• 한국항해항만학회지
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• 제38권6호
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• pp.645-653
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• 2014

A Bridge Navigational Watch Alarm System (hereafter 'BNWAS') is to monitor and detect if an officer of watch(hereafter 'OOW') keeps a sharp lookout on the bridge. The careless lookout of an OOW could lead to marine accidents. For this reason on June 5th, 2009, IMO decided that a ship is equipped with a BNWAS. However, an existing BNWAS gives the OOW a lot of inconvenience and stress in its operation. It requires that the OOW should press reset buttons to confirm their alert watch on the bridge at every three to twelve minute. Many OOWs have complained that at some circumstances they cannot focus on their bridge activities including watch-keeping due to a lots of resetting inputs of BNWAS. Accordingly, IMO has allowed the use of a motion sensor as a resetting device. The motion sensor detects the movements of human body on the bridge and subsequently sends reset signals directly to BNWAS automatically. As a result, OOWs can work uninterrupted. However, some of classification societies and flag authorities have a slightly different stance on the use of motion sensor as a resetting method for BNWAS. The reason is that the motion sensor may trigger false reset signals caused by the motion of objects on the bridge, especially a slight movement such as toss and turn of human body which can extend the period of careless watch. As a basic study to minimize the false reset signals, this paper proposes a simple configuration of BNWAS, which consists of only three motion sensors associated with 'AND' and 'OR' logic gates. Additionally, several considerations are also proposed for the implementation of motion sensors. This study found that the proposed configuration which consists of three motion sensors is better than an existing one by reducing false reset signals caused by a slight movement of human body in one's sleep. The proposed configuration in this paper filters false reset signals and is simple to be implemented on existing vessels. In addition, it can be easily installed just by a basic electrical knowledge.

• 한국산학기술학회논문지
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• 제21권4호
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• pp.26-32
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• 2020

최근 웨어러블 장치와 IoT 기술들이 다양하게 개발 및 상용화되면서, 이에 발맞추어 다양한 종류의 센서 들이 개발되었고, 이런 새로운 종류의 센서들이 실생활에서 다양하게 접목되면서 다양한 응용 제품들이 개발되어 왔다. 새로운 센서 기술들이 현실화되면서 의학분야에서도 많이 적용되고 있으며, 특히 자기장 센서는 의학분야에서 다양한 목적으로 활용되어져 왔다. 본 논문에서는 소형의 영구자석과 이를 측정하기 위한 자기장 센서를 활용하여 손목의 재활 훈련이나 운동량을 측정하는 모델과 방법을 제시하고자 한다. 자석과 자기장 센서 사이에는 전기적인 선들의 연결이 없이도 자석과 자기장 센서 사이의 자기장을 측정할 수 있어, 이렇게 측정된 자기장 값들을 실제 자석과 자기장 센서간의 거리로 환산하여 측정할 수 있는 장점이 있다. 하지만, 자기장의 특징은 그 자체만으로도 비선형적인 자기장이 생성되기 때문에, 자기장 센서 패드와 손목동작의 비선형 모델로 인하여, 아주 복잡한 모델과 많은 계산이 요구하게 된다. 따라서 본 논문에서는 이런 구현상의 어려운 단점들을 보완하고 정확한 장기장센서 데이터를 측정하기 위하여, 손에 설치된 자석과 손목에 설치된 자기장 센서를 모델링하고 캘리브레이션하는 방법을 제안한다.

• 한국통신학회논문지
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• 제34권2B호
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• pp.151-161
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• 2009

PULSE 프로토콜은 센서 노드의 슬립을 통해 소모 전력량을 크게 줄인다. 그러나 이 프로토콜은 싱크 노드의 이동을 고려하지 않는 문제가 있다. 모바일 싱크 노드를 가진 센서 네트워크를 위한 라우팅 프로토콜은 빠른 경로 복구와 전력 소모 최소화를 모두 달성해야 한다. 본 논문은 두 목적을 달성하기 위해 모바일 PULSE 프로토콜을 제안한다. 또한, 실험을 통해 제안한 프로토콜의 경로 복구 능력과 전력 소모량을 확인하였다. 이 프로토콜은 기존의 PULSE 프로토콜에 비해 약 40% 정도 경로 복구 시간을 단축하였고, 드롭되는 패킷의 양도 약 1/2 수준으로 줄였다. 전력 소모량 면에서는 최대 0.8%의 증가만이 나타남으로써, 기존의 PULSE 프로토콜의 전력 효율적인 특징을 그대로 유지함을 보였다. 본 논문은 모바일 PULSE 프로토콜의 경로 복구 능력과 전력 소모량을 확인함으로써 모바일 센서 네트워크에 적합한 프로토콜로서의 가능성을 보여준다.

• 한국컴퓨터정보학회논문지
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• 제22권9호
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• pp.73-80
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• 2017

In this paper, we design and implement a mobile game based on Kinect sensor. This game is a motion recognition maze game based on Kinect sensor using XNA Game Studio. The game consists of three stages. Each maze has different size and clear time limit. A player can move to the next stage only if the player finds the exit within a limited time. However, if the exit is not found within the time limit, the game ends. In addition, two kinds of mini games are included in the game. The first game is a fruit catch game using motion recognition tracking of the Kinect sensor, and player have to pick up a certain number of randomly falling fruits. If a player acquire a certain number of fruits at this time, the movement speed of the player is increased. However, if a player takes a skeleton that appears randomly, the movement speed will decrease. The second game is a Quiz game using the speech recognition function of the Kinect sensor, and a question from random genres of common sense, nonsense, ancient creature, capital, constellation, etc. are issued. If a player correctly answers more than 7 of 10 questions, the player gets useful items to use in finding the maze. This item is a navigator fairy that helps the player to escape the forest.

