• 제목/요약/키워드: Short pulse

검색결과 551건 처리시간 0.023초

비접촉 SPL기법을 이용한 단결정 실리콘 웨이퍼 표면의 극초단파 펄스 전기화학 초정밀 나노가공 (Nanomachining on Single Crystal Silicon Wafer by Ultra Short Pulse Electrochemical Oxidation based on Non-contact Scanning Probe Lithography)

  • 이정민;김선호;김택현;박정우
    • 한국생산제조학회지
    • /
    • 제20권4호
    • /
    • pp.395-400
    • /
    • 2011
  • Scanning Probe Lithography is a method to localized oxidation on single crystal silicon wafer surface. This study demonstrates nanometer scale non contact lithography process on (100) silicon (p-type) wafer surface using AFM(Atomic force microscope) apparatuses and pulse controlling methods. AFM-based experimental apparatuses are connected the DC pulse generator that supplies ultra short pulses between conductive tip and single crystal silicon wafer surface maintaining constant humidity during processes. Then ultra short pulse durations are controlled according to various experimental conditions. Non contact lithography of using ultra short pulse induces electrochemical reaction between micro-scale tip and silicon wafer surface. Various growths of oxides can be created by ultra short pulse non contact lithography modification according to various pulse durations and applied constant humidity environment.

맥진기 결과에 대한 판독자간의 판독 일치율 비교 연구 (Comparative Studies on the Concordance Rate of Pulse Condition Interpretation between Interpreters and Pulse Analyser)

  • 강세영;장인수;김락형
    • Korean Journal of Acupuncture
    • /
    • 제28권4호
    • /
    • pp.91-99
    • /
    • 2011
  • Objectives : The purpose of our investigation is to determine degrees of concordance rate among interpreters. Furthermore, we have examined how much concordance rate to come out when beginners have been compared with the pulse analyzer. Methods : Thirty-nine volunteers were enrolled for this study. These subjects took a 5-minute rest in a sitting position as instructed by the protocol. As they were not allowed to move or speak, radial artery pulse conditions were measured on the lower arm of each subject by means of the pulse analyzer under investigation. Two Korean medical doctors, who did not know the status of default pulse conditions, were also instructed to intuitively choose the most corresponding one in comparison with 13 default pulse conditions. Subsequently, we investigated results between interpreters as well as results between interpreter and pulse analyzer. Results : The total concordance rate, with similar concordance rates being included, between interpreters, between interpreter A and pulse analyzer, and between interpreter B and pulse analyzer was 56.4%, 79.5%, and 71.8% respectively. In faint fine weak pulse(微細弱脈) case, interpreter A and B selected 6 and 7 cases respectively, matched the concordance rate 5, and corresponded separately with the pulse analyzer interpreting 8 cases. Conclusions : In case of skipping pulse 2(促2脈), short pulse(短脈), faint fine weak pulse(微細弱脈), the concordance between interpreters also matches with results drawn from the pulse analyzer. The concordance rate goes higher in proportion with such smaller pulse conditions as faint fine weak pulse(微細弱脈) and short pulse(短脈).

짧은 전류 펄스를 이용한 전류 유도 자화 반전에서 에너지 장벽 분포의 효과 (Effect of Energy Barrier Distribution on Current-Induced Magnetization Switching with Short Current Pulses)

  • 김우영;이경진
    • 한국자기학회지
    • /
    • 제21권2호
    • /
    • pp.48-51
    • /
    • 2011
  • 본 논문에서는 짧은 전류 펄스를 이용한 미소자기 소자에서의 전류 유도 자화 반전에 대한 매크로 스핀 시뮬레이션 연구를 수행하였다. 자화 반전 전류 분포에 있어서 에너지 장벽이 미치는 효과에 특별히 주목하였다. 자화 반전 전류의 크기 및 분포는 전류 펄스 폭의 감소에 따라 증가했다. 여기서 긴 전류 펄스 폭 영역에서는 에너지 장벽과 자화 반전 전류 분포 사이의 관계가 아레니우스-닐 법칙에 의해 서술된다. 하지만 짧은 전류 펄스 폭의 영역에서는 이 관계가 풀리지 않은 채로 남아있다. 이는 짧은 전류 펄스로 인한 자화 반전이 열적 활성화에 의해서가 아닌 세차 운동에 의해 좌우되기 때문이며, 이를 해결하는 데에 있어서 어려움이 발생한다. 그러므로 포커-플랑크 방정식을 풀어서 짧은 전류 펄스 영역에서의 자화 반전에 대한 정확한 공식을 얻어내는 것이 필요하며 이를 통해 짧은 전류 펄스 영역에서의 자화 반전 양상을 이해 할 수 있을 것으로 본다.

