• Journal of the Korean Society of Industry Convergence
• /
• v.25 no.3
• /
• pp.477-491
• /
• 2022

This study proposed the performance analysis and hydraulic control system design of forklift structure manipulator with 5 joints for untact working in lilited environment. The performance analysis of the control system analyzed the control response to load and pressure fluctuations. The reliability of proposed control system was verified by simulation test under the various condition.

• International Journal of Internet, Broadcasting and Communication
• /
• v.14 no.3
• /
• pp.8-16
• /
• 2022

In this paper, we propose a method of reconstructing the file system to obtain digital forensics information from the APFS file system when meta information that can know the structure of the file system is deleted due to partial damage to the disk. This method is to reconstruct the tree structure of the file system by only retrieving the B-tree node where file/directory information is stored. This method is not a method of constructing nodes based on structural information such as Container Superblock (NXSB) and Volume Checkpoint Superblock (APSB), and B-tree root and leaf node information. The entire disk cluster is traversed to find scattered B-tree leaf nodes and to gather all the information in the file system to build information. It is a method of reconstructing a tree structure of a file/directory based on refined essential data by removing duplicate data. We demonstrate that the proposed method is valid through the results of applying the proposed method by generating numbers of user files and directories.

• The Journal of Korean Association of Computer Education
• /
• v.12 no.4
• /
• pp.57-64
• /
• 2009

Protein structure comparison is a task that requires a lot of computing resources because many atoms in proteins need to be processed. To address the issue, Grid computing environment has been employed for processing time-consuming jobs in a distributed manner. However, controling the Grid computing environment may not be easy for non-experts. In this paper, we present a JXTA-based system for protein structure comparison that can be easily controled by non-experts. To search proteins similar to a query protein, the geometric hashing algorithm that consists of preprocessing and recognition was employed. Experimental results indicate that the system can find the correct protein structure for a given query protein structure and the proposed system can be easily extended to solve the protein docking problem. It is expected that the proposed system can be useful for non-experts, especially users who do not have sophisticated knowledge of distributed systems in general such as college students who major in biology or chemistry.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.19 no.6
• /
• pp.293-302
• /
• 2015

ASCE 4 requires that a hard stop be built around the seismic isolation system in nuclear power plants. In order to maintain the function of the isolation system, this hard stop is required to have clearance-to-stop, which should be no less than the 90th-percentile displacements for 150% Design Basis Earthquake (DBE) shaking. Huang et al. calculated clearance-to-stop by using a Latin Hypercube Sampling technique, without considering the rocking behavior of the isolated structure. This paper investigates the effects on estimation of clearance-to-stop due to 1) rocking behavior of the isolated structure and 2) sampling technique for considering the uncertainties of isolation system. This paper explains the simplified analysis model to consider the rocking behavior of the isolated structure, and the input earthquakes recorded at Diablo Canyon in the western United States. In order to more accurately approximate the distribution tail of the horizontal displacement in the isolated structure, a modified Latin Hypercube Sampling technique is proposed, and then this technique was applied to consider the uncertainty of the isolation system. Through the use of this technique, it was found that rocking behavior has no significant effect on horizontal displacement (and thus clearance-to-stop) of the isolated structure, and the modified Latin Hypercube Sampling technique more accurately approximates the distribution tail of the horizontal displacement than the existing Latin Hypercube Sampling technique.

• Journal of Navigation and Port Research
• /
• v.28 no.3
• /
• pp.221-225
• /
• 2004

This paper deals with a nonlinear system modelling using neural network and genetic algorithm Application q{ neural network to control and identification is actively studied because of their approximating ability of nonlinear function. It is important to design the neural network with optimal structure for minimum error and fast response time. Genetic algorithm is getting more popular nowadays because of their simplicity and robustness. in this paper, we optimize a neural network structure using genetic algorithm The genetic algorithm uses binary coding for neural network structure and searches for an optimal neural network structure of minimum error and fast response time. Through an extensive simulation, the optimal neural network structure is shown to be effective for identification of nonlinear system.

