• Title/Summary/Keyword: Quantitative Feedback

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Issues and Methodological Status of System Dynamics (시스템다이내믹스의 발전과 방법론적 위상)

  • 문태훈
    • Korean System Dynamics Review
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    • v.3 no.1
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    • pp.61-77
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    • 2002
  • This paper reviews issues and methodological status of system dynamics and suggest some research agenda for its development in Korea. After reviewing some characteristics of system dynamics approach, including dynamic feedback perspective and endogenous point of view, the paper pointed out methodological characteristics of system dynamics. It seems to be the most notable characteristics of System Dynamics that it use both quantitative and qualitative approach in explaining and modelling reality. Besides, System Dynamicists rely more heavily on refutationism than instrumentalism and this allows System Dynamicists follow more strict way of scientific inquiry. For the development of System Dynamics in Korean academic circle, developing training program and curriculum, networking scattered System Dynamicist all over the country, would be the most important task.

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A Development of Evaluation System on Technological Information Analysis by Retired Scientists & Engineers (고경력/퇴직 과학기술자의 기술정보분석 실적평가 방안)

  • 김석진;조흥곤;유영복;민완기
    • Journal of Korea Technology Innovation Society
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    • v.5 no.3
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    • pp.307-320
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    • 2002
  • The purpose of this paper was to design evaluation process on technological information analysis done by re-tired scientists and engineers. Existing studies on evaluation system and methodology were analyzed and their implications are as follows. To provide useful feedback to the retired scientists, indicators of evaluation should be simplified and method of evaluation confined to the quantitative one. And the results of evaluation need to be utilized in direction to encourage the old scientists and engineers.

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원전 증기발생기 저출력 수위제어를 위한 강인제어기법에 관한 연구

  • 안국훈
    • Proceedings of the Korean Nuclear Society Conference
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    • 1997.10a
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    • pp.259-264
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    • 1997
  • 본 논문에서는 Westinghouse(WH)사에서 공급한 고리 3, 4호기의 증기발생기 모델에 강인제어 기법의 하나인 QFT(Quantitative Feedback Theory)를 적용하여 플랜트에 존재하는 불확실성이나 외란에 대해 강인성을 보장하는 제어기를 설계하였다. 증기발생기의 주파수응답 한계조건은 MATLAB QFT Toolbox를 이용하였으며, loop shaping에 의한 전달함수 식별을 위해서 근사화 기법을 적용하였다. 그리고 5∼20[%]의 저출력구간에서 모의실험을 하여 본 논문의 유용성을 보였다.

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A Study on the Development of Topic Map for Analysis of Customer Satisfaction in Tourism Industry (관광산업의 고객만족도 분석을 위한 토픽맵 개발에 관한 연구)

  • Kang, Min Shik
    • Journal of the Korea Convergence Society
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    • v.8 no.10
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    • pp.249-255
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    • 2017
  • The domestic tourism industry mostly relies on quantitative surveys for customer satisfaction. However, customer participation of the questionnaires is extremely low and the improvement of the dissatisfactory factors is not being performed promptly. In this paper, we propose a new topic map system and prove its empirical effectiveness to improve the accuracy of customer feedback information and the efficiency of the analysis process. The topic map system is a system for analyzing large amounts of customer feedback data in real time. It uses text mining and ontology techniques by integrating data collected over a certain period from real-time SNS and quantitative data obtained from existing survey systems. The effect after improving the analyzed factors of dissatisfaction is also a new and innovative evaluation system for monitoring customer satisfaction in real time. The classification based on this integrated data is a classification system that is specific to the product or the customer. According to this classification, it is possible to measure the effect of the recognition and improvement of the complaint factor in real time on the topic map system. This provides a sophisticated prioritization of the improvement factors and enables customer satisfaction quality control as a PDCA feedback system. In addition, the survey period and costs are greatly shortened, and responses can be more precise to the existing survey method. As a practical application, this system is applied to the largest H travel agency in Korea to prove the accuracy and efficiency of the proposed system.

