• The Journal of the Acoustical Society of Korea
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• v.25 no.6
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• pp.305-311
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• 2006

In this paper the performance of a array invariant method is evaluated for source-range estimation in horizontally stratified shallow water ocean waveguide. The method has advantage of little computationally effort over existing source-localization methods. such as matched field processing or the waveguide invariant and array gain is fully exploited. And. no knowledge of the environment is required except that the received field should not be dominated by purely interference This simple and instantaneous method is applied to simulated acoustic propagation filed for testing range estimation performance. The result of range estimation according to the SNR for the underwater impulsive source with broadband spectrum is demonstrated. The spatial smoothing method is applied to suppress the effect of mutipath propagation by high frequency signal. The result of performance test for range estimation shows that the error rate is within 20% at the SNR above 10dB.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.36-41
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• 2017

The mobile mapping system first introduced at Ohio State University in 1991 is being developed in various forms as sensor technology develops. The mobile mapping system can acquire geospatial information around amoving object quickly using the information gathered using the position and attitude information of the moving object and the data from various sensors. The mobile mapping system can rapidly acquire large amounts of Geospatial information and MMS provides maximum productivity in the same measurement methods as existing GNSS and total stations. Currently, a variety of systems are being launched, mainly by foreign companies, and they are applied to the construction of geospatial information. On the other hand, the application of domestic technology development or production is insufficient. This paper provides basic data for the introduction of a mobile mapping system to geospatial information related business by conducting the status survey and feature analysis of a commercialized system focusing on the ground-based mobile mapping system. The research identified the current status and characteristics of high-priced, low-priced, indoor, and handheld mobile mapping systems based on vehicles and suggest that the recent system development trends are moving toward lowering the unit prices. The mobile mapping system is currently being developed as a platform for the application of geospatial information construction and the launch of low-cost models. The development of data processing technologies, such as automatic matching and the launch of low-cost models, are forming a basis for the application of mobile mapping systems in the field of geospatial information construction.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1015-1023
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• 2022

The Entry-Descent-Landing process of a lander involves many environmental and technical challenges. To solve these problems, recently, terrestrial relative navigation (TRN) technology has been essential for landers. TRN is a technology for estimating the position and attitude of a lander by comparing Inertial Measurement Unit (IMU) data and image data collected from a descending lander with pre-built reference data. In this paper, we present a method for generating descent dataset and extracting landmarks, which are key elements for developing TRN technologies to be used on Mars. The proposed method generates IMU data of a descending lander using a simulated Mars landing trajectory and generates descent images from high-resolution ortho-map and digital elevation map through a ray tracing technique. Landmark extraction is performed by an area-based extraction method due to the low-textured surfaces on Mars. In addition, search area reduction is carried out to improve matching accuracy and speed. The performance evaluation result for the descent dataset generation method showed that the proposed method can generate images that satisfy the imaging geometry. The performance evaluation result for the landmark extraction method showed that the proposed method ensures several meters of positioning accuracy while ensuring processing speed as fast as the feature-based methods.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.1
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• pp.99-105
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• 2014

Purpose : We compared the set-up accuracy and right-left Shoulder position variation of the manufactured device and other commercial shoulder-retractors in the head and neck radiation treatment. Materials and Methods : Six patients consist of three groups which were used three different Shoulder retractors. We measured position corrections of left and right Shoulder and the couch after the image guidance by using on board imager (OBI) for six head and neck patients who has the extended target to the neck node lower region. Results : The position variation correction of left (right) Shoulder after image guidance were $1.07{\pm}3.99mm$ ($-4.35{\pm}2.09mm$), $-0.37{\pm}5.91mm$ ($1.26{\pm}5.28mm$), $-0.63{\pm}2.44mm$ ($0.25{\pm}1.61mm$) for group A, B and C. The vertical, lateral, longitudinal position and angular corrections of the couch after image guidance were $-2.06{\pm}2.68$, $-1.11{\pm}8.15$, $0.34{\pm}3.78mm$, and $0.51{\pm}0.77$ degree for group A, $-1.18{\pm}1.82$, $-0.94{\pm}2.13$, $-0.67{\pm}1.98mm$, and $0.91{\pm}1.04$ degree for group B and $0.12{\pm}2.18$, $-0.79{\pm}2.64$, $0.79{\pm}2.64$, and $0.00{\pm}0.49$ degree for group C. Conclusion : In this preliminary study, we found the positioning accuracy of the manufactured Shoulder retractor is comparable to other commercial Shoulder retractors. We expect that the reproducibility and accuracy of the patient set-up could be improved by using the home made Shoulder retractor in the head and neck radiation treatment.

