• Transactions of the Korean Society of Automotive Engineers
• /
• v.16 no.6
• /
• pp.48-57
• /
• 2008

This paper shows the procedure to decide an optimal design principle for improving the disassemblability with considering of disassembly conditions. On the bssis of the disassembly mechanism of products and the structure of parts and subassembly, the disassemblability is classified into four categories: graspability, accessibility, transmission of disassembly power and handling. The weighting values of the influential factors are calculated by the method of AHP(Analytic Hierarchy Process). The disassemblability is evaluated quantitatively. We established some score tables for the evaluation. Using these score tables, several principles for higher disassemblability in accordance with work conditions can be decided. An optimal design principle can be found by the comparison with the total scores of some disassembly conditions.

• Journal of Korean Institute of Industrial Engineers
• /
• v.29 no.1
• /
• pp.49-64
• /
• 2003

Although assembly sequence planning is an essential task in assembly process planning, it is known as one of the most difficult and time consuming jobs because its complexity is increased geometrically when the number of parts in an assembly is increased. The purpose of this study is to develop a more efficient algorithm for generating assembly sequences automatically. By considering subassemblies, a new heuristic method generates a preferred parallel assembly sequence that can be used in robotic assembly systems. A parallel assembly sequence concept provides a new representation scheme for an assembly in which the assembly sequence precedence information is not required. After an user inputs both the directional mating relation information and the mating condition information, an assembly product is divided into subgroups if the product has cut-vertices. Then, a virtual disassembly process is executed to generate alternate parallel assembly sequences with intermediate assembly stability. Through searching parts relations in the virtual disassembly process, stable subassemblies are extracted from translation-free parts along disassembling directions and this extraction continues until no more subassemblies are existed. Also, the arithmetic mean parallelism formula as a preference criterion is adapted to select the best parallel assembly sequence among others. Finally a preferred parallel assembly sequence is converted to an assembly BOM structure. The results from this study can be utilized for developing CAAPP(Computer-Aided Assembly Process Planning) systems as an efficient assembly sequence planning algorithm.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.1289-1295
• /
• 2003

Most industrial products nowadays have been manufactured by being made up of many parts what these are made from various kinds of materials. These parts and goods should be disassembled simply and classified easily by material or kinds of parts for the recycling. But it is not so easy to know how to take disassembly ways and those orders must be known and also analyzed the assembled points and directions of the every part. This research presents an design process for recycling that it will be considering whole design process for recycling about easiness of disassembling units as the prior condition to reuse the parts and used material, and to reduce waste parts.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38B no.1
• /
• pp.80-86
• /
• 2013

The 3-Dimensional(3D) localization system based on beacon expansion and coordinate-space disassembly for the design of the 3D localization system in indoor environment is proposed and the performance of the proposed system is analyzed in this paper. The localization ratio of the 3D localization system adapts the proposed algorithm is analyzed by the calculation of errors occurred in the coordinates that the mobile node locates. It is indicated that the average error distance of the 3D localization system adapts the proposed algorithm is less than that of the 3D localization system not adapts the proposed algorithm as 0.47m. The localization average distance error in 12 coordinates is indicated that the 1.5m case is less than 2.5m case as 0.38m by some experimentations under the condition that the distances between the ceiling and the mobile node are 1.5m and 2.5m measured from the ceiling respectively. It is seen that the 3D localization system based on beacon expansion and coordinate-space disassembly can improved the degradation of the quality of service that is caused by some conditions and performance differences in sensors.

• Proceedings of the KSR Conference
• /
• 1999.11a
• /
• pp.368-375
• /
• 1999

This paper describes the evaluation methods and criteria used verify field performance of automatic multi-coupler for the PMC rolling stock. Automatic multi-coupler was designed and manufactured by KRRI , Woojin electric machinery CO., and Yujinchajeon MFG.CO., LTD in 1999. Through field performance test of PMC rolling stock, vibration, brake system, assembly and disassembly of complex train were measured on the condition of service operation. As a result, test results meet the criteria proposed by KNR and KRRI.

