An Empirical Study on Credit Card Usage

정혜민,조성진,Justin Chung 한양대학교 경제연구소 2013 JOURNAL OF ECONOMIC RESEARCH Vol.18 No.1

This paper is an empirical examination of the pattern of credit card usage and its implications for the profitability of the credit card companies. Using a detailed micro dataset obtained from one of the leading credit card companies, we first verify the validity of several conjectures regarding credit card usage of customers, and then try to compare the characteristics of the most and least profitable customers to the company. We then proceed to identifying occupational groups of the customers based on the purchasing pattern of customers. Finally, we attempt to replicate the credit card company's own credit rating system using a simple regression, and successfully identify several important factors affecting the credit ratings of the customers. We believe that the paper plays an important role in providing substantial information on the factors affecting the credit rating of customers and on credit card usage at the micro level.

Proposal of Smart Cart Design to Improve User Experience

Hyemin Chung(정혜민),Hanyoung Lee(이한영),Sechon Park(박세천) 대한인간공학회 2021 대한인간공학회 학술대회논문집 Vol.2021 No.11

Objective: The aim of this study is to improve users’ shopping experience through smart shopping cart design, which complements the inconvenience of existing shopping carts. Background: Consumers experience several difficulties in supermarkets. Common problems are spending time searching for products and waiting in line at the counter. For the convenience of customers, unmanned technology is in progress, and cases of using smart shopping carts are increasing. Method: To figure the focus points for design, we first divided the research field into three; general, unmanned, and smart carts. We then identified each category’s (1) shopping path, (2) how to find the goods, and (3) how users pay. The wasted time while shopping was discovered through this comparative analysis, and we looked into factors that could reduce shopping time. Through the prototype testing, we figured out that it is necessary to optimize the speed of product recognition. This is because lower barcode recognition functions also affect user shopping experiences. Results: The smart shopping cart noticeably reduced shopping times and routes through installed payment function and touchscreen. There is no need to take out and put the goods back in for payment, since the search for product’s location information on the touchscreen can be obtained immediately without having to wander or look for staff. The app linkage also increased the user’s shopping quality in the supermarket. Conclusion: Nowadays the users are oriented towards convenience. In line with the user trends, supermarkets are becoming unmanned using self-counters. The smart shopping cart we designed is also one of the ways to improve the user shopping experience. Smart shopping carts compensate for consumers’ inconveniences that could not be met only by self-checkout counters. Application: This study will provide smart shopping carts that can easily be used to help consumers save time and improve user’s shopping experience.

우리나라 쌀의 호화양상

김성곤(Sung Kon Kim),정혜민(Hye Min Chung),김상순(Sang Soon Kim) 한국응용생명화학회 1984 Applied Biological Chemistry (Appl Biol Chem) Vol.27 No.2

Amylograms of 12 traditional (j) and 9 high-yielding (j×i) rice varieties revealed that the high-yielding rice varieties had higher values for peak (P), hot-paste (H) and cold-paste (C) viscosities and showed the less variation among varieties. Peak viscosity had significant negative correlations with C/P and C/H, but no eorrelation with H/P.

쌀 , 옥수수 , 칡 및 생강 전분의 알카리 호화

김성곤(Sung Kon Kim),정혜민(Hye Min Chung),조만희(Man Hee Cho) 한국응용생명화학회 1984 Applied Biological Chemistry (Appl Biol Chem) Vol.27 No.3

Alkali gelatinization of rice, corn, arrow root and ginger root starches at various sodium hydroxide concentrations was investigated. Critical concentrations of alkali for starch gelatinization ranged from 2.33 to 3.17 meq NaOH per gram of starch. Ginger root starch was most resistant to alkali gelatinization and arrow root starch was least stable to alkali.

