Bi-factor MIRT True-Score Equating for Testlet-Based Tests

이규민(Gue min Lee),Won Chan Lee,Michael J Kolen,박인용(In Yong Park),Dong In Kim,Ji Seung Yang 한국교육평가학회 2015 교육평가연구 Vol.28 No.2

Lee and Lee (2014) proposed bi-factor multidimensional item response theory model (BFM) "observed-score" equating procedures. The main purposes of this study were to develop BFM "true-score" equating procedures, and to investigate applicability of the proposed procedures with actual data. Eight equating methods (including both true- and observed-score) based on dichotomous IRT (2-parameter logistic model: 2PL), polytomous IRT (graded response model: GRM), testlet response model (TRM), and BFM were compared with target equipercentile equating. Data for this study were from the Reading Comprehension test for a large-scale state assessment program, which consisted of several passages and corresponding groups of items. True- and observed-score equating methods based upon 2PL and BFM produced similar equating results. The GRM true- and observed-score equating methods provided equating results somewhat different from others, and more similar to the target equipercentile equating. Lee와 Lee(2014) 연구는 혼합형 검사에서의 bi-factor 다차원 문항반응모형을 적용한 IRT "관찰점수" 동등화 절차를 제안하였다. 이 연구는 Lee와 Lee(2014) 연구의 추수연구로 단위검사를 대상으로 bi-factor 다차원 문항반응모형을 적용한 IRT "진점수" 동등화 절차를 제안하고, 그 적용 가능성을 실제 자료를 이용하여 탐색하고자 하였다. 이를 위해 단위검사로 구성된 대규모 독해 검사 자료를 이용하여, 2모수 로지스틱 모형(2-parameter logistic model: 2PL), 등급반응모형(graded response model: GRM), 단위검사모형(testlet response model: TRM), bi-factor 모형(bi-factor model: BFM)을 적용하였으며, 관찰점수 및 진점수 동등화를 시행하여 총 8개의 동등화 방법을 적용하고, 산출된 결과를 동백분위 동등화 결과와 비교하였다. 연구 결과, 2PL과 BFM을 적용한 관찰점수 및 진점수 동등화는 유사한 결과를 산출하였으며, GRM을 적용한 관찰점수 및 진점수 동등화 방법은 다른 방법들과 다소 차이를 보이는 결과를 산출하였고, 비교 기준이 된 동백분위 동등화 결과와 보다 유사한 결과를 보였다.

How 2020-2021 Changed the Life Perspectives of Composer Chihchun Chi-sun Lee

( Michael Sidney Timpson ),( Chichchun Chi-sun Lee ) 한국음악학학회 2021 음악학 Vol.29 No.2

대만계 미국인 작곡가 치천 지선 리는 서울에 거주는 프리랜서 작곡가이다. 치천 지선 리는 보스턴 심포니 오케스트라의 위촉을 받은 최초의 대만 작곡가이자, 2001년과 2018년 하버드 대학교 프롬 음악 재단의 위촉을 받고, 2015년에는 구겐하임 펠로우를 받은 세계적인 작곡가이다. 세계를 횡단하며 활동하던 작곡가 치천 지선 리는 코로나 19가 가져온 전지구적 영향으로 연주자들과 함께하는 리허설, 관객을 대상으로 하는 무대가 불가능해지면서 작곡가로서의 일상에 큰 변화를 겪었다. 계속해서 여러 음악 단체들과 협연을 기획하며 연주 활동을 이어가야 하는 프리랜서 작곡가에게는 치명적인 영향이 아닐 수 없다. 이 글은 코로나 19가 전 지구를 휩쓴 지난 2년 치천 지선 리가 프리랜서 작곡가로서 겪을 수밖에 없었던 활동의 변화와 그럼에도 악착같이 작곡을 이어나간 그녀의 창작활동을 소개한다. 치천 지선 리는 코로나 19가 가져온 위기를 기회로 바꾸어 디지털 기술을 활용해 물리적 제한 없이 더욱 다양한 지역의 사람들과 소통했다. 코로나 19는 전지구적 단위에서 현재 벌어지고 있는 여러 사회 현안들을 보다 자세하게 들여다볼 기회를 제공했다. 성공적인 코로나 방역을 자랑하지만 여전히 세계정치에서 소외된 그녀의 모국 대만, 미국의 치열한 정치와 선거, 다양한 지역의 전통 민요와 동요 등은 팬데믹 시기 치천 지선 리가 새로 발견하고 경험한 작곡의 원천이다. Taiwanese American Chichun Chi-sun Lee is a freelance composer who resides in Seoul, South Korea. She was the first Taiwanese composer to be commissioned by the Boston Symphony Orchestra and she was also commissioned by the Fromm Music Foundation at Harvard University, in both 2001 and 2018. Additionally, Lee received the prestigious Guggenheim Fellow in 2015. These great honors prove that she was approaching a milestone of a successful composition career. However, COVID-19, which has affected all universally, breaks her routine to succeed in her carrier as a composer who inevitably requires social gathering for rehearsal, practice, and live performance. This paper demonstrates how Chichun Chi-sun Lee as a freelancer composer overcame the worldwide lockdown via COVID-19 and created her musical pieces during the last two years. She has turned the crisis into opportunities and took advantage of technologies to communicate much globally without physical restriction. Moreover, pandemic gave her a chance to look at the issues in globalized society under the microscope. She shares what she has produced during the last two years through experiences in her native country Taiwan which has successfully prevented COVID-19 but is still alienated from global society, fraught elections and politicizing in the US, and multi-local traditional folk music and plays she has found through digital media.

