• 제목/요약/키워드: two-step

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Two-Step Incision for Periarterial Sympathectomy of the Hand

  • Jeon, Seung Bae;Ahn, Hee Chang;Ahn, Yong Su;Choi, Matthew Seung Suk
    • Archives of Plastic Surgery
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    • 제42권6호
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    • pp.761-768
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    • 2015
  • Background Surgical scars on the palmar surface of the hand may lead to functional and also aesthetic and psychological consequences. The objective of this study was to introduce a new incision technique for periarterial sympathectomy of the hand and to compare the results of the new two-step incision technique with those of a Koman incision by using an objective questionnaire. Methods A total of 40 patients (17 men and 23 women) with intractable Raynaud's disease or syndrome underwent surgery in our hospital, conducted by a single surgeon, between January 2008 and January 2013. Patients who had undergone extended sympathectomy or vessel graft were excluded. Clinical evaluation of postoperative scars was performed in both groups one year after surgery using the patient and observer scar assessment scale (POSAS) and the Wake Forest University rating scale. Results The total patient score was 8.59 (range, 6-15) in the two-step incision group and 9.62 (range, 7-18) in the Koman incision group. A significant difference was found between the groups in the total PS score (P-value=0.034) but not in the total observer score. Our analysis found no significant difference in preoperative and postoperative Wake Forest University rating scale scores between the two-step and Koman incision groups. The time required for recovery prior to returning to work after surgery was shorter in the two-step incision group, with a mean of 29.48 days in the two-step incision group and 34.15 days in the Koman incision group (P=0.03). Conclusions Compared to the Koman incision, the new two-step incision technique provides better aesthetic results, similar symptom improvement, and a reduction in the recovery time required before returning to work. Furthermore, this incision allows the surgeon to access a wide surgical field and a sufficient exposure of anatomical structures.

CeO2/ZrO2 Foam Device를 이용한 고온 태양열 열화학 싸이클의 수소 생산 (Hydrogen Production with High Temperature Solar Heat Thermochemical Cycle using CeO2/ZrO2 Foam Device)

  • 이진규;서태범
    • 한국태양에너지학회 논문집
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    • 제34권6호
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    • pp.11-18
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    • 2014
  • Two-step water splitting thermochemical cycle with $CeO_2$ foam device was investigated by using a solar simulator composed of 2.5 kW Xe-Arc lamp and mirror reflector. The hydrogen production of $CeO_2$ foam device depending on reaction temperature of Thermal-Reduction step and Water-Decomposition step was analyzed, and the hydrogen production of $CeO_2$ and $NiFe_2O_4/ZrO_2$ foam devices was compared. As a result, the amount of reduced $CeO_2$ considerably varies according to the reaction temperature of Thermal-Reduction step. and hydrogen production was not much when the amount of reduced $CeO_2$ decreased even if the reaction temperature of Water-Decomposition step was high. Therefore, it is very important to keep the reaction temperature of Thermal-Reduction step high in two-step thermochemical cycle with $CeO_2$.

Comparison of Two Step LEEP and Cold Conisation For Cervical Intraepithelial Lesions to Decrease Positive Surgical Margins

  • Senol, Taylan;Polat, Mesut;Ozkaya, Enis;Karateke, Ates
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권7호
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    • pp.3317-3320
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    • 2016
  • Purpose: To assess the success rates of two step loop electrosurgical excision procedure (LEEP) compared with conventional cold conization procedures for decreasing positive surgical margins. Materials and Methods: This study was conducted on 70 patients who underwent colposcopic evaluation in Zeynep Kamil Women and Children's Health Training and Research Hospital between 2013-2015 with indications of CIN 2/3 or persistent CIN 1 for more than 2 years. The study included age matched groups of patients with similar histopathololical lesions who underwent cold conization (n=40) or LEEP (N=30). Results: Comparison of tissue characteristics between the two groups revealed significantly higher deepest depth and lower volume of tissue removed by the two step LEEP. Ectocervical positivity rate was similar between groups (1/39 versus 0/29, P>0.05), while endocervical surgical margin positivity rate was significantly higher in the cold conization group (9/39 versus 0/29, P<0.05). Surgical margin positive cases were significantly older than the cases with negative margins (P<0.05). Conclusions: Two step LEEP made it easier to reach the squamocolumnar junction in the endocervical region with lower blood loss and applicability in office settings. Our study suggests to use two step approach in cases with high grade and glandular CIN.

2단계 아세톤 침전법으로부터 얻어진 Candida rugosa Lipase를 이용한 (R,S)-Naproxen Ester의 광학선택성 수화반응 (Enantioselective Hydrolysis of (R,S)-Naproxen Methyl Ester Using Two-step Acetone-treated Candida rugosa Lipase)

  • 이은교;최순자;정봉현
    • 한국미생물·생명공학회지
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    • 제28권4호
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    • pp.223-227
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    • 2000
  • A novel two-step acetone treatment method was developed to enhance the enantioselectivity of Candida rugosa lipase (CRL) toward the hydrolysis of racemic naproxen methyl ester. The acetone-teated CRL was considerably more enantioselective than the crude CRL, yielding an enantiomeric excess of 98~100%. The crude and acetone-treated CRLs were subjected to anion exchange chromatography, and their chromatography profiles were compared. In consequence, both chromatography profiles were found to be almost identical, resulting in two separate lipase peaks (lipase A and B). The lipase B, which is known to be less enantioselective, was treated with acetone using a two-step treatment method. The enantioselectivity of acetone-treated lipase B was dramatically increased, yielding an enantiomeric excess of 99%.