부모의 정서적 자녀가치, 양육행동, 유아의 학습준비도 및 학업능력 간의 구조적 관계: 자기-상대방효과를 중심으로

이주아 ( Lee Joo Ah ),박지은 ( Park Ji Eun ),정혜민 ( Chung Hye Min ),이순형 ( Yi Soon Hyung ) 한국유아교육학회 2017 유아교육연구 Vol.37 No.4

이 연구는 자기-상대방 상호의존모형(Actor-Partner Interdependence Model, APIM)을 적용하여 유아기 자녀를 둔 아버지와 어머니의 정서적 자녀가치와 양육행동 간의 자기효과와 상대방효과를 검증하고, 부모의 정서적 자녀가치가 양육행동을 매개로 자녀의 학습준비도와 학업능력에 미치는 영향을 확인하였다. 유아교육기관에서 초등학교로의 전이과정에서 부모의 정서적 자녀가치와 양육행동, 유아의 학습준비도와 학업능력 간의 관계를 살펴보고, 초등학교에서의 안정적인 적응을 위한 전이 준비의 중요성을 확인하는데 목적이 있다. 그 결과, 첫째, 어머니와 아버지의 정서적 자녀가치가 온정적 및 통제적 양육행동에 미치는 유의한 자기효과가 나타났다. 둘째, 어머니의 정서적 자녀가치가 아버지의 온정적 양육행동에 미치는 유의한 상대방효과가 나타났다. 셋째, 어머니와 아버지의 정서적 자녀가치가 유아의 학습준비도 및 학업능력에 미치는 영향은 부모의 양육행동에 의해 완전 매개하는 것으로 나타났다. 부모 자녀가치와 양육행동의 상호작용이 유아의 학습준비도와 학업능력에 영향을 주는 것을 구체적으로 살펴보아 초등학교로의 적응을 위한 전이 준비의 중요성을 확인할 수 있었다. 본 연구는 이러한 결과를 바탕으로 부모의 정서적 자녀가치 증진과 양육행동이 유아의 학습준비도와 학업능력을 발달시키기 위한 부모교육의 기초정보를 제공하는데 도움을 주고자 한다. This study examined the dyadic relationship between mothers and fathers in their emotional value of children and parenting behavior and their effects on preschoolers school readiness and scholastic competence. This research made use of 6th and 7th year data from Panel Study of Korean Children(PSKC). Participants numbered 1,041 parents and their children. Data were analyzed upon the Actor-Partner Interdependence Model(APIM) using SPSS 21.0 and Amos 21.0. The results can be summarized as follows. First, both mothers and fathers emotional value of children had a significant positive actor effect on their own warm and controlled parenting behavior. Second, only mothers emotional value of children showed a significant positive partner effect on fathers warm parenting behavior, but no partner effect of fathers was found. Third, parenting behavior completely mediated the effects between both parents emotional value of children and preschoolers school readiness and scholastic competence. These results suggested that the widespread parenting programs would be necessary for acknowledging their values of children and proper parenting, which would eventually affect child s school life.

아버지의 정서적 자녀가치에 따른 양육행동이 취학 전후 남녀 아동의 학습준비도와 실행기능에 미치는 영향

박지은(Ji Eun Park),이주아(Joo Ah Lee),정혜민(Hye Min Chung),최나야(Naya Choi) 한국아동학회 2018 아동학회지 Vol.39 No.5

Objectives: The purpose of this study was to examine successful adaptation of first graders to elementary school by analyzing the relationships among fathers’ emotional valuation of children and parenting behaviors and children’s school readiness and executive function, and to identify gender differences in the pathways. Methods: Data were drawn from waves 6-8 of the Panel Study of Korean Children (PSKC). Participants were 987 fathers and their children. Data were analyzed using structural equation modeling and multiple group analysis with SPSS 22.0 and AMOS 21.0. Results: First, fathers’ emotional valuation of children had a significant effect on both warm and controlled parenting behaviors, and parenting behaviors completely mediated the effects between fathers’ emotional valuation and children’s school readiness and executive function. Furthermore, the results of multiple group analysis revealed that some path weights appeared differently by gender. For boys, fathers’ emotional valuation had a significant effect on children’s school readiness through warm parenting behaviors; however, there was no effect on executive function. For girls, emotional valuation completely mediated the effects of children’s school readiness and executive function through both parenting behaviors. Conclusion: The implications of these findings provide specific, basic information for parent education and instruction regarding the perception and performance of the fathers role emphasizing its the importance in the family.

