• 제목/요약/키워드: Dead time control

Search Result 332, Processing Time 0.028 seconds

The Crisis of Painting and Its Response (회화의 위기, 회화의 대안)

  • Bhak, Young-Taik
    • The Journal of Art Theory & Practice
    • /
    • no.2
    • /
    • pp.7-26
    • /
    • 2004
  • Since the 20th century, it was often announced that a painting was dead, but it is still alive. Even in the epoch of recently increasing virtuality, painting is still appealing, consistently pursed by many with a thirst. Thus, it is said that the mission of a picture is to maintain its reality without being trapped in virtuality. In the history of Western painting spanning over several hundreds of years the myriad of techniques and styles have emerged, going though a huge variety of changes: namely, its not possible any longer to find the new ways of expression in painting. Hence, painters today feel that it becomes more gradually difficult for them to execute something. In the midst of swiftly changing, diversely evolving trends of contemporary art, the painters incessantly pose a question why they go on working on painting, and seek to find its answer. Why the painters still try to say something about painting? Is that because they consider it the quintessence of fine arts or think that it is in no way possible or meaningful to comment on fine arts without relying on painting? If then, is there any avenue of escape for the painting? The question of the 'crisis of painting' is still raised, when reviewing the rapidly changing conditions of inventing artworks. That is also why the recent works failed to offer a conceptually unified, universally shared perspective of painting. Moreover, painting is left to shrink comparatively with the pervasive existence of videos and installations briskly employing digital images and technologies in their creations. Whats more problematic is the fact that there is a growing sense of crisis not only in the sphere of painting hut also in the entire realm of art. As the organizers and curators of big-scale exhibitions and art projects tend to exploit their space spectacularly, focusing primarily on their abilities to control the space, there is a pervasive notion amongst them that painting is a medium that is not properly to suit such purposes and requests. Today, the death of painting is, in fact, the death of modernist painting, which assumed a central role in the history of art for a considerable amount of time, rather than the death of painting itself. Employing a new paradigm of invention, a picture is now entering a new domain which is perhaps unknown to us. Moving beyond the stereotypical concepts of painting, physical property and flatness, pictures today reveal the introduction of time and space and the penetration of new media such as installation, photography, video and the Internet. Despite such trends, the dexterity and tactile capability of painters is still to be considered significant in the future. The renewal of painting is made in an entirely unexpected manner and place.

  • PDF

Protective immunity against Naegzeria meningoencephalitis in mice (Naegleria fowleri 감염에 대한 방어면역에 관한 실험적 연구)

  • Lee, Sun-Gon;Im, Gyeong-Il;Lee, Geun-Tae
    • Parasites, Hosts and Diseases
    • /
    • v.23 no.2
    • /
    • pp.293-299
    • /
    • 1985
  • This study is to verify the protective ability against experimental Naegleria meningoencephalitis by immunization with Naegleria fowleri in mice. Naegleria fewleri, strain 0359, and Naegleria gruberi, strain EGB, were used in this study, and cultured in CGVS medium akenically. Inbred BALB/C mice, weighing about 20g, were immunized by three intraperitoneal injection of $1{\times}10^6$ N. fowleri trophozoites at the interval of one week. This N. fowleri trophozoites antigen was fixed with 5% formaldehyde. N. fowleri trophozoites from culture were homogenized with soiicator at $4^{\circ}C$ as monitored by phase contrast microscopy, and their membrane and cell content preparations were made for the immunization of mice. Their inoculation dose in volume was equivalent to the $1{\times}10^6$ trophozoites in each injection for immunization. And N. gruberi trophosoites, whieh was fixed with 5% formaldehyde, were also used for immunisation. Mice were inoculated intranasally with $5{\times}10^4$ N. fowleri trophozoites in a 511 suspension under anesthesia by as intraperitoneal injection of about 1 mg secobarbiturate. Nervousness, rotation or sluggish behaviour were observed in the mice which were infected with N. fewleri. Necrotic lesion was demonstrated in the anterior portion of brain, especially in the olfactory lobe. The inflammatory cell infiltration with numerous H. fowleri trophozoites was noticed. This pathological changes were more extensive in the control than in the experimental groups. Mice were dead due to experimental primary amoebic meningoencephalitis that developed between 8 days and 23 days after inoculation. Mortality rate of the mice was low in the immunized experimental group. Mean survival time, which is the survival duration of mice from the infection to death, was prolonged significantly in the immunized mice except in the mice immunized with JV, fowleri membrane. Even in the mice immunized with N. gruberi, survival time was delayed. In summary, the effectiveness of immunization is demonstrated in terms of protective immunity against Naegleria meningoencephalitis in mice.

