• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.10
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• pp.911-920
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• 2016

For the pitch and yaw axis attitude control of launch vehicle, thrust vector control which changes the direction of thrust during the engine combustion is commonly used. Hydraulic actuation system has been used generally as a drive system for the thrust vector control of launch vehicles with the advantage of power-to-weight ratio. Nowadays, due to the developments of highly efficient electric motor and motor control techniques, it has done a lot of research to adopt electro-mechanical actuator for thrust vector control of small-sized launch vehicles. This paper describes system design and test results of the prototype of direct drive electro-mechanical actuation system which is being developed for the thrust vector control of $3^{rd}$ stage engine of KSVL-II.

• Nuclear Engineering and Technology
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• v.27 no.6
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• pp.911-917
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• 1995

로듐 자기 기전력형 중성자 계측기는 단위 중성자당 발생되는 전류 신호가 매우 커 계측성이 우수하나 연소율이 빨라 자주 교체해야 하므로 재장전 기간 연장 및 새로운 로듐계측기 구입 등의 문제점이 있다. 75% 연소에 해당하는 제5핵 연료 주기 기간 동안 영광 3, 4호기와 같은 C-E 원자로에 사용되고 있는 로듐 자기 기전력형 중성자 계측기의 연소 거동이 C-E에 의해서 연구되었다. 약 제3핵연료주기까지 분석한C-E의 초창기 연구에서는 중성자 방사화율 개념에 근거하여 약 66%연소시점까지 로듐계측기 연소특성곡선은 선형적임이 밝혀진 바 있다. ［l, 2］ 그 후 C-E의 연구에 의하면 약 75% 연소에 해당하는 제5핵연료 주기까지도 로듐계측기 연소 특성 곡선은 선형적임이 밝혀졌다. 그 결과로 C-E형 원자력발전소에서 사용되는 로듐 노내계측기의 수명을 약 60%연소에서 66%연소 시점까지 연장시킬 수 있게 되었다. ［3］이 정도의 계측기 수명 연장은 약 반년의 원자로 운전 기간에 해당되며 차기 핵연료주기에서 많은 로듐 노내계측기를 계속 사용할 수 있게 한다. 특히 영광 3, 4호기가 12개월 핵연료 주기에서 18개월 핵연료 주기로 재장전 전략을 바꿀 경우 로듐 노내계측기의 수명 이 연장되지 않으면 계측기 교체가 빈번해 질 것으로 사료되어 로듐 수명 연장과 관련된 기술 특히 C-E 및 B&W의 로듐 노내계측기 연소도 특성곡선 불확실도 평가 및 출력 측정 계통 오차 분석 기술을 소개하고자 한다. 영광3, 4호기에서 사용중인 로듐 노내계측기 수명을 현재 연소도 기준 66%내로 한정하고 있는데 C-E 및 B&W의 로듐 노내계측기연소 특성에 관한 연구 내용을 분석한 결과 노내계측기 수명을 연소도가 66%를 초과하는 계측기가 있어도 전체적으로 불확실도가 안전한계를 넘지 않으면 노내상주가 가능한 것으로 평가되었다.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.909-911
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• 2002

Rises of current level at power applications, such as transformer, motor, power cable need for using stacked HTS tapes. In this paper, we measured rises of temperature and tap voltage in 4-stacked HTS tapes under over-current condition. We measured 4-stacked HTS tapes properties under over-current condition with a little temperature rise as well as a large temperature rise. Rises of temperature and tap voltage are measured by using E-type thermocouples and voltage taps, respectively. According to the results of measurement, rises of tap voltage under over-current condition with a large temperature rises depends on rises of temperature.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.608-611
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• 2005

The existing wired emergency call such as 119, 112 have its own location information to serving immediate rescue service. For the case of wireless emergency call by mobile phone, the location information should be provided by wireless network. This paper describes the network architecture and protocol for mobile emergency service referring TIAlEWJ-SID-036-A with reviews about technical issues, legacy factors and related researches. The mobile emergency service is divided into mobile emergency rescue service and mobile emergency alert service. The network reference model for mobile emergency rescue service is released in KOREA. In this paper, the interfaces between elements of the network reference model, and service scenarios, message flows are defined. Supplement to mobile emergency rescue service, the network reference model, interfaces and message flows for mobile emergency alert service are developed. The protocol is described by DID, and the proposed works are on processing for domestic standard of TTA.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.114.4-114
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• 2001

Recently, variety services are more and more developed due to supply of PDA, cellular phone, and etc. Also, a services based on location information are very helpful in traffic, shopping, and emergency. Thus the user position is positively necessary for these services. One of the latest applications in GPS is the E911 call service for wireless phones. In this case, current GPS Navigation accuracy meets the FCC requirements but the hardware size and power consumption of GPS is issued for implementation. And, some case of applications need to snapshot location solution with fast TTFF(Time-To-Fist-Fix) than continuous location solution. The software GPS receiver could be the solution ...

