• Title/Summary/Keyword: AT Command

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Correction of the delay faults of command reception in satellite command processor (위성용 명령 처리기의 명령 입수 지연 오류 정정)

  • Koo, Cheol-Hea;Choi, Jae-Dong
    • Proceedings of the KIEE Conference
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    • 2005.05a
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    • pp.194-196
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    • 2005
  • The command processor in satellite handles the capability of the process of command transmitted from ground station and deliver the processed data to on board computer in satellite. The command processor is consisted of redundant box to increase the reliability and availability of the capability. At each command processor, the processing time of each command processor is different, so the mismatch of processing time makes it difficult to timely synchronize the reception to on board computer and even will be became worse under the command processor's fault. To minimize the tine loss induced by the command processor's fault on board computer must analyze the time distribution of command propagation. This paper presents the logic of minimizing the delay error of command propagation the logic of analyzing the output of command processor.

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The Clinical and Prognostic Significance of Command Hallucinations in Schizophrenic Patients (정신분열병 환자에서 명령환각의 임상적 및 예후적 의의)

  • Yun, Kyu-Wol
    • Korean Journal of Psychosomatic Medicine
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    • v.5 no.1
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    • pp.82-88
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    • 1997
  • Background : Patients with command hallucinations are commonly assumed to be at high risk for dangerous behavior. However the issue of whether command hallucinations hold any clinical relevance in schizophrenic patients has not been established. Method : The author analyzed the clinical and research records of schizophrenic patients with auditory hallucinations who participated in outpatient research follow-up for 9 months after discharge. Patients with auditory hallucinations were classified as experiencing or not experiencing command hallucinations based on clinical psychiatric assessment. Results : Of 63 patients with auditory hallucinations, 29(46%) reported the command hallucinations and these hallucinations often were violent in content(44.8%). Patients with command hallucinations were not significantly different from patients without command hallucinations on sociodemographic and clinical characteristics, and clinical or prognostic course variables, but patients with command hallucinations had significantly more short hospitalizations(less than one month) than patients without command hallucinations. 3 of the patients with command hallucinations who committed suicide during the follow up periods were died. Conclusion : Command hallucinations may be frequent, and in most cases they have minimal influence on the outcome of schizophrenia, but if the patients with command hallucinations have a history of suicide attempts before admission, the possibility of suicide attempts by command hallucinations should be considered.

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A Study on the Necessity of Mission Command in Navy Through the Study of Naval Battle Comparison - Focus on Battle of St. Vincent and Battle of Jutland - (해전 비교연구를 통한 해군의 임무형 지휘 필요성에 관한 연구 - 세인트 빈센트 곶 해전과 유틀란트 해전을 중심으로 -)

  • Cho, Seon-Gjin;Jeon, Yoon-Jae
    • Strategy21
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    • s.46
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    • pp.205-238
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    • 2020
  • The origin of mission command can be traced to the era of the Prussian military reforms led by General Gerhard von Scharnhorst after defeats in battle of Jena and Auerstadt in 1806 against Napoleon I. Mission Command is the conduct of military operations through decentralized execution based upon mission-type orders. Commanders issue mission-type orders focused on the purpose of the operation rather than details of how to perform assigned tasks. The mission command has become the command philosophy of the German military and recently many countries in the west accept it as a command philosophy. This study compare and analyze the Battle of St. Vincent and the Battle of Jutland to make sure if the army-initiated mission commands were also useful for the navy. From the late 18th century, represented by the era of Nelson, Royal navy changed from the inherited rigid command culture to guaranteeing the disciplined initiative of its subordinate commanders. In the Battle of St. Vincent in 1797, Nelson acted contrary to the commander's orders at the crucial moment, which gave Britain a decisive victory. On the contrary more than 100 years later, the command culture of the Royal navy changed into a centralized command culture. In the Battle of Jutland in 1916, Royal Navy couldn't win because the rigid command culture did not guarantee initiative of subordinate commanders and subordinate commander's passive attitude of waiting for the commander's instructions even at critical moments. Therefore, a mission command that guarantees the initiative of subordinate commanders is a useful concept even in the navy because it makes subordinate commanders to take full advantage of a sudden change in battle. Today's advanced information and communication technologies have raised questions about mission command. But even advanced technology can't completely eliminate the fundamental nature of the war-the fog of war. War is chaotic and unpredictable. In the flood of lots of informations, senior commander's judgement is not always right because he(she) is also human, he(she) can make mistakes. In the age of informatization, mission command is still effective because it involves increasing interaction and synergy between senior and subordinate commanders by ensuring their independence. Therefore ROK navy also needs to activate mission command. ROK navy must dismantle the zero-defect mentality and apply from educations as Prussian did to establish a mission command culture.

