• 대한기계학회논문집
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• 제18권1호
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• pp.150-155
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• 1994

An Approximate solution for plane two-dimensional incompressible laminar jet issuing from a finite opening with arbitrary initial profile into the same ambient fluid is proposed. For an arbitrary initial velocity profile, the problem is generated from the well known similarity solution for the jet of infinitesimal opening and provides good approximations in the region where the similarity solution cannot be used as an approximation. The asymptotic behavior of this solution is investigated and it is shown that, as goes downstream, the present solution approachs the similarity solution.

• Journal of applied mathematics & informatics
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• 제31권5_6호
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• pp.631-642
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• 2013

In this paper we reconsider the problem of steady mixed convection boundary-layer flow over a vertical flat plate studied in [6],[7] and [13]. Under favorable assumptions, we prove existence of multiple similarity solutions, we study also their asymptotic behavior. Numerical solutions are carried out using a shooting integration scheme.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권3호
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• pp.181-187
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• 2014

Dealing with uncertainty is always a challenging problem. Intuitionistic fuzzy sets was presented to manage situations in which experts have some membership and non-membership value to assess an alternative. Hesitant fuzzy sets was used to handle such situations in which experts hesitate between several possible membership values to assess an alternative. In this paper, the concept of intuitionistic hesitant fuzzy set is introduced to provide computational basis to manage the situations in which experts assess an alternative in possible membership values and non-membership values. Distance measure is defined between any two intuitionistic hesitant fuzzy elements. Fuzzy technique for order preference by similarity to ideal solution is developed for intuitionistic hesitant fuzzy set to solve multi-criteria decision making problem in group decision environment. An example is given to illustrate this technique.

• Journal of Advanced Marine Engineering and Technology
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• 제29권7호
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• pp.779-784
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• 2005

This paper presents the theory of similarity transformations applied to the momentum and energy equations for laminar, forced, external boundary layer flow over a horizontal flat plate which leads to a set of non-linear, ordinary differential equations of phase change material slurry(PCM Slurry). The momentum and energy equation set numerically to obtain the non-dimensional velocity and temperature profiles in a laminar boundary layer are solved. The heat transfer characteristics of PCM slurry was numerically investigated with similar method. It is clarified that the similar solution method of Newtonian fluid can be used reasonably this type of PCM slurry which has low concentration. The data of local wall heat flux and convective heat transfer coefficient of PCM slurry are higher than those of water more than 150$\~$200$\%$, approximately.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 춘계학술대회논문집
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• pp.298-302
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• 2009

Numerical analysis of two dimensional incompressible laminar free jet flow was carried out by using finite difference SMAC scheme. Flow characteristics of free jet flow such as jet width, similarity of jet velocity and hypothetical origin were investigated for different Reynolds numbers of Re=30 and 100. The reliability of predictions were confirmed by comparison with exact solution. Non-dimensional velocity distribution showed similarity of jet flow velocity after initial region. In the region of laminar flow, the location of hypothetical origin becomes more distant with Reynolds number.

• 경영과학
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• 제24권1호
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• pp.91-111
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• 2007

In this paper an effective two-phase approach adopting modified p-median mathematical model is proposed for grouping machines and parts in cellular manufacturing(CM). Unlike the conventional methods allowing machines and parts to be improperly assigned to cells and families, the proposed approach seeks to find the proper block diagonal solution where all the machines and parts are properly assigned to their most associated cells and families in term of the actual machine processing and part moves. Phase 1 uses the modified p-median formulation adopting new inter-machine similarity coefficient based on the non-binary production data-based part-machine incidence matrix(PMIM) that reflects both the operation sequences and production volumes for the parts to find machine cells. Phase 2 apollos iterative reassignment procedure to minimize inter-cell part moves and maximize within-cell machine utilization by reassigning improperly assigned machines and parts to their most associated cells and families. Computational experience with the data sets available on literature shows the proposed approach yields good-quality proper block diagonal solution.