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.908-911
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• 2002

Over the past 30 years, many efficient 2D video coding techniques have been presented and developed from many research centers for commercialization. However, direct application of these monocular compression schemes is not optimal for stereo video coding. In this paper, we present a new technique for coding stereo video sequences based on Discrete Wavelet Transform (DWT). The proposed technique exploits Zerotree Entropy Coding (ZTE) that makes use of the wavelet block concept to achieve low bit rate stereo video coding. The one of two image streams, called main stream, is independently coded by modified MPEG-4 encoder and the other stream, called auxiliary stream, is coded by predicting from its corresponding image, its previous image or its follow image.

• Electrical & Electronic Materials
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• v.9 no.9
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• pp.911-917
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• 1996

Platinum thin films were deposited on Si-wafer by DC rnagnetron sputtering for RTD (resistance thermometer devices). We investigated the physical and electrical characteristics of these films under various conditions, the input power, working vacuum, temperature of substrate and also after annealing these films. The deposition rate was increased with increasing the input power but decreased with increasing Ar gas pressure. The resistivity and sheet resistivity were decreased with increasing the temperature of substrate and the annealing time at 1000.deg. C. At substrate temperature of >$300^{\circ}C$, input power of 7 w/cm$^{2}$, working vacuum of 5 mtorr and annealing conditions of 1000.deg. C and 240 min, we obtained 10.65.mu..ohm..cm, resistivity of Pt thin films and 3800-3900 ppm/.deg. C, TCR(temperature coefficient of resistance). These values are close to the bulk value. These results indicate that the Pt thin films deposited by DC magnetron sputtering have potentiality for the development of Pt RTD temperature sensor.

• Journal of the Korean Mathematical Society
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• v.59 no.5
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• pp.911-926
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• 2022

Let u be a function on a locally finite graph G = (V, E) and Ω be a bounded subset of V. Let 𝜀 > 0, p > 2 and 0 ≤ λ < λ₁(Ω) be constants, where λ₁(Ω) is the first eigenvalue of the discrete Laplacian, and h : V → ℝ be a function satisfying h ≥ 0 and $h{\not\equiv}0$. We consider a perturbed Yamabe equation, say $$\{\begin{array}{lll}-{\Delta}u-{\lambda}u={\mid}u{\mid}^{p-2}u+{\varepsilon}h,&&\text{ in }{\Omega},\\u=0,&&\text{ on }{\partial}{\Omega},\end{array}$$ where Ω and ∂Ω denote the interior and the boundary of Ω, respectively. Using variational methods, we prove that there exists some positive constant 𝜀₀ > 0 such that for all 𝜀 ∈ (0, 𝜀₀), the above equation has two distinct solutions. Moreover, we consider a more general nonlinear equation $$\{\begin{array}{lll}-{\Delta}u=f(u)+{\varepsilon}h,&&\text{ in }{\Omega},\\u=0,&&\text{ on }{\partial}{\Omega},\end{array}$$ and prove similar result for certain nonlinear term f(u).

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.906-911
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• 2008

Because the perimeter of buildings is strongly influenced by solar and the outdoor air temperature, the area has different environmental properties compared to the interior of a building, as in summer heat gain, and in winter heat loss. In particular, if the external wall is glass, the characteristics of the glass material make it pervious to outside conditions, thereby making big changes to the thermal environment. By combining shading device and the efficient exhaust system, an energy saving can be achieved compared to no air barrier systems. The simplified air barrier system is developed with the idea that energy could be conserved by carefully and effectively blowing out the air caught between the glass surface and the roller blind. The way it is configured is therefore by making the roller blind's air-path, and by placing the air output ducts in the most optimum positions. This simplified air barrier system will give improvement in the thermal environment of the parameter area that is strongly affected by solar and the outdoor condition.

• Perspectives in Nursing Science
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• v.9 no.1
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• pp.51-60
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• 2012

Purpose: The purpose of this study was to develop a self-directed e-learning program for ICU nurses and to evaluate how the proposed e-learning program affects the level of knowledge, nursing performance and job satisfaction of ICU nurses. Methods: The e-learning program was developed with the Computer Assisted Instruction Design Model using sources of self-efficacy which included the inactive attainment, vicarious experience, and verbal persuasion of ICU nurses. The program was evaluated by experts. Following the revision of the program, it was applied to a total of 59 ICU nurses (experimental group n=29, control group n=30) from three hospitals. Four weeks later, we measured the level of knowledge, nursing performance and job satisfaction. Results: The level of knowledge significantly improved in the experimental group (t=5.691, p<.001). Moreover, the level of nursing performance significantly increased in the areas of circulatory diagnostic test (t=2.143, p=.039), EKG (t=2.911, p=.006), aortic balloon pump (t=2.491, p=.017), and nebulizer therapy (t=2.085, p=.044). Overall, job satisfaction did not significantly increase (t=1.664, p=.105); however, job satisfaction in terms of relationships with coworkers (t=2.371, p=.023) and the needs of nursing performance (t=2.940, p=.006) were significantly increased. Conclusion: The results showed that the proposed e-learning program using sources of self-efficacy from ICU nurses was an effective learning method to increase the level of knowledge and nursing performance. The propose de-learning program would be a useful teaching tool for ICU nurses improving the quality of ICU patient care.