• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.3
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• pp.215-222
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• 2022

The purpose of air traffic flow management is to balance demand and capacity in the national airspace, and its performance relies on an accurate capacity prediction of the airport or airspace. This paper developed a regression model that predicts the number of aircraft actually departing and arriving in a terminal maneuvering area. The regression model is based on a boosting ensemble learning algorithm that learns past aircraft operational data such as time, weather, scheduled demand, and unfulfilled demand at a specific airport in the terminal maneuvering area. The developed model was tested using historical departure and arrival flight data at Incheon International Airport, and the coefficient of determination is greater than 0.95. Also, the capacity of the terminal maneuvering area of interest is implicitly predicted by using the model.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.401-404
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• 2004

본 논문에서는 모바일 에드-혹 네트워크를 위한 분산 이동성 관리 방법으로 적응적 RDG(Randomized Database Group) 방법을 제안한다. 이 방법에서는 네트워크 노드의 위치를 저장하고 노드의 이동성을 관리하기 위하여 데이터베이스가 사용된다. 모바일의 위치가 바뀌면, 모바일의 선호도를 고려하여 동적으로 무작위로 선택된 다수의 데이터베이스가 갱신된다. 호 도착과 같은 모바일의 위치가 필요할 때, 다수의 무작위로 선택된 데이터베이스가 질의된다. 그리고 분석적 방법으로 제안된 방법의 전체 위치 관리 비용을 평가하고, 그것의 성능을 기존의 RDG 방법과 비교 평가 한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.01a
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• pp.127-128
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• 2018

본 프로젝트에서는 IoT를 활용한 스마트한 풋살 대관 예약 시스템이다. 최근 건강 및 취미에 관심이 많아지면서 하나의 국면으로 풋살에 대한 관심이 많아지고 있다. 이러한 관심은 관련 블로그 등과 같은 그룹 활동으로 많은 정보를 공유하고 있다. 하지만 풋살장 예약, 팀매칭, 용병에 구하기 등과 풋살장 관리에도 어려움이 있다. 이러한 문제점들을 해결하기 위해 본 프로젝트는 웹과 앱을 활용한 커뮤니티 제공, 풋살장 관리, 팀매칭, 용병 등을 실시간으로 공유하고 활용할 수 있도록 하였다. 팀매칭 및 용병은 실시간으로 상대팀과 채팅 통해 조율할 수 있고 용병게시판을 이용하여 용병을 구할 수 있다. 앱에서는 상대팀이 예약시간의 지각, 불참석을 하면 도착알림을 오게 해주고 풋살장에 도착하여 구장문을 열거나 닫고, 구장 조명을 키거나 끄거나, 구장 실시간 영상, 구장 실시간 이용현황 등을 볼 수 있는 기능들을 제공하며, IoT를 활용한 스마트하게 풋살장 관리 및 운영, 활용할 수 있는 시스템이다.

• Journal of Internet Computing and Services
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• v.3 no.6
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• pp.43-51
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• 2002

In this paper, we study the new packet dropping scheme using an active queue management algorithm. Active queue management mechanisms differ from the traditional drop tail mechanism in that in a drop tail queue packets are dropped when the buffer overflows, while in active queue management mechanisms, packets may be dropped early before congestion occurs, However, it still incurs high packet loss ratio when the buffer size is not large enough, By detecting congestion and notifying only a randomly selected fraction of connection, RED causes to the global synchronization and fairness problem. And also, it is the biggest problem that the network traffic characteristics need to be known in order to find the optimum average queue length, We propose a new efficient packet dropping method based on the active queue management for congestion control. The proposed scheme uses the per-flow rate and fair share rate estimates. To this end, we present the estimation algorithm to compute the flow arrival rate and the link fair rate, We shows the proposed method improves the network performance because the traffic generated can not cause rapid fluctuations in queue lengths which result in packet loss

• The Korean Society of Law and Medicine
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• v.19 no.2
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• pp.209-233
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• 2018

