Cone-beam CT로부터 제작된 측모 두부계측방사선사진의 정확도 평가

강지영,임성훈,김광원 대한치과교정학회 2007 대한치과교정학회지 Vol.37 No.6

최근 computed tomography (CT) 데이터로부터 실제 두부계측방사선사진 촬영기에서 촬영한 사진과 동일한 확대율을 갖는 두부계측방사선사진을 형성할 수 있는 기능을 갖춘 소프트웨어 (Accurex, CyberMed, Seoul, Korea)가 소개되었다. 이에 본 연구에서는 cone-beam CT (이하 CBCT) 데이터로부터 이 소프트웨어를 이용하여 제작된 측모두부계측방사선사진과 기존의 두부계측방사선사진촬영기로 촬영된 측모 두부계측방사선사진에서 각각 두부계측방사선사진 분석을 시행하여 그 차이를 비교함으로써 소프트웨어를 통해 CBCT로부터 제작된 측모 두부계측방사선사진의 활용 가능성을 평가하고자 하였다. 20명의 교정 환자를 대상으로 CBCT와 측모 두부계측방사선사진을 동시에 촬영하였다. CBCT로부터 제작된 측모 두부계측방사선사진과 기존 방식의 측모 두부계측방사선사진에서 두부계측방사선사진 분석을 시행한 후 두 사진의 계측치의 차이를 paired t-test로 검정하였다. 23개의 계측치들 중, 20개 항목에서는 통계학적으로 유의한 차이가 관찰되지 않았으나, U1-FH, Mx6 to PTV, Maxillomandibular difference의 항목에서는 유의한 차이가 나타났다. 이러한 차이는 CBCT로부터 형성된 측모 두부계측방사선사진의 해상도가 낮아 일부 해부학적 지표를 확인하기 어렵기 때문이며, 임상에서 CBCT로부터 제작된 측모 두부계측방사선사진을 porion, PTV, condylion과 같은 일부 해부학적 지표를 이용하지 않는 SNA, SNB, U1 to SN, IMPA, interincisal angle 등 흔히 사용되는 간단한 측모 두부계측방사선사진 계측에 활용 가능할 것이다. Objective: Three-dimensional approaches for the diagnosis and analysis of the dentofacial area are becoming more popular in accordance with the development of cone-beam CT (CBCT). The purposes of this study were to evaluate the reliability of cephalometric measurements of lateral cephalograms generated from a CBCT image by making comparisons with the traditional digital lateral cephalogram, and to evaluate the possibility of the clinical application of CBCT generated cephalogram images. Methods: Twenty patients whose external auditory meatus could be identified in the CBCT image were selected, and both CBCT and digital cephalograms were taken. Differences between the measurements of both cephalograms were tested by paired t-test. Results: Among the 22 measurements used, only U1-FH, Mx6 to PTV, and maxillomandibular difference showed statistically significant differences between the CBCT generated cephalogram and the digital cephalogram. Conclusions: The results suggest that the CBCT generated cephalogram can be used for some cephalometric measurements not requiring porion, PTV, condylion as a landmark (SNA, SNB, U1 to SN, IMPA, interincisal angle, etc.).

악성 갑상선 우연종의 임상상 및 초음파 소견의 진단적 가치

강한욱,김광원,이병완,강보현,김형훈,김범진,정재훈,민용기,이명식,이문규 대한내분비학회 2002 Endocrinology and metabolism Vol.17 No.5