• Journal of Digital Contents Society
• /
• v.19 no.9
• /
• pp.1727-1737
• /
• 2018

In this paper, we propose a system to detect spatial structures in land cover maps and to detect time-series spatial structure changes. At first, the proposed system detects patches in a certain area at different times and calculates their measures to analyse spatial structure patterns of the area. Then the system conducts patch mapping among the detected time-series patches and decides 6 types of patch changes such as keeping, creating, disappearing, splitting, merging, and changing in a mixed way. Also, the system stores the patch-based spatial structure patterns of time-series land cover maps in binary form to extract changes. This demonstrated that the proposed change detection system can be used as a basis for planning the reconstruction of the urban spatial structure by measuring the degree of urban sprawl.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.5
• /
• pp.757-772
• /
• 2018

Recently, earthquakes have occurred in large cities such as Gyeongju and Pohang, and seismic analysis studies have been actively conducted in various fields. However, since most of the previous seismic analyses have dealt with ground structures and the ground separately, there is a lack of a study on the complete soil-structure dynamic interaction. Therefore, in this study, a sensitivity analysis is conducted with MIDAS GEN and MIDAS GTS NX to apply the underground structure fixed-end model considering only the building and the complete system model considering both the building and the ground, respectively and the validity of dynamic analysis considering SSI is examined. As a result of the study, in most conditions it is found that the maximum horizontal displacement of the tall building in case of the underground structure fixed-end model is estimated to be smaller, the bending stress is larger, and the range of the weak part is smaller than that of the complete system model. Therefore, it is expected to be more reasonable to use the complete system model considering soil-structure interaction in seismic analysis.

• Fire Science and Engineering
• /
• v.30 no.5
• /
• pp.100-107
• /
• 2016

Today, high-rise buildings expected to meet various needs and improve the quality of frequency of fire and the potential risks are increasing. In particular, the fire spread risk in the vertical direction is increasing. As a result there is a problem with delays in the evacuation time of occupants. To overcome this problem, there is a need to consider the structure of the building and develop a system for the early detection of fire by applying a fire alarm system according to the risk ranking. Therefore, this paper describes the vertical fire spread characteristics of a multistory double-skin and stairs structure with risk. The data were compared with that from the national and international fire alarms as well as with. smoke density, smoke detectors, visibility, and CO concentration using FDS. A fire alarm system for each structure is proposed.

• Geomechanics and Engineering
• /
• v.13 no.5
• /
• pp.715-742
• /
• 2017

Earth berms are often left in place to support retaining walls or piles in order to eliminate horizontal struts in excavations of soft soil areas. However, if the excavation depth is relatively large, an earth berm-supported retaining system may not be applicable and could be replaced by a multi-bench retaining system. However, studies on multi-bench retaining systems are limited. The goal of this investigation is to study the deformation characteristics, internal forces and interaction mechanisms of the retaining structures in a multi-bench retaining system and the failure modes of this retaining system. Therefore, a series of model tests of a two-bench retaining system was designed and conducted, and corresponding finite difference simulations were developed to back-analyze the model tests and for further analysis. The tests and numerical results show that the distance between the two rows of retaining piles (bench width) and their embedded lengths can significantly influence the relative movement between the piles; this relative movement determines the horizontal stress distribution in the soil between the two rows of piles (i.e., the bench zone) and thus determines the bending moments in the retaining piles. As the bench width increases, the deformations and bending moments in the retaining piles decrease, while the excavation stability increases. If the second retaining piles are longer than a certain length, they will experience a larger bending moment than the first retaining piles and become the primary retaining structure. In addition, for varying bench widths, the slip surface formation differs, and the failure modes of two-bench retained excavations can be divided into three types: integrated failure, interactive failure and disconnected failure.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.25 no.4
• /
• pp.61-68
• /
• 2002

This paper provides a method of consciousness structure analysis for research and development project evaluation using fuzzy structure modeling(FSM). Fuzzy structure modeling, which is a modeling method for consciousness structure, has a large number of pairwise comparison by human subjective judgement and is difficult to check the consistency index of denoting the precision for human judgement. Thus, in this paper, we analyzed the structure of consciousness by fuzzy structural modeling method, introducing the concept of pairwise comparison matrix in Analytic Hierarchy Process.