• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.301-306
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• 1998

Korea Aerospace Research Institute (KARI) is developing a Korea Multi-Purpose Satellite I (KOMPSAT-I) which accommodates Electro-Optical Camera (EOC), Ocean Scanning Multi-spectral Imager (OSMI), and Space Physics Sensor (SPS). The satellite has the weight of about 500kg and will be operated on the 10:50 AM sun-synchronized orbit with the altitude of 685 km. The satellite will be launched in 1999 and its lifetime is expected to be over 3 years. The main mission of EOC is the cartography to provide the images from a remote earth view for the production of 1/25000-scale maps of KOREA. EOC collects 510 ~ 730 nm panchromatic imagery with the ground sample distance(GSD) of 6.6 m and the swath width of 17 km by push broom scanning. EOC also can scan $\pm$45 degree across the ground track using body pointing method. The primary mission of OSMI is worldwide ocean color monitoring for the study of biological oceanography. It will generate 6 band ocean color images with 800 km swath width and 1km GSD by whiskbroom scanning. OSMI is designed to provide on-orbit spectral band selectability in the spectral range from 400 nm to 900 nm through ground command. This flexibility in band selection can be used for various applications and will provide research opportunities to support the next generation sensor design. SPS consists of High Energy Particle Detector (HEPD) and ionosphere Measurement Sensor (IMS). HEPD has missions to characterize the low altitude high-energy Particle environment and to study the effects of radiation environment on microelectronics. IMS measures densities and temperature of electrons in the ionosphere and monitors the ionospheric irregularities at the KOMPSAT orbit.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.491-491
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• 2011

Transparent and flexible electronic devices that are light-weight, unbreakable, low power consumption, optically transparent, and mechanical flexible possibly have great potential in new applications of digital gadgets. Potential applications include transparent displays, heads-up display, sensor, and artificial skin. Recent reports on transparent and flexible field-effect transistors (tf-FETs) have focused on improving mechanical properties, optical transmittance, and performances. Most of tf-FET devices were fabricated with transparent oxide semiconductors which mechanical flexibility is limited. And, there have been no reports of transparent and flexible all-organic tf-FETs fabricated with organic semiconductor channel, gate dielectric, gate electrode, source/drain electrode, and encapsulation for sensor applications. We present the first demonstration of transparent, flexible all-organic sensor based on multifunctional organic FETs with organic semiconductor channel, gate dielectric, and electrodes having a capability of sensing infrared (IR) radiation and mechanical strain. The key component of our device design is to integrate the poly(vinylidene fluoride-triflouroethylene) (P(VDF-TrFE) co-polymer directly into transparent and flexible OFETs as a multi-functional dielectric layer, which has both piezoelectric and pyroelectric properties. The P(VDF-TrFE) co-polumer gate dielectric has a high sensitivity to the wavelength regime over 800 nm. In particular, wavelength variations of P(VDF-TrFE) molecules coincide with wavelength range of IR radiation from human body (7000 nm ~14000 nm) so that the devices are highly sensitive with IR radiation of human body. Devices were examined by measuring IR light response at different powers. After that, we continued to measure IR response under various bending radius. AC (alternating current) gate biasing method was used to separate the response of direct pyroelectric gate dielectric and other electrical parameters such as mobility, capacitance, and contact resistance. Experiment results demonstrate that the tf-OTFT with high sensitivity to IR radiation can be applied for IR sensors.

