• Title/Summary/Keyword: combined systems

Search Result 2,639, Processing Time 0.025 seconds

Aviation stability analysis with coupled system criterion of theoretical solutions

  • C.C. Hung;T. Nguyen
    • Coupled systems mechanics
    • /
    • v.12 no.3
    • /
    • pp.221-239
    • /
    • 2023
  • In our research, we have proposed a solid solution for aviation analysis which can ensure the asymptotic stability of coupled nonlinear plants, according to the theoretical solutions and demonstrated method. Because this solution employed the scheme of specific novel theorem of control, the controllers are artificially combined by the parallel distribution computation to have a feasible solution given the random coupled systems with aviation stability analysis. Therefore, we empathize and manually derive the results which shows the utilized lemma and criterion are believed effective and efficient for aircraft structural analysis of composite and nonlinear scenarios. To be fair, the experiment by numerical computation and calculations were explained the perfectness of the methodology we provided in the research.

Research on Intelligent Combat Robot System as a Game-Changer in Future Warfare

  • Byung-Hyo Park;Sang-Hyuk Park
    • International Journal of Advanced Culture Technology
    • /
    • v.11 no.4
    • /
    • pp.328-332
    • /
    • 2023
  • The Army has presented eight game-changers for future warfare through 'Army Vision 2050,' including Intelligent Combat Robots, Super Soldiers, Energy Weapons, Hypersonic Weapons, Non-lethal Weapons, Autonomous Mobile Equipment, Intelligent Command and Control Systems, and Energy Supply Systems. This study focuses on Intelligent Combat Robots, considering them as the most crucial element among the mentioned innovations. How will Intelligent Combat Robots be utilized on the future battlefield? The future battlefield is expected to take the form of combined human-robot warfare, where advancements in science and technology allow intelligent robots to replace certain human roles. Especially, tasks known as Dirty, Difficult, Dangerous, and Dull (4D) in warfare are expected to be assigned to robots. This study suggests three forms of Intelligent Robots: humanoid robots, biomimetic robots, and swarm drones.

Which Agent is More Captivating for Winning the Users' Hearts?: Focusing on Paralanguage Voice and Human-like Face Agent

  • SeoYoung Lee
    • Asia pacific journal of information systems
    • /
    • v.34 no.2
    • /
    • pp.585-619
    • /
    • 2024
  • This paper delves into the comparative analysis of human interactions with AI agents based on the presence or absence of a facial representation, combined with the presence or absence of paralanguage voice elements. The "CASA (Computer-Are-Social-Actors)" paradigm posits that people perceive computers as social actors, not tools, unconsciously applying human norms and behaviors to computers. Paralanguages are speech voice elements such as pitch, tone, stress, pause, duration, speed that help to convey what a speaker is trying to communicate. The focus is on understanding how these elements collectively contribute to the generation of flow, intimacy, trust, and interactional enjoyment within the user experience. Subsequently, this study uses PLS analysis to explore the connections among all variables within the research framework. This paper has academic and practical implications.

Characteristics and Research Trend of Agrivoltaics (영농형 태양광 발전시스템의 특성 및 연구동향)

  • Seok Jin Jang;Jinjoo Park;Junsin Yi
    • Current Photovoltaic Research
    • /
    • v.12 no.3
    • /
    • pp.74-79
    • /
    • 2024
  • Photovoltaics (PV) is gaining attention as an alternative energy source to fossil fuels. Although the demand for PV is increasing, it requires more than three times the space compared to conventional power generation, leading to limtation of available land for PV installations. Agrivoltaics is combined with agriculture and solar power generation at the same space, making it highly efficient in terms of land use. This review explores various forms of agrivoltaics systems currently being researched and examines the relationship between energy production and agricultural productivity in these systems. With agrivoltaics, about 70-80% of the energy production of conventional solar power can be achieved, while agricultural yields can reach up to 90% of those produced through conventional farming methods.

