• 전력전자학회논문지
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• 제16권2호
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• pp.145-151
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• 2011

본 논문은 신 재생에너지원 중 태양광을 이용한 계통연계형 PV PCS의 단독운전 검출 성능을 극대화하고, 출력 전력의 품질 악화를 최소화 할 수 있는 개선된 능동 주파수 변이기법의 외란의 크기를 모델링, 시뮬레이션 및 실험을 통하여 검증하고, 이를 근거로 계통 보호 협조 및 안전을 위한 개선된 능동적 주파수 변이기법의 타당성을 검증하고자 한다.

• 한국철도학회논문집
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• 제10권2호
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• pp.179-185
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• 2007

In large station with high density traffic, trains can be hardly controlled by CTC but by station dispatcher because CTC has difficulties in monitoring all states of affairs happening within each station such as departures, arrivals of many trains from different lines and shunting of trains to move between yards and platforms, etc. Therefore the station's dispatcher has to make quick decision about how to reschedule the times and routes for all the trains scheduled within a specific time window. And such decision becomes harder when an unexpected delay occurs because a delay occurring in a train propagates other trains as time goes on. Generally, it is called the conflict detection and resolution to adjust beforehand the distorted schedule due to a delay to original schedule. Our research is different from the state of the arts in that ours determines simultaneously the routes and the times of arrival and departure of trains, although others do only the arrival and departure time of the trains without considering the alternative routes and shunting of the station. This study suggests a mathematical approach for how to detect in advance and resolve efficiently the conflicts occurring within a station and it will be shown how to reduce delay using our approach by means of analysing the schedule of ChyungRyangRi station.

• 산업공학
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• 제23권4호
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• pp.349-356
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• 2010

The role of Intelligent Transportation System (ITS) is to efficiently manipulate the traffic flow and reduce the cost in logistics by using the state of the art technologies which combine telecommunication, sensor, and control technology. Especially, the hardware part of ITS is rapidly adapting to the up-to-date techniques in GPS and telematics to provide essential raw data to the controllers. However, the software part of ITS needs more sophisticated techniques to take care of vast amount of on-line data to be analyzed by the controller for their decision makings. In this paper, the authors develop a traffic congestion prediction model based on several different parameters from the sensory data captured in the Vehicle Detection System (VDS). This model uses the neural network technology in analyzing the traffic flow and predicting the traffic congestion in the designated area. This model also validates the results by analyzing the errors between actual traffic data and prediction program.

• 한국컴퓨터정보학회논문지
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• 제4권3호
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• pp.28-34
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• 1999

본 논문에서는 DCT 영역에서 DCT블록내의 DC성분과 매크로블록내의 움직임 벡터성분을 이용하여 동영상 장면전환 자동 검출에 관한 방법을 제안한다. 제안하는 방법은 압축된 MPEG 신호열내의 픽쳐 종류와 상관없이 임의의 신호열에서 장면전환을 검출한다. 이를 위해 MPEG 신호열의 DCT 영역에서 픽쳐구성요소의 특징을 이용하여 새로운 비교잣대를 정의하고 움직임 벡터에 예민한 B-picture 의 특성을 이용하여 정확한 장면전환을 검출한다. 이때. I-picture를 가지고 급격한(cut) 장면전환을 검출하고 P. B picture 를 가지고 점진적인(gradual) 장면 전환을 검출한다. 제안한 방법은 다양한 MPEG 신호열에 대하여 시험결과 그 효율성이 우수함을 보인다.

• 한국지능시스템학회논문지
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• 제19권5호
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• pp.609-614
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• 2009

본 논문에서는 내부 운전자에게 위협이 될 수 있는 실시간 금속 물체 탐지 시스템을 제안한다. 제안된 시스템은 퍼지 이론를 이용하여 금속 물체를 탐지할 수 있는 색상 필터를 설계하는 알고리즘과 차량안의 특정 영역 내에서 FSCF(Fuzzy Skin Color Filter)를 이용하여 운전자의 얼굴 영역을 탐지하는 알고리즘을 제안한다. 또한, 탐지된 동승자의 손 영역을 기점으로 색상기반 원형탐색 기법을 사용하여 최종적으로 위협을 가할 수 있는 금속물체의 후보영역을 설정하고, 제안된 금속 물체 필터를 적용하여 최종적인 금속물체영역을 탐지 한다. 마지막으로 제안된 방법은 여러 실험을 통해 내부 운전자 보호를 위한 금속물체 탐지 시스템의 우수성을 증명한다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 춘계학술대회
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• pp.337-340
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• 2009