  • PDF

Effect of Plowing Frequency and Sowing Dates on the Agronomic Characteristics, Feed Value, Weed Yield and Palatability of Silage Corn (경운횟수와 파종기 이동이 사일리지용 옥수수의 생육특성, 사료가치, 잡초발생 및 가축의 기호성에 미치는 영향)

  • Lee, Sang-Moo;Kim, Byoung-Tae;Hwang, Joo-Hwan;Jeon, Byoung-Tae;Moon, Sang-Ho
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.27 no.3
    • /
    • pp.209-218
    • /
    • 2007
  • This experiment was conducted to investigate effect of plowing frequency and sowing dates on the agronomic characteristics, feed value, weed yield and palatability of silage corn. Treatments were a basal treatment(C: May 5 seeding, plowing once, weeding control once), T1(May 12 seeding, plowing twice, weeding control 0 time), T2(May 19 seeding, plowing three times, weeding control 0 time, T3(May 26 seeding, plowing four times, weeding control 0 time) and T4(June 2 seeding, plowing five times, weeding control 0 time). The experiment was performed at the College of Life and Natural Sciences of Sangju University in Sangju in 2006. The plant height and ear height showed highly in order to C > T1 > T2 > T3 > T4 treatment, leaf length was the highest at T2 (96.0cm). Leaf width and number of dead leaf were the highest at C and T3 (11.2cm), C, C and T1 (4.6), respectively. Stem diameter was the highest at T3 as 31mm, while T2 was the lowest as 25mm (p<0.05). Ear circle showed highly in order of C > T1 > T4 > T3 > T4 (p<0.05), and tip filling degree was the highest at C treatment as 8.8, while T4 treatment was the lowest as 6.0 (p<0.05). The stem hardness and grain hardness were C < T1 < T2 < T3 < T4 (p<0.05). Stem saccharinity was T1(6.1%) was the highest, while T2(3.0%) was the lowest(P<0.05). Fresh yield of weed was the lowest at C treatment as 500 kg/ha, but T1 treatment was the highest as 44,100 kg/ha (p<0.05). Weed coverage rate showed highly in order of T1 > T2 > T3 > T4 > C treatment (p<0.05). Fresh yield of corn was the highest at C treatment as T3,550 kg/ha, but T4 treatment was the lowest as 65,500 kg/ha (p<0.05). Dry matter yield of corn showed highly in order of C(26,978 kg/ha) > T1(26,130 kg/ha) > T2(20,255 kg/ha) > T3(20,255 kg/ha) > T4(17,508 kg/ha) treatment (p<0.05). Crude protein content was T1(7.69%) > T4(7.42%) > T2(6.34%) > T3(5.99%) > C(5.91%) treatment (p<0.05), and Crude fat content showed highly in order of C (2.13%) > T1(2.04%) > T2(1.96%) > T3(1.95%) > T4(1.84%) treatment. Relative palatability of Holstein, Korean native goat and spotted deer was the highest at C treatment, but Korean native cattle was the highest at T1 treatment.

Effects of Various Physical and Chemical Factors on the Death of Trouble Seaweed Ulva australis (구멍갈파래(Ulva australis) 해조류 사멸에 미치는 여러 물리화학적 요인들의 영향)

