• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 춘계학술대회 논문집
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• pp.552-558
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• 1995

Stereolithography is a process used to rapidly produce polymer components directly from a computer-representation of the part. There are several considerations to be made for the efficient use of te process. Especially, the build-up orientation of part critically affect to the part accuracy, total build time and the volume of support structures. Te purpose of this study is to determine the optimal build-up part orientation for the SLA process with improving part accuracy, minimizing total build time, and the volume of supprot structures. The first factor is related to the area of surfaces which have staircase protrusions after solidification, the second factor is related to the total number of layers, and the third factor is related to the area of the surfaces which need to be supported with support structures. An algorithm is developed to calculate the staircase area with quantifying the process planning errors that the volume of materials is supposed to be removed or added to the part, and the optimal layer thickness for the SLA system whichcan hadle the variable layer thickness in different orientations achieved by rotating the given part to the specified finite directions. So the optimal part orientation is determined based on the user's selections of primary criterion and the optimal thickness of layers is calculated at any part orientations.

• 아동학회지
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• 제37권5호
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• pp.19-31
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• 2016

Objective: The purpose of this study was to test the mediating effects of ego-resilience on relationship between perceived parenting attitudes and regulatory focus among college students. Methods: In this study, 256 college students were surveyed. The collected data were put through correlation analysis using PASW Statistics 18.0. In addition, 3-stage multiple regression analyses and the Sobel test were used to test any mediating effects. Results: The findings show that the diversity of concerns and interests, emotion control, and positive future orientation, the subfactors of ego-resiliency, all have partial mediating effects on the relationship between father's care and promotion focus. Only positive future orientation had partial mediating effects on the relationship between mother's care and promotion focus. Conclusion: Father's care turned out to be an independent variable to explain better the mediating effects of ego-resiliency on relations between parenting attitudes and regulatory focus, which implies the influence and importance of father's care on college students.

• Journal of Biosystems Engineering
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• 제22권3호
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• pp.325-332
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• 1997

The use of a robotic transplanter reduces the labor requirement in the greenhouse by carrying out repetitive tasks in an accurate and reliable manner. The transplanter manipulates seedlings by means of end-effector. The end-effector is designed differently from an industrial robot because it manulates biological seedlings of variable size, shape, position, and orientation. This study was conducted to develop an end-effector of a robotic transplanter for bedding plants. The development of an end-effector included selection of the best finger type for the transplanting operation. The performance of developed end-effector was tested and compared with two different transplanting schemes depending on the leaf-orientation consideration. The end-effector developed in this research reliably handled seedlings during transplanting task. Results showed that the shovel type finger was suitable for transplanting with the damaging seedlings.

• Journal of Advanced Marine Engineering and Technology
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• 제27권1호
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• pp.100-107
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• 2003

This study was to control magnetic field orientation-typed sensorless vector control by applying the theory of a rotor flux observer to drive an induction motor. This research suggested a new speed estimation method that estimates speed with the rotor flux obtained by using a flux observer and the variable of state current detected by a current sensor without a speed sensor. Because the speed estimation method is independent from the motor constants, it is not necessary to control the gain of the parameters and the algorithm is simple. In the findings of the study, the researcher was convinced of the control function and the possibility of realization in the simulation experiment of sensorless vector control system by using DSP(Digital Signal Prosessor).

• Structural Engineering and Mechanics
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• 제57권3호
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• pp.441-456
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• 2016

This work reports wave propagation in the nanocomposite cylinders that reinforced by straight single-walled carbon nanotubes based on a mesh-free method. Moving least square shape functions have been used for approximation of displacement field in weak form of motion equation. The straight carbon nanotubes (CNTs) are assumed to be oriented in specific or random directions or locally aggregated into some clusters. In this simulation, an axisymmetric model is used and also the volume fractions of the CNTs and clusters are assumed to be functionally graded along the thickness. So, material properties of the carbon nanotube reinforced composite cylinders are variable and estimated based on the Eshelby-Mori-Tanaka approach. The effects of orientation, aggregation and volume fractions of the functionally graded clusters and CNTs on dynamic behavior of nanocomposite cylinders are studied. This study results show that orientation and aggregation of CNTs have significant effects on the effective stiffness and dynamic behaviors.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.287-292
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• 1998