Highly lithium-ion conductive battery separators from thermally rearranged polybenzoxazole

Lee, Moon Joo,Kim, Ji Hoon,Lim, Hyung-Seok,Lee, So Young,Yu, Hyung Kyun,Kim, Jong Hun,Lee, Joo Sung,Sun, Yang-Kook,Guiver, Michael D.,Suh, Kyung Do,Lee, Young Moo The Royal Society of Chemistry 2015 Chemical communications Vol.51 No.11

<P>High power density lithium ion battery (HLIB) separators were fabricated for the first time from thermally rearranged poly(benzoxazole-<I>co</I>-imide) (TR-PBOI) nanofibrous membranes coated with TR-PBOI nanoparticles, which show distinct thermal and dimensional stabilities as well as excellent cycle retention and rate capability.</P> <P>Graphic Abstract</P><P>Lithium ion battery separators were fabricated for the first time from thermally rearranged poly(benzoxazole-<I>co</I>-imide) (TR-PBOI) nanofibrous membranes coated with TR-PBO nanoparticles. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4cc09411e'> </P>

Structural influence of hydrophobic diamine in sulfonated poly(sulfide sulfone imide) copolymers on medium temperature PEM fuel cell

Lee, Kang Hyuck,Lee, So Young,Shin, Dong Won,Wang, Chenyi,Ahn, Sang-Hyun,Lee, Kee-Jung,Guiver, Michael D.,Lee, Young Moo Elsevier 2014 Polymer Vol.55 No.6

<P><B>Abstract</B></P> <P>Sulfonated poly(sulfide sulfone imide) copolymers containing flexible sulfide bond and six-membered imide ring were synthesized by random polycondensation. Two types of membranes were prepared by using sulfide (S-PSI) and sulfide sulfone (S-PSFI) based non-sulfonated diamines to investigate the effects of the hydrophobic component. IEC<SUB>w</SUB> values were controlled to 1.51−1.94 meq g<SUP>−1</SUP> depending on the degree of sulfonation (DS) which was in the range of 50–80%. The membrane series showed good thermal stability up to 310 °C and mechanical properties (tensile strength >30 MPa). Dimensional stabilities were excellent with 23−35% increases, even at 100 °C. Proton conductivities of membranes composed of different hydrophobic diamines display a relatively good correlation with water content and morphology. In fuel cell tests, the S-PSI60 membrane shows relatively high current density of 250 mA cm<SUP>−2</SUP> at 0.6 V and maximum power density of 175 mW cm<SUP>−2</SUP> at 120 °C, 35% RH, 1.5 atm.</P> <P><B>Graphical abstract</B></P> <P>The S-PSI60 having 8 nm sized ionic clustered morphology showed 250 mA cm<SUP>−2</SUP> of current density at 0.6 V and 175 mW cm<SUP>−2</SUP> of maximum power density at 120 °C, 35% RH, 1.5 atm.</P> <P>[DISPLAY OMISSION]</P>

Morphological transformation during cross-linking of a highly sulfonated poly(phenylene sulfide nitrile) random copolymer

