소아 심장 CT 검사시 Dual Source CT의 High pitch mode를 이용한 선량감소에 관한 연구

이예나(Ya Na Lee),강헌효(Heon Hyo Kang),손성실(Sung Sil Son),박찬혁(Chan Hyuk Park),현진경(Jin Kyung Hyun),신명호(Myung Ho Shin),김준혁(Jun Hyuk Kim),강동원(Dong Won Kang) 대한CT영상기술학회 2012 대한CT영상기술학회지 Vol.14 No.1

I. Purpose This study examines if accurate images can be realized with less dose than sequential mode, one of the existing methods applying DSCT’s high-pitch mode in pediatric cardiography. II. Materials and Methods For 20 patients who came to our hospital from Jan. 1 to Jun. 30, 2011, a test was carried out using MDCT 128 channel dual source; Somatom Definition Flash (Siemens Medical System: Germany). As the test method, the veins of the lower limbs of the patients were secured and contrast medium of 7ml was injected at 0.3ml/s anda CT scan was carried out about 36 s. later. Af first, sequential mode was used, and then high-pitch mode was followed as follow-up examination. The DLP (Dose Length Product) provided by the equipment and effective dose were compared for the assessment of the dose exposed to the patients, after the CT scan. The effective does was calculated by multiplying children’s chest index: 0.021 of the effective dose rate of EUR16262 (European Guide) to DLP value. The images scaned in high-pitch method were compared and assessed quantitatively by a heart decoding specialist and 2 radiologists if the typical diseases of pediatric cardiacs such as coarctation of aorta, atresia of the pulmonary artery and Tetralogy of Fallot can be assessed. III. Results When it was compared to sequential mode, one of the existing cardiography, the effective dose exposed to the patient had decrease by 32% in high-pitch mode. As a result of a comparison with imaging assessment, it was also evaluated as a better imaging than sequential mode IV. Conclusion Pediatric Cardiography using high pitch in Dual source MDCT showed superior effects on the reduction of exposed does than sequential mode, which is considered a useful testing method. 목적 본 연구에서는 소아 심장 검사 시 DSCT의 High-pitch mode를 적용하여 기존의 검사방법 중 하나인 Sequential mode보다 적은 선량으로도 정확한 영상을 구현할 수 있는지 알아본다. 대상 및 방법 2011년 1월 1일부터 6월 30일까지 본원에 내원한 20명의 환자를 대상으로 하여 MDCT 128 channel dual source; Somatom Definition Flash(Siemens medical system: Germany) 장비를 사용하여 검사를 시행하였다. 검사방법은 환자의 하지에 정맥을 확보하고 조영제를 0.3 ml/s로 7ml를 주입한 후 36초 후에 CT검사를 하였다. 처음에는 Sequential mode로 검사한 후 추적 검사할 땐 High-pitch mode로 검사한다. 환자가 받은 피폭선량의 평가는 선량평가는 CT검사 후 장비에서 제공하는 DLP(dose length product)와 유효선량(effective dose)를 비교하였다. 유효선량은 DLP 값에 EUR16262(European Guide) 유효선량비 중 소아 흉부 지수 0,021을 곱하여 계산하였다. 검사한 영상을 심장 판독 전문의 1명과 방사선사 2명이 high-pitch mode로 검사한 영상을 소와 심장의 대표적 질환인 대동맥협착증, 폐동맥 폐쇄증, 팔로씨 사증을 평가할 수 있는지 비교하여 정성적으로 평가하였다. 결과 기존의 심장 검사방법 중 하나인 Sequential mode와 비교했을 때 High pitch mode로 검사했을 때에 32%의 선량 감소 효과가 있었다. 또한 영상 평가 비교 결과 Sequential mode 보다 좋은 영상으로 평가되었다. 결론 Dual source MDCT로 소아심장 검사를 할 때 high pitch mode를 이용하면 sequential mode로 검사했을 때보다 환아가 받는 피폭선량은 낮고 더 우수한 영상을 획득하여 심장질환을 진단하는데 유용한 검사법으로 사료된다.

正祖의 훈련대장 具善復 제거와 壯勇大將 임명

김준혁(Kim Jun-hyuk) 역사실학회 2011 역사와실학 Vol.44 No.-

미생물 연료 전지에서 산화전극 전류 컬렉터 구조에 따른 전기화학적 성능 평가

김준혁 ( Jun Hyuk Kim ),김어진 ( Eojin Kim ),구본영 ( Bonyoung Koo ),정석희 ( Sokhee P Jung ) 한국물환경학회(구 한국수질보전학회) 2019 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2019 No.-

