• Title/Summary/Keyword: passive zone

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A Study on the Characteristics of Ambient Volatile Organic Compounds in Gimhae (김해 지역 대기 중 휘발성유기화합물 특성연구)

  • Bong, Sang-Hun;Jeong, Seong-Wook;Park, Heung-Jai;Kim, Woo-Seong;Kim, Sung-Hun
    • Journal of Environmental Science International
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    • v.17 no.8
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    • pp.871-878
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    • 2008
  • In this study, we measured volatile organic compounds in Gimhae city, South Korea. We selected twenty site and measured volatile organic compounds in ambient air by passive sampler when at sampling intervals of two month from April to December 2005. Passive sampler was exposed for fifteen day in ambient air. And samples were analyzed by GC/FID for volatile organic compounds. The results of each measured functional zone, mean concentration of each compound measured were generally higher the industrial complex area and traffic pollution area than residental area. Each area showed similar pattern for the observation period. concentration of measured each compound were the following order: winter > fall > spring > summer.

The Fruits of Crataegus pinnatifida Bunge ameliorates Learning and Memory Impairments Induced by Scopolamine (기억력 감퇴모델에서 산사의 기억력 개선 효과에 관한 연구)

  • Wang, Su-Bin;Ahn, Eun-Mi;Jung, Ji-Wook
    • The Korea Journal of Herbology
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    • v.24 no.4
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    • pp.165-171
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    • 2009
  • Objectives : In the present study, we assessed the effects of the ethanolic extract of Crataegus pinnatifida Bunge on the learning and memory impairments induced by scopolamine using the passive avoidance and the Morris water maze tasks in mice. Methods : The cognition-enhancing effect of C. pinnatifida was investigated using a passive avoidance test, the Morris water maze test and Y-maze test in mice. Drug-induced amnesia was induced by treating animals with scopolamine (1 mg/kg, i.p.). Results : The ethanolic extract of C. pinnatifida (100, and 200 mg/kg) significantly reversed the scopolamine-induced cognitive impairments in the passive avoidance test (p < 0.05). Moreover, C. pinnatifida (200 mg/kg) also improved escape latencies in training trials and increased swimming times and distances within the target zone of the Morris water maze (p < 0.05). On the Y-maze test, C. pinnatifida (100, and 200 mg/kg) also significantly reversed scopolamine- induced cognitive impairments in mice (p < 0.05). Conclusions : The ethanolic extract of Crataegus pinnatifida dramatically possesses the anti-amnestic and cognitive-enhancing activities related to the memory processes, and these activities were parallel to treatment duration and dependent on the learning models.

A Novel Hybrid Islanding Detection Method Using Digital Lock-In Amplifier (디지털 록인 앰프를 이용한 새로운 하이브리드 방식의 단독운전 검출법)

  • Ashraf, Muhammad Noman;Choi, Woojin
    • Proceedings of the KIPE Conference
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    • 2019.07a
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    • pp.77-79
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    • 2019
  • Islanding detection is one of the most important issues for the distributed generation (DG) systems connected to the power grid. The conventional passive islanding detection methods inherently have a non-detection zone (NDZ), and active islanding detection methods may deteriorate the power quality of a power system. This paper proposes a novel hybrid islanding detection method based on Digital Lock-In Amplifier with no NDZ by monitoring the harmonics present in the grid. Proposed method detects islanding by passively monitoring the grid voltage harmonics and verify it by injecting small perturbation for only three-line cycles. Unlike FFT for the harmonic extraction, DLA HC have lower computational burden, moreover, DLA can monitor harmonic in real time, whereas, FFT has certain propagation delay. The simulation results are presented to highlight the effectiveness of the proposed technique. In order to prove the performance of the proposed method it is compared with several passive islanding detection methods. The experimental results confirm that the proposed method exhibits outstanding performance as compared to the conventional methods.

