• Journal of Bio-Environment Control
• /
• v.24 no.3
• /
• pp.135-146
• /
• 2015

To provide the data necessary to determine the design wind speed for calculating the wind load acting on a greenhouse, we measured the wind speed below 10m height and analyzed the power law exponents at Buan and Gunwi. A wind speed greater than $5m{\cdot}s^{-1}$ is appropriate for calculating the power law exponent necessary to determine the wind speed distribution function according to height. We observed that the wind speed increased according to a power law function with increased height at Buan, showing a similar trend to the RDC and JGHA standards. Therefore, this result should be applied when determining the power law function for calculating the design wind speed of the greenhouse structure. The ordinary trend is that if terrain roughness increases the value of power law exponent also increases, but in the case of Gunwi the value of power law exponent was 0.06, which shows contrary value than that of the ordinary trend. This contrary trend was due to the elevations difference of 2m between tower installed and surrounding area, which cause contraction in streamline. The power law exponent started to decrease at 7 am, stopped decreasing and started to increase at 3 pm, and stopped increasing and remained constant at 12 pm at Buan. These changes correspond to the general change trends of the power law exponent. The calculated value of the shape parameter for Buan was 1.51, confirming that the wind characteristics at Buan, a reclaimed area near the coast, were similar to those of coastal areas in Jeju.

• Journal of Institute of Control, Robotics and Systems
• /
• v.2 no.4
• /
• pp.279-286
• /
• 1996

In this paper, variable structure control(VSC) based on reaching law method with fuzzy inference for nonlinear systems is proposed. The reaching law means the reaching condition which forces an initial state of system to reach switching surface in finite time, and specifies the dynamics of a desired switching function. Since the conventional reaching law has fixed coefficients, the chattering can be existed largely in sliding mode. In the design of a proposed fuzzy reaching law, we fuzzify RP(representative point)'s orthogonal distance to switching surface and RP's distance the origin of the 2-dimensional space whose coordinates are the error and the error rate. The coefficients of the reaching law are varied appropriately by the fuzzy inference. Hence the state of system in reaching mode reaches fastly switching surface by the large values of reaching coefficients and the chattering is reduced in sliding mode by the small values of those. And the effectiveness of the proposed fuzzy reaching law method is showen by the simulation results of the control of a two link robot manipulator.

• East Asian Journal of Business Economics (EAJBE)
• /
• v.11 no.4
• /
• pp.41-50
• /
• 2023

Purpose - This study aims to examine the role of contract law in mergers and acquisitions (M&A) and to examine whether or not contract law is necessary in M&A. The study also discusses how contract law can be utilized in M&A, as well as some of the problems that arise from the use of contracts in this area. Research design, data, and methodology - To minimize bias and errors, this study used only peer-reviewed articles and book excluding internet news articles, conference papers, and dissertations. For a well-organized screen and selection process, the author conducted the extraction procedure thoroughly to eliminate some duplicated resources. Result: This study indicates that complex deals carry a high risk but also have the potential to yield substantial revenue for stakeholders. Thus, contract law is essential to the success of M&A because it helps to define the (1) terms of the transaction, (2) reduces risk, (3) offers legal safeguards, and ensures that the (4) agreement is enforced. Conclusion - This study concludes that an understanding of contract law is essential to the profitable merging of two businesses. The application of contract law provides a mechanism for enforcing the agreement, which can increase the likelihood that the stipulations of the M&A will be satisfied.

• 제어로봇시스템학회:학술대회논문집
• /
• 1988.10a
• /
• pp.164-168
• /
• 1988

This paper utilizes an optimal control law for the accurate tracking servo system design. The devivation of a simple control law implementing microprocessor is made to minimize position and speed error of the controller. The 16 bit microprocessor receives command angular position and calculate the control algorithm for accurate tracking and provides control system gain scheduling to achieve very short settling time. Simulation results and some experimental results of the position controlled tracking using 4.5Kw DC servo motor are shown.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.10 no.2
• /
• pp.53-60
• /
• 2007

This paper presents a robust nonlinear autopilot design method based on dynamic inversion and PI(Proportional-Integral) control law. The new controller structure which is different from previous work is composed of classical linear PI control law and nonlinear fast dynamic inversion. A pitch axis model of highly maneuverable missiles and a linearized model for designing Pl controller are presented. The performance of proposed method is illustrated via nonlinear simulations including aerodynamic uncertainties and actuator dynamics.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.3 no.1
• /
• pp.93-99
• /
• 2003