正祖代 壯勇衛 설치의 政治的 推移

김준혁(Kim Jun-Hyuk) 한국사학회 2005 史學硏究 Vol.- No.78

정조시대 개혁정책의 주요 핵심은 爲民을 강조하며 궁극적으로 왕권강화를 추구하는 것이었다. 정조에게 있어 왕권을 강화하는 전제 조건은 軍權을 장악하는 일이었다. 기존의 중앙 군영들이 戚臣들의 정치적 영향력으로부터 자유로울 수 없는 구조적인 문제를 안고 있었기에 軍權을 장악하지 않고는 黨派를 통제할 수 없었다.<br/> 정조의 군제개혁의 명분은 단순한 군영의 통합이 아니라 군비의 낭비를 방지하여 민생을 활성화하자는 것이었다. 그래서 즉위 초부터 수어청과 총융청의 통합을 주도하였으나 기득권층의 반발로 인하여 실현되지 못했다. 따라서 정조는 군영개혁의 시발로서 자신의 친위부대를 양성하고자 하였다. 정조는 이를 위해 자신에 대한 반대세력의 시해 기도를 반전시켜 호위기구 창설의 명분을 확립하였다. 이에 따라 숙위소를 설치하고 홍국영을 숙위대장으로 임명하였다. 하지만 자신의 국왕 등극에 절대적 역할을 한 홍국영의 國本철회 움직임에 홍국영을 제거하고 宿衛所를 혁파하였다.<br/> 정조는 홍국영의 종제인 홍복영 일파의 역모 사건을 확대하여 숙위소를 능가하는 壯勇衛를 창설하였다. 장용위는 禁軍의 무예출신중 局出身을 선발하여 창설하고 장기적으로 확대 개편하였다.<br/> 정조의 호위기구 창립은 군제개혁의 출발점으로 이루어진 왕권강화를 위한 정치적 행위였으며, 장기적으로 五軍營의 통폐합을 통해 군비를 축소하여 민생의 안정을 추구하고자 의도를 내포하고 있는 것이었다. The main core of reform policy in the era of King Jeongjo was to pursue strengthening of king's authority besides emphasis of people's wellbeing. For him precondition of strengthening king's authority was to seize power of military commandership. He could not control political parties without grasping military commandership, because the existing central military camps were not free from the power of related subjects' influence in politics. Justification of King Jeongjo's reform of military organization didn't aim at simple unification of military camps, but activation of people's livelihood by virtue of not wasting army expenditure. From the early days of his accession to the throne he took the leadership to unify sueocheong (one of five military camps with chongyungcheong (one of five military camps), but in vain, because of repulsion of the existing military authorities. Accordingly, With availing himself of his murdering by opposite power's attempt, King King Jeongjo established the justification of foundation of a military guard organization, sukwiso and appointed Hong Kuk Yeong as its general for an onset of military camp reform. However, he removed Hong Kuk Yeong, who played an absolute role for his enthronement, owing to the withdrawal movement of national foundation. He removed sukwiso, too. With King Jeong's expanded interpretation of the plot of treason planned by Hong Bok Yeong who was Hong Kuk Yeoung's younger cousin of parental side, Jangyongwi was established, which was superior to sukwiso. Jangyongwi was founded b! y masters of military arts of king's guards and enlarged and reformed for a long term. King Jeongjo's establishment of guard organization was a political activity at the onset of military organization reform, which was intended to pursue stability of people's livelihood with armament reduction through unification of five military camps.

정조시대 壯勇營外營의 兵農一致 군제개혁 구상과 屯田經營

김준혁(Kim, Jun Hyuk) 한국사연구회 2015 한국사연구 Vol.- No.168

물류시스템 분석을 위한 행위자 기반 모형 적용에 대한 제언

김준혁(Jun-Hyuk Kim) 한국항만경제학회 2010 韓國港灣經濟學會誌 Vol.26 No.3

현대 물류시스템은 점점 더 다각화 되고 복잡한 형태로 변화하고 있다. 그 결과 시스템의 거시적인 행태 분석과 예측은 더욱 더 어려워지고 있다. 전통적 분석 방법은 하향식 분석 방법으로 복잡성이 높은 물류시스템에 대한 적용에 있어 한계를 갖는다. 행위자 기반 모형은 상향식 분석 방법으로 시스템 모형화에 있어 새로운 사고방식의 틀을 제공한다. 행위자 기반 모형은 전체시스템의 하위시스템, 즉 행위자의 상호작용에 초점을 맞춘다. 전체시스템의 거시적인 행태는 행위자의 미시적인 상호작용을 결집시킴으로서 발현된다. 행위자 기반 모형은 행위자 기능의 정의에 따라, 분석의 영역을 자유롭게 조정할 수 있고, 각 행위자의 상호작용 모형화와 이를 통해 얻어진 전체시스템의 거시적인 행태와의 인과관계 분석도 가능하다. 물류시스템의 복잡성은 시스템 내 존재하는 다수의 참가자들의 복잡한 상호작용과 시스템의 목적과 독립적인 의사결정 등에 기인한다. 행위자 기반 모형은 행위자를 자신의 목적 달성을 위하여 외부, 다른 행위자 간 상호작용을 통해 습득한 단순명료한 규칙에 기반하여 행동한다고 가정한다. 행위자 기반 모형의 이점은 모형화 과정을 보다 단순하게 만들고 이를 통하여 각 하위시스템의 특성만으로는 설명할 수 없는 현상, 즉 창발성을 파악할 수 있다는 점이다. 따라서 행위자 기반 모형은 물류시스템과 같은 복잡하고 동적인 시스템의 분석에 매우 유용한 기법으로 이에 대한 많은 연구와 적용이 이루어져야 한다. The purpose of this paper is to propose applying agent-based model(ABM) for analyzing logistics system. Logistics problems become more complex and multi-faceted. As a result, the behavior of the system becomes more and more difficult to predict, we see the limitations of the traditional top-down approach in handling complexity. The ABM, that is the bottom-up approach, provides new modeling framework in system modeling. The ABM focuses on the interactions of subsystem or agents in whole system. Then the macroscopic picture of the whole system behavior is emerged as the microscopic interactions of agents are aggregated. The ABM assumes that each agent acts based on simple rules learned from dynamic interactions among other agents or its surrounding environment. The ABM has a great advantage in understanding emergent phenomenon that cannot be explained only through considering individual attributes. The ABM is an extremely useful method to analyze complex system such as logistics system. Therefore, the great research efforts and applications on the ABM to logistics system are encouraged in future.

