• 한국통신학회논문지
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• 제34권11B호
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• pp.1200-1206
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• 2009

본 논문에서는 유비쿼터스 센서네트워크(USN, Ubiquitous Sensor Network) 환경을 위한 에너지 효율적 상황인 식 매체접근제어(MAC, Medium Access Control) 프로토콜을 제안한다. 제안한 CASMAC(Context Aware Sensor MAC)은 상황정보를 이용하여 에너지 효율적으로 동작한다. CASMAC의 동작원리는 사전에 예측 가능한 상황을 시나리오로 작성하여 설정한 상황정보를 서버에 저장하며, 특정 센서 노드에서 이벤트가 발생할 경우, 그 이후부터 3회의 샘플 데이터를 서버로 전송한다. 서버는 전송 받은 샘플 데이터를 기 설정된 상황정보에 따라 처리한다. 만약 샘플 데이터가 이벤트로 처리되면, 서버는 해당 노드로 지속적인 데이터 전송 요청 신호를 보내 데이터를 전송 받고, 데이터 전송을 더이상 원하지 않으면 데이터 전송 중지 요청 신호를 보낸다. 또한 이벤트가 아니라고 처리할 경우에는, 무응답을 통해 샘플 데이터를 무효 처리한다. CASMAC의 성능 분석을 위해, 에너지 소모 테이블을 작성하여 에너지 소모 모델을 도출하였고, 모의 실험을 수행하였다. 그 결과 SMAC 대비 약 5.7 퍼센트의 에너지 소모 감소를 통한 성능 개선 효과를 얻었다.

• 한국응급구조학회지
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• 제23권1호
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• pp.49-60
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• 2019

Purpose: This study was conducted to analyze job stress, ego-resilience, and results of the impact of event scale in order to verify the actual job stress of firefighters and provide baseline data for developing resolution programs. Methods: Data were collected via e-mail from 270 firefighters working at 119 safety centers and firehouses in the regions of Gyeonggi, Chungcheong, Busan, and Gyeongsang-do between the $1^{st}$ and $30^{th}$ of July, 2017. Results: Regarding gender differences in job stress, women ($2.16{\pm}0.65$) showed statistically significant job stress compared to men ($1.93{\pm}0.57$). As for the results of the incident impact of event scale statistically significant differences were observed (p=.001), and ego-resilience in men ($4.15{\pm}0.54$) was significantly higher than that in women ($3.79{\pm}0.75$) (p=.006). Depending on the work period, there were statistically significant differences (p=.000) in job stress, ego-resilience (p=.002), and impact of event scale (p=.000). Conclusion: Since job stress, ego-resilience, and results of the impact of event scale were closely related to dispatch frequency and work period of the firefighters, detailed and continuous stress management programs that consider these factors need to be developed.

• 통합자연과학논문집
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• 제8권2호
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• pp.128-134
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• 2015

This paper focuses on the applicability of a continuous monitoring method on trace sulfur compounds in the ambient air by TD and GC/PFPD. The target compounds for monitoring include H2S(hydrogen sulfide), Methyl mercaptan, Dimethyl Sulfide, and Dimethyl disulfide. The result of QA/QC on monitoring instruments satisfies all the standards of Odor Measurement and Analysis Method, showing that the reproductivity of the compounds by concentration is within 10%, linearity is above 0.98 of a correlation efficient, method detection limit is 0.16 ppb by MM standard, and recovery rate is over 70%. Monitoring was conducted for two years from March 2006 to February 2008. As a result of the monitoring, the average concentration of H2S was 0.08 ppb, with the maximum concentration at 16.15 ppb. The result indicates that it is reasonable to do continuous monitoring as there appears a spontaneous event of high concentration by the condition of the site during monitoring odor-causing substances. Therefore, it is suggested that the continuous monitoring method used in this paper is appropriate to identify the characteristics of sudden occurrence and concentration variations of sulfur compounds.

• Childhood Kidney Diseases
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• 제6권2호
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• pp.251-258
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• 2002

저자들은 다장기 부전과 패혈증에 의한 ?상태의 급성 신부전 환아 세 명에서 펌프를 이용한 CVVH를 이용하여 효과적으로 한외여과액을 유지할 수 있었던 경험을 문헌 고찰과 함께 보고하는 바이다.

