• Journal of Astronomy and Space Sciences
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• v.34 no.4
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• pp.289-302
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• 2017

The key risk analysis technologies for the re-entry of space objects into Earth's atmosphere are divided into four categories: cataloguing and databases of the re-entry of space objects, lifetime and re-entry trajectory predictions, break-up models after re-entry and multiple debris distribution predictions, and ground impact probability models. In this study, we focused on reentry prediction, including orbital lifetime assessments, for space situational awareness systems. Re-entry predictions are very difficult and are affected by various sources of uncertainty. In particular, during uncontrolled re-entry, large spacecraft may break into several pieces of debris, and the surviving fragments can be a significant hazard for persons and properties on the ground. In recent years, specific methods and procedures have been developed to provide clear information for predicting and analyzing the re-entry of space objects and for ground-risk assessments. Representative tools include object reentry survival analysis tool (ORSAT) and debris assessment software (DAS) developed by National Aeronautics and Space Administration (NASA), spacecraft atmospheric re-entry and aerothermal break-up (SCARAB) and debris risk assessment and mitigation analysis (DRAMA) developed by European Space Agency (ESA), and semi-analytic tool for end of life analysis (STELA) developed by Centre National d'Etudes Spatiales (CNES). In this study, various surveys of existing re-entry space objects are reviewed, and an efficient re-entry prediction technique is suggested based on STELA, the life-cycle analysis tool for satellites, and DRAMA, a re-entry analysis tool. To verify the proposed method, the re-entry of the Tiangong-1 Space Lab, which is expected to re-enter Earth's atmosphere shortly, was simulated. Eventually, these results will provide a basis for space situational awareness risk analyses of the re-entry of space objects.

• Journal of the Korean Society for information Management
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• v.32 no.4
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• pp.167-203
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• 2015

This study tends to apprehend how much public library contributes to a role of upbuilder of digital integrated local society through a survey. For this, I performed the survey on 935 organization of public library in the whole country registered in national library statistical system. As a result, firstly, it's apprehended that equipment infra, Internet infra, etc like computer, laptop, scanner, tablet PC, etc are in relatively high level. Secondly, service or resource like electronic book, digital and virtual reference service, library service mobile App, etc that users can use are in relatively high level but software supporting cooperation and group task, fusibility of participating space, etc are shown very low level. Thirdly, the rate of literacy training relating to technology were only 22.4%, education subject focused on resource searching subject and somewhat future-oriented technical education like directions of video conference technique, cloud computing application education, etc wasn't conducted. Finally, we should consider expansion of providing technology and equipment and provision of future-oriented service and education according to a flow of the time that needs to seek change in various roles of library as enjoying culture space or creative space.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.8
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• pp.425-433
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• 2020

This paper aims to develop a conceptual framework for evaluating the impact of motivational factors on the work results of lecturers at Vietnam National University, Hanoi (VNU), one of two leading multidisciplinary and multi-sectoral national universities in Vietnam. This study has considered wages and other benefits (WB), training and development (TD), working environment (WE) and working motivation (WM) as motivational factors, and proposed a structural model of the impact of motivational factors on the work results of lecturers at VNU. The empirical analysis used data from the survey data of 321 university lecturers. Comprehensive, valid, and reliable tools (SPSS 26 and SmartPLS 3.0 software) are used to evaluate rigorous statistical tests including convergence validity, discriminatory validity, reliability, and average variance extracted to analyze and verify the gathered data, and the hypotheses developed. The result of path analysis shows that four motivational factors constitute a structured system with different degrees of influence on the work results of lecturers. There is also a positive relationship between the motivational factors and the work results of lecturers. As a result, it can be concluded that all hypotheses developed are supported. Several recommendations are further suggested to improve the performance of lecturers at VNU.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.189-192
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• 2008

