• 수산해양교육연구
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• 제27권1호
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• pp.108-114
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• 2015

The purpose of this study is to find the relationships among communication competency, social network centrality(trust centrality and knowledge sharing centrality), discussion performance, and online boarding activity in the team based learning situation. For investigating this topic, 44 students are participated in the classes of educational technology. In order to find out the relationships among communication competency, social network centrality, discussion performance, and online boarding activity, compared t-test and path analysis are used. Followings are the results of the research: (a) Communication competency is improved significantly after team based learning. (b) Trust centrality effects significantly on the knowledge sharing centrality. (c) Knowledge sharing effects significantly on discussion performance. (d) Trust centrality effects on the online boarding activity in the team based learning.

• 대한교통학회지
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• 제32권2호
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• pp.152-161
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• 2014

현재 KHCM이 출판될 당시와 현재의 대중교통 환경이 달라져 승하차시간 산정방법이 달라질 필요가 있다고 판단된다. 이에 본 연구에서는 승하차시간에 영향을 주는 승하차수, 입석자수, 상면지상고를 변수로 총승하차시간값을 도출하는 모형을 다중회귀모형을 통해 분석하였다. 그 결과 총승차시간의 경우는 승하차수, 입석자수, 상면지상고 순으로 영향력의 차이가 있었으며, 총하차시간의 경우는 하차자수, 상면지상고 순으로 분석되었고, 두 개의 모형에서의 독립변수들은 모두 종속변수와 양의 상관관계를 가지는 것으로 나타났다. 모형을 통해 예측된 순수 승하차시간은 기존의 버스정류장은 물론 TOD를 고려한 신도시 등의 신설 버스정류장 용량 산정에 유용할 것으로 판단된다.

• 로봇학회논문지
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• 제18권1호
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• pp.10-17
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• 2023

Recently, robots have been actively utilized for logistics and delivery services in various places such as restaurants, hotels, and hospitals. In addition, it provides a safer environment, convenience, and cost efficiency to the customers. However, when it comes to autonomous delivery in a multi-floor environment, the task is still challenging. Especially for wheeled mobile robots, it is necessary to deal with elevators to perform the last-mile delivery services. Therefore, we present a multi-floor route planning algorithm that enables a wheeled mobile robot to traverse an elevator for the delivery service. In addition, an elevator boarding mission algorithm was developed to perceive the drivable region within the elevator and generate a feasible path that is collision-free. The algorithm was tested with real-world experiments and was demonstrated to perform autonomous postal delivery service in a multi-floor building. We concluded that our study could contribute to building a stable autonomous driving robot system for a multi-floor environment.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2013년도 춘계학술대회
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• pp.239-241
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• 2013

This paper surveyed & analyzed the career path of the 586 female cadets who graduated from the Korea Maritime University. According to the analysis, 154 graduates have the seafaring experience onboard, while 432 have no chance to work onboard. The figure indicated that one of the challenge is the number of female maritime officers who can engage in the boarding works was relatively limited. However, it is significant implication that about 80% of the graduate have been employed in a maritime industry including shipping, shipbuilding, public sectors and etc.

• 한국위성정보통신학회논문지
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• 제10권4호
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• pp.28-31
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• 2015

빌딩의 고층화 및 공공시설물의 대형화로 인해 승강기는 매우 중요해지고 있다. 특히 공연장, 극장과 같이 관람객이 동시에 이동을 할 경우 엘리베이터 사용에 병목이 발생하고 있다. 따라서 본 논문에서는 병목을 제거하고 관람객의 이동 동선을 유도하여 엘리베이터 사용 효율을 증대하기 위한 기술을 제안한다. 제안 기술의 구성은 재난 발생 시 엘리베이터 이용 상태 및 대기자를 감지하는 센서부와 센싱 데이터를 취합하여 이동 경로를 생성하는 프로세싱부, 관람객의 이동을 돕는 이동 경로 표지부로 나뉘어진다. 이에 대한 기술을 설계하고 이를 구현하여 성능을 검증하였다.

