• 한국태양에너지학회 논문집
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• 제33권5호
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• pp.51-59
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• 2013

It is usual to evaluate the performance of the cool roof by measuring in-site rooftop temperature using thermal infra-red camera. The principal advantage of rooftop thermal infrared image acquired in oblique vantage point of super high-rise building as a remote sensor is to provide, in a cost-effective manner, area-wide information required for a scattered rooftop target with different colors, utilizing wide view angle and multi-temporal data coverage. This research idea was formulated by incorporating the concept of traditional remote sensing into rooftop temperature monitoring. Correlations between infrared image of super high-rise building and in-situ data were investigated to compare rooftop surface temperature for a total of four different rooftop locations. The results of the correlations analyses indicate that the rooftop surface temperature by the infrared images of super high-rise building alone could be explained yielding $R^2$ values of 0.951. The visible permanent record of the oblique thermal infra-red image was quite useful in better understanding the nature and extent of rooftop color that occurs in sampling points. This thermal infrared image acquired in oblique vantage point of super high-rise made it possible to identify area wide patterns of rooftop temperature change subject to many different colors, which cannot be acquired by traditional in-site field sampling. The infrared image of super high-rise building breaks down the usual concept of field sampling established as a conventional cool roof performance evaluation technique.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.286-288
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• 2003

In this paper, we present our implementation of the direct camera model (image to ground) for SPOT5 and use it to assess the geometric accuracy of SPOT5 imagery. Our assessment confirms the location accuracy of SPOT5 imagery (without use of GCPs) is less than 50m. We further introduce a few attitude parameters to refine the camera model with GCPs. The model is applied to two SPOT5 supermode images, one near vertical, incidence angle of 3 degrees, and one far oblique, incidence angle of 27 degrees. The results show that accuracy (rms of check points) of about one pixel (2.5m) can be achieved with about 4 GCPs by using only 3 parameters to correct the yaw, pitch and roll of the satellite.

• The Journal of Korean Physical Therapy
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• 제28권5호
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• pp.297-302
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• 2016

Purpose: This study was conducted to evaluate the effects of bridge exercise on the structural characteristics of trunk muscles in patients with lumbar pain by applying the exercise on either a stable or an unstable surface. Methods: Thirty subjects participated in the experiment and were randomly divided into an unstable bridge exercise group (UBEG) and a stable bridge exercise group (SBEG). The exercise program for each group was conducted three times a week over a six-week period. The structural characteristics of trunk muscles were measured by obtaining images using an ultrasound imaging device. Results: The thicknesses of the external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) and the fiber angle of the erector spinae (ES) in the UBEG and the SBEG showed statistically significant increases in all items measured after the experiment. A comparison of groups conducted after the experiment to determine the effects of the exercise on each group showed no significant differences between groups for any of the measured items. Conclusion: A comprehensive review of the study results showed statistically significant increases in the thicknesses of the EO, IO, and TrA and the fiber angle of ES in both the UBEG and the SBEG. While the comparison of the groups with respect to the effects of the exercise revealed no significant differences, there were relatively larger effects in the UBEG than in the SBEG.

• 대한기계학회논문집B
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• 제26권7호
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• pp.1031-1038
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• 2002

The pressure sensitive paint (PSP) has recently received a considerable attention in the fields of aerodynamics and fluid mechanics as a new revolutionary optical technique to measure pressure fields on a body surface. In this study, the feasibility and effectiveness of the PSP pressure field measurement technique have been investigated experimentally. Seven different PSP formulations including two porphyrins(PtOEP and PtTFPP) and four polymers(Polystyrene, cellulous acetate butyrate, GP-197 and Silicon-708) were tested to check the performance and characteristics of each combination. The static calibration of each PSP formulation was carried out in a constant-pressure chamber. The PSP technique was applied to an oblique impinging jet flow to measure variation of pressure field on the impinging plate at on oblique jet angle of ${\theta}=60^{\circ}$. Pressure field images were captured by an 12bit intensified CCD(ICCD, $1K{\times}1K$)camera. As a result, the dynamic response of PSP depends on the oxygen permeability of polymer and the photochemical interaction between luminophore and polymer as well as the reaction of luminophore itself. The reaction of luminophore was changed by employing different polymers. In conclusion, Among 7 PSP formulation tested, the combination of PtTFPP and cellulous acetate butyrate show the best performance. In addition, the detail pressure field of an oblique high-speed impinging jet was measured effectively using the PSP technique.