학교영어수업 만족도와 부모의 학업성과압력이 고등학생의 영어학습 동기와 행동에 미치는 영향 : 일반고와 특목고의 비교

최나야(Choi, Naya),정수지(Jung, Suji),박유미(Park, You-Me),정혜민(Chung, Hyemin) 학습자중심교과교육학회 2020 학습자중심교과교육연구 Vol.20 No.2

본 연구의 목적은 일반고와 어문계열 특목고 학생의 영어학습 실태를 파악하고, 학교 유형에 따라 학교영어수업 만족도와 부모의 학업성과압력이 영어학습 동기와 영어학습 행동에 미치는 영향에 차이가 있는지 알아보는 것이다. 서울, 경기, 충청, 경상, 강원지역의 일반고 5곳과 특목고 4곳에서 1, 2학년 학급을 무선 표집하여, 일반고 학생 283명과 특목고 학생 235명을 대상으로 질문지 조사를 실시하였다. 주요 연구 결과는 다음과 같다. 첫째, 일반고와 특목고 학생의 영어학습 관련 변인에 차이가 있었다. 영어학습 및 영어사교육 시작 시점, 영어권 해외경험, 유형별 영어학습 시간과 같은 영어학습 경험에서 두 집단 간 차이가 나타났다. 학교영어수업 만족도, 통합적 영어학습 동기, 영어학습 행동은 특목고 학생이 일반고 학생보다 높았지만, 부모의 학업성과압력은 일반고 집단에서 더 높았다. 둘째, 학교영어수업 만족도, 부모의 학업성과압력, 영어학습 동기가 영어학습 행동에 영향을 미치는 경로가 두 집단 간에 달랐다. 통합적 동기는 일반고 모형에서 부모의 학업성과압력이 영어학습 행동에 미치는 영향을 완전매개하였지만, 특목고 모형에서는 학교영어수업 만족도가 영어학습 행동에 미치는 영향을 완전매개하였다. 본 연구 결과는 다양한 학생의 학습권을 보장하는 교육정책 마련을 위한 기초자료로 활용될 수 있을 것이다. The purpose of this study was to compare English learning experiences and the effects of school English instruction and parents’ pressure for academic achievement on English learning motivation and behavior between general and special-purpose high school students. 283 general high school students and 235 special-purpose high schools students from five general high schools and four special-purpose high schools in Seoul, Gyeonggi, Chungcheong, Gyeongsang, and Gangwon district in South Korea participated in the study. The main findings of this study were as follows. First, there were differences in English learning experiences before and after high school entrance between general and special-purpose high school. Second, the paths that satisfaction with school English instruction and parents’ pressure for academic achievement had effects on student’s English learning motivation and behavior were different between two types of school. Third, integrative motivation fully mediated the effect of parents’ pressure for academic achievement on English learning behavior in general high school students, while integrative motivation fully mediated the effect of satisfaction with school English instruction on English learning behavior. The results of this study can be used as preliminary data to establish educational policy to guarantee learning rights of students with different needs.

X-ray 회절법에 의한 쌀의 취반시 호화도 측정

김성곤(Sung Kon Kim),박홍연(Hong Hyun Park),정혜민(Hye Min Chung),김관(Kwan Kim) 한국응용생명화학회 1983 Applied Biological Chemistry (Appl Biol Chem) Vol.26 No.4

Degree of gelatinization during cooking of Akibare(Janponica) and Milyang 23 (Indica) rice was determined by X-ray diffractometry using a buit-in internal standard approach. The method had a total coefficient of variation of 99.9%. Milyang 23 showed slightly higher degree of gelatinization than Akibare during cooking at 100℃. Both rice was completely gelatinized after 20 minute cooking.

