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.

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.

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

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.

장티푸스의 혈청학적 진단을 위한 Vi-수동혈구응집법, SD$^{(R)}$ Kit 및 Widal 시험에 대한 효용성 평가

김성훈,김석호,이덕용,이에스더,박미선,이복권,Kim, Sung-Hun,Kim, Shuk-Ho,Lee, Deog-Yong,Lee, Esther,Park, Mi-Sun,Lee, Bok-Kwon 한국미생물학회 2010 미생물학회지 Vol.46 No.2

본 연구는 장티푸스 환자에 대한 혈청학적 시험법인 Vi-PHA, $SD^{(R)}$ kit, Widal 시험(O & H)에 대하여 평가를 위해 수행하였다. 2005년부터 2006년까지 수집된 36건의 혈청검체를 대상으로 하였으며, 9건은 배양검사를 통하여 장티푸스균이 검출된 확진환자의(Typhoid fever) 검체이며, 27건은 비장티푸스성 열성환자의(Non-typhoid fever) 검체이다. 시험결과 Vi-PHA는 환자 혈청 9건 중 양성 8건으로 민감도 88.9% (P<0.001; Fisher's exact test), 비장티푸스성 열성환자 27건 중 1건이 양성을 보여 특이도 96.3%로 나타났다. $SD^{(R)}$ kit는 민감도 100% (P<0.001), 특이도 92.6%로 나타났다. Widal (O & H) 시험의 민감도는 각각 88.9% (P=0.001), 100% (P<0.001), 특이도는 77.8%, 70.4%로 나타났다. 민감도는 $SD^{(R)}$ kit와 Widal H 검사법이 가장 높은 것으로 확인되었으며, 특이도는 Vi-PHA가 가장 높게 나타났다. 장티푸스의 효과적인 혈청학적 진단을 위하여 급성 또는 유행지역에서는 특이도가 높은 Vi-PHA로 검사를 수행하고, 장티푸스 비 유행지역과 고위험군에 대하여는 민감도가 높은 Widal H와 $SD^{(R)}$ kit를 적용하는 것이 진단의 유의수준을 높일 수 있을 것으로 판단된다. In this study, we evaluated Vi-passive hemagglutination (Vi-PHA), SD Salmonella Typhi IgG/IgM ($SD^{(R)}$ kit) and Widal test for the rapid laboratory diagnosis of typhoid fever patients. A total of 36 serum samples from febrile patients in Korea from 2005 to 2006 were used. Among 36 patients, 27 were fever patients without typhoid, 9 were typhoid fever. Vi-PHA showed 8 positive results out of 9 typhoid fever patients (sensitivity 88.9%) and 1 positive and 26 negative results out of 27 febrile patients without typhoid (specificity 96.3%). The sensitivity and the specificity of $SD^{(R)}$ kit were 100% and 92.6%, respectively. However, the sensitivity and the specificity of Widal O & H tests were 88.9%, 100%, and 77.8%, 70.4%, respectively. Consequently, Widal H and $SD^{(R)}$ kit showed higher sensitivity and Vi-PHA showed higher specificity. To efficient diagnosis, Vi-PHA may be sufficient diagnosis method in acute cases and $SD^{(R)}$ kit and Widal test may be sufficient in sporadic area and high risk group.

제39회 한일기술사 합동심포지엄 특집 - 심포지엄 참관기 - 축구

김성훈,Kim, Sung-Hoon 한국기술사회 2010 技術士 Vol.43 No.1

활혈거어약물(活血祛瘀藥物)이 항혈관신생(抗血管新生)에 미치는 영향(影響)에 관(關)한 연구(硏究)

김성훈,심범상,최승훈,안규석,Kim, Sung-Hoon,Shim, Bum-Sang,Choi, Seung-Hoon,Ahn, Kyoo-Seok 대한암한의학회 2001 大韓癌韓醫學會誌 Vol.7 No.1

