• Proceedings of the Korean Geotechical Society Conference
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• 1995.10a
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• pp.1031-1040
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• 1995

Recently, a more strict regulation has become effective on ground vibration and noise induced by construction activities. Consequently the demand for the most widely used method of installing precast piles, i.e. driven piles, is declining. At the same time the demand for low noise and low vibration piling method increased sharply. Currently there are several different low noise and low vibration methods of installing precast piles, mostly preboring method. However, the actual level of ground vibration and noise of these method of construction has not yet been clearly understood. In this paper, through field measurement, suggestion has been made to meet the requirements of the revised regulation.

• Journal of Korean Library and Information Science Society
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• v.20
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• pp.133-153
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• 1993

The purpose of this study is to form a different evaluation method of academic libraries in Korea. In order to this product life cycle and product portfolio matrix have been used. While they are based upon products and services, their general concept is useful for library managers as they help to distinguish which books have potential for growth. Writer tried to transform them into book life cycle and book portfolio matrix as a tool for assessing the quality of stock on the library shelves. With this method, writer a n.0, ppraised practically the Sociology Collection of Pusan National University Library by the state of usage and classified them into four groups that were development books, growth books, maturity books, and declining books.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.3
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• pp.162-170
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• 2005

Although the numbers of pedestrian fatalities and injuries are steadily declining worldwide, pedestrian protection is still an important issue. Extensive researches have been carried out in the field of pedestrian protection in order to establish pedestrian safety regulations. The automobile hoods and bumpers, which pedestrians frequently run into during accidents, should be safely designed for pedestrians. Two analysis methods are utilized to design safe structures of the hood and the bumper. They are real experiment and computer simulation. In this research, a method is developed to simultaneously utilize the results from the experiment and the simulation. For design, orthogonal arrays are employed to combine the two methods. Based on this method, a hood and a bumper are designed to protect pedestrians.

• Journal of the Ergonomics Society of Korea
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• v.5 no.2
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• pp.17-25
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• 1986

In recent years, the average life span of people in advanced countries has increased. Conwequently, the number of middle-aged and old workers who have the will to work has increased. On the other hand, the declining birth rate has decreased the number of young workers. However, because many enterprises in advanced countries have extended their mandatory retirement age from 55 to 60 years, labor accidents involving aged workers are on the increase. As a result, the need for a method to evaluate the work skills of middle-age and old workers has become urgent. To explore one such method, this study investigated the relationship between aging and manual dexterity. Dexterity was found to deteriorate with age, but with large variability from individual to individual. The parameters of dexterity used in this experiment were found to be reliable.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.10
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• pp.1509-1516
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• 2004

During fuel irradiation tests, all parts of cylindrical structure with multiple holes act as heat sources due to fussion heat and ${\gamma}$-flux. The high temperature is especially generated in the center of pellet. Because of the high temperature, many problems occur, such as melting of pellet and declining of heat transfer between cladding and coolant. In this paper, it is attempted to minimize the temperature of pellet using optimization method. For thermal and optimization analysis of structure, the finite element method code, ANSYS 5.7 is used. Through the optimum design process, the temperature of SBT diminished 10％ and the temperature of OBT diminished 18％.

• Journal of the Korean Institute of Educational Facilities
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• v.28 no.2
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• pp.3-10
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• 2021

Community-based design is also becoming important in Korea recently. However, the existing design methods of the "conformity" method had the problem of excluding the participation of residents. Therefore, the "decision-making" method, in which residents participate in the design themselves, is drawing attention. Development of specific methods is important for residents to actively participate in "decision making." The theory of "Design Games" has long been studied as a method of community-based design in many countries. The old downtown areas of Jeju Special Self-Governing Province are increasing in number of buildings abandoned due to aging and declining. Abandoned buildings are causing many social problems. A decision-making method has been developed in Jeju for the regeneration design of abandoned buildings. This study conducted a design workshop involving residents on abandoned buildings in the old city center of Jeju City. The possibility and task of decision-making method were analyzed. As a result, participating residents were actively involved in decision-making. It also helped residents understand and learn about the attractions of the neighborhood. Meanwhile, there were also difficulties in communicating among some participants. This is a structural problem with this method. Studies have also shown that it is important for residents themselves to try to understand the neighborhood.