LOS Moving Algorithm Design of Electro-Optical Targeting Pod for Joystick Command (조이스틱 명령에 따른 Electro-Optical Targeting Pod의 LOS 이동 알고리즘 설계)

  • Seo, Hyoungkyu;Park, Jaeyoung;Ahn, Jung-Hun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.10
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    • pp.1395-1400
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    • 2018
  • EO TGP(Electro-Optical Targeting Pod) is an optical tracking system which has various functions such as target tracking and image stabilization and LOS(Line of Sight) change. Especially, it is very important to move the LOS into a interest point for joystick command. When pilot move joystick in order to observe different scene, EO TGP gimbals should be operated properly. Generally, most EOTS just operate corresponding gimbal for joystick command. For example, if pilot input horizontal command in order to observe right hand screen, it just drive azimuth gimbal at any position. But in the screen, the image dosen't move in a horizontal direction because gimbal structure is Euler angle. And image rotation is occurred by elevation gimbal angle. So we need to move Pitch gimbal. So in the paper, we designed LOS moving algorithm which convert LOS command to gimbal velocity command to move LOS properly. We modeled a differential kinematic equation and then change the joystick command into velocity command of gimbals. This algorithm generate velocity command of each gimbal for same horizontal direction command. Finally, we verified performance through MATLAB/Simulink.

The Application of Mission Command for the Korea Coast Guard (임무형 지휘의 해양경찰 적용에 관한 연구)

  • Moon, Joong-Sik;Cho, Jun-Eok
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.5
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    • pp.444-453
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    • 2016
  • In this study, I suggested 'Mission command' as the on-scene commander's leadership intended to save people's lives quickly and safely when occured marine accident. First, I considered the concepts and limitations, efforts to introduce and settle the mission command, discussed why the introduction of mission command for Korea Coast Guard, the scope and specific way when applied. Korea Coast Guard must apply the Mission command as the on-scene commander's leadership to achieve efficient rescue work at the scene of an accident, even for incidents that can-not be foreseen. However, mission command cannot be established overnight: long-term, systematic efforts to stably develop mission command at the organizational level are required. We will strive to apply mission command across all aspects of the system, including education, training, personnel, and procedures, equipping each component with the basic requirements for mission command.

Water Solubilities and Vapor Pressures of Chlorothalonil and Command (농약 Chlorothalonil 과 Command 의 수용성 및 증기압)

  • Kim, Kyun;Kim, Yong-Bae;Kim, Yong-Hwa;Roh, Jung-Koo
    • Korean Journal of Environmental Agriculture
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    • v.6 no.2
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    • pp.84-93
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    • 1987
  • The water solubilities and vapor pressures of chlorothalonil and Command were measured following the guidelines of the U.S. EPA and OECD. Water solubility of the two compounds is consistent with respective values in the literature. However, the vapor pressures of Chlorothalonil and Command were 5,000 times$(2{\times}10^{-7}\;torr\;at\;25^{\circ}C)$ and 100 times$(<1{\times}10^{-6}\;torr\;at\;45^{\circ}C)$ lower than the literature values, respectively. Courteous use of the vapor pressure values in the handbooks is suggested. With this study, experimental difficulties involved were recognized. Based on the low vapor pressure of Command, the cause of the accidental bleach of non-target plants in the United States might not be attributed to the volatilization of Command, but to the drift during the application of the herbicide. These approaches will be utilized to predict the environmental fate of new chemicals under development, to screen the potential environmental pollutants among chemicals already in use, and to assess measures to minimize the hazards.

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Dynamic Control Allocation for Shaping Spacecraft Attitude Control Command

