• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.441-449
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• 1996

This study was conducted to find the changes of growth, seed yield and several characteristics of sesame by leaf spray of boron as a solution which is likely to be lack in the soil. It is carried out at low land developed 5 years ago. The amount of 200l /l0a boron as boric acid is sprayed in each treatment at the 11 node stage of sesame in main stem. The spraying concentrations of boric acid are 0.0, 0.2 and 0.4% in each treatment of the level low plot and the ridge height 15cm plot. The result shows that leaf area is increased in proportion to the concentration of boric acid in each treatment of the level low and the ridge height 15cm, and the degree of increase of each node order is remarkable in lower leaves and is more remarkable in the treatment of level low plot. The effects of leaf spray of boric acid are not only the increase of leaf area but also dry weight, no. of capsule per plant, 1,000 grains weight of capsule setting under middle position. As a result, the amount of seed is increased in 53% in the treatment of level low. The change of major characteristics according to leaf spray of boric acid is generally great in the treatment of level low. Especially the increase of leaf area in the part of upper leaves and low leaves is effective to improve other characteristics.

• Journal of Preventive Medicine and Public Health
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• v.22 no.4 s.28
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• pp.578-590
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• 1989

This study was conducted to assess the equity in the regional insurance scheme through analysis of the computerized data from one regional insurance society and National Federation of Medical Insurance. We analysed the insurance contribution and benefit by the classes based on total and income-related contribution per household. The major findings of this study are as follows : 1. The average proportion of income-related contribution among the total was 39.2% and the upper classes show higher proportion of the income-related contribution. 2. The upper classes show higher health care utilization rate than the lower classes. It suggests that the lower classes have relatively large unmet medical needs. 3. The analysis through the Lorenz curve reveals that there exists transference of contributions from the upper to lower classes. But the cumulative percentage of insurance benefit is smaller than that of the number of the insured. It implies that regional medical insurance scheme in Korea has still some inequity in the context of social security principles.

• International Journal of Highway Engineering
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• v.13 no.1
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• pp.1-11
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• 2011

This study is aimed at suggesting a plan for creating a landscape environment by grasping a landscape preference according to the change of middle span and sag ratio which is a consideration factor when designing the suspension bridge representing long-span bridges and image property of the bridge while applying SD method to a relation between landscape preference and image factor, and a connection of design element with image factor. An analysis on landscape preference about the bridge landscape showed from what the longer the length of middle span, the extent of sag ratio of preference decreased, the longer the middle span low sag ratio was preferred and the higher the landscape preference became. In landscape preference and image factor, the attribute of sag ratio with high landscape preference was all positively correlated with "stability", "plasticity", and "aesthetic" but an influence of "plasticity" was insignificant. In the relation between design element and image factor, the factor of middle span and sag ratio was more related to the factor of "stability" and the lower the sag ratio and the longer the middle span, the higher the "stability" was rated. This result showed the image property of "plasticity" was insignificant among the one of preference in landscape and to highlight the one of "plasticity" a complementary experiment was done with a change in balance and symmetry elements not in proportional element of middle span and sag ratio. The result showed the image property of "plasticity" was more highlighted in the suspension bridge of 3-tower and different bilateral symmetry at sag, and when designing the landscape of suspension bridge later on, the elements of balance and symmetry as well as the proportional element should be considered and reflected in the design.

• Investigative Magnetic Resonance Imaging
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• v.8 no.1
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• pp.42-49
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• 2004

Purpose : The quantization noise in magnetic resonance imaging (MRI) systems is analyzed. The signal-to-quantization noise ratio (SQNR) in the reconstructed image is derived from the level of quantization in the signal in spatial frequency domain. Based on the derived formula, the SQNRs in various main magnetic fields with different receiver systems are evaluated. From the evaluation, the quantization noise could be a major noise source determining overall system signal-to-noise ratio (SNR) in high field MRI system. A few methods to reduce the quantization noise are suggested. Materials and methods : In Fourier imaging methods, spin density distribution is encoded by phase and frequency encoding gradients in such a way that it becomes a distribution in the spatial frequency domain. Thus the quantization noise in the spatial frequency domain is expressed in terms of the SQNR in the reconstructed image. The validity of the derived formula is confirmed by experiments and computer simulation. Results : Using the derived formula, the SQNRs in various main magnetic fields with various receiver systems are evaluated. Since the quantization noise is proportional to the signal amplitude, yet it cannot be reduced by simple signal averaging, it could be a serious problem in high field imaging. In many receiver systems employing analog-to-digital converters (ADC) of 16 bits/sample, the quantization noise could be a major noise source limiting overall system SNR, especially in a high field imaging. Conclusion : The field strength of MRI system keeps going higher for functional imaging and spectroscopy. In high field MRI system, signal amplitude becomes larger with more susceptibility effect and wider spectral separation. Since the quantization noise is proportional to the signal amplitude, if the conversion bits of the ADCs in the receiver system are not large enough, the increase of signal amplitude may not be fully utilized for the SNR enhancement due to the increase of the quantization noise. Evaluation of the SQNR for various systems using the formula shows that the quantization noise could be a major noise source limiting overall system SNR, especially in three dimensional imaging in a high field imaging. Oversampling and off-center sampling would be an alternative solution to reduce the quantization noise without replacement of the receiver system.

