Priority Method Research Articles

해외 LNG 플랜트 리스크요인 도출 및 우선순위 평가 - 설계단계를 중심으로 -

국내 건설기업은 1960년대 처음으로 해외건설시장에 진출한 이래 지속적으로 성장해왔으며 2010년에는 해외건설시장에서 716억 달러를 수주하는 등 국가 경제에 많은 기여를 해왔다. 특히 플랜트산업의 경우 2010년에 사상 최대인 574억 달러를 수주하여 전제 해외건설 수주금액의 80% 이상을 차지하였다. 그럼에도 불구하고 국내 건설기업은 해외 선전기업에 비해 설계단계의 기술경쟁력 부족 및 사업관리 능력의 부족으로 해외 플랜트 사업을 수행하는데 있어 어려움이 크다. 본 연구는 최근 국제 유가의 상승, 에너지 수요의 증가, 친환경 건설에 대한 관심의 증가로 시장규모가 확대되고 있는 해외 LNG 플랜트사업의 수익률 안정을 위해 설계단계의 리스크를 규명하고, 이를 보다 합리적으로 평가하기 위한 방법을 제시하였다. 본 연구의 결과로서 첫째, 기존문헌의 분석, 기업 설계보고서, 전문가 인터뷰를 통해 해외 플랜트 설계단계에서 총 57개 리스크 요인을 도출하였다. 둘째 기존의 우선순위 평가방법(이축, PI)에 플랜트의 특성을 반영 할 수 있는 조정지수(Coordination Index, CI)를 추가하여 해외 LNG 플랜트 설계단계에 보다 적합한 삼축(PIC)우선순위 평가방법을 제시하였다. 마지막으로 전문가 설문조사 및 인터뷰를 통해 삼축 평가방법의 적절성 및 실무 적용성을 확인하였다. 따라서 국내 건설기업이 자신의 경험을 바탕으로 본 연구에서 제시된 리스크 요인과 평가방법을 해외 LNG 플랜트 설계단계에 적용한다면, 보다 합리적이고 객관적인 리스크 관리가 가능할 것으로 기대된다. Korean contractors have been maintained sustainable growth since entering into overseas construction market for the first time in 1960' s. In 2010, Korean contractors ordered 761 billion (USD) from overseas markets. Especially, billion (USD) were earned by Korean contractors in overseas plant construction market which account for more than 80% of the total amount by Korean contractors. Nevertheless, many Korean contractors are suffering from lack of technological competitiveness and construction management skills in the design phase compared with global leading contractors. These conditions have directly effect on the success of projects in terms of cost, duration, and quality. So, this study focused on identifying the risk factors and developing risk priority method for the design phase of LNG plant projects whose market is expanding. Research procedures were conducted by the following three steps. First, total 57 risk factors were identified in design phase through extensive literature reviews and experts survey. Second, the authors developed risk priority method which are more suitable for design phase of LNG plant projects by using three criteria, Probability(P), Impact(I), and Coordination Index(CI). Finally, the suitability of risk priority method and practical applicability were verified through expert survey and interview. Consequently, if korean contractors use the suggested risk factors and priority method based on their own know-how and experiences, then more reasonable and rational risk management will be conducted in the design phase of LNG plant projects.

New parametric prioritization methods for an analytical hierarchy process based on a pairwise comparison matrix

In this paper, new parametric prioritization methods (PPMs) to determine a family of priority vectors in an analytical hierarchy process (AHP) are proposed, pointing out the logical relation of elements in the comparative matrix. The scales and consistency cannot determine the priorities, but only the order of the alternatives. To derive the priorities of alternatives, a series of theorems and mathematical programming models is given based on a pairwise comparison matrix. This refers to parameters θ , α , β , by which there exists a family of priorities for the same judgment matrix. The discrimination of alternatives can be easily improved when using the proposed priority method by modifying the values of the parameters. Some false cognitions about how to determine the priority of an analytical hierarchy process are rectified. One should not elicit priority vectors from the judgment matrix; the information is incomplete, and the parameters must be considered. Finally, the meanings of parameters are explained in practical applications and an approach for determining the values of the parameters is proposed. Examples are also used to illustrate the features and applicability of the new approach in an AHP.

