• Title/Summary/Keyword: Margins

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개별꽃속(석죽과)의 신종: 애기개별꽃(Pseudostellaria baekdusanensis M. Kim) (A new species of Pseudostellaria (Caryophyllaceae): P. baekdusanensis M. Kim)

  • 조현;신창근;김무열
    • 식물분류학회지
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    • 제44권3호
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    • pp.171-174
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    • 2014
  • 백두산에서 개별꽃속의 신종인 애기개별꽃(Pseudostellaria baekdusanensis M. Kim)을 새로이 발견하여 기재하였다. 애기개별꽃은 잎의 크기가 비슷하며 꽃은 줄기 끝에 액생 또는 정생하고 꽃잎은 요두인 특징을 가져 긴개별꽃(P. japonica (Korshinsky) Pax)과 유사하다. 그러나 애기개별꽃은 식물체가 9-13 cm로 소형이고 1줄의 털이 줄기에 있고 엽신 가장자리 기부에만 긴 털이 있으며 꽃잎은 깊은 요두형이고 화주는 2개이며 폐쇄화가 식물체에 달리지 않는다. 반면에 긴개별꽃은 식물체는 25-35 cm로 대형이고 1-2줄의 털이 줄기에 있고 엽신 가장자리와 이면 중륵에 긴 털이 밀생하며 꽃잎은 얕은 요두형이고 화주는 (2) 3개이며 폐쇄화가 엽액에 달린다는 점에서 뚜렷하게 차이를 보인다.

한계의 철학 : 수학과 철학 사이 (The Philosophy of Limits: Between Mathematics and Philosophy)

  • 박창균
    • 한국수학사학회지
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    • 제29권1호
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    • pp.31-44
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    • 2016
  • This essay aims to suggest roughly the "philosophy of limits." The limits mainly refer to those of human experiences and rational thoughts. The philosophy of limits consist of three theses and two consequences(L, M). (1) The limits are necessarily supervenient in the course of searching knowledge. (2) The limits cannot be dissipated ultimately. (3) To recognize the limits is not only an intellectual recognition but also a beginning of whole personality's reaction. (L) It is a rational decision to accept the limits and leave the margins (yeoback/yeoheuck) rather than to try to remove them. (M) To leave the margins (yeoback/yeoheuck) is characteristic of being human, and enables one to harmoniously communicate with others. To justify the philosophy of limits, this essay examine the limits discussed in mathematics and philosophy: set theory, Godel's Incompleteness Theorem, Galois Theorem in mathematics; and Hume, Kant, Kierkegaard, and Wittgenstein in philosophy. I try to interpret consciousness of limits in various cultures. I claim that consciousness of the limits contribute to lucidity of human identity, communication between persons, stimulation of creative thinking.

강제대류 아냉각비등에서 급격한 기포발생점의 예측 (Prediction of the Onset of Significant Void in Forced-Convection Subcooled Boiling)

  • 이상천;남상철
    • 대한기계학회논문집
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    • 제18권3호
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    • pp.681-689
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    • 1994
  • A model to predict the onset of significant void (OSV) in vertical flow between parallel plates has been developed. The model was compared to the experimental data of Whittle and Forgan (1967) and Dougherty et al. (1990), showing excellent agreement. The model was also compared with the Saha-Zuber(1974) correlation, which has been widely used in computer codes for nuclear safety analysis. The present theory is more conservative than this correlation, and further shows that, contrary to this correlation, the Stanton number is not solely related to the Peclet number. This may explain the large error margins required for the Saha-Zuber correlation, and also the scatter beyond the error margins specified by the authors. The steady-state OSV heat fluxes for equal and unequal heating cases between parallel plates were compared. The arithmetic mean of heat fluxes for unequal heating cases is less than the heat flux for equal heating cases. The result may imply that OSV is controlled by local thermal parameters rather than bulk parameters.