• Proceedings of the KIEE Conference
• /
• 2006.10a
• /
• pp.182-183
• /
• 2006

It has been studied about the important consideration in designing and construction of the reliability assessment facilities including the combined testing system for simulating condition of acceleratedly deteriorated environment, which enable to test and evaluate the large-sized HV power apparatus without any disassembly up to transmission class in this paper. Also it is described simply about its ratings and main technical specifications and trial running of the system. To evaluate the performance characteristics against combined test condition for various power installation, especially for the polymer type insulators and kinds of bushings, brief investigation and an analysis of test objects and related international codes and standards have been conducted.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.11a
• /
• pp.513-517
• /
• 2005

The condition monitoring of rotating machinery such as turbines, pumps and compressors, determine what repairs are needed to avoid shutdown and disassembly of the machine in an industrial plant Many diagnosis methods have been developed for use when the machine is running at steady state, the stationary condition. But much information can be gained about a rotor's condition during non-stationary conditions such as run-up and run-down. Order tracking analysis is a powerful tool for analyzing the condition of a rotating machine when its speed changes over time. Powerful OTA using digital signal processing has some advantages(cheap hardware, the powerful methods, the accurate post processing) and also some disadvantages(calculation time, high speed sampling). New OTA tool based on the chirplet transform is similar to the short time Fourier transform. But, it has good resolution at high speed like other OTA methods based STFT and more resolution for constant frequency components than re-sampling OTA.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.5
• /
• pp.707-713
• /
• 2013

Coupling bolts have replaced conventional fitted bolts in applications where the operator's safety during assembly/disassembly is of concern or where the cost of process interruption is significant. Coupling bolts have been installed on rotating flange couplings in a wide range of marine and power applications worldwide. Their use has been approved by all leading international and national classification societies and regulatory bodies. A coupling bolt is a hydraulically tensioned fitted bolt that creates a stable and rigid link between coupling flanges and simplifies assembly and disassembly. We measure the bolt dimensions for reverse engineering and study the standard of assembly-load using a mechanical formula in order to localize a coupling bolt for a shaft in a power plant. We experimentally obtain the friction coefficient and confirm the condition of bolt sets through structure analysis. We show the variation of contact pressure for the shape parameter in order to consider the result when redesigning a bolt.

• Journal of Korean Institute of Industrial Engineers
• /
• v.33 no.3
• /
• pp.355-363
• /
• 2007

This paper presents a method of an automatic work time evaluation based on the verification of a disassemblability and assembly configuration. Even though a work time evaluation is an important field of concern for planning assembly lay-out, there are some limitations using cumbersome user query or approximated work time data without considering assembly condition. To overcome such restriction, this paper presents a method to mathematically verify assembly conditions based on the disassemblability, which is defined by the separability and stability cost. The separability cost represents a facility of the part disassembly operation, and the stability cost which represents a degree of the stability for the base assembly motion. Based upon the results, we propose a new approach of evaluating work time using neural networks. The proposed method provides an effective means of solving the work time evaluation problem and gives a design guidance of planning assembly lay-out in flexible manufacturing application. Example study is given to illustrate the concepts and procedure of the proposed schemes.

• Conservation Science in Museum
• /
• v.29
• /
• pp.47-64
• /
• 2023

Daehye Bogakseonsaseo (Letters of Master Bogak) in the possession of the National Museum of Korea is a Goryeo-era book produced in 1387, which was acquired in 2005 in a state of severe general damage. Subsequently, its production techniques and materials were examined using bibliographical characteristics and scientific analysis, based on which an overall conservation treatment was carried out. Janghwang(mounting) in bibliographical characteristics is a five-hole-stitch binding (五針眼線裝本), a single-lined rectangular box (四周單邊), and no column lines. The conservation treatment was examined in two aspects: the basic form and the conservation treatment process. The book is composed of the outer cover, original cover, end paper, and inner paper of 0.04-0.07mm thick, which is significantly thinner than general book paper. The conservation treatment was applied after the entire book was disassembled, based on the assessment that both the cover and the inner sheets of paper were in a dire condition due to deterioration. The conservation treatment comprised of the process of disassembly, cleaning, reinforcement of defective parts, scanning, and binding, with a paulownia box made for its storage. At the time of disassembly, samples were made for the inner sheets and the book string in order to conduct fiber identification. The fibers were identified using Safranin and C-stains. Safranin staining identified a thick fiber wall, in addition to cross-marking, dislocation, and transparent membranes. C-stain staining identified the fiber as mulberry, given the dark red residue. The book strap has a flat, circular cross-section, and was identified as cotton fiber, since a lumen was observed in the center.