• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.60 no.4
• /
• pp.241-245
• /
• 2011

In this paper, when photovoltaic (PV) systems are connected to power distribution system, most effective capacity and connected-point of PV system are presented considering power distribution system reliability. The reliability model of PV system is presented considering the duration of sunshine. Also the model of time-varying load and reliability test system bus2 model are used. To simulate the effects of PV system, various cases are selected; (1) base case which is no connection of PV system to power distribution system when faults are occurred, (2) 3MW case which is 3[MW] connection of PV system (3) 4[MW] case, and (4) 20[MW] case which is 20[MW] connection of PV system to the bus of power distribution system. The capacity limit of connected PV system is settled to 14[MW] for all cases except case 4. The reliability for residential, general, industrial, and educational customer is evaluated.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.13 no.2
• /
• pp.34-41
• /
• 2014

The purpose of this study is to present the improvement of connection system between traffic information centers for reliable traffic information service. We recognized traffic information error caused by too much time in conjunction between traffic information centers, lack of reliability of traffic information caused by absence of generation time and generation institution of traffic information. We presented minimization methods of connection time, improvement methods of reliability of traffic information and development methods of connection state management system.

• Steel and Composite Structures
• /
• v.37 no.2
• /
• pp.151-173
• /
• 2020

This paper aims to probabilistically evaluate performance of two types of I beam to box column (IBBC) connection. With the objective of considering the variability of seismic loading demand, statistical features of the inter-story drift ratio corresponding to the second, fifth and eleventh story of a 12-story steel special moment resisting frames are extracted through incremental dynamic analysis at global collapse state. Variability of geometrical variables and material strength are also taken into account. All of these random variables are exported as inputs to a probabilistic finite element model which simulates the connection. At the end, cumulative distribution functions of local seismic demand for each component of each connection are provided using histogram sampling. Through a parametric study on probabilistic local seismic demand, the influence of some geometrical random variables on the performance of IBBC connections is demonstrated. Furthermore, the probabilistic study revealed that IBBC connection with widened flange has a better performance than the un-widened flange. Also, a design procedure is proposed for WF connections to achieve a same connection performance in different stories.

• Journal of Korean Society of Water and Wastewater
• /
• v.26 no.2
• /
• pp.249-256
• /
• 2012

The paper describes a design methodology that can select a proper reliability factor and apply the selected reliability factor into the real water distribution system. Reliability factors which are used for the assesment of water supply networks, can be categorized by a connectivity, a reachability, an expected shortage and an availability. Among these factors, an expected shortage is the most proper reliability factor in the aspect of economic evaluation. Therefore, the expected shortage is applied to draw a water supply reliability into Changwon water supply systems. And the economic pipe diameter can be determined as 600mm for a connection pipe in the pipe network from the estimation of the expected shortage. Also, a quantitative effect of the connection pipe can be expressed in terms of the reduction, which is estimated by the expected shortage of 30,269$m^{3}$ from 68,705$m^{3}$ at initial condition to 38,436$m^{3}$ under the connected condition with the diameter 600mm pipe.

• Journal of the Korean Society of Safety
• /
• v.34 no.1
• /
• pp.53-61
• /
• 2019

This study performs reliability analysis of three-dimensional temporary shoring structures with three different models. The first model represents a field model which does not have diagonal bracing members. The installation of bracing members is often neglected in the field for convenience. The second model corresponds to a design model which has the bracing members with the hinge connection of horizontal and bracing members at joints. The third model is similar to the second model but the hinge connection is replaced with partial rotational stiffness. The reliability analysis results revealed that the vertical members of the three models are safe enough in terms of axial force, but the vertical and horizontal members exhibit a big difference among the three models in terms of combination stress of axial force and bi-axial bending moments. The field model showed significant increase in failure probability for the horizontal member, and thus the results demonstrate that the bracing member should be installed necessarily for the safety of the temporary shoring structures.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.64 no.5
• /
• pp.67-77
• /
• 2022

