• 한국농공학회논문집
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• 제65권6호
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• pp.1-13
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• 2023

Irrigation return flow plays an important role in river flow forecasting, basin water supply planning, and determining irrigation water use. Therefore, accurate calculation of irrigation return flow rate is essential for the rational use and management of water resources. In this study, EPA-SWMM (Environmental Protection Agency-Storm Water Management Model) modeling was used to analyze the irrigation return flow and return flow rate of each intake work using irrigation canal network. As a result of the EPA-SWMM, we tried to estimate the quick return flow and delayed return flow using the water supply, paddy field, drainage, infiltration, precipitation, and evapotranspiration. We selected 9 districts, including pumping stations and weirs, to reflect various characteristics of irrigation water, focusing on the four major rivers (Hangang, Geumgang, Nakdonggang, Yeongsangang, and Seomjingang). We analyzed the irrigation period from May 1, 2021 to September 10, 2021. As a result of estimating the irrigation return flow rate, it varied from approximately 44 to 56%. In the case of the Gokseong Guseong area with the highest return flow rate, it was estimated that the quick return flow was 4,677 10³ m³ and the delayed return flow was 1,473 10³ m³ , with a quick return flow rate of 42.6% and a delayed return flow rate of 13.4%.

• 정보처리학회논문지D
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• 제8D권3호
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• pp.257-264
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• 2001

본 논문은 데이터 슬라이스에서의 데이터 토큰들의 정보 흐름에 기초하여 프로그램에서의 정보 흐름을 모델링하는 SIFG(Slicw-based information Graph)를 개발하였다. 다음으로, SIFG에서의 정보 흐름의 복잡도 측정을 통해서 프로그램의 복잡도를 측정하기 위해 SCM(Slice-based Complexity Measure)을 정의하였다. SCM은 Briand가 제시하는 복잡도 메트릭에 필요한 특성들을 만족하였고, 그리고 기존 척도들과는 달리, SCM은 프로그램 내에서의 제어와 데이터 흐름뿐만 아니라 프로그램의 물리적 크기를 반영하는 측정이 이루어졌다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2016년도 춘계학술발표대회
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• pp.86-87
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• 2016

본 논문에서는 optical flow sensor를 이용하여 실내의 바닥 영상인식를 통한 영상처리기법을 이용해 움직임 없는 hovering을 할 수 있는 방법을 제안한다. 또한 optical flow와 BLE finger printing 기법을 혼합해 위치 인식 정밀도를 높일 수 있다. 본 고에서는 optical flow sensor와 BLE finger printing의 두 기술을 혼합하면 드론 스스로 실내에서 정밀도 높은 위치인식이 가능 하며 실외에서만 사용할 수 있는 GPS 비행모드를 대신 할 수 있어 실내에서 자동 경로 비행이 가능하게 하고 위치 안내, 실내 방송촬영, 이동식 CCTV등 질 높은 서비스를 제공하고자 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권10호
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• pp.4825-4847
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• 2016

In this paper, we focus on the per-flow throughput analysis of IEEE 802.11 multi-hop ad hoc networks. The importance of an accurate saturation throughput model lies in establishing the theoretical foundation for effective protocol performance improvements. We argue that the challenge in modeling the per-flow throughput in IEEE 802.11 multi-hop ad hoc networks lies in the analysis of the freezing process and probability of collisions. We first classify collisions occurring in the whole transmission process into instantaneous collisions and persistent collisions. Then we present a four-dimensional Markov chain model based on the notion of the fixed length channel slot to model the Binary Exponential Backoff (BEB) algorithm performed by a tagged node. We further adopt a continuous time Markov model to analyze the freezing process. Through an iterative way, we derive the per-flow throughput of the network. Finally, we validate the accuracy of our model by comparing the analytical results with that obtained by simulations.

