• 한국태양에너지학회 논문집
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• 제26권1호
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• pp.81-89
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• 2006

Building integrated photovoltaic (BIPV) system operates as a multi-functional building construction material. They not only produce electricity, but also are building integral components such as facade, roof, window and shading device. On the other hands lots of architectural considerations should be reflected such as Installation position, shading, temperature effect and so on. As PV modules function like building envelope in BIPV, combined thermal and PV performance should be simultaneously evaluated This study is on the combined thermal and PV performance evaluation of BIPV modules. The purpose of this study is to investigate a temperature effect of PV module depending on the ventilation type of PV module backside. Test cell experiment was performed to identify the thermal and power effect of PV modules. Measurement results on the correlation of temperature and power generation were obtained. Those results can be utilized for the development of optimal BIPV installation details in the very early design stage.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.52-52
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• 2003

Junctate is a newly identified integral ER/SR membrane $Ca^{2+}$ binding protein, which is an alternative splicing form of the same gene generating aspartyl $\square$-hydroxylase and junctin. To elucidate the functional role of junctate in heart, transgenic (TG) mice overexpressing mouse cardiac junctate-1 under the control of mouse $\square$$^{~}$ myosin heavy chain promoter were generated. Overexpression of junctate in mouse heart resulted in cardiac hypertrophy, increased fibrosis, bradycardia, arrhythmias and impaired contractility. Overexpression of junctate also led to down-regulation of SERCA2, calsequestrin, calreticulin and RyR, but to up-regulation of NCX and PMCA. The SR $Ca^{2+}$ content decreased and the L-type $Ca^{2+}$ current density and the action potential durations increased in TG cardiomyocytes, which could be the cause for the bradycardia in TG heart. The present work has provided an important example of pathogenesis leading to cardiac hypertrophy and arrhythmia, which was caused by impaired $Ca^{2+}$ handling by overexpression of junctate in heart.n heart.

• 한국전산구조공학회논문집
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• 제18권3호
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• pp.255-263
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• 2005

본 논문에서는 다양한 문제들의 형상 설계 민감도 해석에 대한 효율적인 경계기반 기법을 제시하였다 우선 문제에서 정의된 일반적인 함수들에 대한 연속체 형태의 식에 근거하여, 경계 적분 형태의 해석적 민감도 식을 유도하였다. 이 식은 다양한 형상 설계 문제들의 경사를 계산하는데 편리하게 사용할 수 있다. 그리고 경계법은 형상 변분 벡터가 전체 도메인이 아닌 경계에서만 요구된다는 장점이 있는데, 여기서 경계 형상 변분은 형상 함수의 복잡한 해석적 미분 대신 형상을 미소 증분시킴으로써 편리하게 계산할 수 있다. 제시한 방법의 효율성을 보이기 위해 포텐셜 유동 문제와 필렛(fillet)에서의 응력 집중 문제에 이를 적용하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1047-1052
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• 2004

An efficient boundary-based technique is developed for addressing shape design sensitivity analysis in supercavitating flow problem. An analytical sensitivity formula in the form of a boundary integral is derived based on the continuum formulation for a general functional defined in potential flow problems. The formula, which is expressed in terms of the boundary solutions and shape variation vectors, can be conveniently used for gradient computation in a variety of shape design in potential flow problems. While the sensitivity can be calculated independent of the analysis means, such as the finite element method (FEM) or the boundary element method (BEM), the FEM is used for the analysis in this study because of its popularity and easy-touse features. The advantage of using a boundary-based method is that the shape variation vectors are needed only on the boundary, not over the whole domain. The boundary shape variation vectors are conveniently computed by using finite perturbations of the shape geometry instead of complex analytical differentiation of the geometry functions. The supercavitating flow problem is chosen to illustrate the efficiency of the proposed methodology. Implementation issues for and optimization procedure are addressed in this flow problem.

• 대한조선학회논문집
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• 제53권2호
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• pp.92-100
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• 2016

A comparative method is applied to evaluate well-known formulas for estimating the size of supercavities of axisymmetric cavitators for the supercavitating underwater vehicle. Basic functional forms of these formulas are derived first for the cavity diameter from a momentum integral estimate and second for the cavity length from an asymptotic analysis of inviscid supercavity flows. The length and the diameter of axisymmetric supercavities estimated by each formula are compared, with available experimental data for a disk and a 45° conical cavitators, and also with computational results obtained by a CFD code, ‘fluent’, for conical cavitators of wide range of cone angles. Results for estimating the length and the diameter of the supercavities show in general a good agreement, which confirms the size of the supercavities for disk and conical cavitators can be estimated accurately by these simple formulas of an elementary function of cavitation number and drag coefficient of the cavitator. These formulas will be useful for from conceptual design of the cavitator to real-time control of the supercavitating underwater vehicle.

