시계열 자료에서의 특이치 발견

최정인,엄인옥,조형준,Choi, Jeong In,Um, In Ok,Choa, Hyung Jun 한국통계학회 2016 응용통계연구 Vol.29 No.5

This study suggests an outlier detection algorithm that uses quantile autoregressive model in time series data, eventually applying it to actual stock manipulation cases by comparing its performance to existing methods. Studies on outlier detection have traditionally been conducted mostly in general data and those in time series data are insufficient. They have also been limited to a parametric model, which is not convenient as it is complicated with an analysis that takes a long time. Thus, we suggest a new algorithm of outlier detection in time series data and through various simulations, compare it to existing algorithms. Especially, the outlier detection algorithm in time series data can be useful in finding stock manipulation. If stock price which had a certain pattern goes out of flow and generates an outlier, it can be due to intentional intervention and manipulation. We examined how fast the model can detect stock manipulations by applying it to actual stock manipulation cases. 본 논문의 목표는 분위수 자기회귀모형을 활용하여 시계열 자료에서 특이치를 발견하는 알고리즘을 제안하고, 기존의 방법들과 그 성능을 비교하여 실제 주가 조작 사례에 적용해 보는 것이다. 지금까지의 특이치 발견 연구는 대부분 일반적인 데이터 형태에서만 있어왔기 때문에 시계열 데이터에서의 연구는 미미한 편이다. 또한 모수적인 방법에만 제한되었는데, 모수적 모형은 복잡할 뿐만 아니라 소요되는 분석 시간도 길기 때문에 편리하지 않다. 따라서 본 연구에서는 분위수 자기회귀모형을 활용한 특이치 발견 알고리즘을 새롭게 제시하고, 다양한 경우의 모의실험을 통해 기존 알고리즘과 비교하도록 한다. 특히 시계열 자료에서의 특이치 발견은 주가 조작을 적발하는 데에 유용하게 활용될 수 있다. 시간에 따라 관측되던 주가가 갑자기 그 동안의 흐름에서 벗어나 특이치로 발견되었다면 혹시 인위적인 개입으로 조작된 것은 아닌지 의심해 볼 수 있기 때문이다. 따라서 실제 주가 조작 사례에 적용해 봄으로써 얼마나 빠른 시일 내에 주가 조작을 적발해 낼 수 있는지 살펴보았다.

복합레진의 수리 시 표면처리가 결합강도에 미치는 영향

최정인,김영재,김정욱,이상훈,김종철,한세현,장기택 大韓小兒齒科學會 2008 大韓小兒齒科學會誌 Vol.35 No.4

본 연구의 목적은 표면처리가 기존의 레진과 새로운 레진 사이의 전단결합강도에 미치는 영향을 평가하는 것이다. 준비된 레진 시편을 6군으로 임의로 배분하여 각각의 표면처리를 한 후 수리용 레진을 축조하였다. 일주일간 보관 후 전단결합강도를 측정하였고 일원분산 분석법으로 통계처리하여 다음과 같은 결과를 얻었다. 1. 3군과 4군(air abrasion)은 1군(산부식)에 비해 전단결합강도가 유의하게 높게 나타났다(p<0.005). 5군과 6군(diamond bur)은 1군(산부식)에 비해 높은 전단결합강도를 나타냈으나 통계적으로 유의하지 않았다(p<0.005). 2. 2군(자가부식 접착제)은 1군(산부식)에 비해 전단결합강도가 낮게 나타났으나 유의한 차이는 없었다(p<0.005). 3. 3군(air abrasion)과 4군(air abrasion +산부식)에서 전단결합강도의 차이는 유의하지 않았다(p<0.005). 4. 5군(diamond bur)과 6군(diamond bur+산부식)에서 전단결합강도의 차이는 유의하지 않았다(p<0.005). 결론적으로,복합레진의 수리 시 air abrasion으로 표면처리를 했을 때의 결합강도가 가장 높았고,산부식 방법과 처리여부는 수리강도에 유의한 영향을 미치지 않았다. The purpose of this study was to evaluate the effect of surface treatment on the shear bond strength between new and old composite resin. The prepared resin specimens were separated 6 groups, and each group then received a different surface treatment. Then the repair material was added. Shear bond strengths for repair were measured after 7 days and the results were analyzed by using one way ANOVA. The results were as follows ; 1. Group 3, 4(air abrasion) showed significantly higher shear bond strength than Group l (phosphoric acid)(p<0.05). Group 5, 6(diamond bur) showed higher bond strength than Group l(phosphoric acid) but not significantly different(p<0.05). 2. Group 2(self-etching adhesive) showed lower shear bond strength than Group 1 (phosphoric acid) but not significantly different (p<0.05). 3. There was no statistically significant difference between Group 3 (air abrasion) and Group 4(air abrasion + etching). 4. There was no statistically significant difference between Group 5(diamond bur) and Group 6(diamond bur+etching). In conclusion, the surface treatment with air abrasion resulted in higher repair bond strength than other methods. Repair bond strength was not significantly affected by acid etching.

