• Journal of Conservation Science
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• v.32 no.2
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• pp.261-271
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• 2016

We have investigated relationship between particle characteristics of oyster shell powder pigments and their performance such as workability and durability. Three types of the powder which have different particle size and shape(spherical, elliptical, columnar and irregular) distributions were made for this study and we evaluated spreadability and uniformity for workability, and adhesion and surface hardness for durability of painted films by each powder paints. As a result, we found out that the workability and durability of the paints were influenced by the particle shape distribution more than the particle size distribution. The durability, especially, was enhanced as the ratio of columnar particles in the powders was increased. This result verifying the important factor affecting the durability can be base data for selecting oyster shell white paint and assessing its quality for conservation and restoration of Dancheong, as well as to produce high quality traditional paints.

• The Korean Journal of Malacology
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• v.5 no.1
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• pp.1-9
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• 1989

A scanning electron microscopic study on the glochidium and glchidial encystment of Anodonta grandis on the guppy was conducted. The shape of the glochidium is apparently triangular and its averge size is 0.45mm X0.4mm when closed, The two glochidial shell valves are of the same size, kept together by a ligament of 120${\mu}{\textrm}{m}$ in length and 7 ${\mu}{\textrm}{m}$ in width. Each of the glochidial shell valves has a 16 ${\mu}{\textrm}{m}$ long hook sitdded with many spines on the superior face. A large area to the apex of the valve surrounding the base of the hook is provided with numerous small spines which become progressively smaller towards the periphery of the area, The external surface of the glochidial shell valve is covered with numerous small processes showing successive change in the shape and the pattern of destribution by part. Besides the processes, there are a number of niches scattered all over the exterior surface. The glochidial shell valve has two layers. One is the outer thin membrane bearing the processes and the niches and the others is the inner layer bearing numerous holes which any accessory structure and 2.65 ${\mu}{\textrm}{m}$ in diameter, emerges from a canal located at center of ventral plate of the mamtle, A total of three types of the hair cells are observed. In present artificial infection of the glochidium to the guppy, it took about three to four hours to complete an early cysts, During the period of encystment, The epithelial cells of the host fish actively migrated toward the attached glochidium and covered it.

• Journal of the Korean Geographical Society
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• v.48 no.6
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• pp.837-855
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• 2013

The remains and relics such as wood vessel, shell middens and acorn hollows related to marine environments were excavated at Bibong-ri, Changnyeong-gun, Gyeongsangnam-do, South Korea, approximately 70km apart from the Nakdong River mouth. The sea-level changes were reconstructed based on characteristics of shell middens and acorn hollows, sedimentary facies, AMS dating, and diatom analysis. The shell middens and acorn hollows were constructed during the early Neolithic Age and provide information on the paleo-sea level, because of influences of marine processes. The sedimentary facies are classified into a bedrock, base gravel and Holocene sediment (marine, terrestrial and back marsh sediments), upward. The sea level fluctuated during the middle Holocene is in harmony with those in Sejuk-ri, Ulsan and Pyeongtaek. In particular, the sea level at Bibong-ri of study area was higher than the mean high tidal level in Gimhae by approximately 1m during 5,000yr BP and maintained the stable condition during 4,000yr BP.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_2
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• pp.1135-1144
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• 2023

In this paper, bending strength and permeability tests were conducted on concrete permeable blocks manufactured by recycling industrial by-products of oyster shell and blast furnace slag to measure and compare bending strength and permeability coefficient, and present experimental research results. To this end, a total of 54 specimens with a size of 200x200x60mm for surface layer and base layer were manufactured, and bending strength and permeability test were carried ourt accoridng to KS F 4419. Eighteen types of mixing designs were implemented by varying the mixing and replacement rates of oyster shells and blast furnace slag. As a result of the experiment, the higher the mixing ratio of oyster shell, the lower the bending strength and the permeability coefficient. Thereafter, a total of three permeable blocks with dimensions of 200x200x60mm were manufactured and subjected to bending strength and permeability tests according to KS F 4419. As a result of the test, the bending strength satisfies the standard of KS F 4419, and the permeability coefficient is 12 times higher than the standard of KS F 4419. It seems that the proper mixing of oyster shells and blast furnace slag increases the amount of air, and further research on durability and economic feasibility of materials used to manufacture permeable blocks is required.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.660-666
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• 1994