• 한국방사선학회논문지
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• 제7권2호
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• pp.107-112
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• 2013

발목 병변을 관찰하는 단순 방사선촬영은 여러 가지가 있다. 그 중에서 Ankle Broden법은 발꿈치뼈(Calcaneus) 및 발목뼈(Ankle Joint)의 결합상태와 발목뼈의 발꿈치뼈 골절(Calcaneus Fracture), Subtentaculum Tali Frature를 관찰하기 위하여 촬영을 한다. 이 촬영법은 전 후면과 측면뿐 아니라, 사면 상(oblique view)이나 축 상(axial view)의 촬영을 하며 잦은 부상이 발생하는 목말뼈 발꿈치뼈간, 발꿈치뼈 발배뼈간 결합상을 보기 위해 주로 촬영을 한다. 본 연구는 석고처치 환자들은 발목관절이 영상에 잘 묘출되기가 어렵기 때문에 발목뼈 사이의 관계 및 연부조직의 구조적 변화와 Subtalar joint, Calcaneus Fracture, Subtentaculum Tali Frature에 따른 목말뼈 발꿈치뼈의 골 결합 (talocalcaneal coalition)을 관찰하기 위한 Harris-Beath View($30^{\circ}{\sim}55^{\circ}$) 촬영 시 평가에 유용한 발목뼈의 결합상을 얻을 수 있는 각도를 알아보고자 하였다. 연구의 진행은 40명의 환자에게서 획득한 영상을 평가하였으며, 평가결과 $25^{\circ}$의 촬영상은 목말밑 관절(subtalar joint)이 열려져 분리되지 않았고 또한, Subtentaculum Tali Frature에 중복되어 보였다. $30^{\circ}$의 촬영상은 발꿈치뼈 골절(Calcaneus Fracture), Subtentaculum Tali Frature, 목말밑관절(subtalar joint과 후방 관절면의 앞부분이 가장 잘 나타나고 Calcaneo Navicularcoalition, Talocal Canealcoalition, Naviculo Cuneiform coalition의 결합상태가 명확하게 보였다. $35^{\circ}$의 촬영상은 목말밑관절(subtalar joimt), 목말뼈(talus), 발뒤꿈치뼈의 뒤쪽관절면이 명확하고 발목발꿈치관절(talocalcaneal joint)의 분리정도가 좋고 발목뼈굴(sinus tarsi)이 넓게 나타나며 좋은 평가가 되었다. $45^{\circ}$영역에서는 연부조직과 석고 분리를 판별할 수 있었고 가쪽복사와 뼈 밀도가 명확하게 보였다. $35^{\circ}$에 비해 발꿈치뼈(Calcaneus)이 분리되었지만 영상이 왜곡되어 보였다. Calcaneus, Subtentaculum Tali Frature는 $25^{\circ}$에서 $1.20{\pm}0.414$, $30^{\circ}$에서는 $2.47{\pm}0.516$, $35^{\circ}$에서는 $2.87{\pm}0.352$, $45^{\circ}$에서는 $2.27{\pm}0.458$로 나타났고 통계적으로 유의한 차이가 나타났다(p<0.05). 왜곡의 정도를 포함시키면 $30^{\circ}$영역의 왜곡이 적게 나타났고, $40^{\circ}$ 영역은 심한 왜곡현상을 보였다. 따라서 Ankle(Broden)촬영에서 $30{\sim}35^{\circ}$상이 가장 좋은 영상이었으며, $30{\sim}40^{\circ}$상에서는 Calcaneus Fracture, Subtentaculum Tali Frature의 진단에 가장 좋은 영상을 묘출하였다.

