• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.44 no.3
• /
• pp.64-69
• /
• 2007

Motion control of the system is a position control of motor. Motion control of an uncertain robot system is considered as one of the most important and fundamental research directions in the robotics. Some distinguished works using linear control, adaptive control, robust control strategies based on computed torque methodology have been reported. However, it is generally recognized within the control community that these strategies suffer from the following problems : the exact robot dynamics are needed and hard to implement, the adaptive control cannot guarantee the performance during the transient period for adaptation under the variation, the robust control algorithms such as the sliding mode control need information on the bounds of the possible uncertainty and disturbance. And it produces a large control input as well. In this dissertation, a motion control for the unmanned intelligent robot system using disturbance observer is studied. This system is affected with an impact vibration disturbance. This paper describes a stable motion control of the system with the consideration of external disturbance. To obtain the stable motion independently against the external disturbance, the disturbance rejection is strongly required. To address the above issue, this paper presents a Disturbance OBserver(DOB) control algorithm. The validity of the suggested DOB robust control scheme is confirmed by several computer simulation results. And the experiments with a motor system is performed to give the validity of applicability in the industrial field. This results make the easier implementation of the controller possible in the field.

• Korean Journal of Social Welfare
• /
• v.1
• /
• pp.51-71
• /
• 1979

During last five years several workshops and seminars among social work educators, in and out country, has taken place. In those gatherings there has been, criticism on American model on which curriculum of social work in Korea has mainly based, and many proposals which most developing countries should consider and adopt for developing their own curriculums. The proposals could be summarized as follows; 1. Specification of developmental functions of social work should be made so that the curriculum could involve. It also must come from own societal needs and own national development task. 2. Social work should participate and make contribution to plan and solve the main social problems in own countries. 3. Clarification of educational objective in undergraduate level should be made and one of them must be related to the first professional degree. 4. There should be the courses which provide the content of macro level participation. How much of the proposals are reflected in the current curriculum of Korea? What are the problems Korean social work education has been faced in connection with reflecting the proposals? What kinds of task we should or could perform in order to adopt the proposals? These are the questions which deserved to be studied. The followings are the answers to the questions; 1. The new courses such as social welfare policy and planning, Social Development, Population Dynamics and Family Planning, Social problems, Special Issues in Social Welfare, etc, are placed in the curriculum. 2. Though the new courses are added the courses of case work, group work, and community organization are strongly remained it means that integrative method is not quite adopted and that conflicts are taking place between new and old fashion. 3. Fieldwork placement policy has been changes from concurrent to block and from social work method oriented to social problem oriented. 4. There are lack of integration among the all courses, of consistency between pre and post courses and connection among the related courses. 5. Establishment of image of social worker with B, A. degree should be urgently taken place. It can't be done by social work field alone but by cooperation with all the forces related to the social work practice. 6. B. A. graduate should have a common base of knowledge and competence. It could be come from the clear and specified objectives of undergraduate level education. And agreement among the member schools on the objectives can call on the fundamental similarities in each curriculums. Different programs from one school to another can be tolerated as long as there are fundamental similarities among the schools. Basic concepts and framework of social work should be kept clearly. It is a slow and long process to make social work recognized as a profession in the developing countries. Korea can't be and exception. Failure of having social work be indegenous can't be the reason to refuse an change the basic concepts of social work. One of he most important task which social work education in Korea must achieve in the near future is to establish the minimum requirement courses in the curriculum. Social work field, on the other hand, must find the positions for the social works in the various settings and institute. Clear role and image of social worker can be obtained by doing that.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.131-131
• /
• 2013

A single-layer graphene has been uniformly grown on a Cu surface at elevated temperatures by thermally processing a poly(methyl methacrylate) (PMMA) film in a rapid thermal annealing (RTA) system under vacuum. The detailed chemistry of the transition from solid-state carbon to graphene on the catalytic Cu surface was investigated by performing in-situ residual gas analysis while PMMA/Cu-foil samples being heated, in conjunction with interrupted growth studies to reconstruct ex-situ the heating process. The data clearly show that the formation of graphene occurs with hydrocarbon molecules vaporized from PMMA, such as methane and/or methyl radicals, as precursors rather than by the direct graphitization of solid-state carbon. We also found that the temperature for vaporizing hydrocarbon molecules from PMMA and the length of time the gaseous hydrocarbon atmosphere is maintained, which are dependent on both the heating temperature profile and the amount of a solid carbon feedstock are the dominant factors to determine the crystalline quality of the resulting graphene film. Under optimal growth conditions, the PMMA-derived graphene was found to have a carrier (hole) mobility as high as ~2,700 cm2V-1s-1 at room temperature, superior to common graphene converted from solid carbon.

