Causal Analyses of Statin to Prevent Liver Disease Progression: A Nationwide Study Using Superlearning Targeted Maximum Likelihood Estimation

Sunyoung Cho(Sunyoung Cho),Heejo Koo(Heejo Koo),Beom Kyung Kim(Beom Kyung Kim),Euna Han(Euna Han) 대한약학회 2024 약학회지 Vol.68 No.1

Many studies have shown that statins reduce the risk of progression to liver cirrhosis (LC) and hepatocellular carcinoma (HCC) among at-risk populations. However, causality has not been proved. This study examined whether statins could prevent LC and HCC in patients with progressive and worsening chronic liver disease, using a robust methodology for causality. Between 2002 and 2013, 52,145 patients with chronic liver diseases were identified from the National Health Insurance Service database in South Korea. The inverse probability weighting (IPW) and superlearning targeted maximum likelihood estimation (TMLE) were used to assess the causality of statin use on the risk of LC and HCC, adjusting for sex, age, comorbidities, and co-medications. Multivariable superlearning TMLE revealed that statin use was associated with reduction in the incidence risk of LC (Marginal odds ratio (MOR) 0.59, 95% confidence interval [CI] 0.50-0.65) and HCC (MOR 0.59, 95% CI 0.50-0.67). Such a protective effect was more evident with atorvastatin and lipophilic statin. This population-based observational study indicated the benefit of statin use, particularly atorvastatin and lipophilic statin, for causally reducing the risk of LC and HCC.

What Drives the Customer Momentum?

Sunyoung Han 한국재무학회 2021 한국재무학회 학술대회 Vol.2021 No.11

This paper investigates possible explanations for the customer momentum documented by Cohen and Frazzini (2008). First, returns to the customer momentum vary significantly over time and can have large crashes during market crises. However, I do not find evidence linking the customer momentum to macroeconomic risk. Second, the customer momentum does not weaken significantly out-of-sample and thus is unlikely to be driven by statistical bias. Third, there is no evidence for the publication effect of Mclean and Pontiff (2016). Hence, the customer momentum does not represent profitable opportunities for arbitrage. Consistently, I show that the customer momentum is concentrated in stocks that are difficult to arbitrage. Moreover, trading on the customer momentum generates high turnovers but the probability of underperformance is not as high in annual frequency. Overall, my evidence suggests that limits-to-arbitrage prevent the incorporation of new information on customer firms into the share prices of suppliers.

Design and Implementation of Virtual Terminal Protocol with Windowing Capability

Han, Sunyoung 건국대학교 1988 學術誌 Vol.32 No.2

컴퓨터 네트워크 환경에서는 서로 다른 특성을 갖는 호스트 컴퓨터가 존재할 뿐 아니라 서로 다른 특성을 갖는 터미날도 존재한다. 네트워크 상에 있는 터미날은 이기종 복수개의 호스트 컴퓨터에 접근할 수 있어야 하며, 호스트 컴퓨터에 있는 응용 프로그램도 네트워크 상에 있는 여러 형태의 터미날에서 사용될 수 있어야 한다. 만약 네트워크 상에 M 종류의 호스트와 N종류의 터미날이 존재한다면 어떤 응용프로그램이 네트워크 상에서 작동하기 위해서는 M×N 종류의 프로그램이 필요하다. 가상터미날은 실재하는 각종 터미날의 기능을 일반화시키고 추상화시켜 정의한 개념적으로 존재하는 표준터미날이다. 원격지 호스트에 있는 응용 프로그램과 로칼 호스트에 있는 터미날 사용자는 서로 가상터미날을 이용하여 통신하고 응용 프로그램은 가상터미날만을 제어하고 가상터미날과 로칼 호스트에 있는 실제 터미날 사이의 매핑은 로칼 호스트가 담당함으로써 M×N 문제가 M+N 문제로 축소된다. 본 논문에서는, 현재 국제 표준화기구(ISO)에서 정의하고 있는 가상터미날 모델에 기초하여 윈도우 기능을 갖는 가상터미날 프로토콜을 설계하고 구현하였다. 윈도우 기능은 bitmap 기 능을 제공하는 고급 터미날이나 워크스테이션 등에서 볼 수 있는 기능으로서, 윈도우 기능을 갖는 터미날은 일반적으로 문자 처리 능력뿐 아니라 그레픽스 및 이미지 처리 능력을 갖고 있다. 본 논문에서는 원격지 호스트에 있는 윈도우 시스템 등의 윈도우 기능을 갖는 소프트웨어를 로칼 호스트에 있는 Bitmap 터미날이나 Workstation등에서 사용할 수 있도록 가상터미날을 설계하고 구현하였다. 본 논문에서 연구한 가상터미날은 4.2BSD UNIX에서 C언어로 구현되었다.

QoS-Based Path Switching Mechanism in Mobile SCTP

Han, Li,Sun, Shimin,Joo, Bokgyu,Han, Sunyoung SAGE Publications 2014 International journal of distributed sensor networ Vol.2014 No.-

QoS-Aware Routing Mechanism in OpenFlow-Enabled Wireless Multimedia Sensor Networks

Han, Li,Sun, Shimin,Joo, Bokgyu,Jin, Xianshu,Han, Sunyoung Taylor & Francis 2016 INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWOR Vol.12 No.7

The Textbook Analysis on Probability: The Case of Korea, Malaysia and U.S. Textbooks

( Han Sunyoung ),( Rosli Roslinda ),( Capraro Robert M. ),( Capraro Mary M. ) 한국수학교육학회 2011 수학교육연구 Vol.15 No.2

"Statistical literacy" is important to be an effective citizen ([Gal, I. (2005). Towards "probability literacy" for all citizens: Building blocks and instructional dilemmas. In: G. A. Jones (Ed.), Exploring probability in school: Challenges for teaching and learning (pp. 39-63). New York: Springer]). Probability and statistics has been connected with real context and can be used to stimulate students` creative abilities. This study aims at identifying the extent that textbooks in three countries include experimental probability concepts and non-routine, open-ended, application and contextual problems. How well textbooks reflect real application situations is important in the sense that students can employ probability concepts when solving real world problems. Results showed that three textbook series did not mention experimental probability. Furthermore, all of textbooks had more routine, close-ended, knowing, and non-contextual problems.

