Earticle

전력계통에서 산업의 발달로 인하여 전력수요량은 증가되고 있다. 그러나 환경과 자원의 고갈에 따른 기 존 에너지원(석탄, 석유, 가스 등)의 사용을 줄이기 위해 에너지기본계획에 따라 전력 에너지원을 다양한 재생 에 너지원으로 전환하고 있다. 에너지기본계획에 따르면 2030년까지 재생 에너지원의 비율은 국내 전력계통의 40.9[%]로 대체시키고, 전력용량 감소정책에 의해 기존의 에너지원은 축소시킬 계획이다. 그러나 재생 에너지는 기후와 계절에 따른 의존도가 높은 에너지원으로서 투입되는 발전력 변동으로 인하여 전력계통에 문제가 발생할 가능성이 있다. 본 논문에서는 가변속 양수발전기를 전력계통에 병입하여 가변적인 재생 에너지원의 변동 발전력 을 보완하는 방법을 연구하였다. 실험은 기존 양수발전기의 용량에 추가된 재생에너지원 및 대용량 발전기 감축에 대한 전력계통의 영향과 가변속 양수발전기의 전력계통의 병입에 따른 영향을 시뮬레이션을 통해 검토하였다. 그 결과 빠른 응답특성을 가진 가변속 양수 또는 LPG 발전을 통해 전력계통의 변동에 대응할 수 있었다.

It has been increasing the demand power for power systems. However, the power system has been converting power energy sources into various renewable energy sources in accordance with the basic energy plan to reduce the use of existing energy sources due to the exhaustion of the environment and resources. The proportion of renewable energy sources would be increased to 40.9 [%] and reduced conventional source by the reduce policy of the power capacity. However, renewable energy is energy source that is highly dependence by climate and season. It has been possibility of problems of the load fluctuations in the power system. In this paper, it has been studied by method of supplementing a power system with a renewable energy source varying due to the power connection of a variable speed pumped hydro generator. The simulation has been reviewed the effect of the power system on the removal of renewable energy sources and large-capacity generators added to the conventional capacity of pumped hydro generators, and the effect on the power connection of variable speed pumped hydro generators. As a result, it was studied that it could cope with fluctuations in the power system through variable speed pumped hydro or LPG power.

본 논문에서는 소프트웨어로 검증된 GPS 신호생성 알고리즘을 FPGA 기반으로 구현함으로써 RF레벨에서 다중 위성신호를 실시간으로 생성 가능한 GPS 신호생성기에 대해 기술한다. 탑재된 신호생성 알고리즘은 궤도 및 환경 오차 모델을 반영하고 수신기 위치를 기반으로 위성 신호를 모의한다. GPS 신호생성기 하드웨어는 16개의 위성 신호를 실시간으로 생성할 수 있는 디지털보드와 IF Data를 RF 신호로 변환해주는 아날로그보드로 구성되어 있다. Windows 기반의 신호생성 시뮬레이터를 제어하는 소프트웨어를 통해 항법신호뿐만 아니라 기만신호, 재밍신호를 생성이 가능하며 GIS 화면위에서 수신기의 경로를 편집할 수 있는 시나리오 구성기능이 제공된다. GPS 신호생성기는 성능은 상용수신기를 이용해 검증하였다. GPS 신호생성기를 이용한 응용 예로써 실내측위 시스템을 구성하고 시험하였으며 실내측위 시스템의 정확도를 개선하는 것은 추가적인 연구를 진행하고 있다.

This paper describes a GPS signal generator that can generate multiple satellite signals in real time at the RF level. It realizes the verified software algorithm on a FPGA. The algorithm models orbits and environmental errors such as ionospheric and tropospheric multipath. The position of a simulated receiver is one of simulation parameters. The hardware which consists of a digital logic board and an analog board can generate 16 simulated satellites signals at the same time. The users can generate spoofing signals and jamming signals as well as satellite signals by using the windows-based control software. In addition, the software provides GIS-based simulation scenarios editing tools. We verified the generator by using commercial receivers. As an application, we configured generators as indoor positioning systems and tested them in a building. To improve the accuracy of indoor systems is our further study.

GNSS 수신기는 자율주행 자동차에 장착되어 항법 장치를 이루는 필수 요소이다. 하지만 의도적인 재밍 신호가 발생하였을 경우, GNSS 수신기 추정 위치 값의 성능 저하로 인해 사고 위험에 노출될 우려가 있다. 이를 방지하기 위한 연구가 필요하며, 그에 따라 재밍 발생 장치가 구비되어야 한다. 그러나 재밍에 관련한 법 조항에 따라 이를 불법으로 규정하고 있다. 본 논문 에서는 법 조항을 준수하고, 주위 GNSS 센서에 영향을 주지 않는 차량 내 재밍 발생 장치를 구현한다. GNSS 알고리즘의 성능 평가를 위해 드라이빙 시뮬레이션을 활용하며, 간섭 환경에 서 발생하는 자율주행 차량의 오작동 및 GNSS 센서에서 출력된 데이터 오차를 분석한다.

