• The Journal of Engineering Research
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• v.6 no.2
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• pp.11-22
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• 2004

A distributed constraint satisfaction problem (distributed CSP) is a constraint satisfaction problem(CSP) in which variables and constraints are distributed among multiple automated agents. ACSP is a problem to find a consistent assignment of values to variables. Even though the definition of a CSP is very simple, a surprisingly wide variety of AI problems can be formalized as CSPs. Similarly, various application problems in DAI (Distributed AI) that are concerned with finding a consistent combination of agent actions can be formalized as distributed CAPs. In recent years, many new backtracking algorithms for solving distributed CSPs have been proposed. But most of all, they have common drawbacks that the algorithm assumes the priority of agents is static. In this thesis, we establish a basic algorithm for solving distributed CSPs called dynamic priority search algorithm that is more efficient than common backtracking algorithms in which the priority order is static. In this algorithm, agents act asynchronously and concurrently based on their local knowledge without any global control, and have a flexible organization, in which the hierarchical order is changed dynamically, while the completeness of the algorithm is guaranteed. And we showed that the dynamic priority search algorithm can solve various problems, such as the distributed 200-queens problem, the distributed graph-coloring problem that common backtracking algorithm fails to solve within a reasonable amount of time. The experimental results on example problems show that this algorithm is by far more efficient than the backtracking algorithm, in which the priority order is static. The priority order represents a hierarchy of agent authority, i.e., the priority of decision-making. Therefore, these results imply that a flexible agent organization, in which the hierarchical order is changed dynamically, actually performs better than an organization in which the hierarchical order is static and rigid. Furthermore, we describe that the agent can be available to hold multiple variables in the searching scheme.

• Korean Journal of Heritage: History & Science
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• v.56 no.1
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• pp.80-97
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• 2023

By taking wallpaper specimens from Gyeongbokgung Palace, Changdeokgung Palace, and Chilgung Palace preserved from the late Joseon Dynasty to the present, we planned in this study to determine the types and characteristics of the paper used as wallpaper in the Joseon royal family. First, we confirmed the features of paper hanging in the palaces with old literature on the wallpaper used by the royal family based on archival research. Second, we conducted a field survey targeting the royal palaces whose construction period was relatively clear, and analyzed the first layer of wallpaper directly attached to the wall structure after sampling the specimens. Therefore, we confirmed that the main raw material was hanji, which was used as a wallpaper by the royal family, and grasped the types of substances(dyes and pigments) used to produce a blue color in spaces that must have formality by analyzing the blue-colored paper. Based on the results confirmed through the analysis, we checked documents and the existing wallpaper by comparing the old literature related to wallpaper records of the Joseon Dynasty palaces. We also built a database for the restoration of cultural properties when conserving the wallpaper in the royal palaces. We examined the changes in wallpaper types by century and the content according to the place of use by extracting wallpaper-related contents recorded in 36 cases of Uigwe from the 17th to 20th centuries. As a result, it was found that the names used for document paper and wallpaper were not different, thus document paper and wallpaper were used without distinction during the Joseon Dynasty. And though there are differences in the types of wallpaper depending on the period, it was confirmed that the foundation of wallpaper continued until the late Joseon Dynasty, with Baekji(white hanji), Hubaekji(thick white paper), jeojuji(common hanji used to write documents), chojuji(hanji used as a draft for writing documents) and Gakjang(a wide and thick hanji used as a pad). As a result of fiber identification by the morphological characteristics of fibers and the normal color reaction(KS M ISO 9184-4: Graph "C" staining test) for the first layer of paper directly attached to the palace wall, the main materials of hanji used by the royal family were confirmed and the raw materials used to make hanii in buildings of palaces based on the construction period were determined. Also, as a result of analyzing the coloring materials of the blue decorative paper with an optical microscope, ultraviolet-visible spectroscopic analysis(UV-Vis), and X-ray diffraction analysis(XRD), we determined that the type of blue decorative paper dyes and pigments used in the palaces must have formality and identified that the raw materials used to produce the blue color were natural indigo, lazurite and cobalt blue.