Effect of Hydrocolloids on the Pasting and Rheological Characteristics of Resistant Starch (Type 4)

이광연,Hua Yao,배인영,이수용,이현규 한국식품과학회 2012 Food Science and Biotechnology Vol.21 No.3

The pasting and rheological properties of resistant starch-type 4 (RS4) and hydrocolloid mixtures were characterized at 2 different concentrations (0.1 and 0.5%, w/v). When RS4 was mixed with 2 hydrocolloids (pectin and xanthan gum), there was the overall tendency that both swelling power and solubility of the RS4 suspensions significantly increased. Steady shear measurements showed that the RS4 and hydrocolloid samples exhibited shearthinning behaviors which could be well characterized by the Power law model. A dramatic increase in the viscosity by xanthan gum was also observed, compared to pectin. In addition, dynamic oscillatory tests indicated that the RS4and hydrocolloid mixtures exhibited more elastic properties with less frequency dependence, compared to RS4 alone. Also, the viscosities of the RS4 suspensions during pasting increased with increasing concentrations of the hydrocolloids used and these effects became significantly dominant when xanthan gum was incorporated.

기상청 현업 일기 예보 생산 및 소통 과정 진단

이광연,임윤진,박정민 한국기상학회 2023 한국기상학회 학술대회 논문집 Vol.2023 No.4

A NOTE ON SIGN CENTRAL MATRICES

이광연 한국전산응용수학회 2002 Journal of applied mathematics & informatics Vol.10 No.1

In this paper we study when a sign pattern matrix A and a sign pattern vector b have the property that the convex hull of the columns of each matrix with sign pattern A contains a vector with sign pattern b. This study generalizes the notion of sign central matrices.

A characterization of the nearly sign central matrices and its minimallity

이광연,You-Ho Lee 한국전산응용수학회 2004 Journal of applied mathematics & informatics Vol.14 No.-

The sign central matrices were characterized by Ando and Brualdi. And, the nearly sign central matrices were characterized by Lee and Cheon. In this paper, we give another characterization of nearly sign central matrices. Also, we introduce the nearly minimal sign central matrices and study the properties of nearly minimal sign central matrices.

그래프 이론을 이용한 고속도로 분석 알고리즘에 관한 연구

이광연,박기섭 한국컴퓨터정보학회 2023 韓國컴퓨터情報學會論文誌 Vol.28 No.6

In this paper, we propose the algorithms of accessibility indices using graph theory to analyze the connectivity of the highway traffic network and predict the central city. First, we find a transportation network that represents the highway traffic network in 2025 using graph theory. And we implement the algorithms of accessibility indices to efficiently and accurately analyze and predict the connectivity of the highway traffic network in 2025 from a given transportation network. Through the analysis results of 2025 obtained by using the proposed algorithm, we can find a city that is the center city of transportation in the highway transportation network, and it is used as information to improve the connectivity of the nationwide highway traffic network in the future. 본 논문에서는 고속도로 교통망의 연결성을 분석하고 중심이 되는 도시를 예측하기 위하여 그래프 이론을 이용하여 접근성 지표의 알고리즘을 제안한다. 먼저 그래프 이론을 이용하여 2025년고속도로 교통망을 운송네트워크로 표현한다. 그리고 운송네트워크로부터 2025년 고속도로 교통망의 연결성을 효율적이고 정확하게 분석하고 예측하기 위한 접근성 지표의 알고리즘을 구현한다. 제안된 접근성 지표의 알고리즘을 통하여 얻은 2025년의 분석 결과를 활용하여 고속도로의운송네트워크에서 교통의 중심도시를 찾을 수 있고, 상대적으로 교통의 접근성이 낮은 도시를 찾아, 향후 전국의 고속도로 교통망의 연결성을 개선시키는 정보로 활용한다.

영상 데이터베이스를 위한 다중시점 영상 부호화 방안 ( Multiviewpoint Image Coding Scheme for Image Database )

이광연,김민섭,조순제,김성대 대한전자공학회 1997 대한전자공학회 학술대회 Vol.1997 No.1

디지털 항공사진 판독기법을 이용한 산사태 발생 위험지 예측에 관한 연구: 우면산 일대를 대상으로

이광연,김경남,장수진,서기범,김범수,전근우 한국방재학회 2016 한국방재학회논문집 Vol.16 No.3

Applying stereovision-typed aerial photo for the landslide analysis of mountain is one of the popular method in the parts of geomorphology and disaster analysis. This study explores the landslide effects by overlapping digital aerial photo, digital terrain map, and DEM on the soft photogrammetry. The standardization for observing the landslide effects is developed, and systematization is explored by interpreting the procedure and know-how, and finally drawing up of a interpretation map. In this way, total of 23 types of interpretation indicator were selected, and able to develop the procedure for overlapping data selected for applying each indicator. Finally, the whole process was applied to the case of Mt. Umyeon in the city of Seoul, and could developed 13 interpretation legends. 항공사진을 입체시하여 산지붕괴와 관련된 전조현상을 파악하기 위한 노력은 지형학과 방재학 분야에서 폭넓게 시도되어 왔다. 이 연구에서는 최근 독립적으로 이용되는 디지털항공사진, 수치지형도 및 DEM을 소프트도화기 상에서 중첩분석하여 토사재해 전조현상을 파악하고자 하였다. 전조현상 파악의 표준화를 위해 토사재해 관련 미지형을 판독지표로 개발하였고, 소프트도화기 상에서 이를 판독하는 절차와 요령 그리고 최종적으로 판독도를 작성하는 방안을 체계화하고자 하였다. 연구를 통하여 총 23종의 판독지표가 선정되었고, 각 지표의 판독적용을 위한 data 간의 중첩분석 절차를 개발할 수 있었다. 최종적으로 2011년 7월 대형 산사태가 발생한 서울시 우면산을 대상으로 전체 판독지표 중 13종의 판독기호를 개발하였다.