• 한국항해항만학회지
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• 제43권2호
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• pp.110-121
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• 2019

Ports play a key role in international trade, as integral hubs where passengers and cargoes are loaded, discharged, and transshipped. However, the function of ports is becoming more diversified, expanding on roles as industrial clusters, as well as logistical centers. Such roles combined, reap numerous and significant benefits, mainly with growth of jobs and wealth creation, for the local population living in the city, and beyond. Citizens' awareness of the function and value of ports may not be positive, because of a range of negative factors such as emissions, noise, and road congestion, which can influence their perception. This study's contribution focuses on empirically evaluating the perception of Busan citizens of the local port, by applying Q methodology. The links connecting the port-city and local population, are assessed by identifying: 1) The level of awareness of the Busan citizens of the port; 2) Factors perceived as positive as well as factors perceived as negative by Busan citizens. There are four main factors, derived from the analysis: 1) Port functional knowledge; 2) Lack of social connectedness port-city; 3) Environmentally concerned and; 4) Absent port's ripple's effect. Policy recommendations suggest focusing on improving citizens' perception of the port, for each of the four main factors derived from the analysis.

• Structural Engineering and Mechanics
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• 제69권5호
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• pp.511-525
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• 2019

This paper presents an analytical study of wave propagation in simply supported graduated functional plates resting on a two-parameter elastic foundation (Pasternak model) using a new theory of high order shear strain. Unlike other higher order theories, the number of unknowns and governing equations of the present theory is only four unknown displacement functions, which is even lower than the theory of first order shear deformation (FSDT). Unlike other elements, the present work includes a new field of motion, which introduces indeterminate integral variables. The properties of the materials are assumed to be ordered in the thickness direction according to the two power law distributions in terms of volume fractions of the constituents. The wave propagation equations in FG plates are derived using the principle of virtual displacements. The analytical dispersion relation of the FG plate is obtained by solving an eigenvalue problem. Numerical examples selected from the literature are illustrated. A good agreement is obtained between the numerical results of the current theory and those of reference. A parametric study is presented to examine the effect of material gradation, thickness ratio and elastic foundation on the free vibration and phase velocity of the FG plate.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권10호
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• pp.3793-3814
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• 2021

Most secure solutions like cryptography are software based and they are designed to mainly deal with the outside attacks for traditional networks, but such soft security is hard to be implemented in wireless sensor networks to counter the inside attacks from internal malicious nodes. To address this issue, reputation has been introduced to tackle the inside malicious nodes. Reputation is essentially a stimulating mechanism for nodes' cooperation and is employed to detect node misbehaviors and improve the trust-worthiness between individual nodes. Among the reputation models, binomial distribution based reputation has many advantages such as light weight and ease of implementation in resource-constraint sensor nodes, and accordingly researchers have proposed many insightful related methods. However, some of them either directly use the modelling results, apply the models through simple modifications, or only use the required components while ignoring the others as an integral part of the whole model, this topic still lacks a comprehensive and systematical review. Thus the motivation of this study is to provide a thorough survey concerning each detailed functional components of binomial distribution based reputation for wireless sensor networks. In addition, based on the survey results, we also argue some open research problems and suggest the directions that are worth future efforts. We believe that this study is helpful to better understanding the reputation modeling mechanism and its components for wireless sensor networks, and can further attract more related future studies.

• Nonlinear Functional Analysis and Applications
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• 제27권2호
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• pp.249-259
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• 2022

Let 𝓐 be a unital C^*-algebra. Then it follows that $\sum\limits_{i=1}^{n}(a_ia^*_i)^{\frac{1}{2}}{\leq}\sqrt{n}\(\sum\limits_{i=1}^{n}a_ia^*_i\)^{\frac{1}{2}}$, ∀n ∈ ℕ, ∀a₁, …, a_n ∈ 𝓐. By modifications of arguments of Botelho-Andrade, Casazza, Cheng, and Tran given in 2019, for certain n-tuple x = (a₁, …, a_n) ∈ 𝓐ⁿ, we give a method to compute a positive element c_x in the C^*-algebra 𝓐 such that the equality $$\sum\limits_{i=1}^{n}(a_ia^*_i)^{\frac{1}{2}}=c_x\sqrt{n}\(\sum\limits_{i=1}^{n}a_ia^*_i\)^{\frac{1}{2}}$$ holds. We give an application for the integral of Kasparov. We also derive a formula for the exact constant for the continuous ℓ₁ - ℓ₂ inequality.

• Steel and Composite Structures
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• 제45권3호
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• pp.305-330
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• 2022

This article aims to investigate the static deflection and stress analysis of bi-directional functionally graded porous plate (BDFGPP) modeled by unified higher order kinematic theories to include the shear stress effects, which not be considered before. Different shear functions are described according to higher order models that satisfy the zero-shear influence at the top and bottom surfaces, and hence refrain from the need of shear correction factor. The material properties are graded through two spatial directions (i.e., thickness and length directions) according to the power law distribution. The porosities and voids inside the material constituent are described by different cosine functions. Hamilton's principle is implemented to derive the governing equilibrium equation of bi-directional FG porous plate structures. An efficient numerical differential integral quadrature method (DIQM) is exploited to solve the coupled variable coefficients partial differential equations of equilibrium. Problem validation and verification have been proven with previous prestigious work. Numerical results are illustrated to present the significant impacts of kinematic shear relations, gradation indices through thickness and length, porosity type, and boundary conditions on the static deflection and stress distribution of BDFGP plate. The proposed model is efficient in design and analysis of many applications used in nuclear, mechanical, aerospace, naval, dental, and medical fields.