현장에서 크레인에 대한 전문적인 지식을 얻는데는 많은 시간과 노력이 소요되고 있으며 전문가의 숫자가 한정되어 있어서 고장 발생시 전문가를 부르는데 시간이 많이 소요된다. 이 문제를 해결하기 위하여 깊은 전문지식 없이 크레인의 고장을 신속히 진단하고 조치방안을 제시하는 전문가 시스템을 개발하였다. 개발범위는 가장 빈번히 고장이 발생하는 전기 부문중 전동기와 브레이크로 범위르 국한시켰다. 우선 크레인의 전기 부문에서 일어나는 고장 원인과 증상을 분석하고, EXSYS라는 전문가 시스템 Shell을 사용해 Rule을 개발하였다. 또한 각 증상에 따른 조치방법을 작업자에게 가르쳐 주기 위하여 FoxPro를 사용하여 Instruction Data Base를 개발하였다.

• Journal of the Korean Operations Research and Management Science Society
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• v.16 no.1
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• pp.35-44
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• 1991

An expert system that diagnoses the malfunction of local area network is developed. The system detects specific devices in the network as the source of thd deta disconnection. These soures are sct to goals in the knowledge base and rules are constructed by uncluding all possible occurrences un thd connection of therminals and host computers. An approach via OR graph is employed for thd systematic rule generation. The system is implemented in a shell and illustrative inference processes are presented.

• Journal of Korean Institute of Industrial Engineers
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• v.20 no.1
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• pp.71-85
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• 1994

Overhead cranes which carry heavy items in construction or production areas consist of structure and electric modules. More than 80% of breakdowns bring out of the electric module. As operators do not know all about cranes, it sometimes takes much time to repair the cranes. In order to resolve this problem, the expert system which can diagnose causes of faults and give instructions for repair to operators, has been developed. The scope of the paper is limited to the electric module. First of all, analyzing symptoms and causes, we have developed a rule base with the expert system shell, EXSYS. Furthermore, for the facility maintenance including repair instructions against the causes, the instruction data base was developed with FOXPRO. On the other hand, for the help of user's understanding the fault causes, the graphic animation module which shows malfunctioning component ports or motions in 3D was developed with the graphic software, TOPAS VGA.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.195-200
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• 2003

An expert system for estimation of fatigue properties from simple tensile data of material is developed, considering nearly all important estimation methods proposed so far, i.e., 7 estimation methods. The expert system is developed using an expert system shell, UNIK, and the knowledge base is constructed with production rules and frames. Forward chaining is employed as a reasoning method. The expert system has three major functions including the function to update the knowledge base. The performance of the expert system is tested using the 54 ${\sigma}-N$ curves consisting of 381 ${\sigma}-N$ data points obtained for 22 materials. It is found that the expert system developed has excellent performance especially for steel materials, and reasonably good for titanium alloys.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.114-119
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• 2001

An expert system for estimation of fatigue properties from simple tensile data of material is developed, considering nearly all important estimation methods proposed so far, i.e., 7 estimation methods. The expert system is developed to utilize for the case of only hardness data available. The knowledge base is constructed with production rules and frames using an expert system shell, UNIK. Forward chaining is employed as a reasoning method. The expert system has three major functions including the function to update the knowledge base. The performance of the expert system is tested using the 54 $\varepsilon$-N curves consisting of 381 $\varepsilon$-N data points obtained for 22 materials. It is found that the expert system developed has excellent performance especially for steel materials, and reasonably good for aluminum alloys.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.55
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• pp.85-96
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• 2000

This paper describes IDMS, a graph-based modeling system that supports problem structuring. We employs influence diagram as a problem representation tool, that is, a modeling tool. In particular, IDMS is designed as domain-independent shell. Therefore, a modeler can change the contents of the knowledge base to suit his/her own interested domain. Since the knowledge base of IDMS contains both modeling knowledge and domain knowledge, IDMS provides not only the syntactic support for modeling tool, but also the semantic support for problem domain. To apply the method in the real world context, we tested IDMS on the process selection problem in business reengineering, which is typical semi-structured problem.