• International Journal of Advanced Culture Technology
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• 제6권4호
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• pp.131-142
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• 2018

This research examines the impact of teachers' self-evaluation on their classroom interactions with students. Changes in class behavior were analyzed by following two experienced middle school teachers for one semester of self-evaluation, comparing their classes at the beginning and end of the semester. A qualitative research method was adopted to take, a deeper look at the effect of changes in the teachers' in class actions. Both of the teachers reported positive effects of implementing self-evaluation on their teaching pedagogy, focusing specifically on their interactions with students when asking question and giving feedback. By the end of semester, they were asking broader questions that encouraged their students to engage in deeper thought and, when giving feedback, the class atmosphere was much brighter with better communication due to the positive reinforcement provided. This research supports research into ways to enhance teachers' expertise and improve their teaching via self-evaluation, centering on teachers' actions in the classroom.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1496-1501
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• 2004

Recently, many Korean firms have been adopting 360$^{circ}$ Degree Feedback System with the environmental change in business world. The reason is that the traditional top-down way of personnel evaluation pattern can not but has many limits in this turbulent changing environment. The main purpose of this article is to depict some aspects of 360$^{circ}$ Degree Feedback System including its current status quo, its positive and negative side, and the effective way of its improvement focusing on A firm.

• 게임&엔터테인먼트 논문지
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• 제1권1호
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• pp.15-22
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• 2005

게임개발에 적용되는 여러 가지 첨단 기술 중에서 가상현실 분야는 게임월드에서 일어나는 다양한 게임 진행상황을 사실적으로 전달하는 효과적인 기술로 주목 받고 있다. 본 논문에서는 가상현실 구현 요소 기술 중에서 운동감재현 기술과 Force-Feedback 기술을 근간으로 하는 게 임 전용 인터페이스, 즉 게임 전용 컨트롤러에 대한 기술분석과 플랫폼별 게임컨트롤러의 장단점을 분석하였다. 이를 토대로 Force-Feedback 기술적용이 가장 미흡한 PC용 게임분야에 보다 범용적이고 효과적으로 그 기능을 사용자에게 전달할 수 있는 방법을 모색하였으며, 진동을 이용하여 이에 만족시킬 수 있는 Force-Feedback Seat를 개발하였다.

• Journal of applied mathematics & informatics
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• 제26권1_2호
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• pp.29-44
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• 2008

By employing the continuation theorem of coincidence degree theory, we derive a sufficient condition for the existence and attractricity of a positive periodic solution for a generalized predator-prey model with diffussion feedback controls.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권2호
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• pp.216-222
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• 2017

The most prominent challenge for MOSFET scaling is to reduce power consumption; however, the supply voltage ($V_{DD}$) cannot be scaled down because of the carrier injection mechanism. To overcome this limit, a new type of field-effect transistor using positive feedback as a carrier injection mechanism (FBFET) has been proposed. In this study we have investigated the electrical characteristics of a $Si_{1-x}Ge_x$ FBFET with one gate and one-sided $Si_3N_4$ spacer using TCAD simulations. To reduce the drain bias dependency, $Si_{1-x}Ge_x$ was introduced as a low-bandgap material, and the minimum subthreshold swing was obtained as 2.87 mV/dec. This result suggests that a $Si_{1-x}Ge_x$ FBFET is a promising candidate for future low-power devices.

• 한국시스템다이내믹스연구
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• 제16권2호
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• pp.5-32
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• 2015

Last year, a disastrous accident happened on the sea. Car ferry Se-wol which was on its way from In-cheon to Je-ju sank in the middle of the western sea. 304 passengers were drowned at the sea in the accident. There were no passengers who were waiting on board ship rescued in the accident. This study is to review the pattern of decision making in the middle of saving a life, right after Se-wol was about to sink. The starting point of this study is decision making on the rescue by rescue corps with no expert knowledge at the initial stage. When it comes to saving victims, there was no expert on rescue on the sea. Failure in rescue at Se-wol disaster lets us find a vicious circle of positive feedback loop. Experts with no experience act like well-qualified persons. Unqualified persons(leaders) have no expertise. Those who pretend to be expert occupy the important post in the hierarchy. It means we could not accumulate expertise of know-how in rescue division. That's why a vicious circle of positive feedback is formed in areas of disasters. It is necessary to train experts in Government Organizations to weaken the vicious circle of positive feedback.

