• Structural Engineering and Mechanics
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• v.17 no.3_4
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• pp.303-329
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• 2004

Magnetostrictive materials are routinely employed as actuator and sensor elements in a wide variety of noise and vibration control problems. In infrastructural applications, other technologies such as hydraulic actuation, piezoelectric materials and more recently, magnetorheological fluids, are being favored for actuation and sensing purposes. These technologies have reached a degree of technical maturity and in some cases, cost effectiveness, which justify their broad use in infrastructural applications. Advanced civil structures present new challenges in the areas of condition monitoring and repair, reliability, and high-authority actuation which motivate the need to explore new methods and materials recently developed in the areas of materials science and transducer design. This paper provides an overview of a class of materials that because of the large force, displacement, and energy conversion effciency that it can provide is being considered in a growing number of quasistatic and dynamic applications. Since magnetostriction involves a bidirectional energy exchange between magnetic and elastic states, magnetostrictive materials provide mechanisms both for actuation and sensing. This paper provides an overview of materials, methods and applications with the goal to inspire novel solutions based on magnetostrictive materials for the design and control of advanced infrastructural systems.

• Journal of the Korea Concrete Institute
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• v.16 no.1 s.79
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• pp.125-129
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• 2004

Hydrating concrete pavement is typically subjected to temperature-induced stresses that drive cracking mechanisms at early concrete ages. Undesired cracking plays a key role in the long-term performance of concrete pavement systems. The loss of support beneath the concrete pavement due to curling caused by temperature changes in the pavement may induce several significant distresses such as punch out pumping, and erosion. The effect of temperature on these distress mechanisms is both significant and intricate. Because thermal conductivity dominates temperature flow in hydrating concrete over time, this material property is back-calculated by transforming governing equation of heat transfer and test data measured in laboratory. Theoretically, the back- calculated thermal conductivity simulates the heat movements in concrete very accurately. Therefore, the back- calculated thermal conductivity can be used to calibrate concrete temperature predicted by models.

• The Journal of the Korean dental association
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• v.50 no.6
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• pp.304-311
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• 2012

Eruption of the teeth can be disturbed by crowding, ectopic eruption path, retention for pathologic condition of follicle and periodontal ligament, local disturbances in the innervation, and delayed eruption for overlying obstacles in the eruption path. Eruption disturbance of permanent posterior teeth is taken with diverse therapeutic approaches according to the patient age, cooperation of patient, tooth position and maturity, degree of impaction, clinical features, and repercussion on the neighboring teeth. However, delayed treatment usually results in less favorable outcomes. Therefore, In order to prevent this situation, periodically radiographic examinations during the early mixed dentition period and early diagnosis of eruption disturbances of permanent posterior teeth are recommended.

• Journal of Biosystems Engineering
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• v.25 no.6
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• pp.511-516
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• 2000

The strength of the connecting joint of boxthorn(Lycium chinense Mill) fruits to tree twigs was determined experimentally at several pulling angles(0$^{\circ}$, 15$^{\circ}$, 30$^{\circ}$,45$^{\circ}$and 60$^{\circ}$) and at different harvesting seasons from August to November 1999 using an universal testing machine. The detachment force of mature fruits of boxthorn decreased as the pulling angle increased and varied with the harvesting season. The detachment force however did not gradually decreased as the harvesting season advanced due to difference of maturity of fruits from one harvesting season to another. Among three varieties of boxthron Cheongyang gugija Cheongyang native and Cheongyang ＃2, the maximum detachment force was 1.24 N at the pulling angle of zero degree. The highest detachment forve(1.29 N) of mature fruits of boxthorn appeared at the harvesting season of August, 1999.

• Journal of the Korean Institute of Navigation
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• v.16 no.3
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• pp.55-64
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• 1992

Officers and ratings as a group might show differences in some aspects of personality , human relations, job attitudes, perception of business environment and surrounding organizational structure. It has been traditionally believed that licenced-officers are required to have nicely-paired leadership and dignity , and ratings obedience in maritime field. This survey revealed that officers and ratings have some differences in the actual behavior, knowledge , understanding attitude etc., In summary , officers as a superstructure of merchant ship's orgnaization are different, to some degree, from ratings as an infrastructure in several aspects. Officers are believed to have the characteristics of maturity by taking concern of business environment , social circumstance away from the vessels which they are on board. In contrast, ratings are greatly interested in the surrounding environment associated with themselves, and also experiencing alienation and technology.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47
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• pp.163-174
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• 2002

