• Geomechanics and Engineering
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• 제24권1호
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• pp.91-103
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• 2021

This paper concerns with forced dynamic response of thick functionally graded (FG) beam resting on viscoelastic foundation including porosity impacts. The dynamic point load is proposed to be triangle point loads in time domain. In current analysis the beam is assumed to be thick, therefore, the two-dimensional plane stress constitutive equation is proposed to govern the stress-strain relationship through the thickness. The porosity and void included in constituent is described by three different distribution models through the beam thickness. The governing equations are obtained by using Lagrange's equations and solved by finite element method. In frame of finite element analysis, twelve-node 2D plane element is exploited to discretize the space domain of beam. In the solution of the dynamic problem, Newmark average acceleration method is used. In the numerical results, effects of porosity coefficient, porosity distribution and foundation parameters on the dynamic responses of functionally graded viscoelastic beam are presented and discussed. The current model is efficient in many applications used porous FGM, such as aerospace, nuclear, power plane sheller, and marine structures.

• 유통과학연구
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• 제21권2호
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• pp.103-110
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• 2023

Purpose: The high-end and variety of recently released items are driving the growth of the distribution industry, which is the purpose of private brand (PB) products. Because PB shortens the distribution process and lowers marketing expenses, such as those associated with various commercials, more people will buy PB while paying lower retail prices. The goal of this study is to make the case that PB can be positioned successfully by determining the influence and direction of each individual constituent concept on how product and store attributes (perceived price, image of retail store) affect the perceived value of PB and the legitimacy of retailers. Research design, data and methodology: The gathered data were examined using PLS-SEM using Smart PLS 3.0 in order to analyze the research model of this study. Internal consistency was verified to demonstrate the measurement model's dependability, and extensive validity analysis, discriminant validity, and analysis were performed to verify the validity. Conclusion: This researcher attempted to gather diverse understandings and viewpoints on PB trends in addition to understanding the existing state of PB products. It is meant to be a unique and successful plan in the PB Brands' marketing strategy. By understanding the brand's value proposition aspects, it is hoped to determine how PB influences brand attitudes based on the findings of this study.

• 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.

• 한국음향학회지
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• 제27권6호
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• pp.263-270
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• 2008

초음파 어레이 센서의 성능은 구성 불성과 많은 구소 변수들에 의해 결정된다. 본 연구에서는 유한 요소해석을 통하여 구조적인 변화에 따른 초음파 어레이 센서의 성능변화를 해석하였다. 해석 결과를 기초로 하여 초음파 어레이 센서가 주파수 대역폭, 중심 주파수 그리고 -20 dB pulse length와 같은 요구 사항을 모두 만족시키며 최대의 감도를 가지도록 구조를 최적화하였다. 최적화 방법으로는 초음파 어레이 센서의 성능을 목적 함수로 하는 SQP-PD 방법을 사용하였다. 최적화된 초음파 어레이 센서는 의료 영상 진단에 적용되기 위한 모든 요구 조건을 만족하였으며, 본 설계 기술은 유사한 형태의 다른 배열형 초음파 센서에 응용 가능하다

• Journal of Information Science Theory and Practice
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• 제1권2호
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• pp.16-35
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• 2013

Relevance has a long history of scholarly investigation and discussion in information science. One of its notable concepts is that of 'user-based' relevance. The purpose of this study is to examine how users construct their perspective on the concept of relevance; to analyze what the constituent elements (facets) of relevance are, in terms of core-periphery status; and to compare the difference of constructions of two groups of users (information users vs. information professionals) as applied with a social representations theory perspective. Data were collected from 244 information users and 123 information professionals through use of a free word association method. Three methods were employed to analyze data: (1) content analysis was used to elicit 26 categories (facets) of the concept of relevance; (2) structural analysis of social representations was used to determine the core-periphery status of those facets in terms of coreness, sum of similarity, and weighted frequency; and, (3) maximum tree analysis was used to present and compare the differences between the two groups. Elicited categories in this study overlap with the ones from previous relevance studies, while the findings of a core-periphery analysis show that Topicality, User-needs, Reliability/Credibility, and Importance are configured as core concepts for the information user group, while Topicality, User-needs, Reliability/Credibility, and Currency are core concepts for the information professional group. Differences between the social representations of relevance revealed that Topicality was similar to User-needs and to Importance. Author is closely related to Title while Reliability/Credibility is linked with Currency. Easiness/Clarity is similar to Accuracy. Overall, information users and professionals function with a similar social collective of shared meanings for the concept of relevance. The overall findings identify the core and periphery concepts of relevance and their relationships in terms of coreness, similarity, and weighted frequency.

