• 한국정밀공학회지
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• 제21권12호
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• pp.100-108
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• 2004

In reverse engineering, data acquisition methodology can generally be categorized into contacting and non-contacting types. Recently, researches on hybrid or sensor fusion of the two types have been increasing. In addition, efficient construction of a geometric model from the measurement data is required, where considerable amount of user interaction to classify and localize regions of interest is inevitable. Our research focuses on the classification of each bounded region into a pre-defined feature shape fer a hybrid measuring scheme, where the overall procedures are described as fellows. Firstly, the physical model is digitized by a non-contacting laser scanner which rapidly provides cloud-of-points data. Secondly, the overall digitized data are approximated to a z-map model. Each bounding curve of a region of interest (featured area) can be 1.aced out based on our previous research. Then each confined area is systematically classified into one of the pre-defined feature types such as floor, wall, strip or volume, followed by a more accurate measuring step via a contacting probe. Assigned to each feature is a specific digitizing path topology which may reflect its own geometric character. The research can play an important role in minimizing user interaction at the stage of digitizing path planning.

• 한국정밀공학회지
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• 제20권2호
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• pp.176-183
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• 2003

The paper presents a feature recognition and segmentation method for surface approximation in reverse engineering. Efficient digitizing plays an important role in constructing a computational surface model from a physical part-surface without its CAD model on hand. Depending on its measuring source (e.g., touch probe or structured light), each digitizing method has its own strengths and weaknesses in terms of speed and accuracy. The final goal of the research focuses on an integration of two different digitizing methods: measuring by the structured light and that by the touch probe. Gathering bulk of digitized points (j.e., cloud-of-points) by use of a laser scanning system, we construct a coarse surface model directly from the cloud-of-points, followed by the segmentation process where we utilize the z-map filleting & differencing to trace out feature boundary curves. The feature boundary curves and the approximate surface model could be inputs to further digitizing by a scanning touch probe. Finally, more accurate measuring points within the boundary curves can be obtained to construct a finer surface model.

• Journal of information and communication convergence engineering
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• 제15권1호
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• pp.14-20
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• 2017

In this paper, we discuss physical layer security techniques in downlink networks, including eavesdroppers. The main objective of using physical layer security is delivering a perfectly secure message from a transmitter to an intended receiver in the presence of passive or active eavesdroppers who are trying to wiretap the information or disturb the network stability. In downlink networks, based on the random feature of channels to terminals, opportunistic user scheduling can be exploited as an additional tool for enhancing physical layer security. We introduce user scheduling strategies and discuss the corresponding performances according to different levels of channel state information (CSI) at the base station (BS). We show that the availability of CSI of eavesdroppers significantly affects not only the beamforming strategy but also the user scheduling. Eventually, we provide intuitive information on the effect of CSI on the secrecy performance by considering three scenarios: perfect, imperfect, and absence of eavesdropper's CSI at the BS.

• The Journal of Korean Physical Therapy
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• 제14권4호
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• pp.423-440
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• 2002

The purpose of this study is to investigate the conception and developmental process of stretching in sports physical therapy. This study is to find conception of stretching, feature and effect, principles and fundamental rule, consideration of enforcement and developmental process in order to use the basic material which is very helpful in the every field and the scene of sports needing stretching. Flexibility is the ability to move muscles and joints through their full ranges of motion. Flexibility is developed by stretching. About player who insufficiency of flexibility, patient and disabled person who restrict of range of motion, older adult who reduce of flexibility, promote of flexibility for upgrading stability and efficiency of body on the based of scientific principles is completed by stretching. The method of stretching has been developed with passive stretching, CR, PNF stretching, PIC stretching, MET stretching in the order. The effects that we can get through stretching are as follows : 1. Enhance physical fitness. 2. Optimize learning, practice and performance of many types of skilled movement. 3. Increase mental and physical relaxation. 4. Promote development of body awareness. 5. Reduce risk of joint sprain or muscle strain. 6. Reduce risk of back problem. 7 Reduce muscular soreness. 8. Reduce the severity of painful menstruation for female athletes. 9. Reduce muscular tension. 10. Advance recognition of body.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권10호
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• pp.1751-1768
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• 2011

Falls are one of the most concerned accidents for elderly people and often result in serious physical and psychological consequences. Many researchers have studied fall detection techniques in various domain, however none released to a commercial product satisfying user requirements. We present a systematic modeling and evaluating procedure for best classification performance and then do experiments for comparing the performance of six procedures to get a statistical classifier based wrist-type fall detector to prevent dangerous consequences from falls. Even though the wrist may be the most difficult measurement location on the body to discern a fall event, the proposed feature deduction process and fall classification procedures shows positive results by using data sets of fall and general activity as two classes.