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Radiation damage to Ni-based alloys in Wolsong CANDU reactor environments

  • Kwon, Junhyun;Jin, Hyung-Ha;Lee, Gyeong-Geun;Park, Dong-Hwan
    • Nuclear Engineering and Technology
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    • 제51권3호
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    • pp.915-921
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    • 2019
  • Radiation damage due to neutrons has been calculated in Ni-based alloys in Wolsong CANDU reactor environments. Two damage parameters are considered: displacement damage, and transmutation gas production. We used the SPECTER and SRIM computer codes in quantifying radiation damage. In addition, damage caused by Ni two-step reactions was considered. Estimations were made for the annulus spacers in a CANDU reactor that are located axially along a fuel channel and made of Inconel X-750. The calculation results indicate that the transmutation gas production from the Ni two-step reactions is predominant as the effective full power year increases. The displacement damage due to recoil atoms produced from Ni two-step reactions accounts for over 30% out of the total displacement damage.

Two-Inductor Non-Isolated DC-DC Converter with High Step-Up Voltage Gain

  • Lee, Sze Sing;Chu, Bing;Lim, Chee Shen;Lee, Kyo-Beum
    • Journal of Power Electronics
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    • 제19권5호
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    • pp.1069-1073
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    • 2019
  • In this paper, an alternative non-isolated DC-DC converter with a high voltage boosting capability is proposed. Two inductors are used and one of them has its flux linkage increases during its charging period to achieve a high step-up voltage gain. Among the three integrated capacitors, one portrays the partial characteristic of the switched-capacitor technique, while the other two are connected in series across the load. With the two switches controlled using the same duty cycle, the proposed topology demonstrates the merits of a higher and wider range of step-up voltage gain when compared with recent topologies. In addition, a reduction in loss is induced and a higher efficiency is ensured with all the voltage stresses constrained within the output voltage. Operation of the proposed converter is analyzed and validated through experimental results obtained with a prototype.

컨테이너터미널에서 다기능 이송차량의 2단계 배차 방안 (A Study on Two-step Dispatching for Multi-function Transport Vehicle at Container Terminal)

  • 최용석;김우선
    • 한국항해항만학회지
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    • 제32권10호
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    • pp.829-835
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    • 2008
  • 본 연구의 목적은 컨테이너터미널에서 사용되는 다기능 이송차량을 위한 2단계 배차전략을 제시하는 것이다. 2단계 배차는 실시간 위치 제어를 사용하여 이송차량과 크레인간의 대기시간을 절감시키기 위한 방법이다. 배차 1단계는 실시간 위치정보를 바탕으로 목적지 위치를 할당하는 것이며, 기존의 실시간 배차에서 이용되는 방식에 모니터링을 보안한 것이다. 배차 2단계는 이송차량의 싣기, 놓기, 집기 등의 기능을 작업장소의 작업상황에 따라 선택하여 작업지시를 내리는 것이다. 다기능 이송차량의 2단계 배차전략은 하역시스템의 대기시간을 감소시켜 생산성 향상에 기여할 것이다.

A Two-Step Screening Algorithm to Solve Linear Error Equations for Blind Identification of Block Codes Based on Binary Galois Field

  • Liu, Qian;Zhang, Hao;Yu, Peidong;Wang, Gang;Qiu, Zhaoyang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제15권9호
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    • pp.3458-3481
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    • 2021
  • Existing methods for blind identification of linear block codes without a candidate set are mainly built on the Gauss elimination process. However, the fault tolerance will fall short when the intercepted bit error rate (BER) is too high. To address this issue, we apply the reverse algebra approach and propose a novel "two-step-screening" algorithm by solving the linear error equations on the binary Galois field, or GF(2). In the first step, a recursive matrix partition is implemented to solve the system linear error equations where the coefficient matrix is constructed by the full codewords which come from the intercepted noisy bitstream. This process is repeated to derive all those possible parity-checks. In the second step, a check matrix constructed by the intercepted codewords is applied to find the correct parity-checks out of all possible parity-checks solutions. This novel "two-step-screening" algorithm can be used in different codes like Hamming codes, BCH codes, LDPC codes, and quasi-cyclic LDPC codes. The simulation results have shown that it can highly improve the fault tolerance ability compared to the existing Gauss elimination process-based algorithms.

SVC를 위한 새로운 이중접속방식의 멀티스텝 인버터 (New Double-Connected Multi-Step Inverter for SVC)

  • 최세완;양승욱;김기용
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1999년도 전력전자학술대회 논문집
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    • pp.460-463
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    • 1999
  • A new multi-step voltage source inverter is proposed in this paper. The proposed scheme is composed of the double-connected 12-step inverter with an auxiliary circuit. The auxiliary circuit includes two voltage dividing capacitors, two switching devices and a low KVA autotransformer. The resultant system is shown to be a 24-step inverter suitable for large scale SVC applications in which the PWM method can not be employed. The design parameters are derived from the analysis of voltages and currents by means of switching functions. The simulation results verify the proposed concept.

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STABILITY AND ERROR OF THE VARIABLE TWO-STEP BDF FOR SEMILINEAR PARABOLIC PROBLEMS

  • EMMRICH ETIENNE
    • Journal of applied mathematics & informatics
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    • 제19권1_2호
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    • pp.33-55
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    • 2005
  • The temporal discretisation of a moderate semilinear parabolic problem in an abstract setting by the two-step backward differentiation formula with variable step sizes is analysed. Stability as well as optimal smooth data error estimates are derived if the ratios of adjacent step sizes are bounded from above by 1.91.