正祖의 武藝圖譜通志 편찬 의도와 壯勇營 강화

김준혁(Kim Jun-Hyuk) 중앙대학교 중앙사학연구소 2005 중앙사론 Vol.21 No.-

To strengthen the national defense from his early reign, King Jeongjo had made many kinds of books on military strategy published in accordance with arms development. And other books on military arts, different from military strategy, were also published, and among them Martial Arts Picture Book was the key of those describing the 24 kinds of military arts of a short sword shown by the pictures of actual size. This includes 24 arts made up of 18 arts of Martial Arts Book and 6 horseback arts by Crown Prince Sado Seja. In 1789 King Jeongjo established the publishing department at the Royal Army and ordered Lee Duckmoo and Park Jeka, book inspector of the archive center named Keujangkak , and Back Dongsoo, the Royal Army captain who were considered the competent persons at that time to publish the Martial Arts Picture Book regardless of their birth as offspring of a concubine. In 1778, he also designed to cultivate men of ability through his political reform view dubbed as Kungjadaeko‘ without respect to their birth and attain a number of illegitimate intellectuals as his supporting power. Among them the key power was Lee Duckmoo who advocated the Northern School as purist. Lee Duckmoo and Park Jeka, the students of Park Jiwon were the important persons of the contemporary Northern School and Pack Dongsoo, brother-in-law of Lee Duckmoo, was the key person of the military nobility from concubine offsprings to demonstrate the skills of the Martial Arts Picture Book ‘. While the breed discrimination was still going on, the king gave them orders to finish the most important work and it was showe d that he could enlarge his own supporting power based on such publishing projects. The king selected the 24 Martial Arts as the subject of the military service examination which was widely distributed in order to train them for the soldiers of the Royal Army. Accordingly he intended to spread the 24 Martial Arts as individual martial arts to utilize the Royal Army as backbone of switching system of military/framing harmony. Consequently, the publication of Martial Arts Picture Book was played an important role to intensify the reign of King Jeongjo.

전기차 폐열 활용을 위한 오프셋 스트립 핀 열교환기에서의 열성능 분석

김준혁(Jun Hyuk Kim),임홍영(Hong Young Lim),신성홍(Sung Hong Shin),오진우(Jin Woo Oh),한욱민(Uk Min Han),박윤재(Yun Jae Park),이소라(Sora Lee),이호성(Hoseong Lee) 대한설비공학회 2022 대한설비공학회 학술발표대회논문집 Vol.2022 No.6

In this study, a new type of heat exchanger performance analysis was conducted. The new type of heat exchanger is a perpendicular flow offset strip fin type and is a multi-heat source heat exchanger, which is a different type of heat exchanger. The working fluid was R1234yf and the coolant was 50% ethylene glycol. In conclusion, The heat transfer coefficient of the coolant was obtained using the Modified Wilson plot method, and an appropriate value was obtained with an error of 1.3% from the experimental value. The heat transfer coefficient of the refrigerant was obtained by utilizing this coolant heat transfer coefficient. As a result, it was found that the offset trip fin type applied as a perpendicular flow had a large effect on the pressure drop. And as a result of comparing the heat transfer coefficients of the refrigerant and the coolant, the heat transfer coefficient of the refrigerant was 67% smaller than the heat transfer coefficient of the coolant.

텍스트 마이닝을 이용한 Bigram-Signature 기반의 자동 이모티콘 추천 모듈

김준혁(Kim Jun Hyuk),박영웅(Park Young Woong),하슬비(Ha Seul Bi),최용석(Choi Yong Suk) 한국정보과학회 2014 한국정보과학회 학술발표논문집 Vol.2014 No.6

정조대 화성유수부의 의료기관 고찰

김준혁(Kim, Jun-Hyuk) 인천대학교 인문학연구소 2009 인문학연구 Vol.12 No.-