Generally, the inspection is hard work and needs a lot of time. So, this work contains subjectivity of inspector owing to carry out the visual evaluations through naked eye. Thus, the result of inspection is not objective and reliable. The purpose of this study is to develop new inspection technique to solve above problems and to provide convenient inspection work. We make a new inspection system using digital image processing technology. This program can stitch each image and detect cracks of surface of concrete bridge. Also, It can extract an investigation drawing from the picture. Also, this program is a kind of management tools designed to have some functions such as converting the image data obtained from cameras to Data-Base format, searching and storing the data. At first, we try to make a automatic extracting program. But, changed by semiautomatic method because of various problems. Through field experiments, the application of this inspection system with specialty software has proven to be much faster, safer, and reliable than the inspections carried out by the naked eyes in managing safety of the bridges. The new inspection method may be able to make the inspection of bridge more efficient and reliable.

• The KIPS Transactions:PartD
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• v.19D no.1
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• pp.81-94
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• 2012

FORM(Feature-Oriented Reuse Method) is one of representative product line engineering methods. The essence of FORM is the FORM architecture models, which can be reused in the development of multiple products of a software product line. The FORM architecture models, however, have the following problems when applied in practice. First, they are not standardized models like UML(Unified Modeling Language) and therefore they can be constructed only through a specific modeling tool. Second, they do not represent architectural variability explicitly. Instead their variability is only managed through a mapping from a feature model. To address these two problems, we developed at first a method for representing the FORM architecture models using UML, which enables the FORM architecture models to be constructed through various available UML modeling tools. Also, we developed an effective method for representing as well as managing the variability of the FORM architecture models through a mapping from a feature model.

• Journal of Digital Contents Society
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• v.2 no.1
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• pp.1-7
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• 2001

The authoring systems for digital contents using multimedia technologies ate requested in many fields such as education, medical science, entertainment market e-commerce and etc. Especially, the emergence of cyber universities and the rapid expansion of on-line education market require the effective contents authoring systems, which have various functions to generate the qualified contents. Therefore, many systems arc developed and currently used. However, since the developed systems considered only the developer's convenience, the generated digital contents by using these systems are failed to draw tile users'(or learners') active interaction with contents. That is, since the users just watch the contents like watching a drama or a film, it causes many problems in delivering the contents effectively or in evaluating the users. This paper presents, develops, and implements the new contents authoring system by using programing languages and/or software tools. The presented, developed, and implemented system mimics the face-to-face education in off-line system, induces the users' active interaction with contents, and continuous evaluation to the users.

• The Korean Journal of Community Living Science
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• v.16 no.1
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• pp.37-47
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• 2005

Education has been emphasized as one of tools of realizing social equality, which has its base on the ideology of equal education opportunity. The Opportunity level of adult education is important in the meaning of social equality. but these days It is being inequality. so The objectives of this study were 1) measuring the opportunity level of adult education in Korea, 2) analysing the difference adult education level by gender, regions, 3) making out the gap of the its level by social educational agencies, 4) to suggest the way to improve the opportunity level of adults educations between adults by gender, regions. The followings are the results from the study: Adult education participation level were lower. Adult education participation level per adult education type showed higher participation at private institutes, lower at cultural center of community and school's human and material resources are not properly utilized in adult educational activities. By adult education participation level per gender and location, women have a higher participation level then men, and urban areas have a higher participation level then rural areas. In case of location, environment variables is most explanatory in adult education participation level. To strive for methods to activate school-oriented adult education activities and to develop political solution to ease the resources gaps for adult education investment among regions in order not to deepen environment gaps of adult education between urban and rural areas. For adult education activation, institution and bodies in charge of adult education should expand and discover hardware and develop and distribute software. Also, adult education specialists who operate and manage these hardware and sofeware efficiently should be recruited.

