• 한국군사과학기술학회지
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• 제17권3호
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• pp.296-303
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• 2014

This paper describes the simplified simulation method of the wire-guided underwater test body with natural supercavitation. In this paper, the simulation based model of the wire-guided underwater body with natural supercavitation is proposed by using preceding research and commercial flow-analysis software. By using the model, the 1-dimensional wire-guided body motion in natural supercavitation can be solved very fast with reliability. The suggested model is validated by the comparison of simulation results with experimental data.

• Journal of Korean Biological Nursing Science
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• 제8권1호
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• pp.15-21
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• 2006

Purpose: The purpose of this study was to test the effect of pleasant guided imagery on the vital signs of elderly. Method: The subjects of this study were 15 elderly women. Collecting data were blood pressure, pulse rate, body temperature, the degree of imagination and relaxation. Data were analyzed using SPSS PC+ program with percentage, paired t-test. Result: After practicing of pleasant guided imagery, systolic blood pressure and pulse rate were significantly lowered than before practicing of pleasant guided imagery. After practicing of pleasant guided imagery, Diastolic blood pressure and body temperature were not significantly changed. After practicing of pleasant guided imagery, the degree of imagination and relaxation were relatively higher in old women. Conclusion: Pleasant guided imagery can be used for elderly patients with hypertension. And it can be used to promote relaxation of elderly with stress.

• Journal of Periodontal and Implant Science
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• 제32권3호
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• pp.475-488
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• 2002

The purpose of this study is to evaluate histologically the resorption and tissue response of various resorbable collagen membranes used for guided tissue regeneration and guided bone regeneration, using a subcutaneous model on the dorsal surface of the rat. In this study, 10 Sprague-Dawley male rats (mean BW 150gm) were used and the commercially available materials included acellular dermal matrix allograft, porcine collagen membrane, freeze-dried bovine dura mater. Animals were sacrificed at 2,6 and 8 weeks after implantation of various resorbable collagen membranes. Specimens were prepared with Hematoxylin-Eosin stain for light microscopic evaluation. The results of this study were as follows: 1. Resorption : Inner portion of porcine collagen membrane was resorbed a lot at 6 weeks, but its function was being kept for infiltration of another tissues were not observed. Freeze-dried bovine dura mater and acellular dermal allograft were rarely resorbed and kept their structure of outer portion for 8 weeks. 2. Inflammatory reactions : Inflammatory reaction was so mild and foreign body reaction didn't happen in all of resorbable collagen membranes, which showed their biocompatibility. 3. In all of resorbable collagen membranes, multinuclcated giant cells by foreign body reactions were not observed. Barrier membranes have to maintain their function for 4-6 weeks in guided tissue regeneration and at least 8 weeks in guided bone regeneration. According to present study, we can find all of the resorbable collagen membranes kept their function and structure for 8 weeks and were rarely resorbed. Foreign body reaction didn't happen and inflammatory reaction was so mild histologically. Therefore, all of collagen membranes used in this experiment were considered proper resorbable membranes for guided tissue regeneration and guided bone regeneration.

• 한국정밀공학회지
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• 제13권2호
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• pp.176-184
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• 1996

The paper describes the vibration characteristics of the mechanical system consisting of a uniform Timoshenko beam with a guided mass and an elastic spring support. The free end of the beam does not rotate and the spring attatched to the guided mass is elastically restrained against translation. The guided mass is assumed to be a rigid body having a finite size, but not a mass point as it has been assumed so far. The effect of magnitudes, rotary inertia and the size of the guided mass on the vibration characteristics is fully investigated by the numerical simulation using FEM and experiment. In order to verify the eigenvalue sensitivity for considered system, comparison exact solutions with FEM is conducted, and a good agreement between two solutions is also highlighted.

• 한국의학물리학회지:의학물리
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• 제32권2호
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• pp.40-49
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• 2021

Purpose: This study aimed to develop a surface-guided radiosurgery system customized for a neurosurgery clinic that could be used as an auxiliary system for improving the accuracy, monitoring the movements of patients while performing hypofractionated radiosurgery, and minimizing the geometric misses. Methods: RGB-D cameras were installed in the treatment room and a monitoring system was constructed to perform a three-dimensional (3D) scan of the body surface of the patient and to express it as a point cloud. This could be used to confirm the exact position of the body of the patient and monitor their movements during radiosurgery. The image from the system was matched with the computed tomography (CT) image, and the positional accuracy was compared and analyzed in relation to the existing system to evaluate the accuracy of the setup. Results: The user interface was configured to register the patient and display the setup image to position the setup location by matching the 3D points on the body of the patient with the CT image. The error rate for the position difference was within 1-mm distance (min, -0.21 mm; max, 0.63 mm). Compared with the existing system, the differences were found to be as follows: x=0.08 mm, y=0.13 mm, and z=0.26 mm. Conclusions: We developed a surface-guided repositioning and monitoring system that can be customized and applied in a radiation surgery environment with an existing linear accelerator. It was confirmed that this system could be easily applied for accurate patient repositioning and inter-treatment motion monitoring.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권7호
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• pp.313-317
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• 2001

This paper proposed a fuzzy logic cross coupled controller which can enhance the path tracking performance of optically guided AGV(Automated Guided Vehicle). The AGV follows the guide path, it cannot be avoid the deviation from the path due to the inevitable error and the deviation must be corrected. Optically guided AGV used in industrial area is controlled by On-Off controller generally, the experimental AGV has three optical sensors in front body. In this structure, we could not know the leaving distance accurately and steering angle from the guided line, so AGV could not be controlled properly with conventional controller in the case of increasing or decreasing velocity. If we mount additional sensors the AGV, we could know the leaving distance and steering angle from the guided line and proper error compensating methode can be applied. But because cost of sensors are high, the cost of total system is increasing. So, in this paper, to improve the tracking performance of AGV which has the minimum number of sensors and fuzzy logic cross coupled controller is proposed. Some simulations and experimental results are presented to illustrate the performance of the proposed controller.

