혼합형 검사에서 IRT문항모수와 기저 능력분포의 동시 추정이 문항모수 추정의 정확도에 미치는 영향

김성훈(Seonghoon Kim) 한국교육평가학회 2013 교육평가연구 Vol.26 No.3

본 연구는 김성훈(2012)의 후속연구로서, 혼합형 검사의 IRT 문항모수를 주변최대우도(MML)/베이지언 최빈치(BM)방법을 통해 추정할 때 사전능력분포를 ‘표준정규 N(0, 1)분포로 지정하는 방식’보다 ‘기저 능력분포의 추정치로 지정하는 방식(즉, 문항모수와 능력분포를 동시에 추정하는 방식)’이 더 우수한지를 모의실험을 통해 확인하고자 하였다. PARSCALE프로그램을 이용하여 혼합형 검사의 선다형 문항은 3모수 로지스틱(3PL)모형으로 분석하고 구성형 문항은 일반화부분점수(GPC)모형으로 분석하였다. 모의실험의 요인으로 기저 능력분포의 유형, IRT분석 모형에 의한 검사의 유형, 검사의 곤란도, 표본의 크기 등을 포함하였다. 김성훈(2012)의 연구 결과와 유사하게, 사전능력분포를 기저 능력분포의 추정치로 지정하는 방식이 디폴트 방식인 N(0, 1)분포로 지정하는 방식보다 고려된 모든 검사 조건에서 우수하거나 대등한 수행을 보였다. 즉, 선다형 검사뿐만 아니라 혼합형 검사에 대해서도 IRT 문항모수와 기저 능력분포의 동시 추정은 문항모수 추정의 정확성과 안정성을 향상시켰다. In item response theory (IRT), the use of marginal maximum likelihood (MML) and Bayesian modal (BM) methods for item parameter estimation requites the specification of a prior distribution for the ability variable. With multiple-choice (MC) tests, Kim (2012) found that in MML/BM estimation of item parameter; the way of specifying the prior ability distribution as the estimate of underlying distribution (i.e., concurrent estimation of item parameters and underlying distribution) outperformed or peformed equally to the way of specifying the prior ability distribution as a standard normal N(0, 1) distribution. As a follow-up study of Kim (2012), this paper attempted to verify through simulations that the previous findings from Me tests should be generalized to mixed-format tests consisting of MC items and constructed-response (CR) items. The PARSCALE program was used to analyze MC and CR items via the 3-paramerer logistic (3PL) and generalized partial credit (GPO models, respectively. The simulation factors considered include type of underlying ability distributions (normal, positively skewed, and negatively skewed), test type by the IRT model used OPL, GPC, and 3PL+GPC), test difficulty (easy, moderately difficult, and difficult), and sample size (500 and 2,000). As found in Kim's study, the way of concurrently estimating the underlying distribution along with item parameters outperformed or peformed equally to the way of specifying the prior distribution as a N(0, 1) in accurate estimation of item parameters with mixed-format tests.

부신의 기능성종양 및 비기능성 부신피질선종을 제외한 부신 양성종양에 대한 임상적 고찰

김성훈,이준호,김지수,최준호,남석진,이정언,김석원,길원호,김정한,Sung Hun Kim,Jun Ho Lee,Jee Soo Kim,Jun-Ho Choi,Seok-Jin Nam,Jeong-Eon Lee,Seok Won Kim,Won Ho Kil,Jung-Han Kim 대한갑상선-내분비외과학회 2014 The Koreran journal of Endocrine Surgery Vol.14 No.4

Purpose: Benign adrenal tumors other than hyper-functioning tumor and non-functioning cortical adenoma are extremely rare. The purpose of this study is to review the clinical features of these rare benign adrenal tumors and to analyze their prevalence and the proper surgical approach for them. Methods: Among patients who underwent adrenalectomy in Samsung Medical Center, between 1997 and 2013, patients with benign adrenal tumor except non-functioning cortical adenoma, malignancy, and hyper-functioning tumor such as pheochromocytoma, aldosteronoma, and cortisol producing tumor were included. Clinical details, radiologic findings and pathologic findings as well as data associated with the surgical procedure were analyzed retrospectively. Results: The percentage of these tumors among 703 surgically removed adrenal tumors was 10.7% (75 cases). They included 30 adrenal cysts, 18 ganglioneuromas, 11 myelolipomas, seven schwannomas, and the other six were rare adrenal tumors. Approximately 40% of the patients were operated under a diagnosis different from original tumors. Operation time and hospital stay of patients who underwent laparoscopic adrenalectomy were shorter than those of patients who underwent open adrenalectomy. Conclusion: These benign adrenal tumors are very rare and difficult to diagnose preoperatively. For the surgical treatment of these tumors, laparoscopic adrenalectomy is more preferable to conventional open adrenalectomy.

