• Land and Housing Review
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• v.1 no.1
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• pp.19-25
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• 2010

Thermal comfort provide satisfaction of thermal environment and affects productivity of occupants in residential building. However, temperature control can not provide the thermal comfort at all the time. because thermal comfort is influenced by many environmental variables such as temperature, relative humidity, air velocity, radiation temperature, activity level and clothing insulation. The purpose of this study is that predicted mean vote(PMV) index is used as control. And, Thermal comfort is evaluated both PMV control and temperature control by simulation. Each other cases were compared, in which set-point temperatures of $22^{\circ}C$ and $24^{\circ}C$ and, set-point PMV index through the respective heating season in the simulation. The results show that PMV control is better to maintain comfort state and save energy than temperature control.

• Journal of the Semiconductor & Display Technology
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• v.3 no.1
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• pp.21-26
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• 2004

Recently with the development of power switching device and DSP which has peripheral devices to control AC servo system, the servo technology has met a new development opportunity. Those things make it possible to reduce the time of developing a AC servo system. Fixed point DSP such as TMS320F240x, and TMS320F28x series have a disadvantage in calculating floating number where TMS320C32 or TMS320C31 are floating point DSP. However they usually become a complex hardware system to implement the AC servo system and it increases the cost. In this study, a DSP based AC servo system with a 3-phase PMSM is proposed. The newly produced DSP TMX320F28l2-version C which has the performance of fast speed, 150MIPS, and a rich peripheral interface such as a 12bit high speed AD converter, QEP(Quadrature Encoder Pulse) circuit, PDPINT(Power Drive Protect Interrupt), SVPWM module and dead time module are used. This paper presents a method to overcome fixed point calculating using scaling all parameters. Also space vector pulse width modulation (SVPWM) using off-set voltage and a digital PI control are implemented to the servo system.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.600-602
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• 1996

The purpose of this paper is to develop a new maximum power point tracking(MPPT) using fuzzy set theory for air conditioning system. Fuzzy algorithm based on linguistic rules describing the operator's control strategy is applied to control step-up chopper for MPPT. Fuzzy algorithm is applied to control boost MPPT converter by temperature compensation effect with 8 bit single chip 8051 microcontroller. In this paper, temperature compensation(Becom Transducer : pf-T type) range is $-40^{\circ}C{\sim}+100^{\circ}C$.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.334-339
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• 1994

In this work, we propose a planar three degree-of-freedom parallel mechanism as another type of assembly device which utilized joint compliances. These joint compliances can be adjusted either by properly replacing the joint compliances or by actively controlling stiffness at joints, in order to generate the desired operational compliance characteristics at RCC point, The operational compliance matrix for this mechanism is explicitly obtained by symbolic manipulation and its operational compliance characteristics are examined, it is found that the RCC point exists at the center of the workspace when the mechanism maintains symmetric configurations. Compliance characteristic and its sensitivity of this mechanism is analyzed with respect to the magnitude of the diagonal compliance components and two different matrix norms measuring compliance sensitivity. It is expected that the analysis results provide the designer with a helpful information to determine a set of optimal parameters of this RCC mechanism.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.9
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• pp.4355-4374
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• 2018

Crowd escape event detection has become one of the hottest problems in intelligent surveillance filed. When the 'escape event' occurs, pedestrians will escape in a disordered way with different velocities and directions. Based on these characteristics, this paper proposes a Direction-Collectiveness Model to detect escape event in crowd scenes. First, we extract a set of trajectories from video sequences by using generalized Kanade-Lucas-Tomasi key point tracker (gKLT). Second, a Direction-Collectiveness Model is built based on the randomness of velocity and orientation calculated from the trajectories to express the movement of the crowd. This model can describe the movement of the crowd adequately. To obtain a generalized crowd escape event detector, we adopt an adaptive threshold according to the Direction-Collectiveness index. Experiments conducted on two widely used datasets demonstrate that the proposed model can detect the escape events more effectively from dense crowd.