A Linear Programming Priority Method for a Fuzzy Transportation Problem with Non-linear Constraints — The Case of a General Contractor Company

Demand and supply pattern for most products varies during their life cycle in the markets. In this paper, the author presents a transportation problem with non-linear constraints in which supply and demand are symmetric trapezoidal fuzzy value. In order to reflect a more realistic pattern, the unit of transportation cost is assumed to be stochastic. Then, the non-linear constraints are linearized by adding auxiliary constraints. Finally, the optimal solution of the problem is found by solving the linear programming problem with fuzzy and crisp constraints and by applying fuzzy programming technique. A new method proposed to solve this problem, and is illustrated through numerical examples. Multi-objective goal programming methodology is applied to solve this problem. The results of this research were developed and used as one of the Decision Support System models in the Logistics Department of Kayson Co.

A new metric model for trustworthiness of softwares

As people depend more and more on softwares, there has been an increasing demand for the trustworthiness of the software. To measure the trustworthiness of software, we need to design appropriate trustworthy metrics. We once proposed four metric criteria for the multi-dimensional trustworthiness of the software and a metric model which satisfies these four criteria. In this paper, we describe a new metric model for the trustworthiness of the software which satisfies almost all these four criteria. Compared with the previous model, this model is better in the view of substitutivity. We also give a polynomial-time combinational algorithm for estimating the weight vectors appeared in the model based on the priority methods.

ПРОБЛЕМА ПРОФЕССИОНАЛЬНОЙ ПОДГОТОВКИ УЧИТЕЛЯ НАЧАЛЬНЫХ КЛАССОВ В СИСТЕМЕ ВЫСШЕГО ПЕДАГОГИЧЕСКОГО ОБРАЗОВАНИЯ В УСЛОВИЯХ ВВЕДЕНИЯ ФЕДЕРАЛЬНОГО ГОСУДАРСТВЕННОГО ОБРАЗОВАТЕЛЬНОГО СТАНДАРТА НАЧАЛЬНОГО ОБЩЕГО ОБРАЗОВАНИЯ ВТОРОГО ПОКОЛЕНИЯ

This article analyzes changes in the target, content and technological aspects of training primary school teachers in higher pedagogical education in the introduction of the federal state educational standards of primary education of second generation. Key idea of the changes in the system of training primary school teachers in high school should be a mastery of the future of teacher experience in the implementation of the activity method in primary school as the priority method in education of young students; experience in organizing the space of spiritual and moral development of junior schoolchildren by means of educational and extracurricular activities, experience of self-expression and self-realization in the independent professional activity.

Fuzzy analytic hierarchy process: A logarithmic fuzzy preference programming methodology

Fuzzy analytic hierarchy process (AHP) proves to be a very useful methodology for multiple criteria decision-making in fuzzy environments, which has found substantial applications in recent years. The vast majority of the applications use a crisp point estimate method such as the extent analysis or the fuzzy preference programming (FPP) based nonlinear method for fuzzy AHP priority derivation. The extent analysis has been revealed to be invalid and the weights derived by this method do not represent the relative importance of decision criteria or alternatives. The FPP-based nonlinear priority method also turns out to be subject to significant drawbacks, one of which is that it may produce multiple, even conflict priority vectors for a fuzzy pairwise comparison matrix, leading to entirely different conclusions. To address these drawbacks and provide a valid yet practical priority method for fuzzy AHP, this paper proposes a logarithmic fuzzy preference programming (LFPP) based methodology for fuzzy AHP priority derivation, which formulates the priorities of a fuzzy pairwise comparison matrix as a logarithmic nonlinear programming and derives crisp priorities from fuzzy pairwise comparison matrices. Numerical examples are tested to show the advantages of the proposed methodology and its potential applications in fuzzy AHP decision-making.

The optimal priority models of the intuitionistic fuzzy preference relation and their application in selecting industries with higher meteorological sensitivity

This paper proposes a least squares method and a goal programming method to get the priority of the intuitionistic fuzzy preference relation (IFPR). The relation between the IFPR and the interval fuzzy number preference relation (IFNPR) is established by splitting the IFPR into the membership degree interval judgment matrix and the non-membership degree interval judgment matrix. Considering the fact that the priority method must be based on the consistent condition, we propose the additive consistent conditions of the IFPR according to that of the IFNPR. However, in real-life decision situations, such consistent conditions are hard to be satisfied. For deriving the priority vector of the IFPR, the least squares model and the goal programming model are put forward. It is also shown that the same methods apply to the circumstance of group decision making. The numerical examples are provided to show that the methods proposed are valid, and the case study of selecting industries with higher meteorological sensitivity by using the intuitionistic fuzzy hierarchic structure model is given to show that the methods proposed are practical.

