• Advances in concrete construction
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• v.10 no.5
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• pp.381-391
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• 2020

This study aimed to develop reference materials (RMs) for mortar that can simulate the initial flow characteristics with constant quality over a long period. Through the previous research on the development of RMs for cement paste, the combination of limestone, glycerol, and water was used as the basic matrix for developing RMs for mortar in this study. In addition, glass beads of three particle sizes (0.5, 1.0, and 2.0 mm) and ISO standard sand were selected as tentative candidates to derive fine aggregate substitutes. The mixture of glass beads could simulate the initial flow characteristics of mortar, but under the same mixing ratio, replicates showed an unstable tendency to indicate inconsistent values due to the generation of electrostatic properties between materials and equipment. On the other hand, the mixture using ISO standard Sand not only simulates the constant flow characteristics for a long period of time, but also shows stable results with little error in replicates. Therefore, limestone, glycerol, ISO standard sand, and water were finally determined as components that met the required properties of RMs for mortar. The effect of each component on the flow characteristics of RMs was analyzed. It was found that glycerol increased the cohesion between the particles of standard sand, resulting in a constant increase both in the plastic viscosity and yield stress. Both limestone and standard sand had a dominant effect on the yield stress. The relationships between various mortar mixing ratios and the corresponding mixing ratios of RMs were established. In addition, the results of the verification experiment showed that the rheological properties of the RMs obtained through the relationships correlated with various water/cement ratios and the fine aggregate volume fractions of mortar obtained with same manner. In other words, the RMs for mortar developed in this study can be used as standard samples because they can simulate the initial flow characteristics of mortar of various mixing ratios for a long period without any chemical changes.

• Journal of Korean Association for Spatial Structures
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• v.8 no.2
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• pp.73-84
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• 2008

The various systems as the seismic resistance systems are used to reduce the seismic response of structure. And the seismic isolation system among them is the system that reduces the seismic vibration to be transmitted from foundation to upper structure. The purpose of isolation system is to lengthen the period of structure and make its period shift from the dominant period of earthquake. In this study, the seismic behavior of arch structure with lead rubber bearing(LRB) and friction pendulum system(FPS) is analyzed. The arch structure is the simplest structure and has the basic dynamic characteristics among large spatial structures. Also, Large spatial structures have large vertical response by horizontal seismic vibration, unlike seismic behavior of normal rahmen structures. When horizontal seismic load is applied to the large spatial structure with isolation systems, the horizontal acceleration response of the large spatial structure is reduced and the vertical seismic response is remarkably reduced.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.1
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• pp.79-90
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• 2016

The second-stage near surface disposal facility for low and very low level radioactive waste's permanent disposal is to be built. During the institutional control period, the inadvertent intrusion of the general public is limited. But after the institutional control period, the access to the general public is not restricted. Therefore human who has purpose of residence and resource exploration can intrude the disposal facility. In this case, radioactive effects to the intruder should be limited within regulatory dose limits. This study conducted the safety assessment of human intrusion on the second-stage surface disposal facility through drilling and post drilling scenario. Results of drilling and post drilling scenario were satisfied with regulatory dose limits. The result showed that post-drilling scenario was more significant than drilling scenario. According to the human intrusion time and behavior after the closure of the facility, dominant radionuclide contributing to the intruder was different. Sensitivity analyses on the parameters about the human behavior were also satisfied with regulatory dose limits. Especially, manual redistribution factor was the most sensitive parameter on exposure dose. A loading plan of spent filter waste and dry active waste was more effective than a loading plan of spent filter waste and other wastes for the radiological point of view. These results can be expected to provide both robustness and defense in depth for the development of safety case further.