연구배경: 최근 갑상선 초음파 검사의 빈번한 시행으로 갑상선 우연종의 발견이 증가하고 있다. 이러한 갑상선 우연종은 임상적으로 어떻게 접근하고 치료를 해야 하는지 적지 않은 문제가 되고 있다. 본 연구에서는 직경 1.5㎝ 이하의 갑상선 우연종의 유병률, 입상적 특징 및 초음파 특성, 그리고 가장 효율적인 진단적 접근에 대해 알아 봤다. 방법: 1999년 1월부터 2000년 12월까지 삼성서울병원 내과 및 일반외과로 갑상선 결절을 주소로 내원한 1457명을 대상으로 후향적 연구를 시행하였다. 우연히 발견된 직경 1.5㎝ 이하의 갑상선 결절을 가지는 환자들에서 갑상선 결절의 촉지 유무, 갑상선 기능검사, 항갑상선 항체, 갑상선 초음파 및 미세침 흡인세포검사, 99m^Tc 갑상선 스켄, 수술 조직검사 및 병기를 검토하였다. 결과: 분석한 갑상선 결절 1475예 중 갑상선 우연종의 유병률은 13.4%(198예)였다. 갑상선 우연종에서 악성률은 28.8%(57예)으로 나왔다. 양성 및 악성 갑상선 우연종에서 나이, 성별, 갑상선 기능검사, 결절 크기에는 의미 있는 차이는 없었다. 갑상선 스켄은 갑상선 우연종의 감별에 적합하지 않았다. 갑상선 결절의 초음파 지표 점수만이 양성 및 악석 갑상선 우연종의 감별에서 초음파 지표 점수의 민감도는 88.9%, 특이도는 74.4%, 양성 예측률은 92.4%로 나왔고 진단적 정환도는 85.5%였다. 갑상선암으로 수술을 받은 50명중 stage 1은 34명, stage 2는 6명, stage 3은 10명으로 대부분의 악성 갑상선 우연종은 낮은 TNM 병기로 나타났으나, 상당수에서는 국소 침범의 소견을 보였다. TNM 병기의 3기 환자 전부는 45세 이상이였고, 주로 갑상선암의 피막 침범에 의한 것이었다. 임파절 전이는 6명의 환자에서 나왔다. 결론: 악성 갑상선 우연종은 비교적 흔히 접할 수 있는 질환이며 양성 우연종과는 임상적으로 구별이 안 된다. 악성 갑상선 우연종은 발견 당시 대부분 낮은 병기이나, 갑상선의 피막 침범 및 임파절 전이가 상당수에서 발견되었다. 갑상선 우연종의 초음파 소견은 향후의 진단 방향을 제시하는 중요한 길잡이가 될 수 있다. 초음파 지표 점수 2점 이상의 갑상선 우연종에서만 초음파 유도 미세침 흡입검사를 권장한다. Background: High-resolution ultrasonography has made the detection of asymptomatic small thyroid possible. Recent increases in the detection of incidentalomas have created a clinical dilemma on how to properly manage such incidental nodules. We investigated the prevalence, clinical and ultrasonographic characteristics, and optimal diagnostic approach toward incidentally detected benign and malignant thyroid nodules of less than 1.5㎝ in size. Methods: A retrospective review was undertaken on the 1,475 patients who had visited Samsung Medical Center, Seoul Korea between January 1999 and December 2000. The review consisted of a physical examination of the thyroid gland, thyroid function test, antithyroid antibodies, thyroid ultrasonography, fine-needle aspiration biopsy, pathology and TNA staging of the incidentally detected thyroid nodules of less than 1.5㎝ in size. Results: The prevalence of thyroid incidentalomas was 13.4% and the malignancy rate within them was 28.8%. There were no significant differences in age, sex, thyroid function test and size between the benign and malignant incidentalomas. Ultrasonographic characteristics showed meaningful diagnostic value for the detection of malignancy in incidentalomas. Most malignant incidentalomas were of a low stage. Conclusion: Occult thyroid cancers are fairly common finding. There are no clinical difference between benign and malignant thyroid nodules less than 1.5㎝; however, ultrasonographic findings can be used to decision of optimal management strategies (J Kor Soc Endocrinol 17:649∼656, 2002).

單一反射音의 最適遲延時間

강성훈,임광호,차일환 연세대학교 산업기술연구소 1983 논문집 Vol.15 No.2

Subjective preference tests with a simulated single reflection in an anechoic chamber were performed in order to find the preferred delay time of the first reflection in the musical sound field. The preferred time delay gap between the direct sound and the first reflection can be determined by the interval of coherence of music and the amplitude of the reflection. The scale value of subjective preference is formulated in terms of the 1.2 power of the normalized parameter which is expressed in the logarithm. This observation is taken into consideration in the design stage of concert halls and in selecting music to be performed in a given concert hall.

