• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.7
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• pp.1074-1080
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• 2015

In the last decades, the increasing interest in unmanned aerial vehicle(UAV) for military, surveillance, and rescue applications made necessary the development of flight control theory and body structure more and more efficient and fast. In this paper, we describe the design and performance of a prototype hexarotor UAV platform featuring an inertial measurement unit(IMU) based autonomous-flying for use in bluetooth communication environments. The proposed system comprises the construction of the test hexarotor platform, the implementation of an IMU, dynamic modeling and simulation in the hexarotor helicopter. Furthermore, the hexarotor helicopter with implemented IMU is connected with a micro controller unit(ARM-cortex) board. The P-PD control algorithm was used to control the hexarotor. We used the Matlab software to help us to tune the P-PD control parameters for quick response and minimizing the fluctuation. The control simulation and experiment on the real system are implemented in the test platform, evaluated and compared against each other.

• Journal of electromagnetic engineering and science
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• v.8 no.1
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• pp.1-5
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• 2008

In this paper, a biconical type antenna is proposed for EMI test site validation above 1 GHz. To achieve broadband and omni-directional radiation patterns required by international standard(CISPR), the proposed antenna consists of general bicones with cylindrical loads and adopts side feeding method to minimize the influence on H-plane pattern due to feeding cable, balun, and connector. The radiation patterns of the fabricated antenna are measured and the results are compared with CISPR criteria and commercial antenna in our interest frequencies. Although the proposed antenna has a few problems in frequency range of 1 GHz to 2 GHz, it has relatively better performance than commercial antenna.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.3
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• pp.287-293
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• 2015

With the rise in oil prices and ongoing concerns about environment, there is an increased amount of interest in automated manual transmission (AMT) vehicles. Torque control in an AMT vehicle is attained by controlling the displacement of the dry-type clutch's actuator. To provide good ride comfort akin to that of an automatic transmission vehicle, the clutch control is vital to an AMT vehicle. In this study, a method of obtaining the clutch torque from a dynamometer test is devised. This method is able to identify the relationship between the displacement of the clutch actuator and the clutch torque. A simulator for estimating the performance of an AMT vehicle is developed using MATLAB Simulink. The results obtained from both the vehicle and simulation exhibit a similar trend.

• Ecology and Resilient Infrastructure
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• v.3 no.2
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• pp.92-99
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• 2016

This study developed a verification and certification method of technologies of green infrastructure (GI) and low impact development (LID) that gained interest recently. The outdoor testbed used in this study consisted of a building type, a road type, a parking lot type, a rain garden type and a bioretention type. Indoor test facilities were ready for testing using hydrology efficient analysis, pavement and soil analysis and water environment analysis. The development of outdoor and indoor test facilities were used to certify the efficiency of GI & LID technologies, and this was expected to contribute to the activation of the related projects by providing reliable data for the application of GI & LID techniques.

• Journal of the Korean Society for Railway
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• v.20 no.4
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• pp.500-511
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• 2017

Recently, as earthquakes have occurred in Gyeongju, interest in the stability of structures against vibration from earthquakes has increased. In Korea, the capacity of load resistance is mainly considered in the design of anchors. However, the vibration resistance characteristics of anchors have not been fully elucidated. The traditional type of anchor, which is a frictional resistance anchor, is often reported to fail due to vibration in construction procedures, such as blasting. The expansion type of anchor, on the other hand, could have more resistance to vibration but its capability of demonstrating vibratory resistance has to be investigated. In order to verify the vibratory resistance characteristics of expansion anchors against blasting and earthquake vibration, field tests and numerical analyses for seismic wave were performed. Field blasting test results show that the expansion anchor has better capability against vibratory load than does the frictional type anchor. Numerical analysis to earthquake also show that the expansion type anchor provides more resistance than does the frictional type anchor.

• Journal of Science Education
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• v.33 no.2
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• pp.248-257
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• 2009

The purpose of this study is to investigate the learning achievement of students who has taken the play-based and activity-oriented programs in the class. These new science class programs and instrument to measure student learning achievement were developed for the "Constellation Favorite" lesson of 4th grade students and Those are verified by science education experts, teachers in serve. The subjects of this study consist of 121 students in four classes who were selected on the basis of midterm examination result before teaching treatment. They were divided into two categories with two classes per each category, one class for experimental group and the other class for control group. The experimental groups were given five classes including five play-based class programs. The control groups were given five conventional instruction-type classes. The students were given questionnaires to test their interest ratings. The results show about 17% increase of their learning achievement with (p<0.005) by independent sample T-test method and 40% increase of interest rating in play-based class sample compared to normal class sample. In conclusion, the play-based science class program is found to enhance the students' learning achievement and to interest the students more effectively.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.10
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• pp.1611-1621
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• 2009

