고속가공에서 2중 신경망을 이용한 표면거칠기 예측과 가공DB 구축 효율화 방안

원종률,남성호,유송민,이석우,최헌종 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

In this paper, a double artificial neural network (ANN) approach and the efficient machining database building scheme are presented for the prediction of surface roughness in high-speed machining. In this approach, 4 machining parameters and used for the prediction of cutting force components, and the combinations of 4 parameters and the predicted cutting force components are finally used for the prediction of surface roughness. The experimental results comparing the these results with the predicted values using simple 4 input nodes have been also investigated to verify the effectiveness of the proposed approach.

악성 섬유성조직구종에서 ras 유전자의 돌연변이

유진영,이아원,강석진,김병기 대한병리학회 2001 Journal of Pathology and Translational Medicine Vol.35 No.3

인체 연부조직 육종에서 Cyclin D1, CDK4,p16 및 Rb 단백의 발현

유진영,이아원,강석진,김병기 대한병리학회 2001 Journal of Pathology and Translational Medicine Vol.35 No.3

VHDL의 파서 구현

元裕憲,金忠錫 弘益大學校 1989 弘大論叢 Vol.21 No.2

In this study, we designed and implemented an analyzer for IEEE standard VHDL. It is one of the five tools in the VHDL support environment. The VHDL analyzer generated from LALR(1) accepts VHDL text to check syntactic and semantic validities. It generates error messages for the source text and an intermediate expression for other VHDL tools. This intermediate expression is made from symbol table and AST. The symbol table contains the information about attributes of identifiers and AST represents the entire structure of the source text. The implementation of symbol table and AST was done by adding C programs to the input of syntactic analysis. The analyzer was implemented in C language with Lex and Yacc in the UNIX system.

풍황자원 예측시 기상청 풍황자료의 유효성

황윤석,이원선,백인수,유능수 江原大學校 産業技術硏究所 2009 産業技術硏究 Vol.29 No.B

The wind data measured from automated weather stations (AWS) at complex terrains in Korea was used to predict the wind velocity at nearby sites that are several kilometers away. The ten-minute averaged wind data was measured at a height of 10 meters. A commercial CFD code, WindSIM, based on the weighted averaged Navier-Stokes equation was employed. The results were compared with the data measured using meteorological masts (MM) at a height of 40 meters. The predictions using the AWS data and WindSIM showed good agreements with the measured data.

성장과 운동수행능력 향상에 도움을 주는 식이조성물의 개발

윤승원,정은희,양동식,이홍석,윤유식 대한지역사회영양학회 2003 대한지역사회영양학회지 Vol.8 No.3

We developed a dietary supplement using natural herbs and nutrients for the growth and exercise performance improvement. It called JR-22 supplement containing distilled extracts of natural herbs to remove bitterness and the addition of Vitamin B1, B6, Ca and xylitol. We investigated on the effect of JR-22 supplementation on the maximal exercise performance, IGF-1 (insulin like growth factor-1) concentration and antioxidant activity in SD rat model. In result, JR-22 supplement group was better than control group about 10% in exercise performance test and increased about 63% of IGF-1 concentration in blood. In addition, the oxidative damage induced by exercise was reduced by JR- 22 supplementation. Therefore, we suggested that JR-22 supplementation enhanced effectively exercise performance and IGF-1 concentration and reduced to oxidative stress in muscles. Also, we analysed biochemical factors in blood for the safety of JR-22 supplement. We known that there is no change of blood lactic acid, ammonia, inorganic phosphorous ion and creatine kinase activity.

WAsP과 WindSIM의 풍력자원예측성 평가

이원선,황윤석,백인수,유능수 江原大學校 産業技術硏究所 2009 産業技術硏究 Vol.29 No.B

Simulations using two well-known commercial codes, WAsP and WindSIM, were performed to predict the wind resources in complex terrains of Korea. The predictions from the codes were compared with the measured data. Cross predictions were performed for two closely located measurement sites. The results from WindSIM were found to be more accurate than those from WAsP. The predictions for wind velocity and direction in five different sites of complex terrain from WAsP and WindSIM were also compared. It was found that if the self prediction of the wind velocity and direction from WAsP is close to the measured wind data, the discrepancies between WAsP results and WindSIM results are also close.