政治, 經濟, 經營的 側面에서 考察한 日本의 發展戰略에 관한 硏究

姜太勳,田馨,李光周 韓日經商學會 1994 韓日經商論集 Vol.10 No.-

The purpose of this paper is to explore the key factors which brought on the Japan's high speed economic growth in the postwar periods. There are largely two approahes which deal with this issue: the state-business relations and the Japanese style management. This study undertook critical reviews on the existing literatures. There are four models in the state-business relations: bureaucratic-led devlopment model; market oriented model; network model; and corporatism. Considering industrial policy as only state intervention into the market, all four models was not able to explain fully different policy patterns in the respective industrial sectors. Acordingly, it is more relevant to consider industrial policy as conflict resolution among actors, existing in the state and market, who realize their interests respectively. In this context, one has to understand policy network patterns in the respective industrial sectors which emerge out of interactions among not only bureaucracy's industrial strategy but also business' strategy, cooperation and competition between business and bureaucracy, and poitician's intervention into the industrial sectors. In the managerial perspectives, not only life employment system, seniority system, corporate union system but also relational theory, technological development, production system were analyzed.

Polytetrafluoroethylene의 길이에 따른 신생내피의 조직학적 변화에 대한 실험적 연구

강기훈,이광석 고려대학교 의과대학 1998 고려대 의대 잡지 Vol.35 No.2

One of the most widely used synthetic grafts in vascular surgery is polytetrafluoroethylene(PTFE). PTFE offers major advantages compared with the other synthetic materials because of its highly electronegative and hydrophobic surface. Neoendothelialization of PTFE is still the most controversial issue and seems to prevent its reliable clinical use in microvascular grafting procedures. It is difficult to compare different studies because of variations in the physical characteristics of synthetic grafts and the investigation periods. The purpose of this study was to investigate the patency rates and the histologic findings of neoendothelialization according to the length of implanted PTFE in rabbit. Thirty New Zealand White rabbits, weighing 3.0 to 3.5kg, were used for this study. Under the operating microscope, all grafts were implanted in the right carotid arteries of rabbits by interrupted end-to-end microanastomosis. They were divided into two groups according to the length of implanted PTFE with an internal diameter of 3mm. Each group comprised fifteen rabbits. All implanted grafts were 25㎛ in fibril length and 0.39mm in wall thickness. The length of graft in group Ⅰ was 8mm and that of graft in group Ⅱ was 24mm. Three grafts per group were harvested at 1, 2, 4, 8, and 12 weeks after implantation respectively. All PTFE grafts were observed for patency rates and the histologic findings with light microscope and scanning electron microscope. The results obtained were as follows : 1. The patency rate was 96.7%(29/30) on the average: 93.3%(14/15) in group Ⅰ and 100%(15/15) in group Ⅱ. There was no difference in patency rates according to the length of implanted PTFE. 2. Light microscopically, the beginning of neointimal lining was noted in both groups at 1 week after implantation. At 8 weeks after implantation, the entire inner surface of implanted PTFE was lined completely by neointima in both groups. At 12 weeks after implantation, neointima and subintimal tissue were noted at the midportion of implanted PTFE in group Ⅰ. However, neointima of group Ⅱ in the midportion of implanted PTFE was composed of single layered neoendothelial cells without subintimal tissue. 3. Scanning electron microscopically. the inner surface of implanted PTFE was lined by amorphous fibrin layer at anastomosis site in both groups at 1 week after implantation. At 2 weeks after implantation, flat irregular layer like normal endothelium was noted at anastomosis site in both groups. At 8 weeks after implantation, the entire inner surface of implanted PTFE was lined by neointima in both groups. At 12 weeks after implantation, closely apposed endothelial-like cells were noted in the mid-portion of implanted PTFE in group Ⅰ, the long axis of neoendothelial cells was parallel to the direction of the blood flow, but the inner surface of implanted PTFE was still noted in group Ⅱ. In conclusion, there was no difference in patency rates according to the length of implanted PTFE, and at 1 week after implantation neoendothelium started to grow from both anastomosis sites toward the center of implanted PTFE in both groups; however, the formation of neointima and subintimal tissue was delayed and incomplete in longer implanted PTFE. In the future, further study must be performed to accelerate the neoendothelialization after implantation of PTFE for the clinical use in microvascular surgery.