• Structural Engineering and Mechanics
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• v.53 no.2
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• pp.205-226
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• 2015

Finite element method (FEM) is an effective quantitative method to solve complex engineering problems. The basic idea of FEM for a complex problem is to be able to find a solution by reducing the problem made simple. If mathematical tools are inadequate to obtain precise result, even approximate result, FEM is the only method that can be used for structural analyses. In FEM, the domain is divided into a large number of simple, small and interconnected sub-regions called finite elements. FEM has been used commonly for linear and nonlinear analyses of different types of structures to give us accurate results of plane stress and plane strain problems in civil engineering area. In this paper, FEM is used to investigate stress analysis of a shear wall which is subjected to concentrated loads and fundamental principles of stress analysis of the shear wall are presented by using matrix displacement method in this paper. This study is consisting of two parts. In the first part, the shear wall is discretized with constant strain triangular finite elements and stiffness matrix and load vector which is attained from external effects are calculated for each of finite elements using matrix displacement method. As to second part of the study, finite element analysis of the shear wall is made by ANSYS software program. Results obtained in the second part are presented with tables and graphics, also results of each part is compared with each other, so the performance of the matrix displacement method is demonstrated. The solutions obtained by using the proposed method show excellent agreements with the results of ANSYS. The results show that this method is effective and preferable for the stress analysis of shell structures. Further studies should be carried out to be able to prove the efficiency of the matrix displacement method on the solution of plane stress problems using different types of structures.

• Journal of the Korea Society for Simulation
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• v.15 no.1
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• pp.11-17
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• 2006

This paper shows a case study of designing a PLC logic simulator that was developed to simulate and verify PLC control programs for nuclear plant systems. The nuclear control system requires strict restrictions rather than normal process control system does, as it works with a high-risky and dangerous nuclear plant. One is that it should assure the safeness of the control programs by exploiting severe testing. The other restriction is that the control programs should be executed fast enough such that they could control multi devices concurrently in real-time. To cope with these restrictions, we devised a logic compiler which generates C-code programs from given PLC logic programs. Once the logic program was translated into C-code, the program could be analyzed by conventional software analysis tools and could be used to construct a fast logic simulator after cross-compiling, in fact, that is a kind of compiled-code simulator.

• Journal of East-West Nursing Research
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• v.6 no.1
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• pp.7-22
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• 2001

This study is a discriptive research to identify stress and powerlessness based on Korean hemodialysis patients' constitution. Research subject was 112 hemodialysis patients who are treatment processing in P university hospital and K hemodialysis hospital in S City, and the data were collected for 60 days from December 20, 1999 to January 30, 2000. The research tools used for the measurement of constitution was "QSCC II", the measurement of the stress was Jeon chi ja's "Scale of Hemodialysis patient's Stress"(1985), and the measurement of powerlessness was Kim joe ja's "Scale of Powerlessness"(1992). The reliability of the scale for stress is Cronbach's Alpha 0.8819 and that of powerlessness is Cronbach's Alpha 0.6993. Data analysis was performed using SPSSWin 9.0 software. We tested them with real number, percentage, average score, standard deviation, t-test, F-test(ANOVA), Pearson's Correlation Coefficient, and Multiple stepwise regression. The results of this study were as follows : 1. Hemodialysis patients' constitution were : Soyangin 38.4%, Taemin 34.8%, and Soeumin 26.8%. 2. The average score of the stress by hemodialysis patients were the mean $89.72{\pm}20.26$ points. The average score of powerlessness was the mean $34.19{\pm}6.46$ points, by hemodialysis patients. 3. The result of the Pearson Correlation showed no correlation between the score of stress and the score of powerlessness. 4. In their relationship between general characteristics and the score of stress : in marriage state, job(P=0.016, P=0.007) and In their relationship between general characteristics and the score of powerlessness : in age, marriage state, educational level, job(P=0.000, P=0.012, P=0.002, P=0.050) have statistically meaningful differences. 5. The factor affecting the powerlessness of hemodialysis patients was physical area of stress and its explanatory power was 18.5%.