• 대한방사선치료학회지
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• 제17권2호
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• pp.95-103
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• 2005

목 적 : 정위적 방사선수술 시 환자의 set up을 정확히 하며 정확한 종양의 위치를 찾아내어 확인하고 평가하는 것은 치료성적을 좌우하는데 매우 중요한 일이다. 특히 체부에 종양이 있는 환자의 경우 호흡 등에 의한 종양의 움직임으로 인하여 정확한 종양위치에 치료를 시행하는데는 많은 어려움이 따르는데 이러한 문제점들을 보완하기 위하여 본원에서 자체 제작한 고정용구를 이용하여 환자의 움직임을 최소화시키고 또한 환자의 호흡에 따른 CT 영상을 획득하였으며 이를 통하여 Image Guided Radiosurgery를 시행함으로써 방사선수술의 정확성을 높이고자 한다. 대상 및 방법 : 본원에서 자체 개발한 Body SRS용 Vacuum cushion (BSRS Vacuum cushion)을 이용하여 환자의 호흡에 따른 CT영상을 세 번에 걸쳐 획득한 후 (shallow, inhalation, exhalation) RTP computer상에서 이들을 fusion하며 Global GTV (PTVsim target)를 찾아내어 가장 적합한 수술계획을 수립한다. 수술 전 위와 같은 방법으로 Global GTV (PTVtx target)를 찾아내어 Posterior Pb ball을 기준으로 처음 수립된 수술계획의 PTVsim target에 PTVtx target을 조합시켜 비교함으로써 환자의 New PTVcenter를 찾아내고 수술을 시행한 후 EPID 영상을 획득하며 환자의 움직임 여부와 정확한 방사선수술이 시행되었는지 확인한다. 결 과 : 환자의 호흡에 따른 target volume의 위치는 Inhalation에서 cranio-caudal 방향으로 최대 10 mm까지 변화되었으며 체적은 Shallow respiration 일 때 $0.93cm^3$로 가장 크게 변화되는 것을 확인할 수 있었다. 수술 전후의 CT 영상을 통하여 New PTVcenter target volume의 위치에 따른 치료 정확성을 DVH로 분석한 결과 100% 전후의 치료 선량이 조사되는 것을 확인할 수 있었다. 결 론 : 체부의 SRS는 환자의 호흡에 따른 종양의 움직임 때문에 환자의 적용에는 회의적인 입장이었으나 고정기구 개발과 IGRT를 접목함으로써 보다 정확한 방사선수술을 시행할 수 있었고 이를 통하여 많은 BSRS에 적용할 수 있을 것으로 사료된다.

• 한국생산제조학회지
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• 제7권3호
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• pp.37-42
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• 1998

The important parts of the developing AGV model are the fabrication of each part and the design technology of body frame. In the present day, design of the body frame depends on the experience of the industrial place. the systematic data need for the optimal design of the frame for the case of model change. In this study, the strength of the early stage AGV(Automatic guided vehicle) is examined with the 3-dimensional finite elemnt method. In order to verify the finite element results, the computed results are compared with the experimental data from the strain-gage output. A New model was designed by rmoving some parts of the early staged(roughyly designed) model and choosing the thickness change of the rectangular-pipes.

• 산업경영시스템학회지
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• 제37권4호
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• pp.269-273
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• 2014

The objective of this study is to safety assessment for human body on the guided missile combustion products. This study is to verify the safety assessment when operating the interior missile ejection take on verify the safety of the human body. During the missile ejection of combustion products, this study is analyzed combustion products. Result are accepted NIOSH and KOSHA of the safe guideline, and 6 exposure gas to the specified values 42% (CO), 22% ($CO_2$), not detected (others) are within minimal exposures criteria of the reference value respectively. Contribution of these results supported that interior missile ejection during combustion products may have been ensured human safely. Therefore, the future for improving the environmental safety of the shooting projectile steel plate round, dust collector, ventilation and other facilities is to improve environmental safety and efficient renovated design needed by target focused areas.

• 한국의학물리학회지:의학물리
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• 제13권4호
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• pp.218-223
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• 2002

두개외 병소 즉, 척추 등에 발생한 종양 혹은 혈관기형 등의 병소에 대해 침습적 수술이 불가한 경우 정위적 방사선 수술이 임상에서 시도되고 있다. 본 연구는 실험적으로 팬텀에 대해 척추 정위 방사선수술을 시행하고 결과 분석을 통하여 두개외 수술 목표점에 대한 방사선수술 위치 정확도를 평가하고자 한다. 이 실험을 위하여 팬텀을 특별히 고안하였으며 수술실에서 방사선 수술 목표점의 위치는 광학적 추적 장치를 이용하여 결정하였고 3 mm 미세다엽시준기(mMLC; mcro Multi-Leaf Collimator)를 사용하여 시술하였다. 팬텀의 목표점에 대한 방사선수술 오차는 $\pm$1 mm 이내였으며 분할방사선 수술 경우도 $\pm$1 mm 이내였다. 결과적으로 광학적 위치추적 장치를 이용한 두개외 목표점의 방사선 수술은 매우 정확하고 유용한 방법으로 판단된다.