Impacts of Value Suggesting Factors of Brand Identity on the Attitude and Buying Depending on the Gender (브랜드 아이덴티티의 가치제안요소가 성별에 따라 태도와 구매에 미치는 영향)

  • Han Kwang-Seok
    • Management & Information Systems Review
    • /
    • v.17
    • /
    • pp.1-24
    • /
    • 2005
  • The purpose of this study is to figure out the effects of advertisements (functional value, sentimental value, self-expressing value) depending on the gender in regard of the attitude towards the advertisement, brand attitude, purchase intention, and the characteristic and quality of the product. From the study on the university students, there was a meaningful interaction among the independent variables in regard of attitude towards advertisement, brand attitude, purchase intention, and characteristic of the product in the four dependent measurements used for the index of advertisement effects. In terms of the attitude towards advertisements, brand attitude, purchase intention, and the characteristic of the product according to the gender and value suggestion, functional convenience was more influential for men compared to the sentimental convenience and self-expressing value. On the other hand, self-expressing value was more influential for women in terms of the advertisement effect and the characteristic of the product. The main effects depending on the gender were common in four dependent values such as attitude towards advertisement, brand attitude, purchase intention and characteristic of the product, and the average of all values was higher from women. Thereby, it can be said that women show more positive advertisement effects in terms of attitude and purchase than men. The main effects on the value suggestion were meaningfully indicated in advertisement attitude, brand attitude, and characteristic of the product except the purchase intention. Also, the functional and self-expressing value made better advertisement effect, while the sentimental value showed a comparatively lower advertisement effect. In terms of the sentimental value, a comparatively low advertisement effect was shown statistically compared to the functional and self-expressing value in all dependent values, but there was no big difference depending on the gender. That is, in terms of the sentimental value, a separate value suggesting advertisement can be more influential when it is combined with the functional value for men, and for women if it is combined with self-expressing value.

  • PDF

An Efficient Iterative Receiver for OFDMA Systems in Uplink Environments (직교 주파수 분할 다중 접속 시스템 상향 전송에 알맞은 효율적인 반복 수신 기법)

  • Hwang, Hae-Gwang;Sang, Young-Jin;Byun, Il-Mu;Kim, Kwang-Soon
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.43 no.11 s.353
    • /
    • pp.8-15
    • /
    • 2006
  • In this paper, we propose the iterative receiver for LDPC-coded OFDMA systems in uplink environments. Applying the Wiener filtering to pilot symbols, an initial channel estimation can be performed effectively. To reduce the complexity of the Wiener filtering, we approximate Wiener filtering coefficients to pre-determined coefficients according to estimated correlation of channel. After an LDPC decoding process, soft symbol derived by extrinsic information of decoder outputs is used to estimate channel. we also derive the error variance of channel estimation and maximum ratio combined results. Using combined results, the channel correlation is re-estimated. Then the proper Wiener filtering coefficients are chosen according to the re-estimated result of the channel correction. Using a computer simulation, we show that the proposed receiver structure has the better performance than the receiver using only pilot symbols.

A Performance of Positioning Accuracy Improvement Scheme using Wavelet Denoising Filter (Wavelet Denoising Filter를 이용한 측위 정밀도 향상 기법 성능)

  • Shin, Dong Soo;Park, Ji Ho;Park, Young Sik;Hwang, Yu Min;Kim, Jin Young
    • Journal of Satellite, Information and Communications
    • /
    • v.9 no.3
    • /
    • pp.9-14
    • /
    • 2014
  • Recently, precision guided munition systems and missile defense systems based on GPS have been taking a key role in modern warfare. In warfare however, unexpected interferences cause by large/small scale fading, radio frequency interferences, etc. These interferences result in a severe GPS positioning error, which could occur late supports and friendly fires. To solve the problems, this paper proposes an interference mitigation positioning method by adopting a wavelet denoising filter algorithm. The algorithm is applied to a GPS/QZSS/Wi-Fi combined positioning system which was performed by this laboratory. Experimental results of this paper are based on a real field test data of a GPS/QZSS/Wi-Fi combined positioning system and a simulation data of a wavelet denoising filter algorithm. At the end, the simulation result demonstrates its superiority by showing a 21.6% improved result in comparison to a conventional GPS system.