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Development of Measurement System for Welding Bead Shape using LabVIEW (LabVIEW를 이용한 용접비드 형상 계측시스템 개발)

  • Kang, Hoon-Hyo;Lee, Da-Hye;Jeon, Euy-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.2
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    • pp.189-194
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    • 2007
  • Recently, as consumer's claim fur car safety is increased, quality inspection method fur welding zone is strengthened. Therefore, from the methods that depend on welding zone bead shape size of seat frame in macrography or passive examination, the quality control by whole recording inspection is required. In this study, the system that is measuring automatically if worker checks welding bead fur quality inspection of seat frame is developed using LabVIEW. If the quality standard for the bead width and length of welding zone is inputted, the system measures automatically whether welding zone is bead length or bead width. Measured data is preserved by points and quality recording of welding zone is stored. The car seat きme welding zone is applied and experimented. The results gave good influence o9 the quality control of work efficiency.

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Evolution of Galaxy Habitability

  • Hong, Sungwook E.;Gobat, Raphael
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.2
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    • pp.53.3-54
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    • 2016
  • We combine a semi-analytic model of galaxy evolution with constraints on circumstellar habitable zones and the distribution of terrestrial planets in order to probe the suitability of galaxies of different mass and type to host habitable planets, and how it evolves with time. We find that the fraction of stars with terrestrial planets in their habitable zone (known as habitability) depends only weakly on galaxy mass, with a maximum around $4{\times}10^{10}M_{\odot}$. We estimate that 0.7% of all stars in Milky Way-type galaxies to host a terrestrial planet within their habitable zone, consistent with the value derived from Kepler observations. On the other hand, the habitability of passive galaxies is slightly but systematically higher, unless we assume an unrealistically high sensitivity of planets to supernovae. We find that the overall habitability of galaxies has not changed significantly in the last ~8 Gyr, with most of the habitable planets in local disk galaxies having formed ~1.5 Gyr before our own solar system. Finally, we expect that ${\sim}1.4{\times}10^9$ planets similar to present-day Earth have existed so far in our galaxy.

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Redistribution of Passive Impurity by Long Waves in Coastal Zone (연안역에서의 장파에 의한 오염원 확산)

  • Ivanov, Vitaly;Pelinovsky, Efim;Talipova, Tatjana
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.5 no.3
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    • pp.232-239
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    • 1993
  • In this paper the effect of wave motion acting on the natural folds of dispersed material in the coastal zone is studied. After integrating the usual diffusion equation with respect to the depth using shallow-water approximation simpler equation for integrated concentration was obtained. which holds for long waves of arbitrary amplitude and far any arbitrary barotropic flows. Different situations of long wave action on impurity concentration in the frame of this equation are considered.

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Horizontal Stress Analysis of Electric Pole using Earth Pressure Cell from Mock-Up Tension Test (전주의 실물인장실험시 토압계를 이용한 수평토압분석)

  • Ahn, Tae-Bong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.8
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    • pp.62-69
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    • 2010
  • Many electric poles in the softground have been collapsed due to external load. In this study, 10 types of tests were performed with variation of location, numbers and depths of anchor blocks as well as depth of poles to find horizontal earth pressure through full scale pull-out tests. The horizontal earth pressure increased with embedded depth of electric pole, and earth pressure of lower passive zone decreased. The deeper of anchor block, earth pressure of passive zone becomes less. 4 anchor blocks decreased earth pressure at G.L.-0.9[m]. It is considered that 4 anchor blocks installed along 80[cm] vertically are main reason. Overall, when more anchor blocks are constructed, excavation area is large, and constructivity such as backfill is bad, therefore one anchor block would be preferred.

Lateral Earth Pressures and Displacements through Full Scaled Lateral Loading Test of Concrete Electric Pole Embedded in Ground (지중에 근입된 콘크리트전주의 실물 수평재하실험에 의한 수평토압과 변위특성)

  • Ahn, Tae-Bong
    • Journal of the Korean GEO-environmental Society
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    • v.12 no.4
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    • pp.43-51
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    • 2011
  • Many electric poles in the softground have been collapsed due to external load. In this study, 10 types of tests were performed with variation of location, numbers and depths of anchor blocks as well as depth of poles to find horizontal earth pressure through full scale pull-out tests. The horizontal earth pressure increased with embedded depth of electric pole, and earth pressure of lower passive zone decreased. The deeper of anchor block, earth pressure of passive zone becomes less. lateral displacements showed differences depending on location, numbers and depth of poles. The bending is generated in the upper part at the initial load, but it moved to central part as load increased. The maximum horizontal displacement decreased to 1/1.6 at -0.5m depth of anchor block and 1.3m additional laying depth of poles into ground.