This paper presents some results of performance evaluation test via actual machines of a new hybrid vector control utilizing a new indirect orientation scheme and stable filter embedded direct orientation scheme for induction motors without speed or position sensor. It is shown through the test by 0.3(kW) and 3.7(kW) motors that the proposed sensorless vector control has the following high potentialities: 1) speed range is 0 to 600(rad/s) or more, 2) zero-speed command is accepted and settles the machines at a stable standstill with no vibration 3) it can make machines to track variable command of acceleration and deceleration $\pm$6,000(rad/s2), 4) it can make machines to drive directly load of at least 26 times larger inertia than that of the machine, 5) it can make machines to produce much larger torque than the rating in torque control mode even at standstill. The performance confirmed by the test is far away for previous schemes or sensorless drive apparatuses.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2003년도 추계학술대회 발표 논문집
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• pp.182-185
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• 2003

We have suggested an equivalent circuit model for switching performance of bipolar spin transistor composed of a nonmagnetic metal film (N) sandwiched between two ferromagnetic metal films (F1 and F2). The 'ON' or 'OFF' operation of this equivalent circuit model is simulated by depending on the orientation of the magnetization of F1 and F2 rather than the strength of the external magnetic filed. Changing the coupling coefficient, turn number of two inductances, (L1:L2) like a transformer, and parallel variable resistance R4 connected to L2 at the collector region, we can explain the magnetic characteristics and the dependence of magneto resistance ratio on the orientation of spin-polarized electrons.

• Asia Marketing Journal
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• 제21권1호
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• pp.89-112
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• 2019

To investigate the interplay between individual and collective self-regulations, the authors propose a dialectic process that describes the changes in the locus of self-regulations between individual self and collective self. The results from three studies display a strong support for the two sets of hypotheses drawn from the proposed process. Our findings demonstrate that consumers can move the locus of self-regulation from individual-self to collective-self when a social identity is activated (preliminary study and study1). Further examination of regulatory swing between individual and collective regulatory orientations revealed group identification as a key variable in determining the locus of self-regulation (study2). While a consumer with a high level of group identification changes her locus of self-regulation from an individual to a collective (a regulatory shift) and evaluated messages and products framed consistent with their group orientation, a consumer with low level of group identification maintains her locus of self-regulation in her personal level of self (a regulatory preservation) and evaluated messages and products framed consistent with their personal regulatory focus.

• 유통과학연구
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• 제15권1호
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• pp.95-104
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• 2017

Purpose - This study focuses on long-term orientation that can lead long-term partnership. A long-term orientation needs a trust and relation commitment between company. So in this study, the researcher conducts a dependent variable as a justice recognition and brand asset value to research model to find out casual relationship among quoted factors. Research design, data, and methodology - The focus of this study was employees who work in a liquor distribution company to figure out factors that effect on long-term relationship in b2b transaction. The development of the research model is based on the literature of the preceding research analysis of justice recognition, brand asset value, trust, relation commitment and long-term orientation. This study have constructs that defined operationally by previous studies, research model design that to figuring casual relationships among the quoted factors. From 2016 Sep. 1st to Oct. 30th, a questionnaire survey was conducted targeting employees who work in liquor distribution company. 176 survey data were used for empirical analysis to prove the research hypotheses. Results - The main results of this study's empirical methodology were as follows. First, procedural justice and interactive justice has a positive significant effect on trust and relation commitment. Also brand image, brand awareness and perceived quality has a positive significant effect on trust and relation commitment. Second, trust and relation commitment has a positive significant effect on long-term orientation. Every hypothesis adopted as the researcher designed for empirical study. Conclusions - Based on empirical results, this study confirmed that trust and relation commitment has empirical relationship with long-term orientation. Based on the analysis, the researcher provided managerial implication by setting 2 way path for making long-term orientation with business company. First path is procedural justice to relation commitment. It contains that procedural justice recognised while business transaction execution, consideration intension and relation development will happen in b2b. Second path is perceived quality to trust. It contains that the perceived quality recognised while business transaction execution, trust will increase rapidly. So when a business company wants to make a partnership, they have to consider procedural justice and perceived quality to make a long-term relationship.

• Structural Engineering and Mechanics
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• 제24권4호
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• pp.479-491
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• 2006

This paper deals with optimal fibre orientations of symmetrically laminated fibre reinforced composite structures for maximising the fundamental frequency of small-amplitude. A set of fiber orientation angles in the layers are considered as design variable. The Modified Feasible Direction method is used in order to obtain the optimal designs. The effects of number of layers, boundary conditions, laminate thicknesses, aspect ratios and in-plane loads on the optimal designs are studied.