One of the methods to simplify the design process for a fuzzy logic controller (FLC) is to reduce the number of variables representing the rule antecedent. This in turn decreases the number of control rules, membership functions, and scaling factors. For this purpose, we designed a single-input FLC that uses a sole fuzzy input variable. However, it is still deficient in the capability of adapting some varying operating conditions although it provides a simple method for the design of FLC's. We here design two simple-structured adaptive fuzzy logic controllers (SAFLC's) using the concept of the single-input FLC. Linguistic fuzzy control rules are directly incorporated into the controller by a fuzzy basis function. Thus some parameters of the membership functions characterizing the linguistic terms of the fuzzy control rules can be adjusted by an adaptive law. In our controllers, center values of fuzzy sets are directly adjusted by an adaptive law. Two SAFLC's are designed. One of them uses a Hurwitz error dynamics and the other a switching function of the sliding mode control (SMC). We also prove that 1） their closed-loop systems are globally stable in the sense that all signals involved are bounded and 2） their tracking errors converge to zero asymptotically. We perform computer simulations using a nonlinear plant.

• Steel and Composite Structures
• /
• v.51 no.4
• /
• pp.363-375
• /
• 2024

Within the optimization field, addressing the intricate posed by fluidic pressure loads on functionally graded structures with frequency-related designs is a kind of complex design challenges. This paper thus introduces an innovative density-based topology optimization strategy for frequency-constraint functionally graded structures incorporating Darcy's law and a drainage term. It ensures consistent treatment of design-dependent fluidic pressure loads to frequency-related structures that dynamically adjust their direction and location throughout the design evolution. The porosity of each finite element, coupled with its drainage term, is intricately linked to its density variable through a Heaviside function, ensuring a seamless transition between solid and void phases. A design-specific pressure field is established by employing Darcy's law, and the associated partial differential equation is solved using finite element analysis. Subsequently, this pressure field is utilized to ascertain consistent nodal loads, enabling an efficient evaluation of load sensitivities through the adjoint-variable method. Moreover, this novel approach incorporates load-dependent structures, frequency constraints, functionally graded material models, and polygonal meshes, expanding its applicability and flexibility to a broader range of engineering scenarios. The proposed methodology's effectiveness and robustness are demonstrated through numerical examples, including fluidic pressure-loaded frequency-constraint structures undergoing small deformations, where compliance is minimized for structures optimized within specified resource constraints.

• Journal of Institute of Control, Robotics and Systems
• /
• v.13 no.1
• /
• pp.6-14
• /
• 2007

Modem version of supersonic jet fighter aircraft must have been guaranteed appropriate controllability and stability in HAoA(High Angle of Attack). Limit value of aircraft entering into the departure in HAoA is related to aircraft configuration design. But, the control law such as AoA and yaw-rate limiter is implemented in digital Fly-By-Wire flight control system of supersonic jet fighter to guarantee the aircraft's safety in HAoA. The HAoA flight control law have two parts, one is control law of departure prevention and the other is control law of departure recovery support. The control laws of departure prevention for advanced jet trainer consist AoA limiter, roll command limiter and rudder fader. The control laws of departure recovery support are consist yaw-rate limiter and MPO(Manual Pitch Override) mode. The guideline of pitch rocking using MPO mode is simple, but operating skill of pitch rocking is very difficult by the pilot with inexperience of departure situation. This paper addresses the design and validation of APR(Automatic Pitch Rocker) control law instead of MPO in order to automatic recovery without manual pitch rocking by the pilot. And, recovery characteristic with APR verifies by the nonlinear analysis and pilot evaluation.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.2560-2565
• /
• 2003

The paper presented here covers the work associated with the flight control law design, ground based and in flight simulation and handling qualities assessment of the Fly-by-Wire type Aircraft (FBWA). The control law was designed for the most unstable aircraft configuration flight regime for the target aircraft (FBWA). The ground based simulation including math-model, real-time pilot-in-the-loop and iron bird simulation were used for validation of the control law before the experimental in-flight simulation on the IFS (In.Flight-Simulator) aircraft. The flight tests results showed that Level 1 handling qualities for the most unstable flight regime were achieved.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.34
• /
• pp.3-26
• /
• 2007

Product liability law lies at the center of the modem world. This law concerns liability for damages arising from the commercial sale of a product that causes personal injury or property damage because it was defective or falsely represented. One engaged in the business of selling or otherwise distributing products who sells or distributes a defective product is subject to liability for harm to persons or property caused by the defect. In short, product defectiveness is the heart of products liability law. Regardless of the underlying cause of action, the plaintiff in nearly every products liability case must prove that the defendant's product contained an unnecessary hazard that caused the harm. The purpose of this paper is to clarify the meaning of the product defectiveness to products liability claims in China. In China, Product to include most movable personal property, but to exclude services. And a product is defective when, at the time of sale or distribution, it contains a manufacturing defect, is defective in design, or is defective because of inadequate instructions or warnings.