• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.1032-1035
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• 1997

The purpose of this paper is to reduce the number of cutting tests and to predict the main cutting force and the specific cutting energy. By using the SOFM neural network, the most suitable cutting test conditions has been found. As a result, the number of cutting tests has been reduced to one-third. And by using MLP neural network and regression analysis, the main cutting force and specific cutting energy has been predicted. Predicted values of main cutting force and specific cutting energy are well concide with the measured ones.

• 한국잠사곤충학회지
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• 제28권2호
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• pp.28-34
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• 1986

The general combining ability (GCV), the specific combining ability (SCA) and the reciprocal combining ability (RCA) effects wereobtained by 8$\times$8 diallel crosses of the silkworms with four Japanese races and four Chinese races, total eight lines. The result are as follows ; 1. The general combining ability (GVA) effects appeared high significant level in the total and the fifth instar periods (TP, FP), a female and a male cocoon weights (FW, MW), a female and a male cocoon layer weights (FL, ML) and a female and a male cocoon layer ratios (FR, MR). Only the reciprocal combining ability (RCA) effects appeared high significant level in the total and the fifth instar periods (TP, FP). 2. The Japanese original silkworm lines varied in the general combining ability effects from -0.864 to 0.578, and the Chinese original silkworm lines did in ones from -0.570 to 1.018. 3. The specific combining ability effects of the silkworm lines made in order of the crossing types of JL (Japanese lines) $\times$CL (Chinese lines)>CL$\times$JL>JL$\times$JL> CL$\times$CL in a total cocoon weights and a cocoon layer weights. 4. The reciprocal combining ability effects of the silkworm lines was in order of the crossing types of JL$\times$CL>JL$\times$JL> CL$\times$CL>CL$\times$JL in a total cocoon weights and cocoon layer weights.

• 한국식품과학회지
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• 제35권5호
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• pp.871-876
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• 2003

본 연구는 뽕잎분말을 케이크의 제조에 기능성 소재로 이용하고자 실시되었으며, 이를 위하여 밀가루의 4, 8, 12, 16, 20%를 뽕잎분말로 대체하여 yellow layer cake를 제조하였다. 케이크의 품질은 반죽의 점도와 비중, 케이크의 baking 특성 및 저장기간중의 텍스쳐 변화를 측정하여 평가하였다. 뽕잎분말의 첨가량이 증가할수록 반죽의 점도와 케이크의 비체적은 증가하였다. 케이크의 대칭지수는 뽕잎분말의 양이 증가함에 따라서 감소하였으나, 총부피지수나 균일성 지수는 변화가 없었다. 저장기간 중의 경도변화는 뽕잎분말의 첨가량이 증가할수록 경도증가율이 낮았으며, 대조구보다 덜 단단한 것으로 나타났다. 관능검사결과 뽕잎분말을 첨가한 케이크의 부드러움성은 차이가 없었으며 촉촉한 정도는 뽕잎분말을 첨가한 케이크가 더 크게 나타났다.

• International Journal of Control, Automation, and Systems
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• 제2권4호
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• pp.423-434
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• 2004

In this paper, we introduce a new topology of Self-Organizing Polynomial Neural Networks (SOPNN) based on genetically optimized Multi-Layer Perceptron (MLP) and discuss its comprehensive design methodology involving mechanisms of genetic optimization. Let us recall that the design of the 'conventional' SOPNN uses the extended Group Method of Data Handling (GMDH) technique to exploit polynomials as well as to consider a fixed number of input nodes at polynomial neurons (or nodes) located in each layer. However, this design process does not guarantee that the conventional SOPNN generated through learning results in optimal network architecture. The design procedure applied in the construction of each layer of the SOPNN deals with its structural optimization involving the selection of preferred nodes (or PNs) with specific local characteristics (such as the number of input variables, the order of the polynomials, and input variables) and addresses specific aspects of parametric optimization. An aggregate performance index with a weighting factor is proposed in order to achieve a sound balance between the approximation and generalization (predictive) abilities of the model. To evaluate the performance of the GA-based SOPNN, the model is experimented using pH neutralization process data as well as sewage treatment process data. A comparative analysis indicates that the proposed SOPNN is the model having higher accuracy as well as more superb predictive capability than other intelligent models presented previously.reviously.

