• Journal of the Korea Concrete Institute
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• v.20 no.6
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• pp.705-712
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• 2008

This study carried out simulation for structural layout design for concrete structures by using the models of the ground structure method. The micro lattice truss is modeled as assemblage of a number of unit cells. The progress of analysis repeat to undergo finite element analysis to feed-back results of stress to the stiffness of each member. Through the repeated this analysis, truss model is represented to form the topological materials and the structural shape with the use of the local stress condition without mathematical optimum tools. It is successful to analyse the shape-layout problem as numerical samples on the lattice truss model.

• Journal of Korean Society of Forest Science
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• v.79 no.3
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• pp.269-277
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• 1990

In planning the disaster prevention by the erosion control facilities, it is essential to focus on the microtopography of the channel bed and the chronological process of sedimental movement in the torrential streams. For this purpose, the microtopographical change of the channel bed and the effects of the erosion control facilities in the mountain torrents were analyzed by the experimental channel and the field survey of the torrents where low-dam series had been constructed in the channel. The results of this experiment showed that the effects of construction of the low-dam series on the channel bed fixiation were the prevention of the local scouring in the experimental channel and the expansion of flow channel width and deposit space. The results are summarized as follows : 1. When the low-dam series were constructed over the whole channel bed (L'/L=1), the conning water and the sediment were seperated, simultaneously resulting in deposition of sediment and reduction of the tractive force for the running water. Therefore, the F.A. (Fluctuation area in cross-section: value was decreased to about 65% compared with that of non-work (L'/L=0). 2. The efficiencies of the low-dam series on the channel width were increased with an increment in length of working space. After the construction of low-dam series on the whole channel bed (L'/L=1), flow channel width was increased to about 1.53 times compared with that of non-work (L'/L=0). 3. It needs a deposition area to store the sediment with decrease in tractive force. The low-dam series in the experimental channel widened the deposition area about 2.10 times compared with that of non-work.

• The Journal of Korean Physical Therapy
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• v.10 no.1
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• pp.1-6
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• 1998

The purpose of this study was to determine the of effective concentration of procaine iontophoresis for durarion of cutaneous local anesthesia. Forty-five healthy students with an age range of 19 to 34 years$(21\pm2.7)$, were participated in this study. The subjects were randomly assigned into 5 groups. Bach 9 subjects received iontophoresis on the flexor surface of dominant forearm with soft cotton pad $(3.5\times3.5cm)$ soaked in 2ml of $2\%$ (pH 5.28), $4\%$ (pH 5.12), $8\%$ (pH 4,98), $16\%$ (pH 4.72), $32\%$ (pH 4.52) procaine hydrochloride solution at 4mA for 10 minutes (total current 40mA min) using anodal direct current. The study was performed in a randomized, double-blind design, After procaine iontophoresis, the duration of anesthesia were evaluated at five minute intervals on five random locations in the iontophoretically area using a 21-gauge sterile hypodermic needle pressed with 1mm invagination unitl sharp pin-pricking pain sensation returned. The data were analyzed with one-way ANOVA to determine significant differences between groups. Duncan post hoc was performed at level .01. The relationship between anesthetic duration and procaine concentration was assessed with Pearson Product-Moment Correlation Coefficients. ANOVA tests showed significant differences in the anesthetic duration between the concentration of procaine solution (p<.001). Procaine iontophoresis with $4\%$ concentration produced cutaneous Socal anesthesia of significantly longer duration(15.56 min) than iontophoresis with $2\%,\;8\%,\;16\%$, and $32\%$ of procaine GCl(p<.01). Whereas the anesthetic duration had no correlation with concentration of procaine solution (r=-0.41, NS). These results support the $4\%$ procaine solution was an effective concentration of iontophoresis for induced cutaneous local anesthesia.

• Journal of Sensor Science and Technology
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• v.11 no.2
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• pp.84-92
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• 2002

A $32{\times}32$ pixels foveated (linear-polar) structure retina chip with the function of local-light adaptation for edge detection has been designed and fabricated using CMOS technology. Human retina can detect a wide range of light intensity. In this study, we use the biologically-inspired visual signal processing mechanism that consists of photoreceptors, horizontal cells, and bipolar cells in order to implement the function of edge detection in the retina chip. For a local-light adaptive function, the size of receptive field is changed locally according to the input light intensity. The spatial distribution of sensing pixels in the foveated retina chip has the advantages of selective reduction of image data and good resolution in central part to carry out the elaborate image processing with still enough resolution in the outer parts. The designed chip has been fabricated using standard $0.6\;{\mu}m$ double-poly triple-metal CMOS technology and optimized using HSPICE simulator.

