• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.339-339
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• 2023

2018년도 연강수량은 1,386.9 mm로 평년 수준의 비가 내렸으나, 7-8월에 발생한 폭염 및 가뭄으로 인해 강원, 전남, 경북, 충남 지역에서 밭작물 중심으로 22,767 ha 피해가 발생하였다. 2019년도 연강수량은 1,171.9 mm로 평년보다 약 10% 적은 수준의 비가 내렸으며, 동일시기에 인천, 강원, 충남 지역에서 논·밭작물 중심으로 3,112 ha 피해가 발생하였다. 기후변화로 인해 강수량이 지역별로 편중되어 국지적 가뭄이 빈발하여 지역별로 가뭄의 영향, 피해, 체감 정도가 상이한 양상을 보이고 있다. 가뭄을 사전에 방지하기 위해서는 가뭄 모니터링과 선제적 대응이 중요하며, 현재 가뭄의 특징, 상황 등의 목적에 따라 다양한 형태의 가뭄 모니터링 시스템이 개발되고 있다. 가뭄의 피해와 영향 정도는 지역 간의 차이가 나타나 지역별로 가뭄을 체감하는 정도가 다르기 때문에 하나의 결과로 나타내기에는 어려움이 있다. 따라서, 가뭄의 발생 시기와 확산 정도를 분석하여 특보 발효 시점과 가뭄 대응 방안에 대한 기준 마련이 중요하다. 본 연구는 현대 사회에서 가장 중요한 요소로써 활용되고 있는 빅데이터 중 비정형 데이터로 분류되는 뉴스데이터와 논·밭의 가뭄을 나타내는 농업 가뭄과 관련된 데이터를 활용하여 농업 가뭄의 전조를 파악해보고자 한다. 2018년부터 2019년까지 전국을 대상으로 농업 가뭄에 관한 키워드 선정 후, 웹 크롤링을 통해 뉴스데이터를 수집해 논 가뭄과 밭 가뭄을 구별하여 각 지역에서 최초로 가뭄 기사가 발행된 시기와 지역별 기사의 빈도를 산출하였다. 뉴스데이터의 농업 가뭄 전조 감지 가능성을 파악하기 위해 국가가뭄정보통계집에서 논 물마름 시기와 밭 시듦 시기 자료를 활용하였다. 가뭄 피해 발생시기와 관련 기사 발행 시기 비교, 농업용수 대상 비상용수 지원 자료를 활용하여 실제 농업 가뭄확산 감지 여부를 분석하여 농업 가뭄 관련 뉴스데이터 간의 상관성을 분석하였다.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.44-54
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• 2012

In wireless sensor networks, a moving object tracking scheme is one of core technologies for real applications such as environment monitering and enemy moving tracking in military areas. However, no works have been carried out on processing the failure of object tracking in sparse sensor networks with holes. Therefore, the energy consumption in the existing schemes significantly increases due to plenty of failures of moving object tracking. To overcome this problem, we propose a novel moving object tracking scheme based on polynomial regression prediction in sparse sensor networks. The proposed scheme activates the minimum sensor nodes by predicting the trajectory of an object based on polynomial regression analysis. Moreover, in the case of the failure of moving object tracking, it just activates only the boundary nodes of a hole for failure recovery. By doing so, the proposed scheme reduces the energy consumption and ensures the high accuracy for object tracking in the sensor network with holes. To show the superiority of our proposed scheme, we compare it with the existing scheme. Our experimental results show that our proposed scheme reduces about 47% energy consumption for object tracking over the existing scheme and achieves about 91% accuracy of object tracking even in sensor networks with holes.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.1
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• pp.1-10
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• 2007

An advantage of the mobile ad hoc network (MANET) is that mobile nodes can self-organize the network topology without the help of network infrastructure. However, for the perfect self-organization of the MANET, each mobile node needs to self-configure its address. Even though a mobile node configures a unique address during the booting time, its address may conflict with nodes in other MANETs since MANETs containing the same address can be merged. The address autoconfiguration protocol implemented in this work consists of the strong DAD (Duplicate Address Detection) and the weak DAD. A unique address of a node is assigned by the strong DAD during the booting time and the weak DAD is used to detect address conflict and resolve address conflict during the ad hoc routing. In this work, we have implemented address autoconfiguration in the IPv6-based MANET using AODV as the routing protocol. We describe how the IPv6 address autoconfiguration is implemented and verify our implementation by showing the test scenarios on our testbed.

