리더십기능이 체육학습에 미치는 효과

이상연,육조영,이성국 한국스포츠리서치 2001 한국 스포츠 리서치 Vol.12 No.4

The purpose of this study was to investigate the relationship between teacher's leadership and task environment recognized by learners and the effect of leadership of sub-group in the class upon organizational behavior. It meant to examine the instructional activity and learning activity from the standpoint of leadership theory. The subjects 139 pupils. 1. Teacher's leadership of task orentation decreased uncertainty of expectancy which conditioned task environment. 2. Teacher's leadership of human orientation and task orientation enhanced valence of learning activity and outcome. 3. Significant positive correlation between sub-group's leadership human orientation and learning effectiveness in favorable task environment for learners were found(p<0.1). 4. Significant positive correlation between sub-group sleadership of human orientation (p<.01) and task orientation (p<.05) and recognition of pleasure in sport were found in favorable task environment

미국의 구기지도에서 본 전술학습 모델의 검토

최경범,육조영,김진국 한국스포츠리서치 2003 한국 스포츠 리서치 Vol.14 No.6

The purpose of this study was to examine the model of tactical approach in games teaching bt analyzing the models of games education in the United States. As a result of this study, the following were clarified: 1) Although the traditional approach to games teaching focused on teaching skills, it didn't bring about any development on student's game performance. For this reason, tactical approach has come to attract a great deal of attention. 2) The model of tactical approach in games teaching guides students to learning both tactical awareness and skill execution which are necessary in a game setting. As a result, it makes it possible for students to develop their game performance. 3) The effectiveness of tactical approach leaves some indistinct points. To put it to practical use, it is necessary for us to add modifications to it's research design and test it continously.

A Study on the Characteristic Evaluation of An HTS Coil with respect to the Winding Methods

Jo, Hyun-Chul,Choi, Suk-Jin,Jang, Jae-Young,Hwang, Young-Jin,Lee, Chang-Young,Ahn, Min-Cheol,Yoon, Yong-Soo,Ko, Tae-Kuk The Korean Society of Superconductivity and Cryoge 2010 한국초전도저온공학회논문지 Vol.12 No.4

In superconducting magnet applications, winding methods of the superconducting magnet can be classified into a layer winding and a pancake winding. The superconducting magnet using high temperature superconductor (HTS) with rectangular shape is generally fabricated using the pancake winding method. On the other hand, low temperature superconducting (LTS) magnet may be wound by either a pancake winding or a layer winding. Compared with the layer winding, the pancake winding method has a merit of easy replacement of a damaged pancake module, but it also has a demerit of requirement of splicing between each double pancake modules. In this paper, we investigated characteristics of the layer and pancake winding methods using HTS. Six samples were wound out of BSCCO and Coated Conductors (CCs) by two winding methods and their characteristics were experimentally observed.

Evaluation on Electrical and Thermal Characteristics of Multi-Stacked HTS Coated Conductor With Various Stabilizers

Young Gun Park,Young Jin Hwang,Jae Young Jang,Hyung Jun Kim,Woo Seung Lee,Hyun Chul Jo,Ho Min Kim,Yong Soo Yoon,Tae Kuk Ko Institute of Electrical and Electronics Engineers 2014 IEEE transactions on applied superconductivity Vol.24 No.3

<P>Transporting large currents through High- Tc (HTS) current leads (CLs) inevitably involves using several HTS tapes in multi-stacked form to obtain a high current density. For safe operation of HTS CLs, the thermal stability of stacked HTS tapes should be considered. In this paper, we investigated electrical and thermal properties of multi-stacked HTS tapes using 2G coated conductor (CC). Three kinds of commercial CC with different specification of stabilizer were used for the experiment. Each stack sample was fabricated by soldering together CC tapes using In-Bi alloy. To verify the effects of a stabilizer on thermal stability for multi-stacked CC tapes, we performed an experiment of minimum quench energy measurements. In addition, transient electrical and thermal behavior were measured as a function of the external heat input energy. Each stack sample has a heater made of nickel-chromium (Ni-Cr) wire to make the external heat disturbance and a type-E thermocouple to measure the temperature. Based on the test results, electrical and thermal characteristics of multi-stacked CC tapes were evaluated.</P>

Cytocompatibility of silkworm cocoon layer extracts

Jo, You-Young,Kim, Sung-Kuk,Lee, Kwang-Gill,Bae, Sung Min,Kim, Jong-Ho,Shin, Bong-Seob,Jeon, Jong-Young,Kweon, HaeYong Korean Society of Sericultural Science 2016 International Journal of Industrial Entomology Vol.33 No.2

Recently silk polymer produced by Bombyx mori silkworm has been considered as biological macromolecules. Silk polymer was extracted in PBS solution at $37^{\circ}C$ for 72 h or $72^{\circ}C$ for 24 h. The effect of EtOH treatment on the cocoon extraction was also examined. The extraction yield of cocoon was less than 1 wt% regardless of extraction conditions. UV spectroscopy showed that the experimental extracts have absorption bands at 280 nm. There is no cytotoxicity effect on the mouse fibroblast L929 cell. The phenotype of L929 cell was not changed under the experimental conditions. The proliferation behavior of L929 cell was not affected by the addition of cocoon extract. Therefore, cocoon extract might be cytocompatible and can be used as promising biomaterials.

