• Title/Summary/Keyword: Dead Space

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Effects of Wearing COVID-19 Protective Face Masks on Respiratory, Cardiovascular Responses and Wear Comfort During Rest and Exercise (휴식과 운동 중 COVID-19 대응 보건용 마스크 착용이 호흡·심혈관계 반응 및 착용감에 미치는 영향)

  • Jung, Jae-Yeon;Kang, ChanHyeok;Seong, Yuchan;Jang, Se-Hyeok;Lee, Joo-Young
    • Fashion & Textile Research Journal
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    • v.22 no.6
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    • pp.862-872
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    • 2020
  • This study explores the effects of facemasks on respiratory, thermoregulatory, cardiovascular responses during exercise on a treadmill and at rest. Five male subjects (25.8 ± 0.8 y, 171.8 ± 9.2 cm in height, 79.8 ± 28.1 kg in weight) participated in the following five experimental conditions: no mask, KF80, KF94, KF99, and N95. Inhalation resistance was ranked as KF80 < KF94 < N95 < KF99 and dead space inside a mask was ranked as KF80 = KF94 < N95 < KF99. The surface area covered by a mask was on average 1.1% of the total body surface area. The results showed no significant differences in body core temperature, oxygen consumption (VO2), carbon dioxide production (VCO2), heart rate or subjective perception among the five experimental conditions; however, cheek temperature, respiratory ventilation and blood pressure were greater for KF80 or KF94 conditions when compared to KF99 or N95 conditions (p<0.05). The differences among mask conditions are attributed to the dead space or specific designs (cup type vs pleats type) rather than the filtration level. In addition, the results suggest that improving mask design can help mitigate respiratory resistance from increased filtration.

Street Environment Improvement Plan Resulting from the Functional Transition of Residential Area - Focused on the land reallocation project in the 1970's of the Metropolitan City of Daegu - (주택지의 기능변화에 따른 가로환경 개선 방안 - 대구시의 1970년대 토지구획정리사업지구를 중심으로 -)

  • Kim, Han-Soo
    • Journal of the Korean housing association
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    • v.25 no.6
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    • pp.19-26
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    • 2014
  • This study aims to derive street design alternative which can be applied to residential area as the functions of land use have been changed. The main findings are as follows; First, the study area in this research is on the process of the functional transition from full residential use to residential-commercial mixed use with cafes and restaurants. Second, dead-end streets in residential areas needs to be widened in order to meet the increasing needs of pedestrians and cars. One of the suggested strategies is to remove fences on the dead-end streets. Third, based on the main findings, this research can suggest following policies. Citizen participation is necessary in building land use plans and space design in old residential areas. Citizens can participate in architectural and landscape contracts, district-unit plan with the help of experts such as urban planners and architects.

A Study on the Theoretical Analysis and Optimal Design Conditions for the $\alpha$ type Stirling Engine ($\alpha$형 스터링 엔진의 최적 설계 조건)

  • 강문규;이택희;유재환
    • Journal of the Korean Society of Safety
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    • v.13 no.4
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    • pp.142-154
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    • 1998
  • A stirling engine is a mechanism used to convert heat to power and operates on a closed regenerative thermodynamic cycle with compression and expansion of the working fluid at different temperature. The performance of a stilting cycle machine is a function of six independent parameters, namely; (1) speed N(r.p.m), (2) pressure of the working fluid p(Pa), (3) ratio of the temperature in the compression and expansion space ${\tau}(=T_C/T_E)$ , (4) ratio of the swept volumes in these two spaces K, (5) phase angle $\alpha$ and (6) dead volume ratio X. This paper describes the procedure and presents the results of computations carried out to establish the optimum combinations of these six parameters for maximum engine output for the machine acting as a prime mover, over a combined temperature range from $300^{\circ}K$ to $1000^{\circ}K$ and dead volume ratio X ranging from 0.1 to 2.0. The output of a stilting cycle machine can be expressed in terms of nondimensional power in several different ways. Four methods were studied in detail, the parameters optimized and design charts and engine power charts prepared. The results of this paper may be useful as a guide to the likely effects on the performance of some of the important design parameters and regenerator design.

