• 한국통신학회논문지
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• 제37C권12호
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• pp.1281-1288
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• 2012

본 논문은 재난 정보를 다양한 모바일방송 규격에 따라 인코딩 및 송출, 수신 및 디코딩하는 멀티모드 방송용 EWS 송 수신 시스템의 설계 및 구현 방법을 제안한다. 제안한 시스템은 전 세계 모바일 방송 표준 중 T-DMB, DVB-H, ISDB-T와 디지털 라디오 규격인 DRM을 지원하며, 각각의 방송 규격에 따라 재난 정보를 인코딩하는 송출부와 각 표준에 따른 RF 방송 신호를 수신 및 디코딩하는 수신부 형태로 구성된다. 제안한 멀티모드 방송용 EWS 송신시스템은 단일 시스템상에서 각각의 방송규격으로 EWS 재난 데이터 생성하고 상용 방송 송출 장비규격에 만족하는 채널 인터페이스를 통해 재난정보가 송출 가능하며 수신 시스템에서는 단일 H/W에서 해당 모드의 재난 정보를 수신, 디코딩하여 단말기 화면에 표출한다. 제안된 시스템은 실시간으로 각 모드별 상용 방송장비에서 송출되는 RF 신호를 수신하여 문자기반의 재난 정보를 표출하는 정합 검증 과정을 통해 정상동작 결과를 제시한다.

• 한국컴퓨터정보학회논문지
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• 제28권2호
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• pp.121-129
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• 2023

이 논문에서 우리는 응급상황에 대응하여 일정 구간의 교통신호를 능동적으로 제어함으로써 재산과 인명 손실을 최소화할 수 있는 응급상황 대응 교통신호 제어 시스템을 개발하였다. 응급 차량 단말기에서 식별정보 및 GPS 정보를 포함한 응급신호를 송출하면 카메라에서 주위 영상을 획득하게 되고, 딥러닝 기반으로 객체를 분석하여 객체의 위치, 종류, 크기 등 정보를 가지는 객체정보를 출력한다. 이 객체를 트래킹한 정보를 생성하여 신호체계를 검출한 후 신호체계를 응급모드로 전환하여 수신받은 GPS 정보를 기준으로 응급 차량을 식별·추적하고 이 응급 차량의 진행 경로 기준으로 긴급 제어신호를 교통신호 제어기로 전송할 수 있는 체계이다. 이 시스템은 응급신호에 따라 우선 적용되는 긴급 제어신호에 의해 응급 차량의 진행이 저지되지 않도록 하여, 교통상 장애에 따른 인명과 재산의 손실을 최소화할 수 있다.

• 전기학회논문지
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• 제67권2호
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• pp.224-232
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• 2018

According to government policy, renewable energy facility such as solar power generation is being implemented for newly constructed buildings. In recent years, the introduction of Energy Storage System (ESS) served as an emergency power for replacing an existing diesel generator has been increasing. Furthermore, in order to expand the efficacy of the ESS operation, operation in combination with renewable energy sources such as solar and wind power generation is increasing. Hence, development of the ESS operation algorithms for emergency mode as well as the peak power cut mode, which is the essential feature of ESS, are necessary. The operational scenarios of ESS need to consider load power requirement and the amount of the power generation by renewable energy sources. For the verification of the developed scenarios, tests under the actual situation are demanded, but there is a difficulty in simulating the emergency operation situation such as system failure in the actual site. Therefore, this paper proposes simulation models for the HILS(Hardware In the Loop Simulation) and operation modes developed through HILS for the ESS operated with renewable energy source under peak power reduction and emergency modes. The paper shows that the ESS operation scenarios developed through HILS work properly at the actual site, and it verifies the effectiveness of the control logic developed by the HILS.

• 보건행정학회지
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• 제19권3호
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• pp.27-44
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• 2009

The length of stay in emergency departments has been used as a quality indicator to reflect the overall efficiency of emergency care. Identifying characteristics associated with length of stay is critical to monitor overcrowding and improve efficient throughput function of emergency departments. This study examined the level of waiting time for initial assessment by physician and length of stay in emergency departments. Furthermore, we investigated the characteristics of patients' attendance associated with length of stay. An observational study was performed for a sample of 1,526 patients visiting ten nation-wide emergency departments. A structured form was designed to collect information about patients' demographics, route of admission, time and mode of arrival, triage level, cause of attendance, initial assessment time by physician, departure time, and disposition. Multiple regression analysis was performed to determine factors associated with length of stay. The average length of stay was 209.4 minutes (95% confidence interval [CI]=197.1-221.7), with a mean waiting time for initial assessment of 5.9 minutes (95% CI=5.1-6.7). After controlling for emergency department characteristics, increasing age, longer waiting times, attendance due to diseases, higher acuity, multiple diagnoses($\geq$2) and requiring admission or transfer to other health care facilities were positively associated with length of stay in emergency departments. The findings suggest that both patients' characteristics and the flow between emergency departments and parent hospitals should be taken into account in predicting length of stay in emergency departments.