전자근관장측정기 Root ZX의 정확도에 관한 실험적 연구

강대훈,정관희,윤수한,배광식 大韓齒科保存學會 1998 Restorative Dentistry & Endodontics Vol.23 No.1

The purpose of this study was to evaluate the in vitro accuracy of Root ZX(Torita Co., Japan) which is the ratio type electronic apex locator. The 86 extracted human palatal roots of maxillary molar with fully formed apices were used. File lengths with the file tip just visible at the foramen were compared to those measured with Root ZX. For length measuring with Root ZX, saline test model with which the apical 1/3 of each root was submerged into normal saline were designed. The root canal lengths were determined with Root ZX and the radiographs were taken with a file in the canal. The distances from file tips of Root ZX lengths to apecies in radiographs also were measured with Profile projector PJ311(Mitutoyo Co., Japan). The results were as follows : 1. The root canal length determined with electronic apex locator was 0.78±0.53 mm shorter than the length with visual measurement. 2. The file tip of Root ZX lengths was located at 0.85±0.49 mm away from the apex in radiograph. 3. The accuracy of the Root ZX was 79.1% within 0.5mm of visual working length and 96.5% within 1.0mm.

캔음료중 epichlorohydrin 의분석법에 관한 연구

이광호,곽인신,최재천,전대훈,김형일,강경모,최병희,김귀정,이철원 식품의약품안전청 2001 식품의약품안전청 연보 Vol.5 No.-

캔식품중에 잔류하는 epichlorohydrin을 분석하기 위한 pu링e & trap-Cc/uf통D 분석법을 확립하여 캔의 lacauer 코팅제에서 식품으로 이행되어 잔류하는 epichtorohydfn을 측정하고, 식품유사용매에 의한 용출시험을 통해 일일추정섭취량을 산출하였다. epichlorohydrin의 검량선은 y=0.0006x+0.OO6?(R큰0.9983)의 직선성·라 0.05#ga의 검출한계를 나타내었다. 각종 음료 및 식품유사용매에 일정량의 epichlorohydrin을 첨가한 후 분석하였을 때 회수을은 72~91%였으며, 실제 시판되는 f5건의 캔음료 중 잔류하는 epichlorohydrin을 측정한 결과 모든 캔음료에서 검출한계(0.1#94) 이하였다. 제관업체에서 구입한 modifed epoxy, epoxy phenolic, vinyl organosol, epoxy phenol ester 등의 BADGE(bisphenol A diglycidyt ether)형 에폭시수지로 lacquer 코팅된 식품용 캔에 식품윤사용매인 10% 또는 95% 에탄올을 층L진한 후 90~121'c의 드라이오븐에서 30분~2시간동안 용출시켰을 패 캔의 lacquer 코팅재에서 식품유사용매로 이행되는 epichBorollydirn은 코팅재질, 그리고 가열온도 및 시간에 문관하게 모든 캔에서 검출한계(0.4#ga)이하 였다. 위의 용출결과를 FD.f_의 "Recommendation for Chemistry Data for Indirect Food Additive Petition" 윽 일일추정섭취량 산출법에 적용하여 얻은 epichtorohydrin의 일딜추정 섭 취 량은 0.2r조persorday이하였다. A sensitive ana1?~7tical method based on gas cl)romatogFapy~mass spectrometry with a selected ion monitoring (GE/hfS-Slhf) and the purge-and-trap concentrator ))·asdeveloped for determining ot'epicillorohydrin in canr;ed be)#erages coated with eporl· resin. Thecalibration rurve in the ranre of 0.j ~50nr had'correlation coefficient of 0.9983 and detection limit of 0.Osrga. Recoveries of epichlorohydrin spiked to beverages were in the range of 72 ~91% with detection limits of 0.1 #ga. fn survey of epichlorohydff in twenty commercialcanned beverage samples, epichlorohydrin was not found in all the samples with the detectionlimit of 0.1 r9a. In migration test of various cans coated with BADGE-based coating cans;modifed epoxy, epoxy phenolic, vinyl organosol, epox?· phenol ester were exposed to the foodsimulants of 10% ethanol and 95% ethanol. flfo delectable epichlorohydrin migrated to foodsiHulants was found in aTl the cars with detection Jimit of 0.4 #9/L. Using the miEration data,along uTith the applicstion of food and beverage cans complied with FDA's "Recommendationfor Chemlstry Data f,3r Indirect Food Additive Petition" , the potential dietary exposure toepichlorohydrin was estlmated to be under 0.2rf/person/day.

