• 수산해양교육연구
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• 제10권1호
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• pp.53-62
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• 1998

Accuracy of positions by GPS receiver at Tongyoung Port were measured and analysed in order to get more credible information on GPS positioning for vessels. Positions were automatically recorded every 5-Min from 1st October, 1997 to 30th of November, 1997 by two identical GPS receivers at the Laboratory of Navigation in the College of Marine Science, Gyeongsang University ($34^{\circ}$ 49' 57.985"N, $128^{\circ}$ 24' 06.562") and at the training ship "Gyeongyang" alongside in the tongyoung passenger port ($34^{\circ}$ 50" 10.080"N, $128^{\circ}$ 25' 16.415") as fixed positions. The results are as follows ; 1. Number of the usable satellites observing Zenith angle between $9^{\circ}$ and $82^{\circ}$ was normally 4 during a day 24 hours except for 3 hours with total Number 20. 2. Accuracy of position with time was widely dispersed around center of standard position as well as directional deviation around mean position. 3. Specific error of GPS receiver showed a little deviation by alternative measurements for consecutive 5 days at each fixed position respectively. 4. Accuracy of GPS position at 2 fixed positions of Tongyoung port was revealed 27.2 m as minimum value while normal accuracy for all day could be less than 50 m.

• 대한기관식도과학회지
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• 제16권2호
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• pp.138-144
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• 2010

Background: Tracheal deviations are encountered frequently in head and neck tumors especially in thyroid cancer. Dyspnea and stridor are symptom calling for surgery. The method of evaluation in tracheal deviation is not well established yet. This paper is aimed to suggest objective tools to evaluate tracheal deviation in relation to cervical vertebra. Material and Method: Ten cases of thyroid cancers were recruited retrospectively. Tracheal inner shadow and shape of cervical vertebra were reconstructed three dimensionally using 3D-doctor to compare position of trachea in relation to vertebral body. Extent of deviation was scored in relation to both lateral borders of vertebral body. Angles between trachea and spinous process were measured in axial CT and compared between study group and control group. Results: Deviation scores were statistically significant between study group (mean=1.1) and control group (mean=0) (p=0.0008). Deviation angles at maximal tumor size in study group (mean=160.3 Degrees) and deviation angles of control group (mean=177.1 Degrees) were statistically significant (p=0.0007). Angles at maximal deviation of three dimensional images ages in study group (mean=162.6 Degrees) and deviation angles of control group (mean=177.1 Degrees) were statistically significant (p=0.0089). Conclusion: Tracheal deviation can be evaluated using scoring of three dimensional images and measuring angle between trachea and vertebral spine.

• 제어로봇시스템학회논문지
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• 제5권6호
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• pp.698-704
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• 1999

There are several types of defects of SMDs mounted on PCB, that is, missing components, misalignment, wrong parts and poor solder joints. This research study mainly focuses on measuring of deviation of SMD leads using the partial image of component, not using the full image. This processing based on the partial image has the advantage of the reduction in calculation time compared to the full image. Since position of lead is calculated with respect of the reduction in calculation time compared to the full image. Since position of lead is calculated with respect to pad, the accuracy of the system is not dependent on percise positioning stage. The grabbed image of gray scale is converted into binary format using a cutomatic threshold. After small fragments in the image is removed by a series of morphology operations such as opening and closing, the centroids of PCB pads and SMD leads is obtained together with labeling of blobs. Translational shift and rotationial angle of SMD are succedingly estimated using above information and chip data. The expression that can calculate the maximum deviation of leads with respect to PCB pads has been derived, and inferior mounting of SMD is judged by a given criterion. Some experiments have been executed to verify this measuring scheme.

