• 제목/요약/키워드: Conversion unit

검색결과 580건 처리시간 0.027초

단위거리 12진부호의 몇가지 특성 (Some Characteristics of Unit-Distance Duo-Decimal Codes)

  • 김병찬
    • 대한전자공학회논문지
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    • 제12권1호
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    • pp.7-11
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    • 1975
  • 12-Tuple DS (digit sequence) (또는 coordinate sequence)의 여러 가지 성질에 관하여 논하였으며 그것을 통일적으로 표시하기 위한 31종의 PDS(prime digit sequence)를 제안하여 이에 단순히 회전변환만을 실시함으로써 실제의 부호를 표시하는 348종의 DS를 얻을 수 있고 또 이것들에 대한번호교환 즉 순열(permutation)과 부호의 초기조건을 고려하면 단위거리 12진 부호의 총수는 120,576종이며 이 중의 임의의 부호를 지정하든지 기술하든지 할 수 있도록 하였다. 그리고 대칭부호(반대부호), Lippel 부호등 특수한 부호를 위한 DS들의 특성과 그것들이 회로화에 대하여도 언급하였다. Investigations on sole characteristics of unit-distance duo-decimal codes are carried out, and 31kinds of Prime Digit Sequence (PDS) are proposed in order to express various digit sequences. From these PDS, by means of the rotational conversion, 348 digit sequences which express the practical GC are obtained, and, ism these digit sequences, it is found that there are 120576 unit distance codes by the permutation of the coordinate number and the initial condition of the codes. Some special codes such as reflected or symmetrical codes and Lippel codes, and their application to the practical GC counter are also studied.

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The effect of light sources and CAD/CAM monolithic blocks on degree of conversion of cement

  • Cetindemir, Aydan Boztuna;Sermet, Bulent;Ongul, Deger
    • The Journal of Advanced Prosthodontics
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    • 제10권4호
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    • pp.291-299
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    • 2018
  • PURPOSE. To assess the degree of conversion (DC) and light irradiance delivered to light-cured and dual-cured cements by application of different light sources through various types of monolithic computer-aided design and computer-aided manufacturing (CAD/CAM) materials. MATERIALS AND METHODS. RelyX Ultimate Clicker light-cured and dual-cured resin cement specimens with 1.5-mm thicknesses (n=300, 10/group), were placed under four types of crystalline core structure (Vita Enamic, Vita Suprinity, GC Ceresmart, Degudent Prettau Anterior). The specimens were irradiated for 40 seconds with an LED Soft-Start or pulse-delay unit or 20 seconds with a QTH unit. DC ratios were determined by using Fourier transform infrared spectroscopy (FTIR) after curing the specimen at 1 day and 1 month. The data were analyzed using the Mann-Whitney U test (for paired comparison) and the Kruskal-Wallis H test (for multiple comparison), with a significance level of P<.05. RESULTS. DC values were the highest for RelyX Ultimate Clicker light-cure specimens polymerized with the LED Soft-Start unit. The combination of the Vita Suprinity disc and RelyX Ultimate Clicker dual-cure resin cement yielded significantly higher values at both timepoints with all light units (all, P<.05). CONCLUSION. Within the limitations of this study, we conclude that the DC of RelyX Ultimate Clicker dual-cure resin cement was improved significantly by the use of Vita Suprinity and the LED Soft-Start light unit. We strongly recommend the combined use of an LED light unit and dual-cure luting cement for monolithic ceramic restorations.

몬테칼로 시뮬레이션에 의한 지표면 오염 방사선장에서의 유효선량 평가 (Assessment of Effective Doses in the Radiation Field of Contaminated Ground Surface by Monte Carlo Simulation)

