• 제목/요약/키워드: Two stage operation

검색결과 571건 처리시간 0.032초

조기 성문암의 방사선 치료 결과 (Radiotherapy Results of Stage I Glottic Cancer)

  • 김재철;박인규
    • Radiation Oncology Journal
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    • 제16권3호
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    • pp.245-250
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    • 1998
  • 목적 : 조기 성문암의 방사선 치료 후 생존율, 실패 양상, 그리고 예후 인자에 대해 분석하였다. 대상 및 방법 : 1985년 6월부터 1992년 11월까지 방사선 치료를 위해 의뢰된 57례의 성문암환자를 대상으로 후향적 분석을 실시하였다. 연령 분포는 17세부터 71세까지 광범위했고 (중앙값 39세), 남자 55례와 여자 2례로 남성에서 호발하였다. 방사선 치료는 6 MV X-ray를 이용하여 1회 선량 2 Gy씩, 주 5회, 총선량 66 Gy를 조사하였다. 결과 : 방사선 치료에 대한 반응은 완전 관해 89.5% (51/57), 부분 관해 혹은 무반응 10.5%(6/57) 였다. 51례의 완전관해 환자 중에서 7례의 재발이 관찰되었고 7례 모두 수술로 구제되었다. 부분 관해 혹은 무반응 6례 중 4례에 대하여 구제수술을 시행하였고 2례에서는 수술을 시행하지 못하였다. 구제수술을 시행한 4례 중 3례가 구제되었고 1례는 다시 국소재발하였다. 3년 및 5년 무병생존율은 각각 72.9% 및 63.8%였다. 병소의 위치에 따른 5년 무병생존율은 후방인 경우 85.5%, 전방인 경우 61.6%였다 (P<0.05). 방사선치료에 대해 부분 관해 혹은 무반응을 보인 5례를 포함하여 13/57 (22.8%) 례의 치료 실패가 관찰되었고 그 중 10/13 (76.9%) 례가 수술로 구제되었다. 최종 5년 국소제어율은 92.3%였고 전체적으로 47/57 (82.5%) 례에서 음성을 보존할 수 있었다. 결론 : 높은 음성 보존율을 고려하면 초기 성문암에서 방사선치료가 우선적으로 고려되어야 한다.

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Rotary Mower의 제작과 그 이용에 관한 연구 (A Study on the Design of Rotary Mower and Its Utilization.)

  • 최규홍
    • 한국농공학회지
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    • 제17권4호
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    • pp.3897-3920
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    • 1975
  • Since the most of Korean dairy and cattle raising farms are too small to introduce western mechanized farming, it is necessary to develope small size equipments. This study has been carried to develop a rotary mower as on attachment of 8 to 10 horse powertiller which is widely spread in rural area. It will not ony be helpfull for the farmers to harvesting hay grass but also desirable to increase the power tiller utility. The protto type rotary mower designed through the fundamental investigations, has been modified and improved through the field trials, and a series of field tests has been carried to investigate its performance and economic feasibility comparing with existing vailable harvesting equipments. The results are as follows; 1. To increase the stability, two guide wheels are attached to both side of the protto type rotary mower. 2. To prevent the clinging of tall grasses, the vertical driving shafts are covered with cylindrical protectors. 3. The cutting height is adjustable in 8 steps from 2.5 to 20 centimeters by changing the length of guide wheel legs. 4. The practical Critical cutting speed were always higher than theoretical value in both case of single cutting blade and three when the cutting depth was 25 millimeter. 5. The peripheral speed of cutting blade was varied in response to the change of engine speed, mean while the peripheral speed was adequate as it was changhed from 25 to 35 meter per second when the power tiller is operated in proper working ground speed. 6. The time requirement to harvest 10 a were 88.7, 54.6 and 41.4 minutes for the first, second and third stage of ground speed respectively, and because of the difficulty of delivery, it was observed that operating with fourth stage of ground speed was not recomanendable when the grass height is taller than 90 centimeters. 7. The performance of rotary mower were 1.1-1.7, 1.4-4.0, 3.8-11.8 and 7.4-22.0 times of reciprocating mower, portable disc type cutter, hay scythe and ordinary sickle respectively. 8. When the slope exceeds, 20 degree the downward harvesting operation was impossible because of the excessive front end weight, while less than 5 degree of land slope did not effect in field operation. 9. Increased traveling spee caused higher cutting height and slight cutting failure, but seems not to effect to the gross yield, and the efficiency of cutting width were from 83 to 94 precent. 10. Tn rank of economy were rotary mower (3,2 stage operation), reciprocating mower, hay scythe, portable disc type cutter and sickle in order when the annul operation exdeeds 100 hours. From the above results, it is convinced that the protto type rotary mower is good enough to the livestock farmers as a hay harvesting equipment because of its economy, hardiness in operating and its out standing performance and hopefully it will contribute to the extension of Korean livestock farming.

