증숙마늘 분말 첨가 조청의 품질특성에 관한 연구

강민정,신정혜,Kang, Min-Jung,Shin, Jung-Hye 한국식품조리과학회 2012 한국식품조리과학회지 Vol.28 No.6

마늘의 섭취를 용이하게 하며, 전통식품과의 접목 방안을 모색하고자 증숙마늘 분말을 5~30% 첨가하여 전통적인 감미제인 조청을 제조하고 그 품질특성을 평가하였다. 탁도 및 착색도는 증숙마늘 분말 첨가량이 많아질수록 증가하는 경향이었는데 증숙마늘 분말 30% 첨가시 착색도는 대조군에 비해 3배 더 높았다. 조청의 점도도 동일한 경향으로 증숙마늘 분말을 30% 첨가하였을 때 점도는 $(272{\pm}2){\times}10^3$ cps로 대조군에 비해 2배 이상 증가하였다. 증숙마늘 분말을 첨가한 조청의 pH는 $4.31{\pm}0.11{\sim}4.58{\pm}0.02$의 범위로 대조군($5.35{\pm}0.12$)에 비해 유의적으로 낮았고, 환원당은 증숙마늘 분말의 첨가량이 많아짐에 따라 유의적으로 증가하여 30% 첨가시에는 $44.66{\pm}0.26$ mg/100 g이었다. HMF 함량은 대조군과 증숙마늘 분말 5% 첨가군과는 유의적인 차이가 없었으나 그 이상 첨가 시 유의적으로 증가하여 $3.55{\pm}0.10{\sim}4.87{\pm}0.08$ mg/kg의 범위였다. 유리당은 maltose, glucose, raffinose 및 fructose 순으로 높게 정량되었고, 증숙마늘 분말 첨가 조청은 대조군에 비해 maltose 및 raffinose의 함량은 낮고 fructose의 함량은 높았다. 관능평가 결과, 증숙마늘 분말 20% 미만 첨가시는 색, 감미, 전반적인 선호도에서 대조군과 유의적인 차이가 없었다. 이상의 결과를 종합하여 볼 때 마늘조청 제조시 증숙마늘 분말은 20% 미만으로 첨가함으로써 관능적 특성 및 이화학적 품질특성이 우수한 조청을 제조 할 수 있을 것으로 기대된다. This study was performed to investigate the effect of steamed garlic powder (SGP) on the quality characteristics of Jochung, saccharide by barley melt. Physicochemical properties and sensory quality were determined in Jochungs were prepared that 5% (SGP 5), 10% (SGP 10), 20% (SGP 20) and 30% (SGP 30) of SGP to sikhe for making jochung and hard boiled (W/W). Turbidity and viscosity of SGP added groups increased than control, significantly. The viscosity was $133{\pm}10^3$ cps in control group, it higher than SGP added groups ($140{\pm}11^3{\sim}272{\pm}2^3$ cps). The pH decreased with increasing SGP concentration. Reducing sugar was significantly higher in SGP added groups than control group, especially 30% SGP addition group in $44.66{\pm}0.26$ mg/100 g. HMF (Hydroxymethyl-furfural) content increased with increasing of SGP concentration, and 30% SGP addition group was higher in 48% than control group. In HPLC determination, free sugars content increased with amounts of SGP addition level. Fructose and glucose contents increased while maltose and raffinose contents decreased. Fructose content was $0.84{\pm}0.02$ mg/100g in control group but $1.36{\pm}0.03{\sim}1.62{\pm}0.01$ mg/100 g in SGP added groups. In the sensory evaluation, the color of Jochung decreased dose dependently with the SGP. Garlic flavor was significantly greater in SGP added groups compared to that of control group. The overall acceptability had not significantly difference among control, SGP 5 and 10 group. Preference was decreased in contain more than 20% of SGP added groups. The optimal concentration of SGP was found in the range of less than 10%.

Peacks over threshold를 이용한 Value at Risk: 모수추정 방법론의 비교

강민정,김지연,송종우,송성주,Kang, Minjung,Kim, Jiyeon,Song, Jongwoo,Song, Seongjoo 한국통계학회 2013 응용통계연구 Vol.26 No.3