  • 장재권;이재기;장시영
    • Journal of Radiation Protection and Research
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    • 제24권4호
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    • pp.205-213
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    • 1999
  • 지표에 오염된 방사성핵종의 단위방사능당 유효선량환산계수를 남성과 여성 인형모의피폭체와 MCNP4A 코드를 이용하여 계산하였다. 모사실험은 40 keV에서 10 MeV 영역의 19개 단일 에너지에 대한 유효선량 계산을 수행하였다. 에너지에 따른 단위 선원강도에 대한 유효선량 E를 기존 연구자들의 결과물인 유효선량당량 $H_E$와 비교한 결과, 본 연구의 E값이 USEPA의 FGR에 주어진 $H_E$ 값에 비해 30%의 편차를 보였다. 에너지와 유효선량의 관계를 polynomial fitting을 통해 구한 유효선량 감응함수는 다음과 같다. $f({\varepsilon})[fSv\;m^2]=\;0.0634\;+\;0.727{\varepsilon}-0.0520{\varepsilon}^2+0.00247{\varepsilon}^3$ 여기서, ${\varepsilon}$는 감마선의 에너지(MeV)이다. 감응함수와 ICRP 38의 방사성핵종 붕괴 자료를 이용하여 지표면과 공기 오염의 단위 방사능농도에 대한 유효선량환산계수를 계산한 후 DOSEFACTOR코드를 사용하여 계산한 베타선에 의한 피부선량을 합하여 90개의 중요 핵종들에 대한 환산계수를 평가하여 도표로 제시하였다. 기존 자료들과 비교를 통해 기존 환산계수를 사용할 경우 특히 저에너지 감마선이나 고에너지 베타선을 방출하는 핵종에 대해서 상당한 과소평가가 이루어질 수 있음을 확인할 수 있었다.

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MIRD 인형팬텀의 넓고 평행한 감마선빔에 대한 선량 환산계수 계산 (Calculation of Dose Conversion Coefficients in the Anthropomorphic MIRD Phantom in Broad Unidirectional Beams of Monoenergetic Photons)

  • 장재권;이재기
    • Journal of Radiation Protection and Research
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    • 제22권1호
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    • pp.47-58
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    • 1997
  • MCNP4A 코드를 이용하여 MIRD 인형팬텀의 정면과 후방에서 입사하는 넓고 평행한 감마선빔에 대한 단위 공기커마당 유효선량 환산계수와 단위 플르언스당 장기의 등가선량을 계산하였다. 본 연구에서 고려한 감마선은 0.03-10 MeV 에너지 구간에서 20개의 단일에너지에 대해 수행되었다. 환산계수의 계산결과를 ICRP/ICRU의 연구결과 발표예정 출판물에 주어진 해당되는 값과 비교한 결과 편차 10%이내에서 일치하고 있다. 결과의 차이가 발생한 이유는 MIRD 팬텀과 ADAM/EVE 팬텀의 기하학적 차이가 주원인이며 또한 계산에 사용된 전산코드와 단면적 차이 등으로 판단된다. 특정 식도 모델을 사용한 결과로부터 얻어진 유효선량과 흉선과 췌장에 대한 등가선량을 채택함으로써 얻어지는 유효선량은 약간(최고 5%)의 차이를 보인다. 기타장기로부터 상부대장을 제외했을 때 본 연구에서 다루었던 감마선 선량학적 측면의 경우에서는 중요하지 않은 것으로 나타났다.

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Conversion of G. hansenii PJK into Non-cellulose-producing Mutants According to the Culture Condition

  • Park, Joong-Kon;Hyun, Seung-Hun;Jung, Jae-Yong
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제9권5호
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    • pp.383-388
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    • 2004
  • The conversion of a cellulose-producing cell ($Cel^+$) from Gluconacetobacter hansenii PJK (KCTC 10505 BP) to a non-cellulose-producing cell ($Cel^-$) was investigated by measuring the colony forming unit (CFU). This was achieved in a shaking flask with three slanted baffles, which exerted a strong shear stress. The addition of organic acid, such as glutamic acid and acetic acid, induced the conversion of microbial cells from a wild type to $Cel^-$ mutants in a flask culture. The supplementation of $1\%$ ethanol to the medium containing an organic acid depressed the con-version of the microbial cells to $Cel^-$ mutants in a conventional flask without slanted baffles. The addition of ethanol to the medium containing an organic acid; however, accelerated the conversion of microbial cells in the flask with slanted baffles. The $Cel^+$ cells from the agitated culture were not easily converted into $Cel^-$ mutants on the additions of organic acid and ethanol to a flask without Slanted baffles, but some portion of the $Cel^+$ cells were converted to $Cel^-$ mutants in a flask with slanted baffles. The conversion ratio of $Cel^+$ cells to $Cel^-$ mutants was strongly re-lated to the production of bacterial cellulose independently from the cell growth.

