Formulation of a reference coordinate system of threedimensional head & neck images : Part Ⅱ. Reproducibitity Ⅱ부 수평기준면과 정중사상면의 재현성

Kim, Nam-Kug,Park, Jae-Woo,Chang, Young-Il 대한치과교정학회 발행 2005 대한치과교정학회지 Vol.35 No.6

This study was performed to investigate the reproducibility of the horizontal and midsagittal planes, and to suggest a stable coordinate system for three-dimensional (3D) cephalometric analysis. Eighteen CT scans were taken and the coordinate system was established using 7 reference points marked by a volume model, with no more than 4 points on the same plane. The 3D landmarks were selected on V works (Cybermed Inc., Seoul, Korea), then exported to V surgery (Cybermed Inc., Seoul, Korea) to calculate the coordinate values. All the landmarks were taken twice with a lapse of 2 weeks. The horizontal and midsagittal planes were constructed and its reproducibility was evaluated. There was no significant difference in the reproducibility of the horizontal reference planes. But, FH planes were more reproducible than other horizontal planes. FH planes showed no difference between the planes constructed with 3 out of 4 points. The angle of infersection made by 2 FH planes, composed of both Po and one Or showed less than 1° difference. This was identical when 2 FH planes were composed of both Or and one Po. But, the latter cases showed a significantly smaller error. The reproducibility of the midsagittal plane was reliable with an error range of 0.61 to 1.93° except for 5 establishments (FMS-Nc, Na-Rh, Na-ANS, Rh-ANS, and FR-PNS). The 3D coordinate system may be constructed with 3 planes; the horizontal plane constructed by both Po and right Or; the midsagittal plane perpendicular to the horizontal plane, including the midpoint of the Foramen Spinosum and Nc; and coronal plane perpendicular to the horizontal and midsagittal planes, including point clinodale, or sella, or PNS. 본연구는 삼차원 두부 영상을 위치시키기 위한 좌표계를 구성하는 방법에 대한 제안하기 위해, CT data에서 기존의 두부방사선 계측사진에서 쓰이는 점들을 선정하고, 이를 바탕으로 수평, 수직평면의 안정성을 조사하였다. 서울대학교 치과병원에 내원한 환자 18명의 CT자료를 채득하였으며, 모든 환자는 서울대학교 병원 진단방사선과에서 촬영하였다. (Somatom Plus 4: Siemens, Eriange, Germany). V works for surgery 4.0 (Cybermed Inc., Seoul, Korea)을 이용하여 3차원 좌측표를 선정하고, 계측점을 선택하였다. 좌표축을 동일하게 설정하기 위해 7개의 점(reference point)을 4·4·2 pixel size의 voxel로 따로 표시하였다. 계측점을 선정한 후 V surgery (Cybermed Inc., Seoul, Korea)에서 각 점의 좌표값을 추출하였다. 각각의 점들은 2회 반복 선정한 후 점들을 조합하여 수평, 수직평면의 재현성을 평가한 결과 다음과 같은 결론을 얻었다 수평 기준면의 재현도는 S-CI평면을 제외하고는 통계적으로 유의한 차이를 보이지 않았으나, 사잇각은 FH평면이 가장 작게 나타났다. FH평면은 Po과 Or중 어느 3점을 선택하더라도, 통계적으로 유사한 재현도를 보였다. FH1과 FH2의 사잇각과 FH3과 FH4의 사잇각은 1° 이하의 적은 오차를 보이며, FH3과 FH4의 사잇각이 통계적으로 더 작은 차이를 보였다. 정중시상면의 재현도는 FMS-Nc, Na-Rh, Na-ANS, Rh-ANS, FR-PNS를 기준으로 설정한 경우를 제외하면, 0.61~1.93° 의 양호한 값을 보였다. 이상의 결과에 의하면 공간에서 정의되는 평면의 재현도는 평면을 정의하는 점 자체의 식별오차뿐 아니라, 각 점의 위치관게에도 영향을 받는 것을 알 수 있었다. 따라서, 안정적인 3차원 기준좌표계를 구성하려면 양측 Po과 편측 Or으로 구성되는 평면을 수평기준면으로, 수평면에 수직이고, Foramen Spinosum의 중점과 Nc를 포함하는 평면을 수직기준면으로, 수평면과 수직면에 수직이고, clinoidale나 sella, PNS를 지나는 평면을 전두면으로 설정하는 것이 바람직할 것으로 생각된다.

장기간 고농도 수유후 발행한 고장성 탈수증 2례

김국환,안영준,양은석,박상기,박영봉,문경래 朝鮮大學校 附設 醫學硏究所 1997 The Medical Journal of Chosun University Vol.22 No.2

Hypernatremia(serum sodium>150meq/L) is caused by conditions that produce an excessive gain of sodium or result in an excessive loss of body fluid that is greater than the loss of sodium. The prognosis for hypernatremic dehydration is poorer than isotonic or hypotonic dehydration, because severe hyperosmolarity may result in cerebral damage( seizures, cerebral hemorrhages, thromboses, and subdural effusions). This cerebral injury may result in a permanent neurologic deficit. We experienced two cases of hypernatremic dehydration. Theses cases may have resulted from faulty preparation of infant formulas, as with the use of condensed milk powder. The first case experienced seizures during treatment, but survived, yet the second case died in spite of intensive care.