국제적인 금융위기가 연달아 발생하면서, 금융리스크관리의 중요성이 어느 때보다 더 커지고 있다. 금융리스크관리의 주요 현안 가운데 하나는 리스크를 어떻게 측정할 것인가이며, 가장 널리 사용되고 있는 방법이 Value at Risk(VaR)이다. 금융자료가 최근 시장에서처럼 두꺼운 꼬리를 갖는 분포를 보일 때, 우리는 극단치 이론을 이용하여 VaR를 측정하는 방법을 고려할 수 있다. 이 논문에서는 꼬리가 매우 두꺼운 분포를 갖는 자료를 적합시킬 때 많이 사용되는 Peaks over Threshold(POT)를 이용하여 VaR를 측정하는 방법을 연구하였다. POT를 이용하기 위해서는 우선 일반화 파레토 분포(GPD)의 모수를 추정해야 하는데, 여기서 우리는 KOSPI 5분 자료를 이용하여 추정된 VaR의 성능을 살펴봄으로써 세 가지 다른 모수추정 방법을 비교하였다. 또한, Normal Inverse Gaussian(NIG) 분포에서 자료를 생성하여 두 가지 다른 모수추정 방법을 비교하기도 하였다. 이러한 비교를 통하여 KOSPI 수익률 자료의 첨도가 매우 큰 경우에는 최근 제안된 모수추정 방법들이 최대가능도 추정법에 비해 월등히 나은 성능을 보임을 알 수 있었고, 모의실험 자료에서도 같은 결과를 확인하였다. The importance of financial risk management has been highlighted after several recent incidences of global financial crisis. One of the issues in financial risk management is how to measure the risk; currently, the most widely used risk measure is the Value at Risk(VaR). We can consider to estimate VaR using extreme value theory if the financial data have heavy tails as the recent market trend. In this paper, we study estimations of VaR using Peaks over Threshold(POT), which is a common method of modeling fat-tailed data using extreme value theory. To use POT, we first estimate parameters of the Generalized Pareto Distribution(GPD). Here, we compare three different methods of estimating parameters of GPD by comparing the performance of the estimated VaR based on KOSPI 5 minute-data. In addition, we simulate data from normal inverse Gaussian distributions and examine two parameter estimation methods of GPD. We find that the recent methods of parameter estimation of GPD work better than the maximum likelihood estimation when the kurtosis of the return distribution of KOSPI is very high and the simulation experiment shows similar results.

어성초 분말을 급여한 돼지 등심의 냉장저장 중 품질특성의 변화

강민정,이준열,신정혜,최선영,이수정,양승미,성낙주,Kang, Min-Jung,Lee, Jun-Yeal,Shin, Jung-Hye,Choi, Sun-Young,Lee, Soo-Jung,Yang, Seung-Mi,Sung, Nak-Ju 한국식품영양과학회 2007 한국식품영양과학회지 Vol.36 No.2

어성초 분말을 사료에 0%, 5% 및 10% 첨가하여 12주간 사육한 돼지 등심의 냉장저장 중 품질특성을 분석하였다. 어성초의 일반성분은 조섬유가 $56.8{\pm}2.6%$로 가장 높은 함량이었으며 불포화지방산인 oleic acid(C18:1)의 비율이 29.6%로 가장 높았다. 각 실험군의 관능평가 결과 어성초 분말 5% 첨가군이 연도와 누린내에서 기호도가 높게 평가되었으며 전체적인 선호도도 가장 우수하였다. 돈육 등심을 23일간 냉장 보관하면서 이화학적인 성분을 분석한 결과, 수분함량은 10% 어성초 분말 첨가 급이군에서 다소 높았으며 조지방 함량은 대조군에 비해 어성초 분말 첨가 급이군에서 유의적으로 낮은 함량이었다. pH는 실험군간 및 저장기간의 경과에 따른 유의적인 차이가 없었으며 육색 중 L값과 a값은 저장기간의 경과와 더불어 증가하는 경향이었고 b값은 저장 초기에 증가하였다가 이후에는 그 변화가 미미하였다. 전단가는 저장 2일에서 9일 사이에 가장 큰 폭으로 감소하였으며 그 이후에는 급격한 연도의 저하는 없었다. This study was carried out to investigate the influence of feeding eosungcho (Houttuynia cordata Thunb) powder on the meat quality of porks at chilled storage. Experimental groups were divided into control group (0%, C), 5% (T1) and 10% (T2) eosungcho powder feeding group, and then administered for 12 weeks. The results of sensory evaluation for softening value and scorched smell showed the highest preference in T1 group. Overall acceptability was also the highest in T1 group than the others. Physicochemical components were analyzed for pork loins that were stored at $4^{\circ}C$ for 23 days after vacuum packing. The moisture contents of pork loins were higher in T1 group than the others. Crude lipid contents were lower in T1 and T2 groups than the control group. The pH values were not significantly different in experimental groups during storage days. The Hunt L and a values increased significantly according to storage days. The Hunt b value was increased for the initial storage days but it did not change after 9 storage days. The Warmer-Bratzler share force of all experimental groups were greatly decreased between 2 and 9 storage days and then little exchanged afterwards.