The Influence of Pelvic Tilt Exercise Using Visual Feedback upon the Gait Characteristics of Patients with Hemiplegia (시각적 되먹임을 이용한 골반경사 운동이 편마비 환자의 보행특성에 미치는 영향)

  • Kim, Byoung-Nam;Lee, Wan-Hee
    • The Journal of Korean Physical Therapy
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    • v.14 no.1
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    • pp.75-88
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    • 2002
  • The purpose of this study was to investigate the influence of anterior, posterior, and lateral pelvic tilt exercise upon the gait characteristics of patients with hemiplegia including their gait velocity, cadence, stride length, step length of the non affected side, step length of the affected side, foot angle of the non affected side, foot angle of the affected side, base of support, and so on. The subject of this study was 24 men and women patients with hemiplegia. The patients, the subject of this study, were classified into 12 patients of treatment group applying pelvic tilt exercise using visual feedback and 12 patients of control group applying general pelvic tilt exercise, and then analyzed their gait before and after exercise. Temporal distance gait analysis (Boening, 1977) was used to analyze their gait, and ink foot-print was applied as on of measurement methods. To find out meaningful difference between control group and treatment group, this study carried out independent sample t-test for each item by utilizing SPSS/Win 10.0, compared changes in control group's and treatment group's gait characteristics before and after exercise as percentage, and applied paired t-test to conduct before-after test in same group. Statistical significance level was ${\alpha}$ < 0.05. The results of this study were as follows. As a result of independent sample t-test for control group's and treatment group's gait characteristics after exercise, it was not statistically significant so there was no meaningful difference between two groups. However, it was statistically significant in the change rate(%) of gait characteristics, and treatment group's patients with hemiplegia had been highly changed in gait characteristics in comparison with control group. From the above-mentioned results, could find that pelvic tilt exercise using visual feedback for patients with hemiplegia was effective to improve their gait ability and it could increase the ability in comparison with general pelvic tilt exercise. In the future, studies on the effect of pelvic tilt exercise using visual feedback shall be continued based on more quantitative methods.

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Active Force Control of Electro-Hydraulic Hybrid Load Simulator using Quantitative Feedback Theory (QFT를 이용한 전기유압 하이브리드 부하 시뮬레이터의 능동 힘제어)

  • Yoon, Joo-Hyeon;Ahn, Kyoung-Kwan;Truong, Dinh Quang;Jo, Woo-Geun
    • Journal of the Korean Society for Precision Engineering
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    • v.26 no.2
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    • pp.45-53
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    • 2009
  • Today, reduction of $CO_2$ exhaustion gas for global-warming prevention becomes important issues in all industrial fields. Hydraulic systems have been widely used in industrial applications due to high power density and so on. However hydraulic pump is always being operated by engine or electric motor in the conventional hydraulic system. Therefore most of the conventional hydraulic system is not efficient system. Recently, an electro-hydraulic hybrid system, which combines electric and hydraulic technology in a compact unit, can be adapted to a wide variety of force, speed and torque requirements. In the electro-hydraulic hybrid system, hydraulic pump is operated by electric motor only when hydraulic power is needed. Therefore the electro-hydraulic system can reduce the energy consumption drastically when compared to the conventional hydraulic systems. This paper presents a new kind of hydraulic load simulator which is composed of electro-hydraulic hybrid system. Disturbances in the real working condition make the control performance decrease or go bad. QFT controller is designed to eliminate or reduce the disturbance and improve the control performance of the electro-hydraulic load simulator. Experimental results show that the proposed controller is verified to apply for electro-hydraulic hybrid system with varied external disturbances.

Analysis Testing of Sociocultural Factors Influence on Human Reliability within Sociotechnical Systems: The Algerian Oil Companies

  • Laidoune, Abdelbaki;Rahal Gharbi, Med El Hadi
    • Safety and Health at Work
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    • v.7 no.3
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    • pp.194-200
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    • 2016
  • Background: The influence of sociocultural factors on human reliability within an open sociotechnical systems is highlighted. The design of such systems is enhanced by experience feedback. Methods: The study was focused on a survey related to the observation of working cases, and by processing of incident/accident statistics and semistructured interviews in the qualitative part. In order to consolidate the study approach, we considered a schedule for the purpose of standard statistical measurements. We tried to be unbiased by supporting an exhaustive list of all worker categories including age, sex, educational level, prescribed task, accountability level, etc. The survey was reinforced by a schedule distributed to 300 workers belonging to two oil companies. This schedule comprises 30 items related to six main factors that influence human reliability. Results: Qualitative observations and schedule data processing had shown that the sociocultural factors can negatively and positively influence operator behaviors. Conclusion: The explored sociocultural factors influence the human reliability both in qualitative and quantitative manners. The proposed model shows how reliability can be enhanced by some measures such as experience feedback based on, for example, safety improvements, training, and information. With that is added the continuous systems improvements to improve sociocultural reality and to reduce negative behaviors.

