왜도 예측을 이용한 Lee-Carter모형의 사망률 예측

이항석,백창룡,김지현,Lee, Hangsuck,Baek, Changryong,Kim, Jihyeon 한국통계학회 2016 응용통계연구 Vol.29 No.1

지속적인 사망률 개선으로 인한 평균 수명연장은 인구 고령화의 주요인이며 연금 공급자의 재정건전성에 심각한 영향을 미치는 원인으로 지목되기에 정확한 미래 사망률의 예측은 현 시점에서 선행되어야할 중요한 과제다. 본 연구는 미래 사망률을 예측하는 대표적인 확률적 사망률 모형인 Lee-Carter 모형을 사용하여 과거 생명표로 산출한 왜도를 기반으로 미래 사망률 지수를 간접적으로 예측하는 왜도예측방식을 제시한다. 기존의 Lee-Carter 모형을 이용한 사망률 예측방식은 사망률 지수를 추정하고 미래값을 직접 예측함으로써 미래 사망률이 지나치게 개선되는 현상을 보이며, 이를 바탕으로 산출된 연금액과 지급기간 추정 등 연금 공급자의 리스크 관리에 영향을 미친다. 본 연구는 기존 예측 방식의 사망률 예측 결과와 제시한 왜도 예측 방식의 사망률 예측 결과를 비교함으로써 기존 사망률 예측 방식의 문제점을 지적한다. 분석결과 왜도 예측을 통한 Lee-Carter 모형의 사망률 예측은 기존 방식보다 사망률 개선효과를 더 적게 반영하며 장수리스크를 덜 왜곡한다는 데 의의가 있다고 할 수 있다. 하지만 기존 방식 간 차이를 감안하여 적정한 미래 사망률 수준을 찾기 위해 임의로 부여한 가중치에 대해 향후 검토가 필요할 것으로 보인다. There have been continuous improvements in human life expectancy. Life expectancy is as a key factor in an aging population and can wreak severe damage on the financial integrity of pension providers. Hence, the projection of the accurate future mortality is a critical point to prevent possible losses to pension providers. However, improvements in future mortality would be overestimated by a typical mortality projection method using the Lee-Carter model since it underestimates the mortality index ${\kappa}_t$. This paper suggests a mortality projection based on the projection of the skewness of the mortality versus the typical mortality projection of the Lee-Carter model based on the projection of the mortality index, ${\kappa}_t$. The paper shows how to indirectly estimate future t trend with the skewness of the mortality and compares the results under each estimation method of the mortality index, ${\kappa}_t$. The analysis of the results shows that mortality projection based on the skewness presents less improved mortality at an elderly ages than the original projection.

Real-Time Arbitrary Face Swapping System For Video Influencers Utilizing Arbitrary Generated Face Image Selection

Jihyeon Lee,Seunghoo Lee,Hongju Nam,Suk-Ho Lee 한국인터넷방송통신학회 2023 International Journal of Internet, Broadcasting an Vol.15 No.2

This paper introduces a real-time face swapping system that enables video influencers to swap their faces with arbitrary generated face images of their choice. The system is implemented as a Django-based server that uses a REST request to communicate with the generative model, specifically the pretrained stable diffusion model. Once generated, the generated image is displayed on the front page so that the influencer can decide whether to use the generated face or not, by clicking on the accept button on the front page. If they choose to use it, both their face and the generated face are sent to the landmark extraction module to extract the landmarks, which are then used to swap the faces. To minimize the fluctuation of landmarks over time that can cause instability or jitter in the output, a temporal filtering step is added. Furthermore, to increase the processing speed the system works on a reduced set of the extracted landmarks.

Remineralization Effects of Silver Fluoride, Silver Diamine Fluoride, and Sodium Fluoride Varnish

Jihyeon Lee,Hwalim Lee,Jongsoo Kim,Joonhaeng Lee,Jongbin Kim,Jisun Shin,Miran Han 대한예방치과학회 2024 International Journal of Clinical Preventive Denti Vol.20 No.1

Objective: This study aimed to compare the remineralization effect of a newly introduced silver fluoride (AgF) agent when applied to dried and saliva-contaminated tooth surfaces with that of silver diamine fluoride (SDF) and sodium fluoride varnish. Methods: Artificial caries were induced on dentin and enamel using bovine incisors. The specimens were divided into four dentin and four enamel groups, and microhardness was measured. The four groups were categorized into control, AF, DF, and NF. In each group, half of the specimens were treated with fluoride agents on dried surfaces, whereas the other half received the agents on saliva-contaminated surfaces. The control group was treated with distilled water. The AF group was treated with Riva Star AquaTM, consisting of AgF (step 1) and potassium iodide (KI, step 2). The DF group was treated withRiva StarTM, containing SDF (step 1) and KI (step 2). The NF group was treated with Fast Release Varnish. After 7 days of pH cycling, the microhardness was measured again to assess the remineralization effects. Results: The AF and DF groups showed a significant increase in microhardness compared to the NF and control groups. There was no statistically significant difference between the AF and DF groups. For dentin caries, there was no statistically significant difference between the dry subgroup and the saliva-contaminated subgroup in the AF and DF groups. Conclusion: The novel AgF agent can be effectively used for remineralization of dentin and enamel carious lesions, despite the presence of saliva contamination in dentin caries.