The purpose of this study was to ascertain whether or not to recover the spontaneous circulation of patients with cardiac arrest before arrival in the emergency room for 5 years (2012 to 2016), and try to investigate the factors affecting this. In this research, we used the "raw material for acute cardiac arrest survey" conducted in "Disease management headquarters" from 2012 to 2016 for the whole country of our country as the main material. In this study, 136,212 cardiac arrest patients were analyzed in the study data of the cardiac arrest in the country during the 5 years from 2012 to 2016. We performed a Chi-square analysis to analyze the recovery of spontaneous circulation before arrival in the emergency room according to general characteristics, social·demographic characteristics, and developmental characteristics. and We performed a Binary logistic regression analysis to determine the factors affecting the recovery of spontaneous circulation. The analysis results of this study show that whether CPR sustained transport before endoplasmic reticulum arrival, whether to witness an acute cardiac arrest before arrival in the emergency room, the type of general cardiopulmonary resuscitation, the location of acute cardiac arrest, the acute heart Causes of stoppage cause factor of whether spontaneous circulation recovery recovers before arrival of the endoplasmic reticulum(P<0.001, P<0.01). Therefore, it is necessary to strengthen systematic government health policy implementation and dissemination and health education focusing on factors that affect recovery of spontaneous circulation of cardiac arrest patients.

• Journal of the Korea Society of Computer and Information
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• v.14 no.2
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• pp.149-155
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• 2009

The frequency is widely used to measure the distance. In the warehouse, however, the frequency is apt to be interrupted by various unmade stuffs and cannot be easily applied to that kind of environment. This study will suggest the method to localize a worker in the warehouse exactly with calculating the time difference of arrival from the base position to a node or between each node and with 3-points pin pointer. This study will propose the localizing method using RFID tag and analyze the result using the suggested method. Also, the efficiency of suggested method will be increased with the simulation based on the information from the RFID tag.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.2
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• pp.1-8
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• 2014

This paper introduces a new framework of predicting the arrival time of an aircraft by incorporating the probabilistic information of what type of trajectory pattern will be applied by human air traffic controllers. The proposed method is based on identifying the major patterns of vectored trajectories and finding the statistical relationship of those patterns with various traffic complexity factors. The proposed method is applied to the traffic scenarios in real operations to demonstrate its performances.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12B
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• pp.2430-2437
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• 1999

This paper introduces an adaptive time-based location update scheme that dynamically determines when to perform location update based on moving distance of mobile station and incoming call arrival probability using fuzzy logic. Comparison with other schemes demonstrate that proposed scheme adapts well to the environment where the characteristics of mobility pattern of mobile station is changed all the time, and reveals better performance in the aspect of network signaling load.

• Resources Recycling
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• v.18 no.3
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• pp.20-26
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• 2009

The objective of this study is to investigate the properties of fresh concrete with recycled coarse and fine aggregates. Four different kinds of aggregate with natural, recycled aggregates were prepared. The concrete mixtures were produced with test parameters of replacement ratio of recycled aggregate. The properties of the fresh concrete were measured by means of slump and air content according to elapsed time. Quality control method to maintain the constant total mixing water for recycled aggregate concrete was suggested. The all concrete mixtures were produced with approximately the same slump on the job site after an hour. Test results indicated that compressive strength of concrete with constant slump is not affected by the replacement ratio of recycled aggregate. Also the practical way for the quality control of recycled aggregate concrete is to maintain the constant total mixing water.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.10-12
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• 2021

유선은 수상에서 고기잡이, 관광, 그 밖의 유락하는 사람을 승선시키는 것 등 「해운법」을 적용받지 아니하는 유선사업에 종사하는 선박으로, 안전관리 부분의 경우 해양경찰청에서 담당하고 있다. 선령기준 초과 유선의 선박검사 및 선박관리평가 기준을 마련하여 해양경찰청에서는 노후 유선에 대한 안전관리를 지속적으로 평가 하고 있으나, 기존의 여객운송사업의 선박관리평가 기준을 준용하여 평가함에 따라 내항만을 통항하고 출발지와 도착지가 동일한 관광등의 유람 목적 등 유선의 특수성 등을 반영하지 못하고 있다. 본 연구에서는 유선의 통항 특성과 일반적인 운영 환경등을 고려하여 유선에 적합한 선령기준 초과 유선의 선박 검사 및 관리평가 기준 마련의 필요성을 제안하였다.