A Study on the Superconducting Synchronous Generator With the Fixed-Type Field Coil

Young Jin Hwang,Sukjin Choi,Jae Young Jang,Jiho Lee,Yong Soo Yoon,Ho Min Kim,Yoon Do Chung,Young-Sik Jo,Mi Hye Jang,Al-Ammar, E. A.,Tae Kuk Ko IEEE 2013 IEEE transactions on applied superconductivity Vol.23 No.3

<P>This paper presents a superconducting synchronous generator with a fixed-type field coil. The feasibility of the proposed design was verified by finite element method analysis. Unlike conventional superconducting synchronous generators, the proposed superconducting synchronous generator has two rotor cores with homopolar and circular superconducting field coils. This structure has advantages in the design and fabrication of excitation and cooling systems for superconducting field coils. In addition, the circular superconducting field coils are easier to manufacture with high tension as compared to the racetrack field coils or similarly shaped field coils for the conventional superconducting synchronous generators. This paper provides useful data for the design and fabrication of a superconducting synchronous generator.</P>

A Study on the Shape of Iron-Core for a Hybrid Electro-Magnetic Suspension System

Young Jin Hwang,Jae Young Jang,Sukjin Choi,Jin Bae Na,Hyun Chul Jo,Chang Young Lee,Tae Kuk Ko Institute of Electrical and Electronics Engineers 2012 IEEE transactions on applied superconductivity Vol.22 No.3

<P>This paper deals with the shape design of the iron-core of a hybrid EMS (electro-magnetic suspension) system. A proto-type hybrid EMS system was developed by Yonsei University in 2010 [1], [2]. It is the first step of study on fundamental technology for advanced railroad systems development. The hybrid EMS system requires cooling systems because it uses superconducting magnets [3], [4]. These cooling systems can influence costs to making and operating the hybrid EMS system. Therefore, a study to reduce the number of cooling systems needs to be carried out in order to economically commercialize the hybrid EMS system. In this paper, a method that reduces the number of cooling systems of the hybrid EMS system was proposed. To achieve this, a small-scale iron-core and coils assembly was fabricated. Using this system, characteristics of levitation force according to the structure of the iron-core was evaluated. Also, numerical analysis using the FEM tool in order to evaluate the levitation force and net force of a full-scale model was performed. This paper can be expected to suggest useful data for the design of a hybrid EMS system.</P>

Design, Fabrication, and Operating Test of the Prototype HTS Electromagnet for EMS-Based Maglev

Chang Young Lee,Jung Min Jo,Young Jae Han,Yoon Do Chung,Yong Soo Yoon,Sukjin Choi,Young Jin Hwang,Hyun Chul Jo,Jae Young Jang,Tae Kuk Ko Institute of Electrical and Electronics Engineers 2012 IEEE transactions on applied superconductivity Vol.22 No.3

<P>The prototype high-T<SUB>c</SUB> superconducting electromagnet (HTS-EM) for high-speed EMS Maglev was successfully demonstrated in EMS system up to the vehicle running speed of 500 km/h. The EM was designed to interface with the existing propulsion system used in the German high-speed Maglev. The rating levitation force of the EM was designed to correspond to the weight of the EM at a 20 mm levitation gap. Electromagnetic forces were simulated and compared with the test results in order to verify the design feasibility of the HTS-EM. Operating tests revealed that the HTS-EM was fully operational in zero-power control mode. However, the operating current of the HTS coil was affected by the control current when the guideway disturbance occurred. The design feasibility and operability of the HTS-EM was verified in the study.</P>

Conceptual Design of Superconducting Linear Synchronous Motor for 600-km/h Wheel-Type Railway

Chang Young Lee,Jin Ho Lee,Jung Min Jo,Chan Bae Park,Won Hee Rye,Yoon Do Chung,Young Jin Hwang,Tae Kuk Ko,Se-Young Oh,Ju Lee Institute of Electrical and Electronics Engineers 2014 IEEE transactions on applied superconductivity Vol.24 No.3

<P>This study introduces 600-km/h wheel-type railway concept propelled by linear synchronous motor (LSM) and deals with the conceptual design for LSM system. The LSM is designed to be of a coreless type, which uses high- T<SUB>c</SUB> superconducting electromagnet (SC-EM) as on-board field magnet. From tentative train parameters, we suggest a conceptual LSM model and its design parameters to achieve the train performances. As high- T<SUB>c</SUB> SC material, we use currently available YBCO tape in designing the SC coil. We produce three SC coil models and estimate tentative design values of each model. The feasibility study described herein provides informative design ranges of LSM for 600-km wheel-type railway.</P>

Conceptual Design for HTS Coil in Superconducting Electromagnet for Maglev

Chang Young Lee,Jung Min Jo,Bubyoung Kang,Young Jea Han,Duck Kweon Bae,Yong Soo Yoon,Yoon Do Chung,Sung Yul Chu,Young Jin Hwang,Tae Kuk Ko IEEE 2011 IEEE transactions on applied superconductivity Vol.21 No.3

<P>This study deals with a conceptual design for a high temperature superconductor (HTS) coil fabricated with YBCO wire in a prototype HTS-electromagnet (HTS-EM) model for the electromagnetic suspension (EMS)-based Maglev. Because the size of the HTS coil and the power it consumes during operation are very critical factors in designing the HTS-EM, we focused on the number of coil turns and the operating conditions needed to generate the required magneto-motive force (MMF) effectively. The winding geometry of the sample HTS coil with the largest Ic value was selected for use in this study. To determine the operating condition corresponding to the number of coil turns, we produced the operating profile for the load current of DC current source and the Ic value of HTS coil. From the profile, the optimal number of coil turns to minimize the operating power is determined to be in the range of 1200 to 1400 turns. And the HTS coil should be operated with the current of 37 to 43 A at the cooling temperature of 73 to 76 K.</P>