• Transactions of the Korean Society of Mechanical Engineers A
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• 제38권6호
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• pp.593-600
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• 2014

This paper proposes a torque assist strategy for operating a hybrid agricultural tractor in the field. In general, different field operations such as baling and rotary tillage require different patterns and amounts of torque. Thus, a large agricultural tractor is used to improve the farming efficiency. Therefore, this research has the goal of developing a hybrid tractor that uses a small electric motor to provide additional torque for specific field operations. To achieve this objective, a rule-based torque assist strategy is proposed and validated for a simulation model in the Autonomie framework, which is a commercial simulation tool. Finally, the work efficiencies and fuel consumptions of a conventional tractor and the hybrid tractor with the proposed torque assist strategy are compared using simulations.

• The Journal of Korean Association of Computer Education
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• 제9권5호
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• pp.1-11
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• 2006

This study aims at identifying what effect ARCS model based instruction and cognitive style have on learning motivation and achievement in computer education. In order to accomplish this goal. 70 high school students were randomly allocated into the experiment group and the control group. And each group was divided into field-independent group and field-dependent group. The results were as follows. First, post test of learning motivation among four groups showed that mean differences were statistical significant. Especially 'ARCS model based instruction-field independent group got higher score than 'traditional instruction field dependent' group. Second, post test of learning achievement showed no significant mean difference among four group. The result of the pre and post test difference analysis showed that the change scores of means were significantly different.

• Journal of Korean Home Economics Education Association
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• 제4권1호
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• pp.17-30
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• 1992

This study aims at finding a new home economics education with will include male students as its teaching objects, and then providing home economics teachers with useful materials. For this purpose I examined the curriculum of foreign home economics education and analized male and female secondary school students’and their recognition and demand to the home economics education. Investigated persons are male and female students of the first year of 3 sendary schools and their parents in Seoul, who are choosen by menas of random sampling. The items analysis of questionnaires was performed by means of random sampling. The items analysis of questionnaires was performed by means of SPSS. The results are marked with percentage and the significance level is verified by t and X(sup)2 analysis methods. The results obtained from the items analysis are as follows：1 According to the increasing number of female employees, the mechanization of household affaires, and so on, male students and male parents got to realize the necessity of home economics education and the importance of men and women’s cooperation to lead a family life. 2. It is shown that the goal of home economics deucation must be to form a right value point of the family life and family. This fact implies that many examinees regards the home economics education in the moral point of view. 3. In the necessity degree according to each field of the home economics education curriculum, moral and social aspects such as family relationship, home management & economics, human development and bringing up are regarded more important than household affairs and the related technical aspects. 4. In the difference between groups to the necessity degree according to each field of the home economics education curriculum, there are few differences between male and female parents, but there are many differences between male and female students. Male students regards the contents of the home economics education curriculum less necessary than female students. Especially in the field of clothing, residence, human development and bringing up, the difference between male and female students is obvious. 5. The necessity degree of the contents related to environmental pollution, saving of energy and resources, utilizing of computer, etc. is very high.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• 제15권2호
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• pp.237-244
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• 1997

The goal of this research is to evaluate methodology that uses satellite data for the analysis of flood and drought damaged area. Land cover classification were performed using satellite data that were acquired at disaster periods and comparatively normal times. Damaged area was extracted by use of overlay analysis in land cover change and compared with the field survey results. The results show analysis of flood damaged area could be carried out with single scene acquired at adequate day, and are corresponded with field survey data very well. And also, some areas that had been missed in field survey were found. The suggested method proved to be more accurate and effective way for mapping inundated areas of floodplains than field survey that would be held a few month later. The results on the analysis of drought damaged area show that drained water could be detected just only in small area, and crop damaged area could not be verified in objective validity. Drought analysis by remote sensing was proved not to be adequate for practical use in this study.

• Smart Structures and Systems
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• 제23권5호
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• pp.449-466
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• 2019

Cable-stayed bridges are attractive due to their beauty, reducing material consumption, less harm to the environment and so on, in comparison with other kinds of bridges. As a massive structure with long period and low damping (0.3 to 2%) under many dynamic loads, these bridges are susceptible to fatigue, serviceability disorder, damage or even collapse. Tuned Mass Damper (TMD) is a suitable controlling system to reduce the vibrations and prevent the threats in such bridges. In this paper, Multi Tuned Mass Damper (MTMD) system is added to the Ahvaz cable stayed Bridge in Iran, to reduce its seismic vibrations. First, the bridge is modeled in SAP2000 followed with result verification. Dead and live loads and the moving loads have been assigned to the bridge. Then the finite element model is developed in OpenSees, with the goal of running a nonlinear time-history analysis. Three far-field and three near-field earthquake records are imposed to the model after scaling to the PGA of 0.25 g, 0.4 g, 0.55 g and 0.7 g. Two MTMD systems, passive and active, with the number of TMDs from 1 to 8, are placed in specific points of the main span of bridge, adding a total mass ratio of 1 to 10% to the bridge. The parameters of the TMDs are optimized using Genetic Algorithm (GA). Also, the optimum force for active control is achieved by Fuzzy Logic Control (FLC). The results showed that the maximum displacement of the center of the bridge main span reduced 33% and 48% respectively by adding passive and active MTMD systems. The RMS of displacement reduced 37% and 47%, the velocity 36% and 42% and also the base shear in pylons, 27% and 47%, respectively by adding passive and active systems, in the best cases.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.375-380
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• 2007