• Journal of IKEEE
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• v.24 no.1
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• pp.40-45
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• 2020

In this paper, we consider an efficient design of quantizers at sensor nodes for sequence-based localization (SBL) systems which recently show a competitive performance for in-door positioning, Since SBL systems locate targets by partitioning the sensor field into subregions, each with an unique sequence number, we use the distance samples between sensors and the sequences for quantizer design in order to propose a low weight design process. Furthermore, we present a new cost function devised to assign the number of samples and the number of unique sequences uniformly into each of quantization partitions and design quantizers by searching the quantization partitions and codewords that minimize the cost function. We finally conduct experiments to demonstrate that the proposed algorithm offers an outstanding localization performance over typical designs while maintaining a substantial reduction of design complexity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.1 no.2
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• pp.209-220
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• 1997

DBS offers actual services to mass-media and communication system of very broad region in information society. Especially, the DBS is the only system to access TV broadcasting service on a sailing ship. But the ship's DBS receiver is required a complex antenna tracking system because ships are under complex moving such as pitch, roll, and yaw etc. This study is motivated to develop a tracking antenna system to receive the koreasat on small silo ship. Therefore, this system is researched to small size, light weight, simple operation, and low cost of the product. The mount structure have been a compact size and easy operation to the Az/El 2-axis type which is operated by step motor. And it is very useful on a ship in the around sea of korean peninsula. The antenna has a plate type of micro-strip array, and is a domestic production. The vibration sensor is selected to gyro sensor of ultra-sonic rate type for ship's moving control. Tracking method is used the step-tracking algorithm, and the ship's moving compensation is adapted to the closed loop control method by ship's moving detection of gyro sensor. Tracking test is operated by the ship's moving simulator, we examined the actual receiving state on sailing shipboard in the near sea of korean peninsular.

• Journal of Sensor Science and Technology
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• v.8 no.3
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• pp.226-231
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• 1999

Pyroelectric infrared sensors have been fabricated using P(VDF/TrFE) film with pyroelectric effect. The weight percent and thickness of the poled P(VDF/TrFE) film are 75/25 percent and $25\;{\mu}m$ respectively. For easier fabrication and connection method new top and bottom electrodes design was adapted for human body detecting pyroelectric infrared sensor. An aluminum infrared absorption electrode and bottom electrode were deposited by thermal evaporator. And the device was mounted in TO-5 housing to detect infrared light of $5.5{\sim}14\;{\mu}m$ wavelength. The responsibility, NEP (noise equivalent power) and specific detectivity $D^*$ of the device were $9.62{\times}10^5\;V/W$, $3.95{\times}10^{-7}\;W$ and $5.06{\times}10^5\;cm/W$ under emission energy of $13\;{\mu}W/cm^2$ respectively.

• Journal of Convergence for Information Technology
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• v.9 no.3
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• pp.22-29
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• 2019

Due to the development of ICT technology, convergence reality contents are utilized as technology for providing services in various industrial fields by visualizing various information such as sensor information and shared information in a service platform showing only simple three-dimensional contents. Research is underway to reduce the weight of applications by transmitting the resources of the object to be enhanced to the network as the information and the contents to be provided increase. In order to provide resources through the network, servers for processing various information such as pattern information, content information, and sensor information must be constructed in a cloud environment. However, in order to authenticate data transmitted and received in real-time in a cloud environment, there is a problem in that the processing is delayed and a delay phenomenon occurs in the rendering process and QoS is lowered. In this paper, we propose a system to distribute cloud server which provides augmented contents of convergent reality service that provides various contents such as sensor information and three - dimensional model, and shorten the processing time of reliable data through distributed relay between servers Respectively.

• Advances in aircraft and spacecraft science
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• v.6 no.2
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• pp.117-144
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• 2019