• Clinics in Shoulder and Elbow
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• v.17 no.1
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• pp.18-24
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• 2014

Background: To evaluate the efficacy of the subclavian portal approach for the arthroscopic repair of isolated subscapularis tendon tear. Methods: We used the subclavian portal to carry out arthroscopic repair of the isolated subscapularis tendon tear. The surgery was carried out in 18 cases (average age of 53) from May 2006 to December 2009 with a mean follow-up period of 35 months. Of these cases, 13 patients had the tear in their dominant arms, 16 were male, and 12 were from traumatic ruptures with on average 7.6 months of symptom period to operation. Additional surgery, acromioplasty and subacromial debridement, were carried out on 4 cases each during the subscapularis repair. The integrity of cuff status was assessed by ultrasonographic examination at 6 months and at 1 year after operation. Results: The initial average range of motion in forward flexion, external rotation, and internal rotation were $160^{\circ}$, $50^{\circ}$ and L4, respectively. At the 1 year follow-up period, these improved to $160^{\circ}$, $52^{\circ}$ and T12, respectively. The initial average functional scores were assessed by KSS, ASES, UCLA, and Constant scoring systems, which were 67, 60, 26, and 65, respectively. These scores improved progressively with time. At 3 months after operation, the scores were 74, 67, 27, and 74; at 6 months, 83, 77, 31, and 75; at 1 year, 88, 86, 32, and 79; and at the final follow-up of 35 months, 84, 92, 34, and 84. Conclusions: In the repair of isolated subscapularis tendon tear, the subclavian portal approach provided a good angle for anchor insertion and sufficient space to manage the upper portion of the tendon tear. In turn, these provisions resulted in satisfactory clinical results.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.6
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• pp.291-296
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• 2015

The tire damage classification method is researched on the periodicity detection of ramdomness ultrasonic signals to occur at the driving vehicle tire. Setting method of adaptive threshold is proposed in order to valid pulse detection by tire damage in ultrasonic noise on the road and used low pass filter for decrease signal ramdomness as preprocessing. Time interval of detected pulse is setted the density function depend on the vehicle's speed and the method of tire damage detection is proposed that measuring the first peak's time of time density function.The result of time density function in case of one damage material, the first peak's time is measured within the error limit of tire's rotation period, 169.8ms and 97.9ms and 81.8ms, about the speed of 50km/h and 80km/h and 100km/h. In case of more than one damage material, the sum of each peak's time is measured within the error limit of tire's rotation period about the speed.

• Korean Journal of Ecology and Environment
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• v.37 no.3 s.108
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• pp.272-281
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• 2004

The Primary production and budget of organic carbon at rainy and dry period was surveyed to evaluate the contribution of primary production in Paldang Reservoir. Primary productivity of phytoplankton showed remarkable differences depending on sampling dates and sites, ranged from 110 to 2,701 mgC $m^{-2}day^{-1}$. In the rainy period of April and August when there had been frequent rainfall resulting short hydraulic retention time and low algal biomass in Paldang Reservoir, autochthonous organic carbon occupied very low ratio, farming approximately 7 percent of total inflow of organic carbon. However in June when it almost never rained and dominant algal species changed from diatoms to green algae and small flagellates, autochthonous organic carbon from primary productivity of phytoplankton formed 29 percent of total inflow of organic carbon.

• Journal of Interdisciplinary Genomics
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• v.3 no.1
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• pp.21-24
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• 2021

Purpose: Activating mutations of the calcium-sensing receptor (CASR) are a rare genetic disorder, and result in autosomal dominant hypocalcemia with hypercalciuria (ADHH). ADHH exhibited varying degrees of hypocalcemia. In this study, we report the clinical and molecular characteristics of activating variants in CASR patients diagnosed in Korea. Methods: This study included three patients with activating variants of CASR confirmed by biochemical and molecular analysis of CASR. Clinical and biochemical findings were reviewed chart retrospectively. Mutation analysis of CASR was performed by Sanger sequencing. Results: Subject 1 showed severe symptoms from the neonatal period and had difficulty in controlling the medications that were administered. Subject 2 was identified as having a novel variant of CASR with hypocalcemia and a low parathyroid hormone that were found in the neonatal period. During a course without medication, hypocalcemia occurred suddenly around 2 years of age. Subject 3 was diagnosed with hypoparathyroidism with hypocalcemic seizures starting from the neonatal period. About 4 years without taking medication with any symptom. However, at 10 years old revisited by repetitive hypocalcemic seizure events. Subject 1 and 3, were heterozygous for c.2474A>T (p.Y825F), c.2395G>A (p.E799K) located in the transmembrane domain (TMD) of CASR. Subject 2 was heterozygous for c.403A>C (S430L) located in the extracellular domain (ECD) of CASR. Conclusion: We reported 3 patients who have activating CASR variant with different onset and severity of symptoms. In the future, further study is needed to determine how the protein level according to the location of the mutation of CASR affects the degree of symptoms.