• Steel and Composite Structures
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• 제35권6호
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• pp.779-788
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• 2020

Multi-Walled Carbon nanotubes (MWCNT) coupled with Silicone Rubber (SR) can represent applicable strain sensors with accessible materials, which result in good stretchability and great sensitivity. Employing these materials and given the fact that the combination of these two has been addressed in few studies, this study is trying to represent a low-cost, durable and stretchable strain sensor that can perform excellently in a high number of repeated cycles. Great stability was observed during the cyclic test after 2000 cycles. Ultrahigh sensitivity (GF>1227) along with good extensibility (ε>120%) was observed while testing the sensor at different strain rates and the various number of cycles. Further investigation is dedicated to sensor performance in the detection of human body movements. Not only the sensor performance in detecting the small strains like the vibrations on the throat was tested, but also the larger strains as observed in extension/bending of the muscle joints like knee were monitored and recorded. Bearing in mind the applicability and low-cost features, this sensor may become promising in skin-mountable devices to detect the human body motions.

• 제어로봇시스템학회논문지
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• 제17권10호
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• pp.1014-1020
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• 2011

This presents a motion and force estimation system of human fingers by using an Electromyography (EMG) sensor module and a data glove system to be proposed in this paper. Both EMG sensor module and data glove system are developed in such a way to minimize the number of hardware filters in acquiring the signals as well as to reduce their sizes for the wearable. Since the onset of EMG precedes the onset of actual finger movement by dozens to hundreds milliseconds, we show that it is possible to predict the pattern of finger movement before actual movement by using the suggested system. Also, we are to suggest how to estimate the grasping force of hand based on the relationship between RMS taken EMG signal and the applied load. Finally we show the effectiveness of the suggested estimation system through several experiments.

• 대한임베디드공학회논문지
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• 제11권3호
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• pp.183-191
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• 2016

Recently, in rehabilitation treatment, the situation that requires a measure of the accuracy of the pose and movement of joints is being increased due to the habits and lifestyle of modern people and the environment. In particular, there is a need for active automated system that can determine itself for the matching rate of pose Basically, a method for measuring the matching rate of pose is used by extracting an image using the Kinect or extracting a silhouette using the imaging device. However, in the case of extracting a silhouette, it is difficult to set the comparison, and in the case of using the Kinect sensor, there is a disadvantages that high accumulated error rate according to movement. Therefore, In this paper, we propose a method to reduce the accumulated error of matching rate of pose getting the rotation angle of joint by measuring the real-time amount of change of 9-axis sensor. In particular, it can be measured same conditions that unrelated of the physical condition and unaffected by the data for the back and forth movement, because of it compares the current rotation angle of the joint. Finally, we show a comparative advantage results by compared with traditional method of extracting a silhouette and a method using a Kinect sensor.

• Structural Monitoring and Maintenance
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• 제9권4호
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• pp.359-371
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• 2022

Bridges are critical to the civil engineering infrastructure network as they facilitate movement of people, the transportation of goods and services. Given the aging of bridge infrastructure, federal officials mandate visual inspections biennially to identify necessary repair actions which are time, cost, and labor-intensive. Additionally, the expansion joints of bridges are rarely monitored due to cost. However, expansion joints are critical as they absorb movement from thermal effects, loadings strains, impact, abutment settlement, and vehicle motion movement. Thus, the need to monitor bridge expansion joints efficiently, at a low cost, and wirelessly is desired. This paper addresses bridge joint monitoring needs to develop a cost-effective, real-time wireless system that can be validated in a full-scale bridge structure. To this end, a wireless expansion joint monitoring was developed using commercial-off-the-shelf (COTS) sensors. An in-service bridge was selected as a testbed to validate the performance of the developed system compared with traditional displacement sensor, LVDT, temperature and humidity sensors. The short-term monitoring campaign with the wireless sensor system with the internet protocol version 6 over the time slotted channel hopping mode of IEEE 802.15.4e (6TiSCH) network showed reliable results, providing high potential of the developed system for effective joint monitoring at a low cost.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1679-1684
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• 2004

This paper introduces a novel approach that can provide the three dimensional information on the movement of a spreader by using two CCD cameras and a laser distance sensor, which enables an ALS (Automatic Landing System) to be used for yard cranes at a harbor. So far a kind of 2D Laser scanner sensor or laser distance measuring units are used as corner detectors for the geometrical matching between the spreader and a container, which provides only 2D information which is not enough for an accurate and fast ALS system required presently. In addition to this deficiency in performance, the price for the system is too high to be adopted widely for the ALS. Therefore, to overcome these defects, a novel method to acquire the three dimensional information for the movement of a spreader including skew and sway angles is proposed using two CCD cameras and a laser distance sensor. To show the efficiency of proposed algorithm, real experiments are performed to show the accuracy improvement in distance measurement by fusing the sensory information of CCD camera and laser distance sensor.

• 대한안전경영과학회지
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• 제15권2호
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• pp.55-61
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• 2013

For years, many studies have mainly been investigated in a complicated human motion analysis. Recently, many motion analysis equipments have been studied and developed. Therefore, the more complex human movement analyses are possible, we have enabled us to perform more and more complicated human movement analyses. A Three-dimensional(3D) motion analysis on of the several methods is a useful tool for analyzing the human motion analysis. The purpose of this study was to develop the 3D human motion analysis using a kalman filter algorithm and a gyro sensor. The algorithm and sensor were used to human motion analysis with high-speed motion capture. In this study, the developed system will be adapted to facilitate golf swing analysis. Using the developed system, golfers and coaches who do not have advanced biomechanical knowledge can easily be used to their golf swing analysis. Future study is necessary for more practical and efficient area such as other sports industries, 3D game industries, rehabilitation training, etc..