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.

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.

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.

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.

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.

Ethylenethiourea의 임신 랫트에 있어서 기관형성기 투여시험 2. 수 미로 시험과 양수내의 α-fetoprotein, 요소 및 유리지방산 함량에 미치는 영향

김성훈,허린수,Kim, Sung-hoon,Huh, Rhin-soo 대한수의학회 1991 大韓獸醫學會誌 Vol.31 No.4

This study was carried out to investigate; the alpha-fetoprotein, urea and free fatty acid in amniotic fluids and water filled multiple T-maze test of fetuses affected by Ethylenethiourea. The S.P.F. Sprague-Dawley female rats(10 weeks) were used in this study and these animals were divided into four groups; control group I (10mg/kg/day), group II(30mg/kg/day), group III(50mg/kg/day). The results obtained were summarized as follows; 1. In the water filled multiple T-maze test of F1 male rats, The time and errors from start point to goal point of 30mg/kg group are significantly(p<0.001) increased from control group in 3rd day of test. In F1 female rats of 2nd day and 3rd day of water filled multiple T-maze test, The time and some errors in 30mg/kg group are significantly (p<0.05) increased from control group. 2. Alpha-fetoprotein values of all treated groups(10mg/kg, 30mg/kg and 50mg/kg) were significantly(p<0.001) decreased from control values in the amniotic fluids. 3. Urea values of ammniotic fluids in 50mg/kg group are significantly increased from control group. 4. Free fatty acid values of ammniotic fluids in 50mg/kg group are significantly increased from control group.

Cysteine antagonism of captafol induced toxicities in rats 1. Effects on hematological and serum biochemical values

김성훈,Kim, Sung-hoon The Korean Society of Veterinary Science 1995 大韓獸醫學會誌 Vol.35 No.3

과일 및 채소류의 곰팡이 억제제로 개발된 captafol은 인간 및 동물에서의 독성작용은 많이 보고된 바 있으나 이들의 독작용을 완화시키거나 치료할 수 있는 제제에 대한 연구는 별로 알려진 바 없다. captafol에 의한 혈액학 및 혈청 생화화적 변화에 따른 cysteine의 방어 작용을 확인할 목적으로 랫트에 5mg/kg 용량의 captafol을 1회 복강 투여하고 동시에 5, 58, 290 및 580mg/kg cysteine을 각각 투여하고 체중의 변화, 부검소견, 절대장기중량, 혈액학 및 혈청 생화학적 소견을 비교 분석 하였다. captafol 단독 투여군에서는 체중 및 간 장기중량 감소, 복강내 장기들의 섬유소에 의한 유착 및 복수 등이 현저하였으며 적혈구 수, hemoglobin 농도, 혈청 AST의 증가가 인정되었으며 또한 혈청 인지질 함량 감소가 확인되었다. 한편, cysteine 58mg/kg 이상의 용량군에서는 복강내 장기들의 유착 및 복수가 확인되지 않았으며 장기중량, 혈액학 및 혈청 생화학적 소견에서도 정상을 나타내었다. 이 연구 결과는 captafol의 중독증상에 대해 cysteine 및 sulfhydryl군을 가진 물질은 그 증세를 감소시키거나 완화시킬 수 있는 효과가 있음을 보여주고 있다. This experiment was carried out to study the preventive effect of cysteine on the toxicities of captafol to the hematological and serum biochemical values. A single dose of captafol(5mg/kg BW, ip) was given to male Sprague-Dawley rats and its toxicities were evalutated by body weitht changes, autopsy findings, absolute organ weight, and hematological and serum biochemical parameters. The single dose of captafol caused significant decreases in body weitht, and absolute liver weight, as-cites, fibrin clot in abdominal cavity, adhesion of liver lobes significant elevation of number of RBC, hemoglobin concentration and serum AST activity, and decreased of serum phospholipid level. Where as cysteine(over 58mg/kg BW) given immediately after captafol appeared to prevent the ascites, fibrin clot in abdominal cavity and liver lobe adhesion. It also prevented the liver and blood, especially RBC toxicites. The results suggest that cysteine and other compounds containing sulfhydryl groups may protect the subjects from captafol-induced toxicity.