• 한국철도학회논문집
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• 제18권6호
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• pp.586-595
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• 2015

최근 Hong et al.[1]은 같은 열차에서 하차한 승객들의 교통카드데이터 퇴장시각이 군집(cluster)을 이루어 나타나는 특성을 이용해 도시철도 승객의 실제 이용 경로와 열차를 추적하는 방법론을 제시하였다. 본 논문에서는 급행열차와 일반열차가 혼합 운영되는 서울 지하철 9호선에서도 퇴장시각이 같은 특성을 보임을 확인하고 Hong et al.[1]의 방법론을 사용하여 승객이 실제 이용한 열차를 추적하였다. 오전 시간대(6시~10시) 상행 승객에 대한 추적결과 전체 승객 중 91% 승객에 대해서 성공하였다. 이 결과를 바탕으로 일반열차와 급행열차에 대한 승객의 선호 및 이용행태를 분석하였다.

• 한국군사과학기술학회지
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• 제13권3호
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• pp.388-396
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• 2010

Generally, flight information is transmitted by voice signal over legacy UHF radio in ground to air communication system. In this paper, we have implemented the transceiver of TDL(tactical data link) which transmits tactical information, such as flight information, using digital signal. For transmitting digital information over radio path, we have designed data modem that is processing CPFSK modulation, and TDMA(Time Division Multiple Access) network for Synchronization among multi user(platform). By simulating aeronautical propagation modeling with the environment of Korea terrain, it is predicted the maximum performance of communication range of the transceiver. As result of the transceiver's aviational boarding test, it is proved that the transceiver of TDL over legacy UHF radio transmits and receives the tactical information in TDMA network within communication range of 160km.

• 한국ITS학회 논문지
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• 제17권6호
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• pp.67-83
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• 2018

본 연구를 아우르는 질문은 "지하철 역사내부를 이동하는 개별승객은 언제 어디서 어떤수단을 이용해서 출발해서 언제 어디로 어떤 수단을 이용해서 갔는가 ?"이다. 이 물음에 답하기 위해서는 지하철 역사를 이동하는 개별승객이 이용한 정류장, 경로, 수단에 대한 파악이 선행되어야 한다. 수도권 통합대중교통요금체계에서는 AFC(자동요금징수체계)자료를 활용하면 개별대중교통이용승객의 통행수단, 정류장, 경로가 파악된다. 본 연구는 AFC자료를 이용하여 수도권의 대중교통역사의 승객이동을 지하철 환승역사의 관점에서 관찰하는 SSA(선별역사분석) 기법을 제안한다. SSA는 환승역사내 개별승객이동을 세분화하고 연계통행관점에서 최초출발역/시간과 최종도착역/시간 정보를 분석한다.

• 센서학회지
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• 제32권2호
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• pp.118-123
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• 2023

This study presents sensor system for autonomous mobile robot capable of floor-to-floor self-navigation. The robot was modified using the Turtlebot3 hardware platform and ROS2 (robot operating system 2). The robot utilized the Navigation2 package to estimate and calibrate the moving path acquiring a map with SLAM (simultaneous localization and mapping). For elevator boarding, ultrasonic sensor data and threshold distance are compared to determine whether the elevator door is open. The current floor information of the elevator is determined using image processing results of the ceiling-fixed camera capturing the elevator LCD (liquid crystal display)/LED (light emitting diode). To realize seamless communication at any spot in the building, the LoRa (long-range) communication module was installed on the self-navigating autonomous mobile robot to support the robot in deciding if the elevator door is open, when to get off the elevator, and how to reach at the destination.

• 한국항해항만학회지
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• 제47권2호
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• pp.75-84
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• 2023

Ships need to ensure safety during their navigation, which makes route determination highly important. It must be accompanied by a route following controller that can accurately follow the route. This study proposes a method for automatically generating the ship route based on deep reinforcement learning algorithm and following it using a route following controller. To generate a ship route, under keel clearance was applied to secure the ship's safety and navigation chart information was used to apply ship navigation related regulations. For the experiment, a target ship with a draft of 8.23 m was designated. The target route in this study was to depart from Busan port and arrive at the pilot boarding place of the Ulsan port. As a route following controller, a velocity type fuzzy P ID controller that could compensate for the limitation of a linear controller was applied. As a result of using the deep Q network, a route with a total distance of 62.22 km and 81 waypoints was generated. To simplify the route, the Douglas-Peucker algorithm was introduced to reduce the total distance to 55.67 m and the number of way points to 3. After that, an experiment was conducted to follow the path generated by the target ship. Experiment results revealed that the velocity type fuzzy P ID controller had less overshoot and fast settling time. In addition, it had the advantage of reducing the energy loss of the ship because the change in rudder angle was smooth. This study can be used as a basic study of route automatic generation. It suggests a method of combining ship route generation with the route following control.