• Title/Summary/Keyword: Flexible Criteria

Search Result 153, Processing Time 0.029 seconds

A Study on Ranking Alternatives Using Analytic Hierarchy Process (AHP 기법을 이용한 대안평가에 관한 연구)

  • 김형준
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.15 no.25
    • /
    • pp.33-40
    • /
    • 1992
  • The analytic hierarchy process(AHP) is a multi-criteria decision methodology developed by T. L. Saaty(1980). The AHP presents flexible, easily understood wily to assist the decision-maker in formulating his problem in a logical and rational manner. This paper addresses the concept of AHP and its application in the selection of radioactive waste disposal concept in Korea.

  • PDF

Analysis of Evaluation Requirement for CC and CEM (CC와 CEM의 평가요구사항 분석)

  • Kang Yeon-Hee;Bang Young-Hwan;Choi Sung-Ja;Lee Gang-Soo
    • Journal of Digital Contents Society
    • /
    • v.5 no.2
    • /
    • pp.95-100
    • /
    • 2004
  • For improve level of information security, the necessity of evaluation and certification of Information Security System(ISS) in increasing. Evalustion and Certification Institute have evaluated ISS for risk prevention of information dysfunction in an advanced countries. But, the problem of the time and cost occurred when it is caused by with application of unlike evaluation criteria each other. The result of effort to solution, Common Criteria(CC) and Common Evaluation Methodology(CEM) is using for evaluation of ISS and mutual recognition. Evaluation participant is needed flexible and active interpretation of CC and CEM for an efficient evaluation preparation and performance.

  • PDF

Design and consturction of single drilled shaft foundation (단일 현장타설말뚝 기초의 설계 및 시공)

  • Jeon, Kyung-Soo;Kim, Kyung-Suk;Kim, Jeong-Yeul
    • 기술발표회
    • /
    • s.2006
    • /
    • pp.86-100
    • /
    • 2006
  • The single drilled shaft foundation has been used in the other countries, but has not used in South Korea at all This foundation is very effective and economic method in South Korea which is easy to meet a good rock mass within 50m depth from the ground We have many experiences to construct 1.52 5m drilled shaft foundations and ability to construct 30m drilled shaft foundation without special efforts The soil behavior is nonlinear, but it can be proposed in linear in practical purpose on bridges. The elastic modulus of soil can be rationally obtained by the method of Road Bridge Design Manual in South Korea using the Schmertmann(1970)'s proposal, and the elastic modulus of rock can be obtained by the field test. In seismic design the column and drilled shaft must be restricted to the elastic design because the behavior of this foundation is flexible and the arrangement of the rebars makes the various defect In this paper the design criteria is compared with FHWA design criteria, and the design criteria is proposed in consistent with Road Bridge Design Manual in South Korea. The single drilled shaft foundation of a test bridge was constructed in the Iksan-Jangsoo highway, and we checked its stability, workability and economy

  • PDF

The preverified test sequence generation method satisfying the completeness criteria (완전표준성을 만족하는 선행검증 시험열 생성방법에 관한 연구)

  • 박진호;양대헌;송주석;임상용
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.23 no.9A
    • /
    • pp.2383-2390
    • /
    • 1998
  • As network provides diverse functionalities recently, many rpotocol standards have become complex and many implementations have appeared. Such trends require us to test th econformance of implementations, called the conformance testing. Many researches have been performed on generating test sequence and on fualt masking base don T,U,D,W methods. At this jpoint, te new problem is suggeste dwhich is calle dthe completenes s criteria. The test sequences for the conformance testing have come up with this problem as well as fault masking. In this paper, we suggest the method of generating the preverified test sequence which can avoid the completeness criteria problem. The preverified test sequence is much more reliable than others by using the preverified edge. For the reliability of conformance testing, we define the immunity of the test sequence and provide the clue for the analysis of the test results using the immunity. The analysis of the results makes it possible for us to test the implementation again with more reliability. Also, the preverified test sequence is flexible so that it is combined with the fault-tolerant sequence for fault masking.

