• Korean Journal of Child Studies
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• v.33 no.2
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• pp.203-222
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• 2012

The purpose of this study was to examine the factors influencing their mathematical learning abilities and mathematical learning potential in an attempt to assist their learning at the preschool level. The findings of the study were as follows : First. the female children performed at a much higher level than their male counterparts in terms of mathematical learning ability and mathematical learning potential training. The young children generally improved in their mathematical learning abilities and mathematical learning potential with age. Second, it was found that the participants had higher levels of both mathematical learning ability and mathematical learning potential when their mathematical attitudes and learning motivation were better. Third, there were significant differences in terms training-test and transfer-test scores between the 4 groups based on their relative levels of mathematical abilities and attitudes.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2764-2766
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• 1999

The information of the motor speed and flux are more necessary than the other informations which have to get for the induction motor drive. which is the exact informations of the speed and flux are known without the speed and flux sensors, many problems for induction motor drive will be solved. In this paper, it is studied on the method able to get the informations of the speed and the flux for the induction motor. The informations for the rotator speed and flux of the induction motor are estimated exactly and rapidly by the observer system proposed in this paper and the induction motor is controlled by those informations of the speed and flux exactly and rapidly by the fuzzy controller set in the observer system.

• Journal of IKEEE
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• v.2 no.1 s.2
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• pp.61-67
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• 1998

In this thesis, experiment have performed with the speaker recognition using multilayer feedforward neural network(MFNN) model using Korean and Japanese digits . The 5 adult males and 5 adult females pronounciate form 0 to 9 digits of Korean, Japanese 7 times. And then, they are extracted characteristics coefficient through Pitch deletion algorithm, LPC analysis, and LPC Cepstral analysis to generate input pattern of MFNN. 5 times among them are used to train a neural network, and 2 times is used to measure the performance of neural network. Both Korean and Japanese, Pitch coefficients is about 4%t more enhanced than LPC or LPC Cepstral coefficients.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.9
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• pp.1075-1080
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• 2004

In this study, performance and emissions characteristics of an liquefied petroleum gas (LPG) engine converted from a diesel engine were examined by using mixer system and liquid propane injection (LPi) system fuel supply methods. A compression ratio for the base diesel engine, 21, was modified into 8, 8.5, 9 and 9.5. The cylinder head and the piston crown were modified to roe the LPG in the engine. Ignition timing was controlled to be at minimum spark advance for best torque (MBT) each case. Engine performance and emissions characteristics are analyzed by investigating engine power, brake mean effective pressure (BMEP), brake specific fuel consumption (BSFC), volumetric efficiency, CO, THC and NOx. Experimental results showed that the LPi system generates higher power and lower emissions than the conventional mixer fuel supply method.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.8 s.173
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• pp.92-99
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• 2005

Tungsten heavy metal is characterized by a high density and novel combination of strength and ductility. Among them, 90W-7Ni-3Fe is used for applications, where the high specific weight of the material plays an important role. They are used as counterweights, rotating inertia members, as well as fur defense purposes(kinetic energy Penetrators, etc.). Because of these applications, it is essential to detemine the dynamic characteristics of tungsten alloy. In this paper, Explicit FEM(finite element method) is employed to investigate the dynamic characteristics of tungsten heavy metal under base of stress wave propagation theory for SHPB, and the model of specimen is divided into two parts to understand the phenomenon that stress wave penetrates through each tungsten base and matrix. This simulation results were compared to experimental one and through this program, the dynamic stress-strain curve of tungsten heavy metal can be obtained using quasi static stress-strain curve of pure tungsten and matrix.

• Journal of Yeungnam Medical Science
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• v.29 no.2
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• pp.125-128
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• 2012

Bleeding is the most common and serious complication of thrombolysis in ST elevation myocardial infarction. Most bleeding cases are associated with an intervention or operation, but spontaneous bleeding such as gastro-intestinal bleeding or intracranial hemorrhage can happen. This is a report on the case of a 76-year-old female patient with retroperitoneal hemorrhage due to spontaneous right colic artery branch bleeding after thrombolysis in ST elevation myocardial infarction.

