• Journal of the Korean Geotechnical Society
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• v.22 no.6
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• pp.27-40
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• 2006

Damage of cut-and-cover tunnel lining can be attributed to physical and mechanical factors. Physical factors include material property, reinforcement corrosion, etc. while mechanical factors include underground water pressure, vehicle loads, etc. This study is limited to the modeling of rigid circular cut and cover tunnel constructed at a depth of $1.0{\sim}1.5D$ in loose sandy ground and subjected to a vibration frequency of 100 Hz. In this study, only damages due to mechanical factors in the form of additional loads were considered. Among the different types of additional, excessive earth pressure acting on the cut-and-cover tunnel lining is considered as one of the major factors that induce deformation and damage of tunnels after the construction is completed. Excessive earth pressure may be attributed to insufficient compaction, consolidation due to self-weight of backfill soil, precipitation and vibration caused by traffic. Laboratory tunnel model tests were performed in order to determine the earth pressure acting on the tunnel lining and to investigate the applicability of existing earth pressure formulas. Based on the difference in the monitored and computed earth pressure, a factor of safety was recommended. Soil deformation mechanism around the tunnel was also presented using the picture analysis method.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.57-67
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• 2012

There is much confusion with the relationship between character and actor. Under the pressure of 'becoming' a character, the actor tends to begin his work apart from his own senses, imagination and memory, and is most likely to fall into the trap of artificiality and clich$\acute{e}$. Like every other art, the actor has to begin honestly with himself who, in nature, has unfathomable possibilities. To be and live as a character, the actor has to experience. To experience, to react. To react, to see with all the senses. Like ours, each character's life goes on from reaction to reaction, reacting to the images from the imagination and the memory. "You are what you see." The actor is put into the extremely unfamiliar circumstances of drama, given only with his own senses, imagination and memory. Fear comes in. However, fear cannot stop the actor's challenging journey to self-discoveries. The actor does and acts, not because he is certain but because he is not. The actor challenges himself to go beyond the limit and uncertainty, so that he will finally come to know and truly understand human beings from the challenges of his own. In a nutshell, acting is a journey to the unknown and the unfamiliar in which the actor unceasingly discover new 'I's.

• Journal of Elementary Mathematics Education in Korea
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• v.10 no.1
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• pp.67-87
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• 2006

This study is to recognize a problem in the practice of performance assessment in elementary school, and to find out some suggestive points for improvement of teaching·learning method in elementary mathematics through assessment by reducing time restriction according to assessment through the practice of self-assessment, peer-assessment and observation, and then by reflecting the results of assessment on teaching learning plan. For that, the questions of study set up are as follows ; 1. How should self-assessment and peer-assessment be applied to in elementary mathematics assessment? 2. How should the time for 'let's play an interesting game' be managed for assessment of elementary mathematics? 3. How should the results of assessment be reflected on the Process of teaching and learning of mathematics? To solve these problems, a researcher of this thesis performed self-assessment, peer-assessment on 40 students of second grade under her charge as a class teacher, and applied observation in the time management process for 'let's play an interesting game' for a semester. self-assessment was made by mathematics journal, self-assessment chart, peer-assessment was by the analysis of conversation record among students in the situations of assessment, and observation was by observation of activity when playing with the results data of play analyzed. the concrete methods of application as follows ; First, mathematics journal was applied $1{\sim}2$ times by each unit with reconstruction into the level of second grade on the basis of the preceding-study models. Second, peer-assessment was applied to the unit-assessment time and the play-activities time by the method of recording·analyzing the contents of conversation among students in the process of assessment. Third, mathematical attitude & dispositions of students making use of the self- assessment table were examined referring to the teaching learning plan. Fourth, the time management for 'let's play an interesting game' was made through the prior recognition of play method and the joyful play-activities by use of the play-plate. Assessment depended on analysis of play-activities results of students making use of an observation form. Fifth, the results of self-assessment, peer-assessment, and observation were analyzed, and then they were made use of as self-observation data, of teacher her/his self, or teaching·learning improvement data. Students' self-assessment datum (mathematics diary, self-assessment sheets, conversation contents in the process of assessment) and observation materials (check lists, Play-activity result materials, conversation contents in the process of play) obtained in the process of application was analyzed as follows ; 1. From the practice of self-assessment in form of mathematics journal, I could obtain not only datum showing how much students was understanding the learning aims by unit time and to any degree they reached but also information about their response to learning datum and favorable type of learning. 2. Assessment by self-assessment chart was useful in planning the mathematics teaching learning process because it helps ascertain mathematical attitude & dispositions of students. 3. Through the application of peer-assessment, students had the opportunity of communicating with other students looking back on his/her explaining process, and teachers could obtain basic materials for assessment of students. 4, In case of time management for 'let's play an interesting game', there was natural extension of play made through time-security by prior looking into the method of play-activity, and then, for a remained time, by making children play a new game. 5, I could easily record the activities of students by use of the observation. form, and make use of it as basic data for descriptive assessment. 6, Each kinds of data obtained from the results of assessment was helpful for securing self-observation materials in the process of teaching learning and for their betterment in mathematics subject. However, because they were in the second grade of elementary school and there was an individual difference, some students could not make use of mathematics diary or self-assessment form properly. In case of these students, assessment data would be obtained through interview or observation. And for effective operation of play, its purpose & method and matters that demand special attention when play-acting should be clearly guided. Also, when applying an effective play in addition to play activities in textbook, to lessons, interesting mathematics lessons could be guided.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.4
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• pp.361-368
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• 2015

