• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.465-469
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• 2000

This paper describes a single-chip full-custom implementation of pipelined adaptive decision-feedback equalizer (PADFE) using a 0.25-${\mu}{\textrm}{m}$ CMOS technology for wide-band wireless digital communication systems. To enhance the throughput rate of ADFE, two pipeline stage are inserted into the critical path of the ADFE by using delayed least-mean-square (DLMS) algorithm Redundant binary (RB) arithmetic is applied to all the data processing of the PADFE including filter taps and coefficient update blocks. When compared with conventional methods based on two's complement arithmetic, the proposed approach reduces arithmetic complexity, as well as results in a very simple complex-valued filter structure, thus suitable for VLSI implementation. The design parameters including pipeline stage, filter tap, coefficient and internal bit-width and equalization performance such as bit error rate (BER) and convergence speed are analyzed by algorithm-level simulation using COSSAP. The singl-chip PADFE contains about 205,000 transistors on an area of about 1.96$\times$1.35-$\textrm{mm}^2$. Simulation results show that it can safely operate with 200-MHz clock frequency at 2.5-V supply, and its estimated power dissipation is about 890-mW.

• Journal of Software Engineering Society
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• v.27 no.1
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• pp.8-14
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• 2018

As cloud computing has emerged as a hot trend in the IT industry, various types of cloud services have emerged. In addition, cloud service broker (CSB) technology has emerged to alleviate the complexity of the process of selecting the desired service that user wants among the various cloud services. One of the key features of the CSB is to recommend the best cloud services to users. In general, CSB can use a method to evaluate a service by receiving feedback about a service from users in order to recommend a cloud service. However, since each user has different criteria for giving a rating, there is a problem that reliability of service evaluation can be low when the rating is only used. In this paper, a method is proposed to supplement evaluation of rating based service by applying machine learning based sentiment analysis to cloud service user's review. In addition, the CSB prototype is implemented based on proposed method. Further, the results of comparing the performance of various learning algorithms is proposed that can be used for sentiment analysis through experiments using actual cloud service review as learning data. The proposed service evaluation method complements the disadvantages of the existing rating-based service evaluation and can reflect the service quality in terms of user experience.

• Journal of Science Education
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• v.32 no.1
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• pp.61-72
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• 2008

The purpose of the study is to research students' proficiency with systems-thinking approach concerning water cycles and to acquire data on Earth System-related concepts based on students' feedback. To achieve the purpose of the study, I chose 4 mid-level high school juniors living in Pohang, where the high school equalization policy has not been implemented, and the students answered a questionnaire about water cycles. Then, based on the results, I created a causal map and evaluated it using systems-thinking analysis. The results of the study are as follows: First of all, among the answers of the subjects, there were 21 concepts related to the conception of the earth system : 14 of the conceptions were linked scientifically, and 7 of the conceptions were not linked scientifically. Secondly, results of the causal map of what the subjects described showed that only two students'(A and C) feedback loops were completed, and that student C's feedback loop included unscientific reasoning. In conclusion, this study indicated that the students failed to understand the water cycle with the systems-thinking approach, or alternatively they applied low-level systems-thinking approach and had a lower understanding of it.

• Journal of Science Education
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• v.39 no.1
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• pp.113-131
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• 2015

The purpose of this study was to analyze the interactive patterns between teacher and students in middle school earthh science classroom, identify difference of discourse types between earthh science classes taught by majored and non-majored teacher, find the relationship between the discourse pattern and the type of teachers' questions. For that purpose, the participants in this study included four teachers and their students of three middle schools in Seoul. The data consisted of two parts. First, we categorized interaction between teacher and students into the types of discourses by the use of Mortimer and Scott's analytical framework(2003). Second, we classified teachers' questions into four different types of question based on MNeill & Pimentel's classification scheme(2009) to examine for the relationship between the discourse pattern and the type of teachers' questions. As a result, all teachers used interactive/authoritative discourse most in middle school earth science class. Therefore, there was more authoritative discourse to non-majored teacher in comparison with majored teacher. And study demonstrated that the discourse pattern was more related to feedback about student's response rather than the type of teachers' question. In other words, the dialogic discourse showed up more frequently when the teacher used delayed feedback with positive and accepting attitude.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.12
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• pp.60-69
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• 2000

This paper describes a single-chip full-custom implementation of pipelined adaptive decision-feedback equalizer(PADFE) using a 0.25-${\mu}m$ CMOS technology for wide-band wireless digital communication systems. To enhance the throughput rate of ADFE, two pipeline stages are inserted into the critical path of the ADFE by using delayed least-mean-square(DLMS) algorithm. Redundant binary (RB) arithmetic is applied to all the data processing of the PADFE including filter taps and coefficient update blocks. When compared with conventional methods based on two's complement arithmetic, the proposed approach reduces arithmetic complexity, as well as results in a very simple complex-valued filter structure, thus suitable for VLSI implementation. The design parameters including pipeline stage, filter tap, coefficient and internal bit-width, and equalization performance such as bit error rate (BER) and convergence speed are analyzed by algorithm-level simulation using COSSAP. The single-chip PADFE contains about 205,000 transistors on an area of about $1.96\times1.35-mm^2$. Simulation results show that it can safely operate with 200-MHz clock frequency at 2.5-V supply, and its estimated power dissipation is about 890-mW. Test results show that the fabricated chip works functionally well.