A GNSS receiver installed in autonomous vehicles is the most essential device for its navigation. However, if an intentional jamming signal is generated, there is a risk of exposure to an accident risk due to deterioration of the GNSS sensor's performance. Research is required to prevent this, and accordingly, a jamming generating device must be provided. However, according to the provisions of the law related to jamming, this is illegal. In this paper, we implement an in-vehicle jamming device that complies with the provisions of the law and does not affect the surrounding GNSS sensors. Driving simulation is used to evaluate the performance of the GNSS algorithm, and the malfunction of autonomous vehicles occurring in the interference environment and data errors output from the GNSS sensor are analyzed.

Vector magnitude calculation is significant in the QR-algorithm by Coordinate Rotation Digital Computer (CORDIC), which is increasingly used in adaptive applications. However, its hardware implementation is extremely difficult. In this paper, a fixed point CORDIC system is constructed to compute the magnitude of a vector by using Model-Based Design. The simulation results show that the proposed method of CORDIC vector magnitude calculator is not only simple in structure and easy to implement, and can improve the speed of operation with good scalability.

A scroll expander exhaust recovery system with the battery is proposed to improve exhaust recovery efficiency. Based on the exhaust flow, storage pressure and the battery current, expander supply pressure was optimized with the loss model based on the expansion and generator loss. And then the supply pressure controller was designed to track the optimized supply pressure reference using the input-output linearization method. DC bus voltage was efficiently regulated by the PI voltage controller, the duty feedforward compensation and the operation mode of battery storage system. Experimental results proved the control strategy validity, realizing the efficiency maximum of the recovery system and exhaust discharging system.

Parents of infants in NICU are facing challenges in the lack of information or in understanding it, in addition to their negative feeling in this stressful experience. One way to support parents is to develop an automatic system that generates a clear and concise summary about infant progress. In order for this system to function properly there is a need for ontology. This project present a simple ontology contains some main concepts in NICU domain. This ontology was developed through a Protégé version 3.4.2 in seven steps that used to create the RDF and OWL. The ontology mainly includes 10 classes, 17 data properties, 8 object properties, some individuals and cardinality restrictions on relationships between classes, and other descriptions. At the end, the author found the ontology consistent after reasoning then executed four different SPARQL query and its result were correct. This ontology can be developed and used in another application around the NICU domain.

Steel making processes are highly energy intensive and comprised of many complex unit operations. Iron ore and coal need preprocessing before feeding into a reactor, and molten metal from different reactors needs to be carefully drawn into a solid metal and then rolled into sheets. Each of these operations has a stake in the quality of steel produced, and needs constant monitoring and need continuous power supply for fabrication. If a power failure occurs the production will be stopped, time delay increases for finishing fabrication. In some cases we can loss consumer due to unsatisfactory. My Project focuses the detection of power failure and takes reflex action to solve the problem with help of modem communication using GSM. The power failure will be intimated to the Microcontroller it drive the GSM modem to send a text message to the concern person mobile number which was already programmed in Microcontroller and also monitoring the parameter are temperature, oil level, fuel level and when they exceed predefined limits an automatically intimated to authorized person and also This system can be designed to send SMS alerts whenever the Circuit Breaker (Relay) trips and simulation result done by using LabVIEW software.

A VMS (Variable Message Signs) has the different sizes and various shapes according to the city scene and the kinds of road and it has to be displayed by variable message on the display device panel in real-time. So, VMS manufacturers must produce the different products each order made. In addition that, they should test and check the correct operation to each VMS order made goods using the variable message frame. That is very time and workers consuming and a VMS emulator with automatic variable message generator system using visualization tool is necessary. In this paper, we implement the visualization tool for the VMS emulator with automatic variable message generator which can generate the data fields that consists of the variable and different message frame and can generate many kinds of window controls in order to in

Using variable speed engine in diesel generator will enhance efficiency of the engine where it will operate continuously at its optimum speed. The high cost of variable speed diesel generator because of using power electronic elements to convert variable frequency voltage to constant frequency voltage (AC/DC-DC/AC)cane be reduced if we use Hybrid System by connecting the PV system to DC Voltage bus directly and using it’s inverter as main inverter of the system studied in this paper is consisted of a Photovoltaic and a Variable Speed Diesel engine driving PMSG .By using FOC we can control the output power of PMSG according to the speed of the engine and vice versa .The change of climatic condition is the main problem of renewable energy specially when the engine–generator operate at it is minimum speed for that SMES which an high power density storage element is used for maintaining the stability of the stability of the system. The simulation of the system was done using Matlab/Simulink and the result of the simulation was discussed.