Object When angiogenesis is excessive, Cancer, RA, Blindness, Psoriasis, Hemangioma, Diabetic retinopathy, Granulation, etc are induced. On the contrary, when it is insufficient, Stroke, Heart disease, Ulcer, Infertility, Scleroderma, artherosclerosis, delay of the wound recovery, etc occur. In recently, the methods which is control of abnormal angiogenesis are researching actively in relathion to anticancer research. This study is search for effective drugs which suppress this angiogenesis, in the ingredients of the herbs that invigorate and dispel blood stasis using to treat intravascular coagulation in the oriental herbal medicine. Methods We maked 80 % methanole extracts of Cnidii Rhizoma, Olibanum, Myrrha, Corydalidis Tuber, Curcumae Radix, Curcumae longe Rhizoma, Zedoariae Rhizoma, Salviae miltiorrhizae Radix, Polygoni cuspidati Rhizoama, Leonuri Herba, Persicae Semen, Carthami Flos, Trogopterorum Faeces, Achyranthis Bidentatae Radix, Manitis Squama, Eupolyphaga, Hirudo, Tabanus, Lycopi Herba, Artemisiae anomalae herba, Vaccariae Semen, Sappan Lignum, Gleditsiae Spina, Draconis Resina, Leonunari Semen, Selaginelliae Folium, Spatholobi Caulis, and these extracts were tested for MTT viabilaty test, BrdU incorporation, Tube foramtion assay on ECV304(immotalized human umbilical vein endothelial cell) at the concentration of $50{\mu}g/ml$, $100{\mu}g/ml$, $200{\mu}g/ml$, $400{\mu}g/ml$ Results All extracts except Draconis Resina have no cytotoxicity at the $100{\mu}g/ml$, and in BrdU incorporation test, proliferation rate were reduced below 60% at the concentaraion of $100{\mu}g/ml$ by Zedoariae Rhizoma, Sappan, Lignum Gleditsiae, Spina Draconis Resina Vaccariae Semen. Zedoariae Rhizoma Sappan Lignum Gleditsiae Spina Draconis Resina Vaccariae Semen Olibanum, Achyranthis Bidentatae Radix showed inhibition effects on tube formation of ECV304 at the concentration of $100{\mu}g/ml$. Conclusion At the concentration of $100{\mu}g/ml$ in which cytotoxicity is not found, Zedoariae Rhizoma, Sappan Lignum, Gleditsiae Spina, Vaccariae Semen showed the inhibition effect on proliferation and tubeformation of ECV304.

Chamber to Chamber Variations of a Cylindrical Ionization Chamber for the Calibration of an $^{192}Ir$ Brachytherapy Source Based on an Absorbed Dose to Water Standards

김성훈,허현도,최상현,김찬형,민철희,신동오,최진호,Kim, Seong-Hoon,Huh, Hyun-Do,Choi, Sang-Hyun,Kim, Chan-Hyeong,Min, Chul-Hee,Shin, Dong-Oh,Choi, Jin-Ho Korean Society of Medical Physics 2009 의학물리 Vol.20 No.1

This work is for the preliminary study for the calibration of an $^{192}Ir$ brachytherapy source based on an absorbed dose to water standards. In order to calibrate brachytherapy sources based on absorbed dose to water standards using a clyndirical ionization chamber, the beam quality correction factor $k_{Q,Q_0}$ is needed. In this study $k_{Q,Q_0}s$ were determined by both Monte carlo simulation and semiexperimental methods because of the realistic difficulties to use primary standards to measure an absolute dose at a specified distance. The 5 different serial numbers of the PTW30013 chamber type were selected for this study. While chamber to chamber variations ran up to maximum 4.0% with the generic $k^{gen}_{Q,Q_0}$, the chamber to chamber variations were within a maximum deviation of 0.5% with the individual $k^{ind}_{Q,Q_0}$. The results show why and how important ionization chambers must be calibrated individually for the calibration of $^{192}Ir$ brachytherapy sources based on absorbed dose to water standards. We hope that in the near future users will be able to calibrate the brachytherapy sources in terms of an absorbed dose to water, the quantity of interest in the treatment, instead of an air kerma strength just as the calibration in the high energy photon and electron beam. 본 논문은 물 흡수선량 표준에 기반하여 근접치료 선원인 $^{192}Ir$을 교정하는 것에 대한 예비적 연구를 위한 것이다. 이온함을 사용하여 물흡수선량 표준에 기반하여 근접치료 선원을 교정하기 위해선, 빔 선질 교정인자인 $k_{Q,Q_0}$가 필요하다. 본 연구에선 일차 표준을 사용하여 지정된 거리에서의 흡수선량를 측정하는 데 있어서의 현실적인 어려움 때문에 몬테칼로 전산모사와 반실험적인 방법을 통하여 $k_{Q,Q_0}$를 결정하였다. 본 연구를 위해 PTW30013 이온함 5개를 선택하였다. 포괄적 $k^{gen}_{Q,Q_0}$ 값의 경우엔 이온함간 변화가 최대 4.0%에 이른 반면, 개별적 $k^{ind}_{Q,Q_0}$ 경우엔 이온함간 변화가 최대 0.5% 이내였다. 이 결과는 물 흡수선량에 기반하여 근접치료 선원인 $^{192}Ir$을 교정시에 이온함을 왜 개별적으로 교정해야 하는지, 개별적인 교정이 얼마나 중요한 지를 보여 준다. 가까운 장래에 공기커마 세기 대신에 사용자가 근접치료 선원을 고에너지 광자빔과 전자빔의 교정에서처럼 치료에서 관심있는 물리량인 물흡수선량의 관점에서 교정할 수 있기를 희망한다.