Coercivity Metering as the Basic Method of a Non-Destructive Testing of Fatigue and as the Priority Method in the Diagnostic Set

Here "coercivity metering" or "coercimetry" (c.m.) means a non-destructive testing of the mechanical properties, deflected mode and fatigue capacity based on measurements of the magnetic characteristic of metal – i.e. coercivity. All listed below merits are most fully achieved when working with coercimeters (magnetic structure scopes) of SSE Company. And it is so not because the authors represent this company but rather because these devices feature a number of consumer and technical merits, which those of other manufacturers do not. Among them, the main thing is the highest clearance insensitivity i.e. when the device readings depend only on the properties of the metal, they do not depend on confounding factors, such as protective coating (paint, film, etc.) up to 6 mm (!) thick on the tested metal, or equivalent to such clearance corrosion layers, roughness, curvature of the surface, etc.

Signal Strategy of Conditional Transit Priority Based on Transit Schedule

Combined with the actual situation of China, drawing on foreign models based on the quantitative methods, this paper gets a model based on conditional bus priority for signal timing design which is combined with the traditional model through the application of conditional bus priority. The model considers more about the actual situation of the intersection, as well as a variety of other general vehicles which also need to pass through the intersection; it is a more moderate, harmonious, and better public transport priority method which does not use at the expense of other general vehicles.

A TFN–ANP based approach to evaluate Virtual Research Center comprehensive performance

The performance evaluation of Virtual Research Center (VRC) is an intrinsically complex multi-dimensional process and it should be evaluated and compared in a multi-criteria analysis method. To solve the problems caused by the fuzzy decision making, quantifying the qualitative indexes and dealing with the interdependence and interaction of some indexes during the process of VRC performance evaluation, a comprehensive performance evaluation method based on triangular fuzzy number and analytic network process (TFN–ANP) is proposed. In the method, an index evaluation system is first established and the interactive relationships of the evaluation indexes are analyzed. Secondly, the index evaluation decision-making matrix is constructed and the indexes attribute values are fuzzed with triangular fuzzy numbers. Thirdly, the evaluative indexes weights are determined by analytic network process. Then the concrete solving process is derived and the fuzzy utility value weights are ranked by the priority method with decision maker risk preference. In the end, the four project teams of Yalong River VRC are taken as examples, then their comprehensive performances are evaluated by TFN–ANP model and the utility value priorities are ranked, which could provide decision supports for VRC to optimize operational performance. In addition, a comparison with the previous method is performed, and experimental results are encouraging, which fully demonstrates the effectiveness and superiority of the proposed approach.

Method of Up-Slope Mitigation Priority for Alishan Mountain Road in Taiwan

Rainfall-induced up-slope failure has been a major issue for the mountain road mitigation. To determine the mitigation priority of the roadside slopes, a model to evaluate the stability of the up-slopes is proposed in this paper. This model is developed using Bayesian classification theorem, historical rainfall and landslide data, and an artificial intelligence skill—Gaussian process. The parameters needed for this model include the up-slope features, catchment area, lithology, vegetation coverage, and rainfall data. Among these parameters, rainfall is considered to be the triggering factor of landslide in this study. In addition, each slope has also demonstrated a unique failure probability relationship with the 72-h accumulated rainfalls. Such a relationship is adopted to define a threshold rainfall factor which is used as an index to estimate the likelihood of landslide occurrence under a rainfall event. Using the threshold rainfall factor of each slope, a priority list is proposed for the mitigation of roadside up-slopes along the Alishan mountain road in Taiwan.

Normalizing rank aggregation method for priority of a fuzzy preference relation and its effectiveness

The aim of this paper is to show that the normalizing rank aggregation method can not only be used to derive the priority vector for a multiplicative preference relation, but also for the additive transitive fuzzy preference relation. To do so, a simple functional equation between fuzzy preference’s element and priority weight is derived firstly, then, based on the equation, three methods are proposed to prove that the normalizing rank aggregation method is simple and effective for deriving the priority vector. Finally, a numerical example is used to illustrate the proposed methods.