• 한국소음진동공학회논문집
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• 제27권2호
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• pp.221-233
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• 2017

The array equations are commonly used for analysis and conceptual design of active sonar projector arrays. Calculation of the radiation impedance matrix poses a major computational bottleneck for the solution of the array equations, which leads to a dramatic increase in computational load as the number of constituent transducers increases. Here, we propose an iteration-based solution method that does not require the calculation of the radiation impedance matrix, as a computationally efficient alternative to the status quo. The validity of the iteration-based analysis is judged against the full finite-element analysis that includes the entire array as well as the medium. The array equations for the 1/3-sector of a cylindrical array comprised of 48 Tonpilz transducers are augmented by the lumped element models, and are solved iteratively for the acoustic and electro-mechanical characteristics. The iteration-based analysis exhibits rapid convergence and accuracy comparable with the FE analysis. Simulations also reveal that the acoustic coupling between transducers has more pronounced effects on the electro-mechanical characteristics of individual transducers than the acoustic performance of the array.

• 한국정보과학회논문지:소프트웨어및응용
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• 제27권3호
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• pp.290-301
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• 2000

일반적으로 형태소 분석 방법은 실행시에 매 어절마다 코드 변환, 형태소 분리, 원형 복원 규칙 적용을 통한 분석 후보 생성, 사전 탐색을 통한 분석 후보의 여과 등의 절차를 거쳐 형태소 분석을 수행하기 때문에 실행 효율의 관점에서 효율적이지 못하다. 이러한 문제점을 완화시키기 위해 도입된 어절단위 기분석 사전에 의한 분석은 실행시 처리에 소요되는 계산 부하를 크게 줄일 수는 있지만 어절의 수가 사실상 무한하므로 사전의 크기 문제 때문에 완전한 처리 방법이 될 수 없다는 단점이 있다. 본 논문에서는 이상과 같은 문제점을 해결하기 위해 두가지 대비되는 방법론을 결합하여 부분 어절별로 기분석 결과를 구축하여 형태소를 분석하는 방법에 대해 기술하고 있다. 이 방법에 의하면, 형태소 분리, 원형 복원 등 형태소 분석에 필요한 계산의 대부분을 실행시에 행하지 않고 기분석 결과의 구축 시에 행함으로써 실행시 계산 부하를 크게 줄일 수 있고 불필요한 중간 결과가 생성되지 않아 사전 탐색 횟수가 크게 절감되는 효과가 있으므로, 실행 효율을 크게 개선할 수 있다. 아울러 음소별 연산을 하지 않으므로 코드 변환 등에 소요되는 계산량도 전혀 필요치 않다는 특징도 있다.

• 산경연구논집
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• 제11권6호
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• pp.41-53
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• 2020

