• Title/Summary/Keyword: Transient period

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Comparison of resorbable plates and titanium plates for fixation stability of combined mandibular symphysis and angle fractures

  • Lim, Ho-Yong;Jung, Chang-Hwa;Kim, Seong-Yong;Cho, Jin-Yong;Ryu, Jae-Young;Kim, Hyeon-Min
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제40권6호
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    • pp.285-290
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    • 2014
  • Objectives: We compared resorbable plates with titanium plates for treatment of combined mandibular angle and symphyseal fractures. Materials and Methods: Patients with mandibular angle and symphysis fractures were divided into two groups. The control (T) group received titanium plates while the experimental (R) group received resorbable plates. All procedures were carried out under general anesthesia using standard surgical techniques. We compared the frequency of wound dehiscence, development of infection, malocclusion, malunion, screw breakage, and any other technical difficulties between the two groups. Results: Thirteen patients were included in the R group, where 39 resorbable plates were applied. The T group consisted of 16 patients who received 48 titanium plates. The mean age in the R and T groups was 28.29 and 24.23 years, respectively. Primary healing of the fractured mandible was obtained in all patients in both groups. Postoperative complications were minor and transient. Moreover, there were no significant differences in the rates of various complications between the two groups. Breakage of 3 screws during the perioperative period was seen in the R group, while no screws or plates were broken in the T group. Conclusion: Resorbable plates can be used to stabilize combined mandibular angle and symphysis fractures.

로켓 엔진의 시동에 관한 해석적 연구 (Numerical Analysis on the Startup of a Rocket Engine)

  • 박순영;설우석
    • 한국추진공학회지
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    • 제11권5호
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    • pp.60-71
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    • 2007
  • 액체로켓 엔진의 시동은 연소기와 가스발생기의 안정적인 점화는 물론 시동에 소요되는 시간을 단축하여 추력 발생과 상관없는 추진제 소모량을 줄이는 방향으로 전개되어야 한다. 특히 엔진시스템의 시동 순서나 규격을 모두 시험적으로 개발하는 데는 한계가 있으며, 안전상의 이유로 시험 조건이나 시동 cyclogram에 대한 해석적인 분석이 선행될 필요가 있다. 이에 본 연구에서는 가스발생기 사이클 액체로켓 엔진의 수학적 모델을 상용 1차원 유체시스템 해석 프로그램인 Flowmaster를 기반으로 개발하였으며, 이를 이용하여 안정된 엔진 시동을 위한 파이로시동기 규격이나 연소기 및 가스발생기 종단밸브의 열림시간 등을 구하는 방법론을 제시하였다. 아울러 해석 결과로 구한 시동특성을 해외 엔진의 시동 해석 결과와 정성적인 비교를 수행하여 비교적 잘 일치함을 파악하였다.

태안해안국립공원 모항 암반조간대 웅덩이의 어류 종조성과 수직분포 (Species Composition and Vertical Distribution Pattern of Fish in Rock Tidal Pools at Mohang, Taeanhaean National Park)

  • 최윤;이흥헌
    • 한국어류학회지
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    • 제25권4호
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    • pp.227-233
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    • 2013
  • 태안반도 모항항의 암반조간대 조수웅덩이에서 2010년 1월부터 12월까지 매월 어류를 채집하여 고도에 따른 종조성분포를 분석하였다. 조사 기간 동안 채집된 어류는 3목 8과 14속 16종이었으며, 이 가운데 망둑어과의 점망둑(Chaenogobius annularis)이 34.6%로 우점하였고, 아우점종으로는 그물베도라치(Chaenogobius annularis)가 22.0%, 조피볼락 (Chaenogobius annularis)이 6.9%, 두줄망둑 (Chaenogobius annularis)이 6.8%순이었다. 그물베도라치는 고도에 관계없이 주거종으로 출현하였으며, 점망둑은 상부조간대에서 가장 우점하였고, 모든 조사 시기에 채집되었다. 주거종의 개체수는 일시주거종과 기회방문종보다 높았으며, 생체량은 주거종이 61.4%로 가장 높았으며, 일시주거종이 14.2%, 기회방문종이 24.4%였다.

급성 폐부종으로 발현된 특발성 과호산구성 증후군 1예 (A Case of Idiopathic Hypereosinophilic Syndrome Presenting Acute Pulmonary Edema)

  • 유경술;김연재;서향은;윤혜진;도윤경;이병기;김원호
    • Tuberculosis and Respiratory Diseases
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    • 제52권2호
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    • pp.166-173
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    • 2002
  • 저자들은 급성 호흡부전으로 발현되어 특별한 원인 없이 말초혈액의 호산구 증가와 골수의 호산구 증식, 그리고 심장 및 폐장의 침범 소견이 있는 환자에서 부신 피질호르몬 치료로 호전을 보였던 특발성 과호산구성 증후군 환자를 경험하였기에 보고하는 바이다.