Perception Based Definition of Construction Quality in Pakistan

  • Awan, Muhammad Yousaf Sadiq;Awan, Dr Muhammad Maqbool Sadiq
    • Journal of Construction Engineering and Project Management
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    • v.5 no.2
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    • pp.24-34
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    • 2015
  • The complexity arises in defining the construction quality due to its perception, based on inherent market conditions and their requirements, the diversified stakeholders itself and their desired output. A quantitative survey based approach was adopted in this constructive study. A questionnaire based survey was conducted, for the assessment of construction quality perception and expectations in the context of quality improvement technique. The survey feedback of professionals, from the leading construction organizations/companies of Pakistan were analyzed. The financial capacity, organizational structure, and construction experience of the construction firms formed basis for their selection. After statistical analysis of survey feedback it was found reliable and valid for the inferential purpose to the target population of construction professionals. The quality perception was found to be project scope oriented, considered as an excess cost for a construction project and keeping the rework minimum by qualifying the required quality tests, keeping the defects minimum by ensuring the specifications of supplied material. Any quality improvement technique was expected to address the financial aspects of the construction project for the employer and contractor, by increasing the profitability through reduction in overall cost, reduction in time, reduction in defects and improving the productivity in a construction project. The study is beneficial for the construction professionals to assess the prevailing construction quality perception and the expectations from implementation of any quality improvement technique in construction projects.

Authoring Tool for Augmented Reality based Product Design (증강현실 기반 제품 디자인을 위한 저작도구)

  • Ha, Tae-Jin;Billinghurst, Mark;Woo, Woon-Tack
    • Journal of the Korea Computer Graphics Society
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    • v.13 no.2
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    • pp.23-29
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    • 2007
  • We are suggesting an authoring tool can be used for prototyping in the augmented reality based product design environment. This tool is for authors without an engineering background to use. Our authoring tool can adjust the properties of visual, sound, and haptic feedback at the same time for more practical prototyping. Also the proposed modulated architecture can be applied flexibly to changes of platforms or hardware. Also user interfaces can be dynamically updated by changing just description files. finally, the suggested authoring methods exploit the advantages of both graphical and tangible user interfaces. Authors can intuitively make adjustments to many parameters using the TUI, and then they can do the same thing precisely using the GVI. The proposed authoring methods can be used for exhibition and entertainment contents using multi-sensory feedback in AR environment. As a future work, qualitative and quantitative usability test will be conducted.

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Chaotic Speech Secure Communication Using Self-feedback Masking Techniques (자기피드백 마스킹 기법을 사용한 카오스 음성비화통신)

  • Lee, Ik-Soo;Ryeo, Ji-Hwan
    • Journal of the Korean Institute of Intelligent Systems
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    • v.13 no.6
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    • pp.698-703
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    • 2003
  • This paper presents analog secure communication system about safe speech transmission using chaotic signals. We applied various conditions that happen in actuality communication environment modifying chaotic synchronization and chaotic communication schemes and analyzed restoration performance of speech signal to computer simulation. In transmitter, we made the chaotic masking signal which is added voice signal to chaotic signal using PC(Pecora & Carroll) and SFB(self-feedback) control techniques and transmitted encryption signal to noisy communication channel And in order to calculate the degree of restoration performance, we proposed the definition of analog average power of recovered error signals in receiver chaotic system. The simulation results show that feedback control techniques can certify that restoration performance is superior to quantitative data than PC method about masking degree, susceptibility of parameters and channel noise. We experimentally computed the table of relation of parameter fluxion to restoration error rate which is applied the encryption key values to the chaotic secure communication.