  • Kim, Jin-Seog;Kwak, Hwa Sook;Kim, Bo Gwan
    • Weed & Turfgrass Science
    • /
    • v.6 no.3
    • /
    • pp.222-234
    • /
    • 2017
  • Green tides, which was mainly caused by Ulva spp., have been increasing in severity and frequency globally, and have negatively affected on marine ecosystems. This study was conducted to investigate effects of various physical and chemical factors on the death of Ulva australis (ULAUS) and to consider a practical measures useful for alleviating Ulva bloom. Soaking of ULAUS thalli in pure water for 8 hr didn't induce a death, but incubation in 1.0-1.5% salinity for 7 d inhibited sporulation by about 70%. Desiccation gave rise to a serious damage when more than 40-50% of initial fresh weight was lost. ULAUS growth was sensitive to temperature and seriously inhibited from more than $30^{\circ}C$. At $35^{\circ}C$, $40^{\circ}C$, $45^{\circ}C$ and $50^{\circ}C$, treatment time required for 90-95% death of ULAUS thalli was 1 d, 10 min, 30 sec, and 1 sec, repectively. ULAUS growth was seriously inhibited at lower than pH 6.0 and completely dead at pH 4.0. Several compounds for ULAUS control was selected and the chemcals causing a rapid death were oxidants such as hydrogen peroxide and sodium percarbonate. Taken together, our results suggest that low salinities, dryness, pH, high temp. and compounds could be selected for Ulva bloom control, and high temperature and compounds seems to be useful for a development of practical control methods.

A Study on Power Conversion System for Fuel Cell Controlled by Micro-Processor (마이크로프로세서에 의해 제어되는 연료전지용 전력변환장치에 관한 연구)

  • Kim, Ju-Yong;Jung, Sang-Hwa;Mun, Sang-Pil;Ryu, Jae-Yup;Suh, Ki-Young
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.21 no.5
    • /
    • pp.10-24
    • /
    • 2007
  • In the dissertation, a power conversion system for fuel cell is composed of a PWM inverter with LC filter in order to convert fuel cell voltage to a single phase 220[V]. In addition, new insulated DC-DC converters are proposed in order that fuel cell voltage is boosted to 380[V]. In this paper, it requires smaller components than existing converters, which makes easy control. The proposed DC-DC converter controls output power by the adjustment of phase-shift width using switch $S_5\;and\;S_6$ in the secondary switch which provides 93-97[%] efficiency in the wide range of output voltage. Fuel cell simulator is implemented to show similar output characteristics to actual fuel cell. Appropriate dead time td enables soft switching to the range where the peak value of excitation current in a high frequency transformer is in accordance with current in the primary circuit. Moreover, appropriate setting to serial inductance La reduces communication loss arisen at light-load generator and serge voltage arisen at a secondary switch and serial diode. Finally, TMS320C31 board and EPLD using PWM switching technique to act a single phase full-bridge inverter which is planed to make alternating current suitable for household

Effects of Fusarium circinatum on Disease Development and Gas Exchange in the Seedlings of Pinus spp. (푸사리움가지마름병균 Fusarium circinatum이 소나무류 묘목의 병 진전과 침엽의 가스교환에 미치는 영향)

  • Woo, Kwan-Soo;Yoon, Jun-Hyuck;Han, Sang-Urk;Woo, Su-Young
    • Research in Plant Disease
    • /
    • v.17 no.2
    • /
    • pp.177-183
    • /
    • 2011
  • Four-year-old seedlings of Pinus thunbergii, Pinus densiflora and Pinus rigida were inoculated with Fusarium circinatum isolate (FT-7), the pitch canker fungus, from P. thunbergii, to evaluate the effects of the pathogen on disease development and gas exchange rate. Needle dehydration was evident on 2 of 10 seedlings of P. thunbergii and P. rigida at 18 and 21 days after inoculation, respectively, while no symptoms were observed in P. densiflora seedlings throughout the experiment. Gas exchange stopped completely in 4 of 5 measured seedlings of P. thunbergii and 2 of 5 measured seedlings of P. rigida at 25 days after inoculation, and in the remaining 3 seedlings of P. rigida at 39 days after inoculation. Disease development in P. thunbergii seedlings was faster than that in P. rigida seedlings. By the time, the experiment was ended at 78 days after inoculation, 9 of 10 seedlings of P. rigida and 8 of 10 seedlings of P. thunbergii seedlings treated with FT-7 was almost dead, but all seedlings of P. densiflora were still healthy. We suggest that P. densiflora is resistant to F. circinatum in the current study, and gas exchange rate of the species after inoculation does not differ significantly compared to that of untreated control.