단공진기 색소레이저의 펄스폭 연속가변 특성 (Continuous variation characteristics of pulse width in short cavity dye laser)

  • 김용평
    • 한국광학회지
    • /
    • 제10권6호
    • /
    • pp.512-517
    • /
    • 1999
  • 이완발진 현상을 이용하는 단공진기 색소레이저(QDL:quenched dye laser)는 극단펄스 광원으로서 많은 장점을 갖고 있다. 본 연구에서는 파장 590nm에서 발진 스펙트럼의 최대값을 갖는 Rhodamine 6G를 레이저 매질로 하고, 파장 308nm의 XeCl 레이저를 펌핑원으로 하여, 이득의 길이가 5mm인 QDL의 이완발진에 의한 극단펄스 발생특성을 컴퓨터 시뮬레이션에 의해 분석하였다. 분석결과, 펌핑광의 펄스폭에 대하여 QDL 출력빔은 1/100 이하로 그 펄스폭이 짧아짐을 밝혀 QDL 이 극단펄스 발생용으로 매우 유용한 레이저임을 밝혔으며, 펌핑광의 공간적 크기를 조절함에 의하여 출력 펄스폭의 연속적인 가변동작이 가능함을 제시하였다.

  • PDF

동의보감(東醫寶鑑)중 맥법(脈法)에 관한 연구(硏究) (A Study on the Way of Pulse-diagnosis by Dongeuibogam)

  • 주신탁;김정국;박원환
    • 대한한의진단학회지
    • /
    • 제15권1호
    • /
    • pp.1-28
    • /
    • 2011
  • Objectives: A study on the importance and consistency of pulse-daignosis in the Dongeuibogam Methods: We used Deyeuk Dongeuibogam of Dongeuibogam publishing company from original photographic edition. Results: The frequency of 27 mek (pulse condition) in Dongeuibogam is as in the following. Bumek (Floating pulse) appeared 120(8.9%) times, wanmek (moderate pulse) appeared 28(2%) times, chokmek (running pulse) appeared 7 (0.5%) times, gyumek (hollow pulse) appeared 19 (1.4%) times, saekmek (uneven pulse) appeared 33 (2.4%) times, sapmek (uneven pulse) appeared 51 (3.8%) times, kyulmek (knotted pulse) appeared 18 (1.3%) times, whalmek (slippery pulse) appeared 69 (5.1%) times, chimek (slow pulse) appeared 43 (3.2%) times, demek (intermittent pulse) appeared 13 (1%) times, silmek (replete pulse) appeared 45 (3.3%) times, bokmek (deep-sited pulse) appeared 29 (2.1%) times, neomek (firm pulse) appeared 4 (0.3%) times, hyunmek (taut pulse) appeared 110 (8.1%) times, yumek (soft pulse) appeared 20 (1.5%) times, dongmek (short and rapid pulse) appeared 16 (1.2%) times, kinmek (tense pulse) appeared 67 (5%) times, yakmek (weak pulse) appeared 46 (3.4%) times, semek (thready pulse) appeared 62 (4.6%) times, hongmek (full pulse) appeared 50 (3.7%) times, jangmek (long pulse) appeared 14 (1%) times, sakmek (rapid pulse) appeared 103 (7.6%) times, mimek (indistinctive pulse) appeared 65 (4.8%) times, danmek (short pulse) appeared 16 (1.2%) times, demek (large pulse) appeared 106 (7.9%) times, chimmek (deep pulse) appeared 112 (8.3%) times, heomek appeared 70 (5.2%) times, sanmek (scattered pulse) appeared 14(1%)times. Conclusions: We can know Donguibogam is given on the basis 27mek (pulse condition), because the frequency of 27mek (pulse condition) is high. But there are another expressions. So we can not say that Donguibogam is consistent in expressing mekbub(the way of pulse-diagnosis).

한국에 서식하는 곤박쥐 Rhinolophus ferrumequinum, 집박쥐 Pipistrellus abramus, 큰발윗수염박쥐 Myotis macrodactylus의 반향정위 형태 (General Patterns in Echolocation Call of Greater Horseshoe Bat Rhinolophus ferrumequinum, Japanese Pipistrelle Bat Pipistrellus abramus and Large-Footed Bat Myotis macrodactylus in Korea)

  • 정철운;한상훈;임춘우;김성철;이화진;권용호;김철영;이정일
    • 한국환경과학회지
    • /
    • 제19권1호
    • /
    • pp.61-68
    • /
    • 2010
  • In this study, we analyzed the pulse-duration, pulse-interval and peak-frequency of echolocation call in three species as Rhinolophus ferrumequinum, Pipistrellus abramus, and Myotis macrodactylus. The peak frequency and pulse duration for above mentioned species were 69 kHz, 47 kHz and 49 kHz and $69.39{\pm}8.76\;ms$, $4.95{\pm}0.77\;ms$ and $3.09{\pm}0.48\;ms$ for R. ferrumequinum, P. abramus and M. macrodactylus, respectively. The pulse intervals for R. ferrumequinum, P. abramus and M. macrodactylus were $103.61{\pm}9.05\;ms$, $67.59{\pm}3.47\;ms$ and $66.35{\pm}4.96\;ms$, respectively. The pulse pattern of R. ferrumequinum was setting into a short FM call and linked to long CF call and went through the short FM call again. The pulse pattern of M. macrodactylus was comprised with serial short FM call and the CF call was not checked up in accordance with the spectrogram analysis. The long FM call and short CF call got join together for the P. abramus and the peak frequency was checked up at the pulse ending as CF call.