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HTGR PROJECTS IN CHINA

  • Wu, Zongxin;Yu, Suyuan
    • Nuclear Engineering and Technology
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    • 제39권2호
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    • pp.103-110
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    • 2007
  • The High Temperature Gas-cooled Reactor (HTGR) possesses inherent safety features and is recognized as a representative advanced nuclear system for the future. Based on the success of the HTR-10, the long-time operation test and safety demonstration tests were carried out. The long-time operation test verifies that the operation procedure and control method are appropriate for the HTR-10 and the safety demonstration test shows that the HTR-10 possesses inherent safety features with a great margin. Meanwhile, two new projects have been recently launched to further develop HTGR technology. One is a prototype modular plant, denoted as HTR-PM, to demonstrate the commercial capability of the HTGR power plant. The HTR-PM is designed as $2{\times}250$ MWt, pebble bed core with a steam turbine generator that serves as an energy conversion system. The other is a gas turbine generator system coupled with the HTR-10, denoted as HTR-10GT, built to demonstrate the feasibility of the HTGR gas turbine technology. The gas turbine generator system is designed in a single shaft configuration supported by active magnetic bearings (AMB). The HTR-10GT project is now in the stage of engineering design and component fabrication. R&D on the helium turbocompressor, a key component, and the key technology of AMB are in progress.

Fine Seek Control of Extended Applicable Range for Optical Disk Drives

  • Ryoo, Jung-Rae;Jin, Kyoung-Bog;Doh, Tae-Young;Chung, Myung-Jin
    • Transactions on Control, Automation and Systems Engineering
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    • 제3권3호
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    • pp.146-151
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    • 2001
  • Optical disk drive has excellent advantage of random accessibility of which performance is measured by access time. However, due to the increased rotational velocity of the disk and constraints of mechanical structure, two-stage seek algorithm which executes coarse and fine seeks sequentially has been adopted in most commercial optical disk drives. Although the laser spot is moved to a target track by a single seek operation, the limited operation range of the fine actuator restricts the application of the fine seek algorithm below a few hundreds of tracks. Especially, excessive movement of the objective lens causes a failure in generation of track-cross pulse and results in an unstable seek operation. In this paper, a new control algorithm for extending the fine seek range is proposed with an appropriate control structure. The coarse actuator is utilized to reduce the misalignment between the objective lens and the laser beam axis, and the fine actuator is controlled to follow the reference velocity trajectory. The proposed algorithm is applied to a CD-ROM drive to show its feasibility and some experimental results are presented.

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다단계 최적화 수법을 이용한 열원 설비 설계법에 관한 연구 (A Study on the Multi-level Optimization Method for Heat Source System Design)

  • 유민경;남유진
    • 설비공학논문집
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    • 제28권7호
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    • pp.299-304
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    • 2016
  • In recent years, heat source systems which have a principal effect on the performance of buildings are difficult to design optimally as a great number of design factors and constraints in large and complicated buildings need to be considered. On the other hand, it is necessary to design an optimum system combination and operation planning for energy efficiency considering Life Cycle Cost (LCC). This study suggests a multi-level and multi-objective optimization method to minimize both LCC and investment cost using a genetic algorithm targeting an office building which requires a large cooling load. The optimum method uses a two stage process to derive the system combination and the operation schedule by utilizing the input data of cooling and heating load profile and system performance characteristics calculated by dynamic energy simulation. The results were assessed by Pareto analysis and a number of Pareto optimal solutions were determined. Moreover, it was confirmed that the derived operation schedule was useful for operating the heat source systems efficiently against the building energy requirements. Consequently, the proposed optimization method is determined by a valid way if the design process is difficult to optimize.

허브 냉간단조품의 공정설계 (Process Sequence Design in Cold Forged Part of Hub)

  • 고대철;김병민;오세욱
    • 대한기계학회논문집A
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    • 제20권11호
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    • pp.3387-3397
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    • 1996
  • The Hub is an auto mobile component used as aircon clutch. The important aspects in cold forging of the Hub with complex geometry are the design of an initial shape of the workpiece, the possibility of the forming by one-stage operation and the determination of number of performs, etc. Based on the systematic procedure of process sequence design, in this paper, the forming operation of cold forged part of the Hub is designed by the rigid-plastic finite element method. The two design criterion of geometrical filling without defect and an even distribution of effective strain in final product are investigated in controlling the initial shape of the workpiece and preform configuration. It is noted that one preforming operation is required in order to obtain final product of the Hub.