• 한국소프트웨어감정평가학회 논문지
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• 제17권1호
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• pp.11-16
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• 2021

정보통신의 발달로 인하여 소프트웨어의 중요성이 증대되고 있으며, 이에 따른 소프트웨어 저작권 분쟁도 증가하는 추세에 있다. 본 논문은 제출된 프로그램들의 소스와 관련하여 프로그램 수행에 필요한 파일들을 감정범위로 하였다. 분석 대상인 대용량 파일 전송 솔루션 프로그램은 데이터에 대한 전자서명 및 암호화를 통하여 기밀성, 무결성, 사용자 인증, 부인방지 기능 등의 부가 기능을 제공하고 있다. 본 논문에서는 프로그램 A, 프로그램 B, 프로그램 C 3개에 대하여 분석을 수행한다. 프로그램 유사율을 산출하기 위하여 다음과 같은 내용을 분석한다. 패키지의 구조, 패키지 이름, 각 패키지 내 소스파일 이름, 소스파일 내 변수명, 함수명, 함수구현 소스코드, 제품의 환경변수 정보에 대하여 유사 여부를 분석하고 프로그램의 전체 유사율을 산출한다. 패키지 구조 및 패키지 이름이 일치되는 정도를 확인하기 위해, 폴더 구조를 비교하여 유사도 판단을 하였다. 또한 패키지 구조 및 패키지 이름이 어느 정도 일치하는지와 각 패키지 내 소스 파일(클래스) 이름이 어느 정도 일치하는지에 대한 분석을 하였다.

• Advances in concrete construction
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• 제15권5호
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• pp.313-319
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• 2023

In this paper, the analytic solution has been found by using truncation approach. With the help of suitable substitution, different physical parameters are yielded in their non-dimensional form. The governing boundary layer partial differential equations are reduced to a set of ordinary ones by using appropriate similarity transformations. The velocity profile across the domain have also been taken into account. The effect normal velocity profiles buoyancy parameter, slip parameter, shrinking parameter, Casson fluid parameter on the heat profile. It is found that the normal velocity profiles rise with the buoyancy parameter and for the slip parameter. It is observed that the normal velocity profile decreases with the increase of shrinking parameter. The reverse behiour is found for the Casson fluid parameter. The results are numerically computed, analyzed and discussed. For the efficiency of present model, the results are compared with earlier investigations.

• Journal of Electrical Engineering and Technology
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• 제9권2호
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• pp.423-432
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• 2014

Non-dominated Sorting Genetic Algorithm-II (NSGA-II) is applied for solving Combined Economic Emission Dispatch (CEED) problem with valve-point loading of thermal generators. This CEED problem with valve-point loading is a nonlinear, constrained multi-objective optimization problem, with power balance and generator capacity constraints. The valve-point loading introduce ripples in the input-output characteristics of generating units and make the CEED problem as a nonsmooth optimization problem. To validate its effectiveness of NSGA-II, two benchmark test systems, IEEE 30-bus and IEEE 118-bus systems are considered. To compare the Pareto-front obtained using NSGA-II, reference Pareto-front is generated using multiple runs of Real Coded Genetic Algorithm (RCGA) with weighted sum of objectives. Comparison with other optimization techniques showed the superiority of the NSGA-II approach and confirmed its potential for solving the CEED problem. Numerical results show that NSGA-II algorithm can provide Pareto-front in a single run with good diversity and convergence. An approach based on Technique for Ordering Preferences by Similarity to Ideal Solution (TOPSIS) is applied on non-dominated solutions obtained to determine Best Compromise Solution (BCS).

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권4호
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• pp.439-449
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• 2018

In this paper, multi-objective optimization of a multi-bubble pressure cabin in the underwater glider with Blended-Wing-Body (BWB) is carried out using Kriging and the Non-dominated Sorting Genetic Algorithm (NSGA-II). Two objective functions are considered: buoyancy-weight ratio and internal volume. Multi-bubble pressure cabin has a strong compressive capacity, and makes full use of the fuselage space. Parametric modeling of the multi-bubble pressure cabin structure is automatic generated using UG secondary development. Finite Element Analysis (FEA) is employed to study the structural performance using the commercial software ANSYS. The weight of the primary structure is determined from the volume of the Finite Element Structure (FES). The stress limit is taken into account as the constraint condition. Finally, Technique for Ordering Preferences by Similarity to Ideal Solution (TOPSIS) method is used to find some trade-off optimum design points from all non-dominated optimum design points represented by the Pareto fronts. The best solution is compared with the initial design results to prove the efficiency and applicability of this optimization method.