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.

소화성 궤양 출혈에서 열탐침 지혈법 후 재출혈의 위험인자

김영호,이석호,이상구,손희정,이규택,최규완,백승운,이종균,이준혁,고광철,이종철,김재준,류광현,이풍렬 대한소화기내시경학회 2000 Clinical Endoscopy Vol.20 No.6

Background/Aims: The precise rebleeding rate and risk factors of rebleeding after heat probe thermocoagulation in peptic ulcer patients with bleeding are not clear and still need to be evaluated. If we could identify the pre-dictors for rebleeding, the mortality rate might be loweted with early retreatment or surgery in these high risk group. Methods: The 94 patients in whom heat probe was applied were enrolled and the 18 patients with bleeding tendencies. Initial hemostasis was defined as hemostasis persisting for 24 hours post-treatment and permanent hemostasis as absence of bleeding for 7 days after therapy. Rebleedig was defined as oozing or spurting hemorrhage in the ulcer base and/or unstable vital signs and continuting tarry or bloody stool or hematemesis after therapy. Results: In 35 patients with active bleeding sign, initial hemostasis was obtained in 30 (85.7%) patients. After having achieved initial hemostasis, 9 (30.0%) patients rebled. In 41 ulcer patients with non-bleeding visible vessel, 40 cases (97.6%) achieved successful pre-vention of rebleeding. No evident complication was observed. With univariate analysis, bleeding ulcer patients with spurting and oozing hemorrhage had a higher re-bleeding rate than those with non-bleeding visible vessel. Conclusions: The heat probe thermocoagulaton is relative safe and effective procedure to protect bleeding in pectic ulcer patients with non-bleeding visible vessel, but insufficient to hemostasis in bleeding peptic ulcer patients with spurting or oozing in ulcer base. Spurting and oozing hemorrhage are the only risk factors of rebleeding after initial hemostasis with heat probe thermocoagulation in peptic ulcer patients with bleeding.

한,미 20대 소비자의 여성 정장과 캐주얼시장 세분화를 위한 글로벌 마케팅 전략 : A Comparison of Evaluation toward women`s formal wear and casual wear among Korean and American consumers in 20s

이승희,임숙자,안춘순,양윤,Sharron J. Lennon 한국의류학회 2001 한국의류학회지 Vol.25 No.4

The purpose of this research was to compare American Korean consumers perceptions or evaluations of womens' formal wear and casual wear. Results revealed that two groups classified differently the products in formal wear, not casual wear. In general, compared to Korean subjects, Americans rated the Korean business formal wear as more fashionable, attractive, stylish and of having higher quality than U.S. formal wear, indicating they were more likely to purchase. On the other hand, compared to U.S. subjects, in general, Koreans rated higher the U.S. casual wear as more liking, purchasing, comfortable, and appealing than Korean casual wear. Regarding clothing image toward each picture, there was a statically difference in both groups. To increase American or Korean exports of apparels, companies must look globally to develop new markets for their products.

한국과 미국의 여성 정장용 소재에 대한 한,미 소비자 선호도 비교연구

이승희,임숙자,안춘순,양윤,Sharron J. Lennon,Sue M. Parker 한국의류학회 2001 한국의류학회지 Vol.25 No.2

The purpose of this research was to investigate the difference in fabric preference of formal wear attire between the Korean and American female consumers. For such purpose, fabrics which were used in the women's formal wear market of Korea(n=25) and U.SA.(n=25) in the 1999 spring/summer season were collected from different fabric converters of the two countries. The respondents were comprised of 50 Korean and 50 U.S.A. female volunteers in the age group of 20s and 40s. A 5 point Likert Scale was used to evaluate the degree of the "like preference of fabrics. T-test and Speannan's rho statistics were conducted for data analysis. The followings are the results. 1. Korean 20s and American 20s preferred Korean fabrics but Korean 40s and American 40s preferred U.S.A. fabrics. 2. Generally, the 20s preferred greyish or tone down color, whereas the 40s preferred both greyish and colorful fabrics. 3. Koreans preferred melange colored fabrics as well as solid color fabrics. 4. Americans liked knit fabrics as well as woven fabrics for formal wear and 20s liked compact density fabrics compared to the 40s age group.

혈액투석 중인 만성 신부전 환자에서 TT Virus의 감염률과 임상적 의의

이용욱,허우성,도재혁,백승운,최문석,김소정,이준행,고광철,이풍렬,이종철,최규완,박상종,이준혁,김재준,오하영,임윤정 대한소화기학회 2001 대한소화기학회지 Vol.37 No.1

Background/Aims: TT virus (TTV) is a unenveloped, single-stranded and circular DNA virus isolated from the serum of a patient with posttransfusion hepatitis of unknown etiology. We evaluated the prevalence, risk factors, and clinical significance of TTV in patients with chronic renal failure(CCRF) undergoing maintenance hemodialysis (HD). Methods: We examined TTV DNA in serum of HD-undergoing patients and healthy controls using the nested polymerase chain reaction. Results: TTV DNA was detected in 15 (20.0%) of 75 HD-undergoing patients and 10 (13.2%) of 76 healthy controls (p$gt;0.05). The prevalence of TTV did not differ according to the duration of HD or transfusion history of the patients. The prevalence of TTV was higher in IgG anti-HBc positive patients than IgG anti-HBc negative patients (27.5% vs. 4.2%, p=0.03). There was no relationship between TTV infection and liver diseases. Conclusions: The prevalence of TTV infection in CRF patients undergoing HD was similar with that of healthy controls. These results suggest that TTV infection may share the route of transmission with HBV infection in adults.