• Magazine of the Korea Concrete Institute
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• v.9 no.5
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• pp.105-114
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• 1997

본 연구는 비부착 긴장재를 갖는 부재에 대한 일련의 연구중 두 번째에 해당한다. 첫 번째 연구(1)에서는 기존연구의 제안식과 현행의 ACI 규준의 문제점을 고찰하고 기존의 총 167개 실험결과와 비교·분석하였다. 본 연구에서는 소성힌지 길이 개념과 변형도 적합조건에 의해서 비부착 긴장재의 응력을 평가할 수 있는 방법에 대한 검토를 통하여, 새로운 설계식을 제안하였다. 이는 이론적인 분석에 의한 변수설정과 기존 실험결과를 이용한 중회귀분석법을 사용하였다. 그리고 제안된 설계식을 기존의 식들과 비교하여 좋은 결과를 얻었으며, 제안된 설계식의 특성을 다음과 같이 설명하였다. (1)비부착 긴장재의 응력산정시 유효프리스트레스, 일반철근의 양, 작용하중의 형태 등은 중요한 변수로 작용할 수 있으므로 설계식에 고려하는 것이 바람직하다. (2)비부착 긴장재의 응력산정식은 현행 ACI 규준식과는 다르게 fc'/ p항의 제곱근과 비례하는 함수관계에 있다. (3)스팬-춤비가 비부착 긴장재의 응력에 미치는 영향은 소성힌지 길이의 개념에 의해서 역학적으로 타당하게 설명할 수 ldT다.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.4
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• pp.388-392
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• 2012

This study proposes a fully non-contact measurement method to assess acoustic nonlinearity of narrowband surface waves generated by a line-arrayed laser beam by using a laser-ultrasonic detector in the way of two-wave mixing (TWM) method. This method was applied to figure out a relationship between plastic deformation and nonlinearity characteristics of a plastically deformed aluminum specimens. The experimental results showed that the acoustic nonlinearity of the laser-generated surface wave increased proportionally to the level of tensile deformation. This tendency is in good agreement with the result of measurement by contact method with PZT-transducer.

• KDI Journal of Economic Policy
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• v.10 no.2
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• pp.49-64
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• 1988

대부분의 수출자율규제실시국(輸出自律規制實施國)들은 총(總)쿼타의 일부를 개방(開放)쿼타로 할당하여 수출단가(輸出單價)와 비규제국(非規制國) 수출실적(輸出實績)에 비례하여 배분하는 2단계(二段階)쿼타배분제도(配分制度)를 택하고 있으며 이는 수출자율규제(輸出自律規制)에서 오는 수출소득(輸出所得)과 수출물량(輸出物量)의 감소를 수출시장다변화(輸出市場多邊化)를 통해 줄이려는 정책적(政策的) 노력(努力)으로 해석된다. 본고(本稿)는 부분균형분석(部分均衡分析)을 통해 비규제국(非規制國) 수출실적(輸出實績)을 개방(開放)쿼타의 배분기준(配分基準)으로 하는 2단계(二段階)쿼타배분제도(配分制度)가 기본(基本)쿼타에만 의존하는 단일(單一)쿼타배분제도(配分制度)보다 비규제국(非規制國) 수출물량(輸出物量)을 증가시키고 이에 따른 수출소득(輸出所得)의 변화는 비규제국(非規制國) 수입수요탄력성(輸入需要彈力性)에 의해 결정됨을 보인 반면 개방(開放)쿼타를 얻기 위한 기업의 경쟁행위가 비규제국(非規制國) 수출가격(輸出價格)을 한계생산비(限界生産費) 이하의 수준으로 하락시켜 자원배분(資源配分)의 비효율(非效率)을 초래할 수 있으며 이는 바로 GATT규정(規定)에 위배되는 덤핑사례(事例)를 유도할 수 있음을 보였다. 따라서 수출(輸出)쿼타배분제도(配分制度)를 운용함에 있어서 자원배분(資源配分)의 효율(效率)과 국제무역환경(國際貿易環境)에 미치는 영향 등을 충분히 고려해야 할 것이다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.6B
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• pp.1203-1210
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• 1999

