• Physical Therapy Korea
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• v.7 no.4
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• pp.39-46
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• 2000

본 연구는 강직성 편측 뇌성마비 환자의 보행 기시(gait initiation)의 특성을 파악하고, 동적 단하지 보조기(dynamic ankle foot orthosis : DAFO)가 이런 환자들의 보행 기시에 미치는 영향을 알아보기 위하여 실시하였다. 연구대상자는 19세 선천성 강직성 우측 뇌성마비를 가진 여자 대학생이었다. 연구대상자는 4개의 다른 보행 기시 조건에서 각 조건당 7회의 보행 기시를 하였는데, 각각의 보행 기시 조건은: 1) 보조기 없이 좌측 하지로 보행 기시; 2) 우측 하지 보조기 착용 상태에서 좌측하지로 보행 기시; 3) 보조기 없이 우측 하지로 보행 기시; 4) 우측 하지 보조기 착용 상태에서 우측 하지로 보행 기시였다. 두개의 힘 판(force plate) 위에서 본인이 선택한 가장 편안한 방법과 속도로 2 m를 걷도록 하였다. 연구대상자가 보행 기시를 하는 동안 양쪽 가자미근과 앞정강근에 부착된 4개의 표면 전극으로부터 근 전도 신호와 보행 기시를 하는 연구 대상의 양 발 아래 놓인 두개의 힘 판의 자료를 분석하여 체중(body weight : BW)으로 정량화 하였다. 실험결과는 각 조건마다 7회 실시된 측정값들의 평균을 이용하였다. 본 사전연구의 결과는 다음과 같다. 1. 보행 기시 전 양다리로 선 상태에서 환측보다 건측으로 많은 체중지지를 하였으나(환측 42.57%BW, 건측 58.03%BW) 보조기의 착용이 환측으로의 체중지지를 향상시켰다(환측 44.46%BW, 건측 55.54%BW). 2. 보행 기시 중 가자미근과 앞정강근의 동시수축(coactivation)이 계속되었는데 이러한 양상은 보조기의 착용 유무에 따라 크게 달라지지 않았다. 3. 힘 판에서 들어온 지면 반발력(ground reaction force)의 수직 분력(vertical element, Fz)과 전후 분력(anterior-posterior element, Fx)을 분석한 결과, 건측 다리로 보행 기시를 할 때 보조기 착용은 가속을 촉진시켜 역학적으로 유리하였다. 이상의 연구 결과는 보조기의 착용이 건측 다리로 보행 기시를 할 때 미치는 신경학적, 역학적 장점들에 대한 구체적 연구의 필요성 및 근거를 제시하고, 환자들의 보행훈련 접근에 보다 효율적인 보행방법을 소개하는데 이용될 수 있다.

• Journal of the Korea Concrete Institute
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• v.15 no.3
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• pp.454-461
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• 2003

This study addressed a procedure to carry out an experimental study on a behavior of simple and continuous concrete beams. For this purpose, sample concrete beams were fabricated and sensors for the measurement of strains and deflections were attached both on the surface of the beams and inside them. Two types of sensors were used to measure strains associated with loading: electric resistance strain sensors and fiber optic sensors. Displacement gauges were also attached on the bottoms of beams to investigate the behavior of beams more rationally. The behavior of the beams was then evaluated throughout the results measured from different sensors while they were subject to steady loading up to failure. From results of this study, it was found that concurrent use of sensors and displacement gauges is helpful in investigating the behavior of concrete beams more effectively. Especially, combined-type strain sensors specifically fabricated in this experiment were found not to be affected by the occurrence of cracks so significantly and to be very effective in monitoring strains of concrete structure. It was also observed that beams show nonlinear force-displacement relationship and reinforcing bars take charge of resisting the external force once cracks occur in concrete beams.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.229-235
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• 2010

In this study, fire resistance performance of high strength concrete specimen with fireproof gypsum board was investigated for possible use in upgrading fire-resistant performance of the existing building and repair of fire damaged structures. Fire test of eight identical high strength concrete columns were carried out for 180 minutes in accordance with ISO-834. The temperature distributions in longitudinal reinforcement and concrete temperature at various depths were recorded. The fireproof performance of gypsum board and explosive spalling of concrete were observed. The specimens with 15 mm thick twoply fireproof gypsum board spalled after gypsum board crumbled regardless of fastening methods. However, when the thickness of fireproof gypsum board was more than 30 mm, it was possible to prevent the explosive spalling and control the rebar temperature. Although the effect of cover thickness could not be compared because the explosive spalling occurred, there seemed to be no difference in insulation efficiency.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.2
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• pp.245-252
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• 2020

Unexpected equipment defects can cause a huge economic losses in the society at large. Although condition monitoring can provide solutions, the signal processing algorithms must be developed to predict mechanical failures using data acquired from various sensors attached to the equipment. The signal processing algorithms used in a condition monitoring requires high computing efficiency and resolution. To improve condition monitoring on a wireless sensor network(WSN), data visualization can maximize the expressions of the data characteristics. Thus, this paper proposes the extraction of visual feature from temperature data over time using condition monitoring based on a WSN to identify environmental conditions of equipment in a large-scale infrastructure. Our results show that time-frequency analysis can visually track temperature changes over time and extract the characteristics of temperature data changes.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.3
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• pp.244-251
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• 2015