High Altitude and Long Endurance (HALE) aircraft are capable of providing intelligence, surveillance and reconnaissance (ISR) capabilities over vast geographic areas when equipped with advanced sensor packages. As their use becomes more widespread, the demand for additional range, endurance and payload capability will increase and designers are exploring non-conventional configurations to meet the increasing demands. One such configuration is the joined-wing concept. A joined-wing aircraft is one that typically connects a front and aft wings in a diamond shaped planform. One such example is the Boeing SensorCraft configuration. While the joined-wing configuration offers potential benefits regarding aerodynamic efficiency, structural weight, and sensing capabilities, structural design requires careful consideration of elastic buckling resulting from the aft wing supporting, in compression, part of the forward wing structural loading. It has been shown already that this is a nonlinear phenomenon, involving geometric nonlinearities and follower forces that tend to flatten the entire configuration, leading to structural overload due to the loss of the aft wing's ability to support the forward wing load. Severe gusts are likely to be the critical design condition, with flight control system interaction in the form of Gust Load Alleviation (GLA) playing a key role in minimizing the structural loads. The University of Victoria Center for Aerospace Research (UVic-CfAR) has built a 3-meter span scaled and flexible wing UAV based on the Boeing SensorCraft design. The goal is to validate the nonlinear structural behavior in flight. The main objective of this research work is to perform Ground Vibration Tests (GVT) to characterize the dynamic properties of the scaled flight vehicle. Results from the experimental tests are used to characterize the modal dynamics of the aircraft, and to validate the numerical models. The GVT results are an important step towards a safe flight test program.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.510-516
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• 2019

In this paper, a snowboard simulator that measures the user's motion and makes the user feel physical changes and enjoy actual snowboarding was developed. The speed and direction of the snowboard are determined by the user's center of gravity. The developed simulator is equipped with four springs on the snowboard plate, so that the slope can change according to the change in the user's weight center and be felt directly. The slope due to the change in the center of gravity of the user is measured using a three-axis acceleration sensor. The friction of the slope generated by the rotation of the snowboard is made possible by the user using the BLDC motor, and the rotation of the snowboard is measured using the hole sensor. For rapid data processing of the simulator, two MCUs are used to transfer the measured data to the PC using the acceleration sensor and motor separately. The developed simulator can experience slopes and friction of the slope directly, and wear measured data and HMD to enjoy more realistic snowboarding.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.3
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• pp.27-35
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• 2011

Design of Sensor nodes in Wireless Sensor Network(WSN) should be considered some properties as electricity consumption, transmission speed, range, etc., and also be needed the protection against various attacks (e.g., eavesdropping, hacking, leakage of customer's secret data, and denial of services). The stream cipher Rabbit, selected for the final eSTREAM portfolio organized by EU ECRYPT and selected as algorithm in part of ISO/IEC 18033-4 Stream Ciphers on ISO Security Standardization recently, is a high speed stream cipher suitable for WSN. Since the stream cipher Rabbit was evaluated the complexity of side-channel analysis attack as 'Medium' in a theoretical approach, thus the method of power analysis attack to the stream cipher Rabbit and the verification of our method by practical experiments were described in this paper. We implemented the stream cipher Rabbit without countermeasures of power analysis attack on IEEE 802.15.4/ZigBee board with 8-bit RISC AVR microprocessor ATmega128L chip, and performed the experiments of power analysis based on difference of means and template using a Hamming weight model.

• Journal of Korean Society for Quality Management
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• v.48 no.4
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• pp.567-580
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• 2020

Purpose: The purpose of this study is to present a preferred parts list, establish a search tool for common parts, and propose a development plan for parts management. Methods: When selecting the preferred parts list, the weight of the selection of the military parts and the online site of the civilian parts were taken into account. By establishing a database of selected preferred parts list, we have established a system for searching common parts. Results: The results of this study are as follows; In order to establish parts management work in Korea's defense, it is necessary to improve the Defense Acquisition Program Act, Enforcement Decree (Rules), and the Regulations for Defense Acquisition Program Administration. Development of performance indicators for parts management is required, and establishment of procedures and standards for selection of preferred parts lists is required. Considerations for the selection of preferred parts list include whether they are used a lot in civilian products, whether they are used a lot, whether they are certified suppliers, whether they are national and industrial standard products, whether they perform well considering reliability, durability, and quality, and whether they can be supplied continuously. Conclusion: It is necessary to establish policies and systems related to parts management and to establish criteria for selecting preferred parts list for the development of domestic parts management tasks.