하천유역조사의 장기유출분석 과정 소개

김성훈,김선우,김태정,이성호,성장현,이연길,Kim, Seong-Hun,Kim, Seon-U,Kim, Tae-Jeong,Lee, Seong-Ho,Seong, Jang-Hyeon,Lee, Yeon-Gil 한국수자원학회 2020 물과 미래(한국수자원학회지) Vol.53 No.7

열통합 기법을 통한 이산화탄소 막 분리공정 에너지 해석

김성훈,김태영,김범석,조현준,여영구,Kim, Seong Hun,Kim, Tae Yong,Kim, Beom Seok,Cho, Hyun-Jun,Yeo, Yeong Koo 한국플랜트학회 2016 플랜트 저널 Vol.12 No.2

이산화탄소 분리공정에 있어서 분리막 공정은 소형, 모듈성, 설치의 용이성, 작동의 유연성, 낮은 설치 비용 및 낮은 에너지 소비량 등의 장점들로 인하여 주목 받고 있다. 본 연구에서는 실험데이터와의 비교를 통해 교차흐름, 병류흐름, 향류흐름 3가지 모델의 정확도를 알아보았다. 실험에서 이용된 이산화탄소 분리공정을 가장 잘 나타내어주는 모델을 토대로 전산모사를 통하여 2단 막 분리 구조에서의 운전조건을 규명하고 분리막의 투과도 및 선택도가 분리성능에 미치는 영향을 알아보았다. 나아가 수증기 sweep을 이용하는 2단 막 분리 구조에서 열교환망 합성기법을 적용하여 열교환기 도입에 따른 소요 전력의 변화와 운전비용 절감효과를 살펴보았다. The membrane separation processes have received attention due to advantages such as compactness, modularity, ease of installation, flexibility of operation, lower capital cost and lower energy consumption. In this study, we evaluated accuracy of cross-flow, co-current and counter-current models. With the most accurate model, we identified the operating conditions of the two-stage membrane separation and examined the effects of permeance and selectivity of the membrane by simulation. Futhermore, power requirements and operating cost savings due to the introduction of the heat exchanger were investigated by applying heat exchanger network synthesis technique in the two-stage membrane separation using vapor sweep.

SELECT 모델을 이용한 트롤 비교 시험조업법에 의한 망목 선택성에 관한 연구

김성훈,김형석,백세나,김재형,김병관,Seonghun KIM,Hyungseok KIM,Sena BAEK,Jaehyung KIM,Pyungkwan KIM 한국수산해양기술학회 2023 수산해양기술연구 Vol.59 No.2

In this study, a comparative test operation was conducted through the alternate haul method to examine the selectivity of the four mesh sizes (60 mm, 90 mm, 110 mm, and 130 mm) of the trawl codend. The selectivity was analyzed using the SELECT model considering the fishing efficiency (split parameter) of each fishing gear in the comparative test fishing operation in the trawl and the maximum likelihood method for parameter estimation. A selectivity master curve was estimated for several mesh sizes using the extended-SELECT model. As a result of analyzing the selectivity for silver croaker based on the results of three times hauls for each experimental gear, it was found that the size of the fish caught increased as the size of the mesh size increased. When the selectivity for each mesh size analyzed by the SELECT model considering the split ratio was evaluated based on the size of the AIC value, the estimated split model was superior to the equal split model. Based on the master curve, the 50% selection length value was 2.893, which was estimated to be 136 mm based on the mesh size of 60 mm. In some selectivity models, there was a large deviance between observed and theoretical values due to the non-uniformity of the distribution of fished length classes. As a result, it is considered that appropriate sea trials and selectivity evaluation methods with high reliability should be applied to present trawl fishery resource management methods.