• 한국소음진동공학회논문집
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• 제14권3호
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• pp.208-213
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• 2004

This paper is concerned with the theoretical estimation of the single-input single-output(SISO) positive position feedback(PPF) controller and the derivation of the stability conditions for the multi-input multi-output (MIMO) PPF controller. Although the stability condition for the SISO PPF controller was derived in the earlier works, the question regarding the performance estimation of the SISO PPF controller has never been studied theoretically. Hence, the SISO PPF controller for the single degree-of-freedom system was first investigated and then control parameters including gain, the filter frequency, and the damping factor of the PPF controller were analyzed in detail thus providing the design methodology for the SISO PPF controller. In the case of real structure. there are infinite number of natural modes so that some modes are to be controlled by a limited number of actuator and sensor. Based on the theoretical results on the SISO PPF controller, the stability condition for the multi-input multi-output PPF controller was derived when only the few number of modes are to be controlled. The control spillover problem is also discussed in detail.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.250-254
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• 2007

As photovoltaic(PV) power generation systems become more common, it will be necessary to investigate islanding detection method for PV systems. Islanding of PV systems can cause a variety of problems and must be prevented. However, if the real and reactive powers of the load and PV system are closely matched, islanding detection by passive methods becomes difficult. Also, most active methods lose effectiveness when there are several PV systems feeding the same island. The active frequency drift positive feedback method(AFDPF) enables islanding detection by forcing the frequency of the voltage in the island to drift up or down. In this paper the research for the minimum value of chopping fraction gain applied digital phase-locked-loop (DPLL) to AFDPF considering output power quality and islanding prevention performance are performed by simulation and experiment according to IEEE Std 929-2000 islanding test.

• JSTS:Journal of Semiconductor Technology and Science
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• 제8권4호
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• pp.289-294
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• 2008

A 77 GHz 3-stage low noise amplifier (LNA) employing one common source and two cascode stages is developed using $0.13{\mu}m$ CMOS process. To compensate for the low gain which is caused by lossy silicon substrate and parasitic element of CMOS transistor, positive feedback technique using parasitic inductance of bypass capacitor is adopted to cascode stages. The developed LNA shows gain of 7.2 dB, Sl1 of -16.5 dB and S22 of -19.8 dB at 77 GHz. The return loss bandwidth of LNA is 71.6 to 80.9 GHz (12%). The die size is as small as $0.7mm\times0.8mm$ by using bias line as inter-stage matching networks. This LNA shows possibility of 77 GHz automotive RADAR system using $0.13{\mu}m$ CMOS process, which has advantage in cost compared to sub-100 nm CMOS process.

• 수산해양교육연구
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• 제23권1호
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• pp.130-139
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• 2011

The purpose of this study is to examine the effects of soccer club teachers' leadership behavior types on elementary and middle school students' psychological factors. The subjects in this study were 561 students who consisted of 245 elementary and 316 middle school students - from 15 elementary and 17 middle school teams. All the teams are registered in the Busan Sports Club. The findings of the study were as follows : Autocratic behavior must be used rarely because it causes great anxiety. Positive feedback behavior is needed to improve students' confidence. Positive feedback behavior and training and instruction behavior are needed for achievement motivation. For this reason, teachers must coach students through positive feedback behavior, training and instruction behavior and social support behavior to build confidence, achievement motivation and cohesion. Since confidence, achievement motivation and cohesion depend on careers, coaching student's early helps students perform better.