Trehalose에 의한 Rahnella aquatilis AY2000 균주가 생산하는 항효모성 물질의 활성보호

강민정,이종환,이복규,김광현,Kang, Min-Jung,Lee, Jong-Hwan,Lee, Bok-Kyu,Kim, Kwang-Hyeon 한국미생물·생명공학회 2009 한국미생물·생명공학회지 Vol.25 No.4

AYS(Anti-yeast substance)는 열에 의해 항효모 활성이 쉽게 약화되는 물질로서 trehalose의 사용이 AYS의 열에 대한 불안정성을 어느 정도 극복할 수 있을 것인지를 조사하기 위해 trehalose가 첨가된 AYS와 trehalose가 첨가되지 않은 AYS에 대한 항효모 활성을 비교 측정하였다. 그 결과 trehalose가 첨가된 AYS는 고온($50-70^{\circ}C$)에서 단시간(2 hr) 동안 열처리한 경우에 trehalose가 함유되지 않은 AYS에 비해 그 활성이 비교적 잘 유지되었다. 따라서 trehalose를 AYS에 첨가하면 열처리 후에도 AYS의 항효모 활성을 다소 보호할 수 있다. Rahnella aquatilis strain AY2000 produces an anti-yeast substance (AYS), however activity of the AYS tends to be decreased by heat. To investigate whether trehalose can protect AYS activity against heat, comparative studies on the AYS with and without trehalose were performed. After heat treatment at high temperatures ($50^{\circ}C-70^{\circ}C$), the AYS with trehalose had higher activity than the AYS without trehalose had. In case of AYS with trehalose (0.3-0.9M), activity of the AYS could be determined at ranging from $7.8\;{\mu}g/mL$ to $31.3\;{\mu}g/mL$ on S. cerevisiae by MTT method. Consequently, activity of the AYS after heating was well maintained by trehalose.

《산학정의(算學正義)》 〈대연(大衍)〉에 나타난 대연구일술(大衍求一術)의 구조

강민정,Kang, Min-Jeong 한국수학사학회 2021 Journal for history of mathematics Vol.34 No.5

The simple simultaneous linear congruence equation solution in 《Sunzi Suanjing孫子算經》 has developed into a systematic general solution in 《Shuxue Jiuzhang數書九章》. The most important parts of it is the creation of the Dayan Qiuyishu大衍求一術. The reason why 《Sanhak Jeongeui算學正義》 deals with the Dayanshu大衍術 which has lost its practicality in the calculation of astronomical calendar, is that one of the best achievement of traditional mathematics cannot be omitted. It is written with an emphasis on the disclosure of the calculation principle. It shows that Nam Byeong-gil南秉吉 and Lee Sang-hyeok李尙爀 had a fairly structural understanding of the Dayan Qiuyishu.

붕괴모의실험을 통한 산사태 조기경보용 계측센서의 반응성 분석 및 활용성 고찰

강민정,서준표,김동엽,이창우,우충식,Kang, Minjeng,Seo, Junpyo,Kim, Dongyeob,Lee, Changwoo,Woo, Choongshik 한국산림과학회 2019 한국산림과학회지 Vol.108 No.2

The goal of this study was to analyze the reactivity of a volumetric water content sensor (soil moisture sensor) and tensiometer and to review their use in the early detection of a shallow landslide. We attempted to demonstrate shallow and rapid slope collapses using three different soil ratios under artificial rainfall at 120 mm/h. Our results showed that the measured value of the volumetric water-content sensor converged to 30~37%, and that of the tensiometer reached -3~-5 kPa immediately before the collapse of the soil under all three conditions. Based on these results, we discussed a temporal range for early warnings of landslides using measurements of the volumetric water content sensors installed at the bottom of the soil slope, but could not generalize and clarify the exact timing for these early warnings. Further experiments under various conditions are needed to determine how to use both sensors for the early detection of shallow landslides. 이 연구는 붕괴모의실험을 통하여 체적함수비센서와 텐시오미터의 반응성을 분석하고, 산사태 조기경보용으로의 활용성을 검토하기 위해 수행되었다. 산림토양과 사질토의 배합비율을 조정한 3개의 토양조건에서 120 mm/h의 인공강우를 적용하여 얕은 깊이에서 빠르게 진행되는 붕괴형태를 실험적으로 모의하고, 그 과정에서의 두 센서의 반응을 분석하였다. 그 결과, 모든 실험조건에서 체적함수비센서 및 텐시오미터의 계측값은 각각 30~37%, -3~-5 kPa으로 수렴된 이후에 붕괴가 발생하였다. 실험결과를 토대로 토층 최하부에 설치된 체적함수비센서의 계측값을 활용하여 조기경보 발생시점의 범위를 논의하였으나, 이를 일반화하여 명확한 시점으로 규정할 수는 없었다. 두 센서를 실용적인 차원에서 산사태 조기경보용으로 활용하기 위해서는 다양한 조건에서의 추가적인 실험 및 검증이 필요할 것으로 생각되었다.