  • PDF

Strategies for Noncontained Lumbar Disc Herniation by an Endoscopic Approach : Transforaminal Suprapedicular Approach, Semi-Rigid Flexible Curved Probe, and 3-Dimensional Reconstruction CT with Discogram

  • Chae, Ki-Hwan;Ju, Chang-Il;Lee, Seung-Myung;Kim, Byoung-Wook;Kim, Saeng-Youp;Kim, Hyeun-Sung
    • Journal of Korean Neurosurgical Society
    • /
    • v.46 no.4
    • /
    • pp.312-316
    • /
    • 2009
  • Objective : The purpose of this study was to evaluate the efficacy of a transforaminal suprapedicular approach, semi-rigid flexible curved probe, and 3-dimensional reconstruction computed tomography (3D-CT) with discogram in the endoscopic treatment of non-contained lumbar disc herniations. Methods : The subjects were 153 patients with difficult, non-contained lumbar disc herniations undergoing endoscopic treatment. The types of herniation were as follows : extraforaminal, 17 patients; foraminal, 21 patients; high grade migration, 59 patients; and high canal compromise, 56 patients. To overcome the difficulties in endoscopic treatment, the anatomic structures were analyzed by 3D reconstruction CT and the high grade disc was extracted using a semi-rigid flexible curved probe and a transforaminal suprapedicular approach. Results : The mean follow-up was 18.3 months. The mean visual analogue scale (VAS) of the patients prior to surgery was 9.48, and the mean postoperative VAS was 1.63. According to Macnab's criteria, 145 patients had excellent and good results, and thus satisfactory results were obtained in 94.77% cases. Conclusion : In a posterolateral endoscopic lumbar discectomy, the difficult, non-contained disc is considered to be the most important factor impeding the success of surgery. By applying a semi-rigid flexible curved probe and using a transforaminal suprapedicular approach, good surgical results can be obtained, even in high grade, non-contained disc herniations.

Enhanced Manufacturing and Performance Analysis of Flexible Composite Propeller (유연 복합재료 프로펠러 제작개선 및 성능분석)

  • Lee, Sang-Gab;Nam, Jae-Hyung;Hyun, Beom-Soo;Paik, Bu-Geun;Lee, Chang-Sup;Jang, Hyun-Gil;Nho, In Sik
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.49 no.6
    • /
    • pp.521-527
    • /
    • 2012
  • It is well known that flexible composite material propeller has superior radiation noise characteristics with outstanding damping effects. In this paper, three flexible composite material propellers were produced using compression molding process, and their hydrodynamic performances and radiation noise characteristics were measured. One propeller, C1, was made up from carbon/epoxy composite laminates, and the other two ones, G1 and G2, from glass/epoxy ones. Their fiber arrays were selected by the progressive damage structural analysis of propellers using composite material model MAT_162 (Composite_DMG_MSC) linked with LS-DYNA code. Carbon/epoxy and glass/epoxy composite specimen tests were performed, their damage mechanisms were figured out, and their parameters were calibrated by their progressive damage structural analysis according to their damage criteria.

Design of Moving Magnet Type Optical Pickup Actuator with High Frequencies of the Flexible Modes (높은 유연 모드 주파수를 갖는 가동 자석형 광 픽업 액추에이터 개발)

  • Song, Myeong-Gyu;Kim, Yoon-Ki;Park, Young-Pil;Yoo, Jeong-Hoon;Park, No-Cheol
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.17 no.11
    • /
    • pp.1043-1049
    • /
    • 2007
  • Data transfer rate and storage capacity are main criteria of the performance of the optical disk drive. The highest data transfer rate and the largest storage capacity is most desirable. To increase these performances, the actuator of the optical disk drive should have a high servo bandwidth to compensate the vibration of an optical disk. The servo bandwidth is limited by some flexible modes of the actuator, thus it is essential to increase the natural frequencies of the flexible modes. In this paper, we suggested a moving magnet type actuator having high frequencies of the flexible modes. Generally, the moving magnet type actuator has an advantage to increase the natural frequencies of the flexible modes because the moving magnet type actuator has simple structure and the Young's modulus of magnet is high. However, large moving mass and inefficiency of EM(electromagnetic) circuit cut down driving sensitivities of the actuator. To improve driving sensitivities, we designed the model with the closed electromagnetic circuit for tracking direction. In addition, driving sensitivities and the natural frequencies of the flexible modes were improved by using DOE(design of experiments) for electromagnetic circuit and modifying the lens holder.