Peanut is one of the principal oil seeds in the world as a rich source of edible oil and protein. Peanut quality arises as a result of a complex interaction of genetic, physiological and biochemistry processes that produce the chemical composition of the peanut seed. The major factors influencing seed quality are degree of maturity and digging and drying, curing and storage as a series of harvesting. The end products, peanut butter, salted seed, confections, roasting stock and by-products are favored in world-wide because of their unique roasted peanut flavor, Literatures are reviewed mainly focusing on the physiological properties and nutritional quality of oil, protein and flavor in peanut. Chemical properties of protein and oil, and volatile flavor component in peanut seeds are studied. The objectives of this paper were to review and summarize the results obtained from the improving quality breeding program and evaluation of the chemical composition in peanut up to now.

• International journal of advanced smart convergence
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• v.10 no.2
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• pp.130-137
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• 2021

In the current software project, it is still very difficult to extract and define clear requirements in the requirement engineering. Informal requirements documents based on natural language can be interpreted in different meanings depending on the degree of understanding or maturity level of the requirements analyst. Also, Furthermore, as the project progresses, requirements continue to change from the customer. This change in requirements is a catastrophic failure from a management perspective in software projects. In the situation of frequent requirements changes, a current issue of requirements engineering area is how to make clear requirements with unclear and ambigousrequirements. To solve this problem, we propose to extract and redefine clear requirements by incorporating Design Thinking methodologies into requirements engineering. We expect to have higher possibilities to improve software quality by redefining requirements that are ambiously and unclearly defined.

• Journal of the Korea Society of Computer and Information
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• v.16 no.1
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• pp.191-199
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• 2011

Under the influence of a paradigm shift for administrative service of public institutions in around the world, the 'Government Affairs Assessment Act' has been enacted in Korea in March 2006. By the law, each local governments have been obligating to conduct self-assessment and resident's satisfaction survey for improving administrative service. Thus, the purpose of this study is to evaluate the administrative service quality of district offices(in seoul) in order to meet the government's efforts, and to derive improvement point of administrative service quality in district office. Consequently, this study shows administrative service quality factors affecting resident's overall satisfaction degree, service value maturity and positive image maturity of district office and then, will explore improvement ways of each district office through attribute analysis of administrative service quality.

• Journal of the Korea Organic Resources Recycling Association
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• v.3 no.1
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• pp.61-71
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• 1995

This study is concerned with the assessment of the possibility of alum sludge composting, as well as changes of some chemical properties during composting. Alum sludge was mixed in different proportions, which are 0%, 25%, 35% and 45%, respectively, with a sewage sludge and sawdust mixture. The final mixtures to be composted are placed on static piles constructed with a perforated aeration pipe on the ground, and composted for more than 50 days. During the composting of some alum sludge treatments, there was not notable difference in changes of pH, C/N ratio, and content of several minerals among the alum sludge treatments, while changes of pile temperatures and CEC were significant and these remarkable differences in related to the pile temperatures and CEC seem suitable for the evaluation of alum sludge maturity. Also, the results suggested that the proper mixing ratio of alum sludge for composting was 25% level.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.5
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• pp.391-397
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• 2006

This study correlated changes in estradiol-l7$\beta$ ($E_2$), testosterone (T), 17$\alpha$,20-dihydroxy-4-pregnen-3-one (DHP), and vitellogenin (VTG) levels with changes in the gonadosomatic index (GSI) and ovarian histology during the annual reproductive cycle of the wild marbled sole, Limanda yokohamae. Synchronous oocyte development occurs in this fish. Ovary maturity was classified into four periods, based on histological observations: the spawning (December to February), post-spawning (February to April), recovery (May to August), and vitellogenic (September to November) periods. Seasonal changes in the GSI were inversely correlated with water temperatures and reflected the degree of ovarian maturity. Plasma VTG levels were correlated with changes in the GSI, which increased from September to a peak in January, and levels remained comparatively high until February. Estradiol-17$\beta$ was at baseline levels (<0.11 ng/mL) during the spring and summer, and peaked rapidly (1.55$\pm$0.445 ng/mL) from October to January. Plasma T and DHP levels had a similar profile; they rose markedly during the spawning period and remained low (or were not detectable) from spring through autumn. These data indicate that changes in plsama steroid hormones and VTG levels are correlated with the annual ovarian activity of the marbled sole. Based on these results and published reports, it appears that in this species DHP is the most important maturation-inducing steroid and that T is also related to final maturation.