Recently, the earthquake has been increasing a lot, damage of electric power facility has been serious as well. Nowadays, the importance of pipe support system such as Hanger, Brace, Snubber connecting the main structure have been emphasized. These devices can prevent pipe from damage so that reduce the vibration and shock acting on the pipe. For this reason, the FCD(Friction Concave Damper) was developed and has been expected to reduce the vibration on the pipe through the Friction Pendulum System. This paper was described the introduction of self-developed mechanical damper using the friction pendulum principle and the characteristic test was performed to verify the performance of the device. Additionally the test results have been compared with predicted F.A.P(FCD Analysis Program-self developed) results. As a result, reliability of design could be improved.

• Journal of the Korean housing association
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• v.24 no.1
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• pp.1-10
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• 2013

Number of children cared by child care centers has getting up almost half of the from zero to five year age group in korea. Home care children' activities are reported more active and natural than those of center care children. So this study seek the design guidelines for the residential core model of child care centers as second home in korea. The residential core model by Anita Lui Olds was selected and ten domestic center cases were surveyed for guidelines. Firstly, daily-residential core model is learning by daily life at home, and is equiped with cooking kitchenet and group activity area in group room. Secondly, play-residental core model is learning by playing by self, and is equiped with acting, eating and reading common area clustering two or three group room. Thirdly, eco-residental core model is learning by eco-friendly activities, and is equiped with companying, cooperating and sharing area. Fourthly, project-residental core model is learning by project by self, and is equiped with drawing, experimenting and presenting common area. Fifthly, the space of residential core model is organized with three or four group room and clustering living or common area. The larger the center is, the more the cluster is vertically. Facility area and outdoor playground per child is about 7 and $3m^2$.

• The Journal of the Korea Contents Association
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• v.16 no.7
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• pp.504-512
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• 2016

This study was performed to explore the institutional treatment system by analyzing the pattern of musical actor's projection and aftereffect subsequent to the completion of performance. In-depth interviews were conducted with 22 top-class musical actors and actresses of the Republic of Korea. The result of the survey indicated that most actors and actresses suffer from projection and it's aftereffect such as depression for more than one month after performance, and that they tend to rely on self-healing based on self-diagnosis rather than seeking for professional counselling. The symptoms of projection were shown more strongly when the actors or actresses were taking on the role of main character, or acting as a negative or realistic character, or when expressing strong and extreme emotions. In this era of Korean culture, the result of this study implies that our country have to establish the actor's mental caring-related new law and private care centers supported enough funds to encourage the actors to receive more effective actor-friendly treatment service before and after the performance.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.8 no.4
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• pp.145-159
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• 2013