Ratio Optimization Between Sizes of Components of Heat Recovery Steam Generator in Combined Cycle Gas Turbine Power Plants (복합사이클 발전플랜트 폐열회수 보일러의 구성요소 크기비의 최적화)

  • In, Jong-Soo;Lee, Sang-Yong
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.33 no.6
    • /
    • pp.403-410
    • /
    • 2009
  • This paper proposes a new approach to find the optimum ratios between sizes of the heat exchangers of the heat recovery steam generator (HRSG) system with limited size to maximize the efficiency of the steam turbine (bottom) cycle of combined cycle power plants (CCPP), but without performing the bottom cycle analysis. This could be achieved by minimizing the unavailable exergy (the sum of the destroyed and the lost exergies) resulted from the heat transfer process of the HRSG system. The present approach is relatively simple and straightforward because the process of the trial-and-error method, typical in performing the bottom cycle analysis for the system optimization, could be avoided. To demonstrate the usefulness of the present method, a single-stage HRSG system was chosen and the optimum evaporation temperature was obtained corresponding to the condition of the maximum useful work. The results show that the optimum evaporation temperature based on the present exergy analysis appears similar to that based on the bottom cycle analysis. Also shown is the dependency of size (NTU) ratios between the heat exchangers on the inlet gas temperature, which is another important factor in determining the optimum condition once overall size of the heat recovery steam generator is given. The present approach turned out to be a useful tool for optimization of the singlestage HRSG systems and can easily be extended to multi-stage systems.

GA-BASED PID AND FUZZY LOGIC CONTROL FOR ACTIVE VEHICLE SUSPENSION SYSTEM

  • Feng, J.-Z.;Li, J.;Yu, F.
    • International Journal of Automotive Technology
    • /
    • v.4 no.4
    • /
    • pp.181-191
    • /
    • 2003
  • Since the nonlinearity and uncertainties which inherently exist in vehicle system need to be considered in active suspension control law design, this paper proposes a new control strategy for active vehicle suspension systems by using a combined control scheme, i.e., respectively using a genetic algorithm (GA) based self-tuning PID controller and a fuzzy logic controller in two loops. In the control scheme, the PID controller is used to minimize vehicle body vertical acceleration, the fuzzy logic controller is to minimize pitch acceleration and meanwhile to attenuate vehicle body vertical acceleration further by tuning weighting factors. In order to improve the adaptability to the changes of plant parameters, based on the defined objectives, a genetic algorithm is introduced to tune the parameters of PID controller, the scaling factors, the gain values and the membership functions of fuzzy logic controller on-line. Taking a four degree-of-freedom nonlinear vehicle model as example, the proposed control scheme is applied and the simulations are carried out in different road disturbance input conditions. Simulation results show that the present control scheme is very effective in reducing peak values of vehicle body accelerations, especially within the most sensitive frequency range of human response, and in attenuating the excessive dynamic tire load to enhance road holding performance. The stability and adaptability are also showed even when the system is subject to severe road conditions, such as a pothole, an obstacle or a step input. Compared with conventional passive suspensions and the active vehicle suspension systems by using, e.g., linear fuzzy logic control, the combined PID and fuzzy control without parameters self-tuning, the new proposed control system with GA-based self-learning ability can improve vehicle ride comfort performance significantly and offer better system robustness.

Measurement and Active Compensation for 3-DOF Motion Errors of an Air Bearing Stage with Magnetic Preloads (자기예압 공기베어링 스테이지의 3 자유도 운동오차 측정 및 능동 보정)

  • Ro, Seung-Kook;Kim, Soo-Hyun;Kwak, Yoon-Keun;Park, Chun-Hong
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.26 no.2
    • /
    • pp.109-117
    • /
    • 2009
  • This paper presents a linear air bearing stage with compensated motion errors by active control of preloads generated by magnetic actuators with combination of permanent and electromagnets. A 1-axis linear stage motorized with a linear motor with 240mm of travel range is built for verifying this design concept and tested its performances. The three motions of the table are controlled with four magnetic actuators driven by current amplifiers and a DSP based digital controller. Three motion errors were measured combined method with laser interferometer and two-probe method with $0.085{\mu}m$ of repeatability for straightness error. The measured motion errors were modeled as functions of the stage position, and compensation were carried out with feedforward control because the characteristics of the motion control with magnetic actuators are linear and independent for each degree-of-freedoms. As the results, the errors were reduced from $1.09{\mu}m$ to $0.11{\mu}m$ for the vertical motion, from 9.42 sec to 0.18 sec for the pitch motion and from 2.42 sec to 0.18 sec for roll motion.