• 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.

• 유통과학연구
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• 제13권1호
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• pp.93-103
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• 2015

Purpose - This study plans to adopt a more sophisticated approach toward service recognition by customers in general supermarkets in order to revise the service quality measurement methods that suit the context of Korean distribution channels. In particular, in general supermarkets, where much of the shopping process is in the form of self-service, there is high reliance on the service recognized by the consumers; therefore, it is highly likely that consumers would make their purchasing decisions based on their recognition of service quality or guarantees. It also utilized service quality elements of a basic level in the KD-SQS development model in order to indicate that the quality recognized by consumers impacts their loyalty to the stores with financial value and abstract value. Research design, data, and methodology - The study suggested a theoretical model comprising 13 hypotheses on relations between theoretic variables, and conducted surveys with consumers using discount stores in Seoul and Gyunggi Metropolitan area in order to verify the hypotheses, while using SPSS 20.0, AMOS 21.0 as the verification program. The survey sheets used amounted to 332, and a structural equation model was used to analyze the reliability and validity of constituent elements and to verify the suggested hypothesis. Therefore, this study analyzes the interrelations between service quality and guarantee factors in the distribution channel and their relations with the loyalty to stores as a dependent variable. Results - First, the results of the hypotheses tests helped identify the relations between service quality, service guarantees, service value, and customer loyalty, providing an opportunity to define the relations between constituent elements. In particular, service convenience in service quality has no impact on financial values. Further, stores' service policy had no impact on abstract values. Service recognition by service convenience has an impact on abstract values such as good image, comfort, and usability, while mileage systems promote financial values for consumers. In order to improve consumer values in service quality and values, general supermarkets should improve their service convenience, membership, and mileage programs using various strategies. Conclusion - In order to improve consumer values in service quality and values, general supermarkets should improve their service convenience, membership, and mileage programs using various strategies. Further, as service guarantee systems have a significant and direct impact on customer loyalty, rather than customer value recognition, service guarantees should be used to encourage customers to re-visit the stores. Finally, this study applied the findings of preceding studies in terms of service quality measurement; it had limitations in referencing preceding studies in a comprehensive manner. It also had limits in expanding upon various preceding studies because it was difficult to apply new measurement tools due to the lack of service quality measurement tools for general supermarkets. Therefore, it is necessary to conduct more studies on service quality to measure service quality and develop measurement tools by incorporating various industry characteristics.

• 한국도서관정보학회지
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• 제49권1호
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• pp.47-75
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• 2018

본 연구는 국립중앙도서관에서 제공하고 있는 근대문학서비스의 이용현황 및 만족도를 조사하고, 이를 기반으로 서비스를 활성화 시킬 수 있는 방안을 이용자의 요구를 기반으로 모색해 보고자 하였다. 그 결과, 이용자의 근대문학 서비스에 대한 이용률은 매우 저조한 것으로 나타났고, 이용경험자의 이용만족도는 보통으로 나타났다. 따라서 이용률과 만족도를 높이기 위해서는 첫째, 현재 제공되고 있는 근대문학 서비스에 대한 적극적인 홍보가 요구된다고 할 수 있다. 둘째, 전시 및 관람 정보에 대한 홍보는 근대문학자료 이용자로의 직접적 발로를 제공하고 있으므로 다양한 형태의 전시, 관람 행사의 진행이 필요한 것으로 보였다. 셋째, 응답자들은 도서관 홈페이지, 포털사이트, SNS 등 온라인을 통한 홍보 매체가 효과적인 홍보방법이라고 하였으나, 저학력과 고연령층에서는 오프라인 매체를 통한 홍보방법을 선호하고 있어 홍보매체의 선정에 있어 심도 깊은 논의와 고민이 필요할 것으로 보인다.

• 한국가정과학회지
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• 제7권2호
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• pp.47-58
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• 2004

This study is designed to provide some basic materials for finding better ways to promote student-parent communication in order to elevate the sense of self-esteem among middle school students and to talk about the importance of communication between students and parents through looking at the current student-parent communication reality resulting from socio-demographic changes among male and female middle school students and analyzing some influences student-parent communication has on students' self-esteem. To attain the aforementioned purpose, total 650 2nd grade and 3rd grade middle school students were asked to fill out the questionnaire. The schools that they are attending are 2 schools in Gwangju City and 2 schools in a township in Jeonnam. 617 students responded to the survey. In order to see the general characteristics and the distribution of major variables of the respondents, the data were used to produce frequency. percentile, standard deviation and correlation quotient. and t-test. one-way Anova, Duncan's multiple range test and multiple regression analysis techniques were put to use. The results from this study are as follows: student groups that have good relations with other students seemed to be more open and active in their communication with their mother and father. Female students and students in their 2nd grade had more open talking relations with their mothers than male students and students in their 3rd grade. Students had more open talking relations with their father when father's occupation is office worker. In the difference of self-esteem that results from variables in communication between students and parents, a significant variance was presented in the level of the self-esteem of middle school students. When they had open communication with both parents, they had a high sense of self-esteem. and when their communication style was problematic, they had a low sense of self-esteem. When they had better relations with other students, when they had more open communication styles with their mother, when they had better school records, when they felt more satisfaction with communication With their father, they showed a higher level of self-esteem.

