• Journal of the Korean School Mathematics Society
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• v.15 no.4
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• pp.643-671
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• 2012

The purpose of this study was to examine How the exploratory activities using Excel and GSP which are exploratory software, in learning analytic geometry affected on the underachievers' analytic geometry concept development process. The subjects of 5 students who received the 8th~9th grades from their examination of the last semester, participated in a total of 7 units based on Skemp's intelligent learning model. The results of the study showed that there were two important cases found to nearly achieve the category $R_2$. One was reflective thinking could happen through exploratory software in category $R_1$. The other was the exploratory activities which could have the same effectiveness as the relational understanding in category $I_2$, as Skemp mentioned that there is a room to be achieved in the elementary level when such relational understanding is achieved.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.9
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• pp.783-790
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• 2016

One of the main factors related to the deterioration of estimation accuracy in inertial measurement unit (IMU)-based orientation determination is the object's acceleration. This is because accelerometer signals under accelerated motion conditions cannot be longer reference vectors along the vertical axis. In order to deal with this issue, some orientation estimation algorithms adopt acceleration-compensating mechanisms. Such mechanisms include the simple switching techniques, mechanisms with adaptive estimation of acceleration, and acceleration model-based mechanisms. This paper compares these three mechanisms in terms of estimation accuracy. From experimental results under accelerated dynamic conditions, the following can be concluded. (1) A compensating mechanism is essential for an estimation algorithm to maintain accuracy under accelerated conditions. (2) Although the simple switching mechanism is effective to some extent, the other two mechanisms showed much higher accuracies, particularly when test conditions were severe.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.11
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• pp.1105-1111
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• 2015

The exhaust system is one of the major sources of vibrations, along with the suspension system and engine. When the exhaust system is connected directly to the engine, it transfers vibrations to the vehicle body through the body mounts. Therefore, in order to reduce the vibrations transmitted from the exhaust system, the vibration characteristics of the exhaust system should be predicted. Thus, the dynamic characteristics of the bellows, which form a key component of the exhaust system, must be modeled accurately. However, it is difficult to model the bellows because of the complicated geometry. Though the equivalent beam modeling technique has been applied in the design stage, it is not sufficiently accurate in the case of the bellows which have complicated geometries. In this paper, we present an improved technique for modeling the bellows in a vehicle. The accuracy of the modeling method is verified by comparison with the experimental results.

• Journal of Convergence for Information Technology
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• v.8 no.2
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• pp.61-65
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• 2018

Our experiment studied that grafted stem cells reduced behavioral deficiency in rodent animal models of clip compressive surgery inducing spinal cord infarction. Our research proved the effect of embryonic stem cells to the spinal cord infarction caused by compressing T9-10 with an aneurysm clip, focusing the application of grafted stem cells for reduction of infarction and regeneration of spinal cord nervous injury. Therefore, our research suggests manifest results that implantation of mouse embryonic stem cell could show behavioral improvement after severe spinal cord damage. Therefore, mouse embryonic stem cell (mESC) could be useful application for the method in neurological injury. Conclusively, stem cell implant therapy may enhance the effectiveness of stem cell implant for central nervous system injury.

• Journal of the Korea Society of Computer and Information
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• v.12 no.5
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• pp.235-241
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• 2007

AThis research is rather on the crime occurrence of target area's space scope than on the approach to the cause of specific area's crime occurrence from the perspective of the environmental criminology emphasizing the crime prevention. By observing the composition of crime distribution, it is intended to search the strategies of crime prevention actually corresponded to the crime problems. For this, after segmenting the city into six sectors, targeting city crimes in Gwangju metropolitan city, in 2004, the basic materials about the crime frequency are analyzed through dividing the types on the base of the present state of crime occurrence, the types of crime, the locations of crime occurrence, the purposes of buildings, the types of intruders, the forms of intrusions. As a result of research. it is suggested that the activation method of community police activities is necessary for the prevention of community crime prevention.

• Journal of the Korean Magnetics Society
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• v.15 no.1
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• pp.30-36
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• 2005

Recently, It has been reported that the spin sprayed ferite film shows better magnetic properties at high frequeny that the ferrite by co-firing over $800^{\circ}C$ . Besides, there is no limitation to select the substrate materials because it can be processed with relatively low temperature below $100^{\circ}C$. Therefore, we fabricated film inductor as a passive device for DC-DC converter by a use of spin sprayed embedded form was completed by via hole process of pad opening. Saturation magnetization of 0.61 T and real part of permeability of 110 were obtained in Ni-Zn ferrite. In addition, inductance of 1.52 ${\mu}H$, quality factor of 24.3 at 5 MHz were measured with spiral 16 turn inductor. The rated current of inductor was 863 mA.

• Journal of Magnetics
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• v.16 no.3
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• pp.211-215
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• 2011

The dynamic magnetostriction characteristics of an Fe-based nanocrystalline FeCuNbSiB alloy are investigated as a function of the dc bias magnetic field. The experimental results show that the piezomagnetic coefficient of FeCuNbSiB is about 2.1 times higher than that of Terfenol-D at the low dc magnetic bias $H_{dc}$ = 46 Oe. Moreover, FeCuNbSiB has a large resonant dynamic strain coefficient at quite low Hdc due to a high mechanical quality factor, which is 3-5 times greater than that of Terfenol-D at the same low $H_{dc}$. Based on such magnetostriction characteristics, we fabricate a new type of transducer with FeCuNbSiB/PZT-8/FeCuNbSiB. Its maximum resonant magnetoelectric voltage coefficient achieves ~10 V/Oe. The ME output power reaches 331.8 ${\mu}W$ at an optimum load resistance of 7 $k{\Omega}$ under 0.4 Oe ac magnetic field, which is 50 times higher than that of the previous ultrasonic-horn-substrate composite transducer and it decreases the size by nearly 86%. The performance indicate that the FeCuNbSiB/PZT-8/FeCuNbSiB transducer is promising for application in highly efficient magnetoelectric energy conversion.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.293-296
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• 2014

본 논문에서는 예측사격과 난전을 통하여 논스톱 액션을 추구하는 게임서버를 구현한다. 게임 서버를 구현하기 위하여 상용 엔진인 ProudNet과 Unity3D를 사용했으며, ProudNet은 강력한 상용 네트워크 엔진이며 Unity3D와 쉽게 데이터 통신을 할 수 있게 해준다. 클래스 다이어그램과 구성도를 통하여 예측 사격과 난전을 통하여 논스톱 액션을 추구하는 게임 서버 개발 방법을 제안한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.311-314
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• 2014

본 논문은 Unity3D와 게임서버엔진인 ProudNet을 이용해 네트워크 게임을 개발한 방법을 설명하였다. ProudNet 서버를 Unity3D 클라이언트와 연결하여 네트워크 기능을 구현할 때 ProudNet의 어떤 기능을 쓰며 또 서버가 보낸 메시지를 클라이언트가 어떠한 방식을 이용하여 메시지를 처리하게 구현하였는지를 설명하였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.481-482
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• 2014

본 논문에서는 동양 신화적 요소들을 게임 기획에 접목 시키는 방법을 제안하고 구현한다. 게임에 접목 시킨 동양 신화적 요소에는 사방신을 채용했으며, 각 사신이 갖는 동물적 형상과 대표 색상으로 나누어 기획에 접목시켜 게임을 디자인하였다.