열간가압소결법으로 제조한 탄화규소의 균열자기치유 특성

김성훈,김경훈,도환수,박주석,김경자,심광보,Kim, Seong-Hoon,Kim, Kyung-Hun,Dow, Hwan-Soo,Park, Joo-Seok,Kim, Kyung-Ja,Shim, Kwang-Bo 한국결정성장학회 2016 韓國結晶成長學會誌 Vol.26 No.2

본 연구에서는 열간가압소결법으로 SiC를 소결하여 균열자기치유 특성을 분석하였다. SiC는 $Al_2O_3$와 $Y_2O_3$를 소결조제로 $1950^{\circ}C$, 50 MPa, 아르곤(Ar) 분위기에서 소결하였다. 소결된 시편을 $3{\times}4{\times}40mm$, 절단 및 가공하고, Vickers 경도기를 이용하여 49.6 N으로 예비균열을 생성하였다. $1200{\sim}1400^{\circ}C$, 1~10시간 산화분위기에서 열처리한 후 XRD, SEM, 3점 굽힘강도를 측정하였다. $1300^{\circ}C$ 1시간에서 741 MPa, 5시간에서 770 MPa로 가장 우수한 균열자기치유 효과를 나타내는 것으로 분석되었다. In this study, it was investigated that characteristic of crack-self-healing of hot-pressed SiC. SiC ceramics was sintered with $Al_2O_3$ and $Y_2O_3$ sintering additive by hot press. Sintering was performed in hot-press furnace in flowing argon (Ar), holding for 3 hr under $1950^{\circ}C$ and 50 MPa. The sintered SiC was machined into 3-point bending strength specimen of $3{\times}4{\times}40mm$, and introduced pre-crack by Vickers indentation at 49.6 N. Specimens were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), 3-point bending strength after heat treatment at $1200{\sim}1400^{\circ}C$ for 1~10 hr. The best crack-self-healing ability was achieved 770 MPa 3-point bending strength by heat treatment at $1300^{\circ}C$ for 5 hr.

토목시설물에 대한 BIM기반 공사관리 기법 연구

김성훈,이상호,남상혁,선오영,Kim, Sung-Hoon,Lee, Sang-Ho,Nam, Sang-Hyeok,Sun, Oh-Young 한국전산구조공학회 2011 한국전산구조공학회논문집 Vol.24 No.4

BIM(Building Information Modeling)은 원칙적으로 건설 전 생애주기에 걸쳐 활용되어야 그 효과를 극대화 할 수 있으나, 아직은 계획 및 설계단계에 비하여 공사단계에서는 그 활용도가 상당히 낮은 수준이었다. 최근 대형 국책사업이 발주, 시공되면서 효율적인 공사관리를 위한 방법으로 3D 성과품 검토나 4D 공정관리 등 BIM기법 중 일부가 도입되고 있다. 본 연구에서는 토목시설물의 공사단계에서 BIM 활용방안에 대하여 제시하였다. 토목공사의 종류별, 관리 분야별 BIM 활용방안에 대하여 논의하고, 서울 지하철 919공구에 실제로 적용하여 그 효용성에 대하여 분석하였다. 특히, 현장에 구축된 BIM 기반의 웹 공사관리 시스템은 공사중, 현장과 본사를 비롯해 발주처와 감리단 등 다수의 공사 주체들이 BIM을 보다 효과적으로 사용하도록 함으로써, BIM의 공사단계 활용성을 높일 뿐만 아니라 유지관리 단계까지 확장하여 이용될 수 있다. BIM(Building Information Modeling) technologies should be applied for the construction life cycle to maximize its efficiency, but the utilization for the construction phase has been significantly lower than that for the planning and design phase. Recently, some of BIM techniques such as 3D design review, 4D schedule management and so on are being introduced for efficient managing to the big national construction projects. In this study, the utilization plans of BIM are presented for the construction phase of civil engineering facilities. The methods of utilization of BIM are discussed for each type of construction, and the techniques applied to the Seoul Subway Lot No. 919 are analyzed for checking the applicability and usability. In particular, a web construction management system based on BIM can help field engineers, headquarters and contractors to use BIM more effectively, and it can be extended to maintenance phase for more efficiencies.