카오스 신호는 공학, 의학 그리고 생물학과 같은 모든 분야에서 많이 이용되고 있으며 최근 카오스 신호를 이용한 디지털 통신시스템에 대한 연구도 활발히 이루어지고 있다. 본 논문은 카오스 신호를 디지털 통신시스템에 적용할 목적으로 System Generator를 이용하여 비선형 방정식으로 구성된 6개의 카오스 신호 발생기를 설계하고 FPGA로 하드웨어를 구현하였다. 이 결과로부터 Hardware co-simulation으로 본 설계를 검증하기 위해 비트 스트림을 FPGA 보드로 로드하였다. 또한 6개의 카오스 발생기의 성능을 평가하기 위해 타이밍 해석을 통한 최대 동작 주파수와 사용한 로직의 resource량을 조사하여 비교하였다.

A chaos signal is used in all fields like engineering, a medical science and a biology very much, and study regarding the digital communication system that used a recent chaos signal is consisting actively. Applied a chaos signal in a digital communication system, and this paper designed six chaos signal generator to have been composed of by nonlinear equations as used System Generator, and implemented hardware to FPGA. Loaded bit stream to a FPGA board in order to verify this design to Hardware co-simulation from these results. Also, compared as investigated the maximum action frequency through timing analysis and resource of logic in order to evaluate performance of six chaos generator.

최근 들어 무선인터넷 단말기로 보다 효율적으로 인터넷에 접근하여 정보를 제공하고자 하는 연구가 활발히 진행되고 있다. 사용자는 유선 인터넷으로 제공받는 컨텐츠를 휴대가 간편한 무선 이동통신으로 제공받고자 하는 욕구가 점점 늘어나고 있고 이러한 원인으로 다양한 무선 컨텐츠의 제공이 요구된다. 그러나 다양한 무선 단말기의 특성에 따라 컨텐츠를 새롭게 개발하는데는 개발비용, 기간이 많이 들게 되므로 기존의 웹 컨텐츠를 활용하여 무선환경에 맞는 문서변환 기술 연구의 필요성이 대두되고 있다. 본 논문에서는 유선 인터넷상의 컨텐츠를 무선 환경으로 손쉽게 변환할 수 있는 XML(eXensible Markup Language)기술을 활용한 변환기(Generator)구조를 설계하고 이와 관련된 XML Generator, RuleSet Management, Clipping Toolkit 등의 기능을 정의하여 보다 효율적으로 무선 컨텐츠로 변환하는 기술을 소개한다.

In this paper new, inverter control system for TG feedback a formula Control was developed. The motor control system with TG feedback controller as an effect of load disturbance, it is very difficult to guarantee the robustness of control system. The function of the implementation are TG feedback type, and temperature scheme. The Inverter Control System approach is based on master-slave control concept. To show validity of the developed new inverter control system, severial experiments are illustrated.

In this paper a new dc-link type wind turbine generator system using a shaft generator system, which is widely used for power sources in a ship, is proposed. The basic configuration of the proposed wind turbine generating system is first explained. And the equations expressing the system are derived. Then the steady-state characteristics of the generating system are discussed. We use an experimental system that can simulate the characteristics of a wind turbine in this study, because it is hard to operate an actual wind turbine in a laboratory. In addition, the transient responses of this system are investigated when the velocity of the wind is changed. It is shown that experimental results were very close to the simulated ones, supporting the usefulness of the theory.

This paper presents results of the development of the Turbo-generator system with structure which is HSG(High Speed Generator) installed to high speed gas-turbine engine directly. Turbo-generator with high speed motor-generator directly has many advantages aspects of weight, size, lubrication system and complexity of the system compared of conventional turbo-generator system with gear-box. But because of direct high speed operation of the high speed generator, we have to need stable high speed motor driving algorithm for perfect engine ignition when gas turbine starting. Also we have to need design of the PCU(Power Conditioning Unit) for converting high speed AC output power to conventional AC power or needed DC power.

The developed security scheme for user authentication, which uses both a password and the various devices, is always open by malicious user. In order to solve that problem, a keystroke dynamics is introduced. A person's keystroke has a unique pattern. That allows the use of keystroke dynamics to authenticate users. However, it has a problem to authenticate users because it has an accuracy problem. And many people use passwords, for which most of them use a simple word such as "password" or numbers such as "1234." Despite people already perceive that a simple password is not secure enough, they still use simple password because it is easy to use and to remember. And they have to use a secure password that includes special characters such as "#!($^*$)^". In this paper, we propose the automatic fortified password generator system which uses special characters and keystroke feature. At first, the keystroke feature is measured while user key in the password. After that, the feature of user's keystroke is classified. We measure the longest or the shortest interval time as user's keystroke feature. As that result, it is possible to change a simple password to a secure one simply by adding a special character to it according to the classified feature. This system is effective even when the cyber attacker knows the password.