• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.5
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• pp.353-360
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• 2014

The model ice is created at KRISO (Korea Research Institute for Ships and Ocean Engineering) ice basin where model ship is tested to obtain the necessary data in order to design the ice breaking vessels and ocean structures operating in the northern pole sea area. Through the model ship test, ice breaking, clearing, ice-ship and ice-propeller interaction behavior can be obtained. Since mechanical properties of ice plate are required for the model test, some tests are performed to obtain the properties in this paper. First, ultrasonic devide is used to measure the thickness of the model ice plate and the results show the possibility of using ultrasonic method, yet more sophisticated device or special sensors are required to measure the ice thickness completely. And the defection of ice plate is measured using LVDT to compute the characteristic length of ice plate on the fluid, which is used to get the effective Young's modulus of model ice.

• Journal of the HCI Society of Korea
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• v.3 no.1
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• pp.1-7
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• 2008

Recently researchers have studied mobile physiological sensing device. However, previous works focused on multiple and real time physiological sensing method, instead of aesthetic shape of sensing devices, sensing comfort during monitoring and sensing reliability against the hand motion artifact. In this work, we propose a stone shaped physiological sensing device to monitor the physiological status in a daily life which maximize the aesthetic feeling and sensing comfort and sensing reliability. We proposed stepwise user centered design process for user centric physiological sensing device and evaluated appropriate sensing positions against the hand motion artifacts and pressure from sensors. From the usability test and experiments, we verified the proposed sensing device provides the aesthetic appeals, sensing comfort and sensing reliability. We expect that this work can be applied in the various health care applications in near future.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.3
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• pp.671-677
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• 2012

A black-box program was implemented in order to monitor abnormal symptoms of human body irregularly occurring during sleep. The system consists of sensor probing body signals, auxiliary devices such as the alarm, lamp, network camera, and signal monitoring computer. Various types of sensors, PPG, ECG, EEG, temperature, respiration sensor, G-sensor, and microphone were used to more exactly identify the causes of abnormal symptoms. If a symptom occurs, the system records the patient's condition to provide information being utilized in the treatment. The sensors are attached on some locations of body being proper to check a specific type of abnormal reaction. Based on the normal range and type of measurement data, criteria of signal levels were set to distinguish abnormal reaction. An abnormal signal being probed, the program starts to operate the lamp, alarm, and network camera at the same time and stores the signal and video data.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.591-598
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• 2017

The changes of technology and the size of markets for unmaned aerial vehicle are getting bigger presently. Damage happens because of user's poor operation since accesses to the drones are easy. To minimize the damage, drone's stabilized flight skills are required, and controlling the motor to balanced speed is also needed. Thus, the essay shows that we use Arduino as a main control device for controlling a drone, and used acceleration sensor and gyro sensor for the drone stabilization. Also, we made it able to hover at a certain height by using a sonar sensor. We also controlled a drone by using an Android application, and made the drone hover stably at 0~2 meters.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.700-708
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• 2007

A midline deviation is divided into three types, such as a skeletal midline deviation, a dental midline deviation, and a combination. Among them, the midline deviation which appear in the early mixed dentition without any skeletal problem can be managed differently by the stage of dental development. The location of the permanent incisors can be improved without using artificial force in consideration of the condition of the space, the eruption timing or the eruption path of the adjacent permanent teeth in early mixed dentition, especially when the permanent incisors are erupting. Therefore, the space supervision technique, which can have the teeth align themselves utilizing physiologic events such as sequence or timing of the eruption of permanent teeth, can be an alternative to orthodontic movement. This case report describes midline deviation improvement by space supervision.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12B
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• pp.2298-2319
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• 1999

In this paper, we propose a new moving mobile base station (MMBS) scheme for very low power and micro-size RMIMS (radio-interfaced micro information monitoring system) terminals. RMIMS terminals can be used in various application service areas such as pollution monitoring, environment surveillance, traffic monitoring, emergency monitoring (e.g., building, bridge, railroad breakdown), security monitoring (e.g., theft, alarm) and military application. For these applications based on wireless transmission technologies, sensor type RMIMS terminals must satisfy low cost and low power design (e.g., solar power, life limited battery) requirement. In RMIMS terminal design, this low power requirement limits transmission range of uplink or reverse link and means small cell size. Also these applications using RMIMS terminals may have a little bit non real-time traffic characteristic and low scattering density in service area.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.520-523
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• 2010

In the field of network sense for the Ubiquitous environment, the technology of RFID is a significant part. Due to the real time processing of information and the property of network, RFID has been used in service field such as distribution, administrative control of physical distribution, remote measuring device, and security, instead of currently used bar-code. The management system of port facilities using the current RFID technology has the effects of reducing working hours and improvement in data processing, but it is not proper for human resource allocation since it is dominantly worked for physical resources. In this paper, we designed and implemented personnel control system using RFID of 2.4GHz in port facilities which presents a monitoring system for safety operation and increase of efficiency using RFID in order to overcome the limitations and problems of current port operation management techniques.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.207-212
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• 2015

Continuous, high-quality supply of electrical energy is the backbone of any modern economy. Any equipment operating at a power station must be reliable and safe. All major power supply components such as transformers, cables, generators, and switchgear need to be kept in perfect operating condition. The lifetime of power cables, used as the main means of transferring electric power, is understood to be about 30 years, from the time of manufacturing. The dielectrics between two conductors of a cable must be able to withstand electrical stresses from high-voltage input. This condition should be verified throughout the lifetime of the cable system. Several techniques, such as VLF-tan${\delta}$, partial discharge, and insulation resistance are used in order to determine the operating conditions of cables. In this paper, we present our work on insulation resistance to diagnose cables in operation at the Western Power station in Taean, Chungcheong Namdo Province, South Korea. As a result we have found cables the life time of which is 38 years.

• Journal of the Korean Data and Information Science Society
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• v.28 no.1
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• pp.163-171
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• 2017

With the advance of function of smart phone system and internet services, mobile trade grows more popular in the area of e-business or banking. These environmental changes, it makes the needs of authorized certificates. Authorized certificate is not only important in these days but also future society. In 2015, 27 millions of Korean people used public key certificate, but most of them does not know the details on the public key certificate. Therefore, in this paper, we explain and investigate the characteristics on the public certificate and explain the relation ship between authorized certificate and public key encrytion. By investigating several papers, internet data, newspapers and books, we found the historical changes, substantial aspects, the encryption systems on the authorized certificate. Also we study the pros and cons of authorized certificate. Finally we predict the number of issued authorized certificate for the future society based on nonparametric statistical method.

• The Journal of Information Technology
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• v.4 no.3
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• pp.165-170
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• 2001

In this paper, we proposed an autopilot of the unmanned piloted vehicle to guide to the specific position and analyzed robustness of the designed autopilot. We divide an aircraft velocity into the three case which are low, crusing and high speed, and designed autopilot gains are gain scheduled. We generated the turbulence for the operational altitudes and analyzed performance of the autopilot about it. We proved robustness of the designed autopilot for the turbulence and gust using simulation.