• Science of Emotion and Sensibility
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• v.15 no.4
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• pp.527-540
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• 2012

We examined the effect of delayed and immediate rewards on short- and long-term memory performance depending on the level of stress. It has been demonstrated that delaying feedback during memory tasks could lead to better retention than presenting it immediately (a.k.a., feedback delay benefit or delay-retention effect). In this study, we manipulated stress level(high-stress or low-stress), reward-timing(delayed or immediate reward), reward-existence(500 or 0 won) and retrieval-timing(delayed or immediate memory test). On the high-stress learning condition, one week later, the number of correct answers with delayed-rewards were significantly more than that of delayed-no-rewards but there was not any difference between immediate-rewards and immediate-no-rewards. On the other hand, in the high-stressful immediate memory test, immediate-rewards only had a positive effect on memory performance. The results indicated that delayed rewards improved long-term memory performance by promoting memory consolidation and the sensitivity to rewards was higher under the high-stress condition.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.540-543
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• 2003

There are many stone monuments which are weathered by natural or artificial factors in Korea. The partly weathering in stone could accelerate the rate of weathering, so it is demanded to keep them from the further weathering. Consolidation is evaluated as one of the efficient treatments which have a good effectiveness in stone monuments. But following the former researches, the effectiveness of consolidation could be different, related to the kinds of stone or consolidants. Therefore, in this study, the change of properties was monitored in the long term for the exact evaluation of the stability of the consolidated stone. It is estimated that the pore structure of consolidated stone was filled by consolidant, according to the measurements of ultrasonic velocity, and the digital image analysis of the sample was shown that the color property of stone surface has varied during the curing.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.10a
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• pp.133-145
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• 2001

This paper presents quality and measure controls of Plastic Board Drains(PBD) for improvement of soft ground. Laboratory and field tests has been carried out to evaluate the quality of PBD focussing on : discharge capacity of flow area; permeability of filter sleeve; migration of fine particles; deformed shape of PBD; consolidation of clay in the close vicinity of PBD; tensile strength of PBD; long-term consolidation behavior of clay-PBD. Test results show that the quality of PBD is sufficient to perform the improvement of soft silty and clayey ground. But, geotechnical engineer must make efforts minimizings of PBD damage and ground disturbance, continuity of drainage system during construction. Adequate monitoring system should apply at ground focussing on number, location, and accuracy of geotechnical instrumentation, measurement and evaluation of data for ground behaviour.

• Journal of the Korean Geotechnical Society
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• v.26 no.8
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• pp.49-58
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• 2010

In this study, in order to investigate the characteristics of secondary consolidation in the soft clay ground, oedometer tests were carried out in a normally consolidated condition, and the consolidation characteristics of the soft clay ground were examined by the Finite Difference Method (FDM) based on the Elasto-Viscous model proposed by Yoshikuni. The consolidation tests adjusted the consolidation load increment ratio(${\Delta}p/p_0$) to 1.0 for the four cases with initial consolidation pressures of 0.8, 1.6, 3.2, and 6.4 kgf/$cm^2$. The long-term consolidation tests were examined by the tests that changed the load increment ratio to clarify the effect of consolidation load increment. Although the numerical analysis was delayed in the primary consolidation process, from the result of the numerical analysis of the laboratory tests, the applicability of the Elasto-Viscous model was verified from the agreement of the secondary consolidation process. Based on the developing of model ground consist of general soft clay, influences of consoliation parameters on the consolidation characteristics were studied by the numerical analysis.

• Proceedings of the Korean Geotechical Society Conference
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• 1992.10a
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• pp.75-86
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• 1992

The elevation of reclamation work in the coastal area for the industrial complex is determined through the investigation and review of marine conditions, drainage plan and fill materials. The embankment to be constructed with crushed stone on the soft soil should be safe against the wave force, immediate and long term consolidation settlement, overturning and sliding due to self-weight and other forces. Because of lack of fill material from the borrow pit, the soft marine clay to be dredged shall be used as the reclamation material. And Paper Drain Board is used as the improvement method for the deep soft clay strata.

• Korean Journal of Cognitive Science
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• v.7 no.3
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• pp.7-36
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• 1996

Recebt neuropsychological studies on neurobiological bases of learning and memory in humans are reviewed. At present, cognitive psychologists belive that memory is not a unitary system. But copmosed of several independent subsystems. Adoption this perspective,this paper summarized findings regarding what kinds of memory discorders result from lesions of which brain areas and which brain areas are activated by what kind of learning/memory tasks. Short-term memory seems to involve widespread areas around the boundaries among the parietal,occipital,and temporal lobes,depending on the type of the type of the tasks and the way of presentation of the stimuli. Implicit memory,a subsystem of long-term memory,is not a unitary system itself. Thus,brain areas involved in implicit memory tasks used. It is well-known that medial temporal lobe is necessary for formation(i,e.,consolidation)of explicit memory,another subsystem of long-term memory. Storage and/or retrieval of episodic and semantic memory involve temporal neocortex. Perfromtal cortex seemas to be involved in several aspects of memory such as short term memory and retrieval of espisodic and semantic memory. Finally, a popular view on the locus of long-term memory storage is described.