NEW PHOTOMETRIC PIPELINE TO EXPLORE TEMPORAL AND SPATIAL VARIABILITY WITH KMTNET DEEP-SOUTH OBSERVATIONS

  • Chang, Seo-Won;Byun, Yong-Ik;Shin, Min-Su;Yi, Hahn;Kim, Myung-Jin;Moon, Hong-Kyu;Choi, Young-Jun;Cha, Sang-Mok;Lee, Yongseok
    • 천문학회지
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    • 제51권5호
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    • pp.129-142
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    • 2018
  • The DEEP-South (the Deep Ecliptic Patrol of the Southern Sky) photometric census of small Solar System bodies produces massive time-series data of variable, transient or moving objects as a by-product. To fully investigate unexplored variable phenomena, we present an application of multi-aperture photometry and FastBit indexing techniques for faster access to a portion of the DEEP-South year-one data. Our new pipeline is designed to perform automated point source detection, robust high-precision photometry and calibration of non-crowded fields which have overlap with previously surveyed areas. In this paper, we show some examples of catalog-based variability searches to find new variable stars and to recover targeted asteroids. We discover 21 new periodic variables with period ranging between 0.1 and 31 days, including four eclipsing binary systems (detached, over-contact, and ellipsoidal variables), one white dwarf/M dwarf pair candidate, and rotating variable stars. We also recover astrometry (< ${\pm}1-2$ arcsec level accuracy) and photometry of two targeted near-earth asteroids, 2006 DZ169 and 1996 SK, along with the small- (~0.12 mag) and relatively large-amplitude (~0.5 mag) variations of their dominant rotational signals in R-band.

전력계통 주파수조정을 위한 SOC 기반의 배터리 에너지저장장치 제어전략 (SOC-based Control Strategy of Battery Energy Storage System for Power System Frequency Regulation)

  • 윤준영;유가람;국경수;노도환;장병훈
    • 전기학회논문지
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    • 제63권5호
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    • pp.622-628
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    • 2014
  • This paper presents the SOC-based control strategy of BESS(Battery Energy Storage System) for providing power system frequency regulation in the bulk power systems. As the life cycle of BESS would be shortened by frequent changes of charge and discharge required for frequency regulation in a steady state, the proposed algorithm operates BESS within a range of SOC where its life cycle can be maximized. However, during a transient period of which occurrence frequency is low, BESS would be controlled to use its full capacity in a wider range of SOC. In addition, each output of multiple BESS is proportionally determined by its SOC so that the balance in SOC of multiple BESS can be managed. The effectiveness of the proposed control strategy is verified through various case studies employing a test system. Moreover, the control result of BESS with the measured frequency from a real system shows SOC of BESS can be maintained within a specific range although the frequency deviation is biased.

Klotho : Expression and Regulation at the Maternal-Conceptus Interface in Pigs

  • Choi, Yohan;Seo, Heewon;Shim, Jangsoo;Hyun, Sang-Hwan;Lee, Eunsong;Ka, Hakhyun
    • 한국수정란이식학회지
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    • 제29권4호
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    • pp.375-383
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    • 2014
  • Klotho (KL) is a single transmembrane protein composed of KL1 and KL2 repeats possessing ${\beta}$-glucuronidase activity and maintains calcium homeostasis in physiological state. It has been implicated in pigs that calcium is important for the establishment and maintenance of pregnancy, and our previous study has shown that transient receptor potential vanilloid type 6 (TRPV6), a calcium ion transporter, is predominantly expressed in the uterine endometrium during pregnancy in pigs. However, expression and function of KL in the uterine endometrium has not been determined in pigs. Thus, the present study determined expression and regulation of KL in the uterine endometrium during the estrous cycle and pregnancy in pigs. Real-time RT-PCR analysis showed that levels of KL mRNA decreased between Days 12 to 15 of the estrous cycle, and its expression showed a biphasic manner during pregnancy. KL mRNA was expressed in conceptuses and in chorioallantoic tissues during pregnancy. Explant culture study showed that expression levels of KL were not affected by treatment of steroid hormones or interleukin-1beta during the implantation period. Furthermore, levels of KL mRNA in the uterine endometrium from gilts carrying somatic cell nuclear transfer (SCNT)-derived embryos were significantly lower than those from gilts carrying natural mating-derived embryos on Day 12 of pregnancy. These results exhibited that KL was expressed at the maternal-conceptus interface in a pregnancy status- and stage-specific manner, and its expression was affected by SCNT procedure, suggesting that KL may play an important role in the establishment and maintenance of pregnancy in pigs.