The Effect of STEM PBL on Students’ Achievement in Four Mathematics Topics

( Sunyoung Han ),( Roslinda Rosli ),( Mary M. Capraro ),( Robert M. Capraro ) 한국수학교육학회 2016 수학교육 학술지 Vol.2016 No.3

Surface Modification of Poly(ethylene terephthalate) Polymeric Films by Inductively Coupled Oxygen Plasma

Han, Dong Cheul,Choi, Young Cheol,Shin, Han Jae,Son, Sunyoung,Kim, Jae Hong,Sohn, Sang Ho,Lee, Do Kyung Informa UK (TaylorFrancis) 2010 Molecular Crystals and Liquid Crystals Vol.532 No.1

Endocrine disruption and consequences of chronic exposure to ibuprofen in Japanese medaka (<i>Oryzias latipes</i>) and freshwater cladocerans <i>Daphnia magna</i> and <i>Moina macrocopa</i>

Han, Sunyoung,Choi, Kyungho,Kim, Jungkon,Ji, Kyunghee,Kim, Sunmi,Ahn, Byeongwoo,Yun, Junheon,Choi, Kyunghee,Khim, Jong Seong,Zhang, Xiaowei,Giesy, John P. Elsevier 2010 Aquatic toxicology Vol.98 No.3

<P><B>Abstract</B></P> <P>Despite frequent detection of ibuprofen in aquatic environments, the hazards associated with long-term exposure to ibuprofen have seldom been investigated. Ibuprofen is suspected of influencing sex steroid hormones through steroidogenic pathways in both vertebrates and invertebrates. In this study, the effect of ibuprofen on sex hormone balance and the associated mechanisms was investigated <I>in vitro</I> by use of H295R cells. We also conducted chronic toxicity tests using freshwater fish, <I>Oryzias latipes</I>, and two freshwater cladocerans, <I>Daphnia magna</I> and <I>Moina macrocopa</I>, for up to 144 and 21d of exposure, respectively. Ibuprofen exposure increased 17β-estradiol (E2) production and aromatase activity in H295R cells. Testosterone (T) production decreased in a dose-dependent manner. For <I>D. magna</I>, the 48h immobilization EC50 was 51.4mg/L and the 21d reproduction NOEC was <1.23mg/L; for <I>M. macrocopa</I>, the 48h immobilization EC50 was 72.6mg/L and the 7d reproduction NOEC was 25mg/L. For <I>O. latipes</I>, 120d survival NOEC was 0.0001mg/L. In addition, ibuprofen affected several endpoints related to reproduction of the fish, including induction of vitellogenin in male fish, fewer broods per pair, and more eggs per brood. Parental exposure to as low as 0.0001mg/L ibuprofen delayed hatching of eggs even when they were transferred to and cultured in clean water. Delayed hatching is environmentally relevant because this may increase the risk of being predated. For <I>O. latipes</I>, the acute-to-chronic ratio of ibuprofen was estimated to be greater than 1000. Overall, relatively high acute-to-chronic ratio and observation of reproduction damage in medaka fish at environmentally relevant ranges of ibuprofen warrant the need for further studies to elucidate potential ecological consequences of ibuprofen contamination in the aquatic environment.</P>

분산 환경상의 망 관리를 위한 요구 브로커 설계 및 구현

한선영(Sunyoung Han),박수명(Soomyung Park),조정래(Jeongrae Cho),김경범(Kyeongbeom Kim),궁상환(Sangwhan Kung) 한국정보과학회 1995 정보과학회논문지 Vol.22 No.6

전통적인 망 관리 환경에서, 대부분의 망 관리 응용들은 단지 SNMP만을 지원하여왔다. 그러나, 이러한 망 관리 환경은 CMIP 및 각종 Proprietary 프로토콜과 같은 서로 상이한 관리 프로토콜을 지원하는 환경에서는 전반적인 분산 망 관리에 많은 어려움을 파생시켰다. 본 논문에서는 이러한 문제들을 분산 망 관리 환경을 설계 및 구현함으로써 해결하였다. 본 분산 망 관리 환경에서 관리 응용들은 서로 상이한 프로토콜 프로그램밍 인터페이스로 작성될 수 있으며, 각각 관리 프로토콜에 해당하는 대리자를 이용할 수 있다. 추가적으로, 관리 응용들의 요구 및 사건 보고 메시지는 본 환경에서 동시에 처리 될 수 있기 때문에, 하나 이상의 관리 응용들이 동시에 수행될 수 있다. In traditional network management, most of the network management applications have supported only SNMP, but that has caused some difficulties in managing the whole distributed network being used different management protocols such as CMIP and proprietary protocols. In this paper, a distributed network management environment was designed and implemented to solve these problems. In the environment management applications can be written in protocol-independent programming interface, and can use the corresponding management protocols to each agents. In addition, requests from management applications and event report messages are concurrently processed in the environment so that one or more management applications can be executed simultaneously.