Recently, the trend in structural analysis and design is moving towards the development of reliable system. The reliability-based method defines various limit states related to usability and failure, thereby enabling multiple levels of design according to the importance of a structure. Meanwhile, an actual structure is composed of a set of several elements, and particularly, a frame type is composed of a system in which the members are connected each other. At this time, the actual connection between members is in a semi-rigid condition, not in complete rigid or hinged. This semi-rigid is found in several structures, especially in agricultural facilities designed with lightweight materials. In this study, a system reliability analysis technique for frame structure was established, and applied to an analysis of the semi-rigid connection. Various conditions of correlation were applied to reflect the connectivity between members, and through this, the limitations of existing structural analysis method and the behavioral characteristics of structure were analyzed. The failure probability of the frame member component and the overall structure system was significantly different in consideration of the semi-rigid connection. In addition, it was evaluated that the behavior of structure can be more accurately analyzed if the correlation according to the position of members in a system is further investigated.

• Structural Engineering and Mechanics
• /
• v.54 no.1
• /
• pp.149-168
• /
• 2015

In the bolted connections, bolt placements are generally described and are generally made in the direction of design effects and in the perpendicular direction to design effects. In these both directions, the reliability of the distance of bolts to the edges of connection plate and the distance of bolts to each other is investigated for high strength steel connections built up with high strength bolts in this study. For this purpose, simple SL (bearing type shear connection) and SLP (bearing type shear connection for body-fit bolts) type steel connections with St 52 grade steel plates with 8 different thicknesses and with 8.8D grade high strength bolts (HV) were constituted and analyzed under H (Dead Loads+Live Loads+Snow Loads+Roof Loads) and HZ (H Loads+Wind Loads+Earthquake Loads) loadings. Geometric properties, material properties and design actions were taken as random variables. Monte Carlo Simulation method was used to compute failure risk and the first order second moment method was used to determine the reliability indexes of those different distances describing the placement of bolts. Results obtained from computations have been presented in graphics and in a Table. Then, they were compared with some values proposed by some structural codes. Finally, new equations were constituted for minimum and maximum values of distances describing bolt placement by regression analyses performed on those results.

• Journal of the Korea Society for Simulation
• /
• v.29 no.1
• /
• pp.31-38
• /
• 2020

Mission reliability is defined by the probability of accomplishing the requirements task that were targeted in product development, and in the case of combat systems, mission reliability is an important factor that will determine victory or defeat, unlike commercial equipment. The mission reliability of the existing domestic combat system was calculated by considering only the physical connections of the equipment involved in the mission performance, but as the equipment becomes increasingly sophisticated and complex, it is impossible to determine the mission relevance solely by physical connection. Thus, in this paper, improved mission reliability was calculated using SysML, the system design modeling language, by taking into account the functional connection as well as physical connection. Based on this research, we look forward that the mission reliability of the combat system that will be developed in the future will be used as a verification material.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2008.04a
• /
• pp.108-111
• /
• 2008

Emergency lantern is an escape equipment of fire fighting. This equipment of obligation installation in buildings. But, We cast doubt on this equipment's reliability. Therefor we have need to study of this equipment's reliability. This paper research general emergency lantern for up grade reliability. For connection to fire alarm system, alarm for get lost general emergency lantern, and pilot lamp for interruption of electric power, and charge to rechargeable battery in general emergency lantern from fire alarm system. Then view very good result in reliability.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.5 no.4
• /
• pp.177-184
• /
• 2001

In this study, three most distinct types of general rigid connections are included in the modelling, with is implemented into a computer code. The cost, functions of connections are constructed by using the estimated unit cost of bolting, welding and connection-steel elements incorporating all the effect of materials, labor, and fabrication work. Bused on the recent developments of the reliability-based structural analysis and design as well as the extending knowledge on the probabilistic characteristics of load and resistances, the probability based design criteria have been successfully developed for many standards. Since the probabilistic characteristics depend highly on the local load and resistances, it is recognized to develop the design criterion compatible with domestic requirements. The existing optimum design methods, which are generally based on the structural theory and certain engineering experience, do not realistically consider the uncertainties of load and resistances and the basic reliability concepts.