침강성 탄산칼슘 생성에 관한 연구

이광래,유동석,강석원 강원대학교 석재복합신소재제품연구센터 1997 석재연 논문집 Vol.2 No.-

수산화칼슘 슬러리(aqueous Ca(OH)₂ slurry) 농도가 비교적 높은 1 wt% ∼7 wt% 범위에서 공정변수인 탄산가스 유량과 교반속도에 다른 물질전달계수를 구하고, 수산화칼슘 슬러리의 농도변화에 따른 입자형태 및 입자크기 변화를 관찰하였다. 수산화칼슘 슬러리의 농도에 따른 탄산화반응은 0차반응이었으며, CO₂에 대해서는 1차반응이었다. 따라서 탄산화반응은 0차반응과 1차반응이 혼재된 준1차반응임을 알 수 있었다. 반응종결점은 수산화칼슘 슬러리의 농도가 증가함에 따라 pH 및 전기전도도법에 의한 예측보다 늦어지는 것으로 나타났다. 물질전달속도는 수산화칼슘 슬러리의 농도(0.158∼7wt%)와 교반속도(300∼700rpm)에 무관하게 각각 일정한 값을 나타내었고, CO₂ 유량의 증가에 따라서는 비례적으로 증가하였다. 이러한 물질전달은 탄산화반응으로 인하여 증진되어짐을 알 수 있었으며, 증진인자(enhancement factor, Φ)는 1.394였다. 기체측 경막저항은 다른 물질 전달저항에 비하여 무시할 수 있을 정도로 작았으며, CO₂와 OH(???)간의 반응이 매우 빠른 반응이므로 탄산화반응시의 물질전달속도를 지배하는 물질전달저항은 OH(???)의 해리속도와 관련된 고-액 경막을 통한 물질전달저항임을 알 수 있었다. 본 실험의 수산화칼슘 슬러리의 농도범위(0.158∼7wt%)에서 생성된 탄산칼슘은 서브마이크론(submicron) 크기의 탄산칼슘이었으며, 결정구도는 방해석(calcite) 구조였다. 생성된 탄산칼슘의 입자형태는 Ca(OH)₂의 포화농도(0.158wt%)에서 판상형태였으며, 수산화칼슘[Ca(OH)₂] 슬러리 농도가 비교적 낮은 lwt%∼3wt% 영역에서는 입방체형태였다. 농도가 비교적 높은 4wt%∼7wt%에서는 수산화칼슘 슬러리 농도가 증가함에 따라 입방체 형태가 사라지고, 입자모양은 응집된 형태로서 길게 크졌다. 입자가 길게 크지면서 입방체형태가 없어지는 것은 슬러리 농도가 증가할수록 응집현상이 지배적으로 나타나기 때문으로 판단된다. Since the concentration of hydrated lime is higher than 1wt% in industrial carbonation processes, the carbonation reactions were conducted in relatively high concentration range of aqueous Ca(OH)₂ slurry from 1wt% to 7wt%. Reaction rate, reaction order, and termination time of carbonation reaction as well as mass transfer coefficients which are major variables for reactor design were investigated with concentration of aqueous Ca(OH)₂ slurry, flow rate of carbon dioxide, and agitation speed. Carbonation was a 0th and a 1st order reaction with respect to the concentration of aqueous Ca(OH)₂ slurry and flow rate of carbon dioxide, respectively. Hence it was found that the carbonation was a pseudo 1st order reaction conjugated with 0th and 1st order. It was exhibited that the termination time of reaction measured by titration technique took longer than that predicted by pH and conductivity method due to the agglomeration effect caused by the high concentration of aqueous Ca(OH)₂ slurry. In the range of the experiments, there was no dependency of mass transfer rates on concentration(0.158∼7wt%) of aqueous Ca(OH)₂ slurry and agitation speed (300∼700rpm). However, mass transfer rates were proportionally increased with increasing flow rate of carbon dioxide. Moreover, mass transfer rates were enhanced by carbonation. The enhancement factor(Φ) was 1.394. Gas-film resistance was negligible because it is so small in comparison with other resistances. The reaction between carbon dioxide and hydroxyl ion was fast enough so that the mass transfer rate was controlled by the diffusion through solid-liquid film due to the dissolution of lime in carbonation. The size of calcium carbonate prepared by carbonation reaction in the concentration range of this experiment(0.158w%∼7wt%) was of submicron. At the saturated concentration (0.158wt%) of aqueous Ca(OH)₂ slurry, particle shape of calcium carbonate was a plate form, and its crystal structure was of calcite. At the relatively low concentration (1∼3wt%) of aqueous Ca(OH)₂ slurry, particle shape of calcium carbonate was a cubic. However, in higher concentration (4wt%∼7wt%) the cubic shape disappeared with increasing concentration of aqueous Ca(OH)₂ slurry. The particles became bigger in size and changed to agglomerate shape. It might be inferred that the change of particle size and shape with increasing concentration of aqueous Ca(OH)₂ slurry is due to the agglomeration effect. The agglomeration effect substantially appeared with increasing concentration(4∼7wt%) of queous Ca(OH)₂ slurry.