Purpose: The purpose of this study is to review the previous studies on the characteristics of the image search service provided by using artificial intelligence, the social impact characteristics, and the moderating effect of perceived anthropomorphism, and conduct empirical analysis to identify the constituent factors affecting purchase intention. To clarify. Through this, I tried to present theoretical and practical implications. Research design, data, and methodology: Research design was that characteristics of image search service (ubiquity and information quality) and social impact characteristics (subjective norms, electronic word of mouth marketing) are affected by mediation of satisfaction and flow, therefore, control of perceived anthropomorphism have an effect on purchase intention to increase. For analysis, research conducted literature review, and developed questionnaires, so that EM firm which is a specialized research institute has collected data. This was conducted on 410 people between the 20s and 50s who have mobile shopping experiences. SPSS Statistics 23 and AMOS 23 had been used to perform necessary analysis such as exploratory factor analysis, reliability analysis, feasibility analysis, and structural equation modeling based on this data. Results: first, ubiquity, information quality and subjective norms were found to have a positive effect on purchase intention through satisfaction and flow parameters. Second, satisfaction and flow were found to have a mediating effect between ubiquity, information quality, and subjective norms and purchase intentions. However, there was no mediating effect between eWOM information and purchase intention. Third, perceived anthropomorphism was found to have a moderating effect between information quality and satisfaction, and it was found that there was no moderating effect on the relationship between information quality and flow. Conclusions: The information quality of image search services using artificial intelligence has a positive effect on satisfaction, and it has been found that there is a positive moderate effect of perceived anthropomorphism in this relationship, which may be an academic contribution to the distribution science utilizing artificial intelligence. Therefore, it is possible to propose a distribution strategy that improves purchase intention by utilizing image search service and anthropomorphism in practical business and providing a more enjoyable immersive experience to customers.

• 한국물환경학회지
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• 제26권6호
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• pp.895-902
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• 2010

The effect of seasonality on water quality variation is very significant. Generally, it reduce the power of the trend extraction. A parametric time-series model was used for detecting trends in historic constituent concentration data. The effect of seasonality is able to remove from time series decomposition technique. According to such statistic methode, long-term water quality trend analysis system (NTrend 1.0) was developed by Nakdong River Water Environmental Research Center. The trend analysis of BOD variation was conducted with NTrend 1.0 at Goreong and Moolkum site in Nakdong river to show the effect of water quality management action plan. Power test of trend extraction was tried each case of 'deseasonalized and deannulized' data and 'deseasonalized' data. Analysis period was from 1989 to 2006, and it's period was divided again three times, 1989~1993, 1994~1999 and 2000~2006 according to action plan period. The BOD trend was downward in Goreong site during three times and it's trend slope was very steep, and upward in Moolkum during 1989~1993, but it was turned downward during 1994~1999 and 2000~2006. It was revealed that it's very effective to reduce the concentration of BOD by water quality management action plan in that watershed. The result of power test was shown that it is high for trend extraction power in case of 'deseasonalized' data.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2011년도 학술발표회
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• pp.58-58
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• 2011

The Texas Commission on Environmental Quality(TCEQ) WAM(Water Availability Modeling) System consists of the generalized Water Rights Analysis Package(WRAP) river/reservoir system water management simulation model, 22 sets of WRAP hydrology and water rights input files for the 23 river basins of Texas, geographic information system tools, and other supporting databases. The WRAP/WAM modeling system, as routinely applied since the late 1990s, has not included consideration of water quality. Recently developed WRAP-SALT(Water Rights Analysis Package) is designed primarily for computing concentration frequency statistics and supply reliability indices at locations of interest in a river system for alternative water development and management scenarios. Though motivated primarily by natural salt pollution, WRAP-SALT water quality modeling features are applicable to essentially any conservative water quality constituent. The Brazos River studies discussed in this paper focus on total dissolved solids, though the available observed data also includes chloride and sulfate which can be modeled as individual constituents. The WRAP-SALT salinity input file contains loads or concentrations of salinity inflows during each month of the hydrologic period-of-analysis and reservoir storage at the beginning of the simulation. The WRAP-SALT model computes salt loads and concentrations for each control point of a river/reservoir system for inflows and outflows during the month and end-of-month reservoir storage for each month of the hydrologic period-of-analysis, for given loads entering the system. River reaches connect control points. The mass balance algorithms proceed from upstream to downstream, with outflow from one river reach contributing to inflow to the next downstream reach. In a given month, for each control point in sequence, the inflow loads are first computed. Loads and concentrations of outflows and reservoir storage at the control point are then determined. Complete mixing during the month is assumed at locations without reservoir storage.