• The Korean Journal of Pain
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• 제35권3호
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• pp.345-352
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• 2022

Background: Optimal needle depth in transforaminal epidural injection (TFEI) is determined by body measurements and is influenced by the needle entry angle. Physician can choose the appropriate needle length and perform the procedure more effectively if depth is predicted in advance. Methods: This retrospective study included patients with lumbosacral pain from a single university hospital. The skin depth from the target point was measured using magnetic resonance imaging transverse images. The depth was measured bilaterally for L4 and L5 TFEIs at 15°, 20°, and 25° oblique angles from the spinous process. Results: A total of 4,632 measurements of 386 patients were included. The lengths of the left and right TFEI at the same level and oblique angle were assessed, and no statistical differences were identified. Therefore, linear regression analysis was performed for bilateral L4 and L5 TFEIs. The R-squared values of height and weight combined were higher than the height, weight, and body mass index (BMI). The following equation was established: Depth (mm) = a - b (height, cm) + c (weight, kg). Based on the equation, maximal BMI capable with a 23G, 3.5-inch, Quincke-type point spinal needle was presented for three different angles (15°, 20°, and 25°) at lumbar levels L4 and L5. Conclusions: The maximal BMI that derived from the formulated equation is listed on the table, which can help in preparations for morbid obesity. If a patient has bigger BMI than the one in the table, the clinician should prepare longer needle than the usual spinal needle.

• 한국측량학회지
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• 제38권6호
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• pp.663-670
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• 2020

본 연구에서는 건물이 혼재한 준 도심 지역에서 발생할 수 있는 재난/재해를 가정하여 네트워크 RTK (Real Time Kinematic) 측위가 가능한 무인기를 이용한 항공삼각측량의 정확도를 평가하였다. 검사점 측위의 신뢰성을 확보하기 위해 검사점을 건물의 옥상에 설치하여 네 시간 이상의 GNSS (Global Navigation Satellite System) 정적 측위를 수행하였다. 객관적인 정확도 평가를 위해 소프트웨어에서 자동으로 인식 가능한 코드화된 대공 타겟을 사용하였다. 무인기에서는 네트워크 RTK 측위의 일종인 VRS (Virtual Reference Station) 방식을 이용하여 영상 취득 당시 카메라의 3차원 좌표를 측정하였고, IMU (Inertial Measurement Unit)와 짐벌 회전각 측정을 통해 카메라의 3축 회전각을 측정하였다. Agisoft Metashape를 이용하여 내·외부 표정요소를 추정·갱신한 결과, 항공삼각측량의 3차원 RMSE (Root Mean Square Error)는 영상의 중복도와 촬영 각도의 조합에 따라 크게는 0.153 m에서 작게는 0.102 m로 나타났다. 더욱 높은 수준의 항공삼각측량 정확도를 확보하기 위해서는 연직 영상의 중복도를 높이는 것이 일반적이나 경사 영상을 추가하는 것이 효과적인 것으로 나타났다. 따라서 대응 단계의 재난/재해 현장에서 긴급하게 무인기 매핑을 수행할 경우 중복도를 높이기 보다는 경사 영상도 함께 취득할 필요가 있다.

• Journal of Mechanical Science and Technology
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• 제15권12호
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• pp.1816-1821
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• 2001

Two-dimensional blow-down type supersonic wind tunnel was designed and built to investigate the transient behavior of the startup of a supersonic flow from rest. The contour of the divergent part of the nozzle was determined by the MOC calculation. The converging part of the nozzle, upstream of fille throat was contoured to make the flow uniform at the throat. The flow characteristics of the steady supersonic condition were visualized using the high-speed schlieren photography. The Mach number was evaluated from the oblique shock wave angle on a sharp wedge with halt angle of 5 degree. The measured Mach number was 2.4 and was slightly less than the value predicted by the design calculation. The initial transient behavior of the nozzle was recorded by a high-speed digital video camera with schlieren technique. The measured transition time from standstill to a steady supersonic flow was estimated by analyzing the serial images. Typical transition time was approximately 0.1sec.