고출력 MHL용 구형저주파 구동 방식의 전자식 안정기 설계 (Electronic Ballast Design Driven by Low Frequency Square Wave for High Power MHL)

  • 김기남;박종연;최영민
    • 전력전자학회논문지
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    • 제15권5호
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    • pp.394-400
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    • 2010
  • 본 논문에서는 Buck Converter 동작 원리를 Full -Bridge Inverter에 적용한 전자식 안정기를 제안하였다. 전자식안정기는 EMI 필터, 수동 PFC, Full-Bridge Inverter로 2-stage로 구성되어 있다. PFC는 신뢰성 확보를 위해 수동 PFC를 사용하였다. Full-Bridge Inverter는 High Side와 Low Side 스위치의 구동 주파수를 각각 고주파와 저주파로 구동하여 Buck Converter의 동작을 구현 하였다. 램프를 저주파수 구형파로 구동하여 음향공명현상을 피하게 되었으며, 고주파수 스위칭으로 인덕터의 부피를 줄였다. 제안한 방법은 시뮬레이션과 실험을 통해 증명하였다.

자기조직화 신경망을 이용한 셀 형성 문제의 기계 배치순서 결정 알고리듬 (Machine Layout Decision Algorithm for Cell Formation Problem Using Self-Organizing Map)

  • 전용덕
    • 산업경영시스템학회지
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    • 제42권2호
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    • pp.94-103
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    • 2019
  • Self Organizing Map (SOM) is a neural network that is effective in classifying patterns that form the feature map by extracting characteristics of the input data. In this study, we propose an algorithm to determine the cell formation and the machine layout within the cell for the cell formation problem with operation sequence using the SOM. In the proposed algorithm, the output layer of the SOM is a one-dimensional structure, and the SOM is applied to the parts and the machine in two steps. The initial cell is formed when the formed clusters is grouped largely by the utilization of the machine within the cell. At this stage, machine cell are formed. The next step is to create a flow matrix of the all machine that calculates the frequency of consecutive forward movement for the machine. The machine layout order in each machine cell is determined based on this flow matrix so that the machine operation sequence is most reflected. The final step is to optimize the overall machine and parts to increase machine layout efficiency. As a result, the final cell is formed and the machine layout within the cell is determined. The proposed algorithm was tested on well-known cell formation problems with operation sequence shown in previous papers. The proposed algorithm has better performance than the other algorithms.

한국 고속철도의 효율적 중련편성 운영방법에 대한 연구 (A Study on an Efficient Double-fleet Operation of the Korean High Speed Rail)

  • 오석문;손무성;최인찬
    • 한국철도학회논문집
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    • 제10권6호
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    • pp.742-750
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    • 2007
  • 본 논문은 장래 도입되는 KTX2 고속차량을 이용한 중련편성 운영계획 최적화를 위한 방법론 제시를 목적으로 한다. 중련편성 운영계획 최적화를 위한 수리적 모형을 제시하고, 제안된 수리적 모형의 적용방안을 제시한다. 특히 확률적 수요를 고려한 모형을 수립하여, 계획수립 단계에서 수요의 확률적 요소를 보다 현실적으로 반영하고, 모형내에서 좌석 서비스 수준을 직접 조정할 수 있다.

Prognostic Factors in Stage IB Gastric Cancer after Surgical Resection

  • Yu, Byunghyuk;Park, Ji Yeon;Park, Ki Bum;Kwon, Oh Kyoung;Lee, Seung Soo;Chung, Ho Young
    • Journal of Gastric Cancer
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    • 제20권3호
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    • pp.328-336
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    • 2020
  • Purpose: The standard treatment for stage IB gastric cancer is curative surgery alone, but some patients show poor survival with disease recurrence after curative surgery. The aim of this study was to identify prognostic factors of recurrence and long-term survival in patients with stage IB gastric cancer after surgery. Materials and Methods: We retrospectively reviewed data from 253 patients with stage IB gastric cancer who underwent gastrectomy between 2011 and 2016 at Kyungpook National University Chilgok Hospital and analyzed the clinicopathological characteristics associated with recurrence and survival. Results: Fourteen patients experienced recurrence with a mean follow-up of 54.1 months. Two of these patients had locoregional recurrence and 12 patients had systemic recurrence. The median interval between the operation day and the day of recurrence was 11 months (range 4-56 months). Multivariate analysis revealed that lymphatic vessel invasion (LVI) (hazard ratio [HR], 3.851; 95% confidence interval [CI], 1.264-11.732) and the elderly (age≥65) (HR, 3.850; 95% CI, 1.157-12.809) were independent risk factors for recurrence after surgery. The LVI (HR, 3.630; 95% CI, 1.105-11.923) was the independent prognostic factors for disease-specific survival (DSS). The 5-year DSS rates were 96.8% in patients who did not have LVI, and 89.3% in patients who had LVI. Conclusions: This study shows that LVI was associated with recurrence and poor survival in patients with stage IB gastric cancer after curative gastrectomy. Patients diagnosed with LVI require careful attention for systemic recurrence during the follow-up period.