Nonequilibrium Heat Transfer Characteristics During Ultrafast Pulse Laser Heating of a Silicon Microstructure

  • Lee Seong Hyuk
    • Journal of Mechanical Science and Technology
    • /
    • 제19권6호
    • /
    • pp.1378-1389
    • /
    • 2005
  • This work provides the fundamental knowledge of energy transport characteristics during very short-pulse laser heating of semiconductors from a microscopic viewpoint. Based on the self-consistent hydrodynamic equations, in-situ interactions between carriers, optical phonons, and acoustic phonons are simulated to figure out energy transport mechanism during ultrafast pulse laser heating of a silicon substrate through the detailed information on the time and spatial evolutions of each temperature for carriers, longitudinal optical (LO) phonons, acoustic phonons. It is found that nonequilibrium between LO phonons and acoustic phonons should be considered for ultrafast pulse laser heating problem, two-peak structures become apparently present for the subpicosecond pulses because of the Auger heating. A substantial increase in carrier temperature is observed for lasers with a few picosecond pulse duration, whereas the temperature rise of acoustic and phonon temperatures is relatively small with decreasing laser pulse widths. A slight lagging behavior is observed due to the differences in relaxation times and heat capacities between two different phonons. Moreover, the laser fluence has a significant effect on the decaying rate of the Auger recombination.

Practical Implementation of Maximum Power Tracking Based Short-Current Pulse Method for Thermoelectric Generators Systems

  • Yahya, Khalid;Bilgin, Mehmet Zeki;Erfidan, Tarik
    • Journal of Power Electronics
    • /
    • 제18권4호
    • /
    • pp.1201-1210
    • /
    • 2018
  • The applications of thermoelectric generators (TEGs) have received a lot of attention both in terms of harvesting waste thermal energy and the need for multi-levels of power. It is critical to track the optimum electrical operating point using DC to DC converters controlled by a pulse that is generated through a maximum power point tracking algorithm (MPPT). In this paper, the hardware implementation of a short-current pulse algorithm has been demonstrated under steady stated and transient conditions. In addition, the MPPT algorithm has been proposed, which is one of the most effective and applicable algorithms for obtaining the maximum power point of TEGs. During this study, the proposed prototype has been validated both analytically and experimentally. It has also demonstrated successful performance, which highlights the claimed advantages of the proposed MPPT solution.

전문가 진단에 기반한 10대 맥상들 간의 연관성에 대한 연구 (Relations between 10 Primary Pulse Conditions Based on Doctors' Pulse Diagnoses)

  • 이재철;강남식;이혜정;김종열;김재욱
    • 동의생리병리학회지
    • /
    • 제24권6호
    • /
    • pp.1077-1081
    • /
    • 2010
  • In this work, we report the diagnostic relations among some primary pulse conditions such as the floating/sunken, deficient/forceful, large/fine, and the long/short pulses. For this purpose, we carried out a clinical test, in which 11 Oriental medical doctors had participated to diagnose the pulses for 1566 healthy subjects. The subjects were divided into 11 subgroups and each subgroup was allocated to an individual doctor. It resulted in that, for 847 subjects (54%), two or more than two pulse conditions were felt simultaneously, for which we counted the frequency of the pairs of the pulse conditions. For the statistical analysis, we used a Chi-square test. As a result, at high frequency, the forceful, large, and the long pulses were diagnosed in pairs or in their triplet, and a similar close relation was found between the deficient, fine, and the short pulses. The pairwise diagnoses of the pulse conditions between the forceful, large, and the long pulses, and between the deficient, fine, and the short pulses imply their close relatedness in clinics. This result is supported by the theory of deficiency/excess syndromes. Moreover, we show that the close relatedness among the pulse conditions can be understood in terms of the geometric features of the radial artery near the prominent bone. This is the first work which reports the relatedness between the primary pulses by an objective clinical test.

LD gain-switching에 의한 초단 광 펄스 발생 해석 (Analysis of ultra-short optical pulse generation by LD gain-switching)

  • 김윤중;김동각;김창민
    • 전자공학회논문지D
    • /
    • 제34D권10호
    • /
    • pp.85-92
    • /
    • 1997
  • For a InGaAsP buried - heterostructrue $1.3\mu\textrm{m}$ LD with fabry-perot cavity structure, the procedures of ultra-short optical pulse genration ar eanalyzed by simulating the rate equations. Investigting the effects of injected current pulse parameters such as bias $J_b$, pulse width $T_d$ and pulse amplitude $J_p$ on the generated optical pulses, we derive the optimum conditions to obtain a single optical pulse with strong peak value. We also observe that the repetition rate of current pulses needs to be restricted under a certain threshold to generate a train of single optical pulses, and that the period doubling phenomenon takes place by increasing the repitition rate.

  • PDF