This study examines the significant relations in clothing behavior according to perceptual body image and appearance management behavior. The sampling method was a convenient sampling of 190 male and 160 female students in Daejeon. The survey was conducted from June to July 2008. The instruments consisted of perceptual body image (Silhouette Task), appearance management behavior (need for plastic surgery and appearance management in ordinary times) and clothing behavior (interest in clothing and fashion, along with conformity and exhibition). The data were analyzed using the frequency analysis, $Cronbach'{\alpha}$, factor analysis, t-test, and variance analysis. The subjects with normal body size perceptions had a strong need for plastic surgery, revealed more appearance management behavior, and had a high interest in clothing. The subjects who were dissatisfied with body apperance showed high conformity to clothing. The subjects who dissatisfied to their too fat body had high needs for plastic surgery and the subjects dissatisfied with a too thin body type did less appearance management in ordinary times. The subjects who had a high need for plastic surgery performed more appearance management, had a high interest in clothing and fashion, showed a high conformity to clothing, and exhibited a high exhibition of clothing. The subjects who had more appearance management in ordinary times had a high interest in clothing and fashion and showed a high conformity and exhibition of clothing.

• Journal of the Optical Society of Korea
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• v.19 no.5
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• pp.467-476
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• 2015

Finger vein recognition, which is a promising biometric method for identity authentication, has attracted significant attention. Considerable research focuses on transmission-type finger vein recognition, but this type of authentication is difficult to implement in mobile consumer devices. Therefore, reflection-type finger vein recognition should be developed. In the reflection-type vein recognition field, the majority of researchers concentrate on palm and palm dorsa patterns, and only a few pay attention to reflection-type finger vein recognition. Thus, this paper presents reflection-type finger vein recognition for biometric application that can be integrated into mobile consumer devices. A database is built to test the proposed algorithm. A novel method of region-of-interest localization for a finger vein image is introduced, and a scheme for effectively extracting finger vein features is proposed. Experiments demonstrate the feasibility of reflection-type finger vein recognition.

• Journal of Korean Dental Hygiene Science
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• v.5 no.2
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• pp.85-96
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• 2022

Background: This study was aimed at determining the relationship of the Dominance, Influence, Steadiness, and Conscientiousness (DISC) personality type with the major satisfactions and job preferences of dental hygiene and technician students. Methods: We enrolled 264 dental hygiene and technician students from a junior college in Chungcheong-do. A questionnaire survey was conducted to determine the DISC behavior type, major satisfaction level, and job preference of the participants. Statistical analyses were performed with the independent-samples t-test, one-way analysis of variance, and multiple regression. Results: Dental technician students had higher major satisfaction (p< .001) and preferred jobs with potential for growth (p= .020) or matching their vocation and interests (p= .013) compared to dental hygiene students. Factors influencing major satisfaction were grade (β= .160, p= .008) and a social personality type (β= .146, p= .070). Factors influencing preference for jobs with high growth potential were the personality type (β= .236, p= .001), grades (β= .157, p= .002), and major satisfaction (β= .429, p< .001). The conscientiousness personality type was conducive to preferencefor jobs with high growth potential. The steadiness personality type was conducive to preference for jobs aligned with vocation and interest (β= .249, p= .004). The conscientiousness personality type (β= .137, p= .041) and high major satisfaction (β= .193, p= .003) were conducive to preference for jobs with a satisfactory working environment. Conclusion: The results of this study could serve as a basis for customized career counseling and education programs according to personality types.

• Journal of the Korean Society of Clothing and Textiles
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• v.14 no.2
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• pp.137-151
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• 1990

Changes in male roles and lifestyle in recent years have brought about an increased interest in appearance and apparel for men. The purpose of this study was to classify consumers into categories based on style of men's business suits and describe the resulting categories in terms of lifestyle, clothing behavior, appearance and demographic variables. Data were obtained from questionnaires completed by 513 consumers 20-69 years of age living in Seoul, and analyzed by factor analysis, multiple discriminant analysis, one-way ANOVA, CROSSTAB, and S-N-K test. Resulting categories of consumers were labeled as formal, semi-formal and casual. Descrip-tive profiles of the three categories were developed differently by 2 lifestyle factors (positive opinion leadership, social participation), 1 clothing factor (conformity), 2 appearance factors (conservative, energetic), and 2 demographic variables (age, marital status). The semi-formal type of man is significantly different from the two other types in his group activities that require social participation and opinion leadership. The formal type is significantly different from the two other types in his conformity in clothing and conservative appearance. The majority of formal and semi-formal types of men were 25-39 years of age and married, while the casual type was younger and unmarried.