• PNF and Movement
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• v.7 no.3
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• pp.29-38
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• 2009

Purpose : The aim of this study is to examine the effect of the phenol compound-cold therapy plus exercise therapy on the carrageenan(CAR)-induced muscle pain. Method : Mice were injected 0.1ml of 2% CAR into the gastrocmemius(GAS) muscle for the induction of muscle pain. After 4 hours from the injection of CAR, the cold therapy with 1% syringic acid was done to GAS muscle. After 2 hours from cold therapy, the exercise therapy such as muscle stretching, climing- and declining-movements was performed three times interval of 10 minutes in each experimental group. After 4, 10 and 24 hours from CAR-induced muscle pain, the measurements of muscle diameter, paw withdrawal latency(PWL) and, tail flick latency(TFL) were carried out. Results : In this study, the thickness of GAS muscle in CAR-induced muscle pain significantly increased compared with control. While, the thickness of GAS muscle adopted cold syringic acid-therapy with exercise-therapy group was significantly decreased than that of CAR-induced muscle pain. In the measurements of PWL and TFL, cold syringic acid-therapy with exercise-therapy group was remarkably increased than CAR-induced muscle pain group in PWL and TFL. All measurements were showed significantly different between the treated-group and the treated-time. Conclusions : From these results, it is suggested that the cold syringic acid-therapy with exercise-therapy such as muscle stretching, climing- and declining-movement was effective in the prevention of CAR-induced muscle pain by the decrease of muscle thickness and the increase of PWL and TFL.

• Journal of The Korean Astronomical Society
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• v.50 no.2
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• pp.21-27
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• 2017

The autoregressive method provides a univariate procedure to predict the future sunspot number (SSN) based on past record. The strength of this method lies in the possibility that from past data it yields the SSN in the future as a function of time. On the other hand, its major limitation comes from the intrinsic complexity of solar magnetic activity that may deviate from the linear stationary process assumption that is the basis of the autoregressive model. By analyzing the residual errors produced by the method, we have obtained the following conclusions: (1) the optimal duration of the past time for the forecast is found to be 8.5 years; (2) the standard error increases with prediction horizon and the errors are mostly systematic ones resulting from the incompleteness of the autoregressive model; (3) there is a tendency that the predicted value is underestimated in the activity rising phase, while it is overestimated in the declining phase; (5) the model prediction of a new Solar Cycle is fairly good when it is similar to the previous one, but is bad when the new cycle is much different from the previous one; (6) a reasonably good prediction of a new cycle can be made using the AR model 1.5 years after the start of the cycle. In addition, we predict the next cycle (Solar Cycle 25) will reach the peak in 2024 at the activity level similar to the current cycle.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.97-115
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• 2023

In recent years, the structure of the population has been changing rapidly, with a declining birthrate and aging population, and the inequality of population distribution is expanding. At this point, changes in population estimation methods are required, and more accurate estimates are needed at the subregional level. This study aims to estimate the population in 2040 at the 500m grid level by applying an explainable machine learning to Busan in order to respond to this need for a change in population estimation method. Comparing the results of population estimation by applying the explainable machine learning and the cohort component method, we found that the machine learning produces lower errors and is more applicable to estimating areas with large population changes. This is because machine learning can account for a combination of variables that are likely to affect demographic change. Overestimated population values in a declining population period are likely to cause problems in urban planning, such as inefficiency of investment and overinvestment in certain sectors, resulting in a decrease in quality in other sectors. Underestimated population values can also accelerate the shrinkage of cities and reduce the quality of life, so there is a need to develop appropriate population estimation methods and alternatives.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.564-569
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• 2003

During fuel irradiation tests, all parts of cylindrical structure with multiple holes act as heat sources due to fussion heal and ${\gamma}-flux$. The high temperature is especially generated over $2500^{\circ}C$ in the center of pellet. Due to the high temperature, many problems occur, such as melting of pellet and declining of heat transfer between cladding and coolant. [n this study, it is attempted 10 minimize the temperature of pellet using optimization method about geometric variables. For thermal and optimization analysis or structure. the finite element method code. ANSYS 5.7 is used. In this procedure. subproblem approximation method is used to the optimization methods. Through the optimum design process, the temperature of sealed basket type is reduced from $2537^{\circ}C$ to $2181^{\circ}C$ and the temperature of open basket type is reduced from $2560^{\circ}C$ to $2106^{\circ}C$.