• 지식경영연구
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• 제19권2호
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• pp.21-45
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• 2018

With the widespread use of smartphones and the development of information technology, an online service called SNS(social network service) has emerged, and as an increasing number of people began to use SNS, extensive research has been conducted on SNS. SNS is an important factor for adolescents who are developing social skills that help them to adapt to the society, and for adults who are stepping into the society. The present study investigates the effects of information search, self-disclosure, interaction, and playfulness, all of which are motivational factors for SNS use, on flow in SNS, and empirically analyzes the degree of these variables influence according to flow in SNS and individual's personal nature(extrovert, introvert). The analysis results showed that information search, self-disclosure, interaction, and playfulness were positively correlated with flow in SNS, and flow in SNS was positively correlated with social skills. The degree of influence varied depending on the individual's personal nature(extrovert, introvert). These findings may provide important insights for researchers studying SNS, SNS managers, and company officials using SNS.

• 한국안전학회지
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• 제17권4호
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• pp.153-159
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• 2002

This experimental study is aimed to increasing the velocity in the sewerage and also development of easy removal method for a corrosion and sand in the flow pipe. And the result by the increasing the out flow per unit time, diameter of sewerage pipe is becoming small size, cut down the construction fee and the same time reducing the tubulent flow pattern in the flow pipe. As a result of detected experimental velocity signal from the probe in the test wall surface, reducing the pump power and increasing the out flow unit time. Apparent water velocity decreases as the value of void ratio increases depends on the varies center of pipe.

• 한국통신학회논문지
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• 제25권6A호
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• pp.910-917
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• 2000

Because the random early detection(RED) algorithm deals all flows with the same best-effort traffic characteristic, it can not correctly control the output link bandwidth for the flows with different traffic characteristics. To remedy this problem, several per-flow algorithms have been proposed. In this paper, we propose a new per-flow type Fair Droptail algorithm which can fairly allocate bandwidth among flows over a shared output link. By evenly allocating buffers per flow, the Fair Droptail can restrict a flow not to use more bandwidth than others. In addition, it can be simply implemented even if it employs the per-flow state mechanism, because the Fair Droptail only keeps each information of flow in active state.

• 한국정보시스템학회지:정보시스템연구
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• 제20권2호
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• pp.177-206
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• 2011

The purpose of this research is to explore the causality of autonomy, competence, and relatedness which are major variables in self-determination theory. This study examines factors affecting intrinsic motivation, which also influences reality, flow, trust, and loyalty. The results firstly indicates that competence and relatedness positively influence reality and autonomy positively influences flow. Secondly, competence significantly influences reality and doesn't significantly influences flow. Thirdly, relatedness significantly influences reality and doesn't significantly influenced flow. Fourthly, reality doesn't significantly influences trust. Fifthly, flow significantly influences trust. Also, above results show that reality influences flow, and reality doesn't directly influence trust and loyalty. However, loyalty significantly influences flow.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2014년도 추계학술발표대회
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• pp.215-217
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• 2014

In Software Defined Network (SDN), data plane and control plane are decoupled. Dummy switches on the data plane simply forward packet based on the flow entries that are stored in its flow table. The flow entries are generated by a centralized controller that acts as a brain of the network. However, the size of flow table is limited and it can conduct a security issue related to Distributed Denial of Service (DDoS). Especially, it related to resource attack that consumes all flow table resource and consumes controller resources. In this paper, we will analyze the impact of flow table limitation to the controller. Then we propose an approach that is called Flow Table Management to handle flow table limitation.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2019년도 제59차 동계학술대회논문집 27권1호
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• pp.145-146
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• 2019

SDN(Software Defined Networking) 환경에서는 OpenFlow 프로토콜을 사용함으로써, 컨트롤러는 스위치가 패킷의 도착이나 Table의 상태에 따라 미리 Flow table의 Entry를 추가, 갱신, 삭제하도록 제어한다. 본 논문에서는 Flow entry의 사용량에 대한 확률을 정확하게 측정하기 위하여 Hidden Markov Mode (HMM)을 적용한 새로운 Flow entry 사전 제거 기법을 제안한다. 본 연구를 통해 HMM을 사용하여 기존 기술들보다 효과적이며 Flow table 관리에 있어 향상된 성능을 목표로 한다.