장내의 탄수화물과 지방 흡수 억제를 통한 체지방 및 비만 개선 효과에 관한 연구

정은희,윤승원,이홍석,윤유식,유경미,황인경 한국조리과학회 2003 한국식품조리과학회지 Vol.19 No.1

In a previous study, a dietary supplement was developed in our lab using natural herbal extracts against digest enzyme activity in GI tract for weight control. This natural herbal extracts could regulate absorption of glucose and lipid by the inhibition of digest enzyme activity. In this study, we screened the natural herbs that inhibit glucoamylase activity and developed an water extract of cinnamon. The cinnamon extract delayed and decreased the increment of carbohydrate degradation through the inhibition of glucoamylase activity in vitro. Fifty volunteers were subjected to the intake of the herbal extracts by taking twice a day for 60 days. As a result, the treated subjects lost 3kg of body weight and 3.5kg of body fat mass after the treatment. Furthermore, the body mass index and waist size were significantly decreased during the experimental period. Above results suggested that the administration of the dietary additives composed of cinnamon and natural herbal extract improves the obesity by the decrement of body weight and body fat mass.

강원대학교 석재복합신소재제품연구센터

조정식,이광래,유동석,강석원 강원대학교 석재복합신소재제품연구센터 1996 석재연 논문집 Vol.1 No.-

석회유의 탄산화반응에 의하여 생성되는 탄산칼슘의 결정화공정에 대한 정량적 해석을 위하여 개체군 수지식(population balance)을 이산화(discretization)하는 방법에 의해 반회분식 침전결정화기에서 생성된 탄산칼슘의 입도분포를 수치모사하여 실험치와 비교하였다. 수치모사에 의한 탄산칼슘의 입도분포는 실험치와 잘 일치하였으며, 응집이 입자크기에 의존(size-dependent agglomeration)한다고 가정한 경우가 응집이 입자크기와는 무관(size-independent agglomeration)하다고 가정한 경우보다 실험치에 더 근사한 결과를 보였다. 또한, 응집핵(agglomeration kernel)이 깨어짐핵(rupture kernel)보다 입도분포에 미치는 영향이 더 큰 것을 알 수 있었다. For the quantitative analysis of crystallization of calcium carbonate formed by carbonation of lime milk, PSD(particle size distribution) of the calcium carbonate, which is the carbonation product of lime milk, was numerically simulated by the method of discretization of population balance and compared with the experimental data of semi-batch precipitative crystallizer. The simulated PSD was well correlated with the experimental data. And the simulated results of PSD for size-dependent agglomeration were well-matched to the experimental data than for the size-independent agglomeration. Moreover, it was shown that agglomeration kernel had greater effects on PSD than rupture kernel.