• Korean Journal of Remote Sensing
• /
• v.23 no.6
• /
• pp.567-573
• /
• 2007

Tidal channel development is influenced by sediment type, grain size, composition and tidal current. Tidal channels are usually characterized by channel formation, density and shape. Quantitative analysis of tidal channels using remotely sensed data have rarely been studied. The objective of this study is to quantify tidal channels in terms of fractal dimension and compare different inter-tidal channel patterns and compare with DEM (Digital Elevation Model). For the fractal analysis, we used box counting method which had been successfully applied to streams, coastlines and others linear features. For a study, the southern part of Ganghwado tidal flats was selected which know for high dynamics of tidal currents and vast tidal flats. This area has different widths and lengths of tidal channels. IKONOS was used for extracting tidal channels, and the box counting method was applied to obtain fractal dimensions (D) for each tidal channel. Yeochari area where channels showed less dense development and low DEM had low fractal dimenwion near $1.00{\sim}1.20$. Area (near Donggumdo and Yeongjongdo) of dendritic channel pattern and high DEM resulted in high fractal dimension near $1.20{\sim}1.35$. The difference of fractal dimensions according to channel development in tidal flats is relatively large enough to use as an index for tidal channel classification. Therefore we could conclude that fractal dimension, channel development and DEM in tidal channel has high correlation. Using fractal dimension, channel development and DEM, it would be possible to quantify the tidal channel development in association with surface characteristics.

• Review of Culture and Economy
• /
• v.20 no.1
• /
• pp.51-80
• /
• 2017

This study aims to analyze various issues and problems in the implementation process of cultural impact assessment in 2016. As a result of the analysis, it is found that the evaluation index of the cultural impact assessment is difficult to understand, and the referring data and materials in the evaluation planning phase in the process of the cultural impact assessment are deficient, and the evaluation planning is based on surveys rather than various methods. And there are some problems with evaluation scales and weighting, and they are focused on the evaluation itself rather than the feedback of the evaluation results. Therefore, this study suggests that, in the evaluation planning phase, the different methods of comparing the evaluation results according to the project execution, the project progress, and the completion time of the project should be adopted, and the project manager and the evaluation group participate developing the evaluation indicators together, and methodology for identifying causal relationship such as system dynamics will be adopted. In the stage of evaluation, it is necessary to introduce various methodology such as diverse residents participation, abundant case study, application of quantitative methodology, and the utilization of expert evaluation teams. In the evaluation feedback stage, it is necessary to provide thorough consulting based on the evaluation results.

• Journal of Korean Society of Forest Science
• /
• v.110 no.4
• /
• pp.577-589
• /
• 2021

Soil seed bank community contributes to the long-term conservation of plant diversity and vegetation dynamics, and their decreasing diversity and density with soil depth provide critical perspectives (deterministic and stochastic) for understanding the community disassembly process. We analyzed changes in species composition and diversity and structuring patterns by soil layer (top and bottom), including surface vegetation, in Gwangneung Forest, a mature forest with a vegetation climate in the temperate central part of the Korean Peninsula. From two layers of soil collected with a vertical difference of 10 cm, 934 specimens of 27 families, 40 genera, 44 species, three varieties, and 47 taxa, germinated. Although species diversity and germination density decreased in most comparative characteristics, including growth type, there was no statistical significance due to large deviations. Within-group variability of species composition was similar in the upper and lower soils, as was the decline pattern in co-occurred species (ζ-diversity) and change in species retention probability. The structuring process of the community composition in the two soil layers was fitted with an exponential correlation rather than a power function, demonstrating the dominance of the stochastic process. The pattern in diversity and species turnover according to soil depth in Gwangneung Forest was discovered to be structured by stochastic random events, such as seed vertical movement rather than interaction with trait characteristics.