• 전기전자학회논문지
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• 제26권4호
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• pp.728-735
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• 2022

이번 연구에서 우리는 낮은 온 저항을 위해 p-well 영역 아래에 도입된 전류 확산층을 변화시켜 고전압 4H-SiC 전력 Diffused MOSFET(DMOSFET)에 대해 연구했다. Current Spreading Layer(CSL)의 두께(T_CSL)를 0~0.9 um, CSL의 도핑 농도(N_CSL)를 1~5×10¹⁶ cm^-3으로 변화시키면서 소자의 전기적 특성을 분석하였다. TCAD 2D-simulation을 통해 최적화되었으며 CSL이 온 저항을 낮추는 것뿐만 아니라 항복전압도 낮춤으로써 CSL의 최적화의 중요성을 확인하였다. 최적화된 구조는 59.61 mΩ·cm²의 온저항, 5 kV의 항복전압, 0.43 GW/cm²의 Baliga's Figure of Merit(BFOM)을 보여주었다.

• 대한기계학회논문집A
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• 제40권12호
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• pp.1013-1019
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• 2016

CFRP는 탄소섬유를 기반으로 수지를 합침하여 제조된 복합소재로, 높은 비 강도와 경량성을 지녀 다양한 분야들에서 널리 사용되어지고 있다. 특히 일방향 탄소섬유는 적층 각도를 적용할 수 있으며 이때 적용된 적층 각도로 구성된 CFRP는 적층 각도가 없는 것보다 더 높은 강성을 가지고 있다. 본 논문에서는 적층 각도 변화에 따른 CFRP 소형 인장시험편의 크랙 전파와 파괴거동에 관한 것으로, 각 적층 각도에 따른 크랙 성장의 특성을 고찰한다. 적층 각도가 증가함에 따라 최대 응력 값이 작게 나타나고 크랙 전파가 더디게 나타나지만, 적층 각도 $60^{\circ}$를 기점으로 그 응력이 다시 증가되므로 서, 적층 각도에 따른 한계를 보이고 있다. 본 연구결과는 기계구조물의 CFRP사용에 있어 구조물내의 결함이 발생하였을 때의 피로파괴 가능성을 검증하는 자료로 사용될 수 있다고 사료된다.

• 한국패류학회지
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• 제31권2호
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• pp.83-92
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• 2015

본 연구는 북방전복 육상 수조 내 고밀도 중간양성 방법을 모색하기 위해 부착면적 확대를 위해 다단식 shelter 설치와 수조 내 중층 이상의 가두리를 설치하여 성장을 비교하고 아울러 전복류 육상 양성방법인 'shallow race way' 국내 도입 가능성을 조사하였다. Shelter 실험구는 PE (polyethylene) 재질의 shelter ($63{\times}98cm$) 1층형 (the single layer shelter, SLS), 2층형 (the double layer shelter, DLS), 3층형 (the triple layer shleter, TLS) 과 육상 가두리 양성방식 (the single layer shelter and net cage culture, SLSNC), 그리고 'shallow race way' 방식을 polyvinyl chloride (PVC)로 제작하여 고랑수로양성 (culture of the ditch raceway tank, CDRT)과 편평한 수로양성 (culture of the floor raceway tank, CFRT) 방식을 설정하였으며, 실험구는 모두 2반복으로 실시되었다. 각 실험구별 SLS 기준 60%밀도로 수용한 실험 전복 (최초 수용 시 평균각장 $25.19{\pm}0.50mm$, 중량 $1.93{\pm}0.14g$), 성장에서 각장의 절대성장율 (absolute growth rate, ARG), 일간성장율 (daily growth rate, DGR) 및 순간성장율 (specific growth rate, SGR) 과 중량의 증중률 (weight gain, WG), 일간증중률 (daily weight gain, DWG) 에서 SLSNC 제외한 모든 실험구가 유의적인 차이가 없었다. 그리고 생존율에서는 CDRT와 CFRT가 유의적으로 낮았다 (P < 0.05). 따라서 shelter를 이용하여 부착면적을 확대한 고밀도 전복치패 육상 중간육성 사육 시 단층과 다단층에서 성장과 생존율에서 차이가 없으며, 호주 등에서 사용되는 shelter 없는 'shallow race way'의 얇은 수심사육은 국내 북방전복 육상 중간양성 방식으로 도입하기에 적합하지 않는 것으로 판단된다.