Lee, So Young,Kang, Na Rae,Shin, Dong Won,Lee, Chang Hyun,Lee, Kwan-Soo,Guiver, Michael D.,Li, Nanwen,Lee, Young Moo The Royal Society of Chemistry 2012 ENERGY AND ENVIRONMENTAL SCIENCE Vol.5 No.12

<P>We present a new approach of morphological transformation for effective proton transport within ionomers, even at partially hydrated states. Highly sulfonated poly(phenylene sulfide nitrile) (XESPSN) random network copolymers were synthesized as alternatives to state-of-the-art perfluorinated polymers such as Nafion<SUP>®</SUP>. A combination of thermal annealing and cross-linking, which was conducted at 250 °C by simple trimerisation of ethynyl groups at the chain termini, results in a morphological transformation. The resulting nanophase separation between the hydrophilic and hydrophobic domains forms well-connected hydrophilic nanochannels for dramatically enhanced proton conduction, even at partially hydrated conditions. For instance, the proton conductivity of XESPSN60 was 160% higher than that of Nafion<SUP>®</SUP> 212 at 80 °C and 50% relative humidity. The water uptake and dimensional swelling were also reduced and mechanical properties and oxidative stability were improved after three-dimensional network formation. The fuel cell performance of XESPSN membranes exhibited a significantly higher maximum power density than that of Nafion<SUP>®</SUP> 212 under partially hydrated environments.</P> <P>Graphic Abstract</P><P>Morphologically transformed XESPSN <I>via</I> simple thermal trimerisation of end ethynyl groups shows enhanced proton transport even at partially hydrated states. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2ee21992a'> </P>

Intermediate-term outcomes after robotic ureteral reconstruction for long-segment (≥4 centimeters) strictures in the proximal ureter: A multi-institutional experience

Matthew Lee,Ziho Lee,Helaine Koster,Minsuk Jun,Aeen M. Asghar,Randall Lee,David Strauss,Neel Patel,Daniel Kim,Sreeya Komaravolu,Alice Drain,Michael J. Metro,Lee Zhao,Michael Stifelman,Daniel D. Eun 대한비뇨의학회 2021 Investigative and Clinical Urology Vol.62 No.1

Purpose: To report our intermediate-term, multi-institutional experience after robotic ureteral reconstruction for the management of long-segment proximal ureteral strictures. Materials and Methods: We retrospectively reviewed our Collaborative of Reconstructive Robotic Ureteral Surgery (CORRUS) database to identify all patients who underwent robotic ureteral reconstruction for long-segment (≥4 centimeters) proximal ureteral strictures between August 2012 and June 2019. The primary surgeon determined the specific technique to reconstruct the ureter at time of surgery based on the patient's clinical history and intraoperative findings. Our primary outcome was surgical success, which we defined as the absence of ureteral obstruction on radiographic imaging and absence of obstructive flank pain. Results: Of 20 total patients, 4 (20.0%) underwent robotic ureteroureterostomy (RUU) with downward nephropexy (DN), 2 (10.0%) underwent robotic ureterocalycostomy (RUC) with DN, and 14 (70.0%) underwent robotic ureteroplasty with buccal mucosa graft (RU-BMG). Median stricture length was 4 centimeters (interquartile range [IQR], 4–4; maximum, 5), 6 centimeters (IQR, 5–7; maximum, 8), and 5 centimeters (IQR, 4–5; maximum, 8) for patients undergoing RUU with DN, RUC with DN, and RU-BMG, respectively. At a median follow-up of 24 (IQR, 14–51) months, 17/20 (85.0%) cases were surgically successful. Two of four patients (50.0%) who underwent RUU with DN developed stricture recurrences within 3 months. Conclusions: Long-segment proximal ureteral strictures may be safely and effectively managed with RUC with DN and RU-BMG. Although RUU with DN can be utilized, this technique may be associated with a higher failure rate.

