• Journal of applied mathematics & informatics
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• v.29 no.1_2
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• pp.279-292
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• 2011

In this paper, we consider anti-periodic solutions of the following BAM neural networks with multiple delays on time scales: $$\{{x^\Delta_i(t)=-a_i(t)e_i(x_i(t))+{\sum\limits^m_{j=1}}c_{ji}(t)f_j(y_j(t-{\tau}_{ji}))+I_i(t),\atop y^\Delta_j(t)=-b_j(t)h_j(y_j(t))+{\sum\limits^n_{i=1}}d_{ij}(t)g_i(x_i(t-{\delta}_{ij}))+J_j(t),}\$$ where i = 1, 2, ..., n,j = 1, 2, ..., m. Using some analysis skills and Lyapunov method, some sufficient conditions on the existence and exponential stability of the anti-periodic solution to the above system are established.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.10
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• pp.923-935
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• 2007

In general, deflection limit criteria of bridge design specifications would have been considered based on the static serviceability and structural stability. Dynamic serviceability induced from bridge vibration, as a comfort limit, actually has not been included in the criteria. Thus, it is necessary for dynamic serviceability to be considered in bridge vibration problems and for comfort limit on vibration to be needed for evaluating dynamic serviceability of bridges. In this paper, comfort limits of bridge structures considering the time duration exposed by vibration were examined with frequency and time dependent comfort limits, and they were evaluated by using the vibration signals measured from the existing bridges. Therefore, it is resulted that the time-dependent comfort limit considering the duration of vibration is an efficient estimate for evaluating dynamic serviceability of bridges.

• Journal of the korean Society of Automotive Engineers
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• v.2 no.1
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• pp.32-38
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• 1980

In the case of a automobile marking skid on road for a period of braking, in general, the automobile velocity just before rapid braking can be obtained by evaluating the coefficient of friction between tires and road. Up to now, the coefficient of friction has been derived from mean velocity measured by a time watch, but the automobile velocity obtained in this manner would be deviated from actual value considerably, due to errors arising from not only measuring time but other various factors. In this paper the presumption method of automobile velocity by accelerometer is presented so as to improve the accuracy of measurement, and to determine the velocity readily. The results obtained in this experiment show that the frictional coefficients between tires and road under the given experimental conditions are considered to take linear relation over the fixed velocity limits 30km/h to 50km/h while for the same limits of velocities the coefficients of friction by the time watch method are not valid ar low velocity range. It will be seen that the former is simple and reliable whilst the latter is cumbersome and unreliable.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.71
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• pp.37-58
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• 2016

CISG Article 50 contains the remedy of price reduction but limits it if the seller has a right to cure. Reduction of price presupposes that the seller delivers non-conforming goods, and that the buyer decides to accept them nevertheless. The remedy of price reduction differs from all other remedies provided in CISG with regard to it effects and to the time-limits. As to the time-limits, unlike Articles 46 and 49, Article 50 does not contain the element within a reasonable time. CISG imposes no period of time for his reducing the price. The buyer's right to declare a reduction of the price is expressly subject to the seller's right to remedy any failure to perform his obligations pursuant to Articles 37 and 48. The problem lies in determining from where to take the figures for comparing the value of the goods contracted and of those delivered. The price level in this place will usually determine his considerations as to resale or repair of the defective goods. The buyer must examine the goods, or cause them to be examined, within, as short a period as is practicable in the circumstances. The buyer loses the right to rely on a lack of conformity of the goods if he does not give notice to the seller specifying the nature of the lack of conformity within a reasonable time after he has discovered it or ought to have discovered it.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.61
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• pp.33-39
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• 2000

In this paper, we present an algorithm for the multicast routing problem when there exit the cell replication limits of ATM switching nodes. This problem can be formulated as a Degree Constrained Minimum Steiner Tree Problem(DCSP). The proposed algorithm is a modification of the shortest path heuristic originally devised for minimum Steiner tree problem. From the experimental results, it can be seen that our algorithm is efficient to obtain a near optimal solution with comparatively low computational time.

• KCI Concrete Journal
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• v.11 no.3
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• pp.45-52
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• 1999

A Computer-based iterative method is provided for the calculation of minimum thickness values for one-way slabs to satisfy the maximum permissible limits given in the ACI Building Code. An algorithm includes the effects of cracking and time-dependent effects due to creep and shrinkage. Comparison of the calculated minimum thickness values with the current ACI limits is conducted to investigate limitations of the current tabulated minimum thickness. which are constant to a range of design conditions.

