악간고정이 호흡기능에 미치는 영향에 대한 임상적 연구

김철환,김미숙,Kim, Chul-Hwan,Kim, Mi-Suk 대한구강악안면외과학회 1999 대한구강악안면외과학회지 Vol.25 No.4

Intermaxillary fixation is routine procedure to oral and maxillofacial area in jaw bone fracture, surgical correction of jaw deformity, osseus reconstruction of jaw. After transoral surgery, accompanied by intermaxillary fixation, dysphagia or airway obstruction may be followed due to blood clot, vomitus, or laryngeal spasm resulting from irritation by blood or secretions. Lingual or pharyngeal edema is other contributing factors of airway obstruction. In addition, intermaxillary fixation itself may cause obstruction of airway. In this study, pulmonary function test and arterial blood gas analysis were evaluated before and after intermaxillary fixation in 30 patients suffered from mandibular fractures. Comparative analysis was performed by estimated values. The results were as followed. 1. The spirometric values of FEV1, FEV1/FVC and FEF25-75% without intermaxillary fixation were reduced from 97.57%, 85.1%, 98.3,% to 71.7%, 66.5%, 61.2% with intermaxillary fixation, indicating the presence of obstructive pulmonary impairment. 2. Spirometric value of MVV, as the most influencing value of sensitive to extrapulmonary factors, was changed from 84.5% to 46.48%. 3. After intermaxillary fixation, the spirometric value of FVC, as indicator of restrictive pattern of pulmonary function, was not reduced significantly as measured from 94.47% to 89.97%. 4. $O_2$ saturation of arterial blood gas analysis without intermaxillary fixation was 97.86%. While intermaxillary fixation, $O_2$ saturation was 97.47%. The results indicate that careful airway management is mandatory undergoing intermaxillary fixation of various oral and maxillofacial surgery.

한국의 재정적자와 환율 : 오차수정모형

김철환,이경호 ( Chul Hwan Kim,Kyung Ho Lee ) 한국경제학회 1997 經濟學硏究 Vol.45 No.3

1970-1995년 사이의 연간 자료를 사용하여 한국의 재정적자와 대미달러 환율 사이의 관계를 실증적으로 분석한 결과 두 변수 사이에 공적분관계가 존재하는 것으로 나타났다. 오차수정모형을 사용하여 두 변수 사이의 인과관계를 추정한 결과 재정적자가 환율에 영향을 미치는 것이 아니라, 환율변동이 재정적자에 영향을 미치는 일방적인 인과방향이 장기적으로 존재하는 것으로 나타났다. 이제까지 우리 나라의 이자율과 환율이 각각 자본시장과 외환시장에서 결정되지 못하고, 정책적으로 결정되어 왔던 점을 감안하면 재정적자가 이자율을 변화시켜 환율에 영향을 주는 것은 기대하기 어렵다. 재정적자가 환율에 영향을 미치지 못하는 것으로 나타난 우리의 추정결과는 이러한 현실을 비교적 잘 반영하고 있다. 환율로부터 재정적자로의 장기적인 인과관계의 존재에 대해서는 명확한 설명이 쉽지 않다. 이러한 관계에 대한 하나의 가능한 설명은 두 변수가 수출, 소득 등의 다른 변수를 매개로 하여 장기적으로 함께 움직이는 경향이 존재 할 수 있다는 점이다.

도로 주변지역의 소음환경 개선방법

김철환,Kim, Chul-Hwan 대한환경공학회 2008 대한환경공학회지 Vol.30 No.6

전외측대퇴유리피판 (Anterolateral Thigh Free Flap)을 이용한 구강안면부 결손의 재건

김철환,방대연,황승연,Kim, Chul-Hwan,Bhang, Dae-Yeon,Hwang, Seung-Yeon 대한악안면성형재건외과학회 2009 Maxillofacial Plastic Reconstructive Surgery Vol.31 No.6