• Korean Journal of Construction Engineering and Management
• /
• v.22 no.2
• /
• pp.12-20
• /
• 2021

Unsafe working environments slow down working speed in that it takes a lot of time to respond in case of an accident, greatly reducing the productivity of construction work. Therefore, proper safety management that does not impede the productivity of construction works is a very important factor for successful construction project. However especially in mega project, the mutual effects of safety management and productivity are complex. Therefore, this study establishes a causal model between safety management and productivity influencing factors based on effectiveness metrics, and analyzes the effect of increased site congestion due to excessive personnel input, irregular safety measures and inefficient change of work schedules. The result of this study, is expected to contribute to enhancing the competitiveness of the construction industry as the basis for establishing a safety management plan that can secure appropriate productivity.

• Journal of Popular Narrative
• /
• v.27 no.1
• /
• pp.99-130
• /
• 2021

This paper examines printed materials such as weekly newsletters and leaflets issued by Dansungsa, a movie theater in Colonial Korea for a promotional purpose as independent modern media. During the 1920s and 1930s, in tandem with the development of the incipient printing houses in Namchon, Gyeongseong, including Suyeongsa, Dansungsa published promotional prints including weekly newsletters and leaflets in a serial manner to compete with Joseon-gukjang and Umigwan. As these materials contain various information including movie programmes, spectatorship, distributional channels, and promotional strategies that bears witness to theater culture of this time, this paper focuses on the dynamics where not only text and image but also audiences and filmic texts are mediated one another. To this end, the paper has three objectives. First, I argue that weekly newsletters and leaflets can be considered as 'flickering media' that meddles in text and image culture. Second, Dansungsa's promotional prints interpellated film audiences as a loyal fan group while mediating audiences and filmic texts. In doing so, I suggest that these print materials established its own cultural domain differentiated from filmic culture itself. Third, these ephemeral materials contributed to narrowing the gap between colonial Joseon and the World in its imaginary geography through the function of mediation.

• 한국노년학
• /
• v.41 no.3
• /
• pp.327-351
• /
• 2021

This study was motivated by the awareness that little attention has been paid to this issue both theoretically and empirically, despite the fact that financial abuse causes serious problems which are difficult for the elderly to recover from. This study intends to explore what the patterns of financial abuse targeting the elderly are, what causes and sustains these abuses, and what makes it difficult to counter such financial abuses. Data analysis was based on individual and group interviews of ten professionals expected to encounter the most financially abused elderly in social welfare institutions. The thematic analysis shows that financial abuse is often caused and maintained in a trusting relationship through care and protection. Because financial abuse was inflicted on the vulnerable elderly in a state of reinforced psychological dependence based on a long and trusting relationship, it appears that it has been made with tacit acknowledgement and consent. Despite those complex dynamics, it is noted that financial abuse can be judged as such only when the elderly claim to suffer from harm. Rather, intervention without victims' acknowledgement tends to be perceived as violating their right to self-determination. This reality naturally leads to the termination of the necessary interventions with the victims in an abusive situation. Based on these results, discussion focused on more realistic and diverse approaches to the issue of financial abuse of older adults.

• International Journal of Computer Science & Network Security
• /
• v.22 no.10
• /
• pp.17-24
• /
• 2022

The article proves that the main goal of informatization of higher education institutions in the EU countries is to improve the quality of education of future specialists by introducing digital educational resources into the education process. The main tasks of informatization of education are defined. Digital educational resources are interpreted as a set of data in digital form that is applicable for use in the learning process; it is an information source containing graphic, text, digital, speech, music, video, photo and other information aimed at implementing the goals and objectives of modern education; educational resources on the Internet, electronic textbooks, educational programs, electronic libraries, etc. The creation of digital educational resources is defined as one of the main directions of informatization of all forms and levels of Education. Types of digital educational resources by educational functions are considered. The factors that determine the effectiveness of using digital educational resources in the educational process are identified. The use of digital educational resources in the training of future specialists in the EU countries is considered in detail. European countries note that digital educational resources in professional use allow you to implement a fundamentally new approach to teaching and education, which is based on broad communication, free exchange of opinions, ideas, information of participants in a joint project, on a completely natural desire to learn new things, expand their horizons; is based on real research methods (scientific or creative laboratories), allowing you to learn the laws of nature, the basics of techniques, technology, social phenomena in their dynamics, in the process of solving vital problems, features of various types of creativity in the process of joint activities of a group of participants; promotes the acquisition by teachers of various related skills that can be very useful in their professional activities, including the skills of using computer equipment and various digital technologies.