• Journal of Mechanical Science and Technology
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• 제18권7호
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• pp.1074-1085
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• 2004

There are many intermediate web guides in cold rolling mills process such as CRM (cold rolling mill), CGL (continuous galvanizing line), EGL (electrical galvanizing line) and so on. The main functions of the web guides are to adjust the center line of the web (strip) to the center line of the steel process. So they are called CPC (center position control). Rapid process speed cause large deviation between the center position of the strip and the process line. Too much deviation is not desirable. So the difference between the center position of the strip and the process line should be compensated. In general, the center position control of the web is obtained by the hydraulic driver and electrical controller. In this paper, we propose modelling and several controller designs for web-guide systems. We model the web and guide by using geometrical relations of the guide ignored the mass and stiffness of the web. To control the systems, we propose PID controllers with their gains tuned by the Ziegler-Nichols method, the H$\_$$\infty$/ controller model-matching method, and the coefficient diagram method (CDM). CDM is modified for high order systems. The results are verified by computer simulations.

• 한국측량학회지
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• 제5권1호
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• pp.13-22
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• 1987

해상작업의 가장 기본적인 것은 위치 결정이다. 해상에서의 위치는 거의 대부분 육상의 고정점과 관련된다. 선박의 위치를 결정하는 전형적인 방법은 고정된 육상의 3개의 기지점을 육분의를 이용하여 수평각을 2배로 관측한후 삼간분도의로 도해후방 교회법으로 작성하는 것이다. 근래 해상위치 결정은 항해 및 어로를 위한 목적에서 해양ㆍ해안의 복합적인 개발이 되고 있다. 본 논문은 이에 부응하여 보다 정확한 해상위치 결정을 위해 전파결정 방식중, 장거리 및 초장거리용에 속하는 NNSS, Loran-C, Omega 등과 같은 해양 계측기기를 중심으로 고정점에서의 편차를 비교 분석하였다.

• 대한치과교정학회지
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• 제43권4호
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• pp.168-177
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• 2013

Objective: In this study, we aimed to examine the relationship between chin deviation and the positional and morphological features of the mandible and to determine the factors that contributed to chin deviation in individuals with a unilateral cleft lip and palate (UCLP). Methods: Cone-beam computed tomography (CBCT) images of 28 adults with UCLP were analyzed in this study. Segmented three-dimensional temporomandibular fossa and mandible images were reconstructed, and angular, linear, and volumetric parameters were measured. Results: For all 28 individuals, the chin was found to deviate to the cleft side by 1.59 mm. Moreover, among these 28 individuals, only 7 showed distinct (more than 4 mm) chin deviation, which was toward the cleft side. Compared to the non-cleft side, the mandibular body length, frontal ramal inclination, and vertical position of the condyle were lower and inclination of the temporomandibular fossa was steeper on the cleft side. Furthermore, the differences in inclination of the temporomandibular fossa, mandibular body length, ramus length, and condylar volume ratio (non-deviated/deviated) were positively correlated with chin deviation. Conclusions: UCLP individuals show mild chin deviation to the cleft side. Statistical differences were noted in the parameters that represented positional and morphological asymmetries of the mandible and temporomandibular fossa; however, these differences were too small to indicate clinical significance.

• Journal of Periodontal and Implant Science
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• 제44권4호
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• pp.184-193
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• 2014

Purpose: The aim of the present study was to evaluate the in vivo accuracy of flapless, computer-aided implant placement by comparing the three-dimensional (3D) position of planned and placed implants through an analysis of linear and angular deviations. Methods: Implant position was virtually planned using 3D planning software based on the functional and aesthetic requirements of the final restorations. Computer-aided design/computer-assisted manufacture technology was used to transfer the virtual plan to the surgical environment. The 3D position of the planned and placed implants, in terms of the linear deviations of the implant head and apex and the angular deviations of the implant axis, was compared by overlapping the pre- and postoperative computed tomography scans using dedicated software. Results: The comparison of 14 implants showed a mean linear deviation of the implant head of 0.56 mm (standard deviation [SD], 0.23), a mean linear deviation of the implant apex of 0.64 mm (SD, 0.29), and a mean angular deviation of the long axis of $2.42^{\circ}$ (SD, 1.02). Conclusions: In the present study, computer-aided flapless implant surgery seemed to provide several advantages to the clinicians as compared to the standard procedure; however, linear and angular deviations are to be expected. Therefore, accurate presurgical planning taking into account anatomical limitations and prosthetic demands is mandatory to ensure a predictable treatment, without incurring possible intra- and postoperative complications.