The purpose of this study is to analyze the structural relationship as to how learning flow and self-directed learning are linked to learning motives and academic self-efficacy in the learning setting of high school students. To accomplish such purpose, based on theoretical backgrounds and preceding research findings evaluation models were put to verification for a valid research model for this study. The initial hypothetical model was that self-directed learning ability would have a direct influence on learning motive, academic efficacy and learning flow, while having an indirect influence on learning flow with learning motive and self-efficacy acting as a mediating variable. But the hypothetical model showed low significance level between self-directed learning and learning motive, and learning motive and learning flow. Therefore, links were adjusted to create the final model within the scope that the adequacy of the model might not be compromised. To verify the model, 900 high school students in Seoul were surveyed and the collected data were statistically analyzed using AMOS v21.0 and SPSS v21.0 But 815 surveys were excluded because they were not sufficiently answered. From the analysis, it was found that self-directed learning and academic efficacy have a direct influence on learning flow while self-directed learning and academic efficacy have an indirect leaning motive and learning flow. This finding means that, in the relationship of self-directed learning and learning flow, learning motive and learning efficacy are positive factors that help high school students experience learning flow. Thus, in order to enhance the experience of self-directed learning ability of high school students, various educational endeavors are needed to draw the experience of learning flow during the regular course of study. In addition, customized educational methods and environments are required to increase academic efficacy of the students.

• Journal of ILASS-Korea
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• v.16 no.1
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• pp.1-6
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• 2011

In recent years, the need for more fuel-efficient and lower-emission vehicles has driven the technical development of alternative fuels such as LPG (Liquefied Petroleum Gas) which is able to meet the limits of better emission levels without many modifications to current engine design. LPG has a high vapor pressure and lower viscosity and surface tension than diesel and gasoline fuels. These different fuel characteristics make it difficult to directly apply the conventional gasoline or diesel fuel pump. Self acting lubricated groove design or coating can be used in high-speed and high precision spindle system like a roller-vane type fuel pump, because of its advantages such as low frictional loss, low heat generation, averaging effect leading better running accuracy and simplicity in manufacturing. Those design method can also affect the atomization of fuel from the injector and the formation of fuel film on the intake manifold. In this study, experiments are carried out to get performance characteristics of initial and steady state operation, The characteristics of vane type fuel pump were investigated to access the applicability on LPLi engine.

• Industrial Engineering and Management Systems
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• v.8 no.4
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• pp.221-227
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• 2009

There are customer services jointly provided by two facilities so that each customer will complete the course made up of both facilities' sub-services. The two facilities are assumed invested respectively by an infrastructure owner and one subordinate facility owner, whose partnership is built on their capital investments. This paper presents a mathematical model of Stackelberg competition between the two facility owners to derive their optimal Nash equilibrium. In this study, each facility owner's profit is consisted of fixed revenue fractions of sold services, operating costs (including depreciation cost) and maintenance costs of her facility. The maintenance costs of one facility are incurred both by failures and deterioration due to usage. Moreover, for both facilities, failures are rectified immediately by minimal repairs and preventive maintenance is carried out at a fixed time epoch. Additional assumptions are also employed to develop the model such as customer arrivals are manipulated to follow a Poisson process, and each facility's lifetime is independently Weibull-distributed. The Stackelberg game proceeds as follows. At the first stage of decision making process, the infrastructure owner (acting as a leader) decides the allocation of revenue shares based on her self-interest. After observing the allocation of revenue shares, the subordinate facility owner determines her own optimal price of services. This paper investigates actions and reactions of the two partners in the system. Then analytical conditions are proposed to achieve a unique optimal Nash equilibrium. Finally, some suggestions for further research are discussed.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.4
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• pp.551-564
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• 2016

High-speed flight vehicles (HSFVs) such as space launch vehicles and missiles undergo severe dynamic loads which are generated during the launch and in in-flight environments. A typical vehicle is composed of thin plate skin structures with high-performance electronic units sensitive to such vibratory loads. Such lightweight structures are then exposed to external dynamic loads which consist of random vibration, shock, and acoustic loads created under the operating environment. Three types of dynamic loads (acoustic loads, rocket motor self-induced excitation loads and aerodynamic fluctuating pressure loads) are considered as major components in this study. The estimation results are compared to the design specification (MIL-STD-810) to check the appropriateness. The objective of this paper is to study an estimation methodology which helps to establish design specification for the dynamic loads acting on both vehicle and electronic units at arbitrary locations inside the vehicle.