모시조개 배지에서의 장내세균 및 비브리오균 증식

김용훈,고광균,이강순 순천향대학교 1992 논문집 Vol.15 No.2

This study was performed to develop a culture medium which fovors the growth of Vibrio vulnificus of the extract with a short-necked clam(Cyclina sinesis). The new plating medium made of the extract of a short-necked clam was tested for the growth of Vibrio vulnificus and a members of Enterobacteriaceae as well as Staphylococcus aureus and their abilities to form colonies in the media were compared with these to form colonies in the medium. The following results were obtained 1. The Vibrio vulnificus grew well and formed large colonies on the Cyclina sinensis agar plate and yeast-extract peptone agar plate. The Cyclina sinensis agar medium was better than the thiosulfate-citrate0bile salt-sucrose(TCBS) agar for the isolation of Vibrio vulnifificus. 2. All the bacteriae of Enterobacteriaceae family grew well on the Cyclina sinensis agar and the Brain Heart Infusion agar plate but the growth was inhibited on the MacConkey agar. 3. The growth of Staphylococcus aureus was much inhibited on the Cyclina sinensis agar media.

여성 생식기 콘딜로마 병변에서의 In Situ Hybridization에 의한 Human Papillomavirus DNA의 검색

서광선,강동욱,이증훈 충남대학교 의과대학 지역사회의학연구소 1992 충남의대잡지 Vol.19 No.2

The in situ hybridization technique, using digoxigenin labeled human papillomavirus(HPV) probes was applied to the detection of HPV DNA types 6 and 11. on paraffin sections of 24 condylomatous and malignant lesions of the uterine cervix, vagina, and vulva were used. They consisted of 9 condyloma acuminata, 10 flat condylomatous lesions associated with cervical intraepithelial neoplasia (CIN) and invasive squamous cell carcinoma(SCC), and 5 noncondylomatous lesions. The HPV DNA probes were stained mainly stained in the loilocytotic nuclei of the superficial portion of the epithelium. The underlying normal, dysplastic, and carcinoma cells were negative. Seven(77.8%) out of 9 condyloma acuminata and 4(57.1%) of 7 CIN Ⅰ/Ⅱ cases were positive for HPV 6 or 11. However, 2 cases of CIN Ⅲ and 6 cases of invasive SCC were negative, irrespective of the presence of koilocytosis. Thus, it was concluded that HPV types 6 and 11 are more commonly associated with benign condylomatous and low grade intrapithelial lesions than high grade lesions and SCC.

퍼지-뉴럴 융합을 이용한 제어시스템의 설계

김용호,강훈,전홍태,임광우 중앙대학교 생산공학연구소 1992 생산공학연구소 논문집 Vol.1 No.1

본 논문에서는 퍼지 논리와 신경회로망의 장점들을 결합한 퍼지-신경망(fuzzy-neural network;FNN)을 제안한다. FNN의 기본적인 구조는 퍼지 제어기의 규칙베이스와 추론의 과정을 신경회로망을 이용하여 구현한 것이며 퍼지 제어기의 중요한 매개변수들은 신경회로망의 가중치들로 표현된다. 그리고, FNN과 일반적인 선형제어기인 P-제어기를 병렬로 연결한 새로운 형태의 퍼지-뉴럴 하이브리드 제어기를 설계한다. 제안한 구조에서 FNN의 규칙베이스는 오차 역전파 학습 알고리듬에 의하여 자동생성된다. 또한, FNN과 병렬 연결한 P-제어기는 FNN의 규칙베이스가 완전히 생성되기 전인 초기상태에서 제어기의 안정성을 보장 할 것이다. 본 논문에서 제안한 방법의 효율성은 2자유도 평면 로봇 매니퓰레이터를 이용한 컴퓨터 모의 실험을 통해 입증된다. In this paper we propose a fuzzy-neural network(FNN) which includes both advantages of the fuzzy logic and the neural network. The basic idea of the FNN is to realize the fuzzy rule-base and the process of reasoning by neural network and to make the corresponding parameters be expressed by the connection weights of neural network. After constructing the FNN, a novel controller consisting of a conventional P-controller and a FNN is explained. In this control scheme, the rule-base of a FNN are automatically generated by error back-propagation algorithm. Also the parallel connection of the P-controller and the FNN can guarantee the stability of a plant at initial stage before the rules are completely created. Finally the effectiveness of the proposed strategy will be verified by computer simulations using a 2 degree of freedom robot manipulator.