• Journal of the Ergonomics Society of Korea
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• v.6 no.2
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• pp.19-28
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• 1987

If an error occurs in the automatic mode when the advanced teleoperator system performs a task in hostile environment, then the mode changes into the manual mode. The operation by program and the operation by hyman recover the error in the manual mode. The system resumew the automatic mode and continues the given task. In order to utilize the inverse kinematics as means of the operation by program in the manual mode, Lee and Nagamachi determined the end point of the robot trajectory planning which varied with the height of the task object recognized by a T.V monitor, solved the end point by the fuzzy set theory, and controlled the position of the robot hand by the inverse kinematics and the posture of the robot hand by the operation by human. But the operation by human did take a lot of task time because the position and the posture of the robot hand were separately controlled. To reduce the task time by human, this paper developes an error recovery expert system (ERES). The position of the robot hand is controlled by the inverse kinematics of the cartesian coordinate system to the end point which is deter- mined by the fuzzy set theory. The posture of the robot hand is controlled by the modulality of the robot hand's motion which is made by the posture of the task object. The knowledge base and the inference engine of the ERES is developed using the muLISP-86 language. The experimental results show that the average task time by human the ERES which was performed by the integration of the position and the posture control of the robot hand is shorter than that of the research, done by the preliminary experiment, which was performed by the separation of the position and the posture control of the robot hand. A further study is likely to research into an even more intelligent robot system control usint a superimposed display and digitizer which can present two-dimensional coordinate of the work space for the convenience of human interaction.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.1
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• pp.55-64
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• 2023

Gas turbine engines are widely used as prime movers of generator and propulsion system in warships. This study addresses the problem of designing a DS-based PID controller for speed control of the LM-2500 gas turbine engine used for propulsion in warships. To this end, we first derive a dynamic model of the LM-2500 using actual sea trail data. Next, the PRC (process reaction curve) method is used to approximate the first-order plus time delay (FOPTD) model, and the DS-based PID controller design technique is proposed according to approximation of the time delay term. The proposed controller conducts set-point tracking simulation using MATLAB (2016b), and evaluates and compares the performance index with the existing control methods. As a result of simulation at each operating point, the proposed controller showed the smallest in %OS, which means that the rpm does not change rapidly. In addition, IAE and IAC were also the smallest, showing the best result in error performance and controller effort.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.1
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• pp.44-54
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• 2023

In this study, the second-order Nomoto's nonlinear expansion model was implemented as a Tagaki-Sugeno fuzzy model based on the heading angular velocity to design the automatic steering system of a ship considering nonlinear elements. A Tagaki-Sugeno fuzzy PID controller was designed using the applied fuzzy membership functions from the Tagaki-Sugeno fuzzy model. The linear models and fuzzy membership functions of each operating point of a given nonlinear expansion model were simultaneously tuned using a genetic algorithm. It was confirmed that the implemented Tagaki-Sugeno fuzzy model could accurately describe the given nonlinear expansion model through the Zig-Zag experiment. The optimal parameters of the sub-PID controller for each operating point of the Tagaki-Sugeno fuzzy model were searched using a genetic algorithm. The evaluation function for searching the optimal parameters considered the route extension due to course deviation and the resistance component of the ship by steering. By adding a penalty function to the evaluation function, the performance of the automatic steering system of the ship could be evaluated to track the set course without overshooting when changing the course. It was confirmed that the sub-PID controller for each operating point followed the set course to minimize the evaluation function without overshoot when changing the course. The outputs of the tuned sub-PID controllers were combined in a weighted average method using the membership functions of the Tagaki-Sugeno fuzzy model. The proposed Tagaki-Sugeno fuzzy PID controller was applied to the second-order Nomoto's nonlinear expansion model. As a result of examining the transient response characteristics for the set course change, it was confirmed that the set course tracking was satisfactorily performed.

• Proceedings of the Korean Reliability Society Conference
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• 2001.06a
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• pp.321-334
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• 2001

EPC seeks to minimize variability by transferring the output variable to a related process input(controllable) variable, while SPC seeks to reduce variability by detecting and eliminating assignable causes of variation. In the case of product control, a very reasonable objective is to try to minimize the variance of the output deviations from the target or set point. We compare three control systems; EPC, combined system with EWMA and EPC, and SPC. This paper shows through simulation that the performance of the integrated model of EPC and SPC is more preferable than that of EPC.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2004.03a
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• pp.224-227
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• 2004