The paper evaluates the effect of the physical property, fineness modulus (FM) and replacement ratio of crushed sand on the characteristics of concrete. This is intended to use crushed sand from Daegu-Kyungbuk region as the fine aggregate of concrete. The experimental result indicates that the replacement ratio of crushed sand needs to be less than 50% to satisfy the mixed gradation of both natural and crushed sand when their FMs are 2.0 and 3.2, respectively. The slump of concrete with crushed sand increased as the replacement ratio of crushed sand increased, while the workability of concrete with the replacement ratio of more than 75% was significantly reduced. The air content and bleeding rate of concrete was reduced as the replacement ratio increased. Furthermore, due to the enhancement of the concrete adhesive regardless of the FM of crushed sand, compressive strength of concrete tended to improve as the replacement ratio increased.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.12
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• pp.1058-1063
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• 2015

In this article, we propose a near field microwave scanning probe structure in which two short conducting rods are attached to the center of the ridged(H-type) aperture, thereby reducing significantly the beam spot area while maintaining the high transmission efficiency through the output coupling H-type(ridged) aperture. Here the two short parallel conducting rods seem to play an important role of concentrating the transmitted electromagnetic energy through the H-type aperture and so reducing the beam area for high resolution. For validation of the proposed theory, the near field waveguide probe is fabricated according to the simulated results and its return loss characteristics versus frequencies are measured. The comparison between theory and experiment is seen to be in good agreements.

• Journal of Aquaculture
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• v.16 no.4
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• pp.223-228
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• 2003

An exfoliation, the detachment of juvenile abalones from a culture substrate, is essential for selection and population density control in abalone culture. Physical instruments and anesthetics are currently available for the exfoliation but the latter is regarded as more effective in reducing physical damage to the animals. In the present study, urea ($Co(NH_2)_2$), a chemical fertilizer, was selected as a anesthetic, and its optimal concentration and sea water temperature for exfoliation of Haliotis discus were determined in order to develop an exfoliation technique which is more economical and effective. A 97% cumulated exfoliation rate was observed within 3 min at all temperatures observed when the concentration rate of urea was 9∼15%. This range of urea concentration can be ideal for both exfoliation and recovery. Also it was found that the higher concentration of urea and temperature the higher exfoliation rate, however, these conditions reduced the recovery rates of the animals tested. These results could indicate that urea is a good tool for exfoliation of various species of young abalones, and urea could substitute for all techniques and anesthetics methods currently available for abalone exfoliation.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.613-616
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• 2008

This study is about appling non-exposure waterproofing method which combines the Cement Polymer Modified Waterproof Membrane coating and Selfadhesive Rubberized Asphalt sheet to the Roof Structure, Because there are a lot of problems in previous methods. So We had the performance tests using waterproofing method which combines two materials, and we analyzed the results. This study showed us very important results. We had bond strength test and tensile test under high, normal and low temperature, and the results were successful. And we also tested for coping with crack and movement. We found that tested materials were safe in those conditions. I think that Non-Exposure waterproofing method which combines the Cement Polymer Modified Waterproof Membrane coating and Selfadhesive Rubberized Asphalt sheet is available to concrete structure.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.2
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• pp.281-288
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• 2016

The natural moving objects are the most non-rigid shapes with randomly time-varying deformation, and its types also very diverse. Methods of non-rigid shape reconstruction have widely applied in field of movie or game industry in recent years. However, a realistic approach requires moving object to stick many beacon sets. To resolve this drawback, non-rigid shape reconstruction researches from input video without beacon sets are investigated in multimedia application fields. In this regard, our paper propose novel CPSRF(Chained Partial Stereo Rigid Factorization) algorithm that can reconstruct a non-rigid 3D shape. Our method is focused on the real-time reconstruction of non-rigid 3D shape and motion from stereo 2D video sequences per frame. And we do not constrain that the deformation of the time-varying non-rigid shape is limited by a Gaussian distribution. The experimental results show that the 3D reconstruction performance of the proposed CPSRF method is superior to that of the previous method which does not consider the random deformation of shape.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.4C
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• pp.494-504
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• 2004

The researches about gaze detection have been much developed with many applications. Most previous researches only rely on image processing algorithm, so they take much processing time and have many constraints. In our work, we implement it with a computer vision system setting a IR-LED based single camera. To detect the gaze position, we locate facial features, which is effectively performed with IR-LED based camera and SVM(Support Vector Machine). When a user gazes at a position of monitor, we can compute the 3D positions of those features based on 3D rotation and translation estimation and affine transform. Finally, the gaze position by the facial movements is computed from the normal vector of the plane determined by those computed 3D positions of features. In addition, we use a trained neural network to detect the gaze position by eye's movement. As experimental results, we can obtain the facial and eye gaze position on a monitor and the gaze position accuracy between the computed positions and the real ones is about 4.2 cm of RMS error.