아끼바레 및 밀양 23호 쌀전분의 이화학적 성질비교

정혜민,안승요,김성곤 한국응용생명화학회 1982 Applied Biological Chemistry (Appl Biol Chem) Vol.25 No.2

아끼바레 및 밀양 23호 쌀 전분의 이화학적 성질, 전분 gel의 노화 및 음이온에 의한 호화양상을 조사하였다. 두 전분입자의 성상은 다각형이며 입자의 크기는 3~6㎛정도였으며, 아끼바레가 밀양 23호 보다 다소 작았다. 두 전분의 X-ray 회절도는 A형으로 peak 형태와 강도에서 약간의 차이를 보였다. 아끼바레 및 밀양 23호 쌀 전분의 아밀로스 함량은 각각 18.5 및 19.5%이었고 물 결합능력은 106 및 100%이었다. 팽화력은 50℃까지는 큰 변화가 없었으나 이후에 급격히 증가하였고 밀양 23호 쌀 전분의 팽화력이 더 컸다. 전분 현탁액(0.1%)의 광투과도는 두 전분 모두 60℃ 이후에서 급격히 증가하였으며 밀양 23호 쌀 전분이 더 큰 광투과도를 보였다. 음이온에 의한 아밀로그람 pattern은 NaCl과 NaF는 동일하였고, NaSCN과 NaI는 유사였다. 호화온도 및 최고점도시의 온도는 SCN^(-)<I^(-)<Cl^(-)<F^(-)<SO₄^(=)의 순으로 증가하였고 SCN^(-) 및 I^(-)이온은 최고 점도를 증가시켰으나 NaCl은 감소시켰다. SO₄^(=)이온을 첨가한 경우 점도는 계속 증가하였고 최고점도에 도달하지 않았다. 아끼바레 및 밀양 23호 전분 gel율 21℃에서 저장한 경우 시간 상수가 각각 6.72 및 6.42일이었다. Morphology, pbysicochemical properties, pasting properties in the presence of various anionic ions and aging of gels of Akibare (Japoica type) and Milyang 39 (Indica type)rice starch were studied Both starches. were polygonal with length in the range of 3~6㎛. Starch granules of Akibare were somewhat smaller than those of Milyang 23. X-ray diffraction study demonstrated that peak shape and intensity were significantly different between the two starches. Akibare and Milyang 23 rice starch had amylose content of 18.5 and 19,5% and water binding capacity of 106 and 100%, respectively. Milyang 23 rice starch had a higher swelling power than Akibare starch. A relationship between percent solubility and swelling power implied that bonding forces within the granules of the both starches were different. The optical transmittance of 0.1% suspension of the two starches increased rapidly from 60℃. In the range of 60~90℃, the two starches showed a single gelatinization pattern. Amylograms of the two starches in the presence of various anionic ions showed that pasting temperature and peak temperature were progressively increased in the order of SCN-<I-<CI-<F-<SO₄=. SCN- and I- ions increased the peak height of Akibare rice starch white only SCN- ion was effective for Milyang 23 rice starch. There were no differences in the rates of retrogradation of 45% gels of the two starches stored at 21℃.

수화그룹별 쌀 전분의 알카리 호화

김성곤,정혜민 한국농화학회 1986 Applied Biological Chemistry (Appl Biol Chem) Vol.29 No.1

Viscosity development pattern, in aqueous sodium hydroxide, of rice starches isolated from various hydration groups of milled rice was investigated. The maximum viscosity and viscosity development rate of Japonica rice starches at a given alkali concentration were loswer than those of J/Indica counterparts. The difference in the viscosity development rate of starches by increment of 0.1N (0.02 meq/g) was greater in J/Indica rice starches in comparison with Japonica ones. Viscosity of rice starch was not correlated to that of rice flour and to hydration rate of milled rice.