  • Choi, Yoon-Hyuk;Bang, Hyo-Choong
    • International Journal of Aeronautical and Space Sciences
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    • v.8 no.1
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    • pp.10-20
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    • 2007
  • For spacecraft attitude control, reaction wheel (RW) steering laws with more than three wheels for three-axis attitude control can be derived by using a control allocation (CA) approach.1-2 The CA technique deals with a problem of distributing a given control demand to available sets of actuators.3-4 There are many references for CA with applications to aerospace systems. For spacecraft, the control torque command for three body-fixed reference frames can be constructed by a combination of multiple wheels, usually four-wheel pyramid sets. Multi-wheel configurations can be exploited to satisfy a body-axis control torque requirement while satisfying objectives such as minimum control energy.1-2 In general, the reaction wheel steering laws determine required torque command for each wheel in the form of matrix pseudo-inverse. In general, the attitude control command is generated in the form of a feedback control. The spacecraft body angular rate measured by gyros is used to estimate angular displacement also.⁵ Combination of the body angular rate and attitude parameters such as quaternion and MRPs(Modified Rodrigues Parameters) is typically used in synthesizing the control command which should be produced by RWs.¹ The attitude sensor signals are usually corrupted by noise; gyros tend to contain errors such as drift and random noise. The attitude determination system can estimate such errors, and provide best true signals for feedback control.⁶ Even if the attitude determination system, for instance, sophisticated algorithm such as the EKF(Extended Kalman Filter) algorithm⁶, can eliminate the errors efficiently, it is quite probable that the control command still contains noise sources. The noise and/or other high frequency components in the control command would cause the wheel speed to change in an undesirable manner. The closed-loop system, governed by the feedback control law, is also directly affected by the noise due to imperfect sensor characteristics. The noise components in the sensor signal should be mitigated so that the control command is isolated from the noise effect. This can be done by adding a filter to the sensor output or preventing rapid change in the control command. Dynamic control allocation(DCA), recently studied by Härkegård, is to distribute the control command in the sense of dynamics⁴: the allocation is made over a certain time interval, not a fixed time instant. The dynamic behavior of the control command is taken into account in the course of distributing the control command. Not only the control command requirement, but also variation of the control command over a sampling interval is included in the performance criterion to be optimized. The result is a control command in the form of a finite difference equation over the given time interval.⁴ It results in a filter dynamics by taking the previous control command into account for the synthesis of current control command. Stability of the proposed dynamic control allocation (CA) approach was proved to ensure the control command is bounded at the steady-state. In this study, we extended the results presented in Ref. 4 by adding a two-step dynamic CA term in deriving the control allocation law. Also, the strict equality constraint, between the virtual and actual control inputs, is relaxed in order to construct control command with a smooth profile. The proposed DCA technique is applied to a spacecraft attitude control problem. The sensor noise and/or irregular signals, which are existent in most of spacecraft attitude sensors, can be handled effectively by the proposed approach.

Conceptual Design of the Artificial Intelligence based Tactical Command Decision Support System using the Functional Analysis Method (기능분석법을 이용한 인공지능 기반 전술제대 지휘결심지원체계의 개념설계)

  • Choi, Keun Ha
    • Journal of the Korea Institute of Military Science and Technology
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    • v.23 no.6
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    • pp.650-658
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    • 2020
  • The research of the AI-based command decision support system was insufficient both quantitatively and qualitatively. In particular, in Korea, there was no research on concrete concept design at the current concept research level. This paper proposed the conceptual design of a tactical echelon command decision support system based on artificial intelligence(AI) according to the current army's doctrine of the operation process. The suggested conceptual design clarified the problem and proposed an appropriate process for design, and applied the function analysis method among rational techniques that enable conceptual design systematically.

Payload-Swing Suppression of a Container Crane: Comparison Between Command Shaping Control and Optimal Control

  • Do, Huh-Chang;Shik, Hong-Keum
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.54.2-54
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    • 2001
  • In this paper two control strategies, command shaping control and optimal control, which aim to the reduction of the residual vibrations of the payload in a container crane system are investigated. Both control methods are open loop control. Due to unmodeled dynamics of the plant and disturbances like initial sway and wind, some residual sway always exists at the end of trolley movement. Command inputs are designed to achieve the control objectives including minimal residual vibration and robustness in the presence of unmodeled dynamics. Simulation results of various command inputs are compared in terms of arrival time, residual sway angle, robustness, and maximum sway distance during the traveling. Command shaping method provides a more competent tool than optimal control.

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Icefex: Protocol Format Extraction from IL-based Concolic Execution

  • Pan, Fan;Wu, Li-Fa;Hong, Zheng;Li, Hua-Bo;Lai, Hai-Guang;Zheng, Chen-Hui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.7 no.3
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    • pp.576-599
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    • 2013
  • Protocol reverse engineering is useful for many security applications, including intelligent fuzzing, intrusion detection and fingerprint generation. Since manual reverse engineering is a time-consuming and tedious process, a number of automatic techniques have been proposed. However, the accuracy of these techniques is limited due to the complexity of binary instructions, and the derived formats have missed constraints that are critical for security applications. In this paper, we propose a new approach for protocol format extraction. Our approach reasons about only the evaluation behavior of a program on the input message from concolic execution, and enables field identification and constraint inference with high accuracy. Moreover, it performs binary analysis with low complexity by reducing modern instruction sets to BIL, a small, well-specified and architecture-independent language. We have implemented our approach into a system called Icefex and evaluated it over real-world implementations of DNS, eDonkey, FTP, HTTP and McAfee ePO protocols. Experimental results show that our approach is more accurate and effective at extracting protocol formats than other approaches.