• 한국군사과학기술학회지
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• 제20권2호
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• pp.181-186
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• 2017

Synthetic aperture radar(SAR) has been widely used for reconnaissance. It provides high-resolution, day-and-night and weather-independent images for a multitude of applications. Because SAR coherently combines many viewing angles to effectively create a large aperture(narrow beam) radar, the test-bed should be capable of moving straightly SAR sensor for the integration angle to meet resolution. This paper describes the test-bed developed to test and evaluate the SAR performance. It forms high-quality images in real time and saves the raw data for the purpose of post processing on the ground.

• 한국전자파학회논문지
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• 제28권9호
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• pp.740-748
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• 2017

본 논문에서는 X-밴드 대역에서 운영되는 레이다 장비를 이용하여 실제 이동하는 해상 표적을 대상으로 역합성 개구면 레이다(Inverse Synthetic Aperture Radar: ISAR) 영상 생성 기법들의 성능을 비교 분석하였다. 성능 비교에 사용된 ISAR 영상 생성 기법들은 1) 거리 순시 도플러(Range Instantaneous Doppler: RID) 기법, 2) 위상보상(phase adjustment) 수행 후의 거리 도플러(Range Doppler: RD) 기법, 그리고 3) 주요 산란원 기법(Prominent Point Proccessing: PPP) 수행 후의 RD 기법들이 있다. 본 논문에서 수행된 성능 비교 결과는 향후 실제 해상 이동 표적의 ISAR 영상 생성을 위한 기반 기술 확보 및 기본 프레임워크(frame work) 구축을 위한 지표를 제공한다는데 그 의의가 있다.

• Applied Biological Chemistry
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• 제23권4호
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• pp.199-205
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• 1980

인삼의 유효약리성분으로 밝혀진 saponin중의 각 ginsenosides를 효과적이고 능률적으로 분리하기 위하여 대량분취전용 고속액체 chromatograph인 preparative HPLC의 응용을 검토하였다. 조(粗) saponin획분을 preparative HPLC인 Prep LC/system-500를 사용하여 부분분획을 하고 각 획분에 함유되어 있는 ginsenosides의 조성을 Analytical HPLC로 동정한 후 Semi-preparative HPLC를 사용하여 인삼주성분 saponin을 단리했다. 그 결과 인삼 주성분 saponin인 $ginsenoside-Rb_1,\;-Rb_2,\;-Rc,\;-Rd,\;-Re$ 및 $-Rg_1$은 약 20 mg / 2.0 ml / injection으로 chromatography를 행하여 $300{\sim}400mg/day$로 대량분취가 가능하였다. 따라서 ginsenosides의 약리 및 임상효능 연구에 크게 기여하게 될 것이다.

• 전력전자학회논문지
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• 제18권3호
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• pp.279-288
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• 2013

This paper proposes a improved speed control system for five-phase squirrel-cage induction motor(IM) injecting 3rd. current harmonic components with field oriented control (FOC) A five-phase IM drives present unique characteristics due to the additional degrees of freedom and also drives possess many others advantage compared with the traditional three-phase motor drive system, such as reducing a amplitude of torque pulsation at low frequency and increasing the reliability. In order to maximize the torque per ampere, the proposed motor has concentrated windings. The produced back-electromotive force is almost trapezoidal, and the motor is supplied with the combined sinusoidal plus third harmonic of currents. There is necessary to controlled 3rd harmonic current in order to high response characteristics. For presenting the superior performance of the proposed the speed control system, experimental results are presented using a 32-bit fixed point TMS320F2812 DSP with 1.5[kW] induction motor.

• 지역사회간호학회지
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• 제21권2호
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• pp.263-272
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• 2010

Purpose: This study was to identify health needs of the elderly at nursing homes by long-term care grade. Methods: The health needs of 116 elders at two nursing homes in Seoul were measured with resident assessment protocols (RAPs), activities of daily living (ADL), and cognitive performance scale (CPS), and pain and depression were measured by resident assessment instrument (RAI). Results: With regard to RAPs, 11 out of 18 items had different distribution in the 3 groups significantly. The 1st-grade elders had a higher percentage of 9 items than the 2nd- and 3rd-grade ones but the 3rd-grade ones had the highest health needs related with activity. The 2nd-grade elders had similar health needs to the 1st-grade ones. In terms of functional level, the 1st-grade elders had the highest percentage of CPS and ADL but the 3rd-grade ones had the highest score of pain and depression out of the 3 groups. The standardized assessment instrument to identify specific health needs by the 3 groups should be developed. Therefore, care plans to meet health needs of the 3 groups will be made. Conclusion: It is suggested that nursing care is required to the elderly of the 1st- and 2nd-grade and safe activity and environment to the 3rd-graded ones.