This paper presents optimal design of controllable magnetorheological (MR) shock absorbers for passenger vehicle. In order to achieve this goal, two MR shock absorbers (one for front suspension; one for rear suspension) are designed using an optimization methodology based on design specifications for a commercial passenger vehicle. The optimization problem is to find optimal geometric dimensions of the magnetic circuits for the front and rear MR shock absorbers in order to improve the performance such as damping force as an objective function. The first order optimization method using commercial finite element method (FEM) software is adopted for the constrained optimization algorithm. After manufacturing the MR shock absorbers with optimally obtained design parameters, their field-dependent damping forces are experimentally evaluated and compared with those of conventional shock absorbers. In addition, vibration control performances of the full-vehicle installed with the proposed MR shock absorbers are evaluated under bump road condition and obstacle avoidance test.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제59권12호
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• pp.2256-2261
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• 2010

A corona discharge system with needle point or wire type corona electrode has been well used as an ionic wind blower. The corona discharge system with a needle point electrode produces ions at lower applied voltage effectively. However, the corona discharge on the needle point electrode transits to the arc discharge at lower voltage, and it is hard to obtain the elevated electric field in the discharge airgap for enhancing the ion migration velocity due to the weak Coulomb force. A cylindrical corona electrode with sharp round tip is reported as one of effective corona electrode, because of its higher breakdown voltage than that of the needle electrode. A basic study, for the effectiveness of cylindrical electrode shape on the ionic wind generation, has been investigated to obtain an maximum wind velocity, which however is the final goal for the real field application of this kind ionic wind blower. In this paper, a parametric study for maximizing the ionic wind velocity utilizing the cylindrical corona electrode and a maximum ion wind velocity of 4.1 m/s were obtained, which is about 1.8 times higher than that of 2.3m/s obtained with the needle corona electrode from the velocity profile.

• The Transactions of the Korean Institute of Electrical Engineers P
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• 제64권4호
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• pp.337-342
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• 2015

The company of 4 core materials that are needed for photovoltaic generation is located in area around this university in Gunsan, Saemangeum. And also, it was almost completed the value chain about the production of Polysilicon, Ingot, Wafer, modules and the design, construction of generation system. The industry-academy-government has understood that because of the relative companies' production and investment, it leads to a supply and demand of manpower and thus will have field centered manpower education. This program will help the problem of lack of manpower in relative companies by establishing competitive major agreement like vocational education system. Also, the university and the participating company in joint have pushed ahead field business education to make the least of industrial-education's mismatch, the training of professional manpower connected with related industries to make the universities chemical characteristics, companies securing excellent manpower and contributed to the revitalization of the regional economy. In this paper, are aware that photovoltaic industry is a future strategic industry for the country, so we will train the immediately site adapting manpower for the area of photovoltaic material and system as our goal. This is shown results of education operation for 4 years.

• Fashion & Textile Research Journal
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• 제16권1호
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• pp.160-166
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• 2014

Patent and utility indicate international competitiveness in the knowledge-based society of the $21^{st}$century where both the quantity and quality of the nation's scientific intelligence and innovative technology represent key criteria to evaluate its strength. Thus, discerning the trends of patents is inevitable for further development. This research is centered on apprehending the technological current of the functional clothing of Korea, through an analysis of patents and utility models. The number of patent applications in Korea was low until the mid-1990s. However, it began to grow rapidly in the 2000s and the number of patents surpassed the number of utility starting in 2006. The technological level of invention in this field has been turned into a higher level. The IPC code with the strongest application was the field related to temperature controllable clothing (A41D 13/005), followed by surgeon or patient apparel related fields (A41D 13/12), and reflective or luminous safety devices (A41D 13/01).The main technological idea was to give functionality that could protect the human body from various hazards and represents the goal of various applied techniques. About 66% of domestic patent applications belong to individuals; however, the proportion of corporate or institutional applications(including universities) remains poor. Consequently, more systematic and long-term support for research on patents is required.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• 제22권12호
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• pp.1220-1226
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• 2012

This paper proposes a novel type of tactile device utilizing magnetorheological(MR) fluid which can be applicable for haptic master of minimally invasive surgery(MIS) robotic system. The salient feature of the controllability of rheological properties by the intensity of the magnetic field(or current) makes this potential candidate of the tactile device. As a first step, an appropriate size of the tactile device is designed and manufactured via magnetic analysis. Secondly, in order to determine proper input magnetic field the repulsive forces of the real body parts such as hand and neck are measured. Subsequently, the repulsive forces of the tactile device are measured by dividing 5 areas. The final step of this work is to obtain desired force in real implementation. Thus, in order to demonstrate this goal a neuro-fuzzy logic is applied to get the desired repulsive force and the error between the desired and actual force is evaluated.