Goal programming approaches to obtain the priority vectors from the intuitionistic fuzzy preference relations

The priority method on the intuitionistic fuzzy preference relation (IFPR) is proposed. In order to avoid the operational difficulty in dealing with the intuitionistic sets, the equivalent interval matrices of the IFPR are introduced. Based on the multiplicative consistent definition of the fuzzy interval preference relation (FIPR), the goal programming models for deriving the priority vector of the IFPR have been put forward by analyzing the relation between the IFNPR and the IFPR. This goal programming method is generalized to the case of group decision making with the weight information defined by each DM. Two numerical examples are provided to illustrate the application of the proposed models.

Simultaneous control of traffic lights and bus departure for priority operation

This article presents a bus priority method for traffic light control based on two modes of operation: immediate and controlled departure. The immediate departure mode is a standard procedure in which the intersection controller grants priority upon request of the bus. Controlled departure acts to avoid a second stop of the bus at the end of the queue formed during red by holding the bus at the bus stop, while still granting priority to the bus lane. Selection of one of the two modes is based on intersection cost that includes bus delay and the impact on the overall traffic near the intersection. The method is applied in a constant cycle scenario where green recall and green extension can only be granted within certain limits. Numerical examples illustrate the application of the approach.

Making Decision of the Maintenance Priority of Power Distribution System using Time Varying Failure Rate and Interruption Cost

The purpose of the this paper is to make decision of the maintenance priority of power distribution system using Time-Varying Failure Rate(TVFR) with interruption cost. This paper emphasizes the practical use of the reliability indices and interruption cost. To make a decision of maintenance priority on power distribution system equipment, the quantification of the reliability level should be represented as a cost. In this paper, the TVFR of power distribution system equipment applied in this paper utilizes analytic method to use the historical data of KEPCO. From this result, the sensitivity analysis on TVFR of equipment was done for the priority, which represents that high priority of the equipment has more effect on system reliability, such as SAIDI or SAIFI, than other equipment. By this priority, the investment plan is established. In this result, customer interruption cost(CIC) could be extracted, and CIC is used as weighting factor to consider a importance of customer. After that, the result calculated the proposal method in this paper is compared with other priority method, such as lifetime, failure rate or only sensitivity.

Accurate Rank Ordering of Error Candidates for Efficient HDL Design Debugging

When hardware description languages (HDLs) are used in describing the behavior of a digital circuit, design errors (or bugs) almost inevitably appear in the HDL code of the circuit. Existing approaches attempt to reduce efforts involved in this debugging process by extracting a reduced set of error candidates. However, the derived set can still contain many error candidates, and finding true design errors among the candidates in the set may still consume much valuable time. A <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">debugging</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">priority</i> method was proposed to speed up the error-searching process in the derived error candidate set. The idea is to display error candidates in an order that corresponds to an individual's degree of suspicion. With this method, error candidates are placed in a rank order based on their probability of being an error. The more likely an error candidate is a design error (or a bug), the higher the rank order that it has. With the displayed rank order, circuit designers should find design errors quicker than with blind searching when searching for design errors among all the derived candidates. However, the currently used confidence score (CS) for deriving the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">debugging</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">priority</i> has some flaws in estimating the likelihood of correctness of error candidates due to the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">masking</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">error</i> situation. This reduces the degree of accuracy in establishing a <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">debugging</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">priority</i> . Therefore, the objective of this work is to develop a new probabilistic confidence score (PCS) that takes the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">masking</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">error</i> situation into consideration in order to provide a more reliable and accurate <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">debugging</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">priority</i> . The experimental results show that our proposed PCS achieves better results in estimating the likelihood of correctness and can indeed suggest a <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">debugging</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">priority</i> with better accuracy, as compared to the CS.