디젤기관 배기 배출물에 있어서 매연 응집체 크기 및 농도의 시간적 계측에 관한 연구 (A Study on Temporal Measurement of Size and Concentration for Soot Aggregates among Exhaust Emissions in Diesel Engines)

  • 배명환;;배창환
    • 한국자동차공학회논문집
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    • 제15권1호
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    • pp.116-124
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    • 2007
  • An optical method to measure the size and number density of soot aggregates in diesel exhaust has been proposed in this study. Two laser beams in co-axial alignment transmit a soot loaded exhaust gas flow, and the transmittance at each wavelength is detected by a photo diode simultaneously. The volume equivalent diameter and number density of soot aggregates in the optical path can be theoretically given by the transmittance values measured at two wavelengths. A test conducted by a single cylinder, 4 cycle, small and DI diesel engine shows that the temporal variations of the size and number density of soot aggregates in the diesel exhaust can be measured by the proposed method at a transient mode operation. It is found that the volume equivalent diameter varied temporally from 70 to 110 nm during the period that high soot concentration is observed. One can also conclude that the optical length longer than 1 m in the dynamic range regarding this method is preferable for measuring soot concentration at the level of $1\;mg/m^3$.

통신위성 배터리 충,방전기 설계 및 해석 (Design and Analysis of a Battery Charge and Discharge Regulator of Communication Satellite)

  • 최재동
    • 한국항공우주학회지
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    • 제31권7호
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    • pp.118-126
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    • 2003
  • 본 연구에서는 모듈형태의 배터리 충-방전기가 정상상태뿐만 아니라 과도상태에서 예기치 못한 결함이 발생할지라도 실패 없이 전원을 공급하는 것이 가능한 병렬형 양방향 컨버터로 설계되어졌다. 컨버터 모듈은 안정성, 성능 및 고신뢰성을 얻기 위해 독립적인 제어가 가능하도록 설계되었으며, 제어기를 위해 사용된 평균전류모드방식은 노이즈 면역, 빠른 응답 및 평균전류 신호 획득과 같은 장점을 갖는다. 병렬 연결된 배터리 충-방전기에 대한 등가모델이 제시되었으며, 충전연속모드, 방전연속/불연속 모드에 대한 전달함수가 분석되었다. 병렬 양방향 컨버터는 스텝 부하변화와 하나의 컨버터 모듈 실패에 대해 각각 수행되었다. 그리고 병렬 양방향 컨버터의 성능이 실험결과들을 통해 검증되었다.

Changes of Afferent Transmission to the SI Cortex by Transient Co-Stimulation of Receptive Field Center and Outside in Anesthetized Rats

  • Yang, Yu-Mi;Lim, Sa-Bina;Won, Chung-Kil;Shin, Hyung-Cheul
    • The Korean Journal of Physiology and Pharmacology
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    • 제5권1호
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    • pp.27-32
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    • 2001
  • We have characterized the aftereffects of impulse activities on the transmission of afferent sensory to the primary somatosensory (SI) cortex of the anesthetized rats (n=22). Following conditioning stimulation (CS, 10 sec, either 5 Hz or 200 Hz) to the receptive field (RF), quantitative determination of the changes of afferent sensory transmission was done by generating post-stimulus time histogram of unit response to the testing stimulation (TS, at 0.5 Hz) to the RF center (RFC) for 60 min. In one group of experiments, CS was delivered to the RF center (RFC). In another group of experiments, CSs were simultaneously given to both RFC and RF outside (RFO, either forepaw or hindpaw). CS of 5 Hz to RFC exerted irreversible facilitation of sensory transmissions evoked by TS. Simultaneous CSs of 5 Hz to RFC and hindpaw RFO exerted reversible suppression of afferent transmission. However, CSs of 5 Hz to RFC and forepaw RFO did not significantly altered afferent sensory transmission to SI cortex neurons. CS of 200 Hz to RFC exerted irreversible suppression of sensory transmissions up to 60 min of experimental period. Simultaneous CSs of 200 Hz to RFC and RFO did not significantly altered afferent sensory transmission to SI cortex neurons. The profiles of CS-induced modulation of afferent sensory transmission were significantly different between two CS conditions. Thus, this study suggests that activity-dependent modulation of afferent transmission from a RF center to the SI cortex may be significantly altered when remote body part was simultaneously activated.

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