• 한국항행학회논문지
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• 제19권5호
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• pp.403-410
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• 2015

ADS-B는 레이더에 비하여 높은 정확도와 빠른 갱신 주기를 제공하여, 레이더를 대체하거나 보완할 수 있는 기술이다. 최근 증가하는 항공교통량과 이에 따른 정확한 감시의 요구에 의하여 ADS-B가 실제 항공기 운영에 적용되고 있다. 본 논문은 항공기가 운항 중 상시 송신하는 ADS-B 신호를 활용한 공한 인근 지역에서 정밀 감시가 가능한지 확인하기 위한 자료 수집과 일부 데이터에 대한 분석을 수행하였다. 이를 위하여 정밀계기 착륙 접근하는 항공기의 ADS-B 항적을 수집하고, 최종접근 구간에서 항적의 분포 특성에 관한 분석을 수행하였다. 분석결과 ADS-B 항적은 활주로 중심선 연장선에 대하여 평균 이격 거리 -0.04 m, 표준편차 6.71 m이고, 또한 비교적 정확한 감시정보의 제공이 가능함을 확인하였다.

• 대한치과교정학회지
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• 제30권5호
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• pp.535-542
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• 2000

본 연구는 안면비대칭 환자의 natural head position(NHP)시 정면에서의 두부 또는 경추의 경사 정도를 알아봄으로써 교정환자의 임상검사시 비대칭의 진단에 도움이 되고자 시행되었다. 두드러진 전후방 골격 이상은 없으나 뚜렷한 좌우 안면비대칭을 보이는 성인 20명을 비대칭군으로, 좌우 대칭적인 외모와 비교적 정상교합을 보이는 성인 21명 을 대칭군으로 선정 한 다음 물방울 수평계를 이용하여 NHP 상태의 정모두부방사선사진을 촬영하고 투사도를 작성하였다. Crista galli와 anterior nasal spine을 연결한 선과 crista galli와 menton을 연결한 선이 이루는 각을 menton의 변위 정도로 정하고, 좌우 supra-orbital margin의 최상방점을 지나는 supra-orbital line과, 제1경추와 제4경추의 중심을 연결한 cervical line이 각각 true vertical line과 이루는 각을 계측한 다음 이들간의 상관관계를 비교 분석하여 다음과 같은 결과를 얻었다. 1. Supra-orbital line이 true vortical line과 이루는 각이 직각에서 벗어난 정도가 대칭군에 비하여 비대칭군에서 통계적으로 유의하게 크게 나타났다. 2. Cervical line이 true vertical line과 이루는 각은 통계적 유의차는 없었으나 비대칭군에서 더 큰 경향을 보였다. 3. 비대칭군에서 supra-orbital line이 true vortical line과 이루는 각이 직각에서 벗어난 정도는 menton의 변위 정도와 통계적으로 유의한 순상관관계를 보였다. 이상의 결과로 안면비대칭 환자는 menton의 변위를 보상하려는 방향으로 기울어진 NHP를 가지는 경향이 있음을 알 수 있었다.

• 대한치과교정학회지
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• 제53권3호
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• pp.163-174
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• 2023

Objective: This study evaluated the influence of various gingival displays on the esthetic perception in the presence of upper dental midline discrepancy. Methods: A smiling image of a male subject was altered digitally to produce five image series: normal smile (series A), decreased tooth show (series B), increased gingival show (series C), maxillary cant (series D), and asymmetric upper lip elevation (series E). In each image series, the midline was deviated to the right and left incrementally. A total of 210 raters (four professional groups and laypersons, n = 42 in each group) determined the midline deviation threshold and the attractiveness of midline position in each series. Results: The right and left thresholds were statistically similar for the symmetrical series (A, B, and C), while for series D, the right threshold was significantly lower. In most rater groups, the mean threshold order was: B > A > E > C > D. In all the series, the raters selected the coincident midline as the most attractive series except for series D, for which 1-2-mm deviations to the left were selected as the most attractive by almost all the groups. Conclusions: It is crucial to establish the coincident midline position in a symmetrical smile, especially when a gummy smile exists. In the asymmetrical gingival show, a coincident midline might not be the most esthetic midline position.