• 한국응용과학기술학회지
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• 제31권3호
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• pp.408-415
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• 2014

In order to prepare high-quality activated carbons (ACs), coal tar pitch (CTP), and mixtures of CTP and petroleum pitch (PP) were activated with KOH. The ACs prepared by activation of CTP in the range of $700{\sim}1000^{\circ}C$ for 1~5 h had very porous textures with large specific surface areas of $2470{\sim}3081m^2/g$. The optimal activation conditions of CTP were determined as CTP/KOH ratio of 1:4, activation temperature of $900^{\circ}C$, and activation time of 3 h. The obtained AC showed the highest micro-pore volume, and pretty high specific surface area and meso-pore volume. The micro-pore volumes and specific areas of activated mixtures of CTP and PP were similar to each other but the meso-pore volume could be increased. In order to change the degree of crystallinity of precursors before KOH activation process, the CTPs were carbonized in the range of $500{\sim}900^{\circ}C$. As the carbonization temperature increased, the specific surface area and pore volume of the activated ACs with the same activation conditions for CTP decreased dramatically. It was demonstrated that the increased pore size distribution of AC electrodes in the range of 1 to 2 nm plays an important role in the performance of electric double-layer capacitor.

• Journal of Biosystems Engineering
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• 제21권1호
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• pp.60-71
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• 1996

The purposes of this study were to develop a simulation model and to determine minimum specific airflow rate requirements for natural air drying of rough rice in Korea. A simulation model was developed considering energy and mass balances within grain bed, drying and rewetting rates, and hysterisis effect between sorption and desorption isotherms. As the results of validation test, the moisture contents predicted by the model agreed very well with the actual data. The criteria for determining minimum specific airflow rate requirements was that the top loom layer in the bin be dried to a moisture content below 16 percent wet basis with less than 0.5% drymatter decomposition. The minimum specific airflow rate requirements in 13 locations of Korea were presented based on the worst one among the past 7 to 13-year weather data. These requirements were also presented for all the combinations of three harvest dates and four harvest moisture contents. Specific airflow rate requirements seemed to be half by each 2 percent reduction in moisture content from 24 percent. As harvest date was delayed by 10 days from October 1, these requirements were reduced by about 20 to 40 percent.

• Transactions on Electrical and Electronic Materials
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• 제10권2호
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• pp.62-65
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• 2009

YBCO-coated conductors, called "second-generation wires," show a remarkably greater increase in the amount or speed of their resistance than BSCCO wires when a quench occurs. This is probably because of the specific resistance at their stabilizer layer, which also affects their voltage grade. YBCO coated conductors with copper as a stabilizer layer have a voltage grade of 1.5-2 V/cm, and those with stainless steel as a stabilizer layer have a voltage grade of about 0.5-0.6 V/cm. The voltage grade of YBCO coated conductors is important in selecting and applying superconducting wires to power instruments later. In this study, two kinds of YBCO-coated conductors with different stabilizer layers and one kind of BSCCO wire were prepared. Among them, based on the YBCO coated conductors that had a stainless steel stabilizer layer with a low voltage grade, five kinds of experimental samples for joining were prepared with the remaining two kinds of wires. Using the prepared samples, the current application properties and the resistance increase in the flux-flow and the quench states of the single wire and the joined wires were compared.