CdS 세라믹 膜의 製作과 應用에 관한 硏究

金永局 경남대학교 환경문제연구소 1985 환경연구 Vol.7 No.-

CdS in one of the most promising materials for the wide band gap window, and there are a number of reports concerning junctions between CdS and other absorber material. To make ohmic contacts to CdS is an important process in the fabrication of devices. The CdS ceramic films were treated by lapping, polishing and chemical etching. After vacuum deposition of In about 1000 Å thick onto CdS ceramic films, heat treatment was carried out at various temperatures for 10 minutes. The lowest resistance of ohmic contacts is obtained at the annealing temperature of 300℃, where the average contact resistance is below 10^(-2)Ωㆍ㎠. The CdS ceramic films sintered at 600℃ in N_(2) gas for 1 hour had a resistivity of about 10^(-1)Ω-cm, mobility μ, of about 20∼30㎠/vㆍsec, carrier concentration n of about 10^(-17)cm^(-3). Under AM_(1) sunlight simulator, the parameters for the typical solar cell are open-circuit voltage V_(OC)=0.4V, Short-circuit current I_(SC)=12mA, fill factor FF=0.55 and conversion efficiency η=3.8%.

Au-GaAs Schottky 障壁 다이오드와 GaAs 發光 다이오드에 관한 硏究

金永局,李秀大,薛貞植 경남대학교 환경문제연구소 1985 환경연구 Vol.7 No.-

Schottky barriers on both undoped GaAs LPE layer and Si doped wafer (doping concentration is about 3.8×10^(18)cm^(-3)) were studied. The growth of oxide interfacial layer had been found to increase the open circuit voltage and the fill factor. Emitted light was detected by using I.R. telescope and solar cell and the intensity of emitted light was detected by using Si solar cell and the relative efficiences of LEDs were measured by the ratio of photocurrent of Si solar cell to diode current, and the best value of the relative efficiency abtained for the Al_(x)Ga_(1-x) As LED was the value of X_(AI)=0.1. The emission spectrum of the LED diodes showed that the wavelength corresponding to the maximum intensities were λ=9,050Å for Al_(0.1)Ga_(0.9)As LED, λ=9,150Å for GaAs(Zn diffusion) LED and λ=9,160Å for GaAs (Ge doping) LED respectively.

전자석을 이용한 주축용 베어링의 예압 조절 장치에 관한 연구

황영국,김웅,이춘만 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

In today's machining environment, heavy cutting at a low speed and light cutting at a high speed, as are often performed on a single machine tool, must be carried out successively for highly efficient machining as well as high speed machining. Therefore, current machine tool spindles require great stiffness and high speed rotation performance simultaneously. To that end, a preload device is needed so that the bearing that can apply a greater preload to raise the stiffness of the spindle at the low-speed range while a smaller preload at the high-speed range to reduce heat generation as opposed to greater stiffness and to allow high-speed rotation. In this study, the new concept of an automatic variable preload device that can adjust the preload applied to spindle bearing using electromagnetic was proposed. A prototype for the automatic variable preload device using electromagnetic was created. With the prototype, it was confirmed that the preload device based on the proposed structure worked properly.

3차원 두부영상의 기준좌표계 설정을 위한 연구 : Ⅰ부CT영상에서 3차원 계측점의 재현성 Part ⅠReproducibility of 3D cephalometric landmarks

