• Korean Journal of Applied Biomechanics
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• 제17권2호
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• pp.157-166
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• 2007

This study was to compare the major kinematic factors between the success and failure group on performing the back somersault motion in floor exercise. Three gymnasts(height : $167.3{\pm}2.88cm$, age : $22.0{\pm}1.0years$, body weight : $64.4{\pm}2.3kg$) were participated in this study. The kinematic data was recorded at 60Hz with four digital video camera. Two successful motions and failure motions for each subject were selected for three dimensional analysis. 1. Success Trail It was appear that success trail was larger than failure group in projection velocity, but success trail was smaller than failure trail in projection angle. Also it was appear that success trail was longer than failure group in the time required. Hand segment velocity and maximum velocity in success trail were larger than those in failure trail, and this result was increasing the projection velocity and finally increasing the vertical height of center of mass. At the take-off(event 2), flection amount of hip and knee joint angle was contributed to the optimal condition for the take-off and at the peak point, hip and knee joint angle was maximum flexed for reducing the moment of inertia. Also in this point, upper extremities of success trail extended more than those of failure trail. in this base, success trail in upward phase(p3) 2. Failure Trail It was appear that failure trail was smaller than success trail in projection velocity, but failure trail was larger than success trail in projection angle. Also it was appear that failure trail was more short than success trail in the time required. Hand segment velocity and maximum velocity in failure trail were smaller than those in success trail, and this result was reducing the projection velocity and finally reducing the vertical high of center of mass. At the take-off(event 2), flection amount of hip and knee joint angle wasn't contributed to the optimal condition for the take-off and at the peak point, hip and knee joint angle wasn't maximum flexed for reducing the moment of inertia. Also in this point, upper extremities of failure trail didn't extended more than those of success trail.

• Progress in Medical Physics
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• 제14권3호
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• pp.167-174
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• 2003

In the radiation treatment planning (RTP) process, especially for stereotactic radiosurgery (SRS), knowing the exact volume and shape and the precise position of a lesion is very important. Sometimes X-ray projection images, such as angiograms, become the best choice for lesion identification. However, while the exact target position can be acquired by bi-projection images, 3D target reconstruction from bi-projection images is considered to be impossible. The aim of this study was to reconstruct the 3D target volume from multiple projection images. It was assumed that we knew the exact target position in advance, and all processes were performed in Target Coordinates, where the origin was the center of the target. We used six projections: two projections were used to make a Reconstruction Box and four projections were for image acquisition. The Reconstruction Box was made up of voxels of 3D matrices. Projection images were transformed into 3D in this virtual box using a geometric back-projection method. The resolution and the accuracy of the reconstructed target volume were dependent on the target size. An algorithm was applied to an ellipsoid model and a horseshoe-shaped model. Projection images were created geometrically using C program language, and reconstruction was also performed using C program language and Matlab ver. 6(The Mathwork Inc., USA). For the ellipsoid model, the reconstructed volume was slightly overestimated, but the target shape and position proved to be correct. For the horseshoe-shaped model, reconstructed volume was somewhat different from the original target model, but there was a considerable improvement in determining the target volume.

• Journal of Korea Entertainment Industry Association
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• 제15권4호
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• pp.45-54
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• 2021

Jeong Sun-Ah built up her performance career for twenty years with bold and energetic acting and solidified her status as a leading actress of Korean musical since her debut. To benefit from the value of her experience this study performed an in-depth interview with her, applying the Theory of "Projection" and "Back-projection", which are the psychological principles of acting, and derived "acting(entering the roles)" and "de-acting(leaving the roles)" techniques. As result, Her acting mechanism involved emptying her ego, embodying a persona by projecting the role created by intensive exploration of materials like previous performance, film of the same title, original novel, and script, and then getting the ego back by back-projecting through dynamic activities such as overseas travel and dance. She pre-studied the roles by physically visiting sites that are important to the characters. She was unique in that she pursued a difference by changing vocal trainers for each musical production and undertook more intense physical training than vocal practice to achieve powerful singing performance. In most of her works (75%), she suffered from aftereffects such as depression, narcissism, hysteria, and insomnia due to disorder caused by breaking away from the roles. However, she relied on self-help and alternatives are needed in the future such as reinforcement of expert counselling. Jeong Sun-Ah appeared on an average of 1.6 productions per year, practiced for an average of 1.7 months, and performed for an average of 3.9 months with an average of 100 days of break between productions. Her performance record from this research demonstrates her constant preparation and passion, as well as the know-how of reserving and distributing energy. So, it has a valuable implications for acting education and self-management of actors and actress.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제28권9호
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• pp.723-732
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• 2017

Simplified factorizing-technique to improve the efficiency on computational procedure and the complexity of the conventional back-projection algorithm, which is used to reconstruct airborne FMCW-SAR image, is suggested, and the reconstruction process of SAR image by this simplified factorizing-technique are presented in this paper. This technique can be efficiently applied to airborne FMCW-SAR having a relatively narrow beamwidth and long synthetic aperture length, and its basic rationale is to exclude the data that has low level of contribution during computational procedure. Using the raw data of practical airborne FMCW-SAR system, performances of this proposed technique such as SAR image quality and processing time were compared and analyzed.