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Chest Wall Reconstruction for Chronic Intrathoracic Wounds Using Various Flaps

  • Hong, Joon Pio;Cho, Pil-Dong;Kim, Sug Won;Chung, Yoon-Kyu;Kim, Eun-Gi
    • Archives of Reconstructive Microsurgery
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    • v.9 no.1
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    • pp.68-74
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    • 2000
  • The treatment of chronic chest wounds should be focused on eradicating the infection and obliterating the dead space thus providing improved pulmonary function. Chronic chest wounds, although the incidence has decreased over the years, is still associated with high morbidity and prolong hospitalization. In cases where the disease is advanced and conventional measures fail, aggressive approaches achieve adequate resolution or significant improvement. This paper reports four cases of chronic chest wound including bronchopleural fistula and osteomyelitis managed by debridement followed by muscle coverage using latissimus dorsi, rectus abdominis, and omental flap. The intrathoracic reconstruction entails thorough debridement of empyema cavities, bronchpleural fistulas and infection focus. The infection must be completely eradicated prior to or at the time of flap transposition. The flaps used for obliteration of dead spaces provided adequate bulk, abundant blood supply, and minimal donor morbidity. The results were satisfactory with improved respiratory function without complications.

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A Two-antenna GPS Receiver Integrated with Dead Reckoning Sensors (Two-antenna 자세 결정용 GPS 수신기와 DR 센서의 통합 시스템)

  • 이재호;서홍석;성태경;박찬식;이상정
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.186-186
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    • 2000
  • In the GPS/DR integrated system, the GPS position(or velocity) is used to compensate the DR output and to calibrate errors in the DR sensor. This synergistic relationship ensures that the calibrated DR accuracy can be maintained even when the GPS signal is blocked. Because of the observability problem, however, the DR sensors are not sufficiently calibrated when the vehicle speed is low. This problem can be solved if we use a multi-antenna GPS receiver for attitude determination instead of conventional one. This paper designs a two-antenna GPS receiver integrated with DR sensors. The proposed integration system has three remarkable features. First, the DR sensor can be calibrated regardless of the vehicle speed with the aid of two-antenna GPS receiver. Secondly, the search space of integer ambiguities in GPS carrier-phase measurements is reduced to a part of the surface of the sphere using DR heading. Thirdly, the detection resolution of cycle-slips in GPS carrier-phase measurements is improved with the aid of DR heading. From the experimental result, it is shown that the search grace is drastically reduced to about 3120 of the non-aided case and the cycle-slips of 1 or half cycle can be detected.

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Localization of Mobile Robot Based on Radio Frequency Identification Devices (RFID를 이용한 이동로봇의 위치인식기술)

  • Lee Hyun-Jeong;Choi Kyu-Cheon;Lee Min-Cheol;Lee Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.1
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    • pp.41-46
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    • 2006
  • Ubiquitous location based services, offer helpful services anytime and anywhere by using real-time location information of objects based on ubiquitous network. Particularly, autonomous mobile robots can be a solution for various applications related to ubiquitous location based services, e.g. in hospitals, for cleaning, at airports or railway stations. However, a meaningful and still unsolved problem for most applications is to develop a robust and cheap positioning system. A typical example of position measurements is dead reckoning that is well known for providing a good short-term accuracy, being inexpensive and allowing very high sampling rates. However, the measurement always has some accumulated errors because the fundamental idea of dead reckoning is the integration of incremental motion information over time. The other hand, a localization system using RFID offers absolute position of robots regardless of elapsed time. We construct an absolute positioning system based on RFID and investigate how localization technique can be enhanced by RFID through experiment to measure the location of a mobile robot. Tags are placed on the floor at 5cm intervals in the shape of square in an arbitrary space and the accuracy of position measurement is investigated . To reduce the error and the variation of error, a weighting function based on Gaussian function is used. Different weighting values are applied to position data of tags since weighting values follow Gaussian function.