• Journal of the korean society of oceanography
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• 제34권1호
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• pp.43-48
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• 1999

The latest-Quaternary paleoceanographic history of the Ulleung Basin, the East Sea (the Sea of Japan) is reconstructed on the base of planktonic foraminifera, oxygen and carbon isotopes, and accelerator mass spectrometer radiocarbon (AMS-$^{14}$C) data from two cores. Sinistral populations of Neogloboquadrina pachyderma are dominant during the last glacial period while dextral forms of Neogloboquadrina pachydeyma are abundant in the Holocene. An abrupt increase in ${\delta}^{18}$O values in both cores that began about 11 ka B.P may indicate the Younger Dryas cooling episode. A low-salinity event, marked by light ${\delta}^{18}$O values (0-1 %), is observed before the Younger Dryas event. As previous works suggested, the low-salinity event is probably due to the freshening of surface water caused by fresh water input from Huang Ho river and/or the excess of precipitation over evaporation. The lowest salinity water in the Ulleung Basin was probably continued from approximately 18 ka B.P. to 15 ka B.P. The ${\delta}^{18}$O values have gradually decreased since the Younger Dryas as a result of the continuous inflow of the warm Tsushima Current into the East Sea.

• 전자공학회논문지C
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• 제36C권10호
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• pp.75-80
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• 1999

고품질의 서비스를 보장할 수 있는 멀티미디어 응용 소프트웨어를 효과적으로 개발하기 위해서는 연속 미디어의 동기화뿐만 아니라 비연속 미디어를 포함하는 동기화를 표현할 수 있는 멀티미디어 동기화 모델이 요구된다. 본 논문에서는 사용자의 이벤트 발생에 의해서 변화되는 동적 키 매체라는 특별한 객체 제어기를 갖게 된다. 이러한 이벤트는 발생시간과 주기를 예측할 수 없는 미디어가 된다. 이벤트 발생은 오디오뿐만 아니라 텍스트, 이미지도 키 매체로 선택하여 수행하는 역할을 한다 객체 제어기는 다음 전이에 정보를 전달하는 역할을 한다. 제안한 모델은 최대 허용 지터값과 최대 허용 스큐값을 재생시간에 포함하여 재생률을 향상시켰고, 시뮬레이션을 통해 제시한 방법의 타당성을 검증하였다.

• 한국인터넷방송통신학회논문지
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• 제13권6호
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• pp.109-114
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• 2013

낮은 저항이나 좋은 전기투과도 지점으로 알려진 생물학적 활성점(biological active points, BAP)인 BAP검출을 위한 새로운 방법으로 적응주파수추적필터와 과도이벤트검출을 기반으로 하는 생체임피던스측정시스템을 사용하는 방식에 대해 제안하였다. 이 생체임피던스장치에 다중주파수 전류주입과 전압측정 모두 표면전극을 사용하였다. 또한 마이크로컨트롤러를 통하여 적응주파수추적필터를 사용한 다중주파수요소에 의해 변조된 신호의 연속적인 복조를 처리하였다. 또한 위상공간방식의 과도이벤트검출방식이 제안된 BAP등가모델에 각주파수에 대해 적용되었다.

• Journal of Ecology and Environment
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• 제45권1호
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• pp.10-16
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• 2021

Background: Ranavirus is an emerging infectious disease which has been linked to mass mortality events in various amphibian species. In this study, we document the first mass mortality event of an adult population of Dybowski's brown frogs (Rana dybowskii), in 2017, within a mountain valley in South Korea. Results: We confirmed the presence of ranavirus from all collected frogs (n = 22) via PCR and obtained the 500 bp major capsid protein (MCP) sequence from 13 individuals. The identified MCP sequence highly resembled Frog virus 3 (FV3) and was the same haplotype of a previously identified viral sequence collected from Huanren brown frog (R. huanrenensis) tadpoles in South Korea. Human habitat alteration, by recent erosion control works, may be partially responsible for this mass mortality event. Conclusion: We document the first mass mortality event in a wild Korean population of R. dybowskii. We also suggest, to determine if ranavirus infection is a threat to amphibians, government officials and researchers should develop continuous, country-wide, ranavirus monitoring programs of Korean amphibian populations.

• 한국가구학회지
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• 제26권3호
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• pp.241-251
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• 2015

Milano Fair is the most authoritative event in the world and the most noticeable exhibition for expecting stream of furniture design and future. Companies and designers, who participate in this event, pioneer independent market through the creative and creative products based on their own identity. Their competitiveness in the market comes from the identity of the brands and it is possible when making continuous efforts to make competitiveness by differentiated designs and products. Upright design culture will be made when respecting the value of designers and designs, making the history and tradition and striving for new challenges and pioneerings.

• 제어로봇시스템학회논문지
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• 제2권3호
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• pp.209-219
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• 1996

Fieldbus provides a real-time data communication among field devices in the process control and manufacturing automation systems. In this paper, a Petri Net model of the 1993 draft of IEC/ISA fieldbus which is proposed as an international standard of fieldbus network is developed. Based on the Petri Net model, discrete-event simulation model of IEC/ISA fieldbus network is developed. This paper evaluates the network induced delay in the data link layer of IEC/ISA fieldbus using the simulation model. In addition, an integrated discrete-event/continuous-time simulation model of fieldbus system and distributed control system is developed. This paper investigates the real-time data processing capability of IEC/ISA fieldbus and the effect of network-induced delay to the performance of control system.