• Title/Summary/Keyword: task condition

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A New Worker Policy for Self-Balancing Production Line with Stations

  • Hirotani, Daisuke;Morikawa, Katsumi;Takahashi, Katsuhiko
    • Industrial Engineering and Management Systems
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    • v.10 no.3
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    • pp.197-202
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    • 2011
  • In traditional production lines, such as assembly lines, each worker is usually assigned to a particular fixed work, and decreasing the task to master the assigned work is valuated. However, when an imbalance exists between workers' speeds, if a worker delays the overall work in the production line, the production rate of the particular line will also decrease. To avoid this problem, the "Self-Balancing Production Line" was introduced. In this type of production line, each worker is assigned work dynamically, and when specific conditions are satisfied, production remains balanced. Characteristics of these lines that can be preempted at any place have already been analyzed by some researchers. A previous paper examined the situation in which only a single worker can process one machine and cannot preempt processing, and the improved policy of an ordinary selfbalancing production line, which specifies which stations workers can process and how workers can behave. This policy achieveda high production rate with only four stations and two workers (Buzacott, 2002). In that paper, worker processing stations and the behavior of a specific worker were limited, andthe paper focused only on specific stations and workers. Therefore, it is not applicable to any worker sequence. In this paper, we focus on other ways to decrease cycle time. In this kind of line, a worker processes at his or her speed. Therefore, if a worker is assigned stations according to his or her speed, the line can decrease cycle time. To do so, we relax the assumptions of this type of line and set a new condition. Under these conditions, we compare our results to the results of previous papers.

A development of the virtual auditory display system that allows listeners to move in a 3D space (청취자가 이동이 가능한 청각 디스플레이 시스템 개발)

  • Kang, Dae-Gee;Lee, Chai-Bong
    • Journal of the Institute of Convergence Signal Processing
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    • v.13 no.1
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    • pp.1-5
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    • 2012
  • In this study, we constructed a virtual auditory display(VAD) that enables listener to move in a room freely. The VAD system was installed in a soundproof room($4.7m(W){\times}2.8m(D){\times}3.0m(H)$). The system consisted of a personal computer, a sound presentation device, and a three-dimensional ultrasound sensor system. This system acquires listener's location and position from a three-dimension ultrasonic sensor system covering the entire room. Localization was realized by convolving the sound source with head related transfer functions(HRTFs) on personal computer(PC). The calculated result is generated through a LADOMi(Localization Auditory Display with Opened ear-canal for Mixed Reality). The HRTFs used in the experiment were measured for each listener with loudspeakers constantly 1.5m away from the center of the listener' s head in an anechoic room. To evaluate the system performance, we experimented a search task of a sound source position in the condition that the listener is able to move all around the room freely. As a result, the positioning error of presented sound source was within 30cm in average for all listeners.

A Study on Multi-Vehicle Control of Electro Active Polymer Actuator based on Embedded System using Adaptive Fuzzy Controller (Adaptive Fuzzy 제어기를 이용한 Embedded 시스템 기반의 기능성 고분자 구동체 다중제어에 관한 연구)

  • 김태형;김훈모
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.2
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    • pp.94-103
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    • 2003
  • In case of environment requiring safety such as human body and requiring flexible shape, a conventional mechanical actuator system does not satisfy requirements. Therefore, in order to solve these problems. a research of various smart material such as EAP (Electro Active Polymer), EAC (Electro Active Ceramic) and SMA (Shape Memory Alloy) is in progress. Recently, the highest preferring material among various smart material is EP (Electrostictive Polymer), because it has very fast response time, powerful force and large displacement. The previous researches have been studied properties of polymer and simple control, but present researches are studied a polymer actuator. An EP (Electostrictive Polymer) actuator has properties which change variably ils shape and environmental condition. Therefore, in order to coincide with a user's purpose, it is important not only to decide a shape of actuator and mechanical design but also to investigate a efficient controller. In this paper, we constructed the control logic with an adaptive fuzzy algorithm which depends on the physical properties of EP that has a dielectric constant depending on time. It caused for a sub-actuator to operate at the same time that a sub-actuator system operation increase with a functional improvement and control efficiency improvement in each actuator, hence it becomes very important to manage it effectively and to control the sub-system which Is operated effectively. There is a limitation on the management of Main-host system which has multiple sub-system, hence it brings out the Multi-Vehicle Control process that disperse the task efficiently. Controlling the multi-dispersion system efficiently, it needs the research of Main-host system's scheduling, data interchange between sub-actuators, data interchange between Main-host system and sub-actuator system, and data communication process. Therefore in this papers, we compared the fuzzy controller with the adaptive fuzzy controller. also, we applied the scheduling method for efficient multi-control in EP Actuator and the algorithm with interchanging data, protocol design.