조혈모세포이식을 받은 급성 골수 백혈병 환자에서 발생한 cyclosporine에 의한 양측 시신경병증

정진권,김한조,박명진,하승주,최경식,이성진,박성희,이상철,이남수,박희숙,원종호 순천향대학교 의학연구소 2007 Journal of Soonchunhyang Medical Science Vol.13 No.2

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암환자에서 단구매개 세포파괴능과 혈청내 Sialic acid농도

승기배,이흥현,서재열,문한림,진종률,박종원,김춘추,김동집 大韓血液學會 1984 大韓血液學會誌 Vol.19 No.1

플라즈마 용사법에 의한 지르코니아 5층 열장벽 피막의 고온마모 물성 및 접착강도에 관한 연구

한주철,송요승,이구현 한국항공대학교 1997 論文集 Vol.35 No.-

항공기나 자동차 에진의 내열 보호피막으로써 주목받아온 Thermal Barrier Coating(TBC)은 그 사용 영역이 디젤 엔진의 실린더 헤드나 피스톤 크라운 등으로 확대됨에 따라 고온에서의 내마모성능 또한 중요성이 커지고 있는 실정이다. 따라서 본 연구에서는 경사기능성 5층 지르코니아 열장벽의 미세구조를 비롯 고온 내마모성능, 부착강도를 시험하여 비교 평가하였다. TBC는 최상단에 100%세라믹의 단열층, 그 이하 75:25, 50:50, 25:75의 비율로 세라믹과 결합금속이 혼합된 3개의 경사기능성 중간층, 그리고 모재 직상에 피막과 모재와의 결합을 도모하기위한 100% 금속의 결합층 등, 총 5개층으로 구성하여 고온에서 발생할 수 있는 열응력을 최소화하고자 하였다. 세라믹 단열재로는 YSZ, MSZ 분말을, 결합금속으로는 NiCrAlY, Inconel 625 SUS 316을 사용하였다. 고온마모시험 결과, YSZ/NiCrAlY TBC가 600℃와 800℃에서 가장 우수한 내마모성능을 보여주었고, 400℃에서는 YSZ/Inconel TBC가 가장 적은 마모량을 나타내었다. 특히, YSZ/ NiCrAlY와 MSZ/NiCrAlY TBC의 경우, 600℃와 800℃의 마모량보다 400℃에서의 마모량이 적었으며, 이는 지르코니아의 저온열화현상에 의한 결과라 사료된다. The Thermal Barrier Coating(TBC) has been used to improve the heat barrier and wear resistant properties of the aircraft engine and the automobile engine in high temperature. Especially, the high temperature tribological properties of the cylinder head and the piston crown of diesel engine was emphasized. Therefore, the purpose of this work was to evaluate the micro structure, tribological property in high temperature and bonding strength of five layers functional gradient TBC for the application of TBC. The five layers were composed with 100% ceramic insulating layer, 75(ceramic):25(metal) layer, 50:50 layer, 25:75 layer and 100% metal bonding layer to reduce the thermal stress. The YSZ and MSZ powders were the insulation ceramics powders. The NiCrAlY, Inconel and SUS powders were the bonding and mixing powders for plasma spra process. According to the result of high temperature wear test, the wear resistance of YSZ/NiCrAlY system was most outstanding at 600 and 800℃. At 400℃, the wear resistance of YSZ/Inconel system was better than others. The amount of wear volume loss of YSZ/ NiCrAlY and MSZ/NiCrAlY TBC at 400℃ were much more than the amount of wear volume loss at other temperature because of the low temperature degradation. The bonding strength of TSZ/ NiCRAlY and YSZ/Inconel 5 layers system is better than others.

Diatom genus Stephanodiscus as eutrophication indicator for water quality assessment

Cho, K.-J 韓國陸水學會 1998 생태와 환경 Vol.31 No.3

Bluetooth DK를 이용한 동영상 전송 시스템 구현

조경연,이승은,최종찬 호서대학교 반도체제조장비국산화연구센터 2001 반도체장비학술심포지움 Vol.2001 No.-

본 논문은 ATMEL Bluetooth Development Kit (DK)를 이용하여 음성과 데이터를 전송하는 시스템을 구현하는 것으로, Bluetooth 디바이스간 연결을 위한 과정을 분석하였다.또한, Synchronous Connection-Oriented (SCO) 링크와 Asynchronous Connectionless (ACL) 링크를 형성하여 음성과 데이터를 송수신하는 어플리케이션을 구현하였다.향후 가정, 사무실, 공장등에서 근거리 무선 통신 기술로 자리잡아갈 Bluetooth 기술을 적용한 어플리케이션 개발은 필수적이다.본 논문에서는 Bluetooth 호스트 컨트롤러 인터페이스 (HCI)를 이용한 어플리케이션 개발 과정을 제시하였다.