Evaluation of Dynamic Lane Allocation Method at Climbing Lane Section (통행속도에 기반한 오르막차로 동적 운영방안 평가)

  • Ko, Han-Geom;Choi, Yoon-Hyuk;Oh, Young-Tae;Kang, Jeong-Gyu
    • Journal of Korean Society of Transportation
    • /
    • v.30 no.1
    • /
    • pp.59-72
    • /
    • 2012
  • In aspects of traffic operation, a climbing lane may cause traffic congestion if the volume of traffic (v/c) grows and the ratio of heavy vehicle increases. Conversely, it would be effective, if the climbing lane is dynamically operated according to changes in traffic flow. However, there are no guideline to effectively control this climbing lane in aspects of traffic operation. In this study, we examine the necessity of flexible traffic operation criteria and its process for dynamic traffic management and also establish and analyze the effect of flexible traffic operation criteria in accordance with traffic properties using an example of climbing lane. We selected the operation criteria (critical travel speed), which decides whether to operate or close the climbing lane when the average travel speed of climbing lane is 50km/h based on VISSM (microscopic traffic simulation) analysis of Nakdong junction towards Masan with the volume of traffic (v/c), ratio of heavy vehicle as the traffic operation parameters. Based on the simulation result in accordance with the volume of traffic by the operation mode of climbing lane, the analysis on the effect of dynamic traffic management of climbing lane showed that the dynamic traffic management provides more convenience compare to the operation and close of climbing lane. Thereby, we proved that the dynamic traffic management of climbing lane is more effective.

Performance Assessment for Rockfall Protection Systems II: Performance Assessment (낙석방지울타리의 성능평가 II: 성능평가)

  • Kim, Kee Dong;Ko, Man Gi;Kim, Dal Sung;Han, Ki Jang
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.35 no.1
    • /
    • pp.49-61
    • /
    • 2015
  • This is the second of two companion papers that describe the performance assessment for flexible rockfall protection systems. Described in a companion paper is the criteria to assess the performance of flexible rockfall protection systems. In this study the performance assessment of domestic rockfall protection fences was implemented using the criteria suggested in the companion paper. It was investigated that the rockfall protection fences for express highways performed well to resist the rockfall energy of 50kJ and the deformed rockfall protection fences right after impacting would not obstruct the vehicle traffic. However, to dissipate the rockfall energy of 50kJ with the level of European standards constantly, the spacing of wireropes was adjusted to be 200mm up to the 8th wirerope from the bottom and spacing-maintainers should be extended to the 8th wirerope. It was figured out that the rockfall protection fences for general highways were required to install spacing-maintainers as those for express highways because they, which did not have spacing-maintenance members, were very prone to the penetration of rockfall even for the very small rockfall impact energies.

Optimum Design of a Helicopter Tailrotor Driveshaft Using Flexible Matrix Composite (유연복합재를 이용한 헬리콥터 꼬리날개 구동축의 최적 설계)

  • Shin, Eung-Soo;Hong, Eul-Pyo;Lee, Kee-Nyeong;Kim, Ock-Hyun
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.28 no.12
    • /
    • pp.1914-1922
    • /
    • 2004
  • This paper provides a comprehensive study of optimum design of a helicopter tailrotor driveshaft made of the flexible matrix composites (FMCs). Since the driveshaft transmits power while subjected to large bending deformation due to aerodynamic loadings, the FMCs can be ideal for enhancing the drivetrain performance by absorbing the lateral deformation without shaft segmentation. However, the increased lateral flexibility and high internal damping of the FMCs may induce whirling instability at supercritical operating conditions. Thus, the purpose of optimization in this paper is to find a set of tailored FMC parameters that compromise between the lateral flexibility and the whirling stability while satisfying several criteria such as torsional buckling safety and the maximum shaft temperature at steadystate conditions. At first, the drivetrain was modeled based on the finite element method and the classical laminate theory with complex modulus approach. Then, an objective function was defined as a combination of an allowable bending deformation and external damping and a genetic algorithm was applied to search for an optimum set with respect to ply angles and stack sequences. Results show that an optimum laminate consists of two groups of layers: (i) one has ply angles well below 45$^{\circ}$ and the other far above 45$^{\circ}$ and (ii) the number of layers with low ply angles is much bigger than that with high ply angles. It is also found that a thick FMC shaft is desirable for both lateral flexibility and whirling stability. The genetic algorithm was effective in converging to several local optimums, whose laminates exhibit similar patterns as mentioned above.