부호 분포에 기반한 한국어 파찰음 인식

이지현(Jihyeon Lee),이재원(JaeWon Lee),이종우(Jongwoo Lee) 한국정보과학회 2012 한국정보과학회 학술발표논문집 Vol.39 No.2B

부호 분포 변동성에 기반한 한국어 음소 ‘ㅅ’, ‘ㅈ’, ‘ㅊ’ 음성인식

이지현(Jihyeon Lee),이재원(JaeWon Lee),이종우(Jongwoo Lee) 한국정보과학회 2013 정보과학회 컴퓨팅의 실제 논문지 Vol.19 No.7

본 논문은 최근 스마트폰의 보급이 확산됨에 따라, 요구가 급속하게 증가하고 있는 음성 인식의 일부로써 한국어 음소 중 ‘ㅅ’, ‘ㅈ’, ‘ㅊ’ 인식에 대한 연구이다. 음소는 음성을 구성하고 있는 최소단위로써 음성을 인식하는데 매우 중요한 역할을 한다. 음소를 기본단위로 하는 음성 인식 시스템은 음절이나 단어단위의 인식보다 매우 효과적인 방법이지만 각각의 음소들을 정확하게 분리하고 인식하려면 발음의 다양성 등으로 인해 많은 어려움이 존재한다. 본 논문에서는 음소를 인식의 기본단위로 하는 음성 인식시스템 구현의 일부로써 한국어 음소 중 인식하기 어려운 음소로 알려진 ‘ㅅ’, ‘ㅈ’, ‘ㅊ’을 인식하기 위한 새로운 지표로 부호 분포 변동성을 제안한다. 2음절 고립단어를 대상으로 실험을 수행한 결과, 기존 방법인 영교차율(ZCR)에 비해 부호 분포 변동성을 이용한 인식 기법이 에러율을 최소 52.8% 이상 감소시키는 성과를 보였다. This paper describes a study on the recognition of ‘ㅅ’, ‘ㅈ’, ‘ㅊ’ among Korean phonemes as a part of speech recognition which is arousing much demand of people while the smart phones are gaining wide popularity. Phoneme is the minimal unit consisting of speech and plays a very important role in recognizing speech. Although speech recognition systems using phonemes as recognition unit work in a very efficient way than those using syllables or words, there remain many difficulties including various variations of speech unresolved in exactly separating and recognizing each constituting phoneme. In this paper, sign distribution volatility is proposed as a novel measure for recognizing ‘ㅅ’, ‘ㅈ’, ‘ㅊ’ which are known to be very difficult to recognize among Korean phonemes, as a part of the implementation of speech recognition system using phonemes as the basic unit of the recognition. According to the experimental results using bi-syllables isolated words, the proposed measure reduced by about 52.8% in the error rate over the existing zero crossing rate.

보건계열과 비보건계열 대학생의 손씻기에 대한 지식, 태도 및 수행도 비교

이지현 ( Lee Jihyeon ),김빛나 ( Kim Bitna ),김은지 ( Kim Eunji ),이하영 ( Lee Hayeong ),이현정 ( Lee Hyeonjeong ),유다운 ( Yu Dawoon ),고은 ( Ko Eun ) 부산대학교 간호과학연구소 2018 글로벌 건강과 간호 Vol.8 No.2

Purpose: This study aimed to compare the knowledge, attitude, and practice related to handwashing among undergraduate students majoring and not majoring in health science. Methods: This descriptive study included 188 undergraduate students with 100 majoring and 88 not majoring in health science. Data were collected using a structured questionnaire and they were analyzed with the IBM SPSS 24.0 program using descriptive statistics, t-tests, Pearson’s correlation coefficients and a multiple regression. Results: Mean scores on knowledge and attitude toward handwashing were 13.86±1.56 and 21.05±2.34 respectively in students majoring health science, whereas the same were 13.22±1.73 and 19.76±2.24 in students not majoring health science respectively. In both groups, there was significant correlations between knowledge and attitude (r=.32, p<.001; r=.33, p=.002), and between attitude and practice (r=.27, p=.006; r=.40, p<.001) respectively. Attitude toward handwashing (β=0.20, p=.028), experience of education about handwashing (β=0.33, p<.001) and perception about health status (β=-0.23, p=.014) were significant predictors of handwashing practice in students majoring health science. On the other hand, only attitude toward handwashing (β=0.37, p<.001) was a significant predictor of handwashing practice in students not majoring health science. Conclusion: The present results reveal the importance continuing various educational programs on handwashing and the need to identify their longitudinal effects to improve handwashing practice among students majoring in health science. Additionally, when developing strategies to improve handwashing habits, we need to consider factors that could help change attitudes toward handwashing.