릴리즈 플랜의 적응적 요구사항 우선순위 프로세스

요구사항에 대한 우선순위는 릴리즈 플랜을 위한 핵심적 활동이기 때문에 요구공학에서 특히, 오픈 시장(Open Market)을 고객으로 하는 시장 주도형 제품개발에 있어서 중요하다. 또한, 요구사항 우선순위는 주어진 요구사항 간의 상호의존 관계를 바탕으로 프로세스 모델, 제품 종류 및 우선순위 프로세스에 대한 경험 등을 사전에 고려하여 우선순위화를 위한 방법과 관점 등을 선택하는 활동이 중요하다. 그러나, 기존 연구들은 요구사항간의 상호의존 관계를 정적 관계만 고려하였고, 고려된 관점들이 비용/가치 등으로 한정적이고 체계적인 우선순위 프로세스를 제공치 못하고 있다. 따라서 본 논문에서는 우선순위화를 위한 모델을 설계하고 개발 제품의 목표와 조직에 적합하도록 우선순위 방법과 관점 등을 선택할 수 있는 적응적 요구사항 우선순위 기법 및 프로세스를 제안한다. 특히, 요구사항간의 정적/동적 상호의존 관계 유형을 정의하고, 다양한 관점에 의한 우선순위화를 통해 릴리즈 플랜의 완성도를 높였다. 이로써 상호의존 관계 및 다양한 관점을 고려한 우선순위 모델기반의 체계적인 우선순위 프로세스를 정립하여 유연하고 충족스러운 우선순위화와 릴리즈 플랜을 통하여 합리적으로 의사결정을 도모할 수 있다. The priority of requirement is important because the priority is a critical activity of release plan especially in software development which has an open market customer. Also, it is important for stakeholders to select a method and aspects to prioritize requirements. The selection is based on the organizational experience of a priority process, the process model of the product, goals and a type of products, and dependencies between requirements. But, the current researches considered only static dependency between requirements and did not suggest a systematic priority process. In addition, the current researches only suggest limited aspects to prioritize requirements, such as cost and value. Therefore, this paper proposes an adjustable priority process based on a priority model to select a method and aspects for the suitable priority for product and organization. Especially, this paper enhances the completeness of a release plan by a definition of static and dynamic dependency types between requirements. This paper suggests a priority model, which considers the dependencies between requirement and various viewpoint of software development. Based on the priority model, the paper suggests a systematic priority process to promote reasonable decisions to the priority and release plan of requirement.

사설망인터페이스에서 효율적 스패닝 트리 토폴로지 요약기법

본 논문에서 제안된 스패닝 트리 토폴로지 요약기법은 모든 경로를 찾는 대신 홉 카운트 기반의 깊이 우선 방식을 사용하여 효율적으로 다중 경로를 탐색할 수 있도록 하였다. 이를 위해 토폴로지 요약 정보를 줄이고 다중링크 요약에 유연성을 부여하기 위하여 대역폭과 지연의 한 쌍으로 구성된 두 개의 라인 세그먼트를 이용하는 수정된 라인 세그먼트 기법을 제안하였다. 그리고, 이를 기존의 스패닝 트리 토폴로지 요약에 적용한 효율적인 토폴로지 요약기법을 제안하였다. 제안된 기법의 성능을 평가하기 위해 기존의 스패닝 트리 기법과 호 성공율, 접근시간 및 크랭크 백 율에 대하여 컴퓨터 시뮬레이션을 통해 비교 분석하였다. 시뮬레이션 분석결과 제안된 스패닝 트리 토폴로지 요약 기법이 기존의 기법보다 성능이 향상됨을 알 수 있었다. The proposed scheme in this paper can search multi-links efficiently using the depth priority method based on hop count instead of searching the all links. To do this, we proposed a modified line segment scheme using two line segment method. The scheme represents two points which consist of delay-bandwidth pair to reduce topology information and provide a flexibility to the multiple-links aggregation. And we apply it to current spanning tree topology aggregation. To evaluate performance of the proposed scheme, we compare/analyze the current method with the proposed scheme with respect to call success rate, access time and crankback rate. Simulation result analysis showed the proposed spanning tree topology aggregation scheme presents the better performance than existing scheme.

A linear goal programming priority method for fuzzy analytic hierarchy process and its applications in new product screening

Fuzzy analytic hierarchy process (AHP) has been widely used for a variety of applications such as supplier selection, customer requirements assessment and the like. The vast majority of the applications, however, were found avoiding the use of sophisticated approaches for fuzzy AHP such as fuzzy least squares method while using a simple extent analysis for the sake of simplicity. The extent analysis proves to be incorrect and may lead to a wrong decision being made. This paper proposes a sound yet simple priority method for fuzzy AHP which utilizes a linear goal programming (LGP) model to derive normalized fuzzy weights for fuzzy pairwise comparison matrices. The proposed LGP priority method is tested with three numerical examples including an application of fuzzy AHP to new product development (NDP) project screening decision making.

Analysis of noise-resistant properties of spline interpolation structures in estimation problems

An analysis of the noise-resistant properties of spline interpolation structures used for arriving at an approximate description of information processes is presented. An algorithm for generating recommendations for selecting priority methods of transmission and processing of such structures is constructed on the basis of the results of the analysis.