• Management & Information Systems Review
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• v.36 no.3
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• pp.17-35
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• 2017

This study investigates the determinants of strategic positional change. Specifically, the study suggests performance feedback affects to a firm's strategic repositioning. Performance feedback is a concept that a firm decides whether success or not by comparing its performance relative to its aspiration level. Prior studies successively discover diverse behaviors. The study suggests three unexplored relationships between performance gaps and strategic positioning. First, when a firm's performance is below relative to its aspiration level, that firm's strategic position will be deviate from the industry norm. Second, as the degree of industrial density increases, the tendency that a firm's strategic position becomes deviate from the industry norm decreases. Third, when the degree of reference group's performance decreases, the tendency that a firm's strategic position becomes deviate from the industry norm decreases. For empirical analysis, this study examines data of 538 firms that in North America crude petroleum and natural gas industry. The result reveals that the direction of a firm's strategic change is shaped when firms' performance is below relative to aspiration level. Also, this relationship is moderated as industrial density changes or when reference groups' performance decreases. This study contributes to the current literature by explaining how a firms' strategic position is decided. Also, this study reveals that reference groups' performance could affect to organizational choice.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5578-5587
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• 2011

The purpose of this study is to confirm how keeping a educational diary in which no feedback is given in the teaching practice in kindergartens affects a teacher efficacy and the educational belief of preschool teachers-to-be as well as the organizational health of kindergartens to practice according to the way teachers feel. With this aim, the study aimed at 34 seniors at the Department of Early Childhood Education in the four-year college in Chungnam. The study conducted this experiment using the nonequivalent control group pretest-posttest design, and carried out a $x^2$ analysis and a t-test according to the data. Concerning the research results, first, keeping a educational diary of teaching practice affirmatively affected a teacher efficacy. Second, it did not significantly affect a teacher's educational belief. Third, it did not significantly affect the organizational health of the kindergarten to practice according to the ways teachers-to-be feel. This study is meaningful in that keeping a reflective journal in which feedback by a guidance teacher for practice becomes the basic proposition may be replaced with the keeping of a diary of practice at the level of practicality. This means that a teacher's sense of efficacy may improve simply by keeping a educational diary of teaching practice without feedback by a guidance teacher.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.2
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• pp.65-74
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• 2012

This paper aimed at the development of a unified wireless control system in order to control various forms of vibration of bridges. This unified wireless control system unified all different systems each of which functioned for difference purpose such as measurement, analysis, judgement, and control of data acquired from the movement of structure. It was designed to control structures with feedback which was returned according to each different situation after analyzing various signals measured about the structure. In this system, every information in each step from measurement to control was wirelessly transmitted to its central system so that a manager was able to effectively monitor the whole process. Just for the case when any system control need to intervene occurred, a graph user interface was designed for better access. In order to evaluate its basic performance, an experiment was carried out to see how signal input and output were done by comparing its results with those of a wired system. On the basis of the experiment, a vibration control experiment was performed on a model of cable-stayed bridge to see if the unified wireless control system worked well in realtime. This was carried out under four conditions, and the graph and quantitative result under each condition were compared each other. All experiments proved that the unified wireless control system functioned as well as the wired one in terms of its basic performance and vibration control.

• Journal of the Society of Disaster Information
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• v.17 no.2
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• pp.306-318
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• 2021

The dispatch law has a negative impact on safety management at construction sites as the command and command relationship to safety assistants of the original contractor are applied to the dispatch law. Purpose: The purpose is to study the importance and impact of safety management according to the dispatch law, and to propose a direction for safety management so that safety assistants can actively and proactively prevent accidents. In this study, we used AHP analysis techniques for experts to achieve the final goal and verified the suitability through logistic regression. Method: AHP analysis technique is used for experts and workers and logistic regression analysis is conducted. Result: The result of analyzing scenario data where the dispatch method can be applied showed the importance in the order of education (SkillUp education), management (work-time management) and direct instructions (feedback instruction). In logistic regression analysis, feedback is the factor that affects direct instruction, and in education management, the ratio of education management is 3.42 times lower than that of other groups when only the team leader of the company gives work instructions. Conclusion: The management of feedback and education is more important than anything else within the range in which the dispatch method is not applied, and the expansion of non-face-to-face online education is judged to avoid the violation of dispatch method because the expansion of non-face-to-face online education due to covid 19 recently has brought more various target for safety education.

• Hwankyungkyoyuk
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• v.10 no.2
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• pp.311-324
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• 1997

General citizens can be a valuable resource for various types of environmental monitoring when they are well-trained and managed. Successful use of volunteer monitors depends on understanding that citizens are partners sharing expanded roles as the guardians of their local environment. Citizen volunteer monitoring programs are developed for three reasons: 1) to supplement environmental data collected by professional staffs in governmental agencies and scientific institutions; 2) to educate the public about local environmental problems; 3) to build a constituency of citizen to practice sound environmental management at a local level and build public support for environmental protection. All three goals can be achieved with a well-organized program which provides useful and credible data. Initial step in planning a successful volunteer monitoring project is to clearly identify the use to be made of the data. Technical advice from the identified potential user groups should be convened early in the planning stage to refine the program objectives and determine if volunteers can provide the level of expertise required. Data users must have confidence in the representativeness, consistency, and accuracy of data collected by volunteers. Effective quality assurance and quality control(QA/QC) procedures are essential to ensure the utility of environmental monitoring data. Volunteers must be trained in advance to carry out specific environmental monitoring tasks. Another components of successful volunteer monitoring programs is to give the volunteers praise and feedback as well as to encourage experienced volunteers to impose increased responsibilities. The increase of volunteer monitoring programs in Korea will play a major role in developing a participatory system in which the people are "empowered" to make decisions and make a difference.