고정화 Brevibacterium ammoniagenes와 Acetate Kinase의 ATP생성계에 의한 NADP생산 (Production of NADP by Immobilized Brevibacterium ammoniagenes and ATP- regenerating System of Acetate Kinase)

  • 조정일
    • 한국식품영양학회지
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    • 제6권3호
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    • pp.158-168
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    • 1993
  • For the conversion of WAD to NADP, Immobilized Brevibacterium ammoniagenes cells with NAD kinase was coupled with ATP-generating system by acetate kinase. The membrane permeability of B. ammoniagenes was improved by toluene treatment of cells. The toluene treated B. ammoniagenes cells were immobilized for stable enzyme activity. Partially purified acetate kinase was used in the reaction system. The optimum conditions for the efficient conversion of UAD to WADP by energy-coupled system were investigated. B. ammoniagenes cells treated with toluene for the Improvement of membrane permeability showed 4.5 fold improved permeability in the conversion of NAD to NADP compared with Intact cells. 3% k-carrageenan as the immobilization matrix of B. ammoniagenes showed the best efficiency for the conversion of NAD to NADP The optimum conditions for the WAR to WARP conversion reaction coupled nth ATP-generating system were 10mM acetylphosphate, 5mM ADP 200mM inorganic phosphate, 10mM MgCl2, 250mg/ml Immobilized cells, 49.3mUnit/ml acetate kinase, pH 7.5 and 37$^{\circ}C$. Under the optimum conditions, 72% of 5mM(340mg/ml ) NAD was converted to UADP In 12 hours.

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Free Voltage Regulation기능을 갖는 교환기용정류기 개발에 관한 연구 (A Study on the Development of A Rectifier Unit for Telecommunication Equipments with Free Input-Voltage Regulations)

  • 김은수;조기연;임근희;김요희;홍성철
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 하계학술대회 논문집 B
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    • pp.821-824
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    • 1993
  • This paper deals with a $3{\phi}$ rectifier unit for telecommunication system. The rectifier unit is developed to Cope with the step-up of the AC input voltatage from 220V to 380V. By using a buck-type converter in the front-end, it keeps the input power factor high and reduces the voltage ripple in the dc output. It also has a very wide voltage regulation range, which lets the unit be applied for both the 220V and 380V input system. The study includes the power conversion scheme, control strategy, snubber circuit and finally, experimental results.

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Robotic Intraoperative Tracheobronchial Repair during Minimally Invasive 3-Stage Esophagectomy

  • Marano, Alessandra;Palagi, Silvia;Pellegrino, Luca;Borghi, Felice
    • Journal of Chest Surgery
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    • 제54권2호
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    • pp.154-157
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    • 2021
  • Tracheobronchial injury (TBI) is an uncommon but potentially fatal event. Iatrogenic lesions during bronchoscopy, endotracheal intubation, or thoracic surgery are considered the most common causes of TBI. When TBI is detected during surgery, concomitant surgical treatment is recommended. Herein we present a case of successful robotic primary repair of iatrogenic tracheal and left bronchial branch tears during a robot-assisted hybrid 3-stage esophagectomy after neoadjuvant chemoradiotherapy. A robotic approach can facilitate the repair of this injury while reducing both the potential risk of conversion to open surgery and the associated increased risk of postoperative respiratory complications.

Mismatch-tolerant Capacitor Array Structure for Junction-splitting SAR Analog-to-digital Conversion

  • Lee, Youngjoo;Oh, Taehyoun;Park, In-Cheol
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제17권3호
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    • pp.387-400
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    • 2017
  • A new junction-splitting based SAR ADC with a redundant searching capacitor array structure in $0.13{\mu}m$ CMOS process to alleviate capacitor mismatch effects, is presented. The normalized average power has a factor of 0.35 to the conventional SAR ADC at 10-bit conversion accuracy. Statistical experiments show the number of missing codes resulting from the mismatch reduces by 95% for 3% unit-capacitor mismatch ratio, while keeping the conversion energy to that of the conventional JS capacitor array.

Oxidation Behavior of UO$_2$in Air at 300~55$0^{\circ}C$

  • Kang, Kweon-Ho;Hwang, Suk-Youl;Kim, Kil-Jeong
    • 에너지공학
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    • 제6권2호
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    • pp.198-202
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    • 1997
  • The oxidation behavior of UO$_2$pellets was studied using a thermogravimetric analyzer and an XRD in the temperature range of 300 to 550$^{\circ}C$ in air. From XRD studies it is found that UO$_2$is converted to U$_3$O$\_$8/ and the weight gains of UO$_2$specimen are characterized by S-shape curves. After complete oxidation the specimens broke into fine powder and the average weight gain was about 3.93 wt%. The activation energy of 50% conversion of UO$_2$to U$_3$O$\_$8/ is 81.6 kJ/mol and the oxidation rate per unit time was found to be as follows dw/dt=6.54${\times}$10$\^$6/ e (equation omitted), wt%/h : at 50% conversion of UO$_2$into U$_3$O$\_$8/ where w, t and T were wt% gain, conversion time and temperature, respectively.

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