치관보철물(齒冠補綴物) 주변(周邊)에 저류(貯留)된 시멘트가 치은조직에 미치는 영향(影響)에 관(關)한 실험적(實驗的) 연구(硏究) (AN EXPERIMENTAL STUDY ON THE EFFECTS OF RETAINED CEMENTS IN THE GINGIVAL SULCUS AROUND ARTIFICIAL CROWNS)

  • 이동악
    • 대한치과보철학회지
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    • 제14권1호
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    • pp.17-21
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    • 1976
  • The author studied the gingival responses to some dental cements in the gingival sulcus around artificial crowns. Abutment preparation for full veneer crown was performed in the canines of the two dogs. The location of cervical margins was about 0.5mm. below the gingival crest. Niranium metal crowns were constructed for the teeth, and cemented with zinc phosphate cement or polycarboxy late cement. In the experimental groups the retained cements in the gingival sulucus were not removed, and in the control groups the cements were removed completely after cementation. The dogs were sacrificed at 3 weeks and 5 weeks respectively after cementation. The gingival responses to these cements were examined histologically. The findings were as follows. 1. There was severe inflammation in the gingiva where the cements had been retained in the gingival sulcus around artificial crowns. 2. There was more severe inflammation in the gingiva which had contacted with zinc phosphate cement than in the gingiva with polycarboxylate cement. 3. There was mild inflammation in the gingiva around the margins of Niranium crowns. 4. The retained cement around the margin of restoration should be completely removed after cementation.

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유기농경지 농업생산경관 구성요소에 대한 전문가 인식 조사 (A Survey of Expert's Perceptions about Landscape Elements in Organic Farmland)

  • 안필균;안난희;신지훈;신재훈
    • 한국유기농업학회지
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    • 제24권4호
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    • pp.681-698
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    • 2016
  • With increasing public concern for environmentally friendly agriculture, ecological aspect of landscape management is of growing importance. AHP (Analytical Hierarchy Process) analysis were conducted based on the delphi survey of 31 experts to evaluate the relative importance and the preference of landscape elements. Landscape components of organic farmland were classified into 2 landscape fields, 5 landscape types, 14 landscape units, and 37 landscape elements. Overall relevance score for the proposed landscape components were about 5.5 on the seven point scale. While the relative importance weight of cropland landscape field was 0.71, the weight of intra-structure landscape field was 0.29. Among the cropland landscape, relatively higher weight was assigned to farming system (0.47) and margins (0.31), as compared with hydrological system (0.22). In the farming system, crop (0.40) and farm land (0.39) were the most important landscape units. In the margins, higher weight was given to Buffer zone (0.44) and Trees (0.42). Biological habitat (0.43) ranked the highest score in the hydrological system. Preferable landscape elements were glass house, companion plants, rice paddy field, diverse crop species, small pond, and small river, which are representing ecological advantage of organic farming systems. This result indicated that the landscape elements identified in the study would be suitable to evaluate ecological aspect of rural landscape in organic farmland.

유연디스크용 가동 코일형 광 픽업 엑추에이터 개발 (Design of Moving Coil Type Optical Pickup Actuator for Flexible Disk)

  • 김윤기;송명규;이동주;박노철;박영필
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 추계학술대회논문집
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    • pp.479-483
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    • 2006
  • As high-definition television(HDTV) broadcasting were generalized, there have been many researches and developments about large storage capacity and fast data transfer rate in optical disk drives(ODD). Pickup actuators must have high flexible mode frequencies and gain margins. Flexible modes are caused by the flexibility of moving parts in the actuator and a servo bandwidth is limited by them. As a result, the system becomes unstable for high-speed operations in high density reading and recording. In this paper, we suggest improved modeling method that considers the bonding layer. And, flexible mode frequency of actuator is improved by Design of Experiment of lens holder. Magnet circuit is designed considering the relation with moving part. Through improving yoke design, the magnetic flux is changed and DC tilt is reduced. Consequently, we designed actuator which has high flexible mode frequency and gain margins.