• Radiation Oncology Journal
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• v.28 no.3
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• pp.166-176
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• 2010

Purpose: To determine the appropriate prostate planning target volume (PTV) margins for 3-dimensitional (3D) conformal radiotherapy (CRT) and intensity-modulated radiation therapy (IMRT) patients treated with an endorectal balloon (ERB) under our institutional treatment condition. Materials and Methods: Patients were treated in the supine position. An ERB was inserted into the rectum with 70 cc air prior to planning a CT scan and then each treatment fraction. Electronic portal images (EPIs) and digital reconstructed radiographs (DRR) of planning CT images were used to evaluate inter-fractional patient's setup and ERB errors. To register both image sets, we developed an in-house program written in visual $C^{++}$. A new method to determine prostate PTV margins with an ERB was developed by using the common method. Results: The mean value of patient setup errors was within 1 mm in all directions. The ERB inter-fractional errors in the superior-inferior (SI) and anterior-posterior (AP) directions were larger than in the left-right (LR) direction. The calculated 1D symmetric PTV margins were 3.0 mm, 8.2 mm, and 8.5 mm for 3D CRT and 4.1 mm, 7.9 mm, and 10.3 mm for IMRT in LR, SI, and AP, respectively according to the new method including ERB random errors. Conclusion: The ERB random error contributes to the deformation of the prostate, which affects the original treatment planning. Thus, a new PTV margin method includes dose blurring effects of ERB. The correction of ERB systematic error is a prerequisite since the new method only accounts for ERB random error.

• The Journal of Korean Philosophical History
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• no.56
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• pp.151-180
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• 2018

Since the completion of the theories on human ethics and moral had been established to pursue by Confucian thinkers like Confucius and Mencius, they generally had agreed to present the basic principles for human education which every human could be the sage. In these principles for human ethics and morality there is on the premise that the knowledge about your own ethical and that the completion of the so-called act(爲) and learning(學). They had given to us that how to get a goal for the ethical and moral lives there are several academic oriented methodology will have act and learning set. In the point of achieving complete figures which act and learning for good society, there was named the sage(聖). This concept sage has two major types. One is on for the political figures that completed, and the other one is for the realm of academic side. Confucian as above mentioned the moral human being is equipped with a complete personality and political ability to make man and society perfect. Confucius has been understood as a complete human being. Yes, ideal for these two types of figures will be fulfilled in some way? They take a mystical ability to a priori or a posteriori, such as human effort can reach the sage. There are many thinkers are obvious and logical answer for this major problem in the system of confucian philosophy I have been trying. About the sage(聖), inherently natural learning(生知) occur to the position sage or knowledge (學知), can lead to there are two of the doctrine for that problem. With the study of learning and knowledge on human beings and real society the two systems concerned together. In fact, the main content of the "Analects of Confucius" we have a set of ethical and moral values not the benevolent conversation about Jin(仁) and his disciples a steady emphasis but on in praise of learning (學) for. However, at the time in Han Tang(漢唐) Han Wi(韓愈) and Wang Chung(王充), according to such thinkers the sage is already a priori determined, cannot be reached by human effort. But At the beginning of the Neo-Confucianism, Cheng I(程?) for the pioneer this Song(宋) scholars, regarding this issue could rebirth the thought that every human could be the sage through the learning as the pre-Chin(先秦) times.