서울 일부 지역 노인의 체지방률, 허리둘레와 체질량지수에 의한 비만 분류 및 만성질환 유병율과의 연관성

강민정,박정영,김정연,이연주,도민희,이상선,Kang, Min Jeong,Park, Jung Young,Kim, Jung Yun,Lee, Yeon Joo,Do, Min Hee,Lee, Sang Sun 한국식품영양학회 2014 韓國食品營養學會誌 Vol.27 No.3

The purpose of this study was to compare the validity of obesity indices among the body mass index (BMI), waist circumference (WC), and body fat percentage (BF%), and to determine which is the most useful index to predict the risk of chronic diseases of elderly people. This study was conducted as a cross-sectional study at welfare centers in Seoul. The total number of subjects was 261 (68 men and 193 women) with age ${\geq}60$ years. The distribution of obesity using 3 obesity indices in the subjects with hypertension, diabetes, or arthritis was BF%>WC>BMI in elderly men and WC>BF%>BMI in elderly women. In elderly women, odds ratios (ORs) for hypertension in BMI and WC quartiles were significantly increased in quartile 2 and 3 (p<0.05). The ORs for hypertension, hyperlipidemia, and arthritis in BF% quartiles were significantly increased in quartile 3 and 4 (p<0.05). The BF% was sensitive obesity index for predicting the occurrence of chronic disease in men, and the WC was sensitive index in women. Our results suggested maintaining BMI less than $23.5kg/m^2$, WC less than 82 cm, and BF less than 35% in order to prevent chronic diseases in elderly women.

자동차 이차전지 제조를 위한 알루미늄과 무산소동의 레이저 용접특성

강민정,박태순,김철희,김정한,Kang, Minjung,Park, Taesoon,Kim, Cheolhee,Kim, Jeonghan 대한용접접합학회 2013 대한용접·접합학회지 Vol.31 No.6

Several joining methods involving resistance welding, laser welding, ultrasonic welding and mechanical joining are currently applied in manufacturing lithium-ion batteries. Cu and Al alloys are used for tab and bus bar materials, and laser welding characteristics for these alloys were investigated with similar and dissimilar material combinations in this study. The base materials used were Al 1050 and oxygen-free Cu 1020P alloys, and a disk laser was used with a continuous wave mode. In bead-on-plate welding of both alloys, the joint strength was higher than the strength of O tempered base material. In overlap welding, the effect of welding parameters on the tensile shear strength and bead shape was evaluated. Tensile shear strength of overlap welded joint was affected by interfacial bead width and weld defect formation. The tensile-shear specimen was fractured at the heat affected zone by selecting proper laser welding parameters.

Al/Fe 이종금속 접합부의 부식특성

강민정,김철희,김준기,김동철,김종훈,Kang, Minjung,Kim, Cheolhee,Kim, Junki,Kim, Dongcheol,Kim, Jonghoon 대한용접접합학회 2014 대한용접·접합학회지 Vol.32 No.4

The use of light-weight Al alloys in the automotive industry is increasing to meet requirements for fuel efficiency and emission reduction. Joining Al alloy to the conventional steel sheet is also very important issue with the increased use of Al alloy, and several joining processes have been introduced to enhance joining strength between dissimilar metals. This paper deals with a galvanic corrosion in the dissimilar metal joining. Salt spray tests up to 2000 hours were conducted on a self-piercing rivet, spot welded, adhesive bonded and weld-bonded joints, and cross-sections and tensile shear strength according the salt spray duration were analyzed at every 500-hour. Self-piercing rivet joint had relative low initial strength but the joint strength did not change regardless of the salt spray duration. The strength of other joints (spot welded, adhesive bonded and weld-bonded joints) decreased with the increase of salt spray duration and the corrosion behaviour of each joint was discussed.

산대셈 개방법(開方法)에 대한 《산학정의》의 독자적 성취: 어림수[상(商)] 배열법 개선을 통한 증승개방법(增乘開方法)의 정련(精鍊)

강민정,Kang, Min Jeong 한국수학사학회 2018 Journal for history of mathematics Vol.31 No.6

The KaiFangFa開方法 of traditional mathematics was completed in ${\ll}$JiuZhang SuanShu九章算術${\gg}$ originally, and further organized in Song宋 $Yu{\acute{a}}n$元 dinasities. The former is the ShiSuoKaiFangFa釋鎖開方法 using the coefficients of the polynomial expansion, and the latter is the ZengChengKaiFangFa增乘開方法 obtaining the solution only by some mechanical numerical manipulations. ${\ll}$SanHak JeongEui算學正義${\gg}$ basically used the latter and improved the estimate-value array by referring to the written-calculation in ${\ll}$ShuLi JingYun數理精蘊${\gg}$. As a result, ZengChengKaiFangFa was more refined so that the KaiFangFa algorithm is more consistent.