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감각통합이론에 근거한 장애와 비장애를 포용하는 놀이터 환경 구성에 관한 연구 (A Study on setting the Environment of Inclusive Playground Including Disabled Children and Children without Disabilities (including at-risk children) based on J. Ayres' Sensory Integration Theory)

  • 김내리
    • 한국실내디자인학회논문집
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    • 제24권3호
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    • pp.205-212
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    • 2015
  • This study starts at the at-risk children(the students in the margins)' needs for the inclusive education environment who increased lately. It is studied in the limited scope, which is about spacially 'playground' and 'Sensory integrative therapy' in terms of the special education therapy. The 6 environmental setting principles are suggested, which is redefined in terms of suitable for applying to the environment design based on the training way and arbitration principle of J. Ayres' Sensory integrative therapy. And then various environment design methods are drawn from above-mentioned 6 principles, they are categorized in 4 elements for environmental setting - sensory element, behavior element, mental element and design expression element. This trial brings daily practice of therapeutic stimulate to sensory integration dysfunction children, and sensory experiential diversity promoting development to general children. Expecially it has some advantage that at-risk children(the students in the margins) feel a sense of belonging as a member of society.

D Flip-Flop과 Confluence Buffer로 구성된 단자속 양자 OR gate의 설계와 측정 (Design and Measurement of an SFQ OR gate composed of a D Flip-Flop and a Confluence Buffer)

  • 정구락;박종혁;임해용;장영록;강준희;한택상
    • Progress in Superconductivity
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    • 제4권2호
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    • pp.127-131
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    • 2003
  • We have designed and measured an SFQ(Single Flux Quantum) OR gate for a superconducting ALU (Arithmetic Logic Unit). To optimize the circuit, we used WRspice, XIC and Lmeter for simulations and layouts. The OR gate was consisted of a Confluence Buffer and a D Flip-Flop. When a pulse enters into the OR gate, the pulse does not propagate to the other input port because of the Confluence Buffer. A role of D Flip-Flip is expelling the data when the clock is entered into D Flip-Flop. For the measurement of the OR gate operation, we attached three DC/SFQs, three SFQ/DCs and one RS Flip -Flop to the OR gate. DC/SFQ circuits were used to generate the data pulses and clock pulses. Input frequency of 10kHz and 1MHzwere used to generate the SFQ pulses from DC/SFQ circuits. Output data from OR gate moved to RS flip -Flop to display the output on the oscilloscope. We obtained bias margins of the D Flip -Flop and the Confluence Buffer from the measurements. The measured bias margins $\pm$38.6% and $\pm$23.2% for D Flip-Flop and Confluence Buffer, respectively The circuit was measured at the liquid helium temperature.

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우리나라 전력계통의 물리적 및 운영 측면에서의 공급 여유력 평가 (Physical and Operational Supply Margin Evaluation of KOREA Power System)

  • 권중지;정상헌;사박;트란트룽틴;최재석;차준민;윤용태
    • 전기학회논문지
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    • 제56권1호
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    • pp.18-27
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    • 2007
  • Successful operation of power system under regulated as well as deregulated electricity markets is very important. This paper presents marginal power flow evaluation of KEPCO system in view point of physical and operation mode by using Physical and Operational Margins (POM Ver.2.2), which is developed by V&R Energy System Research. This paper introduces feature and operation mode of POM Ver.2.2 and then evaluates scenarios of 6 lines contingencies of 765kv of KEPCO system at peak load time on summer in 2006 you. The case study for actual 2006 year KEPCO system shows that this POM program is applicable sufficiently to KEPCO system. Futhermore, it demonstrates that it is helpful for operator's operating the system successfully by evaluating physical and operational margins quickly for various contingencies occurred in KEPCO system. Eventually, it will assist operators to operate more reliably the KEPCO system in future.