• Journal of Mechanical Science and Technology
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• v.20 no.12
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• pp.2061-2078
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• 2006

The main purpose of this paper is to establish the high temperature structural integrity evaluating procedures for the next generation reactors, which are to be operated at over 500$^{\circ}C$ and for 60 years. To do this, comparison studies of the high temperature structural design codes and assessment procedures such as the ASME-NH (USA), RCC-MR (France), DDS (Japan), and R5 (UK) are carried out in view of the accumulated inelastic strain and the creep-fatigue damage evaluations. Also the application procedures of the ASME-NH rules with the actual thermal and structural analysis results are described in detail. To overcome the complexity and the engineering costs arising from a real application of the ASME-NH rules by hand, all the procedures established in this study such as the time-dependent primary stress limits, total accumulated creep ratcheting strain limits, and the creep-fatigue damage limits are computerized and implemented into the SIE ASME-NH program. Using this program, the selected high temperature structures subjected to two cycle types are evaluated and the parametric studies for the effects of the time step size, primary load, number of cycles, normal temperature for the creep damage evaluations and the effects of the load history on the creep ratcheting strain calculations are investigated.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.6
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• pp.540-546
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• 2013

This paper presents a trajectory planning algorithm for TMR (Two-wheeled Mobile Robots). The trajectory is developed in joint space and considers the physical limits of a TMR. First, we present a process for generating a smooth curve through a Bezier curve. The trajectory for the center of the TMR following the Bezier curve is developed through a convolution operator taking into consideration its physical limits. The trajectory along the Bezier curve is regenerated using time-dependent parameters which correspond to the distance driven by the velocity of the center of the TMR in a sampling time. The velocity commands in the Cartesian space are converted to actuator commands for two wheels. In case that the actuator commands exceed the maximum velocity, the trajectory is redeveloped with compensated center velocity. We also suggest a smooth trajectory planning algorithm in joint space for the two segmented paths. Finally, the effectiveness of the algorithm is shown through numerical examples and application to a simulator.

• Journal of Korean Institute of Industrial Engineers
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• v.40 no.1
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• pp.43-51
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• 2014

Statistical process control (SPC) is an important technique for monitoring and managing the manufacturing process. In spite of its easiness and effectiveness, some problematic sides of application exist such that the SPC techniques are hardly reflect the changes of the process conditions. Especially, update of control limits at the right time plays an important role in acquiring a reasonable performance of control charts. Therefore, we propose the control chart performance evaluation index (CPEI) based on count data model to monitor and manage the performance of control charts. The CPEI could indicate the degree of control chart performance and be helpful to detect the proper update cycle of control limits in real time. Experiments using real manufacturing data show that the proper update intervals are made by proposed method.

• Korean Journal of Hazardous Materials
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• v.6 no.2
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• pp.23-29
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• 2018

The fire and explosion properties necessary for waste, safe storage, transport, process design and operation of handling flammable substances are lower explosion limits(LEL), upper explosion limits(UEL), flash point, AIT( minimum autoignition temperature or spontaneous ignition temperature), fire point etc., An accurate knowledge of the combustion properties is important in developing appropriate prevention and control measures fire and explosion protection in chemical plants. In order to know the accuracy of data in MSDSs(material safety data sheets), the flash point of phenol was measured by Setaflash, Pensky-Martens, Tag, and Cleveland testers. And the AIT of phenol was measured by ASTM 659E apparatus. The explosion limits of phenol was investigated in the reference data. The flash point of phenol by using Setaflash and Pensky-Martens closed-cup testers were experimented at $75^{\circ}C$ and $81^{\circ}C$, respectively. The flash points of phenol by Tag and Cleveland open cup testers were experimented at $82^{\circ}C$ and $89^{\circ}C$, respectively. The AIT of phenol was experimented at $589^{\circ}C$. The LEL and UEL calculated by using Setaflash lower and upper flash point value were calculated as 1.36vol% and 8.67vol%, respectively. By using the relationship between the spontaneous ignition temperature and the ignition delay time proposed, it is possible to predict the ignition delay time at different temperatures in the handling process of phenol.