• Journal of Internet Computing and Services
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• v.24 no.2
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• pp.37-45
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• 2023

In line with the 4th Industrial Revolution, facility maintenance technologies for building smart factories are receiving attention and are being advanced. In addition, technology is being applied to smart farms and smart fisheries following smart factories. Among them, in the case of a recirculating aquaculture system, there is a motor pump that circulates water for a stable quality environment in the tank. Motor pump maintenance activities for recirculating aquaculture system are carried out based on preventive maintenance and data obtained from vibration sensor. Preventive maintenance cannot cope with abnormalities that occur before prior planning, and vibration sensors are affected by the external environment. This paper proposes an anomaly detection algorithm that utilizes ADTK, a Python open source, for motor pump anomaly detection based on data collected through current sensors that are less affected by the external environment than noise, temperature and vibration sensors.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.231-234
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• 2005

In this paper, propose device that all of AC Power could do switching because uses fire flame sensor(UV TRON R2868) and sensor driving circuit. Used OrCAD program for analysis of consisted Power On/Off Set, and this manufactures and experimented driving circuit actually. The experimental result is considered that can refer to data of circuit design in case of apply to actual field of practical use that need alarm after sense flame, and special quality that give an alarm sensing flame in experiment wave and given environment relatively stable. With this result Power On/off Set and that action of embodied serrounding system can utilize actually verify.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.10
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• pp.95-102
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• 2016

Pipeline is making the most use of transportation of petroleum products on the land. But due to tremendous accident or environmental disaster by oil pipeline leak or pipeline stolen, leak detection systems have been used for preventing it. Leak detection method based on negative pressure wave has been used at the long distance pipeline. But even if it has showed good leak detection quality, due to making a lot of false alarm, it has weak point that disturbs concentration to system. This study suggests algorithm and method of using volume balance to decrease false-alarm of pipeline leak detection system based on negative pressure wave.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.28-30
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• 2021

In this paper, an algorithm that detects the user's finger direction using the YOLO (You Only Look Once) library was proposed. The processing stage of the proposed finger direction detection algorithm consists of a learning data management stage, a data learning stage, and a finger direction detection stage. As a result of the experiment, it was found that the distance between the camera and the finger had a very large influence on the accuracy of detecting the direction of the finger. We plan to apply this function to Turtlebot3 after improving the accuracy and reliability of the proposed algorithm in the future.

• Smart Media Journal
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• v.9 no.4
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• pp.102-108
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• 2020

In this paper, we propose a real-time method of detecting hand motions and extracting the signal frame induced by EF(Electric Field) sensors. The signal induced by hand motion includes not only noises caused by various environmental sources as well as sensor's physical placement, but also different initial off-set conditions. Thus, it has been considered as a challenging problem to detect the motion signal and extract the motion frame automatically in real-time. In this study, we remove the PLN(Power Line Noise) using LPF with 10Hz cut-off and successively apply MA(Moving Average) filter to obtain clean and smooth input motion signals. To sense a hand motion, we use two thresholds(positive and negative thresholds) with offset value to detect a starting as well as an ending moment of the motion. Using this approach, we can achieve the correct motion detection rate over 98%. Once the final motion frame is determined, the motion signals are normalized to be used in next process of classification or recognition stage such as LSTN deep neural networks. Our experiment and analysis show that our proposed methods produce better than 98% performance in correct motion detection rate as well as in frame-matching rate.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.1
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• pp.39-43
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• 2008

It is generally recognized that monitering of bio-molecules, which are related to the ocean environment, becomes more important. So far, for the detection of the bio-molecules, ocean samples were brought to laboratory to be analyzed using a complicate and expensive measuring system The "ship and dip" method takes a relatively long time to complete a analysis cycle and causes significant errors due to the time difference between the analysis processes. In order to overcome the drawbacks, developments of sensors for the detection of bio-molecules were suggested using nano-technology, such as nano-spintronic device, carbon nano tube device, and nano-semiconductors. The pros and cons of the technology were examined and reinvestigated to overcome the technical problems in the application to real sensors.

• Journal of Digital Contents Society
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• v.15 no.3
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• pp.319-326
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• 2014

IEEE 802.11 WLAN uses CSMA/CA(Carrier Sense Multiple Access/Collision Avoidance) method in MAC(Media Access Control) protocol, and through the carrier sense checks whether other users use the channel during the data transmission to avoid the data collision. Currently, IEEE 802.11 standard recommends the use of a fixed threshold which gives an impact on carrier sensing range. However, the existing scheme using the fixed threshold causes the operation of network to be inefficiency owing to the mobility in MANET(Mobile Ad hoc NETwork). In this paper, we found the better network throughput to be obtained by applying the proposed scheme, which chooses properly the carrier sensing threshold and transmission rate considering SINR(Signal to Interference-plus-Noise Ratio), to the MANET.