• 대한원격탐사학회지
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• 제20권3호
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• pp.207-214
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• 2004

This study focused on providing a methodology to utilize temporal information obtained from remotely sensed data for monitoring a wide variety of targets on the earth's surface. Generally, a methodology in understanding of global changes is composed of mapping, quantifying, and monitoring changes in the physical characteristics of land cover. The selected processing and analysis technique affects the quality of the obtained information. In this research, feature extraction methodology is proposed based on segmentation. It requires a series of processing of multitempotal images: preprocessing of geometric and radiometric correction, image subtraction/thresholding technique, and segmentation/thresholding. It results in the mapping of the change-detected areas. Here, the appropriate methods are studied for each step and especially, in segmentation process, a method to delineate the exact boundaries of features is investigated in multiresolution framework to reduce computational complexity for multitemporal images of large size.

• 말소리와 음성과학
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• 제8권2호
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• pp.17-22
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• 2016

This paper devises a model to diagnose physical fatigue using speech features. This paper presents a machine learning method through an SVM algorithm using the various feature parameters. The parameters used include the significant speech parameters, questionnaire responses, and bio-signal parameters obtained before and after the experiment imposing the fatigue. The results showed that performance rates of 95%, 100%, and 90%, respectively, were observed from the proposed model using three types of the parameters relevant to the fatigue. These results suggest that the method proposed in this study can be used as the physical fatigue diagnostic model, and that fatigue can be easily diagnosed by speech technology.

• Journal of Biosystems Engineering
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• 제24권1호
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• pp.1-8
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• 1999

In this study, the physical properties of live garlic at the harvesting season were measured and analyzed as a fundamental study for developing a garlic harvester. A universal testing machine and a machine vision system were used to obtain mechanical and morphological properties of live garlic, respectively. The moisture content of live garlic at the harvesting season was 50% higher than that of dried garlic. The root of live garlic elongated greatly with respect to the applied tensile force. The relationship between the projected area and the weight of a bulb of live garlic was linear. Such a feature would be applied to develop an effective garlic harvester or garlic quality grader. Other useful physical properties of live garlic at the harvesting season were represented in the study.

• Advances in nano research
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• 제13권3호
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• pp.269-284
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• 2022

Nanomachines can be pretty helpful in curing diseases. Nanomototors, thanks to their self-propelled feature, are one of the best structures to be utilized as drug delivery devices. These devices have been employed in biomedical application as they can improve the efficiency of drug delivery. In this study stability of a designed nanomotor in the bloodstream is investigated when the physical activities have been done considering the physical activities. Sports training, as well as exercise enhance the bloodstream, and this factor can significantly impact the drug-delivery quality. The mathematical simulation of nanomotor movement in the condition of the sports is done based on the mechanical sciences, and the impact of various essential parameters is discussed in detail.

• 정신신체의학
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• 제4권2호
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• pp.198-206
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• 1996

To assess premenstrual changes in adolescents, a self rating retrospective premenstrual assessment from(PAF) and a prospective daily rating form(DRF) were administered to 230 high school students who reported premenstrual changes. The results were as follows 1) According to typological categories of retrospective premenstrual assessment form, the most commonly reported changes in mood and behavior were major depressive syndrome(40.0%), impulsive syndrome(20.9%). Especially among the subtype of depressive syndrome, hostility feature and withdrawal feature were most frequent. The most commonly reported changes in physical condition were general discomfort(73.5%), fatigue(33.9%). 50.9% of all subjects reported impaired social function. 2) 41.2% of the subjects who met the criteria for typological categories of retrospective premenstrual assessment form were confirmed by prospective daily rating form. 3) According to different criteria of percent change method of assessing symptom change, 38.7% of all subjects had at least one mild premenstrual change and 23.5% had at least one moderate premenstrual change. 4) Using prospective daily rating form, overall psychological changes were confirmed more frequently than physical changes. Of the mild premenstrual changes, 'low energy, tired & weak', 'less or impaired work' were most common changes. Of the moderate premenstrual changes, the most common change was 'low energy, tired & weak'. 5) As attitude toward menstruation, 44.9% of the subjects with confirmed premenstrual changes had more negative attitude(disgusted) toward menstruation. 6) The subjects with confirmed mild or moderate premenstrual changes had only dysphoric mood changes or both physical and dysphoric mood changes, but did not have only physical changes. These results suggest that retrospective reports of premenstrual changes were partially confirmed by daily prospective ratings. A substantial number of adolescents appeared to experience premenstrual changes, and the most common confimed premenstrual change of mild or moderate severity was 'low energy, tired and weak'.