• The Korean Journal of Zoology
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• v.21 no.2
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• pp.67-75
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• 1978

The auther investigated the distribution and seasonal variations of Copepods and Branchiopods in Myeongam Lake located in Cheongju City, Chungchungbuk Do. Air and Water temperature, pH, and the amount of dissolved oxygen were also measured eleven times from July 29 to November 5, 1977. The results obtained are as follows: 1. The mean values of air and water temperature, pH, and dissolved oxygen during the investigation period were $25^{\circ}C , $23.7^{\circ}C, 6.86, and 10.75 ppm, respectively. 2. The total number of species collected in this lake were 13 species (1) thermocyclops taihokuensis (Harada) (2) Thermocyclops hyalinus (Rehberg) (3) Mesocyclops leuckarti (Claus) (4) Diacyclops disjunctus (Thallwitz) (5) Paracyclops fimbriatus (Fischer) (6) Cyclops sp. a (7) Cyclops sp. b (8) Diaphanosoma brachyurum (Lievin) (9) Daphnia pulex Leydig (10) Daphnia longispina (O. F. Muller) (11) Daphnia sp. (12) Moina dubia De Guerne et Richard (13) Chydorus sphaericus (O. F. Muller) 3. Among these species, 4 species (1, 3, 8, 10) were collected continually throughout the investigation period. 4. The dominant species was Diaphanosoma brachyurum during the investigation period.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.60-73
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• 2024

Background: The available information on terrestrial pest gastropods and their impact on the environment worldwide is scarce and outdated. The present study aimed to address this gap by conducting the first comprehensive survey of pest gastropods in the Nuwara Eliya District, an important vegetable growing area in the highlands of Sri Lanka. Eighty agricultural lands were surveyed over two years by establishing ten 1 m2 sampling plots per crop type in each agricultural land. Geo-coordinates, air temperature, elevation, relative humidity, daily rainfall, soil pH, species richness and abundance were recorded for rainy and non-rainy periods. The relationship between species composition and environmental variables was analyzed using multi-regression models and distribution maps. Results: Out of the 14 species recorded in agricultural lands, nine were identified as exotic pest species. Species abundance (t = 4.69, p < 0.05) and diversity was higher in the rainy period and the dominant species during this period were Bradybaena similaris (t = 2.69, p < 0.05) and Deroceras reticulatum (t = 2. 46, p < 0.05). Eggs and estivating adults were found in soil and under decaying organic matter during the non-rainy period. The exotic species showed broader preferences for the measured environmental factors and showed a wider range in distribution compared to the native species. Variation in pest gastropod composition was significantly accounted for by elevation, relative humidity, soil pH and daily rainfall. Additionally, the species richness and abundance varied across locations due to the combined effects of elevation, crop type and stage, and field type. Conclusions: The study emphasizes the importance of understanding the biology and ecology of gastropod pests to develop effective management strategies. By considering the influence of environmental factors and implementing appropriate soil management techniques, such as targeting specific habitats and crop stages, it is possible to mitigate pest populations and minimize their impact on agricultural lands. Overall, this research contributes valuable insights into the dynamics and interactions of terrestrial gastropods in agricultural ecosystems, supporting sustainable pest management practices.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.4
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• pp.272-281
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• 2008

Seasonal and annual variation in the species composition of bag-net catch in the coastal waters of Incheon, Korea were examined from April 2000 to November 2004. To analyze seasonal variation of the fisheries data, we implemented a self-organizing map(SOM), an unsupervised artificial neural network, with the catch amount of 97 species. Over 5 years, we caught 68 species of fish, 23 species of crustaceans and six species of cephalopods. The total number of fish species were gradually increased during the study period. The number of species was higher during the spring than the autumn. The SOM identified four groups of the sampling months based on seasonal changes in communities. In the spring, the dominant species were Leptochela gracilis and Pholis fangi; whereas, in the autumn, Engraulis japonicus and Portunus trituberculatus were dominant species in bag-net catch. Our results will be used to estimate seasonal and annual variation in fisheries resources of Korean coastal waters.