박재우,김남국,장영일 대한치과교정학회 2005 대한치과교정학회지 Vol.35 No.5

이 연구는 기존의 두부방사선사진에서 사용되었던 계측점들을 3차원으로 재구성한 CT자료에서 다시 정의하고, 그 점들의 재현도를 조사함으로써, 재현성이 높고 해부학적 특징을 잘 표현하는 점들을 제안하고자 시행하였다. 3차원 영상에서 상대적 좌표값을 구하기 위해 어느 4점도 같은 평면에 존재하지 않는 7개의 고정점을 선정하여 기준 좌표계를 설정하였다. V works 4.0 (Cybermed Inc., Seoul, Korea)을 이용하여 고정점과 Ⅰ점 설정을 위한 volume model (voxel size=4*4*2, threshold value = 639)을 형성한 후 계측점을 선택하였으며, 나머지 점들은 모두 volume mode의 MPR 창을 이용하여 선정하였다. 이렇게 선정한 계측점을 V surgery(Cybermed Inc., Seoul Korea)로 이출하여 각 점의 상대적 공간 좌표값을 구하였다. 모든 자료는 2주 간격으로 2번 측정한 후 재현도를 계산하였다. 각 계측점의 재현도는 x축 0.13~1.24mm. y축 0.23~1.53mm, z축 0.15~1.81mm로 유사한 범위를 보였다. 재현도가 우수한 것은 고정점을 이용한 I점이며 봉합에 의해 정의되는 J점의 재현도가 비교적 낮게 나타났다. The purpose of this study was to redefine the cephalometric landmarks in three-dimensional (3D) images, which are used in orthodontic cephalometric radiography, and to evaluate the reproducibility of each landmark for 3D cephalometric analysis. Eighteen CT scans were taken at the Department of Diagnostic Radiology at Seoul National University Dental Hospital and manipulated with V works 4.0(Cybermed Inc., Seoul, Korea). The coordinate system was established using 7 reference points, with no more than 4 points on the same plane. These 7 points were generated as a volume model, the voxel size of which was 4 by 4 by 2 (threshold value=639). The cephalometric landmarks were selected at the multiplanar reformation (MPR) window on the volume mode of V works 4.0. The selected landmarks were exported to V surgery (Cybermed Inc., Seoul, Korea) for the calculation of coordinate values. All the data were taken twice with a lapse of 2 weeks by one investigator. The reproducibility of each landmark was 0.17~1.21 mm in the x axis, 0.30~1.53 mm in the y axis, and 0.27~1.81 mm in the z axis. In all three axes, the range of error was similar. These error ranges were acceptable with regards to the pixel space and slice thickness. The most reproducible points were I points which were selected on the basis of the volume model. The least reproducible points were J points that were defined by sutures.

폴리에스테르 모르타르의 경화수축

최낙운,김완기,조영국,소양섭 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

The setting shrinkage behavior in polyester mortars with two-phase shrinkage reducing agent(SRA) was observed at the ambient temperature. Polyester mortars were prepared with various styrene contents and two-phase shrinkage reducing agent(SRA) contents. The length change and exotherm temperature of polyester mortars were continuously monitored by a noncontact-type automatic length change measuring apparatus and a thermocouple embedded respectively. Low-shrinkage or non-shrinkage of polyester mortars should be accomplished by adjusting styrene content and SRA content.

스크린 프린트 方法에 依한 CdS/Cu_(x)S 太陽電池 製作 및 特性조사

薛貞植,金永局 경남대학교 환경문제연구소 1982 환경연구 Vol.4 No.-

CdS/Cu_(x)S solar cells were prepared by using a screen printing method. A low resistivity CdS film was obtained by screen printing CdS paste on a glass substrate and then sintering it in N₂gas including a small amount of Cd vapor. CdS paste for screen printing was prepared by mixing loog CdS powder and 7g CdCl₂powder with propylen glycol(binder) in an agate mortar. CdCl₂was used as a flux. CdS paste was printed on a borosilicate glass substrate by a screen printing method, and then sintered at 640℃ in N₂gas for 1 hour using a furnace, a Cd metal was placed on the inlet side of N₂gas in the furnace and held at 400℃. The CdS film thus sintered had a resistivity of about 5~15Ω-cm, mobility μ_(e) of about 200~270㎠/Vㆍsec, a thickness of about 50~500㎛ and grain size of 5-lO㎛. Fabrication of a low resistivity CdS film and heat treatment in H₂gas after applying electrodes were very important factors in obtaining a high efficiency cell. Under AM1 sunlight simulator, the parameters for the typical cell are open-circuit voltage V_(DC)=0.4V, short-circuit current I_(SC)=5mA, fill factor FF=0.55 and conversion efficiency Л=1.12%.

Al/p-Si MOS型 太陽電池의 製作

羅炳旭,金永局,李原鎭 慶北大學校 1980 論文集 Vol.30 No.-

Al/p-silicon MOS solar cells, consisting of Al on p-type silicon with a thin interfacial layer of SiO_2 have been found to have good light conversion efficiency for solar radiation. The effects of the oxide layer thickness between metal and substrate were investigated. Under AM1 simulated sunlight illumination the best cell has open circuit voltage V_oc=0.48V, short circuit current I_sc=27mA/㎠, fill-factor FF=0.66 and conversion efficiency η=8.6%.

용액 Spray法에 의한 CdS 및 In_2O_3 : Sn의 薄膜 製作과 이의 特性 Sn Thin Films by Pyrolitic Spray Method and It's Characteristics

李相潤,李原鎭,金永局 경북대학교 교육대학원 1980 논문집 Vol.12 No.-

Transparents and conductive thin films of CdS and In_2O_3:Sn have been prepared using the simple pyrolitic spray method. The best results were obtained when the substrate temperatures were 450˚∼500℃, and the resistivities of those films were several hundreds of KΩ-㎝∼several tens of MΩ-㎝ for CdS and about 10^-3Ω-㎝ for In_2O_3:Sn.