Wireless tele-home-care application gives new possibilities for ECG (electrocardiogram) monitoring system with wearable biomedical sensors. Thus, continuously development of high convenient ECG monitoring system for high-risk cardiac patients is essential. This paper describes to monitor a person's ECG using wearable approach. A wearable belt-type ECG electrode with integrated electronics has been developed and has proven long-term robustness and monitoring of all electrical components. The measured ECG signal is transmitted via an ultra low power consumption wireless sensor node. ECG signals carry a lot clinical information for a cardiologist especially the R-peak detection in ECG. R-peak detection generally uses the threshold value which is fixed thus it bring errors due to motion artifacts and signal size changes. Variable threshold method is used to detect the R-peak which is more accurate and efficient. In order to evaluate the performance analysis, R-peak detection using MIT-BIH databases and Long Term Real-Time ECG is performed in this research. This concept able to allow patient to follow up critical patients from their home and early detecting rarely occurrences of cardiac arrhythmia.

• 인터넷정보학회논문지
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• 제23권2호
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• pp.37-44
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• 2022

With the outbreak of COVID-19, non-face-to-face activities such as remote learning and telecommuting have increased rapidly. As a result, the number of people staying at home and the number of hours spent inside the house have also increased since the pandemic. Our team had previously worked on methods for detecting abnormal conditions in a person's health in various circumstances within the house by converging single sensor-based algorithms. In our previous research, we installed IoT sensors indoors to detect people emergency situations requiring aids, the scope of detection was limited to indoor space due to the limitation in sensors. In this study, we have come up with a system that integrates our previous study with a new method for detecting abnormal conditions in outdoor environments using outdoor security cameras and wearable devices. The proposed system enables users to be notified of emergency situations in both indoor and outdoor areas and respond to them as quickly as possible.

• International Journal of Computer Science & Network Security
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• 제23권4호
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• pp.69-78
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• 2023

With the global rise of digital data, the uncontrolled quantity of data is susceptible to cyber warfare or cyber attacks. Therefore, it is necessary to improve cyber security systems. This research studies the behavior of malicious acts and uses Higuchi Fractal Dimension (HFD), which is a non-linear mathematical method to examine the intricacy of the behavior of these malicious acts and anomalies within the cyber physical system. The HFD algorithm was tested successfully using synthetic time series network data and validated on real-time network data, producing accurate results. It was found that the highest fractal dimension value was computed from the DoS attack time series data. Furthermore, the difference in the HFD values between the DoS attack data and the normal traffic data was the highest. The malicious network data and the non-malicious network data were successfully classified using the Receiver Operating Characteristics (ROC) method in conjunction with a scaling stationary index that helps to boost the ROC technique in classifying normal and malicious traffic. Hence, the suggested methodology may be utilized to rapidly detect the existence of abnormalities in traffic with the aim of further using other methods of cyber-attack detection.

• 대한가정학회지
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• 제37권3호
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• pp.111-125
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• 1999

This study aims at prediction of the children's in participation household work and supply of basic data for the children's home education to get a desirable family life through the investigation into their household work participation degree and its character and through the detection in its influencing factor. The research consequence can be summarized on the followings. The children's total participation degree of the household work records 3.13. Girls take part in the household work more than boys do in almost all household work areas. Variables which h3d influences on their participation are praise, sex distinction, assistant, and father's participation in house work.

• 한국식품위생안전성학회지
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• 제39권2호
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• pp.102-108
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• 2024

본 연구는 2020년 10월 중 충청남도내 단체 급식소에서 발생한 대규모 집단 식중독 원인에 대하여 분석하였다. 전체 급식원 135명 중 21명(15.6%)에서 음식을 섭취한 후 1시간 이내에 주로 매스꺼움과 구토 증상을 보였다. 유증상자 21명 중 11명과, 조리종사자 1명, 조리기구 2건과 보존식 8건에서 B. cereus가 검출됨에 따라 B. cereus에 의한 집단 식중독으로 판단하였다. 분리된 21개의 균주를 PFGE 분석한 결과, 19개의 균주가 동일한 것으로 판단되었고, 이들 균주가 가지고 있는 독소 유전자는 CER, nheA, entFM이었다. 실험결과, CER을 포함하고, 증상 발현 시간이 1시간 이내로 매우 짧아 B. cereus의 구토형 식중독으로 판단하였다. 집단식중독 원인으로 안전하지 않은 급식환경과 제대로 관리되지 않은 음식에 의한 것이라 조사되었다. 이러한 결과는 단체급식에서의 급식환경과 제공되는 음식이 철저하게 관리되어야 한다는 것을 보여준다. 이와 더불어 보존식에서 원인 병원체를 찾아내는 것은 식중독의 원인을 추정하는데 매우 중요하므로, 집단급식소에서 규정에 맞는 보존식 용기를 이용하여 이를 적정온도에 잘 보관해야한다. 또한 정밀한 식중독 역학조사를 기반으로 사례를 분석하고 결과를 전파함으로써 유사한 식중독이 재발하지 않도록 해야 한다.