• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.274-275
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• 2000

This paper introduces new ordering algorithms using the graph of data structure and forward/backward substitution of LU decomposition using recursive function. The performance of the algorithm is compared with Tinney's algorithm using 14 bus systems. Test results show that the new fill-in element of Jacobian matrix using the proposed ordering algorithm is same as that of Tinner scheme 3 and the forward/backward substitution can reduce the computation time

• Journal of Pharmaceutical Investigation
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• 제1권1호
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• pp.90-100
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• 1971

It is well known that the commonly used granular enzymic digestives are easy to diminish it's potency through preparation and custody. We made an experinent to know the proper way of manufacturing and keeping the granules without a loss of potency by $L_8$ orthogonal Tables. The factors, we considered, decomposition of enzyme activity through manufacturing are (1) sufficiency of granules drying (2) with or without sodium bicarbonate $(NaHCO_3)$ in gramules (3) separate wet granulation of enzyme and the rest of the component or mix together (4) kind of packing materials (Polycello or quartet silner paper) Besides we counted (5) humidity (6) temperature as block factors. Then we tested the potency of each sample by intervals of. a week, 2 weeks and we foretelled the potency of after one year by the life test. From the experimental results, main factor of activity loss is preserving humidity. Therefor the sufficiency of packing is became a main problem and the granules have to be made by separate wet granulation to inhibit it's decomposition. Temperature is the factor that accelerates loss of activity by humidity but does not so much by itself mixing enzyme toge therwith $NaHCO_3$ is not became a matter so far as it is dried.

• 대한화학회지
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• 제35권2호
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• pp.111-118
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• 1991

기체 상태의 오존(0.5 torr)과 이산화황간의 반응속도를 연구하였다. 이산화황은 7∼22 torr 의 압력범위에서 90∼155$^{\circ}$C의 온도영역에서 반응시켰다. 오존과 이산화황의 반응속도는 이산화탄소와의 반응보다 빨리 진행되었다. 오존과 이산화황의 반응속도식은 -d(O$_3 )/dt = k _0 (SO _2 )(M)(O _3)+2k _1(SO_2 )(O _3$)였다. 이 속도식의 첫 항은 3분자 반응으로 낮은 온도에서 우세하게 진행되었으며, 속도상수 k$_0 =(9.35{\pm}8.6){\times}10^9e^{-(11.05{\pm}2.04)kcal/RT}(M^{-2}s^{-1}$)이다. 속도식의 두번째 항은 2분자 열분해 반응으로부터 유도된 주된 반응으로 속도상수 k$_1=(1.53{\pm}1.5){\times}10^{11}e^{-22.7 kcal/RT}$이다. 전 반응차수는 주로 2차 반응이며 3차 반응과 복합반응으로 진행되었다.

• International Journal of Contents
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• 제4권3호
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• pp.1-9
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• 2008

The Korean life insurance industry has undergone profound changes, such as the beginning of the variable insurance in July 2001 and the bancassurance enforcement in August 2003. However, little empirical research has analyzed data that includes the bancassurance of life insurance companies operating in Korea. In response to this lack of research, this paper applies DEA (data envelopment analysis) models to measure and decompose their efficiency. We discovered that life insurance companies operating in Korea are a little different in their composition ratio of inputs and outputs, due to the increased variety of distribution channels and new products. We provided efficiency scores, return to scale, and reference frequencies. We also decomposed CCR, BCC, and SBM efficiency into scale efficiency and MIX efficiency. So, we try to investigate whether the sources of inefficiency were caused by the inefficient operation of DMU, disadvantageous conditions, the difference of the composition ratio in inputs and outputs with reference sets, or any combination of the above. Most companies in the sample display had either constant or decreasing returns to scale. The efficiency rankings were less consistent among models and efficient DMUs. In response to this problem, we used the super-efficiency model to rank them and then compared the rankings of the DMUs among the various models. It was also concluded that the availability of panel data, rather than cross-sectional data, would greatly improve the validity of the efficiency estimates.

• Ocean Systems Engineering
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• 제6권3호
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• pp.217-231
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• 2016

This paper presents a new approach for underwater image analysis using the bi-dimensional empirical mode decomposition (BEMD) technique and the phase congruency information. The BEMD algorithm, fully unsupervised, it is mainly applied to texture extraction and image filtering, which are widely recognized as a difficult and challenging machine vision problem. The phase information is the very stability feature of image. Recent developments in analysis methods on the phase congruency information have received large attention by the image researchers. In this paper, the proposed method is called the EP model that inherits the advantages of the first two algorithms, so this model is suitable for processing underwater image. Moreover, the receiver operating characteristic (ROC) curve is presented in this paper to solve the problem that the threshold is greatly affected by personal experience when underwater image edge detection is performed using the EP model. The EP images are computed using combinations of the Canny detector parameters, and the binaryzation image results are generated accordingly. The ideal EP edge feature extractive maps are estimated using correspondence threshold which is optimized by ROC analysis. The experimental results show that the proposed algorithm is able to avoid the operation error caused by manual setting of the detection threshold, and to adaptively set the image feature detection threshold. The proposed method has been proved to be accuracy and effectiveness by the underwater image processing examples.