Recently, the anterolateral thigh(ALT) flap, based on the septocutaneous vessels or musculocutaneous perforators from the descending branch of the lateral circumflex femoral artery has gained popularity in head and neck soft-tissue reconstruction. It has some advantages in free-flap surgery with respect to the radial forearm free flap, such as low donor site morbidity, availability of different tissues with large amounts of skin, adaptability as a sensate or flow-through flap (with the possibility of harvesting a long pedicle with a suitable vessel diameter). Moreover, the thickness of the flap is adjustable until the subdermal fat level, allowing it to be used as a thin or ultrathin flap. This clinical cases are ALT free flap reconstructions without functional impairment of the donor limbs (transitory and permanent) based on anastomosis with superficial temporal arteries and veins in patient of huge resection defect on face, lip and tongue.

구강암 수술 및 재건 환자에서의 C-Reactive Protein 수치의 변화

김철환,황승연,Kim, Chul-Hwan,Hwang, Seung-Yeon 대한악안면성형재건외과학회 2010 Maxillofacial Plastic Reconstructive Surgery Vol.32 No.5

Purpose: The aim of this study is that we evaluate the change of the White Blood Cell(WBC) count, Absolute Neutrophil Count (ANC), Erythrocyte Sedimentation Rate (ESR) and C-reactive Protein (CRP) values, and try to make standardization for postoperative sequels before and after the oral cancer resection and reconstructive surgery. Materials and Methods: The study was comprised of 34 patients (male 15, female 19) who were diagnosed as an oral cancer and had performed ablation and reconstructive surgery at Dankook university dental hos-pital. Each blood specimen was collected from patients and estimated WBC count, Neutrophil count, ESR, CRP on first, third, fifth, seventh day efore and after surgery and analyzing inter relationship between each value. Classifying Group I (resection with reconstructive surgery patients) and Group II (resection without reconstructive surgery patients). Also classifying group A (below 4 hours of operation time), Group B (4 to 8 hours of operation time), Group C (above 8 hours of operation time), each group was analyzed and compared. The Following results were induced. Results: (1) In coefficient of correlation, the CRP and WBC has highest value except WBC count and Neutrophil count. (2) There was no significant difference any lapse in the progress between Group I and II of WBC count, Neutrophil count, but the CRP shows statistically higher level in group I than group II at immediate postoperative day, and 1 to 5 days after surgery. (3) There is no significant difference any lapse in the progress between Group A, B, C of WBC count, Neutrophil count, but CRP shows statistically significant difference in 1 day, 3 days after surgery Conclusion: It should be suggested that, determination of CRP is most valuable parameter for postopera-tive management and determination of postoperative clinical changes than other parameter such as WBC count, neutrophil count, and ESR values in oral cancer patient after resection and reconstructive surgery, based on the results of this study.

한국의 재정적자와 환율 ; 오차수정모형 (誤差修正模型) ( 경제학문헌목록 주제분류 : H6 )

김철환,이경호 ( Chul Hwan Kim,Kyung Ho Lee ) 한국경제학회 1997 經濟學硏究 Vol.45 No.3

보일러빌딩 내부 환기현상에 관한 수치적 연구

김철환 ( Chul Hwan Kim ),유근종 ( Geun Jong Yoo ),최훈기 ( Hoon Ki Choi ) 한국산업위생학회 2005 한국산업보건학회지 Vol.15 No.3

Ventilation effect is analyzed for boiler building with multiple heat sources. Air flow inside the boiler building is characterized as turbulent mixed convection. Analysis methodology is set up with two different k-ε type models (standard k-ε, RNG k-ε). Two different cases with high and low outside temperature are analyzed. In case of high outside temperature condition, mixed convection is well realized inside the boiler building. With different upper louver opening rate, air flow is also well established and proper opening rate is found to meet design limit in case of low outside temperature condition. Difference of analysis results for two different turbulence models are not significant. Therefore, analysis methodology with simple k-ε turbulence model is found to be reliable for the boiler building ventilation analysis. However, more simplified geometrical model is desired to expand its application.