Coefficients of the adaptive filter are misadjusted by primary signals which are uncorrelated with reference signals of the adaptive filter. In this paper, the normalized sign algorithm is analyzed and compared with the NLMS algorithm by the steady state performance and the transient characteristics when target signals are included in primary signals. The excess mean square error of the NLMS algorithm is proportional to the power of target signals. That of normalized sign algorithm is proportional to the square root of the target signal power. However, the convergence speed of the normalized sign algorithm is slower than that of NLMS algorithm. In this paper, it is shown that theoretical analysis of the steady state performance and the transient characteristics are well consisted with the results of computer simulation.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.450-450
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• 2013

플래시 메모리는 소형화가 용이하고, 낮은 구동 전압과 빠른 속도의 소자 장점을 가지기 때문에 휴대용 전자기기에 많이 사용되고 있다. 현재 사용되고 있는 플로팅 게이트를 이용한 플래시 메모리 소자는 비례축소에 의해 발생하는 단 채널 효과, 펀치스루 효과 및 소자 간 커플링 현상과 같은 문제로 소자의 크기를 줄이는데 한계가 있다. 이 문제를 해결하기 위해 FinFET, nanowire FET, 3차원 수직 구조와 같은 구조를 가진 플래시 메모리에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 비례축소의 용이함과 낮은 누설 전류의 장점을 가진 FinFET 구조를 가진 낸드 플래시 메모리의 전기적 특성에 대해 조사하였다. 메모리의 집적도를 높이기 위하여 비대칭 FinFET 구조를 가진 더블 게이트 낸드 플래시 메모리 소자를 제안하였다. 비대칭 FinFET 구조는 더블 게이트를 가진 낸드 플래시에서 각 게이트 간 간섭을 막기 위해 FinFET 구조의 도핑과 위치가 비대칭으로 구성되어 있다. 3차원 TCAD 시뮬레이션툴인 Sentaurus를 사용하여 이 소자의 동작특성을 시뮬레이션하였다. 낸드 플래시 메모리 소자의 게이트 절연 층으로는 high-k 절연 물질을 사용하였고 터널링 산화층의 두께는 두 게이트의 비대칭 구조를 위해 다르게 하였다. 두 게이트의 비대칭 구조를 위해 각 fin은 다른 농도로 인으로 도핑하였다. 각 게이트에 구동전압을 인가하여 멀티비트 소자를 구현하였고 각 구동마다 전류-전압 특성과 전하밀도, 전자의 이동도와 전기적 포텐셜을 계산하였다. 기존의 같은 게이트 크기를 가진 플로팅 게이트 플래시 메모리 소자에 비해 전류-전압곡선에서 subthreshold swing 값이 현저히 줄어들고 동작 상태 전류의 크기가 늘어나며 채널에서의 전자의 밀도와 이동도가 증가하여 소자의 성능이 향상됨을 확인하였다. 또한 양족 게이트의 구조를 비대칭으로 구성하여 멀티비트를 구현하면서 게이트 간 간섭을 최소화하여 각 구동 동작마다 성능차이가 크지 않음을 확인하였다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.4
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• pp.123-128
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• 2017

This paper relates with the Hybrid-SMMA adaptive equalization algorithm that is possible to improve the equalization performance based on adaptive modulus and adaptive stepsize which is propotional to the output power of equalizer in the current SMMA (Sliced Multi Modulus Algorithm). The fixed statistic modulus of transmitted signal is used in current SMMA algorithm in order to generate the error signal for updating the tap coefficient of equalizer. The proposed Hybrid-SMMA based on the adaptive modulus which is propotion to the equalizer output signal power and adaptive stepsize which is fuction of the nonlinearties of error signal. The computer simulation was performed in order to confirm the improved equalization performance of proposed algorithm. As a result of computer simulation, the proposed Hybrid-SMMA has fairly good in every performance than the current SMMA.