• Annual Conference on Human and Language Technology
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• 1994.11a
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• pp.253-258
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• 1994

이 글에서 살펴본 바는 다음과 같다. 1) ISO 10646-1 한글 부호계의 운용 방안은, 앞으로 얼마동안은 2,350 완성형 소리마디를 쓸 수도 있겠지만, 길게 보아서는 첫가끝 부호계 238 글자로 통일하는 것이 바람직하다고 본다. 2) ISO 2022 틀을 따르면서 한글을 완벽하계 지원하는 한 바이트 한글 부호계를 개발하여, 국제 등록부 (International Register) 에 등록하여, Escape Sequence을 받아서, ISO 2022 를 따르는 분야에서 쓸 수 있도록 하여야하겠다. 3) ISO 10646-1 을 개정하여 4,516 소리마디를 넣자는 안은, 완성형으로만 한글을 지원하게 되어 바람직하지 않다고 본다. 모아쓰기 글자를 지원하는 세계 추세가 조합방식이므로, 10646-1 을 현재대로 두고, 첫가끝 방식의 238 글자를 쓰는 것이 바람직하다고 본다. 4) 10646-1 을 재대로 지원할 수 있는 세벌식 자판을 정부의 복수 표준으로 채택할 것을 제안한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1210-1215
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• 2000

Investigation is performed on the stability of general form of dynamic system under colored noise random disturbance whose damping and stiffness are varying in irregular manner along time, which is a preliminary result in the course of research on the characteristic and the control of the stochastic system. Adopted physical model is airfoil under random atmospheric disturbance, which becomes a "time-varying system" whose the governing equation is derived via F-P-K approach in stochastic sense. Control performance and effect of 'Heo-stochastic controller for colored noise' is studied. Also stochastic feature of flutter boundary is discussed as well.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1292-1297
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• 2000

For dynamic system under the external irregular disturbance, a performance of the controller designed by using of the 'Heo-stochastic control methodology' is investigated by simulations and experiments. MIMO Flexible cantilever beam, sticked with piezoceramics used as a sensor and actuator, under the irregular disturbance at bottom is modelled in physical domain. Dynamic moment equation about the system is derived through both the Ito's stochastic differential equation and Fokker-Planck-Kolmogoroff equation and also system's characteristics in stochastic domain is analyzed. In this study, the controller suppresses the amplitude of the system's moment response to the external disturbance. MIMO PI controller('Heo-stochastic MIMO PI controller') is designed in the stochastic domain and the response characteristics are investigated in the time domain

• Radiation Oncology Journal
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• v.29 no.4
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• pp.277-282
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• 2011

Purpose: This study was performed to evaluate the change in the lumpectomy cavity volumes before and after whole breast radiation therapy (WBRT) and to identify factors associated with the change of volume. Materials and Methods: From September 2009 to April 2010, the computed tomography (CT) simulation data from 70 patients obtained before and after WBRT was evaluated. The lumpectomy cavity volumes were contoured based on surgical clips, seroma, and postoperative changes. Significant differences in the data from pre-WBRT CT and post-WBRT CT were assessed. Multiple variables were examined for correlation with volume reduction in the lumpectomy cavity. Results: The mean and median volume reduction in the lumpectomy cavity after WBRT were 17.6 $cm^3$ and 16.1 $cm^3$, respectively with the statistical significance (p < 0.001). The volume reduction in the lumpectomy cavity was inversely correlated with time from surgery to radiation therapy (R = 0.390). The presence of seroma was significantly associated with a volumetric change in the lumpectomy cavity after WBRT (p = 0.011). Conclusion: The volume of lumpectomy cavity reduced significantly after WBRT. As the time from surgery to the start ot WBRT increased, the volume reduction in the lumpectomy cavity during WBRT decreased. A strong correlation was observed between the presence of seroma and the reduced volume. To ensure appropriate coverage and to limit normal tissue exposure during boost irradiation in patients who has seroma at the time of starting WBRT, repeating CT simulation at boost planning is suggested.