악골 병소의 켬퓨터 촬영상에서 Hounsfield Unit에 관한 연구

김철환(Chul-Hwan Kim),정종일(Jong-Il Jung) 대한구강악안면외과학회 2006 대한구강악안면외과학회지 Vol.32 No.4

The CT number is called Hounsfield unit(HU). Generally HU has a score between +1000 from -1000, and it is standardized usingthe air(-1000), water(0), and compact bone(+1000). Hounsfield Unit to standardize the density in computed tomography using the air and water has been used to analysis of lesion in other medical field. Computed tomography is popular method to analysis of lesion in oral & maxillofacial field but the analysis about density of lesion by Hounsfield unit is still obscure. For this study, computed tomography taken in Dankook University Dental Hospital and Hounsfield unit was measured to compare the difference of jaw bone lesion as cystic lesion, benign tumor, malignant tumor.

형태 유형 분석을 통해 본 미스 반 데어 로에의 독일시대 사무소 건축에 관한 연구

김철환(Kim, Chul-Hwan) 한국산학기술학회 2014 한국산학기술학회논문지 Vol.15 No.10

본 논문은 미스 반 데어 로에의 독일시대 사무소 프로젝트의 형태 유형과 그에 따라 형성되는 공공 공간을 분석하는 것을 주제로 삼는다. 사무소 계획안들의 투시도와 도면을 통해 형태 유형의 발생과 변화, 유형과 공공 공간의 관계, 위계에 따른 형태와 공공 공간 구성 등을 분석하였다. 본 연구의 결론을 요약하면 아래와 같다 1. 초기에는 ㄷ자, ㅡ자 유형을 사용했고 후에 곡선 유형을 도입하여 ㅡ자 유형과 함께 형태들로 분절했다. 2. 단순한 형태 유형들 전면에는 진입광장을 계획했고 곡선 유형과 함께 다양한 위계의 중정과 후원을 형성했다. 3. 미스가 여러 시도를 통해 형태 유형과 공공 공간에 대한 생각을 구축해 가던 시기였음을 알 수 있다. This study examined the formal types and public space of Mies van der Rohe's office designs in Germany. The characteristics of the formal types, the relationship between public space and formal types, and the composition of public space were analyzed by hierarchy with perspective drawings and plans. The conclusions were as follows. Mies used the formal types, such as U shape and I shape in his early days. Later, he adopted the curved shape and tried to fragment the forms by combining the curved shape with an I shape. Mies designed the entry space in front of the simple formal types. The curved shape was used to create various hierarchical courtyards and rear gardens. The results suggest that Mies developed his own ideas on the formal types and public space utilizing a variety of methods.

단백질 상호 작용 예측을 위한 SVM의 부정예제 생성방법론

김철환(Chul-hwan Kim),정유진(Yoojin Chung) 한국정보과학회 2004 한국정보과학회 학술발표논문집 Vol.31 No.1B

생명체의 기본 정보가 저장된 DNA에서 생성되는 단백질은 생명 현상의 중요한 기능적 역할을 수행하기 때문에 단백질과 관련된 다양한 연구가 진행되고 있다. 본 논문에서는 단백질간 상호작용(protein-protein interaction)을 예측하기 위해 시스템을 통계학적 모델인 Support Vector Machine(SVM)을 사용하였다. SVM 시스템은 상호작용이 있는 데이터(긍정예제)와 상호작용이 없는 데이터(부정예제)를 입력으로 하여 모델링 생성과 테스트를 하는데, 상호작용이 있는 데이터는 DIP에 있는 interaction list로 해결이 가능하지만 상호작용이 없는 데이터는 현재 존재하지 않기 때문에 이를 생성하기 위한 생성방법이 필요하다. 이 논문에서는 shuffling, non-interaction list, 그리고 앞의 두 방법을 보완하는 non-interaction list + shuffling이라는 방법을 제시하고 기존의 실험 결과를 상회하는 부정예제 생성방법을 제시한다.