고기능 EL소자용 고분자/유기 재료의 합성 및 전기 광학적 특성(Ⅱ) Squarylium 색소를 이용한 EL소자의 특성

김성훈,배진석,황석환,박이순,Kim, Sung Hoon,Bae, Jin Seok,Hwang, Seok Hwan,Park, Lee Soon 대한화학회 1997 대한화학회지 Vol.41 No.3

N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine(TPD)를 정공수송층으로, squarylium색소를 발광제로, 액정성 폴리머를 TPD의 matrix로 사용하여 electroluminescence(EL) 소자를 제작하였다. ITO 투명전극과 Mg 전극을 각각 홀주입, 전자주입 전극으로 사용하였다. Polymer/TPD 농도를 0.005 wt%로 하여 spin coating법으로 소자를 제작하였을 때 가장 안전한 ELD가 얻어졌다. ITO/polymer-TPD/SQ dye/Mg 구조의 ELD는 인가전압 23 volt에서 붉은색의 발광이 나타났으며 전류는 102 mA/$cm^2$이었다. Organic electroluminescence devices(ELD) were fabricated using by molecularly doped method with N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine(TPD) as a hole transport agent, squarylium dye as an emitting agent, and side chain liquid crystalline polymer(MCH) as matrix for TPD. An indium-tin-oxide(ITO) coated glass and an Mg electrode were used as the hole and the electron injecting electrode, respectively. The highest stability of ELD was obtained by spin coating method using dichloroethane as a solvent at a polymer/TPD concentration of 0.005 wt%. For the EL cell with ITO/polymer-TPD/SQ dye/Mg structure, we achieved light red luminescence at a current of 102 mA/$cm^2$ with an applied voltage of 23 V.

뉵血에 대한 文獻的 考察 (外治法을 中心으로)

김성훈,유미경,정동환,심상희,박수연,김종한,최정화,Kim, Sung-Hun,Yu, Mi-Kyoung,Jeong, Dong-hwan,Sim, Sang-hee,Park, Su-Yeon,Kim, Jong-han,Choi, Jung-hwa 대한한방안이비인후피부과학회 2003 한방안이비인후피부과학회지 Vol.16 No.3

The epistaxis is commonplace and temporary disease in the field of ENT. In most cases, it is a slight illness, but sometimes, it leads to death because of copious bleeding. The first treatment of epistaxis is stoping hemorrhage, but the real state of treatment in oriental medical is not thoroughgoing enough. So we referred to oriental medical journals and sundry records about etiology and remedy of epistaxis, we got this results. 1. The etiology of epistaxis was mostly bleeding due to heat in the blood by dysfunction of Jang and Bu Gi, there were affection wind-cold by exopathogen, spleen heat to liver, excessive fire of lung meridian, stagnated fire-heat of upper Cho, excessive drinking, bruise and so on. 2. The treatment was used much to remove heat from the blood and activating blood, in case of getting no better, it's used to enriching the blood or clear Gi. 3. The internal remedy of epistaxis was the most used 20times SeogakJihwangtang(犀角地黃湯) to remove heat from the blood and activating blood, and used Jihwangtang(地黃湯), Samhwangbohyultang(三黃補血湯), Jiyuksan(止육散), hueksinsan(黑神散), etc. The drugstuffs were the most used 51times Radix Rehmanniae Preparata((生地黃) to clear heat and remove heat from the blood, produce the body fluids, yin, and used Radix Paeoniae Alba(芍樂) and Radix Glycyrrhizae(甘草), Radix Angelicae Gignatis(當歸), Radix Scutellariae(黃岑), Rhizoma Coptidis(黃連) and Fructus Gardeniae(梔子), etc. 4. The external medical treatment of epistaxis was the most used 16times spraying the granular medication into the cavity and attaching Allii Bulbus(大蒜) to center of the sole or binding the middle finger, etc.

점진적 체중지지와 보행속도 증가 훈련이 뇌졸중 환자의 보행에 미치는 효과

김성훈,최종덕,Kim, Sung-Hoon,Choi, Jong-Duk 대한물리치료학회 2013 대한물리치료학회지 Vol.25 No.5

Purpose: The aim of this study was to evaluate the effect of progressive body weight decrease combined with increasing level of overground walking speed training for patients with chronic stroke. Methods: Eighteen subjects with chronic stroke were composed of the control group (5% body weight support combined with increasing speed training) and the experimental group (progressive body weight decrease with increasing speed training); three sets, three times per week over a period of four weeks. Results: Significant differences in terms of comfortable gait speed (CGS) and the rate of change of CGS were observed between the control and experimental groups (p<0.05). However, no significant difference in the dynamic gait index was observed between the control and experimental groups (p>0.05). A significant difference in the 6 minute walking test (6MWT) was observed for the experimental group, and a significant difference in the rate of change for the 6MWT was observed between the control and experimental groups (p<0.05). Conclusion: The progressive body weight decrease combined with increasing in level of overground walking speed training may be a better and more effective method for community walking and reintegration.