we examined the effectiveness of BESS against the conventional governor properties.

• 한국통신학회논문지
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• 제21권12호
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• pp.3183-3195
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• 1996

As a method for effective utilization of the limited power and frequency resources in satellite communications, this paper develops software which can assigns the optimal power of input carrier groups inthe multi-level SCPC systems and performs evaluation to a various satellite link environment. Using the developed software, the paper presents performance according to the frequency plan of carrier groups and suggest a frequency play method for performance improvement of satellite link. A various interference and noise caused by satellite link are analyzed for reliable performance evaluation. The performance criteria for evaluation is classified into 2 categories according to the CNR of destination receiver earth station.

• 한국구조물진단유지관리공학회 논문집
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• 제2권3호
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• pp.161-167
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• 1998

A problem of frequency in the field of low-frequencies such as high-rise apartment building or construction vibration are often found. In this study, damage reason of a 25 stories apartment building was searched on the basis of actual damage. To find the damage reason, structural design procedure were reviewed and low-frequency vibration test was conducted. The results indicate that the main damage reason is not by the low-frequency vibration but the asymmetrical plan of that building.

• 환경영향평가
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• 제25권4호
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• pp.296-306
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• 2016

기후변화에 대한 영향 및 위험은 지역적, 국지적 차원에서 더욱 확장되므로 기후변화에 따른 지역적 영향 및 특성을 반영한 기후변화 적응대책 마련의 필요성이 커지고 있다. 이에 본 연구에서는 기초지자체 적응대책의 분야별 사업 수 및 예산의 특성을 분석하고 피해사례와 비교 검토하여 기후변화 적응대책의 개선방향을 제시하고자 했다. 기초지자체 적응대책 특성 분석을 위해 군집분석을 통하여 지자체 적응대책의 유형별 특성을 파악 했다. 적응대책의 계획이 실제 기후변화로 인한 피해 내용을 잘 반영하고 있는지 검토하기 위하여 과거 24년 동안 지자체별 관측 영향 결과(신문기사 2,565건)와 비교 분석을 수행했다. 군집분석 수행 결과 군집은 4가지 유형으로 구분되었다. 전국 피해 유형으로 재난재해, 건강 부분에서 공통적으로 피해 빈도가 높은 것으로 분석되었으며, 적응계획 또한 재난재해, 건강, 농업, 물 관리 순서로 높은 비율을 보였다. 하지만 피해 사례 반영의 비중과 단기 및 장기 미래에 대한 고려 수준에 따라서 각 군집별로 피해빈도와 적응계획의 특성에서 차이를 보였다. 본 연구의 결과는 향후 기초지자체 특성 및 지역별 실질적 피해에 기반 한 적응대책 마련의 기초자료로 활용될 수 있을 것이라고 판단된다.