A Study on the Legal Responsibility of Nurse (간호사의 법적 책임에 관한 연구)

  • Beom, Kyung Chul
    • The Korean Society of Law and Medicine
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    • v.15 no.2
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    • pp.285-316
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    • 2014
  • As the number of medical disputes regarding nurses has increased after medical disputes have increase, there is a need for a study on it. However, the legal relationship between nurses and patients has not yet been analyzed. Recently, the role and function of nurses are expanded according to the development of the science of nursing; moreover their activity and limitation of responsibility are also expanded. For this reason, the medical disputes regarding nurses have been increasing. However, the majority of these kind of dispute are just passed over because their practice is usually considered to be a mere action to assist doctor's role. In addition, nurse practice is not a secondary action of doctor's role, but forms part of a medical treatment. Of course, nurses handle many secondary tasks after doctors finish their medical treatment. But this is only part of the whole tasks of nurses. Furthermore, the general details of their medical treatment are not different from those of doctors because they also belong to the medical service personnel. Considering these features of nurse and the medical condition in South Korea, their task is becoming increasingly developed and specialized and they are also establishing their own field. With this stream of times, there is a growing interest in enacting a Nursing Practice Act, in other words, the independent law on nurse for the sake of patient safety and national health promotion. Then, their responsibility will distinctly be expanded as much more. That is, the time that nurses practice their medical care by following doctors' order and also pass over their responsibility to doctors is closed. Thus, this study examines the features and responsibilities of nursing practice, and discusses an institutional framework to efficiently cope with the legal disputes between nurses and patients. It aims to throw light on the decision making on nurse-patient disputes in future.

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A Robot End-effector for Biopsy Procedure Automation with Spring-Triggered Biopsy Gun Mechanism (스프링 격발형 생검총 구조를 가진 생검 시술 자동화 로봇 말단장치)

  • Won, Jong-Seok;Moon, Youngjin;Park, Sang Hoon;Choi, Jaesoon
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.8
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    • pp.590-596
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    • 2016
  • Biopsy is a typical needle type intervention procedure performed under radiographic image equipment such as computed tomography (CT) and cone-beam CT. This minimal invasive procedure is a simple and effective way for identifying cancerous condition of a suspicious tissue but radiation exposure for the patients and interventional radiologists is a critical problem. In order to overcome such trouble and improve accuracy in targeting of the needle, there have been various attempts using robot technology. Those devices and systems, however, are not for full procedure automation in biopsy without consideration for tissue sampling task. A robotic end-effector of a master-slave tele-operated needle type intervention robot system has been proposed to perform entire biopsy procedure by the authors. However, motorized sampling adopted in the device has different cutting speed from that of biopsy guns used in the conventional way. This paper presents the design of a novel robotic mechanism and protocol for the automation of biopsy procedure using spring-triggered biopsy gun mechanism. An experimental prototype has been successfully fabricated and shown its feasibility of the automated biopsy sequence.

Improved Text Recognition using Analysis of Illumination Component in Color Images (컬러 영상의 조명성분 분석을 통한 문자인식 성능 향상)

  • Choi, Mi-Young;Kim, Gye-Young;Choi, Hyung-Il
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.3
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    • pp.131-136
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    • 2007
  • This paper proposes a new approach to eliminate the reflectance component for the detection of text in color images. Color images, printed by color printing technology, normally have an illumination component as well as a reflectance component. It is well known that a reflectance component usually obstructs the task of detecting and recognizing objects like texts in the scene, since it blurs out an overall image. We have developed an approach that efficiently removes reflectance components while preserving illumination components. We decided whether an input image hits Normal or Polarized for determining the light environment, using the histogram which consisted of a red component. We were able to go ahead through the ability to extract by reducing the blur phenomenon of text by light because reflection component by an illumination change and removed it and extracted text. The experimental results have shown a superior performance even when an image has a complex background. Text detection and recognition performance is influenced by changing the illumination condition. Our method is robust to the images with different illumination conditions.

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Ethical Premises for Maintenance of Outdoor Sculpture (야외 조형물의 보존에 있어 최근 보존윤리이론에 대한 비판적 주석)

  • Kim, Ken
    • 한국문화재보존과학회:학술대회논문집
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    • 2004.10a
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    • pp.25-32
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    • 2004
  • All the works including sculpture created by modern artists contain a message that represents both the ideas and spirit of an era. We are entrusted with the responsibility of transmitting to future generations modern art in as nearly as perfect condition as possible. Thus despite the challenges we face in preserving modern art, we are obliged to conserve it. Especially, outdoor sculpture can be considered as not only works of art themselves, but also a public art. The work of contemporary sculptors often refers to the complexity of social relationships between the art and the public space, so that the public space tends to include the actual public in the art. The conservator at this point needs to preserve tile concept of the public art which is incorporated in the public participation in the sculpture, in addition to the materials of the sculpture itself. Once the sculpture is damaged, it will need restoration. Restoration may be essential to prevent further deterioration, or it may be necessary in order to make an object usable again. It is difficult to generalize about restoration because, as with preventive treatment, the acceptable degree of intervention varies from one discipline to another The degree of treatment including restoration may depend on such variables as available resources, the future use of the object, and the needs of the particular discipline to which it belongs. When conservators start to treat artworks or during the treatment, they will face many moments where they have to make a choice. Codes of ethics are necessary in order to provide a basis for making choices. Even though ethics have always been subject to change depending on an era or culture, the ethics subject will be much easier to reached an agreement on than one involving aesthetic value. The aesthetic value will be one of the most prominent factors for defining the damage: even minor loss of parts or discolouration can be considered as fatal damage for artworks. Sometimes, an alteration of the appearancecould be intended by the artist himself so that the artist's intention could be important factor for judging the damage of artworks. But, modern hermeneutic theories show that the artist's intention cannot be the only factor for consideration, so that the interpretation and application of artist's intent should be an interdisciplinary task regarding distinctive social and cultural backgrounds.