The Effect of Plant Coverage on the Constructed Wetlands Performance and Development and Management of Macrophyte Communities (식생피도가 인공습지의 질소 및 인 처리효율에 미치는 영향과 습지식물의 조성 및 관리)

  • Ham, Jong-Hwa;Kim, Hyung-Chul;Koo, Won-Seok;Shin, Hyun-Bhum;Yun, Chun-Gyeong
    • Korean Journal of Ecology and Environment
    • /
    • v.38 no.3 s.113
    • /
    • pp.393-402
    • /
    • 2005
  • The field scale experiment was performed to examine the effect of plant coverage on the constructed wetland performance and recommend the optimum development and management of macrophyte communities. Four sets (each set of 0.88 ha) of wetland (0.8 ha) and pond (0.08 ha) systems were used. Water flowing into the Seokmoon estuarine reservoir from the Dangjin stream was pumped into wetland system. Water depth was maintained at 0.3 ${\sim}$ 0.5 m and hydraulic retention time was managed to about 2 ${\sim}$ 5 days; emergent plants were allowed to grow in the wetlands. After three growing seasons of the construction of wetlands, plant coverage was about 90%, even with no plantation, from bare soil surfaces at the initial stage. During the start up period of constructed wetlands, lower water levels should be maintained to avoid flooding newly plants, if wetland plants are to be started from germinating seeds. Effluent T-N concentration in low plant coverage wetland was higher in winter than high plant coverage wetland, whereas no T-P effluent concentration and removal efficiency difference was observed within 15% plant coverage. Dead vegetation affected nitrogen removal during winter because it is a source of organic carbon which is an essential parameter in denitrification. Biomass harvesting is not a realistic management option for most constructed wetland systems because it could only slightly increase the removal rate and provide a minor nitrogen removal pathway due to lack of organic carbon.

An Analysis of Primary Causes for Waiting for Inpatient Admission and Length of stay at Emergency Medical Center(EMC) (응급의료 센터의 체류 및 입원대기 시간 지연 요인 - 일개 의료기관을 중심으로 -)

  • Kil Suk-Yong;Kim Ok-Jun;Park Jin-Sun
    • Journal of Korean Academy of Fundamentals of Nursing
    • /
    • v.6 no.3
    • /
    • pp.522-531
    • /
    • 1999
  • This research identifies the ingress to egress primary factors that causes a patient to receive delayed emergency medical care. This material was collected between February 1st to 28th, 1998. Research envolved 4,118 people who visited the college emergency medical center in Kyeongido Province, South Korea. Medical records were examined, using the retrospective method. to determine the length of stay and the main cause for waiting. Results are as follows : 1. The age group with the highest admission rate was 10 and under, approximately 1,394 (33.9%). Followed by an even distribution for ages between 11-50 at 10-15% for their respective ranges. The lowest admission rate was 50 years and above. 2. From the 4,118 records examined, 3,489 received outpatient treatment (84.7%); 601 were admitted for inpatient care (14.6%); 25 arrived dead on arrival (0.6%); and 4 people died at the hospital. 3. Between 7PM to 12AM, 42.9% were admitted to the EMC. The hours from 9PM to 11PM recorded the highest admission rate and 5AM to 8AM was the lowest From 8PM to 12AM, the most beds were occupied. 4. For most patients. the average length of stay was approximately 2.2 hours. By medical department, external medicine was the longest for 2.8 hours. Pediatrics was the shortest for 1.6 hours. The average waiting period for inpatient admission was 2.6 hours. Inpatient admission for pediatrics and external medicine was 3.4 hours and 2.2 hours respectively. 5. Theses are primary factors for delay at EMC: 1) pronged medical consultations to decide between inpatient versus outpatient treatment, and delaying to be inpatient, 2) when you call physicians they are delayed to come 3) Understaffing during peak or critical hours, 4) Excessive consulting with different medical departments, 5) some patients require longer monitoring periods, 6) medical records are delayed in transit between departments, 7) repeated laboratory tests make delay the result, 8) overcrowded emergency x-ray place causes delay taking x-ray and portable x-ray, 9) the distance between EMC and registration and cashier offices is too far. 10) hard to control patient's family members. The best way to reduce EMC waiting and staying time is by cooperation between departments, both medical and administrative. Each department must work beyond their job description or duty and help each other to provide the best medical service and satisfy the patient needs. The most important answer to shortened the EMC point from ingress to egress is to see things from a patient point of view and begin from there to find the solution.