• Radiation Oncology Journal
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• v.15 no.3
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• pp.251-254
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• 1997

Purpose : Simple hysterectomy is not a standard surgery for invasive cervical carcinoma. This study was performed to investigate the efficacy of radiotherapy following simple hysterectomy in the invasive cervical cancer. Materials and Methods : Retrospective analysis was done for 19 patients with invasive cervical carcinoma who were treated with radiotherapy following simple hysterectomy from April 1989 to December 1993 The median a9e of patients was 47 years old. Patients were treated with external beam radiation therapy alone (17) or external beam radiation therapy plus intra vaginal ovoid irradiation (2). The median follow up period was 46 months. Results : The 4 year overall survival rate was $75\%$. The 4 rear local control rate was $89\%$. Two patients had recurred at the locoregional and distant sites, and another two patients at distant sites. Conclusion : We confirmed that radiotherapy is the adequate treatment modality for patients with invasive cervical cancer who underwent simple hysterectomy.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.4
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• pp.501-507
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• 2007

In the first part of this study, the moving least squares finite difference method for solving solid mechanics problems was formulated. This second part verified the accuracy, robustness and effectiveness of the developed method through several numerical examples. It was shown that the method gives excellent convergence rate for elasticity problem. The solution process of elastic crack problems showed the easiness in discontinuity modeling and demonstrates the accuracy and efficiency in finding singular stress solution based on adaptive node distribution. The applicability to the engineering problem with abrupt change in displacement and stresses gradient fields is verified through a localization band problem. The developed method is expected to be extended to the various special engineering problems.

• Journal of the Korean Institute of Telematics and Electronics
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• v.19 no.3
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• pp.19-27
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• 1982

Minimization of total routing and number of cuts has been adopted for the placement problem in LSI and printed wire board as the object function, recently. Although it is considered that in the general situation this object function reflects the final goal which is wiring of 100% of layout, it often seems to be insufficient because it does not exhibit partial wire congestion. This paper introduces a new concept called the wire congestion of segestion to get the partial wire congestion and proposes the object function to minimize the wire congestion of segmests. In order to optimize this object function, an effective heuristic algorithm is also suggestsl Experimental results show that this algorithm sustains its efficiency. The experimental consequences point out that if the total routing length is short, maximum wire congestion of segment is small and vice versa. Therefore control parameter, that is, congestion parameter, which mintnizes total length and concurrently reduces maximal wire congestion of segment, is obtained by experiment.

• Journal of Korea Multimedia Society
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• v.3 no.1
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• pp.23-33
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• 2000

In this paper, we describe an algorithm which can extract human faces with natural pose from complex backgrounds. This method basically adopts the concept that facial region has the nearly same gray level for all pixels within appropriately scaled blocks. Based on the idea, we develop a hierarchial process that first, a block image data with pyramid structure of input image is generated, and some candidate regions for facial regions in the block image are Quickly determined, then finally the detailed facial features; organs are decided. To find the features easily, we introduce a local gray level transform which emphasizes dark and small regions, and estimate the geometrical triangle constraints among the facial features. The merit of our method is that we can be freed from the parameter assignment problem since the algorithm utilize a simple brightness computation, consequently robust systems not being depended on specific parameter values can be easily constructed.

• The Journal of the Acoustical Society of Korea
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• v.42 no.5
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• pp.388-394
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• 2023

When the vibration of the thin panel by exciting single point is used to radiate sound, the inherent vibration characteristic of the plate itself causes influence on the radiated sound. A conventional panel speaker system usually uses the single or double point excitations for generating the sound through the panel itself. The radiated sound can be easily distorted due to the modal characteristics of the plate so it is difficult to expect sufficient sound power or high radiation efficiency. In this paper, to achieve an immersive sound field, the multiple speaker zones on a thin panel are created with the limited number of actuators. The designated vibration field which can generates directional sound is realized by employing the vibro-acoustic inverse rendering methods. Actuators are arranged from the positions which have the advantage of implementing with multi-modal excitations. The location and number of actuators are compared with the location and number of controllable speaker zones by conducting numerical simulations.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.433-436
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• 2010

In this paper, heat/mass transfer characteristics on a film cooled stationary rotor blade are investigated using the naphthalene sublimation method. A row-speed annular wind tunnel with a single annular turbine stage is used. Three rows of film cooling holes are machined on the leading edge of the test blade. Detailed heat/mass transfer distributions are measured with changing the blowing rate from 1.0 to 2.0. As the blowing ratio increases, overall heat/mass transfer increases and the lower peak formed on the pressure side were disappeared.