• Structural Engineering and Mechanics
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• 제19권1호
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• pp.73-96
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• 2005

For the spatially coupled free vibration analysis of shear deformable thin-walled non-symmetric curved beam subjected to initial axial force, an exact dynamic element stiffness matrix of curved beam is evaluated. Firstly equations of motion and force-deformation relations are rigorously derived from the total potential energy for a curved beam element. Next a system of linear algebraic equations are constructed by introducing 14 displacement parameters and transforming the second order simultaneous differential equations into the first order simultaneous differential equations. And then explicit expressions for displacement parameters are numerically evaluated via eigensolutions and the exact $14{\times}14$ dynamic element stiffness matrix is determined using force-deformation relations. To demonstrate the accuracy and the reliability of this study, the spatially coupled natural frequencies of shear deformable thin-walled non-symmetric curved beams subjected to initial axial forces are evaluated and compared with analytical and FE solutions using isoparametric and Hermitian curved beam elements and results by ABAQUS's shell elements.

• East Asian mathematical journal
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• 제36권1호
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• pp.13-24
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• 2020

The main purpose of this paper is to introduce Apostol type (p, q)-Frobenius-Genocchi numbers and polynomials of order α and investigate some basic identities and properties for these polynomials and numbers including addition theorems, difference equations, derivative properties, recurrence relations. We also obtain integral representations, implicit and explicit formulas and relations for these polynomials and numbers. Furthermore, we consider some relationships for Apostol type (p, q)-Frobenius-Genocchi polynomials of order α associated with (p, q)-Apostol Bernoulli polynomials, (p, q)-Apostol Euler polynomials and (p, q)-Apostol Genocchi polynomials.

• E2M - 전기 전자와 첨단 소재
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• 제7권2호
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• pp.107-116
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• 1994

In the manufacturing of VLSI circuits, variations of device characteristics due to the slight differences in process parameters drastically aggravate the performances of fabricated devices. Therefore, it is very important to establish optimal process conditions in order to minimize deviations of device characteristics. In this paper, we used one-dimensional process simulator, SUPREM-II, and two dimensional device simulator, MINIMOS 4.0 in order to extract optimal process parameter which can minimize changes of the device characteristics caused by process parameter variation in the case of short channel nMOSFET and pMOSFET device. From this simulation, we have derived the dependence relations between process parameters and device characteristics. Here, we have suggested a method to extract process parameters from design trend curve(DTC) obtained by these dependence relations. And we have discussed short channel effects and device limitations by scaling down MOSFET dimensions.

• 재무관리연구
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• 제25권4호
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• pp.117-144
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• 2008

This article examines the information transmission process between the KOSPI 200 futures market and its underlying stock market, using the 10-second quote and trade data. The VAR analysis reveals that quote revisions through limit orders in general lead trades through market orders. In addition, the VAR analysis shows that the futures market tends to lead the stock market in terms of quote revisions and trades, even though the other direction is also observable. Even when we focus on the events causing large movements in quote revisions and trades, those lead and lag relations between those markets and between quote revisions and order imbalances are confirmed.

• 한국정밀공학회지
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• 제21권7호
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• pp.163-170
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• 2004

In order to automatically determine the sequences of block assembly operations in shipbuilding, a process planning system using case-based reasoning (CBR) is developed. A block-assembly planning problem is modeled as a constraint satisfaction problem where the precedence relations between operations are considered constraints. The process planning system generates an assembly sequence by adapting information such as solutions and constraints collected from similar cases retrieved from the case base. In order to find similar cases, the process planning system first matches the parts of the problem and the parts of each case based on their roles in the assembly, and then it matches the relations related to the parts-pairs. The part involved in more operations are considered more important. The process planning system is applied to simple examples fur verification and comparison.

• Structural Engineering and Mechanics
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• 제71권1호
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• pp.99-107
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• 2019

Wave propagation analysis of a porous graphene platelet reinforced (GPLR) nanocomposite shell is investigated for the first time. The homogenization of the utilized material is procured by extending the Halpin-Tsai relations for the porous nanocomposite. Both symmetric and asymmetric porosity distributions are regarded in this analysis. The equations of the shell's motion are derived according to Hamilton's principle coupled with the kinematic relations of the first-order shear deformation theory of the shells. The obtained governing equations are considered to be solved via an analytical solution which includes two longitudinal and circumferential wave numbers. The accuracy of the presented formulations is examined by comparing the results of this method with those reported by former authors. The simulations reveal a stiffness decrease in the cases which porosity influences are regarded. Also, one must pay attention to the effects of longitudinal wave number on the wave dispersion curves of the nanocomposite structure.