• Journal of the Korean Geotechnical Society
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• v.36 no.7
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• pp.5-14
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• 2020

Kansai International Airport (KIX) was opened in September 1994. Although 26 years have passed since the completion of the first island, long-term settlement is still in progress. This settlement occurs in the Pleistocene layer. For it is not easy to determine the permeability of the Pleistocene sand layer because the thickness and the degree of fine content in the horizontal direction are constantly changing. In addition, it is also a difficult to predict the interactive behavior of the ground due to the construction of the second phase island adjacent to it. In order to solve this problem, a two-dimensional finite element analysis considering elasto-viscoplastic was performed to evaluate the long-term deformation, including the interactive behavior of the alternating Pleistocene foundation due to the construction of two adjacent reclaimed islands. In general, two-dimensional analysis can be used when a section can represent the entire sections. However, Kansai Airport is an artificial reclaimed island so two-dimensional analysis cannot solve the problem such as the stress deformation in the corners of the island. Additionally, the structure of the actual sub-ground through physical exploration is non-homogeneity and its thickness is also not constant. Therefore, there are limitations for the two-dimensional analysis to explain the phenomena. That is, three-dimensional analysis is strongly required. Due to these demands, the author extended the existing two-dimensional program capable of elasto-viscoplastic analysis to three-dimensional and completed the verification of the three-dimensional program developed through one-dimensional consolidation analysis. In order to demonstrate the validity of the developed 3D program that has been verified, an analysis is performed under the same analysis conditions as the existing research using a two-dimensional program. The effectiveness of the developed 3D numerical analysis program was demonstrated by comparing the analysis results with the 2D results and actual measurement data.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.4
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• pp.94-102
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• 1998

This paper aims at developing the prediction technique of the deformation for the embankment such as sea dike and shore protection relevant to reclamation project along the southern coast of the Korean Peninsula. Generally total deformation of a sea dike over clayey foundation are composed of immediate settlement, plastic deformation and consolidation settlement. Plastic deformation occurs when the ultimate bearing capacity is less than overburden pressure containing the stress increment due to the construction of an embankment. The reliable prediction of total settlement is very important since deformed final geometry of sea dike is directly connected for analysing the safety of the long-term slope failure and piping. During this study, plastic deformation, major part of deformation was analysed using the program developed by authors, whereas immediate settlement and consolidation settlement were predicted by Mochinaka and Sena's method and Terzaghi's 1-dimensional theory of consolidation respectively. In order to validate the prediction technique for the deformation, a case study of Koheung Bay reclamation works was carried out. A good agreement was obtained between observation and prediction, which means the applicability of the technique.

• Journal of the Korean GEO-environmental Society
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• v.19 no.9
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• pp.21-28
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• 2018

In this study, a standard consolidation test (Oedometer) was performed on the relative density of sand in the south coast to evaluate long-term creep settlement characteristics. Experimental results show that the cumulative settlement at the final loading stage decreases as the relative density increases and the variation of the void ratio decreases. As a result of analyzing the settlement rate of long-term creep of sand, creep settlement of 4.7~11.0% occurred depending on relative density with respect to total settlement. The creep parameter, Beta, of Schmertmann et al. (1978) was estimated to be 0.17~0.40 (average 0.21), and it tended to converge to a certain value when the load step becomes more than a certain level. It was found that there is no significant difference in the creep parameter depending on the layer thickness, and it was confirmed that the creep parameter could be applied regardless of the field layer thickness.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.8
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• pp.1315-1324
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• 2009

This study is on the consolidation process of the conservation process of fabric with golden thread found in relics. Gold film was glued to pieces of Korean paper and satin using hide glue, which is a natural adhesive and resin Paraloid B-72, which is a liquid type adhesive. This study examines the types and concentration of the adhesives that are appropriate for consolidating gold film on fabric. The advantage of hide glue is that it is harmless to humans and has a high stability. This glue is also believed to be the closest to the adhesive that was used when the relic was originally made. Its weakness is that it is stiff and weaker than chemical glues, but after being washed with water the adhesion level increases. Therefore, hide glue is appropriate in the following instances: a) when washing after consolidation b) when the substrate of gold threads are significantly damaged, and c) when treating greater sized relics that take a longer time to work on. However, Paraloid B-72 has a better adhesion and flexibility than hide glue, but tends to spread out into a greater area, and the area where it is applied tends to absorb less water than before the application. In addition, it is noxious and can be harmful in long-term exposure. Therefore, Paraloid-72 is appropriate in the following instances: a) when consolidating the fabric after washing, and b) when working on smaller relics and consolidating smaller parts of a relic. The necessary concentration levels for consolidants for gold film are 30% for liquid type hide glue and at least 10% for Paraloid B-72 in order for the gold film to stay intact on the fabric during washing, consolidation, exhibition, and conservation.