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Ergonomic Evaluation of Workload in Imbalanced Lower Limbs Postures

  • Kim, Eun-Sik;Yoon, Hoon-Yong
    • Journal of the Ergonomics Society of Korea
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    • v.30 no.5
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    • pp.671-681
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    • 2011
  • Objective: The purpose of this study is to compare the workload level at each lower limbs posture and suggest the ergonomic workstation guideline for working period by evaluating the imbalanced lower limbs postures from the physiological and psychophysical points of view. Background: Many workers like welders are working in various imbalanced lower limbs postures either due to the narrow working conditions or other environmental conditions. Method: Ten male subjects participated in this experiment. Subjects were asked to maintain 3 different lower limbs postures(standing, squatting and bending) with 3 different working conditions(balanced floor with no scaffold, imbalanced floor with 10cm height of scaffold, and imbalanced floor with 20cm height of scaffold). EMG data for the 4 muscle groups(Retus Femoris, Vastus Lateralis, Tibialis Anterior, Gastrocnemius) from each lower limbs posture were collected for 20 seconds every 2 minutes during the 8 minutes sustaining task. Subjects were also asked to report their discomfort ratings of body parts such as waist, upper legs, lower legs, and ankle. Results: The ANOVA results showed that the EMG root mean square(RMS) values and the discomfort ratings(CR-10 Rating Scale) were significantly affected by lower limbs postures and working time(p<0.05). The correlation was analyzed between the EMG data and the discomfort ratings. Also, prediction models for the discomfort rating for each posture were developed using physical condition, working time, and scaffold height. Conclusion: We strongly recommend that one should not work more than 6 minutes in a standing or squatting postures and should not work more than 4 minutes in a bending posture. Application: The results of this study could be used to design and assess working environments and methods. Furthermore, these results could be used to suggest ergonomic guidelines for the lower limbs postures such as squatting and bending in the working fields in order to prevent fatigue and pain in the lower limbs body.

Space(空問) and Sky-Earth(天地) - View of Space in the Architectures of the East and the West - (공간(空間)과 천지(天地) - 동서양 건축에서의 공간관 -)

  • Kim, Sung-Woo
    • Journal of architectural history
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    • v.14 no.4 s.44
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    • pp.7-28
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    • 2005
  • We are so used to the concept of the term 'space' that we do not question its conceptual validity. However, this paper argues that the notion of space prevailing all over the world, is not a universal concept that can be applicable to all architectures of the world, but is a particular concept that is generated from the Western way of thinking. This paper alms to identify the conceptual structure of the idea of space as it is originated in the tradition of the West, and, as an alternative view of space, tries to identify the nature of the view of space perceived in the tradition of the Eastern architecture. Comparison of the two views, that of the East and the West, and their meaning in the future of architecture, is another task to discuss in this paper. To be able to clarify the meaning of space in East Asian tradition, a set of new perspective of understanding of space was invited. They are ; 1. sky-earth(天地); insisting that the notion of space should be replaced within the context of sky, which is one half of sky-earth totality 2. energy of the air (空氣), space is not empty part inside of a building, but is a dynamic condition of air that is a part of the sky which always exist in form of energy 3. place(자리): instead of space, which, basically. is a man-made concept, idea of place is necessary, which include not only space but also earth Such concept of space which is different from the notion of space of the West, is meaningful not only to identify the idea of space in the East, but also to be able to contribute for more dynamic, varied, and balanced understanding of space.

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Model of ICT Utilization Curriculum for Preservice Teachers (예비교사를 위한 ICT 활용 교육과정 모형)

  • Lee, Chul-Hyun;Shin, Soo-Bum;Yoo, In-Hwan;Lee, Tae-Wuk
    • The Journal of Korean Association of Computer Education
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    • v.3 no.1
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    • pp.87-95
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    • 2000
  • In current computer education, we have inclined to emphasize information literacy for k-12 students. On the other hand, in spite that teachers are core variable in school education system, we have neglected teacher's education of information and communication technology. In addition, we haven't made a effort to expand preservice teacher's ability to utilize information and communication technology in the teacher's college and the college of education. With these recognitions, we made a diagnosis of problems by analysis of current condition of curriculum of the teacher's college and the college of education and explored the vision of ICT utilization education in k-12 computer education in this study. In addition, we suggested educational objectives and contents based on national requiring standards for ICT in teacher preparation, required ICT capability of preservice teachers for kind of teacher's task and the direction of computer education.

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