플라워링 하트: 비주얼 패션 검색을 활용한 증강 현실 서비스

이승재(Seungjae Lee),고종국(JongGook Ko),이근동(Keundong Lee),이수웅(Suwoong Lee),손형관(Hyung Kwan Son),이효윤(Hyo Yun Lee),김태영(Tae Young Kim),강규욱(Kyuuk Kang),박지현(Jihyeon Park) 한국통신학회 2019 한국통신학회 학술대회논문집 Vol.2019 No.1

Structure-dependent catalytic properties of mesoporous cobalt oxides in furfural hydrogenation

Nguyen-Huy, Chinh,Lee, Jihyeon,Seo, Ji Hui,Yang, Euiseob,Lee, Jaekyoung,Choi, Keunsu,Lee, Hosik,Kim, Jae Hyung,Lee, Man Sig,Joo, Sang Hoon,Kwak, Ja Hun,Lee, Jun Hee,An, Kwangjin Elsevier 2019 Applied Catalysis A Vol.583 No.-

<P><B>Abstract</B></P> <P>As the development of noble metal free catalysts became important in the biomass conversion, catalytic hydrogenation of furfural (FAL) is investigated over ordered mesoporous cobalt oxide (<I>m</I>-Co<SUB>3</SUB>O<SUB>4</SUB>). When <I>m</I>-Co<SUB>3</SUB>O<SUB>4</SUB> is reduced at 350 and 500 °C in hydrogen, the original crystal structure of Co<SUB>3</SUB>O<SUB>4</SUB> is changed to CoO and Co, respectively. Here we examine the effect of the structure, porosity, and oxidation state of <I>m</I>-Co<SUB>3</SUB>O<SUB>4</SUB> to identify catalytically active species for hydrogenation of FAL. Among cobalt oxide catalysts having different crystal structures and symmetry, <I>m</I>-CoO having <I>p6mm</I> symmetry exhibits the highest activity. In product selectivity, the CoO phase induces FAL hydrogenolysis by selective production of 2-methyl furan (MF), while the Co<SUB>3</SUB>O<SUB>4</SUB> and Co phases promote preferential hydrogenation of side chain (carbonyl group) of FAL to furfuryl alcohol. Density functional theory calculations also reveal that the adsorption of FAL on CoO(111) is higher than Co(111). Overall, these studies demonstrate that CoO as the most active phase is responsible for the high FAL conversion and the distinct pathway of FAL to MF.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Mesoporous cobalt oxide catalysts are developed for furfural hydrogenation. </LI> <LI> CoO is proven to be the most active phase in furfural hydrogenation. </LI> <LI> The CoO site induces selective hydrogenation of furfuryl alcohol to methyl furan. </LI> <LI> Furfural is adsorbed much strongly on CoO(111) than on Co(111). </LI> <LI> Cobalt oxides have low production cost and high efficiency for biomass conversion. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Development of simple sequence repeat (SSR) markers from ramie (Boehmeria nivea L.) and application to the genetic resources

Yoon Kyung Uhm,Hye-young Lee,Jinkyu Woo,JiHyeon Kim,Young-Mi Kim,Yong-Su Jung,Hyun Sam Lee,Sanghyun Lee,Ho Bang Kim 한국육종학회 2015 한국육종학회 심포지엄 Vol.2015 No.07

Ramie (Boehmeria nivea L.) is a hardy perennial herbaceous plant of the Urticaceae family and has been grown as a fiber crop in several countries including Korea for many centuries. Ramie leaves also have been traditionally used as a major ingredient of a type of rice cake called ‘Song-pyun’ in the Southwest area of Korea, especially Yeong-Gwang province. Despite its economic importance, the molecular genetics of ramie have not been studied in detail yet. Genetic resources of ramie were widely collected from domestic local sites by Bioenergy Crop Research Center (RDA) and Yeong-Gwang Agricultural Technology Center. For the systematic and efficient management of the genetic resources, we developed SSR (simple sequence repeat) markers of ramie. To do this, we generated microsatellite-enriched genomic DNA libraries using magnetic bead hybridization selection method. 247 non-redundant contigs containing SSR motif were generated using nucleotide sequences of 376 clones from the libraries. Primer sets were designed from the flanking sequences of the repeat motif. Finally, we selected 10 SSR markers, possibly showing polymorphism among the genetic resources. Results on the genotype analysis of the ramie genetic resources using the SSR markers will be presented.

Development of gene delivery carries based on cellulose nanocrystal

Jihyeon LEE,Hanjin YU,Kwang Suk LIM 한국생물공학회 2018 한국생물공학회 학술대회 Vol.2018 No.10