한국인 영어 학습자의 총칭 정관사와 유일 정관사 습득 양상

최정인 서강대학교 언어정보연구소 2019 언어와 정보 사회 Vol.37 No.-

This study examines English generic expressions in L2 acquisition by looking at whether Korean L2 English learners can distinguish between definite generic the and definite unique the. Definite generic can refer to more than one individual thing when it is accompanied by a predicate like be extinct. Definite Unique is when the definite article refers to one individual thing not generic things. Seventy Korean students and twelve native English speakers participated in this study. The TOEIC scores of Korean learners of English in the experiment were divided into the advanced and the beginner. We employed a picture matching task(PMT) and a forced-choice elicitation task(FCET). PMT and FCET were implemented to both native English speakers and Korean English learners. The results of this study showed that Korean L2 learners could not perform on the PMT for definite generic the, but the FCET results revealed differences between the three groups(control, advanced and beginner). In addition, this study showed that education on definite generic the in English education is necessary by showing the perception of Korean learners for definite generic the and definite unique the.

國民學校 體育 專擔敎師制의 必要性에 관한 硏究

최정인 이화여자대학교 체육대학 1985 建美 Vol.- No.18

한구석 밝히기에 있어서 빛과 빛깔 및 운동에 대한 탐구

최정인 뿌리 1997 한구석밝히기 Vol.1997 No.-

아사이베리를 첨가한 샐러드드레싱의 품질특성 및 항산화활성

최정인,정해정,Choi, Jeong-In,Chung, Hai-Jung 한국식생활문화학회 2017 韓國食生活文化學會誌 Vol.32 No.5

This study was conducted to evaluate the quality characteristics and antioxidant activities of salad dressing prepared with acaiberry powder (0, 1, 3, and 5%). The pH and titratable acidity increased as the acaiberry powder increased. The sugar content showed no significant differences between samples. The viscosity was lowest in the controls and increased with increasing amounts of the acaiberry powder. The lightness and yellowness values decreased, while the redness values increased with increasing amounts of acaiberry powder. The total polyphenol content ranged from 10.26-45.19 mg GAE/100 g, increasing with increased acaiberry powder levels. The antioxidant activities measured via DPPH radical scavenging activity, reducing power and FRAP also increased with increasing acaiberry powder concentrations. Finally, a consumer acceptance test revealed that up to 3% acaiberry powder could be added to salad dressing to provide high antioxidant activity without sacrificing sensory quality.

김치선 목사의 생애

최정인 안양대학교 신학연구소 2000 신학지평 Vol.13 No.-

한국인 영어 학습자의 영어 동사구 종결성 습득 양상: 동사의 상 유형과 명사구를 중심으로

최정인,전지현 한국중등영어교육학회 2018 중등영어교육 Vol.11 No.2

This study aimed to examine second language acquisition of English verb phrases and investigated how Korean English speakers and native English speakers interpret English verb phrases in compliance with the verbal aspects and noun phrases. 241 Korean English learners and 37 native English speakers participated in this study. The telicity test depending on the verbal aspects and noun phrases was implemented to both native English speakers and Korean English learners who were classified into three groups according to their English proficiency. The results of this study showed how Korean English learners and native English speakers differentiate regarding English verb phrase telicity according to both verbal aspects and noun phrases and indicated that the way most Korean English leaners interpret English verb phrases is influenced by Korean. In addition, learners who are in the beginner group have more difficulty in acquiring English verb phrases depending on both verbal aspects and noun phrases. The directions of further studies were discussed with the limitations of this study

Arts PROPEL의 이론과 실제

최정인 한국유초등음악교육학회 2002 음악교육 Vol.2 No.-

고춧가루의 저장 온도와 기간에 따른 이화학적 품질 특성 변화

최정인,오혜인,조미숙,오지은,Choi, Jeong In,Oh, Hye In,Cho, Mi Sook,Oh, Ji Eun 한국식생활문화학회 2018 韓國食生活文化學會誌 Vol.33 No.2

This study was carried out to determine the optimal storage conditions by examining the effects of the storage conditions on the quality of red pepper powder during storage in households. Red pepper powder was stored at room temperature ($20^{\circ}C$), refrigeration (2 and $-1^{\circ}C$) and frozen (-5 and $-20^{\circ}C$) for 3, 6, 9 and 12 months. The ASTA color value, capsanthin content and redness ($a^{\ast}$) of the red pepper powders stored at -5 and $-20^{\circ}C$ were not decreased significantly depending on the storage temperatures until 9 months. The pH of red pepper powder stored at $20^{\circ}C$ decreased significantly until 9 months and increased at 12 months. The microbiological quality of the red pepper powder stored at -5 and $-20^{\circ}C$ was more stable during long-term storage. In the sensory evaluation of red pepper powder stored under all conditions, the overall freshness, redness, hot flavor, moisture release, and edibility decreased with increasing storage period from the control to 12 months. Moisture release increased from 3 months to 12 months. Overall, red pepper should be stored at low temperatures (2, $-1^{\circ}C$) for up to 6 months, and frozen (${\geq} -5^{\circ}C$) for 6 to 9 months. The optimal temperature for long-term storage (${\geq}9$ months) was $-20^{\circ}C$.