The effect of captafol on the hematological value, erythrocyte membrane and plasma biochemical value in vitro

김성훈,황화선,차신우,한상섭,노정구,Kim, Sung-hoon,Hwang, Hwa-seon,Cha, Shin-woo,Han, Sang-seop,Roh, Jung-koo The Korean Society of Veterinary Science 1993 大韓獸醫學會誌 Vol.33 No.3

Captafol은 phthalimide계통의 항진균제로써 difolatan이란 상품명으로 개발되어 과일, 채소의 탄저병 및 원목 등의 곰팡이 구제에 널리 사용되고 있는 것으로 국내에서도 두번째로 많이 생산, 사용되는 품목이나 독성실험에 관한 보고는 거의 없는 상태이다. 이에 본 연구에서는 captafol 자체에 대한 독성기전의 일부를 확인하고자 동물체내에서 일어나는 여러가지 대사작용이 배제된 시험관내에서 실험을 수행하였다. 랫트 혈액을 후대정맥으로 부터 채혈하여 4개의 시험관에 $2.5m{\ell}$씩 분주한 후 captafol 농도가 $0.1{\times}10^{-4}M$, $1{\times}10^{-3}M$, $1{\times}10^{-2}M$이 되도록 한 ethanol용액 $25{\mu}{\ell}$씩 넣고 $CO_2$ incubator에서 2시간 동안 부드럽게 혼합하여 혈액학적 성상 및 적혈구 취약성 시험을 수행하였다. 또한 원심분리하여 얻어진 혈장에서 생화학적 성상 등을 조사한 결과 다음과 같은 성적을 얻었다. 1. 적혈구수 및 hematocrit치는 captafol 투여량에 비례적으로 유의한(p<0.05) 감소를 나타내었다. 2. 적혈구막 취약성 실험에서 $1{\times}10^{-3}M$ 및 $1{\times}10^{-2}M$ 농도에서 대조군에 비하여 유의한(p<0.01) 증가를 나타내었다. 3. 혈장내 potassium이온의 농도는 captafol의 투여량에 비례적으로 증가하였다. 4. Total bilirubin 및 creatine kinase가 대조군에 비하여 각각 증가 및 감소하였다. The effect of captafol on the hematological value, erythrocyte membrane and plasma biochemical value was investigated using blood of SPF Sprague-Dawley male rats in vitro. For the anticoagulations, we used 0.5mg of heparin per $10m{\ell}$ of blood from vena cava. Three con-centrations($0.1{\times}10^{-4}M$, $1{\times}10^{-3}M$ and $1{\times}10^{-2}M$) captafol in ethanol were added to the each $2.5m{\ell}$ blood so that the linal concentration of ethanol was 1%. The blood contained with each concentration of captafol was incubated at $37^{\circ}C$ C for 2 hours under 5% $CO_2$ gas The whole blood and plasma were examined for hematological vaJues, erythrocyte membrane damage and biochemical values, respectively. The results obtained were summarized as follows ; 1. The number of RBC in $1{\times}10^{-2}M$ group and the concentration of MCHC in $1{\times}10^{-3}M$ group were significantly (p<0.05) decreased and increased from that of control values, respectively. The percentage of Hct was significantly (p<0.05) decreased with dose-response. 2. Erythrocyte fragility rate of $1{\times}10^{-3}M$ and $1{\times}10^{-2}M$ group were significantly (p<0.01) increased from that control with dose response. 3. Potassium ion level of $1{\times}10^{-2}M$ was significantly (p<0.05) increased from that of control. 4. The concentration of total bilirubin in the $1{\times}10^{-3}M$ and $1{\times}10^{-2}M$ groups were significantly increased from that of control. The enzyme level of creatine kinase in $1{\times}10^{-2}M$ group was significanlty (p<0.05) decreased from control value.

URC를 위한 로봇 S/W 아키텍처 기술

김성훈,김중배,Kim Seong-Hun,Kim Jung-Bae 대한전자공학회 2006 전자공학회지 Vol.33 No.3

URC(Ubiquitous Robotic Companion) 환경에서 소프트웨어 로봇은 인공지능 기술과 네트워크 기술을 활용하여 상황에 따라 사용자에게 맞는 맞춤형 서비스를 제공하는 지능형 에이전트 기술로 정의할 수 있다. 소프트웨어 로봇은 인터넷 상에 존재하는 가상의 로봇이며, 실물 로봇을 제어하기 위해서는 로봇 내부에 로봇의 태스크와 행위, 하드웨어 디바이스를 제어하기 위한 아키텍처가 필요하다. 본 고에서는 소프트웨어 로봇이 실물 로봇을 제어하기 위해서 필요한 로봇 내부의 소프트웨어 아키텍처의 요구사항과 시스템을 소개한다.