BF₃ 함유 이분자형 키랄 살렌 촉매에 의한 고광학순도의 에피클로로히드린 합성

이광연,카테카라울,김건중,Lee, Kwang-Yeon,Rahul, B. Kawthekar,Kim, Geon-Joong 한국공업화학회 2007 공업화학 Vol.18 No.4

In this study, new dinuclear chiral Co (salen) complexes bearing $BF_3$ have been synthesized and their properties as the asymmetric catalyst have been examined. The NMR, UV and ESCA analyses were performed to determine the structure of synthesized catalysts. Their catalytic activity and selectivity have been demonstrated for the asymmetric ring opening of various terminal epoxides by hydrolytic kinetic resolution technology. The easily prepared dimeric complexes exhibited very high enantioselectivity for the asymmetric ring opening of epoxides with $H_2O$ nucleophile, providing enantiomerically enriched terminal epoxides (> 99 %ee). The dimeric structured chiral salen showed remakablely enhanced reactivity and may be employed substantially lower loadings than its monomeric analogues, and in addition no racemization happened during the separation of product epoxides. The system described in this work is very efficient for the sinthesis of chiral epoxide and 1,2-diol intermediates. 본 연구에서는 $BF_3$를 함유한 키랄성 코발트 살렌 촉매를 합성하고 비대칭촉매특성을 평가하였다. 촉매의 구조를 결정하기 위하여 NMR, UV 및 ESCA분석을 수행하였다. 합성한 촉매는 여러 종류의 에폭사이드 유도체의 가수분해 속도차에 의한 비대칭 고리열림반응에 적용하여 그 활성과 선택성을 조사하였다. 살렌과 $BF_3$의 비를 다르게 하여 합성한 촉매는 전혀 다른 촉매 활성을 나타내었으며, 그 비를 2 : 1로 하여 합성한 2분자구조의 살렌착체 촉매는 물을 친핵체로 하는 라세믹 에폭사이드의 고리 열림을 통하여 99 %ee 이상의 매우 높은 광학선택성을 보였다. 특히 2분자형의 살렌 촉매는 단분자형의 촉매에 비하여 촉매량을 적게 첨가하여도 현저히 향상된 촉매활성을 나타내었고 얻어진 생성물의 분리과정에서 라세믹화를 유발시키지 않았다. 본 연구에서 적용한 촉매시스템은 키랄 에폭사이드 및 1,2-디올 중간체의 제조에 매우 효과적이었다.

Effect of the Degree of Enzymatic Hydrolysis on the Physicochemical Properties and in vitro Digestibility of Rice Starch

이광연,Suyong Lee,이현규 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.5

Rice starch was subjected to enzymatic treatment with pullulanase and the physicochemical properties of the modified rice starch were investigated as a function of the degree of hydrolysis which ranged from 0.9 to 10.2%. The enzymatic hydrolysis of rice starch caused a decrease in the fraction of rapidly digestible starch (RDS) (78.31→44.65%), whereas the levels of slowly digestible starch (SDS) (0.8→22.18%) and resistant starch (RS) (20.79→34.43%) increased, consequently reducing in vitro starch digestibility. In addition, the swelling factor of rice starch decreased with increasing enzyme concentration while an increase in its syneresis was observed. In rapid visco analyser (RVA) measurement, dramatic decreases in the peak viscosity (452.5→12.0 cp), breakdown (307.0→4.5cp), and setback (207.0→3.0 cp) were observed in the enzyme-treated rice starch of which X-ray diffraction showed that there was the coexistence of A-and V-type crystallinity.

Effect of Modified Dietary Fiber Extracted from Wholegrain Wheat on the Physicochemical and Cake Properties

이광연,Ka Hwa Park,이현규 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.2

Dietary fiber (DF) extracted from whole wheat was chemically modified by cross-linking (CL), carboxymethylation (CM), and hydroxypropylation (HP) and their physicochemical properties and baking performance were evaluated. CM contributed to the increase in soluble DF (SDF) contents and water solubility. While CL and HP contributed to the decrease in water solubility as insoluble DF (IDF) contents increased. In comparison to the chemically modified DF, CLDF deteriorated textural and physical properties of cakes. On the other hand, the cakes with CMDF and HPDF had improved cake qualities such as appearance, higher volume and lower hardness compared to cake with native DF. Consequently, this study suggested that the chemical modifications of wheat DF can effectively regulate the IDF/SDF ratio and total dietary fiber (TDF) contents, resulting in the change of physicochemical properties of them. When applied to cake, modified wheat DF diversified the physicochemical properties and quality by a functional group.