• 한국대기환경학회지
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• 제24권3호
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• pp.357-366
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• 2008

In this study, the analytical performance of trimethylamine (TMA) were investigated with respect to headspace-solid phase microextraction (HS-SPME) method. In order to induce the elution of aqueous TMA to headspace, NaOH was added as a decomposition reagent to aqueous TMA standard. By controlling the combination of three major variables for TMA extraction, the extent of extraction was compared between the two contrasting conditions for each variable (i.e., reaction time (long (L) vs short (S)), exposure temperature (30 vs $50^{\circ}C$), and exposure time (10 vs 30 min)). The results of this comparative analysis showed that the extraction efficiency for all eight types of HS-SPME combinations decreased on the order: L-30-30>L-50-10>L-30-10>L-50-30>S-30-30>S-50-30>S-50-10>S-30-10. The effect of reaction time appeared to exert significant influences on the relative recovery rate of HS-SPME at 90% confidence level. However, the effects of exposure temperature or exposure time were not so significant as reaction time. When the recovery rate of HS-SPME is compared against the direct injection of liquid standard into GC injector, it recorded as 2%. According to this comparative study, the reaction conditions for HS-SPME application can exert significant influences on the analysis of TMA.

• The Korean Journal of Ecology
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• 제4권1_2호
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• pp.33-37
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• 1981

본 연구는 수양버들 꽃의 분해에 따르는 성분변화를 조사하기 위하여 행하였으며 얻어진 결과는 다음과 같다. 1. 수양버들 꽃의 분해는 매우 빠르기 때문에 분해 40일에는 그 완전한 형태를 알아보기 어려웠다. 2. 분해 40일후의 시료의 무게는 50%의 감소를 나타냈으며 작열소실량도 초기에는 급감하였다가 점차로 감소하였다. 3. 탄소함량은 초기 20일간에 반감하였으며 그 후 20일간도 급감하였다. 4. 총질소와 인의 함량변화는 초기에 완만하였으나 (초기 20일간) 그 후에는 급감하였다. 이상과 같은 현상은 수양버들 꽃이 수분. 질소. 인의 함량이 높을뿐 아니라 비교적 온도가 높기때문에 분해가 빠른것으로 사료된다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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• pp.217-224
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• 2003

ISO 14649 is a new interface (or language) standard for the CAD-CAM -CNC chain, currently under establishment by ISO TC184 SCI and SC4 . Upon completion, it will replace ISO 6983, so called M amp; G codes used for CNC since 1950' s. As the new language is being established, a new CNC controller called STEP-CNC (STEP­compliant CNC), capable of carrying out various intelligent tasks using the new language as an input, receives worldwide attention. In this paper, we present a distributed architecture for STEP-NC system based on the generic paradigm of STEP-NC. The STEP-NC system is consisted of 3 sub-systems: 1) CGS (Code Generation System), 2) CES (Code Edit System), and 3) ACS (Autonomous Control System). Also presented in this paper is algorithm for delta volume decomposition, a crucial algorithm for developing CGS. First method is based on the cutting tool and the second method is based on the turning features commonly used in the shop floor. An illustrative example is given to compare the two methods, and to illustrate usage scenario of the delta volume in the turning STEP- NC system under development.

• 한국작물학회지
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• 제34권s02호
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• pp.115-120
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• 1989

인삼의 연작장해의 증상, 원인 및 방제법에 대하여 고찰하였다. 1. 연작장해의 증상은 인삼의 생장억제 근부에 의한 근수량 저하였으며 품질에는 영향을 주지 않았다. 2. 연작장해는 토양병원미생물과 인삼유체 분해산물의 식물에 대한 직접적인 독작용, 그리고 이들 유체 및 그 분해산물에 희한 토양내 전속화합물의 용해 또는 결합에 따른 전속이온의 식물에 대한 독작용 등이 상호 복합적으로 나타난 것으로 보인다. 3. 토양은 근부유발형과 근부억제형 토양으로 구분되며, 토양이화학성이 연작장해를 조장시키지는 않았다. 4. 연작장해의 방제법은 살균제에 의한 효과는 기대하기 어렵고, 훈증제(싸이론, 크로로피크린)를 처리하여 연작할 경우 고년근에서 근부병 발생이 심하기 때문에 훈증제와 길항미생물의 혼합처리가 효과적이다. 또 답전윤환이 가능한 논에서 3∼4년간 벼를 재배한 후 인삼을 연작하는 방법이 실용화되고 있다.

• Communications for Statistical Applications and Methods
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• 제28권3호
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• pp.233-250
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• 2021

This paper studies if the accuracies of mortality models (LC model vs. 4-parametric model) are aggravated if a mortality structure changes due to the impact of COVID-19. LC model (LCM) uses dimension reduction for fitting to the log mortality matrix so that the performance of the dimension reduction method may not be good when the matrix structure changes. On the other hand, 4-parametric factor model (4-PFM) is designed to use factors for fitting to log mortality data by age groups so that it would be less affected by the change of the mortality structure. In fact, the forecast accuracies of LCM are better than those of 4-PFM when life-tables are used whereas those of 4-PFM are better when the mortality structure changes. Thus this result shows that 4-PFM is more reliable in performance to the structural changes of the mortality. To support the accuracy changes of LCM the functional aspect is explained by computing eigenvalues produced by singular vector decomposition