• Journal of Yeungnam Medical Science
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• 제39권1호
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• pp.31-38
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• 2022

Background: To prepare for future work stoppages in the medical industry, this study aimed to identify the effects of healthcare worker strikes on the mortality rate of patients visiting the emergency department (ED) at six training hospitals in Daegu, South Korea. Methods: We used a retrospective, cross-sectional, multicenter design to analyze the medical records of patients who visited six training hospitals in Daegu (August 21-September 8, 2020). For comparison, control period 1 was set as the same period in the previous year (August 21-September 8, 2019) and control period 2 was set as July 1-19, 2020. Patient characteristics including age, sex, and time of ED visit were investigated along with mode of arrival, length of ED stay, and in-hospital mortality. The experimental and control groups were compared using t-tests, and Mann-Whitney U-test, chi-square test, and Fisher exact tests, as appropriate. Univariate logistic regression was performed to identify significant factors, followed by multivariate logistic regression analysis. Results: During the study period, 31,357 patients visited the ED, of which 7,749 belonged to the experimental group. Control periods 1 and 2 included 13,100 and 10,243 patients, respectively. No significant in-hospital mortality differences were found between strike periods; however, the results showed statistically significant differences in the length of ED stay. Conclusion: The ED resident strike did not influence the mortality rate of patients who visited the EDs of six training hospitals in Daegu. Furthermore, the number of patients admitted and the length of ED stay decreased during the strike period.

• 제어로봇시스템학회논문지
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• 제21권3호
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• pp.224-232
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• 2015

In order to develop an active safety system which avoids or mitigates collisions with preceding vehicles such as autonomous emergency braking (AEB), accurate state estimation of the nearby vehicles is very important. In this paper, an algorithm is proposed using 3 dynamic models to better estimate the state of a vehicle which has various dynamic patterns in both longitudinal and lateral direction. In particular, the proposed algorithm is based on the Interacting Multiple Model (IMM) method which employs three different dynamic models, in cruise mode, lateral maneuver mode and longitudinal maneuver mode. In addition, a Probabilistic Data Association Filter (PDAF) is utilized as a data association algorithm which can improve the reliability of the measurement under a clutter environment. In order to verify the performance of the proposed method, it is simulated in comparison with a Kalman filter method which employs a single dynamic model. Finally, the proposed method is validated using radar data obtained from the field test in the proving ground.

• 드라이브 ㆍ 컨트롤
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• 제14권2호
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• pp.45-51
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• 2017

Semi-submersible drilling rigs are offshore plants that perform functions such as ocean exploration for oil and gas acquisition, drilling and production, and storage and unloading of crude oil and gas. Semi-submersible drilling rigs use watertight dampers as emergency buoyancy holders. Since the watertight damper is an emergency shutoff device, it is mainly driven by a pneumatic driving system that can operate without a power supply. The pneumatic driving system has highly non-linear characteristics due to compressibility of air and external disturbance such as static and Coulomb friction. In this paper, a new control algorithm is proposed for a watertight damper driving system based on the sliding mode control with a disturbance observer. To evaluate control performance and robust stability of the designed controller, the control results were compared with the results obtained using the state feedback controller. As a result, it was confirmed that the pneumatic driving system for driving the watertight damper using the sliding mode controller with a disturbance observer can obtain excellent control performance against the parameter changes and the disturbance input.

• 한국멀티미디어학회논문지
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• 제23권2호
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• pp.293-300
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• 2020

Since the communication networks like the Internet collapses at disaster and calamity sites, a maintenance system that can be operated offline is required for the maintenance of various facilities. In this paper, we propose a system that memory tags attached on the facilities may transmit the emergency manual to a smart-phone, and the smart phone displays it off-line. The main issue is to design low energy mode memory tags. This study presents two kinds of methods and analyzes each's energy consumption mode. The first one is to develop memory tags by using one chip, and the next one is to design memory tags by forming multi-modules. Both ways show proper application fields under the low energy mode. This research selects the off-line maintenance system by using one chip design, and proposes the direction of contents for enhancing the effectiveness of the system. And we expect that this memory tags will be valuable for disaster scenes as well as battle fields.

• 전력전자학회논문지
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• 제11권1호
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• pp.72-78
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• 2006

분산발전시스템에 비상부하 등의 전용부하가 접속되어 있는 경우, 주전원에 고장이 발생하러라도 비상전용부하에는 지속적인 전력을 공급하기 위하여 의도적인 단독운전을 하게 된다. 기존의 계통연계형 인버터는 주전원에 전력을 주입하기 위하여 평소에 전류제어모드로 운전을 하기 때문에, 의도적인 단독운전 상황이 발생하는 경우 비상부하에 안정된 전압을 공급해 주기 위하여 전압제어모드로 운전을 전환하여야한다. 이러한 운전모드의 전환시 인버터의 출력단 전압에 심각한 과도문제가 발생된다. 본 논문에서는 의도적인 단독운전 발생시 인버터 운전모드 전환에 따른 출력전압의 과도현상을 최소화하기 위한 인버터 토폴로지와 제어알고리즘을 제안한다. 제안된 간접전류제어 알고리즘에 적합한 LCL필터 설계방법과 설계데이터를 제시한다.

• Advances in aircraft and spacecraft science
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• 제5권3호
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• pp.319-334
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• 2018

In this study, the failure mode and energy absorption capabilities of a composite shock absorber device, during an emergency landing are evaluated. The prototype has been installed and tested in laboratory simulating an emergency landing test condition. The crash absorber presents an innovative configuration able to reduce the loads transmitted to a helicopter fuselage during an emergency landing. It consists of a composite tailored tube installed on the landing gear strut. During an emergency landing this crash absorber system should be able to absorb energy through a pre-designed deformation. This solution, compared to an oleo-pneumatic shock absorber, avoids sealing checks, very high values of the shock absorber pressure, and results to be lighter, easy in maintenance, inspect and use. The activities reported in this paper have become an attractive research field both from the scientific viewpoint and the prospect of industrial applications, because they offer benefits in terms of energy absorbing, weight savings, increasing the safety levels, and finally reducing the costs in a global sense.