• Journal of KIISE:Software and Applications
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• 제34권3호
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• pp.266-274
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• 2007

This paper proposes a new reconstruction method of high-resolution facial image from a low-resolution facial image based on top-down machine learning and recursive error back-projection. A face is represented by a linear combination of prototypes of shape and that of texture. With the shape and texture information of each pixel in a given low-resolution facial image, we can estimate optimal coefficients for a linear combination of prototypes of shape and those that of texture by solving least square minimizations. Then high-resolution facial image can be obtained by using the optimal coefficients for linear combination of the high-resolution prototypes. In addition, a recursive error back-projection procedure is applied to improve the reconstruction accuracy of high-resolution facial image. The encouraging results of the proposed method show that our method can be used to improve the performance of the face recognition by applying our method to reconstruct high-resolution facial images from low-resolution images captured at a distance.

• Journal of the Institute of Electronics Engineers of Korea SP
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• 제48권1호
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• pp.33-45
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• 2011

In this paper, we present a method for extracting video objects efficiently by using the modified graph cut algorithm based on contour information. First, we extract objects at the first frame by an automatic object extraction algorithm or the user interaction. To estimate the objects' contours at the current frame, motion information of objects' contour in the previous frame is analyzed. Block-based histogram back-projection is conducted along the estimated contour point. Each color model of objects and background can be generated from back-projection images. The probabilities of links between neighboring pixels are decided by the logarithmic based distance transform map obtained from the estimated contour image. Energy of the graph is defined by predefined color models and logarithmic distance transform map. Finally, the object is extracted by minimizing the energy. Experimental results of various test images show that our algorithm works more accurately than other methods.

• Radiation Oncology Journal
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• 제16권1호
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• pp.81-86
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• 1998

Purpose : To generate the axial, coronal and sagittal images from conventional simulation images, as a preliminary study of broad-beam simulator CT. Methods and Materials : Volumetric filtered back-projection was performed using 90 sheets of films from conventional simulator for every $4^{\circ}$ gantry angle. Two mAs exposure condition for 120kvp beam qualify at SFD 140cm was given to each film. Outside the silhouette portion was removed and scatter component was deconvolved before back-projection. Results : The axial, the sagittal and the coronal images with same spatial resolutions over all direction could be obtained. But image quality was very poor. Conclusion : CT images could be obtained using broad-beam. Scatter deconvolution technique was effective for this reconstruction. The fact that same spatial resolutions over all direction tells us the possibility of application of this technique to DRR or Simulator-CT. But the quality of image should be improved for clinical application practically.

• Korean Journal of Remote Sensing
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• 제39권2호
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• pp.157-168
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• 2023

Image segmentation and supervised classification techniques are widely used to monitor the ground surface using high-resolution remote sensing images. In order to classify various objects, a process of defining a class corresponding to each object and selecting samples belonging to each class is required. Existing methods for extracting class samples should select a sufficient number of samples having similar intensity characteristics for each class. This process depends on the user's visual identification and takes a lot of time. Representative samples of the class extracted are likely to vary depending on the user, and as a result, the classification performance is greatly affected by the class sample extraction result. In this study, we propose an image classification technique that minimizes user intervention when extracting class samples by applying the histogram back-projection technique and has consistent intensity characteristics of samples belonging to classes. The proposed classification technique using histogram back-projection showed improved classification accuracy in both the experiment using hue subchannels of the hue saturation value transformed image from Compact Advanced Satellite 500-1 imagery and the experiment using the original image compared to the technique that did not use histogram back-projection.

• The Research Journal of the Costume Culture
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• 제14권2호
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• pp.271-285
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• 2006

The purpose of this study was to develop a new basic skirt pattern for 4 lower body types of Plus-sized women. To reduce a time and economic loss about putting it on, This study applied a 3D sample module in the course to develop a basic skirt pattern which is fit, functional and beautiful. A data analysis used the SPSS 11.0 statistics program. To verify the difference, This study used the variance analysis and Duncan's test for the postmortem verification. The result was as follows. To reflect a feature according to an abdomen projection and hip projection, we added the maximum hip circumference to the waist circumference and hip circumference for necessary for a skirt draft item. The front hip circumference sets to the H/4+1cm(ease)+D/4. The back hip circumference set to the H/4+0.5cm(ease)+D/4. The D is the hip circumference in the maximum hip circumference to subtract. The front waist circumference sets to the W/4+0.5cm(ease)+0.5cm(A front and back's difference)+D/4. The back waist circumference sets to the W/4+0.5cm(ease)-0.5cm(A front and back's difference)-D/4. Compare with 4 lower body types of Plus-sized Women, A type 2 and type 4 abdomen projections are bigger. We raised a front waistline of skirt pattern to a 0.3cm upside, and take about 1.3cm down the skirt length from a developed skirt pattern. Consequently, the appearance of a front skirt length was improved with a side skirt length.

• Journal of Forest and Environmental Science
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• 제39권4호
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• pp.203-212
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• 2023

Directional felling is a felling method practised by the Forestry Department in Peninsular Malaysia as prescribed in Field Work Manual (1997) for Selective Management Systems (SMS) in forest harvesting. Determining the direction of tree felling in Peninsular Malaysia is conducted during the pre-felling inventory 1 to 2 years before the felling operation. This study aimed to predict and analyze the direction of tree felling using the vector-based path distance back link method in Geographic Information Systems (GIS) and compare it with the felling direction observed on the ground. The study area is at Balah Forest Reserve, Kelantan, Peninsular Malaysia. A Path Distance Back Link (spatial analyst) function in ArcGIS Pro 3.0 was used in predicting tree felling direction. Meanwhile, a binary classification was used to compare the felling direction estimated using GIS and the tree felling direction observed on the ground. Results revealed that 61.3% of 31 trees predicted using the vector-based projection method were similar to the felling direction observed on the ground. It is important to note that dynamic changes of natural constraints might occur in the middle of tree felling operation, such as weather problems, wind speed, and unpredicted tree falling direction.