Loop Suture Technique for Flexor Digitorum Profundus Tendon Repair in the Insertion Site (고리 봉합법을 이용한 심부 수지 굴건 종지부에서의 건봉합)

  • Lee, Kyu-Cheol;Lee, Dong-Chul;Kim, Jin-Soo;Ki, Sae-Hwi;Roh, Si-Young;Yang, Jae-Won
    • Archives of Plastic Surgery
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    • v.37 no.5
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    • pp.650-658
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    • 2010
  • Purpose: In the case of repair for far distal parts of FDP (Flexor digitorum profundus) division, the method of either pull-out suture or fixation of tendon to the distal phalanx is preferred. In this paper, the results of a modified loop suture technique used for the complete division of FDP from both zone 1a and distal parts of zone 1b in Moiemen classification are presented. Methods: From July 2006 to July 2009, the modified loop suture technique was used for the 10 cases of FDP in complete division from zone 1a and distal parts of zone 1b, especially where insertion sites were less than 1 cm apart from a tendon of a stump. In a suture technique, a loop is applied to each distal and proximal parts of tendon respectively. Core suture of 2-strand and epitendinous suture are done with PDS 4-0. Out of 10 patients, the study was done on 6 patients who were available for the followup. The average age of the patients was 49.1 years (in the range from 26 to 67). 5 males and 1 female patients were involved in this study. There were 3 cases with zone 1a and distal parts of zone 1b. The average distance to the distal tendon end was 0.6 cm. There were 5 cases underwent microsurgical repair where both artery and nerve divided. One case of only tendon displacement was presented. The dorsal protective splint was kept for 5 weeks on average. The results of the following tests were measured: active & passive range of motion, grip strength test, key pinch and pulp pinch test. Results: The follow-up period on average was 11 months, in the range from 2 to 20 months. There was no case of re-rupture, but tenolysis was performed in 1 cases. In all 6 cases, the average active range of motion of distal interphalangeal joint was 50.8 degree. The grip strength (ipsilateral/contralateral) was measured as 88.7% and the pulp pinch test was 79.2% as those of contralateral side. Flexion contracture was presented in 2 cases (15 degree on average) and there was no quadrigia effect found. Conclusion: Despite short length of tendon from the insertion site in FDS rupture in zone 1a and distal parts of zone 1b, sufficient functional recovery could be expected with the tendon to tendon repair using the modified loop suture technique.

A Study on Acceptable Thermal Comfort Zone and Resident Behavior of Operating Cooling Devices in Apartments (공동주택의 여름철 수용 쾌적온도 범위와 거주자의 냉방기 사용행위에 관한 연구)

  • Chun Chung-Yoon;Bae Nu-Ri
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.5
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    • pp.477-486
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    • 2005
  • In this study, indoor thermal environment, resident behavior of operating cooling device, and thermal comfort vote are investigated at the living room of apartment during summertime in Seoul. Based on the results of the investigation, indoor air temperatures that residents turn air conditioners (especially for cooling load in this research) on and off were found out. The relationships between outdoor weather condition and the number of days using air conditioner, and whether operating patterns of the devices were also found out. The acceptable thermal comfort zone is figured out from these results, and this research is expected to contribute to the development of household air conditioner. The results can be summarized as the followings; Residents turned the air conditioner on at $29.76^{\circ}C$ of indoor air temperature, and $28.89^{\circ}C$ of $SET^\ast$. And turned the air conditioner off at $27.31^{\circ}C$ of indoor air temperature, and $23.70^{\circ}C$ $SET^\ast$. Therefore, acceptable thermal comfort zone could be lied between these temperatures. If comfortable indoor thermal environment can be obtained with various architectural passive cooling techniques based on the results, energy consumption of cooling devices will be reduced.