Auto-guiding Performance from IGRINS Test Observations (Immersion GRating INfrared Spectrograph)

Hye-In Lee,Soojong Pak,Huynh Anh N.Le,Wonseok Kang,Gregory Mace,Michael Pavel,Daniel T.Jaffe,Jae-Joon Lee,Ueejeong Jeong,Michael Pavel,Daniel T.Jaffe,Jae-Joon Lee,Ueejeong Jeong,Moo-Young Chun,Chan Pa 한국천문학회 2014 天文學會報 Vol.39 No.2

Human Raf-1 proteins associate with Rad24 and Cdc25 in cell-cycle checkpoint pathway of fission yeast, Schizosaccharomyces pombe

Lee, Michael,Yoo, Hyang-Sook Wiley Subscription Services, Inc., A Wiley Company 2007 Journal of cellular biochemistry Vol.101 No.2

<P>Raf-1 is a serine/threonine protein kinase that connects cell surface receptor signals to nuclear transcription factors. By screening Schizosaccharomyces pombe (S. pombe) cDNA library, we isolated Rad24, which is a 14-3-3 homolog that is important in the DNA damage checkpoint in S. pombe, as a Raf-1 interacting protein. The interaction found in yeast was confirmed by co-immunoprecipitation. Furthermore, Cdc25, which has been known to bind to Rad24, also associated with Raf-1 and was phosphorylated in vitro by catalytically active Raf-1. However, in the presence of Raf-1, an interaction between Rad24 and Cdc25 was inhibited in triple hybrid assay, indicating that Raf-1 inhibits the interaction between Rad24 and Cdc25. An in vitro competition assay showed that the binding of Cdc25 and of Rad24 to Raf-1 is mutually exclusive. Western blots of whole cell lysates probed with polyclonal antibodies specific for tyrosine-15-phosphorylated Cdc2 showed that overproduction of Rad24 led to the dephosphorylation of tyrosine residue on Cdc2, which is known to be activated through dephosphorylation by Cdc25 phosphatase. Unexpectedly, overexpression of catalytically inactive mutant protein of Raf-1, S624A, also caused tyrosine dephosphorylation of Cdc2. Thus, these data suggest that Raf-1 may interfere with the role of Rad24 by competing with Rad24 for binding to Cdc25 or a direct phosphorylation of Cdc25, bypassing the checkpoint pathway in DNA repair through Cdc25 activation. J. Cell. Biochem. 101: 488–497, 2007. © 2007 Wiley-Liss, Inc.</P>

Epilepsy Surgery in Children versus Adults

Lee, Ki Hyeong,Lee, Yun-Jin,Seo, Joo Hee,Baumgartner, James E.,Westerveld, Michael The Korean Neurosurgical Society 2019 Journal of Korean neurosurgical society Vol.62 No.3

Epilepsy is one of the most common chronic neurological disorder affecting 6-7 per 1000 worldwide. Nearly one-third of patients with newly diagnosed epilepsy continue to have recurrent seizures despite adequate trial of more than two anti-seizure drugs : drug-resistant epilepsy (DRE). Children with DRE often experience cognitive and psychosocial co-morbidities requiring more urgent and aggressive treatment than adults. Epilepsy surgery can result in seizure-freedom in approximately two-third of children with improvement in cognitive development and quality of life. Understanding fundamental differences in etiology, co-morbidity, and neural plasticity between children and adults is critical for appropriate selection of surgical candidates, appropriate presurgical evaluation and surgical approach, and improved overall outcome.

A review of liver fibrosis and cirrhosis regression

Michael J. Lee 대한병리학회 2023 Journal of Pathology and Translational Medicine Vol.57 No.4

Cirrhosis has traditionally been considered an irreversible process of end-stage liver disease. With new treatments for chronic liver disease, there is regression of fibrosis and cirrhosis, improvement in clinical parameters (i.e. liver function and hemodynamic markers, hepatic venous pressure gradient), and survival rates, demonstrating that fibrosis and fibrolysis are a dynamic process moving in two directions. Microscopically, hepatocytes push into thinning fibrous septa with eventual perforation leaving behind delicate periportal spikes in the portal tracts and loss of portal veins. Obliterated portal veins during progressive fibrosis and cirrhosis due to parenchymal extinction, vascular remodeling and thrombosis often leave behind a bile duct and hepatic artery within the portal tract. Traditional staging classification systems focused on a linear, progressive process; however, the Beijing classification system incorporates both the bidirectional nature for the progression and regression of fibrosis. However, even with regression, vascular lesions/remodeling, parenchymal extinction and a cumulative mutational burden place patients at an increased risk for developing hepatocellular carcinoma and should continue to undergo active clinical surveillance. It is more appropriate to consider cirrhosis as another stage in the evolution of chronic liver disease as a bidirectional process rather than an end-stage, irreversible state.