• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2000년도 ITC-CSCC -1
• /
• pp.521-524
• /
• 2000

It is well known that the OFDM system is weak against the frequency offset. The frequency offset attenuates the received signal power and makes the performance bound in the OFDM transmission. We show the performance bound of the OFDM transmission with the frequency offset under the additive white Gaussian noise channel by the numerical method. According to the results, increasing the transmitting power is not useful to improve the performance, when the frequency offset exits. The performance degradation is very severe as the frequency offset increases.

• 전기화학회지
• /
• 제17권2호
• /
• pp.94-102
• /
• 2014

바나듐 레독스 흐름 전지 (Vanadium redox flow battery, VRB) 시스템 운전 중 양이온 교환막을 통한 바나듐이온의 투과로 인하여 성능이 저하되는 문제점을 보완하기 위해 판상형태의 탄소물질인 산화그라핀 (Graphene Oxide, GO)을 기존에 사용하였던 양이온 교환막인 Nafion 양이온 교환막 표면에 열압착 방식으로 코팅하여 양이온 교환막 개선 및 VRB 성능 향상을 도모하였다. 개선된 양이온 교환막의 물리화학적 특성분석을 위하여 SEM (Scanning Electron Microscopy)분석, 이온 교환 용량, 수분 흡수 및 수소이온 전도도를 측정하였다. 산화그라핀층을 코팅한 결과, SEM 분석을 통해 양이온 교환막 표면에 약 $0.93{\mu}m$의 산화그라핀층이 형성된 것을 확인할 수 있었다. 산화그라핀을 코팅하여 개선된 양이온 교환막의 수소이온 전도도 측정 결과, 상용 양이온 교환막의 27% 수준으로 감소하였음을 확인하였으며, 동시에 바나듐이온 투과실험을 실시한 결과, 개선된 양이온 교환막의 바나듐이온 투과도가 기존 상용 양이온 교환막의 25% 이하 수준으로 감소하였음을 확인할 수 있었다. VRB 단위전지 성능실험을 실시하여 충-방전 특성을 분석한 결과, 산화그라핀을 코팅하여 개선된 양이온 교환막을 VRB 시스템에 적용하였을 경우, 바나듐이온의 투과도 감소로 인하여 쿨롱효율이 증가하였음을 확인할 수 있었고, 그로 인하여 전체적인 에너지효율이 상용막을 적용하였을 때 보다 증가하였음을 확인할 수 있었다. 따라서, 본 연구를 통해 양이온 교환막 표면에 판상형태의 탄소물질인 산화그라핀을 코팅하는 방법이 바나듐이온 투과도를 저하시키고 VRB의 시스템성능을 향상시킬 수 있는 효과적인 방법임을 제시할 수 있었다.

• 정보보호학회지
• /
• 제21권1호
• /
• pp.57-73
• /
• 2011

IT 진화의 다른 면으로는 정보 보안 위협의 심각화와 개별 위험 증가도 잠재하고 있어 이에 대응하는 정보 보안 정책도 나날이 변화가 요구된다. 이에 따라 미국에서는 연방정보보안관리법을 제정하여 연방정부의 운영 및 자산에 대한 정보보안 통제항목의 효율성을 강화하기 위한 총괄적인 프레임워크를 제공한다. 또한 연방정부 및 정보 시스템 보호를 위한 최소 통제 및 유지 방안 개발을 제공한다. 따라서 본 고에서는 미국의 연방정보보안관리법의 각 단계별 보안 활동을 분석하고자 한다.

• 대한예방의학회:학술대회논문집
• /
• 대한예방의학회 2002년도 제54차 추계 학술대회 연제집
• /
• pp.254-255
• /
• 2002

• 한국가스학회:학술대회논문집
• /
• 한국가스학회 2005년도 춘계학술대회 및 특별심포지움
• /
• pp.204-204
• /
• 2005

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2012년도 추계학술대회 논문집
• /
• pp.673-674
• /
• 2012

• 대한한방내과학회지
• /
• 제40권5호
• /
• pp.752-759
• /
• 2019

Objective: The purpose of this case study was to report the effect of Korean medicine treatment on a patient diagnosed with a nasal polyp. Methods: A 62-year-old female patient with a nasal polyp visited the clinic sixteen times from September 11th, 2018 to December 18th, 2018. The patient was treated with Eunhwayeongyo-tang, Haeyeol-tang, Hongsamkyungok-go extract, and acupuncture during the treatment period. We evaluated the improvement of symptoms by nasoendoscopy. Results: After the Korean medicine treatment, the nasal polyp was completely eradicated. Hyperemia of the nasal mucous membrane and rhinorrhea were also relieved. Conclusion: The study findings suggested that Korean medicine treatment (Eunhwayeongyo-tang, Haeyeol-tang, and Hongsamkyungok-go extract, and acupuncture) might be effective for treatment of patients diagnosed with nasal polyps.

• 대한한방내과학회지
• /
• 제31권3호
• /
• pp.667-674
• /
• 2010

Objective : To investigate the therapeutic effects of Hang-Am-Dan(HAD) on gallbladder cancer patients. Method : We prescribed HAD three times a day(3,000-6,000 mg/day) during a treatment period of 8 and 34 months respectively. Computed tomography(CT) was taken to evaluate the therapeutic efficacy. Results : Two patients diagnosed with gallbladder cancer were recommended to go through chemotherapy. However, they refused the standard regimen due to their old age and the fear of side effects, and chose to go with Oriental medicine treatments instead. The patients were treated for 8 and 34 months respectively. Each patient showed stable disease(SD) state during the treatment period. Conclusion : According to these cases, it could be concluded that HAD may offer potential benefits in treating gallbladder cancer patients.

• 수산경영론집
• /
• 제39권2호
• /
• pp.41-60
• /
• 2008

This study is basically to investigate the possibility of revitalizing the fishing village economy by targeting on trip type, propensity, and awareness of visitors who visited Gogunsan in JeonBuk by applying Blue Amenity. As the result of survey, it showed that visitors in Gosunsan islands generally were satisfied with trip, and they had considerably higher intention of revisit. However, it showed that the improvement and publicity of various travel services including resources and facilities were demanded. In particular, it should pay attention to requirements depending on age and selection of main visitors with reference to revisit, and as the result, the factors having the most important influence on are traffic, and natural scenery, so it is considered that these factors must be maintained to increase the rate of revisit with full of concentration. Besides, it is confirmed that Visitors are unfamiliar with Blue Amenity applying fishing village's own historical cultural resources with reference to preferring islands trip, and they were much concerned about the establishment of tentatively named "regional(urban - fishing village) center" to revitalize the fishing village economy. Moreover it could grasp the tourist industry operated jointly by fishing villages, the pride of town to characterize, advantage in promoting the tourist industry as compared with other regions, and difficulties or recommendations in promoting the tourist industry. And comprehensive investigation of Blue Amenity resources in this region and the measures of improving life environment must be performed in future.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2001년도 창립10주년 제20회 학술발표회
• /
• pp.52-52
• /
• 2001