• The Journal of Advanced Prosthodontics
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• 제7권3호
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• pp.240-248
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• 2015

PURPOSE. To explore whether there is matching relation between the length and the tilting angle of terminal implants in the All-on-Four protocol by studying the effects of different implant configurations on stress distributions of implant, bone, and framework. MATERIALS AND METHODS. Four implants were employed to support a full-arch fixed prosthesis and five three-dimensional finite element models were established with CT images, based on the length (S and L) and distal tilt angle ($0^{\circ}$, $30^{\circ}$ and $45^{\circ}$) of terminal implants for an edentulous mandible, which named: Tilt0-S, Tilt30-S, Tilt30-L, Tilt45-S and Tilt45-L. An oblique 240 N was loaded at second molar. The von Mises Stresses were analyzed. The implants were consecutively named #1 to #4 from the loading point. RESULTS. 1) Tilt0-S had the greatest stress on the implants, with the other groups exhibiting variable reductions; the four implants of Tilt45-L demonstrated the greatest reduction in stress. 2) Tilt0-S had the greatest stress at bone around #1 implant neck, and Tilt45-L exhibited the least stress, which was a 36.3% reduction compared to Tilt0-S. 3) The greatest stress in the framework was found on the cantilevers distal to #1 implant. Tilt45-S exhibited the least stress. CONCLUSION. Matching different length and tilting angle of the terminal implants led to variable stress reductions on implants, bone and the superstructure. By optimizing implant configuration, the reduction of stress on implants and surrounding bone could be maximized. Under the present condition, Tilt45-L was the preferred configuration. Further clinical testings are required.

• 대한방사선기술학회지:방사선기술과학
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• 제31권2호
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• pp.109-114
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• 2008

어깨의 병변을 관찰하는 단순 방사선촬영법들 중 견관절을 보기 위한 대표적인 검사법으로 Shoulder oblique법(Grashey법)이 있다. 이 검사는 견관절의 정면상을 볼 수 있는 검사로 누운 자세에서 검사할 때는 몸의 한쪽 면을 거상시키는 자세를 취하여 검사를 시행한다. 하지만 몸이 불편하거나 수술직후의 환자들의 경우에는 이러한 자세를 취하는 것이 힘들기 때문에 견관절이 잘 묘출되는 영상을 얻기가 어렵다. 이러한 어려움을 개선하면서 견관절이 잘 나타나는 영상을 얻을 수 있는 방법을 모색해 보고자 누운 자세에서 몸의 한쪽면을 거상시키는 자세를 취하는 대신에 누운 자세를 취한상태에서 X-선관의 각도를 Medio-Lateral(몸의 중심에서 바깥쪽으로) 방향으로 변화시켜 영상을 획득하였다. 총 15명(남: 9, 여: 6)을 대상으로 검사를 시행하였으며 획득한 영상은 Picture archiving and communication system(PACS) 모니터에서 전문가 4명(정형외과 전문의 2명, 방사선과 전문의 2명)이 각각 독립적으로 평가하여 점수를 부여하였다. 그 결과, X-선관의 각도를 Medio-Lateral로 변화시킨 정도가 $25^{\circ}$인 영상에서는 상완골두와 견갑골이 겹쳐보였으며, $30^{\circ}$와 $35^{\circ}$인 영상에서는 상완골두와 견갑골이 분리되어 보였고, $40^{\circ}$인 영상에서는 상완골두와 견갑골이 분리되어 보였으나 영상이 많이 왜곡되어 나타났다. 영상의 평가점수는 각각 $25^{\circ}1.20{\pm}0.414$ (평균$\pm$표준편차), $30^{\circ}2.47{\pm}0.516$, $35^{\circ}2.87{\pm}0.352$, $40^{\circ}2.27{\pm}0.458$로 나타났고 통계적으로 유의한 차이를 나타냈다(p < 0.05). 왜곡의 정도는 $30^{\circ}$에서 적게 나타났고 $40^{\circ}$에서 심하게 나타났다. 누운 자세를 취한상태에서 X선관의 각도를 Medio-Lateral 방향으로 $30{\sim}35^{\circ}$ 주는 경우 가장 좋은 견관절 영상을 얻을 수 있었으나 이 방법이 Shoulder Oblique법보다 상완골두의 왜곡을 더 발생시키는 것도 확인할 수 있었다. 하지만 이 방법은 몸이 불편한 환자들의 견관절을 검사하는데 매우 유용하게 사용할 수 있고 특히 응급환자의 경우 환자의 체위변화 없이 사용가능하다는 장점이 있다. 뿐만 아니라 체위변화가 없는 이 촬영법은 환자의 추적 검사 시에도 최적의 동일 X선관의 각도를 적용하기 때문에 이전검사와 거의 같은 영상을 얻을 수 있어서 영상의 비교에도 유용할 것으로 사료된다.