The Oriental Idea and the Existential Affliction of Don Quijote (돈키호테의 실존적 고뇌와 동양사상)

  • Lim, Juin
    • Cross-Cultural Studies
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    • v.22
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    • pp.151-175
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    • 2011
  • In this article, I have analyzed the signification of the death of Don Quijote from the oriental religious and philosophical point of view, comparing with the novels of Kim, DongRi. We are able to read Cervantes' hope for his absolute ideal to be lasting forever via the death of Don Quijote, in the base of a strong will named of Gukyeong's life. In the same time, we can also discovery death as lasting of life in the basis of buddhist idea and death as the unification with nature via the meeting between the living and the dead in the Montesinos Cave. Montesinos Cave symbolizes a unclassified and chaotic space, which the Shamanist can meet the dead with a extatic ceremony and both supernatural life and daily life coexist. Therefore, the symbolic death of Don Quijote in Montesinos Cave is abe to be explained by approaching to absolute freedom named of Hatal, in other words, voluntary and conscious death to escape from the yugo of being. Considering the fact that Kim, Dongri emphasized on the unification of sky, earth and human being, keeping a racial identification in the face of the stream of occidental materialism in the time of Japanese conquest, we can look for the similarity with Cervantes' ideal. Contrary to the religious dogmatic ideal, Cervantes treated to recover the human nature and vitality, transcending the occidental rationalism and religious ideology in the time of Counter-reformation.

Controller Design using Sliding Mode Techniques for Satellite Formation Flying

  • Lim, Hyung-Chul;Bang, Hyo-Choong;Park, Kwan-Dong;Park, Pil-Ho;Jo, Jeong-Ho
    • Bulletin of the Korean Space Science Society
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    • 2003.10a
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    • pp.41-41
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    • 2003
  • Satellite formation flying is currently an active area of research in the aerospace engineering. There are many categories for this research such as the determination of initial conditions, formation keeping, configuration and reconfiguration. In this study, a tracking controller using sliding mode techniques is designed to control a satellite for the satellite formation flying. In general, Hill's equations are used to describe the relative motion of the follower satellite with respect to the leader satellite. But, the modified Hill's equations considering J2 perturbation were used for the design of sliding mode controller. Sliding mode control law causes the chattering phenomenon because it is a discontinuous control. Dead-zone was used to avoid the chattering. The Extended Kalman filter was applied to estimate the state vector based on the measurements of relative distance and velocity between two satellites.

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Research on the collision avoidance of manipulators based on the global subgoals and a heuristic graph search

  • Inoue, Y.;Yoshimura, T.;Kitamura, S.
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.609-614
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    • 1989
  • A collision avoidance algorithm based on a heuristic graph search and subgoals is presented. The joint angle space is quantized into cells. The evaluation function for a heuristic search is defined by the sum of the distance between the links of a manipulator and middle planes among the obstables and the distance between the end-effector and the subgoals on desired trajectory. These subgoals reduce the combinatorial explosion in the search space. This method enables us to avoid a dead-lock in searching. Its effectiveness has been verified by simulation studies.

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ASG(Amorphous Silicon TFT Gate driver circuit)Technology for Mobile TFT-LCD Panel

  • Jeon, Jin;Lee, Won-Kyu;Song, Jun-Ho;Kim, Hyung-Guel
    • Journal of Information Display
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    • v.5 no.2
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    • pp.1-5
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    • 2004
  • We developed an a-Si TFT-LCD panel with integrated gate driver circuit using a standard 5-MASK process. To minimize the effect of the a-Si TFT current and LC's capacitance variation with temperature, we developed a new a-Si TFT circuit structure and minimized coupling capacitance by changing vertical architecture above gate driver circuit. Integration of gate driver circuit on glass substrate enables single chip and 3-side free panel structure in a-Si TFT-LCD of QVGA ($240{\times}320$) resolution. And using double ASG structure the dead space of TFT-LCD panel could be further decreased.