  • PDF

A study on the Improvement Method of the Report and Reward System on an Illegal Behavior of the Emergency Exit (비상구 불법행위 신고포상제도의 개선방안에 관한 연구)

  • Kim, Myeong Sik;Lee, Tae Shik;Cho, Won Cheol
    • Journal of Korean Society of Disaster and Security
    • /
    • v.5 no.2
    • /
    • pp.49-59
    • /
    • 2012
  • The safety management of the emergency exit, by directly related to the $civil^{\circ}$Øs dead in the fire situation, have limited by which the fire station take the on-side and control-centered way of business processing, it is expect to the effects in which the citizen have to concern and to take part. From 2010 years in the back-ground, it is operated nationally the report and reward system on an illegal behavior of the emergency exit, it is happened to the unfit operating situation in the mission and direction of the system up which the exit paparazzi act with intent to receive the reward payments. The study suggests solution through analyzing the illegal emergency exit operation result of sixteen counties and the Seoul metropolitan from year 2010 to 2011. Firstly, the report destination is adjusted to the multiple use establishments and the large-scale multiple use facilities over the limit level is limited under five times the report events of the same people in the minor endorsement. And the fine incomes should be invested to the disaster prevention acting related with the exit. Secondly, for upgrade of the report accuracy, a reporter is received the possible information for the confirmation of an illegal act, has become to lead the pre-monitoring act which the reporter is can to take the safety education and to guide the information about season and vulnerable business location. Finally, considering the support way about the encounter facility, the fire officer is not happen to occur the repetitive report in the same place, is related to the volunteer service system the report acts, consider as the volunteer service time, and must support them to act as the disaster prevention volunteer.

INNOVATIVE CONCEPT FOR AN ULTRA-SMALL NUCLEAR THERMAL ROCKET UTILIZING A NEW MODERATED REACTOR

  • NAM, SEUNG HYUN;VENNERI, PAOLO;KIM, YONGHEE;LEE, JEONG IK;CHANG, SOON HEUNG;JEONG, YONG HOON
    • Nuclear Engineering and Technology
    • /
    • v.47 no.6
    • /
    • pp.678-699
    • /
    • 2015
  • Although the harsh space environment imposes many severe challenges to space pioneers, space exploration is a realistic and profitable goal for long-term humanity survival. One of the viable and promising options to overcome the harsh environment of space is nuclear propulsion. Particularly, the Nuclear Thermal Rocket (NTR) is a leading candidate for nearterm human missions to Mars and beyond due to its relatively high thrust and efficiency. Traditional NTR designs use typically high power reactors with fast or epithermal neutron spectrums to simplify core design and to maximize thrust. In parallel there are a series of new NTR designs with lower thrust and higher efficiency, designed to enhance mission versatility and safety through the use of redundant engines (when used in a clustered engine arrangement) for future commercialization. This paper proposes a new NTR design of the second design philosophy, Korea Advanced NUclear Thermal Engine Rocket (KANUTER), for future space applications. The KANUTER consists of an Extremely High Temperature Gas cooled Reactor (EHTGR) utilizing hydrogen propellant, a propulsion system, and an optional electricity generation system to provide propulsion as well as electricity generation. The innovatively small engine has the characteristics of high efficiency, being compact and lightweight, and bimodal capability. The notable characteristics result from the moderated EHTGR design, uniquely utilizing the integrated fuel element with an ultra heat-resistant carbide fuel, an efficient metal hydride moderator, protectively cooling channels and an individual pressure tube in an all-in-one package. The EHTGR can be bimodally operated in a propulsion mode of $100MW_{th}$ and an electricity generation mode of $100MW_{th}$, equipped with a dynamic energy conversion system. To investigate the design features of the new reactor and to estimate referential engine performance, a preliminary design study in terms of neutronics and thermohydraulics was carried out. The result indicates that the innovative design has great potential for high propellant efficiency and thrust-to-weight of engine ratio, compared with the existing NTR designs. However, the build-up of fission products in fuel has a significant impact on the bimodal operation of the moderated reactor such as xenon-induced dead time. This issue can be overcome by building in excess reactivity and control margin for the reactor design.