• 한국군사과학기술학회지
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• 제17권3호
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• pp.364-377
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• 2014

In this paper, we have developed a target recognition algorithm based on a template matching technique using Synthetic Aperture Radar (SAR) images. For efficient computations, Radon transform-based azimuth estimation algorithm was used with the template matching. MSTAR data set was divided into two groups according to the depression angles, which were a train set and a test set. Template data were generated by rotating and cropping chips which were from MSTAR train set using the azimuth estimation algorithm. Then the template matching process between test data and template data was performed under various conditions. Performance variation according to contrast enhancement preprocessing which is scarce in open literature was also presented. The analysis results show that the target recognition algorithm could be useful for the automatic target recognition using SAR images.

• 한국군사과학기술학회지
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• 제17권5호
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• pp.680-687
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• 2014

PGA(phase gradient autofocus) has been widely used to remove motion induced phase errors in the ISAR(inverse synthetic aperture radar) imaging. The critical process for the processing time and image quality is windowing stage in PGA. In this paper, the new method to determine window size based on polynomial least square approximation is proposed. Moreover, dominant range bins are selected for efficient phase error estimation, which improve image quality and speed up convergence. The simulation results show that the proposed algorithm provides high quality ISAR images while computational efficiency of inherent PGA is retained.

• 전기학회논문지P
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• 제61권4호
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• pp.206-213
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• 2012

This paper propose a improved speed control system for five-phase squirrel-cage induction motor(IM) considering effects of 3rd. harmonic current components with field oriented control(FOC) A five-phase IM drives present unique characteristics due to the additional degrees of freedom and also drives possess many others advantage compared with the traditional three-phase motor drive system, such as reducing a amplitude of torque pulsation at low frequency and increasing the reliability. In order to maximize the torque per ampere, the proposed motor has concentrated windings. The produced back-electromotive force is almost trapezoidal, and the motor is supplied with the combined sinusoidal plus third harmonic of currents. There is necessary to controlled 3rd harmonic current. For presenting the superior performance of the proposed the speed control system, experimental results are presented using a 32-bit fixed point TMS320F2812 DSP with 1.5[KW] induction motor.

• Journal of Biosystems Engineering
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• 제29권4호
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• pp.335-340
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• 2004

This study was conducted to evaluate the internal quality of Korean red ginseng using VIS/NIR transmittance spectra. To classify the internal qualities, partial least squares(PLS) regression was conducted. The main results are as follows: To develop the PLS model, several wave bands were divided and incorporated into the model. Among the bands, the wavelength range of 550-1,020nm, excluded noise signal, showed the best evaluation results. Effect of step size on the performance of quality evaluation showed optimal at 15 steps. In order to enhance the accuracy of quality evaluation, the abnormal spectrum shape was considered first and then the PLS model was applied. Among the 150 samples, 12 samples were evaluated by the spectrum shape. In this study, to develop the optimal PLS regression model, among the 150 samples, 138 samples was used with exception of 12 samples which could evaluate the spectrum shape. The result of quality evaluation was promising as SEC and correlation coefficient were 1.09 and 0.967, respectively, and SEP and correlation coefficient were 1.04 and 0.958, respectively.

• 한국초등과학교육학회지:초등과학교육
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• 제17권2호
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• pp.11-22
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• 1998

The present educational and social circumstances require the improvement of science education and the promotion of scientific technology simultaneously Under this situation, it is necessary to develop the performance assessment evaluating the ability of scientific inquiry. The purpose of this study is to develop a valid and reliable instrument of the performance assessment that is can evaluate the scientific inquiring ability. The characteristics of the instrument developed through this study, are as follows, 1. The performance assessment can be impartially achieved for all the elements of scientific inquiry, which are required in the units of elementary science from 3rd to 6th grade of elementary school. 2. To maintain the objectivity of performance assessment, the detailed standpoints and standards are established. 3. The instruments are devised to evaluate the thinking skills with the experimental reports of student, the operation skills by the check list of evaluation that the teacher's observation for the student are recorded. 4. Considering the level of elementary school student, the items required the complex thinking and the investigative skills are exclude as much as possible. 5. The items are arranged according to the learning steps of elementary school, so that the evaluation may be achieved in parallel with the process of the real teaching -learning in class. 6. According to circumstances, make use of these materials for the evaluation as the practical teaching-learning materials instead of the normal teaching-learning materials The first field trial with the instrument was carried out, using a sample of 20 students from the 3rd to 6th at K and Y elementary school located in Kwangju city. The results of mean achievement quotient for each grade are as follows, the first term of 3rd grade (experiment and exercise skills ; 85%, inquiry thinking skills ; 74%), the second term of 3rd grade (experiment and exercise skills : 81%, inquiry thinking skills ; 76%), the first term of 4th grade (experiment and exercise skills ; 70%, inquiry thinking skills ; 59%), the second term of 4th grade (experiment and exercise skills ; 61%, inquiry thinking skills ; 71%), the first term of 5th grade (experiment and exercise skills ; 84%, inquiry thinking skills ; 67%), the second term of 5th grade (experiment and exercise skills; 73%, inquiry thinking skills ; 70%), the first term of 6th grade (experiment and exercise skills : 83%, inquiry thinking skills ; 84%), the second term of 6th grade (experiment and exercise skills ; 87%, inquiry thinking skills ; 81%).